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1.
存储一致性模型研究   总被引:2,自引:0,他引:2  
讨论了分布式共享存储系统(D S M)的通用结构及页面管理机制,给出了各种存储一致性模型的正确性条件,并以互斥问题为例,说明了在分布式环境下编程的一些特点,最后,基于作者本人的工作,还讨论了如何提高D S M 系统性能的问题。  相似文献   

2.
在银行系统等有多个实体同时活跃的分布式应用中,必须妥善解决不同实体对资源的需求,即同步与互斥。本文基于令牌的K资源互斥算法,提出了基于消息槽的K资源互斥算法,该算法能有效满足K资源分布式环境下同步与互斥的要求。  相似文献   

3.
一种基于消息槽的K资源互斥算法   总被引:1,自引:0,他引:1  
在分布式操作系统等一些有多个进程同时活跃的应用中,必须妥善解决不同进程对资源的需求,即同步与互斥问题.文章提出了一种基于消息槽的K资源互斥算法,介绍了该算法的原理,详细描述了该算法的运作过程,并进行了深入的分析.分析结果表明,该算法能够有效地满足K资源分布式环境下同步与互斥的要求.  相似文献   

4.
协同式干线邮运调度专家系统的并行处理   总被引:2,自引:0,他引:2  
本文介绍了协同式干线邮运调度专家系统的并行机制,同时给出了在分布式问题求解环境下实现并发智能体间同步与互斥的一种有效方法。  相似文献   

5.
本文给出了在PC机环境下开发实时多任务软件的方法,提出了实时内核所需的各种数据结构及其支持的原语操作,并针对多任务对共享资源的存取提出了信号量互斥和管理进程两种解决办法。  相似文献   

6.
王晓燕  王平 《计算机工程》2007,33(6):273-274
针对嵌入式系统的资源受限问题,提出了EPA通信协议在内存管理和资源同步等方面的一种设计方案。采用静态内存池的方式来避免内存碎片问题,使用阻塞/唤醒机制来同步多线程,使用互斥锁来互斥访问临界资源,从而提高EPA通信协议的实时性和稳定性;给出了EPA通信协议主要模块在嵌入式Linux下的实现过程及EPA协议的一致性测试结果。  相似文献   

7.
本文提出了一种在分布式环境下求解读写器问题的方法,该算法通过对Lamport面包师互斥算法的改进,达到了理想的效果。  相似文献   

8.
本文提出了一种在分布式环境下求解写器问题的方法,该算法通过对Lamport面包师互斥算法的改进,达到了理想的效果。  相似文献   

9.
目前人们已经提出了很多分布式互斥算法。为简化问题,这些算法多数要求假设系统的节点与通信均可靠,因此不存在容错处理问题。部分在先假定节点与通信可靠的基础上讨论的算法,为达到其结论的逻辑严密性,补充了节点与通信不可靠时的容错处理,但这些容错处理方式都是作为其分布式互斥算法的补充提出来的,有较大程度的理想化成分,基本上没用进行充分的性能分析。本文根据分布式互斥算法节点容错处理方式的不同,将其分为两类并对其对消息复杂度的影响进行详细讨论。在此基础上,提出一种混合的分布式互斥节点容错处理方法,以降低非稳定环境下分布式互斥算法的平均消息复杂度。  相似文献   

10.
目前人们已经提出了很多分布式互斥算法.为简化问题,这些算法多数要求假设系统的节点与通信均可靠,因此不存在容错处理问题.部分在先假定节点与通信可靠的基础上讨论的算法,为达到其结论的逻辑严密性,补充了节点与通信不可靠时的容错处理,但这些容错处理方式都是作为其分布式互斥算法的补充提出来的,有较大程度的理想化成分,基本上没用进行充分的性能分析.本文根据分布式互斥算法节点容错处理方式的不同,将其分为两类并对其时消息复杂度的影响进行详细讨论.在此基础上,提出一种混合的分布式互斥节点容错处理方法,以降低非稳定环境下分布式互斥算法的平均消息复杂度.  相似文献   

11.
Expert system verification and validation: a survey and tutorial   总被引:2,自引:0,他引:2  
Assuring the quality of an expert system is critical. A poor quality system may make costly errors resulting in considerable damage to the user or owner of the system, such as financial loss or human suffering. Hence verification and validation, methods and techniques aimed at ensuring quality, are fundamentally important. This paper surveys the issues, methods and techniques for verifying and validating expert systems. Approaches to defining the quality of a system are discussed, drawing upon work in both computing and the model building disciplines, which leads to definitions of verification and validation and the associated concepts of credibility, assessment and evaluation. An approach to verification based upon the detection of anomalies is presented, and related to the concepts of consistency, completeness, correctness and redundancy. Automated tools for expert system verification are reviewed. Considerable attention is then given to the issues in structuring the validation process, particularly the establishment of the criteria by which the system is judged, the need to maintain objectivity, and the concept of reliability. This is followed by a review of validation methods for validating both the components of a system and the system as a whole, and includes examples of some useful statistical methods. Management of the verification and validation process is then considered, and it is seen that the location of methods for verification and validation in the development life-cycle is of prime importance.  相似文献   

12.
Complexity, complication, contradiction, consumption, confusion, delusion, depression. Opportunity, inspiration, ingenuity, compassion, wisdom. Our world is perplexing, our times are fast moving, and our choices are many. To find an appropriate path is a daunting yet vital challenge that confronts us as individuals, as communities, and as a civilization. How sustainable is our world? How reasonable are our behaviors? The present article is a collection of thoughts on a series of intertwined issues related to the contemporary world, its environmental dimensions, and their present-day problems. The goal is to survey the landscape through a lens of Environmental Design, to provide some perspectives, to raise some questions, and to explore systems, beliefs, and values informing and influencing actions. It is important to consider how people's belief systems influence, inform, and shape actions. This holds true in realms political, spiritual, and cultural. It also proves relevant in the ways in which we imagine, design, develop, and construct our buildings, cities, spaces, and places.

Appropriate solutions to some of our most daunting problems will arise through the concerted efforts, open dialogue, and collective wisdom of the wide array of stakeholders, professionals, politicians, decision makers, and citizens (both engaged and disenfranchised) who have the will and wherewithal to make a difference and to make the world safer, healthier, and better. It seems vital for us to critically examine, and question, our belief systems and their connections to the ways we define, refine, and realize progress. Architecture and Environmental Design, in both a philosophical and a practical sense, reflect as well as form greater aspirations, directions, and events of our times.  相似文献   

13.
近期元宇宙热潮席卷全球,主要国家和知名企业纷纷布局以争夺未来数字领域话语权,但目前关于元宇宙并没有形成较为统一的标准定义和终极形态描述。我国在促进电子信息产业高质量发展、保障网络空间安全的需求下,亟需科学认识元宇宙的本质特征、演变趋势及安全风险。运用文献调研和情报分析相结合的研究方法,首先基于技术应用迭代、经济商业模式、社会关系作用等核心理念归纳提出了元宇宙的基本概念,根据空间范畴、时空维度、关键技术、虚实交互等演进程度,将元宇宙发展演变依次划分为数据创生、数字仿生、虚拟镜生、虚实共生4个阶段并阐述了各阶段特征及对应形态;接着从创新应用需求、虚拟生活转变、商业价值驱动、政治力量推动等角度,分析了元宇宙广受关注的主要原因;然后针对挑战国家治理体系、冲击主流意识形态、操纵收割资本市场、引发诸多社会问题、误导技术产业布局等方面,重点研判了元宇宙浪潮带来的政治、文化、经济、社会和技术等多重安全风险和威胁。研究建议,目前元宇宙尚处于概念完善和产品探索阶段,应理性把握元宇宙发展机遇,立足我国电子信息产业现状,提前做好风险应对准备,构建数字治理监管体系,激发产业创新开放发展,夯实网络信息安全支撑,营...  相似文献   

14.
李元    王石荣    于宁波   《智能系统学报》2018,13(3):445-451
移动机器人在各种辅助任务中需具备自主定位、建图、路径规划与运动控制的能力。本文利用RGB-D信息和ORB-SLAM算法进行自主定位,结合点云数据和GMapping算法建立环境栅格地图,基于二次规划方法进行平滑可解析的路径规划,并设计非线性控制器,实现了由一个运动底盘、一个RGB-D传感器和一个运算平台组成的自主移动机器人系统。经实验验证,这一系统实现了复杂室内环境下的实时定位与建图、自主移动和障碍物规避。由此,为移动机器人的推广应用提供了一个硬件结构简单、性能良好、易扩展、经济性好、开发维护方便的解决方案。  相似文献   

15.
图像标题生成与描述的任务是通过计算机将图像自动翻译成自然语言的形式重新表达出来,该研究在人类视觉辅助、智能人机环境开发等领域具有广阔的应用前景,同时也为图像检索、高层视觉语义推理和个性化描述等任务的研究提供支撑。图像数据具有高度非线性和繁杂性,而人类自然语言较为抽象且逻辑严谨,因此让计算机自动地对图像内容进行抽象和总结,具有很大的挑战性。本文对图像简单标题生成与描述任务进行了阐述,分析了基于手工特征的图像简单描述生成方法,并对包括基于全局视觉特征、视觉特征选择与优化以及面向优化策略等基于深度特征的图像简单描述生成方法进行了梳理与总结。针对图像的精细化描述任务,分析了当前主要的图像“密集描述”与结构化描述模型与方法。此外,本文还分析了融合情感信息与个性化表达的图像描述方法。在分析与总结的过程中,指出了当前各类图像标题生成与描述方法存在的不足,提出了下一步可能的研究趋势与解决思路。对该领域常用的MS COCO2014(Microsoft common objects in context)、Flickr30K等数据集进行了详细介绍,对图像简单描述、图像密集描述与段落描述和图像情感描述等代表性模型在数据集上的性能进行了对比分析。由于视觉数据的复杂性与自然语言的抽象性,尤其是融合情感与个性化表达的图像描述任务,在相关特征提取与表征、语义词汇的选择与嵌入、数据集构建及描述评价等方面尚存在大量问题亟待解决。  相似文献   

16.
元宇宙是虚拟数字世界与真实物理世界无缝融合的新生态,近来引发了各界的广泛关注。区块链、人工智能、虚拟现实/增强现实及传感技术、移动通信及泛在计算等各种新型互联网技术愈发成熟,使元宇宙的进一步发展成为可能。关于元宇宙的研究主要涉及产业项目、基础设施、关键技术、隐私安全等方面,这些研究虽然涉及区块链技术,但未具体指出区块链应用于元宇宙的优势及具体应用方式。区块链技术不仅可以为元宇宙提供开放自由的去中心化环境,而且可以为其提供公平合理的数字资产分配机制。主要从区块链赋能元宇宙中数字身份和数字资产管理的角度出发,分析了元宇宙的发展历程和特征,讨论了元宇宙发展所需核心技术及面临的挑战。同时研究了区块链的关键技术,并从区块链的本质特征及与其他技术融合优势两个方面对区块链应用于元宇宙做可行性分析。进一步提出元宇宙生态体系架构,重点详细分析了基于区块链的自我主权身份管理模型、区块链-非同质化通证(NFT,non-fungible token)工作流程及其在元宇宙中的应用。结合区块链和元宇宙的最新研究进展,从基础设施、通信和计算资源管理机制、监管与隐私保护以及区块链可扩展和互操作性4个方面指出区块链应用...  相似文献   

17.
吴一全      周建伟 《智能系统学报》2020,15(3):435-444
为进一步加强布谷鸟算法的搜寻能力并提升收敛速度,加快对算法的研究与应用进程,综述了布谷鸟算法的原理、研究概况和其他同类群体智能优化算法的比较及发展趋势。首先给出了算法的基本模型和实现步骤;然后重点阐述了基于发现概率和步长控制量、基于自适应步长、基于混沌理论、与其他算法混合、基于种群特征和种群变异、结合优化策略及基于种群多样性等方面的改进方法,总结了算法的主要应用领域及其进展;随后将其与遗传算法、蚁群优化算法、粒子群优化算法及人工蜂群优化算法的优点、缺点及适用性诸方面进行了对比;最后指出了布谷鸟搜索算法尚存在的缺陷并对进一步的研究方向进行了展望。  相似文献   

18.
This paper proposes a method for robust reduced-order H filter design for polytopic uncertain systems, using linear matrix inequalities (LMIs). Sufficient LMI conditions for both robust full- and reduced-order H filter design are derived. Convex optimization problems are formulated and solved to obtain optimal H filters by using the resulting LMI conditions. The resulting conditions do not involve any non-convex rank constraints, and thus the proposed method for H filter design guarantees global optimum solutions. Numerical examples are presented to show the effectiveness of the proposed method. Recommended by Editorial Board member Huanshui Zhang under the direction of Editor Young Il Lee. This work was supported by the Brain Korea 21 Project and the Basic Research Program of the Korea Science and Engineering Foundation under grant R01-2006-000-11373-0. Hyoun-Chul Choi received the B.S., M.S., and Ph.D. degrees in Control and Instrumentation Engineering from Ajou University, Suwon, Korea, in 1995, 1997, and 2006, respectively. He was a Visiting Researcher at Griffith University, Brisbane, Australia, from 2001 to 2002, and a Postdoctoral researcher at Ajou University, Suwon, Korea, from 2006 to 2007. Since 2008, he has been with ASRI, School of Electrical Engineering and Computer Science, Seoul National University, Seoul, Korea, where he is currently a Postdoctoral Researcher. His research interests include LMI-based control, optimal and robust control, network-based control, and mechatronics. Dongkyoung Chwa received the B.S. and M.S. degrees from the Department of Control and Instrumentation Engineering in 1995 and 1997, respectively, and the Ph.D. degree from the School of Electrical and Computer Engineering in 2001, all from Seoul National University, Seoul, Korea. From 2001 to 2003, he was a Postdoctoral Researcher with Seoul National University. In 2003, he was a Visiting Research Fellow at The University of New South Wales, Australian Defence Force Academy, and was the Honorary Visiting Academic at the University of Melbourne, Melbourne, Australia. In 2004, he was a BK21 Assistant Professor with Seoul National University. Since 2005, he has been an Assistant Professor with the Department of Electrical and Computer Engineering, Ajou University, Suwon, Korea. His research interests are nonlinear, robust, and adaptive control theories and their applications to the robotics, underactuated systems including wheeled mobile robots, underactuated ships, cranes, and guidance and control of flight systems. Suk-Kyo Hong received the B.S., M.S., and Ph.D. degrees in Electrical Engineering from Seoul National University, Seoul, Korea, in 1971, 1973, and 1981, respectively. His major graduate research works were centered on speed control of induction motors. He was an Exchange Professor at Rensselaer Polytechnic Institute, Troy, NY, from 1982 to 1983, and at the Institut National de Recherche en Informatique et en Automatique, France, from 1988 to 1989. He has been with the faculty of the Department of Electrical and Computer Engineering, Ajou University, Suwon, Korea, since 1976, and was a Visiting Professor at Griffith University, Australia, in 2001 and 2002. His current research interests include robust robot control, microprocessor applications, factory automation, and computer integrated manufacturing.  相似文献   

19.
In this paper, we propose a new topology called theDual Torus Network (DTN) which is constructed by adding interleaved edges to a torus. The DTN has many advantages over meshes and tori such as better extendibility, smaller diameter, higher bisection width, and robust link connectivity. The most important property of the DTN is that it can be partitioned into sub-tori of different sizes. This is not possible for mesh and torus-based systems. The DTN is investigated with respect to allocation, embedding, and fault-tolerant embedding. It is shown that the sub-torus allocation problem in the DTN reduces to the sub-mesh allocation problem in the torus. With respect to embedding, it is shown that a topology that can be embedded into a mesh with dilation δ can also be embedded into the DTN with less dilation. In fault-tolerant embedding, a fault-tolerant embedding method based on rotation, column insertion, and column skip is proposed. This method can embed any rectangular grid into its optimal square DTN when the number of faulty nodes is fewer than the number of unused nodes. In conclusion, the DTN is a scalable topology well-suited for massively parallel computation. Sang-Ho Chae, M.S.: He received the B.S. in the Computer Science and Engineering from the Pohang University of Science and Technology (POSTECH) in 1994, and the M.E. in 1996. Since 1996, he works as an Associate Research Engineer in the Central R&D Center of the SK Telecom Co. Ltd. He took part in developing SK Telecom Short Message Server whose subscribers are now over 3.5 million and Advanced Paging System in which he designed and implemented high availability concepts. His research interests are the Fault Tolerance, Parallel Processing, and Parallel Topolgies. Jong Kim, Ph.D.: He received the B.S. degree in Electronic Engineering from Hanyang University, Seoul, Korea, in 1981, the M.S. degree in Computer Science from the Korea Advanced Institute of Science and Technology, Seoul, Korea, in 1983, and the Ph.D. degree in Computer Engineering from Pennsylvania State University, U.S.A., in 1991. He is currently an Associate Professor in the Department of Computer Science and Engineering, Pohang University of Science and Technology, Pohang, Korea. Prior to this appointment, he was a research fellow in the Real-Time Computing Laboratory of the Department of Electrical Engineering and Computer Science at the University of Michigan from 1991 to 1992. From 1983 to 1986, he was a System Engineer in the Korea Securities Computer Corporation, Seoul, Korea. His major areas of interest are Fault-Tolerant Computing, Performance Evaluation, and Parallel and Distributed Computing. Sung Je Hong, Ph.D.: He received the B.S. degree in Electronics Engineering from Seoul National University, Korea, in 1973, the M.S. degree in Computer Science from Iowa State University, Ames, U.S.A., in 1979, and the Ph.D. degree in Computer Science from the University of Illinois, Urbana, U.S.A., in 1983. He is currently a Professor in the Department of Computer Science and Engineering, Pohang University of Science and Technology, Pohang, Korea. From 1983 to 1989, he was a staff member of Corporate Research and Development, General Electric Company, Schenectady, NY, U.S.A. From 1975 to 1976, he was with Oriental Computer Engineering, Korea, as a Logic Design Engineer. His current research interest includes VLSI Design, CAD Algorithms, Testing, and Parallel Processing. Sunggu Lee, Ph.D.: He received the B.S.E.E. degree with highest distinction from the University of Kansas, Lawrence, in 1985 and the M.S.E. and Ph.D. degrees from the University of Michigan, Ann Arbor, in 1987 and 1990, respectively. He is currently an Associate Professor in the Department of Electronic and Electrical Engineering at the Pohang University of Science and Technology (POSTECH), Pohang, Korea. Prior to this appointment, he was an Associate Professor in the Department of Electrical Engineering at the University of Delaware in Newark, Delaware, U.S.A. From June 1997 to July 1998, he spent one year as a Visiting Scientist at the IBM T. J. Watson Research Center. His research interests are in Parallel, Distributed, and Fault-Tolerant Computing. Currently, his main research focus is on the high-level and low-level aspects of Inter-Processor Communications for Parallel Computers.  相似文献   

20.
针对跨年龄人脸验证任务中面部纹理、形状特征变化的问题,提出一种基于双编码平均局部二值模式(dual-coded average local binary pattern,DCALBP)与深度学习算法相结合的多任务人脸验证算法.首先,使用多任务卷积神经网络(multi-task convolutional neural ...  相似文献   

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