17 resultados para Computer Simulation
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Our new simple method for calculating accurate Franck-Condon factors including nondiagonal (i.e., mode-mode) anharmonic coupling is used to simulate the C2H4+X2B 3uC2H4X1 Ag band in the photoelectron spectrum. An improved vibrational basis set truncation algorithm, which permits very efficient computations, is employed. Because the torsional mode is highly anharmonic it is separated from the other modes and treated exactly. All other modes are treated through the second-order perturbation theory. The perturbation-theory corrections are significant and lead to a good agreement with experiment, although the separability assumption for torsion causes the C2 D4 results to be not as good as those for C2 H4. A variational formulation to overcome this circumstance, and deal with large anharmonicities in general, is suggested
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Per tal que un edifici de sortida de telecabines d'Espui obtingui una qualificaci energtica, es fa un estudi mitjanant sistemes de simulaci energtica
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Estudi de leficincia aerodinmica de les carrosseries de vehicles pesants de cara a reduir el consum de combustible en autocars de llarg trajecte. Lestudi es basa en tres aspectes: validaci del programa de simulaci, estudi aerodinmic de diferents carrosseries dautocar de mercat i estudi aerodinmic de diferents complements
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La dinmica de fluids computacional (CFD) s una eina que serveix per analitzar mitjanant computadors diferents problemes que involucren fluxos de fluids. Els programes de CFD usen expressions matemtiques no lineals que defineixen les equacions fonamentals de fluxos i transport de calor en fluids. Aquestes es resolen amb complexos algoritmes iteratius. Actualment aquesta eina s una part fonamental en els procs de disseny en moltes empreses relacionades amb la dinmica de fluids. Les simulacions que es realitzen amb aquests programes sha demostrat que sn fiables i que estalvien temps i diners, ja que eviten haver de realitzar els costosos processos dassaig-error. En el projecte sutilitza el programa de CFD Ansys CFX 11.0 per simular una agitaci bifsica composta per aigua i aire a temperatura ambient. Els objectius sn determinar els parmetres ptims de simulaci que permetin recrear aquesta agitaci, per posteriorment dissenyar un nou impulsor
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Lobjectiu daquest projecte s realitzar lanlisi, disseny i implementaci duna nova eina per analitzar les diferencies entre el paper que sest produint i les mostres de referncia, que millori els resultats obtinguts pel prototipus anterior i faciliti la interpretaci dels resultats obtinguts, per part dels operaris de lempresa. Partint de dos imatges escannejades que anomenem patr i mostra, que corresponen respectivament a les imatges de referncia i de la mostra de producci
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Un bon sistema dil.luminaci juga un paper molt important per tal que els videojocs siguin realistes i atractius per a lusuari. El projecte intenta optimitzar el sistema dil.luminaci de manera que la crrega que representa per al sistema sigui inferior, sense haver de renunciar a la qualitat que tindrem sense fer servir aquest sistema. Amb dos objectius molt concrets: entendre i implementar lalgoritme de lightcuts i aconseguir una optimitzaci en una escena utilitzant aquest algoritme
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This paper overviews the field of graphical simulators used for AUV development, presents the taxonomy of these applications and proposes a classification. It also presents Neptune, a multivehicle, real-time, graphical simulator based on OpenGL that allows hardware in the loop simulations
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This paper presents the distributed environment for virtual and/or real experiments for underwater robots (DEVRE). This environment is composed of a set of processes running on a local area network composed of three sites: 1) the onboard AUV computer; 2) a surface computer used as human-machine interface (HMI); and 3) a computer used for simulating the vehicle dynamics and representing the virtual world. The HMI can be transparently linked to the real sensors and actuators dealing with a real mission. It can also be linked with virtual sensors and virtual actuators, dealing with a virtual mission. The aim of DEVRE is to assist engineers during the software development and testing in the lab prior to real experiments
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A long development time is needed from the design to the implementation of an AUV. During the first steps, simulation plays an important role, since it allows for the development of preliminary versions of the control system to be integrated. Once the robot is ready, the control systems are implemented, tuned and tested. The use of a real-time simulator can help closing the gap between off-line simulation and real testing using the already implemented robot. When properly interfaced with the robot hardware, a real-time graphical simulation with a "hardware in the loop" configuration, can allow for the testing of the implemented control system running in the actual robot hardware. Hence, the development time is drastically reduced. These paper overviews the field of graphical simulators used for AUV development proposing a classification. It also presents NEPTUNE, a multi-vehicle, real-time, graphical simulator based on OpenGL that allows hardware in the loop simulations
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El Projecte sha desenvolupat dintre del Grup de Geometria i Grfics de la Udg on es treballa amb projectes de desenvolupament urbanstic 3D. Lobjectiu del projecte consisteix en construir una aplicaci per simular levoluci de ciutats expandint els carrers al llarg del temps. Laplicaci es desenvolupar dintre del projecte urbanEngine incorporant la possibilitat dexpandir ciutats com una extensi daquest. A ms es vol dissenyat una interfcie grfica dusuari que faciliti les tasques de configuraci i supervisi del sistema
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This paper presents a control strategy for blood glucose(BG) level regulation in type 1 diabetic patients. To design the controller, model-based predictive control scheme has been applied to a newly developed diabetic patient model. The controller is provided with a feedforward loop to improve meal compensation, a gain-scheduling scheme to account for different BG levels, and an asymmetric cost function to reduce hypoglycemic risk. A simulation environment that has been approved for testing of artificial pancreas control algorithms has been used to test the controller. The simulation results show a good controller performance in fasting conditions and meal disturbance rejection, and robustness against modelpatient mismatch and errors in meal estimation
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Piecewise linear models systems arise as mathematical models of systems in many practical applications, often from linearization for nonlinear systems. There are two main approaches of dealing with these systems according to their continuous or discrete-time aspects. We propose an approach which is based on the state transformation, more particularly the partition of the phase portrait in different regions where each subregion is modeled as a two-dimensional linear time invariant system. Then the Takagi-Sugeno model, which is a combination of local model is calculated. The simulation results show that the Alpha partition is well-suited for dealing with such a system
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La problemtica tiene como eje central el deficiente perfil profesional alcanzado por los egresados de las Escuelas Tcnicas Industriales (en adelante ETIs) del Estado Bolvar. Este insipiente perfil alcanzado nos indica la ausencia de las necesarias competencias que hoy reclama el vivir un paso despus de la postmodernidad. En un mundo que exige ms y mejores experticias en lo tecnolgico, las competencias virtuales se hacen imprescindibles y al momento de buscar trabajo nos encontramos un mundo formado por ecosistemas tecnolgicos que todo lo abraza. Al ahondar en el problema del perfil profesional encontramos que para entender las causas que han incidido en esta situacin discrepante que afecta a los Tcnicos Medios (TM) se requerira necesariamente abordar varios aspectos, todos los cuales guardan estrecha vinculacin en s, y con el tema de investigacin
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Bimodal dispersal probability distributions with characteristic distances differing by several orders of magnitude have been derived and favorably compared to observations by Nathan [Nature (London) 418, 409 (2002)]. For such bimodal kernels, we show that two-dimensional molecular dynamics computer simulations are unable to yield accurate front speeds. Analytically, the usual continuous-space random walks (CSRWs) are applied to two dimensions. We also introduce discrete-space random walks and use them to check the CSRW results (because of the inefficiency of the numerical simulations). The physical results reported are shown to predict front speeds high enough to possibly explain Reid's paradox of rapid tree migration. We also show that, for a time-ordered evolution equation, fronts are always slower in two dimensions than in one dimension and that this difference is important both for unimodal and for bimodal kernels
A variational approach for calculating Franck-Condon factors including mode-mode anharmonic coupling
Resumo:
We have implemented our new procedure for computing Franck-Condon factors utilizing vibrational configuration interaction based on a vibrational self-consistent field reference. Both Duschinsky rotations and anharmonic three-mode coupling are taken into account. Simulations of the first ionization band of Cl O2 and C4 H4 O (furan) using up to quadruple excitations in treating anharmonicity are reported and analyzed. A developer version of the MIDASCPP code was employed to obtain the required anharmonic vibrational integrals and transition frequencies
