We introduce a technique to rapidly generate summed-area tables using graphics hardware. Summed area tables, originally introduced by Crow, provide a way to filter arbitrarily large rectangular regions of an image in ...
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We introduce a technique to rapidly generate summed-area tables using graphics hardware. Summed area tables, originally introduced by Crow, provide a way to filter arbitrarily large rectangular regions of an image in a constant amount of time. Our algorithm for generating summed-area tables, similar to a technique used in scientific computing called recursive doubling, allows the generation of a summed-area table in O(log n) time. We also describe a technique to mitigate the precision requirements of summed-area tables. The ability to calculate and use summed-area tables at interactive rates enables numerous interesting rendering effects. We present several possible applications. First, the use of summed-area tables allows real-time rendering of interactive, glossy environmental reflections. Second, we present glossy planar reflections with varying blurriness dependent on a reflected object's distance to the reflector. Third, we show a technique that uses a summed-area table to render glossy transparent objects. The final application demonstrates an interactive depth-of-field effect using summed-area tables.
This study analyses unsymmetrical voltage sag effects on the torque and speed deviation in induction motor (IM) adjustable speed drives. The following three general types of IM drives control are analysed: scalar cont...
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This study analyses unsymmetrical voltage sag effects on the torque and speed deviation in induction motor (IM) adjustable speed drives. The following three general types of IM drives control are analysed: scalar controlled (V/Hz), rotor-field oriented and direct-torque controlled. The analytical expressions for dc-link voltage variations incorporated into the corresponding drive models as well as formulas for assessment of current/torque deviation are derived depending on the applied control algorithm. The analytically predicted theoretical results for the IM drive performance deterioration as a result of voltage sags have been validated experimentally. Measurements of sag-caused current/torque ripple and mechanical vibrations have been used for additional verification of the obtained results.
In the paper, combinatorial issues of the factorization of linear ordinary differential operators are studied. It is proved that any finite distributive lattice is that of right divisors of some d'Alembert linear ...
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In the paper, combinatorial issues of the factorization of linear ordinary differential operators are studied. It is proved that any finite distributive lattice is that of right divisors of some d'Alembert linear ordinary differential operator with the coefficients belonging to the differential field C(x) of rational functions.
Statistical mathematical models are developed for forecasting qualitative indexes of the products of atmospheric block in an atmospheric-and-vacuum distillation unit. Fuzzy logic control algorithmis proposed and analy...
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Statistical mathematical models are developed for forecasting qualitative indexes of the products of atmospheric block in an atmospheric-and-vacuum distillation unit. Fuzzy logic control algorithmis proposed and analyzed for the qualitative indexes;rule database is organized on the basis of expert appraisals. A static mathematical model of the control object is created in UNISIM Design. An approach is suggested for integrating Matlab (including Simulink) and UNISIM Design. Finally, a computing experiment is conducted to assess efficiency of the control algorithm for the qualitative indexes using the mathematical model.
The matrix method for localization of a faulty block that was proposed earlier by the present author was considered as applied to a discrete device with multi-output blocks At that, the question of reducing the amount...
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The matrix method for localization of a faulty block that was proposed earlier by the present author was considered as applied to a discrete device with multi-output blocks At that, the question of reducing the amount of the test hardware was solved by constructing appropriately the matrix of block outputs. An algorithm for such construction was given.
In this paper, we propose a data processing algorithm for the working parameters of a jib crane. The system simulates the actions of a human operator during load positioning. The algorithm of control actions generatio...
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In this paper, we propose a data processing algorithm for the working parameters of a jib crane. The system simulates the actions of a human operator during load positioning. The algorithm of control actions generation plays the main role in operation of the automatic control system.
Artificial Neural Networks (ANN) have been used in the past to predict the performance of printed circuit heat exchangers (PCHE) with satisfactory accuracy. Typically published literature has focused on optimizing ANN...
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Artificial Neural Networks (ANN) have been used in the past to predict the performance of printed circuit heat exchangers (PCHE) with satisfactory accuracy. Typically published literature has focused on optimizing ANN using a training dataset to train the network and a testing dataset to evaluate it. Although this may produce outputs that agree with experimental results, there is a risk of over-training or over-learning the network rather than generalizing it, which should be the ultimate goal. An over-trained network is able to produce good results with the training dataset but fails when new datasets with subtle changes are introduced. In this paper we present EBaLM-OTR (error back propagation and Levenberg-Marquardt algorithms for over training resilience) technique, which is based on a previously discussed method of selecting neural network architecture that uses a separate validation set to evaluate different network architectures based on mean square error (MSE), and standard deviation of MSE. The method uses k-fold cross validation. Therefore in order to select the optimal architecture for the problem, the dataset is divided into three parts which are used to train, validate and test each network architecture. Then each architecture is evaluated according to their generalization capability and capability to conform to original data. The method proved to be a comprehensive tool in identifying the weaknesses and advantages of different network architectures. The method also highlighted the fact that the architecture with the lowest training error is not always the most generalized and therefore not the optimal. Using the method the testing error achieved was in the order of magnitude of within 10(-5)-10(-3). It was also show that the absolute error achieved by EBaLM-OTR was an order of magnitude better than the lowest error achieved by EBaLM-THP. (C) 2011 Elsevier B.V. All rights reserved.
This study theoretically establishes a sequential variational (SVAR) method for the data assimilation in oceanography and meteorology defined on the model space. Requiring a significantly smaller amount of computer me...
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This study theoretically establishes a sequential variational (SVAR) method for the data assimilation in oceanography and meteorology defined on the model space. Requiring a significantly smaller amount of computer memory, theoretically SVAR gives the same optimal model state estimate as the four-dimensional variational data assimilation method. Its computational cost is similar to that of the four-dimensional variational data assimilation and representer methods. In addition to the optimal state estimates, SVAR computes error covariances at the end of the assimilation window. These advantageous properties of the new algorithm are obtained by combining the sequential methodology with suitable definitions of several new l(2) norms, which implicitly provide required estimates.
A laboratory facility LuVeX consisting of a smooth horizontal table and models moving on its surface was developed at ZARM for adjustment of control algorithms for group motion of satellites. This paper describes the ...
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A laboratory facility LuVeX consisting of a smooth horizontal table and models moving on its surface was developed at ZARM for adjustment of control algorithms for group motion of satellites. This paper describes the facility and implemented control algorithms for air-breathing pulsed jet engines mounted on moving models to provide their translational and rotational motion. The facility performance is proved by the results of numerical simulation of the control algorithm for the motion of a group of models along a given trajectory.
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