Yukio Sadahiro
Biographic Data
| ID | 1521382 |
|---|---|
| NAME | Yukio Sadahiro |
| GIVEN NAMES | Yukio |
| FAMILY NAME | Sadahiro |
| SIGNATURE | SADAHIRO Y |
| AFFILIATIONS | The University of Tokyo |
| ORCID | 0000-0002-7577-0160 |
| VERIFIED | Yes |
| TOTAL WORKS | 17 |
| TOTAL CITATIONS | 2 |
| AUTHOR COUNT | 17 |
| EDITOR COUNT | 0 |
| FIRST PUBLICATION YEAR | 1995 |
| LATEST PUBLICATION YEAR | 2026 |
| H-INDEX | 1 |
Spatial Proportionality Between Two Types of Points
This paper discusses the relationship between two types of points with a focus on spatial proportionality. The spatial proportionality referred to in this paper indicates the relationship in which one type of points is evenly distributed in relation to the other type of points. Examples include the spatial relationship between supermarkets and individuals, crimes and low‐income residents, nursery schools and pupils, and so forth. Though analysis …
A New Statistical Method for Analyzing Point Collocations
This article proposes a new method for analyzing the collocation of spatial objects represented as points. We consider the methodological aspect of point collocation. Our focus is on the collocation of more than two types of points, such as the collocation of clothing, accessory, and shoe stores, as well as that of hamburger, sandwich, and pizza stores. Although such collocations are often discussed in geography, analytical methods have not yet b…
Event Pattern Analysis
This article proposes two exploratory methods for analyzing event patterns. Events in this article refer to zero‐dimensional objects in the spatiotemporal dimension, such as crimes, earthquakes, and traffic accidents. One method detects the peaks in event patterns, evaluates the degree of event concentration at the peaks, and visualizes its spatial variation. Another method evaluates the similarity between different event patterns and visualizes …
Population and Morphological Change
As cities adapt to new needs and challenges, their forms change in close relation to population dynamics. This article focuses on the link between population dynamics and the evolution of building hull types. The case study is the Osaka‐Kobe city‐region in Japan, a country globally witnessing an intense population decline. Morphometric indicators are coupled with a tree‐like classificatory model in order to label buildings into consistent classes…
Descriptive Measures of Point Distributions Summarized with Respect to Spatial Scale in Visualization
Visual exploration plays a critical role in point pattern analysis. It permits analysts to grasp a wide variety of spatial patterns in point distributions that are not necessarily detectable by mathematical and statistical methods. Since spatial patterns are scale-dependent, grid and kernel density maps are effective in analysis that can visualize point distributions at various scales from small to large. Visual exploration of these maps, however…
Computer-aided design of bus route maps
The bus route map is a diagram that aims to convey necessary information for map readers to find an appropriate way of moving from an origin to a destination. Design of bus route map is a complicated and time-consuming task that requires careful consideration of readability and aesthetics. This paper proposes a new computational method for designing bus route maps. The method helps us to reduce six types of undesirable elements in bus route maps,…
Spatiotemporal analysis of the distribution of urban facilities in terms of accessibility
A tale of two Japans
The Japanese economy has been in crisis for more than a decade and, during this time, fiscal and other measures have failed substantially to restore the bases for sustainable growth. There have been many suggestions that the relevant authorities in Japan resort to inflationary strategies to overcome deflationary pressures or undertake large-scale regulatory reform to remove some of the supply-side obstacles to growth. In 2001, Koizumi Jun'ichir l…
A Graphical Method for Exploring Spatiotemporal Point Distributions
A spatiotemporal point distribution is a set of points defined by the combination of a spatial region and a time period. It is used for representing a set of discrete events, such as traffic accidents, and a set of points that characterize line and polygon objects such as the turning points of insect movement. Analysis of a spatiotemporal point distribution is more difficult than an ordinary spatial point distribution because it has to be treated…
An Exploratory Method for Analyzing a Spatial Tessellation in Relation to a Set of other Spatial Tessellations
Spatial tessellation is one of the most important spatial structures in geography. There are various types of spatial tessellations such as administrative units, school districts, and census tracts. Spatial tessellations are often closely related to each other; school districts are determined by, say, administrative units and land uses; electoral districts are related to administrative units, local communities, census tracts, and so forth. Such r…
Analysis of the effect of land use patterns on the anthropogetic energy discharged from air conditioning and hot water supply using a modified CSU mesoscale model
Perception of Spatial Dispersion in Point Distributions
This paper analyzes the perception of spatial dispersion on point distributions. Spatial dispersion is one of the major concepts communicated by dot maps. To promote efficient communication of this concept, two experiments were conducted to investigate the relationship between the perception of spatial dispersion and such map characteristics as spatial arrangement of points, number of points, symbol size, and map scale. Regression models were bui…
A computational procedure for joining separate map sheets
A PDF-based analysis of the spatial structure of retailing
Cluster Perception in the Distribution of Point Objects
This paper aims to develop a model representing cluster perception in the distribution of point objects. Three spatial factors—that is, proximity, concentration, and density change—are considered to cause cluster perception. To measure these factors, two spatial notions based on the density of point objects are proposed: local density and relative local density. These densities are defined as the functions of a location in a map, and indicate how…
An Illusion of Spatial Hierarchy
In this paper we show the properties of a spatial hierarchy found in a random configuration in which points are randomly placed on a plane and ranks are randomly assigned to these points. First we show a method of detecting a spatial hierarchy in a configuration of ranked points on a plane (not necessarily the random configuration). Second, using this method we obtain the spatial hierarchy of the random configuration mentioned above, and examine …
Size of Map Labels Used in GIS and Loss of Literal Information
The size of letters used in GIS greatly affects legibility of map labels. To provide a criterion for the size of letters to keep legibility at a certain level, this paper analyzes the relationship between the size of letters and the loss of literal information. The amount of information loss is measured by two different indices: a visibility ratio that indicates the ratio of visible letters to total letters, and a legibility ratio that represents…
A Graphical Method for Exploring Spatiotemporal Point Distributions
A spatiotemporal point distribution is a set of points defined by the combination of a spatial region and a time period. It is used for representing a set of discrete events, such as traffic accidents, and a set of points that characterize line and polygon objects such as the turning points of insect movement. Analysis of a spatiotemporal point distribution is more difficult than an ordinary spatial point distribution because it has to be treated…
A computational procedure for joining separate map sheets
Size of Map Labels Used in GIS and Loss of Literal Information
The size of letters used in GIS greatly affects legibility of map labels. To provide a criterion for the size of letters to keep legibility at a certain level, this paper analyzes the relationship between the size of letters and the loss of literal information. The amount of information loss is measured by two different indices: a visibility ratio that indicates the ratio of visible letters to total letters, and a legibility ratio that represents…
An Illusion of Spatial Hierarchy
In this paper we show the properties of a spatial hierarchy found in a random configuration in which points are randomly placed on a plane and ranks are randomly assigned to these points. First we show a method of detecting a spatial hierarchy in a configuration of ranked points on a plane (not necessarily the random configuration). Second, using this method we obtain the spatial hierarchy of the random configuration mentioned above, and examine …
Cluster Perception in the Distribution of Point Objects
This paper aims to develop a model representing cluster perception in the distribution of point objects. Three spatial factors—that is, proximity, concentration, and density change—are considered to cause cluster perception. To measure these factors, two spatial notions based on the density of point objects are proposed: local density and relative local density. These densities are defined as the functions of a location in a map, and indicate how…
Perception of Spatial Dispersion in Point Distributions
This paper analyzes the perception of spatial dispersion on point distributions. Spatial dispersion is one of the major concepts communicated by dot maps. To promote efficient communication of this concept, two experiments were conducted to investigate the relationship between the perception of spatial dispersion and such map characteristics as spatial arrangement of points, number of points, symbol size, and map scale. Regression models were bui…
A computational procedure for joining separate map sheets
A PDF-based analysis of the spatial structure of retailing
Analysis of the effect of land use patterns on the anthropogetic energy discharged from air conditioning and hot water supply using a modified CSU mesoscale model
A Graphical Method for Exploring Spatiotemporal Point Distributions
A spatiotemporal point distribution is a set of points defined by the combination of a spatial region and a time period. It is used for representing a set of discrete events, such as traffic accidents, and a set of points that characterize line and polygon objects such as the turning points of insect movement. Analysis of a spatiotemporal point distribution is more difficult than an ordinary spatial point distribution because it has to be treated…
An Exploratory Method for Analyzing a Spatial Tessellation in Relation to a Set of other Spatial Tessellations
Spatial tessellation is one of the most important spatial structures in geography. There are various types of spatial tessellations such as administrative units, school districts, and census tracts. Spatial tessellations are often closely related to each other; school districts are determined by, say, administrative units and land uses; electoral districts are related to administrative units, local communities, census tracts, and so forth. Such r…
A tale of two Japans
The Japanese economy has been in crisis for more than a decade and, during this time, fiscal and other measures have failed substantially to restore the bases for sustainable growth. There have been many suggestions that the relevant authorities in Japan resort to inflationary strategies to overcome deflationary pressures or undertake large-scale regulatory reform to remove some of the supply-side obstacles to growth. In 2001, Koizumi Jun'ichir l…
Spatiotemporal analysis of the distribution of urban facilities in terms of accessibility
Computer-aided design of bus route maps
The bus route map is a diagram that aims to convey necessary information for map readers to find an appropriate way of moving from an origin to a destination. Design of bus route map is a complicated and time-consuming task that requires careful consideration of readability and aesthetics. This paper proposes a new computational method for designing bus route maps. The method helps us to reduce six types of undesirable elements in bus route maps,…
Descriptive Measures of Point Distributions Summarized with Respect to Spatial Scale in Visualization
Visual exploration plays a critical role in point pattern analysis. It permits analysts to grasp a wide variety of spatial patterns in point distributions that are not necessarily detectable by mathematical and statistical methods. Since spatial patterns are scale-dependent, grid and kernel density maps are effective in analysis that can visualize point distributions at various scales from small to large. Visual exploration of these maps, however…
Event Pattern Analysis
This article proposes two exploratory methods for analyzing event patterns. Events in this article refer to zero‐dimensional objects in the spatiotemporal dimension, such as crimes, earthquakes, and traffic accidents. One method detects the peaks in event patterns, evaluates the degree of event concentration at the peaks, and visualizes its spatial variation. Another method evaluates the similarity between different event patterns and visualizes …
Population and Morphological Change
As cities adapt to new needs and challenges, their forms change in close relation to population dynamics. This article focuses on the link between population dynamics and the evolution of building hull types. The case study is the Osaka‐Kobe city‐region in Japan, a country globally witnessing an intense population decline. Morphometric indicators are coupled with a tree‐like classificatory model in order to label buildings into consistent classes…
A New Statistical Method for Analyzing Point Collocations
This article proposes a new method for analyzing the collocation of spatial objects represented as points. We consider the methodological aspect of point collocation. Our focus is on the collocation of more than two types of points, such as the collocation of clothing, accessory, and shoe stores, as well as that of hamburger, sandwich, and pizza stores. Although such collocations are often discussed in geography, analytical methods have not yet b…
Spatial Proportionality Between Two Types of Points
This paper discusses the relationship between two types of points with a focus on spatial proportionality. The spatial proportionality referred to in this paper indicates the relationship in which one type of points is evenly distributed in relation to the other type of points. Examples include the spatial relationship between supermarkets and individuals, crimes and low‐income residents, nursery schools and pupils, and so forth. Though analysis …
Computer Science (13 works) · Mathematics (12 works) · Geography (11 works) · Statistics (9 works) · Artificial Intelligence (6 works) · Cartography (6 works) · Geometry (6 works) · Data Management and Algorithms (5 works) · Data mining (5 works) · Geographic Information Systems Studies (4 works)