泛系思维与应用：科学技术,方法论,创新与智能信息处理（Ⅱ）（上）

本文续前论述乏系思维的框架和方法论、创新运筹与智能信息处理问题,简化强化地介绍了几十种泛系理法及其应用,具体内容包括：泛系思维简式、泛系原则、泛系螺旋、显生原则、系统原则、广义系统、局整关系、分析与综合、整体性、结构与功能、遗憾原则、竞分三故、等价原则、竞标律、层标模型、简化５０计、转化原则、泛系数学建模总体转化模式、泛对称普适原则、广义量化、泛积原理、模糊控制、故障诊断的专家系统、数学建模三范畴     

泛系思维与应用：科学技术,方法论,创新与智能信息处理（Ⅱ）（下）

本文续前期论述泛系思维的框架和方法论、创新运筹与智能信息处理问题,简化强化地介绍了几十种泛系理法及其应用,具体内容包括：泛系思维简式、泛系原则、泛系螺旋、显生原则、系统原则,广义系统、局整关系、分析与综合、整体性、结构与功能、遗憾原则、况分三故、等价原则、竞标律、层标模型、简休５０计、转化原则、泛系数学建模总体转化模式、泛对称普适原则、广义量化、泛积原理、模糊控制、故障诊断的专家系统、数学建模三范     

车联网隐私保护技术研究

随着汽车智能化、网联化程度的不断加深,车辆、用户及第三方机构之间的数据共享日益成为刚需,由车辆、用户、路边单元等通信实体之间构建的网络车联网应运而生,而车联网的高移动性和网络拓扑多变性使其更容易遭受攻击,进而导致严重的车联网用户隐私泄露问题。如何平衡数据共享和隐私保护之间的关系成为车联网产业发展所面临的一个关键挑战。近年来,学术界针对车联网隐私保护问题进行了深入的研究,并提出了一系列解决方案,然而,目前缺少对这些方案从隐私属性方面进行分析。为此,本文首先从车联网的系统架构、通信场景及标准进行阐述。然后对车联网隐私保护的需求、攻击模型及隐私度量方法进行分析与总结。在此基础上从车联网身份隐私、匿名认证位置隐私和车联网位置服务隐私三个方面出发,介绍了匿名认证、假名变更、同态加密、不经意传输等技术对保护车联网用户隐私起到的重要作用,并讨论了方案的基本原理及代表性实现方法,将方案的隐私性从不可链接性、假名性、匿名性、不可检测性、不可观察性几个方面进行了分析与总结。最后探讨了车联网隐私保护技术当前面临的挑战及进一步研究方向,并提出了去中心化的车辆身份隐私技术以保护车辆身份隐私、自适应假名变更技术以支持匿名认证、满足个性化隐私需求的位置服务隐私保护技术,以期望进一步推动车联网隐私保护技术研究的发展与应用。     

基于H.263解压算法和UDP协议的多方视频会议系统

简要概括了视频会议系统的设计原理,重点讲述了视频会议系统的实现过程,从视音频俘获、视音频数据压缩,数据传送、数据接收、数据解压,到音频数据播放、视频数据显示的整个过程.特别是对实现过程中的模拟会议室的创建过程、命令解析、视音频同步、音频数据的混音处理、中间代理服务器转发等做了详细的讲解.并对视频会议系统的发展和应用前景进行了认真的分析.     

Sixty years of cybernetics

Fundamental aspects of cybernetics, such as goals, problems, methods, tools, brief history, and correlation with other sciences, are considered. Cybernetics in its classical interpretation is the science of information management, communication, and processing. As cybernetics developed, this definition was formalized as the science of methods and processes of information acquisition, storage, processing, analysis, and evaluation, which allows it to apply to decision making in complex control systems. These systems include all engineering, biological, administrative, social, ecological, and economical systems. The main thesis that determined the goals, problems, subject matter, and development of cybernetics as a whole up to the present is the similarity in management and communication processes in machines, living organisms, and both animal and human societies. First of all, these are processes of transfer, storage, and processing of information, i.e., various signals, messages, and data. Any signal and any information may be considered independently from its particular content and destination as a certain choice between two or more values having the known probabilities (selective concept of information). It allows us to treat all processes on the basis of a unified measure and statistical apparatus. The idea of the general theory of control and communication, that is, cybernetics, is based on this hypothesis.     

Fuzzy risk analysis based on the ranking of generalized trapezoidal fuzzy numbers

In this paper, we present a new method for fuzzy risk analysis based on the ranking of generalized trapezoidal fuzzy numbers. The proposed method considers the centroid points and the standard deviations of generalized trapezoidal fuzzy numbers for ranking generalized trapezoidal fuzzy numbers. We also use an example to compare the ranking results of the proposed method with the existing centroid-index ranking methods. The proposed ranking method can overcome the drawbacks of the existing centroid-index ranking methods. Based on the proposed ranking method, we also present an algorithm to deal with fuzzy risk analysis problems. The proposed fuzzy risk analysis algorithm can overcome the drawbacks of the one we presented in [7]. Shi-Jay Chen was born in 1972, in Taipei, Taiwan, Republic of China. He received the B.S. degree in information management from the Kaohsiung Polytechnic Institute, Kaohsiung, Taiwan, and the M.S. degree in information management from the Chaoyang University of Technology, Taichung, Taiwan, in 1997 and 1999, respectively. He received the Ph.D. degree at the Department of Computer Science and Information Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan, in October 2004. His research interests include fuzzy systems, multicriteria fuzzy decisionmaking, and artificial intelligence. Shyi-Ming Chen was born on January 16, 1960, in Taipei, Taiwan, Republic of China. He received the Ph.D. degree in Electrical Engineering from National Taiwan University, Taipei, Taiwan, in June 1991. From August 1987 to July 1989 and from August 1990 to July 1991, he was with the Department of Electronic Engineering, Fu-Jen University, Taipei, Taiwan. From August 1991 to July 1996, he was an Associate Professor in the Department of Computer and Information Science, National Chiao Tung University, Hsinchu, Taiwan. From August 1996 to July 1998, he was a Professor in the Department of Computer and Information Science, National Chiao Tung University, Hsinchu, Taiwan. From August 1998 to July 2001, he was a Professor in the Department of Electronic Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. Since August 2001, he has been a Professor in the Department of Computer Science and Information Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan. He was a Visiting Scholar in the Department of Electrical Engineering and Computer Science, University of California, Berkeley, in 1999. He was a Visiting Scholar in the Institute of Information Science, Academia Sinica, Republic of China, in 2003. He has published more than 250 papers in referred journals, conference proceedings and book chapters. His research interests include fuzzy systems, information retrieval, knowledge-based systems, artificial intelligence, neural networks, data mining, and genetic algorithms. Dr. Chen has received several honors and awards, including the 1994 Outstanding Paper Award o f the Journal of Information and Education, the 1995 Outstanding Paper Award of the Computer Society of the Republic of China, the 1995 and 1996 Acer Dragon Thesis Awards for Outstanding M.S. Thesis Supervision, the 1995 Xerox Foundation Award for Outstanding M.S. Thesis Supervision, the 1996 Chinese Institute of Electrical Engineering Award for Outstanding M.S. Thesis Supervision, the 1997 National Science Council Award, Republic of China, for Outstanding Undergraduate Student's Project Supervision, the 1997 Outstanding Youth Electrical Engineer Award of the Chinese Institute of Electrical Engineering, Republic of China, the Best Paper Award of the 1999 National Computer Symposium, Republic of China, the 1999 Outstanding Paper Award of the Computer Society of the Republic of China, the 2001 Institute of Information and Computing Machinery Thesis Award for Outstanding M.S. Thesis Supervision, the 2001 Outstanding Talented Person Award, Republic of China, for the contributions in Information Technology, the 2002 Institute of information and Computing Machinery Thesis Award for Outstanding M.S. Thesis Supervision, the Outstanding Electrical Engineering Professor Award granted by the Chinese Institute of Electrical Engineering (CIEE), Republic of China, the 2002 Chinese Fuzzy Systems Association Best Thesis Award for Outstanding M.S. Thesis Supervision, the 2003 Outstanding Paper Award of the Technological and Vocational Education Society, Republic of China, the 2003 Acer Dragon Thesis Award for Outstanding Ph.D. Dissertation Supervision, the 2005 “Operations Research Society of Taiwan” Award for Outstanding M.S. Thesis Supervision, the 2005 Acer Dragon Thesis Award for Outstanding Ph.D. Dissertation Supervision, the 2005 Taiwan Fuzzy Systems Association Award for Outstanding Ph.D. Dissertation Supervision, and the 2006 “Operations Research Society of Taiwan” Award for Outstanding M.S. Thesis Supervision. Dr. Chen is currently the President of the Taiwanese Association for Artificial Intelligence (TAAI). He is a Senior Member of the IEEE, a member of the ACM, the International Fuzzy Systems Association (IFSA), and the Phi Tau Phi Scholastic Honor Society. He was an administrative committee member of the Chinese Fuzzy Systems Association (CFSA) from 1998 to 2004. He is an Associate Editor of the IEEE Transactions on Systems, Man, and Cybernetics - Part C, an Associate Editor of the IEEE Computational Intelligence Magazine, an Associate Editor of the Journal of Intelligent & Fuzzy Systems, an Editorial Board Member of the International Journal of Applied Intelligence, an Editor of the New Mathematics and Natural Computation Journal, an Associate Editor of the International Journal of Fuzzy Systems, an Editorial Board Member of the International Journal of Information and Communication Technology, an Editorial Board Member of the WSEAS Transactions on Systems, an Editor of the Journal of Advanced Computational Intelligence and Intelligent Informatics, an Associate Editor of the WSEAS Transactions on Computers, an Editorial Board Member of the International Journal of Computational Intelligence and Applications, an Editorial Board Member of the Advances in Fuzzy Sets and Systems Journal, an Editor of the International Journal of Soft Computing, an Editor of the Asian Journal of Information Technology, an Editorial Board Member of the International Journal of Intelligence Systems Technologies and Applications, an Editor of the Asian Journal of Information Management, an Associate Editor of the International Journal of Innovative Computing, Information and Control, and an Editorial Board Member of the International Journal of Computer Applications in Technology. He was an Editor of the Journal of the Chinese Grey System Association from 1998 to 2003. He is listed in International Who's Who of Professionals, Marquis Who's Who in the World, and Marquis Who's Who in Science and Engineering.     

Mapping complexity of spatial distribution of faults using fractal and multifractal models: vectoring towards exploration targets

In this paper, fractal and multifractal analyses are demonstrated as effective tools for mapping complexity in the spatial distribution of faults. Faults within the eastern part of Gejiu mining area, Yunnan province, west southern China were chosen to demonstrate mapping of the complexity of their spatial distributions using fractal and multifractal models. The results show that (1) the fractal dimensions of the spatial distributions of all faults, NW-trending faults, and NE-trending faults are 1.68, 1.49, and 1.42, respectively, indicating differences in spatial distributions of different sets of faults; (2) the fractal dimensions of the spatial distributions of faults in the four Sn fields in the Gejiu mining district, namely Malage, Gaosong, Laochang, and Kafang (arranged in the order of increasing proportions of surface-projected areas of Sn orebodies) are 1.38, 1.57, 1.65, and 1.41, respectively; and (3) complexity of the spatial distributions of faults, represented by fractal dimension, correlates well with surface-projected areas of Sn orebodies, and lengths of faults satisfy the multifractal statistical and singularity index α, which can be used to quantify the complexity of the spatial distributions of faults.     

云模式事件混沌关联特征提取的物联网大数据聚类算法

目前的聚类方法单纯从某个角度研究数据聚类问题,对基于云模式的混沌的物联网大数据聚类的考虑不足,聚类质量不高。为实现敏捷、智能、平稳的物联网大数据聚类,基于开展物联网事件的云模式通用描述模型、物联网事件混沌关联特征的云模式通用解析模型、基于云模式的物联网事件混沌关联特征提取算法、基于云模式混沌关联特征的物联网大数据关联挖掘研究,改进分解奇异值算法、网格耦合聚类算法、K-means算法、决策树学习法、分析主成分法、分层合并法等算法和分布概率函数,设计了一种基于事件混沌关联特征、敏捷、智能、平稳的物联网大数据聚类算法。最后,开展实验验证,并与传统算法进行性能对比分析。实验结果表明,相比传统算法,该算法聚类时间短、误差小,且敏捷性、智能性、动态演化性和平稳性高。因此,该算法实现了基于云模式的具有混沌关联特征的物联网事件大数据的有效聚类,具有较高的应用价值。     

Content-based image retrieval at the end of the early years

Presents a review of 200 references in content-based image retrieval. The paper starts with discussing the working conditions of content-based retrieval: patterns of use, types of pictures, the role of semantics, and the sensory gap. Subsequent sections discuss computational steps for image retrieval systems. Step one of the review is image processing for retrieval sorted by color, texture, and local geometry. Features for retrieval are discussed next, sorted by: accumulative and global features, salient points, object and shape features, signs, and structural combinations thereof. Similarity of pictures and objects in pictures is reviewed for each of the feature types, in close connection to the types and means of feedback the user of the systems is capable of giving by interaction. We briefly discuss aspects of system engineering: databases, system architecture, and evaluation. In the concluding section, we present our view on: the driving force of the field, the heritage from computer vision, the influence on computer vision, the role of similarity and of interaction, the need for databases, the problem of evaluation, and the role of the semantic gap     

基于大数据的烟草企业信息化战略布局研究

为了提升烟草企业自身的生产、经营、决策和管理的水平,做强品牌,做大企业,做实市场,本文基于大数据技术,结合企业数据应用现状,从数据管理、品牌定位、物流运营及市场投放层面着手,提出了烟草企业如何借助数据分析调整战略布局。应用大数据技术后,烟草企业通过清晰客户需求,实现品牌精准定位,运营模式由规模性制造转向为个性化定制;通过掌控业务流程、品牌营销、市场竞争等方面的数据,实现市场的支配,企业决策方式由业务驱动转型为数据驱动;通过内外部数据采集、筛选、存储、分析和决策,以支撑预测、辅助决策,实现决策机制由被动式演变为预判式。     

面向海洋的多模态智能计算：挑战、进展和展望

海洋是高质量发展的要地,海洋科学大数据的发展为认知和经略海洋带来机遇的同时也引入了新的挑战。海洋科学大数据具有超多模态的显著特征,目前尚未形成面向海洋领域特色的多模态智能计算理论体系和技术框架。因此,本文首次从多模态数据技术的视角,系统性介绍面向海洋现象/过程的智能感知、认知和预知的交叉研究进展。首先,通过梳理海洋科学大数据全生命周期的阶段演进过程,明确海洋多模态智能计算的研究对象、科学问题和典型应用场景。其次,在海洋多模态大数据内容分析、推理预测和高性能计算3个典型应用场景中展开现有工作的系统性梳理和介绍。最后,针对海洋数据分布和计算模式的差异性,提出海洋多模态大数据表征建模、跨模态关联、推理预测以及高性能计算4个关键科学问题中的挑战,并提出未来展望。     

伦理智能体及其设计:现状和展望

智能体一直是人工智能的主要研究领域之一,任何独立的能够同环境交互并自主决策的实体都可以抽象为智能体.随着人工智能从计算智能到感知智能,再到认知智能的发展,智能体已逐步渗透到无人驾驶、服务机器人、智能家居、智慧医疗、战争武器等人类生活密切相关的领域.这些应用中,智能体与环境、尤其是与人类和社会的交互愈来愈突出,其中的伦理...     

Datamatic baseoperations in factory management systems

A research program, oriented towards the development of a new generation software for engineering-economic factory management systems, is being carried out jointly by the Electric Power Engineering Department, Technical University of Denmark, and the Production Engineering Laboratory NTH-SINTEF, University of Trondheim. An outline of this program, emphasizing the more fundamental aspects, is the purpose of the present account. Essentially, the basic idea is that, independent of the size of the industrial firm, a flexible design of any such system must take place putting together standardized building-blocks. Hence, the aim is to develop, to formulate, and to test in industrial practice datamatic or data-processing base operations forming such blocks. The outcome of the program, therefore, paves the way for a new technique of system generation. A technique which, based on a high degree of software reuse, is especially suited to meet the demands of the future; that is, demands such as user-controlled system development, specific factory adjustment, fast system production, and cheaper, modular, extendable, and transparent solutions. A characteristics feature of a program like this, is that it combines knowledge from a variety of different fields comprising in particular system science, production engineering and data processing techniques. Accordingly, the program is subdivided into a series of mutually coordinated, doctoral projects carried through at the two institutions in close cooperation with interested Danish and Norwegian industrial firms. Each of these projects deals with selected parts of the comprehensive problem area which, in its entirety, the program attempts to cover.     

运用多媒体教学减轻学生语文学习负担

随着教育改革的不断深入,推进素质教育,最大限度地提高课堂效率,减轻学生负担,成为摆在我们每一个教育工作者面前的重要问题。要减轻学生负担,首先要提高课堂效率。研究资料表明:同一时间内,人们从听觉获得的知识只能掌握百分之十五,从视觉获得的知识只能掌握百分之二十五,而视听结合接受的知识则能掌握百分之六十五。因此要合理的运用多媒体教学,通过多媒体生动、形象的音、形、色把记录语言的符号变为生动逼真的画面和富有感染力的声音一一再现出来,让学生通过视觉、听觉等感官直接感知具体的教学内容,调动他们的思维,激发他们的想象。这样多媒体教学将音乐、美术、语文等各学科集于一身,同时作用于人们的多种感官,有利于调动学生的积极性和主动性,让学生乐于动脑、动口、动手探究新知,同时也可以改变以往的枯燥单一的只是依靠板书和重复讲解造成的高耗低效课堂——时间无效浪费、学生课堂练习少,无实践无操作,课后作业重,无效果。     

Impact of environmental variables on spectral signatures acquired by the LANDSAT thematic mapper

Eleven environmental variables, elevation, slope angle, slope aspect, surface roughness, soil type, geology, percentage of vegetation, percentage of trees, percentage of shrubs, percentage of herbs, and percentage of bare ground, are evaluated as to their impact on LANDSAT thematic mapper (TM) spectral signatures. Multiple regression models indicate that a combination of percentage of trees and shrubs have the most significant impact on TM spectral response, and, in fact, mask the effects of other tested environmental variables. Regression models are also developed for major soil types which significantly predict the amount of trees and shrubs present on a site.     

MFR (Multipurpose Field Robot) for installing construction materials

The objective of the study was to propose a MFR (Multipurpose Field Robot) in hazardous operation environments. This system combines a basic system composed of a multi-DOF (Degree Of Freedom) manipulator and a mobile platform with an additional module for construction, national defense and emergency-rescue. According to an additional module type combined with a basic system, it can be used in a various fields. In this study, we describe a prototype of construction robot which helps a human operator handle easily construction materials in case of using the cooperation system on construction site. This study introduces an additional module for construction and a robot control algorithm for a HRC (Human-Robot Cooperation). In addition, it proposes a novel construction method to install construction materials with robot on construction site. Seung Yeol Lee received the B.S. degree from the Department of Mechanical Engineering, Myungji University, Seoul, Korea in 2002, and the M.S. degree from the Department of Mechatronics Engineering, Hanyang University, Seoul, Korea in 2005. He is a Ph.D. degree candidate from the Department of Mechanical Engineering, Hanyang University, Seoul, Korea. From 2003, He is currently a visiting researcher in the Research Institute of Technology, Construction Group at the Samsung Corporation, Korea conducting the design and implementation of construction robot and automation system for construction project. His research interests include design, control, and application of construction robots, field robotic systems and ergonomic design of robotic systems. He is a member of the Korea Society of Mechanical Engineers, Architectural Institute of Korea, and Ergonomics Society of Korea. Yong Seok Lee received the B.S. degree from the Department of Precision Mechanical Engineering, Kunsan national University, Kunsan, Korea in 2002, and the M.S. degree from the Department of Precision Mechanical Engineering, Hanyang University, Seoul, Korea in 2005. Currently, he is the Post Master in Hanyang University, Korea. His major interests include design and kinematic/dynamic analysis on multi-purpose field robots and service robots. He is a member of the Architectural Institute of Korea. Bum Seok Park received the B.S. degree from the Department of Mechanical Engineering, Hanyang University, Ansan, Kyung-gi Do, Korea in 1993, and the M.S. degree from the Department of Mechatronics Engineering, Hanyang University, Seoul, Korea in 1998. He is a Ph.D. from the Department of Mechatronics System Engineering, Hanyang University, Seoul, Korea From 2006. He is currently the post-doctor in Hanyang University, Korea. His major interests include embedded robot control system on multi-purpose field robot and service robot. He is a member of the Korea Society of Mechanical Engineers, Korean Society of Machine Tool Engineers. Sang Heon Lee graduated with the B.S. degree in Precision Mechanical Engineering from Hanyang University, Seoul, Korea in 1992. He received the M.S. degree in Precision Engineering from KAIST, Taejon, Korea in 1994 and the Ph.D. degree in Mechanical Engineering from KAIST in 2001. Currently, he is a senior researcher in Samsung Corporation, Korea. His major interests include the kinematic/dynamic analysis on multi-body system, application of field robots, and automation in construction. ChangSoo Han received the B.S. degree from the Department of Mechanical Engineering, Seoul National University Technology, Seoul, Korea in 1983, and the M.S. and Ph.D. degrees from the Department of Mechanical Engineering, University of Texas at Austin, in 1985 and 1989, respectively. From May 1988 to September 1989, he was a Research Assistant, Robotics Lab in Mechanical Engineering about manufacturing of the high resolution micro manipulator module. In March 1990, he joined Hanyang University, Ansan, Kyungki-Do, Korea as a Professor, Department of Mechanical Engineering. From March 1993 to February 1995, he was a Vice President, The Research Institute of Engineering & Technology of the Hanyang University. From August 1996 to July 1997, he was a Visiting Professor, Univ. of California at Berkeley. From September 1997 to February 1999, he was a Director, Hanyang Business Incubator. In August 2000, he joined a Branch President, The Korean Society of Mechanical Engineers. In January 2002, he joined a Committee Member, The Korean Society of Mechanical Engineers. From January 2001 to December 2001, he was an International Cooperation Director, The Institute of Control, Automation and Systems, Korea. His research interests include design, control, and application of robot, automation systems, and advanced vehicle.     

节材节能生产的计算机仿真优化系统的开发

该文在分析产品生产成本构成变量的基础上,建立了优化目标,确立了系统的总体模型和模块构成,阐述了系统优化的过程和方法,描述了系统的研制方法、系统特点以及在企业中的使用效果。该系统具有实用性和先进性,实现了节材节能生产和最优化设计,提高了产品生产的科学技术水平,降低了生产成本,提高了企业在市场中的竞争力。     

Construction method of shop-floor digital twin based on MBSE

Digital twin (DT) technology is essential for achieving the fusion of virtual-real cyber-physical systems. Academics and companies have made great strides in the theoretical research and case studies of constructing the shop-floor digital twin (SDT), which is the premise of applying DT technology on the shop floor. A shop floor is a large complex system that involves many elements including people, machines, materials, methods, and the environment and processes, such as the technical flow, business process, logistics, and control flow. However, most of the developed cases lack a hierarchical, structured and modularized implementation framework for the development of an SDT system, which leads to problems such as a low reuse rate of the system blocks, lack of scalability, and high upgrade and maintenance costs. In response to these issues, we propose a construction method of the DT for the shop floor based on model-based systems engineering from the perspective of the system. In this method, a comprehensive DT model for the shop floor is gradually constructed by using system modeling language, the modeling method “MagicGrid,” and the “V model” of systems engineering. The model includes four dimensions of the shop-floor requirements, structure, behavior, and parameters, as well as three stages (the problem domain, solution domain, and implementation domain), and connects nine steps of the “V model,” including the system requirements, system architecture, subsystem implementation, subsystem integration, and system verification. Then, based on an example of a real NC machining shop floor, subsystems including a visualization system, synchronization system, and simulation system, are discussed. Finally, the functions of the integrated systems are verified based on the requirements, including the real-time synchronization of “man, machine, material, and method” and the transient simulation in real time. The numerical indicators of the integrated system are verified, including the model completeness and synchronization timeliness.     

Nondegeneracy tests for hexahedral cells

The aims of the paper are to consider the nondegeneracy requirement for computational grids and to analyze eight tests used to check the nondegeneracy of hexahedral cells. The paper starts with consideration of nondegeneracy requirement and formulation of definitions and common theorems utilized for estimation of nondegeneracy of grids both structured and unstructured. Then hexahedral cells are introduced and sufficient nondegeneracy conditions (Ushakova, 2000) for them are given. Sufficient nondegeneracy conditions are 27 inequalities for 32 tetrahedral volumes. Besides sufficient nondegeneracy conditions other conditions are applied as nondegeneracy tests in grid generation theory and practice. Considered nondegeneracy tests are the checks for positivity of different values. Tests 1, 2, 3, 4, 5, 6 check the positivity of 8, 10, 24, 32, 58, 48 tetrahedral volumes, correspondingly. Test 7 verifies the positivity of the volume of a cell. Test 8 checks the positivity of the Jacobian of the mapping used for generation of a cell. The check is performed at the corners of a cell and hex center. Tests 1, 7, 8 are often used in commercial packages. For the most part, nondegeneracy tests are not sufficient nondegeneracy conditions, however they are used for the purpose of constructing nondegenerate grids and, some times, instead of sufficient nondegeneracy conditions. The effectiveness and reliability of such substitutions are investigated in special numerical experiments with random numbers. In the numerical experiment for each test, hexahedral cells are generated randomly. Results of such experiments are the following. Among eight tests, test 2 is considered the best since it verifies the volumes of only 10 tetrahedra for positiveness, guarantees the nondegeneracy in most of cases (68.7% randomly generated hexahedral cells satisfying test 2) and covers a wide class of cells (about 60% of nondegenerate cells). Tests 1, 3, 4, 5, 6, 7, 8 have success in 31.7%, 83.1%, 100%, 100%, 39.5%, 0.2%, 34% of cases and cover 100%, 7.9%, 7.9%, 4.2%, 59.5%, 100%, 100% of nondegenerate cells, correspondingly. Because of high rate of success, tests 3, 4, 5 also can be used for grid generation purpose. All tests are illustrated by the examples of structured grids.     

无线便携式LED屏控制终端设计

随着社会经济快速发展,金融市场、交通港口、体育场馆等领域的信息提示大多采用LED屏显示,LED屏的显示控制已成为当前研究的热点。但是,采用传统的控制方式存在系统开机、开屏较繁杂、线路架设复杂、更新信息不稳定、显示内容单易被篡改等问题。针对这一现状,设计完成了一款无线便携式控制终端,可以实现在200米范围内控制LED屏内容的更新,显示信息安全稳定、终端成本低、体积小、携带方便、操作更加灵活便捷。