Lican Huang

Virtual and dynamic hierarchical architecture for e-science grid

This paper presents an e-Science Grid architecture called as Virtual and Dynamic Hierarchical Architecture (VDHA). VDHA is a decentralized architecture with some P2P properties. VDHA has scalable, autonomous properties, and full and effective service discovery. The synchronization can be easily achieved by using VDHA. Further more, VDHA has the security architecture fulfilling the requirements of Grid. VDHA was adopted by Chinese University e-Science Grid as its architecture. In this paper, the advantages and several protocols of VDHA are also discussed.

Enhancement of workflow flexibility by composing activities at run-time

Flexibility has recently grown to be one of the major research topics in the area of workflow management. A workflow system that supports flexible processes will benefit organizations more. In this paper, we present a workflow model offering flexibility by enabling activities to be composed automatically or manually at run-time. Our model uses selection constraints and composition constraints to guide end users to build valid workflow specifications. As an application of this model, we outline the architecture of our multi-agent based workflow management system, of which model agents play the role to complete workflow specifications according to run-time information of instances. We put forward an important algorithm related to the model agent, which is to compose activities into a valid subprocess with the shortest critical path.

Modeling Complex Architectures Based on Granular Computing on Ontology

We propose granular computing (GrC) on ontology as a solution to the problem of modeling complex architectures. We expressed the architectures formally as ontology domains, which include two components: the set of basic vocabularies and a knowledge library of rules. The set of basic vocabularies contains elements or basic architecture components. The knowledge library comprises rules that control the combination and construction of the basic elements. As the rules are often given by architectural experts subjectively, they may contain redundant, conflicting, and overlapping rules, especially in certain styles of ancient southeast Chinese architecture. It is difficult to distinguish or identify these rules; therefore, we apply the multilevel approach on ontology [Y. Liu, C. Xu, Q. Zhang, and Y. Pan, ¿Smart architect: Scalable ontology-based modeling for ancient chinese architecture,¿ IEEE Intell. Syst., vol. 23, no. 1, pp. 49-56, Jan./Feb. 2008] and approximation theory of GrC. In this process, we present a measurement that is based on roughness functions to evaluate the degrees of approximation between the selected set and certain architecture domains. With the monotonicity characteristic of roughness functions, we can design a heuristic algorithm to select a suitable knowledge base (rule set) to assist in integrating the parts into final architectures, via several levels. Experiments with a real architectural project, i.e., modeling ancient southeast Chinese architectures, show that our method is effective and may simplify the design of the automodeling system and enhance its performance.

A P2P Framework of Virtual Society Based on Virtual Hierarchical Tree Grid Organizations (VIRGO)

This paper presents a P2P framework for Virtual Societybased on virtual hierarchical tree Grid organizations(VIRGO). The virtual social persons, which have humans actions and responses modelled by computer algorithms, join VIRGO network to construct virtual society, which simulates real society. The nodes hosting virtual social persons construct n-tuple overlay virtual hierarchical overlay network according to their joining to virtualorganizations. Because of the cached addresses of nodes, the overload of traffic in tree structure can be avoided. Every virtual social person can find each other effectively. We can use this framework to simulate social phenomena. We also give out a primary design of virtual society simulation.

Locating Interested Subsets of Peers for P2PSIP

Location for Peers plays an important role on SIP applications. This paper presents a proposal for location and discovery of interested peers based on virgo P2P technologies. The peers are virtually grouped by classifying their interested topics into hierarchical domains. They construct n-tuple overlay virtual hierarchical tree overlay network according to their domains. With cached addresses of peers, the overload of traffic in tree structure can be avoided. This proposal supports flexible queries for subsets of filtered interested peers by a SQL-like query statement. In this paper, we also describe the protocols of VIRGOP2PSIP and the primary implementation of the prototype.

A workflow portal supporting multi-language interoperation and optimization

In this paper we present a workflow portal for Grid applications, which supports different workflow languages and workflow optimization. We present an XSLT converter that converts from one workflow language to another and enables the interoperation between different workflow languages. We discuss strategies for choosing the optimal service from several semantically equivalent Web services in a Grid application. The dynamic selection of Web services involves discovering a set of semantically equivalent services by filtering the available services based on metadata, and selecting an optimal service based on real‐time data and/or historical data recorded during prior executions. Finally, we describe the framework and implementation of the workflow portal which aggregates different components of the project using Java portlets. Copyright

Constructing Large Scale Cooperative Multi-Agent Systems from Semantic P2P Networks

When we construct “Smarter Planet” by gathering all information and cooperating all objects of physical and digital world in the era of Internet of Things, the agents as hubs and gateways play very important roles. As the Network becomes huge scale, large scale multi-agent systems become more and more important. Multi-agent systems play important roles in various applications. However, large scale multi-agent systems encounter many big issues such as scalability and inter-operability. This chapter presents a different approach of large scale multiagent system architecture based on semantic P2P Network- Virtual Hierarchical Tree Grid Organizations (VIRGO) in mathematic terms. Other than unstructured and DHT-based structured P2P networks, VIRGO keeps the semantic meanings of the nodes according to their roles in the communities. In VIRGO approach, the agents are identified as domain names classified by the semantic meaning of roles in the organizations. The agents construct the VIRGO network by joining the virtual groups with the same names as their domains.We proof by mathematics that in this approach each agent has at least one path to communicate with any other agent and the performance is effective as maximin hops is less than log(N), where N is total number of agents. The performance bottle-neck of tree-like topology can be avoided by cache policies. Here, we also introduce a SQL-like language for inter-operation among agents. The application cases of large scale multi agent systems based on semantic P2P networks are also described.

Large Scale Distributed Database Systems Based on Semantic P2P networks

There are the trends that the users hope to retrieve information among lots of individual database systems distributed in lots of virtual organizations. To connect all these individual database systems into a virtual database system is a significant issue. This paper presents VIRGO DDBMS, a framework of distributed database system based on virtual hierarchical tree Grid organizations(VIRGO) P2P network. The table space are classified as hierarchical domains like DNS. The servers hosting database systems joins several groups of VIRGO network according to the owned tables’ domains. VIRGO DDBMS is effective for data update and retrieve by using distributed SQL statements. We use the policies which cache the host machines’ addresses of database systems to avoid the overload of traffic of root nodes in tree structure. The proposal presented here can construct a virtual distributed database system which can manages huge volumes of data by connecting all database systems together which are owned by the individual virtual organizations. Keywords-Distributed database system; semantic P2P networks; distributed SQL

Framework for Workflow Parallel Execution in Grid Environment

This paper presents a framework for Web Service based workflow optimisation in Grid environment. In this framework, parallel service is introduced as adaptor and container of parallel block of workflow. In parallel service, workflow is divided into multi sub-workflows, which are dispatched and executed in parallel at different workflow engines in different grid nodes. By this strategy, the performance of workflow can be enhanced greatly. In this paper, we also give a strategy how to guarantee the correctness in complicated network environment by redundant computing.

Workflow optimisation for e-science applications

Grid computing is converging on a service-oriented architecture in which applications are composed from geographically dispersed, interacting Web services, and expressed in a workflow description language. The discovery of resources is of key importance to the effective and flexible use of such an architecture. This paper describes work to date in the Workflow Optimisation Services for e-Science Applications (WOSE) project which is investigating techniques for discovering services and optimising the execution of service composite workflows.