Metadata Catalog Research Articles

Availability and coverage of hydrologic data in the US geological survey National Water Information System (NWIS) and US Environmental Protection Agency Storage and Retrieval System (STORET)

The need for a unified and improved data access system for the nation’s vast hydrologic data holdings has increased over the past few years as researchers strive for better understanding the human impact on the nation’s water cycle. Large mission oriented data repositories such as the USGS’ National Water Information System (NWIS) and EPA’s Storage and Retrieval System (EPA STORET) play a crucial role in providing a substantial amount of the nationwide coverage, however they do differ regionally in terms of coverage (parameters) and geospatial data density. Besides the differences in geographic distribution, repositories tend to undergo changes in mission statements and as such have different foci in their data collection activities that change as time progresses. This paper places the two water information systems next to each in an attempt to work out the differences in terms of coverage and content and how they complement each other when overlaid. This is done through the use of a number the CUAHSI Hydrologic Information Systems components, namely a web-service suite called WaterOneFlow that permits interrogation of the available data content of a national water metadata catalogue into which these two information systems have been integrated.

Defining Linkages between the GSC and NSF's LTER Program: How the Ecological Metadata Language (EML) Relates to GCDML and Other Outcomes

The Genomic Standards Consortium (GSC) invited a representative of the Long-Term Ecological Research (LTER) to its fifth workshop to present the Ecological Metadata Language (EML) metadata standard and its relationship to the Minimum Information about a Genome/Metagenome Sequence (MIGS/MIMS) and its implementation, the Genomic Contextual Data Markup Language (GCDML). The LTER is one of the top National Science Foundation (NSF) programs in biology since 1980, representing diverse ecosystems and creating long-term, interdisciplinary research, synthesis of information, and theory. The adoption of EML as the LTER network standard has been key to build network synthesis architectures based on high-quality standardized metadata. EML is the NSF-recognized metadata standard for LTER, and EML is a criteria used to review the LTER program progress. At the workshop, a potential crosswalk between the GCDML and EML was explored. Also, collaboration between the LTER and GSC developers was proposed to join efforts toward a common metadata cataloging designer's tool. The community adoption success of a metadata standard depends, among other factors, on the tools and trainings developed to use the standard. LTER's experience in embracing EML may help GSC to achieve similar success. A possible collaboration between LTER and GSC to provide training opportunities for GCDML and the associated tools is being explored. Finally, LTER is investigating EML enhancements to better accommodate genomics data, possibly integrating the GCDML schema into EML. All these action items have been accepted by the LTER contingent, and further collaboration between the GSC and LTER is expected.

Security in distributed metadata catalogues

AbstractCatalogue services provide the discovery and location mechanisms that allow users and applications to locate data on Grids. Replication is a highly desirable feature in these services, since it provides the scalability and reliability required on large data Grids and is the basis for federating catalogues from different organizations. Grid catalogues are often used to store sensitive data and must have access control mechanisms to protect their data. Replication has to take this security policy into account, making sure that replicated information cannot be abused but allowing some flexibility such as selective replication for the sites depending on the level of trust in them. In this paper we discuss the security requirements and implications of several replication scenarios for Grid catalogues based on experiences gained within the EGEE project. Using the security infrastructure of the EGEE Grid as a basis, we then propose a security architecture for replicated Grid catalogues, which, among other features, supports partial and total replication of the security mechanisms on the master. The implementation of this architecture in the AMGA metadata catalogue of the EGEE project is then described including the application to a complex scenario in a biomedical application. Copyright © 2008 John Wiley & Sons, Ltd.

Two graphical browsers for the AMGA metadata catalogues

Two different browser applications for the AMGA (ARDA Metadata Grid Application) metadata catalogues are presented. The first one is a generic AMGA GUI (Graphical User Interface) which allows an interactive exploration of the metadata schema and entries plus the possibility to issue SQL queries on the catalogue itself. The second browser is a specialised version of the former particularly developed for the LHCb experiment.

WATeRS: an open Web Map Service with near‐real time MODIS Level‐2 standard chlorophyll products of the North Sea

WATeRS (http://ivm10.ivm.vu.nl/mapserver/WATeRS) is a portal for near‐real time (NRT) satellite‐derived water quality (chlorophyll) information products that is openly and interactively available for all on the Internet. It is based on automated conversion of remotely sensed data (in scientific formats) to geographic information system (GIS) formats, and comprises a customized Arc Internet Map Server (ArcIMS) application with an OpenGIS compliant Web Map Server connector. The resulting GIS‐based open map service comprises a simple, clear and intuitive user interface, grid‐cell query functionality, and is complemented by a metadata catalogue that provides full lineage of the chlorophyll maps, and automated archiving. WATeRS enables users to interactively explore remote sensing products, and to seamlessly combine this with other geographical data.

The AMGA Metadata Service

We present the AMGA metadata catalogue, which was developed as part of the EGEE (enabling Grids for EsciencE) project’s gLite Grid middleware. AMGA provides access to meta data for files stored on the Grid, as well as a simplified general access to relational data stored in database systems. Design and implementation of AMGA was done in close collaboration with the very diverse EGEE user community to make sure all functionality, performance and security requirements were met. In particular, AMGA targets the needs of the high energy physics community to rapidly access very large amounts of metadata, as well as the needs for security of the biomedical community. AMGA therefore tightly integrates fine grained access control making use of a virtual organisation management system. In addition, it offers advanced federation and features to increase dependability, performance and data security.

The QuarkNet/Grid Collaborative Learning e-Lab

This paper describes a case study that uses grid computing techniques to support the collaborative learning of high school students investigating cosmic rays. Students gather and upload science data to an e-Lab website. They explore those data using techniques from the GriPhyN collaboration. These techniques include virtual data transformations, workflows, metadata cataloging and indexing, data product provenance and persistence, as well as job planners for execution locally and on the grid. Students use web browsers and a custom interface that extends the GriPhyN Chiron portal to perform all of these tasks. They share results in the form of online posters and ask each other questions in this asynchronous environment. Students can discover and extend the research of other students, modeling the processes of modern large-scale scientific collaborations. Also, the e-Lab provides tools for teachers to guide student work throughout an investigation. http://quarknet.uchicago.edu/elab/cosmic

Federated Database Services for Wind Tunnel Experiment Workflows

Enabling the full life cycle of scientific and engineering workflows requires robust middleware and services that support effective data management, near-realtime data movement and custom data processing. Many existing solutions exploit the database as a passive metadata catalog. In this paper, we present an approach that makes use of federation of databases to host data-centric wind tunnel application workflows. The user is able to compose customized application workflows based on database services. We provide a reference implementation that leverages typical business tools and technologies: Microsoft SQL Server for database services and Windows Workflow Foundation for workflow services. The application data and user's code are both hosted in federated databases. With the growing interest in XML Web Services in scientific Grids, and with databases beginning to support native XML types and XML Web services, we can expect the role of databases in scientific computation to grow in importance.

Creating and using the urgent metadata catalogue and thesaurus

The Urban Regeneration and the Environment Research Programme (URGENT) required a system for cataloguing its datasets and enabling its scientific community to discover what data were available to it. This community was multidisciplinary in nature and therefore needed a range of facilities for searching. Of particular importance were facilities to help those unfamiliar with specialist terminology. To meet these needs, four applications were designed and developed: a Metadata Capture Tool for describing datasets in compliance with the National Geospatial Data Framework (NGDF) standard, a Term Entry Tool for creating an ISO compliant thesaurus, a Thesaurus Builder for merging thesauri and a Search Tool. To encourage users to help in cataloguing data, the capture tools were written as stand alone applications, which users could keep and use to build their own metadatabases. The tools contained export and import facilities that allowed the URGENT Data Centre to build a central database and publish it upon the web. During the development work, it was found necessary to extend the NGDF standard as it could not adequately describe time variant or 3-D atmospheric datasets. The four applications met their design objectives. However, a number of ergonomic issues will need to be addressed if the system is to meet the needs of the much larger up coming programmes. The main challenges will be moving from the NGDF standard to the ISO standard, hence bringing the work into line with the recommendations of the INSPIRE Project, and merging the metadatabase with the scientific database, which enable metadata maintenance to be semi-automated.

Supply and Demand for Catalogers

This paper presents results from a fall 2003 survey of heads of cataloging at Association of Research Libraries United States academic libraries. The survey focused on the current number of professional catalogers and their responsibilities as well as future projections for demand for catalogers and thoughts about their roles. The study found that the numbers of professional catalogers are remaining constant or decreasing, and approximately one-third are projected to retire in the next decade. In addition, the role of the professional cataloger is perceived as continuing to evolve toward more cataloging-related activities and management and less direct cataloging. Most respondents predicted the professional cataloger has a role in the future and felt prepared for that future. Some respondents suggested that metadata cataloging would be a growing role in that future. This paper concludes with additional questions about the future of professional catalogers and cataloging.

Cooperating Services for Data-Driven Computational Experimentation

The Linked Environments for Atmospheric Discovery (LEAD) project seeks to provide on-demand weather forecasting. A triad of cooperating services provides the core functionality needed to execute experiments and manage the data. In this article, we focus on three MyLEAD services - the metadata catalog service, notification service, and workflow service - that together form the core services for managing complex experimental meteorological investigations and managing the data products used in and generated during the computational experimentation. We show how the services work together on the user's behalf, easing the technological burden on the scientists and freeing them to focus on more of the science that compels them.

The European Forest Information System—an Internet based interface between information providers and the user community

Improving access to forestry information is an important component in addressing the implementation of national and international commitments towards sustainable forest management, climate change and biological diversity. A demonstrator of a European Forest Information System (EFIS) has been developed within the framework of the EU regulation (EEC) No. 1615/89 on establishing a European Forest Information and Communication System (EFICS). EFIS includes elements that allow: (a) searching of metadata catalogues (Resource Discovery), and (b) importing of identified data for exploratory data analysis (Visualisation Toolkit). The authors describe the set-up of EFIS and its functionality by presenting two examples of possible uses of the system. They also discuss the steps necessary for the development of the demonstrator into an operational component within an EFICS.

Active Management of Scientific Data

Sophisticated data-distribution schemes and recent developments in sensors and instruments that can monitor the lower kilometers of the atmosphere at high levels of resolution have rapidly expanded the quantity of information available to mesoscale meteorology. The myLEAD personalized information-management tool helps geoscience users make sense of this vastly expanded information space. MyLEAD extends the general globus metadata catalog service and leverages a well-known general and extensible schema. Its orientation makes it an active player in large-scale distributed computation environments characterized by interacting grid and Web services.

The Design of Metadata Interchange for Chinese Information and Implementation of Metadata Management System

With the development of Internet, digital libraries/museums have received worldwide attention and many developed countries are doing extensive researches on digital libraries/museums. In Taiwan, many institutions have digitized their collections. In addition, major research projects such as Digital Museum Project, Digital Archive Program, Digital Local Document Program, and CMNet are either in progress or about to begin. To digitize resources and present them on the WWW is the first priority; nevertheless, it is more important to organize these resources based on their characteristics, so users may retrieve and use them effectively. In digital library/museum systems, metadata plays a crucial role: its formulation has to begin with understanding the user demands and object characteristics, and standardization is essential for * The work is partially supported by National Science Council under grant NSC 89-2750-P-002-012.

An Adaptive Object-Oriented Approach to Integration and Access ofHeterogeneous Information Sources

A large-scale interoperable database system operating in a dynamic environment should provide Uniform access to heterogeneous information sources, Scalability to the growing number of information sources, Evolution and Composability of software and information sources, and Autonomy of participants, both information consumers and information producers. We refer to these set of properties as the USECA properties [29]. To address the research issues presented by such systems in a systematic manner, we introduce the Distributed Interoperable Object Model (DIOM). DIOM promotes an adaptive approach to interoperation via intelligent mediation [46, 47], aimed at enhancing the robustness and scalability of the services provided for integrating and accessing heterogeneous information sources. DIOM‘s main features include (1) the recursive construction and organization of information access through a network of application-specific mediators, (2) the explicit use of interface composition meta operations (such as specialization, generalization, aggregation, import and hide) to support the incremental design and construction of consumer‘s domain query model, (3) the deferment of semantic heterogeneity resolution to the query result assembly time instead of before or at the time of query formulation, and (4) the systematic development of the query mediation framework and the procedure of each query processing step from query routing, query decomposition, parallel access planning, query translation to query result assembly. To make DIOM concrete, we outline the DIOM-based information mediation architecture, which includes important auxiliary services such as domain-specific metadata library and catalog functions, object linking databases, and associated query services. Several practical examples and application scenarios illustrate the flavor of DIOM query mediation framework and the usefulness of DIOM in multi-database query processing.