@book{AbedjanGolabNaumannetal., author = {Abedjan, Ziawasch and Golab, Lukasz and Naumann, Felix and Papenbrock, Thorsten}, title = {Data Profiling}, series = {Synthesis lectures on data management, 52}, journal = {Synthesis lectures on data management, 52}, publisher = {Morgan \& Claypool Publishers}, address = {San Rafael}, isbn = {978-1-68173-446-0}, pages = {xviii, 136}, language = {en} } @book{AbedjanNaumann2011, author = {Abedjan, Ziawasch and Naumann, Felix}, title = {Advancing the discovery of unique column combinations}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-148-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53564}, publisher = {Universit{\"a}t Potsdam}, pages = {25}, year = {2011}, abstract = {Unique column combinations of a relational database table are sets of columns that contain only unique values. Discovering such combinations is a fundamental research problem and has many different data management and knowledge discovery applications. Existing discovery algorithms are either brute force or have a high memory load and can thus be applied only to small datasets or samples. In this paper, the wellknown GORDIAN algorithm and "Apriori-based" algorithms are compared and analyzed for further optimization. We greatly improve the Apriori algorithms through efficient candidate generation and statistics-based pruning methods. A hybrid solution HCAGORDIAN combines the advantages of GORDIAN and our new algorithm HCA, and it significantly outperforms all previous work in many situations.}, language = {en} } @book{AdamBrehmerHuettenrauchetal.2006, author = {Adam, Christian and Brehmer, Bastian and H{\"u}ttenrauch, Stefan and Jeske, Janin and Polze, Andreas and Rasche, Andreas and Sch{\"u}ler, Benjamin and Schult, Wolfgang}, title = {Aspektorientierte Programmierung : {\"U}berblick {\"u}ber Techniken und Werkzeuge}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-23-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33796}, publisher = {Universit{\"a}t Potsdam}, pages = {88}, year = {2006}, abstract = {Inhaltsverzeichnis 1 Einf{\"u}hrung 2 Aspektorientierte Programmierung 2.1 Ein System als Menge von Eigenschaften 2.2 Aspekte 2.3 Aspektweber 2.4 Vorteile Aspektorientierter Programmierung 2.5 Kategorisierung der Techniken und Werkzeuge f ¨ ur Aspektorientierte Programmierung 3 Techniken und Werkzeuge zur Analyse Aspektorientierter Softwareprogramme 3.1 Virtual Source File 3.2 FEAT 3.3 JQuery 3.4 Aspect Mining Tool 4 Techniken und Werkzeuge zum Entwurf Aspektorientierter Softwareprogramme 4.1 Concern Space Modeling Schema 4.2 Modellierung von Aspekten mit UML 4.3 CoCompose 4.4 Codagen Architect 5 Techniken und Werkzeuge zur Implementierung Aspektorientierter Softwareprogramme 5.1 Statische Aspektweber 5.2 Dynamische Aspektweber 6 Zusammenfassung}, language = {de} } @book{AlbrechtNaumann2012, author = {Albrecht, Alexander and Naumann, Felix}, title = {Understanding cryptic schemata in large extract-transform-load systems}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-201-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-61257}, publisher = {Universit{\"a}t Potsdam}, pages = {19}, year = {2012}, abstract = {Extract-Transform-Load (ETL) tools are used for the creation, maintenance, and evolution of data warehouses, data marts, and operational data stores. ETL workflows populate those systems with data from various data sources by specifying and executing a DAG of transformations. Over time, hundreds of individual workflows evolve as new sources and new requirements are integrated into the system. The maintenance and evolution of large-scale ETL systems requires much time and manual effort. A key problem is to understand the meaning of unfamiliar attribute labels in source and target databases and ETL transformations. Hard-to-understand attribute labels lead to frustration and time spent to develop and understand ETL workflows. We present a schema decryption technique to support ETL developers in understanding cryptic schemata of sources, targets, and ETL transformations. For a given ETL system, our recommender-like approach leverages the large number of mapped attribute labels in existing ETL workflows to produce good and meaningful decryptions. In this way we are able to decrypt attribute labels consisting of a number of unfamiliar few-letter abbreviations, such as UNP_PEN_INT, which we can decrypt to UNPAID_PENALTY_INTEREST. We evaluate our schema decryption approach on three real-world repositories of ETL workflows and show that our approach is able to suggest high-quality decryptions for cryptic attribute labels in a given schema.}, language = {en} } @book{AlnemrPolyvyanyyAbuJarouretal.2010, author = {Alnemr, Rehab and Polyvyanyy, Artem and AbuJarour, Mohammed and Appeltauer, Malte and Hildebrandt, Dieter and Thomas, Ivonne and Overdick, Hagen and Sch{\"o}bel, Michael and Uflacker, Matthias and Kluth, Stephan and Menzel, Michael and Schmidt, Alexander and Hagedorn, Benjamin and Pascalau, Emilian and Perscheid, Michael and Vogel, Thomas and Hentschel, Uwe and Feinbube, Frank and Kowark, Thomas and Tr{\"u}mper, Jonas and Vogel, Tobias and Becker, Basil}, title = {Proceedings of the 4th Ph.D. Retreat of the HPI Research School on Service-oriented Systems Engineering}, editor = {Meinel, Christoph and Plattner, Hasso and D{\"o}llner, J{\"u}rgen Roland Friedrich and Weske, Mathias and Polze, Andreas and Hirschfeld, Robert and Naumann, Felix and Giese, Holger}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-036-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40838}, publisher = {Universit{\"a}t Potsdam}, pages = {Getr. Z{\"a}hlung}, year = {2010}, language = {en} } @book{AppeltauerHirschfeld2012, author = {Appeltauer, Malte and Hirschfeld, Robert}, title = {The JCop language specification : Version 1.0, April 2012}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-193-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60208}, publisher = {Universit{\"a}t Potsdam}, pages = {iv, 48}, year = {2012}, abstract = {Program behavior that relies on contextual information, such as physical location or network accessibility, is common in today's applications, yet its representation is not sufficiently supported by programming languages. With context-oriented programming (COP), such context-dependent behavioral variations can be explicitly modularized and dynamically activated. In general, COP could be used to manage any context-specific behavior. However, its contemporary realizations limit the control of dynamic adaptation. This, in turn, limits the interaction of COP's adaptation mechanisms with widely used architectures, such as event-based, mobile, and distributed programming. The JCop programming language extends Java with language constructs for context-oriented programming and additionally provides a domain-specific aspect language for declarative control over runtime adaptations. As a result, these redesigned implementations are more concise and better modularized than their counterparts using plain COP. JCop's main features have been described in our previous publications. However, a complete language specification has not been presented so far. This report presents the entire JCop language including the syntax and semantics of its new language constructs.}, language = {en} } @book{AsheuerBelgassemEichornetal.2013, author = {Asheuer, Susanne and Belgassem, Joy and Eichorn, Wiete and Leipold, Rio and Licht, Lucas and Meinel, Christoph and Schanz, Anne and Schnjakin, Maxim}, title = {Akzeptanz und Nutzerfreundlichkeit der AusweisApp : eine qualitative Untersuchung ; eine Studie am Hasso-Plattner-Institut f{\"u}r Softwaresystemtechnik im Auftrag des Bundesministeriums des Innern}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-229-2}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63971}, publisher = {Universit{\"a}t Potsdam}, pages = {83}, year = {2013}, abstract = {F{\"u}r die vorliegende Studie »Qualitative Untersuchung zur Akzeptanz des neuen Personalausweises und Erarbeitung von Vorschl{\"a}gen zur Verbesserung der Usability der Software AusweisApp« arbeitete ein Innovationsteam mit Hilfe der Design Thinking Methode an der Aufgabenstellung »Wie k{\"o}nnen wir die AusweisApp f{\"u}r Nutzer intuitiv und verst{\"a}ndlich gestalten?« Zun{\"a}chst wurde die Akzeptanz des neuen Personalausweises getestet. B{\"u}rger wurden zu ihrem Wissensstand und ihren Erwartungen hinsichtlich des neuen Personalausweises befragt, dar{\"u}ber hinaus zur generellen Nutzung des neuen Personalausweises, der Nutzung der Online-Ausweisfunktion sowie der Usability der AusweisApp. Weiterhin wurden Nutzer bei der Verwendung der aktuellen AusweisApp beobachtet und anschließend befragt. Dies erlaubte einen tiefen Einblick in ihre Bed{\"u}rfnisse. Die Ergebnisse aus der qualitativen Untersuchung wurden verwendet, um Verbesserungsvorschl{\"a}ge f{\"u}r die AusweisApp zu entwickeln, die den Bed{\"u}rfnissen der B{\"u}rger entsprechen. Die Vorschl{\"a}ge zur Optimierung der AusweisApp wurden prototypisch umgesetzt und mit potentiellen Nutzern getestet. Die Tests haben gezeigt, dass die entwickelten Neuerungen den B{\"u}rgern den Zugang zur Nutzung der Online-Ausweisfunktion deutlich vereinfachen. Im Ergebnis konnte festgestellt werden, dass der Akzeptanzgrad des neuen Personalausweises stark divergiert. Die Einstellung der Befragten reichte von Skepsis bis hin zu Bef{\"u}rwortung. Der neue Personalausweis ist ein Thema, das den B{\"u}rger polarisiert. Im Rahmen der Nutzertests konnten zahlreiche Verbesserungspotenziale des bestehenden Service Designs sowohl rund um den neuen Personalausweis, als auch im Zusammenhang mit der verwendeten Software aufgedeckt werden. W{\"a}hrend der Nutzertests, die sich an die Ideen- und Prototypenphase anschlossen, konnte das Innovtionsteam seine Vorschl{\"a}ge iterieren und auch verifizieren. Die ausgearbeiteten Vorschl{\"a}ge beziehen sich auf die AusweisApp. Die neuen Funktionen umfassen im Wesentlichen: · den direkten Zugang zu den Diensteanbietern, · umfangreiche Hilfestellungen (Tooltips, FAQ, Wizard, Video), · eine Verlaufsfunktion, · einen Beispieldienst, der die Online-Ausweisfunktion erfahrbar macht. Insbesondere gilt es, den Nutzern mit der neuen Version der AusweisApp Anwendungsfelder f{\"u}r ihren neuen Personalausweis und einen Mehrwert zu bieten. Die Ausarbeitung von weiteren Funktionen der AusweisApp kann dazu beitragen, dass der neue Personalausweis sein volles Potenzial entfalten kann.}, language = {de} } @book{BauckmannAbedjanLeseretal.2012, author = {Bauckmann, Jana and Abedjan, Ziawasch and Leser, Ulf and M{\"u}ller, Heiko and Naumann, Felix}, title = {Covering or complete? : Discovering conditional inclusion dependencies}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-212-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62089}, publisher = {Universit{\"a}t Potsdam}, pages = {34}, year = {2012}, abstract = {Data dependencies, or integrity constraints, are used to improve the quality of a database schema, to optimize queries, and to ensure consistency in a database. In the last years conditional dependencies have been introduced to analyze and improve data quality. In short, a conditional dependency is a dependency with a limited scope defined by conditions over one or more attributes. Only the matching part of the instance must adhere to the dependency. In this paper we focus on conditional inclusion dependencies (CINDs). We generalize the definition of CINDs, distinguishing covering and completeness conditions. We present a new use case for such CINDs showing their value for solving complex data quality tasks. Further, we define quality measures for conditions inspired by precision and recall. We propose efficient algorithms that identify covering and completeness conditions conforming to given quality thresholds. Our algorithms choose not only the condition values but also the condition attributes automatically. Finally, we show that our approach efficiently provides meaningful and helpful results for our use case.}, language = {en} } @book{BauckmannLeserNaumann2010, author = {Bauckmann, Jana and Leser, Ulf and Naumann, Felix}, title = {Efficient and exact computation of inclusion dependencies for data integration}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-048-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41396}, publisher = {Universit{\"a}t Potsdam}, pages = {36}, year = {2010}, abstract = {Data obtained from foreign data sources often come with only superficial structural information, such as relation names and attribute names. Other types of metadata that are important for effective integration and meaningful querying of such data sets are missing. In particular, relationships among attributes, such as foreign keys, are crucial metadata for understanding the structure of an unknown database. The discovery of such relationships is difficult, because in principle for each pair of attributes in the database each pair of data values must be compared. A precondition for a foreign key is an inclusion dependency (IND) between the key and the foreign key attributes. We present with Spider an algorithm that efficiently finds all INDs in a given relational database. It leverages the sorting facilities of DBMS but performs the actual comparisons outside of the database to save computation. Spider analyzes very large databases up to an order of magnitude faster than previous approaches. We also evaluate in detail the effectiveness of several heuristics to reduce the number of necessary comparisons. Furthermore, we generalize Spider to find composite INDs covering multiple attributes, and partial INDs, which are true INDs for all but a certain number of values. This last type is particularly relevant when integrating dirty data as is often the case in the life sciences domain - our driving motivation.}, language = {en} } @book{BeckerGiese2012, author = {Becker, Basil and Giese, Holger}, title = {Cyber-physical systems with dynamic structure : towards modeling and verification of inductive invariants}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-217-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62437}, publisher = {Universit{\"a}t Potsdam}, pages = {iv, 27}, year = {2012}, abstract = {Cyber-physical systems achieve sophisticated system behavior exploring the tight interconnection of physical coupling present in classical engineering systems and information technology based coupling. A particular challenging case are systems where these cyber-physical systems are formed ad hoc according to the specific local topology, the available networking capabilities, and the goals and constraints of the subsystems captured by the information processing part. In this paper we present a formalism that permits to model the sketched class of cyber-physical systems. The ad hoc formation of tightly coupled subsystems of arbitrary size are specified using a UML-based graph transformation system approach. Differential equations are employed to define the resulting tightly coupled behavior. Together, both form hybrid graph transformation systems where the graph transformation rules define the discrete steps where the topology or modes may change, while the differential equations capture the continuous behavior in between such discrete changes. In addition, we demonstrate that automated analysis techniques known for timed graph transformation systems for inductive invariants can be extended to also cover the hybrid case for an expressive case of hybrid models where the formed tightly coupled subsystems are restricted to smaller local networks.}, language = {en} } @book{BeckerGieseNeumann2009, author = {Becker, Basil and Giese, Holger and Neumann, Stefan}, title = {Correct dynamic service-oriented architectures : modeling and compositional verification with dynamic collaborations}, organization = {System Analysis and Modeling Group}, isbn = {978-3-940793-91-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30473}, publisher = {Universit{\"a}t Potsdam}, year = {2009}, abstract = {Service-oriented modeling employs collaborations to capture the coordination of multiple roles in form of service contracts. In case of dynamic collaborations the roles may join and leave the collaboration at runtime and therefore complex structural dynamics can result, which makes it very hard to ensure their correct and safe operation. We present in this paper our approach for modeling and verifying such dynamic collaborations. Modeling is supported using a well-defined subset of UML class diagrams, behavioral rules for the structural dynamics, and UML state machines for the role behavior. To be also able to verify the resulting service-oriented systems, we extended our former results for the automated verification of systems with structural dynamics [7, 8] and developed a compositional reasoning scheme, which enables the reuse of verification results. We outline our approach using the example of autonomous vehicles that use such dynamic collaborations via ad-hoc networking to coordinate and optimize their joint behavior.}, language = {en} } @book{BerovHenningMattisetal.2013, author = {Berov, Leonid and Henning, Johannes and Mattis, Toni and Rein, Patrick and Schreiber, Robin and Seckler, Eric and Steinert, Bastian and Hirschfeld, Robert}, title = {Vereinfachung der Entwicklung von Gesch{\"a}ftsanwendungen durch Konsolidierung von Programmierkonzepten und -technologien}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-231-5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64045}, publisher = {Universit{\"a}t Potsdam}, pages = {186}, year = {2013}, abstract = {Die Komplexit{\"a}t heutiger Gesch{\"a}ftsabl{\"a}ufe und die Menge der zu verwaltenden Daten stellen hohe Anforderungen an die Entwicklung und Wartung von Gesch{\"a}ftsanwendungen. Ihr Umfang entsteht unter anderem aus der Vielzahl von Modellentit{\"a}ten und zugeh{\"o}rigen Nutzeroberfl{\"a}chen zur Bearbeitung und Analyse der Daten. Dieser Bericht pr{\"a}sentiert neuartige Konzepte und deren Umsetzung zur Vereinfachung der Entwicklung solcher umfangreichen Gesch{\"a}ftsanwendungen. Erstens: Wir schlagen vor, die Datenbank und die Laufzeitumgebung einer dynamischen objektorientierten Programmiersprache zu vereinen. Hierzu organisieren wir die Speicherstruktur von Objekten auf die Weise einer spaltenorientierten Hauptspeicherdatenbank und integrieren darauf aufbauend Transaktionen sowie eine deklarative Anfragesprache nahtlos in dieselbe Laufzeitumgebung. Somit k{\"o}nnen transaktionale und analytische Anfragen in derselben objektorientierten Hochsprache implementiert werden, und dennoch nah an den Daten ausgef{\"u}hrt werden. Zweitens: Wir beschreiben Programmiersprachkonstrukte, welche es erlauben, Nutzeroberfl{\"a}chen sowie Nutzerinteraktionen generisch und unabh{\"a}ngig von konkreten Modellentit{\"a}ten zu beschreiben. Um diese abstrakte Beschreibung nutzen zu k{\"o}nnen, reichert man die Dom{\"a}nenmodelle um vormals implizite Informationen an. Neue Modelle m{\"u}ssen nur um einige Informationen erweitert werden um bereits vorhandene Nutzeroberfl{\"a}chen und -interaktionen auch f{\"u}r sie verwenden zu k{\"o}nnen. Anpassungen, die nur f{\"u}r ein Modell gelten sollen, k{\"o}nnen unabh{\"a}ngig vom Standardverhalten, inkrementell, definiert werden. Drittens: Wir erm{\"o}glichen mit einem weiteren Programmiersprachkonstrukt die zusammenh{\"a}ngende Beschreibung von Abl{\"a}ufen der Anwendung, wie z.B. Bestellprozesse. Unser Programmierkonzept kapselt Nutzerinteraktionen in synchrone Funktionsaufrufe und macht somit Prozesse als zusammenh{\"a}ngende Folge von Berechnungen und Interaktionen darstellbar. Viertens: Wir demonstrieren ein Konzept, wie Endnutzer komplexe analytische Anfragen intuitiver formulieren k{\"o}nnen. Es basiert auf der Idee, dass Endnutzer Anfragen als Konfiguration eines Diagramms sehen. Entsprechend beschreibt ein Nutzer eine Anfrage, indem er beschreibt, was sein Diagramm darstellen soll. Nach diesem Konzept beschriebene Diagramme enthalten ausreichend Informationen, um daraus eine Anfrage generieren zu k{\"o}nnen. Hinsichtlich der Ausf{\"u}hrungsdauer sind die generierten Anfragen {\"a}quivalent zu Anfragen, die mit konventionellen Anfragesprachen formuliert sind. Das Anfragemodell setzen wir in einem Prototypen um, der auf den zuvor eingef{\"u}hrten Konzepten aufsetzt.}, language = {de} } @book{BeyhlBlouinGieseetal.2016, author = {Beyhl, Thomas and Blouin, Dominique and Giese, Holger and Lambers, Leen}, title = {On the operationalization of graph queries with generalized discrimination networks}, number = {106}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-372-5}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-96279}, publisher = {Universit{\"a}t Potsdam}, pages = {33}, year = {2016}, abstract = {Graph queries have lately gained increased interest due to application areas such as social networks, biological networks, or model queries. For the relational database case the relational algebra and generalized discrimination networks have been studied to find appropriate decompositions into subqueries and ordering of these subqueries for query evaluation or incremental updates of query results. For graph database queries however there is no formal underpinning yet that allows us to find such suitable operationalizations. Consequently, we suggest a simple operational concept for the decomposition of arbitrary complex queries into simpler subqueries and the ordering of these subqueries in form of generalized discrimination networks for graph queries inspired by the relational case. The approach employs graph transformation rules for the nodes of the network and thus we can employ the underlying theory. We further show that the proposed generalized discrimination networks have the same expressive power as nested graph conditions.}, language = {en} } @book{BeyhlGiese2015, author = {Beyhl, Thomas and Giese, Holger}, title = {Efficient and scalable graph view maintenance for deductive graph databases based on generalized discrimination networks}, number = {99}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-339-8}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-79535}, publisher = {Universit{\"a}t Potsdam}, pages = {148}, year = {2015}, abstract = {Graph databases provide a natural way of storing and querying graph data. In contrast to relational databases, queries over graph databases enable to refer directly to the graph structure of such graph data. For example, graph pattern matching can be employed to formulate queries over graph data. However, as for relational databases running complex queries can be very time-consuming and ruin the interactivity with the database. One possible approach to deal with this performance issue is to employ database views that consist of pre-computed answers to common and often stated queries. But to ensure that database views yield consistent query results in comparison with the data from which they are derived, these database views must be updated before queries make use of these database views. Such a maintenance of database views must be performed efficiently, otherwise the effort to create and maintain views may not pay off in comparison to processing the queries directly on the data from which the database views are derived. At the time of writing, graph databases do not support database views and are limited to graph indexes that index nodes and edges of the graph data for fast query evaluation, but do not enable to maintain pre-computed answers of complex queries over graph data. Moreover, the maintenance of database views in graph databases becomes even more challenging when negation and recursion have to be supported as in deductive relational databases. In this technical report, we present an approach for the efficient and scalable incremental graph view maintenance for deductive graph databases. The main concept of our approach is a generalized discrimination network that enables to model nested graph conditions including negative application conditions and recursion, which specify the content of graph views derived from graph data stored by graph databases. The discrimination network enables to automatically derive generic maintenance rules using graph transformations for maintaining graph views in case the graph data from which the graph views are derived change. We evaluate our approach in terms of a case study using multiple data sets derived from open source projects.}, language = {en} } @book{BoeddinghausMeinelSack2011, author = {Boeddinghaus, Wilhelm and Meinel, Christoph and Sack, Harald}, title = {Einf{\"u}hrung von IPv6 in Unternehmensnetzen : ein Leitfaden}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-156-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-54582}, publisher = {Universit{\"a}t Potsdam}, pages = {51}, year = {2011}, language = {de} } @book{BreestBoucheGrundetal.2006, author = {Breest, Martin and Bouch{\´e}, Paul and Grund, Martin and Haubrock, S{\"o}ren and H{\"u}ttenrauch, Stefan and Kylau, Uwe and Ploskonos, Anna and Queck, Tobias and Schreiter, Torben}, title = {Fundamentals of Service-Oriented Engineering}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-35-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33801}, publisher = {Universit{\"a}t Potsdam}, pages = {Getr. Z{\"a}hlung}, year = {2006}, abstract = {Since 2002, keywords like service-oriented engineering, service-oriented computing, and service-oriented architecture have been widely used in research, education, and enterprises. These and related terms are often misunderstood or used incorrectly. To correct these misunderstandings, a deeper knowledge of the concepts, the historical backgrounds, and an overview of service-oriented architectures is demanded and given in this paper.}, language = {en} } @book{CalmezHesseSiegmundetal.2013, author = {Calmez, Conrad and Hesse, Hubert and Siegmund, Benjamin and Stamm, Sebastian and Thomschke, Astrid and Hirschfeld, Robert and Ingalls, Dan and Lincke, Jens}, title = {Explorative authoring of Active Web content in a mobile environment}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-232-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64054}, publisher = {Universit{\"a}t Potsdam}, pages = {132}, year = {2013}, abstract = {Developing rich Web applications can be a complex job - especially when it comes to mobile device support. Web-based environments such as Lively Webwerkstatt can help developers implement such applications by making the development process more direct and interactive. Further the process of developing software is collaborative which creates the need that the development environment offers collaboration facilities. This report describes extensions of the webbased development environment Lively Webwerkstatt such that it can be used in a mobile environment. The extensions are collaboration mechanisms, user interface adaptations but as well event processing and performance measuring on mobile devices.}, language = {en} } @book{DraisbachNaumannSzottetal.2012, author = {Draisbach, Uwe and Naumann, Felix and Szott, Sascha and Wonneberg, Oliver}, title = {Adaptive windows for duplicate detection}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-143-1}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53007}, publisher = {Universit{\"a}t Potsdam}, pages = {41}, year = {2012}, abstract = {Duplicate detection is the task of identifying all groups of records within a data set that represent the same real-world entity, respectively. This task is difficult, because (i) representations might differ slightly, so some similarity measure must be defined to compare pairs of records and (ii) data sets might have a high volume making a pair-wise comparison of all records infeasible. To tackle the second problem, many algorithms have been suggested that partition the data set and compare all record pairs only within each partition. One well-known such approach is the Sorted Neighborhood Method (SNM), which sorts the data according to some key and then advances a window over the data comparing only records that appear within the same window. We propose several variations of SNM that have in common a varying window size and advancement. The general intuition of such adaptive windows is that there might be regions of high similarity suggesting a larger window size and regions of lower similarity suggesting a smaller window size. We propose and thoroughly evaluate several adaption strategies, some of which are provably better than the original SNM in terms of efficiency (same results with fewer comparisons).}, language = {en} } @book{DyckGiese2017, author = {Dyck, Johannes and Giese, Holger}, title = {k-Inductive invariant checking for graph transformation systems}, number = {119}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-406-7}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-397044}, publisher = {Universit{\"a}t Potsdam}, pages = {45}, year = {2017}, abstract = {While offering significant expressive power, graph transformation systems often come with rather limited capabilities for automated analysis, particularly if systems with many possible initial graphs and large or infinite state spaces are concerned. One approach that tries to overcome these limitations is inductive invariant checking. However, the verification of inductive invariants often requires extensive knowledge about the system in question and faces the approach-inherent challenges of locality and lack of context. To address that, this report discusses k-inductive invariant checking for graph transformation systems as a generalization of inductive invariants. The additional context acquired by taking multiple (k) steps into account is the key difference to inductive invariant checking and is often enough to establish the desired invariants without requiring the iterative development of additional properties. To analyze possibly infinite systems in a finite fashion, we introduce a symbolic encoding for transformation traces using a restricted form of nested application conditions. As its central contribution, this report then presents a formal approach and algorithm to verify graph constraints as k-inductive invariants. We prove the approach's correctness and demonstrate its applicability by means of several examples evaluated with a prototypical implementation of our algorithm.}, language = {en} } @book{DyckGiese2015, author = {Dyck, Johannes and Giese, Holger}, title = {Inductive invariant checking with partial negative application conditions}, number = {98}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-333-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-77748}, publisher = {Universit{\"a}t Potsdam}, pages = {43}, year = {2015}, abstract = {Graph transformation systems are a powerful formal model to capture model transformations or systems with infinite state space, among others. However, this expressive power comes at the cost of rather limited automated analysis capabilities. The general case of unbounded many initial graphs or infinite state spaces is only supported by approaches with rather limited scalability or expressiveness. In this report we improve an existing approach for the automated verification of inductive invariants for graph transformation systems. By employing partial negative application conditions to represent and check many alternative conditions in a more compact manner, we can check examples with rules and constraints of substantially higher complexity. We also substantially extend the expressive power by supporting more complex negative application conditions and provide higher accuracy by employing advanced implication checks. The improvements are evaluated and compared with another applicable tool by considering three case studies.}, language = {en} } @book{DyckGieseLambers2017, author = {Dyck, Johannes and Giese, Holger and Lambers, Leen}, title = {Automatic verification of behavior preservation at the transformation level for relational model transformation}, number = {112}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-391-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-100279}, publisher = {Universit{\"a}t Potsdam}, pages = {viii, 112}, year = {2017}, abstract = {The correctness of model transformations is a crucial element for model-driven engineering of high quality software. In particular, behavior preservation is the most important correctness property avoiding the introduction of semantic errors during the model-driven engineering process. Behavior preservation verification techniques either show that specific properties are preserved, or more generally and complex, they show some kind of behavioral equivalence or refinement between source and target model of the transformation. Both kinds of behavior preservation verification goals have been presented with automatic tool support for the instance level, i.e. for a given source and target model specified by the model transformation. However, up until now there is no automatic verification approach available at the transformation level, i.e. for all source and target models specified by the model transformation. In this report, we extend our results presented in [27] and outline a new sophisticated approach for the automatic verification of behavior preservation captured by bisimulation resp. simulation for model transformations specified by triple graph grammars and semantic definitions given by graph transformation rules. In particular, we show that the behavior preservation problem can be reduced to invariant checking for graph transformation and that the resulting checking problem can be addressed by our own invariant checker even for a complex example where a sequence chart is transformed into communicating automata. We further discuss today's limitations of invariant checking for graph transformation and motivate further lines of future work in this direction.}, language = {en} } @book{DoellnerKirschNienhaus2005, author = {D{\"o}llner, J{\"u}rgen Roland Friedrich and Kirsch, Florian and Nienhaus, Marc}, title = {Visualizing Design and Spatial Assembly of Interactive CSG}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-56-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33771}, publisher = {Universit{\"a}t Potsdam}, pages = {8}, year = {2005}, abstract = {For interactive construction of CSG models understanding the layout of a model is essential for its efficient manipulation. To understand position and orientation of aggregated components of a CSG model, we need to realize its visible and occluded parts as a whole. Hence, transparency and enhanced outlines are key techniques to assist comprehension. We present a novel real-time rendering technique for visualizing design and spatial assembly of CSG models. As enabling technology we combine an image-space CSG rendering algorithm with blueprint rendering. Blueprint rendering applies depth peeling for extracting layers of ordered depth from polygonal models and then composes them in sorted order facilitating a clear insight of the models. We develop a solution for implementing depth peeling for CSG models considering their depth complexity. Capturing surface colors of each layer and later combining the results allows for generating order-independent transparency as one major rendering technique for CSG models. We further define visually important edges for CSG models and integrate an image-space edgeenhancement technique for detecting them in each layer. In this way, we extract visually important edges that are directly and not directly visible to outline a model's layout. Combining edges with transparency rendering, finally, generates edge-enhanced depictions of image-based CSG models and allows us to realize their complex, spatial assembly.}, language = {en} } @book{EidSabbaghHeweltWeske2013, author = {Eid-Sabbagh, Rami-Habib and Hewelt, Marcin and Weske, Mathias}, title = {Business process architectures with multiplicities : transformation and correctness}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-257-5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66780}, publisher = {Universit{\"a}t Potsdam}, pages = {18}, year = {2013}, abstract = {Business processes are instrumental to manage work in organisations. To study the interdependencies between business processes, Business Process Architectures have been introduced. These express trigger and message ow relations between business processes. When we investigate real world Business Process Architectures, we find complex interdependencies, involving multiple process instances. These aspects have not been studied in detail so far, especially concerning correctness properties. In this paper, we propose a modular transformation of BPAs to open nets for the analysis of behavior involving multiple business processes with multiplicities. For this purpose we introduce intermediary nets to portray semantics of multiplicity specifications. We evaluate our approach on a use case from the public sector.}, language = {en} } @book{FeinbubeRichterGerstenbergetal.2016, author = {Feinbube, Lena and Richter, Daniel and Gerstenberg, Sebastian and Siegler, Patrick and Haller, Angelo and Polze, Andreas}, title = {Software-Fehlerinjektion}, number = {109}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-386-2}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-97435}, publisher = {Universit{\"a}t Potsdam}, pages = {viii, 47}, year = {2016}, abstract = {Fehlerinjektion ist ein essentielles Werkzeug, um die Fehlertoleranz komplexer Softwaresysteme experimentell zu evaluieren. Wir berichten {\"u}ber das Seminar zum Thema Software-Fehlerinjektion, das am Fachgebiet f{\"u}r Betriebssysteme und Middleware am Hasso-Plattner-Institut der Universit{\"a}t Potsdam im Sommersemester 2015 stattfand. In dem Seminar ging es darum, verschiedene Fehlerinjektionsans{\"a}tze und -werkzeuge anzuwenden und hinsichtlich ihrer Anwendbarkeit in verschiedenen Szenarien zu bewerten. In diesem Bericht werden die studierten Ans{\"a}tze vorgestellt und verglichen.}, language = {de} } @book{FelgentreffBorningHirschfeld2013, author = {Felgentreff, Tim and Borning, Alan and Hirschfeld, Robert}, title = {Babelsberg : specifying and solving constraints on object behavior}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-265-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67296}, publisher = {Universit{\"a}t Potsdam}, pages = {53}, year = {2013}, abstract = {Constraints allow developers to specify desired properties of systems in a number of domains, and have those properties be maintained automatically. This results in compact, declarative code, avoiding scattered code to check and imperatively re-satisfy invariants. Despite these advantages, constraint programming is not yet widespread, with standard imperative programming still the norm. There is a long history of research on integrating constraint programming with the imperative paradigm. However, this integration typically does not unify the constructs for encapsulation and abstraction from both paradigms. This impedes re-use of modules, as client code written in one paradigm can only use modules written to support that paradigm. Modules require redundant definitions if they are to be used in both paradigms. We present a language - Babelsberg - that unifies the constructs for en- capsulation and abstraction by using only object-oriented method definitions for both declarative and imperative code. Our prototype - Babelsberg/R - is an extension to Ruby, and continues to support Ruby's object-oriented se- mantics. It allows programmers to add constraints to existing Ruby programs in incremental steps by placing them on the results of normal object-oriented message sends. It is implemented by modifying a state-of-the-art Ruby virtual machine. The performance of standard object-oriented code without con- straints is only modestly impacted, with typically less than 10\% overhead compared with the unmodified virtual machine. Furthermore, our architec- ture for adding multiple constraint solvers allows Babelsberg to deal with constraints in a variety of domains. We argue that our approach provides a useful step toward making con- straint solving a generic tool for object-oriented programmers. We also provide example applications, written in our Ruby-based implementation, which use constraints in a variety of application domains, including interactive graphics, circuit simulations, data streaming with both hard and soft constraints on performance, and configuration file Management.}, language = {en} } @book{FelgentreffHirschfeldMillsteinetal.2015, author = {Felgentreff, Tim and Hirschfeld, Robert and Millstein, Todd and Borning, Alan}, title = {Babelsberg/RML}, number = {103}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-348-0}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83826}, publisher = {Universit{\"a}t Potsdam}, pages = {68}, year = {2015}, abstract = {New programming language designs are often evaluated on concrete implementations. However, in order to draw conclusions about the language design from the evaluation of concrete programming languages, these implementations need to be verified against the formalism of the design. To that end, we also have to ensure that the design actually meets its stated goals. A useful tool for the latter has been to create an executable semantics from a formalism that can execute a test suite of examples. However, this mechanism so far did not allow to verify an implementation against the design. Babelsberg is a new design for a family of object-constraint languages. Recently, we have developed a formal semantics to clarify some issues in the design of those languages. Supplementing this work, we report here on how this formalism is turned into an executable operational semantics using the RML system. Furthermore, we show how we extended the executable semantics to create a framework that can generate test suites for the concrete Babelsberg implementations that provide traceability from the design to the language. Finally, we discuss how these test suites helped us find and correct mistakes in the Babelsberg implementation for JavaScript.}, language = {en} } @book{GayvoronskayaMeinelSchnjakin2018, author = {Gayvoronskaya, Tatiana and Meinel, Christoph and Schnjakin, Maxim}, title = {Blockchain}, number = {113}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-394-7}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103141}, publisher = {Universit{\"a}t Potsdam}, pages = {109}, year = {2018}, abstract = {Der Begriff Blockchain ist in letzter Zeit zu einem Schlagwort geworden, aber nur wenige wissen, was sich genau dahinter verbirgt. Laut einer Umfrage, die im ersten Quartal 2017 ver{\"o}ffentlicht wurde, ist der Begriff nur bei 35 Prozent der deutschen Mittelst{\"a}ndler bekannt. Dabei ist die Blockchain-Technologie durch ihre rasante Entwicklung und die globale Eroberung unterschiedlicher M{\"a}rkte f{\"u}r Massenmedien sehr interessant. So sehen viele die Blockchain-Technologie entweder als eine Allzweckwaffe, zu der aber nur wenige einen Zugang haben, oder als eine Hacker-Technologie f{\"u}r geheime Gesch{\"a}fte im Darknet. Dabei liegt die Innovation der Blockchain-Technologie in ihrer erfolgreichen Zusammensetzung bereits vorhandener Ans{\"a}tze: dezentrale Netzwerke, Kryptographie, Konsensfindungsmodelle. Durch das innovative Konzept wird ein Werte-Austausch in einem dezentralen System m{\"o}glich. Dabei wird kein Vertrauen zwischen dessen Knoten (z.B. Nutzer) vorausgesetzt. Mit dieser Studie m{\"o}chte das Hasso-Plattner-Institut den Lesern helfen, ihren eigenen Standpunkt zur Blockchain-Technologie zu finden und dabei dazwischen unterscheiden zu k{\"o}nnen, welche Eigenschaften wirklich innovativ und welche nichts weiter als ein Hype sind. Die Autoren der vorliegenden Arbeit analysieren positive und negative Eigenschaften, welche die Blockchain-Architektur pr{\"a}gen, und stellen m{\"o}gliche Anpassungs- und L{\"o}sungsvorschl{\"a}ge vor, die zu einem effizienten Einsatz der Technologie beitragen k{\"o}nnen. Jedem Unternehmen, bevor es sich f{\"u}r diese Technologie entscheidet, wird dabei empfohlen, f{\"u}r den geplanten Anwendungszweck zun{\"a}chst ein klares Ziel zu definieren, das mit einem angemessenen Kosten-Nutzen-Verh{\"a}ltnis angestrebt werden kann. Dabei sind sowohl die M{\"o}glichkeiten als auch die Grenzen der Blockchain-Technologie zu beachten. Die relevanten Schritte, die es in diesem Zusammenhang zu beachten gilt, fasst die Studie f{\"u}r die Leser {\"u}bersichtlich zusammen. Es wird ebenso auf akute Fragestellungen wie Skalierbarkeit der Blockchain, geeigneter Konsensalgorithmus und Sicherheit eingegangen, darunter verschiedene Arten m{\"o}glicher Angriffe und die entsprechenden Gegenmaßnahmen zu deren Abwehr. Neue Blockchains etwa laufen Gefahr, geringere Sicherheit zu bieten, da {\"A}nderungen an der bereits bestehenden Technologie zu Schutzl{\"u}cken und M{\"a}ngeln f{\"u}hren k{\"o}nnen. Nach Diskussion der innovativen Eigenschaften und Probleme der Blockchain-Technologie wird auf ihre Umsetzung eingegangen. Interessierten Unternehmen stehen viele Umsetzungsm{\"o}glichkeiten zur Verf{\"u}gung. Die zahlreichen Anwendungen haben entweder eine eigene Blockchain als Grundlage oder nutzen bereits bestehende und weitverbreitete Blockchain-Systeme. Zahlreiche Konsortien und Projekte bieten „Blockchain-as-a-Service" an und unterst{\"u}tzen andere Unternehmen beim Entwickeln, Testen und Bereitstellen von Anwendungen. Die Studie gibt einen detaillierten {\"U}berblick {\"u}ber zahlreiche relevante Einsatzbereiche und Projekte im Bereich der Blockchain-Technologie. Dadurch, dass sie noch relativ jung ist und sich schnell entwickelt, fehlen ihr noch einheitliche Standards, die Zusammenarbeit der verschiedenen Systeme erlauben und an die sich alle Entwickler halten k{\"o}nnen. Aktuell orientieren sich Entwickler an Bitcoin-, Ethereum- und Hyperledger-Systeme, diese dienen als Grundlage f{\"u}r viele weitere Blockchain-Anwendungen. Ziel ist, den Lesern einen klaren und umfassenden {\"U}berblick {\"u}ber die Blockchain-Technologie und deren M{\"o}glichkeiten zu vermitteln.}, language = {de} } @book{GellerHirschfeldBracha2010, author = {Geller, Felix and Hirschfeld, Robert and Bracha, Gilad}, title = {Pattern Matching for an object-oriented and dynamically typed programming language}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-065-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-43035}, publisher = {Universit{\"a}t Potsdam}, pages = {81}, year = {2010}, abstract = {Pattern matching is a well-established concept in the functional programming community. It provides the means for concisely identifying and destructuring values of interest. This enables a clean separation of data structures and respective functionality, as well as dispatching functionality based on more than a single value. Unfortunately, expressive pattern matching facilities are seldomly incorporated in present object-oriented programming languages. We present a seamless integration of pattern matching facilities in an object-oriented and dynamically typed programming language: Newspeak. We describe language extensions to improve the practicability and integrate our additions with the existing programming environment for Newspeak. This report is based on the first author's master's thesis.}, language = {en} } @book{Giese2008, author = {Giese, Holger}, title = {Quo vadis, Modellierung? : Antrittsvorlesung 2008-12-11}, publisher = {Univ.-Bibl.}, address = {Potsdam}, year = {2008}, abstract = {Zum Thema "Quo vadis, Modellierung?" h{\"a}lt Prof. Dr. Holger Giese am 11. Dezember 2008 seine Antrittsvorlesung an der Universit{\"a}t Potsdam. Der Wissenschaftler bekleidet eine Professur f{\"u}r Systemanalyse und Modellierung. Es handelt sich um eine gemeinsame Berufung der Universit{\"a}t Potsdam mit dem Hasso-Plattner- Institut f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsdam. Seit den Anf{\"a}ngen der Informatik vollzieht sich die Entwicklung von detaillierten, l{\"o}sungsorientierten und eher technisch gepr{\"a}gten Modellen hin zu solchen, die immer abstrakter und eher an den Problemen beziehungsweise Anwendungsbereichen orientiert sind. Diese erm{\"o}glichen es, die Komplexit{\"a}t heutiger Systeme besser zu beherrschen. Der Einsatz f{\"u}hrt in einigen Anwendungsbereichen heute schon zu bedeutend h{\"o}herer Produktivit{\"a}t und Qualit{\"a}t sowie geringeren Entwicklungszeiten. Anderseits hat sich aber auch in anderen Anwendungsgebieten gezeigt, dass die st{\"a}ndige Anpassung der Software an sich {\"a}ndernde Anforderungen oder Organisationsstrukturen dazu f{\"u}hrt, dass in fr{\"u}hen Entwicklungsphasen entstandene Modelle in der Praxis oft sehr schnell nicht mehr mit der Software {\"u}bereinstimmen. In seiner Antrittsvorlesung will Holger Giese diese Entwicklung Revue passieren lassen und der Frage nachgehen, was dies f{\"u}r die Zukunft der Modellierung bedeutet, mit welchen aktuellen Ans{\"a}tzen man diesem Problem zu begegnen versucht und welche zuk{\"u}nftigen Entwicklungen f{\"u}r die Modellierung zu erwarten sind.}, language = {de} } @book{GieseBecker2013, author = {Giese, Holger and Becker, Basil}, title = {Modeling and verifying dynamic evolving service-oriented architectures}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-246-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65112}, publisher = {Universit{\"a}t Potsdam}, pages = {97}, year = {2013}, abstract = {The service-oriented architecture supports the dynamic assembly and runtime reconfiguration of complex open IT landscapes by means of runtime binding of service contracts, launching of new components and termination of outdated ones. Furthermore, the evolution of these IT landscapes is not restricted to exchanging components with other ones using the same service contracts, as new services contracts can be added as well. However, current approaches for modeling and verification of service-oriented architectures do not support these important capabilities to their full extend.In this report we present an extension of the current OMG proposal for service modeling with UML - SoaML - which overcomes these limitations. It permits modeling services and their service contracts at different levels of abstraction, provides a formal semantics for all modeling concepts, and enables verifying critical properties. Our compositional and incremental verification approach allows for complex properties including communication parameters and time and covers besides the dynamic binding of service contracts and the replacement of components also the evolution of the systems by means of new service contracts. The modeling as well as verification capabilities of the presented approach are demonstrated by means of a supply chain example and the verification results of a first prototype are shown.}, language = {en} } @book{GieseHildebrandt2009, author = {Giese, Holger and Hildebrandt, Stephan}, title = {Efficient model synchronization of large-scale models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-940793-84-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-29281}, publisher = {Universit{\"a}t Potsdam}, pages = {27}, year = {2009}, abstract = {Model-driven software development requires techniques to consistently propagate modifications between different related models to realize its full potential. For large-scale models, efficiency is essential in this respect. In this paper, we present an improved model synchronization algorithm based on triple graph grammars that is highly efficient and, therefore, can also synchronize large-scale models sufficiently fast. We can show, that the overall algorithm has optimal complexity if it is dominating the rule matching and further present extensive measurements that show the efficiency of the presented model transformation and synchronization technique.}, language = {en} } @book{GieseHildebrandtLambers2010, author = {Giese, Holger and Hildebrandt, Stephan and Lambers, Leen}, title = {Toward bridging the gap between formal semantics and implementation of triple graph grammars}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-078-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45219}, publisher = {Universit{\"a}t Potsdam}, pages = {26}, year = {2010}, abstract = {The correctness of model transformations is a crucial element for the model-driven engineering of high quality software. A prerequisite to verify model transformations at the level of the model transformation specification is that an unambiguous formal semantics exists and that the employed implementation of the model transformation language adheres to this semantics. However, for existing relational model transformation approaches it is usually not really clear under which constraints particular implementations are really conform to the formal semantics. In this paper, we will bridge this gap for the formal semantics of triple graph grammars (TGG) and an existing efficient implementation. Whereas the formal semantics assumes backtracking and ignores non-determinism, practical implementations do not support backtracking, require rule sets that ensure determinism, and include further optimizations. Therefore, we capture how the considered TGG implementation realizes the transformation by means of operational rules, define required criteria and show conformance to the formal semantics if these criteria are fulfilled. We further outline how static analysis can be employed to guarantee these criteria.}, language = {en} } @book{GieseHildebrandtNeumannetal.2012, author = {Giese, Holger and Hildebrandt, Stephan and Neumann, Stefan and W{\"a}tzoldt, Sebastian}, title = {Industrial case study on the integration of SysML and AUTOSAR with triple graph grammars}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-191-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60184}, publisher = {Universit{\"a}t Potsdam}, pages = {vi, 51}, year = {2012}, abstract = {During the overall development of complex engineering systems different modeling notations are employed. For example, in the domain of automotive systems system engineering models are employed quite early to capture the requirements and basic structuring of the entire system, while software engineering models are used later on to describe the concrete software architecture. Each model helps in addressing the specific design issue with appropriate notations and at a suitable level of abstraction. However, when we step forward from system design to the software design, the engineers have to ensure that all decisions captured in the system design model are correctly transferred to the software engineering model. Even worse, when changes occur later on in either model, today the consistency has to be reestablished in a cumbersome manual step. In this report, we present in an extended version of [Holger Giese, Stefan Neumann, and Stephan Hildebrandt. Model Synchronization at Work: Keeping SysML and AUTOSAR Models Consistent. In Gregor Engels, Claus Lewerentz, Wilhelm Sch{\"a}fer, Andy Sch{\"u}rr, and B. Westfechtel, editors, Graph Transformations and Model Driven Enginering - Essays Dedicated to Manfred Nagl on the Occasion of his 65th Birthday, volume 5765 of Lecture Notes in Computer Science, pages 555-579. Springer Berlin / Heidelberg, 2010.] how model synchronization and consistency rules can be applied to automate this task and ensure that the different models are kept consistent. We also introduce a general approach for model synchronization. Besides synchronization, the approach consists of tool adapters as well as consistency rules covering the overlap between the synchronized parts of a model and the rest. We present the model synchronization algorithm based on triple graph grammars in detail and further exemplify the general approach by means of a model synchronization solution between system engineering models in SysML and software engineering models in AUTOSAR which has been developed for an industrial partner. In the appendix as extension to [19] the meta-models and all TGG rules for the SysML to AUTOSAR model synchronization are documented.}, language = {en} } @book{GroeneKnoepfelKugeletal.2004, author = {Gr{\"o}ne, Bernhard and Kn{\"o}pfel, Andreas and Kugel, Rudolf and Schmidt, Oliver}, title = {The Apache Modeling Project}, isbn = {978-3-937786-14-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33147}, publisher = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {This document presents an introduction to the Apache HTTP Server, covering both an overview and implementation details. It presents results of the Apache Modelling Project done by research assistants and students of the Hasso-Plattner-Institute in 2001, 2002 and 2003. The Apache HTTP Server was used to introduce students to the application of the modeling technique FMC, a method that supports transporting knowledge about complex systems in the domain of information processing (software and hardware as well). After an introduction to HTTP servers in general, we will focus on protocols and web technology. Then we will discuss Apache, its operational environment and its extension capabilities— the module API. Finally we will guide the reader through parts of the Apache source code and explain the most important pieces.}, language = {en} } @book{HagedornSchoebelUflackeretal.2007, author = {Hagedorn, Benjamin and Sch{\"o}bel, Michael and Uflacker, Matthias and Copaciu, Flavius and Milanovic, Nikola}, title = {Proceedings of the fall 2006 workshop of the HPI research school on service-oriented systems engineering}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-58-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33052}, publisher = {Universit{\"a}t Potsdam}, pages = {Getr. Z{\"a}hlung}, year = {2007}, abstract = {1. Design and Composition of 3D Geoinformation Services Benjamin Hagedorn 2. Operating System Abstractions for Service-Based Systems Michael Sch{\"o}bel 3. A Task-oriented Approach to User-centered Design of Service-Based Enterprise Applications Matthias Uflacker 4. A Framework for Adaptive Transport in Service- Oriented Systems based on Performance Prediction Flavius Copaciu 5. Asynchronicity and Loose Coupling in Service-Oriented Architectures Nikola Milanovic}, language = {en} } @book{HauptMarrHirschfeld2011, author = {Haupt, Michael and Marr, Stefan and Hirschfeld, Robert}, title = {CSOM/PL : a virtual machine product line}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-134-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-52332}, publisher = {Universit{\"a}t Potsdam}, pages = {26}, year = {2011}, abstract = {CSOM/PL is a software product line (SPL) derived from applying multi-dimensional separation of concerns (MDSOC) techniques to the domain of high-level language virtual machine (VM) implementations. For CSOM/PL, we modularised CSOM, a Smalltalk VM implemented in C, using VMADL (virtual machine architecture description language). Several features of the original CSOM were encapsulated in VMADL modules and composed in various combinations. In an evaluation of our approach, we show that applying MDSOC and SPL principles to a domain as complex as that of VMs is not only feasible but beneficial, as it improves understandability, maintainability, and configurability of VM implementations without harming performance.}, language = {en} } @book{HebigGiese2012, author = {Hebig, Regina and Giese, Holger}, title = {MDE settings in SAP : a descriptive field study}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-192-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60193}, publisher = {Universit{\"a}t Potsdam}, pages = {64}, year = {2012}, abstract = {MDE techniques are more and more used in praxis. However, there is currently a lack of detailed reports about how different MDE techniques are integrated into the development and combined with each other. To learn more about such MDE settings, we performed a descriptive and exploratory field study with SAP, which is a worldwide operating company with around 50.000 employees and builds enterprise software applications. This technical report describes insights we got during this study. For example, we identified that MDE settings are subject to evolution. Finally, this report outlines directions for future research to provide practical advises for the application of MDE settings.}, language = {en} } @book{HebigGieseBatoulisetal.2015, author = {Hebig, Regina and Giese, Holger and Batoulis, Kimon and Langer, Philipp and Zamani Farahani, Armin and Yao, Gary and Wolowyk, Mychajlo}, title = {Development of AUTOSAR standard documents at Carmeq GmbH}, number = {92}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-317-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-71535}, publisher = {Universit{\"a}t Potsdam}, pages = {52}, year = {2015}, abstract = {This report documents the captured MDE history of Carmeq GmbH, in context of the project Evolution of MDE Settings in Practice. The goal of the project is the elicitation of MDE approaches and their evolution.}, language = {en} } @book{HerbstMaschlerNiephausetal.2015, author = {Herbst, Eva-Maria and Maschler, Fabian and Niephaus, Fabio and Reimann, Max and Steier, Julia and Felgentreff, Tim and Lincke, Jens and Taeumel, Marcel and Hirschfeld, Robert and Witt, Carsten}, title = {ecoControl}, number = {93}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-318-3}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-72147}, publisher = {Universit{\"a}t Potsdam}, pages = {viii, 142}, year = {2015}, abstract = {Eine dezentrale Energieversorgung ist ein erster Schritt in Richtung Energiewende. Dabei werden auch in Mehrfamilienh{\"a}usern vermehrt verschiedene Strom- und W{\"a}rmeerzeuger eingesetzt. Besonders in Deutschland kommen in diesem Zusammenhang Blockheizkraftwerke immer h{\"a}ufiger zum Einsatz, weil sie Gas sehr effizient in Strom und W{\"a}rme umwandeln k{\"o}nnen. Außerdem erm{\"o}glichen sie, im Zusammenspiel mit anderen Energiesystemen wie beispielsweise Photovoltaik-Anlagen, eine kontinuierliche und dezentrale Energieversorgung. Bei dem Betrieb von unterschiedlichen Energiesystemen ist es w{\"u}nschenswert, dass die Systeme aufeinander abgestimmt arbeiten. Allerdings ist es bisher schwierig, heterogene Energiesysteme effizient miteinander zu betreiben. Dadurch bleiben Einsparungspotentiale ungenutzt. Eine zentrale Steuerung kann deshalb die Effizienz des Gesamtsystems verbessern. Mit ecoControl stellen wir einen erweiterbaren Prototypen vor, der die Kooperation von Energiesystemen optimiert und Umweltfaktoren miteinbezieht. Dazu stellt die Software eine einheitliche Bedienungsoberfl{\"a}che zur Konfiguration aller Systeme zur Verf{\"u}gung. Außerdem bietet sie die M{\"o}glichkeit, Optimierungsalgorithmen mit Hilfe einer Programmierschnittstelle zu entwickeln, zu testen und auszuf{\"u}hren. Innerhalb solcher Algorithmen k{\"o}nnen von ecoControl bereitgestellte Vorhersagen genutzt werden. Diese Vorhersagen basieren auf dem individuellen Verhalten von jedem Energiesystem, Wettervorhersagen und auf Prognosen des Energieverbrauchs. Mithilfe einer Simulation k{\"o}nnen Techniker unterschiedliche Konfigurationen und Optimierungen sofort ausprobieren, ohne diese {\"u}ber einen langen Zeitraum an realen Ger{\"a}ten testen zu m{\"u}ssen. ecoControl hilft dar{\"u}ber hinaus auch Hausverwaltungen und Vermietern bei der Verwaltung und Analyse der Energiekosten. Wir haben anhand von Fallbeispielen gezeigt, dass Optimierungsalgorithmen, welche die Nutzung von W{\"a}rmespeichern verbessern, die Effizienz des Gesamtsystems erheblich verbessern k{\"o}nnen. Schließlich kommen wir zu dem Schluss, dass ecoControl in einem n{\"a}chsten Schritt unter echten Bedingungen getestet werden muss, sobald eine geeignete Hardwarekomponente verf{\"u}gbar ist. {\"U}ber diese Schnittstelle werden die Messwerte an ecoControl gesendet und Steuersignale an die Ger{\"a}te weitergeleitet.}, language = {de} } @book{HerschelNaumann2008, author = {Herschel, Melanie and Naumann, Felix}, title = {Space and time scalability of duplicate detection in graph data}, isbn = {978-3-940793-46-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32851}, publisher = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {Duplicate detection consists in determining different representations of real-world objects in a database. Recent research has considered the use of relationships among object representations to improve duplicate detection. In the general case where relationships form a graph, research has mainly focused on duplicate detection quality/effectiveness. Scalability has been neglected so far, even though it is crucial for large real-world duplicate detection tasks. In this paper we scale up duplicate detection in graph data (DDG) to large amounts of data and pairwise comparisons, using the support of a relational database system. To this end, we first generalize the process of DDG. We then present how to scale algorithms for DDG in space (amount of data processed with limited main memory) and in time. Finally, we explore how complex similarity computation can be performed efficiently. Experiments on data an order of magnitude larger than data considered so far in DDG clearly show that our methods scale to large amounts of data not residing in main memory.}, language = {en} } @book{HerzbergWeske2013, author = {Herzberg, Nico and Weske, Mathias}, title = {Enriching raw events to enable process intelligence : research challenges}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-241-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64012}, publisher = {Universit{\"a}t Potsdam}, pages = {30}, year = {2013}, abstract = {Business processes are performed within a company's daily business. Thereby, valuable data about the process execution is produced. The quantity and quality of this data is very dependent on the process execution environment that reaches from predominantly manual to fullautomated. Process improvement is one essential cornerstone of business process management to ensure companies' competitiveness and relies on information about the process execution. Especially in manual process environments data directly related to the process execution is rather sparse and incomplete. In this paper, we present an approach that supports the usage and enrichment of process execution data with context data - data that exists orthogonally to business process data - and knowledge from the corresponding process models to provide a high-quality event base for process intelligence subsuming, among others, process monitoring, process analysis, and process mining. Further, we discuss open issues and challenges that are subject to our future work.}, language = {de} } @book{HuCordelMeinel2006, author = {Hu, Ji and Cordel, Dirk and Meinel, Christoph}, title = {A virtual machine architecture for creating IT-security laboratories}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-13-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33077}, publisher = {Universit{\"a}t Potsdam}, pages = {50}, year = {2006}, abstract = {E-learning is a flexible and personalized alternative to traditional education. Nonetheless, existing e-learning systems for IT security education have difficulties in delivering hands-on experience because of the lack of proximity. Laboratory environments and practical exercises are indispensable instruction tools to IT security education, but security education in con-ventional computer laboratories poses the problem of immobility as well as high creation and maintenance costs. Hence, there is a need to effectively transform security laboratories and practical exercises into e-learning forms. This report introduces the Tele-Lab IT-Security architecture that allows students not only to learn IT security principles, but also to gain hands-on security experience by exercises in an online laboratory environment. In this architecture, virtual machines are used to provide safe user work environments instead of real computers. Thus, traditional laboratory environments can be cloned onto the Internet by software, which increases accessibilities to laboratory resources and greatly reduces investment and maintenance costs. Under the Tele-Lab IT-Security framework, a set of technical solutions is also proposed to provide effective functionalities, reliability, security, and performance. The virtual machines with appropriate resource allocation, software installation, and system configurations are used to build lightweight security laboratories on a hosting computer. Reliability and availability of laboratory platforms are covered by the virtual machine management framework. This management framework provides necessary monitoring and administration services to detect and recover critical failures of virtual machines at run time. Considering the risk that virtual machines can be misused for compromising production networks, we present security management solutions to prevent misuse of laboratory resources by security isolation at the system and network levels. This work is an attempt to bridge the gap between e-learning/tele-teaching and practical IT security education. It is not to substitute conventional teaching in laboratories but to add practical features to e-learning. This report demonstrates the possibility to implement hands-on security laboratories on the Internet reliably, securely, and economically.}, language = {en} } @book{KlauckMaschlerTausche2017, author = {Klauck, Stefan and Maschler, Fabian and Tausche, Karsten}, title = {Proceedings of the Fourth HPI Cloud Symposium "Operating the Cloud" 2016}, number = {117}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-401-2}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-394513}, publisher = {Universit{\"a}t Potsdam}, pages = {32}, year = {2017}, abstract = {Every year, the Hasso Plattner Institute (HPI) invites guests from industry and academia to a collaborative scientific workshop on the topic Every year, the Hasso Plattner Institute (HPI) invites guests from industry and academia to a collaborative scientific workshop on the topic "Operating the Cloud". Our goal is to provide a forum for the exchange of knowledge and experience between industry and academia. Co-located with the event is the HPI's Future SOC Lab day, which offers an additional attractive and conducive environment for scientific and industry related discussions. "Operating the Cloud" aims to be a platform for productive interactions of innovative ideas, visions, and upcoming technologies in the field of cloud operation and administration. On the occasion of this symposium we called for submissions of research papers and practitioner's reports. A compilation of the research papers realized during the fourth HPI cloud symposium "Operating the Cloud" 2016 are published in this proceedings. We thank the authors for exciting presentations and insights into their current work and research. Moreover, we look forward to more interesting submissions for the upcoming symposium later in the year. Every year, the Hasso Plattner Institute (HPI) invites guests from industry and academia to a collaborative scientific workshop on the topic "Operating the Cloud". Our goal is to provide a forum for the exchange of knowledge and experience between industry and academia. Co-located with the event is the HPI's Future SOC Lab day, which offers an additional attractive and conducive environment for scientific and industry related discussions. "Operating the Cloud" aims to be a platform for productive interactions of innovative ideas, visions, and upcoming technologies in the field of cloud operation and administration.}, language = {en} } @book{KleineHirschfeldBracha2011, author = {Kleine, Matthias and Hirschfeld, Robert and Bracha, Gilad}, title = {An abstraction for version control systems}, series = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsdam}, journal = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsdam}, number = {54}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-158-5}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-55629}, publisher = {Universit{\"a}t Potsdam}, pages = {77}, year = {2011}, abstract = {Versionsverwaltungssysteme (VCS) erm{\"o}glichen es Entwicklern, {\"A}nderungen an Softwareartifakten zu verwalten. VCS werden mit Hilfe einer Vielzahl verschiedener Werkzeuge bedient, wie z.\,B. graphische Front-ends oder Kommandozeilenwerkzeuge. Es ist w{\"u}nschenswert mit einzelnen solcher Werkzeuge unterschiedliche VCS bedienen zu k{\"o}nnen. Bislang hat sich jedoch keine Abstraktion f{\"u}r Versionsverwaltungssysteme durchgesetzt, mit deren Hilfe solche Werkzeuge erstellt werden k{\"o}nnen. Stattdessen implementieren Werkzeuge zur Interaktion mit mehreren VCS ad-hoc L{\"o}sungen. Diese Masterarbeit stellt Pur vor, eine Abstraktion {\"u}ber Versionsverwaltungskonzepte. Mit Hilfe von Pur k{\"o}nnen Anwendungsprogramme entwickelt werden, die mit mehreren Versionsverwaltungssystemen interagieren k{\"o}nnen. Im Rahmen dieser Arbeit wird eine Implementierung dieser Abstraktion bereitgestellt und mit Hilfe eines Anwendungsprogramms validiert.}, language = {en} } @book{KrauseGiese2012, author = {Krause, Christian and Giese, Holger}, title = {Quantitative modeling and analysis of service-oriented real-time systems using interval probabilistic timed automata}, publisher = {Universit{\"a}tsverlah Potsdam}, address = {Potsdam}, isbn = {978-3-86956-171-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-57845}, publisher = {Universit{\"a}t Potsdam}, pages = {45}, year = {2012}, abstract = {One of the key challenges in service-oriented systems engineering is the prediction and assurance of non-functional properties, such as the reliability and the availability of composite interorganizational services. Such systems are often characterized by a variety of inherent uncertainties, which must be addressed in the modeling and the analysis approach. The different relevant types of uncertainties can be categorized into (1) epistemic uncertainties due to incomplete knowledge and (2) randomization as explicitly used in protocols or as a result of physical processes. In this report, we study a probabilistic timed model which allows us to quantitatively reason about nonfunctional properties for a restricted class of service-oriented real-time systems using formal methods. To properly motivate the choice for the used approach, we devise a requirements catalogue for the modeling and the analysis of probabilistic real-time systems with uncertainties and provide evidence that the uncertainties of type (1) and (2) in the targeted systems have a major impact on the used models and require distinguished analysis approaches. The formal model we use in this report are Interval Probabilistic Timed Automata (IPTA). Based on the outlined requirements, we give evidence that this model provides both enough expressiveness for a realistic and modular specifiation of the targeted class of systems, and suitable formal methods for analyzing properties, such as safety and reliability properties in a quantitative manner. As technical means for the quantitative analysis, we build on probabilistic model checking, specifically on probabilistic time-bounded reachability analysis and computation of expected reachability rewards and costs. To carry out the quantitative analysis using probabilistic model checking, we developed an extension of the Prism tool for modeling and analyzing IPTA. Our extension of Prism introduces a means for modeling probabilistic uncertainty in the form of probability intervals, as required for IPTA. For analyzing IPTA, our Prism extension moreover adds support for probabilistic reachability checking and computation of expected rewards and costs. We discuss the performance of our extended version of Prism and compare the interval-based IPTA approach to models with fixed probabilities.}, language = {en} } @book{KunzeWeske2016, author = {Kunze, Matthias and Weske, Mathias}, title = {Behavioural Models}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-44958-6}, publisher = {Universit{\"a}t Potsdam}, pages = {279}, year = {2016}, abstract = {This textbook introduces the basis for modelling and analysing discrete dynamic systems, such as computer programmes, soft- and hardware systems, and business processes. The underlying concepts are introduced and concrete modelling techniques are described, such as finite automata, state machines, and Petri nets. The concepts are related to concrete application scenarios, among which business processes play a prominent role. The book consists of three parts, the first of which addresses the foundations of behavioural modelling. After a general introduction to modelling, it introduces transition systems as a basic formalism for representing the behaviour of discrete dynamic systems. This section also discusses causality, a fundamental concept for modelling and reasoning about behaviour. In turn, Part II forms the heart of the book and is devoted to models of behaviour. It details both sequential and concurrent systems and introduces finite automata, state machines and several different types of Petri nets. One chapter is especially devoted to business process models, workflow patterns and BPMN, the industry standard for modelling business processes. Lastly, Part III investigates how the behaviour of systems can be analysed. To this end, it introduces readers to the concept of state spaces. Further chapters cover the comparison of behaviour and the formal analysis and verification of behavioural models. The book was written for students of computer science and software engineering, as well as for programmers and system analysts interested in the behaviour of the systems they work on. It takes readers on a journey from the fundamentals of behavioural modelling to advanced techniques for modelling and analysing sequential and concurrent systems, and thus provides them a deep understanding of the concepts and techniques introduced and how they can be applied to concrete application scenarios.}, language = {en} } @book{KuropkaMeyer2005, author = {Kuropka, Dominik and Meyer, Harald}, title = {Survey on Service Composition}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {3-937786-78-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33787}, publisher = {Universit{\"a}t Potsdam}, pages = {35}, year = {2005}, abstract = {It is predicted that Service-oriented Architectures (SOA) will have a high impact on future electronic business and markets. Services will provide an self-contained and standardised interface towards business and are considered as the future platform for business-to-business and business-toconsumer trades. Founded by the complexity of real world business scenarios a huge need for an easy, flexible and automated creation and enactment of service compositions is observed. This survey explores the relationship of service composition with workflow management—a technology/ concept already in use in many business environments. The similarities between the both and the key differences between them are elaborated. Furthermore methods for composition of services ranging from manual, semi- to full-automated composition are sketched. This survey concludes that current tools for service composition are in an immature state and that there is still much research to do before service composition can be used easily and conveniently in real world scenarios. However, since automated service composition is a key enabler for the full potential of Service-oriented Architectures, further research on this field is imperative. This survey closes with a formal sample scenario presented in appendix A to give the reader an impression on how full-automated service composition works.}, language = {en} } @book{LangeBoehmNaumann2010, author = {Lange, Dustin and B{\"o}hm, Christoph and Naumann, Felix}, title = {Extracting structured information from Wikipedia articles to populate infoboxes}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-081-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-45714}, publisher = {Universit{\"a}t Potsdam}, pages = {27}, year = {2010}, abstract = {Roughly every third Wikipedia article contains an infobox - a table that displays important facts about the subject in attribute-value form. The schema of an infobox, i.e., the attributes that can be expressed for a concept, is defined by an infobox template. Often, authors do not specify all template attributes, resulting in incomplete infoboxes. With iPopulator, we introduce a system that automatically populates infoboxes of Wikipedia articles by extracting attribute values from the article's text. In contrast to prior work, iPopulator detects and exploits the structure of attribute values for independently extracting value parts. We have tested iPopulator on the entire set of infobox templates and provide a detailed analysis of its effectiveness. For instance, we achieve an average extraction precision of 91\% for 1,727 distinct infobox template attributes.}, language = {en} } @book{Lendholt2005, author = {Lendholt, Matthias}, title = {Ressourcenpartitionierung f{\"u}r Grid-Systeme}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-72-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33121}, publisher = {Universit{\"a}t Potsdam}, pages = {97}, year = {2005}, abstract = {1 Einleitung 1.1 Motivation 1.2 Aufgabenstellung 1.3 Aufbau der Arbeit 2 Fachliches Umfeld 2.1 Grid Computing 2.2 Idle Time Computing 3 Ressourcenpartitionierung 3.1 Ressourcenpartitionierung und Scheduling 3.2 Ressourcenpartitionierung in Idle Time Computing 3.2.1 Administrative Kontrolle der Ressourcen 3.2.2 Mindestgarantien zur Sicherstellung der Lauff{\"a}higkeit 3.3 Vorhandene L{\"o}sungen und verwandte Arbeiten 3.3.3 Ressourcenmanagement im Globus Toolkit 3.3.4 Ressourcenmanagement in Condor 3.3.5 Das GARA Framework 3.3.6 Distributed Resource Management Application API 3.3.7 Grid Resource Allocation Agreement Protocol 3.3.8 SNAP 3.3.9 OGSI-Agreement 3.3.10 PBS/Maui und andere Batch Systeme 3.3.11 Wide Area Distributed Computing 3.3.12 Weitere verwandte Arbeiten 3.3.13 {\"U}berlegungen zum Ressourcenbedarf 4 Ressourcenkontrolle in Desktopbetriebssystemen 4.1 Ressourcen 4.2 Ressourcenpartitionierung unter Linux 4.2.14 Festplattenkapazit{\"a}t 4.2.15 Arbeitsspeicher 4.2.16 Netzwerkbandbreite 4.2.17 CPU Kapazit{\"a}t 4.3 Ressourcenpartitionierung unter Microsoft Windows XP 4.3.18 Festplattenkapazit{\"a}t 4.3.19 Arbeitsspeicher 4.3.20 Netzwerkbandbreite 4.3.21 CPU Kapazit{\"a}t 4.4 Fazit 5 Entwurf und Design des Frameworks 5.1 Entwurfsgrundlage - Komponentenarchitektur 5.2 Architektur 5.2.22 Broker Server 5.2.23 Broker Software auf den Clients 5.2.24 Schnittstellen 5.3 Komponententypmodell 5.4 Ressourcenidentifikation und Ressourcenzuordnung 5.5 Anbindung ans Grid 5.6 Datenbankentwurf 5.7 XML RPC Schnittstelle 6 Implementierung 6.1 Broker Server 6.1.25 Datenbank 6.1.26 Komponenten 6.1.27 Webserverskripte 6.1.28 Database Crawler 6.2 Komponenten 6.2.29 Network 6.2.30 DSCP 6.2.31 Quota 6.2.32 FSF 6.3 Linux Client 6.3.33 Broker Client 6.3.34 Komponenten 6.4 Windows Client 6.5 Abh{\"a}ngigkeiten 7 Evaluierung 7.1 Durchgef{\"u}hrte Test- und Anwendungsf{\"a}lle 7.1.35 Test der Clientsoftware 7.1.36 Test der Serversoftware 7.1.37 Durchf{\"u}hrbare Anwendungsf{\"a}lle 7.2 Evaluierung der Frameworkimplementierung 7.2.38 Performanz der Serverimplementierung 7.2.39 Zuverl{\"a}ssigkeit der Partitionierungen 7.3 Evaluierung von Traffic Shaping mit iproute2 7.3.40 Szenario 1 7.3.41 Szenario 2 7.3.42 Szenario 3 7.3.43 Fazit 8 Zusammenfassung und Ausblick 8.1 Fazit 8.2 Weiterentwicklung 8.2.44 Weiterentwicklungen auf Entwurfsebene 8.2.45 Weiterentwicklungen auf Implementierungsebene Anhang A: Details zum Datenbankentwurf Anhang B: Bildschirmfotos der Weboberfl{\"a}che Anhang C: Quellcode Linux Broker Client Anhang D: Inhalt des beiliegenden Datentr{\"a}gers}, language = {de} } @book{LinckelsMeinel2005, author = {Linckels, Serge and Meinel, Christoph}, title = {An e-librarian service : natural language interface for an efficient semantic search within multimedia resources}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-89-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33088}, publisher = {Universit{\"a}t Potsdam}, pages = {40}, year = {2005}, abstract = {1 Introduction 1.1 Project formulation 1.2 Our contribution 2 Pedagogical Aspect 4 2.1 Modern teaching 2.2 Our Contribution 2.2.1 Autonomous and exploratory learning 2.2.2 Human machine interaction 2.2.3 Short multimedia clips 3 Ontology Aspect 3.1 Ontology driven expert systems 3.2 Our contribution 3.2.1 Ontology language 3.2.2 Concept Taxonomy 3.2.3 Knowledge base annotation 3.2.4 Description Logics 4 Natural language approach 4.1 Natural language processing in computer science 4.2 Our contribution 4.2.1 Explored strategies 4.2.2 Word equivalence 4.2.3 Semantic interpretation 4.2.4 Various problems 5 Information Retrieval Aspect 5.1 Modern information retrieval 5.2 Our contribution 5.2.1 Semantic query generation 5.2.2 Semantic relatedness 6 Implementation 6.1 Prototypes 6.2 Semantic layer architecture 6.3 Development 7 Experiments 7.1 Description of the experiments 7.2 General characteristics of the three sessions, instructions and procedure 7.3 First Session 7.4 Second Session 7.5 Third Session 7.6 Discussion and conclusion 8 Conclusion and future work 8.1 Conclusion 8.2 Open questions A Description Logics B Probabilistic context-free grammars}, language = {en} } @book{Luebbe2011, author = {L{\"u}bbe, Alexander}, title = {The effect of tangible media on individuals in business process modeling : a controlled experiment = Der Einfluss greifbarer Medien auf einzelne Personen bei der Gesch{\"a}ftsprozessmodellierung : ein kontrolliertes Experiment}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-108-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49001}, publisher = {Universit{\"a}t Potsdam}, pages = {42}, year = {2011}, abstract = {In current practice, business processes modeling is done by trained method experts. Domain experts are interviewed to elicit their process information but not involved in modeling. We created a haptic toolkit for process modeling that can be used in process elicitation sessions with domain experts. We hypothesize that this leads to more effective process elicitation. This paper brakes down "effective elicitation" to 14 operationalized hypotheses. They are assessed in a controlled experiment using questionnaires, process model feedback tests and video analysis. The experiment compares our approach to structured interviews in a repeated measurement design. We executed the experiment with 17 student clerks from a trade school. They represent potential users of the tool. Six out of fourteen hypotheses showed significant difference due to the method applied. Subjects reported more fun and more insights into process modeling with tangible media. Video analysis showed significantly more reviews and corrections applied during process elicitation. Moreover, people take more time to talk and think about their processes. We conclude that tangible media creates a different working mode for people in process elicitation with fun, new insights and instant feedback on preliminary results.}, language = {en} } @book{MaximovaGieseKrause2017, author = {Maximova, Maria and Giese, Holger and Krause, Christian}, title = {Probabilistic timed graph transformation systems}, number = {118}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-405-0}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-397055}, publisher = {Universit{\"a}t Potsdam}, pages = {34}, year = {2017}, abstract = {Today, software has become an intrinsic part of complex distributed embedded real-time systems. The next generation of embedded real-time systems will interconnect the today unconnected systems via complex software parts and the service-oriented paradigm. Therefore besides timed behavior and probabilistic behaviour also structure dynamics, where the architecture can be subject to changes at run-time, e.g. when dynamic binding of service end-points is employed or complex collaborations are established dynamically, is required. However, a modeling and analysis approach that combines all these necessary aspects does not exist so far. To fill the identified gap, we propose Probabilistic Timed Graph Transformation Systems (PTGTSs) as a high-level description language that supports all the necessary aspects of structure dynamics, timed behavior, and probabilistic behavior. We introduce the formal model of PTGTSs in this paper and present a mapping of models with finite state spaces to probabilistic timed automata (PTA) that allows to use the PRISM model checker to analyze PTGTS models with respect to PTCTL properties.}, language = {en} } @book{MeinelPlattnerDoellneretal.2014, author = {Meinel, Christoph and Plattner, Hasso and D{\"o}llner, J{\"u}rgen Roland Friedrich and Weske, Mathias and Polze, Andreas and Hirschfeld, Robert and Naumann, Felix and Giese, Holger and Baudisch, Patrick}, title = {Proceedings of the 7th Ph.D. Retreat of the HPI Research School on Service-oriented Systems Engineering}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-273-5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63490}, publisher = {Universit{\"a}t Potsdam}, pages = {ii, 218}, year = {2014}, abstract = {Design and Implementation of service-oriented architectures imposes a huge number of research questions from the fields of software engineering, system analysis and modeling, adaptability, and application integration. Component orientation and web services are two approaches for design and realization of complex web-based system. Both approaches allow for dynamic application adaptation as well as integration of enterprise application. Commonly used technologies, such as J2EE and .NET, form de facto standards for the realization of complex distributed systems. Evolution of component systems has lead to web services and service-based architectures. This has been manifested in a multitude of industry standards and initiatives such as XML, WSDL UDDI, SOAP, etc. All these achievements lead to a new and promising paradigm in IT systems engineering which proposes to design complex software solutions as collaboration of contractually defined software services. Service-Oriented Systems Engineering represents a symbiosis of best practices in object-orientation, component-based development, distributed computing, and business process management. It provides integration of business and IT concerns. The annual Ph.D. Retreat of the Research School provides each member the opportunity to present his/her current state of their research and to give an outline of a prospective Ph.D. thesis. Due to the interdisciplinary structure of the Research Scholl, this technical report covers a wide range of research topics. These include but are not limited to: Self-Adaptive Service-Oriented Systems, Operating System Support for Service-Oriented Systems, Architecture and Modeling of Service-Oriented Systems, Adaptive Process Management, Services Composition and Workflow Planning, Security Engineering of Service-Based IT Systems, Quantitative Analysis and Optimization of Service-Oriented Systems, Service-Oriented Systems in 3D Computer Graphics sowie Service-Oriented Geoinformatics.}, language = {en} } @book{MeinelRenzGrellaetal.2017, author = {Meinel, Christoph and Renz, Jan and Grella, Catrina and Karn, Nils and Hagedorn, Christiane}, title = {Die Cloud f{\"u}r Schulen in Deutschland}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-397-8}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103858}, publisher = {Universit{\"a}t Potsdam}, pages = {50}, year = {2017}, abstract = {Die digitale Entwicklung durchdringt unser Bildungssystem, doch Schulen sind auf die Ver{\"a}nderungen kaum vorbereitet: {\"U}berforderte Lehrer/innen, infrastrukturell schwach ausgestattete Unterrichtsr{\"a}ume und unzureichend gewartete Computernetzwerke sind keine Seltenheit. Veraltete Hard- und Software erschweren digitale Bildung in Schulen eher, als dass sie diese erm{\"o}glichen: Ein zukunftssicherer Ansatz ist es, die Rechner weitgehend aus den Schulen zu entfernen und Bildungsinhalte in eine Cloud zu {\"u}berf{\"u}hren. Zeitgem{\"a}ßer Unterricht ben{\"o}tigt moderne Technologie und eine zukunftsorientierte Infrastruktur. Eine Schul-Cloud (https://hpi.de/schul-cloud) kann dabei helfen, die digitale Transformation in Schulen zu meistern und den f{\"a}cher{\"u}bergreifenden Unterricht mit digitalen Inhalten zu bereichern. Den Sch{\"u}ler/innen und Lehrkr{\"a}ften kann sie viele M{\"o}glichkeiten er{\"o}ffnen: einen einfachen Zugang zu neuesten, professionell gewarteten Anwendungen, die Vernetzung verschiedener Lernorte, Erleichterung von Unterrichtsvorbereitung und Differenzierung. Die Schul-Cloud bietet Flexibilit{\"a}t, f{\"o}rdert die schul- und f{\"a}cher{\"u}bergreifende Anwendbarkeit und schafft eine wichtige Voraussetzung f{\"u}r die gesellschaftliche Teilhabe und Mitgestaltung der digitalen Welt. Neben den technischen Komponenten werden im vorliegenden Bericht ausgew{\"a}hlte Dienste der Schul-Cloud exemplarisch beschrieben und weiterf{\"u}hrende Schritte aufgezeigt. Das in Zusammenarbeit mit zahlreichen Expertinnen und Experten am Hasso-Plattner-Institut (HPI) entwickelte und durch das Bundesministerium f{\"u}r Bildung und Forschung (BMBF) gef{\"o}rderte Konzept einer Schul-Cloud stellt eine wichtige Grundlage f{\"u}r die Einf{\"u}hrung Cloud-basierter Strukturen und -Dienste im Bildungsbereich dar. Gemeinsam mit dem nationalen Excellence-Schulnetzwerk MINT-EC als Kooperationspartner startet ab sofort die Pilotphase. Aufgrund des modularen, skalierbaren Ansatzes der Schul-Cloud kommt dem infrastrukturellen Prototypen langfristig das Potential zu, auch {\"u}ber die begrenzte Anzahl an Pilotschulen hinaus bundesweit effizient eingesetzt zu werden.}, language = {de} } @book{MeinelSackBross2008, author = {Meinel, Christoph and Sack, Harald and Bross, Justus}, title = {Erster Deutscher IPv6 Gipfel}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32865}, publisher = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {Inhalt: KOMMUNIQU{\´E} GRUßWORT PROGRAMM HINTERGR{\"U}NDE UND FAKTEN REFERENTEN: BIOGRAFIE \& VOTRAGSZUSAMMENFASSUNG 1.) DER ERSTE DEUTSCHE IPV6 GIPFEL AM HASSO PLATTNER INSTITUT IN POTSDAM - PROF. DR. CHRISTOPH MEINEL - VIVIANE REDING 2.) IPV6, ITS TIME HAS COME - VINTON CERF 3.) DIE BEDEUTUNG VON IPV6 F{\"U}R DIE {\"O}FFENTLICHE VERWALTUNG IN DEUTSCHLAND - MARTIN SCHALLBRUCH 4.) TOWARDS THE FUTURE OF THE INTERNET - PROF. DR. LUTZ HEUSER 5.) IPV6 STRATEGY \& DEPLOYMENT STATUS IN JAPAN - HIROSHI MIYATA 6.) IPV6 STRATEGY \& DEPLOYMENT STATUS IN CHINA - PROF. WU HEQUAN 7.) IPV6 STRATEGY AND DEPLOYMENT STATUS IN KOREA - DR. EUNSOOK KIM 8.) IPV6 DEPLOYMENT EXPERIENCES IN GREEK SCHOOL NETWORK - ATHANASSIOS LIAKOPOULOS 9.) IPV6 NETWORK MOBILITY AND IST USAGE - JEAN-MARIE BONNIN 10.) IPV6 - R{\"U}STZEUG F{\"U}R OPERATOR \& ISP IPV6 DEPLOYMENT UND STRATEGIEN DER DEUTSCHEN TELEKOM - HENNING GROTE 11.) VIEW FROM THE IPV6 DEPLOYMENT FRONTLINE - YVES POPPE 12.) DEPLOYING IPV6 IN MOBILE ENVIRONMENTS - WOLFGANG FRITSCHE 13.) PRODUCTION READY IPV6 FROM CUSTOMER LAN TO THE INTERNET - LUTZ DONNERHACKE 14.) IPV6 - DIE BASIS F{\"U}R NETZWERKZENTRIERTE OPERATIONSF{\"U}HRUNG (NETOPF{\"U}) IN DER BUNDESWEHR HERAUSFORDERUNGEN - ANWENDUNGSFALLBETRACHTUNGEN - AKTIVIT{\"A}TEN - CARSTEN HATZIG 15.) WINDOWS VISTA \& IPV6 - BERND OURGHANLIAN 16.) IPV6 \& HOME NETWORKING TECHINCAL AND BUSINESS CHALLENGES - DR. TAYEB BEN MERIEM 17.) DNS AND DHCP FOR DUAL STACK NETWORKS - LAWRENCE HUGHES 18.) CAR INDUSTRY: GERMAN EXPERIENCE WITH IPV6 - AMARDEO SARMA 19.) IPV6 \& AUTONOMIC NETWORKING - RANGANAI CHAPARADZA 20.) P2P \& GRID USING IPV6 AND MOBILE IPV6 - DR. LATIF LADID}, language = {en} } @book{MeinelSchnjakinMetzkeetal.2014, author = {Meinel, Christoph and Schnjakin, Maxim and Metzke, Tobias and Freitag, Markus}, title = {Anbieter von Cloud Speicherdiensten im {\"U}berblick}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-274-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-68780}, publisher = {Universit{\"a}t Potsdam}, pages = {84}, year = {2014}, abstract = {Durch die immer st{\"a}rker werdende Flut an digitalen Informationen basieren immer mehr Anwendungen auf der Nutzung von kosteng{\"u}nstigen Cloud Storage Diensten. Die Anzahl der Anbieter, die diese Dienste zur Verf{\"u}gung stellen, hat sich in den letzten Jahren deutlich erh{\"o}ht. Um den passenden Anbieter f{\"u}r eine Anwendung zu finden, m{\"u}ssen verschiedene Kriterien individuell ber{\"u}cksichtigt werden. In der vorliegenden Studie wird eine Auswahl an Anbietern etablierter Basic Storage Diensten vorgestellt und miteinander verglichen. F{\"u}r die Gegen{\"u}berstellung werden Kriterien extrahiert, welche bei jedem der untersuchten Anbieter anwendbar sind und somit eine m{\"o}glichst objektive Beurteilung erlauben. Hierzu geh{\"o}ren unter anderem Kosten, Recht, Sicherheit, Leistungsf{\"a}higkeit sowie bereitgestellte Schnittstellen. Die vorgestellten Kriterien k{\"o}nnen genutzt werden, um Cloud Storage Anbieter bez{\"u}glich eines konkreten Anwendungsfalles zu bewerten.}, language = {de} } @book{MeinelThomasWarschofskyetal.2011, author = {Meinel, Christoph and Thomas, Ivonne and Warschofsky, Robert and Menzel, Michael and Junker, Holger and Schwenk, J{\"o}rg and Roth, Volker and Peters, Jan and Raepple, Martin and St{\"o}rtkuhl, Thomas and Quint, Bruno and Kleinhenz, Michael and Wagner, Daniel}, title = {SOA Security 2010 : Symposium f{\"u}r Sicherheit in Service-orientierten Architekturen ; 28. / 29. Oktober 2010 am Hasso-Plattner-Institut}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-110-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49696}, publisher = {Universit{\"a}t Potsdam}, pages = {80}, year = {2011}, abstract = {"Forschung meets Business" - diese Kombination hat in den vergangenen Jahren immer wieder zu zahlreichen interessanten und fruchtbaren Diskussionen gef{\"u}hrt. Mit dem Symposium "Sicherheit in Service-orientierten Architekturen" f{\"u}hrt das Hasso-Plattner-Institut diese Tradition fort und lud alle Interessenten zu einem zweit{\"a}gigen Symposium nach Potsdam ein, um gemeinsam mit Fachvertretern aus der Forschung und Industrie {\"u}ber die aktuellen Entwicklungen im Bereich Sicherheit von SOA zu diskutieren. Die im Rahmen dieses Symposiums vorgestellten Beitr{\"a}ge fokussieren sich auf die Sicherheitsthemen "Sichere Digitale Identit{\"a}ten und Identit{\"a}tsmanagement", "Trust Management", "Modell-getriebene SOA-Sicherheit", "Datenschutz und Privatsph{\"a}re", "Sichere Enterprise SOA", und "Sichere IT-Infrastrukturen".}, language = {de} } @book{MeinelWillems2014, author = {Meinel, Christoph and Willems, Christian}, title = {openHPI : 哈索•普拉特纳研究院的 MOOC（大规模公开在线课）计划}, number = {89}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-291-9}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-70380}, publisher = {Universit{\"a}t Potsdam}, pages = {22}, year = {2014}, abstract = {摘要。哈索•普拉特纳研究院 (HPI) 的新型互动在线教育平台 openHPI (https://openHPI.de) 可以为从事信息技术和信息学领域内容的工作和感兴趣的学员提供可自由访问的、免费的在线课程。与斯坦福大学于 2011 年首推，之后也在美国其他精英大学提供的"网络公开群众课"（简称 MOOC）一样，openHPI 同样在互联网中提供学习视频和阅读材料，其中综合了支持学习的自我测试、家庭作业和社交讨论论坛，并刺激对促进学习的虚拟学习团队的培训。与"传统的"讲座平台，比如 tele-TASK 平台 (http://www.tele-task.de) 不同（在该平台中，可调用以多媒体方式记录的和已准备好的讲座），openHPI 提供的是按教学法准备的在线课程。这些课程的开始时间固定，之后在连续六个课程周稳定的提供以多媒体方式准备的、尽可能可以互动的学习材料。每周讲解课程主题的一章。为此在该周开始前会准备一系列学习视频、文字、自我测试和家庭作业材料，课程学员在该周将精力用于处理这些内容。这些计划与一个社交讨论平台相结合，学员在该平台上可以与课程导师和其他学员交换意见、解答问题和讨论更多主题。当然，学员可以自己决定学习活动的类型和范围。他们可以为课程作出自己的贡献，比如在论坛中引用博文或推文。之后其他学员可以评论、讨论或自己扩展这些博文或推文。这样学员、教师和提供的学习内容就在一个虚拟的团体中与社交学习网络相互结合起来。}, language = {de} } @book{MeinelWillems2013, author = {Meinel, Christoph and Willems, Christian}, title = {openHPI : the MOOC offer at Hasso Plattner Institute}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-264-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67176}, publisher = {Universit{\"a}t Potsdam}, pages = {21}, year = {2013}, abstract = {The new interactive online educational platform openHPI, (https://openHPI.de) from Hasso Plattner Institute (HPI), offers freely accessible courses at no charge for all who are interested in subjects in the field of information technology and computer science. Since 2011, "Massive Open Online Courses," called MOOCs for short, have been offered, first at Stanford University and then later at other U.S. elite universities. Following suit, openHPI provides instructional videos on the Internet and further reading material, combined with learning-supportive self-tests, homework and a social discussion forum. Education is further stimulated by the support of a virtual learning community. In contrast to "traditional" lecture platforms, such as the tele-TASK portal (http://www.tele-task.de) where multimedia recorded lectures are available on demand, openHPI offers didactic online courses. The courses have a fixed start date and offer a balanced schedule of six consecutive weeks presented in multimedia and, whenever possible, interactive learning material. Each week, one chapter of the course subject is treated. In addition, a series of learning videos, texts, self-tests and homework exercises are provided to course participants at the beginning of the week. The course offering is combined with a social discussion platform where participants have the opportunity to enter into an exchange with course instructors and fellow participants. Here, for example, they can get answers to questions and discuss the topics in depth. The participants naturally decide themselves about the type and range of their learning activities. They can make personal contributions to the course, for example, in blog posts or tweets, which they can refer to in the forum. In turn, other participants have the chance to comment on, discuss or expand on what has been said. In this way, the learners become the teachers and the subject matter offered to a virtual community is linked to a social learning network.}, language = {en} } @book{MeinelWillems2013, author = {Meinel, Christoph and Willems, Christian}, title = {openHPI : das MOOC-Angebot des Hasso-Plattner-Instituts}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-259-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66802}, publisher = {Universit{\"a}t Potsdam}, pages = {22}, year = {2013}, abstract = {Die neue interaktive Online-Bildungsplattform openHPI (https://openHPI.de) des Hasso-Plattner-Instituts (HPI) bietet frei zug{\"a}ngliche und kostenlose Onlinekurse f{\"u}r interessierte Teilnehmer an, die sich mit Inhalten aus dem Bereich der Informationstechnologien und Informatik besch{\"a}ftige¬n. Wie die seit 2011 zun{\"a}chst von der Stanford University, sp{\"a}ter aber auch von anderen Elite-Universit{\"a}ten der USA angeboten „Massive Open Online Courses", kurz MOOCs genannt, bietet openHPI im Internet Lernvideos und weiterf{\"u}hrenden Lesestoff in einer Kombination mit lernunterst{\"u}tzenden Selbsttests, Hausaufgaben und einem sozialen Diskussionsforum an und stimuliert die Ausbildung einer das Lernen f{\"o}rdernden virtuellen Lerngemeinschaft. Im Unterschied zu „traditionellen" Vorlesungsportalen, wie z.B. dem tele-TASK Portal (http://www.tele-task.de), bei dem multimedial aufgezeichnete Vorlesungen zum Abruf bereit gestellt werden, bietet openHPI didaktisch aufbereitete Onlinekurse an. Diese haben einen festen Starttermin und bieten dann in einem austarierten Zeitplan von sechs aufeinanderfolgenden Kurswochen multimedial aufbereitete und wann immer m{\"o}glich interaktive Lehrmaterialien. In jeder Woche wird ein Kapitel des Kursthemas behandelt. Dazu werden zu Wochenbeginn eine Reihe von Lehrvideos, Texten, Selbsttests und ein Hausaufgabenblatt bereitgestellt, mit denen sich die Kursteilnehmer in dieser Woche besch{\"a}ftigen. Kombiniert sind die Angebote mit einer sozialen Diskussionsplattform, auf der sich die Teilnehmer mit den Kursbetreuern und anderen Teilnehmern austauschen, Fragen kl{\"a}ren und weiterf{\"u}hrende Themen diskutieren k{\"o}nnen. Nat{\"u}rlich entscheiden die Teilnehmer selbst {\"u}ber Art und Umfang ihrer Lernaktivit{\"a}ten. Sie k{\"o}nnen in den Kurs eigene Beitr{\"a}ge einbringen, zum Beispiel durch Blogposts oder Tweets, auf die sie im Forum verweisen. Andere Lernende k{\"o}nnen diese dann kommentieren, diskutieren oder ihrerseits erweitern. Auf diese Weise werden die Lernenden, die Lehrenden und die angebotenen Lerninhalte in einer virtuellen Gemeinschaft, einem sozialen Lernnetzwerk miteinander verkn{\"u}pft.}, language = {de} } @book{MeinelWillemsRoschkeetal.2011, author = {Meinel, Christoph and Willems, Christian and Roschke, Sebastian and Schnjakin, Maxim}, title = {Virtualisierung und Cloud Computing : Konzepte, Technologiestudie, Markt{\"u}bersicht}, isbn = {978-3-86956-113-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49708}, publisher = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Virtualisierung und Cloud Computing geh{\"o}ren derzeit zu den wichtigsten Schlagworten f{\"u}r Betreiber von IT Infrastrukturen. Es gibt eine Vielzahl unterschiedlicher Technologien, Produkte und Gesch{\"a}ftsmodelle f{\"u}r vollkommen verschiedene Anwendungsszenarien. Die vorliegende Studie gibt zun{\"a}chst einen detaillierten {\"U}berblick {\"u}ber aktuelle Entwicklungen in Konzepten und Technologien der Virtualisierungstechnologie - von klassischer Servervirtualisierung {\"u}ber Infrastrukturen f{\"u}r virtuelle Arbeitspl{\"a}tze bis zur Anwendungsvirtualisierung und macht den Versuch einer Klassifikation der Virtualisierungsvarianten. Bei der Betrachtung des Cloud Computing-Konzepts werden deren Grundz{\"u}ge sowie verschiedene Architekturvarianten und Anwendungsf{\"a}lle eingef{\"u}hrt. Die ausf{\"u}hrliche Untersuchung von Vorteilen des Cloud Computing sowie m{\"o}glicher Bedenken, die bei der Nutzung von Cloud-Ressourcen im Unternehmen beachtet werden m{\"u}ssen, zeigt, dass Cloud Computing zwar große Chancen bietet, aber nicht f{\"u}r jede Anwendung und nicht f{\"u}r jeden rechtlichen und wirtschaftlichen Rahmen in Frage kommt.. Die anschließende Markt{\"u}bersicht f{\"u}r Virtualisierungstechnologie zeigt, dass die großen Hersteller - Citrix, Microsoft und VMware - jeweils Produkte f{\"u}r fast alle Virtualisierungsvarianten anbieten und hebt entscheidende Unterschiede bzw. die St{\"a}rken der jeweiligen Anbieter heraus. So ist beispielsweise die L{\"o}sung von Citrix f{\"u}r Virtual Desktop Infrastructures sehr ausgereift, w{\"a}hrend Microsoft hier nur auf Standardtechnologie zur{\"u}ckgreifen kann. VMware hat als Marktf{\"u}hrer die gr{\"o}ßte Verbreitung in Rechenzentren gefunden und bietet als einziger Hersteller echte Fehlertoleranz. Microsoft hingegen punktet mit der nahtlosen Integration ihrer Virtualisierungsprodukte in bestehende Windows-Infrastrukturen. Im Bereich der Cloud Computing-Systeme zeigen sich einige quelloffene Softwareprojekte, die durchaus f{\"u}r den produktiven Betrieb von sogenannten privaten Clouds geeignet sind.}, language = {de} } @book{MeyerPufahlFahlandetal.2013, author = {Meyer, Andreas and Pufahl, Luise and Fahland, Dirk and Weske, Mathias}, title = {Modeling and enacting complex data dependencies in business processes}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-245-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65103}, publisher = {Universit{\"a}t Potsdam}, pages = {40}, year = {2013}, abstract = {Enacting business processes in process engines requires the coverage of control flow, resource assignments, and process data. While the first two aspects are well supported in current process engines, data dependencies need to be added and maintained manually by a process engineer. Thus, this task is error-prone and time-consuming. In this report, we address the problem of modeling processes with complex data dependencies, e.g., m:n relationships, and their automatic enactment from process models. First, we extend BPMN data objects with few annotations to allow data dependency handling as well as data instance differentiation. Second, we introduce a pattern-based approach to derive SQL queries from process models utilizing the above mentioned extensions. Therewith, we allow automatic enactment of data-aware BPMN process models. We implemented our approach for the Activiti process engine to show applicability.}, language = {en} } @book{MeyerSmirnovWeske2011, author = {Meyer, Andreas and Smirnov, Sergey and Weske, Mathias}, title = {Data in business processes}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-144-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-53046}, publisher = {Universit{\"a}t Potsdam}, pages = {40}, year = {2011}, abstract = {Process and data are equally important for business process management. Process data is especially relevant in the context of automated business processes, process controlling, and representation of organizations' core assets. One can discover many process modeling languages, each having a specific set of data modeling capabilities and the level of data awareness. The level of data awareness and data modeling capabilities vary significantly from one language to another. This paper evaluates several process modeling languages with respect to the role of data. To find a common ground for comparison, we develop a framework, which systematically organizes process- and data-related aspects of the modeling languages elaborating on the data aspects. Once the framework is in place, we compare twelve process modeling languages against it. We generalize the results of the comparison and identify clusters of similar languages with respect to data awareness.}, language = {de} } @book{MeyerWeske2014, author = {Meyer, Andreas and Weske, Mathias}, title = {Weak conformance between process models and synchronized object life cycles}, number = {91}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-303-9}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71722}, publisher = {Universit{\"a}t Potsdam}, pages = {31}, year = {2014}, abstract = {Process models specify behavioral execution constraints between activities as well as between activities and data objects. A data object is characterized by its states and state transitions represented as object life cycle. For process execution, all behavioral execution constraints must be correct. Correctness can be verified via soundness checking which currently only considers control flow information. For data correctness, conformance between a process model and its object life cycles is checked. Current approaches abstract from dependencies between multiple data objects and require fully specified process models although, in real-world process repositories, often underspecified models are found. Coping with these issues, we introduce the concept of synchronized object life cycles and we define a mapping of data constraints of a process model to Petri nets extending an existing mapping. Further, we apply the notion of weak conformance to process models to tell whether each time an activity needs to access a data object in a particular state, it is guaranteed that the data object is in or can reach the expected state. Then, we introduce an algorithm for an integrated verification of control flow correctness and weak data conformance using soundness checking.}, language = {en} } @book{MeyerKuropka2005, author = {Meyer, Harald and Kuropka, Dominik}, title = {Requirements for service composition}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-81-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33096}, publisher = {Universit{\"a}t Potsdam}, pages = {27}, year = {2005}, abstract = {1 Introduction 2 Use case Scenario 3 General Composition Requirements 4 Functional Requirements of Service Composition 5 Non-Functional Requirements 6 Conclusion}, language = {en} } @book{NeuhausPolzeChowdhuryy2011, author = {Neuhaus, Christian and Polze, Andreas and Chowdhuryy, Mohammad M. R.}, title = {Survey on healthcare IT systems : standards, regulations and security}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-128-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51463}, publisher = {Universit{\"a}t Potsdam}, pages = {53}, year = {2011}, abstract = {IT systems for healthcare are a complex and exciting field. One the one hand, there is a vast number of improvements and work alleviations that computers can bring to everyday healthcare. Some ways of treatment, diagnoses and organisational tasks were even made possible by computer usage in the first place. On the other hand, there are many factors that encumber computer usage and make development of IT systems for healthcare a challenging, sometimes even frustrating task. These factors are not solely technology-related, but just as well social or economical conditions. This report describes some of the idiosyncrasies of IT systems in the healthcare domain, with a special focus on legal regulations, standards and security.}, language = {en} } @book{NeumannGiese2013, author = {Neumann, Stefan and Giese, Holger}, title = {Scalable compatibility for embedded real-time components via language progressive timed automata}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-226-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63853}, publisher = {Universit{\"a}t Potsdam}, pages = {vi, 67}, year = {2013}, abstract = {The proper composition of independently developed components of an embedded real- time system is complicated due to the fact that besides the functional behavior also the non-functional properties and in particular the timing have to be compatible. Nowadays related compatibility problems have to be addressed in a cumbersome integration and configuration phase at the end of the development process, that in the worst case may fail. Therefore, a number of formal approaches have been developed, which try to guide the upfront decomposition of the embedded real-time system into components such that integration problems related to timing properties can be excluded and that suitable configurations can be found. However, the proposed solutions require a number of strong assumptions that can be hardly fulfilled or the required analysis does not scale well. In this paper, we present an approach based on timed automata that can provide the required guarantees for the later integration without strong assumptions, which are difficult to match in practice. The approach provides a modular reasoning scheme that permits to establish the required guarantees for the integration employing only local checks, which therefore also scales. It is also possible to determine potential configuration settings by means of timed game synthesis.}, language = {de} } @book{Nicolai2005, author = {Nicolai, Johannes}, title = {Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme : Evaluation verschiedener Ans{\"a}tze und Einsatz an vier Fallbeispielen}, isbn = {978-3-937786-73-5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33101}, publisher = {Universit{\"a}t Potsdam}, year = {2005}, abstract = {Vorwort 1. Einleitung 2. Statische vs. dynamische Analyse 3. Kriterien f{\"u}r den Erfolg statischer Quellcodeanalysemethoden 3.1. Theoretische Vor{\"u}berlegungen 3.2. 1. Kriterium: Verf{\"u}gbarkeit des Quellcodes 3.3. 2. Kriterium: Unterst{\"u}tzung der Programmiersprache 3.4. 3. Kriterium: Zulassung von „echten" Programmen der Problemdom{\"a}ne 3.5. 4. Kriterium: Bew{\"a}ltigung der auftretenden Komplexit{\"a}t 3.6. 5. Kriterium: Schutz vor b{\"o}swilliger Speichermanipulation 3.7. 6. Kriterium: Garantie f{\"u}r die Umgebung des laufenden Prozesses 3.8. Fazit 3.9. Verwandte Arbeiten 4. Bewertung von statischen Methoden f{\"u}r C/C++ typische Programme 4.1. Hintergrund 4.2. Pr{\"a}missen 4.3. 1. Problemfeld: Programmgr{\"o}ße und Interferenz 4.4. 2. Problemfeld: Semantik 4.5. 3. Problemfeld: Programmfluss 4.6. 4. Problemfeld: Zeigerarithmetik 4.7. Dynamische Konzepte zur Erf{\"u}llung des f{\"u}nften Kriteriums auf Quellcodebasis 4.8. Fazit 4.9. Verwandte Arbeiten 5. Kriterien f{\"u}r den Erfolg dynamischer Ans{\"a}tze 5.1. Hintergrund 5.2. Verf{\"u}gbarkeit des Quellcodes 5.3. Unterst{\"u}tzung der Programmiersprache 5.4. Zulassung von „echten" Programmen aus der Problemdom{\"a}ne 5.5. Bew{\"a}ltigung der auftretenden Komplexit{\"a}t 5.6. Schutz vor b{\"o}swilliger Speichermanipulation 5.7. Garantie f{\"u}r die Umgebung des laufenden Prozesses 5.8. Fazit 6. Klassifikation und Evaluation dynamischer Ans{\"a}tze 6.1. Hintergrund 6.2. Quellcodesubstitution 6.3. Bin{\"a}rcodemodifikation/Binary-Rewriting 6.4. Maschinencodeinterpreter 6.5. Intrusion-Detection-Systeme 6.6. Virtuelle Maschinen/Safe Languages 6.7. Mechanismen zur „H{\"a}rtung" von bestehenden Code 6.8. SandBoxing/System-Call-Interposition 6.9. Herk{\"o}mmliche Betriebssystemmittel 6.10. Access-Control-Lists/Domain-Type-Enforcement 6.11. Fazit 7. Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme im Kontext von RealTimeBattle 7.1. Vorstellung von RealTimeBattle 7.2. Charakterisierung des Problems 7.3. Alternative L{\"o}sungsvarianten/Rekapitulation 7.4. {\"U}bertragung der Ergebnisse statischer Analysemethoden auf RealTimeBattle 7.5. {\"U}bertragung der Ergebnisse dynamischer Analysemethoden auf RealTimeBattle 7.5.1. Vorstellung der RSBAC basierten L{\"o}sung 7.5.2. Vorstellung der Systrace basierten L{\"o}sung 7.6. Fazit 7.7. Verwandte Arbeiten 8. Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme im Kontext von Asparagus 8.1. Vorstellung von Asparagus 8.2. Charakterisierung des Problems 8.3. L{\"o}sung des Problems 8.4. Fazit 8.5. Verwandte Arbeiten 9. Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme im Kontext vom DCL 9.1. Vorstellung des DCL 9.2. Charakterisierung des Problems 9.3. Experimente im DCL und die jeweilige L{\"o}sung 9.3.1. Foucaultsches Pendel 9.3.2. Lego Mindstorm Roboter 9.3.3. Hau den Lukas 9.4. Fazit 9.5. Verwandte Arbeiten 10. Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme im Kontext der semiautomatischen Korrektur von Betriebssystemarchitektur-{\"U}bungsaufgaben 10.1. Vorstellung des {\"U}bungsbetriebes zur Vorlesung „Betriebssystsemarchitektur 10.2. Charakterisierung des Problems 10.3. L{\"o}sungsvorschl{\"a}ge 10.3.1. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Authentifizierungs-Problem 10.3.2. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Transport-Problem 10.3.3. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Build-Problem 10.3.4. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Ausf{\"u}hrungs-Problem 10.3.5. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Ressourcen-Problem 10.3.6. L{\"o}sungsvorschl{\"a}ge f{\"u}r das Portabilit{\"a}ts-Problem 10.4. Fazit 10.5. Verwandte Arbeiten 11. Schlussbetrachtungen Literaturverzeichnis Anhang -create_guardedrobot.sh: Die RealTimeBattle Security Infrastructure -vuln.c: Ein durch Puffer{\"u}berlauf ausnutzbares Programm -exploit.c: Ein Beispielexploit f{\"u}r vuln.c. -aufg43.c: L{\"o}sung f{\"u}r eine Aufgabe im Rahmen der Betriebssystemarchitektur-{\"U}bung -Handout: Sichere Ausf{\"u}hrung nicht vertrauensw{\"u}rdiger Programme}, language = {de} } @book{NienhausGoochDoellner2006, author = {Nienhaus, Marc and Gooch, Bruce and D{\"o}llner, J{\"u}rgen Roland Friedrich}, title = {Visualizing movement dynamics in virtual urban environments}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-52-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33065}, publisher = {Universit{\"a}t Potsdam}, pages = {7}, year = {2006}, abstract = {Dynamics in urban environments encompasses complex processes and phenomena such as related to movement (e.g.,traffic, people) and development (e.g., construction, settlement). This paper presents novel methods for creating human-centric illustrative maps for visualizing the movement dynamics in virtual 3D environments. The methods allow a viewer to gain rapid insight into traffic density and flow. The illustrative maps represent vehicle behavior as light threads. Light threads are a familiar visual metaphor caused by moving light sources producing streaks in a long-exposure photograph. A vehicle's front and rear lights produce light threads that convey its direction of motion as well as its velocity and acceleration. The accumulation of light threads allows a viewer to quickly perceive traffic flow and density. The light-thread technique is a key element to effective visualization systems for analytic reasoning, exploration, and monitoring of geospatial processes.}, language = {en} } @book{OttoPollakWerneretal.2015, author = {Otto, Philipp and Pollak, Jaqueline and Werner, Daniel and Wolff, Felix and Steinert, Bastian and Thamsen, Lauritz and Taeumel, Marcel and Lincke, Jens and Krahn, Robert and Ingalls, Daniel H. H. and Hirschfeld, Robert}, title = {Exploratives Erstellen von interaktiven Inhalten in einer dynamischen Umgebung​}, number = {101}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-346-6}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83806}, publisher = {Universit{\"a}t Potsdam}, pages = {vii, 115}, year = {2015}, abstract = {Bei der Erstellung von Visualisierungen gibt es im Wesentlichen zwei Ans{\"a}tze. Zum einen k{\"o}nnen mit geringem Aufwand schnell Standarddiagramme erstellt werden. Zum anderen gibt es die M{\"o}glichkeit, individuelle und interaktive Visualisierungen zu programmieren. Dies ist jedoch mit einem deutlich h{\"o}heren Aufwand verbunden. Flower erm{\"o}glicht eine schnelle Erstellung individueller und interaktiver Visualisierungen, indem es den Entwicklungssprozess stark vereinfacht und die Nutzer bei den einzelnen Aktivit{\"a}ten wie dem Import und der Aufbereitung von Daten, deren Abbildung auf visuelle Elemente sowie der Integration von Interaktivit{\"a}t direkt unterst{\"u}tzt.}, language = {de} } @book{PapeTrefferHirschfeldetal.2013, author = {Pape, Tobias and Treffer, Arian and Hirschfeld, Robert and Haupt, Michael}, title = {Extending a Java Virtual Machine to Dynamic Object-oriented Languages}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-266-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67438}, publisher = {Universit{\"a}t Potsdam}, pages = {163}, year = {2013}, abstract = {There are two common approaches to implement a virtual machine (VM) for a dynamic object-oriented language. On the one hand, it can be implemented in a C-like language for best performance and maximum control over the resulting executable. On the other hand, it can be implemented in a language such as Java that allows for higher-level abstractions. These abstractions, such as proper object-oriented modularization, automatic memory management, or interfaces, are missing in C-like languages but they can simplify the implementation of prevalent but complex concepts in VMs, such as garbage collectors (GCs) or just-in-time compilers (JITs). Yet, the implementation of a dynamic object-oriented language in Java eventually results in two VMs on top of each other (double stack), which impedes performance. For statically typed languages, the Maxine VM solves this problem; it is written in Java but can be executed without a Java virtual machine (JVM). However, it is currently not possible to execute dynamic object-oriented languages in Maxine. This work presents an approach to bringing object models and execution models of dynamic object-oriented languages to the Maxine VM and the application of this approach to Squeak/Smalltalk. The representation of objects in and the execution of dynamic object-oriented languages pose certain challenges to the Maxine VM that lacks certain variation points necessary to enable an effortless and straightforward implementation of dynamic object-oriented languages' execution models. The implementation of Squeak/Smalltalk in Maxine as a feasibility study is to unveil such missing variation points.}, language = {en} } @book{PlattnerZeier2012, author = {Plattner, Hasso and Zeier, Alexander}, title = {In-Memory Data Management}, publisher = {Springer}, address = {Wiesbaden}, isbn = {978-3-8349-4378-1}, publisher = {Universit{\"a}t Potsdam}, pages = {200}, year = {2012}, abstract = {Nach 50 Jahren erfolgreicher Entwicklunghat die Business-IT einen neuenWendepunkt erreicht. Hier zeigen die Autoren erstmalig, wieIn-Memory Computing dieUnternehmensprozesse k{\"u}nftig ver{\"a}ndern wird. Bisher wurden Unternehmensdaten aus Performance-Gr{\"u}nden auf verschiedene Datenbanken verteilt: Analytische Datenresidieren in Data Warehouses und werden regelm{\"a}ßig mithilfe transaktionaler Systeme synchronisiert. Diese Aufspaltung macht flexibles Echtzeit-Reporting aktueller Daten unm{\"o}glich. Doch dank leistungsf{\"a}higerMulti-Core-CPUs, großer Hauptspeicher, Cloud Computing und immerbesserer mobiler Endger{\"a}te lassen die Unternehmen dieses restriktive Modell zunehmend hinter sich. Die Autoren stellen Techniken vor, die eine analytische und transaktionale Verarbeitung in Echtzeit erlauben und so dem Gesch{\"a}ftsleben neue Wege bahnen.}, language = {de} } @book{PolyvyanyyKuropka2007, author = {Polyvyanyy, Artem and Kuropka, Dominik}, title = {A quantitative evaluation of the enhanced topic-based vector space model}, isbn = {978-3-939469-95-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33816}, publisher = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {This contribution presents a quantitative evaluation procedure for Information Retrieval models and the results of this procedure applied on the enhanced Topic-based Vector Space Model (eTVSM). Since the eTVSM is an ontology-based model, its effectiveness heavily depends on the quality of the underlaying ontology. Therefore the model has been tested with different ontologies to evaluate the impact of those ontologies on the effectiveness of the eTVSM. On the highest level of abstraction, the following results have been observed during our evaluation: First, the theoretically deduced statement that the eTVSM has a similar effecitivity like the classic Vector Space Model if a trivial ontology (every term is a concept and it is independet of any other concepts) is used has been approved. Second, we were able to show that the effectiveness of the eTVSM raises if an ontology is used which is only able to resolve synonyms. We were able to derive such kind of ontology automatically from the WordNet ontology. Third, we observed that more powerful ontologies automatically derived from the WordNet, dramatically dropped the effectiveness of the eTVSM model even clearly below the effectiveness level of the Vector Space Model. Fourth, we were able to show that a manually created and optimized ontology is able to raise the effectiveness of the eTVSM to a level which is clearly above the best effectiveness levels we have found in the literature for the Latent Semantic Index model with compareable document sets.}, language = {en} } @book{PolyvyanyySmirnovWeske2008, author = {Polyvyanyy, Artem and Smirnov, Sergey and Weske, Mathias}, title = {Reducing the complexity of large EPCs}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32959}, publisher = {Universit{\"a}t Potsdam}, year = {2008}, abstract = {Inhalt: 1 Introduction 2 Motivation and Goal 3 Fundamentals 4 Elementary Abstractions 5 Real World Example 6 Conclusions}, language = {en} } @book{PolyvyanyySmirnovWeske2008, author = {Polyvyanyy, Artem and Smirnov, Sergey and Weske, Mathias}, title = {The triconnected abstraction of process models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-940793-65-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32847}, publisher = {Universit{\"a}t Potsdam}, pages = {17}, year = {2008}, abstract = {Contents: Artem Polyvanny, Sergey Smirnow, and Mathias Weske The Triconnected Abstraction of Process Models 1 Introduction 2 Business Process Model Abstraction 3 Preliminaries 4 Triconnected Decomposition 4.1 Basic Approach for Process Component Discovery 4.2 SPQR-Tree Decomposition 4.3 SPQR-Tree Fragments in the Context of Process Models 5 Triconnected Abstraction 5.1 Abstraction Rules 5.2 Abstraction Algorithm 6 Related Work and Conclusions}, language = {en} } @book{PolzeSchnor2005, author = {Polze, Andreas and Schnor, Bettina}, title = {Grid-Computing : [Seminar im Sommersemester 2003]}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-28-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33162}, publisher = {Universit{\"a}t Potsdam}, pages = {1-34 ; 2-36}, year = {2005}, abstract = {1. Applikationen f{\"u}r weitverteiltes Rechnen Dennis Klemann, Lars Schmidt-Bielicke, Philipp Seuring 2. Das Globus-Toolkit Dietmar Bremser, Alexis Krepp, Tobias Rausch 3. Open Grid Services Architecture Lars Trieloff 4. Condor, Condor-G, Classad Stefan Henze, Kai K{\"o}hne 5. The Cactus Framework Thomas Hille, Martin Karlsch 6. High Performance Scheduler mit Maui/PBS Ole Weidner, J{\"o}rg Schummer, Benedikt Meuthrath 7. Bandbreiten-Monitoring mit NWS Alexander Ritter, Gregor H{\"o}fert 8. The Paradyn Parallel Performance Measurement Tool Jens Ulferts, Christian Liesegang 9. Grid-Applikationen in der Praxis Steffen Bach, Michael Blume, Helge Issel}, language = {de} } @book{PufahlMeyerWeske2013, author = {Pufahl, Luise and Meyer, Andreas and Weske, Mathias}, title = {Batch regions : process instance synchronization based on data}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-280-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69081}, publisher = {Universit{\"a}t Potsdam}, pages = {18}, year = {2013}, abstract = {Business process automation improves organizations' efficiency to perform work. In existing business process management systems, process instances run independently from each other. However, synchronizing instances carrying similar characteristics, i.e., sharing the same data, can reduce process execution costs. For example, if an online retailer receives two orders from one customer, there is a chance that they can be packed and shipped together to save shipment costs. In this paper, we use concepts from the database domain and introduce data views to business processes to identify instances which can be synchronized. Based on data views, we introduce the concept of batch regions for a context-aware instance synchronization over a set of connected activities. We also evaluate the concepts introduced in this paper with a case study comparing costs for normal and batch processing.}, language = {de} } @book{RoggeSoltiMansvanderAalstetal.2013, author = {Rogge-Solti, Andreas and Mans, Ronny S. and van der Aalst, Wil M. P. and Weske, Mathias}, title = {Repairing event logs using stochastic process models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-258-2}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-66797}, publisher = {Universit{\"a}t Potsdam}, pages = {19}, year = {2013}, abstract = {Companies strive to improve their business processes in order to remain competitive. Process mining aims to infer meaningful insights from process-related data and attracted the attention of practitioners, tool-vendors, and researchers in recent years. Traditionally, event logs are assumed to describe the as-is situation. But this is not necessarily the case in environments where logging may be compromised due to manual logging. For example, hospital staff may need to manually enter information regarding the patient's treatment. As a result, events or timestamps may be missing or incorrect. In this paper, we make use of process knowledge captured in process models, and provide a method to repair missing events in the logs. This way, we facilitate analysis of incomplete logs. We realize the repair by combining stochastic Petri nets, alignments, and Bayesian networks. We evaluate the results using both synthetic data and real event data from a Dutch hospital.}, language = {en} } @book{SchmiedgenRhinowKoeppenetal.2015, author = {Schmiedgen, Jan and Rhinow, Holger and K{\"o}ppen, Eva and Meinel, Christoph}, title = {Parts without a whole?}, number = {97}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-334-3}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-79969}, publisher = {Universit{\"a}t Potsdam}, pages = {143}, year = {2015}, abstract = {This explorative study gives a descriptive overview of what organizations do and experience when they say they practice design thinking. It looks at how the concept has been appropriated in organizations and also describes patterns of design thinking adoption. The authors use a mixed-method research design fed by two sources: questionnaire data and semi-structured personal expert interviews. The study proceeds in six parts: (1) design thinking¹s entry points into organizations; (2) understandings of the descriptor; (3) its fields of application and organizational localization; (4) its perceived impact; (5) reasons for its discontinuation or failure; and (6) attempts to measure its success. In conclusion the report challenges managers to be more conscious of their current design thinking practice. The authors suggest a co-evolution of the concept¹s introduction with innovation capability building and the respective changes in leadership approaches. It is argued that this might help in unfolding design thinking¹s hidden potentials as well as preventing unintended side-effects such as discontented teams or the dwindling authority of managers.}, language = {en} } @book{SchneiderLambersOrejas2017, author = {Schneider, Sven and Lambers, Leen and Orejas, Fernando}, title = {Symbolic model generation for graph properties}, number = {115}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-396-1}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103171}, publisher = {Universit{\"a}t Potsdam}, pages = {48}, year = {2017}, abstract = {Graphs are ubiquitous in Computer Science. For this reason, in many areas, it is very important to have the means to express and reason about graph properties. In particular, we want to be able to check automatically if a given graph property is satisfiable. Actually, in most application scenarios it is desirable to be able to explore graphs satisfying the graph property if they exist or even to get a complete and compact overview of the graphs satisfying the graph property. We show that the tableau-based reasoning method for graph properties as introduced by Lambers and Orejas paves the way for a symbolic model generation algorithm for graph properties. Graph properties are formulated in a dedicated logic making use of graphs and graph morphisms, which is equivalent to firstorder logic on graphs as introduced by Courcelle. Our parallelizable algorithm gradually generates a finite set of so-called symbolic models, where each symbolic model describes a set of finite graphs (i.e., finite models) satisfying the graph property. The set of symbolic models jointly describes all finite models for the graph property (complete) and does not describe any finite graph violating the graph property (sound). Moreover, no symbolic model is already covered by another one (compact). Finally, the algorithm is able to generate from each symbolic model a minimal finite model immediately and allows for an exploration of further finite models. The algorithm is implemented in the new tool AutoGraph.}, language = {en} } @book{SchreiberKrahnIngallsetal.2016, author = {Schreiber, Robin and Krahn, Robert and Ingalls, Daniel H. H. and Hirschfeld, Robert}, title = {Transmorphic}, number = {110}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-387-9}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98300}, publisher = {Universit{\"a}t Potsdam}, pages = {100}, year = {2016}, abstract = {Defining Graphical User Interfaces (GUIs) through functional abstractions can reduce the complexity that arises from mutable abstractions. Recent examples, such as Facebook's React GUI framework have shown, how modelling the view as a functional projection from the application state to a visual representation can reduce the number of interacting objects and thus help to improve the reliabiliy of the system. This however comes at the price of a more rigid, functional framework where programmers are forced to express visual entities with functional abstractions, detached from the way one intuitively thinks about the physical world. In contrast to that, the GUI Framework Morphic allows interactions in the graphical domain, such as grabbing, dragging or resizing of elements to evolve an application at runtime, providing liveness and directness in the development workflow. Modelling each visual entity through mutable abstractions however makes it difficult to ensure correctness when GUIs start to grow more complex. Furthermore, by evolving morphs at runtime through direct manipulation we diverge more and more from the symbolic description that corresponds to the morph. Given that both of these approaches have their merits and problems, is there a way to combine them in a meaningful way that preserves their respective benefits? As a solution for this problem, we propose to lift Morphic's concept of direct manipulation from the mutation of state to the transformation of source code. In particular, we will explore the design, implementation and integration of a bidirectional mapping between the graphical representation and a functional and declarative symbolic description of a graphical user interface within a self hosted development environment. We will present Transmorphic, a functional take on the Morphic GUI Framework, where the visual and structural properties of morphs are defined in a purely functional, declarative fashion. In Transmorphic, the developer is able to assemble different morphs at runtime through direct manipulation which is automatically translated into changes in the code of the application. In this way, the comprehensiveness and predictability of direct manipulation can be used in the context of a purely functional GUI, while the effects of the manipulation are reflected in a medium that is always in reach for the programmer and can even be used to incorporate the source transformations into the source files of the application.}, language = {en} } @book{SchwalbKruegerPlattner2013, author = {Schwalb, David and Kr{\"u}ger, Jens and Plattner, Hasso}, title = {Cache conscious column organization in in-memory column stores}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-228-5}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63890}, publisher = {Universit{\"a}t Potsdam}, pages = {v, 84}, year = {2013}, abstract = {Cost models are an essential part of database systems, as they are the basis of query performance optimization. Based on predictions made by cost models, the fastest query execution plan can be chosen and executed or algorithms can be tuned and optimised. In-memory databases shifts the focus from disk to main memory accesses and CPU costs, compared to disk based systems where input and output costs dominate the overall costs and other processing costs are often neglected. However, modelling memory accesses is fundamentally different and common models do not apply anymore. This work presents a detailed parameter evaluation for the plan operators scan with equality selection, scan with range selection, positional lookup and insert in in-memory column stores. Based on this evaluation, a cost model based on cache misses for estimating the runtime of the considered plan operators using different data structures is developed. Considered are uncompressed columns, bit compressed and dictionary encoded columns with sorted and unsorted dictionaries. Furthermore, tree indices on the columns and dictionaries are discussed. Finally, partitioned columns consisting of one partition with a sorted and one with an unsorted dictionary are investigated. New values are inserted in the unsorted dictionary partition and moved periodically by a merge process to the sorted partition. An efficient attribute merge algorithm is described, supporting the update performance required to run enterprise applications on read-optimised databases. Further, a memory traffic based cost model for the merge process is provided.}, language = {en} } @book{SmirnovReijersNugterenetal.2010, author = {Smirnov, Sergey and Reijers, Hajo A. and Nugteren, Thijs and Weske, Mathias}, title = {Business process model abstraction : theory and practice}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-054-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41782}, publisher = {Universit{\"a}t Potsdam}, pages = {17}, year = {2010}, abstract = {Business process management aims at capturing, understanding, and improving work in organizations. The central artifacts are process models, which serve different purposes. Detailed process models are used to analyze concrete working procedures, while high-level models show, for instance, handovers between departments. To provide different views on process models, business process model abstraction has emerged. While several approaches have been proposed, a number of abstraction use case that are both relevant for industry and scientifically challenging are yet to be addressed. In this paper we systematically develop, classify, and consolidate different use cases for business process model abstraction. The reported work is based on a study with BPM users in the health insurance sector and validated with a BPM consultancy company and a large BPM vendor. The identified fifteen abstraction use cases reflect the industry demand. The related work on business process model abstraction is evaluated against the use cases, which leads to a research agenda.}, language = {en} } @book{SmirnovWeidlichMendlingetal.2009, author = {Smirnov, Sergey and Weidlich, Matthias and Mendling, Jan and Weske, Mathias}, title = {Action patterns in business process models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-009-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33586}, publisher = {Universit{\"a}t Potsdam}, pages = {19}, year = {2009}, abstract = {Business process management experiences a large uptake by the industry, and process models play an important role in the analysis and improvement of processes. While an increasing number of staff becomes involved in actual modeling practice, it is crucial to assure model quality and homogeneity along with providing suitable aids for creating models. In this paper we consider the problem of offering recommendations to the user during the act of modeling. Our key contribution is a concept for defining and identifying so-called action patterns - chunks of actions often appearing together in business processes. In particular, we specify action patterns and demonstrate how they can be identified from existing process model repositories using association rule mining techniques. Action patterns can then be used to suggest additional actions for a process model. Our approach is challenged by applying it to the collection of process models from the SAP Reference Model.}, language = {en} } @book{SmirnovZamaniFarahaniWeske2011, author = {Smirnov, Sergey and Zamani Farahani, Armin and Weske, Mathias}, title = {State propagation in abstracted business processes}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-130-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-51480}, publisher = {Universit{\"a}t Potsdam}, pages = {16}, year = {2011}, abstract = {Business process models are abstractions of concrete operational procedures that occur in the daily business of organizations. To cope with the complexity of these models, business process model abstraction has been introduced recently. Its goal is to derive from a detailed process model several abstract models that provide a high-level understanding of the process. While techniques for constructing abstract models are reported in the literature, little is known about the relationships between process instances and abstract models. In this paper we show how the state of an abstract activity can be calculated from the states of related, detailed process activities as they happen. The approach uses activity state propagation. With state uniqueness and state transition correctness we introduce formal properties that improve the understanding of state propagation. Algorithms to check these properties are devised. Finally, we use behavioral profiles to identify and classify behavioral inconsistencies in abstract process models that might occur, once activity state propagation is used.}, language = {en} } @book{TessenowFelgentreffBrachaetal.2016, author = {Tessenow, Philipp and Felgentreff, Tim and Bracha, Gilad and Hirschfeld, Robert}, title = {Extending a dynamic programming language and runtime environment with access control}, number = {107}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-373-2}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-92560}, publisher = {Universit{\"a}t Potsdam}, pages = {83}, year = {2016}, abstract = {Complexity in software systems is a major factor driving development and maintenance costs. To master this complexity, software is divided into modules that can be developed and tested separately. In order to support this separation of modules, each module should provide a clean and concise public interface. Therefore, the ability to selectively hide functionality using access control is an important feature in a programming language intended for complex software systems. Software systems are increasingly distributed, adding not only to their inherent complexity, but also presenting security challenges. The object-capability approach addresses these challenges by defining language properties providing only minimal capabilities to objects. One programming language that is based on the object-capability approach is Newspeak, a dynamic programming language designed for modularity and security. The Newspeak specification describes access control as one of Newspeak's properties, because it is a requirement for the object-capability approach. However, access control, as defined in the Newspeak specification, is currently not enforced in its implementation. This work introduces an access control implementation for Newspeak, enabling the security of object-capabilities and enhancing modularity. We describe our implementation of access control for Newspeak. We adapted the runtime environment, the reflective system, the compiler toolchain, and the virtual machine. Finally, we describe a migration strategy for the existing Newspeak code base, so that our access control implementation can be integrated with minimal effort.}, language = {en} } @book{TietzPelchenMeineletal.2017, author = {Tietz, Christian and Pelchen, Chris and Meinel, Christoph and Schnjakin, Maxim}, title = {Management Digitaler Identit{\"a}ten}, number = {114}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-395-4}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-103164}, publisher = {Universit{\"a}t Potsdam}, pages = {65}, year = {2017}, abstract = {Um den zunehmenden Diebstahl digitaler Identit{\"a}ten zu bek{\"a}mpfen, gibt es bereits mehr als ein Dutzend Technologien. Sie sind, vor allem bei der Authentifizierung per Passwort, mit spezifischen Nachteilen behaftet, haben andererseits aber auch jeweils besondere Vorteile. Wie solche Kommunikationsstandards und -Protokolle wirkungsvoll miteinander kombiniert werden k{\"o}nnen, um dadurch mehr Sicherheit zu erreichen, haben die Autoren dieser Studie analysiert. Sie sprechen sich f{\"u}r neuartige Identit{\"a}tsmanagement-Systeme aus, die sich flexibel auf verschiedene Rollen eines einzelnen Nutzers einstellen k{\"o}nnen und bequemer zu nutzen sind als bisherige Verfahren. Als ersten Schritt auf dem Weg hin zu einer solchen Identit{\"a}tsmanagement-Plattform beschreiben sie die M{\"o}glichkeiten einer Analyse, die sich auf das individuelle Verhalten eines Nutzers oder einer Sache st{\"u}tzt. Ausgewertet werden dabei Sensordaten mobiler Ger{\"a}te, welche die Nutzer h{\"a}ufig bei sich tragen und umfassend einsetzen, also z.B. internetf{\"a}hige Mobiltelefone, Fitness-Tracker und Smart Watches. Die Wissenschaftler beschreiben, wie solche Kleincomputer allein z.B. anhand der Analyse von Bewegungsmustern, Positionsund Netzverbindungsdaten kontinuierlich ein „Vertrauens-Niveau" errechnen k{\"o}nnen. Mit diesem ermittelten „Trust Level" kann jedes Ger{\"a}t st{\"a}ndig die Wahrscheinlichkeit angeben, mit der sein aktueller Benutzer auch der tats{\"a}chliche Besitzer ist, dessen typische Verhaltensmuster es genauestens „kennt". Wenn der aktuelle Wert des Vertrauens-Niveaus (nicht aber die biometrischen Einzeldaten) an eine externe Instanz wie einen Identit{\"a}tsprovider {\"u}bermittelt wird, kann dieser das Trust Level allen Diensten bereitstellen, welche der Anwender nutzt und dar{\"u}ber informieren will. Jeder Dienst ist in der Lage, selbst festzulegen, von welchem Vertrauens-Niveau an er einen Nutzer als authentifiziert ansieht. Erf{\"a}hrt er von einem unter das Limit gesunkenen Trust Level, kann der Identit{\"a}tsprovider seine Nutzung und die anderer Services verweigern. Die besonderen Vorteile dieses Identit{\"a}tsmanagement-Ansatzes liegen darin, dass er keine spezifische und teure Hardware ben{\"o}tigt, um spezifische Daten auszuwerten, sondern lediglich Smartphones und so genannte Wearables. Selbst Dinge wie Maschinen, die Daten {\"u}ber ihr eigenes Verhalten per Sensor-Chip ins Internet funken, k{\"o}nnen einbezogen werden. Die Daten werden kontinuierlich im Hintergrund erhoben, ohne dass sich jemand darum k{\"u}mmern muss. Sie sind nur f{\"u}r die Berechnung eines Wahrscheinlichkeits-Messwerts von Belang und verlassen niemals das Ger{\"a}t. Meldet sich ein Internetnutzer bei einem Dienst an, muss er sich nicht zun{\"a}chst an ein vorher festgelegtes Geheimnis - z.B. ein Passwort - erinnern, sondern braucht nur die Weitergabe seines aktuellen Vertrauens-Wertes mit einem „OK" freizugeben. {\"A}ndert sich das Nutzungsverhalten - etwa durch andere Bewegungen oder andere Orte des Einloggens ins Internet als die {\"u}blichen - wird dies schnell erkannt. Unbefugten kann dann sofort der Zugang zum Smartphone oder zu Internetdiensten gesperrt werden. K{\"u}nftig kann die Auswertung von Verhaltens-Faktoren noch erweitert werden, indem z.B. Routinen an Werktagen, an Wochenenden oder im Urlaub erfasst werden. Der Vergleich mit den live erhobenen Daten zeigt dann an, ob das Verhalten in das {\"u}bliche Muster passt, der Benutzer also mit h{\"o}chster Wahrscheinlichkeit auch der ausgewiesene Besitzer des Ger{\"a}ts ist. {\"U}ber die Techniken des Managements digitaler Identit{\"a}ten und die damit verbundenen Herausforderungen gibt diese Studie einen umfassenden {\"U}berblick. Sie beschreibt zun{\"a}chst, welche Arten von Angriffen es gibt, durch die digitale Identit{\"a}ten gestohlen werden k{\"o}nnen. Sodann werden die unterschiedlichen Verfahren von Identit{\"a}tsnachweisen vorgestellt. Schließlich liefert die Studie noch eine zusammenfassende {\"U}bersicht {\"u}ber die 15 wichtigsten Protokolle und technischen Standards f{\"u}r die Kommunikation zwischen den drei beteiligten Akteuren: Service Provider/Dienstanbieter, Identit{\"a}tsprovider und Nutzer. Abschließend wird aktuelle Forschung des Hasso-Plattner-Instituts zum Identit{\"a}tsmanagement vorgestellt.}, language = {de} } @book{VogelGiese2013, author = {Vogel, Thomas and Giese, Holger}, title = {Model-driven engineering of adaptation engines for self-adaptive software : executable runtime megamodels}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-227-8}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63825}, publisher = {Universit{\"a}t Potsdam}, pages = {vi, 59}, year = {2013}, abstract = {The development of self-adaptive software requires the engineering of an adaptation engine that controls and adapts the underlying adaptable software by means of feedback loops. The adaptation engine often describes the adaptation by using runtime models representing relevant aspects of the adaptable software and particular activities such as analysis and planning that operate on these runtime models. To systematically address the interplay between runtime models and adaptation activities in adaptation engines, runtime megamodels have been proposed for self-adaptive software. A runtime megamodel is a specific runtime model whose elements are runtime models and adaptation activities. Thus, a megamodel captures the interplay between multiple models and between models and activities as well as the activation of the activities. In this article, we go one step further and present a modeling language for ExecUtable RuntimE MegAmodels (EUREMA) that considerably eases the development of adaptation engines by following a model-driven engineering approach. We provide a domain-specific modeling language and a runtime interpreter for adaptation engines, in particular for feedback loops. Megamodels are kept explicit and alive at runtime and by interpreting them, they are directly executed to run feedback loops. Additionally, they can be dynamically adjusted to adapt feedback loops. Thus, EUREMA supports development by making feedback loops, their runtime models, and adaptation activities explicit at a higher level of abstraction. Moreover, it enables complex solutions where multiple feedback loops interact or even operate on top of each other. Finally, it leverages the co-existence of self-adaptation and off-line adaptation for evolution.}, language = {en} } @book{WassermannFelgentreffPapeetal.2016, author = {Wassermann, Lars and Felgentreff, Tim and Pape, Tobias and Bolz, Carl Friedrich and Hirschfeld, Robert}, title = {Tracing Algorithmic Primitives in RSqueak/VM}, number = {104}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-355-8}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-91277}, publisher = {Universit{\"a}t Potsdam}, pages = {45}, year = {2016}, abstract = {When realizing a programming language as VM, implementing behavior as part of the VM, as primitive, usually results in reduced execution times. But supporting and developing primitive functions requires more effort than maintaining and using code in the hosted language since debugging is harder, and the turn-around times for VM parts are higher. Furthermore, source artifacts of primitive functions are seldom reused in new implementations of the same language. And if they are reused, the existing API usually is emulated, reducing the performance gains. Because of recent results in tracing dynamic compilation, the trade-off between performance and ease of implementation, reuse, and changeability might now be decided adversely. In this work, we investigate the trade-offs when creating primitives, and in particular how large a difference remains between primitive and hosted function run times in VMs with tracing just-in-time compiler. To that end, we implemented the algorithmic primitive BitBlt three times for RSqueak/VM. RSqueak/VM is a Smalltalk VM utilizing the PyPy RPython toolchain. We compare primitive implementations in C, RPython, and Smalltalk, showing that due to the tracing just-in-time compiler, the performance gap has lessened by one magnitude to one magnitude.}, language = {en} } @book{Wendt2004, author = {Wendt, Siegfried}, title = {Auf dem Weg zu einem Softwareingenieurwesen}, isbn = {978-3-937786-37-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33184}, publisher = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {(1) {\"U}ber die Notwendigkeit, die bisherige Informatik in eine Grundlagenwissenschaft und eine Ingenieurwissenschaft aufzuspalten (2) Was ist Ingenieurskultur? (3) Das Kommunikationsproblem der Informatiker und ihre Unf{\"a}higkeit, es wahrzunehmen (4) Besonderheiten des Softwareingenieurwesens im Vergleich mit den klassischen Ingenieurdisziplinen (5) Softwareingenieurspl{\"a}ne k{\"o}nnen auch f{\"u}r Nichtfachleute verst{\"a}ndlich sein (6) Principles for Planning Curricula in Software Engineering}, language = {de} } @book{WeyandChromikWolfetal.2017, author = {Weyand, Christopher and Chromik, Jonas and Wolf, Lennard and K{\"o}tte, Steffen and Haase, Konstantin and Felgentreff, Tim and Lincke, Jens and Hirschfeld, Robert}, title = {Improving hosted continuous integration services}, number = {108}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-377-0}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94251}, publisher = {Universit{\"a}t Potsdam}, pages = {viii, 114}, year = {2017}, abstract = {Developing large software projects is a complicated task and can be demanding for developers. Continuous integration is common practice for reducing complexity. By integrating and testing changes often, changesets are kept small and therefore easily comprehensible. Travis CI is a service that offers continuous integration and continuous deployment in the cloud. Software projects are build, tested, and deployed using the Travis CI infrastructure without interrupting the development process. This report describes how Travis CI works, presents how time-driven, periodic building is implemented as well as how CI data visualization can be done, and proposes a way of dealing with dependency problems.}, language = {en} } @book{WistSchaeferVogleretal.2010, author = {Wist, Dominic and Schaefer, Mark and Vogler, Walter and Wollowski, Ralf}, title = {STG decomposition : internal communication for SI implementability}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-037-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40786}, publisher = {Universit{\"a}t Potsdam}, pages = {36}, year = {2010}, abstract = {STG decomposition is a promising approach to tackle the complexity problems arising in logic synthesis of speed independent circuits, a robust asynchronous (i.e. clockless) circuit type. Unfortunately, STG decomposition can result in components that in isolation have irreducible CSC conflicts. Generalising earlier work, it is shown how to resolve such conflicts by introducing internal communication between the components via structural techniques only.}, language = {en} } @book{WistWollowski2007, author = {Wist, Dominic and Wollowski, Ralf}, title = {STG decomposition : avoiding irreducible CSC conflicts by internal communication}, isbn = {978-3-940793-02-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-32968}, publisher = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {Inhalt: 1 Introduction 2 Basic Definitions 3 Achieving SI Implementability by Internal Communication 4 Towards a Structural Method 5 Examples 6 Conclusions and Future Work}, language = {en} } @book{WaetzoldtGiese2015, author = {W{\"a}tzoldt, Sebastian and Giese, Holger}, title = {Modeling collaborations in self-adaptive systems of systems}, number = {96}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-324-4}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-73036}, publisher = {Universit{\"a}t Potsdam}, pages = {72}, year = {2015}, abstract = {An increasing demand on functionality and flexibility leads to an integration of beforehand isolated system solutions building a so-called System of Systems (SoS). Furthermore, the overall SoS should be adaptive to react on changing requirements and environmental conditions. Due SoS are composed of different independent systems that may join or leave the overall SoS at arbitrary point in times, the SoS structure varies during the systems lifetime and the overall SoS behavior emerges from the capabilities of the contained subsystems. In such complex system ensembles new demands of understanding the interaction among subsystems, the coupling of shared system knowledge and the influence of local adaptation strategies to the overall resulting system behavior arise. In this report, we formulate research questions with the focus of modeling interactions between system parts inside a SoS. Furthermore, we define our notion of important system types and terms by retrieving the current state of the art from literature. Having a common understanding of SoS, we discuss a set of typical SoS characteristics and derive general requirements for a collaboration modeling language. Additionally, we retrieve a broad spectrum of real scenarios and frameworks from literature and discuss how these scenarios cope with different characteristics of SoS. Finally, we discuss the state of the art for existing modeling languages that cope with collaborations for different system types such as SoS.}, language = {en} } @book{OPUS4-3141, title = {Java language conversion assistant : an analysis}, editor = {Richter, Stefan and Henze, Stefan and B{\"u}ttner, Eiko and Bach, Steffen and Polze, Andreas}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-10-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33151}, publisher = {Universit{\"a}t Potsdam}, pages = {166}, year = {2004}, abstract = {This document is an analysis of the 'Java Language Conversion Assistant'. Itr will also cover a language analysis of the Java Programming Language as well as a survey of related work concerning Java and C\# interoperability on the one hand and language conversion in general on the other. Part I deals with language analysis. Part II covers the JLCA tool and tests used to analyse the tool. Additionally, it gives an overview of the above mentioned related work. Part III presents a complete project that has been translated using the JLCA.}, language = {en} } @book{OPUS4-3143, title = {Conceptual architecture patterns : FMC-based representations}, editor = {Gr{\"o}ne, Bernhard and Keller, Frank}, isbn = {978-3-935024-98-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33173}, publisher = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {This document presents the results of the seminar "Coneptual Arachitecture Patterns" of the winter term 2002 in the Hasso-Plattner-Institute. It is a compilation of the student's elaborations dealing with some conceptual architecture patterns which can be found in literature. One important focus laid on the runtime structures and the presentation of the patterns. 1. Introduction 1.1. The Seminar 1.2. Literature 2 Pipes and Filters (Andr{\´e} Langhorst and Martin Steinle) 3 Broker (Konrad H{\"u}bner and Einar L{\"u}ck) 4 Microkernel (Eiko B{\"u}ttner and Stefan Richter) 5 Component Configurator (Stefan R{\"o}ck and Alexander Gierak) 6 Interceptor (Marc F{\"o}rster and Peter Aschenbrenner) 7 Reactor (Nikolai Cieslak and Dennis Eder) 8 Half-Sync/Half-Async (Robert Mitschke and Harald Schubert) 9 Leader/Followers (Dennis Klemann and Steffen Schmidt)}, language = {en} } @book{OPUS4-3946, title = {Proceedings of the 9th Workshop on Aspects, Components, and Patterns for Infrastructure Software (ACP4IS '10)}, editor = {Adams, Bram and Haupt, Michael and Lohmann, Daniel}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-043-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41221}, publisher = {Universit{\"a}t Potsdam}, pages = {47}, year = {2010}, abstract = {Aspect-oriented programming, component models, and design patterns are modern and actively evolving techniques for improving the modularization of complex software. In particular, these techniques hold great promise for the development of "systems infrastructure" software, e.g., application servers, middleware, virtual machines, compilers, operating systems, and other software that provides general services for higher-level applications. The developers of infrastructure software are faced with increasing demands from application programmers needing higher-level support for application development. Meeting these demands requires careful use of software modularization techniques, since infrastructural concerns are notoriously hard to modularize. Aspects, components, and patterns provide very different means to deal with infrastructure software, but despite their differences, they have much in common. For instance, component models try to free the developer from the need to deal directly with services like security or transactions. These are primary examples of crosscutting concerns, and modularizing such concerns are the main target of aspect-oriented languages. Similarly, design patterns like Visitor and Interceptor facilitate the clean modularization of otherwise tangled concerns. Building on the ACP4IS meetings at AOSD 2002-2009, this workshop aims to provide a highly interactive forum for researchers and developers to discuss the application of and relationships between aspects, components, and patterns within modern infrastructure software. The goal is to put aspects, components, and patterns into a common reference frame and to build connections between the software engineering and systems communities.}, language = {en} } @book{OPUS4-4677, title = {Selected Papers of the International Workshop on Smalltalk Technologies (IWST'10) : Barcelona, Spain, September 14, 2010}, editor = {Haupt, Michael and Hirschfeld, Robert}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-106-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-48553}, publisher = {Universit{\"a}t Potsdam}, pages = {34}, year = {2010}, abstract = {The goal of the IWST workshop series is to create and foster a forum around advancements of or experience in Smalltalk. The workshop welcomes contributions to all aspects, theoretical as well as practical, of Smalltalk-related topics.}, language = {en} } @book{OPUS4-3139, title = {Konzepte der Softwarevisualisierung f{\"u}r komplexe, objektorientierte Softwaresysteme}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-937786-54-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33136}, publisher = {Universit{\"a}t Potsdam}, pages = {99}, year = {2005}, abstract = {1. Grundlagen der Softwarevisualisierung Johannes Bohnet und J{\"u}rgen D{\"o}llner 2. Visualisierung und Exploration von Softwaresystemen mit dem Werkzeug SHriMP/Creole Alexander Gierak 3. Annex: SHriMP/Creole in der Anwendung Nebojsa Lazic 4. Metrikbasierte Softwarevisualisierung mit dem Reverse-Engineering-Werkzeug CodeCrawler Daniel Brinkmann 5. Annex: CodeCrawler in der Anwendung Benjamin Hagedorn 6. Quellcodezeilenbasierte Softwarevisualisierung Nebojsa Lazic 7. Landschafts- und Stadtmetaphern zur Softwarevisualisierung Benjamin Hagedorn 8. Visualisierung von Softwareevolution Michael Sch{\"o}bel 9. Ergebnisse und Ausblick Johannes Bohnet Literaturverzeichnis Autorenverzeichnis}, language = {de} } @book{OPUS4-3213, title = {Proceedings of the 2nd International Workshop on e-learning and Virtual and Remote Laboratories}, editor = {Rabe, Bernhard and Rasche, Andreas}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-940793-17-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-34315}, publisher = {Universit{\"a}t Potsdam}, pages = {vi, 98}, year = {2008}, abstract = {Content Session 1: Architecture of Virtual \& Remote Laboratory Infrastructures (I) An Internet-Based Laboratory Course in Chemical Reaction Engineering and Unit Operations Internet Based Laboratory for Experimentation with Multilevel Medium-Power Converters Session 2: Architecture of Virtual \& Remote Laboratory Infrastructures (II) Content management and architectural issues of a remote learning laboratory Distributed Software Architecture and Applications for Remote Laboratories Tele-Lab IT-Security: an architecture for an online virtual IT security lab Session 3: New e-learning Techniques for Virtual \& Remote Laboratories NeOS: Neuchˆatel Online System A Flexible Instructional Electronics Laboratory with Local and Remote LabWorkbenches in a Grid Simulation of an Intelligent Network - Basic Call State Model Remote Laboratory Session 4: Service-Orientation in Virtual \& Remote Laboratories SOA Meets Robots - A Service-Based Software Infrastructure For Remote Laboratories Service Orientation in Education - Intelligent Networks for eLearning / mLearning}, language = {de} }