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ABSTRACT: Web services have become the technology of choice for service-oriented computing implementation, where Web services can be composed in response to some users' needs. It is critical to verify the compatibility of component Web services to ensure the correctness of the whole composition in which these components participate. Traditionally, two conditions need to be satisfied during the verification of compatibility: reachable termination and proper termination. Unfortunately, it is complex and time consuming to verify those two conditions. To reduce the complexity of this verification, we model Web services using colored Petri nets (PNs) so that a specific property of their structures is looked into, namely, well structuredness. We prove that only reachable termination needs to be satisfied when verifying behavioral compatibility among well-structured Web services. When a composition is declared as valid and in the case where one of its component Web services fails at run time, an alternative one with similar behavior needs to come into play as a substitute. Thus, it is important to develop effective approaches that permit one to analyze the similarity of Web services. Although many existing approaches utilize PNs to analyze behavioral compatibility, few of them explore further appropriate definitions of behavioral similarity and provide a user-friendly tool with automatic verification. In this paper, we introduce a formal definition of context-independent similarity and show that a Web service can be substituted by an alternative peer of similar behavior without intervening other Web services in the composition. Therefore, the cost of verifying service substitutability is largely reduced. We also provide an algorithm for the verification and implement it in a tool. Using the tool, the verification of behavioral similarity of Web services can be performed in an automatic way.
IEEE Transactions on Systems Man and Cybernetics - Part A Systems and Humans 06/2011; · 2.12 Impact Factor
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ABSTRACT: New technologies have been continuously emerging to enable effective reuse of an ever-growing amount of data on the Web. Innovative firms can leverage the available technologies and data to provide useful services. Comparison-shopping services are an example of reusing existing data to make bargain-finding easier. Certain reuses have caused conflicts with the firms whose data has been reused. Countries in the European Union have implemented the Database Directive to provide legal protection for database creators, but the impact and the interpretation of the new law are unclear and still evolving. Lawmakers in the U.S. have not decided on a policy concerning database protection and data reuse. Both data creating and data reusing firms need to develop strategies to operate effectively in this uncertain environment. Comparison-shopping and other data reuse services face similar legal and strategic challenges. Thus we address these challenges in the broader data reuse context. We use economic reasoning to formulate strategies in anticipation of the likely policy choices and interpretations of existing legislation. Both data creating firms and data reusing firms should focus on innovative ways of using or reusing data to create differentiated products and services. For firms that gather data from multiple sources, they can also use the insights gained from integrated data to provide other value-added services.
Journal of Electronic Commerce Research. 01/2010; 11(3).
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ABSTRACT: Organizations have been increasingly investing in technology to collect and process vast volumes of data. Even so, they often
find themselves stymied in their efforts to effectively use the data to improve business processes and to make better decisions.
This difficulty is often caused by information quality issues within the organization and other related organizations.
10/2009: pages 315-333;
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ABSTRACT: Independently developed Web services often have different assumptions about the interpretation of the exchanged data, such as inconsistent data representation, unit, precision, and scaling. In practice, data misinterpretation results in many data quality problems and further hampers the execution of service composition. In this paper, we present a context-based mediation approach to handle inconsistent data interpretations and improve data quality for Web services composition. The assumptions about data interpretation of the involved services are made explicit and represented as contexts. A common ontology is defined to describe the contexts. Necessary conversions between elements of the contexts are implemented using XPath functions and external (e.g., third-party) services to reconcile inconsistent contexts. The WSDL descriptions of Web services are annotated with appropriate contexts using the W3C standard SAWSDL. Given a naïve composition ignoring contexts, the reasoning engine can automatically detect context conflicts within the naïve composition and reconcile these conflicts by producing a mediated composition that incorporates appropriate conversions. A proof-of-concept prototype, Context Mediation Tool (CMT), has been developed to validate and demonstrate the approach.
10/2009;
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Commun. ACM. 01/2009; 52:123-128.
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Ingénierie des Systèmes d'Information. 01/2009; 14:59-74.
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Proceedings of the International Conference on Information Systems, ICIS 2009, Phoenix, Arizona, USA, December 15-18, 2009; 01/2009
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J. Data and Information Quality. 01/2009; 1.
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IEEE International Conference on Web Services, ICWS 2009, Los Angeles, CA, USA, 6-10 July 2009; 01/2009
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IJEB. 01/2008; 6:319-341.
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J. of Management Information Systems. 01/2008; 25:199-232.
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ABSTRACT: As an open standard for electronic communication of business and financial data, XBRL has the potential of improving the efficiency of the business data supply chain. A number of jurisdictions have developed different XBRL taxonomies as their data standards. Semantic heterogeneity exists in these taxonomies, the corresponding instances, and the internal systems that store the original data. Consequently, there are still substantial difficulties in creating and using XBRL instances that involve multiple taxonomies. To fully realize the potential benefits of XBRL, we have to develop technologies to reconcile semantic heterogeneity and enable interoperability of various parts of the supply chain. In this paper, we analyze the XBRL standard and use examples of different taxonomies to illustrate the interoperability challenge. We also propose a technical solution that incorporates schema matching and context mediation techniques to improve the efficiency of the production and consumption of XBRL data.
Massachusetts Institute of Technology (MIT), Sloan School of Management, Working papers. 01/2008;
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ABSTRACT: There are many different kinds of ontologies used for different purposes in modern computing. Lightweight ontologies are easy to create, but difficult to deploy; formal ontolgies are relatively easy to deploy, but difficult to create. This paper presents an approach that combines the strengths and avoids the weaknesses of lightweight and formal ontologies. In this approach, the ontology includes only high level concepts; subtle differences in the interpretation of the concepts are captured as context descriptions outside the ontology. The resulting ontology is simple, thus it is easy to create. The context descriptions facilitate data conversion composition, which leads to a scalable solution to semantic interoperability among disparate data sources and contexts.
Massachusetts Institute of Technology (MIT), Sloan School of Management, Working papers. 01/2007;
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Ontologies-Based Databases and Information Systems, First and Second VLDB Workshops, ODBIS 2005/2006 Trondheim, Norway, September 2-3, 2005, Seoul, Korea, September 11, 2006, Revised Papers; 01/2006
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ABSTRACT: The underlying assumptions for interpreting the meaning of data often change over time, which further complicates the problem
of semantic heterogeneities among autonomous data sources. As an extension to the Context Interchange (COIN) framework, this
paper introduces the notion of temporal context as a formalization of the problem. We represent temporal context as a multi-valued
method in F-Logic; however, only one value is valid at any point in time, the determination of which is constrained by temporal
relations. This representation is then mapped to an abductive constraint logic programming framework with temporal relations
being treated as constraints. A mediation engine that implements the framework automatically detects and reconciles se-mantic
differences at different times. We articulate that this extended COIN framework is suitable for reasoning on the Semantic
Web.
09/2004: pages 90-101;
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ABSTRACT: In this paper, we first identify semantic heterogeneities that, when not resolved, often cause serious data quality problems. We discuss the especially challenging problems of temporal and aggregational ontological heterogeneity, which concerns how complex entities and their relationships are aggregated and reinterpreted over time. Then we illustrate how the COntext INterchange (COIN) technology can be used to capture data semantics and reconcile semantic heterogeneities in a scalable manner, thereby improving data quality. Singapore-MIT Alliance (SMA)
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ABSTRACT: Web aggregation has been available regionally for several years, but this service has not been offered globally. As an example, using multiple regional comparison aggregators, we analyze the global prices for a Sony camcorder, which differ by more than three times. We further explain that lack of global comparison aggregation services partially contribute to such huge price dispersion. We also discuss difficulties encountered in the manual integration of global web sources. Motivated by this example, we propose a context mediation architecture for global aggregation to address semantic disparities of global information sources. Global aggregation services can bring efficiency to the global market and can be useful for market research and other business uses. Singapore-MIT Alliance (SMA)
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ABSTRACT: The underlying assumptions for interpreting the meaning of data often change over time, which further complicates the problem of semantic heterogeneities among autonomous data sources. As an extension to the COntext INterchange (COIN) framework, this paper introduces the notion of temporal context as a formalization of the problem. We represent temporal context as a multi-valued method in F-Logic; however, only one value is valid at any point in time, the determination of which is constrained by temporal relations. This representation is then mapped to an abductive constraint logic programming framework with temporal relations being treated as constraints. A mediation engine that implements the framework automatically detects and reconciles semantic differences at different times. We articulate that this extended COIN framework is suitable for reasoning on the Semantic Web. Singapore-MIT Alliance (SMA)
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ABSTRACT: Many online services access a large number of autonomous data sources and at the same time need to meet different user requirements. It is essential for these services to achieve semantic interoperability among these information exchange entities. In the presence of an increasing number of proprietary business processes, heterogeneous data standards, and diverse user requirements, it is critical that the services are implemented using adaptable, extensible, and scalable technology. The COntext INterchange (COIN) approach, inspired by similar goals of the Semantic Web, provides a robust solution. In this paper, we describe how COIN can be used to implement dynamic online services where semantic differences are reconciled on the fly. We show that COIN is flexible and scalable by comparing it with several conventional approaches. With a given ontology, the number of conversions in COIN is quadratic to the semantic aspect that has the largest number of distinctions. These semantic aspects are modeled as modifiers in a conceptual ontology; in most cases the number of conversions is linear with the number of modifiers, which is significantly smaller than traditional hard-wiring middleware approach where the number of conversion programs is quadratic to the number of sources and data receivers. In the example scenario in the paper, the COIN approach needs only 5 conversions to be defined while traditional approaches require 20,000 to 100 million. COIN achieves this scalability by automatically composing all the comprehensive conversions from a small number of declaratively defined sub-conversions. Singapore-MIT Alliance (SMA)
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ABSTRACT: The development of web technology has led to the emergence of web aggregation, a service that collects existing web data and turns them into more useful information. We review the development of both comparison and relationship aggregation and discuss their impacts on various stakeholders. The aggregator’s capability of transparently extracting web data has raised challenging issues in database and privacy protection. Consequently, new regulations are introduced or being proposed. We analyze the interactions between aggregation and related policies and provide our insights about the implications of new policies on the development of web aggregation. Singapore-MIT Alliance (SMA)
