966 research outputs found
Designing Web-enabled services to provide damage estimation maps caused by natural hazards
The availability of building stock inventory data and demographic information is an important requirement for risk assessment studies when attempting to predict and estimate losses due to natural hazards such as earthquakes, storms, floods or tsunamis. The better this information is provided, the more accurate are predictions on damage to structures and lifelines and the better can expected impacts on the population be estimated. When a disaster strikes, a map is often one of the first requirements for answering questions related to location, casualties and damage zones caused by the event. Maps of appropriate scale that represent relative and absolute damage distributions may be of great importance for rescuing lives and properties, and for providing relief. However, this type of maps is often difficult to obtain during the first hours or even days after the occurrence of a natural disaster. The Open Geospatial Consortium Web Services (OWS) Specifications enable access to datasets and services using shared, distributed and interoperable environments through web-enabled services. In this paper we propose the use of OWS in view of these advantages as a possible solution for issues related to suitable dataset acquisition for risk assessment studies. The design of web-enabled services was carried out using the municipality of Managua (Nicaragua) and the development of damage and loss estimation maps caused by earthquakes as a first case study. Four organizations located in different places are involved in this proposal and connected through web services, each one with a specific role
Multi-Paradigm Reasoning for Access to Heterogeneous GIS
Accessing and querying geographical data in a uniform way has become easier in recent years. Emerging standards like WFS turn
the web into a geospatial web services enabled place. Mediation
architectures like VirGIS overcome syntactical and semantical heterogeneity
between several distributed sources. On mobile devices,
however, this kind of solution is not suitable, due to limitations,
mostly regarding bandwidth, computation power, and available storage
space. The aim of this paper is to present a solution for providing
powerful reasoning mechanisms accessible from mobile applications
and involving data from several heterogeneous sources.
By adapting contents to time and location, mobile web information
systems can not only increase the value and suitability of the
service itself, but can substantially reduce the amount of data delivered
to users. Because many problems pertain to infrastructures
and transportation in general and to way finding in particular, one
cornerstone of the architecture is higher level reasoning on graph
networks with the Multi-Paradigm Location Language MPLL. A
mediation architecture is used as a âgraph providerâ in order to
transfer the load of computation to the best suited component â
graph construction and transformation for example being heavy on
resources. Reasoning in general can be conducted either near the
âsourceâ or near the end user, depending on the specific use case.
The concepts underlying the proposal described in this paper are
illustrated by a typical and concrete scenario for web applications
XML Encoding and Web Services for Spatial OLAP Data Cube Exchange: an SOA Approach
XML and Web Services technologies have revolutionized the way data are exchanged on the Internet. Meanwhile, Spatial OLAP (SOLAP) tools have emerged to bridge the gap between the Business Intelligence and Geographic Information Systems domains. While Web Services specifications such as XML for Analysis enable the use of OLAP tools in Service Oriented Architecture (SOA) environments, no solution addresses the exchange of complete SOLAP data cubes (comprising both spatial and descriptive data and metadata) in an interoperable fashion.
This paper proposes a new XML grammar for the exchange of SOLAP data cubes, containing both spatial and descriptive data and metadata. It enables the delivery of the cube schema, dimension members (including the geometry of spatial members) and fact data. The use of this XML format is then demonstrated in the context of a Web Service. Such services can be deployed in various situations, not limited to traditional client-server platforms but also ubiquitous mobile computing environments
A Geospatial Cyberinfrastructure for Urban Economic Analysis and Spatial Decision-Making
abstract: Urban economic modeling and effective spatial planning are critical tools towards achieving urban sustainability. However, in practice, many technical obstacles, such as information islands, poor documentation of data and lack of software platforms to facilitate virtual collaboration, are challenging the effectiveness of decision-making processes. In this paper, we report on our efforts to design and develop a geospatial cyberinfrastructure (GCI) for urban economic analysis and simulation. This GCI provides an operational graphic user interface, built upon a service-oriented architecture to allow (1) widespread sharing and seamless integration of distributed geospatial data; (2) an effective way to address the uncertainty and positional errors encountered in fusing data from diverse sources; (3) the decomposition of complex planning questions into atomic spatial analysis tasks and the generation of a web service chain to tackle such complex problems; and (4) capturing and representing provenance of geospatial data to trace its flow in the modeling task. The Greater Los Angeles Region serves as the test bed. We expect this work to contribute to effective spatial policy analysis and decision-making through the adoption of advanced GCI and to broaden the application coverage of GCI to include urban economic simulations
Prototyping Information Visualization in 3D City Models: a Model-based Approach
When creating 3D city models, selecting relevant visualization techniques is
a particularly difficult user interface design task. A first obstacle is that
current geodata-oriented tools, e.g. ArcGIS, have limited 3D capabilities and
limited sets of visualization techniques. Another important obstacle is the
lack of unified description of information visualization techniques for 3D city
models. If many techniques have been devised for different types of data or
information (wind flows, air quality fields, historic or legal texts, etc.)
they are generally described in articles, and not really formalized. In this
paper we address the problem of visualizing information in (rich) 3D city
models by presenting a model-based approach for the rapid prototyping of
visualization techniques. We propose to represent visualization techniques as
the composition of graph transformations. We show that these transformations
can be specified with SPARQL construction operations over RDF graphs. These
specifications can then be used in a prototype generator to produce 3D scenes
that contain the 3D city model augmented with data represented using the
desired technique.Comment: Proc. of 3DGeoInfo 2014 Conference, Dubai, November 201
Extending THREDDS middleware to serve OGC community
International audienceAs far as interoperability is concerned, in a service-oriented framework, it is possible to distinguish different service tiers; each tier contains systems and tools which implement that tier's specific task. The present paper analyses such a framework for the Earth Sciences and the GIS information communities. For the Earth Sciences community, the heterogeneity of existing protocols and data models is outlined, considering the experience of the Unidata community. For the GIS community, the interoperability opportunities laid by the OGC's specifications are briefly introduced. The need of achieving the two communities' frameworks interoperability, and its importance for science Digital Library applications are introduced. A solution is presented and discussed; it is based on the following technologies: THREDDS Data Server, OGC WCS/WFS and ncML-GML. An OGC interoperability experiment, which tests the proposed solution, is briefly presented
Automatic Geospatial Data Conflation Using Semantic Web Technologies
Duplicate geospatial data collections and maintenance are an extensive problem across Australia government organisations. This research examines how Semantic Web technologies can be used to automate the geospatial data conflation process. The research presents a new approach where generation of OWL ontologies based on output data models and presenting geospatial data as RDF triples serve as the basis for the solution and SWRL rules serve as the core to automate the geospatial data conflation processes
UncertWeb processing service:making models easer to access on the web
Models are central tools for modern scientists and decision makers, and there are many existing frameworks to support their creation, execution and composition. Many frameworks are based on proprietary interfaces, and do not lend themselves to the integration of models from diverse disciplines. Web based systems, or systems based on web services, such as Taverna and Kepler, allow composition of models based on standard web service technologies. At the same time the Open Geospatial Consortium has been developing their own service stack, which includes the Web Processing Service, designed to facilitate the executing of geospatial processing - including complex environmental models. The current Open Geospatial Consortium service stack employs Extensible Markup Language as a default data exchange standard, and widely-used encodings such as JavaScript Object Notation can often only be used when incorporated with Extensible Markup Language. Similarly, no successful engagement of the Web Processing Service standard with the well-supported technologies of Simple Object Access Protocol and Web Services Description Language has been seen. In this paper we propose a pure Simple Object Access Protocol/Web Services Description Language processing service which addresses some of the issues with the Web Processing Service specication and brings us closer to achieving a degree of interoperability between geospatial models, and thus realising the vision of a useful 'model web'
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