Addressing the challenges of shrinking cities globally remains complex, with underlying causes still requiring in-depth exploration. In Japan, the phenomenon of shrinking cities is intricately linked to Tokyo’s Unipolar Concentration. Despite governmental initiatives aimed at decentralizing metropolitan growth and revitalizing declining regions, these trend–mirroring patterns observed in other East Asian nations such as South Korea and China–continues unabated. East Asia provides a unique setting for studying urbanization and population dynamics, as these countries experience rapid urban life cycles with minimal immigration influence compared to Western nations. As the first East Asian country to undergo urbanization, Japan is characterized by both population decline and the intensifying regional disparities driven by Tokyo’s Unipolar Concentration. This study uncovers a critical relationship between population decline and geographic structure, revealing how remote, non-metropolitan areas are increasingly excluded from the later stages of the city life cycle. It also identifies the “mega-city paradox,” where the unsustainable growth of megacities eventually reaches a point where expansion stalls. By exploring the intrinsic link between population and geography, this research offers fresh insights and underscores the need for more holistic and sustainable population planning strategies.
@article{XU2024105445,type={article},title={Are East Asian “shrinking cities” falling into a loop? Insights from the interplay between population decline and metropolitan concentration in Japan},journal={Cities},volume={155},pages={105445},year={2024},issn={0264-2751},doi={https://doi.org/10.1016/j.cities.2024.105445},url={https://www.sciencedirect.com/science/article/pii/S0264275124006590},author={Xu, Xizi and Ma, Jue and Sho, Kojiro and Seta, Fumihiko},keywords={Shrinking cities, Life cycle of cities, Unipolar concentration in Tokyo, Population decline, Megacity paradox}}
Cities
A cost-and-effect simulation model for compact city approaches: A case study in Japan
Jue Ma, Yuya Shibuya, Yanbo Pang, and 2 more authors
Japan’s compact-city policy addresses rapid population decline and aging to ensure sustainable development. However, its implementation requires significant time, financial resources, and complex stakeholder collaborations. Faced with these challenges, we asked: How can the cost-and-effect of planning be simply and automatically recognized by stakeholders? To address this, a simulation model was developed for evaluating urban planning strategies within the compact-city framework. Our model integrates pseudo-people-flow data and includes three fundamental modules and five sub-models to simulate and predict urban metrics, including population, administrative costs, visitors, and traffic volume from 2015 to 2040. Four scenarios-baseline, location optimization, new road and new station installation-were analyzed. Findings suggest that 1) new station project could mitigate population decline, 2) both location optimization and new station projects improve public services efficiency and sustainability, 3) urban vitality could be enhanced by new station construction, generating a new urban core, and 4) compact city policy may also reduce and concentrate traffic volume, shortening car trips. The model’s efficiency and uncertainty were examined, and user experiments highlighted the potential of digital tools to democratize urban planning, making it accessible for non-expert stakeholders and fostering informed participation. This research advances the use of technology in participatory urban planning.
@article{ma2024cities,type={article},title={A cost-and-effect simulation model for compact city approaches: A case study in Japan},journal={Cities},volume={152},pages={},year={2024},issn={105212},doi={https://doi.org/10.1016/j.cities.2024.105212},url={https://www.sciencedirect.com/science/article/pii/S0264275124004268},author={Ma, Jue and Shibuya, Yuya and Pang, Yanbo and Omata, Hiroshi and Sekimoto, Yoshihide},keywords={cost-and-effect estimation, pseudo-people-flow data, compact city, simulation model}}
2023
IEEE
WindSR: Improving Spatial Resolution of Satellite Wind Speed Through Super-Resolution
Ashutosh Kumar, Tanvir Islam, Jue Ma, and 3 more authors
Prediction of accurate wind speed is necessary for a variety of applications such as energy production, agriculture, climate modeling, and weather forecasting. Various satellites orbiting the earth measure the wind speed, which is particularly useful as they provide measurements of wind speed over large areas and in remote locations that might be difficult to measure using other methods. However, satellite-based wind speed measurements have relatively low spatial resolution compared to other methods, such as ground-based radar. In this research, we develop WindSR and a lightweight tiny-WindSR to improve the resolution of satellite wind speed data by four times from the NASA’s GEOS-5 Nature Run dataset. WindSR has SRResNet-based architecture consisting of several Residual-in-Residual Dense Blocks to compute features from low spatial resolution (28 km) wind speed for upscaling. We train WindSR with more than 20,000 pairs of low-resolution (28 km) and corresponding high-resolution (7 km) wind speed data and evaluate its performance on the validation set consisting of 2,102 wind speed images. Experimental results show that WindSR outperforms classical upsampling algorithms, such as Bicubic interpolation and Lanczos interpolation by 17.89% and general-purpose super-resolution GANs such as BSRGAN and SwinIR by up to 11.35% on the RMSE metric. The dataset developed in this research is publicly available at: https://github.com/sekilab/WindSR_Dataset.
@article{kumarashutosh2023,type={article},author={Kumar, Ashutosh and Islam, Tanvir and Ma, Jue and Kashiyama, Takehiro and Sekimoto, Yoshihide and Mattmann, Chris},journal={IEEE Access},title={WindSR: Improving Spatial Resolution of Satellite Wind Speed Through Super-Resolution},year={2023},volume={11},number={},pages={69486-69494},keywords={},doi={10.1109/ACCESS.2023.3292966},issn={2169-3536},month={}}
2022
CEUS
Development of current estimated household data and agent-based simulation of the future population distribution of households in Japan
Kento Kajiwara, Jue Ma, Toshikazu Seto, and 3 more authors
In response to the declining population and aging infrastructure in Japan, local governments are implementing compact city policies in the form of location normalization plans. To optimize the reorganization of urban public infrastructure, it is important to provide detailed and accurate forecasts of the distribution of urban populations and households. However, several local governments do not have the necessary data and forecasting capability. Moreover, current forecasts of gender- and age-based population data only exist at the municipal level, and household data are exclusively available by family type at the prefecture level. Meanwhile, the accuracy is limited with an assumption of the same rate of change of population in all municipalities and within each city. Therefore, the aim of this study was to develop an agent-based microsimulation household transition model, with the household as the unit and agent. Household data was estimated for all cities in Japan from 2015. Estimated household data comprised of family type, house type, and address, age, and gender of household members, obtained from the national census, and building data. The resulting household transition model was used to forecast the attributes of each household every five years. Simulations in Toyama and Shizuoka Prefectures, Japan from 1980 to 2010 provided highly accurate estimates of municipal-level population by age and household volume by family type. The proposed model was further applied to predict the future distribution of disappearing villages and vacant houses in Japan.
@article{KAJIWARA2022101873,type={article},title={Development of current estimated household data and agent-based simulation of the future population distribution of households in Japan},journal={Computers, Environment and Urban Systems},volume={98},pages={101873},year={2022},issn={0198-9715},doi={https://doi.org/10.1016/j.compenvurbsys.2022.101873},url={https://www.sciencedirect.com/science/article/pii/S019897152200117X},author={Kajiwara, Kento and Ma, Jue and Seto, Toshikazu and Sekimoto, Yoshihide and Ogawa, Yoshiki and Omata, Hiroshi},keywords={Population forecast, Household, Microsimulation model, Vacant house, Disappearing village}}
2021
Prototyping of a citizen-oriented regional planning tool to automated digital design process: A case study on the new station planning in Susono, Shizuoka Prefecture
Jue Ma, Toshikazu Seto, Hiroya Omata, and 1 more author
Proceedings of The City Planning Institution of Japan, 2021
2019
An Empirical Study on Role of Art to Raising City Image from the Context of Youth Perceptions: Semarang City, Indonesia
Effendy Sigit, Nadira Elkalam, Jue Ma, and 1 more author