Context-aware communication

Describes the Mercury system, whereby a user of an electronic message service receives messages on a device and in a format appropriate to his context (travelling, in a meeting, etc.); and ConChat, whereby besides transmitting his message he automatically transmits contextual information such as his location, the number and identities of other people in the room, the room's ambient temperature, lighting, and sound, other applications and devices running in the room, his mood, his personal status (on the 'phone, out to lunch, etc), and any activity in the room.     

一种基于事件的情境感知框架

为更好地满足用户的个性化需求、支持情境感知服务,提出一种基于事件的情境感知框架。该框架包括传感器层、事件总线和应用服务层,采用事件触发的方式调用应用服务与用户交互,并建立基于规则的事件过滤机制,对无效事件进行屏蔽。应用结果表明,该框架可提高系统的感知性能和重用性。     

基于本体的上下文感知系统

普适计算自20世纪90年代中期被提出以后得到了普遍的关注。上下文感知作为实现普适计算的关键技术已成为重要的研究课题。在分析上下文感知系统以及组成模块的基础上,借鉴软件方法学中的快速原型模型思想,通过本体标记语言OWL给出了系统中感应模块搭建的实例。     

Exploring Context-aware Information Push

Despite much interest over recent years in the area of context-aware computing, there are still a number of significant gaps in our understanding of the HCI issues associated with such systems. One particular issue that remains relatively unexplored is how to design around the apparently conflicting goals of adapting to changes in context while at the same time adhering to the principle of predictability. In this paper, we describe our exploration into this issue through two alternative designs of an interactive context-aware tourist guide. One original design was based around information pull, i.e. the emphasis is on the user to decide when context-aware information is presented. Our second design incorporates the notion of information push whereby the actual presentation of context-aware information is triggered by contextual events, e.g. changes in the user’s location or changes to the opening times of attractions. Through the evaluation of these alternative designs we hope to gain a better understanding of the usability implications relating to push vs. pull in both this specific domain and in interactive context-aware systems in general.     

基于情境感知的API个性化推荐

在软件开发的过程中,开发人员在遇到编程困境时通常会检索合适的API来完成编程任务.情境信息和开发者画像在有效的API推荐中起着至关重要的作用,却在很大程度上被忽视了.因而文中提出了一种基于情境感知的API个性化推荐方法.该方法利用程序静态分析技术,对代码文件做抽象语法树解析,提取信息构建代码库,并对开发者API使用偏好建模.然后计算开发者当前查询语句与历史代码库中查询的语义相似度,检索出top-k个相似历史查询.最终利用查询语句信息、方法名信息、情境信息以及开发者API使用偏好信息对API进行重排序并推荐给开发者.通过模拟编程任务开发的不同阶段,使用MRR,MAP,Hit,NDCG评估指标来验证所提方法的有效性.实验结果表明,所提方法的API推荐效果优于基准方法,能够为开发者推荐更想要的API.     

可定制的情境感知计算框架原型

分析现存情境感知框架的特点与不足,提出一种面向不同应用领域的可定制的情境感知框架原型,重点阐述原型的体系结构设计和软件运行时基于服务的软件架构。讨论情境感知过程中4个关键问题,包括情境感知系统的可定制化问题、情境规则的迭代与演化、情境感知的交互机制以及情境模式。最后,以该原型为基础,通过在医疗导诊场景下实现情境感知应用验证其实现领域定制的可行性。     

Context-aware personal communication for teleliving

Personal communication with mixed voice and data can be offered as a very rich set of applications, which can be rapidly introduced at low cost. Wireless and positioning technologies in combination with the Internet's demonstrated capability to integrate voice and data are further leveraged by the use of software agents. Our work clearly demonstrates the benefits of providing context-aware personal communication in terms of its potential to bringing about the rapid introduction, at low cost, of a rich communication space where artefacts, people, and non-physical entities are integral parts.     

基于贝叶斯网络的上下文推荐算法

将上下文推荐系统同贝叶斯网络相结合,提出了一个上下文推荐算法,并设计了上下文资源推荐系统架构。首先利用贝叶斯网络,通过计算用户访问时间和资源信息的联合概率分布来取得用户在该环境下对资源的兴趣,然后比较当前用户所处环境所选取的资源与过去环境用户选取的资源的相似度,从而为用户提供合适的资源列表。最后将所提算法同其他常用的推荐系统算法进行了比较,系统架构按照M/G/1队列进行建模,对系统架构性能和稳定性进行了验证,取得较好结果。     

一种规则驱动的觉察上下文计算模式

以面向服务的体系结构和产生式推理技术为基础,提出一种规则驱动的自适应觉察上下文计算模式。在该模式中,用户的需求及服务复合策略的语义用产生式表示。在动态普适计算运行环境中,规则推理引擎能够在运行期间,根据当前的上下文知识自动选择服务构件,动态合成应用软件完成预定目标。     

The Calculus of Context-aware Ambients

We present the Calculus of Context-aware Ambients (CCA in short) for the modelling and verification of mobile systems that are context-aware. This process calculus is built upon the calculus of mobile ambients and introduces new constructs to enable ambients and processes to be aware of the environment in which they are being executed. This results in a powerful calculus where both mobility and context-awareness are first-class citizens. We present the syntax and a formal semantics of the calculus. We propose a new theory of equivalence of processes which allows the identification of systems that have the same context-aware behaviours. We prove that CCA encodes the π-calculus which is known to be a universal model of computation. Finally, we illustrate the pragmatics of the calculus through many examples and a real-world case study of a context-aware hospital bed.     

Context-aware adaptive IP mobility anchoring

The novel distributed mobility management trend is a promising direction to cope with the increasing mobile data traffic and flatten network architectures. Most of the novel mobility approaches distribute the mobility anchors through the access level, as opposed to the centralized mobility anchoring model. Other recent approaches argue that mobility anchors closer to the content servers may be the solution to optimize the mobility performance. However, none of the mobility anchoring models is ideal for all scenarios, since it depends on the user, the session and the network. Hence, we propose an IP mobility approach driven by the context of the user, sessions and the network, where the mobility anchors for IP address allocation and for routing/forwarding are distributed through the network nodes, while the mobility context is managed by the mobile devices. Although each session is properly anchored in the establishment phase, the routing/forwarding is adapted over time, according to the user, the session and the network context: the proposed approach is able to signal different mobility anchors to optimize the routing path to new and ongoing sessions of the user. The outcome of the evaluation shows that the proposed approach overall reduces the data cost, the data delay, the tunneled packets and the tunnel length, when compared with other anchoring models.     

基于本体的上下文感知中间件框架

上下文感知是普适计算的核心技术之一,而描述和理解上下文信息是上下文感知的前提。由于上下文信息种类繁多、感知方式迥异,目前开发面向特定应用的上下文感知系统缺乏统一的机制和通用的架构,增加了系统开发的成本。引入语义Web技术,利用本体对上下文信息进行建模,采用本体描述语言描述上下文模型,提供了一个公共的上下文本体以实现多个独立开发的上下文感知系统对知识的共享和推理,构建了通用的上下文感知中间件框架,从而实现对域内上下文知识的共同理解。     

移动Agent上下文知晓模型研究

随着Internet规模的不断扩大,网上的各种知识迅速增长。将移动Agent和上下文知晓相结合,设计了一种移动Agent上下文知晓模型。它能够结合用户的上下文信息,分析用户的实际需求,利用移动Agent去感知、处理和管理上下文信息,从而为用户提供所需的准确知识。最后我们使用Aglet软件平台,具体设计和实现了移动Agent上下文知晓原型系统MABCA,对用户的背景上下文进行了知晓,较好地体现了上下文知晓的特点。     

Context-aware trails [mobile computing]

The emergence of converged mobile devices with a wide range of computing, communications, entertainment, and sensing capabilities represents a major step in the evolution of wireless computing. Such devices increasingly shift the decision-making power from the user to the machine, which has the capacity to be better informed about the current environment and can respond more quickly. A trail is a collection of locations, together with associated information about these locations and a recommended order for visiting them. Mobile, context-aware trails-based applications range from single-user systems that focus on individual daily activities to multimedia groupware that supports a wide collection of user requirements. The trails metaphor makes it possible to explore adaptive characteristics common to all mobile, context-aware applications. Adaptation in this context involves altering the set of interest points on a trail and their visiting order with timeliness, accuracy, and relevance while remaining in tune with user expectations.     

Context-aware design of adaptable multimodal documents

In this paper we present a model and an adaptation architecture for context-aware multimodal documents. A compound virtual document describes the different ways in which multimodal information can be structured and presented. Physical features are associated to media instances, while properties describe the context. Concrete documents are instantiated from virtual documents by selecting and synchronizing proper media instances based on the user context: the situation, the environment, the device and the available communication resources. The relations between the context features and the media properties are described by a rule based system.     

Context-aware artifacts: two development approaches

To create context-aware artifacts, developers can choose a self-supported or infrastructure-based approach. This article surveys these approaches and their implementations in various devices, also considering associated challenges and future research directions. Creating context awareness generally follows two main approaches. In self-supported context awareness, designers build the ability to perceive context, reason with it, and act accordingly into the device or its dedicated hardware support. In infrastructure-supported context awareness, designers obtain context-aware capabilities by harnessing a hardware and software infrastructure external to and associated with the device's space. Such an infrastructure might implement the context-aware behavior of specific objects and devices or act as a general context-aware infrastructure.     

Context-aware mobile communication in hospitals

A, collaborative handheld system extends the instant messaging paradigm by adding context-awareness to support the intensive and distributed nature of information management within a hospital setting.