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Takashi Akamatsu

Section

Graduate School of Information Sciences

Job title

Professor

Degree

工学博士（東京大学）
工学修士（東京大学）

researchmap

https://researchmap.jp/takashi.akamatsu

J-GLOBAL ID

200901039403541151

e-Rad No.

90262964

Research History 5

2005/05 - Present

Tohoku University　Professor
2000/04 - 2005/04

Tohoku University　Associate Professor
1995/04 - 2000/03

Toyohashi University of Technnology　Associate Professor
1998/04 - 1999/02

University of California-Berkeley　College of Engineering　Visiting scholar
1990/04 - 1994/03

Nomura Research Institute, Inc.

Education 4

The University of Tokyo　Graduate School of Engineering

1985/04 - 1990/03
The University of Tokyo　Faculty of Engineering　Department of Civil Engineering

1983/04 - 1985/03
The University of Tokyo

1981/04 - 1983/03
Dr. of Engineering, The University of Tokyo

1990/03 -

Professional Memberships 10

The Operations Research Society of Japan
交通工学研究会
日本応用数理学会
日本ファイナンス学会
Institute for Operations Research and the Management Sciences
応用地域学会
土木学会
Japan Society for Industrial and Applied Mathematics
Regional Science Association International
Japan Society of Civil Engineers

︎Show all ︎Show first 5

Research Interests 7

リスク
transportation planning
空間経済
ネットワーク
risk management
spatial economics
network

Research Areas 4

Humanities & social sciences / Economic policy /
Social infrastructure (civil Engineering, architecture, disaster prevention) / Social systems engineering /
Informatics / Mathematical informatics /
Social infrastructure (civil Engineering, architecture, disaster prevention) / Civil engineering (planning and transportation) /

Awards 5

JSCE Paper Prize

2015　Japan Society of Civil Engineers
The First Kometani-Sasaki Prize

2006　Institute of Systems Science Research
JSCE Paper Prize

2005　Japan Society of Civil Engineers
JSCE Paper Prize

1998　Japan Society of Civil Engineers
JSCE Young Scholor Paper Prize

1995　Japan Society of Civil Engineers

Papers 129

A market-based efficient matching mechanism for crowdsourced delivery systems with demand/supply elasticities Peer-reviewed

Yuki Oyama, Takashi Akamatsu

Transportation Research Part C: Emerging Technologies　174　105110-105110　2025/05
Publisher: Elsevier BV
DOI： 10.1016/j.trc.2025.105110 　

ISSN： 0968-090X
A fluid–particle decomposition approach to matching market design for crowdsourced delivery systems Peer-reviewed

Takashi Akamatsu, Yuki Oyama

Transportation Research Part C: Emerging Technologies　166　Article 104738　2024/09
Publisher: Elsevier BV
DOI： 10.1016/j.trc.2024.104738 　

ISSN： 0968-090X
Queue replacement principle for corridor problems with heterogeneous commuters Peer-reviewed

Takara Sakai, Takashi Akamatsu, Koki Satsukawa

Transportation Research Part B: Methodological　187　Article 103024　2024/09

DOI： 10.1016/j.trb.2024.103024 　 10.48550/arXiv.2210.03357 　
A paradox of telecommuting and staggered work hours in the bottleneck model Peer-reviewed

Takara Sakai, Takashi Akamatsu, Koki Satsukawa

Transportation Science　58　(6)　1335-1351　2024/07
Publisher: Institute for Operations Research and the Management Sciences (INFORMS)
DOI： 10.1287/trsc.2024.0520 　

ISSN： 0041-1655

eISSN： 1526-5447

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We study the long- and short-term effects of telecommuting (TLC), staggered work hours (SWH), and their combined scheme on peak-period congestion and location patterns. In order to enable a unified comparison of the schemes’ long- and short-term effects, we develop a novel equilibrium analysis approach that consistently synthesizes the long-term equilibrium (location and percentage of telecommuting choice) and short-term equilibrium (preferred arrival time and departure time choice). By exploiting their special mathematical structures similar to optimal transport problems, we derive the closed-form solution to the long- and short-term equilibrium while explicitly considering their interaction. These closed-form solutions elucidate the discrepancies between the effects of each scheme and uncover a paradoxical finding: the introduction of SWH, in conjunction with TLC, may increase the total commuting costs compared with the scenario with only TLC, without yielding any improvement in worker utility. History: This paper has been accepted for the Transportation Science Special Issue on ISTTT25 Conference. Funding: This work was supported by Council for Science, Technology and Innovation (CSTI), Cross-ministerial Strategic Innovation Promotion Program (SIP), the 3rd period of SIP “Smart Infrastructure Management System” [Grant JPJ012187] (Funding agency: PublicWorks Research Institute, Japan). This work was also supported by Japan Society for the Promotion of Science (JSPS) KAKENHI [Grants JP20J21744, JP21H01448, JP24K00999, JP20K14843, and JP23K13418] and the Support Program for Urban Studies of the Obayashi Foundation. Supplemental Material: The online appendix is available at https://doi.org/10.1287/trsc.2024.0520 .
Dynamic traffic assignment in a corridor network: Optimum versus equilibrium Peer-reviewed

Haoran Fu, Takashi Akamatsu, Koki Satsukawa, Kentaro Wada

Transportation Research Part B: Methodological　161　218-246　2022/07
Publisher: Elsevier BV
DOI： 10.1016/j.trb.2022.04.007 　

ISSN： 0191-2615
Markovian traffic equilibrium assignment based on network generalized extreme value model Peer-reviewed

Yuki Oyama, Yusuke Hara, Takashi Akamatsu

Transportation Research Part B: Methodological　155　135-159　2022/01
Publisher: Elsevier BV
DOI： 10.1016/j.trb.2021.10.013 　

ISSN： 0191-2615
A new look at departure time choice equilibrium models with heterogeneous users Peer-reviewed

Takashi Akamatsu, Kentaro Wada, Takamasa Iryo, Shunsuke Hayashi

Transportation Research Part B: Methodological　148　152-182　2021/06
Publisher: Elsevier BV
DOI： 10.1016/j.trb.2021.04.003 　

ISSN： 0191-2615
Model-based analysis on social acceptability and feasibility of a focused protection strategy against the COVID-19 pandemic Peer-reviewed

Takashi Akamatsu, Takeshi Nagae, Minoru Osawa, Koki Satsukawa, Takara Sakai, Daijiro Mizutani

Scientific Reports　11　(1)　2003-1-2003-9　2021/01
Publisher: Springer Science and Business Media LLC
DOI： 10.1038/s41598-021-81630-9 　

eISSN： 2045-2322

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<title>Abstract</title>This paper studies the social acceptability and feasibility of a focused protection strategy against coronavirus disease 2019 (COVID-19). We propose a control scheme to develop herd immunity while satisfying the following two basic requirements for a viable policy option. The first requirement is social acceptability: the overall deaths should be minimized for social acceptance. The second is feasibility: the healthcare system should not be overwhelmed to avoid various adverse effects. To exploit the fact that the disease severity increases considerably with age and comorbidities, we assume that some focused protection measures for those high-risk individuals are implemented and the disease does not spread within the high-risk population. Because the protected population has higher severity ratios than the unprotected population by definition, the protective measure can substantially reduce mortality in the whole population and also avoid the collapse of the healthcare system. Based on a simple susceptible-infected-recovered model, social acceptability and feasibility of the proposed strategy are summarized into two easily computable conditions. The proposed framework can be applied to various populations for studying the viability of herd immunity strategies against COVID-19. For Japan, herd immunity may be developed by the proposed scheme if <inline-formula><alternatives><tex-math>$${\mathcal {R } }_0 \le 2.0$$</tex-math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msub> <mml:mi>R</mml:mi> <mml:mn>0</mml:mn> </mml:msub> <mml:mo>≤</mml:mo> <mml:mn>2.0</mml:mn> </mml:mrow> </mml:math></alternatives></inline-formula> and the severity rates of the disease are 1/10 times smaller than the previously reported value, although as high mortality as seasonal influenza is expected.
Can a herd immunity strategy become a viable option against COVID-19? A model-based analysis on social acceptability and feasibility

Takashi Akamatsu, Takeshi Nagae, Minoru Osawa, Koki Satsukawa, Takara Sakai, Daijiro Mizutani

medRxiv　2020.05.19.20107524　2020/05
Publisher: Cold Spring Harbor Laboratory
DOI： 10.1101/2020.05.19.20107524 　

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<title>Abstract</title>This paper studies the social acceptability and feasibility of “herd immunity” strategies against coronavirus disease 2019 (COVID-19). To this end, we propose a control scheme that aims to develop herd immunity while satisfying the following two basic requirements for a viable policy option. The first requirement is social acceptability: the overall deaths should be minimized for social acceptance. The second is feasibility: the healthcare system should not be overwhelmed to avoid diverse adverse effects. Exploiting the fact that the severity of the disease increases considerably with age, the proposed control scheme protects high-risk individuals that mainly consist of the elderly. The protection of high-risk individuals reduces the average severity of the disease in the unprotected population, thereby substantially reducing mortality and avoiding the collapse of the healthcare system. Social acceptability (in terms of the resulting mortality) and feasibility (in terms of the healthcare system capacity) of the proposed herd immunity strategy are summarized into two respective, easily computable conditions by building on a simple susceptible–infected–recovered (SIR) model. For its parsimony, the proposed framework can provide a rule of thumb that applies to various populations for studying the viability of herd immunity strategies against COVID-19. For Japan, herd immunity may be developed by the considered control scheme if <inline-formula><alternatives><inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="20107524v1_inline1.gif" /></alternatives></inline-formula> and the severity rates of the disease are 1/10 times smaller than the previously reported value, although as high mortality as seasonal influenza is expected.
Equilibrium refinement for a model of non-monocentric internal structures of cities: A potential game approach Peer-reviewed

MinoruOsawa, TakashiAkamatsu

Journal of Economic Theory　187　105025-1-105025-40　2020/05

DOI： 10.1016/j.jet.2020.105025 　

ISSN： 0022-0531
Network throughput under dynamic user equilibrium: Queue spillback, paradox and traffic control Peer-reviewed

Kentaro Wada, Koki Satsukawa, Mike Smith, Takashi Akamatsu

Transportation Research Part B: Methodological　126　391-413　2019/08
Publisher: Elsevier BV
DOI： 10.1016/j.trb.2018.04.002 　

ISSN： 0191-2615
First-best dynamic assignment of commuters with endogenous heterogeneities in a corridor network Peer-reviewed

Minoru Osawa, Haoran Fu, Takashi Akamatsu

Transportation Research Part B: Methodological　117　811-831　2018/11

DOI： 10.1016/j.trb.2017.09.003 　

ISSN： 0191-2615
Trading mechanisms for bottleneck permits with multiple purchase opportunities Peer-reviewed

Pengfei Wang, Kentaro Wada, Takashi Akamatsu, Takeshi Nagae

Transportation Research Part C: Emerging Technologies　95　414-430　2018/10
Publisher: Elsevier BV
DOI： 10.1016/j.trc.2018.07.011 　

ISSN： 0968-090X
First-Best Dynamic Assignment of Commuters with Endogenous Heterogeneities in a Corridor Network Peer-reviewed

Minoru Osawa, Haoran Fu, Takashi Akamatsu

Transportation Research Procedia: Papers Selected for the 22nd International Symposium on Transportation and Traffic Theory (ISTTT 2017)　23　303-321　2017/07

DOI： 10.1016/j.trpro.2017.05.018 　

ISSN： 2352-1465
Tradable network permits: A new scheme for the most efficient use of network capacity Peer-reviewed

Takashi Akamatsu, Kentaro Wada

Transportation Research Part C: Emerging Technologies　79　178-195　2017/06

DOI： 10.1016/j.trc.2017.03.009 　

ISSN： 0968-090X
Harris and Wilson (1978) model revisited: The spatial period doubling bifurcation cascade in an urban retail model Peer-reviewed

Minoru Osawa, Takashi Akamatsu, Yuki Takayama

Journal of Regional Science　57　(3)　442-466　2017/06

DOI： 10.1111/jors.12306 　

ISSN： 0022-4146

eISSN： 1467-9787
Discrete-space agglomeration model with social interactions: Multiplicity, stability, and continuous limit of equilibria Peer-reviewed

Takashi Akamatsu, Shota Fujishima, Yuki Takayama

Journal of Mathematical Econocmics　69　22-37　2017/03

DOI： 10.1016/j.jmateco.2016.12.007 　

ISSN： 0304-4068
Agglomeration patterns in a long narrow economy of a new economic geography model: Analogy to a racetrack economy Invited Peer-reviewed

Kiyohiro Ikeda, Kazuo Murota, Takashi Akamatsu, Yuki Takayama

International Journal of Economic Theory　13　(1)　113-145　2017/03

DOI： 10.1111/ijet.12120 　

ISSN： 1742-7355

eISSN： 1742-7363
A Critical Note on Recent Empirical Studies based on Spatial Agglomeration Models Peer-reviewed

Minoru OSAWA, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　73　(1)　1-15　2017/01
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.73.1 　

eISSN： 2185-6540

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 We analytically study a discrete-space version of the spatial model of agglomeration proposed by Allen and Arkolakis.¹⁾ Employing the bifurcation analysis method developed by Akamatsu et al.,¹⁴⁾ we show that the model exhibits, if any, only mono-centric or unimodal spatial concentration patterns of mobile agents. The properties we reveale in this paper pose one simple but significant issue: Can we justify fitting the model to the actual spatial patterns, which are typically not mono-centric but poly-centric? We argue that, the unobserved amenity approach, which Allen and Arkolakis and other recent studies employ to circumvent the issue, is an inappropriate one as it can replicate any observed data with any model.
Post Mega-Disaster Gasoline Distribution Strategies to Reduce Social-Economic Losses: Lessons from the Great East Japan Earthquake Invited Peer-reviewed

Takashi Akamatsu, Minoru Osawa, Takeshi Nagae, Hiromichi Yamaguchi

Journal of JSCE Series D3: Infrastructure Planning and Management　72　(5)　I_1-I_19　2016/12/01
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.72.I_1 　

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In the Great East Japan Earthquake on 11th March, 2011, the Tohoku region was faced with serious gasoline shortages for an extended period due to the severe damage on its only oil refinery and the major oil terminals on the Pacific coast by the earthquake and subsequent tsunami. Such gasoline shortages not only hampered relief and restoration efforts but also dampened socio-economic activities in the entire Tohoku region. In this study, using actual data, we first clarify that the fundamental reason for the gasoline shortages was a failure in adjusting the amount and shipping patterns of gasoline in response to the spatial changes in the production areas caused by the disaster. We then show that the gasoline shortages could have been reduced considerably by some post-disaster gasoline distribution strategies to redirect a certain amount of gasoline into the Tohoku region from other unaffected areas. It is also discussed that a traditional price adjustment policy is not suitable for mitigating socio-economic losses due to such large-scale disaster. Finally, we estimate the cost required to execute such a gasoline distribution strategy as well as its economic effect, demonstrating that although the cost is only 300 million yen, the benefit amounts to over 200 billion yen.
The corridor problem with discrete multiple bottlenecks Peer-reviewed

Takashi Akamatsu, Kentaro Wada, Shunsuke Hayashi

Transportation Research Part B: Methodological　81　(3)　808-829　2015/11

DOI： 10.1016/j.trb.2015.07.015 　

ISSN： 0191-2615
The corridor problem with discrete multiple bottlenecks Peer-reviewed

Takashi Akamatsu, Kentaro Wada, Shunsuke Hayashi

Transportation Research Procedia: 21st International Symposium on Transportation and Traffic Theory (ISTTT 2015)　7　474-498　2015

DOI： 10.1016/j.trpro.2015.06.025 　

ISSN： 2352-1465
Self-organization of hexagonal agglomeration patterns in new economic geography models Peer-reviewed

Kiyohiro Ikeda, Kazuo Murota, Takashi Akamatsu, Tatsuhito Kono, Yuki Takayama

Journal of Econocmic Behavior & Organization　99　32-52　2014/03

DOI： 10.1016/j.jebo.2013.12.008 　

ISSN： 0167-2681

eISSN： 1879-1751
Spatio-Temporal Analysis of Gasoline Shortages in the Tohoku Region after the Great East Japan Earthquake Invited Peer-reviewed

Takashi Akamatsu, Minoru Osawa, Takeshi Nagae, Hiromichi Yamaguchi

Journal of JSCE　1　(1)　447-469　2013/12/27
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalofjsce.1.1_447 　

ISSN： 2187-5103

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In this study, we analyzed the actual amount of gasoline transported into the Tohoku region during the first month after the Great East Japan Earthquake. We found that: (1) the amount of gasoline supplied in the Tohoku region during the first two weeks was only 1/3 of the normal demand; (2) the shortage of supply in the first two weeks led to a huge "back-log of demand"; (3) it took four weeks for the backlog to be cleared and the lost (suppressed) demand during the period was equivalent to the amount of normal demand for 7 days; (4) the gaps between gasoline supply and demand in the Pacific coast areas were huge, compared with those in the Japan sea coast areas, while the gap in each prefecture of the Tohoku region was gradually reduced over time in the following order: Akita, Aomori, Iwate, Yamagata, and finally, Miyagi prefecture.
A hybrid implementation mechanism of tradable network permits system which obviates path enumeration: An auction mechanism with day-to-day capacity control Peer-reviewed

Kentaro Wada, Takashi Akamatsu

Transportation Research Part E: Logistics and Transportation Review　60　94-112　2013/12

DOI： 10.1016/j.tre.2013.05.008 　

ISSN： 1366-5545
Spatio-Temporal Analysis of Gasoline Shortages in the Tohoku Region after the Great East Japan Earthquake Peer-reviewed

Takashi Akamatsu, Minoru Osawa, Takeshi Nagae, Hiromichi Yamaguchi

Journal of JSCE Series D3: Infrastructure Planning and Management　69　(2)　187-205　2013/06

DOI： 10.2208/jscejipm.69.187 　
A hybrid implementation mechanism of tradable network permits system which obviates path enumeration: an auction mechanism with day-to-day capacity control Peer-reviewed

Kentaro Wada, Takashi Akamatsu

Procedia - Social and Behavioral Sciences: 20th International Symposium on Transportation and Traffic Theory (ISTTT 2013)　80　304-326　2013

DOI： 10.1016/j.sbspro.2013.05.018 　

ISSN： 1877-0428
Spatial discounting, Fourier, and racetrack economy: A recipe for the analysis of spatial agglomeration models Peer-reviewed

Takashi Akamatsu, Yuki Takayama, Kiyohiro Ikeda

Journal of Economic Dynamics & Control　36　(11)　1729-1759　2012/11

DOI： 10.1016/j.jedc.2012.04.010 　

ISSN： 0165-1889
Spatial period-doubling agglomeration of a core-periphery model with a system of cities Peer-reviewed

Kiyohiro Ikeda, Takashi Akamatsu, Tatsuhito Kono

Journal of Economic Dynamics & Control　36　(5)　754-778　2012/05

DOI： 10.1016/j.jedc.2011.08.014 　

ISSN： 0165-1889
Self-organization of Lösch's hexagons in economic agglomeration for core-periphery models Peer-reviewed

Kiyohiro Ikeda, Kazuo Murota, Takashi Akamatsu

International Journal of Bifurcation and Chaos　22　(8)　2012

DOI： 10.1142/S0218127412300261 　

ISSN： 0218-1274
A network of options: Evaluating complex interdependent decisions under uncertainty Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

Journal of Economic Dynamics & Control　35　(5)　714-729　2011/05

DOI： 10.1016/j.jedc.2011.01.004 　

ISSN： 0165-1889
An e-Market Mechanism for Implementing Tradable Bottleneck Permits Peer-reviewed

Kentaro WADA, Takashi AKAMATSU

JSCE Journal of Infrastructure Planning and Management (Doboku Gakkai Ronbunshuu D)　66　(2)　160-177　2010
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejd.66.160 　

ISSN： 1880-6058

eISSN： 1880-6058
Bifurcation Mechanism of the Core-Periphery System of Cities Model Peer-reviewed

Takashi Akamatsu, Yuki Takayama, Kiyohiro Ikeda, Akiko Sugasawa

JSCE Journal of Infrastructure Planning and Management　66　(4)　442-460　2010

DOI： 10.2208/jscejd.66.442 　

ISSN： 1880-6058
A generalized complementarity approach to solving real option problems Peer-reviewed

Takeshi Nagae, Takashi Akamatsu

Journal of Economic Dynamics & Control　32　(6)　1754-1779　2008/06

DOI： 10.1016/j.jedc.2007.04.010 　

ISSN： 0165-1889
Dynamic Ramp Metering Strategies for Risk Averse System Optimal Assignment Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

Transportation and Traffic Theory　17　87-110　2007
A System of Tradable Bottleneck Permits for Transportation Networks Peer-reviewed

Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　63　(3)　287-301　2007

DOI： 10.2208/jscejd.63.287 　

ISSN： 1880-6058
Equilibrium Dynamics of Interregional Migration Timing Decision in Agglomeration Economies Peer-reviewed

Toshimori Otazawa, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　63　(4)　567-578　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejd.63.567 　

ISSN： 1880-6058

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We propose a novel long-term migration dynamics that can overcome the equilibrium indeterminacy of Core-Periphery (CP) model a la Krugman (The Quarterly Journal of Economics 106 (1991) 651-667). This goal is achieved by introducing uncertainty of economic environment into CP model with Perfect foresight migration dynamics. We show that an equilibrium path of migration dynamics can be uniquely determined in accordance with each stochastic sample path. We also reveal some properties of long-run outcomes.
Dynamic revenue management of a toll road project under transportation demand uncertainty Peer-reviewed

Takeshi Nagae, Takashi Akamatsu

Networks & Spatial Economics　6　(3-4)　345-357　2006/09

DOI： 10.1007/s11067-9288-5 　

ISSN： 1566-113X
A Financial Engineering Approach to Managing Infrastructure Project Risks Invited Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

Infrastructure Planning Review　23　(1)　1-21　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.23.1 　

ISSN： 0913-4034
Tradable Time-of-Day Bottleneck Permits for Morning Commuters Peer-reviewed

Takashi Akamatsu, Shintaro Sato, Nguyen Xuan Long

JSCE Journal of Infrastructure Planning and Management　62　(4)　605-620　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejd.62.605 　

ISSN： 1880-6058

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This paper presents a novel transportation demand management scheme that can completely eliminate traffic jam at a bottleneck. In the proposed scheme, a road manager issues "bottleneck permits" that allow road users to pass a pre-specified bottleneck at a pre-specified time, and they are traded (and priced) among road users in auction markets. We then prove that the introduction of the proposed system in morning rush-hour not only eliminates traffic jam but also can achieve Pareto optimality in equilibrium. Through this analysis, we reveal that the equilibrium problem of the proposed system is mathematically isomorphic to an equilibrium model of urban residential location.
Variational Inequality Approach to Infrastructure Investment Problems under Uncertainty Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

JSCE Journal of Infrastructure Planning and Management　(765)　155-171　2004
Publisher:
DOI： 10.2208/jscej.2004.765_155 　

ISSN： 0289-7806 1882-7187
Detecting dynamic traffic assignment capacity paradoxes in saturated networks Peer-reviewed

T Akamatsu, B Heydecker

Transportation Science　37　(2)　123-138　2003/05

DOI： 10.1287/trsc.37.2.123.15245 　

ISSN： 0041-1655
An efficient algorithm for dynamic traffic equilibrium assignment with queues Peer-reviewed

T Akamatsu

Transortation Science　35　(4)　389-404　2001/11

DOI： 10.1287/trsc.35.4.389.10435 　

ISSN： 0041-1655
Dynamic user optimal assignment with physical queues for a many-to-many OD pattern Peer-reviewed

M Kuwahara, T Akamatsu

Transportation Research Part B: Methodological　35　(5)　461-479　2001/06

DOI： 10.1016/S0191-2615(00)00005-9 　

ISSN： 0191-2615
A dynamic traffic equilibrium assignment paradox Peer-reviewed

T Akamatsu

Transportation Research Part B: Methodological　34　(6)　515-531　2000/08

DOI： 10.1016/S0191-2615(99)00036-3 　

ISSN： 0191-2615
Dynamic Network Analyses - Present Knowledge and Future Exploration Invited Peer-reviewed

Masao Kuwahara, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　IV-48　(653)　3-16　2000
Publisher:
DOI： 10.2208/jscej.2000.653_3 　

ISSN： 1882-7187 0289-7806
A capacity increasing paradox for a dynamic traffic assignment with departure time choice Peer-reviewed

T Akamatsu, M Kuwahara

Transportation and Traffic Theory　14　301-324　1999
Decomposition of path choice entropy in general transport networks Peer-reviewed

T Akamatsu

Transportation Science　31　(4)　349-362　1997/11

DOI： 10.1287/trsc.31.4.349 　

ISSN： 0041-1655
Decomposition of the reactive dynamic assignments with queues for a many-to-many origin-destination pattern. Peer-reviewed

M Kuwahara, T Akamatsu

Transportation Research Part B: Methodological　31　(1)　1-10　1997/02

DOI： 10.1016/S0191-2615(96)00020-3 　

ISSN： 0191-2615
Cyclic flows, Markov process and stochastic traffic assignment Peer-reviewed

T Akamatsu

Transportation Research Part B: Methodological　30　(5)　369-386　1996/10

DOI： 10.1016/0191-2615(96)00003-3 　

ISSN： 0191-2615
The Theory of Dynamic Traffic Network Flows Invited Peer-reviewed

Takashi Akamatsu

Infrastructure Planning Review　13　23-48　1996

DOI： 10.2208/journalip.13.23 　
Dynamic User Equilibrium Assignment on Oversaturated Road Networks Peer-reviewed

Takashi Akamatsu, Masao Kuwahara

Doboku Gakkai Ronbunshu　1994　(488)　21-30　1994/04/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.1994.488_21 　

ISSN： 0289-7806

eISSN： 1882-7187
Dynamic Equilibrium Assignment with Queues for a One-to-Many OD Pattern Peer-reviewed

Masao Kuwahara, Takashi Akamatsu

Selected Papers of the 12th International Symposium on Transportation and Traffic Theory (12th ISTTT)　12　185-204　1993
Publisher:
An Efficient Algorithm for Solving Stochastic User Equilibrium Assignment Peer-reviewed

Takashi Akamatsu, Yuji Tsuchiya, Nobuhiro Kawakami

Traffic Engineering　26　(1)　51-58　1991
Parallel Distributed Processing on Neural Networks for Some Transportation Equilibrium Assignment Problems Peer-reviewed

Takashi Akamatsu, Yuji Tsuchiya, Toshikazu Shimaxaki

Selected Papers of the 11th International Symposium on Transportation and Traffic Theory (11th ISTTT)　11　307-323　1990
A Stochastic Network Equilibrium Model with Elastic Demand and Its Solution Method Peer-reviewed

Takashi Akamatsu, Yoshiji Matsumoto

JSCE Journal of Infrastructure Planning and Management　IV-10　(401)　109-118　1989
Publisher:
DOI： 10.2208/jscej.1988.121 　

ISSN： 0289-7806 1882-7187
Optimal Toll Pattern on a Road Network under Stochastic Equilibrium with Elastic Demand Peer-reviewed

Takashi Akamatsu, Masao Kuwahara

Selected Proceedings of the 5th World Conference on Transportation Research　5　259-273　1989
A Time-Space Network Equilibrium Model of Rail Commuters and Its Application to the Evaluation of Train Diagrams from the View Point of User Welfare Peer-reviewed

Hitoshi Ieda, Takashi Akamatsu, Jun Takagi

Infrastructure Planning Review　6　177-184　1988

DOI： 10.2208/journalip.6.177 　
A Fast Algorithm for Fujita-Ogawa Model in Discrete Two-Dimensional Space Peer-reviewed

Takara SAKAI, Masanao WAKUI, Takashi AKAMATSU

Japanese Journal of JSCE　79　(4)　22-00341　2023
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejj.22-00341 　

eISSN： 2436-6021
An Effcient Algorithm for Solving Dynamic User Equiibrium Traffic Assignment in Large-scale Networks Peer-reviewed

Masanao WAKUI, Takara SAKAI, Takashi AKAMATSU

Japanese Journal of JSCE　79　(4)　22-00301　2023
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejj.22-00301 　

eISSN： 2436-6021
An Efficient Matching Mechanism for Large-scale Crowdsourced Delivery Systems: A Generalized Model with Price Elasticity of Supply and Demand Peer-reviewed

Tsubasa TAKEDA, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　78　(4)　190-209　2022/10
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.78.4_190 　

eISSN： 2185-6540
Decomposition Strategies for Solving Crowdsourced-Delivery Matching Problems Peer-reviewed

Taiki WATANABE, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　77　(2)　83-96　2021/05
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.77.2_83 　

eISSN： 2185-6540
Departure Time Choice Problems with Heterogeneous Values of Schedule Delay in Tandem Bottlenecks Peer-reviewed

Takara SAKAI, Takashi AKAMATSU, Koki SATSUKAWA

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　77　(4)　330-345　2021
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.77.4_330 　

ISSN： 2185-6540

eISSN： 2185-6540
A Quadratic Programming Approach for Solving a Dynamic Uuser Equilibrium with Simultaneous Departure Time and Route Choice Peer-reviewed

Takeshi NAGAE, Takashi AKAMATSU, Ren SHIMIZU, Haoran FU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　76　(3)　264-281　2020/09
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.76.3_264 　

eISSN： 2185-6540
Evaluating Post-Megadisaster Strategies against Region-Wide Gasoline Shortages in the Aftermath of the Great East Japan Earthquake Peer-reviewed

Takeshi Nagae, HIromichi Yamaguchi, Minoru Osawa, Takashi Akamatsu

2019/05
Stability of Traffic Congestion Patterns and Macroscopic Fundamental Diagrams in Tokyo Metropolitan Expressway Network Peer-reviewed

Takara SAKAI, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　75　(2)　97-108　2019
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.75.97 　

ISSN： 2185-6540

eISSN： 2185-6540
Stochastic Stability Analysis of a Model of Polycentric Urban Configurations: Linear City vs. Circular City Peer-reviewed

Shuhei YAMAGUCHI, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　75　(2)　109-127　2019
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.75.109 　

eISSN： 2185-6540
Modeling Spatial Agglomeration with Input-Output Linkages and Multi-Scale Spatial Structure Peer-reviewed

Tomoki ISHIKURA, Yuki TAKAYAMA, Takashi AKAMATSU

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　74　(3)　203-216　2018/08
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.74.203 　

eISSN： 2185-6540

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Evolution of hierarchical urban/regional system is observed in various spatial economic scales. This paper develops a multi-regional economy model with hierarchical (multi-scale) spatial structure and input-output linkages. We conduct numerical simulations to explore how the changes in interregional and intraregional transport cost affect the spatial distribution of economic activities. The results indicate that transport cost reduction causes re-dispersion from monocentric agglomeration, which is consistent with propositions in previous studies. We furthermore find some properties on industrial agglomeration patterns in the multi-scale spatial structure.
Characterization of Macroscopic Fundamental Diagrams Based on a Long-term Detector Data: A Case Study of Sendai and Kyoto Cities Peer-reviewed

Pengfei Wang, Takashi Akamatsu, Kentaro Wada, Masatoshi Sugita, Toshikazu Nagoya, Hiroshi Sumi

JSTE Journal of Traffic Engineering　2　(5)　11-20　2016/07/01
Publisher:
DOI： 10.14954/jste.2.5_11 　

ISSN： 0454-4595
Development of a Spatial Computable General Equilibrium Model with Factor Mobility and Agglomeration Economies Peer-reviewed

Yuki Takayama, Takashi Akamatsu, Tomoki Ishikura

Journal of JSCE Series D3: Infrastructure Planning and Management　72　(2)　211-230　2016/06/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.72.211 　

eISSN： 2185-6540

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This study develops a spatial computable general equilibrium model that considers agglomeration economies and mobility of production factors, including labor and capital. To this end, we extend the new economic geography models of industrial location and agglomeration with factor mobility. We then present parameter estimation and calibration procedures and an approach for obtaining the stable equilibrium that emerges with changes in structural parameters. Applying these methods, this study quantifies the effects of the trade cost reductions in Japan to clearly describe characteristics of the developed model.
Bifurcation Analysis of a Retail Location Model with Agglomeration Economy Peer-reviewed

Minoru Osawa, Takashi Akamatsu, Yuki Takayama

Journal of JSCE Series D3: Infrastructure Planning and Management　71　(3)　141-155　2015/09/20
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.71.141 　

ISSN： 2185-6540

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The present paper demonstrates that the bifurcation analysis method proposed by Akamatsu et al.¹⁵⁾ is readily applicable to the retail location model due to Harris & Wilson (1978)¹⁾. Employing 4-zone example, we analytically predict when and in which zone the agglomeration of retailers emerge. Our analysis also suggests that "spatial period doubling cascade" previously observed in some new economic geography models, proved in Ikeda et al.¹⁴⁾ and Akamatsu et al.¹⁵⁾, exists in Harris & Wilson model.
An Empirical Analysis of Macroscopic Fundamental Diagrams for Sendai Road Networks Peer-reviewed

Pengfei Wang, Kentaro Wada, Takashi Akamatsu, Yusuke Hara

Interdisciplinary Information Sciences　21　(1)　49-61　2015/03/01
Publisher: Tohoku University
DOI： 10.4036/iis.2015.49 　

ISSN： 1340-9050

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The purpose of this paper is to explore the features of the Macroscopic Fundamental Diagram (MFD) for Sendai road networks. In order to achieve this, we used the observed data of 5-minute periods throughout one year (5/1/2012–4/30/2013) to draw the MFDs for Sendai road networks. The result of the empirical verification shows the following: (1) the hysteresis loops always form in an MFD on weekdays with good weather, and their formation times correspond to the peak hours of the morning and evening; (2) the shape of the MFD is invariant throughout the year; (3) loops do not form on Sundays (or holidays) when the peak of traffic demand is lower than on weekdays; (4) loops that are larger than those in a typical MFD form when the driving environment is poor; and (5) if the analysis area for drawing the MFD shrinks, then the variation of the MFD expands.
Stochastic User Equilibrium Traffic Assignment with a Network GEV based Route Choice Model Peer-reviewed

Yusuke Hara, Takashi Akamatsu

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　70　(5)　611-620　2014/12/31
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.70.I_611 　

ISSN： 2185-6540

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Using a network GEV based route choice model, we propose a new extension of logit type stochastic user equilibrium (SUE) traffic assignment. The multinomial logit model structure cannot capture similarities among alternatives because of the independence of irrelevant alternatives (IIA) property and hence is not suitable to model route choice. In this paper, we propose a network GEV based SUE and this model described the route choice behavior which is consistent of random utility theory and captured the path correlation structure. And our model does not need explicit path enumeration and calculation of overlap link length unlike in the case of probit model and cross nested logit model.
Development of a SCGE model based on New Economic Geography Peer-reviewed

Yuki Takayama, Takashi Akamatsu, Tomoki Ishikura

Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)　70　(4)　245-258　2014/12/19
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.70.245 　

ISSN： 2185-6540

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In the last two decades, a large number of studies have attempted to develop spatial computable general equilibrium (SCGE) models based on new economic geography (NEG). Although these studies provide SCGE models with agglomeration economies, their framework is oversimplified for computational purposes and inconsistent with NEG. This study develops an SCGE model consistent with NEG that has the following two characteristics to overcome the shortcomings of previous studies: 1) this model considers vertical linkages (input-output linkages) as in Venables¹⁾, which ensures the theoretical consistency; 2) the stable equilibrium that emerges after implementation of policies can be obtained. Furthermore, we present a numerical example to demonstrate that our model can be applied to practical applications.
Agglomeration Patterns of a Core-Periphery Model with Multi-Scale Spatial Structure Peer-reviewed

Yuki Takayama, Takashi Akamatsu, Naohiro Kosaka

Journal of JSCE Series D3: Infrastructure Planning and Management　70　(1)　113-130　2014/03/20

DOI： 10.2208/jscejipm.70.113 　
新経済地理学に基づく空間応用一般均衡モデルによる便益評価

高山雄貴, 赤松隆, 石倉智樹

土木計画学研究・講演集　49　2014
Emergence of Urban Hierarchies in One-Dimensional Space: Bifurcation Analysis of a Multi-Industrial Core-Periphery Model with Relocation Costs Peer-reviewed

Yuki Takayama, Takashi Akamatsu, Akiko Sugasawa

Journal of JSCE Series D3: Infrastructure Planning and Management　69　(3)　250-266　2013/09

DOI： 10.2208/jscejipm.69.250 　
A Quantitative Analysis of the Oil Shortage in Tohoku Region during the First Month after the Great East Japan Earthquake Peer-reviewed

Takashi Akamatsu, Hiromichi Yamaguchi, Takeshi Nagae, Hajime Inamura

Transport Policy Studies' Review　16　(1)　31-41　2013/04

ISSN： 1344-3348
Agglomeration Mechanism of a System of Cities on a Line Segment Peer-reviewed

Kiyohiro Ikeda, Takashi Akamatsu, Tatsuhito Kono, Yuki Takayama, Kenji Sakamoto, Reza Sobhaninejad

Journal of JSCE Series D3: Infrastructure Planning and Management　69　(1)　53-63　2013/03

DOI： 10.2208/jscejipm.69.53 　
階層化された空間スケールを持つ空間経済システムにおける経済集積と輸送費

石倉智樹, 赤松隆, 高山雄貴

土木計画学研究・講演集　48　2013
A Control Strategy to Prevent Delay Propagation in High-Frequency Railway Systems Peer-reviewed

Kentaro Wada, Sangjoon Kil, Takashi Akamatsu, Minoru Osawa

Journal of JSCE Series D3: Infrastructure Planning and Management　68　(5)　1025-1034　2012/12
Publisher:
DOI： 10.2208/jscejipm.68.I_1025 　
Auction Mechanisms for Implementing Tradable Network Permits Peer-reviewed

Kentaro Wada, Takashi Akamatsu

Journal of JSCE Series D3: Infrastructure Planning and Management　67　(3)　376-389　2011/09
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejipm.67.376 　

ISSN： 2185-6540

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This paper proposes a new auction mechanism for implementing the tradable network permit markets. Assuming that each user makes a trip from an origin to a destination along a path in a specific time period, we design an auction mechanism that enables each user to purchase a bundle of permits corresponding to a set of links in the user's preferred path. The objective of the proposed mechanism is to achieve a socially optimal state with minimal revelation of users' private information. In order to achieve this, the mechanism employs an evolutionary approach that has an auction phase and a path capacity adjustment phase, which are repeated on a day-to-day basis. We prove that the proposed mechanism has the following desirable properties: (1) truthful bidding is the dominant strategy for each user and (2) the proposed mechanism converges to an approximate socially optimal state in the sense that the achieved value of the social surplus reaches its maximum value when the number of users is large.
Emergence of Multiple CBDs from a Combination of Spatial Interaction and Competition Peer-reviewed

Yuki Takayama, Takashi Akamatsu

Journal of JSCE Series D3: Infrastructure Planning and Management　67　(1)　1-20　2011/01

DOI： 10.2208/jscejipm.67.1 　
STOCHASTIC CONVERGENCE OF A HYBRID SCHEME OF TRADABLE BOTTLENECK PERMITS AND CONGESTION PRICING Peer-reviewed

Kentaro Wada, Takashi Akamatsu, Takeshi Nagae

TRANSPORTATION AND URBAN SUSTAINABILITY　173-180　2010
Non-Uniqueness and Stability of Equilibrium Urban Configuration for Beckmann's Spatial Interaction Model Peer-reviewed

Yuki TAKAYAMA, Takashi AKAMATSU

JSCE Journal of Infrastructure Planning and Management (Doboku Gakkai Ronbunshuu D)　66　(2)　232-245　2010
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejd.66.232 　

ISSN： 1880-6058

eISSN： 1880-6058
Emergence of Industrial Hierarchy in One-dimensional Space: Bifurcation Analysis of a Multi-industry Location Model with Communication Externality Peer-reviewed

Yuki Takayama, Takashi Akamatsu

Infrastructure Planning Review　27　(2)　285-295　2010

DOI： 10.2208/journalip.27.285 　
Bifurcation Analysis of a Core-Periphery Model on a Two-dimensional Triangular Lattice Peer-reviewed

Yuki Takayama, Takashi Akamatsu

Infrastructure Planning Review　27　(1)　109-120　2010

DOI： 10.2208/journalip.27.109 　
Irreducibility of Dynamic Traffic Conditions in a Model of Residential Location and Departure Time Choice Equilibrium with Bottleneck Congestion Peer-reviewed

Yuki Takayama, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　65　(1)　39-52　2009

DOI： 10.2208/jscejd.65.39 　
Welfare Analysis of a Core-Periphery Model with Consumer Heterogeneity Peer-reviewed

Akiko Sugasawa, Takashi Akamatsu, Yuki Takayama

Infrastructure Planning Review　26　(2)　393-402　2009

DOI： 10.2208/journalip.26.393 　
Efficient Algorithms for Semi-dynamic Traffic Equilibrium Assignment with a Many-to-One OD Pattern Peer-reviewed

Sangjoon Kil, Takashi Akamatsu, Shiro Kikuchi, Sinichi Inoue

Infrastructure Planning Review　26　(5)　989-997　2009

DOI： 10.2208/journalip.26.989 　
Convergence of day-to-day traffic flow dynamics under tradable bottleneck permits Peer-reviewed

K. Wada, T. Akamatsu, S. Kikuchi

WIT Transactions on the Built Environment　101　579-588　2008

DOI： 10.2495/UT080561 　

ISSN： 1743-3509
A Core-Periphery Model with a Knowledge Transfer Mechanism Peer-reviewed

Shintaro Sato, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　64　(2)　239-251　2008
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscejd.64.239 　

ISSN： 1880-6058

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It is getting more and more important that skilled labors pass down their knowledge to the younger generations under declining population. We construct a Core-Periphery model in which young labors migrate between cities aiming at learning from skilled labors. The analysis of the model reveals that decrease in young generations increases each young labor's chances of learning through urban agglomeration. Furthermore, we demonstrate that the preferential tax policy for young labors has a disastrous effect that leads to the death of the city while the opposite policy is effective for growth of population in the city.
Convergence of day-to-day traffic flow dynamics under tradable bottleneck permits Peer-reviewed

K. Wada, T. Akamatsu, S. Kikuchi

URBAN TRANSPORT XIV　101　579-+　2008

DOI： 10.2495/UT080561 　

ISSN： 1746-4498
Bifurcation Patterns of a Core-Periphery Model with Multiple Industries Peer-reviewed

Iori Kasahara, Takashi Akamatsu

Journal of the City Planning Institute of Japan　43　(3)　109-114　2008

DOI： 10.11361/journalcpij.43.3.109 　
Pareto Improvement Properties of Tradable Permit Systems for a Tandem Bottleneck Network Peer-reviewed

Masanobu Yodoshi, Takashi Akamatsu, Yuki Takayama

Infrastructure Planning Review　25　(4)　897-908　2008
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.25.897 　

ISSN： 0913-4034

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Akamatsu et al.(2006) proposed "tradable bottleneck permits"(TBP) system and showed theoretical properties of the TBP system for a single bottleneck network. In this paper, we examine some economic properties of the TBP system for a tandem bottleneck network. We first reveal that the equilibrium dynamic flow pattern under the TBP system minimizes the total travel cost of the network. We then show that under the TBP system, (1) Pareto improvement can be achieved, if revenue from the permits is redistributed to users, (2) Pareto improvement is not necessarily achieved, otherwise.
Dynamics of Decentralized Multi-Agent Systems for Implementing Tradable Network Permits Peer-reviewed

Shiro Kikuchi, Takashi Akamatsu

Infrastructure Planning Review　25　(3)　589-596　2008
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.25.589 　

ISSN： 0913-4034

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This paper proposes a multi-agent system for implementing tradable bottleneck permits for general transportation networks. The aim of the proposed system is to achieve the socially optimal state in which total transportation cost is minimized by decentralized behavior of agents. As a concrete step of designing the proposed system, we first define some micro behavior rules of the agents. We then derive day-to-day dynamics of aggregated (macroscopic) variables (i. e. flows and permits prices) from the micro behavior rules. By analyzing the macro dynamics, we prove that the mean dynamics of aggregated variables converges to the socially optimal state.
Socially Optimal Dynamic Allocation in Core-Periphery Models with Economic Uncertainty Peer-reviewed

Toshimori Otazawa, Takashi Akamatsu, Shuichi Yamazaki

Infrastructure Planning Review　25　(1)　245-254　2008
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.25.245 　

ISSN： 0913-4034

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In this paper, we propose a Dynamic Social Optimal (DSO) migration model under economic uncertainty. The proposed migration model attempts to maximize expected net present value of the sum of consumer utility by controlling amount of migration flow. We show that the optimal migration strategy takes the form of impulse control that depends on population and transportation cost. Comparing the equilibrium migration flow with the optimal one, we find that the direction of equilibrium migration flow is opposite to the direction of optimal one for medium transportation cost.
An Efficient Algorithm for A Maximin Routing Model for Hazardous Materials Peer-reviewed

Nagae, T, Akamatsu, T

The 3rd International Symposium on Transport Network Reliability　2007/07
Dynamic System Optimal Traffic Control based on Realtime Observation of Stochastic Travel Time Peer-reviewed

Takeshi Nagae, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　63　(3)　311-327　2007

DOI： 10.2208/jscejd.63.311 　

ISSN： 1880-6058
Real Option Problems with Stochastic Interest Rates Peer-reviewed

Kei TAKAHASHI, Takashi AKAMATSU, Go MIZUTANI

Infrastructure Planning Review　24　(1)　111-120　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.24.111 　

ISSN： 0913-4034

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This paper studies real option problems with stochastic interest rates and the tam structure of interest rates. Numerical experiments reveal that both threshold value of the project cashflow and option value show wrong value in the conventional methods with deterministic interest rates. For a typical example, threshold value of the project cashflow is about 5 times larger than that in the conventional methods, and the option value is about 4 times larger than that in the conventional model. We conclude that we need considering stochastic interest rates and the term structure of interest rates, when we deal with real estate investment problems.
Proposal of a Bifurcation Analysis Procedure of Core-Periphery Model by Computational Bifurcation Theory Peer-reviewed

Akito YANAGIMOTO, Kiyohiro IKEDA, Takashi AKAMATSU, Tatsuhito KONO, Syunji YAMAKI

Infrastructure Planning Review　24　(1)　191-196　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.24.191 　

ISSN： 0913-4034

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It is known that the model that expresses the city accumulation phenomenon by the change of transportation cost has multiple equilibria for two or three cities. However, there is no research on the pattern of spatial accumulation and decentralization of the population when the number of cities was increased further. In this research, the numerical analysis procedure based on computational bifurcation theory is carried out on the Core-Periphery model for many cities with the same population that are located evenly on a circle. As a result, complex bifurcation behaviors of the model has successfully been traced by means of this procedure.
Core-Periphery Equilibrium Dynamics under Uncertainty: Nonlinear Complementarity Approach Peer-reviewed

Toshimori OTAZAWA, Takashi AKAMATSU, Makoto FUJIWARA

Infrastructure Planning Review　24　(1)　197-206　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.24.197 　

ISSN： 0913-4034

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We propose a novel long-term migration dynamics that can overcome the equilibrium indeterminacy of Core-Periphery (CP) model a la Krugman [1991d] This goal is achieved by introducing uncertainty of economic environment into CP model with forward-looking migration dynamics. We first disclose that the equilibrium condition of migration dynamics can be represented as a NCP (Nonlinear Complementarity Problem) and then develop an efficient solution algorithm for the problem. We demonstrate from a numerical experience that an equilibrium path of migration dynamics can be uniquely determined in accordance with each stochastic sample path.
A Semi-dynamic Traffic Equilibrium Assignment Model with Link Arrival and Departure Rates Peer-reviewed

Shirou KIKUCHI, Takashi AKAMATSU

Infrastructure Planning Review　24　(3)　577-586　2007
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.24.577 　

ISSN： 0913-4034

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This paper presents a semi-dynamic traffic equilibrium assignment model with link queue evolution by distinguishing arrival rate and departure rate. Specifically, 1) time is divided into discrete time periods, 2) the link queue evolution is represented by the state equation with arrival rate and departure rate, 3) each time period is treated as the static equilibrium state. We reveal that the model can be reduced to the standard form of the nonlinear complementarity problem. By examining the mapping, we then show that the structural correspondence of the proposed model and the DUE/DUO models.
Catastrophe Averse Strategies for Routing and Siting in the Disposal of Hazardous Materials Peer-reviewed

Takeshi Nagae, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Managemen　63　(4)　509-523　2007

DOI： 10.2208/jscejd.63.509 　

ISSN： 1880-6058
Symmetry Breaking Bifurcation of Krugman's Core-Periphery Model with Many Regions: Group Theoretic Approach Peer-reviewed

Kiyohiro Ikeda, Tatsuhito Kono, Takashi Akamatsu, Akito Yanagimoto, Syunji Yamaki

JSCE Journal of Infrastructure Planning and Management　63　(4)　553-566　2007

DOI： 10.2208/jscejd.63.553 　

ISSN： 1880-6058
Managing Regional Economic Risks due to the Entry and Exit of Global Firms: A Study on Hedging Strategies with Financial Options Peer-reviewed

Takashi Akamatsu, Kei Takahashi

Infrastructure Planning Review　23　(1)　51-58　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.23.51 　

ISSN： 0913-4034

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This paper studies financial hedging strategies against regional economic risks due to the entry and exit of global firms. It is shown that the landowner's optimal hedging strategy based on utility maximization agrees with a dynamic portfolio replicating strategy. Comparing three hedging strategies, 1) using financial options, 2) setting penalties for firm's exit behavior, and 3) laissez-faire, we disclose that using financial options is not necessarily the best strategy for the landowner. Furthermore, we show that using financial options cannot achieve Pareto improvement.
A Simultaneous Equilibrium Model of Work Start Time & Departure Time Choices with Bottleneck Congestion Peer-reviewed

Shintaro Sato, Takashi Akamatsu

Infrastructure Planning Review　23　(4)　903-910　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.23.903 　

ISSN： 0913-4034

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Staggered work hours in a city have been introduced to mitigate commuting congestion. However, it may lead to decline in mutual dealing chances between firms, and there is a possibility that total productivity in the city decreases. In this paper, we construct a model in which work start time choices by firms and departure time choices by commuters determine total productivity and commuting congestion in the city. Analyzing of the model, we show that 1) multiple equilibrium patterns of time choices can occur, 2) the equilibrium pattern where work start time is staggered is desirable if congestion tax cannot be levied, and 3) the equilibrium pattern where work start time is concentrated is desirable if congestion tax can be evied.
Risk Averse Dynamic System Optimal Traffic Assignment Peer-reviewed

Shuichi Yamazaki, Takashi Akamatsu

Infrastructure Planning Review　23　(4)　963-972　2006
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.23.963 　

ISSN： 0913-4034

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This paper presents a method for solving a dynamic system optimal (DSO) traffic assignment problem with uncertain travel time. Formulating the DSO assignment in a network with two parallel links as a stochastic control problem, we derive the optimality conditions of the assignment problem. We then show that the optimality conditions can be equivalently stated as a dynamical system of generalized complementarity problems (GCP). Based on this reformulation, we provide an efficient algorithm for solving the stochastic control problem.
Dynamic Revenue Management of Toll Road Projects under Transportation Demand Uncertainty Peer-reviewed

Nagae, T, Akamatsu, T

The 2nd International Symposium on Transport Network Reliability　75-87　2004/08
Dynamic Pricing and Hedging of Projects with Stochastic Cash Flow Streams Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

JSCE Journal of Infrastructure Planning and Management　IV-62　(751)　39-54　2004
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2004.39 　

ISSN： 1882-7187 0289-7806

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We present a new approach for dynamic pricing of infrastructure investment projects with stochastic cash flow streams. In our framework, projects are viewed as options in an incomplete market, whose prices are determined by a stochastic discount factor (SDF) reflecting an option writer/buyer's aversion to “basis risks”. We first formulate a “regularized inverse problem” that estimates a unique arbitrage-free SDF from observed asset prices. We then show that the problem is equivalent to a dynamic risk control (hedging) problem with CARA utility. Our analysis further reveals that ask/bid price of an option significantly depends on the correlation between option pay-off and asset prices traded in security markets.
A Stochastic Control Model of Project Decisions Represented as a Graph Structure Peer-reviewed

Takashi Akamatsu, Takeshi Nagae

JSCE Journal of Infrastructure Planning and Management　IV-65　(772)　185-202　2004
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.2004.772_185 　

ISSN： 1882-7187 0289-7806

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Infrastructure projects often involve multiple activities and interrelated decisions to switch between activities under uncertainty. This article provides a novel quantitative approach for evaluating such complex projects as a set of real options. In our framework, an infrastructure project is represented as a directed graph where the nodes correspond to economic activities in the project and the links denote options to switch between activities. We first show that evaluating a project in this framework is formulated as a variational inequality problem. It is then proved that the problem can be decomposed into solving a series of tractable complementarity problems in a successive manner. This graph-theoretic decomposition scheme enable us to develop an efficient numerical algorithm for solving the project evaluation problems with any graph structure.
Pricing of Real Options in an Incomplete Market Peer-reviewed

Takeshi nagae, Takashi Akamatsu

Journal of Applied Regional Science　8　(2)　81-93　2003
A Hybrid Schemes of Congestion Pricing and Reservations in Transportation Networks Peer-reviewed

Toshikazu Hayazaki, Takashi Akamatsu

Advances in Infrastrucure Planning Applications of MPEC　37-60　2002
混雑料金と割当て制の合成スキームによるパレート改善 Peer-reviewed

早崎俊和, 赤松隆

MPEC にもとづく交通・地域政策分析　37-60　2002
Optimal Dispersion of Morning Commuters in Road Networks with Queuing Peer-reviewed

Takashi Akamatsu, Yuki Maeda, Toshikazu Hayazaki

Infrastructure Planning Review　16　979-989　1999
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.16.979 　

ISSN： 0913-4034

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The purpose of this study is to derive an optimal distribution of work start times (W-curve) that effectively minimizes the social cost for morning commuters in road networks with queuing. Specifically, we consider the following bi-level programming problem: the lower-level problem describes equilibrium flow patterns under a given W-curve, and the upper-level problem optimizes a W-curve under the equilibrium constraints. We first derive the optimal W-curve for a basic model where homogeneous commuters pass through a single bottleneck. We then extend the analysis to the case where both route choice and departure time choice are simultaneously determined.
Dynamic Traffic Assignment and Origin-Destination Patterns Peer-reviewed

Takashi Akamatsu, Nozomu Takamatsu

JSCE Journal of Infrastructure Planning and Management　618　(618)　39-51　1999
Publisher:
DOI： 10.2208/jscej.1999.618_39 　

ISSN： 1882-7187 0289-7806
Semi-dynamic Traffic Assignment Models with Queue Evolution and Elastic OD Demands Peer-reviewed

Takashi Akamatsu, Yukio Makino, Eikou Takahashi

Infrastructure Planning Review　15　535-545　1998

DOI： 10.2208/journalip.15.535 　
Variational Inequality Approach to Multi-Regional Computable General Equilibrium Modeling Peer-reviewed

Takashi Akamatsu, Masaki Handa, Takeshi Nagae

Infrastructure Planning Review　15　175-185　1998
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.15.175 　

ISSN： 0913-4034

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This paper proposes a general framework for analyzing multi-regional CGE models. The framework is based on the theory of Variational Inequality Problems, which gives us the systematic methods for two indispensable works in developing the CGE models: analyzing the properties of the models such as existence, uniqueness and stability of equilibria; developing the efficient and convergent algorithms for solving equilibria of the large scale models. In this paper, we first show the framework using a prototype multi-regional CGE model, and then consider a particular model that reduces to a convex programming, which demonstrates a typical example of the merit obtained by employing this framework.
Feasible Office-Location Patterns for the Existence of the Combined Transportation Network and Residential Location Equilibrium Peer-reviewed

Takashi Akamatsu, Masaki Handa

Infrastructure Planning Review　14　253-258　1997
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.14.253 　

ISSN： 0913-4034

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This paper considers the problem of finding the feasible office-location patterns subject to the capacity constraints of transport networks. We first construct the combined transportation-location equilibrium model to represent the transportation demands on networks induced by office-locations in CBDs. We then define the mathematical problem of finding the feasible office-location patterns which ensure the existence of the combined equilibrium. By utilizing the network transformation technique, we show that the problem reduces to finding the maximum OD demands under the Wardrop equilibrium constraints. Finally, we develops an efficient algorithm for obtaining a unique solution, which can be applied to large-scale networks.
Reactive Dynamic User Optimal Assignment with Physical Queues for a Many-to-Many OD Pattern Peer-reviewed

Masao Kuwahara, Takashi Akamatsu

JSCE Journal of Infrastructure Planning and Management　555　(555)　91-102　1997
Publisher:
DOI： 10.2208/jscej.1997.91 　

ISSN： 1882-7187 0289-7806
Dynamic User Optimal Assignment with Physical Queues for a Many-to-Many OD Pattern

Kuwahara M, Akamatsu T

生産研究　48　(8)　35-38　1996/08
Publisher: The University of Tokyo
ISSN： 0037-105X
Efficient Algorithms for Solving Nested LOGIT type Combined Residential-Location and Transportation Network Equilibrium Models Peer-reviewed

Takashi Akamatsu, Masaki Handa

Infrastructure Planning Review　13　279-287　1996
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.13.279 　

ISSN： 0913-4034

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The purpose of this study is to present some efficient algorithms for solving the nested LOGIT type combined residential-location and transportation network equilibrium model. Preliminary to the analyses of the combined location and transportation model, we first formulate the nested LOGIT type transportation network equilibrium problem as a mathematical programming. The uniqueness and equivalence of the solution are proved and an efficient algorithm that can be applied to large scale networks is presented. Then, the model above is extended to the combined residential-location and transportation equilibrium model. Based on the equivalent mathematical programming formulation of the model, we develop some efficient algorithms that are proved to converge to the equilibrium solution. Finally, the efficiency of the proposed algorithms is examined by numerical experiments.
Maximum Network Capacity Problems with Traffic Equilibrium Constraints Peer-reviewed

Takashi Akamatsu, Osamu Miyawaki

Infrastructure Planning Review　12　719-729　1995
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.12.719 　

ISSN： 0913-4034

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This paper considers the problem of finding the maximum OD flow pattern for the capacity constrained transportaion network under the condition that the flow pattern is described by the user equilibrium assignment. We first show the theoretical relation between the network capacity problem and the particular class of equilibrium assignment models. Then, the mathematical formulation and the efficient algorithms for the problem are shown. Moreover, the uniqueness of the maximum OD pattern is discussed and the method for obtaining the unique solution is proposed. Finally, some results of numerical experiments are reported.
Stock Index Futures in Japan Peer-reviewed

Tomio Arai, Takashi Akamatsu, Akihiro Yoshioka

The Journal of International Securities Markets　17　159-164　1993
On the Rank of Network Incidence Matrices Peer-reviewed

Takashi Akamatsu, Masao Kuwahara

JSCE Journal of Infrastructure Planning and Management　(449)　223-226　1992
Publisher:
DOI： 10.2208/jscej.1992.449_223 　

ISSN： 0289-7806 1882-7187
確率的利用者均衡配分の効率的計算法の開発 Peer-reviewed

赤松隆, 土屋雄二, 川上喜博

交通工学　26　(1)　51-58　1991
Some Numerical Results on the Iterative Algorithms for Stochastic User Equilibrium Assignment Peer-reviewed

Takashi Akamatsu, Nobuhiro Kawakami, Yuji Tsuchiya

Infrastructure Planning Review　8　89-96　1990
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.8.89 　

ISSN： 0913-4034

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This paper provides some efficient algorithms for calculating the stochastic network equilibrium (SUE) assignment problem. First, the paper shows the linkbased formulation of the SUE problem, which is represented by path variables in conventional formulation. Then, the new solution algorithms are presented and implemented in various network conditions. The numerical results exhibit that the methodsachieve fast convergence to rigorous solution. The paper also discusses the reason for efficient calculation of the new algorithms. Finally, the guide lines forselecting an algorithm in practical applications are given.
Neural Network Approach to the Equilibrum Traffic Assignment Problem Peer-reviewed

Takashi Akamatsu, Yuji Tsuchiya

Infrastructure Planning Review　7　227-234　1989
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/journalip.7.227 　

ISSN： 0913-4034

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This paper considers the method for calculating the transportation equilibrium assignment problem on the "neural network". The method proposed in this paper represents link flows by many "neurons", which have parallel dynamics. First, the equations of neuron dynamics are derived for deterministic multi-commodity equilibrium assignment problem from the correspondence between Lagrangian of the problem and Lyapunov function of neural network. Next, the method are implemented in a moderately large size network and the numerical properties are investigated. Furthermore, relation between the method and the stochastic equilibrium theory are considered.
Optimal Road Pricing under Stochastic User Equilibrium Assignment Peer-reviewed

Takashi Akamatsu, Masao Kuwahara

JSCE Journal of Infrastructure Planning and Management　1988　(389)　121-129　1988
Publisher: Japan Society of Civil Engineers
DOI： 10.2208/jscej.1988.121 　

ISSN： 1882-7187 0289-7806

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This paper discusses the optimal road pricing, which minimizes the total travel time, under Stochastic User Equilibrium (SUE) in the general transportation network. We analyse the structure of the problem formulated as a bilevel programming, using the conception of duality. As the result, we learn that the system optimum flow pattern can be attained in an arbitrary network by setting an appropriate toll pattern and the general solution has a form extending the conventional marginal cost pricing to the stochastic user behavior. Moreover, the uniqueness of the optimum link toll is proved in the case of logit-based SUE.

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Misc. 33

超大規模離散空間におけるFujita-Ogawaモデルの効率的解法

Takara SAKAI, Masanao WAKUI, Takashi AKAMATSU

Japanese Journal of JSCE　79　(4)　n/a-n/a　2022/10
Publisher: Japan Society of Civil Engineers
DOI： 10.51094/jxiv.187 　

eISSN： 2436-6021
Non-existence of queues for system optimal departure patterns in tree networks

Takara Sakai, Koki Satsukawa, Takashi Akamatsu

arXiv　2022/05

DOI： 10.48550/arXiv.2205.06015 　
スケジュールコストの異質性を考慮したタンデムボトルネック出発時刻選択問題

酒井高良, 酒井高良, 赤松隆, 佐津川功季

土木計画学研究・講演集(CD-ROM)　63　2021
多起点多終点コリドーネットワークにおける動的システム最適配分

酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　61　2020
多起点多終点コリドーネットワークにおける動的利用者均衡配分

酒井高良, 酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　62　2020
テンソル分解を用いた首都圏高速道路網における渋滞特性抽出

馬場静羽, 酒井高良, 赤松隆, 井上亮

土木計画学研究・講演集(CD-ROM)　62　2020
経路・出発時刻の選択を内生化した動的利用者均衡配分の効率的解法

河向隆志, 酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　59　2019
首都圏高速道路網における経路選択パターンの規則性

石川裕太郎, 酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　59　2019
首都圏高速道路網における動的OD交通量推定モデルのパラメータ推定

石川裕太郎, 酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　60　2019
環状ネットワークにおける動的システム最適配分

酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　60　2019
Departure time choice equilibrium and optimal transport problems

Takashi Akamatsu, Kentaro Wada, Takamasa Iryo, Shunsuke Hayashi

MPRA Paper No. 90361　2018/12
首都圏高速道路網における渋滞パターンの時空間規則性

酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　57　2018
首都圏高速道路網における渋滞の時空間分布の安定性

酒井高良, 赤松隆

交通工学研究発表会論文集(CD-ROM)　38th　2018

ISSN： 1884-300X
首都圏高速道路網における渋滞パターンとMFDの関係性

酒井高良, 赤松隆

土木計画学研究・講演集(CD-ROM)　58　2018
Spatial scale of agglomeration and dispersion: Theoretical foundations and empirical implications

Takashi Akamatsu, Tomoya Mori, Minoru Osawa, Yuki Takayama

MPRA Discussion Paper　84145　1-93　2017/01
巨大災害時のガソリン不足に対する戦略とその社会経済評価:東日本大震災における実証分析

赤松隆, 大澤実, 長江剛志, 山口裕通

土木計画学研究・講演集(CD-ROM)　52　ROMBUNNO.S-1　2015/11
Dynamic Network Traffic Flow Problems (in Japanese) Invited

Takashi Akamatsu, Kentaro Wada

Proceedings of the Twenty-Sixth RAMP Symposium　31-46　2014/10
東日本大震災時の東北地域のガソリン不足の軽減方策とその経済効果の推計

山口裕通, 長江剛志, 赤松隆, 大澤実

土木計画学研究・講演集(CD-ROM)　49　ROMBUNNO.309　2014/06
3.11震災時の東北地域で生じたガソリン需給ギャップの時空間分析

赤松隆, 大澤実, 長江剛志, 山口裕通

土木計画学研究・講演集(CD-ROM)　47　ROMBUNNO.331　2013/06
東日本大震災時の東北地域に対する石油製品輸送実態の把握

山口裕通, 赤松隆, 長江剛志, 円山琢也, KIM Jin Young

土木計画学研究・講演集(CD-ROM)　45　ROMBUNNO.243　2012/06
渋滞と混雑を解消する交通需要管理施策の確率的インプリメンテーション

和田健太郎, 赤松隆, 長江剛志

土木計画学研究・講演集(CD-ROM)　42　2010
流出事故の“低頻度・大損害”特性を考慮したリスク回避的危険物輸送問題

長江剛志, 赤松隆

土木計画学研究・講演集(CD-ROM)　35　2007
リアルタイム観測情報を活用した確率動学的システム最適配分問題

長江剛志, 赤松隆

土木計画学研究・講演集(CD-ROM)　33　2006
不確実な経済環境における都市集積の均衡ダイナミクス

藤原誠, 織田澤利守, 赤松隆

土木計画学研究・講演集(CD-ROM)　34　2006
社会基盤整備・運用事業の経済リスク管理問題に対するファイナンス工学的アプローチ

赤松隆, 長江剛志

土木計画学研究・講演集(CD-ROM)　32　2005
連鎖的意思決定構造を考慮した不確実性下でのプロジェクト評価手法

長江剛志, 赤松隆

土木計画学研究・講演集(CD-ROM)　28　2003
リアル・オプション価格の統一的計算法:相補性問題アプローチ

長江剛志, 赤松隆

土木計画学研究・講演集(CD-ROM)　28　2003
動学的不確実性下でのプロジェクト価格評価逆問題アプローチ

長江剛志, 赤松隆

土木計画学研究・講演集　26(CD-ROM)　(Pt.2)　2002

ISSN： 0913-4026
交通ネットワーク・フロー・モデル分析とデータ革命 (特集モデルとデータ(交通現象の理論と観測))

赤松隆

交通工学　37　(5)　22-32　2002
Publisher: 交通工学研究会
ISSN： 0454-4595
容量パラドクス理論に基づくランプ流入制御ルール

赤松隆, 長江剛志, 長野修

土木計画学研究・講演集　(23,Pt.2)　2000

ISSN： 0913-4026
Some Properties of “Capacity Paradox” in General Queuing Networks.

赤松隆, 長江剛志, 高橋栄行

土木計画学研究・講演集　(22,Pt.1)　1999

ISSN： 0913-4026
交通ネットワ-ク・フロ-理論の概要

赤松隆

交通工学　32　(5)　11-23　1997/09
Publisher: 交通工学研究会
ISSN： 0454-4595
Stochastic Network Equilibrium Traffic Assignment without Cycle Flows

AKAMATSU Takashi

IPSJ SIG Notes　1996　(91)　9-16　1996/09/13
Publisher: Information Processing Society of Japan (IPSJ)
ISSN： 0919-6072

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This paper develops the LOGIT type stochastic (equilibrium) assignment that satisfies three requirements: first, the path set for the loading should be defined by the simple paths without any restictions, which do not depend on the travel cost pattern; secondly, the model should give small probabilities for the paths with mazy structure, while the number of paths defined by the first requirement itself is enormous; and finally, the model should be efficiently computable even in large scale networks. To achieve the purpose, we employ two strategies: first, we incorporate not only the conventional travel times but also the geometric attributes of paths into the model; and secondly, we construct the algorithm making fully use of the Markov property of LOGIT model. The incorporation of the geometric aspects into the model is not only natural to satisfy the second requirement but also effectively utilized to achieve the first requirement. Moreover, the strategy combined with the Markov chain theory enables the model to inherit the computational efficiency of Markov Chain Assignment (MCA) developed by SASAKI(1965), BELL(1995) and AKAMATSU(1996). This property stems from the fact that the new model can be regarded as a mathematically natural extension of MCA: the conventional MCA reduces to a system of linear equations in real number space; and the new assignment model yields the almost same form of linear equations in complex number space. Finaly, an algorithm for the flow dependent case (i.e. stochastic equilibrium case) is also pressented by extending the results for the flow independent model.

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Books and Other Publications 5

道路交通需要予測の理論と適用・第Ⅱ編

土木学会　2006
Handbook on Traffic Demand Forecasting Vol. II

Takashi Akamatsu

JSCE　2006
道路交通需要予測の理論と適用・第Ⅰ編

土木学会　2003
Handbook on Traffic Demand Forecasting Vol. I

Takashi Akamatsu

JSCE　2003
Equilibrium Analysis of Transportation Networks

Takashi Akamatsu

1998

Research Projects 36

マルチスケール時空間経済系における粒子・流体表現を統合したメカニズム設計理論

赤松隆, 大山雄己, 佐津川功季

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2024/04 - 2027/03
交通・物流システム効率化のための市場型マッチング・システムの設計・評価法構築

赤松隆, 和田健太郎, 大山雄己, 佐津川功季

Offer Organization: 日本学術振興会

System: 科学研究費助成事業

Category: 基盤研究(B)

Institution: 東北大学

2021/04 - 2024/03

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本研究の目的は，大都市における(A)公共交通，(B)道路交通，(C)クラウド型物流（CSD）システムに対して，混雑問題を解消する／運用効率を高める市場型マッチング・システムの導入を提案し，その市場メカニズムのデザインおよびシステム評価の方法論を開発することである．本研究は，(A)～(C)の各交通システムに対する目的(1)と(2)を実現する Phase 1，及び，統合型交通システムに対する目的(3)を実現する Phase 2から構成される．本年度は，各システムに対して，Phase 1 の「基本モデル」に対する理論を以下の手順で構築した： Step 1. 市場メカニズム及びその実装法を開発． Step 2. 市場システム導入効果の評価法を構築．上記の Step 1 は，以下の手順に分解して研究を進めた：a) 社会的最適状態モデルを構築；b) システム(A)～(C)の構造的特徴に応じた適切な階層分解法を検討し，マスター問題 MP と子問題 SP を導出；c) 問題 MP の効率的解法を開発；d) 大規模数値実験によってアルゴリズムの性能，及び，問題MPの近似精度やメカニズム全体の効率を評価した．また， Step 2 は，以下の手順に分解して研究を進めた：a) 市場導入後の（渋滞が解消した）動的システム最適(DSO)状態（問題MP の解）の特性を理論的に解析；b) 市場導入前の（渋滞が発生する）動的利用者均衡(DUE)状態のモデルを構築；c) 理論的考察と数値実験によってDSO状態とDUE状態の間に成立する顕著な規則性を発見し，両者の理論的関係を解明した．
Infrastructure and design for next-generation transport systems in the MaaS + CV era

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Scientific Research (A)

Institution: Tohoku University

2020/04 - 2024/03
大都市高速道路網における交通流変動特性の解明とミクロ・マクロ階層的制御法の開発 Competitive

赤松隆

Offer Organization: 日本学術振興会

System: 科学研究費補助金・基盤研究 (B)

2018 - 2020
Agglomeration and spatial economy: Reconstruction of theoretical and empirical framework Competitive

Tomoya MORI

Offer Organization: Japan Society for the Promotion of Science (JSPS)

System: Grant-in-Aid for Scientific Research (A)

2017 - 2020
Self-organizing regularity in a spatial economy: Development of new theoretical and empirical framework

Mori Tomoya, Akamatsu Takashi, Takayama Yuki

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Challenging Exploratory Research

Institution: Kyoto University

2016/04 - 2019/03

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This research aimed to develop a systematic numerical framework for studying micro-founded general equilibrium models for endogenous city formation based on agglomeration economies. Specifically, a recent development of numerical optimization theory has been incorporated in the self-organization of the location process of mobile agents. This in turn made it possible to identify stable equilibria of an economy despite the non-linearity in a high-dimensional system. This in turn made it possible to generate a reasonable amount of Monte-Carlo samples of stable equilibria of a hypothetical economy with essentially the same order of diversity in the degrees of increasing returns in the reality. Furthermore, based on the data from Japan, US, Europe, China and India, empirical evidence for the self-organizing regularity in size, spacing and industrial composition of cities were established. The developed numerical methods are applied to theoretially replicate these regularities.
渋滞のない近未来型道路交通システム設計のための理論基盤構築 Competitive

赤松隆

Offer Organization: 日本学術振興会

System: 科学研究費補助金・挑戦的研究 (萌芽)

2018 - 2019
ポスト・ビッグデータ時代に向けた次世代交通システムの動学的マネジメント手法の構築 Competitive

井料隆雅

Offer Organization: 日本学術振興会

System: 科学研究費補助金・基盤研究 (A)

2016 - 2019
Exploration and Exploitation of Properties of Macroscopic Fundamental Diagrams for Managing Traffic Congestion in Road Networks Competitive

Takashi AKAMATSU

Offer Organization: Japan Society for the Promotion of Science (JSPS)

System: Grant-in-Aid for Scientific Research (B)

2015 - 2017

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This study explores the empirical properties of Macroscopic Fundamental Diagrams(MFD) linking vehicle accumulation and traffic production in road networks, and then develops traffic control methods exploiting the properties of MFDs and a theory to explain them. More specifically, (1) by analyzing long term detectors data (traffic flow-speed data observed every 1-minute throughout one year) of Japanese major cities, we revealed the basic properties of MFDs, and characterized the conditions for emergence of a well-defined MFD;(2) we developed a theory (mathematical models) to explain the mechanisms for the empirically observed properties of MFDs and the relationships between congestion patterns and MFD features;(3)we developed traffic control methods (signal control and ramp metering strategies) to improve performance (throughput) of congested networks based on the theory developed in (2).
Spatial frequency analysis of industrial agglomeration patterns Competitive

Takashi AKAMATSU

Offer Organization: Japan Society for the Promotion of Science (JSPS)

System: Grant-in-Aid for Challenging Exploratory Research

2015 - 2016

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This study provides a method for extracting spatial regularities observed in a variety of industrial agglomeration patterns that emerge in system of cities with agglomeration economies. Specifically, (1) based on Fourier transformation techniques and group-theoretic bifurcation theory, we developed a method that gives the spatial period/frequency of industrial location patterns obtained as stable equilibria of spatial agglomeration models in a homogeneous space, and (2) we extended the method so as to be able to identify spatial regularities from actual observed data of industrial location patterns in a real geographical space.
Development of Theories on Dynamic Travel Behaviour and Traffic Flow Analysis for Transport Network Risk Management Competitive

Yasuo ASAKURA

Offer Organization: Japan Society for the Promotion of Science (JSPS)

System: Grant-in-Aid for Scientific Research (A)

2013 - 2016

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Our modern society has required dynamic risk management for transport network to minimize the negative effects of a system failure caused by traffic incident and/or natural disaster. This study aims to establish theoretical basis of advanced travel behaviour analysis and transport network analysis for dynamic risk management of transport network. Four years research with 14 researchers has achieved to develop advanced methods in travel behaviour survey based on the Probe Person survey, and to establish dynamic network traffic flow analysis methods by utilizing travel and traffic data with higher resolution. We have contributed to investigate fundamental theories on dynamic risk management of transport networks incorporating advanced travel behaviour models into dynamic network flow models. As a part of research activities, some of the research members organized three international symposiums in the field of traffic and transport theories in 2015 and 2017.
A spatial economic theory of the regularities in spatial patterns and size distributions of cities and firms Competitive

Takashi AKAMATSU

Offer Organization: Japan Society for the Promotion of Science (JSPS)

System: Grant-in-Aid for Challenging Exploratory Research

2013 - 2014

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Statistical distributions of economic activities are known to exhibit a robust regularity called rank-size rule, or Zipf's law. This study shows that rank-size rule of city size distribution emerges as an equilibrium outcome of a multi-industry spatial competition model with agglomeration economies, along with another well-known regularity, urban hierarchy principle. We then demonstrate that the distribution of firm size also obeys rank-size rule if the degree of heterogeneity of firms and industries (variance in the distribution of a parameter representing the heterogeneity) are larger than some threshold..
Urban Hierarchy Principles in a Multi-scale Spatial Economy Competitive

Takashi AKAMATSU

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2012 - 2014

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This study presents a theoretical model to explain the mechanism of the formation of hierarchical urban systems. Specifically, we develop multi-industrial core-periphery (CP) models with hierarchical (i.e.,multi-scale) spatial structure which introduces the interaction between inter-regional and intra-regional transportation costs explicitly. We then analyze bifurcation phenomena of the equilibrium by the analytical and numerical approaches developed by Akamatsu et al.(2012). The results of our analysis reveal that combinations of inter-regional and intra-regional transport costs can yield a wide variety of agglomeration patterns depending on the transportation parameter values, and that hierarchical industrial location patterns emerge as stable equilibria of the model. Furthermore, we develop multi-scale Computable General Equilibrium (CGE) models with agglomeration economies, and demonstrate their applicability to practical problems.
A Stable Game Approach to Distributed Control of Transportation Systems Competitive

Takashi AKAMATSU

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Challenging Exploratory Research

Category: 挑戦的萌芽研究

Institution: 東北大学

2011 - 2012

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This study proposes a game theoretic approach to designing real-time vehicle operation strategies that prevent vehicle bunching and delay propagation in railway/bus systems. We formulate dynamical systems of vehicle (train/bus) motion that includes two types of delay propagation models: one is a passenger boarding model at each station, and the other is a car-following model in each section between stations. We then introduce some distributed control schemes to maintain scheduled operation. By mapping the control scheme to a stable game framework, it is proved that the dynamical system under the proposed scheme is asymptotically stable at some equilibrium states
Theoretical system incorporating with mobile observation and simulation for evaluating risks of transport networks in hazardous situation Competitive

Yasuo ASAKURA

System: Grant-in-Aid for Scientific Research (A)

2009 - 2012

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The purpose of this study is to develop and validate a theoretical system for evaluation of transportation network reliability considering natural disasters. Based on outcomes of our previous research conducted in Grant-in-Aid for Scientific Research (A) (Research Project Number: 17206053), we developed "Data collection and its analysis systems for travel behavior" and "Evaluation theories for reliability of road network in natural disasters". These systems and theories were realized by incorporating the following three parts: (i) Behavioral survey and analysis considering situations in a disaster, (ii) Traffic simulation on transportation network affected by disaster, and (iii) Evaluation model for reliability utilizing traffic simulation. The proposed system was confirmed to be applicable for evaluating transportation network reliability considering possible natural disasters in Japan.
Self-organization of Spatial Agglomeration in Economic Activities Competitive

Takashi AKAMATSU, 池田清宏, 斉木功, 河野達仁, 織田澤利守

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2009 - 2011

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Two-location Core-Periphery (CP)models in New Economic Geography exhibit a bifurcation from a symmetric equilibrium to an asymmetric one, depending on transportation costs. This study reveals interesting bifurcation properties of the CP models in more general settings, such as a two-dimensional space and a multi-industry economy. Some of the major findings of this study are 1) Christaller's hexagonal agglomeration patterns are proven to exist as stable equilibria of the CP models on a two-dimensional lattice, 2)"Hierarchy principle" of industry agglomeration patterns holds for the multi-industry CP models, 3) the multi-industry CP models generate the population distributions that follow"central place regularities", i.e, the distribution satisfies a rank-size rule, a hierarchy principle, and a number-average size rule.
Auction Mechanisms for Implementing Tradable Network Permits Competitive

Takashi AKAMATSU

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Challenging Exploratory Research

Category: 萌芽研究, 挑戦的萌芽研究

Institution: 東北大学

2008 - 2009
Bifurcation Analysis of Agglomeration Economies in a System of Cities Competitive

Takashi AKAMATSU, Ikeda KIYOHIRO, Kono TATSUHITO, Otazawa TOSHIMORI

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2007 - 2008
Constructing a new urban and regional system with incorporating both autonomy and cooperation Competitive

Komei SASAKI, 福山敬, Masateru HINO, Tadashi HASEBE, Kazuho KOBAYASHI, Nobuhiko TERUI, 山本啓, Kei FUKUYAMA, Hiraku YAMAMOTO, Takashi AKAMATSU, Yoshiyuki TOKUNAGA, Yasuhisa HAYASHIYAMA, Naoto TOKUGAWA, Katsuya HIRANO, Fusao ITO, Yoshiyuki MURAYAMA, Takahisa YOKOI, Yang ZHANG

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (A)

Category: 基盤研究(A)

Institution: 東北大学

2005 - 2008
A system evaluating risks of transport networks in hazardous situations based on measurements by mobile communication instruments Competitive

Yasuo ASAKURA, 多々納裕一, 山本俊行, Eiji HATO, Takamasa IRYO, Takeshi NAGAE, 中山晶一朗, Takashi AKAMATSU, Hirokazu TATANO, Shoichiro NAKAYAMA, Toshio YOSHII, Toshiyuki YAMAMORTO

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (A)

Category: 基盤研究(A)

Institution: 神戸大学

2005 - 2008
A Study on Tradable Time-of-Day Bottleneck Permits for Morning Commuters: Optimal Allocation of Priority Road Services Competitive

Takashi AKAMATSU

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Exploratory Research

Category: 萌芽研究

Institution: 東北大学

2006 - 2007
Complying with the Kyoto Protocol under Competitive and Environmental Pressure: From the Viewpoints of Industrial Structural Reform and Trade Policy Competitive

Hajime INAMURA, 森杉壽芳, 赤松隆, 石黒一彦, 加河茂美

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grants-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2005 - 2007

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Standard eco-efficiency analysis has typically focused on changes in the production technologies and consumption in the being investigated. These studies have conventionally examined the reasons underlying changes in eco-efficiencies and more-efficient activity vectors of both desirable and undesirable outputs, such that the goods are maximized and the bads are minimized. In contrast, this paper focused on international eco-efficiencies and evaluated more-efficient activity distributions within the context of total domestic final demand at the international level being maximized under condi...
Study of Dynamic Processes of Infrastructure Planning Corresponding to the Population Changes in Quantity and Quality Competitive

Asao ANDO, 森杉壽芳, 佐々木公明, 赤松隆, 福山敬, 河野達仁

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (A)

Category: 基盤研究(A)

Institution: 東北大学

2004 - 2007

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A rapid population decrease happens in Japan as a result of the fertility decline. There is no problem in population decrease itself from the viewpoint of the resource allocation. Econom ical and/or social strains may occur in the transitional phase. The population is changing qualitatively, too. A decrease in labor force alters production and demands for goods and services. On the other hand, the increase in fossil fuel consumption, which caused by population growth and improving living standards in developing countries, is more important issue for the entire world. This is the reason why ...
Managing Regional Economic Risks due to the Entry and Exit of Global Firms Competitive

Takashi AKAMATSU, 福山敬

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2005 - 2006

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This study presents a theory that the entry and exit behavior of global firms to/from a local city amplifies global economic risks to a regional economy. The theory employs the dynamic option game framework for capturing landwoner's starategic behaviors against the entry/exit of a global firm to a local city. The analysis reveals that the landlord's equilibrium strategy is to permit the firm's entry immediately when the volatility of the economic factor is sufficiently small, and that in the equilibrium under the firm's free exit rule, the landlord raises the rent as the volatility increase...
地域通貨の発生・流通・維持メカニズムとその経済的効果に関する理論的研究 Competitive

赤松隆

Offer Organization: 文部科学省

System: 科学研究費補助金(萌芽研究)

Category: 萌芽研究

Institution: 東北大学

2004 - 2005

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本研究は,地域通貨の発生・流通・維持に関する以下の2つの課題からなる.第1の課題は,地域通貨の成立と維持のための必要条件を明らかにする数理的モデルの構築である.第2の課題は,地域通貨が地域経済システムに対してもちうる機能とメカニズムを理論的に整理し,その特性を明らかにすることである.この目的を達成するために,まず,地域通貨の実態を調査・整理し,次に,本研究で構築する数理モデルと関連の深い確率的ネットワーク成長モデルに関する研究の包括的レビューとそれに基づいた考察を行なった.その結果,Internet上でのfile size分布やweb pageの規模分布が冪分布/対数正規分布に従うことを説明する最近のネットワーク成長モデルの多くは,数理的に本質的な部分では,Simon modelと(ほぼ)同じ構造といえることが判った.また,冪分布と対数正規分布の各々を生成するモデルは,独立したものではなく,両者にはある関係があることや,観測時刻のランダムネスから冪乗則を説明するモデルがreal option/optimal stopping問題と関連した構造を持つことを明らかにした.これらの考察の後,地域通貨を介した財の交換過程に関する経済主体の意思決定問題(本研究で構築する確率動学モデルの状態推移確率を決定するサブ・モデル)をオプション・モデルとして記述し,その計算法を開発した.数値実験の...
Option Exercise Games in Spatial Economies Competitive

Takashi AKAMATSU, 福山敬

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2003 - 2004

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This study consists of two parts. The first part develops a theory that explains strategic behavior of oligopoly firms under dynamic uncertainty (ie. "option game theory"). Specifically, we consider dynamic equilibrium strategies of oligopoly firms producing a single commodity with random demand fluctuation, assuming that each firm can change its strategic variables (such as output price level) at any time. We find a dependence relation of the equilibrium strategies and stochastic state variables, and show that the result dramatically changes depending on whether commodity demands are compl...
Transportation Benefit Measurement under the Second Best Economy Competitive

Hisayoshi MORISUGI, 石黒一彦, 上田孝行, 赤松隆

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2002 - 2004

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This research showed followings among others :(1)Transportation benefit under the core-periphery model with market distortion and multiple equilibriums can be measured by the consumer's surplus of artificial demand functions which is derived from the symmetric equilibrium.(2)The total value of environmental quality can be expressed by additive separation of direct use value, indirect use vale and non-use value, which can be measured respectively by the observable revealed preference data.(3)Pricing 'real option' in an incomplete market which bridges the gap between arbitrage -free pricing a...
国際研究セミナー"Behaviors in Network"の企画調査 Competitive

羽藤英二, 吉井稔雄, 朝倉康夫, 赤松隆, 桑原雅夫, 藤井聡

Offer Organization: 文部科学省

System: 科学研究費補助金(基盤研究(C))

Category: 基盤研究(C)

Institution: 愛媛大学

2002 - 2002

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本研究では,国際会議"Behaviors in Network"開催の企画調査を実施した.企画調査にあたってネットワーク上の交通行動に関する研究課題の分類を行なった.分類した各課題ごとにテーマを設け,2002年8月19日〜20日にかけて北海道で国際会議を前倒しで開催した.主な参加者は,ネットワーク配分の分野では,Yang, H.Wong, S.C., Iryo, T., Lam, W.H.K, シミュレーション分野では,Yoshii, T., Lo, H.P.Bekhor, S.Hato,行動モデル分野では,Lee, S.Fujii, S.Asakura, Yで,それぞれ各分野の研究成果を持ちよって議論すると共に,既往の研究課題の整理とレビューをあわせて実施した.行動モデルについては,経路重複の記述可能性と.計算可能なアルゴリズムを実装したネットワークモデルへの組み込み可能性が今後の大きな研究課題であることが示された.次に.2003年3月15日東北大学において,同分野の今後の方向性について,モデルとデータ,ミクロとマクロの関連性の2つにしぼって,国内の研究者を中心に今後の研究課題の展望を行った.行動モデルの分野からは羽藤,佐々木,モデルの適用可能性については井料,円山が,ミクロとマクロのモデル化については赤松,奥村が,一般均衡の枠組みにおける行動モデルの役割については上田が,...
Mathematical Methods for Flexible Planning of Infrastructure Investment Projects under Uncertainty Competitive

Takashi AKAMATSU, 森杉壽芳

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 東北大学

2001 - 2002

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This study presents a framework and mathematical methods for dynamic decision-makings of infrastructure investment/management under economic uncertainly. Specifically, an infrastructure project is defined as a bundle of complex options (assets) with stochastic cash flow streams, and is formulated as a stochastic impulse control problem in which control variables have interdependency represented as a graph-structure. We then focuses on two problems(1) controlling the activities of the bundle of options with complex chain-structure(2) evaluating "incomplete market (basis) risks" intrinsic in ...
不確実性下での土地関連権利の価格づけと都市空間利用パターンに関する研究 Competitive

赤松隆

Offer Organization: 文部科学省

System: 科学研究費補助金(萌芽的研究)

Category: 萌芽的研究

Institution: 豊橋技術科学大学->東北大学

1999 - 2000

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土地関連権利の評価は,一種のオプション価格づけ問題である.従って,その理論的な解析は,(1)Financial Option理論(eg.Black-Sholes-Merton),(2)Real Option理論(eg.Brennan-Schwartz,Pindyck-Dixit),(3)Quasi-option理論(eg.Arrow-Fisher-Henry)と関連している.しかし,前年度からの包括的レビューの結果,土地関連権利の理論的な解析のためには,これら従来研究における以下の問題点を解決しなければならないことを明らかにした:(1)理論(1),(2)は不完備市場における不確実性要因を無視;(2)理論(3)は完備市場における不確実性要因の評価が無裁定市場条件と不整合;(3)複数のエージェント間での戦略的意志決定条件が考慮されていない;(4)複数の関連する離散・連続的意志決定変数が同時的に導入されていない.そこで,本研究では,上記(1)と(2)の課題を解決するために,オプション評価問題を適切なマルチンゲール測度(orそれと1対1対応にある"market price of risk")推定のための逆問題として捉え直す枠組みを考察した.より具体的には,無裁定条件のみでは解が一意に決まらない不完備市場でのマルチンゲール測度推定問題を,エントロピー基準,分散基準等の導入によって"適切...
Infrastructure Project Valuation and Decisions under Uncertainty Competitive

2000 -
大規模ネットワークにおける動的な交通均衡配分理論に関する研究 Competitive

赤松隆

Offer Organization: 文部科学省

System: 科学研究費補助金(基盤研究(B))

Category: 基盤研究(B)

Institution: 豊橋技術科学大学

1997 - 1998

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本研究は,交通サービス供給および交通需要の状態記述に関して要求される基本的条件を具備した動的な交通ネットワーク配分モデルを数理的に構築する.ただし,シミュレーション・アプローチ等による様々なモデルに対するベンチマークとなりうる理論を構築するために,本研究では,利用者の反復行動による学習・フィードバック機構条件について,動的(利用者)均衡の考え方を採用したいくつかの数理モデルを構築する.そして,それらモデルについて,(1)変分不等式問題の枠組みに基づいたモデルの統一的記述,(2)基本特性・各モデル固有の特性の解析,(3)大域的収束が保証され大規模ネットワークで適用可能な効率的アルゴリズムの開発;を行い,さらに動的均衡解の各種安定性に関する理論を構築することが本研究の目的である.平成9年度は,多起点・1終点および1起点・多終点のネットワークの各々の場合におけるa)経路選択のみの動的均衡モデル,b)経路選択と出発時刻の同時均衡モデルを構築し・解析した.より具体的には,各モデルについて,以下の3ステップを完了した:Step1 モデルの構築(基本的定式化と変分不等式問題等の標準型への変換等),Step2 モデルの基本特性解析(解の存在・一意性やモデル固有の特性の理論的解析),Step3 モデルの計算法開発(大域的に収束的かつ効率的なアルゴリズムの開発).さらに,多起点・1終点および1起...
消費者の時空選択行動とその相互干渉による社会的時間・空間利用パターン形成原理 Competitive

赤松隆

Offer Organization: 文部科学省

System: 科学研究費補助金(萌芽的研究)

Category: 萌芽的研究

Institution: 豊橋技術科学大学

1997 - 1998

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本研究は,空間利用パターンと時間利用パターンの各々に対する理論(一例を出せば,立地均衡理論と出発時刻均衡理論)間に成立する共通点・相違点・各種関係を統一的な観点から整理し,さらには,空間・時間の相互作用のあるシステムに関する一般的理論の基礎を得ることを目的とする。その研究内容は,より具体的には,以下のステップに分けて考案される:第一のステップは,空間・時間の各システムに対する部分パターン形成原理に関する理論の比較検討である。第二のステップは,空間・時間の各システムに対する一般的なパターン形成に関する理論の対応付けである.そして,第三のステップにおいて,空間と時間に対する選択が同時に入った状況での時間・空間利用パターンを統合的に扱いうる理論を構築することを狙う.平成9年度は,ステップ1(空間・時間の各システムに対する部分パターン形成原理に関する理論の比較検討)に関して以下のような検討を行った.:Step 1-1 立地均衡モデルに代表される空間的な地点選択理論に関する包括的レビュー.Step 1-2 出発時刻選択モデルに代表される時刻選択理論に関する包括的レビュー.Step 1-3 各々の代表的(経済)理論を変分不等式の枠組みで統一的に再定式化.Step 1-4 共通点・相違点の体系的な整理と根本的なパターン形成メカニズムの抽出.また,ステップ2(空間・時間の各システムに対する一...
Modelling Transportation Network Under New Transportation Technologies Competitive

Hiroshi MATSUI, 赤松隆, 高山純一, 朝倉康夫, 溝上章志, 宮城俊彦

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 基盤研究(B)

Institution: 名古屋工業大学

1996 - 1997

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Rescently, there has been a lot of needs to develop models for analyzing transpotati on net work under enhancement of traffic information and transportation technoloque. In this background it is very useful to reconsider social significance and position of transportation net work models under new transport technologies. In this report our final target is to analyze transpotation net work dynamically and psychologically. Through this report, we obtained the following results :(1) We developed the simultaneous model of departure time distribution/assignment that departure time choice model wa...
On Some Transportation Management Problems for Ensuring Stable Network Equilibria Competitive

Takashi AKAMATSU

Offer Organization: Ministry of Education, Culture, Sports, Science and Technology

System: Grant-in-Aid for Scientific Research (B)

Category: 一般研究(B), 基盤研究(B)

Institution: 豊橋技術科学大学

1995 - 1996

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This study proposes a framework for designing / managing transportation networks based on the concept of "stable equilibria" which means that the transportation demand and supply equilibrate within non-saturated region. To consider a policy that ensures the stable equilibria, we first define the following three transportation design / management problems : 1) Upward-shift of transportation performance curves (= "Congestion toll problem"), 2) Right-shift of transportation performance curves (= "Capacity-increase problem"), 3) Downward-shift of transportation demand curves (= "Feasible locati...
A Study on Transportation Network Model Based on Stochastic Equilibrium Theory

SHIMAZAKI Toshikazu, AKAMATSU Takashi, MIAYAKI Yasuyuki, MATSUMOTO Yoshiji, SANO Kazushi, IEDA Hitoshi

Offer Organization: Japan Society for the Promotion of Science

System: Grants-in-Aid for Scientific Research

Category: Grant-in-Aid for Co-operative Research (A)

Institution: Tokyo Univ

1989 - 1990

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Transportation network equilibrium assignment model which originates from the one step in conventional transportation demand analysis has grown to one of the important model in various area, e. g. transportation planning, land use planning, traffic management etc., with the developments of integrated demand analysis model or generalized equilibrium model. When we apply this model to the real transportation network, however, the model often includes numerous number of variables and enormous calculational costs are required. To reduce the computational burden, various method, for example, Frank-Wolfe method, projection gradient method, sub-gradient method etc., are proposed. The computational times and costs required in these methods, however, are not yet easy to dealt with large scale network for the practical wide area analysis. As the result, we often see the situations that these transportation models which are developed as the tool for giving planners qualitative and accurate information are not fully utilized. So far as we premise to use the existing serial processing computer, radical improvement of this problem may be difficult. Considering the fact that all the variables used in in the network assignment model have similar expression and structure, however, it may be possible to solve the problem very rapidly by parallel calculation, assuming that there are some parallel processing method based on proper principle.

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Teaching Experience 9

交通工学　工学部
社会システム解析特論　大学院工学研究科
一般システム論　工学部
数学物理学演習　工学部
建築社会環境工学演習　工学部
応用確率統計学　工学部
システムズ・アナリシス　工学部
交通計画　工学部
数理都市解析　大学院情報科学研究科，工学研究科

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