首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 97 毫秒
1.
Distributed information system makes itself be placed in changing file storage position according to the users' request pattern. In this paper, we rebuild the model for a management system to turn the process of file managing into a 0-1 programming problem, and present a new individual form to improve the operating efficiency. Aiming at the model, we define a neighborhood span to make segmentation for searching space by using the fitness, based on the region contraction algorithm, present a new evolution algorithm which has the capability of self-adaptively generating new individuals, and ultimately solve the management problem of the distributed file system.  相似文献   

2.
Measuring the difference between fuzzy numbers is often needed in many fuzzy optimization problems such as manufacturing system production line scheduling with uncertainty environments. In this paper, based on the distance function of plane R2 and the level importance function, we establish the UID-metric and LPID-metric of measuring the difference between fuzzy numbers, and discuss the basic properties of UID-metric and LPID-metric, and prove that fuzzy number spaces are metric spaces about UID-metric and LPID-metric if and only if the level importance function I(λ)≠0 almost everywhere on [0, 1]. Further, we discuss the convergence, separability and completeness of UID-metric and LPID-metric based on the norms of plane R2. Finally, we analyze the characteristics of UID-metric and LPID-metric by some application examples.  相似文献   

3.
A cellular model based on the Incrementally Modular Abstraction Hierarchy(IMAH)is a novel model that can represent the architecture of and changes in cyberworlds,preserving invariants from a general level to a specific one.We have developed a data processing system called the Cellular Data System(CDS).In the development of business applications,you can prevent combinatorial explosion in the process of business design and testing by using CDS.In this paper,we have first designed and implemented wide-use algebra on the presentation level.Next,we have developed and verified the effectiveness of two general business applications using CDS:1)a customer information management system,and 2)an estimate system.  相似文献   

4.
来强  邢春晓 《计算机科学》2003,30(6):179-182
It is one of the most important task in digital library to develop a universal and customized user interface for search and retrieval in heterogeneous,distributed environment.In this paper,we briefly introduce working principles and workflow of SiteSearch system developed by OCLC.Based on analyzing the functions of this system,we study and design composing elements and implementation mechanism of the customized interface.By analyzing and illustrating the examples,we develop Java based component library for dynamically generating the customized interface in Chinese information platform of SiteSearch system.Finally,we make some remarks on the difference of develop-ment of this system with other similar systems.  相似文献   

5.
《自动化博览》2011,(Z2):155-163
Efficiency of supply chains management mostly depends on the process coordination and information integration between the supply chain companies.The well-known integrated circuit design houses,the wafer fabrication industries, and the integrated circuit packaging/testing business has together formed a contiguous supply chain from materials to system in Taiwan during the past decades.Logistic management of the wafer hence becomes the key linkage in the semiconductor foundry supply chain.The objective of this paper is to develop the wafer warehouse management system for global wafer logistics.Current operations for wafer logistics management are firstly reviewed. The system requirements are analyzed by the model-driven business transformation approach.The business operation model and the platform-independent solution architecture for the wafer logistics management are constructed.A prototype information system is also developed for validation.Results of this research can improve the effectiveness and efficiency in wafer logistics management for the semiconductor foundry supply chain.  相似文献   

6.
Several researches propose the identifier/locator separation architecture to tackle the scMing prob- lems of today's Internet routing and addressing system. And scalable and seamless mobility support is an important task in mobile identifier/locator separation networks. In this paper, by analyzing the features, such as direct separation, flexible mapping and identifier replacement, we show that the new architecture delivers data packets more efficiently and protects location privacy better than traditional mobile IP networks, and is able to implement soft handover conveniently. Then we present a distributed Hash table (DHT) based fast handover management (DFHM) scheme for the new architecture, which improves the reactive handover mode of FMIPv6 and eliminates the duplicate address detection (DAD) and return routability (RR) processes in MIPv6. And we propose a generic analysis framework for handover management. Further, we demonstrate the validity of our framework by simulation and quantificationMly study the effects of network scale and movement velocity. The results show that DFHM has good scalability and low handover latency, and has great advantages in the signaling cost and fast mobility support.  相似文献   

7.
The research and implementation of the volume management is the key technology in Network Attached Storage (NAS) ,which is also the important part in the research of virtual storage system, This paper researches the volume management technology and its error-control mechanism based on DAGs model,optimizes the online recovery mechanism, and improves the method of the hot-plug technology, Finally, we implement the optimum volume management based on FreeBSD.  相似文献   

8.
Several researches propose the identifer/locator separation architecture to tackle the scaling problems of today’s Internet routing and addressing system.And scalable and seamless mobility support is an important task in mobile identifer/locator separation networks.In this paper,by analyzing the features,such as direct separation,flexible mapping and identifer replacement,we show that the new architecture delivers data packets more efciently and protects location privacy better than traditional mobile IP networks,and is able to implement soft handover conveniently.Then we present a distributed Hash table(DHT)based fast handover management(DFHM)scheme for the new architecture,which improves the reactive handover mode of FMIPv6 and eliminates the duplicate address detection(DAD)and return routability(RR)processes in MIPv6.And we propose a generic analysis framework for handover management.Further,we demonstrate the validity of our framework by simulation and quantifcationally study the efects of network scale and movement velocity.The results show that DFHM has good scalability and low handover latency,and has great advantages in the signaling cost and fast mobility support.  相似文献   

9.
The proportional fairness scheduling algorithm on multi-classes   总被引:1,自引:0,他引:1  
In this paper, we study resource management models and algorithms that satisfy multiple performance objects simultaneously. We realize the proportional fairness principle based QoS model, which defines both delay and loss rate requirements of a class, to include fairness, which is important for the integration of multiple service classes. The resulting Proportional Fairness Scheduling model formalizes the goals of the network performance, user's QoS requirement and system fairness and exposes the fundamental tradeoffs between these goals. In particular, it is difficult to simultaneously provide these objects. We propose a novel scheduling algorithm called Proportional Fairness Scheduling (PFS) that approximates the model closely and efficiently. We have implemented the PFS scheduling in Linux. By performing simulation and measurement experiments, we evaluate the delay and loss rate proportional fairness of PFS, and determine the computation overhead.  相似文献   

10.
The Internet of Things(Io T)as an emerging network paradigm is bringing the next scientific and technological revolution for ubiquitous things’interactions in cyber-physical-social spaces.The Io T influences the current science and technology system by enabling its relatively stable interrelations for an inevitable architecture reconfiguration.In this paper,we aim to explore an updated science and technology framework for the Io T.Particularly,a novel cyber-physical-social-thinking(CPST)space is established by involving an attractive concept of the Internet of Thinking(Io Tk),and a science and technology framework is accordingly proposed referring to both scientific aspect(i.e.,cyber-physical,social,and noetic sciences)and technological aspect(i.e.,fundamental,physical,cyber,and social technologies).According to the perspective of the traditional Chinese culture,we explain the established science and technology framework,in which the"Five Elements"(i.e.,wood,fire,earth,metal,and water)have common properties with the restructured cyber-physical science in the Io T.Moreover,we introduce a scenario of smart city to identify the technological aspect in the Io T,and discuss the key enabling technologies,including resource management,energy management,data management,session management,security and privacy,loop control,space-time consistency,nanotechnology,and quantum technology.It turns out that the established science and technology framework will launch an innovation for academia and industry communities.  相似文献   

11.
The lack of an effective cooperation between the data, control and management plane of QoS routing solutions presented so far, prevents the implementation of service differentiation in the context of pure IP-based networks. Most of paths calculation proposals performed by the control plane are unaware of service characteristics of each flow. Scalable data plane QoS proposals ignore the issue about selecting the best paths to route the traffic. Proposed management plane schemes do not perform the network state maintenance and service level monitoring. Multi-service routing is a flow-based forwarding protocol that implements the service differentiation in pure IP-based networks, using a straight cooperation between data, control and management plane. This cooperation is accomplished by a data plane supporting the DiffServ model and performs route selection based on flows service class, which is exploited by the management plane to carry out the network state maintenance, and performance monitoring by using the RTCP protocol, to provide service metrics to control plane for route calculation. Simulation experiments show better performance results achieved by Multi-service routing compared to those obtained by traditional link state protocol with the DiffServ model and QoS routing in heavy loaded network scenarios of mixed traffic having different service requirements.  相似文献   

12.
In this paper, we present a separable, reusable middleware solution that provides coordinated, end-to-end QoS management over any type of service component, and can use existing (legacy) QoS management solutions (by using wrappers) in a distributed multimedia system. Our middleware solution incorporates strategic and tactical QoS managers, and supports protocols and messages between tactical managers and managed application components, and between QoS managers in the management hierarchy. Strategic QoS managers take a global view of QoS provided by a set of application components within the manager's policy domain. Tactical QoS managers provide local control over application components. We introduce the concept of QoS policy domains to scope the authority of a strategic QoS manager. We describe how the management hierarchy is dynamically configured and reconfigured based on runtime needs of the application.  相似文献   

13.
基于网格的流媒体服务QoS管理框架及实现   总被引:1,自引:0,他引:1  
流媒体服务是Internet上一类高带宽需求和高实时性约束的应用,对服务质量(Quality of Service,QoS)有较高的要求。流媒体服务的发展导致传统的QoS管理框架难以适应平台的异构性和复杂性。本文提出了一种基于网格的流媒体服务QoS管理框架,为由异构的系统构成的流媒体服务提供集成的、平台无关的QoS管理机制。在谈框架的基础上,我们设计了一个基于网格的流媒体服务QoS管理系统。  相似文献   

14.
Most work related to quality of service (QoS) is concerned with individual system components, such as the operating system or the network. However, to support distributed multimedia applications, the entire distributed system must participate in providing the guaranteed performance levels. In recognition of this, a number of QoS architectures have been proposed to provide QoS guarantees. The mechanisms and schemes proposed by those architectures are used in a rather static manner since the involved entities, e.g., the network, sender and receiver, are known before the connection (call) set-up phase. In contrast to these architectures, we propose a general QoS management framework which supports the dynamic choice of a configuration of system components to support the QoS requirements for the user of a specific application. We consider different possible system configurations and select the most appropriate one depending on the desired QoS and the available resources. In this paper we present an overview of this general framework; especially, we concentrate on QoS negotiation and adaptation mechanisms. To show the feasibility of this approach, we designed and implemented a QoS manager for distributed multimedia presentational applications, such as news-on-demand. The negotiation and adaptation mechanisms which are supported by the QoS manager are specializations of the general framework. The proposed framework allows to improve the utilization of system resources, and thus to increase the system availability; it also allows to recover automatically, if this is possible, from QoS degradations. Furthermore, it provides the flexibility to incorporate different resource reservation schemes and scheduling policies, and to accommodate new system component technologies.  相似文献   

15.
QoS管理近年来引起了人们的关注,尤其是分布式多媒体系统中QoS管理更是一研究热点,本文则独辟蹊径,探讨点到点可视电话系统中的端到端的QoS管理,以填补当前研究中的一个空白,本文给出了可视电话系统中的QoS参考模型,管理策略以及可视电话系统的结构。  相似文献   

16.
曲延盛  李伟  罗军舟  王鹏 《软件学报》2011,22(11):2782-2794
基于前期工作——可信可控网络体系结构TCNA(trustworthy and controllable network architecture),提出了一种QoS资源控制模型(resource control model for QoS,简称RCMQ).该模型从网络可控角度将QoS控制分为4层:QoS决策层面、QoS观测层面、QoS接口层面和QoS资源层面,模型部署包括独立集中的域内控制和一致性分布式控制.RCMQ模型闭环控制结构保证了QoS控制的有效性,而独立集中的QoS决策层面使得模型具有可扩展性.最后,通过仿真实验验证了RCMQ资源控制模型与InterServ模型相比,能够提供更为稳定的QoS传输,并且极大地减少了QoS状态维护,同时也从侧面说明可信可控网络体系比传统TCP/IP网络具有更高的可控性.  相似文献   

17.
Maintaining end-to-end quality of service (QoS) is a challenge in distributed real time embedded systems due to dynamically changing network environments and resource requirements. The authors' middleware QoS management approach encapsulates QoS behaviors as software components. Using the Corba component model, they build these specialized QoS components and combine them to produce a comprehensive management system that maintains QoS. The authors illustrate the approach by building a real-world medium-scale system with these components. Using this example, they demonstrate the reusability of each component in different contexts.  相似文献   

18.
We present a novel bandwidth broker architecture for scalable support of guaranteed services that decouples the QoS control plane from the packet forwarding plane. More specifically, under this architecture, core routers do not maintain any QoS reservation states, whether per-flow or aggregate. Instead, the QoS reservation states are stored at and managed by a bandwidth broker. There are several advantages of such a bandwidth broker architecture. Among others, it avoids the problem of inconsistent QoS states faced by the conventional hop-by-hop, distributed admission control approach. Furthermore, it allows us to design efficient admission control algorithms without incurring any overhead at core routers. The proposed bandwidth broker architecture is designed based on a core stateless virtual time reference system developed recently. This virtual time reference system provides a unifying framework to characterize, in terms of their abilities to support delay guarantees, both the per-hop behaviors of core routers and the end-to-end properties of their concatenation. We focus on the design of efficient admission control algorithms under the proposed bandwidth broker architecture. We consider both per-flow end-to-end guaranteed delay services and class-based guaranteed delay services with flow aggregation. Using our bandwidth broker architecture, we demonstrate how admission control can be done on a per domain basis instead of on a "hop-by-hop" basis. Such an approach may significantly reduce the complexity of the admission control algorithms. In designing class-based admission control algorithms, we investigate the problem of dynamic flow aggregation in providing guaranteed delay services and devise a new apparatus to effectively circumvent this problem. We conduct detailed analyses to provide theoretical underpinning for our schemes as well as to establish their correctness. Simulations are also performed to demonstrate the efficacy of our schemes.  相似文献   

19.
Thispaper presents resource management techniques that achieve thequality of service (QoS) requirements of dynamic real-time systemsusing open architectures and commercial off-the-shelf technologies(COTS). Dynamic real-time systems are subject to constant changessuch as a varying external environment, overload of internalsystems, component failure, and evolving operational requirements.Examples of such systems include the emerging generation of computer-based,command and control systems of the U.S. Navy. To enable the engineeringof such systems, we present adaptive resource management middlewaretechniques that achieve the QoS requirements of the system. Themiddleware performs QoS monitoring and failure detection, QoSdiagnosis, and reallocation of resources to adapt the systemto achieve acceptable levels of QoS. Experimental characterizationsof the middleware using a real-time benchmark illustrate itseffectiveness for adapting the system for achieving the desiredreal-time and survivability QoS during overload situations.  相似文献   

20.
服务质量QoS管理是满足分布式环境中端到端QoS需求的关键,而中间件是一种分布式系统中的主要交互平台.首先对中间件和QoS的相关概念进行介绍,在分析传统QoS管理模型的基础上,提出一种基于消息中间件(MOM)的QoS管理模型,重点分析多维QoS在该模型中的应用,最后结合一个实例说明多维QoS在实际系统中的应用.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号