作者：
De Brito, Halisson MatosStrauch, JuliaDe Souza, Jano MoreiraOsthoff, CarlaCOPPE/UFRJ
Systems Engineering and Computer Science Program Federal University of Rio de Janeiro PO Box 68511 ZIP Code: 21945-970 Rio de Janeiro RJ Brazil ENCE /IBGE
National School of Statistical Sciences 106 S. 401 ZIP Code: 20231-050 R. André Cavalcanti Rio de Janeiro RJ Brazil LNCC
National Laboratory for Scientific Computing Av. Getulio 333 Quitandinha Vargas Petrópolis RJ Brazil IM/UFRJ
Institute of Mathematics Federal University of Rio de Janeiro PO Box 68511 ZIP Code: 21945-970 Rio de Janeiro RJ Brazil
This paper presents MODENA, an architecture for scientific models management using Computational Grid platform. This architecture is comprised of two systems: ModManager and ModRunner. ModManager deals with knowledge ...
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This paper presents MODENA, an architecture for scientific models management using Computational Grid platform. This architecture is comprised of two systems: ModManager and ModRunner. ModManager deals with knowledge management about scientific models, acting as a scientific models library allowing for cataloguing, searching, reutilization and generation of new models. To achieve this, a metamodel is proposed to classify models, in order to support the organization, searching and retrieving of models. ModRunner manages the execution of models in a Grid environment allowing for model composition to generate a scientific Grid Workflow to be executed by distributed services offered by Grid Services. An initial prototype of ModManager is presented.
Synapses are a critical element of biologically-realistic, spike-based neural computation, serving the role of communication, computation, and modification. Many different circuit implementations of synapse function e...
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ISBN:
(纸本)0262201526
Synapses are a critical element of biologically-realistic, spike-based neural computation, serving the role of communication, computation, and modification. Many different circuit implementations of synapse function exist with different computational goals in mind. In this paper we describe a new CMOS synapse design that separately controls quiescent leak current, synaptic gain, and time-constant of decay. This circuit implements part of a commonly-used kinetic model of synaptic conductance. We show a theoretical analysis and experimental data for prototypes fabricated in a commercially-available 1.5μm CMOS process.
A novel microwave nondestructive testing technique is presented for breast cancer detection. A method utilizing the reflection coefficient at the aperture of a waveguide sensor radiating into a breast is described res...
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A novel microwave nondestructive testing technique is presented for breast cancer detection. A method utilizing the reflection coefficient at the aperture of a waveguide sensor radiating into a breast is described resulting in theoretical microwave images that clearly indicate the presence of a tumor. These images demonstrate the feasibility of detecting breast tumors using this approach
Integrated, low-power, low-noise CMOS neural amplifiers have recently grown in importance as large microelectrode arrays have begun to be practical. With an eye to a future where thousands of signals must be transmitt...
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Integrated, low-power, low-noise CMOS neural amplifiers have recently grown in importance as large microelectrode arrays have begun to be practical. With an eye to a future where thousands of signals must be transmitted over a limited bandwidth link or be processed in situ, we are developing low-power neural amplifiers with integrated pre-filtering and measurements of the spike signal to facilitate spike-sorting and data reduction prior to transmission to a data-acquisition system. We have fabricated a prototype circuit in a commercially-available 1.5 /spl mu/m, 2-metal, 2-poly CMOS process that occupies approximately 91,000 square /spl mu/m. We report circuit characteristics for a 1.5 V power supply, suitable for single cell battery operation. In one specific configuration, the circuit bandpass filters the incoming signal from 22 Hz to 6.7 kHz while providing a gain of 42.5 dB. With an amplifier power consumption of 0.8 /spl mu/W, the rms input-referred noise is 20.6 /spl mu/V.
We present the WebComposer tool for the automatic composition and execution of Web service-based workflows. We use ontologies to describe and browse workflows. We associate messages and operations with workflow domain...
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We present the WebComposer tool for the automatic composition and execution of Web service-based workflows. We use ontologies to describe and browse workflows. We associate messages and operations with workflow domain concepts using WSDL extensibility. The automatic workflow implementation through WebComposer enables the full separation of the workflow logic and the implementation technology. WebComposer provides the execution of ad-hoc programs by users and the automatic maintenance of these programs, as the available Web services are altered.
The semantic Web technology and the Web services description language extensibility may be combined to describe services in an unambiguous and machine interpretable way, automating Web services discovery, selection an...
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The semantic Web technology and the Web services description language extensibility may be combined to describe services in an unambiguous and machine interpretable way, automating Web services discovery, selection and invocation. In this paper, we present an algorithm and a prototype for the automatic composition of Web services that implement workflows described in a high level language. Our approach has many advantages comparing to the manual creation of a simple program composition, such as smaller implementation time and cost, reliability with the generation of contingency plans, greater capacity to evolve with the dynamic service discovery, and faster execution time with the use of heuristics. We use the OWLS ontology to semantically describe Web services metadata and indexes to help selecting them. The proposed algorithm considers that equivalent services may have different interfaces and also respects preferences of the users.
In this paper we consider a method for finding several eigenvalues and corresponding eigenvectors of large-scale generalized eigenvalue problems. In this method, a small matrix pencil that has only the desired eigenva...
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In this work, we present and analyze the use of a reconfigurable job scheduling simulator called RJSSim as an aid tool for parallel processing learning. This software is a functional and performance Java-based simulat...
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Dynamic programming (DP) is a principled way to design optimal controllers for certain classes of nonlinear systems;unfortunately, DP is computationally very expensive. The Reinforcement Learning methods known as Adap...
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Dynamic programming (DP) is a principled way to design optimal controllers for certain classes of nonlinear systems;unfortunately, DP is computationally very expensive. The Reinforcement Learning methods known as Adaptive Critics (AC) provide computationally feasible means for performing approximate Dynamic programming (ADP). The term 'adaptive ' in A C refers to the critic 's improved estimations of the Value Function used by DP. To apply DP, the user must craft a Utility function that embodies all the problem-specific design specifications/criteria. Model Reference Adaptive Control methods have been successfully used in the control community to effect on-line redesign of a controller in response to variations in plant parameters, with the idea that the resulting closed loop system dynamics will mimic those of a Reference Model. The work reported here 1) uses a reference model in ADP as the key information input to the Utility function, and 2) uses ADP off-line to design the desired controller. Future work will extend this to on-line application. This method is demonstrated for a hypersonic shaped airplane called LoFL YTE®;its handling characteristics are natively a little "hotter" than a pilot would desire. A control augmentation subsystem is designed using ADP to make the plane "feel like " a better behaved one, as specified by a Reference Model. The number of inputs to the successfully designed controller are among the largest seen in the literature to date.
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