移动情境感知系统的实时性与可靠性

With the development of sensor technology, the context information obtained by sensors has become increasingly rich in recent years. As a result, context-awareness as a key technology for linking physical space to the cyberspace in Pervasive Computing and Internet of Things has attracted considerable interests. Some formal methods based on various process algebras have been applied to explore context-aware systems, in order to ensure that the computing entities are capable of precisely acquiring, transferring, understanding, and using the context information and so as to provide users with better service. However, with the rapid development of IT the real-time and reliability requirements of context- aware systems are getting higher and higher in the various areas of applications such as safety-critical systems and business-critical systems. Therefore, this project turns from the qualitative research of the context-aware systems which is based on process algebra to the quantitative one. We model and analyze the mobile context-aware systems in distributed application scenarios. To describe the requirements of the real-time performance of contexts and messages and the system reliability in a noisy environment, we develop both the timed calculus of context- aware systems and the calculus of context-aware systems with noisy channels, and then define and investigate the system behavior equivalences, the verification of timed properties, and the measure of system reliability and its improvement. Finally, the results are applied to the modeling and analysis of location-based services. The research of the project is useful to formally specify, develop, and verify the real-time performance and the reliability of a context-aware system.

近年来，随着传感器技术的发展，通过传感器获取的情境信息日益丰富，情境感知作为普适计算和物联网中融合物理空间与信息空间的关键技术受到了广泛关注。为了确保系统中计算实体能够精准地获取、传送、理解和使用情境信息，从而为用户提供更好的服务，以进程代数为代表的形式化方法被用于情境感知系统的研究。然而，随着信息技术的飞速发展，各个应用领域，尤其是安全关键系统和业务关键系统，对情境感知系统的实时性和可靠性要求越来越高。为此，本项目从情境感知系统基于进程代数的定性研究转向定量研究。我们建模和分析分布式应用场景下的移动情境感知系统，针对这类系统中情境和消息的实时性以及噪音环境下系统的可靠性需求，分别建立时间和噪音情境感知演算，进而定义并研究系统行为等价、时间性质验证、可靠性度量及改进等。同时，我们将研究成果应用于基于位置服务的建模与分析。本项目的研究有助于形式化描述、开发和验证情境感知系统的实时性和可靠性。

近年来，随着传感器技术的发展，通过传感器获取的情境信息日益丰富，情境感知作为普适计算和物联网中融合物理空间与信息空间的关键技术受到了广泛关注。为了确保情境感知系统中计算实体能够精准地获取、传送、理解和使用情境信息，从而为用户提供更好的服务，以进程代数为代表的形式化方法被用于情境感知系统的研究。特别地，基于ambient演算，英国Siewe等人最近创建了一种情境感知演算CCA，用于建模和分析具有移动性和情境感知能力的系统。然而，随着信息技术的飞速发展，各个应用领域，尤其是安全关键系统和业务关键系统，对情境感知系统的实时性和可靠性要求越来越高。为此，本项目从情境感知系统基于进程代数的定性研究转向了定量研究。我们对分布式应用场景下的移动情境感知系统进行了较为系统深入的研究，主要研究内容包括情境信息及情境感知系统的建模、情境信息的推理、情境信息及情境感知系统的验证等，得到了一些有意义的原创性成果。本项目的研究成果可用于形式化描述、开发和验证情境感知系统的可靠性。