TY - CHAP A1 - Curzon, Paul A1 - Kalas, Ivan A1 - Schubert, Sigrid A1 - Schaper, Niclas A1 - Barnes, Jan A1 - Kennewell, Steve A1 - Bröker, Kathrin A1 - Kastens, Uwe A1 - Magenheim, Johannes A1 - Dagiene, Valentina A1 - Stupuriene, Gabriele A1 - Ellis, Jason Brent A1 - Abreu-Ellis, Carla Reis A1 - Grillenberger, Andreas A1 - Romeike, Ralf A1 - Haugsbakken, Halvdan A1 - Jones, Anthony A1 - Lewin, Cathy A1 - McNicol, Sarah A1 - Nelles, Wolfgang A1 - Neugebauer, Jonas A1 - Ohrndorf, Laura A1 - Schaper, Niclas A1 - Schubert, Sigrid A1 - Opel, Simone A1 - Kramer, Matthias A1 - Trommen, Michael A1 - Pottbäcker, Florian A1 - Ilaghef, Youssef A1 - Passig, David A1 - Tzuriel, David A1 - Kedmi, Ganit Eshel A1 - Saito, Toshinori A1 - Webb, Mary A1 - Weigend, Michael A1 - Bottino, Rosa A1 - Chioccariello, Augusto A1 - Christensen, Rhonda A1 - Knezek, Gerald A1 - Gioko, Anthony Maina A1 - Angondi, Enos Kiforo A1 - Waga, Rosemary A1 - Ohrndorf, Laura A1 - Or-Bach, Rachel A1 - Preston, Christina A1 - Younie, Sarah A1 - Przybylla, Mareen A1 - Romeike, Ralf A1 - Reynolds, Nicholas A1 - Swainston, Andrew A1 - Bendrups, Faye A1 - Sysło, Maciej M. A1 - Kwiatkowska, Anna Beata A1 - Zieris, Holger A1 - Gerstberger, Herbert A1 - Müller, Wolfgang A1 - Büchner, Steffen A1 - Opel, Simone A1 - Schiller, Thomas A1 - Wegner, Christian A1 - Zender, Raphael A1 - Lucke, Ulrike A1 - Diethelm, Ira A1 - Syrbe, Jörn A1 - Lai, Kwok-Wing A1 - Davis, Niki A1 - Eickelmann, Birgit A1 - Erstad, Ola A1 - Fisser, Petra A1 - Gibson, David A1 - Khaddage, Ferial A1 - Knezek, Gerald A1 - Micheuz, Peter A1 - Kloos, Carlos Delgado ED - Brinda, Torsten ED - Reynolds, Nicholas ED - Romeike, Ralf ED - Schwill, Andreas T1 - KEYCIT 2014 BT - key competencies in informatics and ICT N2 - In our rapidly changing world it is increasingly important not only to be an expert in a chosen field of study but also to be able to respond to developments, master new approaches to solving problems, and fulfil changing requirements in the modern world and in the job market. In response to these needs key competencies in understanding, developing and using new digital technologies are being brought into focus in school and university programmes. The IFIP TC3 conference "KEYCIT – Key Competences in Informatics and ICT (KEYCIT 2014)" was held at the University of Potsdam in Germany from July 1st to 4th, 2014 and addressed the combination of key competencies, Informatics and ICT in detail. The conference was organized into strands focusing on secondary education, university education and teacher education (organized by IFIP WGs 3.1 and 3.3) and provided a forum to present and to discuss research, case studies, positions, and national perspectives in this field. T3 - Commentarii informaticae didacticae (CID) - 7 KW - Schlüsselkompetenzen KW - Informatik KW - Bildung KW - ICT KW - Informatikdidaktik KW - Key Competencies KW - Informatics KW - education KW - ICT KW - Computer Science Education Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-70325 SN - 978-3-86956-292-6 PB - Universitätsverlag Potsdam CY - Potsdam ER - TY - THES A1 - Wust, Johannes T1 - Mixed workload managment for in-memory databases BT - executing mixed workloads of enterprise applications with TAMEX Y1 - 2015 ER - TY - THES A1 - Jung, Jörg T1 - Efficient credit based server load balancing Y1 - 2015 ER - TY - JOUR A1 - Liang, Feng A1 - Liu, Yunzhen A1 - Liu, Hai A1 - Ma, Shilong A1 - Schnor, Bettina T1 - A Parallel Job Execution Time Estimation Approach Based on User Submission Patterns within Computational Grids JF - International journal of parallel programming N2 - Scheduling performance in computational grid can potentially benefit a lot from accurate execution time estimation for parallel jobs. Most existing approaches for the parallel job execution time estimation, however, require ample past job traces and the explicit correlations between the job execution time and the outer layout parameters such as the consumed processor numbers, the user-estimated execution time and the job ID, which are hard to obtain or reveal. This paper presents and evaluates a novel execution time estimation approach for parallel jobs, the user-behavior clustering for execution time estimation, which can give more accurate execution time estimation for parallel jobs through exploring the job similarity and revealing the user submission patterns. Experiment results show that compared to the state-of-art algorithms, our approach can improve the accuracy of the job execution time estimation up to 5.6 %, meanwhile the time that our approach spends on calculation can be reduced up to 3.8 %. KW - User submission pattern KW - Parallel job execution time estimation KW - Computational grid Y1 - 2015 U6 - https://doi.org/10.1007/s10766-013-0294-1 SN - 0885-7458 SN - 1573-7640 VL - 43 IS - 3 SP - 440 EP - 454 PB - Springer CY - New York ER - TY - JOUR A1 - Jung, Jörg A1 - Kiertscher, Simon A1 - Menski, Sebastian A1 - Schnor, Bettina T1 - Self-Adapting Load Balancing for DNS JF - Journal of networks N2 - The Domain Name System belongs to the core services of the Internet infrastructure. Hence, DNS availability and performance is essential for the operation of the Internet and replication as well as load balancing are used for the root and top level name servers. This paper proposes an architecture for credit based server load balancing (SLB) for DNS. Compared to traditional load balancing algorithms like round robin or least connection, the benefit of credit based SLB is that the load balancer can adapt more easily to heterogeneous load requests and back end server capacities. The challenge of this approach is the definition of a suited credit metric. While this was done before for TCP based services like HTTP, the problem was not solved for UDP based services like DNS. In the following an approach is presented to define credits also for UDP based services. This UDP/DNS approach is implemented within the credit based SLB implementation salbnet. The presented measurements confirm the benefit of the self-adapting credit based SLB approach. In our experiments, the mean (first) response time dropped significantly compared to weighted round robin (WRR) (from over 4 ms to about 0.6 ms for dynamic pressure relieve (DPR)). KW - Load Balancing KW - Cluster Computing KW - Performance Evaluation Y1 - 2015 U6 - https://doi.org/10.1109/SPECTS.2014.6879994 VL - 10 IS - 4 SP - 222 EP - 231 PB - Kluwer Academic Publishers CY - Oulu ER - TY - JOUR A1 - Pablo Alarcon, Pedro A1 - Arroyo, Fernando A1 - Bordihn, Henning A1 - Mitrana, Victor A1 - Mueller, Mike T1 - Ambiguity of the multiple interpretations on regular languages JF - Fundamenta informaticae N2 - A multiple interpretation scheme is an ordered sequence of morphisms. The ordered multiple interpretation of a word is obtained by concatenating the images of that word in the given order of morphisms. The arbitrary multiple interpretation of a word is the semigroup generated by the images of that word. These interpretations are naturally extended to languages. Four types of ambiguity of multiple interpretation schemata on a language are defined: o-ambiguity, internal ambiguity, weakly external ambiguity and strongly external ambiguity. We investigate the problem of deciding whether a multiple interpretation scheme is ambiguous on regular languages. KW - Multiple interpretation scheme KW - regular language KW - o-ambiguity KW - internal ambiguity KW - external ambiguity Y1 - 2015 U6 - https://doi.org/10.3233/FI-2015-1200 SN - 0169-2968 SN - 1875-8681 VL - 138 IS - 1-2 SP - 85 EP - 95 PB - IOS Press CY - Amsterdam ER - TY - JOUR A1 - Childs, Dorothee A1 - Grimbs, Sergio A1 - Selbig, Joachim T1 - Refined elasticity sampling for Monte Carlo-based identification of stabilizing network patterns JF - Bioinformatics N2 - Motivation: Structural kinetic modelling (SKM) is a framework to analyse whether a metabolic steady state remains stable under perturbation, without requiring detailed knowledge about individual rate equations. It provides a representation of the system's Jacobian matrix that depends solely on the network structure, steady state measurements, and the elasticities at the steady state. For a measured steady state, stability criteria can be derived by generating a large number of SKMs with randomly sampled elasticities and evaluating the resulting Jacobian matrices. The elasticity space can be analysed statistically in order to detect network positions that contribute significantly to the perturbation response. Here, we extend this approach by examining the kinetic feasibility of the elasticity combinations created during Monte Carlo sampling. Results: Using a set of small example systems, we show that the majority of sampled SKMs would yield negative kinetic parameters if they were translated back into kinetic models. To overcome this problem, a simple criterion is formulated that mitigates such infeasible models. After evaluating the small example pathways, the methodology was used to study two steady states of the neuronal TCA cycle and the intrinsic mechanisms responsible for their stability or instability. The findings of the statistical elasticity analysis confirm that several elasticities are jointly coordinated to control stability and that the main source for potential instabilities are mutations in the enzyme alpha-ketoglutarate dehydrogenase. Y1 - 2015 U6 - https://doi.org/10.1093/bioinformatics/btv243 SN - 1367-4803 SN - 1460-2059 VL - 31 IS - 12 SP - 214 EP - 220 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Lemcke, Stefanie A1 - Haedge, Kora A1 - Zender, Raphael A1 - Lucke, Ulrike T1 - RouteMe: a multilevel pervasive game on mobile ad hoc routing JF - Personal and ubiquitous computing N2 - Pervasive educational games have the potential to transfer learning content to real-life experiences beyond lecture rooms, through realizing field trips in an augmented or virtual manner. This article introduces the pervasive educational game "RouteMe" that brings the rather abstract topic of routing in ad hoc networks to real-world environments. The game is designed for university-level courses and supports these courses in a motivating manner to deepen the learning experience. Students slip into the role of either routing nodes or applications with routing demands. On three consecutive levels of difficulty, they get introduced with the game concept, learn the basic routing mechanisms and become aware of the general limitations and functionality of routing nodes. This paper presents the pedagogical and technical game concept as well as findings from an evaluation in a university setting. KW - E-learning KW - Educational game KW - Mobile application KW - Pervasive computing KW - Location awareness KW - Ad hoc routing KW - AODV Y1 - 2015 U6 - https://doi.org/10.1007/s00779-015-0843-2 SN - 1617-4909 SN - 1617-4917 VL - 19 IS - 3-4 SP - 537 EP - 549 PB - Springer CY - London ER - TY - JOUR A1 - Videla, Santiago A1 - Guziolowski, Carito A1 - Eduati, Federica A1 - Thiele, Sven A1 - Gebser, Martin A1 - Nicolas, Jacques A1 - Saez-Rodriguez, Julio A1 - Schaub, Torsten H. A1 - Siegel, Anne T1 - Learning Boolean logic models of signaling networks with ASP JF - Theoretical computer science N2 - Boolean networks provide a simple yet powerful qualitative modeling approach in systems biology. However, manual identification of logic rules underlying the system being studied is in most cases out of reach. Therefore, automated inference of Boolean logical networks from experimental data is a fundamental question in this field. This paper addresses the problem consisting of learning from a prior knowledge network describing causal interactions and phosphorylation activities at a pseudo-steady state, Boolean logic models of immediate-early response in signaling transduction networks. The underlying optimization problem has been so far addressed through mathematical programming approaches and the use of dedicated genetic algorithms. In a recent work we have shown severe limitations of stochastic approaches in this domain and proposed to use Answer Set Programming (ASP), considering a simpler problem setting. Herein, we extend our previous work in order to consider more realistic biological conditions including numerical datasets, the presence of feedback-loops in the prior knowledge network and the necessity of multi-objective optimization. In order to cope with such extensions, we propose several discretization schemes and elaborate upon our previous ASP encoding. Towards real-world biological data, we evaluate the performance of our approach over in silico numerical datasets based on a real and large-scale prior knowledge network. The correctness of our encoding and discretization schemes are dealt with in Appendices A-B. (C) 2014 Elsevier B.V. All rights reserved. KW - Answer set programming KW - Signaling transduction networks KW - Boolean logic models KW - Combinatorial multi-objective optimization KW - Systems biology Y1 - 2015 U6 - https://doi.org/10.1016/j.tcs.2014.06.022 SN - 0304-3975 SN - 1879-2294 VL - 599 SP - 79 EP - 101 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Kaufmann, Benjamin T1 - High performance answer set solving Y1 - 2015 ER -