The use of floating-point calculations limits the accuracy of solutions obtained by standard LP software. We present a simplex-based algorithm that returns exact rational solutions, taking advantage of the speed of fl...
详细信息
The use of floating-point calculations limits the accuracy of solutions obtained by standard LP software. We present a simplex-based algorithm that returns exact rational solutions, taking advantage of the speed of floating-point calculation, and attempting to minimize the operations performed in rational arithmetic. Extensive computational results are presented. (C) 2007 Elsevier B.V. All rights reserved.
A systematic method is proposed for automating the design synthesis of ground vehicle suspensions. This method combines optimisation algorithms and numerical multibody dynamics software and considers ISO 2631 standard...
详细信息
A systematic method is proposed for automating the design synthesis of ground vehicle suspensions. This method combines optimisation algorithms and numerical multibody dynamics software and considers ISO 2631 standard requirements on ride quality. The proposed method is tested and evaluated by optimising three ground vehicle models. It is recommended that stochastic global search algorithms be used with numerical multibody dynamics software in the initial design optimisation, whereas gradient-based algorithms should be used in the fine stage of fine-tuning the parameters. Results show that compared with suspension stiffness and damping coefficients or inertial property parameters, geometric parameters have a more significant effect on the ride quality.
The paper presents a novel camera calibration method using a two-step approach. First, a genetic algorithm is used to find a good enough approximation of the solution. Then a multidimensional unconstrained nonlinear m...
详细信息
The paper presents a novel camera calibration method using a two-step approach. First, a genetic algorithm is used to find a good enough approximation of the solution. Then a multidimensional unconstrained nonlinear minimization (Nelder-Mead simplex) algorithm is used to refine the solution. This approach avoids errors due to linearizations and. automatically finds a very good initial point for the error minimizing procedure. All the camera parameters (intrinsic and extrinsic) are determined simultaneously, giving a consistent solution. Tested on several cases, the proposed method proved to be an efficient tool for determining the camera parameters needed for various applications, like analytical photogrammetry, 3-D space reconstruction from 2-D images and vision-based head tracking.
This paper introduces a new formalism to deal with constrained dynamic systems. It shows that, when the constraints are linear, the controller can take advantage of linear programming algorithms (such as the simplex) ...
详细信息
ISBN:
(纸本)9781424406012
This paper introduces a new formalism to deal with constrained dynamic systems. It shows that, when the constraints are linear, the controller can take advantage of linear programming algorithms (such as the simplex) to guarantee that the constraints will be satisfied. To illustrate the contribution of the approach, the control problem of a wheeled stair-climbing robot is considered. Masses supported by the robot have to be moved in order to avoid any sliding of the wheels. For such control problems where strong nonlinearities occur, conventional control methods fail to provide any reliable controller.
A software platform for the optimization of frequency response characteristic function used for the characterization of catalysts has been developed based on LabVIEW. The optimization algorithm of simplex algorithm an...
详细信息
A software platform for the optimization of frequency response characteristic function used for the characterization of catalysts has been developed based on LabVIEW. The optimization algorithm of simplex algorithm and Powell method were introduced, as well as fundamental principles refer to catalyst models and objective functions. The flow chart of program platform was presented. Design procedures, the graphic programs and some other techniques for main program VI and model configuration, simplex method, theory model, etc. were also described.
This paper addresses some pitfalls of some fuzzy data envelopment analysis models which have been provided in recent published papers. This study deals with these papers from both computational and theoretical points ...
详细信息
This paper addresses some pitfalls of some fuzzy data envelopment analysis models which have been provided in recent published papers. This study deals with these papers from both computational and theoretical points of view. Moreover, a new approach to deal with fuzzy data in DEA framework is provided, which does not have the mentioned pitfalls. (c) 2006 Elsevier Inc. All rights reserved.
Based on simplex algorithm of optimal design, the multicomponent mixture regression model was used to investigate physical properties of submerged arc welding flux. The effect of complex interaction of seven component...
详细信息
Based on simplex algorithm of optimal design, the multicomponent mixture regression model was used to investigate physical properties of submerged arc welding flux. The effect of complex interaction of seven components in agglomerated flux on softening temperature was analyzed. The results indicate that the interaction of MgO-TiO2-CaCOa-AI20a increases the softening temperature of flux, but the additions of CaF2 and ZrO2 can decrease the softening temperature.
We prove that RANDOM EDGE, the simplex algorithm that always chooses a random improving edge to proceed on, can take a mildly exponential number of steps in the model of abstract objective functions (introduced by Wil...
详细信息
We prove that RANDOM EDGE, the simplex algorithm that always chooses a random improving edge to proceed on, can take a mildly exponential number of steps in the model of abstract objective functions (introduced by Williamson Hoke [Completely unimodal numberings of a simple polytope, Discrete Appl. Math. 20 (1988) 69-81.] and by Kalai [A simple way to tell a simple polytope from its graph, J. Combin. Theory Ser. A 49(2) (1988) 381-383.] under different names). We define an abstract objective function on the n-dimensional cube for which the algorithm, started at a random vertex, needs at least exp(const.n(1/3)) steps with high probability. The best previous lower bound was quadratic. So in order for RANDOM EDGE to succeed in polynomial time, geometry must help. (C) 2005 Elsevier Inc. All rights reserved.
Image registration is a key to many image processing tasks such as image fusion, image change detection, GIS overlay operations, 3D visualization etc. The task of image registration needs to become efficient and autom...
详细信息
ISBN:
(纸本)9780819465122
Image registration is a key to many image processing tasks such as image fusion, image change detection, GIS overlay operations, 3D visualization etc. The task of image registration needs to become efficient and automatic to process enormous amount of remote sensing data. A number of feature and intensity based image registration techniques are in vogue. The aim of this study is to evaluate the applicability and performance of the two intensity based similarity metrics, namely mutual information and cluster reward algorithm. Image registration task has been mapped as an optimization problem. A combination of a global optimizer namely Genetic algorithm and a local optimizer namely Nelder Mead simplex algorithm have been successfully used to search registration parameters from the coarsest to the finest level of the image pyramid formed using wavelet transformation. For sound investigations, registration of remote sensing images acquired with varied spatial, spectral characteristics from the ASTER sensor have been considered. The image registration experiments suggest that both the similarity metrics have the capability of successfully registering the images with high accuracy and efficiency. In general, mutual information has yielded more accurate results than cluster reward algorithm.
A rectangular thermosyphon loop is analyzed parametrically using a numerical technique in this study. A two-dimensional model with uniform wall temperature through heated and cooled sections of the thermosyphon is dev...
详细信息
ISBN:
(纸本)9789608758421
A rectangular thermosyphon loop is analyzed parametrically using a numerical technique in this study. A two-dimensional model with uniform wall temperature through heated and cooled sections of the thermosyphon is developed and the numerical results are obtained by solving the continuity, momentum and energy equations through the simplex algorithm for laminar flow case. Thermal behavior of the thermosyphon loop concerned with Prandtl and Grashof numbers, and the elevation difference between the heat transfer sections is investigated numerically.
暂无评论