Novel algorithm for synthesis of fiber gratings

A novel algorithm for the synthesis of fiber gratings is presented.For the first time we propose an effective optimal approach to construct a coupling coefficient function by employing 4th-order Runge-Kutta (R-K) analysis method for calculating the reflection spectra of fiber gratings.The numerical results show that with this proposed method, some required optical filters have been yielded with better features compared with other methods such as Gel'Fand-Levitan-Marchenko (GLM) algorithm.In addition, the performance of different interpolation functions particularly utilized in our algorithm, including linear-type, spline-type, and Hermit-type, are discussed in detail.     

基于FWD动态弯沉盆的模量反算方法简述

全面总结了国内外利用动态弯沉盆来反算路面各结构层模量的各种方法,并指出了目前模量反算中存在的问题,在此基础上,提出了模量反算中需要进一步研究的重点问题,其结论对今后的模量反算研究具有一定意义。     

Hilbert空间的自反广义逆算子

本文主要借鉴Moore-Penrose广义逆,给出Hilber空间自反广义逆算子的定义,并讨论了自反广义逆算子的存在性和它的一些性质.     

Analytical inverse kinematics with body posture control

This paper presents a novel whole‐body analytical inverse kinematics (IK) method integrating collision avoidance and customizable body control for animating reaching tasks in real‐time. Whole‐body control is achieved with the interpolation of pre‐designed key body postures, which are organized as a function of the direction to the goal to be reached. Arm postures are computed by the analytical IK solution for human‐like arms and legs, extended with a new simple search method for achieving postures avoiding joint limits and collisions. In addition, a new IK resolution is presented that directly solves for joints parameterized in the swing‐and‐twist decomposition. The overall method is simple to implement, fast, and accurate, and therefore suitable for interactive applications controlling the hands of characters. The source code of the IK implementation is provided. Copyright © 2007 John Wiley & Sons, Ltd.     

Detection of void and metallic inclusion in 2D piezoelectric cantilever beam using impedance measurements

The aim of current work is to improve the existing inverse methodology of void-detection based on a target impedance curve, leading to quick-prediction of the parameters of single circular void. In this work, mode-shape dependent shifting phenomenon of peaks of impedance curve with change in void location has been analyzed. A number of initial guesses followed by an iterative optimization algorithm based on univariate method has been used to solve the problem. In each iteration starting from each initial guess, the difference between the computationally obtained impedance curve and the target impedance curve has been reduced. This methodology has been extended to detect single circular metallic inclusion in 2D piezoelectric cantilever beam. A good accuracy level was observed for detection of flaw radius and flaw-location along beam-length, but not the precise location along beam-width.     

A self‐calibrating led‐based solar test platform

A compact platform for testing solar cells is presented. The light source comprises a multi‐wavelength high‐power LED (light emitting diode) array allowing the homogenous illumination of small laboratory solar cell devices (substrate size 50 × 25 mm) within the 390–940 nm wavelength range. The spectrum can be synthesized by independent tuning of the 18 different wavelengths to mimic AM1.5G as well as various indoor lamp spectra. The intensity can be controlled with a 2¹⁴‐bit accuracy and intensities up to 3 suns are possible with an approximate AM1.5G spectral distribution. For several wavelengths intensities up to 10 suns is possible, and for a few wavelengths up to 30 suns can be reached. The setup is equipped with reference diodes and an optical fibre coupling enabling calibration, monitoring and control of the light impinging on the sample. Through a computer controlled interface, it is possible to perform all the commonly employed measurements on the solar cell at very high speed without moving the sample. In particular, the LED‐based illumination system provides an alternative to light‐biased incident photon‐to‐current efficiency measurement to be performed which we demonstrate. Both top and bottom contact is possible and the atmosphere can be controlled around the sample during measurements. The setup was developed for the field of polymer and organic solar cells with particular emphasis on enabling different laboratories to perform measurements in the same manner and obtain a common basis for comparing data. The use of the platform is demonstrated using a standard P3HT:PCBM polymer solar cell but is generally applicable to any solar cell technology with a spectral response in the 390–950 nm region. Copyright © 2010 John Wiley & Sons, Ltd.     

Clustering assisted artificial neural network for handling noisy big data: An application for estimation of parameter in combined mode conduction and radiation heat transfer

A pattern net assisted mapping artificial neural network (PAMANN) model for estimation of parameters in problem with large data (1300 × 121 matrix size) is reported. A pattern net-based multilayer perceptron neural network (MLPNN) model for clustering the data, followed by mapping MLPNN model for mapping the target with the input, is developed as PAMANN model. A heat transfer problem with combined mode conduction and radiation in porous medium is solved numerically, and is called direct model. In the inverse model, a PAMANN model is developed by using data generated through the direct model. The PAMANN model is able to estimate two parameters (extinction coefficient β and convective coupling P₂) after taking temperature profile as input. The model is tested for different number of neurons in hidden layer, and different levels of noise in input data. Twelve different algorithms are explored in training of mapping MLPNN, and compared for performance. Levenberg–Marquardt algorithm is found to estimate the parameters with high accuracy, but took high CPU time. Bayesian regularization is found to consume very high CPU time with moderate accuracy in estimation of parameters. Variations in hidden layer neuron number and noise in input data, were done to analyze the performance of mapping MLPNN with different training algorithms. Algorithms O-Step Secant, conjugate gradient with Polak-Ribiére updates, and conjugate gradient with Fletcher-Reeves updates are able to handle all variations of noise and number of neurons in hidden layer, with good accuracy of estimation and low CPU time consumption. Under high computational resource LM algorithm can be used for all cases. Up to 0.99132 value of regression coefficient is obtained in mapping MLPNN model with 15 hidden neurons, indicating the high accuracy of the model. With the help of PAMANN model, highly accurate (absolute error 1.78%) estimation of parameters is obtained. The model can handle upto 1% noise in input data, while giving accurate results.     

同步电动机的热过载保护算法

为使电动机故障前的工作状态能较真实地反映电动机故障情况下的发热状况,运用对称分量法,提出一种电动机热过载保护的方法,使电动机充分发挥过载能力的同时免于损坏,提高电力拖动系统的可靠性和生产的连续性。重点介绍同步电动机热过载保护的原理及算法。实验表明,所提出的方法更接近电动机发热的真实状况。     

有机磷一元酸溶剂萃取体系中的反胶束和微乳液

介绍了有机磷一元酸碱金属盐的微乳液体系以及有机磷一元酸溶剂萃取体系中金属-萃取剂络合物聚集方面的研究进展。     

在二(2-乙基己基)磷酸钠的微乳液中金属萃合物对水增溶的影响

测算了由二（2－乙基己基）磷酸钠，金属盐（CoSO4,NiSO4,ZnSO4,MgCl2或Cr(NO3)3)水溶液，正辛醇和正辛烷组成的微乳液中正辛醇从连续油相到界面的ΔGo→i^o和水的极限增容量φ'H2O。用金属萃取络合物反胶束的形成及其亲油性解释了金属离子对φ'H2O和ΔGo→i^o的影响。