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E-Commerce &
E-Government Research Lab |
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Department of Computer Science |
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A Middleware for Composing and Managing Web Services In this project, we investigate the design and
implementation of a middleware that will form the basis for defining, running,
and managing Web services. The concepts and techniques developed in this
middleware must cope with the characteristics of Web services where: (i)
users must be able to quickly and easily create and manage services and (ii)
business transactions must operate efficiently in an environment with the
added degree of dynamism, unpredictability and distribution. This project is
specifically aimed at addressing the following issues: · Service Discovery: the space from which users can locate a Web service is large and highly dynamic. The important issue here is how users can efficiently discover previously unknown services from the huge amount of available Web services. A fundamental premise of our research is that, in a dynamic environment such as the Web, users would have to be incrementally made aware of available Web services. · Service Composition: composite services will not be built from scratch; they will make use of existing autonomous component services. Since scalability and flexibility are of great importance in Web-based environments, we anticipate that the composition techniques must cater for the creation of both dynamic and transient relationships as well as long-term relationships among services. More precisely, it should be possible to create a new service from a: (i) fixed and relatively small number of loosely coupled services or (ii) variable and possibly large number of loosely coupled services where the life time of relationships between the participants may be short-lived or changing dynamically. · Change Management: In a Web-based environment, new services could come on-line, existing services might be removed, and the content and capabilities of a service may be updated. We investigate the infrastructural support for: reporting on service changes, keeping track of service change history, and predicting and monitoring the behavior of service execution. Service-centered Querying of Web Databases In this research, we consider an architecture composed of service providers that compete in offering their different services. Users and applications submit requests that would be resolved by combining invocations to several service providers. The primary focus is on performance, more precisely on "service-oriented performance", which is differentiated from "system-oriented performance" considered in traditional data-centric approaches. "Service-oriented performance" is tightly related to the semantics of the request and the service providers. We are currently designing an algorithm for processing the submitted requests while delivering the appropriate level of performance. Security and Privacy in Digital Government Applications We investigate technology-based solutions for the deployment
of secure and privacy preserving Digital Government (DG) infrastructures. In the DG security track, we investigate the derivation of
solutions destined to the DG context from those proposed for general
distributed information systems that support workflow-based applications
across several domains. Our research also focuses on investigating the
applicability (adaptability) of existing solutions for securing e-business
infrastructures to DG infrastructures. The second
focus is to extend our WebDG system with privacy preserving
capabilities. Our initial design is
based on two principles. First, filtering mechanisms must be integrated
within government databases to guarantee minimal exposure of citizens'
information. The second principle is
that those filtering mechanisms have to adapt to the nature of the querying
source: DG infrastructures must expose different views to different users and
different entities. We proposed
a privacy preserving DG architecture based on digital privacy credentials,
filtering agents and code watermarking. Privacy credentials define the scope of
access of a DG entity to another entity's sensitive data. Filtering agents
use digital privacy credentials to control the access of remote entities to
local data. When a DG entity is
authorized to This research work is part of a multi-track research conducted by other members of CISC (Commonwealth Information Security Center) and that also includes: secure mobile commerce, secure groupware, and impersonation and certificate management. Database Middleware for Distributed Ontologies in State and Federal Family & Social Services The aim of the project is to enable the citizens of Indiana and FSSA social workers get timely information and services from local, state, and federal governments. The disadvantaged citizens would have most of their needs satisfied in one single meeting. Social workers would be able to access all necessary information using one single interface: the Web. Collecting benefits using current FSSA systems is a time-consuming, frustrating, and complex process for needy citizens and social workers. As depicted in the figure above, the current system requires citizens to visit several offices in and outside the towns in which they reside to receive the benefits they are entitled to. In many cases, dealing with this process prevents the underprivileged citizens from devoting adequate time to enhancing their prospects for becoming self-supporting with a consequential harmful impact on their health and safety. In this project, we investigate the design and implementation of a middleware for organizing, accessing, and managing government welfare databases and services. In particular, we aim at addressing the following issues: · Government Databases: FSSA agencies typically consist of dozens of autonomous departments providing services to the needy and indigent citizens. They use a plethora of databases to manage and provide services and resources under their jurisdiction. One of the major problems facing these agencies is the use of isolated, heterogeneous and autonomous information systems that are hard to interoperate. The quality and cost-effectiveness of government services could tremendously be improved if techniques are available to access government databases in a seamless fashion. · Government Services: Several rehabilitation programs are provided within FSSA to help disadvantaged citizens. Currently FSSA social workers must deal with different situations that depend on the particular needs of each citizen (disability, pregnancy, children health, etc). For each situation, they must typically delve into a large number of applications and determine those that best meet citizens’ needs. To facilitate the use of FSSA application, we investigate the development of techniques to efficiently organize and discover FSSA applications. We also investigate means for the declarative composition of services to build value added services. Web-based Workflow Support for Virtual Enterprises Our current focus in this research track is on dynamic inter-enterprise workflow. As Workflow Management Systems (WfMSs) move into more complex domains (e.g., production control, telecommunication service provision, military applications, and e-services, etc.), traditional static workflow models are no longer adequate to handle complicated real life workflows due to their lack of ability to predict all the cases and future changes. As a result, inconsistencies between the business processes in the real world and the models happen frequently due to different types of changes and the models themselves are frequently invalidated. Dynamic workflow technologies are needed to address domain uncertainty and volatility. We are currently focusing on the following aspects of dynamic workflow: · Partially automated generation of the definition and creation of workflow processes customized to the environment, business practices and goals. · Continuous adaptation (preventive measure) or compensation (reactive measure) of the execution of a workflow process. ·
Dynamic
scheduling and allocation of activities to execution resources with uncertain
and varied availability and capability. This research also covers inter-enterprise workflow technologies. Inter-enterprise workflow technologies can be used to share business processes in a Virtual Enterprise (VE) environment. There are many challenges facing this daunting task and they are represented along three dimensions for the design choices: autonomy, distribution and heterogeneity. Heterogeneity points to the need of interoperability, autonomy the need of a fair and mutually beneficial trading mechanism to balance the need for sharing workflow services and the cost associated with providing the service, and distribution the need of correctness verification (absence of deadlock and starvation). For interoperability, because workflow is composed of parts from different enactment environments, a particularly important issue is how to mediate data generated by a part of the workflow that need to be shared elsewhere. Finally, a dynamic inter-enterprise workflow environment needs to address all the issues from these two areas at the same time. When dynamic workflow and inter-enterprise workflow are put together, they aggravate each other’s complexity. For instance, in such a workflow environment, processes and process controls are distributed and propagation of an upgrade due to a change to processing sites could be difficult due to the autonomy and distribution of sites. A comprehensive framework is needed first to put all the issues in perspective. This framework will use highly expressive process representation, flexible plan generation, granularity of monitoring, dynamic plan switching, and execution of a combination of portions from multiple plans, to reflect the complex nature of the new environment. Performance of Satellite-based Mobile Databases The current focus of this project is on broadcast-based data access in wireless environments. Broadcast is one of the most suitable forms of information dissemination over wireless networks. It is particularly attractive for resource limited mobile clients in asymmetric communications. To support faster access to information and conserve battery power of mobile clients, a number of data access methods have been proposed in recent years. In this research, we study some of the most representative data access methods. We developed an adaptive test bed for evaluating wireless data access methods. Exhaustive simulations of these access methods have been conducted. As a result, selection criteria for the suitability of the data access methods for different applications are proposed. |