Search results for "Computer simulation"
showing 10 items of 1054 documents
Statistical geometric affinity in human brain electric activity
2007
10 pages, 9 figures.-- PACS nrs.: 87.19.La; 05.45.Tp.-- ISI Article Identifier: 000246890100105
Measuring the agreement between brain connectivity networks.
2016
Investigating the level of similarity between two brain networks, resulting from measures of effective connectivity in the brain, can be of interest from many respects. In this study, we propose and test the idea to borrow measures of association used in machine learning to provide a measure of similarity between the structure of (un-weighted) brain connectivity networks. The measures here explored are the accuracy, Cohen's Kappa (K) and Area Under Curve (AUC). We implemented two simulation studies, reproducing two contexts of application that can be particularly interesting for practical applications, namely: i) in methodological studies, performed on surrogate data, aiming at comparing th…
Multi-level optimization of a fiber transmission system via nonlinearity management
2006
Nonlinearity management is explored as a complete tool to obtain maximum transmission reach in a WDM fiber transmission system, making it possible to optimize multiple system parameters, including optimal dispersion pre-compensation, with fast simulations based on the continuous-wave approximation. © 2006 Optical Society of America.
An Information-Theoretic Framework to Measure the Dynamic Interaction between Neural Spike Trains
2021
Understanding the interaction patterns among simultaneous recordings of spike trains from multiple neuronal units is a key topic in neuroscience. However, an optimal approach of assessing these interactions has not been established, as existing methods either do not consider the inherent point process nature of spike trains or are based on parametric assumptions that may lead to wrong inferences if not met. This work presents a framework, grounded in the field of information dynamics, for the model-free, continuous-time estimation of both undirected (symmetric) and directed (causal) interactions between pairs of spike trains. The framework decomposes the overall information exchanged dynami…
CoCoDat: a database system for organizing and selecting quantitative data on single neurons and neuronal microcircuitry.
2004
We present a novel database system for organizing and selecting quantitative experimental data on single neurons and neuronal microcircuitry that has proven useful for reference-keeping, experimental planning and computational modelling. Building on our previous experience with large neuroscientific databases, the system takes into account the diversity and method-dependence of single cell and microcircuitry data and provides tools for entering and retrieving published data without a priori interpretation or summarizing. Data representation is based on the framework suggested by biophysical theory and enables flexible combinations of data on membrane conductances, ionic and synaptic current…
Motion Control of Large Inertia Loads Using Electrohydrostatic Actuation
2020
Electrohydrostatic actuation is an emerging technology combining the advantages of hydraulic and electric actuation, resulting in energy efficient solutions that appear electric from the outside while hydraulic on the inside. Conventional solutions, however, significantly reduce the natural frequency of the system compared to traditional hydraulic actuators. This may result in considerable loss of performance under feedback control. In this paper, a simple modification for increasing the natural frequency of the system involving a high-pressure accumulator is proposed and investigated. Theoretical analysis demonstrates the potential for considerable improvements using the proposed solution,…
Numerical simulation of radiated EMI in 42V electrical automotive architectures
2006
The work is focused on the evaluation of radiated electromagnetic interference generated by dc/dc converters in 42 V systems automotive environment. The results obtained by using the method of moments and the finite difference time domain method, separately, are presented and validated in comparison with those measured in a semi-anechoic electromagnetic chamber. A measurement system set up by the authors is employed. Both the used numerical approaches are proved to be an useful tool for radiated disturbance prediction, and also for electromagnetic compatibility oriented design of the vehicle electrical architecture.
Numerical Simulation of Thermal Effects in Coupled Optoelectronic Device-circuit Systems
2008
The control of thermal effects becomes more and more important in modern semiconductor circuits like in the simplified CMOS transceiver representation described by U. Feldmann in the above article Numerical simulation of multiscale models for radio frequency circuits in the time domain. The standard approach for modeling integrated circuits is to replace the semiconductor devices by equivalent circuits consisting of basic elements and resulting in so-called compact models. Parasitic thermal effects, however, require a very large number of basic elements and a careful adjustment of the resulting large number of parameters in order to achieve the needed accuracy.
An efficient swap algorithm for the lattice Boltzmann method
2007
During the last decade, the lattice-Boltzmann method (LBM) as a valuable tool in computational fluid dynamics has been increasingly acknowledged. The widespread application of LBM is partly due to the simplicity of its coding. The most well-known algorithms for the implementation of the standard lattice-Boltzmann equation (LBE) are the two-lattice and two-step algorithms. However, implementations of the two-lattice or the two-step algorithm suffer from high memory consumption or poor computational performance, respectively. Ultimately, the computing resources available decide which of the two disadvantages is more critical. Here we introduce a new algorithm, called the swap algorithm, for t…
Thermal simulation of a power transformer
2019
In the article we propose a method of thermally constructive optimization of a 110/20 kV power transformer by numerical simulation (by the finite element method) of the thermal field in the transformer. The thermal simulation was done in the Comsol module called Heat Transfer Module, based on the documentation in Catia V5, and the experimental validation was done by thermography.