%0 Conference Paper %B Proceedings of the 2005 national conference on Digital government research %D 2005 %T An efficient nearest neighbor algorithm for P2P settings %A Tanin,Egemen %A Nayar,Deepa %A Samet, Hanan %K geographic information systems %K nearest neighbor query %K peer-to-peer networks %K quadtree %K spatial data %X New Peer-to-Peer (P2P) applications like P2P job-employee seeker networks and P2P virtual cities, for application domains such as collaborative urban planning and forming virtual communities, are about to emerge. An important component in these applications is spatial data, i.e., data with locational components. Many requests initiated on spatial data involve finding the spatial objects that are nearest to a query location. In this paper, we propose an efficient algorithm that finds the spatial objects that are nearest to a given query location on a P2P network in the order of their minimum distance to the query point. The proposed algorithm makes use of a distributed spatial index that does not rely on the use of a central server. The algorithm is designed to be more efficient by utilizing the parallel nature of the P2P network. A demonstration of the proposed algorithm was implemented as a prototype P2P application that finds events and places of interest in a city. %B Proceedings of the 2005 national conference on Digital government research %S dg.o '05 %I Digital Government Society of North America %P 21 - 28 %8 2005/// %G eng %U http://dl.acm.org/citation.cfm?id=1065226.1065237 %0 Conference Paper %B Fifth International Conference on Information Visualisation, 2001. Proceedings %D 2001 %T Dynamic queries and brushing on choropleth maps %A Dang,G. %A North,C. %A Shneiderman, Ben %K brushing %K business %K cartography %K choropleth maps %K color coding %K colour graphics %K complex data sets %K Computational Intelligence Society %K Computer science %K data visualisation %K Data visualization %K demographic data %K Demography %K Dynamaps %K dynamic queries %K economic data %K Educational institutions %K geographic information system %K geographic information systems %K Joining processes %K map representations %K map-based information visualization %K Query processing %K Scattering %K scatterplot view %K tabular representations %K user interface %K User interfaces %K World Wide Web %X Users who must combine demographic, economic or other data in a geographic context are often hampered by the integration of tabular and map representations. Static, paper-based solutions limit the amount of data that can be placed on a single map or table. By providing an effective user interface, we believe that researchers, journalists, teachers, and students can explore complex data sets more rapidly and effectively. This paper presents Dynamaps, a generalized map-based information visualization tool for dynamic queries and brushing on choropleth maps. Users can use color coding to show a variable on each geographic region, and then filter out areas that do not meet the desired criteria. In addition, a scatterplot view and a details-on-demand window support overviews and specific fact-finding %B Fifth International Conference on Information Visualisation, 2001. Proceedings %I IEEE %P 757 - 764 %8 2001/// %@ 0-7695-1195-3 %G eng %R 10.1109/IV.2001.942141 %0 Conference Paper %B Geoscience and Remote Sensing Symposium, 1999. IGARSS '99 Proceedings. IEEE 1999 International %D 1999 %T Developing the next generation of Earth science data systems: the Global Land Cover Facility %A Lindsay,F.E. %A Townshend,J.R.G. %A JaJa, Joseph F. %A Humphries,J. %A Plaisant, Catherine %A Shneiderman, Ben %K Computer architecture %K data archiving %K data distribution system %K Data systems %K Distributed computing %K Earth science data products %K Earth science data system %K ESIP %K geographic information system %K geographic information systems %K Geography %K geophysical measurement technique %K geophysical signal processing %K geophysical techniques %K Geoscience %K GIS %K GLCF %K Global Land Cover Facility %K High performance computing %K Indexing %K information service %K Information services %K Institute for Advanced Computer Studies %K land cover %K NASA %K next generation %K PACS %K Remote sensing %K terrain mapping %K UMIACS %K University of Maryland %K User interfaces %K web-based interface %X A recent initiative by NASA has resulted in the formation of a federation of Earth science data partners. These Earth Science Information Partners (ESIPs) have been tasked with creating novel Earth science data products and services as well as distributing new and existing data sets to the Earth science community and the general public. The University of Maryland established its ESIP activities with the creation of the Global Land Cover Facility (GLCF). This joint effort of the Institute for Advanced Computer Studies (UMIACS) and the Department of Geography has developed an operational data archiving and distribution system aimed at advancing current land cover research efforts. The success of the GLCF is tied closely to assessing user needs as well. As the timely delivery of data products to the research community. This paper discusses the development and implementation of a web-based interface that allows users to query the authors' data holdings and perform user requested processing tasks on demand. The GLCF takes advantage of a scaleable, high performance computing architecture for the manipulation of very large remote sensing data sets and the rapid spatial indexing of multiple format data types. The user interface has been developed with the cooperation of the Human-Computer Interaction Laboratory (HCIL) and demonstrates advances in spatial and temporal querying tools as well as the ability to overlay multiple raster and vector data sets. Their work provides one perspective concerning how critical earth science data may be handled in the near future by a coalition of distributed data centers %B Geoscience and Remote Sensing Symposium, 1999. IGARSS '99 Proceedings. IEEE 1999 International %I IEEE %V 1 %P 616-618 vol.1 - 616-618 vol.1 %8 1999/// %@ 0-7803-5207-6 %G eng %R 10.1109/IGARSS.1999.773583