Branch and Bound Based Load Balancing for Parallel Applications

Abstract. Many parallel applications are highly dynamic in nature. In some, computation and communication patterns change gradually dur-ing the run; in others those characteristics change abruptly. Such dy-namic applications require an adaptive load balancing strategy. We are exploring an adaptive approach based on multi-partition object-based decomposition, supported by object migration. For many applications, relatively infrequent load balancing is needed. In these cases it becomes economical to spend considerable computation time toward arriving at a nearly optimal mapping of objects to processors. We present an optimal-seeking branch and bound based strategy that finds nearly optimal so-lutions to such load balancing problems quickly, and can continuously improve such solutions as time permits.

Process-aware information systems : design, enactment and analysis

Process-aware information systems support operational business processes by combining advances in information technology with recent insights from management science. Workflow management systems are typical examples of such systems. However, many other types of information systems are also "process aware" even if their processes are hard-coded or only used implicitly (e.g., ERP systems). The shift from data orientation to process orientation has increased the importance process-aware information systems. Moreover, advanced analysis techniques ranging from simulation and verification to process mining and activity monitoring allow for systems that support process improvement in various ways. This article provides an overview of process-aware information systems and also relates these to business process management, workflow management, process analysis techniques, and process flexibility

Pairwise cardinality networks

Abstract. We introduce pairwise cardinality networks, networks of comparators, derived from pairwise sorting networks, which express cardinality constraints. We show that pairwise cardinality networks are superior to the cardinality networks introduced in previous work which are derived from odd-even sorting networks. Our presentation identifies the precise relationship between odd-even and pairwise sorting networks. This relationship also clarifies why pairwise sorting networks have significantly better propagation properties for the application of cardinality constraints.

Concurrently Decomposable Constraint Systems

Abstract. In constraint satisfaction, decomposition is a common technique to split a problem in a number of parts in such a way that the global solution can be efficiently assembled from the solutions of the parts. In this paper, we study the decomposition problem from an autonomous agent perspective. Here, a con-straint problem has to be solved by different agents each controlling a disjoint set of variables. Such a problem is called concurrently decomposable if each agent is (i) capable to solve its own part of the problem independently of the others, and (ii) the individual solutions always can be merged to a complete solution of the total problem. First of all, we investigate how difficult it is to decide whether or not a given constraint system and agent partitioning allows for such a concur-rent decomposition. Secondly, we investigate how difficult it is to find suitable reformulations of the original constraint problem that allow for concurrent de-composition.