关键词： Ship manoeuvrability   Mathematical model   System identification   Genetic algorithm   White noise   Hausdorff's metric  

摘要： An identification algorithm for ship manoeuvring mathematical models has been developed. The identification procedure is based on the classic genetic algorithm used for minimizing a distance between the reference and recovered time histories. The distance was measured using 5 different metrics including the Hausdorff metric. Validation of the algorithm was carried out using simulated responses artificially polluted with the white noise of various levels. It was demonstrated that by only using the Hausdorff metric it was possible to reach necessary robustness of the identification algorithm. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Nikhilam Sutra   Urdhva Tiryagbhyam Sutra   very high-speed integrated circuit hardware description language   Vedic multiplier  

摘要： This article presents the design of a new high-speed multiplier architecture using Nikhilam Sutra of Vedic mathematics. The proposed multiplier architecture finds out the compliment of the large operand from its nearest base to perform the multiplication. The multiplication of two large operands is reduced to the multiplication of their compliments and addition. It is more efficient when the magnitudes of both operands are more than half of their maximum values. The carry save adder in the multiplier architecture increases the speed of addition of partial products. The multiplier circuit is synthesised and simulated using Xilinx ISE 10.1 software and implemented on Spartan 2 FPGA device XC2S30-5pq208. The output parameters such as propagation delay and device utilisation are calculated from synthesis results. The performance evaluation results in terms of speed and device utilisation are compared with earlier multiplier architecture. The proposed design has speed improvements compared to multiplier architecture presented in the literature. View full text

关键词： 算理   课堂教学   北师大版   形式定义   分子分母   除法运算   建构主义理论   数形结合   快捷方便   活动经验  

摘要： 人们为了简单明了,快捷方便,常常会将除法转变为乘法来进行计算,由此出现了倒数的概念。从外在形式定义,交换分子分母的位置即为原分数的倒数,但从运算角度而言,两个数的乘积是1,这两个数互为倒数。这是倒数概念的本质定义。倒数是分数除法运算的基础,如何让学生在算理上理解倒数,算法上掌握倒数是教学的关键。

关键词： AdaBoost算法   弱分类器   强分类器  

摘要： 本文对AdaBoost算法进行了介绍,并从整个数学推导过程中分析怎样挑选分类器并设置权值,最终通过一组弱分类器组合构成强分类器。

关键词： 数学形态学   中轴变换   二值图像  

摘要： 对二值图像处理中中轴变换的算法进行了研究,介绍了基于形态学的中轴变换算法,同时,对数学形态学的相关理论做了介绍。并利用该算法对地图图像进行了中轴变换的处理,取得了良好的实验效果。通过实验研究可以看出,该算法设计灵活,便于实现,具有一定的实用性。

关键词： PLS1 algorithms   bidiagonalization   orthogonal and non-orthogonal weights   scores and projections   change of coordinates and bases   truncation   QR factorization   singular value decomposition   reorthogonalization  

摘要： The insight from, and conclusions of this paper motivate efficient and numerically robust new' variants of algorithms for solving the single response partial least squares regression (PLS1) problem. Prototype MATLAB code for these variants are included in the Appendix. The analysis of and conclusions regarding PLS1 modelling are based on a rich and nontrivial application of numerous key concepts from elementary linear algebra. The investigation starts with a simple analysis of the nonlinear iterative partial least squares (NIPALS) PLS1 algorithm variant computing orthonormal scores and weights.A rigorous interpretation of the squared P-loadings as the variable-wise explained sum of squares is presented. We show that the orthonormal row-subspace basis of W-weights can be found from a recurrence equation. Consequently, the NIPALS deflation steps of the centered predictor matrix can be replaced by a corresponding sequence of Gram-Schmidt steps that compute the orthonormal column-subspace basis of T-scores from the associated non-orthogonal *** transitions between the non-orthogonal and orthonormal scores and weights (illustrated by an easy-to-grasp commutative diagram), respectively, are both given by QR factorizations of the non-orthogonal matrices. The properties of singular value decomposition combined with the mappings between the alternative representations of the PLS1 truncated' X data (including (PW)-W-t) are taken to justify an invariance principle to distinguish between the PLS1 truncation alternatives. The fundamental orthogonal truncation of PLS1 is illustrated by a Lanczos bidiagonalization type of algorithm where the predictor matrix deflation is required to be different from the standard NIPALS deflation.A mathematical argument concluding the PLS1 inconsistency debate (published in 2009 in this journal) is also presented. Copyright (c) 2014 John Wiley & Sons, Ltd. The PLS1 problem starting from the NIPALS algorithm is treated with mathematical rigo

关键词： aircraft structural parts   chaotic simulated annealing   toolpath  

摘要： An intelligent toolpath (processing sequence) planning for fabricating aircraft structural parts is developed to obtain a minimum-length toolpath while maintaining the required machining time. The problem is first solved in the following ways. Firstly, an abstraction of the machining process is proposed to pick up the feed/retract points of each feature to be machined as the toolpath calculation basis. Secondly, the chaotic simulated annealing method is improved through storing the optimal solution, adding the control condition and selecting each parameter reasonably during the iteration of the algorithm so as to enhance its performance. What's more, three solution-generating methods are used chaotically to obtain a better result. Lastly, the verification is conducted on four different aircraft structural parts, and the results prove that the proposed algorithm performs very well in terms of toolpath quality and computation time.

关键词： Lithium ion cell   Reduced order model   Volume averaging   Profile based approximations   Explicit algebraic algorithm   Battery management system  

摘要： The detailed isothermal electrochemical model for a lithium ion cell has ten coupled partial differential equations to describe the cell behavior. In an earlier publication [Journal of Power Sources, 222, 426 (2013)], a reduced order model (ROM) was developed by reducing the detailed model to a set of five linear ordinary differential equations and nonlinear algebraic expressions, using uniform reaction rate, volume averaging and profile based approximations. An arbitrary current profile, involving charge, rest and discharge, is broken down into constant current and linearly varying current periods. The linearly varying current period results are generic, since it includes the constant current period results as well. Hence, the linear ordinary differential equations in ROM are solved for a linearly varying current period and an explicit algebraic algorithm is developed for lithium ion cell voltage prediction. While the existing battery management system (BMS) algorithms are equivalent circuit based and ordinary differential equations, the proposed algorithm is an explicit algebraic algorithm. These results are useful to develop a BMS algorithm for on-board applications in electric or hybrid vehicles, smart phones etc. This algorithm is simple enough for a spread-sheet implementation and is useful for rapid analysis of laboratory data. (c) 2013 Elsevier B.V. All rights reserved.