Presenter/Author Information

R. M. Argent
C. Maul
T. Krämerkämper

Keywords

extensible markup language, xml, data framework, component-based modelling

Start Date

1-7-2002 12:00 AM

Description

Developers of environmental modelling software are adopting modern software engineering approaches that use a combination of model components to provide appropriate modelling services. One of the key issues in this development is easy and reliable storage, exchange and display of data, often using distributed sources and tools. This, in turn, requires standard methods for providing and describing data. Extensible Markup Language (XML) is a set of standards and protocols that has been adopted by commerce and industry for exchanging and displaying data, and it also provides a metadata standard that can be used to specify interfaces and data requirements for model components. Associated with the adoption of XML is the development of a broad range of open source software for XML parsing, processing, and search or query functions. Parsing involves analysing an input stream of XML data and determining structure and context of elements, tags and attributes, whereas processing is used to transform XML documents into something that can be displayed, such as HTML or XHTML. The paper describes a data framework for environmental modelling. The framework uses XML-based parsing and processing to form the input and output filters for data delivery to model components, or to on-screen display. In this system, data are stored in an SQLcompliant DBMS, an object-oriented database, or in a system that stores XML directly or possesses an interface to XML. Implementation of the data framework is made in a fashion similar to Java Enterprise Beans which use XML to connect a program (a Bean) and a container. The container provides services such as load distribution, transaction monitoring and connection to the remote interfaces. The additional services provided by the data framework include structure of records, comprehensiveness of data, origin and time. In conjunction with open source web servers, use of the XML standard and the open source software available provide an inexpensive, flexible, central data repository for component-based environmental modelling.

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Jul 1st, 12:00 AM

Data Frameworks for Environmental Modelling

Developers of environmental modelling software are adopting modern software engineering approaches that use a combination of model components to provide appropriate modelling services. One of the key issues in this development is easy and reliable storage, exchange and display of data, often using distributed sources and tools. This, in turn, requires standard methods for providing and describing data. Extensible Markup Language (XML) is a set of standards and protocols that has been adopted by commerce and industry for exchanging and displaying data, and it also provides a metadata standard that can be used to specify interfaces and data requirements for model components. Associated with the adoption of XML is the development of a broad range of open source software for XML parsing, processing, and search or query functions. Parsing involves analysing an input stream of XML data and determining structure and context of elements, tags and attributes, whereas processing is used to transform XML documents into something that can be displayed, such as HTML or XHTML. The paper describes a data framework for environmental modelling. The framework uses XML-based parsing and processing to form the input and output filters for data delivery to model components, or to on-screen display. In this system, data are stored in an SQLcompliant DBMS, an object-oriented database, or in a system that stores XML directly or possesses an interface to XML. Implementation of the data framework is made in a fashion similar to Java Enterprise Beans which use XML to connect a program (a Bean) and a container. The container provides services such as load distribution, transaction monitoring and connection to the remote interfaces. The additional services provided by the data framework include structure of records, comprehensiveness of data, origin and time. In conjunction with open source web servers, use of the XML standard and the open source software available provide an inexpensive, flexible, central data repository for component-based environmental modelling.