Gu Jianhua

Multilevel Trust Management Framework for Pervasive Computing

A multilevel trust management framework in pervasive environment is proposed in this paper. In the framework, the trust, the reputation, reciprocity and related concepts are defined newly. The multilevel discrete trust metric finds a good way to solve the problems, which the granularity of binary trust is coarse and the calculation of continuous trust is complex. The design of storage counter in the framework makes up the deficiency that storage capacity of pervasive devices is limited. The experimental result indicates preliminarily that the multilevel trust metric has good effect on trusted authentication in pervasive environment.

Object Service Provision in Internet of Things

In this paper, we take the interoperability and collaborative problems among various objects belong to different smart space into account and propose the features for object service provision in smart space. On the basis of the above features, we give a semantic and automatic framework for objects service in smart space. In the framework, techniques of object service provision, context-aware, semantic reasoning, and pervasive service management are smoothly synthesized. A conceptual architecture is introduced in the light of functional characteristics of framework. It enables objects in smart space to interact spontaneously, provides semantic-integration context awareness, and supports meta-service based adaptability and scalability. Several technical challenges to develop Internet of Things need to be addressed is introduced in the last section.

A flexible hybrid communication model based messaging middleware

As network-centric computing becomes more pervasive and applications become more distributed, the demand for flexible and efficient message delivery is increasing. Messaging middleware is a key technique of message delivery between distributed computing applications. The main communication models of current messaging middleware are publish/subscribe and point-to-point. The two communication models have their own characteristics. However, neither of them can achieve efficiency and flexibility simultaneously. In this paper, we proposed and implemented a hybrid communication model based messaging middleware (HCM3), which takes full advantages of two models. Performance result shows that HCM3 can deliver message in heterogeneous environment with the features of high efficiency, flexibility and reliability.

Design, implementation, and evaluation of an agent-based adaptive program personalization system

The abundance of DTV (digital television) programs precipitates a need for new tools to help people find interesting programs and personalize TV viewing experience. We describe the design, implementation, and evaluation of an agent based adaptive program personalization system, which is designed to assist users by adapting to their personal preferences. We provide the architecture of the system, details its components, and presents the inter agent communication mechanism for the multiagent system. In our system, the feature representation and similarity measurement is based on VSM (vector space model), while the preference knowledge learning algorithm is using relevance feedback. We describe the prototype implementation, which has been implemented on PC/Linux. Thirdly, it describes our experiments and performance evaluation on the prototype. The experiment results are encouraging, which shows that the system proposed is useful to TV consumers. Finally, we summarizes the conclusions, and ends with directions for future work.

A hybrid filter for program personalization

The current exponential growth of DTV programs precipitates a need for new filtering techniques to provide program personalization for people. Several filtering methods, notably Boolean filtering and similarity-based filtering, have been proposed in information filtering. This paper first briefly describes the architecture of program personalization, XML based metadata representation, and discusses Boolean and similarity-based filtering, as well as their advantages and disadvantages. Then a new hybrid filter is proposed. The hybrid filter consists of VSM based filtering, which is a similarity-based filtering, and XML query filtering, which is a Boolean filtering. This hybrid filter is effective and efficient for program personalization in future DTV with local storage.

Research and implementation of distributed time service in distributed object environment

Distributed time service is a basic object service in distributed computing environment based on CORBA. We present a clock synchronization method based on clock groups. We divide machines in a system into groups, while nodes in a group are in the same LAN. There is a master clock and several slave clocks in a group, which carry out intra-group synchronization. Master clocks of all groups together accomplish inter-group synchronization. Such a dividing-to-group synchronization method makes the system scalable and flexible. At the same time, it reduces machines spanning LANs to attend synchronization, thus synchronization overhead is reduced. We have implemented clock synchronization based on clock groups in our experimental distributed object environment.