header logo

Aggregates in Answer Set Programming

Prof. Wolfgang Faber, University of Huddersfield (UK)

2.7.2015,   14:00-15:30 Uhr,   E.1.42

Well-studied and commonly used in database query languages, aggregates form an intuitive means of representing knowledge. Since logic programs can be viewed as a database query language, it is natural to consider aggregates also in their context. However, logic programs allow for recursive specifications, which are either disallowed or allowed only in a restricted form in most database query languages. It turns out that aggregates used in connection with recursion raise a number of semantic issues, some of them reminiscent of issues with the semantics of negation, a hot topic in logic programming about three decades ago. One of the semantics for logic programs with negation that emerged and has proved itself to be viable is the stable model semantics or answer set semantics. In this talk we will show how ideas from this semantics can be transferred to programs with aggregates, what issues arise when doing so, and what options there are to overcome these. Furthermore, we will outline properties of the resulting semantics and the availability of system support. Finally, we show that all of these considerations are not really limited to aggregates, but more general constructs, such as those found in HEX programs or description logic programs.

Wolfgang Faber serves as Professor of Artificial Intelligence at the University of Huddersfield (UK). Before that, he was a Reader at the same university, an Associate Professor at the University of Calabria (Italy), and an Assistant Professor at the Vienna University of Technology, where he also obtained his PhD in 2002. From 2004 to 2006 he was on an APART grant of the Austrian Academy of Sciences. His general research interests are in knowledge representation, logic programming, nonmonotonic reasoning, planning, and knowledge-based agents. He has published more than 100 refereed articles in major journals, collections and conference proceedings in these areas. He is one of the architects of DLV, a state-of-the-art system for computing answer sets of disjunctive deductive databases, which is used all over the world. He has acted as a chair for several workshops and conferences, and has been on the program committees of many of the major conferences of his research areas, and has served on the editorial board and as a reviewer for many journals and conferences on Artificial Intelligence, Knowledge Representation, and Logic Programming.


Dealing with Temporal Business Processes: from Medical Applications to Checking Dynamic Controllability

Carlo Combi and Roberto Posenato

9.7.2015,   11:00 Uhr,   E.2.37


Business Process (BP) technology has emerged as one of the leading technologies in modeling, redesigning, and executing organisational processes in several different application domains. Among them, the representation and management of health and clinical processes have been attracting a growing interest. Such processes are in general related to the way each health organization provides the required healthcare services. Health and clinical processes underlie the specification and application of clinical protocols, clinical guidelines, clinical pathways, and the most common clinical/administrative procedures. Current BP systems are lacking in effective management of three general key aspects that are common (not only) in the clinical/health context: data dependencies, exception handling, and temporal constraints.
In this talk we will first introduce and discuss recent advances in business process modeling with respect to the healthcare/medical domain. Then, we will introduce some recent results on algorithms for checking temporal properties of business processes in presence of explicit temporal constraints among tasks.

Bio Carlo Combi:Combi

In 1987 he received the Laurea Degree in E.E. by the Politecnico of Milan. In 1993 he received the Ph.D. degree in biomedical engineering. Since November 2001, he is with the Department of Computer Science of the University of Verona: from November 2001 to February 2005, he was Associate Professor of Computer Science; since March 2005, he is Professor of Computer Science. From October 2007 to September 2012 he was head of the Computer Science Department. Main research interests are related to the database and information system field, with an emphasis on the management of clinical information. The two main areas are temporal information systems (time-oriented data and process modelling) and multimedia databases. He is author of more than 100 papers published on international journals and proceedings of international conferences. He is author, with Elpida Keravnou – University of Cyprus and Yuval Shahar – Ben-Gurion University of the Negev, of the book “Temporal Information Systems in Medicine”, Springer, 2010. He is involved in the scientific activity of several scientific international journals and conferences. Since January 1999 he is editorial Board Member, journal Artificial Intelligence in Medicine. Since July 2009 he is chair of the Artificial Intelligence in Medicine Society (AIME). He is guest editor of several special issues of international journals (Methods of Information in Medicine, Annals of Mathematics and Artificial Intelligence, Artificial Intelligence in Medicine, Journal of Intelligent Information Systems, Computers in Biology and Medicine, ACM Transactions on Intelligent Systems and Technology).

Bio Roberto Posenato:

He took a degree in Computer Science in 1991 and a doctor’s degree in Computational Mathematics in 1996 at the University of Milan (Italy). Since November 2000, he is assistant professor at the same department. He has been lecturer for some courses in the theory of algorithms and computational complexity since 1996. Main research interests are related to approximation algorithms for combinatorial optimization problems, with emphasis for graph-based problems; moreover, he is interested into the study of time reasoning in workflow/business process systems and in temporal constraint networks. He is reviewer for national and international journals, magazines, and conferences and he has been involved in several national research projects.

Why do smart systems need telecommunications? Opportunities for advances in communication technology

Antrittsvorlesung von Univ.-Prof. Dr. Andrea M. Tonello | 23. Juni 2015 | 17 Uhr c.t. im HS 2

ANDREA M. TONELLO received the laurea in electrical engineering (1996) and the Ph.D in telecommunications (2003) from the University of Padova, Italy. On February 1997, he joined Lucent Technologies where he worked on cellular communications in the Bell Labs Advanced Wireless Technology Laboratory, Whippany, NJ. He was promoted to technical manager in 2002 and appointed managing director of the Bell Labs Italy di- vision. In January 2003, he joined the Uni- versity of Udine, Italy. He became aggregate professor in 2005 and associate professor in 2014. Herein, he founded the Wireless and Power Line Communications Lab and the spin-off company WiTiKee. He was awarded the Italian full professor habilitation in 2013. In September 2014, he became full professor at the University of Klagenfurt, Austria, where he chairs the group on Embedded Communication Systems.

His research focuses on wireless and power line communications, embed- ded and smart systems. He received the Bell Labs Recognition of Excellence award (2003), the Distinguished Visiting Fellowship from the Royal Academy of Engineering, UK (2010) and the Distinguished Lecturer Award by the IEEE Vehicular Technology Society (2011-15). He is the co-recipient of five best paper awards. He was the general chair of IEEE ISPLC 2011 and IEEE Smart- GridComm 2014. He serves as an associate editor for the IEEE Transactions on Communications and IEEE Access. He is the chair of the IEEE ComSoc Technical Committee on Power Line Communications.


Wir freuen uns sehr auf Ihre/Deine Teilnahme und bitten um kurze Bestätigung per E-Mail an marlene.starc@aau.at.

Lehre, Forschung und Think Tank für die Industrie

Screen Shot 2015-06-02 at 20.30.34Mittlerweile schon ein Fixtermin im Juni, findet auch heuer wieder die TeWi-Veranstaltung „Lehre, Forschung und Think Tank für die Industrie“ in Kooperation mit der Industriellenvereinigung Kärnten am 25.6. ab 16 Uhr statt.

Die Welt der Fakultät für Technische Wissenschaften soll sichtbar gemacht werden, sichtbar für die Industrie, die Wirtschaft, die Politik, für Kolleginnen und Kollegen der Universität Klagenfurt und all ihren Studierenden. Es wird aufgezeigt wie wichtig das Studium technischer Berufe ist und wie groß der Durst der Wirtschaft nach jungen Technikerinnen und Technikern in unserem Bundesland und auch im Rest Österreichs ist. Kaum eine Studienrichtung hat solch eine geringe Arbeitslosenquote vorzuweisen wie technische Studiengänge. Kärnten ist dabei sich als hervorragender Standort für Technologie zu etablieren, doch das geht nur indem man genug geeignetes Personal vorfindet.

Mit ständig steigenden Studierendenzahlen ist die TeWi dabei genau diesen Weg möglich zu machen und die Zukunft Kärntens mit zu gestalten. Dekan Gerhard Friedrich meint dazu, dass „…wir gar nicht so viele Absolventinnen und Absolventen produzieren können, wie von der Wirtschaft gebraucht werden“ aber die Kapazitäten wären ausreichend die Zahl erheblich zu steigern.

Wie in jedem Jahr, werden auch heuer wieder die besten studentischen Leistungen an unserer Fakultät belohnt. Die jeweils besten Studenten aus den Studienrichtungen Informatik, Informationsmanagement, Informationstechnik und technische Mathematik, ebenso wie die beste Masterarbeit des Jahres, werden mit Urkunden und Geldpreisen bedacht.

logo bitmovin_transparentDie Verflechtung der TeWi mit der Kärntner Wirtschaft ist sehr gut was Grundlagenforschung, Problemlösungen und Expertisen angeht. Natürlich sind darüber hinaus aus unserer Fakultät auch schon einige Unternehmen hervorgegangen die sich äußerst erfolgreich am Markt behaupten. In diesem Jahr werfen wir bei unserer Veranstaltung einen Blick auf „bitmovin“, die von TeWi-Absolventen Stefan Lederer, Christopher Müller und TeWi-Kollegen Christian Timmerer gegründet wurde. Die Firma bietet die weltweit schnellsten Lösungen im Bereich des Online-Streamings an und hat Partner überall auf dem Globus.

Die Kollegen Markus Zanker und Mathias Lux werden Einblicke in ihre Forschungsarbeit geben und kurze Präsentationen zu den Themen „Online Empfehlungssysteme – Funktionsweise und Wirkung“ bzw. „Bildsuche: Von der Forschung zur praktischen Anwendung“ halten. Wir bieten unseren Gästen auch die Möglichkeit sich aktiv in die Forschung einzubringen und eine kurze Fahrt in unserem Fahrsimulator zu absolvieren. Dabei messen wir Herzfrequenz, Transpiration und Reaktionsgeschwindigkeit der Probanden und können so Rückschlüsse auf den Stresslevel der Fahrer ziehen.

Um den Stresspegel danach wieder zu senken, stellen wir ein reichhaltiges Buffet zur Verfügung und laden all unsere Gäste zu einem gemütlichen Fingerfood Networking ein.

Das genaue Programm finden Sie hier in der offiziellen Einladung. Wir freuen uns sie alle bei uns begrüßen zu dürfen und bitten um Anmeldung unter technik@aau.at.

Rückblick: Empirical Results on Cloning and Clone Detection [Slides]

Der Rückblick zum TEWI-Kolloquium von Prof. Stefan Wagner am 1.6.2015 beinhaltet die Folien:

Abstract: Cloning means the use of copy-paste as method in developing software artefacts. This practice has several problems, such as unnecessary increase of these artefacts, and thereby increased comprehension and change efforts, as well as potential inconsistencies. The automatic detection of clones has been a topic for research for several years now and we have made huge progress in terms of precision and recall. This led to a series of empirical analyses we have performed on the effects and the amount of cloning in code, models and requirements. We continue to investigate the effects of cloning and work on extending clone detection to functionally similar code. This talk will give insights into how clone detection works and the empirical results we have gathered.

Short CV: Stefan Wagner is full professor for software engineering at the University of Stuttgart. He holds a PhD in computer science from TU Munich, where he also worked as a post-doc. His main research interests are quality engineering, requirements engineering, agile software development and safety engineering; all tackled using empirical research.

Side-Channel Analysis and Countermeasures: the Good, the Bad and the Ugly of Cryptographic Implementations

Hermann Seuschek, Fabrizio De Santis, TU München

30. 06. 2015,   12:00 - 14:00 Uhr,   E.1.42

Side-channel analysis have been introduced in the late nineties by Kocher et al. [1] to recover the secret keys of cryptographic implementations by exploiting the information leaked over side-channels. For embedded cryptographic devices typical side-channels are represented by the power consumption or by the electro-magnetic (EM) field emanations of physical implementations when executing cryptographic algorithms. Over the last two decades a lot of side-channel attacks have been developed and a variety of countermeasures have been proposed in literature to thwart side-channel analysis. Nevertheless, the quest after improved attacks and countermeasures is still a very active area of research, as testified by the many conferences and recent developments. In this talk, we provide an introduction to side-channel attacks covering some main topics like measurement setup, leakage models and statistical analysis. Then, we provide an overview on typical countermeasures against side-channel attacks covering different level of abstractions (circuit, algorithmic and protocol level).

[1] P. Kocher, J. Jaffe, and B. Jun. Differential Power Analysis. In M.J. Wiener, editor, Advances in Cryptology – CRYPTO ?99, volume 1666 of Lecture Notes in Computer Science, pages 388-397. Springer, 1999.

Hermann Seuschek studied electrical engineering and information technology at Technische Universität München. Afterwards he worked for the central research and development department within the Siemens AG on topics related to applied cryptography and security for embedded systems. He left Siemens and joined the Institute for Security in Information Technology at Technische Universität München to pursue research in the field of automated side channel hardening of cryptographic algorithms.

Fabrizio De Santis studied computer engineering at Politecnico di Milano and completed his thesis at Advanced System Technology (AST) Laboratories (R&D) of STMicroelectronics. In 2011 he joined the Institute for Security in Information
Technology at Technische Universität München. In the period 2011 – 2013 he worked on the development of secure cryptographic implementations at Infineon Technologies AG in München.

Optimization Problems in Answer Set Programming

Dr. Mario Alviano, University of Calabria

29. 05. 2015,   10:00 Uhr,   E.1.42

The goal of the lecture is to present the latest achievements in Answer Set Programming (ASP). In particular, the focus of the lecture is on algorithms for solving optimization problems in ASP, that is, problems encoded by ASP programs with weak constraints. As usual in ASP, solutions of a problem instance are represented by its stable models, or answer sets. If the input program also comprises weak constraints, each of its stable model is associated with a cost determined by the unsatisfied weak constraints. Hence, weak constraints define a cost function, so that stable models of smaller cost are preferred.
The lecture overviews several algorithms for computing the most preferred, or optimal, stable models, and provides some details on core-guided algorithms, which proved to be effective on industrial instances of MaxSAT, the optimization variant of the satisfiability problem for propositional formulas. These algorithms work by iteratively checking satisfiability of a formula that is relaxed at each step by using the information provided by unsatisfiable cores, i.e., sets of weak constraints that cannot be jointly satisfied by any stable model of the input program.
The lecture is of the interest for both students visiting Logic Programming course as well as researchers of technical faculty working on declarative solving of hard problems.

Dr. Mario Alviano received his master degree from University of Calabria in 2007 and his PhD in 2010 from the same university. Both works were distinguished by awards: the master thesis won the “Italian best thesis in Artificial Intelligence” a prize awarded by AI*IA, the Italian Association for Artificial Intelligence and PhD thesis was one among three dissertations awarded with a honorable mention by the European Coordinating Committee for Artificial Intelligence (ECCAI). Since 2011 he worked as a post doc and then as Assistant Professor at the Department of Mathematics and Computer Science, University of Calabria. The research interests of Dr. Alviano are spread throughout the field of knowledge representation and reasoning with the main focus on theoretical background and applications of answer set programming.

Controllable Face Privacy

Dr. Terence Sim, National University of Singapore

06. 05. 2015,   11:00 s.t.,   Room L4.1.114 Lakeside Labs


We present the novel concept of Controllable Face Privacy. Existing methods that alter face images to conceal identity inadvertently also destroy other facial attributes such as gender, race or age. This all-or-nothing approach is too harsh. Instead, we propose a flexible method that can independently control the amount of identity alteration while keeping unchanged other facial attributes. To achievethis flexibility, we apply a subspace decomposition onto our face encoding scheme, effectively decoupling facial attributes such as gender, race, age, and identity into mutually orthogonal subspaces, which in turn enables independent control of these attributes. Our method is thus useful for nuanced face de-identification, in which only facial identity is altered, but others, such gender, race and age, are retained. These altered face images protect identity privacy, and yet allow other computer vision analyses, such as gender detection, to proceed unimpeded. Controllable Face Privacy is therefore useful for reaping the benefits of surveillance cameras while preventing privacy abuse. Our proposal also permits privacy to be applied not just to identity, but also to other facial attributes as well. Furthermore, privacy-protection mechanisms, such as k-anonymity, L-diversity, and t-closeness, may be readily incorporated into our method. Extensive experiments with a commercial facial analysis software show that our alteration method is indeed effective.


Dr. Terence Sim is an Associate Professor at the School of Computing, National University of Singapore. He teaches an undergraduate course in digital special effects, as well as a graduate course in multimedia. For research, Terence works primarily in these areas: face recognition, biometrics, and computational photography. He is also interested in computer vision problems in general, such as shape-from-shading, photometric stereo, object recognition. On the side, he dabble with some aspects of music processing, such as polyphonic music transcription. Terence also serves as President of the Pattern Recognition and Machine Intelligence Association (PREMIA), a national professional body for pattern recognition, affiliated with the International Association for Pattern Recognition (IAPR). Terence counts it a blessing and a joy to graduate from three great schools: Carnegie Mellon University, Stanford, and MIT.
Personal Website: https://www.comp.nus.edu.sg/~tsim/

Zur Bedeutung der Methodenvielfalt für Forschung und Lehre der Informatik

Dr. Andreas Harrer, TU Clausthal

10. 04. 2015,   16:00-17:45 Uhr,   E.2.42

In diesem Vortrag stellen wir unsere Beiträge zur Auswahl und Anwendung von Methoden der Informatik in Forschung und Lehre vor. Neben aktuellen Forschungsarbeiten im Bereich des computer-gestützten kollaborativen Lernens (CSCL) mittels Triangulation sich ergänzender Forschungsmethoden führen wir auch das fachdidaktische Konzept der Methodenausbildung an der TU Clausthal für den Übergang zwischen Bachelor- und Masterstudium ein. Dieses ist für den internationalen Charakter des Fachbereiches und die hohe Fluktuation zwischen beiden Studienabschnitten von hoher Bedeutung für die Qualität der Lehre.

Informatik – Von der Profession zum “Kinderspiel”

Assoc. Prof. DI Dr. Andreas Bollin, Institut für Informatiksysteme

10. 04. 2015,   09:00-10:45 Uhr,   E.2.42

Die Informatik ist ein wissenschaftliches Fachgebiet, in dem es in nur wenigen Jahrzehnten wesentliche von Schlüsselpersonen getragene Entwicklungen gab – und wohl auch weiterhin geben wird. Diese rasante Weiterentwicklung des Fachs Informatik sowie der Wandel des Erscheinungsbildes in der Öffentlichkeit legen nahe, dass sich deren Inhalte wie Prinzipien nicht einfach in unterrichtsspezifische Dosen abpacken lassen. Der Vortrag beleuchtet daher unterschiedliche Gebiete der Informatik und zeigt anhand von einigen konkreten Beispielen, wie Wissen und informatische Konzepte, die zunächst nur einigen wenigen Experten vorbehalten waren, alters- und entwicklungsstufengerecht Einzug in den Unterricht halten konnten und können.