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21.
When considering the full range of Web service-related activities, it becomes clear that dealing with context is a major challenge, requiring greater expressiveness, reasoning capabilities, and architectural components than are provided by the current widely accepted building blocks of the Web services stack. This paper presents an informal overview of concepts, requirements and challenges for handling contextual knowledge in connection with Web services, and briefly discusses several interesting projects in this area of research.  相似文献   
22.
Comments on the original article, The dismantling of our health system: Strategies for the survival of psychological practice by Nicholas A. Cummings (see record 1986-22651-001). In response to this article, the current author says "no, no, no!" He believes that "survival with this degree of compromise amounts to doing anything for a buck." (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
23.
The research done by the Tenet Group in multimedia networking has reached a point where it may be useful to reflect on the significance of its results for the current debate on how integrated-services internetworks should be designed. Such reflections constitute the main subject of this paper. The principles of the work and the conclusions reached so far by the Tenet researchers are discussed in the light of the conflict between the two major technologies being proposed to build future information infrastructures: namely, the Internet and the ATM technologies. The Tenet approach suggests one feasible way for resolving the conflict to the advantage of all the users of those infrastructures. This paper discusses various fundamental aspects of integrated-services network design: the choice of the service model, the type of charging policy to be adopted, and the selection of a suitable architecture.  相似文献   
24.
软件服务外包作为一个新型的软件产业方兴未艾,这种贸易方式加强了国际间的合作与区域性产业的互补。作为中国的近邻日本,这种互补方式的优势显得尤为突出。但是,由于中国外包企业的竞争力较弱、技术力量不够雄厚、企业规模尚未形成等弱点存在,大大制约着中国软件服务外包业的进一步发展。特别是随着诸多新兴接包国家和地区的崛起,使得中国所面临的竞争进一步加大,从前的低成本优势将得到削弱。这些都严重地制约着中国软件服务外包行业的健康发展。有序地调整以低端为主的产业结构,提高自主创新能力,加大服务外包在国家IT(Information Technology)产业中的比重,从而增强核心竞争力。  相似文献   
25.
Cyberattacks are difficult to prevent because the targeted companies and organizations are often relying on new and fundamentally insecure cloud-based technologies, such as the Internet of Things. With increasing industry adoption and migration of traditional computing services to the cloud, one of the main challenges in cybersecurity is to provide mechanisms to secure these technologies. This work proposes a Data Security Framework for cloud computing services (CCS) that evaluates and improves CCS data security from a software engineering perspective by evaluating the levels of security within the cloud computing paradigm using engineering methods and techniques applied to CCS. This framework is developed by means of a methodology based on a heuristic theory that incorporates knowledge generated by existing works as well as the experience of their implementation. The paper presents the design details of the framework, which consists of three stages: identification of data security requirements, management of data security risks and evaluation of data security performance in CCS.  相似文献   
26.
文章提出了一种基于虚拟化的服务备份技术,该技术能够以较低的成本投入实现在提供的服务崩溃时迅速恢复服务,提高用户对服务的满意度,同时,文章对就影响该技术实现效果的服务备份速度、服务恢复速度、负载均衡三个因素进行了研究,提出了解决方案。  相似文献   
27.
Many P2P applications require security services such as privacy, anonymity, authentication, and non-repudiation. Such services could be provided through a hierarchical Public Key Infrastructure. However, P2P networks are usually Internet-scale distributed systems comprised of nodes with an undetermined trust level, thus making hierarchical solutions unrealistic. In this paper, we propose Chord-PKI, a distributed PKI architecture which is build upon the Chord overlay network, in order to provide security services for P2P applications. Our solution distributes the functionality of a PKI across the peers by using threshold cryptography and proactive updating. We analyze the security of the proposed infrastructure and through simulations we evaluate its performance for various scenarios of untrusted node distributions.  相似文献   
28.
Distributed match-making   总被引:1,自引:0,他引:1  
In many distributed computing environments, processes are concurrently executed by nodes in a store- and-forward communication network. Distributed control issues as diverse as name server, mutual exclusion, and replicated data management involve making matches between such processes. We propose a formal problem called distributed match-making as the generic paradigm. Algorithms for distributed match-making are developed and the complexity is investigated in terms of messages and in terms of storage needed. Lower bounds on the complexity of distributed match-making are established. Optimal algorithms, or nearly optimal algorithms, are given for particular network topologies.The work of the second author was supported in part by the Office of Naval Research under Contract N00014-85-K-0168, by the Office of Army Research under Contract DAAG29-84-K-0058, by the National Science Foundation under Grant DCR-83-02391, and by the Defence Advanced Research Projects Agency (DARPA) under Contract N00014-83-K-0125. Current address of both authors: CWI, Kruislaan 413, 1098 SJ Amsterdam, The Netherlands.  相似文献   
29.
在本文中,以利用适地性服务机制之设计,来建立一个行动导览系统带领用户体验空间和主题维度的古迹导览服务。为了满足此需求,设计了一套后设数据(Metadata)来描述导览内容,并且在适地性服务机制设计上,提供包含适地性内容方法有效取得使用者附近的内容,并藉由适地性内容的暂存与安排方法,减少网络间的讯息传递,提供用户结构化的介绍内容,并在适当的时机触发内容的呈现。最后,以所提供之内容的相关性来比较所提方法与一般适地性服务之差异。邀请用户进行实地系统测试,以了解系统的实用性,取得测试者的建议。结果证实所设计之导览系统可以是导览解说员的多媒体辅助工具,或在没有导览解说员时,为使用者提供景点导览解说的服务。  相似文献   
30.
一种基于全IP蜂窝网络的实时业务传输机制*   总被引:1,自引:0,他引:1  
针对无线蜂窝网络和Internet的业务特点,分析了在信道带宽有限、传输误码率高的无线网络中传输基于IP的实时业务所面临的问题.针对下一代蜂窝网络中基于IP技术实现多媒体业务要求,从无线网络上实际传送的码流角度,结合ROHC机制提出一种在信道传输速率不变的条件下,提高码流传输效率的方法,并且探究了空中链路的全IP机制.从采样编码后输出的净码流和经过封装后的码流两个角度来分析,提出了高效的针对全IP的蜂窝网络的实时交互式语音业务的新方案.  相似文献   
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