Showing papers presented at "Dagstuhl Seminar Proceedings in 2013"

Software Engineering for Self-Adaptive Systems : A Second Research Roadmap

Abstract: The goal of this roadmap paper is to summarize the state-of-the-art and identify research challenges when developing, deploying and managing self-adaptive software systems. Instead of dealing with a wide range of topics associated with the field, we focus on four essential topics of self-adaptation: design space for self-adaptive solutions, software engineering processes for self-adaptive systems, from centralized to decentralized control, and practical run-time verification & validation for self-adaptive systems. For each topic, we present an overview, suggest future directions, and focus on selected challenges. This paper complements and extends a previous roadmap on software engineering for self-adaptive systems published in 2009 covering a different set of topics, and reflecting in part on the previous paper. This roadmap is one of the many results of the Dagstuhl Seminar 10431 on Software Engineering for Self-Adaptive Systems, which took place in October 2010.

Exponential Algorithms: Algorithms and Complexity Beyond Polynomial Time (Dagstuhl Seminar 13331)

Abstract: This report documents the program and the outcomes of Dagstuhl Seminar 13331 "Exponential Algorithms: Algorithms and Complexity Beyond Polynomial Time". Problems are often solved in practice by algorithms with worst-case exponential time complexity. It is of interest to find the fastest algorithms for a given problem, be it polynomial, exponential, or something in between. The focus of the Seminar is on finer-grained notions of complexity than np-completeness and on understanding the exact complexities of problems. The report provides a rationale for the workshop and chronicles the presentations at the workshop. The report notes the progress on the open problems posed at the past workshops on the same topic. It also reports a collection of results that cite the presentations at the previous seminar. The docoument presents the collection of the abstracts of the results presented at the Seminar. It also presents a compendium of open problems. (Less)

Rounds in Combinatorial Search

Abstract: A set system \(\mathcal{H} \subseteq2^{[m]}\) is said to be separating if for every pair of distinct elements x,y∈[m] there exists a set \(H\in\mathcal{H}\) such that H contains exactly one of them. The search complexity of a separating system \(\mathcal{H} \subseteq 2^{[m]}\) is the minimum number of questions of type “x∈H?” (where \(H \in\mathcal{H}\)) needed in the worst case to determine a hidden element x∈[m]. If we receive the answer before asking a new question then we speak of the adaptive complexity, denoted by \(\mathrm{c} (\mathcal{H})\); if the questions are all fixed beforehand then we speak of the non-adaptive complexity, denoted by \(\mathrm{c}_{na} (\mathcal{H})\). If we are allowed to ask the questions in at most k rounds then we speak of the k-round complexity of \(\mathcal{H}\), denoted by \(\mathrm{c}_{k} (\mathcal{H})\). It is clear that \(|\mathcal{H}| \geq\mathrm{c}_{na} (\mathcal{H}) = \mathrm{c}_{1} (\mathcal{H}) \geq\mathrm{c}_{2} (\mathcal{H}) \geq\cdots\geq\mathrm{c}_{m} (\mathcal{H}) = \mathrm{c} (\mathcal{H})\). A group of problems raised by G.O.H. Katona is to characterize those separating systems for which some of these inequalities are tight. In this paper we are discussing set systems \(\mathcal{H}\) with the property \(|\mathcal{H}| = \mathrm{c}_{k} (\mathcal{H}) \) for any k≥3. We give a necessary condition for this property by proving a theorem about traces of hypergraphs which also has its own interest.