用西门子数控系统双电动机驱动消隙功能提高机床传动精度

介绍了西门子数控系统双电动机驱动消隙功能及原理,阐述了双电动机驱动消隙功能在数控龙门镗铣床上的应用方法。     

Simplification of fuzzy switching functions

This paper is concerned with the study of simplification of fuzzy switching functions. A novel algorithm for generating all fuzzy prime implicants is introduced, followed by a new method of simplification of fuzzy switching functions. This algorithm is then reduced to a simple algorithm that produces only those fuzzy prime implicants that are essential. There areonly two other valid techniques for the minimization of fuzzy switching functions in the literature,^(1,2) and those methods are not very suitable for computerized application. Thus, the principal advantages of this technique are the new concept of direct simplification via essential fuzzy prime implicants (without generation of all of the fuzzy prime implicants), and the fact that the algorithm is the first one to be suitable for efficient computer implementation.On leave from the Computer Science Department, New Mexico Institute of Mining and Technology, Socorro, New Mexico.     

OPTIMAL COMPENSATION OF NONUNIFORMLY LOADED RADIAL FEEDERS,WITH APPLICATIONS

ABSTRACT

This paper presents a generalized mathematical model for assessing the loss reduction in nonunlformly loaded radial feeders by capacitor shunt compensation. The model allows for the simultaneous presence of linearly increasing feeder load density in addition to a concentrated load at the feeder end. Any number of compensating capacitors can be included in the analysis. The model is then applied to study the effect of the number of feeders on the achieveable optimal reduction in the feeder copper loss. The paper also gives the optimal size and locations of these capacitors, for any number of radial feeders eraenatlng from a distribution substation to serve a certain total load.     

Metaheuristic-based energy management strategies for fuel cell emergency power unit in electrical aircraft

This paper aims at presenting a comparative analysis of different metaheuristic algorithms in the application of energy management for fuel cell-based hybrid emergency power unit within electrical aircraft. Two energy management conventional strategies are employed while optimizing the operating temperature. Both the external energy maximization and the equivalent consumption minimization strategies are dealt with. The most efficient up-to-date metaheuristic techniques such as the artificial bee colony, the grey wolf optimization, the cuckoo search, the mine blast algorithm, the whale optimization algorithm, the moth swarm algorithm, the harmony search, the modified flower pollination algorithm and the electromagnetic field optimization are considered. The overall index of optimization performance is considered as a function of hydrogen consumption, overall system efficiency, variations of states of charge and stresses in different energy sources. The numerical simulations, through Matlab™/Simulink, highlights the capability of the different metaheuristic optimization techniques towards reducing the amount of consumed hydrogen in fuel cell-based emergency power unit in electrical aircrafts. The electromagnetic field optimization method results in significant hydrogen consumption reduction in comparison with the other proposed techniques.     

放射性废物管理和核设施退役中几个问题的讨论

从满足放射性废物管理和核设施退役工作的需要出发,讨论了《电离辐射防护与辐射源安全基本标准》中有关排除、豁免、解控以及排放、废源处置、去污、废物最少化、防护最优化等几项规定的实施问题,并对其中一些问题提出了继续深入研究的意见。     

放射性废物的安全管理及最小化

我国放射性废物的安全管理和最小化与发达国家相比存在一定差距。研究并应用放射性废物的安全管理及应采取的最小化措施,对实现其安全管理并有效降低处理、处置费用,降低环境辐射危害具有实际意义。本文对核能生产、核技术应用和核设施退役等方面产生的放射性废物安全管理和最小化进行了较系统的研究和论述,总结并提出了放射性废物的安全管理手段及最小化措施与方法。     

IPSEC和组播协同工作系统设计

IPSEC是解决IP层安全的协议,它是一种点到点的协议,IPSEC和IKE协同工作可以解决单播通信的安全,同时IKE是点到点的密钥管理协议,它也不适宜于在组播环境下使用,因为在组播环境下,同一个包却有多个接收者,有时许多发送者都将包传给一个特定的多播地址。该文建立了一个IPSEC与组播协同工作的环境,重点解决组播环境下密钥管理的问题。并且提出了三种密钥管理方式,分析了它们的性能优劣,特别指出采用完全密钥二叉树,并使用布尔函数化简技术可以有效解决IPSEC和组播环境协同工作下的密钥分配问题。     

从明暗恢复形状（SFS）的几类典型算法分析与评价

从明暗恢复形状（shape from shading,简称SFS）是计算机视觉中三维形状恢复问题的关键技术之一,其任务是利用单幅图象中物体表面的明暗变化来恢复其表面三维形状。为了使人们对SFC研究现状及求解SFS问题的各种算法的优缺点有个概略了解,首先介绍了求解传统SFS问题的4类方法中几个典型算法的基本原理及求解方法,并给出了实验结果,然后从算法解的唯一性、对真解的逼近程度、求解效率及适用范围等方面对这4类算法进行了比较和评价。     

HSMC-SVM的二次逼近快速训练算法

HSMC-SVM是一种直接型高速多类支持向量机,适合用于类别较多的分类场合,但由于SMO算法采用经验方法选择工作集,使得在用SMO算法训练HSMC-SVM时,收敛速度较慢。为提高HSMC-SVM的收敛速度,该文提出用基于二次逼近的可行方向法来训练HSMC-SVM,并使用了样本缩减策略。实验表明,这种方法可以有效提高HSMC-SVM的收敛速度,其收敛速度已经超过了基于libsvm的组合多类支持向量机,完全可以用于分类类别多、样本数量大的分类场合。     

三值T门组合网络化简的一种方法——真值表分割法

本文给出三值T门组合网络化简的一种方法——真值表分割法。该方法可以使三值T门组合网络化简到最小化或者接近最小化,而且操作时间较短,易于编程,上机操作。