16,343 research outputs found
Management of Multiply Represented Geographic Entities
Multiple representation of geographic information occurs when a real-world entity is represented more than once in the same or different databases. In this paper, we propose a new approach to the modeling of multiply represented entities and the relationships among the entities and their representations. A Multiple Representation Management System is outlined that can manage multiple representations consistently over a number of autonomous databases. Central to our approach is the Multiple Representation Schema Language that is used to configure the system. It provides an intuitive and declarative means of modeling multiple representations and specifying rules that are used to maintain consistency, match objects representing the same entity, and restore consistency if necessary
Named Entity Extraction and Disambiguation: The Reinforcement Effect.
Named entity extraction and disambiguation have received much attention in recent years. Typical fields addressing these topics are information retrieval, natural language processing, and semantic web. Although these topics are highly dependent, almost no existing works examine this dependency. It is the aim of this paper to examine the dependency and show how one affects the other, and vice versa. We conducted experiments with a set of descriptions of holiday homes with the aim to extract and disambiguate toponyms as a representative example of named entities. We experimented with three approaches for disambiguation with the purpose to infer the country of the holiday home. We examined how the effectiveness of extraction influences the effectiveness of disambiguation, and reciprocally, how filtering out ambiguous names (an activity that depends on the disambiguation process) improves the effectiveness of extraction. Since this, in turn, may improve the effectiveness of disambiguation again, it shows that extraction and disambiguation may reinforce each other.\u
Techniques for Statistical Data Visualization in GIS
This paper proposes an original solution to present statistical data using the facilities provided by the Geographical Information Systems, to improve the means of statistical data figure and distribution inside the territorial profile. The proposed solution allows to represent more statistical data sets, on the same map, using two different methods of data representation: using a color ramp to represent the territorial distribution of an aggregate indicator and a set of charts overlapped to represent the proportions of the variables that form the indicator. On the other hand, there is a way to represent statistical data using 3D cartograms. Thus, in GIS, the users can distinguish the intensity of the studied economic or social phenomenon because of the heights of the administrative units will be different.Geographical Information Systems, Spatial Visualization, ArcObjects, 2D and 3D Cartograms
Management and Conflation of Multiple Representations within an Open Federation Platform
Building up spatial data infrastructures involves the task of dealing with heterogeneous data sources which often bear inconsistencies and contradictions, respectively. One main reason for those inconsistencies emerges from the fact that one and the same real world phenomenon is often stored in multiple representations within different databases. It is the special goal of this paper to describe how the problems arising from multiple representations can be dealt with in spatial data infrastructures, especially focusing on the concepts that have been developed within the Nexus project of the University of Stuttgart that is implementing an open, federated infrastructure for context-aware applications. A main part of this contribution consists of explaining the efforts which have been conducted in order to solve the conflicts that occur between multiple representations within conflation or merging processes to achieve consolidated views on the underlying data for the applications
Context Mediation Demonstration of Counter-Terrorism Intelligence (CTI) Integration
Examination of intelligence failures prior to the 9/11/01 attacks made clear it that lack of effective information exchange among government agencies hindered the capability of identifying potential threats and preventing terrorist actions. A 2002 National Research Council study noted that âAlthough there are many private and public databases that contain information potentially relevant to counterterrorism programs, they lack the necessary context definitions (i.e., metadata) and access tools to enable interoperation with other databases and the extraction of meaningful and timely information.â[14] This report clearly recognized the importance of problems that the semantic data integration research community has been studying
Wood Products and Carbon Storage: Can Increased Production Help Solve the Climate Crisis?
This report draws on a variety of sources to illuminate the greenhouse gas impacts of wood products and wood biomass fuels throughout their life-cycles. While detailed analyses are rare, the picture is complete enough to show the variability of the processing path followed by different types of trees in various parts of the country. Taking the entire life-cycle of these products into account, it becomes clear that an increased use of wood fuels and lumber will have very little net effect on climate change. To the contrary, the impact is as likely to be negative as positive.The report also takes a closer look at the use of forest-carbon offsets in voluntary or regulatory programs. Because such offsets are expected to balance emissions from other sources, it is important that the additional carbon sequestration be real. This document outlines several criteria for carbon offset standards to account for the full effects of harvested wood carbon
Managing community membership information in a small-world grid
As the Grid matures the problem of resource discovery across communities,
where resources now include computational services, is becoming more
critical. The number of resources available on a world-wide grid is set to grow
exponentially in much the same way as the number of static web pages on
the WWW. We observe that the world-wide resource discovery problem can
be modelled as a slowly evolving very-large sparse-matrix where individual
matrix elements represent nodesâ knowledge of one another. Blocks in the
matrix arise where nodes offer more than one service. Blocking effects also
arise in the identification of sub-communities in the Grid. The linear algebra
community has long been aware of suitable representations of large, sparse
matrices. However, matrices the size of the world-wide grid potentially number
in the billions, making dense solutions completely intractable. Distributed
nodes will not necessarily have the storage capacity to store the addresses of
any significant percentage of the available resources. We discuss ways of modelling
this problem in the regime of a slowly changing service base including
phenomena such as percolating networks and small-world network effects
Context Mediation Demonstration of Counter-Terrorism Intelligence Integration
In this report, we demonstrate the applicability and value of the context mediation approach in facilitating the effective and correct use of counter-terrorism intelligence information coming from diverse heterogeneous sources
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