用有限元法计算特征值问题的一种新的动态凝聚方法

有限元法是常用的建模方法,由于所建模型具有较大的自由度,通常需要进行降阶处理.一般来讲,模型前几阶特征值和特征向量可以较精确地得到,利用所得到的特征值和主振型分量(在特征向量中与所给定的主自由度对应的振型分量),本文提出了一种新的动态凝聚方法,该方法是通过迭代方式,利用所得到的特征值和主振型分量对Guyan降阶法所得到的降阶模型进行修正.与同类方法相比,本文方法具有较高的计算精度和很小的计算量,且迭代收敛的稳定性很好.最后本文给出了一个计算实例.     

邻域粗糙集在属性约简及权重计算中的应用

为了减少航天器特征值属性的冗余性并提高其权重的准确性,提出了一种基于邻域粗糙集的属性约简及权重计算方法。通过对不同重要度下限分类精度的对比分析,给出了确定邻域半径的新规则。在信息观权值最优计算公式的基础上,提出了一种基于信息熵的特征值权重计算方法;给出了代数观和信息观最优组合权值确定方法,解决了代数观和信息观方法的权衡问题。将其应用于某卫星姿控系统特征值分析中,与其他方法的比较表明该方法能有效减少特征值的数目,提高特征值权重的准确性。     

脊波导特征值的有限元分析

本文主要运用电磁场有限元方法来分析计算脊波导的特征值以及截止波长。编制了一个计算各种对称和不对称单脊、双脊波导和矩形波导特征值的通用程序,并提出了一种简单的强加边界条件方法。给出了双脊波导的计算的结果。     

脊波导特征值的有限元分析

本文主要运用电磁场有限元方法来分析计算脊波导的特征值以及截止波长。编制了一个计算各种对称和不对称单脊、双脊波导和矩形波导特征值的通用程序，并提出了一种简单的强加边界条件方法。给出了双脊波导的计算的结果。     

基于FPGA的卷积神经网络加速器动态余数处理映射模型

将卷积计算转化为矩阵乘法是FPGA上一种高效实现,而现有的转化方法无法根据卷积参数的不同动态调整,限制了卷积计算的并行度.提出一种新的动态余数处理映射模型.该映射模型包含有3个子模型:特征值映射模型,权值映射模型,和输出映射模型.特征值映射模型将特征值转化为特征值矩阵,权值映射模型将权值转化为权值矩阵,特征值矩阵和权值矩阵通过乘累加计算阵列得到卷积计算结果,由输出映射模型将卷积计算结果存储到内存中.在卷积计算过程中,卷积的输出通道数通常不是乘累加计算阵列行数的整数倍,3个子映射模型会根据产生的余数动态调整映射方法,提高乘累加计算阵列的利用率.通过实验表明,采用动态余数处理映射模型能够将余数并行度的倍数至多提高到卷积核大小,使整个加速器达到了更高的实际吞吐量和能量效率.     

三角网格曲面角点的鲁棒性检测算法

为有效检测三角网格曲面上的角点特征,提出一种基于最小主曲率的角点检测算法.首先通过计算网格顶点处的最小主曲率,利用加权最小主曲率定义角点特征函数,并计算角点特征值;然后利用迭代阈值法自动产生检测阈值,以去除噪声和特征不明显的角点;最后采用非极大值抑制法消除局部邻域内的角点聚簇获取特征明显的角点.在此基础上,在多个尺度下分别计算每个网格顶点处的角点特征值,并通过加权将其合并成多尺度角点特征值,新的角点特征值使得角点检测算法具有较高的稳定性和鲁棒性.通过重复检测率实验和部分重叠曲面的配准实验,验证了文中算法的有效性与实用性.     

基于改善特征值离散度的信源数目估计

相比于传统的信源数目估计方法,基于特征值差值法的信源数目估计具有较小运算量的优点,但是因为在低信噪比时效果差,且在色噪声下效果不稳定等多种缺点一直未能在实际中应用。因此分析了特征值离散度对差值法估计的影响,提出一种基于对数函数拟合改善特征值发散程度的方法,并利用拟合特征值进行差值法进行估计。该算法很大程度上减少了相邻信源特征值之间的差值,使信源特征值和噪声特征值之间的差值更加明显,大大提升了差值法的估计性能,同时保证了较小的运算量。经实验仿真表明,该方法在白噪声和色噪声下都能进行稳定估计,在较低信噪比和低快拍数下依然具有良好估计性能的优点。     

解一类非线性特征值问题的数值算例

刻画玻色-爱因斯坦凝聚态(BEC)的Gross-Pitaevskii方程通过差分方法离散,转化成一类非线性特征值问题(BEC问题).在这篇文章中,讨论了对BEC问题的求解方法,并给出数值算例.通过半定松弛的方法(SDP松弛方法)和交替方向乘子法(ADMM),计算BEC问题的最小非线性特征值的一个界;通过Lasserre半定松弛,可以依次地计算BEC问题的所有实非线性特征值.在数值算例中,从求解问题的规模和求解速度两方面比较了SDP松弛方法和ADMM,同时用matlab自带的fmincon方法来求解,初步比较了它们的数值计算结果.     

基于近似熵的心肌猝死预警诊断

为提高传统线性分析方法的准确性,提出一种非线性动力学与时频分析相结合的心电信号分类方法。利用经验模式分解和阈值法抑制噪声,从而更有效地分解心电信号得到内蕴模式函数,分别计算其近似熵特征值,利用支持向量机分类器验证特征值的分类效果。实验结果表明,该方法能有效实现信号的自动分类识别,简便快速地初步诊断心肌猝死疾病的发生,正常和异常心电信号的分类识别准确率均达到90%以上。     

基于多重启发式规则的中文文本特征值提取方法

本文根据中文文本的特点，以一种新的同义概念来替代传统的词为单位，并给出了同义概念之间权值的全新计算方法。我们不仅考虑了文本中词汇概率信息，还结合文本语义等多方面来提取文本特征值，从而提出了一种基于多重启发式规则的中文文本特征值提取方法，并给出了特征值提取模型和算法。通过与传统特征值提取方法的比较实验，证证明本文中提出的特征值提取方法能有效地提高文本分类正确率，并达到了有效降低特征向量维数的目的。     

THINGS†

A concept of concrete object, or thing, is built that turns out to subsume the special concepts of thing found in the sciences. The construction proceeds in three stages. In the first, the concept of a substantial individual is introduced as anything that can combine with other individuals. The set of individuals is assigned the semi-group structure, and a number of notions, in particular those of part and of aggregate, are defined. In the second phase the notion of a substantial property, as different from that of attribute, is characterized. It is construed as a function on the set of substantial individuals. The assumption is made that properties are all definite and that they can conjoin but not disjoin; nor are negative properties countenanced. Further, the notions of.property precedence and of property neighbourhood are defined. It is postulated that substantial properties come in clusters. Laws are counted as special properties, namely as functional relations among substantial properties. In the third stage the notion of state is introduced and a thing is defined as a substantial individual equipped with all its possible states. Natural kinds or species are then defined with the help of the concept of a law, namely as the sets of things satisfying certain laws. The real world is assumed to be unique and to be constituted by things alone. Finally the notion of a concrete system is defined as a set of things together with the set of connections among them. The paper employs elementary logical, algebraic and set theoretical notions, and is hoped to belong in exact philosophy.     

A method of defuzzification based on the approach of areas' ratio

The new method of defuzzification of output parameters from the base of fuzzy rules for a Mamdani fuzzy controller is given in the paper. The peculiarity of the method is the usage of the universal equation for the area computation of the geometric shapes. During the realization of fuzzy inference linguistic terms, the structure changes from the triangular into a trapezoidal shape. That is why the universal equation is used. The method is limited and can be used only for the triangular and trapezoidal membership functions. Gaussian functions can also be used while modifying the proposed method. Traditional defuzzification models such as Middle of Maxima − MoM, First of Maxima − FoM, Last of Maxima − LoM, First of Suppport − FoS, Last of Support − LoS, Middle of Support − MoS, Center of Sums − CoS, Model of Height − MoH have a number of systematic errors: curse of dimensionality, partition of unity condition and absence of additivity. The above-mentioned methods can be seen as Center of Gravity − CoG, which has the same errors. These errors lead to the fact that accuracy of fuzzy systems decreases, because during the training root mean square error increases. One of the reasons that provokes the errors is that some of the activated fuzzy rules are excluded from the fuzzy inference. It is also possible to increase the accuracy of the fuzzy system through properties of continuity. The proposed method guarantees fulfilling of the property of continuity, as the intersection point of the adjustment linguistic terms equals 0.5 when a parametrized membership function is used. The causes of errors and a way to delete them are reviewed in the paper. The proposed method excludes errors which are inherent to the traditional and non- traditional models of defuzzification. Comparative analysis of the proposed method of defuzzification with traditional and non-traditional models shows its effectiveness.     

Open ended intelligence: the individuation of intelligent agents

Artificial general intelligence is a field of research aiming to distil the principles of intelligence that operate independently of a specific problem domain and utilise these principles in order to synthesise systems capable of performing any intellectual task a human being is capable of and beyond. While “narrow” artificial intelligence which focuses on solving specific problems such as speech recognition, text comprehension, visual pattern recognition and robotic motion has shown impressive breakthroughs lately, understanding general intelligence remains elusive. We propose a paradigm shift from intelligence perceived as a competence of individual agents defined in relation to an a priori given problem domain or a goal, to intelligence perceived as a formative process of self-organisation. We call this process open-ended intelligence. Starting with a brief introduction of the current conceptual approach, we expose a number of serious limitations that are traced back to the ontological roots of the concept of intelligence. Open-ended intelligence is then developed as an abstraction of the process of human cognitive development, so its application can be extended to general agents and systems. We introduce and discuss three facets of the idea: the philosophical concept of individuation, sense-making and the individuation of general cognitive agents. We further show how open-ended intelligence can be framed in terms of a distributed, self-organising network of interacting elements and how such process is scalable. The framework highlights an important relation between coordination and intelligence and a new understanding of values.     

Schematic classification problems and their solution

The necessity arises in a variety of tasks to classify items on the basis of the presence of one of a number of criterial sets of co-related feature values. Such sets are called class characteristics. Because such classification problems require the identification of characteristics on the basis of limited training information, they entail a difficult search problem. Consideration of the differences between the theoretical models underlying characteristic and volume pattern generators suggests a schematic approach. Schemata, sets of commonly co-occuring features values, are probabilistic indicators of class membership whenever the characteristics are unknown but the characteristic model prevails. Formal and algorithmic solutions to the classification problem when exemplars are simple (consist only of M feature or attribute values) are described. The relevance of these procedures to problems involving general (relational) data structures is also indicated.     

基于SRMET的软件可靠性测试研究

SRMET测试工具作为研究对象,阐述了软件可靠性测试理论,采用SRMET3.0进行可靠性评估,得到了可靠性评估指标。     

人和人工智能系统的概念形成过程研究

概念的形成是实现人工智能的基础,为研究人工智能系统中概念的形成过程,从人对事物形成概念的过程出发进行了研究。比较人和人工智能系统的概念形成过程得到了如下特点:人的优势在于能自主地确定对象表象和对象功能中的各种特征和划分等,能在对象、描述性定义和功能性定义对应关系不完备情况下通过思维和联想建立概念;人工智能系统的优势在于丰富的对象表象感知能力,对象的各种特征和划分的长期存储、运算和分析能力;而人工智能的概念形成过程存在的缺点基本与人的概念形成过程的优点对应。因此本文认为人工智能的概念形成过程必须关注因素的智能识别、功能的系统实践和人经验知识的有师学习。现有技术在缺乏人经验知识的情况下,人工智能系统不能自主建立概念和知识库,不能实现智能过程。     

Delay-Insensitivity and Semi-Modularity

The study of asynchronous circuit behaviors in the presence of component and wire delays has received a great deal of attention. In this paper, we consider asynchronous circuits whose components can be any non-deterministic sequential machines of the Moore type, and describe a formal model for these circuits and their behaviors under the inertial delay model.We model an asynchronous circuit C by a network N of modules with delays associated with its components and/or wires. We compute the behavior of N assuming arbitrary inertial delays in the modules, and take this behavior to be correct. We define N to be strongly delay-insensitive if its behavior remains correct in the presence of arbitrary stray delays, where correctness is defined through the notion of observational equivalence (or bisimulation), one of the strongest forms of behavioral equivalence. We introduce the notion of quasi semi-modularity, which generalizes Muller's definition of semi-modularity to non-deterministic networks. We prove that a circuit, with all the wire delays taken into account, is strongly delay-intensitive if and only if its behavior is quasi semi-modular.     

Biomechanical analysis of materials handling manipulators in short distance transfers of moderate mass objects: joint strength,spine forces and muscular antagonism

Although often suggested as a control measure to alleviate musculoskeletal stresses, the use of mechanical assistance devices (i.e. manipulators) in load transfers has not been extensively studied. Without data describing the biomechanical effects of such devices, justification for decisions regarding implementation of such tools is difficult. An experimental study of two types of mechanical manipulators (articulated arm and overhead hoist) was conducted to determine whether biomechanical stresses, and hence injury risk, would be alleviated. Short distance transfers of loads with moderate mass were performed both manually and with manipulator assistance under a variety of task conditions. Using analysis and output from new dynamic torso models, strength demands at the shoulders and low back, lumbar spine forces, and lumbar muscle antagonism were determined. Strength requirements decreased significantly at both the shoulders and low back when using either manipulator in comparison with similar transfers performed manually. Peak spine compression and anteriorposterior (a-p) shear forces were reduced by about 40% on average, and these reductions were shown to be primarily caused by decreases in hand forces and resultant spinal moments. Two metrics of muscular antagonism were defined, and analysis showed that torso muscle antagonism was largest overall when using the hoist. The results overall suggest that hoist-assisted transfers, although better in reducing spine compression forces, may impose relatively higher demands on coordination and/or stability at extreme heights or with torso twisting motions. The relatively higher strength requirements and spine compression associated with the articulated arm may be a result of the high inertia of the system. Potential benefits of practice and training are discussed, and conclusions regarding implementation of mechanical manipulators are given.     

LMI-based H ∞ synchronization of second-order neutral master-slave systems using delayed output feedback control

The H _∞ synchronization problem of the master and slave structure of a second-order neutral master-slave systems with time-varying delays is presented in this paper. Delay-dependent sufficient conditions for the design of a delayed output-feedback control are given by Lyapunov-Krasovskii method in terms of a linear matrix inequality (LMI). A controller, which guarantees H _∞ synchronization of the master and slave structure using some free weighting matrices, is then developed. A numerical example has been given to show the effectiveness of the method. The simulation results illustrate the effectiveness of the proposed methodology. Recommended by Editorial Board member Bin Jiang under the direction of Editor Jae Weon Choi. This research has been partially funded by the German Research Foundation (DFG) as part of the Collaborative Research Center 637 ‘Autonomous Cooperating Logistic Processes: A Paradigm Shift and its Limitations’ (SFB 637). This work was supported in part by the National Natural Science Foundation of China (60504008), by the Research Fund for the Doctoral Program of Higher Education of China (20070213084), by the Fok Ying Tung Education Foundation (111064). Hamid Reza Karimi born in 1976, received the B.Sc. degree in Power Systems Engineering from Sharif University of Technology in 1998 and M.Sc. and Ph.D. degrees both in Control Systems Engineering from University of Tehran in 2001 and 2005, respectively. From 2006 to 2007, he was a Post-doctoral Research Fellow of the Alexander-von-Humboldt Stiftung with both Technical University of Munich and University of Bremen in Germany. He held positions as Assistant Professor at the Department of Electrical Engineering of the University of Tehran in Iran, Senior Research Fellow in the Centre for Industrial Mathematics of the University of Bremen in Germany and Research Fellow of Juan de la Cierva program at the Department of Electronics, Informatics and Automation of the University of Girona in Spain before he was appointed as an Associate Professor in Control Systems at the Faculty of Technology and Science of the University of Agder in Norway in April 2009. His research interests are in the areas of nonlinear systems, networked control systems, robust filter design and vibration control of flexible structures with an emphasis on applications in engineering. Dr. Karimi was the recipient of the German Academic Awards (DAAD Award) from 2003 to 2005 and was a recipient of the Distinguished Researcher Award from University of Tehran in 2001 and 2005. He received the Distinguished PhD Award of the Iranian President in 2005 and the Iranian Students Book Agency’s Award for Outstanding Doctoral Thesis in 2007. He also received first rank of Juan de la Cierva research program in the field of Electrical, Electronic and Automation Engineering in Spain in 2007. Huijun Gao was born in Heilongjiang Province, China, in 1976. He received the M.S. degree in Electrical Engineering from Shenyang University of Technology, Shengyang, China, in 2001 and the Ph.D. degree in Control Science and Engineering from Harbin Institute of Technology, Harbin, China, in 2005. He was a Research Associate with the Department of Mechanical Engineering, The University of Hong Kong, Hong Kong, from November 2003 to August 2004. From October 2005 to September 2007, he carried out his postdoctoral research with the Department of Electrical and Computer Engineering, University of Alberta, Canada, supported by an Alberta Ingenuity Fellowship and an Honorary Izaak Walton Killam Memorial Postdoctoral Fellowship. Since November 2004, he has been with Harbin Institute of Technology, where he is currently a Professor. His research interests include network-based control, robust control/filter theory, model reduction, time-delay systems, multidimensional systems, and their engineering applications. Dr. Gao is an Associate Editor for the IEEE Transactions on Systems, Man and Cybernetics Part B: Cybernetics, the Journal of Intelligent and Robotics Systems, the Circuits, System and Signal Processing etc. He serves on the Editorial Board of the International Journal of Systems Science, the Journal of the Franklin Institute etc. He was the recipient of the University of Alberta Dorothy J. Killam Memorial Postdoctoral Fellow Prize in 2005 and was a corecipient of the National Natural Science Award of China in 2008. He was a recipient of the National Outstanding Youth Science Fund in 2008 and the National Outstanding Doctoral Thesis Award in 2007. He was an outstanding reviewer for IEEE Transactions on Automatic Control and Automatica in 2008 and 2007 respectively, and an appreciated reviewer for IEEE Transactions on Signal Processing in 2006.     

浅谈嵌入式处理器的特点与进展

该文论述了嵌入式微控制器,通用微处理器、数字信号处理器和片上系统等几类主流嵌入式处理器各自的特点,应用范围,发展及现状以及在此基础上新的发展趋势,并指出今后技术融合的趋势。