16796441
Information integration with attribution support for corporate profiles
The proliferation of electronically available data within large organizations as well as publicly available data (e.g. over the World Wide Web) poses challenges for users who wish to efficiently interact with and integrate multiple heterogeneous sources. This paper presents CI3, a corporate information integrator, which applies XML as a tool to facilitate data mediation and integration amongst heterogeneous sources in the context of financial analysts creating corporate profiles. Sources include Lotus Notes, relational databases, and the World Wide Web. CI3 applies a unified XML data model to automate integration. By preserving metadata about the source of each datum in the integrated result set, CI3 supports source attribution. Users may trace the attribution metadata from the result back to the underlying sources and leverage their expertise in interpreting the data and, if necessary, use their judgment in assessing the authenticity and veracity of results. We present a functional overview of CI3, its system architecture including the XML data model, and the integration procedures. We conclude by reflecting on lessons learned.
9033123
Process Aggregation Using Web Services
This paper examines the opportunities and challenges related to data and process integration architectures in the context of Web Services. A primary goal of most enterprises in today's economic environment is to improve productivity by streamlining and aggregating business processes. This paper illustrates how integration architectures based on Web Services offer new opportunities to improve productivity that are expedient and economical. First, the paper introduces the technical standards associated with Web Services and provides business example for illustration. Abstracting from this example, we introduce a concept we call Process Aggregation that incorporates data aggregation and workflow to improve productivity. We show that Web Services will have a major impact on Process Aggregation, making it both faster and less expensive to implement. Finally, we suggest some research directions relating to the Process Aggregation challenges facing Web Services that are not currently being addressed by standards bodies or software vendors. These include context mediation, trusted intermediaries, quality and source selection, licensing and payment mechanisms, and systems development tools.
5563723
Data Integration Using Web Services
In this paper we examine the opportunities for data integration in the context of the emerging Web Services systems development paradigm. The paper introduces the programming standards associated with Web Services and provides an example of how Web Services can be used to unlock heterogeneous business systems to extract and integrate business data. We provide an introduction to the problems and research issues encountered when applying Web Services to data integration. We provide a formal definition of aggregation (as a type of data integration) and discuss the impact of Web Services on aggregation. We show that Web Services will make the development of systems for aggregation both faster and less expensive to develop. A system architecture for Web Services based aggregation is presented that is representative of products available from software vendors today. Finally, we highlight some of the challenges facing Web Services that are not currently being addressed by standards bodies or software vendors. These include context mediation, trusted intermediaries, quality and source selection, licensing and payment mechanisms, and systems development tools. We suggest some research directions for each of these challenges.
2677077
Context interchange: new features and formalisms for the intelligent integration of information
The Context Interchange strategy presents a novel perspective for mediated data access in which semantic conflicts among heterogeneous systems are not identified a priori, but are detected and reconciled by a context mediator through comparison of contexts axioms corresponding to the systems engaged in data exchange. In this article, we show that queries formulated on shared views, export schema, and shared “ontologies” can be mediated in the same way using the Context Interchange framework. The proposed framework provides a logic-based object-oriented formalsim for representing and reasoning about data semantics in disparate systems, and has been validated in a prototype implementation providing mediated data access to both traditional and web-based information sources.
3110757
Context Knowledge Representation and Reasoning in the Context Interchange System
The Context Interchange Project presents a unique approach to the problem of semantic conflict resolution among multiple heterogeneous data sources. The system presents a semantically meaningful view of the data to the receivers (e.g. user applications) for all the available data sources. The semantic conflicts are automatically detected and reconciled by a Context Mediator using the context knowledge associated with both the data sources and the data receivers. The results are collated and presented in the receiver context. The current implementation of the system provides access to flat files, classical relational databases, on-line databases, and web services. An example application, using actual financial information sources, is described along with a detailed description of the operation of the system for an example query.
17041428
Context interchange in a client-server architecture
Abstract Many organizations today require information from diverse information systems, and government efforts are moving toward a national information infrastructure for sharing information. However, the systems used by these organizations lack the capabilities to meaningfully translate information among semantically heterogeneous environments. Because the meaning of data acquired from a source environment is usually different from that needed or expected in the receiver's environment, the effectiveness of information exchange is dependent on the system's capability for context interchange, i.e., the representation, exchange, comparison, and transformation of context knowledge. We show here a practical means for developing context interchange capabilities in a client-server architecture by use of semantic values (i.e., data and their context(as the unit of data exchange. The key components in this architecture are the context mediator server, whose job is to identify and construct the semantic values being sent, determine when the exchange is meaningful, and convert the semantic values to the form required by the client (i.e., receiver), and the data environment server, whose job is to assist in the location, access, development, and maintenance of the context knowledge for all clients and servers.
9192328
Translation Validation for Synchronous Languages
Translation validations an alternative to the verification of translators (compilers, code generators). Rather than proving in advance that, the compiler always produces a target code which correctly implements the source code (compiler verification), each individual translation (i.e. a run of the compiler) is followed by a validation phase which verifies that the target code producted on this run correctly implements the submitted source program. In order to be a practical alternative to compiler verification, a key feature of this validation is its full automation.
1155385
Implementing statecharts in PROMELA/SPIN
We translate statecharts into PROMELA, the input language of the SPIN verification system, using extended hierarchical automata as an intermediate format. We discuss two possible frameworks for this translation, leading to either sequential or parallel code. We show that in this context the sequential code can be verified more efficiently than the parallel code. We conclude with a discussion of an application of the resulting translator to a well-known case study, which demonstrates the feasibility of linear temporal logic model checking of statecharts.
6090717
From Testing Theory to Test Driver Implementation
In this article we describe the theoretical foundations for the VVT-RT test system (Verification, Validation and Test for Reactive Real-Time Systems) which supports automated test generation, test execution and test evaluation for reactive systems. VVT-RT constructs and evaluates tests based on formal CSP specifications [6], making use of their representation as labelled transition systems generated by the CSP model checker FDR [3]. The present article provides a sound formal basis for the development and verification of high-quality test tools: Since, due to the high degree of automation offered by VVT-RT, human interaction becomes superfluous during critical phases of the test process, the trustworthiness of the test tool is an issue of great importance. The VVT-RT system will therefore be formally verified so that it can be certified for testing safety-critical systems. The present article represents the starting point of this verification suite, where the basic strategies for test generation and test evaluation used by the system are formally described and verified. VVT-RT has been designed to support automation of both untimed and real-time tests. The present article describes the underlying theory for the untimed case. Exploiting these results, the concepts and high-level algorithms used for the automation of real-time tests are described in a second report which is currently prepared [14]. At present, VVT-RT is applied for hardware-in-the-loop tests of railway and tramway control computers.
43742881
Erratum ("The small model property: how small can it be?" Volume 178, Number 1 [2002], pages 279-293)
15409109
Untwist your brain - Efficient debugging and diagnosis of complex assertions
Assertions are recognized in the industry to be a major improvement in functional RTL verification flows. Today's standard assertion languages, such as SVA [1] and PSL [2], are very expressive, capable of describing sophisticated temporal design behavior at different abstraction levels. Nevertheless, most assertion users stick to writing simple assertions because of the intricacy and effort required to debug complex assertions - one of the major bottlenecks in assertion based verification. We present debugging and diagnosis techniques that automatically identify those parts of an assertion that cause the assertion to fail for a given design and that provide additional automation to efficiently identify the root cause of the failure. These techniques enable major effort savings when working with complex assertions, allowing engineers to use the full capabilities of assertion languages. This enables further productivity and quality improvements in functional verification by lifting mainstream assertion usage to higher abstraction levels such as efficient capture and verification of high-level design features, operations, and transactions. Advanced debugging automation is key for this progress - solving a problem that many designers and verification engineers face in their daily work.