数字城市模型服务系统设计

提出了数字城市建设应当在"数据服务"的基础上向"应用服务"转变,指出了"应用服务"的两个方面:面向公众的信息服务和面向专业领域的信息服务.针时讨论较少的后一种应用问题,设计了数字城市的模型服务系统来支持所需的信息服务.讨论了系统在数字城市应用服务平台中的地位和作用,分析了系统的结构,提出了模型的接口规范和系统的工作流程.最后,对实现的教字城市模型服务系统原型进行了探讨.     

面向云应用的拟态云服务架构

针对单执行体的云应用服务缺乏异构性和动态性,难以应对未知漏洞和后门的安全威胁问题,提出一种拟态云服务架构,把云平台向用户提供的应用服务节点构造成基于拟态防御技术的服务包,使应用服务具有拟态构造带来的内生安全特性和鲁棒性,同时讨论了策略调度和裁决机制等两项关键的拟态云服务运行机制.经实验分析表明,拟态云服务具有较好的安全...     

个人云存储发展迅猛 竞争激烈

目前,面向个人用户的云存储服务主要有两类,一类是像Dropbox的网盘类应用服务,另一类是像Evernote的笔记类应用服务。这两者既有重合也有互补的关系,同时使用两类服务的用户比例也较高。根据艾瑞咨询近期发布的《2012年中国云存储行业及用户行为研究报告》中的研究结果显示,目前的个人云存储应用尚处于起步阶段,积累用户是此阶段的     

基于虚拟化技术的私有云APCS平台设计

为提高分布式管理信息系统的硬件资源利用率和运营维护管理效率,并为业务用户提供应用系统的按需使用服务,提出一种基于虚拟化技术的管理信息系统私有云APCS解决方案。通过云服务基础架构平台ACSIP建设,实现对底层硬件平台的整合利用,提高系统硬件资源利用率,保障业务应用系统的连续性,提供可动态配置的应用服务。使用云服务管理平台ACSMP建设,实现系统运行资源的动态分配管理、系统集中运维监控管理和安全管理。     

基于UDDI的应用服务注册中心的设计

服务注册与发现技术是当前企业级应用集成系统研究的热点.基于统一表述、发现和集成(UDDI)协议的应用服务注册系统是面向服务软件体系结构的重要组件,其目的是促进企业间的服务资源共享,以及企业间跨越互联网的业务整合,UDDI协议包括服务注册系统程序接口规范和数据结构规范.应用服务注册系统采用.NET平台下的C#语言开发,适用于在线web服务交易.为了确保信息的可靠性,系统对UDDI协议作了扩展,提供了对将要发布的信息的审批机制和基于角色的用户管理.     

网格计算环境下的ASP服务模型

随着新技术的不断涌现以及企业对于商业应用服务的需求，人们对ASP服务模型的探讨又活跃了起来。本文比较了网格环境下的P2P，web服务等技术，指出了web服务技术能将各种分布的、异构的、由单一企业提供或者由各外部共享资源和应用服务提供商联合提供的动态服务整合起来的特性，并分析了ASP的演化将由传统的一对多模式转向web服务的趋势。最后结合具体的科研项目，提出了一种通用的ASP服务模型，还探讨了它在实际应用中的价值。     

SaaS：信息安全新途径

SaaS是Software-as-a-Service（软件即服务）的简称，是随着互联网技术的发展和应用软件的成熟而在21世纪开始兴起的一种完全创新的托管式应用服务模式：厂商将应用软件统一部署在自己的服务器上，客户可以根据自己的实际需求，通过互联网获得厂商提供的应用服务。     

P2P网络资源服务性能分析

P2P网络针对具体资源能提供多少搜索和传输服务能力?资源搜索的成功率和查全率是多少?目前,针对类似问题的研究还较少发现。针对非结构化P2P网络,建立P2P网络排队模型,研究P2P网络针对具体资源提供的搜索服务能力、传输服务能力以及资源搜索成功率和查全率;研究发现：资源搜索的查全率只与P2P网络属性相关,而与具体资源的数量无关;当TTL≥4时,可以保证多数情况下资源搜索的成功率和查全率。     

北美ASP市场观察

随着市场的发展,对ASP的定义正在从应用程序服务供应商倾向于应用服务供应商,服务形式从应用托管、外包向应用服务转变,而服务内容则从提供数据中心和应用程序服务向电子商务应用服务升级。”租赁高科技”的口号让人们深刻体会到IT行业的本质即是服务的道理,当ASP使IT事务不再成为左右企业核心竞争力的因素,整个IT产业和全球电子商务格局为之倾倒时,我们有理由相信:一种新的商业模式出现了。     

基于上下文感知的移动Web服务

移动Web服务的目的是随时、随地为资源有限的任何移动设备提供信息服务。该文以一个移动旅游者娱乐系统为例,阐述移动Web应用服务系统的体系结构、主要组件对象之间的交互及用户个性化服务的实现。讨论上下文管理机制的功能、模型和相关实现技术,介绍其接口与WSDL的实现。     

一种基于QoS的Internet服务管理体系结构

服务定位协议(SLP)是IETF提出的基于IP网络的服务定位标准。而这一标准并没有考虑对QoS的支持。未来的互联网络是一个具有QoS保证的网络。服务发现仅仅是Internet服务管理中的一个方面，发现服务不是最终目的，最终目的是为了使用这一服务。在对SLP体系结构、下一代互联网QoS服务管理及相关技术充分研究的基础上，提出了一种新奇的基于QoS的Internet服务管理体系结构模型。为使在服务表示与发现层支持QoS，对SLP定位协议进行了一些扩充。对服务定位协议扩充后，当用户代理在向服务代理发布请求时，可以在请求消息中绑定QoS对象参数，一旦服务代理接收到这一消息，就可以利用这些QoS参数与域管理器进行协商，协商结果可通过服务代理反馈给用户代理。这样不仅减小了网络开销，而且降低了传统的用户代理与域管理器协商的次数，在服务发现的同时用户代理还可以直接获得该服务的QoS信息。     

Access and service convergence over the mobile internet – A survey

Next generation heterogeneous wireless networks are expected to interwork with Internet Protocol (IP)-based infrastructures. Conventional network services operate like silos in that a specific set of services are offered over a specific type of access network. It is desirable for users to be able to roam between fixed and mobile networks that employ different access technologies. Therefore, mobility management with quality of service (QoS) support is of particular importance and one of the driving forces of convergence. Since service providers often provide more than one service to their subscribers, it is important to facilitate convergence of network charging architecture through a common charging framework. One of the main issues of IP-based convergence is security and privacy. This requires coordination of different security policies in diverse networks that have different security levels and capabilities. The business case for migration to an IP-based platform motivates operators to deliver more powerful services for customers as well as a better user experience. This paper provides an overview of converged mobile Internet architectures and their implications on QoS, charging/billing and security, as well as emerging business models for telecommunication services.     

基于下一代Internet的服务管理研究

Internet is best effort network, on the whole, it doesn't provide any quality of service assurance for services. Especially,all kinds of stream media need more network performance and quality of service. Currently, because of existing many heterogeneous networks, such as telecommunication network, IP data network , mobile network and so on ,in order to break off this heterogeneous network isolated complexion ,research and developmentnext generation network must be carried out,only by this way,can these isolated heterogeneous network be merged into an all IP network. This network will provide enormous services for service users,how to manage these services effectively is a topic proposed by next generation internet. [1] gave research status for service management and advance,this paper researches service management requirement for next generation Internet and workflow etc,and based on these technique,a service management architecture model is proposed. It consists of service access layer, service deployment layer, service providing layer, service mapping layer, policy control layer and network element managing layer. These layers coordinate to implement service management.     

SLA-controlled interconnection charging in next generation networks

Next generation network (NGN) should facilitate a single party to establish quality of service (QoS) enabled path between the two IP providers mutually interconnected by one or more transit providers. For that purpose, an end-to-end service level agreement (SLA) should be negotiated and maintained. In this article, we propose interconnection charging, which is controlled by the end-to-end SLA. Relationships between the required, offered, and actually achieved inter-provider QoS are quantified through the degrees of offering and provisioning, at both end-to-end and per-domain levels. Nominal retail price offered to end users and interconnection costs related with particular SLA are then corrected if needed, depending on the offered and provisioned QoS levels. We further propose five policies for interconnection charging and compare them under different QoS provisioning scenarios. Results of the analysis indicate that a properly selected SLA-controlled interconnection charging policy should encourage providers: (1) to offer services with different QoS levels; (2) to offer service that perfectly or most approximately matches the required QoS and (3) to achieve the contracted QoS level.     

A study on the monitoring model development for quality measurement of internet traffic

The recent trend of integration among new network services such as the long-term evolution (LTE) based on internet protocol (IP) needs reputable analyses and prediction information on the internet traffic. The IP along with increased internet traffics due to expanding new service platforms such as smartphones will reflect policies such as network QoS according to new services. The establishment of monitoring methods and analysis plans is thus required for the development of internet traffics that will analyze their status and predict their future. The paper with the speed of Internet traffic model is developed for monitoring the state of the experiment and verified. The problem is that the proposed service Internet service provider (ISP) to resolve the conflict between the occurrences can be considerably Internet traffic and that the state of data may be helpful in understanding. The paper advancement policy to reflect the network traffic volume of Internet services and users irradiation with increased traffic due to the development and management of the analysis was carried out experimental measurements.     

基于优先级服务的排队系统模型的计算机模拟研究

基于TCP／IP协议的拥塞问题、Internet QoS分析都需考虑优先级服务的排队系统。讨论了服务规则为服从优先级服务的模拟模型，分别在串并联混合情形下建立四类模拟模型，最后给出模拟实例。     

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.     

Bandwidth Aggregation-Aware Dynamic QoS Negotiation for Real-Time Video Streaming in Next-Generation Wireless Networks

In next generation wireless networks, Internet service providers (ISPs) are expected to offer services through several wireless technologies (e.g., WLAN, 3G, WiFi, and WiMAX). Thus, mobile computers equipped with multiple interfaces will be able to maintain simultaneous connections with different networks and increase their data communication rates by aggregating the bandwidth available at these networks. To guarantee quality-of-service (QoS) for these applications, this paper proposes a dynamic QoS negotiation scheme that allows users to dynamically negotiate the service levels required for their traffic and to reach them through one or more wireless interfaces. Such bandwidth aggregation (BAG) scheme implies transmission of data belonging to a single application via multiple paths with different characteristics, which may result in an out-of-order delivery of data packets to the receiver and introduce additional delays for packets reordering. The proposed QoS negotiation system aims to ensure the continuity of QoS perceived by mobile users while they are on the move between different access points, and also, a fair use of the network resources. The performance of the proposed dynamic QoS negotiation system is investigated and compared against other schemes. The obtained results demonstrate the outstanding performance of the proposed scheme as it enhances the scalability of the system and minimizes the reordering delay and the associated packet loss rate.     

一种考虑QoS动态变化的服务选择方法

随着Web服务相关技术的高度发展,网络上存在着多个完成相似功能的Web服务。如何选择适合的服务来生成满足用户要求的组合服务成为服务领域的重要研究课题之一。现有的基于服务质量QoS(Quality of Service)的服务选择方法通常都是假定服务提供者发布的QoS数值是真实且固定不变的,然而服务的质量往往在实际运行中 发生变化。为此,针对该问题提出了一种考虑QoS数据动态变化的服务选择方法。该方法引入了QoS分时可靠的思想,将作为选择依据的QoS数值根据以往的服务执行情况给出不同时段上的不同表现数值,这样可以更加贴合地描述服务运行的实际情况。该方法按服务在不同时间段上的可靠性变化划分为不同的子服务,利用冗余的思想在不同的时间段下为用户提供多个满足要求的备选服务。最后通过一组模拟实验说明该方法的可用性和有效性。     

A trustworthy QoS-based collaborative filtering approach for web service discovery

Many network services which process a large quantity of data and knowledge are available in the distributed network environment, and provide applications to users based on Service-Oriented Architecture (SOA) and Web services technology. Therefore, a useful web service discovery approach for data and knowledge discovery process in the complex network environment is a very significant issue. Using the traditional keyword-based search method, users find it difficult to choose the best web services from those with similar functionalities. In addition, in an untrustworthy real world environment, the QoS-based service discovery approach cannot verify the correctness of the web services’ Quality of Service (QoS) values, since such values guaranteed by a service provider are different from the real ones. This work proposes a trustworthy two-phase web service discovery mechanism based on QoS and collaborative filtering, which discovers and recommends the needed web services effectively for users in the distributed environment, and also solves the problem of services with incorrect QoS information. In the experiment, the theoretical analysis and simulation experiment results show that the proposed method can accurately recommend the needed services to users, and improve the recommendation quality.