2009
Autores
Santos, V; Oliveira, D; Oliveira, IC; Cunha, JPS;
Publicação
HEALTHINF 2009: PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON HEALTH INFORMATICS
Abstract
The Rede Telematica da Saude (RTS) is a telematic network connecting health care providers in the Aveiro region (Portugal), aiming at supporting the continuity of care. Using the RTS, health care professionals and institutions can securely share clinical data. RTS makes use of an integration engine, which accesses the scattered data sources to create a virtual unified view of patients' information. RTS is deployed over a wide-area private network, shared among a great variety of bandwidth links, systems and applications, which can impact the infrastructure service levels in multiple ways. In this paper, we describe the development of a toolkit for monitoring the performance of the distributed integration process. These analysis mechanisms make it is possible to detect bottlenecks and introduce optimizations in the system, especially with respect to the integration engine module. Its deployment in the production RTS health telematic network assists the maintenance team and the decision taking process to handle usage trends and systems needs.
2009
Autores
Barbosa, MA; Barbosa, LS;
Publicação
SCIENCE OF COMPUTER PROGRAMMING
Abstract
Service-oriented computing is an emerging paradigm with increasing impact on the way modern software systems are designed and developed. Services are autonomous, loosely coupled and heterogeneous computational entities able to cooperate to achieve common goals. This paper introduces a model for service orchestration, which combines a exogenous coordination model, with services' interfaces annotated with behavioural patterns specified in a process algebra which is parametric on the interaction discipline. The coordination model is a variant of REO for which a new semantic model is proposed. (C) 2009 Published by Elsevier B.V.
2009
Autores
Campos, MD; Barbosa, LS;
Publicação
Electronic Notes in Theoretical Computer Science
Abstract
Even though concurrent programming has been a hot topic of discussion in Computer Science for the past 30 years, the community has yet to settle on a, or a few standard approaches to implement concurrent programs. But as more and more cores inhabit our CPUs and more and more services are made available on the web the problem of coordinating different tasks becomes increasingly relevant. The present paper addresses this problem with an implementation of the orchestration language Orc as a domain specific language in Haskell. Orc was, therefore, realized as a combinator library using the lightweight threads and the communication and synchronization primitives of the Concurrent Haskell library. With this implementation it becomes possible to create orchestrations that re-use existing Haskell code and, conversely, re-use orchestrations inside other Haskell programs. The complexity inherent to distributed computation, entails the need for the classification of efficient, reusable, concurrent programming patterns. The paper discusses how the calculus of recursive schemes used in the derivation of functional programs, scales up to a distributed setting. It is shown, in particular, how to parallelize the entire class of binary tree hylomorphisms.
2009
Autores
Fontes, DBMM; Goncalves, JF;
Publicação
IJCCI 2009: PROCEEDINGS OF THE INTERNATIONAL JOINT CONFERENCE ON COMPUTATIONAL INTELLIGENCE
Abstract
In this work we propose a multi-population genetic algorithm for tree-shaped network design problems using random keys. Recent literature on finding optimal spanning trees suggests the use of genetic algorithms. Furthermore, random keys encoding has been proved efficient at dealing with problems where the relative order of tasks is important. Here we propose to use random keys for encoding trees. The topology of these trees is restricted, since no path from the root vertex to any other vertex may have more than a pre-defined number of arcs. In addition, the problems under consideration also exhibit the characteristic of flows. Therefore, we want to find a minimum cost tree satisfying all demand vertices and the pre-defined number of arcs. The contributions of this paper are twofold: on one hand we address a new problem, which is an extension of the well known NP-hard hop-constrained MST problem since we also consider determining arc flows such that vertices requirements are met at minimum cost and the cost functions considered include a fixed cost component and a nonlinear flow routing component; on the other hand, we propose a new genetic algorithm to efficiently find solutions to this problem.
2009
Autores
Sorensen, P; Manzur, A; Dahl, CE; Angle, J; Aprile, E; Arneodo, F; Baudis, L; Bernstein, A; Bolozdynya, A; Coelho, LCC; DeViveiros, L; Ferella, AD; Fernandes, LMP; Fiorucci, S; Gaitskell, RJ; Giboni, KL; Gomez, R; Hasty, R; Kastens, L; Kwong, J; Lopes, JAM; Madden, N; Manalaysay, A; McKinsey, DN; Monzani, ME; Ni, K; Oberlack, U; Orboeck, J; Plante, G; Santorelli, R; dos Santos, JMF; Shagin, P; Shutt, T; Schulte, S; Winant, C; Yamashita, M;
Publicação
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT
Abstract
XENON10 is an experiment designed to directly detect particle dark matter. It is a dual phase (liquid/gas) xenon time-projection chamber with 3D position imaging. Particle interactions generate a primary scintillation signal (S1) and ionization signal (S2), which are both functions of the deposited recoil energy and the incident particle type. We present a new precision measurement of the relative scintillation yield L(eff) and the absolute ionization yield 2, for nuclear recoils in xenon. A dark matter particle is expected to deposit energy by scattering from a xenon nucleus. Knowledge of L(eff) is therefore crucial for establishing the energy threshold of the experiment; this in turn determines the sensitivity to particle dark matter. Our L(eff) measurement is in agreement with recent theoretical predictions above 15 keV nuclear recoil energy, and the energy threshold of the measurement is similar to 4 keV. A knowledge of the ionization yield 2(y) is necessary to establish the trigger threshold of the experiment. The ionization yield 2(y) is measured in two ways, both in agreement with previous measurements and with a factor of 10 lower energy threshold.
2009
Autores
Gama, J; Costa, VS; Jorge, A; Brazdil, P;
Publicação
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
Abstract
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