... Unlike GML, the primary stated purpose of SOTF is to support archiving and transfer of object... more ... Unlike GML, the primary stated purpose of SOTF is to support archiving and transfer of object-oriented ... of G-XML is to develop a standard XML-based protocol for spatial data exchange ... large extent with GML); the Point and Direction Based G-XML (to support mobile and wireless ...
... Student and CBEO Test-Bed Team Member, Dept. of Geography and Envir. Engrg., Johns Hopkins Un... more ... Student and CBEO Test-Bed Team Member, Dept. of Geography and Envir. Engrg., Johns Hopkins Univ., 3400 North Charles At., Baltimore, MD 21218. E-mail: rebecca.murphy@jhu.edu) , Eric Perlman , (Grad. Student and CBEO Test-Bed Team Member, Dept. ...
Abstract: The goal of the INCF Digital Atlasing Program is to provide the vision and direction ne... more Abstract: The goal of the INCF Digital Atlasing Program is to provide the vision and direction necessary to make the rapidly growing collection of multidimensional data of the rodent brain (images, gene expression, etc.) widely accessible and usable to the international ...
In this paper, we investigate a mediation-based approach to integrating information from geospati... more In this paper, we investigate a mediation-based approach to integrating information from geospatial information sources such as GIS’s and databases of geo-referenced imagery. This approach is based on the use of XML to represent the information at the sources, by exporting XML Document Type Definitions (DTD’s) associated with each source, and employing XMLbased query languages to query integrated views of information at the mediator. Our goal is to enable users to issue a single query to the mediator, and provide the capability to return a result that seamlessly combines information from multiple sources. This paper describes issues in designing such a mediated system for geospatial data. Our notion of mediation for geospatial data is the “logical integration” of data achieved by creating correspondences between related spatial information, similar to the way mediation is done in “standard” databases. Thus, this notion of mediation does not depend on the development of spatial algorithms that operate on images or vector data and achieve “physical integration” through techniques such as image conflation. However, the mediator architecture does allow for the integration of physical integration techniques. The paper discusses issues related to wrapping of GIS and other geospatial sources and issues in querying such sources using an XML-based query language.
Abstract This paper reviews challenges and accomplishments of spatial information mediation exten... more Abstract This paper reviews challenges and accomplishments of spatial information mediation extending the SDSC MIX (mediation of information using XML) framework. enhancements to MIX necessitated by the spatio-temporal nature of queries and ...
Web-based federated spatial databases usually do not support accuracy-aware query processing desp... more Web-based federated spatial databases usually do not support accuracy-aware query processing despite growing availability of individual data quality descriptions. This paper introduces a mechanism for making data quality information operational through the process of accuracy-based query rewriting. A number of keywords are added to SQL to express accuracy constraints in a spatial query. Depending on the specification of error in underlying data sets, a query containing accuracy constraints is rewritten as a single or a set of crisp spatial queries, i.e. those that do not require further accuracy-based disambiguation. The rewriting uses binding of GIS spatial operations to error models via a collection of error propagation templates. This mechanism is implemented as a Web service that works in conjunction with a spatial mediator to aid in rewriting spatial queries in the presence of accuracy metadata.
This paper addresses the issue of long-term preservation of and access to digital government info... more This paper addresses the issue of long-term preservation of and access to digital government information. We show how the preservation process is enhanced by storing an infrastructure-independent representation of the raw data, together with a model dependency graph (an executable graph of database view mappings). This allows for the design of decision-support tools and services for improving government transparency and promoting citizen access to eGOV data. A case-study, the Florida Ballots Project, is used to illustrate the approach.
... collections, data types and formats (most recently datasets with different semantics), as w... more ... collections, data types and formats (most recently datasets with different semantics), as well as computational services; Persistent archiving: ability to ... Working in unison with a Metadata Catalog (MCAT) [14], it provides a scalable facility for publishing and sharing scientific ...
... Unlike GML, the primary stated purpose of SOTF is to support archiving and transfer of object... more ... Unlike GML, the primary stated purpose of SOTF is to support archiving and transfer of object-oriented ... of G-XML is to develop a standard XML-based protocol for spatial data exchange ... large extent with GML); the Point and Direction Based G-XML (to support mobile and wireless ...
... Student and CBEO Test-Bed Team Member, Dept. of Geography and Envir. Engrg., Johns Hopkins Un... more ... Student and CBEO Test-Bed Team Member, Dept. of Geography and Envir. Engrg., Johns Hopkins Univ., 3400 North Charles At., Baltimore, MD 21218. E-mail: rebecca.murphy@jhu.edu) , Eric Perlman , (Grad. Student and CBEO Test-Bed Team Member, Dept. ...
Abstract: The goal of the INCF Digital Atlasing Program is to provide the vision and direction ne... more Abstract: The goal of the INCF Digital Atlasing Program is to provide the vision and direction necessary to make the rapidly growing collection of multidimensional data of the rodent brain (images, gene expression, etc.) widely accessible and usable to the international ...
In this paper, we investigate a mediation-based approach to integrating information from geospati... more In this paper, we investigate a mediation-based approach to integrating information from geospatial information sources such as GIS’s and databases of geo-referenced imagery. This approach is based on the use of XML to represent the information at the sources, by exporting XML Document Type Definitions (DTD’s) associated with each source, and employing XMLbased query languages to query integrated views of information at the mediator. Our goal is to enable users to issue a single query to the mediator, and provide the capability to return a result that seamlessly combines information from multiple sources. This paper describes issues in designing such a mediated system for geospatial data. Our notion of mediation for geospatial data is the “logical integration” of data achieved by creating correspondences between related spatial information, similar to the way mediation is done in “standard” databases. Thus, this notion of mediation does not depend on the development of spatial algorithms that operate on images or vector data and achieve “physical integration” through techniques such as image conflation. However, the mediator architecture does allow for the integration of physical integration techniques. The paper discusses issues related to wrapping of GIS and other geospatial sources and issues in querying such sources using an XML-based query language.
Abstract This paper reviews challenges and accomplishments of spatial information mediation exten... more Abstract This paper reviews challenges and accomplishments of spatial information mediation extending the SDSC MIX (mediation of information using XML) framework. enhancements to MIX necessitated by the spatio-temporal nature of queries and ...
Web-based federated spatial databases usually do not support accuracy-aware query processing desp... more Web-based federated spatial databases usually do not support accuracy-aware query processing despite growing availability of individual data quality descriptions. This paper introduces a mechanism for making data quality information operational through the process of accuracy-based query rewriting. A number of keywords are added to SQL to express accuracy constraints in a spatial query. Depending on the specification of error in underlying data sets, a query containing accuracy constraints is rewritten as a single or a set of crisp spatial queries, i.e. those that do not require further accuracy-based disambiguation. The rewriting uses binding of GIS spatial operations to error models via a collection of error propagation templates. This mechanism is implemented as a Web service that works in conjunction with a spatial mediator to aid in rewriting spatial queries in the presence of accuracy metadata.
This paper addresses the issue of long-term preservation of and access to digital government info... more This paper addresses the issue of long-term preservation of and access to digital government information. We show how the preservation process is enhanced by storing an infrastructure-independent representation of the raw data, together with a model dependency graph (an executable graph of database view mappings). This allows for the design of decision-support tools and services for improving government transparency and promoting citizen access to eGOV data. A case-study, the Florida Ballots Project, is used to illustrate the approach.
... collections, data types and formats (most recently datasets with different semantics), as w... more ... collections, data types and formats (most recently datasets with different semantics), as well as computational services; Persistent archiving: ability to ... Working in unison with a Metadata Catalog (MCAT) [14], it provides a scalable facility for publishing and sharing scientific ...
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Papers by Ilya Zaslavsky