The personalization of security selection: An application of fuzzy set theory

We apply the theory of fuzzy subsets to the multiple objective decision problem of stock selection. We allow our objectives to have varying degrees of importance. We discuss various criteria used in selecting stocks. We indicate some procedures for subjectively evaluating the membership functions associated with these criteria.     

On identification in fuzzy systems and its applications in control problems

The problem of identification in fuzzy systems described by the use of fuzzy equation is considered. The identification method and its performance index is also presented. The formal procedure of the identification algorithm is illustrated by means of a numerical example. The possibility of using the proposed algorithm for the solution of a control problem is given as well.     

不同表面结构特征圆柱导体的太赫兹散射特性

太赫兹频段下导体表面的细微结构、粗糙度等细节将对目标电磁散射行为产生影响。为衡量这一影响程度,以圆柱导体为例研究了太赫兹频段下目标表面不同结构特征的电磁散射现象及其在图像域的表现规律。利用高频电磁计算方法获得了表面分别为理想光滑、带刻痕和周期粗糙的三种圆柱多姿态角、多频点单站散射场;基于转台成像算法重建了小转角下目标的二维图像。从仿真结果可以看出:m量级的细节特征在太赫兹雷达图像上有着显著的表现,表明太赫兹雷达能够获取更加丰富和精细的目标信息,从而为目标探测识别提供新的特征和技术手段。     

基于模糊PID的助行机器人调速系统的研究

助行机器人对系统的动态特性要求较高,而且在其爬楼的过程中有诸多不确定的因素,基于传统控制策略的单闭环负反馈控制系统调速效果难以令人满意。在这种情况下建立了系统的数学模型,设计了基于模糊PID的双闭环调速控制系统,并和传统的PID控制进行了对比。为了保证助行机器人爬楼过程的平稳性和乘坐者的舒适性,参考电梯运行的速度曲线,设计了正弦速度给定曲线。仿真结果表明：在助行机器人调速系统中,模糊PID控制比传统PID控制启动和制动过程更平稳,舒适性更高,误差更小,精度更高。     

Fusion of infrared polarization and intensity images using support value transform and fuzzy combination rules

Infrared polarization and intensity imagery provide complementary and discriminative information in image understanding and interpretation. In this paper, a novel fusion method is proposed by effectively merging the information with various combination rules. It makes use of both low-frequency and high-frequency images components from support value transform (SVT), and applies fuzzy logic in the combination process. Images (both infrared polarization and intensity images) to be fused are firstly decomposed into low-frequency component images and support value image sequences by the SVT. Then the low-frequency component images are combined using a fuzzy combination rule blending three sub-combination methods of (1) region feature maximum, (2) region feature weighting average, and (3) pixel value maximum; and the support value image sequences are merged using a fuzzy combination rule fusing two sub-combination methods of (1) pixel energy maximum and (2) region feature weighting. With the variables of two newly defined features, i.e. the low-frequency difference feature for low-frequency component images and the support-value difference feature for support value image sequences, trapezoidal membership functions are proposed and developed in tuning the fuzzy fusion process. Finally the fused image is obtained by inverse SVT operations. Experimental results of visual inspection and quantitative evaluation both indicate the superiority of the proposed method to its counterparts in image fusion of infrared polarization and intensity images.     

粗糙热传导表面下激光介质温度场的计算分析

提出了一种计算温度场的面热源自适应调整算法,该方法通过在研究对象的封闭边界上引入虚拟面热源来求解稳态热传导方程的边值问题。建立了导热联结的具有粗糙表面介质的接触模型,在此基础上建立了随机分布的表面散热边界条件,并用面热源自适应调整算法计算了激光介质的温度场。结果表明,由于实际激光介质散热表面不能完全紧密接触,其温度场呈现一定程度的随机起伏,越靠近边界,随机起伏越明显,介质中心区域随机起伏则不明显;有效热接触面积越小,这种随机起伏越强烈。计算表明热接触面积占50%时,比接触面积占75%时温度场的随机性更明显。     

热流计校准装置自适应温度控制方法研究

以热流计校准装置为研究对象,建立了热板温度仿真模型。根据模糊控制原理和BP神经网络原理,分别设计了模糊PID控制器和BP神经网络PID控制器,并在Matlab的Simulink下进行了不同控制方法的仿真对比实验。仿真结果表明:模糊PID有更快的响应速度、更短的稳定时间,BP神经网络PID有更小的超调量。     

Tableau method for residuated logic

Residuated logic is a generalization of intuitionistic logic, which does not assume the idempotence of the conjunction operator. Such generalized conjunction operators have proved important in expert systems (in the area of Approximate Reasoning) and in some areas of Theoretical Computer Science. Here we generalize the intuitionistic tableau procedure and prove that this generalized tableau method is sound for the semantics (the class of residuated algebras) of residuated propositional calculus (RPC). Since the axioms of RPC are complete for the semantics we may conclude that whenever a formula 0 is tableau provable, it is deducible in RPC. We present two different approaches for constructing residuated algebras which give us countermodels for some formulas φ which are not tableau provable. The first uses the fact that the theory of residuated algebras is equational, to construct quotients of free algebras. The second uses finite algebras. We end by discussing a number of open questions.     

机械结构的模糊优化设计

本文阐述了机械结构模糊优化设计的必要性及方法，并以用于５５千瓦风力发电机组的ＮＧＷ９２型行星齿轮传动为例，说明这一现代设计方法的实施及优良设计特性。     

模糊传感器训练算法

本文提出了模糊传感器的一种分段式训练调参方法。对温度模糊传感器的仿真结果表明，该方法能在不同的测量结构下，较好地解决人类感知温度的模糊语言描述问题。