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Most of the information stored in web pages contains geographic context, such as place names, address, and coordinates. Such geographic information often contains great values and is worth retrieving and analyzing. Traditional search engine is limited in its capability of extracting meaningful geographic messages from mass of unstructured and textual source. Even with the retrieved geographic information,...
Geographic Information System (GIS) not only has the function of managing geographic information and processing graphics, but also can resolve the problems of complex spatial analysis, spatial simulation and spatial decision-making. Geographic fractal research, whether measuring fractal dimension or simulating fractal structure, is a rule and complicated process. Some popular GIS software has many...
The effective representation of thematic data in 3D GIS can not only visualize tabular data intuitively in 3D environment, but also enable users to analyze thematic data directly on 3D GIS platform, thereby facilitating the decision making process. This paper proposes a method for representing thematic data in 3D GIS. Three steps are included in the method. In the first step, user is required to input...
Traditional data collection methods for geological investigation, profile measurement, and other field survey in the research community of geosciences are generally based on the manual measuring and recording by the investigators. The most popular “instruments” used in the traditional survey are pencils as well as printed hard copy charts. The methods are obviously complicated and inefficient, at...
Spatial indexing is one of the most important techniques in the field of spatial data management. Many kinds of techniques of spatial indexing have been successfully developed, and each of them has advantages towards special applications. As a type of spatial data structure, Hierarchical Triangular Mesh (HTM) has excellent features of global continuity, stability, hierarchy and uniformity, which has...
Mobile Geographic Information Systems (GIS) is an outcome of integrating GIS, wireless communication, embeds and mobile computing technologies. Based on .NET Compact Framework and GPRS a Mobile GIS with own patent is developed. Services in the system include: downloading map by General Packet Radio Service (GPRS), defining geographical coordinate system of maps, Global Position System (GPS) connection...
Ontologies are put forward to resolve the problem of information integration and heterogeneous knowledge sharing. Aiming at the issue of data redundancy and inefficient sharing, we propose a data sharing framework of microscopic traffic simulation and GIS based on ontology driven. The building process of requirement, analysis, design and implementation of the microscopic traffic simulation ontology...
An application system is presented to implement the integration of microscopic traffic simulation and GIS, and a spatio-temporal data model is proposed as the solution for the integration. We mainly discuss the framework, spatio-temporal data model and dynamic map layer of integrative system. The representative microscopic traffic simulation system, MITSIM, is adopted as the model to analyze the simulation...
A mobile GIS for field data collection is a system which can facilitate the entire process from indoor preparation, data collection, to data processing. It is a combination of positioning and wireless communication technologies. The paper aims to demonstrate how to design and implement such a mobile GIS. Data of the system consist of three parts: background reference layer, with which spatial reference...
A standardized data model is proposed for the solution of data sharing between geographic information systems (GIS) and microscopic traffic simulation systems. The object oriented technology, layer and package expression are used to abstract the characteristics of the proposed model, which then is described with the UML technique. The definition of entity and E-R diagram of the basic road and public...
For years, Beijing government has put large sums of capital into transport infrastructure constructions, building expressways and implementing advanced transport management systems to alleviate urban traffic congestions. However, what bothers the government decision makers is that they often have deficient information on whether the new expressway and applications of the system they proved do perform...
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