Jiazao Lin

Extending BPEL2.0 for Grid-Based Scientific Workflow Systems

SWF, short for scientific workflow, has recently emerged as a paradigm for orchestrating large-scale e-Science applications. SWF specification connects workflow designer with workflow engine, which makes it act ass one of the key components in SWF systems. We adopted BPEL as the Gird-based SWF specification because of its potential benefits to promote SWF sharing and reproducibility. However, grid-based SWF has unique features, which pure BPEL is not capable to handle. Appropriate ways to extend BPEL to fulfill the special needs should be found. We concluded three most necessary requirements and three kinds of alternative methods to extend BPEL within China Grid Support Platform, and implemented the method of adding additional abstractions upon BPEL to enhance user experience. Our work and findings suggest that our extension approach is feasible and would manifest potential advantage to SWF systems and finally innovate in the e-Science research and applications.

On the design of a mobile agent environment for context-aware M-commerce

Due to technological advances of handheld computing and communication devices, Mobile commerce (M-commerce) has emerged and attracted a growing number of research efforts. M-commerce not only extends Internet-based Electronic commerce (E-commerce), but also offers a unique business opportunity with its own features, such as ubiquity, accessibility, portability, etc. In this paper, we discuss some important issues in the design of an M-commerce platform based on agent technology and context-aware workflow analysis. Deploying mobile agents and context-awareness in M-commerce can reduce unnecessary network traffic, tolerate poor network connectivity, provide more advanced services, support automation of decision-making, reduce participation costs and improve trading efficiencies.

Application-Objected Workflow Management System Based on Abstract Service

Since numerous large-scale scientific applications executed on Grids are expressed as complex scientific workflows, workflow management has appeared as one of the most important service in Grid environment in past few years. However, most of the management systems do not fully hide the complexity of the underlying orchestration language. Meanwhile, Grid environment is dynamic when each scientist involves in different requirements to submit their computational jobs to heterogeneous executing environment. Therefore, in order to solve the issues of complexity, heterogeneity and dynamism, in this paper we developed Application- objected Workflow Management System based on Abstract Service. The Abstract Service is an abstract combination service for a group web service with similar function. And we presented Service Center, which contains a large number of abstract services to form a virtual uniform view to shield the diversity among various web services. We also developed a visual workflow designer, which allows scientists to orchestrate an abstract workflow by just dragging or dropping the graphical representations of abstract services to (or from) the canvas. Especially, the Requirement Description Document (RDD) was proposed to describe the special demands of individual computational jobs in XML grammar. And we implemented a Workflow Application Management System (WFAMS), which translates abstract workflow in well-defined order to concrete workflow, and manages, controls and decomposes the workflow, and then combines the scientist’s relational data and submits workflow to job pool in Grid platform. Finally, the solutions to the key problems in the workflow management system are considered, including the definition of abstract workflow, the mechanism to support failure handling, the workflow template and the mechanism to isolate the control flow and data flow.

A context-aware recommender system for M-commerce applications

M-commerce is an attractive research area due to its relative novelty, rapid growth, and great potential in business applications. However, the development of M-commerce applications is facing with some physical constraints of mobile devices and barriers of existing execution models. Moreover, the nomadic users might consume enormous time to search for satisfactory products or services from abundant options with the limited capability of physical devices. Therefore, a sophisticated recommendation algorithm which attempts to recommend a list of user-preferred products or services should be incorporated in M-commerce applications. In this paper, we propose a personalized Context-aware M-commerce Recommender System which exploits the advantages of collaborative filtering and common understanding of contextual information. Since the recommendation algorithm is embedded in a layered system and closed related with other system components, we will present a comprehensive framework to integrate the concepts of mobile agent, ontology-based context model as well as service discovery and selection mechanism. We have developed a prototype to evaluate the feasibility and effectiveness of our proposal.

A User-Friendly Task Editor Environment for Large-scale Virtual Screening Application

Virtual Screening (VS) is a large-scale parallel Bag-of-Tasks application whose tasks are independent with no data dependency and communication. Grid computing facilitates VS by providing shared computational resources across different international institutions. However, the traditional grid middle wares do not provide mechanism of task decomposition, and users usually need to decompose the large-scale independent tasks into small sub-tasks manually to make the most of the heterogeneous resources. Such method can be complex and may place a burden on the users. In this paper we propose a user-friendly Task Editor Environment extending JSDL for VS, including GUI Designer Data Description Module and Task Editor Module. The advantage of the proposal is to separate the data description from task definition description and ensure the task execution optimism. At last we present a case study, which turns out that our proposal not only satisfies the users’ need to perform the VS application in grid environment with a Task Editor Environment, but also improves the efficiency of VS application.

A QoS-Based Scheduling Approach for Complex Workflow Applications

In dynamic and heterogeneous Grid environments, the majority of the scientific applications require to be expressed as complex workflows which assemble multiple Web Services to implement complex scientific tasks. In addition, most workflow management systems are bound to concrete services distributed in different physical domains or concrete environments. Therefore, scientists still need to discover resources manually and schedule the jobs directly onto the Grid, and it could not meet users’ requirement of scheduling workflow with large scale services. In this paper, we provide a comprehensive QoS (Quality of Service) model to support the possibility that a service instance is capable of offering to satisfy the user’s requirements. Further we propose a complex workflow scheduling approach using dynamic programming, which focus on how to select a global optimal path for workflow scheduling based on QoS, and addressing services binding problem. At last, we demonstrate the efficiency and accuracy of the proposed approach by simulating experiments in heterogeneous and dynamic grid environment.

CGSP-DAI A Heterogeneous Databases Access and Integration on CGSP

Grid has attracted great attention of researchers during the past years. With its developing, it has coped with an increasing amount of complicated data and huge heterogeneous databases. So it is indispensable to develop a middleware that could access and integrate heterogeneous databases. Therefore, we propose a new fundamental architecture of the heterogeneous database access and integration in grid, called CGSP-DAI, which is based on the ChinaGrid Support Platform project. In this paper, we present a virtual table mechanism to access and integrate all kinds of heterogeneous, distributed and complex database resources. It also provides uniform Web service-based interfaces, which can help users to share, query and use resources conveniently. Moreover, it is the most important that it provides distributed join query span the heterogeneous database resources. Finally, this paper shows the experiment to evaluate the performance of CGSP-DAI, and proves the availability and efficiency of CGSP-DAI on database access and integration.

Call U Back: An Agent-Based Infrastructure for Mobile Commerce

Mobile commerce (M-commerce) is an attractive research area due to its relative novelty, rapid growth, and great potential in business applications. Over the last decade, various M-commerce applications have been geared to target mobile users and achieved great success. However, most M-commerce applications are developed by different retailers for special purposes and thus lack fully automated business processes to integrate various existing services. This paper presents a novel infrastructure, Call U Back (CUB), for M-commerce applications. The proposed scheme integrates concepts of agent and contextaware workflow to implement automated trading tasks and compose services dynamically. The context awareness is based on ontology and logic models which derive from a set of descriptive contextual attributes for knowledge sharing and logical inference. Based upon the context-aware workflow analysis, the system will generate automated intelligent agents to conduct commerce transactions on behalf of mobile users. The middleware layer of the CUB server has been implemented. An experimental prototype of the system is under development and testing.

A Comprehensive Task Management system for large-scale Virtual Screening applications

Virtual Screening (VS), a productive and cost-effective technology in quest for novel lead compounds, is a new approach in the pharmaceutical industry. This kind of applications belongs to the family of large scale loosely coupled parallel applications, whereas concurrent tasks are independent of each other, and are most suited to run on the Grid environments. However, there are some important practical issues should be investigated, namely, the complicated scale of VS applications with diverse data sets, complexity of Grid Job Description Language and dynamic and heterogeneous grid environments. In this paper we propose a Comprehensive Task Management in the context of performing VS applications on Grid environments. First, we propose an extension of the Job Submission Description Language (JSDL) to specify the large scale data set packet strategy and a visual Task Editor to make the complexity of underlying task description transparent. Then we provide a coordinating mechanism to integrate multiple Grid platforms for VS applications. Furthermore, we present a task-level predictive model on estimating of execution time from historical information. Finally, we conduct a case study on discovering leads drug against Avian Influenza Virus H5N1 to highlight technical feasibility of our proposal.

GCP: A load-balancing tool in e-Science environment

In e-Science environment researchers can submit complex tasks as scientific workflows. However, because the network may be blocked or even interrupted sometimes, it can hinder the researchers to submit tasks, as well as the overload on the server. Additionally, many tasks submitted by researchers may use the same resources, which may result in the overload of the specific resources. Meanwhile, some of tasks may be the same, so it is not necessary to waste the resources and spend extra time to execute the tasks again. Furthermore, it is difficult for the researchers to select the most appropriate resources from multitudinous resources in the e-Science environment. Therefore, in this paper we developed the Grid Computing Pool (GCP) to solve the problems. It contains Client Buffer Pool (CBP) and Server Computing Pool (SCP). CBP deployed on each client is used to save the tasks temporarily to relieve the server load. SCP deployed in grid platform is used to optimize the resource allocation and task execution according to the current condition of the environment. Finally it shows simulations to evaluate the availability and efficiency of the GCP.