Shudong Chen

Service-oriented Advanced Metering Infrastructure for Smart Grids

Advanced Metering Infrastructure (AMI) enables smart grids to involve power consumers in the business process of power generation, transmission, distribution and consumption. However, the participant of consumers challenges the current power systems with system integration and cooperation and security issues. In this paper, we introduce a service-oriented approach to AMI aiming at solving the intercommunication problem and meanwhile providing a trust and secure environment for smart grids. In this approach heterogeneous systems expose services to the network. System integration and cooperation are done through service composition. A generic service interfacing method is designed to develop standardized services for heterogeneous power systems. Moreover, role-based access control mechanism is used to guarantee the secure access to smart grids. With the seamless communication between consumers and power systems and among power systems themselves, this service-oriented AMI can associate consumers with actual system workload and furthermore support the intelligent running of power systems.

Evaluating continuous top-k queries over document streams

At the age of Web 2.0, Web content becomes live, and users would like to automatically receive content of interest. Popular RSS subscription approach cannot offer fine-grained filtering approach. In this paper, we propose a personalized subscription approach over the live Web content. The document is represented by pairs of terms and weights. Meanwhile, each user defines a top-k continuous query. Based on an aggregation function to measure the relevance between a document and a query, the user continuously receives the top-k most relevant documents inside a sliding window. The challenge of the above subscription approach is the high processing cost, especially when the number of queries is very large. Our basic idea is to share evaluation results among queries. Based on the defined covering relationship of queries, we identify the relations of aggregation scores of such queries and develop a graph indexing structure (GIS) to maintain the queries. Next, based on the GIS, we propose a document evaluation algorithm to share query results among queries. After that, we re-use evaluation history documents, and design a document indexing structure (DIS) to maintain the history documents. Finally, we adopt a cost model-based approach to unify the approaches of using GIS and DIS. The experimental results show that our solution outperforms the previous works using the classic inverted list structure.

VICSDA: using virtual communities to secure service discovery and access

Service Oriented Architecture (SOA) is emerging as an enabling technology for sharing distributed heterogeneous resources on the network. Consequently, securing services is an increasing concern. Research issues include privacy protection for service providers, transparent access control for service consumers, secure service discovery and composition. In this paper, we present an access control approach which uses virtual communities to secure service discovery and access (VICSDA). Services grouped in virtual communities can only be discovered and accessed by authenticated community members. Meanwhile, services are autonomous to define their local access control policy. Moreover, behavior of these autonomous services is monitored in order to guarantee a better QoS provision. Using a virtual community overlay network on top of a SOA infrastructure, VICSDA can provide authentication, message confidentiality and integrity to secure service discovery and access. Better application performance can be achieved through VICSDA. We integrated VICSDA with a 3D video streaming application. This example provides us with some initial evidence that VICSDA is a viable solution to our target problems.

A grid resource management approach based on P2P technology

This paper presents a resource management approach in grid computing environment. Using P2P technology, this novel approach can manage dynamic grid computing resources efficiently. Different kinds of grid computing resources are organized into a P2P overlay network and available information is published in type of grid service. Task requests for computational resources are also presented as grid services. Problem of resources scheduling, is solved by services discovery. During the course of allocating computing resources to an application, task requests are forward in the P2P overlay network following the Chord routing protocol. With this approach, the computational resources of a grid system can be scheduled dynamically according to the real-time workload on each peer. Furthermore, the application of this approach is introduced into DDGRID, a grid system for drug discovery and design, to evaluate the performance. Solid experimental results show that computational resources of a grid system can be managed efficiently, and the system can hold a perfect load balance state and robustness

Toward a security model for a body sensor platform

Body Sensor Networks (BSNs) are used in the ubiquitous healthcare to measure human body functions like vital physiological data (e.g. heart beat). As the privacy-sensitive sensor data are transferred over the unreliable wireless connection and can be shared among various BSN applications, it is necessary to protect this data against potential threats. The purpose of this paper is to introduce an approach to design a lightweight security model with respect to limited resource constraints of our special purpose sensor platform.

A Novel Agent-Based Load Balancing Algorithm for Grid Computing

This paper presents an agent-based resource scheduling algorithm for Grid computing systems. With this scheduling algorithm, the computational resources of the Grid can be dynamically scheduled according to the real-time working load on each node. Thus a Grid system can hold an excellent load balance state. Furthermore, the application of this algorithm is introduced into the practical protein molecules docking applications, which run at the DDG, a Grid computing system for drug discovery and design. Solid experimental results show the load balance and robustness of the proposed algorithm.

A SOA-BPM-Based Architecture for Intelligent Power Dispatching System

The issue of difficult interoperations among existing power systems cause by their heterogeneous hardware platform, developed language and supported communication protocols has hampered the development of power dispatching business, which is one of most important part of smart grid. A flexible, scalable and reliable architecture is required to be designed aiming at developing new functionalities through reusing the available systems. SOA and BPM technologies provide a desirable solution for system architecture. Web Services in SOA encapsulate functions as services to enable system integration. BPM coordinates Web Services to implement business processes while takes business process optimization as its core goal. In this paper, we propose a SOA-BPM-based architecture for intelligent power dispatching system. It is designed to provide flexibility and scalability to the existing power dispatching systems. We explored the requirements of East China Power Dispatching Center and concluded that the proposed design is feasible and is flexible enough to meet the rapidly changing business demands coming from the intelligent power dispatching systems.

PBiz: An E-business Model Based on Peer-to-Peer Network

The resource of e-Business is distributed, but the existing e-Business resource management is processed in a centralized approach, which has the limitations of single point failure and performance bottleneck. We propose PBiz, an e-Business model based on peer-to-peer to overcome these limitations. In PBiz, resource is managed in a totally decentralized approach. Moreover, we extend the routing algorithm Chord with XML to enable PBiz could support SQL-like query. Experimental results show that PBiz has good robustness and extensibility.

Virtual community management for enabling P2P services in the IMS network

This paper addresses forming and management of a virtual community (VC) in the IP multimedia subsystem (IMS) network. A VC provides scope for mobile peer-to-peer (P2P) service sharing among end users and allows them control of sharing. The paper describes a number of services that enable forming and management of virtual communities and presents several service-oriented system architecture alternatives focusing on distribution of service access control and service discovery control between end users and operators as the owners of the IMS home-networks. Presented architecture alternatives are IMS compatible since they only introduce 5 additional services into the existing IMS architecture. A key service is an orchestrator that exposes new services composed of other services. A proof-of-concept realization of the IMS architecture in which control of mobile service sharing is distributed among end users and operators is shown.

A cooperative computing platform for drug discovery and design

This work presents a novel peer-to-peer based application scheduling algorithm for a cycle-sharing cluster computing system for drug discovery and design. Using the idle cycles donated by the clusters scattered over the Internet, data-intensive biologic applications in the field of drug discovery can be computed in this computing system. Clusters that donate idle cycles are organized in peer-to-peer overlay networks to eliminate problems caused by traditional client-server model. A novel application-based scheduling algorithm is designed to assign idle cycles to tasks efficiently. This algorithm also ensures the routing path length on the overlay network is close to the real network routing distance. Solid experimental results show the good performance of the proposal system.