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Conference on Optical Measurement Systems for Industrial Inspection XI held at SPIE Optical Metrology Symposium

作者： Claussen, Gunnar Blohm, Werner Jade Univ Appl Sci Sch Engn D-26389 Wilhelmshaven Germany

ISBN: (数字)9781510627925

ISBN: (纸本)9781510627925

Step-index fibers consisting of two (or more) concentric layers of different transparent materials are common in optical telecommunication technology. Our aim is to establish algorithms allowing for the determination of the parameters (e.g., diameters) of these layers by evaluation of the lateral scattering pattern originating under plane-wave monochromatic illumination perpendicular to the fiber axis. We investigate numerical simulations only, i.e. applying the corresponding parameter estimation algorithms to numerically generated scattering patterns with known geometry and optical parameter values. We consider three algorithms for parameter determination. The first is the iteratively regularized Gauss-Newton (IRGN) algorithm, which minimizes the norm parallel to F(q) - u(infinity)parallel to(2) of the difference between the pattern for the parameters q(n) and the input u(infinity), but only locally. However, local minima in the norm "landscape" are spaced periodically, which we utilize. The second approach treats parameter determination as the optimization problem of minimizing parallel to F(q) - u(infinity)parallel to(2) globally, subject to the Dividing Rectangles (direct) algorithm. The third approach hybridizes both optimization methods. The results show that the modified IRGN algorithm is considerably faster for cases where the scattering intensities are superimposed with no or little noise. In terms of precision, the direct algorithm and its hybrid variant perform slightly better. These algorithms also terminate quicker for increasing noise. This, however, highlights the general trade-off between calculation times and precision.

关键词： Lorenz-Mie scattering cylinder scattering optical waveguides optical fibers diameter measurement inverse scattering problem direct algorithm Gauss-Newton algorithm

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A Regression Tree as Acquisition Function for Low-Dimensional Optimisation 16th

A Regression Tree as Acquisition Function for Low-Dimensiona...

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16th Mexican Conference on Pattern Recognition (MCPR)

作者： de Paz, Erick G. G. Vaquera Huerta, Humberto Albores Velasco, Francisco Javier Bauer Mengelberg, John R. Romero Padilla, Juan Manuel Colegio Postgrad Texcoco 56230 Mexico Mexico Univ Autonoma Tlaxcala Apizaco 90341 Tlaxcala Mexico

ISBN: (纸本)9783031628351;9783031628368

direct-type optimisation algorithms recursively explore the domain of an objective function by means of a hierarchical partition. In this context, a regression tree can be estimated with the exploration data and be used to quickly reach the optimum. This regression tree allows to apply Bayesian optimisation techniques instead of the poorly adaptive rules applied within the original direct algorithm. Although based on a probabilistic framework, this approach can perform a deterministic search, a remarkable attribute of direct-type algorithms. This method based on a machine learning algorithm and Bayesian inference is compared with several R libraries for optimisation, including the original direct algorithm and three representative evolutionary algorithms. For a collection of well-known benchmark functions, the proposal is statistically more reliable and robust than direct with respect of dimensionality, but not enough to beat the evolutionary alternatives.

关键词： Regression Tree direct algorithm Bayesian Optimisation

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Minimal Join Graphs' Set Synthesis: Performance Statistical Estimate of the Decremental algorithm 19

Minimal Join Graphs' Set Synthesis: Performance Statistical ...

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19th IEEE International Conference on Soft Computing and Measurements (SCM)

作者： Berezin, Alexey I. Ivanova, Anna V. Zotov, Mikhail A. St Petersburg State Univ Dept Comp Sci St Petersburg Inst Informat & Automat RAS SPIIRAS St Petersburg Russia St Petersburg State Univ Dept Software Engn St Petersburg Russia

ISBN: (纸本)9781467389198

The aim of the work is to develop the minimal join graphs' set synthesis decremental algorithm and to provide a comparative analysis of both direct and decremental algorithms. The algorithm was developed and implemented, and its consistency was confirmed with the mathematics proof. Comparative analysis was carried out as statistical tests which show temporal work ratios of the cited algorithms on primary structures of different capacities. Statistical experiments demonstrated that decremental algorithm is faster than the direct one in range of 4-12 vertices, but the further statistical analysis isn't possible due to the exponential growth of calculations. The statistical experiments' results are visualised in graphs.

关键词： algebraic Bayesian networks secondary structure synthesis direct algorithm decremental algorithm performance complexity statistical estimate minimal join graph

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NUMERICAL AND EXPERIMENTAL STUDY OF THERMAL MANAGEMENT ON HB LED DEVICES

NUMERICAL AND EXPERIMENTAL STUDY OF THERMAL MANAGEMENT ON HB...

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4th International Microsystems, Packaging, Assembly and Circuits Technology Conference

作者： Chu, Shao-Shu Wang, Yuen-Ting Selva, Carlos Fernando Moreira Kun Shan Univ Dept Mech Engn Yung Kang 71003 Tainan County Taiwan

ISBN: (纸本)9781424443413

A finite element method based on a direct algorithm is applied in this study to estimate the time-dependent and time-independent convection heat transfer of high-bright LED(HB LED) heat dissipating mechanisms. Numerically simulation and experimental measurement are both performed to investigate the thermal characteristics of HB LED devices. By monitoring the transient temperatures at the different measurement positions of the device, it is placed into well controlling ambient temperature environment when the LED is subjected to different thermal loading. Experimental data is subjected to the numerical tests in order to verify the accuracy of simulation models. Therefore, the thermal management of HB LED devices can be investigated. The results indicate that established models are not only proved to enhance heat dissipating of LED but also well consistency to the experimental data. Finally, a simple design of HB LED device is demonstrated to prove the success of this research and can it be applied in the present industry.

关键词： direct algorithm HB LED heat transfer mechanisms thermal management

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Adaptive control of servo motor by MRAC method

Adaptive control of servo motor by MRAC method

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IEEE Vehicle Power and Propulsion Conference (VPPC)

作者： Ehsani, M. S. Isfahan Univ Comp Eng Dept Esfahan Iran

ISBN: (纸本)9780780397606

This paper describes the design of a multi input multi output (MIMO) non-linear Model Reference Adaptive controller (MRAC) system for the digital servo motor. The complete design is developed determining the rate of gradient adaptation to MRAC in this paper. The MIT rule is used in the original MRAC. The main goal is to follow the desired position set as square wave. The important role of computer aided-design tools is illustrated using MATLAB and associated toolboxes. The control algorithm is implemented using a Pentium computer running the lab-tech notebook control program. The adaptive controlled system satisfactorily controls set point changes in velocity and position.

关键词： direct algorithm emulation MIT rule rate of gradient adaptation simulink model sensitivity derivative

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Voxel-based, image source-independent 3D asymmetry quantification in the maxillofacial region

Voxel-based, image source-independent 3D asymmetry quantific...

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International Conference on Management, Manufacturing and Materials Engineering (ICMMM 2011)

作者： Lin, Yu-Cheng Fang, Jing-Jing Natl Cheng Kung Univ Dept Mech Engn Tainan 70101 Taiwan

ISBN: (纸本)9783037853511

This study proposes a voxel-based method, independent of image sources, for the evaluation, quantification, symmetry ratio definitions, and assessment of the optimal symmetry plane. Craniomaxillofacial bones can be evaluated through their symmetry ratio and the optimal symmetry plane can be used as a guide for oral and maxillofacial surgical planning and reconstruction after the removal of facial tumors, or as a guide for orthognathic surgery in jaw correction. This quantification analysis technique can be used in growth tracing planning, pre- and post-surgical comparisons, and the planning of follow-up therapy.

关键词： three-dimensional symmetry analysis optimal symmetry ratio optimal symmetry plane direct algorithm

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Generalization and acceleration of an algorithm of Sebastião e Silva and its duals

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Numerische Mathematik 1975年第4期25卷 365-377页

作者： Chung, Soon Park Dept. of Mathematics Univ. of Michigan Dearborn 48128 Michigan United States

In this paper, we extend Householder's [4] generalization of an algorithm of Sebastião e Silva [11] by adding a new elimination rule for defining the sequences which converge to the factors of the given polynomial. We then present the dual algorithm and show that the dual algorithm becomes equivalent to the direct algorithm in the generalized form. Next, we give accelerated forms of these algorithms which are quadratically convergent. We also study the relation of these methods to other methods. © 1976 Springer-Verlag.

关键词： Mathematical Method direct algorithm Elimination Rule Dual algorithm Accelerate Form

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隐函救最小二乘曲线拟合的直接算法

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厦门大学学报(自然科学版) 1987年第5期 627-630页

作者：陈昆厦门大学物理学系

达到的小.式中N为观测点的总数,W1为权重因子,y为因变量,m代表测量值,c代表计算值。当待拟合的函数为显式函数时,y1c可由如下解析表达式直接算得

关键词： Curve fitting direct algorithm Implicit function Objec tive function

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Global Optimization of Transmitter Placement for Indoor Wireless Communication Systems

Global Optimization of Transmitter Placement for Indoor Wire...

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作者： He, Jian Virginia Tech | University

The direct (DIviding RECTangles) algorithm JONESJOTi, a variant of Lipschitzian methods for bound constrained global optimization, has been applied to the optimal transmitter placement for indoor wireless systems. Power coverage and BER (bit error rate) are considered as two criteria for optimizing locations of a specified number of transmitters across the feasible region of the design space. The performance of a direct implementation in such applications depends on the characteristics of the objective function, the problem dimension, and the desired solution accuracy. Implementations with static data structures often fail in practice because of unpredictable memory requirements. This is especially critical in $S^4W$ (Site-Specific System Simulator for Wireless communication systems), where the direct optimization is just one small component connected to a parallel 3D propagation ray tracing modeler running on a 200-node Beowulf cluster of Linux workstations, and surrogate functions for a WCDMA (wideband code division multiple access) simulator are also used to estimate the channel performance. Any component failure of this large computation would abort the entire design process. To make the direct global optimization algorithm efficient and robust, a set of dynamic data structures is proposed here to balance the memory requirements with execution time, while simultaneously adapting to arbitrary problem size. The focus is on design issues of the dynamic data structures, related memory management strategies, and application issues of the direct algorithm to the transmitter placement optimization for wireless communication systems. Results for two indoor systems are presented to demonstrate the effectiveness of the present work.

关键词： bit error rate direct search direct algorithm global optimization transmitter placement dynamic data structures power coverage Thesis

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Deterministic Parallel Global Parameter Estimation for a Model of the Budding Yeast Cell Cycle

Deterministic Parallel Global Parameter Estimation for a Mod...

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作者： Panning, Thomas D. Virginia Tech | University

Two parallel deterministic direct search algorithms are combined to find improved parameters for a system of differential equations designed to simulate the cell cycle of budding yeast. Comparing the model simulation results to experimental data is difficult because most of the experimental data is qualitative rather than quantitative. An algorithm to convert simulation results to mutant phenotypes is presented. Vectors of the 143 parameters defining the differential equation model are rated by a discontinuous objective function. Parallel results on a 2200 processor supercomputer are presented for a global optimization algorithm, direct, a local optimization algorithm, MADS, and a hybrid of the two. A second formulation is presented that uses a system of smooth inequalities to evaluate the phenotype of a mutant. Preliminary results of this formulation are given.

关键词： computational biology MADS algorithm direct search direct algorithm Thesis

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