The purpose of this study is to propose the directed network Voronoi diagram (NVD) and to develop a tool for generating directed NVD. First, the paper defines two types of the directed NVD which are called outward NVD and inward NVD. Next, the paper shows roundtrip shortest path region is constructed by the above directed NVDs. Third, the paper shows the outlines of the tool of the directed NVDs and the algorithm of this tool. Forth, the paper shows examples of the applications of these NVDs. Last, the paper shows the difference between the non-directed NVD and the directed NVD.

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Natural disaster might cause traffic congestion, changing traffic network. In this paper, we propose the way of developing the road condition analysis, animated traffic simulations of GIS and apply to the traffic situation under the Tokai downpour by using travel survey and tachometer of the drivers who had been driving under the disaster, from 9.11 to 9.12, 2000. As a result, it was revealed that many drivers who had driven at that time had involved chronic traffic jam and it took many hours to reach to destination.

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Spatial smoothing is one of the spatial operations in GIS. It makes spatial information vague and ambiguous to some extent, in order to hide the exact location or attribute of spatial objects. Since spatial smoothing is a kind of conversion of spatial data, use of visualized spatial data also changes with spatial smoothing. The degree of smoothing affects the way and result of map use. Though this has been widely recognized in cartography and GIS, few studies have been done in the literature. To fill the gap of the research, this paper analyzes the effect of spatial smoothing in map use. The experiment is performed on the focus to a facility choice on a map. The observed data are used to build and estimate a stochastic model representing the hotel choice behavior. The model serves for not only explaining the choice behavior of a hotel but also discussing it in relation to the degree of spatial smoothing.

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Urban land-use pattern occurs not only at certain spatial scale but also at certain classification system. Study of spatial scale effect on urban land-use pattern analysis for construction of spatial model of urban land-use changes entails consideration of urban land-use classification system selected. The objective of this paper is to investigate the effect characteristics of spatial scale on the result of urban land-use pattern analysis for two different classification systems in terms of spatial autocorrelation and fuzzy mathematics by an empirical study in the CBD (Central Business District) of Tokyo so as to provide some useful information for construction of multi-scale or hierarchical spatial model of urban dynamics. The results show that while spatial autocorrelation of all the categories of urban land-use at different classification systems in this study is scale-dependent, characteristics of the spatial scale effect on pattern of urban land-use categories are different for different classification systems. However, the general change trends of spatial autocorrelation of urban land-use for different classification systems show similar across a range of scale. Reducing number of urban land-use categories for one classification system may diminish the loss of information of land-use area across the range of scale and the effect of spatial scale on urban land-use pattern analysis in the certain extent.

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Because most spatial data are provided by public agencies in Japan, it is desirable that public officials study continuously new applications for GIS technologies in many fields. This paper examines the differences in office environments and attitudes towards Continuing Professional Development in GIS between public officials and private corporation employees. Five factors are extracted by factor analysis from answers to a questionnaire. The results of Kolmogorov-Smirnov testing and cluster analysis of the factor scores showed that public officials have a lower expectation for high pay if certified as GIS professionals than do private corporation employees. The low motivation by public officials to understand the new applied technologies is of concern.

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In this paper we propose a method for measuring the area of attainable region from a given railroad station over the Tokyo metropolitan area in which railroad network is well developed. By calculating time distance between arbitral two stations using railroad network databases for 1960, 1980, and 2000, changes in the area of attainable region are used as a measure for advantage of the given place. We reveal that the growth of railroad network and the introduction of express train systems have affected not only on the reduction of travel time but also on the formation of multinucleated urban structure.

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In this paper, walking distance and diverting ratio from Shibuya station, Tokyo, where redevelopment around the station is planned, to all surrounding facilities are calculated using pedestrian path network in the neighbor of the station. We observe that walking distance is shorter in northern and western parts, whereas it is longer in southern and eastern parts, and that diverting ratio is high in circumference and southern part of the station where the influence of a pedestrian overpass to stride over Route 246. We also estimate that average walking distance decreases by 139 meters by the installation of the high-level pedestrian decks around the station, which is planned in a redevelopment plan in the neighbor of Shibuya station.

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