Search results for "SIM"

showing 10 items of 10139 documents

SHARING THE BENEFITS OF COOPERATION IN HIGH SEAS FISHERIES: A CHARACTERISTIC FUNCTION GAME APPROACH

1998

Characteristic function (convex analysis)0208 environmental biotechnology02 engineering and technology010501 environmental sciencesEnvironmental Science (miscellaneous)01 natural sciencesShapley value020801 environmental engineeringMicroeconomicsInternational watersModeling and SimulationEconomicsMathematical economics0105 earth and related environmental sciencesNatural Resource Modeling
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Analysis of neuronal networks in the visual system of the cat using statistical signals

1976

If the input signals of the visual system in the cat are statistical patterns in space and time, a complete system analysis can be carried out. What counts here as a system are the neuronal networks between retina and recording site. In the case of linearity, one obtains the temporal impulse response functions at every point in the receptive field with the aid of correlation methods. The measuring time is about one minute. Some aspects of the procedure are explained in terms of examples. The method of measurement also makes it possible to determine the characteristic function of the system in time and space between different recording sites within the cortex. It is possible to specialize th…

Characteristic function (convex analysis)Systems AnalysisGeneral Computer ScienceModels NeurologicalStatistics as TopicComplex systemLinearityNonlinear systemSimple (abstract algebra)Receptive fieldCatsElectronic engineeringAnimalsVisual PathwaysPoint (geometry)AlgorithmImpulse responseBiotechnologyMathematicsBiological Cybernetics
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Thermomechanical effects in the flow of a fluid in porous media

2002

This paper deals with analysis, by methods of extended thermodynamics, of the thermomechanical effects which arise in the flow of a weakly viscous fluid in a porous medium. Under the hypothesis that the fluid fills all the interstices among the powder and that the size of the powder grains and of the interstices is much lower than a suitable characteristic length, linearized field equations are written, which include, in a natural way, terms which take into account the Dufour, Soret, and virtual mass effects. As a limiting case when the evolution time of the heat flux goes to infinite and no entropy flux is carried, the flow of liquid helium II in a porous medium is obtained.

Characteristic lengthThermodynamicsViscous liquidComputer Science ApplicationsPhysics::Fluid DynamicsHeat fluxModeling and SimulationMass transferModelling and SimulationHeat transferFluid dynamicsBoundary value problemPorous mediumMathematicsMathematical and Computer Modelling
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Application of Genetic Algorithm on Parameter Optimization of Three Vehicle Crash Scenarios

2017

Abstract This paper focuses on the development of mathematical models for vehicle frontal crashes. The models under consideration are threefold: a vehicle into barrier, vehicle-occupant and vehicle to vehicle frontal crashes. The first model is represented as a simple spring-mass-damper and the second case consists of a double-spring-mass-damper system, whereby the front mass and the rear mass represent the vehicle chassis and the occupant, respectively. The third model consists of a collision of two vehicles represented by two masses moving in opposite directions. The springs and dampers in the models are nonlinear piecewise functions of displacements and velocities respectively. More spec…

ChassisComputer scienceModeling010103 numerical & computational mathematics02 engineering and technologyCollision01 natural sciencesCrash testfrontal crashvehicle-occupantDamperNonlinear system020303 mechanical engineering & transports0203 mechanical engineeringControl theoryControl and Systems EngineeringGenetic algorithmparameters estimationgenetic algorithm0101 mathematicsSimulationfrontal crash; genetic algorithm; Modeling; parameters estimation; vehicle-occupant; Control and Systems EngineeringMotor vehicle crash
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Numerical investigations of single mode gyrotron equation

2009

A stationary problem with the integral boundary condition arising in the mathematical modelling of a gyrotron is numerically investigated. The Chebyshev's polynomials of the second kind are used as the tool of calculations. The main result with physical meaning is the possibility to determine the maximal value of electrons efficiency. First published online: 14 Oct 2010

Chebyshev polynomialsMathematical analysisSingle-mode optical fiberElectronChebyshev filterfinite‐difference schemeslaw.inventionChebyshev's polynomials of the second kindlawModeling and SimulationGyrotronQA1-939Boundary value problemMathematicsAnalysismathematical modelling of gyrotronMathematicsMathematical Modelling and Analysis
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Inverse simulated annealing for the determination of amorphous structures

2013

We present a new and efficient optimization method to determine the structure of disordered systems in agreement with available experimental data. Our approach permits the application of accurate electronic structure calculations within the structure optimization. The new technique is demonstrated within density functional theory by the calculation of a model of amorphous carbon.

Chemical Physics (physics.chem-ph)Condensed Matter - Materials ScienceMaterials scienceStatistical Mechanics (cond-mat.stat-mech)Structure (category theory)Experimental dataInverseMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesElectronic structureDisordered Systems and Neural Networks (cond-mat.dis-nn)Computational Physics (physics.comp-ph)Condensed Matter - Disordered Systems and Neural NetworksCondensed Matter PhysicsMolecular physicsElectronic Optical and Magnetic MaterialsAmorphous solidAmorphous carbonPhysics - Chemical PhysicsSimulated annealingDensity functional theoryPhysics - Computational PhysicsCondensed Matter - Statistical Mechanics
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On interactive multiobjective optimization with NIMBUS® in chemical process design

2005

We study multiobjective optimization problems arising from chemical process simulation. The interactive multiobjective optimization method NIMBUS®, developed at the University of Jyvaskyla, is combined with the BALAS® process simulator, developed at the VTT Technical Research Center of Finland, in order to provide a new interactive tool for designing chemical processes. Continuous interaction between the method and the designer provides a new efficient approach to explore Pareto optimal solutions and helps the designer to learn about the behaviour of the process. As an example of how the new tool can be used, we report the results of applying it in a heat recovery system design problem rela…

Chemical processPareto optimalMathematical optimizationComputer scienceProcess (engineering)Strategy and ManagementHeat recovery ventilationGeneral Decision SciencesProcess designProcess simulationMulti-objective optimizationIndustrial engineeringResearch centerJournal of Multi-Criteria Decision Analysis
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Short hydrogen bonds enhance nonaromatic protein-related fluorescence

2021

Significance Intrinsic fluorescence of nonaromatic amino acids is a puzzling phenomenon with an enormous potential in biophotonic applications. The physical origins of this effect, however, remain elusive. Herein, we demonstrate how specific hydrogen bond networks can modulate fluorescence. We highlight the key role played by short hydrogen bonds, present in the protein structure, on the ensuing fluorescence. We provide detailed experimental and molecular evidence to explain these unusual nonaromatic optical properties. Our findings should benefit the design of novel optically active biomaterials for applications in biosensing and imaging.

Chemical transformationOptics and PhotonicsGlutamineIntrinsic fluorescenceMolecular Dynamics SimulationPhotochemistryFluorescenceAb initio molecular dynamicsAmmoniaHumansSingle amino acidshort hydrogen bondDensity Functional TheoryMultidisciplinaryHydrogen bondChemistryintrinsic fluorescenceultraviolet fluorescenceHydrogen BondingConical intersectionFluorescenceBiophysics and Computational BiologyExcited statePhysical Sciences408PeptidesProceedings of the National Academy of Sciences of the United States of America
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Assessment of the Potential Energy Hypersurfaces in Thymine within Multiconfigurational Theory: CASSCF vs. CASPT2

2016

The present study provides new insights into the topography of the potential energy hypersurfaces (PEHs) of the thymine nucleobase in order to rationalize its main ultrafast photochemical decay paths by employing two methodologies based on the complete active space self-consistent field (CASSCF) and the complete active space second-order perturbation theory (CASPT2) methods: (i) CASSCF optimized structures and energies corrected with the CASPT2 method at the CASSCF geometries and (ii) CASPT2 optimized geometries and energies. A direct comparison between these strategies is drawn, yielding qualitatively similar results within a static framework. A number of analyses are performed to assess t…

Chemistry Multidisciplinary2-DIMENSIONAL ELECTRONIC SPECTROSCOPYPharmaceutical Sciencephotostability0305 Organic Chemistry01 natural sciencesLOWEST TRIPLET-STATEAnalytical ChemistryInterpretation (model theory)Molecular dynamicschemistry.chemical_compoundComputational chemistryDrug DiscoveryComplete active spacePerturbation theoryRETINAL CHROMOPHORE MODELComputingMilieux_MISCELLANEOUSAB-INITIOphotochemistry010304 chemical physicsBasis (linear algebra)ChemistryCOUPLED-CLUSTER METHODSPhotochemical ProcessesPotential energy[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistryChemistryChemistry (miscellaneous)2ND-ORDER PERTURBATION-THEORYPhysical SciencesANO BASIS-SETSCASSCF/CASPT2Molecular MedicineThermodynamicsLife Sciences & BiomedicineBiochemistry & Molecular BiologyField (physics)INITIO MOLECULAR-DYNAMICSMolecular Dynamics Simulation010402 general chemistryMolecular physicsArticlelcsh:QD241-441lcsh:Organic chemistryCASSCF/CASPT2; photochemistry; DNA; thymine; photostability0103 physical sciencesthyminePhysical and Theoretical ChemistryULTRAFAST INTERNAL-CONVERSIONScience & TechnologyOrganic ChemistryDNAEXCITED-STATE DYNAMICS0104 chemical sciencesThymineModels ChemicalMolecules; Volume 21; Issue 12; Pages: 1666
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Ring diameter effects on determination of field-saturated hydraulic conductivity of different loam soils

2017

Abstract Establishing ring diameter effects on the field-saturated soil hydraulic conductivity, Kfs, determined with ponding infiltrometer methods can help to find a compromise between the need to sample a large area with an individual measurement and the impracticality of using large rings in the field. Five ring sizes (diameter, D = 5.5, 10.9, 16.0, 27.8 and 31.8 cm) were used to determine Kfs by the simplified falling head (SFH) technique in four loamy soils with different salinity (electrical conductivity of saturated extract, ECe = 0.9–29.4 dS/m) and sodicity (exchangeable sodium percentage, ESP = 2.7–81.3%) levels. According to USDA classification, two soils were non-saline, non-sodic…

Chemistry0208 environmental biotechnologySoil ScienceSoil science04 agricultural and veterinary sciences02 engineering and technologyRing (chemistry)020801 environmental engineeringSalinitySaturated soil hydraulic conductivityHydraulic conductivitySalt-affected soilElectrical resistivity and conductivitySimplified falling head techniqueLoamSoil water040103 agronomy & agriculture0401 agriculture forestry and fisheriesSettore AGR/08 - Idraulica Agraria E Sistemazioni Idraulico-ForestaliInfiltrometerPonding infiltration methodPonding
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