Ontology Based Integration of Distributed and Heterogeneous Data Sources in ACGT.

In this work, we describe the set of tools comprising the Data Access Infrastructure within Advancing Clinic-genomic Trials on Cancer (ACGT), a R&D Project funded in part by the European. This infrastructure aims at improving Post-genomic clinical trials by providing seamless access to integrated clinical, genetic, and image databases. A data access layer, based on OGSA-DAI, has been developed in order to cope with syntactic heterogeneities in databases. The semantic problems present in data sources with different nature are tackled by two core tools, namely the Semantic Mediator and the Master Ontology on Cancer. The ontology is used as a common framework for semantics, modeling the domain and acting as giving support to homogenization. SPARQL has been selected as query language for the Data Access Services and the Mediator. Two experiments have been carried out in order to test the suitability of the selected approach, integrating clinical and DICOM image databases

A distributed implementation of the SWAN peer-to-peer look-up system using mobile agents

We present an agent-based implementation of the SWAN system. SWAN is a peer-to-peer look-up system that functions by letting the participating nodes self-organise in a virtual Small World Network. We have used DIET, a lightweight ecologically inspired multi-agent platform, to implement a test application of SWAN. We describe the implementation of the test application and present experiments in which the application runs on a cluster of computers. Our results show that the system is robust to failure and shows promising scalability

Towards a minimal hosting specification for open agent systems:the lessons of IP

In this paper we observe that the strategies adopted by many standards projects may unnecessarily restrict the range of agent control, addressing and communication strategies which can be hosted, and hence limit the adoption of conformant hosting platforms. We argue that a minimal hosting platform is required to achieve convergence to common standards. Using the example of Internet Protocol - a minimal communication standard addressing issues common to all supervening protocols - we hope to stimulate discussion of a minimal hosting specification, which could address issues common to the hosting of all supervening agent strategies. We draw the reader's attention to issues of resource contention and other conflicts of interest which are expected to arise in open, heterogeneous, agent systems. An analogy is drawn between the resource contention strategies adopted to manage IP route conflicts and the those required to manage hosting resource conflicts

A Genetic Approach to the Overlapped Scheduling of Iterative Data-Flow Graphs for Target Architectures with Communication Delays

This paper presents a method to solve the overlapped fully-static multiprocessor scheduling problem. An iterative data-flow graph (IDFG) is mapped on a target architecture that allows fine-grain parallelism. The goal is the minimization of the iteration period. The method can deal with nonzero delay times to communicate data between processors as well as with link capacities in the interconnection network. Excellent results for benchmark IDFGs have been obtained by the method that consists of three layers, each concentrating on a different aspect of the optimization problem. I. Introduction An algorithm that contains computations that can be executed simultaneously, offers possibilities of exploiting the parallelism present by implementing it on appropriate hardware such as a multiprocessor system. The class of algorithms considered in this paper is limited to algorithms that can be represented by homogeneous synchronous dataflow graphs [1], also called iterative data-flow graphs (ID..