@article{KrasnovaVeltriSpengleretal.2013, author = {Krasnova, Hanna and Veltri, Natasha F. and Spengler, Klaus and G{\"u}nther, Oliver}, title = {"Deal of the Day" Platforms what drives Consumer loyalty?}, series = {Business \& information systems engineering : the international journal of Wirtschaftsinformatik}, volume = {5}, journal = {Business \& information systems engineering : the international journal of Wirtschaftsinformatik}, number = {3}, publisher = {Springer}, address = {Heidelberg}, issn = {1867-0202}, doi = {10.1007/s12599-013-0268-2}, pages = {165 -- 177}, year = {2013}, abstract = {"Deal of the Day" (DoD) platforms have quickly become popular by offering savings on local services, products and vacations. For merchants, these platforms represent a new marketing channel to advertise their products and services and attract new customers. DoD platform providers, however, struggle to maintaining a stable market share and profitability, because entry and switching costs are low. To sustain a competitive market position, DoD providers are looking for ways to build a loyal customer base. However, research examining the determinants of user loyalty in this novel context is scarce. To fill this gap, this study employs Grounded Theory methodology to develop a conceptual model of customer loyalty to a DoD provider. In the next step, qualitative insights are enriched and validated using quantitative data from a survey of 202 DoD users. The authors find that customer loyalty is in large part driven by monetary incentives, but can be eroded if impressions from merchant encounters are below expectations. In addition, enhancing the share of deals relevant for consumers, i.e. signal-to-noise ratio, and mitigating perceived risks of a transaction emerge as challenges. Beyond theoretical value, the results offer practical insights into how customer loyalty to a DoD provider can be promoted.}, language = {en} } @article{BrainGebserPuehreretal.2007, author = {Brain, Martin and Gebser, Martin and P{\"u}hrer, J{\"o}rg and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {"That is illogical, Captain!" : the debugging support tool spock for answer-set programs ; system description}, year = {2007}, language = {en} } @article{JuergensenKonstantinidis2006, author = {J{\"u}rgensen, Helmut and Konstantinidis, Stavros}, title = {(Near-)inverses of sequences}, issn = {0020-7160}, doi = {10.1080/00207160500537801}, year = {2006}, abstract = {We introduce the notion of a near-inverse of a non-decreasing sequence of positive integers; near-inverses are intended to assume the role of inverses in cases when the latter cannot exist. We prove that the near-inverse of such a sequence is unique; moreover, the relation of being near-inverses of each other is symmetric, i.e. if sequence g is the near-inverse of sequence f, then f is the near-inverse of g. There is a connection, by approximations, between near- inverses of sequences and inverses of continuous strictly increasing real-valued functions which can be exploited to derive simple expressions for near-inverses}, language = {en} } @inproceedings{KnothKiy2014, author = {Knoth, Alexander Henning and Kiy, Alexander}, title = {(Self-)confident through the introductory study phase with the Reflect App}, series = {CEUR Workshop Proceedings}, booktitle = {CEUR Workshop Proceedings}, number = {1227}, publisher = {CEUR-WS}, address = {Freiburg}, issn = {1613-0073}, pages = {172 -- 179}, year = {2014}, language = {en} } @inproceedings{OPUS4-39635, title = {11. Workshop Testmethoden und Zuverl{\"a}ssigkeit von Schaltungen und Systemen}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-9806494-1-4}, pages = {137 Seiten}, year = {1999}, language = {de} } @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} } @article{DelgrandeSchaubTompitsetal.2004, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans and Wang, Kewen}, title = {A classification and survey of preference handling approchaches in nonmonotonic reasoning}, issn = {0824-7935}, year = {2004}, abstract = {In recent years, there has been a large amount of disparate work concerning the representation and reasoning with qualitative preferential information by means of approaches to nonmonotonic reasoning. Given the variety of underlying systems, assumptions, motivations, and intuitions, it is difficult to compare or relate one approach with another. Here, we present an overview and classification for approaches to dealing with preference. A set of criteria for classifying approaches is given, followed by a set of desiderata that an approach might be expected to satisfy. A comprehensive set of approaches is subsequently given and classified with respect to these sets of underlying principles}, language = {en} } @article{Wang2001, author = {Wang, Kewen}, title = {A comparative study of disjunctive well-founded semantics}, isbn = {3-540-42593-4}, year = {2001}, language = {en} } @article{SchaubWang2001, author = {Schaub, Torsten H. and Wang, Kewen}, title = {A comparative study of logic programs with preference}, year = {2001}, language = {en} } @article{SchaubWang2001, author = {Schaub, Torsten H. and Wang, Kewen}, title = {A comparative study of logic programs with preference}, isbn = {1-558-60777-3}, issn = {1045-0823}, year = {2001}, language = {en} } @article{DelgrandeSchaubTompits2000, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A compilation of Brewka and Eiter's approach to prioritizationtion}, isbn = {3-540-41131-3}, year = {2000}, language = {en} } @article{SarsakovSchaubTompitsetal.2004, author = {Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {A compiler for nested logic programming}, isbn = {3-540- 20721-x}, year = {2004}, language = {en} } @article{DelgrandeSchaubTompits2000, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A compiler for ordered logic programs}, year = {2000}, language = {en} } @phdthesis{Awad2010, author = {Awad, Ahmed Mahmoud Hany Aly}, title = {A compliance management framework for business process models}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-49222}, school = {Universit{\"a}t Potsdam}, year = {2010}, abstract = {Companies develop process models to explicitly describe their business operations. In the same time, business operations, business processes, must adhere to various types of compliance requirements. Regulations, e.g., Sarbanes Oxley Act of 2002, internal policies, best practices are just a few sources of compliance requirements. In some cases, non-adherence to compliance requirements makes the organization subject to legal punishment. In other cases, non-adherence to compliance leads to loss of competitive advantage and thus loss of market share. Unlike the classical domain-independent behavioral correctness of business processes, compliance requirements are domain-specific. Moreover, compliance requirements change over time. New requirements might appear due to change in laws and adoption of new policies. Compliance requirements are offered or enforced by different entities that have different objectives behind these requirements. Finally, compliance requirements might affect different aspects of business processes, e.g., control flow and data flow. As a result, it is infeasible to hard-code compliance checks in tools. Rather, a repeatable process of modeling compliance rules and checking them against business processes automatically is needed. This thesis provides a formal approach to support process design-time compliance checking. Using visual patterns, it is possible to model compliance requirements concerning control flow, data flow and conditional flow rules. Each pattern is mapped into a temporal logic formula. The thesis addresses the problem of consistency checking among various compliance requirements, as they might stem from divergent sources. Also, the thesis contributes to automatically check compliance requirements against process models using model checking. We show that extra domain knowledge, other than expressed in compliance rules, is needed to reach correct decisions. In case of violations, we are able to provide a useful feedback to the user. The feedback is in the form of parts of the process model whose execution causes the violation. In some cases, our approach is capable of providing automated remedy of the violation.}, language = {en} } @article{DelgrandeSchaub2003, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {A concictency-based paradigm for belief change}, issn = {0004-3702}, year = {2003}, language = {en} } @article{BrueningSchaub2000, author = {Br{\"u}ning, Stefan and Schaub, Torsten H.}, title = {A connection calculus for handling incomplete information}, year = {2000}, language = {en} } @article{DelgrandeSchaub2007, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {A consistency-based framework for merging knowledge bases}, issn = {1570-8683}, year = {2007}, language = {en} } @article{DelgrandeSchaub2000, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {A consistency-based model for belief change: preliminary report}, isbn = {0-262-51112-6}, year = {2000}, language = {en} } @article{DelgrandeSchaub2000, author = {Delgrande, James Patrick and Schaub, Torsten H.}, title = {A consistency-based model for belief change: preliminary report}, year = {2000}, language = {en} } @article{BesnardSchaub1993, author = {Besnard, Philippe and Schaub, Torsten H.}, title = {A context-based framework for default logics}, isbn = {0-262-51071-5}, year = {1993}, language = {en} } @phdthesis{Luckow2009, author = {Luckow, Andr{\´e}}, title = {A dependable middleware for enhancing the fault tolerance of distributed computations in grid environments}, address = {Potsdam}, pages = {235 S.}, year = {2009}, language = {en} } @article{DelgrandeSchaubTompits2003, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A framework for compiling preferences in logic programs}, year = {2003}, language = {en} } @article{KreowskyStabernack2021, author = {Kreowsky, Philipp and Stabernack, Christian Benno}, title = {A full-featured FPGA-based pipelined architecture for SIFT extraction}, series = {IEEE access : practical research, open solutions / Institute of Electrical and Electronics Engineers}, volume = {9}, journal = {IEEE access : practical research, open solutions / Institute of Electrical and Electronics Engineers}, publisher = {Inst. of Electr. and Electronics Engineers}, address = {New York, NY}, issn = {2169-3536}, doi = {10.1109/ACCESS.2021.3104387}, pages = {128564 -- 128573}, year = {2021}, abstract = {Image feature detection is a key task in computer vision. Scale Invariant Feature Transform (SIFT) is a prevalent and well known algorithm for robust feature detection. However, it is computationally demanding and software implementations are not applicable for real-time performance. In this paper, a versatile and pipelined hardware implementation is proposed, that is capable of computing keypoints and rotation invariant descriptors on-chip. All computations are performed in single precision floating-point format which makes it possible to implement the original algorithm with little alteration. Various rotation resolutions and filter kernel sizes are supported for images of any resolution up to ultra-high definition. For full high definition images, 84 fps can be processed. Ultra high definition images can be processed at 21 fps.}, language = {en} } @article{DelgrandeSchaubTompits2007, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A general framework for expressing preferences in causal reasoning and planning}, issn = {0955-792X}, doi = {10.1093/logcom/exm046}, year = {2007}, abstract = {We consider the problem of representing arbitrary preferences in causal reasoning and planning systems. In planning, a preference may be seen as a goal or constraint that is desirable, but not necessary, to satisfy. To begin, we define a very general query language for histories, or interleaved sequences of world states and actions. Based on this, we specify a second language in which preferences are defined. A single preference defines a binary relation on histories, indicating that one history is preferred to the other. From this, one can define global preference orderings on the set of histories, the maximal elements of which are the preferred histories. The approach is very general and flexible; thus it constitutes a base language in terms of which higher-level preferences may be defined. To this end, we investigate two fundamental types of preferences that we call choice and temporal preferences. We consider concrete strategies for these types of preferences and encode them in terms of our framework. We suggest how to express aggregates in the approach, allowing, e.g. the expression of a preference for histories with lowest total action costs. Last, our approach can be used to express other approaches and so serves as a common framework in which such approaches can be expressed and compared. We illustrate this by indicating how an approach due to Son and Pontelli can be encoded in our approach, as well as the language PDDL3.}, language = {en} } @article{DelgrandeSchaubTompits2001, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A generic compiler for ordered logic programs}, isbn = {3-540-42593-4}, year = {2001}, language = {en} } @article{AngerKonczakLinkeetal.2005, author = {Anger, Christian and Konczak, Kathrin and Linke, Thomas and Schaub, Torsten H.}, title = {A Glimpse of Answer Set Programming}, issn = {0170-4516}, year = {2005}, language = {en} } @incollection{KiyGessnerLuckeetal.2015, author = {Kiy, Alexander and Geßner, Hendrik and Lucke, Ulrike and Gr{\"u}newald, Franka}, title = {A Hybrid and Modular Framework for Mobile Campus Applications}, series = {i-com}, volume = {2015}, booktitle = {i-com}, number = {14}, publisher = {de Gruyter}, address = {Berlin}, issn = {2196-6826}, doi = {10.1515/icom-2015-0016}, publisher = {Universit{\"a}t Potsdam}, pages = {63 -- 73}, year = {2015}, abstract = {Mobile devices and associated applications (apps) are an indispensable part of daily life and provide access to important information anytime and anywhere. However, the availability of university-wide services in the mobile sector is still poor. If they exist they usually result from individual activities of students and teachers. Mobile applications can have an essential impact on the improvement of students' self-organization as well as on the design and enhancement of specific learning scenarios, though. This article introduces a mobile campus app framework, which integrates central campus services and decentralized learning applications. An analysis of strengths and weaknesses of different approaches is presented to summarize and evaluate them in terms of requirements, development, maintenance and operation. The article discusses the underlying service-oriented architecture that allows transferring the campus app to other universities or institutions at reasonable cost. It concludes with a presentation of the results as well as ongoing discussions and future work}, language = {en} } @article{TiwariPrakashGrossetal.2020, author = {Tiwari, Abhishek and Prakash, Jyoti and Groß, Sascha and Hammer, Christian}, title = {A large scale analysis of Android}, series = {The journal of systems and software}, volume = {170}, journal = {The journal of systems and software}, publisher = {Elsevier}, address = {New York}, issn = {0164-1212}, doi = {10.1016/j.jss.2020.110775}, pages = {17}, year = {2020}, abstract = {Many Android applications embed webpages via WebView components and execute JavaScript code within Android. Hybrid applications leverage dedicated APIs to load a resource and render it in a WebView. Furthermore, Android objects can be shared with the JavaScript world. However, bridging the interfaces of the Android and JavaScript world might also incur severe security threats: Potentially untrusted webpages and their JavaScript might interfere with the Android environment and its access to native features. No general analysis is currently available to assess the implications of such hybrid apps bridging the two worlds. To understand the semantics and effects of hybrid apps, we perform a large-scale study on the usage of the hybridization APIs in the wild. We analyze and categorize the parameters to hybridization APIs for 7,500 randomly selected and the 196 most popular applications from the Google Playstore as well as 1000 malware samples. Our results advance the general understanding of hybrid applications, as well as implications for potential program analyses, and the current security situation: We discovered thousands of flows of sensitive data from Android to JavaScript, the vast majority of which could flow to potentially untrustworthy code. Our analysis identified numerous web pages embedding vulnerabilities, which we exemplarily exploited. Additionally, we discovered a multitude of applications in which potentially untrusted JavaScript code may interfere with (trusted) Android objects, both in benign and malign applications.}, language = {en} } @article{HlawiczkaGoesselSogomonyan1997, author = {Hlawiczka, A. and G{\"o}ssel, Michael and Sogomonyan, Egor S.}, title = {A linear code-preserving signature analyzer COPMISR}, isbn = {0-8186-7810-0}, year = {1997}, language = {en} } @unpublished{Arnold2009, author = {Arnold, Holger}, title = {A linearized DPLL calculus with clause learning (2nd, revised version)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-29080}, year = {2009}, abstract = {Many formal descriptions of DPLL-based SAT algorithms either do not include all essential proof techniques applied by modern SAT solvers or are bound to particular heuristics or data structures. This makes it difficult to analyze proof-theoretic properties or the search complexity of these algorithms. In this paper we try to improve this situation by developing a nondeterministic proof calculus that models the functioning of SAT algorithms based on the DPLL calculus with clause learning. This calculus is independent of implementation details yet precise enough to enable a formal analysis of realistic DPLL-based SAT algorithms.}, language = {en} } @article{Arnold2007, author = {Arnold, Holger}, title = {A linearized DPLL calculus with learning}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-15421}, year = {2007}, abstract = {This paper describes the proof calculus LD for clausal propositional logic, which is a linearized form of the well-known DPLL calculus extended by clause learning. It is motivated by the demand to model how current SAT solvers built on clause learning are working, while abstracting from decision heuristics and implementation details. The calculus is proved sound and terminating. Further, it is shown that both the original DPLL calculus and the conflict-directed backtracking calculus with clause learning, as it is implemented in many current SAT solvers, are complete and proof-confluent instances of the LD calculus.}, language = {en} } @phdthesis{Scherfenberg2012, author = {Scherfenberg, Ivonne}, title = {A logic-based Framwork to enable Attribute Assurance for Digital Identities in Service-oriented Architectures and the Web}, address = {Potsdam}, pages = {126 S.}, year = {2012}, language = {en} } @article{BesnardHunter2001, author = {Besnard, Philippe and Hunter, Anthony}, title = {A logic-based theory of deductive arguments}, issn = {0004-3702}, year = {2001}, language = {en} } @article{SaposhnikovSaposhnikovGoesseletal.1999, author = {Saposhnikov, V. V. and Saposhnikov, Vl. V. and G{\"o}ssel, Michael and Morosov, Andrej}, title = {A method of construction of combinational self-checking units with detection of all single faults}, year = {1999}, language = {en} } @phdthesis{Andjelkovic2021, author = {Andjelkovic, Marko}, title = {A methodology for characterization, modeling and mitigation of single event transient effects in CMOS standard combinational cells}, doi = {10.25932/publishup-53484}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-534843}, school = {Universit{\"a}t Potsdam}, pages = {xxiv, 216}, year = {2021}, abstract = {With the downscaling of CMOS technologies, the radiation-induced Single Event Transient (SET) effects in combinational logic have become a critical reliability issue for modern integrated circuits (ICs) intended for operation under harsh radiation conditions. The SET pulses generated in combinational logic may propagate through the circuit and eventually result in soft errors. It has thus become an imperative to address the SET effects in the early phases of the radiation-hard IC design. In general, the soft error mitigation solutions should accommodate both static and dynamic measures to ensure the optimal utilization of available resources. An efficient soft-error-aware design should address synergistically three main aspects: (i) characterization and modeling of soft errors, (ii) multi-level soft error mitigation, and (iii) online soft error monitoring. Although significant results have been achieved, the effectiveness of SET characterization methods, accuracy of predictive SET models, and efficiency of SET mitigation measures are still critical issues. Therefore, this work addresses the following topics: (i) Characterization and modeling of SET effects in standard combinational cells, (ii) Static mitigation of SET effects in standard combinational cells, and (iii) Online particle detection, as a support for dynamic soft error mitigation. Since the standard digital libraries are widely used in the design of radiation-hard ICs, the characterization of SET effects in standard cells and the availability of accurate SET models for the Soft Error Rate (SER) evaluation are the main prerequisites for efficient radiation-hard design. This work introduces an approach for the SPICE-based standard cell characterization with the reduced number of simulations, improved SET models and optimized SET sensitivity database. It has been shown that the inherent similarities in the SET response of logic cells for different input levels can be utilized to reduce the number of required simulations. Based on characterization results, the fitting models for the SET sensitivity metrics (critical charge, generated SET pulse width and propagated SET pulse width) have been developed. The proposed models are based on the principle of superposition, and they express explicitly the dependence of the SET sensitivity of individual combinational cells on design, operating and irradiation parameters. In contrast to the state-of-the-art characterization methodologies which employ extensive look-up tables (LUTs) for storing the simulation results, this work proposes the use of LUTs for storing the fitting coefficients of the SET sensitivity models derived from the characterization results. In that way the amount of characterization data in the SET sensitivity database is reduced significantly. The initial step in enhancing the robustness of combinational logic is the application of gate-level mitigation techniques. As a result, significant improvement of the overall SER can be achieved with minimum area, delay and power overheads. For the SET mitigation in standard cells, it is essential to employ the techniques that do not require modifying the cell structure. This work introduces the use of decoupling cells for improving the robustness of standard combinational cells. By insertion of two decoupling cells at the output of a target cell, the critical charge of the cell's output node is increased and the attenuation of short SETs is enhanced. In comparison to the most common gate-level techniques (gate upsizing and gate duplication), the proposed approach provides better SET filtering. However, as there is no single gate-level mitigation technique with optimal performance, a combination of multiple techniques is required. This work introduces a comprehensive characterization of gate-level mitigation techniques aimed to quantify their impact on the SET robustness improvement, as well as introduced area, delay and power overhead per gate. By characterizing the gate-level mitigation techniques together with the standard cells, the required effort in subsequent SER analysis of a target design can be reduced. The characterization database of the hardened standard cells can be utilized as a guideline for selection of the most appropriate mitigation solution for a given design. As a support for dynamic soft error mitigation techniques, it is important to enable the online detection of energetic particles causing the soft errors. This allows activating the power-greedy fault-tolerant configurations based on N-modular redundancy only at the high radiation levels. To enable such a functionality, it is necessary to monitor both the particle flux and the variation of particle LET, as these two parameters contribute significantly to the system SER. In this work, a particle detection approach based on custom-sized pulse stretching inverters is proposed. Employing the pulse stretching inverters connected in parallel enables to measure the particle flux in terms of the number of detected SETs, while the particle LET variations can be estimated from the distribution of SET pulse widths. This approach requires a purely digital processing logic, in contrast to the standard detectors which require complex mixed-signal processing. Besides the possibility of LET monitoring, additional advantages of the proposed particle detector are low detection latency and power consumption, and immunity to error accumulation. The results achieved in this thesis can serve as a basis for establishment of an overall soft-error-aware database for a given digital library, and a comprehensive multi-level radiation-hard design flow that can be implemented with the standard IC design tools. The following step will be to evaluate the achieved results with the irradiation experiments.}, language = {en} } @phdthesis{Wolter2010, author = {Wolter, Christian}, title = {A methodology for model-driven process security}, address = {Potsdam}, pages = {xv, 144 S. : graph. Darst.}, year = {2010}, language = {en} } @article{BrueningSchaub1996, author = {Br{\"u}ning, Stefan and Schaub, Torsten H.}, title = {A model-based approach to consistency-checking}, isbn = {3-540-61286-6}, year = {1996}, language = {en} } @article{DelgrandeSchaubTompitsetal.2013, author = {Delgrande, James and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {A model-theoretic approach to belief change in answer set programming}, series = {ACM transactions on computational logic}, volume = {14}, journal = {ACM transactions on computational logic}, number = {2}, publisher = {Association for Computing Machinery}, address = {New York}, issn = {1529-3785}, doi = {10.1145/2480759.2480766}, pages = {46}, year = {2013}, abstract = {We address the problem of belief change in (nonmonotonic) logic programming under answer set semantics. Our formal techniques are analogous to those of distance-based belief revision in propositional logic. In particular, we build upon the model theory of logic programs furnished by SE interpretations, where an SE interpretation is a model of a logic program in the same way that a classical interpretation is a model of a propositional formula. Hence we extend techniques from the area of belief revision based on distance between models to belief change in logic programs. We first consider belief revision: for logic programs P and Q, the goal is to determine a program R that corresponds to the revision of P by Q, denoted P * Q. We investigate several operators, including (logic program) expansion and two revision operators based on the distance between the SE models of logic programs. It proves to be the case that expansion is an interesting operator in its own right, unlike in classical belief revision where it is relatively uninteresting. Expansion and revision are shown to satisfy a suite of interesting properties; in particular, our revision operators satisfy all or nearly all of the AGM postulates for revision. We next consider approaches for merging a set of logic programs, P-1,...,P-n. Again, our formal techniques are based on notions of relative distance between the SE models of the logic programs. Two approaches are examined. The first informally selects for each program P-i those models of P-i that vary the least from models of the other programs. The second approach informally selects those models of a program P-0 that are closest to the models of programs P-1,...,P-n. In this case, P-0 can be thought of as a set of database integrity constraints. We examine these operators with regards to how they satisfy relevant postulate sets. Last, we present encodings for computing the revision as well as the merging of logic programs within the same logic programming framework. This gives rise to a direct implementation of our approach in terms of off-the-shelf answer set solvers. These encodings also reflect the fact that our change operators do not increase the complexity of the base formalism.}, language = {en} } @article{SogomonyanSinghGoessel1998, author = {Sogomonyan, Egor S. and Singh, Adit D. and G{\"o}ssel, Michael}, title = {A multi-mode scannable memory element for high test application efficiency and delay testing}, year = {1998}, language = {en} } @article{SogomonyanSinghGoessel1999, author = {Sogomonyan, Egor S. and Singh, Adit D. and G{\"o}ssel, Michael}, title = {A multi-mode scannable memory element for high test application efficiency and delay testing}, year = {1999}, language = {en} } @phdthesis{Ghasemzadeh2005, author = {Ghasemzadeh, Mohammad}, title = {A new algorithm for the quantified satisfiability problem, based on zero-suppressed binary decision diagrams and memoization}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6378}, school = {Universit{\"a}t Potsdam}, year = {2005}, abstract = {Quantified Boolean formulas (QBFs) play an important role in theoretical computer science. QBF extends propositional logic in such a way that many advanced forms of reasoning can be easily formulated and evaluated. In this dissertation we present our ZQSAT, which is an algorithm for evaluating quantified Boolean formulas. ZQSAT is based on ZBDD: Zero-Suppressed Binary Decision Diagram , which is a variant of BDD, and an adopted version of the DPLL algorithm. It has been implemented in C using the CUDD: Colorado University Decision Diagram package. The capability of ZBDDs in storing sets of subsets efficiently enabled us to store the clauses of a QBF very compactly and let us to embed the notion of memoization to the DPLL algorithm. These points led us to implement the search algorithm in such a way that we could store and reuse the results of all previously solved subformulas with a little overheads. ZQSAT can solve some sets of standard QBF benchmark problems (known to be hard for DPLL based algorithms) faster than the best existing solvers. In addition to prenex-CNF, ZQSAT accepts prenex-NNF formulas. We show and prove how this capability can be exponentially beneficial.}, subject = {Bin{\"a}res Entscheidungsdiagramm}, language = {en} } @article{Gohlke1995, author = {Gohlke, Mario}, title = {A new approach for model-based recognition using colour regions}, year = {1995}, language = {en} } @article{SaposhnikovMorosovSaposhnikovetal.1998, author = {Saposhnikov, V. V. and Morosov, Andrej and Saposhnikov, Vl. V. and G{\"o}ssel, Michael}, title = {A new design method for self-checking unidirectional combinational circuits}, year = {1998}, language = {en} } @article{Richter1995, author = {Richter, Peter}, title = {A new deterministic approach for the optimization of cable layouts for power supply systems}, year = {1995}, language = {en} } @article{Goessel1999, author = {G{\"o}ssel, Michael}, title = {A new method of redundancy addition for circuit optimization}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {1999, 08}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, publisher = {Univ.}, address = {Potsdam}, issn = {0946-7580}, pages = {9 Bl.}, year = {1999}, language = {en} } @article{SogomonyanGoessel1995, author = {Sogomonyan, Egor S. and G{\"o}ssel, Michael}, title = {A new parity preserving multi-input signature analyser}, year = {1995}, language = {en} } @book{SogomonyanMarienfeldOcheretnijetal.2003, author = {Sogomonyan, Egor S. and Marienfeld, Daniel and Ocheretnij, V. and G{\"o}ssel, Michael}, title = {A new self-checking sum-bit duplicated carry-select adder}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {2003, 5}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, publisher = {Univ.}, address = {Potsdam}, issn = {0946-7580}, pages = {10 S.}, year = {2003}, language = {en} } @article{GoesselSogomonyan1996, author = {G{\"o}ssel, Michael and Sogomonyan, Egor S.}, title = {A new self-testing parity checker for ultra-reliable applications}, year = {1996}, language = {en} } @article{GoesselSogomonyanMorosov1999, author = {G{\"o}ssel, Michael and Sogomonyan, Egor S. and Morosov, Andrej}, title = {A new totally error propagating compactor for arbitrary cores with digital interfaces}, year = {1999}, language = {en} } @article{KawanabeBlanchardSugiyamaetal.2006, author = {Kawanabe, Motoaki and Blanchard, Gilles and Sugiyama, Masashi and Spokoiny, Vladimir G. and M{\"u}ller, Klaus-Robert}, title = {A novel dimension reduction procedure for searching non-Gaussian subspaces}, issn = {0302-9743}, doi = {10.1007/11679363_19}, year = {2006}, abstract = {In this article, we consider high-dimensional data which contains a low-dimensional non-Gaussian structure contaminated with Gaussian noise and propose a new linear method to identify the non-Gaussian subspace. Our method NGCA (Non-Gaussian Component Analysis) is based on a very general semi-parametric framework and has a theoretical guarantee that the estimation error of finding the non-Gaussian components tends to zero at a parametric rate. NGCA can be used not only as preprocessing for ICA, but also for extracting and visualizing more general structures like clusters. A numerical study demonstrates the usefulness of our method}, language = {en} } @article{LiangLiuLiuetal.2015, author = {Liang, Feng and Liu, Yunzhen and Liu, Hai and Ma, Shilong and Schnor, Bettina}, title = {A Parallel Job Execution Time Estimation Approach Based on User Submission Patterns within Computational Grids}, series = {International journal of parallel programming}, volume = {43}, journal = {International journal of parallel programming}, number = {3}, publisher = {Springer}, address = {New York}, issn = {0885-7458}, doi = {10.1007/s10766-013-0294-1}, pages = {440 -- 454}, year = {2015}, abstract = {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 \%.}, language = {en} } @article{GoesselSogomonyan1996, author = {G{\"o}ssel, Michael and Sogomonyan, Egor S.}, title = {A parity-preserving multi-input signature analyzer and it application for concurrent checking and BIST}, year = {1996}, language = {en} } @article{PearceSarsakovSchaubetal.2002, author = {Pearce, David and Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {A polynomial translation of logic programs with nested expressions into disjunctive logic programs}, isbn = {3-540-43930-7}, year = {2002}, language = {en} } @article{PearceSarsakovSchaubetal.2002, author = {Pearce, David and Sarsakov, Vladimir and Schaub, Torsten H. and Tompits, Hans and Woltran, Stefan}, title = {A polynomial translation of logic programs with nested expressions into disjunctive logic programs : preliminary report}, year = {2002}, language = {en} } @article{DelgrandeSchaubTompits2007, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A preference-based framework for updating logic programs}, isbn = {978-3-540- 72199-4}, year = {2007}, language = {en} } @article{DelgrandeSchaubTompits2006, author = {Delgrande, James Patrick and Schaub, Torsten H. and Tompits, Hans}, title = {A Preference-Based Framework for Updating logic Programs : preliminary reports}, year = {2006}, language = {en} } @book{PolyvyanyyKuropka2007, author = {Polyvyanyy, Artem and Kuropka, Dominik}, title = {A Quantitative Evalution of the Enhanced Topic-based Vector Space Model}, series = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsda}, volume = {19}, journal = {Technische Berichte des Hasso-Plattner-Instituts f{\"u}r Softwaresystemtechnik an der Universit{\"a}t Potsda}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-939469-95-7}, issn = {1613-5652}, pages = {88 S.}, year = {2007}, language = {en} } @phdthesis{Mueller2012, author = {M{\"u}ller, J{\"u}rgen J.}, title = {A real-time in-memory discovery service}, address = {Potsdam}, pages = {XXV, 172 S.}, year = {2012}, language = {en} } @article{Boerner1998, author = {B{\"o}rner, Ferdinand}, title = {A remark on the finite lattice representation problem}, year = {1998}, language = {en} } @article{Schoebel2010, author = {Sch{\"o}bel, Michael}, title = {A runtime environment for online processing of operating system kernel events}, isbn = {978-3-86956-036-6}, year = {2010}, language = {en} } @article{SogomonyanSinghGoessel1998, author = {Sogomonyan, Egor S. and Singh, Adit D. and G{\"o}ssel, Michael}, title = {A scan based concrrent BIST approach for low cost on-line testing}, year = {1998}, language = {en} } @phdthesis{Chen2023, author = {Chen, Junchao}, title = {A self-adaptive resilient method for implementing and managing the high-reliability processing system}, doi = {10.25932/publishup-58313}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-583139}, school = {Universit{\"a}t Potsdam}, pages = {XXIII, 167}, year = {2023}, abstract = {As a result of CMOS scaling, radiation-induced Single-Event Effects (SEEs) in electronic circuits became a critical reliability issue for modern Integrated Circuits (ICs) operating under harsh radiation conditions. SEEs can be triggered in combinational or sequential logic by the impact of high-energy particles, leading to destructive or non-destructive faults, resulting in data corruption or even system failure. Typically, the SEE mitigation methods are deployed statically in processing architectures based on the worst-case radiation conditions, which is most of the time unnecessary and results in a resource overhead. Moreover, the space radiation conditions are dynamically changing, especially during Solar Particle Events (SPEs). The intensity of space radiation can differ over five orders of magnitude within a few hours or days, resulting in several orders of magnitude fault probability variation in ICs during SPEs. This thesis introduces a comprehensive approach for designing a self-adaptive fault resilient multiprocessing system to overcome the static mitigation overhead issue. This work mainly addresses the following topics: (1) Design of on-chip radiation particle monitor for real-time radiation environment detection, (2) Investigation of space environment predictor, as support for solar particle events forecast, (3) Dynamic mode configuration in the resilient multiprocessing system. Therefore, according to detected and predicted in-flight space radiation conditions, the target system can be configured to use no mitigation or low-overhead mitigation during non-critical periods of time. The redundant resources can be used to improve system performance or save power. On the other hand, during increased radiation activity periods, such as SPEs, the mitigation methods can be dynamically configured appropriately depending on the real-time space radiation environment, resulting in higher system reliability. Thus, a dynamic trade-off in the target system between reliability, performance and power consumption in real-time can be achieved. All results of this work are evaluated in a highly reliable quad-core multiprocessing system that allows the self-adaptive setting of optimal radiation mitigation mechanisms during run-time. Proposed methods can serve as a basis for establishing a comprehensive self-adaptive resilient system design process. Successful implementation of the proposed design in the quad-core multiprocessor shows its application perspective also in the other designs.}, language = {en} } @article{SchaubWang2003, author = {Schaub, Torsten H. and Wang, Kewen}, title = {A semantic framework for prefernce handling in answer set programming}, year = {2003}, language = {en} } @article{GoesselChakrabartyOcheretnijetal.2004, author = {Goessel, Michael and Chakrabarty, Krishnendu and Ocheretnij, V. and Leininger, Andreas}, title = {A signature analysis technique for the identification of failing vectors with application to Scan-BIST}, issn = {0923-8174}, year = {2004}, abstract = {We present a new technique for uniquely identifying a single failing vector in an interval of test vectors. This technique is applicable to combinational circuits and for scan-BIST in sequential circuits with multiple scan chains. The proposed method relies on the linearity properties of the MISR and on the use of two test sequences, which are both applied to the circuit under test. The second test sequence is derived from the first in a straightforward manner and the same test pattern source is used for both test sequences. If an interval contains only a single failing vector, the algebraic analysis is guaranteed to identify it. We also show analytically that if an interval contains two failing vectors, the probability that this case is interpreted as one failing vector is very low. We present experimental results for the ISCAS benchmark circuits to demonstrate the use of the proposed method for identifying failing test vectors}, language = {en} } @article{BesnardSchaub1996, author = {Besnard, Philippe and Schaub, Torsten H.}, title = {A simple signed system for paraconsistent reasoning}, isbn = {3-540-61630-6}, year = {1996}, language = {en} } @article{SeuringGoesselSogomonyan1998, author = {Seuring, Markus and G{\"o}ssel, Michael and Sogomonyan, Egor S.}, title = {A structural approach for space compaction for concurrent checking and BIST}, year = {1998}, language = {en} } @book{SeuringGoesselSogomonyan1997, author = {Seuring, Markus and G{\"o}ssel, Michael and Sogomonyan, Egor S.}, title = {A structural approach for space compaction for concurrent checking and BIST}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {1997, 01}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, publisher = {Univ. Potsdam}, address = {Potsdam [u.a.]}, issn = {0946-7580}, pages = {19 S. : Ill.}, year = {1997}, language = {en} } @article{SeuringGoessel1999, author = {Seuring, Markus and G{\"o}ssel, Michael}, title = {A structural approach for space compaction for sequential circuits}, year = {1999}, language = {en} } @book{SeuringGoessel1998, author = {Seuring, Markus and G{\"o}ssel, Michael}, title = {A structural approach for space compaction for sequential circuits}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {1998, 05}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, publisher = {Univ.}, address = {Potsdam}, issn = {0946-7580}, pages = {16 Bl. : graph. Darst.}, year = {1998}, language = {en} } @article{SeuringGoessel1999, author = {Seuring, Markus and G{\"o}ssel, Michael}, title = {A structural method for output compaction of sequential automata implemented as circuits}, year = {1999}, language = {en} } @article{LuckeRensing2014, author = {Lucke, Ulrike and Rensing, Christoph}, title = {A survey on pervasive education}, series = {Pervasive and mobile computing}, volume = {14}, journal = {Pervasive and mobile computing}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1574-1192}, doi = {10.1016/j.pmcj.2013.12.001}, pages = {3 -- 16}, year = {2014}, abstract = {Researchers and developers worldwide have put their efforts into the design, development and use of information and communication technology to support teaching and learning. This research is driven by pedagogical as well as technological disciplines. The most challenging ideas are currently found in the application of mobile, ubiquitous, pervasive, contextualized and seamless technologies for education, which we shall refer to as pervasive education. This article provides a comprehensive overview of the existing work in this field and categorizes it with respect to educational settings. Using this approach, best practice solutions for certain educational settings and open questions for pervasive education are highlighted in order to inspire interested developers and educators. The work is assigned to different fields, identified by the main pervasive technologies used and the educational settings. Based on these assignments we identify areas within pervasive education that are currently disregarded or deemed challenging so that further research and development in these fields are stimulated in a trans-disciplinary approach. (C) 2013 Elsevier B.V. All rights reserved.}, language = {en} } @article{AngerKonczakLinke2001, author = {Anger, Christian and Konczak, Kathrin and Linke, Thomas}, title = {A system for non-monotonic reasoning under answer set semantics}, isbn = {3-540-42593-4}, year = {2001}, language = {en} } @misc{FrankKreitz2018, author = {Frank, Mario and Kreitz, Christoph}, title = {A theorem prover for scientific and educational purposes}, series = {Electronic proceedings in theoretical computer science}, journal = {Electronic proceedings in theoretical computer science}, number = {267}, publisher = {Open Publishing Association}, address = {Sydney}, issn = {2075-2180}, doi = {10.4204/EPTCS.267.4}, pages = {59 -- 69}, year = {2018}, abstract = {We present a prototype of an integrated reasoning environment for educational purposes. The presented tool is a fragment of a proof assistant and automated theorem prover. We describe the existing and planned functionality of the theorem prover and especially the functionality of the educational fragment. This currently supports working with terms of the untyped lambda calculus and addresses both undergraduate students and researchers. We show how the tool can be used to support the students' understanding of functional programming and discuss general problems related to the process of building theorem proving software that aims at supporting both research and education.}, language = {en} } @article{Wang2001, author = {Wang, Kewen}, title = {A top-down procedure for disjucntive well-founded semantics}, year = {2001}, language = {en} } @article{Wang2001, author = {Wang, Kewen}, title = {A top-down procedure for disjucntive well-founded semantics}, isbn = {3-540-42254-4}, year = {2001}, language = {en} } @article{LyTarkhanov2009, author = {Ly, Ibrahim and Tarkhanov, Nikolai Nikolaevich}, title = {A variational approach to the Cauchy problem for nonlinear elliptic differential equations}, issn = {0928-0219}, doi = {10.1515/Jiip.2009.037}, year = {2009}, abstract = {We discuss the relaxation of a class of nonlinear elliptic Cauchy problems with data on a piece S of the boundary surface by means of a variational approach known in the optimal control literature as "equation error method". By the Cauchy problem is meant any boundary value problem for an unknown function y in a domain X with the property that the data on S, if combined with the differential equations in X, allow one to determine all derivatives of y on S by means of functional equations. In the case of real analytic data of the Cauchy problem, the existence of a local solution near S is guaranteed by the Cauchy-Kovalevskaya theorem. We also admit overdetermined elliptic systems, in which case the set of those Cauchy data on S for which the Cauchy problem is solvable is very "thin". For this reason we discuss a variational setting of the Cauchy problem which always possesses a generalised solution.}, language = {en} } @incollection{KiyListLucke2017, author = {Kiy, Alexander and List, Christoph and Lucke, Ulrike}, title = {A virtual environment and infrastructure to ensure future readiness of Computer Centers}, series = {European Journal of Higher Education IT}, volume = {2017}, booktitle = {European Journal of Higher Education IT}, number = {1}, issn = {2519-1764}, publisher = {Universit{\"a}t Potsdam}, year = {2017}, abstract = {The ongoing digitalization leads to a need of continuous change of ICT (Information and Communi-cation Technology) in all university domains and therefore affects all stakeholders in this arena. More and more ICT components, systems and tools occur and have to be integrated into the existing processes and infrastructure of the institutions. These tasks include the transfer of resources and information across multiple ICT systems. By using so-called virtual environments for domains of re-search, education, learning and work, the performance of daily tasks can be aided. Based on a user requirement analysis different short- and long-term objectives were identified and are tackled now in the context of a federal research project. In order to be prepared for the ongoing digitalization, new systems have to be provided. Both, a service-oriented infrastructure and a related web-based virtual learning environment constitute the platform Campus.UP and creates the necessary basis to be ready for future challenges. The current focus lies on e-portfolio work, hence we will present a related focus group evaluation. The results indicate a tremendous need to extend the possibilities of sharing resources across system boundaries, in order to enable a comfortable participation of exter-nal cooperating parties and to clarify the focus of each connected system. The introduction of such an infrastructure implies far-reaching changes for traditional data centers. Therefore, the challenges and risks of faculty conducting innovation projects for the ICT organization are taken as a starting point to stimulate a discussion, how data centers can utilize projects to be ready for the future needs. We are confident that Campus.UP will provide the basis for ensuring the persistent transfer of innovation to the ICT organization and thus will contribute to tackle the future challenges of digitalization.}, language = {en} } @phdthesis{Hu2006, author = {Hu, Ji}, title = {A virtual machine architecture for IT-security laboratories}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-7818}, school = {Universit{\"a}t Potsdam}, year = {2006}, abstract = {This thesis discusses challenges in IT security education, points out a gap between e-learning and practical education, and presents a work to fill the gap. E-learning is a flexible and personalized alternative to traditional education. Nonetheless, existing e-learning systems for IT security education have difficulties in delivering hands-on experience because of the lack of proximity. Laboratory environments and practical exercises are indispensable instruction tools to IT security education, but security education in conventional computer laboratories poses particular problems such as immobility as well as high creation and maintenance costs. Hence, there is a need to effectively transform security laboratories and practical exercises into e-learning forms. In this thesis, we introduce the Tele-Lab IT-Security architecture that allows students not only to learn IT security principles, but also to gain hands-on security experience by exercises in an online laboratory environment. In this architecture, virtual machines are used to provide safe user work environments instead of real computers. Thus, traditional laboratory environments can be cloned onto the Internet by software, which increases accessibility to laboratory resources and greatly reduces investment and maintenance costs. Under the Tele-Lab IT-Security framework, a set of technical solutions is also proposed to provide effective functionalities, reliability, security, and performance. The virtual machines with appropriate resource allocation, software installation, and system configurations are used to build lightweight security laboratories on a hosting computer. Reliability and availability of laboratory platforms are covered by a virtual machine management framework. This management framework provides necessary monitoring and administration services to detect and recover critical failures of virtual machines at run time. Considering the risk that virtual machines can be misused for compromising production networks, we present a security management solution to prevent the misuse of laboratory resources by security isolation at the system and network levels. This work is an attempt to bridge the gap between e-learning/tele-teaching and practical IT security education. It is not to substitute conventional teaching in laboratories but to add practical features to e-learning. This thesis demonstrates the possibility to implement hands-on security laboratories on the Internet reliably, securely, and economically.}, subject = {Computersicherheit}, language = {en} } @article{BrueningSchaub1999, author = {Br{\"u}ning, Stefan and Schaub, Torsten H.}, title = {A voiding non-ground variables}, year = {1999}, language = {en} } @article{Respondek2014, author = {Respondek, Tobias}, title = {A workflow for computing potential areas for wind turbines}, series = {Process design for natural scientists: an agile model-driven approach}, journal = {Process design for natural scientists: an agile model-driven approach}, number = {500}, publisher = {Springer}, address = {Berlin}, isbn = {978-3-662-45005-5}, pages = {200 -- 215}, year = {2014}, abstract = {This paper describes the implementation of a workflow model for service-oriented computing of potential areas for wind turbines in jABC. By implementing a re-executable model the manual effort of a multi-criteria site analysis can be reduced. The aim is to determine the shift of typical geoprocessing tools of geographic information systems (GIS) from the desktop to the web. The analysis is based on a vector data set and mainly uses web services of the "Center for Spatial Information Science and Systems" (CSISS). This paper discusses effort, benefits and problems associated with the use of the web services.}, language = {en} } @article{Schwill2001, author = {Schwill, Andreas}, title = {Ab wann kann man mit Indern Informatik machen? : eine Studie {\"u}ber informatische F{\"a}higkeiten von Kindern}, year = {2001}, language = {de} } @article{KonczakVogel2005, author = {Konczak, Kathrin and Vogel, Ralf}, title = {Abduction and Preferences in Linguistics}, year = {2005}, language = {en} } @article{KonczakVogel2005, author = {Konczak, Kathrin and Vogel, Ralf}, title = {Abduction and preferences in linguistics : Extended abstract}, issn = {0302-9743}, year = {2005}, language = {en} } @book{PupkaBartlKelleretal.1999, author = {Pupka, Reiner and Bartl, Peter and Keller, Vera and Kupries, Mario and Reichel, Ingrid and Schmidt, Maren and Tiede, Gabriele}, title = {Abschlußbericht zum Verbundprojekt "Rechnergest{\"u}tzte Modellierung und Steuerung der Vorgangsbearbeitung in verteilten Verwaltungs- und Organisationssystemen"}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {1999, 01}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, publisher = {Univ.}, address = {Potsdam}, issn = {0946-7580}, pages = {120, [21] Bl. : graph. Darst.}, year = {1999}, language = {de} } @article{Polyvyanyy2010, author = {Polyvyanyy, Artem}, title = {Abstraction of process specifications}, isbn = {978-3-86956-036-6}, year = {2010}, language = {en} } @article{FabianKunzKonnegenetal.2012, author = {Fabian, Benjamin and Kunz, Steffen and Konnegen, Marcel and M{\"u}ller, Sebastian and G{\"u}nther, Oliver}, title = {Access control for semantic data federations in industrial product-lifecycle management}, series = {Computers in industry : an international, application oriented research journal}, volume = {63}, journal = {Computers in industry : an international, application oriented research journal}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0166-3615}, doi = {10.1016/j.compind.2012.08.015}, pages = {930 -- 940}, year = {2012}, abstract = {Information integration across company borders becomes increasingly important for the success of product lifecycle management in industry and complex supply chains. Semantic technologies are about to play a crucial role in this integrative process. However, cross-company data exchange requires mechanisms to enable fine-grained access control definition and enforcement, preventing unauthorized leakage of confidential data across company borders. Currently available semantic repositories are not sufficiently equipped to satisfy this important requirement. This paper presents an infrastructure for controlled sharing of semantic data between cooperating business partners. First, we motivate the need for access control in semantic data federations by a case study in the industrial service sector. Furthermore, we present an architecture for controlling access to semantic repositories that is based on our newly developed SemForce security service. Finally, we show the practical feasibility of this architecture by an implementation and several performance experiments.}, language = {en} } @phdthesis{Zhou2008, author = {Zhou, Wei}, title = {Access control model and policies for collaborative environments}, address = {Potsdam}, pages = {199 S. : graph. Darst.}, year = {2008}, language = {en} } @book{OPUS4-11818, title = {Accessible Media : Pre-Proceedings of a Workshop Potsdam 8-9 May, 2006}, series = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, volume = {2006, 7}, journal = {Preprint / Universit{\"a}t Potsdam, Institut f{\"u}r Informatik}, editor = {J{\"u}rgensen, Helmut}, publisher = {Univ.}, address = {Potsdam}, issn = {0946-7580}, year = {2006}, language = {en} } @phdthesis{Sawade2012, author = {Sawade, Christoph}, title = {Active evaluation of predictive models}, publisher = {Universit{\"a}tsverlag Potsdam}, address = {Potsdam}, isbn = {978-3-86956-255-1}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-65583}, school = {Universit{\"a}t Potsdam}, pages = {ix, 157}, year = {2012}, abstract = {The field of machine learning studies algorithms that infer predictive models from data. Predictive models are applicable for many practical tasks such as spam filtering, face and handwritten digit recognition, and personalized product recommendation. In general, they are used to predict a target label for a given data instance. In order to make an informed decision about the deployment of a predictive model, it is crucial to know the model's approximate performance. To evaluate performance, a set of labeled test instances is required that is drawn from the distribution the model will be exposed to at application time. In many practical scenarios, unlabeled test instances are readily available, but the process of labeling them can be a time- and cost-intensive task and may involve a human expert. This thesis addresses the problem of evaluating a given predictive model accurately with minimal labeling effort. We study an active model evaluation process that selects certain instances of the data according to an instrumental sampling distribution and queries their labels. We derive sampling distributions that minimize estimation error with respect to different performance measures such as error rate, mean squared error, and F-measures. An analysis of the distribution that governs the estimator leads to confidence intervals, which indicate how precise the error estimation is. Labeling costs may vary across different instances depending on certain characteristics of the data. For instance, documents differ in their length, comprehensibility, and technical requirements; these attributes affect the time a human labeler needs to judge relevance or to assign topics. To address this, the sampling distribution is extended to incorporate instance-specific costs. We empirically study conditions under which the active evaluation processes are more accurate than a standard estimate that draws equally many instances from the test distribution. We also address the problem of comparing the risks of two predictive models. The standard approach would be to draw instances according to the test distribution, label the selected instances, and apply statistical tests to identify significant differences. Drawing instances according to an instrumental distribution affects the power of a statistical test. We derive a sampling procedure that maximizes test power when used to select instances, and thereby minimizes the likelihood of choosing the inferior model. Furthermore, we investigate the task of comparing several alternative models; the objective of an evaluation could be to rank the models according to the risk that they incur or to identify the model with lowest risk. An experimental study shows that the active procedure leads to higher test power than the standard test in many application domains. Finally, we study the problem of evaluating the performance of ranking functions, which are used for example for web search. In practice, ranking performance is estimated by applying a given ranking model to a representative set of test queries and manually assessing the relevance of all retrieved items for each query. We apply the concepts of active evaluation and active comparison to ranking functions and derive optimal sampling distributions for the commonly used performance measures Discounted Cumulative Gain and Expected Reciprocal Rank. Experiments on web search engine data illustrate significant reductions in labeling costs.}, language = {en} } @article{SawadeBickelvonOertzenetal.2013, author = {Sawade, Christoph and Bickel, Steffen and von Oertzen, Timo and Scheffer, Tobias and Landwehr, Niels}, title = {Active evaluation of ranking functions based on graded relevance}, series = {Machine learning}, volume = {92}, journal = {Machine learning}, number = {1}, publisher = {Springer}, address = {Dordrecht}, issn = {0885-6125}, doi = {10.1007/s10994-013-5372-5}, pages = {41 -- 64}, year = {2013}, abstract = {Evaluating the quality of ranking functions is a core task in web search and other information retrieval domains. Because query distributions and item relevance change over time, ranking models often cannot be evaluated accurately on held-out training data. Instead, considerable effort is spent on manually labeling the relevance of query results for test queries in order to track ranking performance. We address the problem of estimating ranking performance as accurately as possible on a fixed labeling budget. Estimates are based on a set of most informative test queries selected by an active sampling distribution. Query labeling costs depend on the number of result items as well as item-specific attributes such as document length. We derive cost-optimal sampling distributions for the commonly used performance measures Discounted Cumulative Gain and Expected Reciprocal Rank. Experiments on web search engine data illustrate significant reductions in labeling costs.}, language = {en} } @article{LuckowJhaKimetal.2009, author = {Luckow, Andre and Jha, Shantenu and Kim, Joohyun and Merzky, Andre and Schnor, Bettina}, title = {Adaptive distributed replica-exchange simulations}, issn = {1364-503X}, doi = {10.1098/rsta.2009.0051}, year = {2009}, abstract = {Owing to the loose coupling between replicas, the replica-exchange (RE) class of algorithms should be able to benefit greatly from using as many resources as available. However, the ability to effectively use multiple distributed resources to reduce the time to completion remains a challenge at many levels. Additionally, an implementation of a pleasingly distributed algorithm such as replica-exchange, which is independent of infrastructural details, does not exist. This paper proposes an extensible and scalable framework based on Simple API for Grid Applications that provides a general-purpose, opportunistic mechanism to effectively use multiple resources in an infrastructure-independent way. By analysing the requirements of the RE algorithm and the challenges of implementing it on real production systems, we propose a new abstraction (BIGJOB), which forms the basis of the adaptive redistribution and effective scheduling of replicas.}, language = {en} } @phdthesis{Hetzer2006, author = {Hetzer, Dirk}, title = {Adaptive Quality of Service based Bandwidth Planning in Internet}, address = {Potsdam}, pages = {190 S. : graph. Darst.}, year = {2006}, language = {en} } @article{Kupries1999, author = {Kupries, Mario}, title = {ADE : An architecture type-based development environment for agent application systems}, year = {1999}, language = {en} } @article{BrewkaEllmauthalerKernIsberneretal.2018, author = {Brewka, Gerhard and Ellmauthaler, Stefan and Kern-Isberner, Gabriele and Obermeier, Philipp and Ostrowski, Max and Romero, Javier and Schaub, Torsten H. and Schieweck, Steffen}, title = {Advanced solving technology for dynamic and reactive applications}, series = {K{\"u}nstliche Intelligenz}, volume = {32}, journal = {K{\"u}nstliche Intelligenz}, number = {2-3}, publisher = {Springer}, address = {Heidelberg}, issn = {0933-1875}, doi = {10.1007/s13218-018-0538-8}, pages = {199 -- 200}, year = {2018}, language = {en} } @phdthesis{Hecher2021, author = {Hecher, Markus}, title = {Advanced tools and methods for treewidth-based problem solving}, doi = {10.25932/publishup-51251}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-512519}, school = {Universit{\"a}t Potsdam}, pages = {xv, 184}, year = {2021}, abstract = {In the last decades, there was a notable progress in solving the well-known Boolean satisfiability (Sat) problem, which can be witnessed by powerful Sat solvers. One of the reasons why these solvers are so fast are structural properties of instances that are utilized by the solver's interna. This thesis deals with the well-studied structural property treewidth, which measures the closeness of an instance to being a tree. In fact, there are many problems parameterized by treewidth that are solvable in polynomial time in the instance size when parameterized by treewidth. In this work, we study advanced treewidth-based methods and tools for problems in knowledge representation and reasoning (KR). Thereby, we provide means to establish precise runtime results (upper bounds) for canonical problems relevant to KR. Then, we present a new type of problem reduction, which we call decomposition-guided (DG) that allows us to precisely monitor the treewidth when reducing from one problem to another problem. This new reduction type will be the basis for a long-open lower bound result for quantified Boolean formulas and allows us to design a new methodology for establishing runtime lower bounds for problems parameterized by treewidth. Finally, despite these lower bounds, we provide an efficient implementation of algorithms that adhere to treewidth. Our approach finds suitable abstractions of instances, which are subsequently refined in a recursive fashion, and it uses Sat solvers for solving subproblems. It turns out that our resulting solver is quite competitive for two canonical counting problems related to Sat.}, language = {en} } @article{WeskevanderAalstVerbeek2004, author = {Weske, Mathias and van der Aalst, Wil M. P. and Verbeek, H. M. W.}, title = {Advances in business process management}, issn = {0169-023X}, year = {2004}, language = {en} } @book{OPUS4-19402, title = {Advances in neural information processing systems 12 : proceedings of the 1999 conference}, editor = {Solla, Sara A. and M{\"u}ller, Klaus-Robert}, publisher = {MIT Press}, address = {Cambridge, Mass.}, isbn = {0-262-19450-3}, year = {2000}, language = {en} } @phdthesis{Mueller2016, author = {M{\"u}ller, Stephan Heinz}, title = {Aggregates Caching for Enterprise Applications}, school = {Universit{\"a}t Potsdam}, pages = {167}, year = {2016}, abstract = {The introduction of columnar in-memory databases, along with hardware evolution, has made the execution of transactional and analytical enterprise application workloads on a single system both feasible and viable. Yet, we argue that executing analytical aggregate queries directly on the transactional data can decrease the overall system performance. Despite the aggregation capabilities of columnar in-memory databases, the direct access to records of a materialized aggregate is always more efficient than aggregating on the fly. The traditional approach to materialized aggregates, however, introduces significant overhead in terms of materialized view selection, maintenance, and exploitation. When this overhead is handled by the application, it increases the application complexity, and can slow down the transactional throughput of inserts, updates, and deletes. In this thesis, we motivate, propose, and evaluate the aggregate cache, a materialized aggregate engine in the main-delta architecture of a columnar in-memory database that provides efficient means to handle costly aggregate queries of enterprise applications. For our design, we leverage the specifics of the main-delta architecture that separates a table into a main and delta partition. The central concept is to only cache the partial aggregate query result as defined on the main partition of a table, because the main partition is relatively stable as records are only inserted into the delta partition. We contribute by proposing incremental aggregate maintenance and query compensation techniques for mixed workloads of enterprise applications. In addition, we introduce aggregate profit metrics that increase the likelihood of persisting the most profitable aggregates in the aggregate cache. Query compensation and maintenance of materialized aggregates based on joins of multiple tables is expensive due to the partitioned tables in the main-delta architecture. Our analysis of enterprise applications has revealed several data schema and workload patterns. This includes the observation that transactional data is persisted in header and item tables, whereas in many cases, the insertion of related header and item records is executed in a single database transaction. We contribute by proposing an approach to transport these application object semantics to the database system and optimize the query processing using the aggregate cache by applying partition pruning and predicate pushdown techniques. For the experimental evaluation, we propose the FICO benchmark that is based on data from a productive ERP system with extracted mixed workloads. Our evaluation reveals that the aggregate cache can accelerate the execution of aggregate queries up to a factor of 60 whereas the speedup highly depends on the number of aggregated records in the main and delta partitions. In mixed workloads, the proposed aggregate maintenance and query compensation techniques perform up to an order of magnitude better than traditional materialized aggregate maintenance approaches. The introduced aggregate profit metrics outperform existing costbased metrics by up to 20\%. Lastly, the join pruning and predicate pushdown techniques can accelerate query execution in the aggregate cache in the presence of multiple partitioned tables by up to an order of magnitude.}, language = {en} } @article{HirschfeldSteinertLincke2011, author = {Hirschfeld, Robert and Steinert, Bastian and Lincke, Jens}, title = {Agile software development in virtual collaboration environments}, isbn = {978-3-642-13756-3}, year = {2011}, language = {en} } @phdthesis{Lindauer2014, author = {Lindauer, T. Marius}, title = {Algorithm selection, scheduling and configuration of Boolean constraint solvers}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-71260}, school = {Universit{\"a}t Potsdam}, pages = {ii, 130}, year = {2014}, abstract = {Boolean constraint solving technology has made tremendous progress over the last decade, leading to industrial-strength solvers, for example, in the areas of answer set programming (ASP), the constraint satisfaction problem (CSP), propositional satisfiability (SAT) and satisfiability of quantified Boolean formulas (QBF). However, in all these areas, there exist multiple solving strategies that work well on different applications; no strategy dominates all other strategies. Therefore, no individual solver shows robust state-of-the-art performance in all kinds of applications. Additionally, the question arises how to choose a well-performing solving strategy for a given application; this is a challenging question even for solver and domain experts. One way to address this issue is the use of portfolio solvers, that is, a set of different solvers or solver configurations. We present three new automatic portfolio methods: (i) automatic construction of parallel portfolio solvers (ACPP) via algorithm configuration,(ii) solving the \$NP\$-hard problem of finding effective algorithm schedules with Answer Set Programming (aspeed), and (iii) a flexible algorithm selection framework (claspfolio2) allowing for fair comparison of different selection approaches. All three methods show improved performance and robustness in comparison to individual solvers on heterogeneous instance sets from many different applications. Since parallel solvers are important to effectively solve hard problems on parallel computation systems (e.g., multi-core processors), we extend all three approaches to be effectively applicable in parallel settings. We conducted extensive experimental studies different instance sets from ASP, CSP, MAXSAT, Operation Research (OR), SAT and QBF that indicate an improvement in the state-of-the-art solving heterogeneous instance sets. Last but not least, from our experimental studies, we deduce practical advice regarding the question when to apply which of our methods.}, language = {en} }