@book{SmirnovWeidlichMendlingetal.2009, author = {Smirnov, Sergey and Weidlich, Matthias and Mendling, Jan and Weske, Mathias}, title = {Action patterns in business process models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-009-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-33586}, publisher = {Universit{\"a}t Potsdam}, pages = {19}, year = {2009}, abstract = {Business process management experiences a large uptake by the industry, and process models play an important role in the analysis and improvement of processes. While an increasing number of staff becomes involved in actual modeling practice, it is crucial to assure model quality and homogeneity along with providing suitable aids for creating models. In this paper we consider the problem of offering recommendations to the user during the act of modeling. Our key contribution is a concept for defining and identifying so-called action patterns - chunks of actions often appearing together in business processes. In particular, we specify action patterns and demonstrate how they can be identified from existing process model repositories using association rule mining techniques. Action patterns can then be used to suggest additional actions for a process model. Our approach is challenged by applying it to the collection of process models from the SAP Reference Model.}, language = {en} } @book{SmirnovReijersNugterenetal.2010, author = {Smirnov, Sergey and Reijers, Hajo A. and Nugteren, Thijs and Weske, Mathias}, title = {Business process model abstraction : theory and practice}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-054-0}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41782}, publisher = {Universit{\"a}t Potsdam}, pages = {17}, year = {2010}, abstract = {Business process management aims at capturing, understanding, and improving work in organizations. The central artifacts are process models, which serve different purposes. Detailed process models are used to analyze concrete working procedures, while high-level models show, for instance, handovers between departments. To provide different views on process models, business process model abstraction has emerged. While several approaches have been proposed, a number of abstraction use case that are both relevant for industry and scientifically challenging are yet to be addressed. In this paper we systematically develop, classify, and consolidate different use cases for business process model abstraction. The reported work is based on a study with BPM users in the health insurance sector and validated with a BPM consultancy company and a large BPM vendor. The identified fifteen abstraction use cases reflect the industry demand. The related work on business process model abstraction is evaluated against the use cases, which leads to a research agenda.}, language = {en} } @misc{Kunde2013, type = {Master Thesis}, author = {Kunde, Felix}, title = {CityGML in PostGIS : Portierung, Anwendung und Performanz-Analyse am Beipiel der 3D City Database von Berlin}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63656}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {Der internationale Standard CityGML ist zu einer zentralen Schnittstelle f{\"u}r die geometrische wie semantische Beschreibung von 3D-Stadtmodellen geworden. Das Institut f{\"u}r Geod{\"a}sie und Geoinformationstechnik (IGG) der Technischen Universit{\"a}t Berlin leistet mit ihren Entwicklung der 3D City Database und der Importer/Exporter Software einen entscheidenden Beitrag die Komplexit{\"a}t von CityGML-Daten in einer Geodatenbank intuitiv und effizient nutzen zu k{\"o}nnen. Die Software des IGG ist Open Source, unterst{\"u}tzte mit Oracle Spatial (ab Version 10g) aber bisher nur ein propriet{\"a}res Datenbank Management System (DBMS). Im Rahmen dieser Masterarbeit wurde eine Portierung auf die freie Datenbank-Software PostgreSQL/PostGIS vorgenommen und mit der Performanz der Oracle-Version verglichen. PostGIS gilt als eine der ausgereiftesten Geodatenbanken und wurde in diesem Jahr mit dem Release der Version 2.0 nochmals um zahlreiche Funktionen und Features (u.a. auch 3D-Unterst{\"u}tzung) erweitert. Die Ergebnisse des Vergleiches sowie die umfangreiche Gegen{\"u}berstellung aller verwendeten Konzepte (SQL, PL, Java) geben Aufschluss auf die Charakteristika beider r{\"a}umlicher DBMS und erm{\"o}glichen einen Erkenntnisgewinn {\"u}ber die Projektgrenzen hinaus.}, language = {de} } @article{Perscheid2021, author = {Perscheid, Cindy}, title = {Comprior}, series = {BMC Bioinformatics}, volume = {22}, journal = {BMC Bioinformatics}, publisher = {Springer Nature}, address = {London}, issn = {1471-2105}, doi = {10.1186/s12859-021-04308-z}, pages = {1 -- 15}, year = {2021}, abstract = {Background Reproducible benchmarking is important for assessing the effectiveness of novel feature selection approaches applied on gene expression data, especially for prior knowledge approaches that incorporate biological information from online knowledge bases. However, no full-fledged benchmarking system exists that is extensible, provides built-in feature selection approaches, and a comprehensive result assessment encompassing classification performance, robustness, and biological relevance. Moreover, the particular needs of prior knowledge feature selection approaches, i.e. uniform access to knowledge bases, are not addressed. As a consequence, prior knowledge approaches are not evaluated amongst each other, leaving open questions regarding their effectiveness. Results We present the Comprior benchmark tool, which facilitates the rapid development and effortless benchmarking of feature selection approaches, with a special focus on prior knowledge approaches. Comprior is extensible by custom approaches, offers built-in standard feature selection approaches, enables uniform access to multiple knowledge bases, and provides a customizable evaluation infrastructure to compare multiple feature selection approaches regarding their classification performance, robustness, runtime, and biological relevance. Conclusion Comprior allows reproducible benchmarking especially of prior knowledge approaches, which facilitates their applicability and for the first time enables a comprehensive assessment of their effectiveness}, language = {en} } @book{BauckmannAbedjanLeseretal.2012, author = {Bauckmann, Jana and Abedjan, Ziawasch and Leser, Ulf and M{\"u}ller, Heiko and Naumann, Felix}, title = {Covering or complete? : Discovering conditional inclusion dependencies}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-212-4}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-62089}, publisher = {Universit{\"a}t Potsdam}, pages = {34}, year = {2012}, abstract = {Data dependencies, or integrity constraints, are used to improve the quality of a database schema, to optimize queries, and to ensure consistency in a database. In the last years conditional dependencies have been introduced to analyze and improve data quality. In short, a conditional dependency is a dependency with a limited scope defined by conditions over one or more attributes. Only the matching part of the instance must adhere to the dependency. In this paper we focus on conditional inclusion dependencies (CINDs). We generalize the definition of CINDs, distinguishing covering and completeness conditions. We present a new use case for such CINDs showing their value for solving complex data quality tasks. Further, we define quality measures for conditions inspired by precision and recall. We propose efficient algorithms that identify covering and completeness conditions conforming to given quality thresholds. Our algorithms choose not only the condition values but also the condition attributes automatically. Finally, we show that our approach efficiently provides meaningful and helpful results for our use case.}, language = {en} } @book{BauckmannLeserNaumann2010, author = {Bauckmann, Jana and Leser, Ulf and Naumann, Felix}, title = {Efficient and exact computation of inclusion dependencies for data integration}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-048-9}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41396}, publisher = {Universit{\"a}t Potsdam}, pages = {36}, year = {2010}, abstract = {Data obtained from foreign data sources often come with only superficial structural information, such as relation names and attribute names. Other types of metadata that are important for effective integration and meaningful querying of such data sets are missing. In particular, relationships among attributes, such as foreign keys, are crucial metadata for understanding the structure of an unknown database. The discovery of such relationships is difficult, because in principle for each pair of attributes in the database each pair of data values must be compared. A precondition for a foreign key is an inclusion dependency (IND) between the key and the foreign key attributes. We present with Spider an algorithm that efficiently finds all INDs in a given relational database. It leverages the sorting facilities of DBMS but performs the actual comparisons outside of the database to save computation. Spider analyzes very large databases up to an order of magnitude faster than previous approaches. We also evaluate in detail the effectiveness of several heuristics to reduce the number of necessary comparisons. Furthermore, we generalize Spider to find composite INDs covering multiple attributes, and partial INDs, which are true INDs for all but a certain number of values. This last type is particularly relevant when integrating dirty data as is often the case in the life sciences domain - our driving motivation.}, language = {en} } @phdthesis{Kugel2005, author = {Kugel, Rudolf}, title = {Ein Beitrag zur Problematik der Integration virtueller Maschinen}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7195}, school = {Universit{\"a}t Potsdam}, year = {2005}, abstract = {Moderne Softwaresysteme sind komplexe Gebilde, welche h{\"a}ufig im Verbund mit anderen technischen und betriebswirtschaftlichen Systemen eingesetzt werden. F{\"u}r die Hersteller solcher Systeme stellt es oft eine große Herausforderung dar, den oft weit reichenden Anforderungen bez{\"u}glich der Anpassbarkeit solcher Systeme gerecht zu werden. Zur Erf{\"u}llung dieser Anforderungen hat es sich vielfach bew{\"a}hrt, eine virtuelle Maschine in das betreffende System zu integrieren. Die Dissertation richtet sich insbesondere an Personen, die vor der Aufgabe der Integration virtueller Maschinen in bestehende Systeme stehen und zielt darauf ab, solche f{\"u}r die Entscheidung {\"u}ber Integrationsfragen wichtigen Zusammenh{\"a}nge klar darzustellen. Typischerweise treten bei der Integration einer virtuellen Maschine in ein System eine Reihe unterschiedlicher Problemstellungen auf. Da diese Problemstellungen oft eng miteinander verzahnt sind, ist eine isolierte Betrachtung meist nicht sinnvoll. Daher werden die Problemstellungen anhand eines zentral gew{\"a}hlten, sehr umfangreichen Beispiels aus der industriellen Praxis eingef{\"u}hrt. Dieses Beispiel hat die Integration der "Java Virtual Machine" in den SAP R/3 Application Server zum Gegenstand. Im Anschluss an dieses Praxisbeispiel wird die Diskussion der Integrationsproblematik unter Bezug auf eine Auswahl weiterer, in der Literatur beschriebener Integrationsbeispiele vertieft. Das Hauptproblem bei der Behandlung der Integrationsproblematik bestand darin, dass die vorgefundenen Beschreibungen, der als Beispiel herangezogenen Systeme, nur bedingt als Basis f{\"u}r die Auseinandersetzung mit der Integrationsproblematik geeignet waren. Zur Schaffung einer verwertbaren Diskussionsgrundlage war es daher erforderlich, eine homogene, durchg{\"a}ngige Modellierung dieser Systeme vorzunehmen. Die Modellierung der Systeme erfolgte dabei unter Verwendung der "Fundamental Modeling Concepts (FMC)". Die erstellten Modelle sowie die auf Basis dieser Modelle durchgef{\"u}hrte Gegen{\"u}berstellung der unterschiedlichen Ans{\"a}tze zur L{\"O}sung typischer Integrationsprobleme bilden den Hauptbeitrag der Dissertation. Im Zusammenhang mit der Integration virtueller Maschinen in bestehende Systeme besteht h{\"a}ufig der Bedarf, zeitgleich mehrere "Programme" durch die integrierte virtuelle Maschine ausf{\"u}hren zu lassen. Angesichts der Konstruktionsmerkmale vieler heute verbreiteter virtueller Maschinen stellt die Realisierung eines "betriebsmittelschonenden Mehrprogrammbetriebs" eine große Herausforderung dar. Die Darstellung des Spektrums an Maßnahmen zur Realisierung eines "betriebsmittelschonenden Mehrprogrammbetriebs" bildet einen zweiten wesentlichen Beitrag der Dissertation.}, subject = {Virtuelle Maschine}, language = {de} } @book{PapeTrefferHirschfeldetal.2013, author = {Pape, Tobias and Treffer, Arian and Hirschfeld, Robert and Haupt, Michael}, title = {Extending a Java Virtual Machine to Dynamic Object-oriented Languages}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-266-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67438}, publisher = {Universit{\"a}t Potsdam}, pages = {163}, year = {2013}, abstract = {There are two common approaches to implement a virtual machine (VM) for a dynamic object-oriented language. On the one hand, it can be implemented in a C-like language for best performance and maximum control over the resulting executable. On the other hand, it can be implemented in a language such as Java that allows for higher-level abstractions. These abstractions, such as proper object-oriented modularization, automatic memory management, or interfaces, are missing in C-like languages but they can simplify the implementation of prevalent but complex concepts in VMs, such as garbage collectors (GCs) or just-in-time compilers (JITs). Yet, the implementation of a dynamic object-oriented language in Java eventually results in two VMs on top of each other (double stack), which impedes performance. For statically typed languages, the Maxine VM solves this problem; it is written in Java but can be executed without a Java virtual machine (JVM). However, it is currently not possible to execute dynamic object-oriented languages in Maxine. This work presents an approach to bringing object models and execution models of dynamic object-oriented languages to the Maxine VM and the application of this approach to Squeak/Smalltalk. The representation of objects in and the execution of dynamic object-oriented languages pose certain challenges to the Maxine VM that lacks certain variation points necessary to enable an effortless and straightforward implementation of dynamic object-oriented languages' execution models. The implementation of Squeak/Smalltalk in Maxine as a feasibility study is to unveil such missing variation points.}, language = {en} } @inproceedings{DeselOpelSiegerisetal.2023, author = {Desel, J{\"o}rg and Opel, Simone and Siegeris, Juliane and Draude, Claude and Weber, Gerhard and Schell, Timon and Schwill, Andreas and Thorbr{\"u}gge, Carsten and Sch{\"a}fer, Len Ole and Netzer, Cajus Marian and Gerstenberger, Dietrich and Winkelnkemper, Felix and Schulte, Carsten and B{\"o}ttcher, Axel and Thurner, Veronika and H{\"a}fner, Tanja and Ottinger, Sarah and Große-B{\"o}lting, Gregor and Scheppach, Lukas and M{\"u}hling, Andreas and Baberowski, David and Leonhardt, Thiemo and Rentsch, Susanne and Bergner, Nadine and Bonorden, Leif and Stemme, Jonas and Hoppe, Uwe and Weicker, Karsten and Bender, Esther and Barbas, Helena and Hamann, Fabian and Soll, Marcus and Sitzmann, Daniel}, title = {Hochschuldidaktik Informatik HDI 2021}, series = {Commentarii informaticae didacticae}, booktitle = {Commentarii informaticae didacticae}, number = {13}, editor = {Desel, J{\"o}rg and Opel, Simone and Siegeris, Juliane}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-548-4}, issn = {1868-0844}, doi = {10.25932/publishup-56507}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-565070}, pages = {299}, year = {2023}, abstract = {Die Fachtagungen HDI (Hochschuldidaktik Informatik) besch{\"a}ftigen sich mit den unterschiedlichen Aspekten informatischer Bildung im Hochschulbereich. Neben den allgemeinen Themen wie verschiedenen Lehr- und Lernformen, dem Einsatz von Informatiksystemen in der Hochschullehre oder Fragen der Gewinnung von geeigneten Studierenden, deren Kompetenzerwerb oder auch der Betreuung der Studierenden widmet sich die HDI immer auch einem Schwerpunktthema. Im Jahr 2021 war dies die Ber{\"u}cksichtigung von Diversit{\"a}t in der Lehre. Diskutiert wurden beispielsweise die Einbeziehung von besonderen fachlichen und {\"u}berfachlichen Kompetenzen Studierender, der Unterst{\"u}tzung von Durchl{\"a}ssigkeit aus nichtakademischen Berufen, aber auch die Gestaltung inklusiver Lehr- und Lernszenarios, Aspekte des Lebenslangen Lernens oder sich an die Diversit{\"a}t von Studierenden adaptierte oder adaptierende Lehrsysteme. Dieser Band enth{\"a}lt ausgew{\"a}hlte Beitr{\"a}ge der 9. Fachtagung 2021, die in besonderer Weise die Konferenz und die dort diskutierten Themen repr{\"a}sentieren.}, language = {de} } @inproceedings{HofukuChoNishidaetal.2013, author = {Hofuku, Yayoi and Cho, Shinya and Nishida, Tomohiro and Kanemune, Susumu and Linck, Barbara and Kim, Seungyon and Park, Seongbin and Van{\´i}ček, Jiř{\´i} and Gujberov{\´a}, Monika and Tomcs{\´a}nyi, Peter and Dagiene, Valentina and Jevsikova, Tatjana and Schulte, Carsten and Sentance, Sue and Thota, Neena and G{\"u}lbahar, Yasemin and İlkhan, Mustafa and Kilis, Selcan and Arslan, Okan and Nakano, Yoshiaki and Izutsu, Katsunobu and Lessner, Daniel and Reffay, Christophe and Miled, Mahdi and Ortiz, Pascal and F{\´e}vrier, Lo{\"i}c and Grgurina, Nataša and Weise, Martin and Bellettini, Carlo and Lonati, Violetta and Malchiodi, Dario and Monga, Mattia and Morpurgo, Anna and Torelli, Mauro and Planteu, Lukas and Standl, Bernhard and Grossmann, Wilfried and Neuwirth, Erich and Benacka, Jan and Ragonis, Noa and Hodges, Steve and Berry, Carol and Kusterer, Peter}, title = {Informatics in schools : local proceedings of the 6th International Conference ISSEP 2013 ; selected papers ; Oldenburg, Germany, February 26-March 2, 2013}, editor = {Diethelm, Ira and Arndt, Jannik and D{\"u}nnebier, Malte and Syrbe, J{\"o}rn}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-222-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-63688}, pages = {162}, year = {2013}, abstract = {The International Conference on Informatics in Schools: Situation, Evolution and Perspectives - ISSEP - is a forum for researchers and practitioners in the area of Informatics education, both in primary and secondary schools. It provides an opportunity for educators to reflect upon the goals and objectives of this subject, its curricula and various teaching/learning paradigms and topics, possible connections to everyday life and various ways of establishing Informatics Education in schools. This conference also cares about teaching/learning materials, various forms of assessment, traditional and innovative educational research designs, Informatics' contribution to the preparation of children for the 21st century, motivating competitions, projects and activities supporting informatics education in school.}, language = {en} } @phdthesis{Doerge2015, author = {D{\"o}rge, Christina}, title = {Informatische Schl{\"u}sselkompetenzen}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-262-9}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-70470}, school = {Universit{\"a}t Potsdam}, pages = {458}, year = {2015}, abstract = {Seit den 60er Jahren gibt es im deutschsprachigen Raum Diskussionen um die Begriffe Schl{\"u}sselqualifikation und (Schl{\"u}ssel-)Kompetenz, welche seit ca. 2000 auch in der Informatikdidaktik angekommen sind. Die Diskussionen der Fachdisziplinen und ihre Bedeutung f{\"u}r die Informatikdidaktik sind Gegenstand des ersten Teils dieser Dissertation. Es werden Rahmenmodelle zur Strukturierung und Einordnung von Kompetenzen entworfen, die f{\"u}r alle Fachdisziplinen nutzbar sind. Im zweiten Teil wird ein methodologischer Weg gezeigt, Schl{\"u}sselkompetenzen herzuleiten, ohne normativ vorgehen zu m{\"u}ssen. Hierzu wird das Verfahren der Qualitativen Inhaltsanalyse (QI) auf informatikdidaktische Ansätze angewendet. Die resultierenden Kompetenzen werden in weiteren Schritten verfeinert und in die zuvor entworfenen Rahmenmodelle eingeordnet. Das Ergebnis sind informatische Schl{\"u}sselkompetenzen, welche ein spezifisches Bild der Informatik zeichnen und zur Analyse bereits bestehender Curricula genutzt werden können. Zusätzlich zeigt das Verfahren einen Weg auf, wie Schl{\"u}sselkompetenzen auf nicht-normativem Wege generell hergeleitet werden können.}, language = {de} } @inproceedings{CurzonKalasSchubertetal.2015, author = {Curzon, Paul and Kalas, Ivan and Schubert, Sigrid and Schaper, Niclas and Barnes, Jan and Kennewell, Steve and Br{\"o}ker, Kathrin and Kastens, Uwe and Magenheim, Johannes and Dagiene, Valentina and Stupuriene, Gabriele and Ellis, Jason Brent and Abreu-Ellis, Carla Reis and Grillenberger, Andreas and Romeike, Ralf and Haugsbakken, Halvdan and Jones, Anthony and Lewin, Cathy and McNicol, Sarah and Nelles, Wolfgang and Neugebauer, Jonas and Ohrndorf, Laura and Schaper, Niclas and Schubert, Sigrid and Opel, Simone and Kramer, Matthias and Trommen, Michael and Pottb{\"a}cker, Florian and Ilaghef, Youssef and Passig, David and Tzuriel, David and Kedmi, Ganit Eshel and Saito, Toshinori and Webb, Mary and Weigend, Michael and Bottino, Rosa and Chioccariello, Augusto and Christensen, Rhonda and Knezek, Gerald and Gioko, Anthony Maina and Angondi, Enos Kiforo and Waga, Rosemary and Ohrndorf, Laura and Or-Bach, Rachel and Preston, Christina and Younie, Sarah and Przybylla, Mareen and Romeike, Ralf and Reynolds, Nicholas and Swainston, Andrew and Bendrups, Faye and Sysło, Maciej M. and Kwiatkowska, Anna Beata and Zieris, Holger and Gerstberger, Herbert and M{\"u}ller, Wolfgang and B{\"u}chner, Steffen and Opel, Simone and Schiller, Thomas and Wegner, Christian and Zender, Raphael and Lucke, Ulrike and Diethelm, Ira and Syrbe, J{\"o}rn and Lai, Kwok-Wing and Davis, Niki and Eickelmann, Birgit and Erstad, Ola and Fisser, Petra and Gibson, David and Khaddage, Ferial and Knezek, Gerald and Micheuz, Peter and Kloos, Carlos Delgado}, title = {KEYCIT 2014}, editor = {Brinda, Torsten and Reynolds, Nicholas and Romeike, Ralf and Schwill, Andreas}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-292-6}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-70325}, pages = {438}, year = {2015}, abstract = {In our rapidly changing world it is increasingly important not only to be an expert in a chosen field of study but also to be able to respond to developments, master new approaches to solving problems, and fulfil changing requirements in the modern world and in the job market. In response to these needs key competencies in understanding, developing and using new digital technologies are being brought into focus in school and university programmes. The IFIP TC3 conference "KEYCIT - Key Competences in Informatics and ICT (KEYCIT 2014)" was held at the University of Potsdam in Germany from July 1st to 4th, 2014 and addressed the combination of key competencies, Informatics and ICT in detail. The conference was organized into strands focusing on secondary education, university education and teacher education (organized by IFIP WGs 3.1 and 3.3) and provided a forum to present and to discuss research, case studies, positions, and national perspectives in this field.}, language = {en} } @phdthesis{Jiang2007, author = {Jiang, Chunyan}, title = {Multi-visualization and hybrid segmentation approaches within telemedicine framework}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-12829}, school = {Universit{\"a}t Potsdam}, year = {2007}, abstract = {The innovation of information techniques has changed many aspects of our life. In health care field, we can obtain, manage and communicate high-quality large volumetric image data by computer integrated devices, to support medical care. In this dissertation I propose several promising methods that could assist physicians in processing, observing and communicating the image data. They are included in my three research aspects: telemedicine integration, medical image visualization and image segmentation. And these methods are also demonstrated by the demo software that I developed. One of my research point focuses on medical information storage standard in telemedicine, for example DICOM, which is the predominant standard for the storage and communication of medical images. I propose a novel 3D image data storage method, which was lacking in current DICOM standard. I also created a mechanism to make use of the non-standard or private DICOM files. In this thesis I present several rendering techniques on medical image visualization to offer different display manners, both 2D and 3D, for example, cut through data volume in arbitrary degree, rendering the surface shell of the data, and rendering the semi-transparent volume of the data. A hybrid segmentation approach, designed for semi-automated segmentation of radiological image, such as CT, MRI, etc, is proposed in this thesis to get the organ or interested area from the image. This approach takes advantage of the region-based method and boundary-based methods. Three steps compose the hybrid approach: the first step gets coarse segmentation by fuzzy affinity and generates homogeneity operator; the second step divides the image by Voronoi Diagram and reclassifies the regions by the operator to refine segmentation from the previous step; the third step handles vague boundary by level set model. Topics for future research are mentioned in the end, including new supplement for DICOM standard for segmentation information storage, visualization of multimodal image information, and improvement of the segmentation approach to higher dimension.}, language = {en} } @phdthesis{Videla2014, author = {Videla, Santiago}, title = {Reasoning on the response of logical signaling networks with answer set programming}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-71890}, school = {Universit{\"a}t Potsdam}, year = {2014}, abstract = {Deciphering the functioning of biological networks is one of the central tasks in systems biology. In particular, signal transduction networks are crucial for the understanding of the cellular response to external and internal perturbations. Importantly, in order to cope with the complexity of these networks, mathematical and computational modeling is required. We propose a computational modeling framework in order to achieve more robust discoveries in the context of logical signaling networks. More precisely, we focus on modeling the response of logical signaling networks by means of automated reasoning using Answer Set Programming (ASP). ASP provides a declarative language for modeling various knowledge representation and reasoning problems. Moreover, available ASP solvers provide several reasoning modes for assessing the multitude of answer sets. Therefore, leveraging its rich modeling language and its highly efficient solving capacities, we use ASP to address three challenging problems in the context of logical signaling networks: learning of (Boolean) logical networks, experimental design, and identification of intervention strategies. Overall, the contribution of this thesis is three-fold. Firstly, we introduce a mathematical framework for characterizing and reasoning on the response of logical signaling networks. Secondly, we contribute to a growing list of successful applications of ASP in systems biology. Thirdly, we present a software providing a complete pipeline for automated reasoning on the response of logical signaling networks.}, language = {en} } @book{WistSchaeferVogleretal.2010, author = {Wist, Dominic and Schaefer, Mark and Vogler, Walter and Wollowski, Ralf}, title = {STG decomposition : internal communication for SI implementability}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-037-3}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40786}, publisher = {Universit{\"a}t Potsdam}, pages = {36}, year = {2010}, abstract = {STG decomposition is a promising approach to tackle the complexity problems arising in logic synthesis of speed independent circuits, a robust asynchronous (i.e. clockless) circuit type. Unfortunately, STG decomposition can result in components that in isolation have irreducible CSC conflicts. Generalising earlier work, it is shown how to resolve such conflicts by introducing internal communication between the components via structural techniques only.}, language = {en} } @article{PawassarTiberius2021, author = {Pawassar, Christian Matthias and Tiberius, Victor}, title = {Virtual reality in health care}, series = {JMIR Serious Games}, volume = {9}, journal = {JMIR Serious Games}, edition = {4}, publisher = {JMIR Publications}, address = {Toronto, Kanada}, issn = {2291-9279}, doi = {10.2196/32721}, pages = {1 -- 19}, year = {2021}, abstract = {Background: Research into the application of virtual reality technology in the health care sector has rapidly increased, resulting in a large body of research that is difficult to keep up with. Objective: We will provide an overview of the annual publication numbers in this field and the most productive and influential countries, journals, and authors, as well as the most used, most co-occurring, and most recent keywords. Methods: Based on a data set of 356 publications and 20,363 citations derived from Web of Science, we conducted a bibliometric analysis using BibExcel, HistCite, and VOSviewer. Results: The strongest growth in publications occurred in 2020, accounting for 29.49\% of all publications so far. The most productive countries are the United States, the United Kingdom, and Spain; the most influential countries are the United States, Canada, and the United Kingdom. The most productive journals are the Journal of Medical Internet Research (JMIR), JMIR Serious Games, and the Games for Health Journal; the most influential journals are Patient Education and Counselling, Medical Education, and Quality of Life Research. The most productive authors are Riva, del Piccolo, and Schwebel; the most influential authors are Finset, del Piccolo, and Eide. The most frequently occurring keywords other than "virtual" and "reality" are "training," "trial," and "patients." The most relevant research themes are communication, education, and novel treatments; the most recent research trends are fitness and exergames. Conclusions: The analysis shows that the field has left its infant state and its specialization is advancing, with a clear focus on patient usability.}, language = {en} } @article{LadleifWeske2021, author = {Ladleif, Jan and Weske, Mathias}, title = {Which event happened first?}, series = {Frontiers in blockchain}, volume = {4}, journal = {Frontiers in blockchain}, publisher = {Frontiers in Blockchain}, address = {Lausanne, Schweiz}, issn = {2624-7852}, doi = {10.3389/fbloc.2021.758169}, pages = {1 -- 16}, year = {2021}, abstract = {First come, first served: Critical choices between alternative actions are often made based on events external to an organization, and reacting promptly to their occurrence can be a major advantage over the competition. In Business Process Management (BPM), such deferred choices can be expressed in process models, and they are an important aspect of process engines. Blockchain-based process execution approaches are no exception to this, but are severely limited by the inherent properties of the platform: The isolated environment prevents direct access to external entities and data, and the non-continual runtime based entirely on atomic transactions impedes the monitoring and detection of events. In this paper we provide an in-depth examination of the semantics of deferred choice, and transfer them to environments such as the blockchain. We introduce and compare several oracle architectures able to satisfy certain requirements, and show that they can be implemented using state-of-the-art blockchain technology.}, language = {en} }