Nonlinear Auto-Disturbance-Rejection-Control controller tuning problem is investigated. The tuning problem is recast into a multi-objective optimal problem The typical Nonlinear Least Square Method Levenberg-Marqudart...
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ISBN:
(纸本)9781424415304
Nonlinear Auto-Disturbance-Rejection-Control controller tuning problem is investigated. The tuning problem is recast into a multi-objective optimal problem The typical Nonlinear Least Square Method Levenberg-Marqudart algorithm and Min-Max optimization Method is utilized to realize the optimal iteration. A new optimal mechanism is introduced which integrate simulink and optimization toolbox of Matlab. Based on this mechanism the parameters of nonlinear PD and Extended state observer is tuned The result of simulation indicate the multi-objective optimization tuning method is effective.
The purpose of this study is to develop a software for optimized registering of film dosimetry with calculated dose for Intensity Modulated Radiation Therapy (IMRT) quality assurance. The newly developed software cons...
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ISBN:
(纸本)9783540368397
The purpose of this study is to develop a software for optimized registering of film dosimetry with calculated dose for Intensity Modulated Radiation Therapy (IMRT) quality assurance. The newly developed software consists of a film device driver and the verification of fluence map. A film device driver follows the TWAIN 32 protocol. This driver enables us to easily calibrate and scan the films in any film scanner. The fluence map verification software is programmed by C++, which is suitable for the extension of future work. Taking advantages of that multi platform Qt (Trolltech, Norway) GUI library, we have made it run on Windows and Linux operating systems even Mac OSX. For drawing and viewing the fluence map in 2 and 3D, OpenGL (SGI Corp., USA) is implemented. Both absolute point dosimetry and 3D film dosimetry were performed throughout the IMRT using Clinac 21EX's millennium MLC. With these custom-written software modules, the measured and calculated dose distributions for axial planes were superimposed by coincidence of their origins, followed by comparison of the point doses at all matched positions. Then, with the optimization algorithm the setup errors were recovered. We have developed customwritten software modules for managing dose-distribution files, optimizing the position, calculating dose differences, and printing out the report. Differences between the calculated and measured doses over the 3% criterion could be reduced by 15% after applying the optimization algorithm. optimization dramatically reduced the difference between measured and calculated dose distributions in all cases investigated.
An improved image encryption/decryption approach is proposed. In the encryption system, a binary amplitude image is encoded in the Fourier domain. Then, the encoded image is scrambled with a random binary phase image ...
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ISBN:
(纸本)9780819466013
An improved image encryption/decryption approach is proposed. In the encryption system, a binary amplitude image is encoded in the Fourier domain. Then, the encoded image is scrambled with a random binary phase image to produce the encrypted image. Both the encoding and encryption processes are done electronically. The encrypted image is stored in an encrypted phase mask of which the transmittance is proportional to the phase components of that image. In the decryption process, the encrypted phase mask is optically descrambled with another phase mask which has the transmittance identical to phase components of the random image used in the encryption process. The descrambled field is inversely Fourier transformed by a Fourier lens in order to reproduce the original image. The simplicity and the misalignment free characteristics are the most significant advantages of our method. The Fourier encoding process using an optimization algorithm with iteration technique is discussed in detail. The effect of noise on the quality of the decrypted image is investigated. The innovation of the system is demonstrated through simulations. The most critical issue of our technique is that the encryption process requires an optimization search which consumes some computation time so that the system is expected to be applied for unreal-time applications.
We propose a feature enhanced image reconstruction method for spotlight mode synthetic aperture radar. Based on the image processing of Computerized tomography model, this method has increased resolution, reduced side...
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ISBN:
(纸本)1424411351
We propose a feature enhanced image reconstruction method for spotlight mode synthetic aperture radar. Based on the image processing of Computerized tomography model, this method has increased resolution, reduced side lobes and reduced speckle by incorporating prior information regarding the features of interested scattering fields. Also, by using the extensions of half quadratic regularization methods, this algorithm effectively deals with the complex valued, random phrase nature of the underlying SAR reflectivities.
Production planning and scheduling (PPS) in dynamic alliance is a complicated and difficult task as it has to be optimal and collaborative both for the individual enterprise and for the whole dynamic alliance network....
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ISBN:
(纸本)9781424415304
Production planning and scheduling (PPS) in dynamic alliance is a complicated and difficult task as it has to be optimal and collaborative both for the individual enterprise and for the whole dynamic alliance network. To acquire quicker response of production process in dynamic alliance environment, new requirements of PPS are analyzed, and the corresponding collaborative PPS model is established. Moreover, the enabling technologies such as the information exchange, coordination and conflict resolution mechanism and PPS optimization algorithm are discussed. The objective of this paper is to find a satisfactory solution and techniques for the optimization and collaboration of PPS system.
We designed a broadband quarter wave plate in the visible range using a twisted nematic liquid crystal film sandwiched between two compensation films. The quarter wave plate exhibits much wider bandwidth than the comm...
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We designed a broadband quarter wave plate in the visible range using a twisted nematic liquid crystal film sandwiched between two compensation films. The quarter wave plate exhibits much wider bandwidth than the commercial product, which is composed of a half wave plate and a quarter wave plate.
This paper describes the application of biologically-inspired algorithms and concepts to the design of wideband antenna arrays. In particular, we address two specific design problems. The first involves the design of ...
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ISBN:
(纸本)9780819466853
This paper describes the application of biologically-inspired algorithms and concepts to the design of wideband antenna arrays. In particular, we address two specific design problems. The first involves the design of a constrained-feed network for a Rotman-lens beamformer. We implemented two evolutionary optimization (EO) approaches, namely a simple genetic algorithm (SGA) and a competent genetic algorithm. We conducted simulations based on experimental data, which effectively demonstrate that the competent GA outperforms the SGA (i.e., finds a better design solution) as the objective function becomes less specific and more "general." The second design problem involves the implementation of polyomino-shaped subarrays for sidelobe suppression of large, wideband planar arrays. We use a modified screen-saver code to generate random polyomino filings. A separate code assigns array values to each element of the tiling (i.e., amplitude, phase, time delay, etc.) and computes the corresponding far-field radiation pattern. In order to conduct a statistical analysis of pattern characteristics vs. tiling geometry, we needed a way to measure the "similarity" between two arbitrary filings to ensure that our sampling of the tiling space was somewhat uniformly distributed We ultimately borrowed a concept from neural network theory, which we refer to as the "dot-product metric," to effectively categorize filings based on their degree of similarity.
The problems related to practical realization (as a computer program) of difference schemes of the solution of diffusion equations that describe pollutants transport in the river water are considered in this paper. In...
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The problems related to practical realization (as a computer program) of difference schemes of the solution of diffusion equations that describe pollutants transport in the river water are considered in this paper. In particular, the problems of optimum choosing of the algorithm parameters on which depend the accuracy, the time and the possibility of practical realization of the equation solution are considered. The demand to reduce as much as possible the time and the errors of calculations, and also the simplicity of the functions of certain classes used in mathematical models and their maximum accordance to real physical conditions are considered as criteria of optimality. (c) 2006 Elsevier Inc. All rights reserved.
An optimization strategy for high speed machining of hardened die/mold steel based on machining feature analysis was studied. It is a further extension of the previously presented study on the thermal mechanism of end...
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An optimization strategy for high speed machining of hardened die/mold steel based on machining feature analysis was studied. It is a further extension of the previously presented study on the thermal mechanism of end milling and constant cutting force control. An objective function concerning machining cost and associated optimization algorithm based on machining time and cutting length calculation was proposed. Constraints to satisfy specific machining strategies when high speed machining the hardened die/mold steel, trochoid tool path pattern in slot end milling to avoid over-heat and feed rate adaptation to avoid over-load, were also discussed. As a case study, the tool selection problem when machining a die part with multiple machining features was investigated.
A new artificial immune algorithm （AIA） simulating the biological immune network system with selfadjustment function is proposed in this paper. AIA is based on the modified immune network model in which two methods ...
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A new artificial immune algorithm （AIA） simulating the biological immune network system with selfadjustment function is proposed in this paper. AIA is based on the modified immune network model in which two methods of affinity measure evaluated are used, controlling the antibody diversity and the speed of convergence separately. The model proposed focuses on a systemic view of the immune system and takes into account cell-cell interactions denoted by antibody affinity. The antibody concentration defined in the immune network model is responsible directly for its activity in the immune system. The model introduces not only a term describing the network dynamics, but also proposes an independent term to simulate the dynamics of the antigen population. The antibodies＇ evolutionary processes are controlled in the algorithms by utilizing the basic properties of the immune network. Computational amount and effect is a pair of contradictions. In terms of this problem, the AIA regulating the parameters easily attains a compromise between them. At the same time, AIA can prevent premature convergence at the cost of a heavy computational amount （the iterative times）. Simulation illustrates that AIA is adapted to solve optimization problems, emphasizing muhimodal optimization.
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