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 15 毫秒
1.
Wireless beyond 3G is a new concept that envisions cellular, BFWA, and DVB systems cooperating in a composite radio infrastructure. In this scheme, instead of rejecting users or degrading their quality of service levels, a network provider can direct them to an alternate radio technology that meets certain environmental, cost, and QoS criteria. To achieve such a system requires upgrading service and network resource management (SNRM). We present work areas for a new SNRM approach that comprises the Universal Mobile Telecommunications System (UMTS), high-performance wireless local area network (HiperLAN 2) technology, and terrestrial DVB (DVB-T) systems.  相似文献   

2.
Multiple products through a flexible manufacturing system (FMS) with limited resources can lead to deadlock. In this paper, the authors study the problem of deadlock avoidance by using the Petri net (PN) model for FMSs and introducing the concept of deadlock structure. The necessary and sufficient conditions to prevent deadlock are characterized. The authors use a state feedback restriction policy which prevents some enabled transitions from firing for avoiding deadlock in the system. In particular, when the number of any key kind of resources is greater than one, this policy is minimally restrictive and allows the maximal use of resources in the system. The authors present the PN realization of these restriction policies when the closed-loop system can be modeled by a live PN. The restriction policies can be easily implemented. An example is provided for illustration  相似文献   

3.
We argue the need for effective resource management mechanisms for sharing resources in commodity clusters. To address this issue, we present the design of Sharc-a system that enables resource sharing among applications in such clusters. Sharc depends on single node resource management mechanisms such as reservations or shares, and extends the benefits of such mechanisms to clustered environments. We present techniques for managing two important resources-CPU and network interface bandwidth-on a cluster-wide basis. Our techniques allow Sharc to 1) support reservation of CPU and network interface bandwidth for distributed applications, 2) dynamically allocate resources based on past usage, and 3) provide performance isolation to applications. Our experimental evaluation has shown that Sharc can scale to 256 node clusters running 100,000 applications. These results demonstrate that Sharc can be an effective approach for sharing resources among competing applications in moderate size clusters.  相似文献   

4.
Contention in performance-critical shared resources affects performance and quality-of-service (QoS) significantly. While this issue has been studied recently in CMP architectures, the same problem exists in SoC architectures where the challenge is even more severe due to the contention of shared resources between programmable cores and fixed-function IP blocks. In the SoC environment, efficient resource sharing and a guarantee of a certain level of QoS are highly desirable. Researchers have proposed different techniques to support QoS, but most existing works focus on only one individual resource. Coordinated management of multiple QoS-aware shared resources remains an open problem. In this paper, we propose a class-of-service based QoS architecture (CoQoS), which can jointly manage three performance-critical resources (cache, NoC, and memory) in a NoC-based SoC platform. We evaluate the interaction between the QoS-aware allocation of shared resources in a trace-driven platform simulator consisting of detailed NoC and cache/memory models. Our simulations show that the class-of-service based approach provides a low-cost flexible solution for SoCs. We show that assigning the same class-of-service to multiple resources is not as effective as tuning the class-of-service of each resource while observing the joint interactions. This demonstrates the importance of overall QoS support and the coordination of QoS-aware shared resources.  相似文献   

5.
Language Resources and Evaluation - The adoption of Semantic Web technologies and the Linked Data paradigm has been driven by the need to ensure the construction of resources that are at the same...  相似文献   

6.
This paper discusses analytical and empirical trends in dealing with human reliability. It reflects on the nature of human error and man-machine reliability, and poses some serious problems of definition which affect numerical results. Techniques for enhancing man-machine system reliability are presented.  相似文献   

7.
Recent years have seen many developing countries taking initiatives aimed at promoting decentralised planning through the application of computer-based information systems at local levels of administration. However, with all these experiments, the key objective of improving the effectiveness of development planning remains unfulfilled. A major reason for this has been the inadequate management of human resource capacity to support the intervention. The problem stems in part from the lack of skilled computer-literate people to operate the machines. This has been acknowledged in the literature. Another problem stems from the complex interaction between the social context of development administration and the process of human resource management. There is, however, a chronic paucity of studies which aim to improve understanding of this interaction. To rectify this, this paper describes a case study of the application of computers for development planning in India. The complex interaction between the social context of development administration and the process of human resources development is examined longitudinally. The findings show that an understanding of this interaction is crucial if information technology is intended to play a meaningful role in managing development.  相似文献   

8.
Evaluating new ideas for job scheduling or data transfer algorithms in large-scale grid systems is known to be notoriously challenging. Existing grid simulators expect to receive a realistic workload as an input. Such input is difficult to obtain in the absence of an in-depth study of representative grid workloads.In this work, we analyze the workload of the ATLAS experiment at CERN at the LHC, processed on the resources of Nordic Data Grid Facility. ATLAS is one of the biggest grid technology users, with extreme demands for CPU power, data volume and bandwidth. The analysis is based on the data sample with ∼1.6 million jobs, 3029 TB of data transfer, and 873 years of processor time. Our additional contributions are (a) scalable workload models that can be used to generate a synthetic workload for a given number of jobs, (b) an open-source workload generator software integrated with existing grid simulators, and (c) suggestions for grid system designers based on the insights of our analysis.  相似文献   

9.
Programming experience is an important confounding parameter in controlled experiments regarding program comprehension. In literature, ways to measure or control programming experience vary. Often, researchers neglect it or do not specify how they controlled for it. We set out to find a well-defined understanding of programming experience and a way to measure it. From published comprehension experiments, we extracted questions that assess programming experience. In a controlled experiment, we compare the answers of computer-science students to these questions with their performance in solving program-comprehension tasks. We found that self estimation seems to be a reliable way to measure programming experience. Furthermore, we applied exploratory and confirmatory factor analyses to extract and evaluate a model of programming experience. With our analysis, we initiate a path toward validly and reliably measuring and describing programming experience to better understand and control its influence in program-comprehension experiments.  相似文献   

10.
11.
The popular and well-tested software process frameworks such as the Software Engineering Institute's Capability Maturity Model and ISO 9001, details key process areas for software development. Focusing more on continuous improvement in code development processes, generic-process frameworks such as the CMM lack key process areas (KPA) that address capabilities for managing distributed software projects, such as establishing mutual knowledge and managing geographically dispersed social networks. We identify 24 new KPAs that address the wide-ranging capabilities needed for managing distributed software development and arrange them in an evolutionary order similar to the CMM framework. The evolutionary or phased approach in improving software management capabilities helps firms systematically assess their situations and plan for improvements. We also report the results of a statistically tested maturity assessment survey and test the overall rigor of our model against industry expert opinion and objective data collected from real-world projects implemented at SAP AG, a leading global-enterprise software firm.  相似文献   

12.
13.
Software Quality Journal - Cloud computing serves as a platform for diverse types of applications, from low-priority to critical. Some of these applications require high levels of system...  相似文献   

14.
针对大型河道三维可视化建模中采用激光雷达、声呐等传感器获取水下地形建模方式操作复杂且成本较高的缺陷,在利用基础测绘成果构建实景地形模型的基础上,采用多源三维模型融合方法对月塘水库小流域进行实景建模。首先采用倾斜摄影三维建模技术对重点水利工程进行实景建模,并利用专业建模软件对重要控制单元进行构件级建模;然后利用已有河道断面数据结合河流面状矢量数据,实现流域内胥浦河河道实景三维建模;最后通过人机交互方式对多源实景模型进行微调与相互印证,实现月塘水库小流域多源三维模型精准融合构建。研究成果可为河道型水库的预报调度与洪水风险分析提供可视化模型基础与决策支撑。  相似文献   

15.
16.
Shared-memory multiprocessor performance is strongly affected by factors such as sequential code, barriers, cache coherence, virtual memory paging, and the multiprocessor system itself with resource scheduling and multiprogramming. Several timing models and analysis for these effects are presented. A modified Ware model based on these timing models is given to evaluate comprehensive performance of a shared-memory multiprocessor. Performance measurement has been done on the Encore Multimax, a shared-memory multiprocessor. The evaluation models are the analyses based on a general shared-memory multiprocessor system and architecture and can be applied to other types of shared-memory multiprocessors. Analytical and experimental results give a clear understanding of the various effects and a correct measure of the performance, which are important for the effective use of a shared-memory multiprocessor  相似文献   

17.
The sharing economy has been recognized a mutually beneficial economic mode. Deriving from the concept of sharing economy, shared manufacturing was proposed under the support of advanced information and manufacturing technologies. As a core part of implementing shared manufacturing, manufacturing resource allocation aims to coordinate cross-organizational resources to provide on-demand services for personalized manufacturing requirements. However, some challenges still hinder effective and efficient resource allocation in shared manufacturing. Traditional centralized optimization methods with only one decision model are difficult to maintain autonomous decision rights of resource providers. Thus, they could hardly adapt to the situation of cross-organizational resource coordination. In addition, the credit of resource providers is rarely considered in the resource allocation process, which is unfavorable for promoting more reliable trades in shared manufacturing. To address these issues, this study proposes an integrated architecture to promote the resource allocation in shared manufacturing. A digital twin-driven service model is built to perform the seamless monitoring and control of shared manufacturing resources. The resource allocation model is constructed based on the consideration of the credit of resource providers. To keep the decision autonomy of resource providers, augment Lagrangian coordination is adopted to analyze the constructed resource allocation model. A case study is further employed to validate the effectiveness and efficiency of the proposed method in performing the resource allocation in shared manufacturing.  相似文献   

18.
Statistical testing and reliability analysis can be used effectively to assure quality for Web applications. To support this strategy, we extract Web usage and failure information from existing Web logs. The usage information is used to build models for statistical Web testing. The related failure information is used to measure the reliability of Web applications and the potential effectiveness of statistical Web testing. We applied this approach to analyze some actual Web logs. The results demonstrated the viability and effectiveness of our approach  相似文献   

19.
时至今日,大幅面打印机已经成功涉足影像、数码打样、喷绘写真、地理信息系统和工程图纸打印等诸多领域,随着应用的多元与深入,尤其是以"艺术微喷 TM"为代表的高端影像市场,对输出画质提出了更高要求,这意味着与色彩表现力息息相关的墨水技术的更新换代必须与时俱进.  相似文献   

20.
随着航空电子系统朝着体系化发展,依靠网络构建包含不同飞行器航电资源在内的多平台航电资源就显得尤为重要。通过综合利用不同飞行平台的资源,发挥不同平台资源的优势,利用协同提升执行任务的能力。多平台航电系统的资源管理和任务调度是其核心功能。为了仿真和验证多平台航电系统资源管理功能,进一步研究资源调度方法,对多平台航电资源建模方法和调度算法进行研究,解决了对多平台航电系统上硬件资源的合理调度问题,增加了任务接受率。首先,利用多层分级拓扑结构对多平台航电资源进行建模,并对多平台航电任务需求进行分析;其次在SST自适应调度算法的基础上增加传感器、优先级等因素,以达到更高的接受率目标,改进后的算法完成一系列任务请求对航电资源的需求分配过程;最后,利用CloudSim仿真实验环境实现改进后的算法,从不同场景对实验结果进行全面分析。实验结果表明,本文设计的算法相比于原始算法任务请求的接受率有较大的改善。  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