基于TTCN-3的移动业务测试平台的设计

为了克服手工测试的缺点,构建了基于TTCN-3的移动业务测试平台。在参考了TTCN-3通用测试系统模型的基础上,针对移动通信协议设计了专门的编解码器和被测系统适配层,并针对各种操作系统平台设计了通用的平台适配层。提出了被测系统适配层采用并行多实体设计,配合采用Socket连接的TRI接口,实现层二协议的分布式处理。通过一个数据呼叫业务的系统测试实例表明了该平台能有效地完成移动业务通信协议的一致性测试。     

实现ATM网中各种承载业务控制

本文描述了ATM信元结构，异步时分复用，适配层的功能以及服务种类，详细讨论了GFR业务类型并与其他业务类型作比较，显示了其在ATM网络中的业务控制。     

WAP增值业务中终端适配的研究

在WAP增值业务中,手机终端差异性是个不可回避的问题,必须进行终端适配。对常用的终端适配处理方案进行了描述,分析了常用方法存在的问题,并提出了改进方案。同时给出了改进后的终端适配的设计和实现。     

面向移动终端的图片动态适配系统的设计与实现

本文设计并实现了一个面向移动终端的图片动态适配系统。该系统基于动态适配技术,提供针对移动终端的图片适配业务,能够通过配置文件对图片质量、图片尺寸、图片格式、图片特性(动画、透明背景等)进行灵活的适配控制,使用缓存机制缩短适配时间提高系统性能,并且可以通过分布式部署增加图片适配业务量。经过测试,该图片动态适配系统在通用性、系统性能和适配效果上均表现良好。     

基于缓存机制的WAP终端适配①

在WAP访问过程中,手机终端差异性是个不可回避的问题,必须进行终端适配, 但终端适配引起性能大幅降低的问题。通过对常用的终端适配处理方案的分析,提出了基于缓存机制的改进方案。介绍了缓存替换原理并选择适合终端适配的缓存替换算法,同时提供了基于LRU改进算法的终端适配设计与实现。在实际的WAP增值业务系统运行中验证缓存机制方案能够有效提高WAP终端适配的性能,同时能够减少内存的消耗。     

面向SOA的企业服务总线研究与实现

针对企业日益增长的信息共享和业务整合的需求,面向SOA的企业服务总线屏蔽各类异构的应用从而实现基于SOA架构的企业应用集成是大势所趋。现有的面向SOA的企业服务总线（s-ESB）大多立足于提供Web服务容器,并没有提供统一的适配机制无缝集成各类企业应用,从而极大限制s-ESB的高可用性和可扩展性。首先,提出了一种新型的基于SOA架构的企业应用集成环境,从而明确了s-ESB在构建企业应用集成中的地位和作用;其次,提出了s-ESB的体系结构模型,并解决了协议适配,服务适配和公共服务等关键技术问题;最后,原型系统证明s-ESB的灵活性,可有效集成各类异构企业应用。     

MPEG-21中的数字项适配技术研究

数字项适配是MPEG-21标准中一项非常重要的关键技术.本文研究MPEG-21中的数字项适配技术以及媒体独立格式的资源适配机制,实现一套基于MPEG-21 DIA的图像适配系统,提供了数字项解析、适配决策形成以及资源适配等功能.并在此基础之上试验了新的基于感兴趣区域的适配方法.试验结果表明该系统是完整和有效的,采用的新的适配方法是新颖的.     

移动服务平台终端智能适配框架的研究

为了满足移动服务平台(MSP)对终端智能适配的要求--智能识别终端,返回用户需要的服务结果,高效地开发移动媒体应用,结合常用开发方法的分析提出了基于移动服务平台终端智能适配框架,介绍了智能适配的框架所采用的模板技术、框架体系结构和框架关键点的设计与实现.在实际的运营中验证智能适配框架具有可复用、易管理、可满足用户人性化要求等良好特性,同时降低了MSP上业务开发难度,解决了平台中多种媒体业务和手机终端间的大量适配问题.     

综合业务接入平台的设计与实现

文章主要介绍了电信业务综合接入的新需求和技术发展状况，并对基于综合业务接入平台的接入适配方案进行了论述，分析了业务适应性和优势，进而介绍了一种基于ATM信元方式的综合业务接入平台的设计与实现。     

工作流引擎中通信适配系统的设计与应用

现代企业资源具有分布式、异构性、跨领域协同工作等特点,工作流管理系统中各种业务系统的远程接入和通信适配已成为企业和机构协同办公的主要瓶颈。首先针对不同类型业务接口间接入和通信适配的需求,提出了一种跨平台工作流管理系统体系结构;然后设计并实现了工作流管理系统中能够完成不同接口间转换的通信适配系统。最后将设计的通信适配系统应用到安全生产监督管理平台中,不仅满足了关键业务分布式、跨组织的特点,同时保证了业务执行的高效性和统一性。     

Dynamic SLAs management in service oriented environments

The increasing adoption of service oriented architectures across different administrative domains, forces service providers to use effective mechanisms and strategies of resource management in order for them to be able to guarantee the quality levels their customers demands during service provisioning. Service level agreements (SLA) are the most common mechanism used to establish agreements on the quality of a service (QoS) between a service provider and a service consumer. The WS-Agreement specification, developed by the Open Grid Forum, is a Web Service protocol to establish agreements on the QoS level to be guaranteed in the provision of a service. The committed agreement cannot be modified during service provision and is effective until all activities pertaining to it are finished or until one of the signing party decides to terminate it. In B2B scenarios where several service providers are involved in the composition of a service, and each of them plays both the parts of provider and customer, several one-to-one SLAs need to be signed. In such a rigid context the global QoS of the final service can be strongly affected by any violation on each single SLA. In order to prevent such violations, SLAs need to adapt to any possible needs that might come up during service provision. In this work we focus on the WS-Agreement specification and propose to enhance the flexibility of its approach. We integrate new functionality to the protocol that enable the parties of a WS-Agreement to re-negotiate and modify its terms during the service provision, and show how a typical scenario of service composition can benefit from our proposal.     

服务自适应模型及其应用

提出了一个基于模糊理论的服务自适应模型。完整地形式化了服务自适应选择过程,使用模糊语言变量和隶属度方程定义了上下文状态和服务策略选择规则。基于当前上下文与服务实现策略标准上下文之间的模糊距离概念,提出了计算服务实现策略合适程度的合适度方程。结合名为“校园助理”的上下文敏感应用场景,阐述了该模型的有效性和具体应用。     

内容适配技术研究综述

内容适配技术是实现通用多媒体接入的技术体系。MPEG-21标准提出了内容适配技术框架和服务环境描述技术规范。针对MPEG-21内容适配框架,从内容适配系统、服务环境数据交换、适配决策等方面,介绍国内外相关研究现状。     

A semantic repository approach to improve the government to business relationship

A major objective in business interactions consists in enhancing the business perspective over service provision by developing strategies and tools to provide support in the selection of services according to the value they have for businesses. This means providing a way to determine the value of services according to specific business criteria, and conceive technologies that support the sharing of knowledge involved in service provision. In this paper we present an approach based on semantic repositories. The repository enables a business perspective over service provision, based on the association between services and business processes, and is related to the problem of supporting businesses in the value-driven service selection. This perspective is addressed in the paper by exploiting expressive semantic representations and reasoning. An ontology for representing relevant semantic properties of services and processes is provided, and an algorithm for value-based service selection is presented. Two real life case studies show the effectiveness of the approach.     

Broker-based SLA-aware composite service provisioning

QoS-aware service composition aims to satisfy users’ quality of services (QoS) needs during service composition. Traditional methods simply attempt to maximize user satisfaction by provisioning the composite service instance with the best QoS. These “best-effort” methods fail to take into account that there also exist other consumers competing for the service resources and their decisions of service selection/composition can impact on QoS. Since user's QoS needs can be met once the demanded level is reached, in this paper, we propose an “on-demand” strategy for QoS-aware service composition to replace the traditional “best-effort” strategy. The service broker is introduced to facilitate implementation of this strategy: it first purchases a number of service instances for each component from providers and then provisions the composite services with different QoS classes to consumers. This paper focuses on how the broker follows the service level agreement (SLA) to provision composite services in the “on-demand” manner. This problem is formally expressed as the minimization of the QoS distance function between SLA and QoS of composite service instances, under a series of constraints. Heuristic approaches are proposed for the problem and experiments are conducted at last to verify their effectiveness and efficiency.     

基于规范流网的Web服务行为适配方法研究

Web服务适配是面向服务计算领域的重要研究内容.针对现有服务行为建模和适配技术在循环服务行为、数据流建模和状态空间爆炸方面存在的问题,提出一种新的服务行为建模和适配方法,并结合实例阐述该方法如何以规范流网为基础,建模服务行为,构造服务行为的符号化可覆盖树,构建数据依赖关系和动作依赖关系,构建符号化执行轨迹适配器,直至最后完成服务行为适配的整个建模和适配过程.     

Lifetime service level agreement management with autonomous agents for services provision

In the web services environment, service level agreements (SLA) refers to mutually agreed understandings and expectations between service consumers and providers on the service provision. Although management of SLA is critical to wide adoption of web services technologies in the real world, support for it is very limited nowadays, especially in web service composition scenarios. There lacks adequate frameworks and technologies supporting various SLA operations such as SLA formation, enforcement, and recovery. This paper presents a novel agent-based framework which utilises the agents’ ability of negotiation, interaction, and cooperation to facilitate autonomous SLA management in the context of service composition provision. Based on this framework, mechanisms for autonomous SLA operations are proposed and discussed. Results from simulations show that by integrating agents and web services the framework can address issues of SLA management drawn from sophisticated service composition scenarios.     

动态Web服务行为适配方法初探

面向服务的计算是当前软件工程领域和软件产业界的研究热点之一。随着Web服务组合技术的广泛应用,服务间的行为交互日趋复杂,已存在的静态Web服务行为适配方法难以支持复杂Web服务间的行为适配。以此为背景,首先介绍Web服务适配的相关概念,然后分析现有的静态Web服务行为适配方法的研究现状和存在的主要问题,最后探讨动态Web服务行为适配的基本原理、一般方法和技术优势。     

移动分布式环境下服务适配系统研究

移动环境给分布式资源共享特别是服务发现和资源定位带来了新的挑战。本文分析了移动性给服务发现和资源定位机制带来的特殊性,介绍了具有服务主动适配能力的服务适配原型系统Service CatalogNet,给出了其中的关键技术：适应移动性需求的支持多样性的服务模型、服务主动适配策略以及基于模糊匹配的服务定位机制。     

QoE-driven and network-aware adaptation capabilities in mobile multimedia applications

This paper deals with the analysis of mobile multimedia services, with special focus on current media resolutions for mobile handsets. Since variable network conditions entail variable quality levels, nowadays several applications implement some kind of dynamic service adaptation in order to mitigate these effects. This paper analyzes the service performance from an end-to-end perspective, taking into account the several agents involved in the service provision. From a detailed study, the different possible sources of degradations are identified as well as their impact into the expected quality as perceived by end users. Based on the obtained results, the possible effects of different adaptation capabilities are discussed. The identification of the main source of degradations at the destination endpoint improves the adaptation capabilities and enhances the service performance in terms of perceived quality.