Fractal dimension applied to plant identification

This article discusses methods to identify plants by analysing leaf complexity based on estimating their fractal dimension. Leaves were analyzed according to the complexity of their internal and external shapes. A computational program was developed to process, analyze and extract the features of leaf images, thereby allowing for automatic plant identification. Results are presented from two experiments, the first to identify plant species from the Brazilian Atlantic forest and Brazilian Cerrado scrublands, using fifty leaf samples from ten different species, and the second to identify four different species from genus Passiflora, using twenty leaf samples for each class. A comparison is made of two methods to estimate fractal dimension (box-counting and multiscale Minkowski). The results are discussed to determine the best approach to analyze shape complexity based on the performance of the technique, when estimating fractal dimension and identifying plants.     

基于LMD的PWM整流电路故障特征提取新方法

脉冲宽度调制(PWM)整流电路结构日益复杂,对其可靠运行提出了更高的要求;对局域均值分解(LMD)用于PWM整流电路的故障特征提取进行研究,提出一种基于LMD和加权频带能量法的特征提取新方法;该方法通过逐步抽取调频调幅成分将故障信号在频域上展开,然后基于信号能量的频带分布特点,充分考虑各频带成分与故障的相关性,构造故障特征向量,实现特征提取;最后以PWM整流电路为例进行仿真,相电压380V,仿真时间0.5s,0.1s时注入故障;结果表明,该方法能有效地提取故障信号的特征,并降低特征向量的维数。     

Quantum analysis of measurement results

It is shown that a stochastic matrix operator (quantum measurement matrix) may be considered in some cases as a density matrix. Results of measurements in the form of figure numbers, interconnected with a matrix of quantum measurements, are similar to quantum observable quantities determined in quantum statistical theory. __________ Translated from Izmeritel’naya Tekhnika, No. 12, pp. 3–8, December, 2006.     

提高规划与管理的科学性,促进小城镇健康发展

提出了科学的城镇规划与管理的基本任务，进而从四个方面阐述了如何把握这个基本任务促进本城镇经济与社会健康、迅速而稳步地发展：１）科学地研究城镇的性质与规模；２）合理地安排城镇用地布局；３）切实地制定近期建设规划；４）宜人地创造本镇风貌特色。     

一种新的多维稀疏规则模糊插值推理方法

经典的插值理论针对一维稀疏规则库的条件，提出了各种不同的插值方法，取得了很多很好的经验．但对多维稀疏规则条件的近似推理，研究很少，仅有的几种插值方法，存在着难以保证推理结果的凸性和正规性等问题．为了在多维稀疏规则条件下能得到好的插值推理结果。提出了一种基于几何相似的插值推理方法．该方法能较好地保证推理结果隶属函数的凸性和正规性，为智能系统中的模糊推理提供了一个十分有用的工具．     

流场尺寸对质子交换膜燃料电池性能的影响

流场的形状和尺寸是设计双极板的核心。合理的流场既要确保电极各处均能获得充足的反应剂供应,同时又要保证反应产物水的排出。研究了不同流场尺寸对质子交换膜燃料电池性能的影响。实验结果表明:在一定范围内,随着开孔率的增加,电极与流场本相及接触电阻也逐渐增加;开孔率相近时,这一电阻相差不大。在相同开孔率的情况下,沟槽尺寸越小,电池性能越好。     

絮凝体的物理特性

从絮凝体的密度,空隙率、絮凝体的粒径分布,絮凝体的强度以及絮凝体的分形维数五个方面综述了絮凝体的物理特性及结构特性,分析了影响絮凝体物理特性的因素。     

k分Cantor集的Hausdorff测度的一种计算

以比较初等的方法重新证明了著名的Ｃａｎｔｏｒ三分集的Ｈａｓｄｏｒｒｆｆ维数为ｓ＝ｌｏｇ２／ｌｏｇ３，Ｈａｕｓｄｏｒｆｆｃ测度为１，并对直线上类似的一类构造集推广了此方法。     

Fractal characteristics of electric properties of coal

In the light of fractal geometry theory, the characteristics of coal＇s electric parameters （including dielectric constant, alternating conductivity, dielectric loss angle tangent and electric polarization constant） were studied by using literature data. The results are shown that the electrical properties of coal have fractal characteristic. The fractal dimensions of dielectric, alternating conductivity, dielectric loss angle tangent were obtained, and are relative to the content of pyrite sulfur, heat and ash content of coal.