Atsushi Takizawa - Academia.edu (original) (raw)

Papers by Atsushi Takizawa

Research paper thumbnail of An Inductive Construction of Minimally Rigid Panel-Hinge Graphs and Application to Design Form

Proceedings of the 19th Conference on Computer Aided Architectural Design Research in Asia (CAADRIA), 2014

A panel-hinge framework is a structure composed of rigid panels connected by hinges. It was recen... more A panel-hinge framework is a structure composed of rigid panels connected by hinges. It was recently proved that for a so-called generic position, the rigidity of panel-hinge frameworks can be tested by examining the combinatorial property of the underlying graph. In this study, we apply such combinatorial characteristics to create design forms. However, such characterization is only valid for so-called "generic" panel-hinge frameworks. When considering the application of design forms, we need to take into account non-generic cases. In this paper, we develop the method to inductively generate non-generic rigid panel-hinge frameworks consisting of orthogonal panels and to inductively generate rigid panel-hinge frameworks based on fractal geometry coupled with space filling 3-dimensional convex polyhedron as a construction unit. We give examples of forms by the proposed method to demonstrate the applicability to design forms.

Research paper thumbnail of Image Recognition Method on Architectural Components from Architectural Photographs Glass Openings Recognition Based on Bayes Classification

Research paper thumbnail of An efficient algorithm for the evacuation problem in a certain class of a network with uniform path-lenths

In this paper, we consider the evacuation problem for a network which consists of a directed grap... more In this paper, we consider the evacuation problem for a network which consists of a directed graph with capacities and transit times on its arcs. This problem can be solved by the algorithm of Hoppe and Tardos [1] in polynomial time. However their running time is high-order polynomial, and hence is not practical in general. Thus it is necessary to devise a faster algorithm for a tractable and practically useful subclass of this problem. In this paper, we consider a dynamic network with a single sink s such that (i) for each vertex v the sum of transit times of arcs on any path from v to s takes the same value, and (ii) for each vertex v the minimum v-s cut is determined by the arcs incident to s whose tails are reachable from v. We propose an efficient algorithm for this network problem. This class of networks is a generalization of the grid network studied in the paper [2].

Research paper thumbnail of 11005 Recognition of Architectural Elements from Image of Building Facade

Summaries of technical papers of Annual Meeting Architectural Institute of Japan. A-2, Fire safety, off-shore engineering and architecture, information systems technology, Jul 31, 2007

Research paper thumbnail of A Heuristic for Quickest Transshipment Problem and its Application to Evacuation Planning

IEICE Technical Report; IEICE Tech. Rep., Mar 3, 2014

Research paper thumbnail of The Mixed Evacuation Problem

Lecture Notes in Computer Science, 2016

A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transi... more A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transit times on its arcs. The quickest transshipment problem is one of the most fundamental problems in dynamic networks. In this problem, we are given sources and sinks. Then the goal of this problem is to find a minimum time limit such that we can send the right amount of flow from sources to sinks. In this paper, we introduce a variant of this problem called the mixed evacuation problem. This problem models an emergent situation in which people can evacuate on foot or by car. The goal is to organize such a mixed evacuation so that an efficient evacuation can be achieved. In this paper, we study this problem from the theoretical and practical viewpoints. In the first part, we prove the polynomial-time solvability of this problem in

Research paper thumbnail of An Efficient Algorithm for Evacuation Problems in Dynamic Network Flows with Uniform Arc Capacity

Springer eBooks, 2006

In this paper, we consider the quickest flow problem in a network which consists of a directed gr... more In this paper, we consider the quickest flow problem in a network which consists of a directed graph with capacities and transit times on its arcs. We present an O(n log n) time algorithm for the quickest flow problem in a network of grid structure with uniform arc capacity which has a single sink where n is the number of vertices in the network.

Research paper thumbnail of Emerging Pattern Based Crime Spots Analysis and Rental Price Prediction

This series aims to capture new developments and applications in data mining and knowledge discov... more This series aims to capture new developments and applications in data mining and knowledge discovery, while summarizing the computational tools and techniques useful in data analysis. This series encourages the integration of mathematical, statistical, and computational methods and techniques through the publication of a broad range of textbooks, reference works, and handbooks. The inclusion of concrete examples and applications is highly encouraged. The scope of the series includes, but is not limited to, titles in the areas of data mining and knowledge discovery methods and applications, modeling, algorithms, theory and foundations, data and knowledge visualization, data mining systems and tools, and privacy and security issues.

Research paper thumbnail of 2-F-5 感性評価を考慮したオフィスビルの賃料推定モデル(マーケティング(1))

日本オペレーションズ・リサーチ学会春季研究発表会アブストラクト集, Mar 25, 2008

Research paper thumbnail of An Efficient Algorithm for the Evacuation Problem in a Certain Class of a Network with Uniform Path-Lengths (Algorithmic Aspects in Information and Management)

Lecture Notes in Computer Science, 2008

In this paper, we consider the evacuation problem for a network which consists of a directed grap... more In this paper, we consider the evacuation problem for a network which consists of a directed graph with capacities and transit times on its arcs. This problem can be solved by the algorithm of Hoppe and Tardos [1] in polynomial time. However their running time is high-order polynomial, and hence is not practical in general. Thus it is necessary to devise a faster algorithm for a tractable and practically useful subclass of this problem. In this paper, we consider a dynamic network with a single sink s such that (i) for each vertex v the sum of transit times of arcs on any path from v to s takes the same value, and (ii) for each vertex v the minimum v-s cut is determined by the arcs incident to s whose tails are reachable from v. We propose an efficient algorithm for this network problem. This class of networks is a generalization of the grid network studied in the paper [2].

Research paper thumbnail of 8103 A Study on the Estimation of Stocks according to the use in the Commercial Facilities

Research paper thumbnail of IMAGE RECOGNITION METHODS OF ARCHITECTURAL COMPONENTS FOR AUTOMATIC INDEXING OF ARCHITECTURAL IMAGE DATABASE : Applying to Tatami and Koshi images

Journal of Environmental Engineering (Transactions of AIJ), 2005

Research paper thumbnail of The Mixed Evacuation Problem

Lecture Notes in Computer Science, 2016

A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transi... more A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transit times on its arcs. The quickest transshipment problem is one of the most fundamental problems in dynamic networks. In this problem, we are given sources and sinks. Then the goal of this problem is to find a minimum time limit such that we can send the right amount of flow from sources to sinks. In this paper, we introduce a variant of this problem called the mixed evacuation problem. This problem models an emergent situation in which people can evacuate on foot or by car. The goal is to organize such a mixed evacuation so that an efficient evacuation can be achieved. In this paper, we study this problem from the theoretical and practical viewpoints. In the first part, we prove the polynomial-time solvability of this problem in

Research paper thumbnail of Enumeration of region partitioning for evacuation planning based on ZDD

11th International Symposium on Operations Research and its Applications in Engineering, Technology and Management 2013 (ISORA 2013), 2013

Japanese cities always have risks of large-scale earthquakes. Thus, it is very important to estab... more Japanese cities always have risks of large-scale earthquakes. Thus, it is very important to establish crisis management systems against large-scale disasters such as big earthquakes, and tsunamis to secure evacuation centers for evacuees. In this respect, it is extremely important to provide sufficient evacuation centers and to appropriately partition the whole region into small areas, such that a unique evacuation center is located in each area and the people living in the area can easily evacuate to the center. However, it is hard to find an optimal region partitioning, due to the uncertainty, such as a fire or collapsed buildings. In this research, we propose a method to enumerate all partitioning patterns using Zero-suppressed Binary Decision Diagram (ZDD) that satisfy several conditions. We apply the proposed method to Kamigyo Ward of Kyoto City, Japan.

Research paper thumbnail of Enumeration of Floor Plans Based on Zero-Suppressed Binary Decision Diagram

Proceedings of the 19th Conference on Computer Aided Architectural Design Research in Asia (CAADRIA), 2014

Open Building (Habraken, 1972) has been the focus of attention due to growing interest in the sus... more Open Building (Habraken, 1972) has been the focus of attention due to growing interest in the sustainable society. For Open Building, it is important to preserve the diversity of feasible floor plans in order to adapt to various lifestyles of residents. Capacity analysis is a method for evaluating the potential diversity. We propose a novel method that evaluates the potential diversity of floor plans by enumerating all feasible floor plans satisfying given constraints based on zero-suppressed binary decision diagram (ZDD) (Minato, 1993).

Research paper thumbnail of Street-level spatial analysis of crime location associated with built environment in Fushimi ward , yoto city 顕在パタンに基づく街頭犯罪分析 京都市伏見区における犯罪発生場所と構築環境の関係に着目した街区レベルの空間分析

We analyze the relationship between bag snatching and spatial relationships in Kyoto City. In par... more We analyze the relationship between bag snatching and spatial relationships in Kyoto City. In particular, we model natural surveillance with various façade components. We then analyze the data as a classification problem that divides space into areas in which crimes occur and areas in which crimes do not occur. Since there exists fuzziness in the categorization of space, we propose a new approach that combines clustering and classification based on semi-supervised learning, which determines the categorization so as to improve classification accuracy. In addition, we use an emerging pattern based classifier and obtain spatial features related to crime.

Research paper thumbnail of Impact of the Urban Exodus Triggered by the COVID-19 Pandemic on the Shrinking Cities of the Osaka Metropolitan Area

Sustainability, 2022

This study aims to clarify the impact of the urban exodus triggered by the COVID-19 pandemic on s... more This study aims to clarify the impact of the urban exodus triggered by the COVID-19 pandemic on shrinking cities in the Osaka metropolitan area, where a declining population is caused by population aging. Analyzing the Osaka metropolitan area enables us to clarify how cities are shrinking due to the urban exodus. This study analyzed the monthly population data of three types of municipalities: ordinance-designed/regional hub cities, ordinary cities, and towns/villages. In conclusion, the study clarified that population change due to the urban exodus occurred in the ordinance-designed/regional hub and ordinary cities from summer to autumn 2020. The most significant population increases occurred in the municipalities in the Osaka metropolitan fringe area, which are located more than 30 km away from the center of the Osaka metropolitan area. The conclusion is important because the population increased not only in the ordinance-designed cities but also in the ordinance-designed/regional...

Research paper thumbnail of 11049 Optimization of spatial form of concert hall by using Discrete Model and Genetic Algorithm

Research paper thumbnail of Which Residential Clusters of Walkability Affect Future Population from the Perspective of Real Estate Prices in the Osaka Metropolitan Area?

Sustainability, 2021

In Japan, where the population is declining and aging significantly, walkability has attracted at... more In Japan, where the population is declining and aging significantly, walkability has attracted attention as a way to improve residents’ lifestyles. Therefore, it is essential to identify the residential clusters where walkability improvement would contribute to the maintenance of the population in order to select urban areas for the implementation of walkable designs. This study aimed to identify the residential clusters in which walkability affects the future population from the perspective of real estate prices. The reason for focusing on real estate prices is that they are expected to be a confounding factor connecting walkability and the future population. The method we used was to analyze the structural equation modeling of the impact of walkability index, real estate prices, and future population change ratio. This analysis was based on the neighborhood association scale. This study clarified that effective residential clusters are the business center cluster and the sprawl cl...

Research paper thumbnail of Estimating Potential Event Occurrence Areas in Small Space based on Semi-supervised Learning

We propose a method for relatively small space that can optimize the size and shape of the neighb... more We propose a method for relatively small space that can optimize the size and shape of the neighborhood of an event occurrence spot on a grid space to minimize the classification error using classification by aggregating emerging patterns based on the concept of semi-supervised learning. We apply this method to data of waiting people in the Umeda Underground Mall and show that the proposed method can improve classification accuracy and understandability of classification rules.

Research paper thumbnail of An Inductive Construction of Minimally Rigid Panel-Hinge Graphs and Application to Design Form

Proceedings of the 19th Conference on Computer Aided Architectural Design Research in Asia (CAADRIA), 2014

A panel-hinge framework is a structure composed of rigid panels connected by hinges. It was recen... more A panel-hinge framework is a structure composed of rigid panels connected by hinges. It was recently proved that for a so-called generic position, the rigidity of panel-hinge frameworks can be tested by examining the combinatorial property of the underlying graph. In this study, we apply such combinatorial characteristics to create design forms. However, such characterization is only valid for so-called "generic" panel-hinge frameworks. When considering the application of design forms, we need to take into account non-generic cases. In this paper, we develop the method to inductively generate non-generic rigid panel-hinge frameworks consisting of orthogonal panels and to inductively generate rigid panel-hinge frameworks based on fractal geometry coupled with space filling 3-dimensional convex polyhedron as a construction unit. We give examples of forms by the proposed method to demonstrate the applicability to design forms.

Research paper thumbnail of Image Recognition Method on Architectural Components from Architectural Photographs Glass Openings Recognition Based on Bayes Classification

Research paper thumbnail of An efficient algorithm for the evacuation problem in a certain class of a network with uniform path-lenths

In this paper, we consider the evacuation problem for a network which consists of a directed grap... more In this paper, we consider the evacuation problem for a network which consists of a directed graph with capacities and transit times on its arcs. This problem can be solved by the algorithm of Hoppe and Tardos [1] in polynomial time. However their running time is high-order polynomial, and hence is not practical in general. Thus it is necessary to devise a faster algorithm for a tractable and practically useful subclass of this problem. In this paper, we consider a dynamic network with a single sink s such that (i) for each vertex v the sum of transit times of arcs on any path from v to s takes the same value, and (ii) for each vertex v the minimum v-s cut is determined by the arcs incident to s whose tails are reachable from v. We propose an efficient algorithm for this network problem. This class of networks is a generalization of the grid network studied in the paper [2].

Research paper thumbnail of 11005 Recognition of Architectural Elements from Image of Building Facade

Summaries of technical papers of Annual Meeting Architectural Institute of Japan. A-2, Fire safety, off-shore engineering and architecture, information systems technology, Jul 31, 2007

Research paper thumbnail of A Heuristic for Quickest Transshipment Problem and its Application to Evacuation Planning

IEICE Technical Report; IEICE Tech. Rep., Mar 3, 2014

Research paper thumbnail of The Mixed Evacuation Problem

Lecture Notes in Computer Science, 2016

A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transi... more A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transit times on its arcs. The quickest transshipment problem is one of the most fundamental problems in dynamic networks. In this problem, we are given sources and sinks. Then the goal of this problem is to find a minimum time limit such that we can send the right amount of flow from sources to sinks. In this paper, we introduce a variant of this problem called the mixed evacuation problem. This problem models an emergent situation in which people can evacuate on foot or by car. The goal is to organize such a mixed evacuation so that an efficient evacuation can be achieved. In this paper, we study this problem from the theoretical and practical viewpoints. In the first part, we prove the polynomial-time solvability of this problem in

Research paper thumbnail of An Efficient Algorithm for Evacuation Problems in Dynamic Network Flows with Uniform Arc Capacity

Springer eBooks, 2006

In this paper, we consider the quickest flow problem in a network which consists of a directed gr... more In this paper, we consider the quickest flow problem in a network which consists of a directed graph with capacities and transit times on its arcs. We present an O(n log n) time algorithm for the quickest flow problem in a network of grid structure with uniform arc capacity which has a single sink where n is the number of vertices in the network.

Research paper thumbnail of Emerging Pattern Based Crime Spots Analysis and Rental Price Prediction

This series aims to capture new developments and applications in data mining and knowledge discov... more This series aims to capture new developments and applications in data mining and knowledge discovery, while summarizing the computational tools and techniques useful in data analysis. This series encourages the integration of mathematical, statistical, and computational methods and techniques through the publication of a broad range of textbooks, reference works, and handbooks. The inclusion of concrete examples and applications is highly encouraged. The scope of the series includes, but is not limited to, titles in the areas of data mining and knowledge discovery methods and applications, modeling, algorithms, theory and foundations, data and knowledge visualization, data mining systems and tools, and privacy and security issues.

Research paper thumbnail of 2-F-5 感性評価を考慮したオフィスビルの賃料推定モデル(マーケティング(1))

日本オペレーションズ・リサーチ学会春季研究発表会アブストラクト集, Mar 25, 2008

Research paper thumbnail of An Efficient Algorithm for the Evacuation Problem in a Certain Class of a Network with Uniform Path-Lengths (Algorithmic Aspects in Information and Management)

Lecture Notes in Computer Science, 2008

In this paper, we consider the evacuation problem for a network which consists of a directed grap... more In this paper, we consider the evacuation problem for a network which consists of a directed graph with capacities and transit times on its arcs. This problem can be solved by the algorithm of Hoppe and Tardos [1] in polynomial time. However their running time is high-order polynomial, and hence is not practical in general. Thus it is necessary to devise a faster algorithm for a tractable and practically useful subclass of this problem. In this paper, we consider a dynamic network with a single sink s such that (i) for each vertex v the sum of transit times of arcs on any path from v to s takes the same value, and (ii) for each vertex v the minimum v-s cut is determined by the arcs incident to s whose tails are reachable from v. We propose an efficient algorithm for this network problem. This class of networks is a generalization of the grid network studied in the paper [2].

Research paper thumbnail of 8103 A Study on the Estimation of Stocks according to the use in the Commercial Facilities

Research paper thumbnail of IMAGE RECOGNITION METHODS OF ARCHITECTURAL COMPONENTS FOR AUTOMATIC INDEXING OF ARCHITECTURAL IMAGE DATABASE : Applying to Tatami and Koshi images

Journal of Environmental Engineering (Transactions of AIJ), 2005

Research paper thumbnail of The Mixed Evacuation Problem

Lecture Notes in Computer Science, 2016

A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transi... more A dynamic network introduced by Ford and Fulkerson is a directed graph with capacities and transit times on its arcs. The quickest transshipment problem is one of the most fundamental problems in dynamic networks. In this problem, we are given sources and sinks. Then the goal of this problem is to find a minimum time limit such that we can send the right amount of flow from sources to sinks. In this paper, we introduce a variant of this problem called the mixed evacuation problem. This problem models an emergent situation in which people can evacuate on foot or by car. The goal is to organize such a mixed evacuation so that an efficient evacuation can be achieved. In this paper, we study this problem from the theoretical and practical viewpoints. In the first part, we prove the polynomial-time solvability of this problem in

Research paper thumbnail of Enumeration of region partitioning for evacuation planning based on ZDD

11th International Symposium on Operations Research and its Applications in Engineering, Technology and Management 2013 (ISORA 2013), 2013

Japanese cities always have risks of large-scale earthquakes. Thus, it is very important to estab... more Japanese cities always have risks of large-scale earthquakes. Thus, it is very important to establish crisis management systems against large-scale disasters such as big earthquakes, and tsunamis to secure evacuation centers for evacuees. In this respect, it is extremely important to provide sufficient evacuation centers and to appropriately partition the whole region into small areas, such that a unique evacuation center is located in each area and the people living in the area can easily evacuate to the center. However, it is hard to find an optimal region partitioning, due to the uncertainty, such as a fire or collapsed buildings. In this research, we propose a method to enumerate all partitioning patterns using Zero-suppressed Binary Decision Diagram (ZDD) that satisfy several conditions. We apply the proposed method to Kamigyo Ward of Kyoto City, Japan.

Research paper thumbnail of Enumeration of Floor Plans Based on Zero-Suppressed Binary Decision Diagram

Proceedings of the 19th Conference on Computer Aided Architectural Design Research in Asia (CAADRIA), 2014

Open Building (Habraken, 1972) has been the focus of attention due to growing interest in the sus... more Open Building (Habraken, 1972) has been the focus of attention due to growing interest in the sustainable society. For Open Building, it is important to preserve the diversity of feasible floor plans in order to adapt to various lifestyles of residents. Capacity analysis is a method for evaluating the potential diversity. We propose a novel method that evaluates the potential diversity of floor plans by enumerating all feasible floor plans satisfying given constraints based on zero-suppressed binary decision diagram (ZDD) (Minato, 1993).

Research paper thumbnail of Street-level spatial analysis of crime location associated with built environment in Fushimi ward , yoto city 顕在パタンに基づく街頭犯罪分析 京都市伏見区における犯罪発生場所と構築環境の関係に着目した街区レベルの空間分析

We analyze the relationship between bag snatching and spatial relationships in Kyoto City. In par... more We analyze the relationship between bag snatching and spatial relationships in Kyoto City. In particular, we model natural surveillance with various façade components. We then analyze the data as a classification problem that divides space into areas in which crimes occur and areas in which crimes do not occur. Since there exists fuzziness in the categorization of space, we propose a new approach that combines clustering and classification based on semi-supervised learning, which determines the categorization so as to improve classification accuracy. In addition, we use an emerging pattern based classifier and obtain spatial features related to crime.

Research paper thumbnail of Impact of the Urban Exodus Triggered by the COVID-19 Pandemic on the Shrinking Cities of the Osaka Metropolitan Area

Sustainability, 2022

This study aims to clarify the impact of the urban exodus triggered by the COVID-19 pandemic on s... more This study aims to clarify the impact of the urban exodus triggered by the COVID-19 pandemic on shrinking cities in the Osaka metropolitan area, where a declining population is caused by population aging. Analyzing the Osaka metropolitan area enables us to clarify how cities are shrinking due to the urban exodus. This study analyzed the monthly population data of three types of municipalities: ordinance-designed/regional hub cities, ordinary cities, and towns/villages. In conclusion, the study clarified that population change due to the urban exodus occurred in the ordinance-designed/regional hub and ordinary cities from summer to autumn 2020. The most significant population increases occurred in the municipalities in the Osaka metropolitan fringe area, which are located more than 30 km away from the center of the Osaka metropolitan area. The conclusion is important because the population increased not only in the ordinance-designed cities but also in the ordinance-designed/regional...

Research paper thumbnail of 11049 Optimization of spatial form of concert hall by using Discrete Model and Genetic Algorithm

Research paper thumbnail of Which Residential Clusters of Walkability Affect Future Population from the Perspective of Real Estate Prices in the Osaka Metropolitan Area?

Sustainability, 2021

In Japan, where the population is declining and aging significantly, walkability has attracted at... more In Japan, where the population is declining and aging significantly, walkability has attracted attention as a way to improve residents’ lifestyles. Therefore, it is essential to identify the residential clusters where walkability improvement would contribute to the maintenance of the population in order to select urban areas for the implementation of walkable designs. This study aimed to identify the residential clusters in which walkability affects the future population from the perspective of real estate prices. The reason for focusing on real estate prices is that they are expected to be a confounding factor connecting walkability and the future population. The method we used was to analyze the structural equation modeling of the impact of walkability index, real estate prices, and future population change ratio. This analysis was based on the neighborhood association scale. This study clarified that effective residential clusters are the business center cluster and the sprawl cl...

Research paper thumbnail of Estimating Potential Event Occurrence Areas in Small Space based on Semi-supervised Learning

We propose a method for relatively small space that can optimize the size and shape of the neighb... more We propose a method for relatively small space that can optimize the size and shape of the neighborhood of an event occurrence spot on a grid space to minimize the classification error using classification by aggregating emerging patterns based on the concept of semi-supervised learning. We apply this method to data of waiting people in the Umeda Underground Mall and show that the proposed method can improve classification accuracy and understandability of classification rules.