AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

Article in monograph or in proceedingsLeiden Inst Advanced Computer Science

Analyse der Hepatitis-C-Situation bei den drogenkonsumierenden Personen in der Schweiz

Die Analyse der Hepatitis-C-Situation bei den drogenkonsumierenden Personen in der Schweiz beruht auf verschiedenen Methoden: Analyse der publizierten und grauen Literatur zu diesem Thema, Sekundäranalyse verfügbarer Daten, Befragung nationaler Fachpersonen, Befragung drogenkonsumierender Personen (DU), Fallstudien in vier Kantonen (Zürich, Waadt, Aargau, Wallis), Internetumfrage bei den Einrichtungen, die DU stationär oder ambulant behandeln, sowie bei den niederschwelligen Einrichtungen zur Risikominderung. In den vergangenen zwei Jahrzehnten erreichte die Zahl der neu gemeldeten Infektionen mit dem Hepatitis-C-Virus (HCV) Ende der 90er-Jahre eine Spitze mit mehr als 2500 Fällen pro Jahr, wobei mehr als 30 % dieser Fälle Personen betrafen, die intravenös Drogen konsumieren (IDU). Die Zahl neu gemeldeter Fälle sank anschliessend bis auf 1500 Fälle im Jahr 2011 und stieg dann wieder auf mehr als 1700 Fälle im Jahr 2013 an. Der Anteil der IDU belief sich auf etwas mehr 20 % (436 Fälle, kein Wiederanstieg der Anzahl neuer Fälle in dieser Bevölkerungsgruppe). Die für die Gesamtbevölkerung der Schweiz geschätzte Prävalenz der HCV-Infektionen bewegt sich je nach Autor zwischen 0,7 % und 1,75 %. Bei Männern, die Sex mit Männern haben (MSM), ist dieser Wert etwas höher (2 %). Bei Staatsangehörigen aus Ländern mit einer höheren Prävalenz (Afrika südlich der Sahara, bestimmte Länder des Nahen Ostens und Südostasiens) ist die Prävalenzrate vermutlich erhöht; es sind jedoch keine Werte bekannt. Auch in Gefängnissen ist die HCV-Prävalenz höher als in der Gesamtbevölkerung, da DU und Staatsangehörige aus Ländern mit höherer Prävalenz stärker vertreten sind (zwischen 5 und 10 %). Es wird davon ausgegangen, dass es bei etwa zwei Drittel der Fälle zu einem chronischen Krankheitsverlauf kommt

Evaluation Techniques and Systems for Answer Set Programming: a Survey

Answer set programming (ASP) is a prominent knowledge representation and reasoning paradigm that found both industrial and scientific applications. The success of ASP is due to the combination of two factors: a rich modeling language and the availability of efficient ASP implementations. In this paper we trace the history of ASP systems, describing the key evaluation techniques and their implementation in actual tools

AutoFolio: An Automatically Configured Algorithm Selector (Extended Abstract)

Algorithms and the Foundations of Software technolog

Swarm Keeping Strategies for Spacecraft under J_2 and Atmospheric Drag Perturbations

This paper presents several new open-loop guidance methods for spacecraft swarms composed of hundreds to thousands of agents with each spacecraft having modest capabilities. These methods have three main goals: preventing relative drift of the swarm, preventing collisions within the swarm, and minimizing the propellant used throughout the mission. The development of these methods progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the J_2 drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics include the two main disturbances for spacecraft in Low Earth Orbit (LEO), J_2 and atmospheric drag. Using this dynamic model, numerical simulations are provided at each step to show the effectiveness of each method and to see where improvements can be made. The main result is a set of initial conditions for each spacecraft in the swarm which provides the trajectories for hundreds of collision-free orbits in the presence of J_2. Finally, a multi-burn strategy is developed in order to provide hundreds of collision-free orbits under the influence of atmospheric drag. This last method works by enforcing the initial conditions multiple times throughout the mission thereby providing collision-free trajectories for the duration of the mission

Antiferromagnetic interlayer exchange coupling across an amorphous metallic spacer layer

By means of magneto-optical Kerr effect we observe for the first time antiferromagnetic coupling between ferromagnetic layers across an amorphous metallic spacer layer. Biquadratic coupling occurs at the transition from a ferromagnetically to an antiferromagnetically coupled region. Scanning tunneling microscopy images of all involved layers are used to extract thickness fluctuations and to verify the amorphous state of the spacer. The observed antiferromagnetic coupling behavior is explained by RKKY interaction taking into account the amorphous structure of the spacer material.Comment: Typset using RevTex, 4 pages with 4 figures (.eps

The DLV System for Knowledge Representation and Reasoning

This paper presents the DLV system, which is widely considered the state-of-the-art implementation of disjunctive logic programming, and addresses several aspects. As for problem solving, we provide a formal definition of its kernel language, function-free disjunctive logic programs (also known as disjunctive datalog), extended by weak constraints, which are a powerful tool to express optimization problems. We then illustrate the usage of DLV as a tool for knowledge representation and reasoning, describing a new declarative programming methodology which allows one to encode complex problems (up to $\Delta^P_3$-complete problems) in a declarative fashion. On the foundational side, we provide a detailed analysis of the computational complexity of the language of DLV, and by deriving new complexity results we chart a complete picture of the complexity of this language and important fragments thereof. Furthermore, we illustrate the general architecture of the DLV system which has been influenced by these results. As for applications, we overview application front-ends which have been developed on top of DLV to solve specific knowledge representation tasks, and we briefly describe the main international projects investigating the potential of the system for industrial exploitation. Finally, we report about thorough experimentation and benchmarking, which has been carried out to assess the efficiency of the system. The experimental results confirm the solidity of DLV and highlight its potential for emerging application areas like knowledge management and information integration.Comment: 56 pages, 9 figures, 6 table

Dynamics of heteropolymers in dilute solution: effective equation of motion and relaxation spectrum

The dynamics of a heteropolymer chain in solution is studied in the limit of long chain length. Using functional integral representation we derive an effective equation of motion, in which the heterogeneity of the chain manifests itself as a time-dependent excluded volume effect. At the mean field level, the heteropolymer chain is therefore dynamically equivalent to a homopolymer chain with both time-independent and time-dependent excluded volume effects. The perturbed relaxation spectrum is also calculated. We find that heterogeneity also renormalizes the relaxation spectrum. However, we find, to the lowest order in heterogeneity, that the relaxation spectrum does not exhibit any dynamic freezing, at the point when static (equilibrium) ``freezing'' transition occurs in heteropolymer. Namely, the breaking of fluctuation-dissipation theorem (FDT) proposed for spin glass dynamics does not have dynamic effect in heteropolymer, as far as relaxation spectrum is concerned. The implication of this result is discussed

Microparticles from patients with metabolic syndrome induce vascular hypo-reactivity via Fas/Fas-ligand pathway in mice

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