支持上下文感知服务的中间件原型*

提出了基于传感器网络环境的上下文感知应用开发中间件原型的体系结构MidCASE,重点阐述了中间件的体系结构设计和软件运行时基于服务的分布式运行架构.讨论了上下文感知过程中的两个关键问题,包括上下文信息建立的方法和感知过程中上下文信息与高层通信的调度模型.最后,以该中间件原型为基础,通过在医疗护理的场景下实现上下文感知应用并证明了其易用性与支撑作用.     

Distributed Context Retrieval and Consistency Control in Pervasive Computing

The challenge of saturating all phases of pervasive service provision with context-aware functionality lies in coping with the complexity of maintaining, retrieving and distributing context information. To efficiently represent and query context information a sophisticated modelling scheme should exist. To distribute and synchronise context knowledge in various context repositories across a multitude of administrative domains, streamlined mechanisms are needed. This paper elaborates on an innovative context management framework that has been designed to cope with free-text and location based context retrieval and efficient context consistency control. The proposed framework has been incorporated in a multi-functional pervasive services platform, while most of the mechanisms it employs have been empirically evaluated.     

一种基于情景感知的Ad Hoc网络功率控制算法

针对战场复杂恶劣环境下 Ad Hoc网络节点易受自然或人为因素影响发生故障,从而造成网络分割并导致通信中断,提出了一种基于情景感知的分布式功率控制算法(DPCAC)。DPCAC 采用 DS证据理论对影响节点失效的多“情景证据”进行融合,推理得到节点的生存状态,依据情景数据库中的信息构建拓扑矩阵,找出故障集并通过调节邻居节点的功率改变网络结构,进而达到恢复通信的目的。仿真实验表明,DPCAC可有效修复网络通信中断的链路,并可在网络恢复连通后通过调节功率降低不必要的能量消耗。     

面向动作的上下文感知应用的规约与运行时验证

面向动作的上下文感知（AOCA）应用组织环境中的资源,为用户动作的顺利进行提供支持.为应对环境和动作相关需求的开放性,这类应用采用轻量级、增量式的开发方法进行开发.相比于在开发阶段描述全局信息的开发方法,AOCA应用的开发可能由不同开发者在不同时间共同参与,这可能会导致较多的不一致等问题,且难以在开发阶段被发现.我们围绕使用运行时验证手段提高AOCA应用可靠性这一目标展开了研究.本文给出了对于AOCA应用运行状态进行形式化规约、对于系统级和应用级性质进行描述的方法.进一步地,我们设计实现了AOCA应用监控器.最后,通过案例分析以及性能评估证实该方法的有效性.     

A Framework for the Service Model of NFC Stack

Abstract--Near field communications （NFC） is a newly thrived technology in recent years. This technology has been installed on many kinds of mobile phone systems, especially the Android. However, there is no unified and complete framework to access NFC so far. The current software stack of NFC merely implements data obtaining features, ignoring the post-processing of data and lacking a certain security mechanism for NFC, which results in inefficiency and inconvenience for software development and maintenance. Above all, security problems could be caused due to the absence of the security mechanism. To propose a solution, this paper presents a brand-new framework for NFC utilization by analyzing and constructing a service model. Thus, the proposed framework encapsulates the current NFC stack on Android, formulating a three-layer structure after implementing the encapsulation and parsing of NFC records, which ultimately enables an XML document to describe the configuration of NFC and its related service flow. Simultaneously, a context-awareness model is proposed and built in this paper to equip the framework with the capability of adapting to different＇physical environment.     

Context-awareness approach in game style application

By combining training content with Game AI, Game Style Training can provide a rich, interactive and engaging educational substance. It supports experiential learning-bydoing. And it can contribute to promote interest and motivation of trainees. In this paper, a Context-Awareness Approach （CAA） is put forward for earthquake rescue training by applying the concept of ambient intelligence. The CAA takes advantage of player profile to monitor player states, utilizes time sensor and location sensor to supervise environment changes. And then, a Reinforcement Learning model based on MAS is designed to update game AI system.     

基于情境感知的服务系统

The paper gives an overview of a recently started research project addressing the question: Can context be exploited to add value to IT-services? Beyond today's way-finding services based on GPS and maps, we believe there is a new class of context-aware pervasive services making good use of a broad range of context information (e.g. identity, time of day, temperature, history as well as relative location of friends and belongings). Last but not least we believe one can find ways of adding value to IT-services by using disembodied conversational agents based on voice, sounds and visual signals integrated into the environment, instead of being guided by explicit directions shown on a display. The project aims at giving both new fundamental insight about the theory behind IT-services, their architecture and user interfaces and at building a number of prototypes demonstrating innovative context-aware pervasive IT-services.     

Adaptive content recommendation for mobile users: Ordering recommendations using a hierarchical context model with granularity

Retrieving timely and relevant information on-site is an important task for mobile users. A context-aware system can understand a user’s information needs and thus select contents according to relevance. We propose a context-dependent search engine that represents user context in a knowledge-based context model, implemented in a hierarchical structure with granularity information. Search results are ordered based on semantic relevance computed as similarity between the current context and tags of search results. Compared against baseline algorithms, the proposed approach enhances precision by 22% and pooled recall by 17%. The use of size-based granularity to compute similarity makes the approach more robust against changes in the context model in comparison to graph-based methods, facilitating import of existing knowledge repositories and end-user defined vocabularies (folksonomies). The reasoning engine being light-weight, privacy protection is ensured, as all user information is processed locally on the user’s phone without requiring communication with an external server.     

Index to Digital Creativity volumes 10-12

This paper advocates the future of the body as a distributed and shared embodiment; an unfolded body that doesn't end at one's skin, but emerges as intercorporeality between bodies and the technological environment. Looking at new tendencies within interaction design and ubiquitous computing to see how these are to an increasing extent focusing on sociality, context-awareness, relations, affects, connectedness and collectivity, we will examine how these new technological movements can change our perception of embodiment towards a distributed and shared one. By examining interactive textiles as part of a future rising landscape of multi-sensory networks, we will exemplify how the new technologies can shutter dichotomies and challenge traditional notions of embodiment and the subject. Finally, we show how this ‘new embodiment’ manifests Deleuze's philosophy of the body as something unstable and changing, and how his refolding of the body can be useful for future interaction designers to understand the context in which they work and the challenges they will meet.     

Context-Sensitive Service Discovery Experimental Prototype and Evaluation

The amount of different networks and services available to users today are increasing. This introduces a need for ways to locate and sort out irrelevant services in the process of discovering available services for a user. In this paper, we describe and evaluate a prototype of an automated discovery and selection system, which locates services that are relevant to a user based on his/her context and the context of the available services. The prototype is based on a multi-level, hierarchical system approach and introduces entities called User-nodes, Super-nodes, and Root-nodes. These entities separates the network into domains that handle the complex distributed service discovery, which is based on dynamically changing context information. In the prototype, a method for performing context-sensitive service discovery has been achieved. The service discovery part utilizes UPnP, which has been extended in order to increase network scalability. The experimental analysis of service discovery times, based on different scenarios is used to optimize parameter settings of the service discovery system in order to achieve short response times.