@phdthesis{AlSaffar2016, author = {Al-Saffar, Loay Talib Ahmed}, title = {Analysing prerequisites, expectations, apprehensions, and attitudes of University students studying computer science}, school = {Universit{\"a}t Potsdam}, pages = {128}, year = {2016}, language = {en} } @phdthesis{AlSaffar2016, author = {Al-Saffar, Loay Talib Ahmed}, title = {Analysing prerequisites, expectations, apprehensions, and attitudes of university students studying Computer science}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-98437}, school = {Universit{\"a}t Potsdam}, pages = {xii, 131}, year = {2016}, abstract = {The main objective of this dissertation is to analyse prerequisites, expectations, apprehensions, and attitudes of students studying computer science, who are willing to gain a bachelor degree. The research will also investigate in the students' learning style according to the Felder-Silverman model. These investigations fall in the attempt to make an impact on reducing the "dropout"/shrinkage rate among students, and to suggest a better learning environment. The first investigation starts with a survey that has been made at the computer science department at the University of Baghdad to investigate the attitudes of computer science students in an environment dominated by women, showing the differences in attitudes between male and female students in different study years. Students are accepted to university studies via a centrally controlled admission procedure depending mainly on their final score at school. This leads to a high percentage of students studying subjects they do not want. Our analysis shows that 75\% of the female students do not regret studying computer science although it was not their first choice. And according to statistics over previous years, women manage to succeed in their study and often graduate on top of their class. We finish with a comparison of attitudes between the freshman students of two different cultures and two different university enrolment procedures (University of Baghdad, in Iraq, and the University of Potsdam, in Germany) both with opposite gender majority. The second step of investigation took place at the department of computer science at the University of Potsdam in Germany and analyzes the learning styles of students studying the three major fields of study offered by the department (computer science, business informatics, and computer science teaching). Investigating the differences in learning styles between the students of those study fields who usually take some joint courses is important to be aware of which changes are necessary to be adopted in the teaching methods to address those different students. It was a two stage study using two questionnaires; the main one is based on the Index of Learning Styles Questionnaire of B. A. Solomon and R. M. Felder, and the second questionnaire was an investigation on the students' attitudes towards the findings of their personal first questionnaire. Our analysis shows differences in the preferences of learning style between male and female students of the different study fields, as well as differences between students with the different specialties (computer science, business informatics, and computer science teaching). The third investigation looks closely into the difficulties, issues, apprehensions and expectations of freshman students studying computer science. The study took place at the computer science department at the University of Potsdam with a volunteer sample of students. The goal is to determine and discuss the difficulties and issues that they are facing in their study that may lead them to think in dropping-out, changing the study field, or changing the university. The research continued with the same sample of students (with business informatics students being the majority) through more than three semesters. Difficulties and issues during the study were documented, as well as students' attitudes, apprehensions, and expectations. Some of the professors and lecturers opinions and solutions to some students' problems were also documented. Many participants had apprehensions and difficulties, especially towards informatics subjects. Some business informatics participants began to think of changing the university, in particular when they reached their third semester, others thought about changing their field of study. Till the end of this research, most of the participants continued in their studies (the study they have started with or the new study they have changed to) without leaving the higher education system.}, language = {en} } @article{BoehneKreitzKnobelsdorf2016, author = {B{\"o}hne, Sebastian and Kreitz, Christoph and Knobelsdorf, Maria}, title = {Mathematisches Argumentieren und Beweisen mit dem Theorembeweiser Coq}, series = {Commentarii informaticae didacticae (CID)}, journal = {Commentarii informaticae didacticae (CID)}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94824}, pages = {69 -- 80}, year = {2016}, abstract = {Informatik-Studierende haben in der Mehrzahl Schwierigkeiten, einen Einstieg in die Theoretische Informatik zu finden und die Leistungsanforderungen in den Endklausuren der zugeh{\"o}rigen Lehrveranstaltungen zu erf{\"u}llen. Wir argumentieren, dass dieser Symptomatik mangelnde Kompetenzen im Umgang mit abstrakten und stark formalisierten Themeninhalten zugrunde liegen und schlagen vor, einen Beweisassistenten als interaktives Lernwerkzeug in der Eingangslehre der Theoretischen Informatik zu nutzen, um entsprechende Kompetenzen zu st{\"a}rken.}, language = {de} } @article{DennertMoellerGarmann2016, author = {Dennert-M{\"o}ller, Elisabeth and Garmann, Robert}, title = {Das „Startprojekt"}, series = {Commentarii informaticae didacticae (CID)}, journal = {Commentarii informaticae didacticae (CID)}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94780}, pages = {11 -- 23}, year = {2016}, abstract = {Absolventinnen und Absolventen unserer Informatik-Bachelorstudieng{\"a}nge ben{\"o}tigen f{\"u}r kompetentes berufliches Handeln sowohl fachliche als auch {\"u}berfachliche Kompetenzen. Vielfach verlangen wir von Erstsemestern in Grundlagen-Lehrveranstaltungen fast ausschließlich den Aufbau von Fachkompetenz und vernachl{\"a}ssigen dabei h{\"a}ufig Selbstkompetenz, Methodenkompetenz und Sozialkompetenz. Gerade die drei letztgenannten sind f{\"u}r ein erfolgreiches Studium unabdingbar und sollten von Anfang an entwickelt werden. Wir stellen unser „Startprojekt" als einen Beitrag vor, im ersten Semester die eigenverantwortliche, {\"u}berfachliche Kompetenzentwicklung in einem fachlichen Kontext zu f{\"o}rdern.}, language = {de} } @inproceedings{DennertMoellerGarmannKujathetal.2016, author = {Dennert-M{\"o}ller, Elisabeth and Garmann, Robert and Kujath, Bertold and Zscheyge, Oliver and Weicker, Karsten and B{\"o}hne, Sebastian and Knobelsdorf, Maria and Kreitz, Christoph and Steen, Alexander and Wisniewski, Max and Benzm{\"u}ller, Christoph and Gebhardt, Kai and Ehlenz, Matthias and Bergner, Nadine and Schroeder, Ulrik}, title = {Hochschuldidaktik der Informatik}, editor = {Schwill, Andreas and Lucke, Ulrike}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-93511}, pages = {102}, year = {2016}, abstract = {Die 7. Fachtagung f{\"u}r Hochschuldidaktik, die 2016 erneut mit der DeLFI E-Learning Fachtagung Informatik stattfand, setzte das erfolgreiche Modell einer Tagung fort, die sich mit hochschuldidaktischen Fragen und der Gestaltung von Studieng{\"a}ngen der Informatik besch{\"a}ftigt. Thema der Tagung waren alle Fragen, die sich der Vermittlung von Informatikgegenst{\"a}nden im Hochschulbereich widmen. Dazu geh{\"o}rten u.a.: • fachdidaktische Konzepte der Vermittlung einzelner Informatikgegenst{\"a}nde • methodische L{\"o}sungen, wie spezielle Lehr- und Lernformen, Durchf{\"u}hrungskonzepte • empirische Ergebnisse und Vergleichsstudien • E-Learning-Ans{\"a}tze, wenn sie ein erkennbares didaktisches Konzept verfolgen • Studienkonzepte und Curricula, organisatorische Fragen, wie Gewinnung von Studierenden, Studieneingangsphase, Abbrecher. Die Fachtagung widmete sich ausgew{\"a}hlten Fragestellungen dieses Themenkomplexes, die durch Vortr{\"a}ge ausgewiesener Experten, durch eingereichte Beitr{\"a}ge und durch Pr{\"a}sentationen und Poster intensiv behandelt wurden. Unser besonderer Dank gilt dem Programmkomitee und den hier nicht genannten Helfern f{\"u}r ihren Einsatz bei der Vorbereitung und Durchf{\"u}hrung der Tagung.}, language = {de} } @phdthesis{Dick2016, author = {Dick, Uwe}, title = {Discriminative Classification Models for Internet Security}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-102593}, school = {Universit{\"a}t Potsdam}, pages = {x, 57}, year = {2016}, abstract = {Services that operate over the Internet are under constant threat of being exposed to fraudulent use. Maintaining good user experience for legitimate users often requires the classification of entities as malicious or legitimate in order to initiate countermeasures. As an example, inbound email spam filters decide for spam or non-spam. They can base their decision on both the content of each email as well as on features that summarize prior emails received from the sending server. In general, discriminative classification methods learn to distinguish positive from negative entities. Each decision for a label may be based on features of the entity and related entities. When labels of related entities have strong interdependencies---as can be assumed e.g. for emails being delivered by the same user---classification decisions should not be made independently and dependencies should be modeled in the decision function. This thesis addresses the formulation of discriminative classification problems that are tailored for the specific demands of the following three Internet security applications. Theoretical and algorithmic solutions are devised to protect an email service against flooding of user inboxes, to mitigate abusive usage of outbound email servers, and to protect web servers against distributed denial of service attacks. In the application of filtering an inbound email stream for unsolicited emails, utilizing features that go beyond each individual email's content can be valuable. Information about each sending mail server can be aggregated over time and may help in identifying unwanted emails. However, while this information will be available to the deployed email filter, some parts of the training data that are compiled by third party providers may not contain this information. The missing features have to be estimated at training time in order to learn a classification model. In this thesis an algorithm is derived that learns a decision function that integrates over a distribution of values for each missing entry. The distribution of missing values is a free parameter that is optimized to learn an optimal decision function. The outbound stream of emails of an email service provider can be separated by the customer IDs that ask for delivery. All emails that are sent by the same ID in the same period of time are related, both in content and in label. Hijacked customer accounts may send batches of unsolicited emails to other email providers, which in turn might blacklist the sender's email servers after detection of incoming spam emails. The risk of being blocked from further delivery depends on the rate of outgoing unwanted emails and the duration of high spam sending rates. An optimization problem is developed that minimizes the expected cost for the email provider by learning a decision function that assigns a limit on the sending rate to customers based on the each customer's email stream. Identifying attacking IPs during HTTP-level DDoS attacks allows to block those IPs from further accessing the web servers. DDoS attacks are usually carried out by infected clients that are members of the same botnet and show similar traffic patterns. HTTP-level attacks aim at exhausting one or more resources of the web server infrastructure, such as CPU time. If the joint set of attackers cannot increase resource usage close to the maximum capacity, no effect will be experienced by legitimate users of hosted web sites. However, if the additional load raises the computational burden towards the critical range, user experience will degrade until service may be unavailable altogether. As the loss of missing one attacker depends on block decisions for other attackers---if most other attackers are detected, not blocking one client will likely not be harmful---a structured output model has to be learned. In this thesis an algorithm is developed that learns a structured prediction decoder that searches the space of label assignments, guided by a policy. Each model is evaluated on real-world data and is compared to reference methods. The results show that modeling each classification problem according to the specific demands of the task improves performance over solutions that do not consider the constraints inherent to an application.}, language = {en} } @article{DittmarBuchholzKuehn2016, author = {Dittmar, Anke and Buchholz, Gregor and K{\"u}hn, Mathias}, title = {Eine Studie zum kollaborativen Modellieren in der Softwaretechnik-Ausbildung}, series = {Commentarii informaticae didacticae (CID)}, journal = {Commentarii informaticae didacticae (CID)}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94806}, pages = {41 -- 53}, year = {2016}, abstract = {Die Vermittlung von Modellierungsf{\"a}higkeiten in der Softwaretechnik-Ausbildung konzentriert sich meist auf Modellierungskonzepte, Notationen und Entwicklungswerkzeuge. Die Betrachtung der Modellierungsaktivit{\"a}ten, etwa die Entwicklung und Gegen{\"u}berstellung alternativer Modellvorschl{\"a}ge, steht weniger im Vordergrund. Die vorliegende Studie untersucht zwei Formen des kollaborativen Modellierens am Tabletop in Bezug auf ihren Einfluss auf die Modellierungsaktivit{\"a}ten in kleinen Gruppen. Die Ergebnisse zeigen, dass sowohl selbstorganisierte als auch moderierte Modellierungssitzungen das Entwickeln eines gemeinsamen Modellverst{\"a}ndnisses f{\"o}rdern. In moderierten Sitzungen wurden zudem mehr alternative L{\"o}sungsideen entwickelt und in st{\"a}rkerem Maße diskutiert.}, language = {de} } @article{EhlenzBergnerSchroeder2016, author = {Ehlenz, Matthias and Bergner, Nadine and Schroeder, Ulrik}, title = {Synergieeffekte zwischen Fach- und Lehramtsstudierenden in Softwarepraktika}, series = {Commentarii informaticae didacticae (CID)}, journal = {Commentarii informaticae didacticae (CID)}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94875}, pages = {99 -- 102}, year = {2016}, abstract = {Dieser Beitrag diskutiert die Konzeption eines Software-Projektpraktikums im Bereich E-Learning, welches Lehramts- und Fachstudierenden der Informatik erm{\"o}glicht, voneinander zu profitieren und praxisrelevante Ergebnisse generiert. Vorbereitungen, Organisation und Durchf{\"u}hrung werden vorgestellt und diskutiert. Den Abschluss bildet ein Ausblick auf die Fortf{\"u}hrung des Konzepts und den Ausbau des Forschungsgebietes.}, language = {de} } @article{Gebhardt2016, author = {Gebhardt, Kai}, title = {Kooperative und kompetenzorientierte {\"U}bungen in der Softwaretechnik}, series = {Commentarii informaticae didacticae (CID)}, journal = {Commentarii informaticae didacticae (CID)}, number = {10}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-376-3}, issn = {1868-0844}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-94867}, pages = {95 -- 98}, year = {2016}, abstract = {Die Unterrichtsmethode Stationsarbeit kann verwendet werden, um Individualisierung und Differenzierung im Lernprozess zu erm{\"o}glichen. Dieser Beitrag schl{\"a}gt Aufgabenformate vor, die in einer Stationsarbeit {\"u}ber das Klassendiagramm aus der Unified Modeling Language verwendet werden k{\"o}nnen. Die Aufgabenformate wurden bereits mit Studierenden erprobt.}, language = {de} } @phdthesis{Hagedorn2016, author = {Hagedorn, Benjamin}, title = {Konzepte und Techniken zur servicebasierten Visualisierung von geovirtuellen 3D-Umgebungen}, school = {Universit{\"a}t Potsdam}, pages = {140}, year = {2016}, language = {de} }