@phdthesis{Lanfermann2002, author = {Lanfermann, Gerd}, title = {Nomadic migration : a service environment for autonomic computing on the Grid}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0000773}, school = {Universit{\"a}t Potsdam}, year = {2002}, abstract = {In den vergangenen Jahren ist es zu einer dramatischen Vervielfachung der verf{\"u}gbaren Rechenzeit gekommen. Diese 'Grid Ressourcen' stehen jedoch nicht als kontinuierlicher Strom zur Verf{\"u}gung, sondern sind {\"u}ber verschiedene Maschinentypen, Plattformen und Betriebssysteme verteilt, die jeweils durch Netzwerke mit fluktuierender Bandbreite verbunden sind. Es wird f{\"u}r Wissenschaftler zunehmend schwieriger, die verf{\"u}gbaren Ressourcen f{\"u}r ihre Anwendungen zu nutzen. Wir glauben, dass intelligente, selbstbestimmende Applikationen in der Lage sein sollten, ihre Ressourcen in einer dynamischen und heterogenen Umgebung selbst zu w{\"a}hlen: Migrierende Applikationen suchen eine neue Ressource, wenn die alte aufgebraucht ist. 'Spawning'-Anwendungen lassen Algorithmen auf externen Maschinen laufen, um die Hauptanwendung zu beschleunigen. Applikationen werden neu gestartet, sobald ein Absturz endeckt wird. Alle diese Verfahren k{\"o}nnen ohne menschliche Interaktion erfolgen. Eine verteilte Rechenumgebung besitzt eine nat{\"u}rliche Unverl{\"a}sslichkeit. Jede Applikation, die mit einer solchen Umgebung interagiert, muss auf die gest{\"o}rten Komponenten reagieren k{\"o}nnen: schlechte Netzwerkverbindung, abst{\"u}rzende Maschinen, fehlerhafte Software. Wir konstruieren eine verl{\"a}ssliche Serviceinfrastruktur, indem wir der Serviceumgebung eine 'Peer-to-Peer'-Topology aufpr{\"a}gen. Diese "Grid Peer Service" Infrastruktur beinhaltet Services wie Migration und Spawning, als auch Services zum Starten von Applikationen, zur Datei{\"u}bertragung und Auswahl von Rechenressourcen. Sie benutzt existierende Gridtechnologie wo immer m{\"o}glich, um ihre Aufgabe durchzuf{\"u}hren. Ein Applikations-Information- Server arbeitet als generische Registratur f{\"u}r alle Teilnehmer in der Serviceumgebung. Die Serviceumgebung, die wir entwickelt haben, erlaubt es Applikationen z.B. eine Relokationsanfrage an einen Migrationsserver zu stellen. Der Server sucht einen neuen Computer, basierend auf den {\"u}bermittelten Ressourcen-Anforderungen. Er transferiert den Statusfile des Applikation zu der neuen Maschine und startet die Applikation neu. Obwohl das umgebende Ressourcensubstrat nicht kontinuierlich ist, k{\"o}nnen wir kontinuierliche Berechnungen auf Grids ausf{\"u}hren, indem wir die Applikation migrieren. Wir zeigen mit realistischen Beispielen, wie sich z.B. ein traditionelles Genom-Analyse-Programm leicht modifizieren l{\"a}sst, um selbstbestimmte Migrationen in dieser Serviceumgebung durchzuf{\"u}hren.}, subject = {Peer-to-Peer-Netz ; GRID computing ; Zuverl{\"a}ssigkeit ; Web Services ; Betriebsmittelverwaltung ; Migration}, language = {en} } @phdthesis{Fudickar2014, author = {Fudickar, Sebastian}, title = {Sub Ghz transceiver for indoor localisation of smartphones}, school = {Universit{\"a}t Potsdam}, pages = {IV, 167}, year = {2014}, language = {en} } @phdthesis{Schindler2016, author = {Schindler, Sven}, title = {Honeypot Architectures for IPv6 Networks}, school = {Universit{\"a}t Potsdam}, pages = {164}, year = {2016}, language = {en} } @phdthesis{Jung2015, author = {Jung, J{\"o}rg}, title = {Efficient credit based server load balancing}, school = {Universit{\"a}t Potsdam}, pages = {353}, year = {2015}, language = {en} } @inproceedings{OPUS4-3955, title = {Proceedings of the 23rd Workshop on (Constraint) Logic Programming 2009}, editor = {Geske, Ulrich and Wolf, Armin}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-026-7}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-37977}, pages = {187}, year = {2010}, abstract = {The workshops on (constraint) logic programming (WLP) are the annual meeting of the Society of Logic Programming (GLP e.V.) and bring together researchers interested in logic programming, constraint programming, and related areas like databases, artificial intelligence and operations research. The 23rd WLP was held in Potsdam at September 15 - 16, 2009. The topics of the presentations of WLP2009 were grouped into the major areas: Databases, Answer Set Programming, Theory and Practice of Logic Programming as well as Constraints and Constraint Handling Rules.}, language = {en} } @inproceedings{GeskeGoltz2010, author = {Geske, Ulrich and Goltz, Hans-Joachim}, title = {Efficiency of difference-list programming}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-41563}, year = {2010}, abstract = {The difference-list technique is described in literature as effective method for extending lists to the right without using calls of append/3. There exist some proposals for automatic transformation of list programs into differencelist programs. However, we are interested in construction of difference-list programs by the programmer, avoiding the need of a transformation step. In [GG09] it was demonstrated, how left-recursive procedures with a dangling call of append/3 can be transformed into right-recursion using the unfolding technique. For simplification of writing difference-list programs using a new cons/2 procedure was introduced. In the present paper, we investigate how efficieny is influenced using cons/2. We measure the efficiency of procedures using accumulator technique, cons/2, DCG's, and difference lists and compute the resulting speedup in respect to the simple procedure definition using append/3. Four Prolog systems were investigated and we found different behaviour concerning the speedup by difference lists. A result of our investigations is, that an often advice given in the literature for avoiding calls append/3 could not be confirmed in this strong formulation.}, language = {en} } @article{LagriffoulAndres2016, author = {Lagriffoul, Fabien and Andres, Benjamin}, title = {Combining task and motion planning}, series = {The international journal of robotics research}, volume = {35}, journal = {The international journal of robotics research}, number = {8}, publisher = {Sage Science Press}, address = {Thousand Oaks}, issn = {1741-3176}, doi = {10.1177/0278364915619022}, pages = {890 -- 927}, year = {2016}, abstract = {Solving problems combining task and motion planning requires searching across a symbolic search space and a geometric search space. Because of the semantic gap between symbolic and geometric representations, symbolic sequences of actions are not guaranteed to be geometrically feasible. This compels us to search in the combined search space, in which frequent backtracks between symbolic and geometric levels make the search inefficient.We address this problem by guiding symbolic search with rich information extracted from the geometric level through culprit detection mechanisms.}, language = {en} } @phdthesis{Smirnov2011, author = {Smirnov, Sergey}, title = {Business process model abstraction}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-60258}, school = {Universit{\"a}t Potsdam}, year = {2011}, abstract = {Business process models are used within a range of organizational initiatives, where every stakeholder has a unique perspective on a process and demands the respective model. As a consequence, multiple process models capturing the very same business process coexist. Keeping such models in sync is a challenge within an ever changing business environment: once a process is changed, all its models have to be updated. Due to a large number of models and their complex relations, model maintenance becomes error-prone and expensive. Against this background, business process model abstraction emerged as an operation reducing the number of stored process models and facilitating model management. Business process model abstraction is an operation preserving essential process properties and leaving out insignificant details in order to retain information relevant for a particular purpose. Process model abstraction has been addressed by several researchers. The focus of their studies has been on particular use cases and model transformations supporting these use cases. This thesis systematically approaches the problem of business process model abstraction shaping the outcome into a framework. We investigate the current industry demand in abstraction summarizing it in a catalog of business process model abstraction use cases. The thesis focuses on one prominent use case where the user demands a model with coarse-grained activities and overall process ordering constraints. We develop model transformations that support this use case starting with the transformations based on process model structure analysis. Further, abstraction methods considering the semantics of process model elements are investigated. First, we suggest how semantically related activities can be discovered in process models-a barely researched challenge. The thesis validates the designed abstraction methods against sets of industrial process models and discusses the method implementation aspects. Second, we develop a novel model transformation, which combined with the related activity discovery allows flexible non-hierarchical abstraction. In this way this thesis advocates novel model transformations that facilitate business process model management and provides the foundations for innovative tool support.}, language = {en} } @phdthesis{Mahr2012, author = {Mahr, Philipp}, title = {Resource efficient communication in network-based reconfigurable on-chip systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-59914}, school = {Universit{\"a}t Potsdam}, year = {2012}, abstract = {The constantly growing capacity of reconfigurable devices allows simultaneous execution of complex applications on those devices. The mere diversity of applications deems it impossible to design an interconnection network matching the requirements of every possible application perfectly, leading to suboptimal performance in many cases. However, the architecture of the interconnection network is not the only aspect affecting performance of communication. The resource manager places applications on the device and therefore influences latency between communicating partners and overall network load. Communication protocols affect performance by introducing data and processing overhead putting higher load on the network and increasing resource demand. Approaching communication holistically not only considers the architecture of the interconnect, but communication-aware resource management, communication protocols and resource usage just as well. Incorporation of different parts of a reconfigurable system during design- and runtime and optimizing them with respect to communication demand results in more resource efficient communication. Extensive evaluation shows enhanced performance and flexibility, if communication on reconfigurable devices is regarded in a holistic fashion.}, language = {en} } @phdthesis{Albrecht2013, author = {Albrecht, Alexander}, title = {Understanding and managing extract-transform-load systems}, pages = {107}, year = {2013}, language = {en} } @article{LewinMcNicol2015, author = {Lewin, Cathy and McNicol, Sarah}, title = {Supporting the Development of 21st Century Skills through ICT}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82672}, pages = {181 -- 198}, year = {2015}, abstract = {The growing impact of globalisation and the development of a 'knowledge society' have led many to argue that 21st century skills are essential for life in twenty-first century society and that ICT is central to their development. This paper describes how 21st century skills, in particular digital literacy, critical thinking, creativity, communication and collaboration skills, have been conceptualised and embedded in the resources developed for teachers in iTEC, a four-year, European project. The effectiveness of this approach is considered in light of the data collected through the evaluation of the pilots, which considers both the potential benefits of using technology to support the development of 21st century skills, but also the challenges of doing so. Finally, the paper discusses the learning support systems required in order to transform pedagogies and embed 21st century skills. It is argued that support is required in standards and assessment; curriculum and instruction; professional development; and learning environments.}, language = {en} } @article{MagenheimNellesNeugebaueretal.2015, author = {Magenheim, Johannes and Nelles, Wolfgang and Neugebauer, Jonas and Ohrndorf, Laura and Schaper, Niclas and Schubert, Sigrid}, title = {Expert Rating of Competence Levels in Upper Secondary Computer Science Education}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82683}, pages = {199 -- 216}, year = {2015}, abstract = {In the project MoKoM, which is funded by the German Research Foundation (DFG) from 2008 to 2012, a test instrument measuring students' competences in computer science was developed. This paper presents the results of an expert rating of the levels of students' competences done for the items of the instrument. At first we will describe the difficulty-relevant features that were used for the evaluation. These were deduced from computer science, psychological and didactical findings and resources. Potentials and desiderata of this research method are discussed further on. Finally we will present our conclusions on the results and give an outlook on further steps.}, language = {en} } @article{OpelKramerTrommenetal.2015, author = {Opel, Simone and Kramer, Matthias and Trommen, Michael and Pottb{\"a}cker, Florian and Ilaghef, Youssef}, title = {BugHunt}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82693}, pages = {217 -- 233}, year = {2015}, abstract = {Competencies related to operating systems and computer security are usually taught systematically. In this paper we present a different approach, in which students have to remove virus-like behaviour on their respective computers, which has been induced by software developed for this purpose. They have to develop appropriate problem-solving strategies and thereby explore essential elements of the operating system. The approach was implemented exemplarily in two computer science courses at a regional general upper secondary school and showed great motivation and interest in the participating students.}, language = {en} } @article{PassigTzurielKedmi2015, author = {Passig, David and Tzuriel, David and Kedmi, Ganit Eshel}, title = {Improving children's Cognitive Modifiability through Mediated Learning and Dynamic Assessment within 3D Immersive Virtual Reality Environment}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82705}, pages = {235 -- 252}, year = {2015}, abstract = {The objectives of this study were to examine (a) the effect of dynamic assessment (DA) in a 3D Immersive Virtual Reality (IVR) environment as compared with computerized 2D and noncomputerized (NC) situations on cognitive modifiability, and (b) the transfer effects of these conditions on more difficult problem solving administered two weeks later in a non-computerized environment. A sample of 117 children aged 6:6-9:0 years were randomly assigned into three experimental groups of DA conditions: 3D, 2D, and NC, and one control group (C). All groups received the pre- and post-teaching Analogies subtest of the Cognitive Modifiability Battery (CMB-AN). The experimental groups received a teaching phase in conditions similar to the pre-and post-teaching phases. The findings showed that cognitive modifiability, in a 3D IVR, was distinctively higher than in the two other experimental groups (2D computer group and NC group). It was also found that the 3D group showed significantly higher performance in transfer problems than the 2D and NC groups.}, language = {en} } @article{Saito2015, author = {Saito, Toshinori}, title = {The Key Competencies in Informatics and ICT viewed from Nussbaum's Ten Central Capabilities}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82718}, pages = {253 -- 266}, year = {2015}, abstract = {This article shows a discussion about the key competencies in informatics and ICT viewed from a philosophical foundation presented by Martha Nussbaum, which is known as 'ten central capabilities'. Firstly, the outline of 'The Capability Approach', which has been presented by Amartya Sen and Nussbaum as a theoretical framework of assessing the state of social welfare, will be explained. Secondly, the body of Nussbaum's ten central capabilities and the reason for being applied as the basis of discussion will be shown. Thirdly, the relationship between the concept of 'capability' and 'competency' is to be discussed. After that, the author's assumption of the key competencies in informatics and ICT led from the examination of Nussbaum's ten capabilities will be presented.}, language = {en} } @article{Webb2015, author = {Webb, Mary}, title = {Considerations for the Design of Computing Curricula}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82723}, pages = {267 -- 283}, year = {2015}, abstract = {This paper originated from discussions about the need for important changes in the curriculum for Computing including two focus group meetings at IFIP conferences over the last two years. The paper examines how recent developments in curriculum, together with insights from curriculum thinking in other subject areas, especially mathematics and science, can inform curriculum design for Computing. The analysis presented in the paper provides insights into the complexity of curriculum design as well as identifying important constraints and considerations for the ongoing development of a vision and framework for a Computing curriculum.}, language = {en} } @article{Curzon2015, author = {Curzon, Paul}, title = {Unplugged Computational Thinking for Fun}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82575}, pages = {15 -- 27}, year = {2015}, abstract = {Computational thinking is a fundamental skill set that is learned by studying Informatics and ICT. We argue that its core ideas can be introduced in an inspiring and integrated way to both teachers and students using fun and contextually rich cs4fn 'Computer Science for Fun' stories combined with 'unplugged' activities including games and magic tricks. We also argue that understanding people is an important part of computational thinking. Computational thinking can be fun for everyone when taught in kinaesthetic ways away from technology.}, language = {en} } @article{Kalas2015, author = {Kalas, Ivan}, title = {Programming at Pre-primary and Primary Levels}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82587}, pages = {29 -- 31}, year = {2015}, language = {en} } @article{MagenheimSchubertSchapert2015, author = {Magenheim, Johannes and Schubert, Sigrid and Schapert, Niclas}, title = {Modelling and Measurement of Competencies in Computer Science Education}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82592}, pages = {33 -- 57}, year = {2015}, abstract = {As a result of the Bologna reform of educational systems in Europe the outcome orientation of learning processes, competence-oriented descriptions of the curricula and competence-oriented assessment procedures became standard also in Computer Science Education (CSE). The following keynote addresses important issues of shaping a CSE competence model especially in the area of informatics system comprehension and object-oriented modelling. Objectives and research methodology of the project MoKoM (Modelling and Measurement of Competences in CSE) are explained. Firstly, the CSE competence model was derived based on theoretical concepts and then secondly the model was empirically examined and refined using expert interviews. Furthermore, the paper depicts the development and examination of a competence measurement instrument, which was derived from the competence model. Therefore, the instrument was applied to a large sample of students at the gymnasium's upper class level. Subsequently, efforts to develop a competence level model, based on the retrieved empirical results and on expert ratings are presented. Finally, further demands on research on competence modelling in CSE will be outlined.}, language = {en} } @article{BarnesKennewell2015, author = {Barnes, Jan and Kennewell, Steve}, title = {Teacher Perceptions of Key Competencies in ICT}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82604}, pages = {61 -- 75}, year = {2015}, abstract = {Regardless of what is intended by government curriculum specifications and advised by educational experts, the competencies taught and learned in and out of classrooms can vary considerably. In this paper, we discuss in particular how we can investigate the perceptions that individual teachers have of competencies in ICT, and how these and other factors may influence students' learning. We report case study research which identifies contradictions within the teaching of ICT competencies as an activity system, highlighting issues concerning the object of the curriculum, the roles of the participants and the school cultures. In a particular case, contradictions in the learning objectives between higher order skills and the use of application tools have been resolved by a change in the teacher's perceptions which have not led to changes in other aspects of the activity system. We look forward to further investigation of the effects of these contradictions in other case studies and on forthcoming curriculum change.}, language = {en} } @article{BroekerKastensMagenheim2015, author = {Br{\"o}ker, Kathrin and Kastens, Uwe and Magenheim, Johannes}, title = {Competences of Undergraduate Computer Science Students}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82613}, pages = {77 -- 96}, year = {2015}, abstract = {The paper presents two approaches to the development of a Computer Science Competence Model for the needs of curriculum development and evaluation in Higher Education. A normativetheoretical approach is based on the AKT and ACM/IEEE curriculum and will be used within the recommendations of the German Informatics Society (GI) for the design of CS curricula. An empirically oriented approach refines the categories of the first one with regard to specific subject areas by conducting content analysis on CS curricula of important universities from several countries. The refined model will be used for the needs of students' e-assessment and subsequent affirmative action of the CS departments.}, language = {en} } @article{DagieneStupuriene2015, author = {Dagiene, Valentina and Stupuriene, Gabriele}, title = {Informatics Education based on Solving Attractive Tasks through a Contest}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82626}, pages = {97 -- 115}, year = {2015}, abstract = {The paper discusses the issue of supporting informatics (computer science) education through competitions for lower and upper secondary school students (8-19 years old). Competitions play an important role for learners as a source of inspiration, innovation, and attraction. Running contests in informatics for school students for many years, we have noticed that the students consider the contest experience very engaging and exciting as well as a learning experience. A contest is an excellent instrument to involve students in problem solving activities. An overview of infrastructure and development of an informatics contest from international level to the national one (the Bebras contest on informatics and computer fluency, originated in Lithuania) is presented. The performance of Bebras contests in 23 countries during the last 10 years showed an unexpected and unusually high acceptance by school students and teachers. Many thousands of students participated and got a valuable input in addition to their regular informatics lectures at school. In the paper, the main attention is paid to the developed tasks and analysis of students' task solving results in Lithuania.}, language = {en} } @article{EllisAbreuEllis2015, author = {Ellis, Jason Brent and Abreu-Ellis, Carla Reis}, title = {Student Perspectives of Social Networking use in Higher Education}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82632}, pages = {117 -- 131}, year = {2015}, abstract = {Social networks are currently at the forefront of tools that lend to Personal Learning Environments (PLEs). This study aimed to observe how students perceived PLEs, what they believed were the integral components of social presence when using Facebook as part of a PLE, and to describe student's preferences for types of interactions when using Facebook as part of their PLE. This study used mixed methods to analyze the perceptions of graduate and undergraduate students on the use of social networks, more specifically Facebook as a learning tool. Fifty surveys were returned representing a 65 \% response rate. Survey questions included both closed and open-ended questions. Findings suggested that even though students rated themselves relatively well in having requisite technology skills, and 94 \% of students used Facebook primarily for social use, they were hesitant to migrate these skills to academic use because of concerns of privacy, believing that other platforms could fulfil the same purpose, and by not seeing the validity to use Facebook in establishing social presence. What lies at odds with these beliefs is that when asked to identify strategies in Facebook that enabled social presence to occur in academic work, the majority of students identified strategies in five categories that lead to social presence establishment on Facebook during their coursework.}, language = {en} } @article{GrillenbergerRomeike2015, author = {Grillenberger, Andreas and Romeike, Ralf}, title = {Teaching Data Management}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82648}, pages = {133 -- 150}, year = {2015}, abstract = {Data management is a central topic in computer science as well as in computer science education. Within the last years, this topic is changing tremendously, as its impact on daily life becomes increasingly visible. Nowadays, everyone not only needs to manage data of various kinds, but also continuously generates large amounts of data. In addition, Big Data and data analysis are intensively discussed in public dialogue because of their influences on society. For the understanding of such discussions and for being able to participate in them, fundamental knowledge on data management is necessary. Especially, being aware of the threats accompanying the ability to analyze large amounts of data in nearly real-time becomes increasingly important. This raises the question, which key competencies are necessary for daily dealings with data and data management. In this paper, we will first point out the importance of data management and of Big Data in daily life. On this basis, we will analyze which are the key competencies everyone needs concerning data management to be able to handle data in a proper way in daily life. Afterwards, we will discuss the impact of these changes in data management on computer science education and in particular database education.}, language = {en} } @article{Haugsbakken2015, author = {Haugsbakken, Halvdan}, title = {The Student Learning Ecology}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82659}, pages = {151 -- 169}, year = {2015}, abstract = {Educational research on social media has showed that students use it for socialisation, personal communication, and informal learning. Recent studies have argued that students to some degree use social media to carry out formal schoolwork. This article gives an explorative account on how a small sample of Norwegian high school students use social media to self-organise formal schoolwork. This user pattern can be called a "student learning ecology", which is a user perspective on how participating students gain access to learning resources.}, language = {en} } @article{Jones2015, author = {Jones, Anthony}, title = {ICT Competencies for School Students}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82663}, pages = {171 -- 179}, year = {2015}, abstract = {This paper discusses results from a small-scale research study, together with some recently published research into student perceptions of ICT for learning in schools, to consider relevant skills that do not appear to currently being taught. The paper concludes by raising three issues relating to learning with and through ICT that need to be addressed in school curricula and classroom teaching.}, language = {en} } @article{Weigend2015, author = {Weigend, Michael}, title = {How Things Work}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82814}, pages = {285 -- 298}, year = {2015}, abstract = {Recognizing and defining functionality is a key competence adopted in all kinds of programming projects. This study investigates how far students without specific informatics training are able to identify and verbalize functions and parameters. It presents observations from classroom activities on functional modeling in high school chemistry lessons with altogether 154 students. Finally it discusses the potential of functional modelling to improve the comprehension of scientific content.}, language = {en} } @article{BottinoChioccariello2015, author = {Bottino, Rosa and Chioccariello, Augusto}, title = {Computational Thinking}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82820}, pages = {301 -- 309}, year = {2015}, abstract = {Digital technology has radically changed the way people work in industry, finance, services, media and commerce. Informatics has contributed to the scientific and technological development of our society in general and to the digital revolution in particular. Computational thinking is the term indicating the key ideas of this discipline that might be included in the key competencies underlying the curriculum of compulsory education. The educational potential of informatics has a history dating back to the sixties. In this article, we briefly revisit this history looking for lessons learned. In particular, we focus on experiences of teaching and learning programming. However, computational thinking is more than coding. It is a way of thinking and practicing interactive dynamic modeling with computers. We advocate that learners can practice computational thinking in playful contexts where they can develop personal projects, for example building videogames and/or robots, share and discuss their construction with others. In our view, this approach allows an integration of computational thinking in the K-12 curriculum across disciplines.}, language = {en} } @article{ChristensenKnezek2015, author = {Christensen, Rhonda and Knezek, Gerald}, title = {The Technology Proficiency Self-Assessment Questionnaire (TPSA)}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82838}, pages = {311 -- 318}, year = {2015}, abstract = {The Technology Proficiency Self-Assessment (TPSA) questionnaire has been used for 15 years in the USA and other nations as a self-efficacy measure for proficiencies fundamental to effective technology integration in the classroom learning environment. Internal consistency reliabilities for each of the five-item scales have typically ranged from .73 to .88 for preservice or inservice technology-using teachers. Due to changing technologies used in education, researchers sought to renovate partially obsolete items and extend self-efficacy assessment to new areas, such as social media and mobile learning. Analysis of 2014 data gathered on a new, 34 item version of the TPSA indicates that the four established areas of email, World Wide Web (WWW), integrated applications, and teaching with technology continue to form consistent scales with reliabilities ranging from .81 to .93, while the 14 new items gathered to represent emerging technologies and media separate into two scales, each with internal consistency reliabilities greater than .9. The renovated TPSA is deemed to be worthy of continued use in the teaching with technology context.}, language = {en} } @article{MainaAngondiWaga2015, author = {Maina, Anthony Gioko and Angondi, Enos Kiforo and Waga, Rosemary}, title = {How does the Implementation of a Literacy Learning Tool Kit influence Literacy Skill Acquisition?}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82856}, pages = {319 -- 326}, year = {2015}, abstract = {This study aimed at following how teachers transfer skills into results while using ABRA literacy software. This was done in the second part of the pilot study whose aim was to provide equity to control group teachers and students by exposing them to the ABRACADABRA treatment after the end of phase 1. This opportunity was used to follow the phase 1 teachers to see how the skills learned were being transformed into results. A standard three-day initial training and planning session on how to use ABRA to teach literacy was held at the beginning of each phase for ABRA teachers (phase 1 experimental and phase 2 delayed ABRA). Teachers were provided with teaching materials including a tentative ABRA curriculum developed to align with the Kenyan English Language requirements for year 1 and 3 students. Results showed that although there was no significant difference between the groups in vocabulary-related subscales which include word reading and meaning as well as sentence comprehension, students in ABRACADABRA classes improved their scores at a significantly higher rate than students in control classes in comprehension related scores. An average student in the ABRACADABRA group improved by 12 and 16 percentile points respectively compared to their counterparts in the control group.}, language = {en} } @article{Ohrndorf2015, author = {Ohrndorf, Laura}, title = {Assignments in Computer Science Education}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82868}, pages = {327 -- 333}, year = {2015}, abstract = {In this paper we describe the recent state of our research project concerning computer science teachers' knowledge on students' cognition. We did a comprehensive analysis of textbooks, curricula and other resources, which give teachers guidance to formulate assignments. In comparison to other subjects there are only a few concepts and strategies taught to prospective computer science teachers in university. We summarize them and given an overview on our empirical approach to measure this knowledge.}, language = {en} } @article{OrBach2015, author = {Or-Bach, Rachel}, title = {Programming for Non-Programmers}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82875}, pages = {335 -- 342}, year = {2015}, abstract = {The study reported in this paper involved the employment of specific in-class exercises using a Personal Response System (PRS). These exercises were designed with two goals: to enhance students' capabilities of tracing a given code and of explaining a given code in natural language with some abstraction. The paper presents evidence from the actual use of the PRS along with students' subjective impressions regarding both the use of the PRS and the special exercises. The conclusions from the findings are followed with a short discussion on benefits of PRS-based mental processing exercises for learning programming and beyond.}, language = {en} } @article{PrestonYounie2015, author = {Preston, Christina and Younie, Sarah}, title = {Mentoring in a Digital World}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82895}, pages = {343 -- 350}, year = {2015}, abstract = {This paper focuses on the results of the evaluation of the first pilot of an e-mentoring unit designed by the Hands-On ICT consortium, funded by the EU LLL programme. The overall aim of this two-year activity is to investigate the value for professional learning of Massive Online Open Courses (MOOCs) and Community Online Open Courses (COOCs) in the context of a 'community of practice'. Three units in the first pilot covered aspects of using digital technologies to develop creative thinking skills. The findings in this paper relate to the fourth unit about e-mentoring, a skill that was important to delivering the course content in the other three units. Findings about the e-mentoring unit included: the students' request for detailed profiles so that participants can get to know each other; and, the need to reconcile the different interpretations of e-mentoring held by the participants when the course begins. The evaluators concluded that the major issues were that: not all professional learners would self-organise and network; and few would wish to mentor their colleagues voluntarily. Therefore, the e-mentoring issues will need careful consideration in pilots two and three to identify how e-mentoring will be organised.}, language = {en} } @article{PrzybyllaRomeike2015, author = {Przybylla, Mareen and Romeike, Ralf}, title = {Key Competences with Physical Computing}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82904}, pages = {351 -- 361}, year = {2015}, abstract = {Physical computing covers the design and realization of interactive objects and installations and allows students to develop concrete, tangible products of the real world that arise from the learners' imagination. This way, constructionist learning is raised to a level that enables students to gain haptic experience and thereby concretizes the virtual. In this paper the defining characteristics of physical computing are described. Key competences to be gained with physical computing will be identified.}, language = {en} } @article{ReynoldsSwainstonBendrups2015, author = {Reynolds, Nicholas and Swainston, Andrew and Bendrups, Faye}, title = {Music Technology and Computational Thinking}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82913}, pages = {363 -- 370}, year = {2015}, abstract = {A project involving the composition of a number of pieces of music by public participants revealed levels of engagement with and mastery of complex music technologies by a number of secondary student volunteers. This paper reports briefly on some initial findings of that project and seeks to illuminate an understanding of computational thinking across the curriculum.}, language = {en} } @article{SysłoKwiatkowska2015, author = {Sysło, Maciej M. and Kwiatkowska, Anna Beata}, title = {Think logarithmically!}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82923}, pages = {371 -- 380}, year = {2015}, abstract = {We discuss here a number of algorithmic topics which we use in our teaching and in learning of mathematics and informatics to illustrate and document the power of logarithm in designing very efficient algorithms and computations - logarithmic thinking is one of the most important key competencies for solving real world practical problems. We demonstrate also how to introduce logarithm independently of mathematical formalism using a conceptual model for reducing a problem size by at least half. It is quite surprising that the idea, which leads to logarithm, is present in Euclid's algorithm described almost 2000 years before John Napier invented logarithm.}, language = {en} } @article{ZierisGerstbergerMueller2015, author = {Zieris, Holger and Gerstberger, Herbert and M{\"u}ller, Wolfgang}, title = {Using Arduino-Based Experiments to Integrate Computer Science Education and Natural Science}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82938}, pages = {381 -- 389}, year = {2015}, abstract = {Current curricular trends require teachers in Baden- Wuerttemberg (Germany) to integrate Computer Science (CS) into traditional subjects, such as Physical Science. However, concrete guidelines are missing. To fill this gap, we outline an approach where a microcontroller is used to perform and evaluate measurements in the Physical Science classroom. Using the open-source Arduino platform, we expect students to acquire and develop both CS and Physical Science competencies by using a self-programmed microcontroller. In addition to this combined development of competencies in Physical Science and CS, the subject matter will be embedded in suitable contexts and learning environments, such as weather and climate.}, language = {en} } @article{Buechner2015, author = {B{\"u}chner, Steffen}, title = {Empirical and Normative Research on Fundamental Ideas of Embedded System Development}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82949}, pages = {393 -- 396}, year = {2015}, language = {en} } @article{Opel2015, author = {Opel, Simone}, title = {On the Way to a "General Model of Contextualised Computer Science Education"}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82953}, pages = {397 -- 400}, year = {2015}, language = {en} } @article{Schiller2015, author = {Schiller, Thomas}, title = {Teaching Information Security (as Part of Key Competencies)}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82960}, pages = {401 -- 404}, year = {2015}, abstract = {The poster and abstract describe the importance of teaching information security in school. After a short description of information security and important aspects, I will show, how information security fits into different guidelines or models for computer science educations and that it is therefore on of the key competencies. Afterwards I will present you a rough insight of teaching information security in Austria.}, language = {en} } @article{WegnerZenderLucke2015, author = {Wegner, Christian and Zender, Raphael and Lucke, Ulrike}, title = {ProtoSense}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82970}, pages = {405 -- 407}, year = {2015}, language = {en} } @article{DiethelmSyrbe2015, author = {Diethelm, Ira and Syrbe, J{\"o}rn}, title = {Let's talk about CS!}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82983}, pages = {411 -- 414}, year = {2015}, abstract = {To communicate about a science is the most important key competence in education for any science. Without communication we cannot teach, so teachers should reflect about the language they use in class properly. But the language students and teachers use to communicate about their CS courses is very heterogeneous, inconsistent and deeply influenced by tool names. There is a big lack of research and discussion in CS education regarding the terminology and the role of concepts and tools in our science. We don't have a consistent set of terminology that we agree on to be helpful for learning our science. This makes it nearly impossible to do research on CS competencies as long as we have not agreed on the names we use to describe these. This workshop intends to provide room to fill with discussion and first ideas for future research in this field.}, language = {en} } @article{LaiDavisEickelmannetal.2015, author = {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 Webb, Mary}, title = {Tackling Educational Challenges in a Digitally Networked World}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-82997}, pages = {415 -- 423}, year = {2015}, language = {en} } @article{Micheuz2015, author = {Micheuz, Peter}, title = {Discussing Educational Standards for Digital Competence and/or Informatics Education at Lower Secondary Level}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83008}, pages = {425 -- 431}, year = {2015}, abstract = {Participants of this workshop will be confronted exemplarily with a considerable inconsistency of global Informatics education at lower secondary level. More importantly, they are invited to contribute actively on this issue in form of short case studies of their countries. Until now, very few countries have been successful in implementing Informatics or Computing at primary and lower secondary level. The spectrum from digital literacy to informatics, particularly as a discipline in its own right, has not really achieved a breakthrough and seems to be underrepresented for these age groups. The goal of this workshop is not only to discuss the anamnesis and diagnosis of this fragmented field, but also to discuss and suggest viable forms of therapy in form of setting educational standards. Making visible good practices in some countries and comparing successful approaches are rewarding tasks for this workshop. Discussing and defining common educational standards on a transcontinental level for the age group of 14 to 15 years old students in a readable, assessable and acceptable form should keep the participants of this workshop active beyond the limited time at the workshop.}, language = {en} } @article{DelgadoKloos2015, author = {Delgado Kloos, Carlos}, title = {What about the Competencies of Educators in the New Era of Digital Education?}, series = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, journal = {KEYCIT 2014 - Key Competencies in Informatics and ICT}, number = {7}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-83015}, pages = {435 -- 438}, year = {2015}, abstract = {A lot has been published about the competencies needed by students in the 21st century (Ravenscroft et al., 2012). However, equally important are the competencies needed by educators in the new era of digital education. We review the key competencies for educators in light of the new methods of teaching and learning proposed by Massive Open Online Courses (MOOCs) and their on-campus counterparts, Small Private Online Courses (SPOCs).}, language = {en} } @phdthesis{Tiwari2019, author = {Tiwari, Abhishek}, title = {Enhancing Users' Privacy: Static Resolution of the Dynamic Properties of Android}, school = {Universit{\"a}t Potsdam}, pages = {xiii, 111}, year = {2019}, abstract = {The usage of mobile devices is rapidly growing with Android being the most prevalent mobile operating system. Thanks to the vast variety of mobile applications, users are preferring smartphones over desktops for day to day tasks like Internet surfing. Consequently, smartphones store a plenitude of sensitive data. This data together with the high values of smartphones make them an attractive target for device/data theft (thieves/malicious applications). Unfortunately, state-of-the-art anti-theft solutions do not work if they do not have an active network connection, e.g., if the SIM card was removed from the device. In the majority of these cases, device owners permanently lose their smartphone together with their personal data, which is even worse. Apart from that malevolent applications perform malicious activities to steal sensitive information from smartphones. Recent research considered static program analysis to detect dangerous data leaks. These analyses work well for data leaks due to inter-component communication, but suffer from shortcomings for inter-app communication with respect to precision, soundness, and scalability. This thesis focuses on enhancing users' privacy on Android against physical device loss/theft and (un)intentional data leaks. It presents three novel frameworks: (1) ThiefTrap, an anti-theft framework for Android, (2) IIFA, a modular inter-app intent information flow analysis of Android applications, and (3) PIAnalyzer, a precise approach for PendingIntent vulnerability analysis. ThiefTrap is based on a novel concept of an anti-theft honeypot account that protects the owner's data while preventing a thief from resetting the device. We implemented the proposed scheme and evaluated it through an empirical user study with 35 participants. In this study, the owner's data could be protected, recovered, and anti-theft functionality could be performed unnoticed from the thief in all cases. IIFA proposes a novel approach for Android's inter-component/inter-app communication (ICC/IAC) analysis. Our main contribution is the first fully automatic, sound, and precise ICC/IAC information flow analysis that is scalable for realistic apps due to modularity, avoiding combinatorial explosion: Our approach determines communicating apps using short summaries rather than inlining intent calls between components and apps, which requires simultaneously analyzing all apps installed on a device. We evaluate IIFA in terms of precision, recall, and demonstrate its scalability to a large corpus of real-world apps. IIFA reports 62 problematic ICC-/IAC-related information flows via two or more apps/components. PIAnalyzer proposes a novel approach to analyze PendingIntent related vulnerabilities. PendingIntents are a powerful and universal feature of Android for inter-component communication. We empirically evaluate PIAnalyzer on a set of 1000 randomly selected applications and find 1358 insecure usages of PendingIntents, including 70 severe vulnerabilities.}, language = {en} } @phdthesis{Decker2009, author = {Decker, Gero}, title = {Design and analysis of process choreographies}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-40761}, school = {Universit{\"a}t Potsdam}, year = {2009}, abstract = {With the rise of electronic integration between organizations, the need for a precise specification of interaction behavior increases. Information systems, replacing interaction previously carried out by humans via phone, faxes and emails, require a precise specification for handling all possible situations. Such interaction behavior is described in process choreographies. Choreographies enumerate the roles involved, the allowed interactions, the message contents and the behavioral dependencies between interactions. Choreographies serve as interaction contract and are the starting point for adapting existing business processes and systems or for implementing new software components. As a thorough analysis and comparison of choreography modeling languages is missing in the literature, this thesis introduces a requirements framework for choreography languages and uses it for comparing current choreography languages. Language proposals for overcoming the limitations are given for choreography modeling on the conceptual and on the technical level. Using an interconnection modeling style, behavioral dependencies are defined on a per-role basis and different roles are interconnected using message flow. This thesis reveals a number of modeling "anti-patterns" for interconnection modeling, motivating further investigations on choreography languages following the interaction modeling style. Here, interactions are seen as atomic building blocks and the behavioral dependencies between them are defined globally. Two novel language proposals are put forward for this modeling style which have already influenced industrial standardization initiatives. While avoiding many of the pitfalls of interconnection modeling, new anomalies can arise in interaction models. A choreography might not be realizable, i.e. there does not exist a set of interacting roles that collectively realize the specified behavior. This thesis investigates different dimensions of realizability.}, language = {en} } @article{SteinertStabernack2022, author = {Steinert, Fritjof and Stabernack, Benno}, title = {Architecture of a low latency H.264/AVC video codec for robust ML based image classification how region of interests can minimize the impact of coding artifacts}, series = {Journal of Signal Processing Systems for Signal, Image, and Video Technology}, volume = {94}, journal = {Journal of Signal Processing Systems for Signal, Image, and Video Technology}, number = {7}, publisher = {Springer}, address = {New York}, issn = {1939-8018}, doi = {10.1007/s11265-021-01727-2}, pages = {693 -- 708}, year = {2022}, abstract = {The use of neural networks is considered as the state of the art in the field of image classification. A large number of different networks are available for this purpose, which, appropriately trained, permit a high level of classification accuracy. Typically, these networks are applied to uncompressed image data, since a corresponding training was also carried out using image data of similar high quality. However, if image data contains image errors, the classification accuracy deteriorates drastically. This applies in particular to coding artifacts which occur due to image and video compression. Typical application scenarios for video compression are narrowband transmission channels for which video coding is required but a subsequent classification is to be carried out on the receiver side. In this paper we present a special H.264/Advanced Video Codec (AVC) based video codec that allows certain regions of a picture to be coded with near constant picture quality in order to allow a reliable classification using neural networks, whereas the remaining image will be coded using constant bit rate. We have combined this feature with the ability to run with lowest latency properties, which is usually also required in remote control applications scenarios. The codec has been implemented as a fully hardwired High Definition video capable hardware architecture which is suitable for Field Programmable Gate Arrays.}, language = {en} } @article{HuangRichterKleickmannetal.2021, author = {Huang, Yizhen and Richter, Eric and Kleickmann, Thilo and Wiepke, Axel and Richter, Dirk}, title = {Classroom complexity affects student teachers' behavior in a VR classroom}, series = {Computers \& education : an international journal}, volume = {163}, journal = {Computers \& education : an international journal}, publisher = {Elsevier}, address = {Oxford}, issn = {0360-1315}, doi = {10.1016/j.compedu.2020.104100}, pages = {15}, year = {2021}, abstract = {Student teachers often struggle to keep track of everything that is happening in the classroom, and particularly to notice and respond when students cause disruptions. The complexity of the classroom environment is a potential contributing factor that has not been empirically tested. In this experimental study, we utilized a virtual reality (VR) classroom to examine whether classroom complexity affects the likelihood of student teachers noticing disruptions and how they react after noticing. Classroom complexity was operationalized as the number of disruptions and the existence of overlapping disruptions (multidimensionality) as well as the existence of parallel teaching tasks (simultaneity). Results showed that student teachers (n = 50) were less likely to notice the scripted disruptions, and also less likely to respond to the disruptions in a comprehensive and effortful manner when facing greater complexity. These results may have implications for both teacher training and the design of VR for training or research purpose. This study contributes to the field from two aspects: 1) it revealed how features of the classroom environment can affect student teachers' noticing of and reaction to disruptions; and 2) it extends the functionality of the VR environment-from a teacher training tool to a testbed of fundamental classroom processes that are difficult to manipulate in real-life.}, language = {en} } @phdthesis{Holz2013, author = {Holz, Christian}, title = {3D from 2D touch}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-67796}, school = {Universit{\"a}t Potsdam}, year = {2013}, abstract = {While interaction with computers used to be dominated by mice and keyboards, new types of sensors now allow users to interact through touch, speech, or using their whole body in 3D space. These new interaction modalities are often referred to as "natural user interfaces" or "NUIs." While 2D NUIs have experienced major success on billions of mobile touch devices sold, 3D NUI systems have so far been unable to deliver a mobile form factor, mainly due to their use of cameras. The fact that cameras require a certain distance from the capture volume has prevented 3D NUI systems from reaching the flat form factor mobile users expect. In this dissertation, we address this issue by sensing 3D input using flat 2D sensors. The systems we present observe the input from 3D objects as 2D imprints upon physical contact. By sampling these imprints at very high resolutions, we obtain the objects' textures. In some cases, a texture uniquely identifies a biometric feature, such as the user's fingerprint. In other cases, an imprint stems from the user's clothing, such as when walking on multitouch floors. By analyzing from which part of the 3D object the 2D imprint results, we reconstruct the object's pose in 3D space. While our main contribution is a general approach to sensing 3D input on 2D sensors upon physical contact, we also demonstrate three applications of our approach. (1) We present high-accuracy touch devices that allow users to reliably touch targets that are a third of the size of those on current touch devices. We show that different users and 3D finger poses systematically affect touch sensing, which current devices perceive as random input noise. We introduce a model for touch that compensates for this systematic effect by deriving the 3D finger pose and the user's identity from each touch imprint. We then investigate this systematic effect in detail and explore how users conceptually touch targets. Our findings indicate that users aim by aligning visual features of their fingers with the target. We present a visual model for touch input that eliminates virtually all systematic effects on touch accuracy. (2) From each touch, we identify users biometrically by analyzing their fingerprints. Our prototype Fiberio integrates fingerprint scanning and a display into the same flat surface, solving a long-standing problem in human-computer interaction: secure authentication on touchscreens. Sensing 3D input and authenticating users upon touch allows Fiberio to implement a variety of applications that traditionally require the bulky setups of current 3D NUI systems. (3) To demonstrate the versatility of 3D reconstruction on larger touch surfaces, we present a high-resolution pressure-sensitive floor that resolves the texture of objects upon touch. Using the same principles as before, our system GravitySpace analyzes all imprints and identifies users based on their shoe soles, detects furniture, and enables accurate touch input using feet. By classifying all imprints, GravitySpace detects the users' body parts that are in contact with the floor and then reconstructs their 3D body poses using inverse kinematics. GravitySpace thus enables a range of applications for future 3D NUI systems based on a flat sensor, such as smart rooms in future homes. We conclude this dissertation by projecting into the future of mobile devices. Focusing on the mobility aspect of our work, we explore how NUI devices may one day augment users directly in the form of implanted devices.}, language = {en} }