网络弹性研究进展

网络弹性(Network Resilience)必将作为下一代异构网络必要的设计与操作属性,被定义为在面临不同的失效或挑战时,能够提供和保持可接受服务水平的能力。从系统的角度对网络弹性进行了深入的研究,首先对网络弹性从定义、模型、实现与评估等方面进行深入的分析,接着讨论基于态势感知的网络弹性研究模型,并详细阐述了模型的每一层功能及实现方法,最后给出了网络弹性研究的发展方向。     

增强学生主体意识,提高计算机实验教学质量

计算机实验教学是计算机课程教学的重要环节,通过计算机实验教学和学生上机实践操作,学生才能更好地理解和掌握计算机的知识。本文从当前学生在实验过程中存在的问题出发,分析了增强学生的主体意识的方法,提出了只有增强学生的主体意识才能切实有效地提高计算机实验教学质量的想法。     

一种XMPP即时消息系统的动态模型的实现

针对用户在利用现有即时消息系统的在线感知模块所提供的感知信息寻找正确交互对象时碰到的问题,通过分析现有的基于XMPP即时消息系统结构和在线感知实现的基本方法,结合在现有XMPP客户端中加入收集用户事件信息组件进行数据的收集,并利用决策树的分类算法对收集数据进行处理,从而实现一种可以预测的用户回应可能性的动态在线感知模型,最后利用仿真实验的方式,对模型进行了仿真分析和验证,从而得出在XMPP协议的即时消息系统中实现这种可预测用户回应的动态的在线感知模型的是可行的(其准确率约为90%),与现有其他在线感知功能模块相比,运用该方法实现的模型由于引入了预测用户行为的动态感知,因此用户在利用该模型寻找正确交互对象时的效率更高,并被用于国家网络科技环境建设的多个项目中,收到了良好效果.     

A lightweight and distributed middleware to provide presence awareness in mobile ubiquitous systems

Several researchers have identified the need to count on presence awareness in ubiquitous systems that support mobile activities, particularly when these systems are used to perform loosely-coupled mobile work. In such a work style, mobile users conduct face-to-face on-demand interactions, therefore counting on awareness information about the position and availability of potential collaborators becomes mandatory for these applications. Most proposed solutions that provide user presence awareness involve centralized components, have reusability limitations, or simply address a part of that service. This article presents a lightweight and fully distributed middleware named Moware, which allows developers to embed presence awareness services in mobile ubiquitous systems in a simple way. The article also describes the Moware architecture, its main components and strategies used to deal with several aspects of the presence awareness support. These design strategies can be reused by software designers to provide presence awareness capabilities into middleware and specific software applications. Moware services were embedded in a mobile ubiquitous system that supports inspectors during the construction inspection process. The preliminary results indicate that the middleware was easy to use for developers, and its services were useful for the end-users.     

Playing MUSIC — building context‐aware and self‐adaptive mobile applications

Although the idea of context‐awareness was introduced almost two decades ago, few mobile software applications are available today that can sense and adapt to their run‐time environment. The development of context‐aware and self‐adaptive applications is complex and few developers have experience in this area. On the basis of several demonstrators built by the joint European research project MUSIC, this paper describes typical context and adaptation features relevant for the development of context‐aware and self‐adaptive mobile applications. We explain how the demonstrators were realised using the open‐source platform MUSIC and present the feedback of the developers of these demonstrators. The main contribution of this paper is to show how the development complexity of context‐aware and self‐adaptive mobile applications can be mastered by using an adaptation framework such as MUSIC. Copyright © 2012 John Wiley & Sons, Ltd.     

一种基于背景声音识别的社会情境感知方法

随着社会需求的不断扩大及技术的不断发展,人与人之间的社会交互也越来越多.理解社会交互特征并能感知用户所处的社会情境语义（如在开会、在上课）,对于促进和辅助用户社会活动具有重要意义.从背景声音的角度对社会交互进行理解,目的是通过对背景声音差异性特征的提取,识别用户所处的社会情境.提出了一种基于背景声音识别的社会情境感知方法,该方法采用Mel frequency cepstral coefficients （MFCCs,即Mel 频率倒谱系数）分析声音信号,将路径搜索限制和搜索过滤的改进Dynamic Time Warping（DTW）算法作为识别器.通过对11 种社会情境背景声音的采集和识别,表明该算法能够有效地识别用户所处的社会情境,且其运算效率与识别率比传统DTW 算法有所提高.     

多媒体协同环境Ashram的设计与实现

设计并实现了一个多媒体协同环境Ashram系统。Ashram系统采用半复制式体系结构,具有友好的界面和简单的操作方式,支持多媒体的协同感知。文章对它的关键技术从工作空间感知和基于角色的访问控制方面作了着重的阐述,之后又对它的实现技术做了详细的讨论,力图给出一个详尽的解决方案。     

网络安全态势感知系统关键技术分析

本文将在对于网络安全态势感知系统的基本结构组成分析的基础上,通过对于Netflow流量统计技术的介绍,进行基于Netflow的网络安全态势感知系统中关键技术的分析论述。     

Group awareness and self-presentation in computer-supported information exchange

A common challenge in many situations of computer-supported collaborative learning is increasing the willingness of those involved to share their knowledge with other group members. As a prototypical situation of computer-supported information exchange, a shared-database setting was chosen for the current study. This information-exchange situation represented a social dilemma: while the contribution of information to a shared database induced costs and provided no benefit for the individual, the entire group suffered when all members decided to withhold information. In order to alleviate the information-exchange dilemma, a group-awareness tool was employed. It was hypothesized that participants would use group awareness for self-presentational purposes. For the examination of this assumption, the personality variable ‘protective self-presentation’ (PSP) was measured. An interaction effect of group awareness and PSP was found: when an awareness tool provided information concerning the contribution behavior of each individual, this tool was used as a self-presentation opportunity. In order to understand this effect in more detail, single items of the PSP-scale were analyzed.     

Peer-it: Stick-on solutions for networks of things

An integrated, autonomous stick-on computing platform is proposed, consisting of (i) the Peer-it stick-on, multi-sensor, multi-actuator computer hardware, (ii) the Peer-it component-based software framework, and (iii) the Peer-it profile markup language PeerML, supporting spontaneous interaction among such platforms. The platform implements Peer-to-Peer computing principles in a self-contained, miniaturized, universal and scalable way, giving raise for application scenarios where the real-world artefacts like e.g. machines, tools or appliances–literally every thing–equipped with Peer-it technology can operate in spontaneously interacting, goal-oriented ensembles.Technically, preferences (like capabilities and goals) and context (like time, geo-position, owner, environmental conditions, etc.) of peers are kept as a profile encoded in PeerML in the local memory of Peer-its, and carried along wherever they move in space. Once peers come into spatial proximity of each other, profiles are exchanged via wireless communication, and the “similarity” of preferences is analyzed. In the case of “matching” preferences, an associated application is notified on both peers.Besides a fully functional autonomous hardware platform integrating multiple sensors, actuator arrays and wireless communication technologies, the Peer-it stick-on computer, a low-memory footprint, OSGi compliant Peer-it software framework has been implemented. We demonstrate in a flexible manufacturing systems (FMS) scenario, how the Peer-it technology can improve over centralized FMSs with respect to fault tolerance, scalability, flexibility in reconfiguration, productivity and efficiency.