A new global optimization algorithm for functions of continuous variables is presented, derived from the “Simulated Annealing” recently introduced in combinatorial optimization. The essentially an iterative random search procedure with adaptive moves along coordinate directions. It permits uphill under control a probabilistic criterion, thus tending to avoid first local minima encountered. has been tested against Nelder and Mead simplex method version Adaptive Random Search. test were...

Procedures for the calibration of computer-controlled network analyzers in reflection measurements are studied. The major aim this paper is to develop an error analysis order define a quality factor, evaluating performances procedure. This done by using invariance property cross ratio, which easily lets one obtain analytical expressions residual errors As application technique, comparison between two actual procedures has been made automatic analyzer. experimental results favorably compare...

A highly accurate electromagnetic characterisation of open-circuited coaxial lines terminating in a circular waveguide has been obtained with view to the employment such devices as calibration standards for microwave measurements. The theoretical results have compared corresponding experimental data range 1 kHz∼18 GHz an open-line standard common use. agreement is very good.

The dynamical behavior of the electrophysiological response at epicardium isolated Langendorff-perfused rabbit heart during different induced arrhythmic conditions is studied with use correlation dimension D 2 and Lyapunov exponents. Different are investigated: normal sinus rhythm (NSR), after ischemia (NSRI), ventricular fibrillation without perfusion (VFWP VF, respectively). Both single lead simultaneous recordings from four leads analyzed. dimensions VF VFWP significantly higher than NSR...

Abstract The rapid evolution of Grid Computing and the development new middleware services make platforms increasingly used not only for best effort scientific jobs but also in industrial business applications. This has taken to growing demand Quality Service (QoS) support. However, QoS issue on is quite difficult, as been originally designed without any support, it a complex system. During previous years some solutions have proposed supply specific classes results focused heterogeneous...

A preliminary analysis of the Lyapunov spectrum determination from a time-series with Jacobian-based approach is presented. The method has been tested on Lorenz attractor obtaining good exponents estimate, then it applied to study ECG signals coming MIT-BIH Arrhythmia Database. We obtained almost always positive first exponent confirming chaotic nature electrical heart activity measured surface EGG. However, estimate often influenced by choice some working parameters. main purpose this work...

We present a distributed approach for grid resource discovery, which combines structured view of resources (single machines, homogeneous and heterogeneous clusters) at the physical organization (PO) level with super-peer network connecting various POs. The proposed architecture is modular independent particular middleware. After general description, we some implementation aspects refer to Globus Toolkit 4 as middleware JXTA platform set-up network. system particularly suitable discovering...

An algorithm is presented for efficient computation of the correlation dimension from a time series. The main feature use variable number points in order to keep close pairs approximately constant at various scales and embedding dimensions. procedure consists steps with decreasing cutoff distance; each step only neighboring are considered, using box-assisted approach. tested by performing some trials on series known model attractors. With respect standard algorithm, one proposed here yields...

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We present a parallel algorithm for computing the correlation dimension (D2) from time series generated by dynamic system, using method of integrals, which essentially requires computation distances among set points in state space. The parallelization is suitable coarse-grained multiprocessor systems with distributed memory and carried out virtually shared model. simultaneously gives all integrals at various space dimensions needed to estimate D2. Two versions are discussed: first computes...

We present a distributed matchmaking methodology based on two-level (low-level and application-level) benchmarking, that allows the specification of both syntactic performance requirements. In particular, we point out how use application-level benchmarks gives more accurate characterization resources, so enabling better exploitation Grid power. The proposed relies standard description languages at application resource sides, to foster interoperability. Moreover, tool is...