Eihan Shimizu

A new algorithm for distance cartogram construction

A distance cartogram is a diagram that visualizes the proximity indices between points in a network, such as time–distances between cities. The Euclidean distances between the points on the distance cartogram represent the given proximity indices. This is a useful visualization tool for the level of service of transport, e.g. difference in the level of service between regions or points in a network and its improvement in the course of time. The two previously proposed methods—multidimensional scaling (MDS) and network time–space mapping—have certain advantages and disadvantages. However, we observe that these methods are essentially the same, and the merits of both these methods can be combined to formulate a generalized solution. In this study, we first formulate the time–space mapping problem, which includes the key features of both of the above stated methods, and propose a generalized solution. We then apply this solution to the time–distances of Japans railway networks to confirm its applicability.

A New Algorithm for Continuous Area Cartogram Construction with Triangulation of Regions and Restriction on Bearing Changes of Edges

A continuous area cartogram is a transformed map in which regions are resized relative to their data. It is considered an effective visualization tool for statistical data, and many solutions have been proposed. However, most of these solutions are not mathematically clear or user friendly; further, they do not provide visually elegant area cartograms. An essential condition for the construction of a visually elegant area cartogram is that the resultant region shape should resemble the corresponding regions on geographical maps. Since it is impossible to determine the shape of a region based only on the information of size, area cartogram construction is an ill-posed problem that requires regularization. In this study, we propose a construction algorithm that involves triangulation of regions and regularization through restrictions on the bearing changes of the edges in order to obtain visually clear results. First, we formulate a construction using nonlinear least squares. Then, by linearizing, we derive a simple formula to create area cartograms. The application of our algorithm to the USA population datasets reveals that our algorithm has mathematical clarity and is user friendly.

A knowledge-based computer system for zoning

Abstract The objective of this paper is to develop a knowledge-based computer system for zoning in land use planning. It discusses how to acquire knowledge from experts and how to utilize this information efficiently. IF-THEN production rules can be derived from the “knowledge structure digraph map,” which is obtained by structuring the conscious expertise of planning professionals. A new model concerning the combination of these rules, based on fuzzy inference, is developed in order to simulate human inference more appropriately. A practical application of the system is given and its applicability is discussed.

Retrieval of 3d video mosaics for fast 3d visualization

3D video mosaics created by 3D image mosaicking, our previous research, are for 3D visualization of the roadside standing building scene captured by a side-looking video camera as a continuous set of vertical-textured planar faces. These vertical faces were concatenated to create an approximate model on which the images could be back-projected as textures. We proposed a retrieval technique of selecting vertical-textured planar faces from archived 3D image mosaics to fast represent a 3D world, where this selection is based on proximity to the user location in the virtual world. The chosen vertical-textured planar faces are recomposed as a continuous set formed stream and are then rendered in 3D virtual space.

3D panoramic mosaicking to suppress the ghost effect at far-range scene for urban area visualization

3D image mosaicking is useful for 3D visualization of the roadside scene of urban area by projecting 2D images to the 3D planes. When a sequence of images are filmed from a side-looking video camera passing far-range areas, the ghost effect in which same objects appear repeatedly occurs. To suppress such ghost effect, the far-range areas are detected by using the distance between the image frame and the 3D coordinate of tracked optical flows. The ghost effects are suppressed by projecting the part of image frames onto 3D multiple planes utilizing vectors passing the focal point of frames and a vertical slit. The vertical slit is calculated by utilizing the first and last frames of the far-range areas. We demonstrated algorithm that creates efficient 3D panoramic mosaics without the ghost effect at the far-range area.

GIS Integrated System for Urban Transport and Development Planning

Growth of population and economic activities in metropolitan areas causes serious issues such as heavy congestion of transport, urban sprawl, and so on. Again with a background of more concern for environmental problems, these urban issues should be discussed not only from the point of economic efficiency, but also from the point of sustainability of a society, or quality of life. Therefore, urban planners or engineers are strongly required to present a set of effective policy options for solving the above problems, under more complex criteria and constraints than ever experienced before.

Visualization of Historical Data in Tokyo

Public participation which plays an important role in urban planning (Craig et al. 2002; Faga 2006), is based on people’s continuing interest and concern for a place. Attractive locations draw the interest of a wide variety of people and capture attention by responding to popular demand for such places. This enables them to continue to meet the needs of people, consequently these spots are always lively for both residents and visitors.