It is shown how a large class of applications can be parallelized by modeling them as tree shaped computations. In particular this class contains many highly irregular and completely unpredictable computations as they occur in heuristic search. We explain why the model even remains useful in the presence of some frequently observed subproblem dependencies.

In this paper we deal with the location of extensive facilities on trees, both discrete and continuous, under the condition that existing facilities are already located. We require that the selected new server is a subtree, although we also specialize to the case of paths. We study the problem with the two most widely used criteria in Location Analysis: center and median. Our main results under...

Description logic (DL) formalisms are extensively used for ontological modelling, e.g., in biology [16] and chemistry [19]. One such example is the ChEBI ontology [20] – a reference terminology adopted by various biological databases for chemical annotation [23,8,10]. Despite their wide range of expressive features, DLs are severely limited in their ability to represent structures that are not ...

Incremental learning is a very important approach to learning when data is presented in short chunks of instances. In such situations, there is an obvious need for improving the performance and accuracy of knowledge representations or data models as new data is available. It would be too costly, in computing time and memory space, to use the batch algorithms processing again the old data togeth...

Non-parametric graph scan (NPGS) statistics are used to detect anomalous connected subgraphs on graphs, and have a wide variety of applications, such as disease outbreak detection, road traffic congestion detection, and event detection in social media. In contrast to traditional parametric scan statistics (e.g., the Kulldorff statistic), NPGS statistics are free of distributional assumptions an...

Parallelizing a problem by statically assigning a xed number of subprob-lems to each processor is very popular due to its simplicity and low communication overhead. In many cases it can be proved to be suucient to randomly assign O(log N) subproblems to each of N processors in order to smooth out load imbalance due to varying subproblem sizes. However, this is not true for the tree structured c...

In this paper, we focus on the problem of scheduling a collection of similar task graphs on a heterogeneous platform, when the task graph is an intree. We rely on steady-state scheduling techniques, and aim at optimizing the throughput of the system. Contrarily to previous studies, we concentrate on practical aspects of steady-state scheduling, when dealing with a collection (or batch) of limit...

The paper presents a high-level declarative language CO4 for describing constraint systems. The language includes user-defined algebraic data types and recursive functions defined by pattern matching, as well as higher-order and polymorphic types. This language comes with a compiler that transforms a high-level constraint system into a satisfiability problem in propositional logic. This is moti...

In recent work on the Clique problem by Chen, Huang, Kanj, and Xia (2006) it was shown that if k-Clique is solvable in no(k) time, then the exponential time hypothesis is false. In this work, we focus on a related parameterized problem called intersection non-emptiness. We show that if intersection non-emptiness for two tree shaped DFA’s is solvable in O(n2− ) time, then the strong exponential ...