@article{Doerge2013, author = {D{\"o}rge, Christina}, title = {Entwicklung eines Kompetenzrahmenmodells f{\"u}r die universit{\"a}re Lehre}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64946}, pages = {91 -- 97}, year = {2013}, abstract = {Zurzeit haben wir es mit der folgenden Situation an Universit{\"a}ten zu tun: Studierende kommen mit unterschiedlichem Wissen und Kompetenzen zur Universit{\"a}t, um informatikbezogene Studieng{\"a}nge zu belegen. Diesem Umstand muss in den universit{\"a}ren Kursen entgegengewirkt werden, um ein einheitliches Bildungsziel zu erreichen. F{\"u}r einige Studierende bedeutet dies oft eine Lehrbelastung in einem ohnehin sehr zeitintensiven Studium, was nicht selten zum Studienabbruch f{\"u}hrt. Ein anderes Problem ist die fehlende Transparenz bez{\"u}glich der Gegenst{\"a}nde des Informatikstudiums: einige angehende Studierende kommen mit einem von der Realit{\"a}t abweichenden Bild der Informatik zur Universit{\"a}t, andere entscheiden sich u. U. deshalb gegen ein Informatikstudium, da ihnen nicht bewusst ist, dass das Studium f{\"u}r sie interessant sein k{\"o}nnte. In diesem Artikel soll ein L{\"o}sungsvorschlag anhand eines Kompetenzrahmenmodells vorgestellt werden, mit dessen Hilfe eine Verbesserung der Hochschulsituation erreicht werden kann.}, language = {de} } @article{AlSaffar2013, author = {Al-Saffar, Loay Talib Ahmed}, title = {Where girls take the role of boys in CS}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65034}, pages = {149 -- 154}, year = {2013}, abstract = {A survey has been carried out in the Computer Science (CS) department at the University of Baghdad to investigate the attitudes of CS students in a female dominant environment, showing the differences between male and female students in different academic years. We also compare the attitudes of the freshman students of two different cultures (University of Baghdad, Iraq, and the University of Potsdam).}, language = {en} } @article{Petre2013, author = {Petre, Marian}, title = {Computing is not a spectator sport}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65045}, pages = {155 -- 159}, year = {2013}, abstract = {This talk will describe My Digital Life (TU100), a distance learning module that introduces computer science through immediate engagement with ubiquitous computing (ubicomp). This talk will describe some of the principles and concepts we have adopted for this modern computing introduction: the idea of the 'informed digital citizen'; engagement through narrative; playful pedagogy; making the power of ubicomp available to novices; setting technical skills in real contexts. It will also trace how the pedagogy is informed by experiences and research in Computer Science education.}, language = {en} } @phdthesis{Glander2012, author = {Glander, Tassilo}, title = {Multi-scale representations of virtual 3D city models}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64117}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {Virtual 3D city and landscape models are the main subject investigated in this thesis. They digitally represent urban space and have many applications in different domains, e.g., simulation, cadastral management, and city planning. Visualization is an elementary component of these applications. Photo-realistic visualization with an increasingly high degree of detail leads to fundamental problems for comprehensible visualization. A large number of highly detailed and textured objects within a virtual 3D city model may create visual noise and overload the users with information. Objects are subject to perspective foreshortening and may be occluded or not displayed in a meaningful way, as they are too small. In this thesis we present abstraction techniques that automatically process virtual 3D city and landscape models to derive abstracted representations. These have a reduced degree of detail, while essential characteristics are preserved. After introducing definitions for model, scale, and multi-scale representations, we discuss the fundamentals of map generalization as well as techniques for 3D generalization. The first presented technique is a cell-based generalization of virtual 3D city models. It creates abstract representations that have a highly reduced level of detail while maintaining essential structures, e.g., the infrastructure network, landmark buildings, and free spaces. The technique automatically partitions the input virtual 3D city model into cells based on the infrastructure network. The single building models contained in each cell are aggregated to abstracted cell blocks. Using weighted infrastructure elements, cell blocks can be computed on different hierarchical levels, storing the hierarchy relation between the cell blocks. Furthermore, we identify initial landmark buildings within a cell by comparing the properties of individual buildings with the aggregated properties of the cell. For each block, the identified landmark building models are subtracted using Boolean operations and integrated in a photo-realistic way. Finally, for the interactive 3D visualization we discuss the creation of the virtual 3D geometry and their appearance styling through colors, labeling, and transparency. We demonstrate the technique with example data sets. Additionally, we discuss applications of generalization lenses and transitions between abstract representations. The second technique is a real-time-rendering technique for geometric enhancement of landmark objects within a virtual 3D city model. Depending on the virtual camera distance, landmark objects are scaled to ensure their visibility within a specific distance interval while deforming their environment. First, in a preprocessing step a landmark hierarchy is computed, this is then used to derive distance intervals for the interactive rendering. At runtime, using the virtual camera distance, a scaling factor is computed and applied to each landmark. The scaling factor is interpolated smoothly at the interval boundaries using cubic B{\´e}zier splines. Non-landmark geometry that is near landmark objects is deformed with respect to a limited number of landmarks. We demonstrate the technique by applying it to a highly detailed virtual 3D city model and a generalized 3D city model. In addition we discuss an adaptation of the technique for non-linear projections and mobile devices. The third technique is a real-time rendering technique to create abstract 3D isocontour visualization of virtual 3D terrain models. The virtual 3D terrain model is visualized as a layered or stepped relief. The technique works without preprocessing and, as it is implemented using programmable graphics hardware, can be integrated with minimal changes into common terrain rendering techniques. Consequently, the computation is done in the rendering pipeline for each vertex, primitive, i.e., triangle, and fragment. For each vertex, the height is quantized to the nearest isovalue. For each triangle, the vertex configuration with respect to their isovalues is determined first. Using the configuration, the triangle is then subdivided. The subdivision forms a partial step geometry aligned with the triangle. For each fragment, the surface appearance is determined, e.g., depending on the surface texture, shading, and height-color-mapping. Flexible usage of the technique is demonstrated with applications from focus+context visualization, out-of-core terrain rendering, and information visualization. This thesis presents components for the creation of abstract representations of virtual 3D city and landscape models. Re-using visual language from cartography, the techniques enable users to build on their experience with maps when interpreting these representations. Simultaneously, characteristics of 3D geovirtual environments are taken into account by addressing and discussing, e.g., continuous scale, interaction, and perspective.}, language = {en} } @article{DuennebierDiethelm2010, author = {D{\"u}nnebier, Malte and Diethelm, Ira}, title = {Ein virtueller Lernraum f{\"u}r die Informatiklehrerweiterbildung}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64359}, pages = {65 -- 70}, year = {2010}, abstract = {Bei der Suche nach M{\"o}glichkeiten, die Weiterbildung f{\"u}r Informatiklehrkr{\"a}fte auszubauen, bietet sich der Einsatz virtueller Lernr{\"a}ume an. Dieses Papier berichtet {\"u}ber ein Projekt, in dem ein exemplarischer virtueller Lernraum f{\"u}r kollaboratives Lernen in der Lehrerweiterbildung in Informatik theoriegeleitet erstellt, erprobt und bewertet wurde. Die erzielten Ergebnisse {\"u}ber das Nutzungsverhalten k{\"o}nnen f{\"u}r weitere E-Learningprojekte in der Lehrerbildung hilfreich sein. Der Schwerpunkt dieses Papiers liegt auf der Gestaltung des Lernraums unter Beachtung der speziellen Situation der Informatiklehrkr{\"a}fte, nicht auf der didaktischen Aufbereitung der betreffenden Lerneinheit.}, language = {de} } @article{BollMeinhardtGronewoldetal.2010, author = {Boll, Susanne and Meinhardt, Rolf and Gronewold, Sabine and Krekeler, Larissa}, title = {Informatik f{\"u}r Migratinnen und Migranten Einf{\"u}hrung eines neuen Studienprogramms an der Universit{\"a}t Oldenburg}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64370}, pages = {79 -- 86}, year = {2010}, abstract = {F{\"u}r die Integration und den Bedarf der hochqualifizierten Migranten auf dem Arbeitsmarkt in Deutschland gibt es viele {\"U}berlegungen, aber noch keine ausreichenden L{\"o}sungen. Dieser Artikel beschreibt eine praktische L{\"o}sung {\"u}ber die Umsetzung des Konzepts f{\"u}r die Qualifizierung der akademischen Migranten am Beispiel eines Studienprogramms in Informatik an der Universit{\"a}t Oldenburg.}, language = {de} } @article{LaroqueSchulteUrban2010, author = {Laroque, Christoph and Schulte, Jonas and Urban, Diana}, title = {KoProV}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64445}, pages = {99 -- 105}, year = {2010}, abstract = {In der universit{\"a}ren Lehre {\"a}ndert sich der Leitgedanke von einer qualifikationsorientierten hin zu einer kompetenzorientierten Ausbildung. Der Begriff Kompetenz l{\"a}sst sich dabei grob in die fachlichen und die {\"u}berfachlichen Kompetenzen unterteilen. Insbesondere die Vermittlung von Schl{\"u}sselqualifikationen hat in der Lehre von naturwissenschaftlichen Fachrichtungen nur unzureichend Einzug erhalten. W{\"a}hrend der klassische Vorlesungsbetrieb auf den Erwerb von Fachkompetenz zielt, stoßen ausschließlich projektorientierte Veranstaltungen schnell an ihre Grenzen hinsichtlich der Teilnehmergr{\"o}ße oder Umfang der Lerninhalte. Um auf geeignete Art und Weise den Erwerb von {\"u}berfachlichen Kompetenzen zu erm{\"o}glichen, bedarf es neuer didaktischer Konzepte, die eine engere Verkn{\"u}pfung von klassischen Vorlesungen und dem projektorientierten Lernen vorsehen. In diesem Sinne versucht der skizzierte Ansatz der koordinierten Projektvorlesung(KoProV) Wissensvermittlung im Rahmen von Vorlesungseinheiten mit koordinierten Praxisphasen in Teilgruppen zu verbinden. F{\"u}r eine erfolgreiche Durchf{\"u}hrung und Erarbeitung des begleitenden Praxisprojektes durch mehrere Teilgruppen sind organisatorische und technische Randbedingungen zu beachten.}, language = {de} } @article{Kiss2010, author = {Kiss, G{\´a}bor}, title = {Analyse der Studienleistungen von Studierenden an der Universit{\"a}t {\´O}buda und deren Implikationen f{\"u}r die Informatikausbildung}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {4}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64364}, pages = {71 -- 77}, year = {2010}, abstract = {In der letzten Jahren ist die Zahl der erfolgreichen Pr{\"u}fungen von Studierenden im Informatikkurs des ersten Studienjahres f{\"u}r verschiedene Studieng{\"a}nge an der Universit{\"a}t {\´O}buda stark gesunken. Dies betrifft Pr{\"u}fungen in den Teilgebieten Rechnerarchitektur, Betrieb von Peripherieger{\"a}ten, Bin{\"a}re Codierung und logische Operationen, Computerviren, Computernetze und das Internet, Steganographie und Kryptographie, Betriebsysteme. Mehr als der H{\"a}lfte der Studenten konnte die Pr{\"u}fungen der ersten Semester nicht erfolgreich absolvieren. Die hier vorgelegte Analyse der Studienleistungen zielt darauf ab, Gr{\"u}nde f{\"u}r diese Entwicklung zu identifizieren, die Zahl der Abbrecher zu reduzieren und die Leistungen der Studenten zu verbessern. Die Analyse zeigt, dass die Studenten die erforderlichen Lehrmaterialen erst ein bis zwei Tage vor oder sogar erst am Tag der Klausuren vom Server downloaden, so dass sie nicht mehr hinreichend Zeit zum Lernen haben. Diese Tendenz zeigt sich bei allen Teilgebieten des Studiengangs. Ein Mangel an kontinuierlicher Mitarbeit scheint einer der Gr{\"u}nde f{\"u}r ein fr{\"u}hes Scheitern zu sein. Ferner zeigt sich die Notwendigkeit, dass bei den Lehrangeboten in Informatik auf eine kontinuierliche Kommunikation mit den Studierenden und R{\"u}ckmeldung zu aktuellen Unterrichtsinhalten zu achten ist. Dies kann durch motivierende Maßnahmen zur Teilnahme an den {\"U}bungen oder durch kleine w{\"o}chentliche schriftliche Tests geschehen.}, language = {de} } @phdthesis{Seibel2012, author = {Seibel, Andreas}, title = {Traceability and model management with executable and dynamic hierarchical megamodels}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64222}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {Nowadays, model-driven engineering (MDE) promises to ease software development by decreasing the inherent complexity of classical software development. In order to deliver on this promise, MDE increases the level of abstraction and automation, through a consideration of domain-specific models (DSMs) and model operations (e.g. model transformations or code generations). DSMs conform to domain-specific modeling languages (DSMLs), which increase the level of abstraction, and model operations are first-class entities of software development because they increase the level of automation. Nevertheless, MDE has to deal with at least two new dimensions of complexity, which are basically caused by the increased linguistic and technological heterogeneity. The first dimension of complexity is setting up an MDE environment, an activity comprised of the implementation or selection of DSMLs and model operations. Setting up an MDE environment is both time-consuming and error-prone because of the implementation or adaptation of model operations. The second dimension of complexity is concerned with applying MDE for actual software development. Applying MDE is challenging because a collection of DSMs, which conform to potentially heterogeneous DSMLs, are required to completely specify a complex software system. A single DSML can only be used to describe a specific aspect of a software system at a certain level of abstraction and from a certain perspective. Additionally, DSMs are usually not independent but instead have inherent interdependencies, reflecting (partial) similar aspects of a software system at different levels of abstraction or from different perspectives. A subset of these dependencies are applications of various model operations, which are necessary to keep the degree of automation high. This becomes even worse when addressing the first dimension of complexity. Due to continuous changes, all kinds of dependencies, including the applications of model operations, must also be managed continuously. This comprises maintaining the existence of these dependencies and the appropriate (re-)application of model operations. The contribution of this thesis is an approach that combines traceability and model management to address the aforementioned challenges of configuring and applying MDE for software development. The approach is considered as a traceability approach because it supports capturing and automatically maintaining dependencies between DSMs. The approach is considered as a model management approach because it supports managing the automated (re-)application of heterogeneous model operations. In addition, the approach is considered as a comprehensive model management. Since the decomposition of model operations is encouraged to alleviate the first dimension of complexity, the subsequent composition of model operations is required to counteract their fragmentation. A significant portion of this thesis concerns itself with providing a method for the specification of decoupled yet still highly cohesive complex compositions of heterogeneous model operations. The approach supports two different kinds of compositions - data-flow compositions and context compositions. Data-flow composition is used to define a network of heterogeneous model operations coupled by sharing input and output DSMs alone. Context composition is related to a concept used in declarative model transformation approaches to compose individual model transformation rules (units) at any level of detail. In this thesis, context composition provides the ability to use a collection of dependencies as context for the composition of other dependencies, including model operations. In addition, the actual implementation of model operations, which are going to be composed, do not need to implement any composition concerns. The approach is realized by means of a formalism called an executable and dynamic hierarchical megamodel, based on the original idea of megamodels. This formalism supports specifying compositions of dependencies (traceability and model operations). On top of this formalism, traceability is realized by means of a localization concept, and model management by means of an execution concept.}, 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{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} } @article{HeinischRomeike2013, author = {Heinisch, Isabelle and Romeike, Ralf}, title = {Outcome-orientierte Neuausrichtung in der Hochschullehre Informatik}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64831}, pages = {9 -- 20}, year = {2013}, abstract = {Die Orientierung am Outcome eines Lernprozesses stellt einen wichtigen Pfeiler einer kompetenzorientierten Informatiklehre dar. Im Beitrag werden Konzeption und Erfahrungen eines Projekts zur outcome-orientierten Neuausrichtung der Informatiklehre unter Ber{\"u}cksichtigung der Theorie des Constructive Alignment beschrieben. Nach der theoretischen Fundierung der Kompetenzproblematik wird anhand eines Formulierungsmodells ein Prozess zur Erarbeitung beobachtbarer Lernergebnisse dargestellt. Die Diskussion der Projektziele und Erfahrungen in der Umsetzung und Evaluierung unterstreichen die Chancen und Herausforderungen f{\"u}r eine Steigerung der Studienqualit{\"a}t.}, language = {de} } @article{HolzBergerSchroeder2013, author = {Holz, Jan and Berger, Nadine and Schroeder, Ulrike}, title = {Anwendungsorientierte Gestaltung eines Informatik-Vorkurses als Studienmotivator}, series = {Commentarii informaticae didacticae : (CID)}, journal = {Commentarii informaticae didacticae : (CID)}, number = {5}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-64871}, pages = {56 -- 66}, year = {2013}, abstract = {Zur Unterst{\"u}tzung von Studierenden in der Studieneingangsphase wurde an der RWTH Aachen ein neuartiger und motivierender Einstieg in den Vorkurs Informatik entwickelt und zum Wintersemester 2011/12 erprobt. Dabei wurde die grafische Programmierung mittels App Inventor eingef{\"u}hrt, die zur Umsetzung anwendungsbezogener Projekte genutzt wurde. In diesem Beitrag werden die Motivation f{\"u}r die Neugestaltung, das Konzept und die Evaluation des Testlaufs beschrieben. Diese dienen als Grundlage f{\"u}r eine vollst{\"a}ndige Neukonzeption des Vorkurses f{\"u}r das Wintersemester 2012/2013.}, 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} } @unpublished{GrapentinHeidlerKorschetal.2014, author = {Grapentin, Andreas and Heidler, Kirstin and Korsch, Dimitri and Kumar Sah, Rakesh and Kunzmann, Nicco and Henning, Johannes and Mattis, Toni and Rein, Patrick and Seckler, Eric and Groneberg, Bj{\"o}rn and Zimmermann, Florian}, title = {Embedded operating system projects}, number = {90}, editor = {Hentschel, Uwe and Richter, Daniel and Polze, Andreas}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-296-4}, issn = {1613-5652}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-69154}, pages = {xi, 87}, year = {2014}, abstract = {In today's life, embedded systems are ubiquitous. But they differ from traditional desktop systems in many aspects - these include predictable timing behavior (real-time), the management of scarce resources (memory, network), reliable communication protocols, energy management, special purpose user-interfaces (headless operation), system configuration, programming languages (to support software/hardware co-design), and modeling techniques. Within this technical report, authors present results from the lecture "Operating Systems for Embedded Computing" that has been offered by the "Operating Systems and Middleware" group at HPI in Winter term 2013/14. Focus of the lecture and accompanying projects was on principles of real-time computing. Students had the chance to gather practical experience with a number of different OSes and applications and present experiences with near-hardware programming. Projects address the entire spectrum, from bare-metal programming to harnessing a real-time OS to exercising the full software/hardware co-design cycle. Three outstanding projects are at the heart of this technical report. Project 1 focuses on the development of a bare-metal operating system for LEGO Mindstorms EV3. While still a toy, it comes with a powerful ARM processor, 64 MB of main memory, standard interfaces, such as Bluetooth and network protocol stacks. EV3 runs a version of 1 1 Introduction Linux. Sources are available from Lego's web site. However, many devices and their driver software are proprietary and not well documented. Developing a new, bare-metal OS for the EV3 requires an understanding of the EV3 boot process. Since no standard input/output devices are available, initial debugging steps are tedious. After managing these initial steps, the project was able to adapt device drivers for a few Lego devices to an extent that a demonstrator (the Segway application) could be successfully run on the new OS. Project 2 looks at the EV3 from a different angle. The EV3 is running a pretty decent version of Linux- in principle, the RT_PREEMPT patch can turn any Linux system into a real-time OS by modifying the behavior of a number of synchronization constructs at the heart of the OS. Priority inversion is a problem that is solved by protocols such as priority inheritance or priority ceiling. Real-time OSes implement at least one of the protocols. The central idea of the project was the comparison of non-real-time and real-time variants of Linux on the EV3 hardware. A task set that showed effects of priority inversion on standard EV3 Linux would operate flawlessly on the Linux version with the RT_PREEMPT-patch applied. If only patching Lego's version of Linux was that easy... Project 3 takes the notion of real-time computing more seriously. The application scenario was centered around our Carrera Digital 132 racetrack. Obtaining position information from the track, controlling individual cars, detecting and modifying the Carrera Digital protocol required design and implementation of custom controller hardware. What to implement in hardware, firmware, and what to implement in application software - this was the central question addressed by the project.}, language = {en} } @phdthesis{Polyvyanyy2012, author = {Polyvyanyy, Artem}, title = {Structuring process models}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59024}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {One can fairly adopt the ideas of Donald E. Knuth to conclude that process modeling is both a science and an art. Process modeling does have an aesthetic sense. Similar to composing an opera or writing a novel, process modeling is carried out by humans who undergo creative practices when engineering a process model. Therefore, the very same process can be modeled in a myriad number of ways. Once modeled, processes can be analyzed by employing scientific methods. Usually, process models are formalized as directed graphs, with nodes representing tasks and decisions, and directed arcs describing temporal constraints between the nodes. Common process definition languages, such as Business Process Model and Notation (BPMN) and Event-driven Process Chain (EPC) allow process analysts to define models with arbitrary complex topologies. The absence of structural constraints supports creativity and productivity, as there is no need to force ideas into a limited amount of available structural patterns. Nevertheless, it is often preferable that models follow certain structural rules. A well-known structural property of process models is (well-)structuredness. A process model is (well-)structured if and only if every node with multiple outgoing arcs (a split) has a corresponding node with multiple incoming arcs (a join), and vice versa, such that the set of nodes between the split and the join induces a single-entry-single-exit (SESE) region; otherwise the process model is unstructured. The motivations for well-structured process models are manifold: (i) Well-structured process models are easier to layout for visual representation as their formalizations are planar graphs. (ii) Well-structured process models are easier to comprehend by humans. (iii) Well-structured process models tend to have fewer errors than unstructured ones and it is less probable to introduce new errors when modifying a well-structured process model. (iv) Well-structured process models are better suited for analysis with many existing formal techniques applicable only for well-structured process models. (v) Well-structured process models are better suited for efficient execution and optimization, e.g., when discovering independent regions of a process model that can be executed concurrently. Consequently, there are process modeling languages that encourage well-structured modeling, e.g., Business Process Execution Language (BPEL) and ADEPT. However, the well-structured process modeling implies some limitations: (i) There exist processes that cannot be formalized as well-structured process models. (ii) There exist processes that when formalized as well-structured process models require a considerable duplication of modeling constructs. Rather than expecting well-structured modeling from start, we advocate for the absence of structural constraints when modeling. Afterwards, automated methods can suggest, upon request and whenever possible, alternative formalizations that are "better" structured, preferably well-structured. In this thesis, we study the problem of automatically transforming process models into equivalent well-structured models. The developed transformations are performed under a strong notion of behavioral equivalence which preserves concurrency. The findings are implemented in a tool, which is publicly available.}, language = {en} } @phdthesis{Meier2017, author = {Meier, Sebastian}, title = {Personal Big Data}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-406696}, school = {Universit{\"a}t Potsdam}, pages = {xxiv, 133}, year = {2017}, abstract = {Many users of cloud-based services are concerned about questions of data privacy. At the same time, they want to benefit from smart data-driven services, which require insight into a person's individual behaviour. The modus operandi of user modelling is that data is sent to a remote server where the model is constructed and merged with other users' data. This thesis proposes selective cloud computing, an alternative approach, in which the user model is constructed on the client-side and only an abstracted generalised version of the model is shared with the remote services. In order to demonstrate the applicability of this approach, the thesis builds an exemplary client-side user modelling technique. As this thesis is carried out in the area of Geoinformatics and spatio-temporal data is particularly sensitive, the application domain for this experiment is the analysis and prediction of a user's spatio-temporal behaviour. The user modelling technique is grounded in an innovative conceptual model, which builds upon spatial network theory combined with time-geography. The spatio-temporal constraints of time-geography are applied to the network structure in order to create individual spatio-temporal action spaces. This concept is translated into a novel algorithmic user modelling approach which is solely driven by the user's own spatio-temporal trajectory data that is generated by the user's smartphone. While modern smartphones offer a rich variety of sensory data, this thesis only makes use of spatio-temporal trajectory data, enriched by activity classification, as the input and foundation for the algorithmic model. The algorithmic model consists of three basal components: locations (vertices), trips (edges), and clusters (neighbourhoods). After preprocessing the incoming trajectory data in order to identify locations, user feedback is used to train an artificial neural network to learn temporal patterns for certain location types (e.g. work, home, bus stop, etc.). This Artificial Neural Network (ANN) is used to automatically detect future location types by their spatio-temporal patterns. The same is done in order to predict the duration of stay at a certain location. Experiments revealed that neural nets were the most successful statistical and machine learning tool to detect those patterns. The location type identification algorithm reached an accuracy of 87.69\%, the duration prediction on binned data was less successful and deviated by an average of 0.69 bins. A challenge for the location type classification, as well as for the subsequent components, was the imbalance of trips and connections as well as the low accuracy of the trajectory data. The imbalance is grounded in the fact that most users exhibit strong habitual patterns (e.g. home > work), while other patterns are rather rare by comparison. The accuracy problem derives from the energy-saving location sampling mode, which creates less accurate results. Those locations are then used to build a network that represents the user's spatio-temporal behaviour. An initial untrained ANN to predict movement on the network only reached 46\% average accuracy. Only lowering the number of included edges, focusing on more common trips, increased the performance. In order to further improve the algorithm, the spatial trajectories were introduced into the predictions. To overcome the accuracy problem, trips between locations were clustered into so-called spatial corridors, which were intersected with the user's current trajectory. The resulting intersected trips were ranked through a k-nearest-neighbour algorithm. This increased the performance to 56\%. In a final step, a combination of a network and spatial clustering algorithm was built in order to create clusters, therein reducing the variety of possible trips. By only predicting the destination cluster instead of the exact location, it is possible to increase the performance to 75\% including all classes. A final set of components shows in two exemplary ways how to deduce additional inferences from the underlying spatio-temporal data. The first example presents a novel concept for predicting the 'potential memorisation index' for a certain location. The index is based on a cognitive model which derives the index from the user's activity data in that area. The second example embeds each location in its urban fabric and thereby enriches its cluster's metadata by further describing the temporal-semantic activity in an area (e.g. going to restaurants at noon). The success of the client-side classification and prediction approach, despite the challenges of inaccurate and imbalanced data, supports the claimed benefits of the client-side modelling concept. Since modern data-driven services at some point do need to receive user data, the thesis' computational model concludes with a concept for applying generalisation to semantic, temporal, and spatial data before sharing it with the remote service in order to comply with the overall goal to improve data privacy. In this context, the potentials of ensemble training (in regards to ANNs) are discussed in order to highlight the potential of only sharing the trained ANN instead of the raw input data. While the results of our evaluation support the assets of the proposed framework, there are two important downsides of our approach compared to server-side modelling. First, both of these server-side advantages are rooted in the server's access to multiple users' data. This allows a remote service to predict spatio-in the user-specific data, which represents the second downside. While minor classes will likely be minor classes in a bigger dataset as well, for each class, there will still be more variety than in the user-specific dataset. The author emphasises that the approach presented in this work holds the potential to change the privacy paradigm in modern data-driven services. Finding combinations of client- and server-side modelling could prove a promising new path for data-driven innovation. Beyond the technological perspective, throughout the thesis the author also offers a critical view on the data- and technology-driven development of this work. By introducing the client-side modelling with user-specific artificial neural networks, users generate their own algorithm. Those user-specific algorithms are influenced less by generalised biases or developers' prejudices. Therefore, the user develops a more diverse and individual perspective through his or her user model. This concept picks up the idea of critical cartography, which questions the status quo of how space is perceived and represented.}, language = {en} } @misc{GebserKaufmannSchaub2012, author = {Gebser, Martin and Kaufmann, Benjamin and Schaub, Torsten H.}, title = {Multi-threaded ASP solving with clasp}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {586}, issn = {1866-8372}, doi = {10.25932/publishup-41397}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413977}, pages = {21}, year = {2012}, abstract = {We present the new multi-threaded version of the state-of-the-art answer set solver clasp. We detail its component and communication architecture and illustrate how they support the principal functionalities of clasp. Also, we provide some insights into the data representation used for different constraint types handled by clasp. All this is accompanied by an extensive experimental analysis of the major features related to multi-threading in clasp.}, language = {en} } @misc{HoosKaminskiLindaueretal.2015, author = {Hoos, Holger and Kaminski, Roland and Lindauer, Marius and Schaub, Torsten H.}, title = {aspeed}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {588}, issn = {1866-8372}, doi = {10.25932/publishup-41474}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414743}, pages = {26}, year = {2015}, abstract = {Although Boolean Constraint Technology has made tremendous progress over the last decade, the efficacy of state-of-the-art solvers is known to vary considerably across different types of problem instances, and is known to depend strongly on algorithm parameters. This problem was addressed by means of a simple, yet effective approach using handmade, uniform, and unordered schedules of multiple solvers in ppfolio, which showed very impressive performance in the 2011 Satisfiability Testing (SAT) Competition. Inspired by this, we take advantage of the modeling and solving capacities of Answer Set Programming (ASP) to automatically determine more refined, that is, nonuniform and ordered solver schedules from the existing benchmarking data. We begin by formulating the determination of such schedules as multi-criteria optimization problems and provide corresponding ASP encodings. The resulting encodings are easily customizable for different settings, and the computation of optimum schedules can mostly be done in the blink of an eye, even when dealing with large runtime data sets stemming from many solvers on hundreds to thousands of instances. Also, the fact that our approach can be customized easily enabled us to swiftly adapt it to generate parallel schedules for multi-processor machines.}, language = {en} } @misc{GebserHarrisonKaminskietal.2015, author = {Gebser, Martin and Harrison, Amelia and Kaminski, Roland and Lifschitz, Vladimir and Schaub, Torsten H.}, title = {Abstract gringo}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {592}, issn = {1866-8372}, doi = {10.25932/publishup-41475}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-414751}, pages = {15}, year = {2015}, abstract = {This paper defines the syntax and semantics of the input language of the ASP grounder gringo. The definition covers several constructs that were not discussed in earlier work on the semantics of that language, including intervals, pools, division of integers, aggregates with non-numeric values, and lparse-style aggregate expressions. The definition is abstract in the sense that it disregards some details related to representing programs by strings of ASCII characters. It serves as a specification for gringo from Version 4.5 on.}, language = {en} } @misc{GebserLeeLierler2011, author = {Gebser, Martin and Lee, Joohyung and Lierler, Yuliya}, title = {On elementary loops of logic programs}, series = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe}, number = {566}, issn = {1866-8372}, doi = {10.25932/publishup-41309}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413091}, pages = {36}, year = {2011}, abstract = {Using the notion of an elementary loop, Gebser and Schaub (2005. Proceedings of the Eighth International Conference on Logic Programming and Nonmonotonic Reasoning (LPNMR'05 ), 53-65) refined the theorem on loop formulas attributable to Lin and Zhao (2004) by considering loop formulas of elementary loops only. In this paper, we reformulate the definition of an elementary loop, extend it to disjunctive programs, and study several properties of elementary loops, including how maximal elementary loops are related to minimal unfounded sets. The results provide useful insights into the stable model semantics in terms of elementary loops. For a nondisjunctive program, using a graph-theoretic characterization of an elementary loop, we show that the problem of recognizing an elementary loop is tractable. On the other hand, we also show that the corresponding problem is coNP-complete for a disjunctive program. Based on the notion of an elementary loop, we present the class of Head-Elementary-loop-Free (HEF) programs, which strictly generalizes the class of Head-Cycle-Free (HCF) programs attributable to Ben-Eliyahu and Dechter (1994. Annals of Mathematics and Artificial Intelligence 12, 53-87). Like an HCF program, an HEF program can be turned into an equivalent nondisjunctive program in polynomial time by shifting head atoms into the body.}, language = {en} } @article{KaitouaRablMarkl2020, author = {Kaitoua, Abdulrahman and Rabl, Tilmann and Markl, Volker}, title = {A distributed data exchange engine for polystores}, series = {Information technology : methods and applications of informatics and information technology}, volume = {62}, journal = {Information technology : methods and applications of informatics and information technology}, number = {3-4}, publisher = {De Gruyter}, address = {Berlin}, issn = {1611-2776}, doi = {10.1515/itit-2019-0037}, pages = {145 -- 156}, year = {2020}, abstract = {There is an increasing interest in fusing data from heterogeneous sources. Combining data sources increases the utility of existing datasets, generating new information and creating services of higher quality. A central issue in working with heterogeneous sources is data migration: In order to share and process data in different engines, resource intensive and complex movements and transformations between computing engines, services, and stores are necessary. Muses is a distributed, high-performance data migration engine that is able to interconnect distributed data stores by forwarding, transforming, repartitioning, or broadcasting data among distributed engines' instances in a resource-, cost-, and performance-adaptive manner. As such, it performs seamless information sharing across all participating resources in a standard, modular manner. We show an overall improvement of 30 \% for pipelining jobs across multiple engines, even when we count the overhead of Muses in the execution time. This performance gain implies that Muses can be used to optimise large pipelines that leverage multiple engines.}, language = {en} } @article{DreselerBoissierRabletal.2020, author = {Dreseler, Markus and Boissier, Martin and Rabl, Tilmann and Uflacker, Matthias}, title = {Quantifying TPC-H choke points and their optimizations}, series = {Proceedings of the VLDB Endowment}, volume = {13}, journal = {Proceedings of the VLDB Endowment}, number = {8}, publisher = {Association for Computing Machinery}, address = {New York}, issn = {2150-8097}, doi = {10.14778/3389133.3389138}, pages = {1206 -- 1220}, year = {2020}, abstract = {TPC-H continues to be the most widely used benchmark for relational OLAP systems. It poses a number of challenges, also known as "choke points", which database systems have to solve in order to achieve good benchmark results. Examples include joins across multiple tables, correlated subqueries, and correlations within the TPC-H data set. Knowing the impact of such optimizations helps in developing optimizers as well as in interpreting TPC-H results across database systems. This paper provides a systematic analysis of choke points and their optimizations. It complements previous work on TPC-H choke points by providing a quantitative discussion of their relevance. It focuses on eleven choke points where the optimizations are beneficial independently of the database system. Of these, the flattening of subqueries and the placement of predicates have the biggest impact. Three queries (Q2, Q17, and Q21) are strongly ifluenced by the choice of an efficient query plan; three others (Q1, Q13, and Q18) are less influenced by plan optimizations and more dependent on an efficient execution engine.}, language = {en} } @article{NavarroOrejasPinoetal.2021, author = {Navarro, Marisa and Orejas, Fernando and Pino, Elvira and Lambers, Leen}, title = {A navigational logic for reasoning about graph properties}, series = {Journal of logical and algebraic methods in programming}, volume = {118}, journal = {Journal of logical and algebraic methods in programming}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {2352-2208}, doi = {10.1016/j.jlamp.2020.100616}, pages = {33}, year = {2021}, abstract = {Graphs play an important role in many areas of Computer Science. In particular, our work is motivated by model-driven software development and by graph databases. For this reason, it is very important to have the means to express and to reason about the properties that a given graph may satisfy. With this aim, in this paper we present a visual logic that allows us to describe graph properties, including navigational properties, i.e., properties about the paths in a graph. The logic is equipped with a deductive tableau method that we have proved to be sound and complete.}, language = {en} } @phdthesis{Makowski2021, author = {Makowski, Silvia}, title = {Discriminative Models for Biometric Identification using Micro- and Macro-Movements of the Eyes}, school = {Universit{\"a}t Potsdam}, pages = {xi, 91}, year = {2021}, abstract = {Human visual perception is an active process. Eye movements either alternate between fixations and saccades or follow a smooth pursuit movement in case of moving targets. Besides these macroscopic gaze patterns, the eyes perform involuntary micro-movements during fixations which are commonly categorized into micro-saccades, drift and tremor. Eye movements are frequently studied in cognitive psychology, because they reflect a complex interplay of perception, attention and oculomotor control. A common insight of psychological research is that macro-movements are highly individual. Inspired by this finding, there has been a considerable amount of prior research on oculomotoric biometric identification. However, the accuracy of known approaches is too low and the time needed for identification is too long for any practical application. This thesis explores discriminative models for the task of biometric identification. Discriminative models optimize a quality measure of the predictions and are usually superior to generative approaches in discriminative tasks. However, using discriminative models requires to select a suitable form of data representation for sequential eye gaze data; i.e., by engineering features or constructing a sequence kernel and the performance of the classification model strongly depends on the data representation. We study two fundamentally different ways of representing eye gaze within a discriminative framework. In the first part of this thesis, we explore the integration of data and psychological background knowledge in the form of generative models to construct representations. To this end, we first develop generative statistical models of gaze behavior during reading and scene viewing that account for viewer-specific distributional properties of gaze patterns. In a second step, we develop a discriminative identification model by deriving Fisher kernel functions from these and several baseline models. We find that an SVM with Fisher kernel is able to reliably identify users based on their eye gaze during reading and scene viewing. However, since the generative models are constrained to use low-frequency macro-movements, they discard a significant amount of information contained in the raw eye tracking signal at a high cost: identification requires about one minute of input recording, which makes it inapplicable for real world biometric systems. In the second part of this thesis, we study a purely data-driven modeling approach. Here, we aim at automatically discovering the individual pattern hidden in the raw eye tracking signal. To this end, we develop a deep convolutional neural network DeepEyedentification that processes yaw and pitch gaze velocities and learns a representation end-to-end. Compared to prior work, this model increases the identification accuracy by one order of magnitude and the time to identification decreases to only seconds. The DeepEyedentificationLive model further improves upon the identification performance by processing binocular input and it also detects presentation-attacks. We find that by learning a representation, the performance of oculomotoric identification and presentation-attack detection can be driven close to practical relevance for biometric applications. Eye tracking devices with high sampling frequency and precision are expensive and the applicability of eye movement as a biometric feature heavily depends on cost of recording devices. In the last part of this thesis, we therefore study the requirements on data quality by evaluating the performance of the DeepEyedentificationLive network under reduced spatial and temporal resolution. We find that the method still attains a high identification accuracy at a temporal resolution of only 250 Hz and a precision of 0.03 degrees. Reducing both does not have an additive deteriorating effect.}, language = {en} } @article{WahlHoelscher2018, author = {Wahl, Marina and H{\"o}lscher, Michael}, title = {Und am Wochenende Blended Learning}, series = {E-Learning Symposium 2018}, journal = {E-Learning Symposium 2018}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, doi = {10.25932/publishup-42191}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-421910}, pages = {17 -- 27}, year = {2018}, abstract = {Berufsbegleitende Studieng{\"a}nge stehen vor besonderen Schwierigkeiten, f{\"u}r die der Einsatz von Blended Learning-Szenarien sinnvoll sein kann. Welche speziellen Herausforderungen sich dabei ergeben und welche L{\"o}sungsans{\"a}tze dagegen steuern, betrachtet der folgende Artikel anhand eines Praxisberichts aus dem Studiengang M. P. A. Wissenschaftsmanagement an der Universit{\"a}t Speyer.}, language = {de} } @article{GautamZhangLandwehretal.2021, author = {Gautam, Khem Raj and Zhang, Guoqiang and Landwehr, Niels and Adolphs, Julian}, title = {Machine learning for improvement of thermal conditions inside a hybrid ventilated animal building}, series = {Computers and electronics in agriculture : COMPAG online ; an international journal}, volume = {187}, journal = {Computers and electronics in agriculture : COMPAG online ; an international journal}, publisher = {Elsevier Science}, address = {Amsterdam [u.a.]}, issn = {0168-1699}, doi = {10.1016/j.compag.2021.106259}, pages = {10}, year = {2021}, abstract = {In buildings with hybrid ventilation, natural ventilation opening positions (windows), mechanical ventilation rates, heating, and cooling are manipulated to maintain desired thermal conditions. The indoor temperature is regulated solely by ventilation (natural and mechanical) when the external conditions are favorable to save external heating and cooling energy. The ventilation parameters are determined by a rule-based control scheme, which is not optimal. This study proposes a methodology to enable real-time optimum control of ventilation parameters. We developed offline prediction models to estimate future thermal conditions from the data collected from building in operation. The developed offline model is then used to find the optimal controllable ventilation parameters in real-time to minimize the setpoint deviation in the building. With the proposed methodology, the experimental building's setpoint deviation improved for 87\% of time, on average, by 0.53 degrees C compared to the current deviations.}, language = {en} } @inproceedings{OPUS4-39635, title = {11. Workshop Testmethoden und Zuverl{\"a}ssigkeit von Schaltungen und Systemen}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-9806494-1-4}, pages = {137 Seiten}, year = {1999}, language = {de} } @phdthesis{Gruetze2018, author = {Gr{\"u}tze, Toni}, title = {Adding value to text with user-generated content}, school = {Universit{\"a}t Potsdam}, pages = {ii, 114}, year = {2018}, abstract = {In recent years, the ever-growing amount of documents on the Web as well as in closed systems for private or business contexts led to a considerable increase of valuable textual information about topics, events, and entities. It is a truism that the majority of information (i.e., business-relevant data) is only available in unstructured textual form. The text mining research field comprises various practice areas that have the common goal of harvesting high-quality information from textual data. These information help addressing users' information needs. In this thesis, we utilize the knowledge represented in user-generated content (UGC) originating from various social media services to improve text mining results. These social media platforms provide a plethora of information with varying focuses. In many cases, an essential feature of such platforms is to share relevant content with a peer group. Thus, the data exchanged in these communities tend to be focused on the interests of the user base. The popularity of social media services is growing continuously and the inherent knowledge is available to be utilized. We show that this knowledge can be used for three different tasks. Initially, we demonstrate that when searching persons with ambiguous names, the information from Wikipedia can be bootstrapped to group web search results according to the individuals occurring in the documents. We introduce two models and different means to handle persons missing in the UGC source. We show that the proposed approaches outperform traditional algorithms for search result clustering. Secondly, we discuss how the categorization of texts according to continuously changing community-generated folksonomies helps users to identify new information related to their interests. We specifically target temporal changes in the UGC and show how they influence the quality of different tag recommendation approaches. Finally, we introduce an algorithm to attempt the entity linking problem, a necessity for harvesting entity knowledge from large text collections. The goal is the linkage of mentions within the documents with their real-world entities. A major focus lies on the efficient derivation of coherent links. For each of the contributions, we provide a wide range of experiments on various text corpora as well as different sources of UGC. The evaluation shows the added value that the usage of these sources provides and confirms the appropriateness of leveraging user-generated content to serve different information needs.}, language = {en} } @book{Mueller2017, author = {M{\"u}ller, Dorothee}, title = {Der Berufswahlprozess von Informatiklehrkr{\"a}ften}, number = {11}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-392-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-101819}, publisher = {Universit{\"a}t Potsdam}, pages = {xiv, 299}, year = {2017}, abstract = {Seit Jahren ist der Mangel an Informatiklehrkr{\"a}ften bekannt und wird fachdidaktisch und politisch diskutiert. Aufgrund der geringen Anzahl von Studierenden mit dem Berufsziel Informatiklehrkraft ist eine Vergr{\"o}ßerung des Mangels vorhersehbar. Es stellt sich die Frage, warum so wenige Studierende sich f{\"u}r das Studienziel Lehramt Informatik entscheiden. Das Ziel der vorliegenden Arbeit ist es, die Berufswahl von Informatiklehrkr{\"a}ften aus der individuellen, biographischen Perspektive der Beteiligten zu erforschen und dabei Faktoren zu identifizieren, die die Berufswahl Informatiklehrkraft positiv oder negativ beeinflussen. Der Forschungsschwerpunkt liegt auf der qualitativen empirischen Untersuchung des Berufswahlprozesses, w{\"a}hrend eine quantitative Befragung aktiver Informatiklehrkr{\"a}fte zu berufswahlrelevanten Aspekten des Berufsbildes diese erg{\"a}nzt. Das Forschungskonzept der qualitativen Untersuchung orientiert sich an der Grounded Theory. Es wurden angehende Informatiklehrkr{\"a}fte zu ihrem Berufswahlprozess befragt, wobei die Daten durch m{\"u}ndliche Interviews, Gruppendiskussionen und schriftliche Berufswahlbiographien erhoben wurden. Die Datenauswertung orientiert sich zudem methodisch an der dokumentarischen Methode nach Ralf Bohnsack. Die Ergebnisse der Untersuchung zeigen, dass der Berufswahlprozess von angehenden Informatiklehrkr{\"a}ften h{\"a}ufig mit Umwegen in Form von Studienzielwechseln verbunden ist. Neben dem eigenen Bild der Informatik und dem Informatikselbstkonzept kommt dem Informatikunterricht der eigenen Schulzeit eine wichtige Rolle in diesem Prozess zu. Von der Lehrerforschung werden die Unterrichtserfahrungen w{\"a}hrend der eigenen Schulzeit im sp{\"a}ter studierten Fach als entscheidend f{\"u}r die Fachwahl identifiziert. Dies best{\"a}tigt sich in den Berufswahlbiographien derjenigen angehenden Informatiklehrkr{\"a}fte, die den Informatikunterricht ihrer eigenen Schulzeit positiv erinnern. Diese streben meist direkt in ihrem ersten Studium das Berufsziel Informatiklehrkraft an. Sie hatten zur Schulzeit ein positives Bild der Informatik und ein hohes Informatikselbstkonzept. Der Informatiklehrkraft ihrer Schulzeit bescheinigen sie oft eine berufliche Vorbildfunktion. Allerdings hatten die meisten der befragten angehenden Informatiklehrkr{\"a}fte selbst keinen Informatikunterricht oder erinnern diesen negativ. Der Weg zum Studium Informatiklehrkraft f{\"u}hrt bei diesen Befragten h{\"a}ufig {\"u}ber den Umweg von zun{\"a}chst anderen Studienentscheidungen, meistens {\"u}ber ein Lehramtsstudium mit anderen F{\"a}chern oder ein Informatikstudium. Die Informatikstudierenden haben zum Zeitpunkt ihrer ersten Studienwahl ein positives Bild der Informatik und ein hohes Informatikselbstkonzept aber kein positives Berufsbild Informatiklehrkraft. Ihr Wechsel von einem Informatikstudium zum Studium mit dem Berufsziel Informatiklehrkraft wird in der Regel durch den Wunsch nach einer st{\"a}rkeren sozialen Komponente im sp{\"a}teren Berufsalltag ausgel{\"o}st. Bei den Lehramtsstudierenden, die h{\"a}ufig zun{\"a}chst ein niedriges Informatikselbstkonzept und/oder ein negatives Bild der Informatik haben, kann es zu einer Umorientierung hin zum Studienziel Informatiklehrkraft kommen, wenn diese Vorstellungen sich w{\"a}hrend des ersten Studiums - z. B. durch den Besuch von universit{\"a}ren Lehrveranstaltungen zu informatischen Inhalten - {\"a}ndern. Die letztliche Entscheidung f{\"u}r den Beruf Informatiklehrkraft wird von denjenigen, die ihr Studienziel wechselten, mit Recht als durch Zuf{\"a}lle bestimmt empfunden.}, language = {de} } @inproceedings{KeilKonertDamniketal.2018, author = {Keil, Reinhard and Konert, Johannes and Damnik, Gregor and Gierl, Mark J. and Proske, Antje and K{\"o}rndle, Hermann and Narciss, Susanne and Wahl, Marina and H{\"o}lscher, Michael and Mariani, Ennio and Jaisli, Isabel and Tscherejkina, Anna and Morgiel, Anna and Moebert, Tobias and Herbstreit, Stephanie and M{\"a}ker, Daniela and Szalai, Cynthia and Braun, Iris and Kapp, Felix and Hara, Tenshi C. and Kubica, Tommy and Stumpf, Sarah}, title = {E-Learning Symposium 2018}, editor = {Lucke, Ulrike and Strickroth, Sven}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, doi = {10.25932/publishup-42071}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-420711}, pages = {71}, year = {2018}, abstract = {In den vergangenen Jahren sind viele E-Learning-Innovationen entstanden. Einige davon wurden auf den vergangenen E-Learning Symposien der Universit{\"a}t Potsdam pr{\"a}sentiert: Das erste E-Learning Symposium im Jahr 2012 konzentrierte sich auf unterschiedliche M{\"o}glichkeiten der Studierendenaktivierung und Lehrgestaltung. Das Symposium 2014 r{\"u}ckte vor allem die Studierenden ins Zentrum der Aufmerksamkeit. Im Jahr 2016 kam es durch das Zusammengehen des Symposiums mit der DeLFI-Tagung zu einer Fokussierung auf technische Innovationen. Doch was ist aus den Leuchtt{\"u}rmen von gestern geworden, und brauchen wir {\"u}berhaupt noch neue Leuchtt{\"u}rme? Das Symposium setzt sich in diesem Jahr unter dem Motto „Innovation und Nachhaltigkeit - (k)ein Gegensatz?" mit mediengest{\"u}tzten Lehr- und Lernprozessen im universit{\"a}ren Kontext auseinander und reflektiert aktuelle technische sowie didaktische Entwicklungen mit Blick auf deren mittel- bis langfristigen Einsatz in der Praxis. Dieser Tagungsband zum E-Learning Symposium 2018 an der Universit{\"a}t Potsdam beinhaltet eine Mischung von Forschungs- und Praxisbeitr{\"a}gen aus verschiedenen Fachdisziplinen und er{\"o}ffnet vielschichtige Perspektiven auf das Thema E-Learning. Dabei werden die Vielfalt der didaktischen Einsatzszenarien als auch die Potentiale von Werk-zeugen und Methoden der Informatik in ihrem Zusammenspiel beleuchtet. In seiner Keynote widmet sich Reinhard Keil dem Motto des Symposiums und geht der Nachhaltigkeit bei E-Learning-Projekten auf den Grund. Dabei analysiert und beleuchtet er anhand seiner {\"u}ber 15-j{\"a}hrigen Forschungspraxis die wichtigsten Wirkfaktoren und formuliert Empfehlungen zur Konzeption von E-Learning-Projekten. Im Gegensatz zu rein auf Kostenersparnis ausgerichteten (hochschul-)politischen Forderungen proklamiert er den Ansatz der hypothesengeleiteten Technikgestaltung, in der Nachhaltigkeit als Leitfrage oder Forschungsstrategie verstanden werden kann. In eine {\"a}hnliche Richtung geht der Beitrag von Iris Braun et al., die {\"u}ber Erfolgsfaktoren beim Einsatz von Audience Response Systemen in der universit{\"a}ren Lehre berichten. Ein weiteres aktuelles Thema, sowohl f{\"u}r die Bildungstechnologie als auch in den Bildungswissenschaften allgemein, ist die Kompetenzorientierung und -modellierung. Hier geht es darum (Probleml{\"o}se-)F{\"a}higkeiten gezielt zu beschreiben und in den Mittelpunkt der Lehre zu stellen. Johannes Konert stellt in einem eingeladenen Vortrag zwei Projekte vor, die den Prozess beginnend bei der Definition von Kompetenzen, deren Modellierung in einem semantischen maschinenlesbaren Format bis hin zur Erarbeitung von Methoden zur Kompetenzmessung und der elektronischen Zertifizierung aufzeigen. Dabei geht er auf technische M{\"o}glichkeiten, aber auch Grenzen ein. Auf einer spezifischeren Ebene besch{\"a}ftigt sich Sarah Stumpf mit digitalen bzw. mediendidaktischen Kompetenzen im Lehramtsstudium und stellt ein Framework f{\"u}r die F{\"o}rderung ebensolcher Kompetenzen bei angehenden Lehrkr{\"a}ften vor. Der Einsatz von E-Learning birgt noch einige Herausforderungen. Dabei geht es oft um die Verbindung von Didaktik und Technik, den Erhalt von Aufmerksamkeit oder den Aufwand f{\"u}r das Erstellen von interaktiven Lehr- und Lerninhalten. Drei Beitr{\"a}ge in diesem Tagungsband besch{\"a}ftigen sich mit dieser Thematik in unterschiedlichen Kontexten und zeigen Best-Practices und L{\"o}sungsans{\"a}tze auf: Der Beitrag von Martina Wahl und Michael H{\"o}lscher behandelt den besonderen Kontext von Blended Learning-Szenarien in berufsbegleitenden Studieng{\"a}ngen. Um die Ver{\"o}ffentlichung eines global frei verf{\"u}gbaren Onlinekurses abseits der großen MOOC Plattformen und den didaktischen Herausforderungen auch hinsichtlich der Motivation geht es im Beitrag von Ennio Marani und Isabel Jaisli. Schließlich schlagen Gregor Damnik et al. die automatische Erzeugung von Aufgaben zur Erh{\"o}hung von Interaktivit{\"a}t und Adaptivit{\"a}t in digitalen Lernressourcen vor, um den teilweise erheblichen Erstellungsaufwand zu reduzieren. Zum Thema E-Learning z{\"a}hlen auch immer mobile Apps bzw. Spiele. Gleich zwei Beitr{\"a}ge besch{\"a}ftigen sich mit dem Einsatz von E-Learning-Tools im Gesundheitskontext: Anna Tscherejkina und Anna Morgiel stellen in ihrem Beitrag Minispiele zum Training von sozio-emotionalen Kompetenzen f{\"u}r Menschen mit Autismus vor, und Stephanie Herbstreit et al. berichten vom Einsatz einer mobilen Lern-App zur Verbesserung von klinisch-praktischem Unterricht.}, language = {de} } @inproceedings{SeegererRomeikeTillmannetal.2018, author = {Seegerer, Stefan and Romeike, Ralf and Tillmann, Alexander and Kr{\"o}mker, Detlef and Horn, Florian and Gattinger, Thorsten and Weicker, Karsten and Schmitz, Dennis and Moldt, Daniel and R{\"o}pke, Ren{\´e} and Larisch, Kathrin and Schroeder, Ulrik and Keverp{\"u}tz, Claudia and K{\"u}ppers, Bastian and Striewe, Michael and Kramer, Matthias and Grillenberger, Andreas and Frede, Christiane and Knobelsdorf, Maria and Greven, Christoph}, title = {Hochschuldidaktik der Informatik HDI 2018}, series = {Commentarii informaticae didacticae (CID)}, booktitle = {Commentarii informaticae didacticae (CID)}, number = {12}, editor = {Bergner, Nadine and R{\"o}pke, Ren{\´e} and Schroeder, Ulrik and Kr{\"o}mker, Detlef}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-435-7}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-413542}, pages = {161}, year = {2018}, abstract = {Die 8. Fachtagung f{\"u}r Hochschuldidaktik der Informatik (HDI) fand im September 2018 zusammen mit der Deutschen E-Learning Fachtagung Informatik (DeLFI) unter dem gemeinsamen Motto „Digitalisierungswahnsinn? - Wege der Bildungstransformationen" in Frankfurt statt. Dabei widmet sich die HDI allen Fragen der informatischen Bildung im Hochschulbereich. Schwerpunkte bildeten in diesem Jahr u. a.: - Analyse der Inhalte und anzustrebenden Kompetenzen in Informatikveranstaltungen - Programmieren lernen \& Einstieg in Softwareentwicklung - Spezialthemen: Data Science, Theoretische Informatik und Wissenschaftliches Arbeiten Die Fachtagung widmet sich ausgew{\"a}hlten Fragestellungen dieser Themenkomplexe, die durch Vortr{\"a}ge ausgewiesener Experten und durch eingereichte Beitr{\"a}ge intensiv behandelt werden.}, language = {de} } @article{BorchertMockTomczaketal.2021, author = {Borchert, Florian and Mock, Andreas and Tomczak, Aurelie and H{\"u}gel, Jonas and Alkarkoukly, Samer and Knurr, Alexander and Volckmar, Anna-Lena and Stenzinger, Albrecht and Schirmacher, Peter and Debus, J{\"u}rgen and J{\"a}ger, Dirk and Longerich, Thomas and Fr{\"o}hling, Stefan and Eils, Roland and Bougatf, Nina and Sax, Ulrich and Schapranow, Matthieu-Patrick}, title = {Correction to: Knowledge bases and software support for variant interpretation in precision oncology}, series = {Briefings in bioinformatics}, volume = {22}, journal = {Briefings in bioinformatics}, number = {6}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1467-5463}, doi = {10.1093/bib/bbab246}, pages = {1}, year = {2021}, language = {en} } @article{IhdePufahlVoelkeretal.2022, author = {Ihde, Sven and Pufahl, Luise and V{\"o}lker, Maximilian and Goel, Asvin and Weske, Mathias}, title = {A framework for modeling and executing task}, series = {Computing : archives for informatics and numerical computation}, volume = {104}, journal = {Computing : archives for informatics and numerical computation}, publisher = {Springer}, address = {Wien}, issn = {0010-485X}, doi = {10.1007/s00607-022-01093-2}, pages = {2405 -- 2429}, year = {2022}, abstract = {As resources are valuable assets, organizations have to decide which resources to allocate to business process tasks in a way that the process is executed not only effectively but also efficiently. Traditional role-based resource allocation leads to effective process executions, since each task is performed by a resource that has the required skills and competencies to do so. However, the resulting allocations are typically not as efficient as they could be, since optimization techniques have yet to find their way in traditional business process management scenarios. On the other hand, operations research provides a rich set of analytical methods for supporting problem-specific decisions on resource allocation. This paper provides a novel framework for creating transparency on existing tasks and resources, supporting individualized allocations for each activity in a process, and the possibility to integrate problem-specific analytical methods of the operations research domain. To validate the framework, the paper reports on the design and prototypical implementation of a software architecture, which extends a traditional process engine with a dedicated resource management component. This component allows us to define specific resource allocation problems at design time, and it also facilitates optimized resource allocation at run time. The framework is evaluated using a real-world parcel delivery process. The evaluation shows that the quality of the allocation results increase significantly with a technique from operations research in contrast to the traditional applied rule-based approach.}, language = {en} } @misc{CombiOliboniWeskeetal.2018, author = {Combi, Carlo and Oliboni, Barbara and Weske, Mathias and Zerbato, Francesca}, title = {Conceptual modeling of processes and data}, series = {Conceptual Modeling, ER 2018}, volume = {11157}, journal = {Conceptual Modeling, ER 2018}, editor = {Trujillo, JC Davis}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-00847-5}, issn = {0302-9743}, doi = {10.1007/978-3-030-00847-5_18}, pages = {236 -- 250}, year = {2018}, abstract = {Business processes constantly generate, manipulate, and consume data that are managed by organizational databases. Despite being central to process modeling and execution, the link between processes and data is often handled by developers when the process is implemented, thus leaving the connection unexplored during the conceptual design. In this paper, we introduce, formalize, and evaluate a novel conceptual view that bridges the gap between process and data models, and show some kinds of interesting insights that can be derived from this novel proposal.}, language = {en} } @inproceedings{GonnermannTeichmann2023, author = {Gonnermann, Jana and Teichmann, Malte}, title = {Influence of pre-experience on learning, usability and cognitive load in a virtual learning environment}, series = {Americas conference on information systems}, booktitle = {Americas conference on information systems}, number = {1871}, publisher = {AIS}, address = {Atlanta}, year = {2023}, abstract = {Virtual reality can have advantages for education and learning. However, it must be adequately designed so that the learner benefits from the technological possibilities. Understanding the underlying effects of the virtual learning environment and the learner's prior experience with virtual reality or prior knowledge of the content is necessary to design a proper virtual learning environment. This article presents a pre-study testing the design of a virtual learning environment for engineering vocational training courses. In the pre-study, 12 employees of two companies joined the training course in one of the two degrees of immersion (desktop VR and VR HMD). Quantitative results on learning success, cognitive load, usability, and motivation and qualitative learning process data were presented. The qualitative data assessment shows that overall, the employees were satisfied with the learning environment regardless of the level of immersion and that the participants asked for more guidance and structure accompanying the learning process. Further research is needed to test for solid group differences.}, language = {en} } @article{CombiOliboniWeskeetal.2021, author = {Combi, Carlo and Oliboni, Barbara and Weske, Mathias and Zerbato, Francesca}, title = {Seamless conceptual modeling of processes with transactional and analytical data}, series = {Data \& knowledge engineering}, volume = {134}, journal = {Data \& knowledge engineering}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-023X}, doi = {10.1016/j.datak.2021.101895}, pages = {14}, year = {2021}, abstract = {In the field of Business Process Management (BPM), modeling business processes and related data is a critical issue since process activities need to manage data stored in databases. The connection between processes and data is usually handled at the implementation level, even if modeling both processes and data at the conceptual level should help designers in improving business process models and identifying requirements for implementation. Especially in data -and decision-intensive contexts, business process activities need to access data stored both in databases and data warehouses. In this paper, we complete our approach for defining a novel conceptual view that bridges process activities and data. The proposed approach allows the designer to model the connection between business processes and database models and define the operations to perform, providing interesting insights on the overall connected perspective and hints for identifying activities that are crucial for decision support.}, language = {en} } @article{Schladebach2022, author = {Schladebach, Marcus}, title = {Satelliten-Megakonstellationen im Weltraumrecht}, series = {Kommunikation \& Recht : K \& R / Beihefter}, journal = {Kommunikation \& Recht : K \& R / Beihefter}, number = {2}, publisher = {dfv-Mediengruppe}, address = {Frankfurt am Main}, issn = {1434-6354}, pages = {26 -- 29}, year = {2022}, language = {de} } @article{KoerppenUllrichBertheau2021, author = {K{\"o}rppen, Tim and Ullrich, Andr{\´e} and Bertheau, Clementine}, title = {Durchblick statt Bauchgef{\"u}hl - Transformation zur Data-Driven Organization}, series = {Wirtschaftsinformatik \& Management}, volume = {13}, journal = {Wirtschaftsinformatik \& Management}, number = {6}, publisher = {Springer Gabler}, address = {Wiesbaden}, issn = {1867-5905}, doi = {10.1365/s35764-021-00370-7}, pages = {452 -- 459}, year = {2021}, abstract = {Um in der digitalisierten Wirtschaft mitzuspielen, m{\"u}ssen Unternehmen, Markt und insbesondere Kunden detailliert verstanden werden. Neben den „Big Playern" aus dem Silicon Valley sieht der deutsche Mittelstand, der zu großen Teilen noch auf gewachsenen IT-Infrastrukturen und Prozessen agiert, oft alt aus. Um in den n{\"a}chsten Jahren nicht g{\"a}nzlich abgeh{\"a}ngt zu werden, ist ein Umbruch notwendig. Sowohl Leistungserstellungsprozesse als auch Leistungsangebot m{\"u}ssen transparent und datenbasiert ausgerichtet werden. Nur so k{\"o}nnen Gesch{\"a}ftsvorf{\"a}lle, das Marktgeschehen sowie Handeln der Akteure integrativ bewertet und fundierte Entscheidungen getroffen werden. In diesem Beitrag wird das Konzept der Data-Driven Organization vorgestellt und aufgezeigt, wie Unternehmen den eigenen Analyticsreifegrad ermitteln und in einem iterativen Transformationsprozess steigern k{\"o}nnen.}, language = {de} } @article{UllrichTeichmannGronau2021, author = {Ullrich, Andr{\´e} and Teichmann, Malte and Gronau, Norbert}, title = {Fast trainable capabilities in software engineering-skill development in learning factories}, series = {Ji suan ji jiao yu = Computer Education / Qing hua da xue}, journal = {Ji suan ji jiao yu = Computer Education / Qing hua da xue}, number = {12}, publisher = {[Verlag nicht ermittelbar]}, address = {Bei jing shi}, issn = {1672-5913}, doi = {10.16512/j.cnki.jsjjy.2020.12.002}, pages = {2 -- 10}, year = {2021}, abstract = {The increasing demand for software engineers cannot completely be fulfilled by university education and conventional training approaches due to limited capacities. Accordingly, an alternative approach is necessary where potential software engineers are being educated in software engineering skills using new methods. We suggest micro tasks combined with theoretical lessons to overcome existing skill deficits and acquire fast trainable capabilities. This paper addresses the gap between demand and supply of software engineers by introducing an actionoriented and scenario-based didactical approach, which enables non-computer scientists to code. Therein, the learning content is provided in small tasks and embedded in learning factory scenarios. Therefore, different requirements for software engineers from the market side and from an academic viewpoint are analyzed and synthesized into an integrated, yet condensed skills catalogue. This enables the development of training and education units that focus on the most important skills demanded on the market. To achieve this objective, individual learning scenarios are developed. Of course, proper basic skills in coding cannot be learned over night but software programming is also no sorcery.}, language = {en} } @book{BarkowskyGiese2023, author = {Barkowsky, Matthias and Giese, Holger}, title = {Triple graph grammars for multi-version models}, number = {155}, isbn = {978-3-86956-556-9}, issn = {1613-5652}, doi = {10.25932/publishup-57399}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-573994}, publisher = {Universit{\"a}t Potsdam}, pages = {28 -- 28}, year = {2023}, abstract = {Like conventional software projects, projects in model-driven software engineering require adequate management of multiple versions of development artifacts, importantly allowing living with temporary inconsistencies. In the case of model-driven software engineering, employed versioning approaches also have to handle situations where different artifacts, that is, different models, are linked via automatic model transformations. In this report, we propose a technique for jointly handling the transformation of multiple versions of a source model into corresponding versions of a target model, which enables the use of a more compact representation that may afford improved execution time of both the transformation and further analysis operations. Our approach is based on the well-known formalism of triple graph grammars and a previously introduced encoding of model version histories called multi-version models. In addition to showing the correctness of our approach with respect to the standard semantics of triple graph grammars, we conduct an empirical evaluation that demonstrates the potential benefit regarding execution time performance.}, language = {en} } @article{BaberowskiLeonhardtRentschetal.2023, author = {Baberowski, David and Leonhardt, Thiemo and Rentsch, Susanne and Bergner, Nadine}, title = {Aufbau informatischer Kompetenzen im Kontext KI bei Lehramtsstudierenden des Faches Politik}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61599}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-615995}, pages = {189 -- 209}, year = {2023}, abstract = {Lehrkr{\"a}fte aller F{\"a}cher ben{\"o}tigen informatische Kompetenzen, um der wachsenden Alltagsrelevanz von Informatik und aktuell g{\"u}ltigen Lehrpl{\"a}nen gerecht zu werden. Beispielsweise verweist in Sachsen der Lehrplan f{\"u}r das Fach Gemeinschaftskunde, Rechtserziehung und Wirtschaft am Gymnasium mit dem f{\"u}r die Jahrgangsstufe 11 vorgesehenem Thema „Digitalisierung und sozialer Wandel" auf K{\"u}nstliche Intelligenz (KI) und explizit auf die Bedeutung der informatischen Bildung. Um die n{\"o}tigen informatischen Grundlagen zu vermitteln, wurde f{\"u}r Lehramtsstudierende des Faches Politik ein Workshop erarbeitet, der die Grundlagen der Funktionsweise von KI anhand von {\"u}berwachtem maschinellen Lernen in neuronalen Netzen vermittelt. Inhalt des Workshops ist es, mit Bezug auf gesellschaftliche Implikationen wie Datenschutz bei Trainingsdaten und algorithmic bias einen informierten Diskurs zu politischen Themen zu erm{\"o}glichen. Ziele des Workshops f{\"u}r Lehramtsstudierende mit dem Fach Politik sind: (1) Aufbau informatischer Kompetenzen in Bezug zum Thema KI, (2) St{\"a}rkung der Diskussionsf{\"a}higkeiten der Studierenden durch passende informatische Kompetenzen und (3) Anregung der Studierenden zum Transfer auf passende Themenstellungen im Politikunterricht. Das Evaluationskonzept umfasst eine Pre-Post-Befragung zur Zuversicht zur Vermittlungskompetenz unter Bezug auf maschinelles Lernen in neuronalen Netzen im Unterricht, sowie die Analyse einer abschließenden Diskussion. F{\"u}r die Pre-Post-Befragung konnte eine Steigerung der Zuversicht zur Vermittlungskompetenz beobachtet werden. Die Analyse der Diskussion zeigte das Bewusstsein der Alltagsrelevanz des Themas KI bei den Teilnehmenden, aber noch keine Anwendung der informatischen Inhalte des Workshops zur St{\"u}tzung der Argumente in der Diskussion.}, language = {de} } @article{ThorbrueggeDeselSchaefer2023, author = {Thorbr{\"u}gge, Carsten and Desel, J{\"o}rg and Sch{\"a}fer, Len Ole}, title = {Vorqualifikationen und Anerkennungsoptionen im Informatikstudium}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61394}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-613942}, pages = {73 -- 89}, year = {2023}, abstract = {Viele Informatikstudierende sammeln bereits vor ihrem Studium berufliche Erfahrungen im Informatikbereich, ohne dass diese inhaltlich und didaktisch im Studium ber{\"u}cksichtigt werden. Dieser Beitrag geht der Frage nach, welche Kompetenzen aus beruflichen Vorqualifikationen bei Informatikstudierenden existieren und wie diese in Bezug zu Anerkennungsoptionen gesetzt werden k{\"o}nnen. Betrachtet werden: die pauschale Anerkennung, die auf erworbenen Zertifikaten beruht; die individuelle Anerkennung, bei der individuell erworbene Kompetenzen nachgewiesen werden; die Adaption von individuellen Lernwegen, die Teilkompetenzen der Studierenden ber{\"u}cksichtigt. Es wird eine Interviewstudie vorgestellt, in der Kompetenzen f{\"u}r ein Sample von Informatikstudierenden mit Vorqualifikation als Fachinformatiker/in erhoben und eine Zuordnung zu den Anerkennungsoptionen vorgenommen wurde. F{\"u}r die pr{\"a}zisere Gestaltung von Anerkennungsprozessen und zur kritischen Reflexion der eingesetzten hochschuldidaktischen Konzepte wurde eine empirische Basis geschaffen. Die vorhandenen Konzepte richten sich traditionell an Abiturienten/ innen mit sehr geringem Informatikhintergrund und ber{\"u}cksichtigen die tats{\"a}chlich existierende Heterogenit{\"a}t der Studienanf{\"a}nger/innen nicht angemessen. Die Ergebnisse zeigen, dass die Befragten aus ihrer Vorqualifikation relevante fachliche Kompetenzen mitbringen, die mit den Anerkennungsoptionen korrespondieren und deren Weiterentwicklung dienen k{\"o}nnen. Dar{\"u}ber hinaus werden aus {\"u}berfachlichen Kompetenzen wie Selbststeuerungskompetenzen weitere Erkenntnisse zur Studiengestaltung gewonnen.}, language = {de} } @article{MarxFreundlichKlotzetal.2021, author = {Marx, Susanne and Freundlich, Heidi and Klotz, Michael and Kyl{\"a}nen, Mika and Niedoszytko, Grazyna and Swacha, Jakub and Vollerthum, Anne}, title = {Towards an Online Learning Community on Digitalization in Tourism}, series = {EMOOCs 2021}, journal = {EMOOCs 2021}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-512-5}, doi = {10.25932/publishup-51598}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-515986}, pages = {9}, year = {2021}, abstract = {Information technology and digital solutions as enablers in the tourism sector require continuous development of skills, as digital transformation is characterized by fast change, complexity and uncertainty. This research investigates how a cMOOC concept could support the tourism industry. A consortium of three universities, a tourism association, and a tourist attraction investigates online learning needs and habits of tourism industry stakeholders in the field of digitalization in a cross-border study in the Baltic Sea region. The multi-national survey (n = 244) reveals a high interest in participating in an online learning community, with two-thirds of respondents seeing opportunities to contributing to such community apart from consuming knowledge. The paper demonstrates preferred ways of learning, motivational and hampering aspects as well as types of possible contributions.}, language = {en} } @article{Weicker2023, author = {Weicker, Karsten}, title = {Peer-Review als Katalysator im Lernprozess}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61602}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-616025}, pages = {257 -- 277}, year = {2023}, abstract = {Peer-Reviews werden seit geraumer Zeit in unterschiedlichen Lehrszenarien eingesetzt. In diesem Paper wird untersucht, inwieweit das Peer- Review die Auseinandersetzung mit den Inhalten eines Grundlagenmoduls in einem pr{\"a}senzfreien Lehrszenario bef{\"o}rdern kann. Dabei scheint in den Ergebnissen die Qualit{\"a}t der selbst erstellten Reviews einer der wichtigsten Einflussfaktoren f{\"u}r den Lernerfolg zu sein, w{\"a}hrend Experten-Feedback und weitere Faktoren deutlich untergeordnet erscheinen. Die F{\"a}higkeit ausf{\"u}hrliche Peer-Reviews zu verfassen geht einher mit dem Erwerb von fachlicher Kompetenz bzw. entsprechenden fachlichen Vorkenntnissen.}, language = {de} } @article{OpelNetzerDesel2023, author = {Opel, Simone and Netzer, Cajus Marian and Desel, J{\"o}rg}, title = {Adaption von Lernwegen in adaptierten Lehrmaterialien f{\"u}r Studierende mit Berufsausbildungsabschluss}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61418}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-614188}, pages = {91 -- 114}, year = {2023}, abstract = {Obwohl immer mehr Menschen nicht direkt ein Studium aufnehmen, sondern zuvor eine berufliche Ausbildung absolvieren, werden die in der Ausbildung erworbenen Kompetenzen von den Hochschulen inhaltlich und didaktisch meist ignoriert. Ein Ansatz, diese Kompetenzen zu w{\"u}rdigen, ist die formale Anrechnung von mitgebrachten Kompetenzen als (f{\"u}r den Studienabschluss erforderliche) Leistungspunkte. Eine andere Variante ist der Einsatz von speziell f{\"u}r die Zielgruppe der Studierenden mit Vorkenntnissen adaptiertem Lehr-Lernmaterial. Um dar{\"u}ber hinaus individuelle Unterschiede zu ber{\"u}cksichtigen, erlaubt eine weitere Adaption individueller Lernpfade den Lernenden, genau die jeweils fehlenden Kompetenzen zu erwerben. In diesem Beitrag stellen wir die exemplarische Entwicklung derartigen Materials anhand des Kurses „Datenbanken" f{\"u}r die Zielgruppe der Studierenden mit einer abgeschlossenen Ausbildung zum Fachinformatiker bzw. zur Fachinformatikerin vor.}, language = {de} } @article{Weber2023, author = {Weber, Gerhard}, title = {Informatik und Barrierefreiheit}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61387}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-613874}, pages = {35 -- 50}, year = {2023}, abstract = {Barrierefreiheit kann durch Methoden der Informatik hergestellt und ausgebaut werden. Dieser eingeladene Beitrag stellt die Anforderungen von Menschen mit den umfangreichsten Benutzererfordernissen an Software vor, die z. B. eigene Schriftsysteme wie Braille und entsprechende taktile Ausgabeger{\"a}te verwenden. Assistive Technologien umfassen dabei auch Software verschiedenster Art. Es werden die wichtigsten Kompetenzen daf{\"u}r vorgestellt. Im Curriculum der Informatik k{\"o}nnen diese Kompetenzen im Rahmen von speziellen Vorlesungen und {\"U}bungen vermittelt werden oder sie werden in die jeweiligen Fachgebiete integriert. Um den Studienbetrieb ebenfalls barrierefrei zu gestalten, sind weitere Anstrengungen notwendig, die Lehrende, Verwaltung und die Hochschulleitung einbeziehen.}, language = {de} } @article{SchellSchwill2023, author = {Schell, Timon and Schwill, Andreas}, title = {„Es ist kompliziert, alles inklusive Privatleben unter einen Hut zu bekommen"}, series = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, journal = {Hochschuldidaktik Informatik HDI 2021 (Commentarii informaticae didacticae)}, number = {13}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-61388}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-613882}, pages = {53 -- 71}, year = {2023}, abstract = {Eine {\"u}bliche Erz{\"a}hlung verkn{\"u}pft lange Studienzeiten und hohe Abbrecherquoten im Informatikstudium zum einen mit der sehr gut bezahlten Nebent{\"a}tigkeit von Studierenden in der Informatikbranche, die deutlich studienzeitverl{\"a}ngernd sei; zum anderen werde wegen des hohen Bedarfs an Informatikern ein formeller Studienabschluss von den Studierenden h{\"a}ufig als entbehrlich betrachtet und eine Karriere in der Informatikbranche ohne abgeschlossenes Studium begonnen. In dieser Studie, durchgef{\"u}hrt an der Universit{\"a}t Potsdam, untersuchen wir, wie viele Informatikstudierende neben dem Studium innerhalb und außerhalb der Informatikbranche arbeiten, welche Erwartungen sie neben der Bezahlung damit verbinden und wie sich die T{\"a}tigkeit auf ihr Studium und ihre sp{\"a}tere berufliche Perspektive auswirkt. Aus aktuellem Anlass interessieren uns auch die Auswirkungen der Covid-19-Pandemie auf die Arbeitst{\"a}tigkeiten der Informatikstudierenden.}, language = {de} } @article{RoostapourNeumannNeumannetal.2022, author = {Roostapour, Vahid and Neumann, Aneta and Neumann, Frank and Friedrich, Tobias}, title = {Pareto optimization for subset selection with dynamic cost constraints}, series = {Artificial intelligence}, volume = {302}, journal = {Artificial intelligence}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0004-3702}, doi = {10.1016/j.artint.2021.103597}, pages = {17}, year = {2022}, abstract = {We consider the subset selection problem for function f with constraint bound B that changes over time. Within the area of submodular optimization, various greedy approaches are commonly used. For dynamic environments we observe that the adaptive variants of these greedy approaches are not able to maintain their approximation quality. Investigating the recently introduced POMC Pareto optimization approach, we show that this algorithm efficiently computes a phi=(alpha(f)/2)(1 - 1/e(alpha)f)-approximation, where alpha(f) is the submodularity ratio of f, for each possible constraint bound b <= B. Furthermore, we show that POMC is able to adapt its set of solutions quickly in the case that B increases. Our experimental investigations for the influence maximization in social networks show the advantage of POMC over generalized greedy algorithms. We also consider EAMC, a new evolutionary algorithm with polynomial expected time guarantee to maintain phi approximation ratio, and NSGA-II with two different population sizes as advanced multi-objective optimization algorithm, to demonstrate their challenges in optimizing the maximum coverage problem. Our empirical analysis shows that, within the same number of evaluations, POMC is able to perform as good as NSGA-II under linear constraint, while EAMC performs significantly worse than all considered algorithms in most cases.}, language = {en} } @inproceedings{KrasnovaGundlachBaumann2022, author = {Krasnova, Hanna and Gundlach, Jana and Baumann, Annika}, title = {Coming back for more}, series = {PACIS 2022 proceedings}, booktitle = {PACIS 2022 proceedings}, publisher = {AIS Electronic Library (AISeL)}, address = {[Erscheinungsort nicht ermittelbar]}, isbn = {9781958200018}, year = {2022}, abstract = {Recent spikes in social networking site (SNS) usage times have launched investigations into reasons for excessive SNS usage. Extending research on social factors (i.e., fear of missing out), this study considers the News Feed setup. More specifically, we suggest that the order of the News Feed (chronological vs. algorithmically assembled posts) affects usage behaviors. Against the background of the variable reward schedule, this study hypothesizes that the different orders exert serendipity differently. Serendipity, termed as unexpected lucky encounters with information, resembles variable rewards. Studies have evidenced a relation between variable rewards and excessive behaviors. Similarly, we hypothesize that order-induced serendipitous encounters affect SNS usage times and explore this link in a two-wave survey with an experimental setup (users using either chronological or algorithmic News Feeds). While theoretically extending explanations for increased SNS usage times by considering the News Feed order, practically the study will offer recommendations for relevant stakeholders.}, language = {en} }