BSML: A Binding Schema Markup Language for Data Interchange in Problem Solving Environments (PSEs)

We describe a binding schema markup language (BSML) for describing data interchange between scientific codes. Such a facility is an important constituent of scientific problem solving environments (PSEs). BSML is designed to integrate with a PSE or application composition system that views model specification and execution as a problem of managing semistructured data. The data interchange problem is addressed by three techniques for processing semistructured data: validation, binding, and conversion. We present BSML and describe its application to a PSE for wireless communications system design

An introduction to Graph Data Management

A graph database is a database where the data structures for the schema and/or instances are modeled as a (labeled)(directed) graph or generalizations of it, and where querying is expressed by graph-oriented operations and type constructors. In this article we present the basic notions of graph databases, give an historical overview of its main development, and study the main current systems that implement them

XGI: A Graphical Interface for XQuery Creation and XML Schema Visualization

XML (Extensible Markup Language) is used in many contexts of modern information technology to facilitate sharing of information between heterogeneous data sources and inter-platform applications. The prevalence of XML implementation in data storage and exchange necessitates a method to adequately query XML data. The World Wide Web Consortium (W3C) is proposing XQuery as the standard querying language for semistructured XML data. XQuery is designed for experienced database programmers, since its syntax and capabilities are analogous to the SQL relational query language. Therefore, the inherent complexity of formulating XQuery statements makes it an intimidating task for anyone, except an expert in the XQuery language, to construct queries. The development of XQuery Graphical Interface (XGI), a visual interface for creating XQuery in a graphical format, is motivated by the need to simplify the query formation for unskilled users and speed up the query construction for expert users. The implementation of XGI is mainly inspired by three existing systems: Query and Reporting Semistructured Data (QURSED), XQuery By Example (XQBE), and XBrain. A review of these systems and many other systems has helped us understand the benefits and drawbacks of various system design approaches, and has assisted us in identifying a set of features for XGI that will successfully reduce the complexity of creating queries in the XQuery language. XGI provides a web interface for users to explore their own XML source data schema, search for specific schema elements, and visually create queries in the XQuery language for the targeted XML data source. A validation of the XGI system has verified its ability to efficiently and accurately create queries for various XML data sources. From the validation, we have recognized some strengths and weaknesses of the XGI system compared to other systems. We also recommend several areas in which XGI can be improved

Modeling ontology views: An abstract view model for semantic web

The emergence of Semantic Web (SW) and the related technologies promise to make the web a meaningful experience. However, high level modelling, design and querying techniques proves to be a challenging task for organizations that are hoping to utilize the SW paradigm for their industrial applications. To address one such issue, in this paper, we propose an abstract view model with conceptual extensions for the SW. First we outline the view model, its properties and some modelling issues with the help of an industrial case study example. Then, we provide some discussions on constructing such views (at the conceptual level) using a set of operators. Later we provide a brief discussion on how such this view model can utilized in the MOVE [1] system, to design and construct materialized Ontology views to support Ontology extraction

Mediated data integration and transformation for web service-based software architectures

Service-oriented architecture using XML-based web services has been widely accepted by many organisations as the standard infrastructure to integrate heterogeneous and autonomous data sources. As a result, many Web service providers are built up on top of the data sources to share the data by supporting provided and required interfaces and methods of data access in a unified manner. In the context of data integration, problems arise when Web services are assembled to deliver an integrated view of data, adaptable to the specific needs of individual clients and providers. Traditional approaches of data integration and transformation are not suitable to automate the construction of connectors dedicated to connect selected Web services to render integrated and tailored views of data. We propose a declarative approach that addresses the oftenneglected data integration and adaptivity aspects of serviceoriented architecture

Beyond XML Query Languages

A query language is essential, if XML is to serve effectively as an exchange medium for large data sets. The design of query languages for XML is in its infancy, and the choice of a standard may be governed more by user acceptance than by any understanding of underlying principles. One would hope that expressive power, performance, and compatibility with other languages will be considered in choosing among alternatives, but it is likely that several contenders will co-exist for some time. It is worth observing that, during the 20-year development of relational query languages, several competing languages were developed; and even today there are several relational query language standards. In spite of this, a great deal of technology was developed that was independent of the surface syntax of a query language. This included technology below the language such as efficient execution models and work above the level of language - such as techniques for view definition and maintenance, triggers, etc. At Penn we are working on some of these language-independent issues. We include a summary of them here. They include execution and data models to support XML and semistructured query languages; the use of schemas and constraints in optimizing XML query languages; and tools for extracting data form existing sources and presenting it as XML