Geospatial data infrastructure: The development of metadata for geo-information in China
Stores of geoscience records are in constant flux. These stores are continually added to by new information, ideas and data, which are frequently revised. The geoscience record is in restrained by human thought and technology for handling information. Conventional methods strive, with limited success, to maintain geoscience records which are readily susceptible and renewable. The information system must adapt to the diversity of ideas and data in geoscience and their changes through time. In China, more than 400,000 types of important geological data are collected and produced in geological work during the last two decades, including oil, natural gas and marine data, mine exploration, geophysical, geochemical, remote sensing and important local geological survey and research reports. Numerous geospatial databases are formed and stored in National Geological Archives (NGA) with available formats of MapGIS, ArcGIS, ArcINFO, Metalfile, Raster, SQL Server, Access and JPEG. But there is no effective way to warrant that the quality of information is adequate in theory and practice for decision making. The need for fast, reliable, accurate and up-to-date information by providing the Geographic Information System (GIS) communities are becoming insistent for all geoinformation producers and users in China. Since 2010, a series of geoinformation projects have been carried out under the leadership of the Ministry of Land and Resources (MLR), including (1) Integration, update and maintenance of geoinformation databases; (2) Standards research on clusterization and industrialization of information services; (3) Platform construction of geological data sharing; (4) Construction of key borehole databases; (5) Product development of information services. "Nine-System" of the basic framework has been proposed for the development and improvement of the geospatial data infrastructure, which are focused on the construction of the cluster organization, cluster service, convergence, database, product, policy, technology, standard and infrastructure systems. The development of geoinformation stores and services put forward a need for Geospatial Data Infrastructure (GDI) in China. In this paper, some of the ideas envisaged into the development of metadata in China are discussed.
A novel computational knowledge-base framework for visualization and quantification of geospatial metadata in spatial data infrastructures
Advances in Metadata research have been instrumental in predictions and ‘fitness-of-use evaluation’ for the effective Decision-making process. For the past two decades, the model has been developed to provide visual assistance for assessing the quality information in metadata and quantifying the degree of metadata population. Still, there is a need to develop a framework that can be generic to adopt all the standards available for Geospatial Metadata. The computational analysis of metadata for specific applications remains uncharted for investigations and studies. This work proposes a computational framework for Geospatial Metadata by integrating TopicMaps and Hypergraphs (HXTM) based on the elements and their dependency relationships. A purpose-built dataset extracted from schemas of various standardisation organisations and existing knowledge in the discipline is utilised to model the framework and thereby evaluate ranking strategies. Hypergraph-Helly Property based Weight-Assignment Algorithm (HHWA) have been proposed for HXTM framework to calculate Stable weights for Metadata Elements. Recursive use of Helly-property ensures predominant elements, while Rank Order Centroid (ROC) method is used to compute standard weights. A real corpus using case studies from FGDC’s Standard for Geospatial Metadata, INSPIRE Metadata Standards, and ISRO Metadata Content Standard (NSDI 2.0) is used to validate the proposed framework. The observations show that the Information Gain (Entropy) of the proposed model along with the algorithm proves to be computationally smart for quantification purposes and visualises the strength of Metadata Elements for all applications. A prototype tool, ‘MetDEVViz- MetaData Editor, Validator & Visualization’ is designed to exploit the benefits of the proposed algorithm for the case studies that acts as a web service to provide a user interface for editing, validating and visualizing metadata elements.
Garnitures mécaniques d'étanchéité
Keywords: etancheite ; mecanique Reference Record created on 2005-11-18, modified on 2016-08-08