Country：Japan

Country：Japan

Publishing type：Research paper (scientific journal)  

DOI： 10.1038/s41598-024-82232-x

Other URL： https://www.nature.com/articles/s41598-024-82232-x

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.habitatint.2024.103197

Publishing type：Research paper (scientific journal)  

DOI： 10.3390/su16229992

Publishing type：Research paper (scientific journal)  

Many developed countries need to plan urban policies based on multidimensional factors related to population change. However, empirical research has been inconsistent with respect to identifying these factors, including economic-, social-, and urban-planning-related factors. The purpose of this study is to clarify the nonlinear multidimensional factors that are correlated with population changes according to the city size. In the analysis, the population change rate was defined as the outcome variable, and 269 economic, social, and educational index (ESE index) were used as predictor variables. Data were stratified according to three city sizes. Using the ESE index, the XGBoost algorithm was used to analyze the nonlinear relationship between the population change rate and multidimensional data. As a key result, population changes were strongly correlated with social-related indicators, such as the population change rate among persons ages 0–14 years in small-sized cities, the natural population change rate in medium-sized cities, and the migration change rate in large-sized cities. Regarding the population decline, Japan has 1304 shrinking cities, which are primarily comprised of medium-sized and small-sized cities. In such cities, other than social-related factors, population changes correlated with the financial strength index as an economic-related factor in medium-sized cities and the designation of underpopulated areas as an urban-planning-related factor in small-sized cities. Among the multidimensional factors, cities of different sizes were characterized by factors other than social-related indicators. These multifaceted factors could provide preliminary insights for urban policymakers to explore various policy measures on which they need to focus, depending on the city’s size.

DOI： 10.1177/23998083241274381

Other URL： https://journals.sagepub.com/doi/full-xml/10.1177/23998083241274381

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.cities.2024.104991

Publishing type：Research paper (scientific journal)  

DOI： 10.20803/jusokenronbunjisen.50.0_329

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jth.2024.101808

International / domestic magazine：International journal  

DOI： https://doi.org/10.3390/su16051715

Publishing type：Research paper (scientific journal)  

DOI： 10.1016/j.jth.2023.101728

International / domestic magazine：International journal  

DOI： https://doi.org/10.3390/su16010309

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1063/5.0170396

Publishing type：Research paper (scientific journal)  

Shrinking cities due to low birthrates and aging populations represent a significant urban planning issue. The research question of this study is: which economic, social, and educational factors affect population decline in Japanese shrinking cities? By modeling shrinking cities using the case of Japanese cities, this study aims to clarify the indicators that affect the population change rate. The study employed Bayesian network analysis, a machine learning technique, using a dataset of economic, social, and educational indicators. In conclusion, this study demonstrates that social and educational indicators affect the population decline rate. Surprisingly, the impact of educational indicators is more substantial than that of economic indicators such as the financial strength index. Considering the limitations in fiscal expenditures, increasing investment in education might help solve the problem of shrinking cities because of low birthrates and aging populations. The results provide essential insights and can function as a planning support system.

DOI： 10.1371/journal.pone.0284134

Publishing type：Research paper (scientific journal)  

DOI： 10.3390/su15043315

DOI： 10.3390/ijerph20032639

Other URL： https://doi.org/10.3390/ijerph20032639

DOI： 10.3390/su15032247

Other URL： https://doi.org/10.3390/su15032247

Publishing type：Research paper (international conference proceedings)  

DOI： 10.1063/5.0105230

Publishing type：Research paper (scientific journal)  

Tourism gentrification has become a social issue in tourist cities worldwide. This paper’s research question is as follows: has tourism gentrification caused a population decline in tourist cities? This study aims to clarify the statistical relationship between the population decline and the location of accommodation on the neighborhood association scale. It analyzes Kyoto City, which is one of the most famous tourist cities worldwide. The statistical relationship between two types of accommodation—hotels and simple accommodation—is analyzed, using geographic natural experiments. The study concludes that the neighborhood association with simple accommodation decreased the population more significantly than that without simple accommodation in the historical center of Kyoto City. This result indicates that the tourism gentrification had caused a population decline in the historical center of Kyoto City. Moreover, it was found that tourism gentrification has affected the outside center of Kyoto City. The population decline might be due to simple accommodation being converted from houses due to tourism gentrification. This study’s results suggest the need for urban policy to regulate zoning for the locations of simple accommodation.

DOI： 10.3390/su141811736

Publishing type：Research paper (scientific journal)  

Control of human mobility is one of the most effective measures to prevent the spread of coronavirus disease 2019 (COVID-19). However, the imposition of emergency restrictions had significant negative impacts on citizens’ daily lives. As vaccination progresses, we need to consider more effective measures to control the spread of the infection. The research question of this study is as follows: Does the control of home range correlate with a reduction in the number of infected people during the COVID-19 pandemic? This study aims to clarify the correlation between home range and the number of people infected with SARS-CoV-2 during the COVID-19 pandemic in Ibaraki City. Home ranges are analyzed by the Minimum Convex Polygon method using mobile phone GPS location history data. We analyzed the time series cross-correlation between home range lengths and the number of infected people. Results reveal a slight positive correlation between home range and the number of infected people after one week during the COVID-19 pandemic. Regarding home range length, the cross-correlation coefficient is 0.4030 even at a lag level of six weeks, which has the most significant coefficient. Thus, a decrease in the home range is a weak factor correlated with a reduction in the number of infected people. This study makes a significant contribution to the literature by evaluating key public health challenges from the perspective of controliing the spread of the COVID-19 infectuion. Its findings has implications for policy makers, practitioners, and urban scientists seeking to promote urban sustainability.

DOI： 10.1371/journal.pone.0267335

Publishing type：Research paper (scientific journal)  

Controlling human mobility is thought to be an effective measure to prevent the spread of the COVID-19 pandemic. This study aims to clarify the human mobility types that impacted the number of COVID-19 cases during the medium-term COVID-19 pandemic in the Osaka metropolitan area. The method used in this study was analysis of the statistical relationship between human mobility changes and the total number of COVID-19 cases after two weeks. In conclusion, the results indicate that it is essential to control the human mobility of groceries/pharmacies to between −5 and 5% and that of parks to more than −20%. The most significant finding for urban sustainability is that urban transit was not found to be a source of infection. Hence governments in cities around the world may be able to encourage communities to return to transit mobility, if they are able to follow the kind of hygiene processes conducted in Osaka.

DOI： 10.1038/s42949-022-00066-w

Other URL： https://www.nature.com/articles/s42949-022-00066-w

Publishing type：Research paper (scientific journal)  

COVID-19 pandemic has been significant impacts on not only infection but also subjective feelings of health. This study aims to clarify the changes in usages of third place and subjective feelings of health during the COVID-19 pandemic. The method was a web questionnaire in Osaka Prefecture on January 12 and 13 2021, during the third wave of the pandemic. This study concluded that the importance of third places such as “cafes and fast food shops,” “large commercial facilities,” libraries”, and “movie theaters” was clarified from the usages of third places and changes in subjective feelings of health.

DOI： 10.3130/aija.87.1485

Publishing type：Research paper (scientific journal)  

Housing poverty was already a social problem in Japan before the COVID-19 pandemic. The research questions of this study were as follows: How many private rental apartments that are affordable for low-income groups exist in the real estate market? Additionally, do these rental apartments have enough rooms? This study aimed to clarify the housing affordability of private rental apartments in Osaka Prefecture according to room type. In this study, we analyzed housing affordability based on room types and housing conditions using a real estate dataset. In conclusion, this study found that housing affordability is problematic in terms of quantity and quality among the private rental apartments for multiple households in Osaka Prefecture. Additionally, it was found that the role of old wooden low-rent housingbuildings has declined as affordable housing. In particular, the total number of two-room and over three-room-type low-rent housing was less than 8000 units, accounting for only 4.2% of all private rental apartments in the real estate market. The distributed supply of low-rent housing has potential risks in maintaining a stable life for low-income groups with multi-person households. Those low-income groups are forced to live in higher-rent housing or one-room-type low-rent housing.

DOI： 10.3390/su14127433

Publishing type：Research paper (scientific journal)  

This study aims to evaluate the future scenario of Old New Town from the perspective of walkability. The methods were multi-scale analysis, scenario planning, and web-based questionnaire. As a result, this study clarified the possible future scenarios of the Old New-Town, which are the new-mobility scenario, the health-care scenario, the living-near-relatives scenario, and the work-from-home scenario. Besides, this study clarified the effectiveness of combining the new-mobility scenario with the health-care scenario and the living-near-relatives scenario, according to the regional characteristics based on the walkability score.

DOI： 10.20803/jusokenronbunjisen.48.0_25

Publishing type：Research paper (scientific journal)  

The COVID-19 pandemic has had a significant impact on work environments. Many workers have been requested or instructed to work from home (WFH). This study aimed to clarify the work-related stress of WFH regarding housemates based on residential types during the COVID-19 pandemic. We conducted a web-based questionnaire survey of 500 workers living with housemates in Osaka Prefecture. The WFH environments were analyzed on the basis of high-stress workers (HSWs), which accounted for 17.4% of all subjects, according to three major types of residences in Japan. The main finding is that HSWs with housemates had problems related to noise regardless of the type of residence. This study of workers living with housemates in an urban area contrasts with the findings of preceding study, which found that satisfaction with noise in the environment was higher at home than in the office. HSWs in detached houses and condominium apartments had problems with the levels of noise created by their housemates. The residents living in these types of residences were found to be relatively older, thus potentially having older children who would require a certain level of privacy. WFH workers with insufficient privacy were unable to adapt to WFH environments and suffered from high stress.

DOI： 10.3390/ijerph19053060

Publishing type：Research paper (scientific journal)  

DOI： 10.3130/aija.87.587

Publishing type：Research paper (scientific journal)  

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

DOI： 10.3390/su14031601

Publishing type：Research paper (scientific journal)  

In Japan, where the population is declining and aging significantly, walkability has attracted attention as a way to improve residents’ lifestyles. Therefore, it is essential to identify the residential clusters where walkability improvement would contribute to the maintenance of the population in order to select urban areas for the implementation of walkable designs. This study aimed to identify the residential clusters in which walkability affects the future population from the perspective of real estate prices. The reason for focusing on real estate prices is that they are expected to be a confounding factor connecting walkability and the future population. The method we used was to analyze the structural equation modeling of the impact of walkability index, real estate prices, and future population change ratio. This analysis was based on the neighborhood association scale. This study clarified that effective residential clusters are the business center cluster and the sprawl cluster. In the business center cluster and the sprawl cluster, the price of apartments for sale is the real estate value, through which the walkability index positively impacts the future population change ratio. This means that it is expected to contribute to the maintenance of the future population through a combination of walkable designs and housing policies that encourage people to change their residence types to apartments for sale when rebuilding old building stock using the location optimization plan policy.

DOI： 10.3390/su132313413

Publishing type：Research paper (scientific journal)  

This study aims to clarify the impact of the COVID-19 pandemic on home range. The home range is the area that individuals traverse in conducting their daily activities, such as working and shopping. In Japan, the central government declared the first state of emergency in April 2020. This study analyzed the panel data for mobile phone GPS location history from April 2019 to April 2020 in Ibaraki City, Osaka Metropolitan area. The study applied the minimum convex polygon method to analyze the data. The results show that the home range decreased significantly between April 2019 and April 2020. Specifically, the home range in 2020 decreased to approximately 50% of that in 2019 because of COVID-19 infection control measures, preventing people from traveling far from their homes and only allowing them to step outside for the bare minimum of daily activities and necessities. The results suggest that the emergency reduced people’s home ranges to the neighborhood scale. Therefore, it is necessary to consider designing new walkable neighborhood environments after the COVID-19 pandemic era.

DOI： 10.3390/su13168974

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

DOI： 10.1007/978-3-030-76059-5_4

Publishing type：Research paper (scientific journal)  

The purpose of this study was to identify the walkable streets where traffic behavior changed according to each residential cluster during the COVID-19 pandemic. By elucidating the changes, it is possible to identify streets that should be redesigned following the changes in traffic behavior in relation to human mobility. This study analyzed Ibaraki City, a suburban city located in the Osaka Metropolitan Area. The analysis compared the panel data of the GPS Location History for April 2020 and April 2019. The analysis method used was Empirical Bayesian kriging. The results show that the speed significantly increased in the dense, sprawl, mountain, and old NT clusters. It was also found that the number of cyclists increased during the COVID-19 pandemic. The results suggest a need to design walkable streets according to each residential cluster for the post-COVID-19 pandemic era. For example, some car lanes need to be converted to bike lanes in the main neighborhood to create walkable streets in the clusters.

DOI： 10.3390/su13137442

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

DOI： 10.3130/aija.86.1443

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

This study aims to clarify the statistical causal relationship between the locations of urban facilities and forecasted population changes according to types of residential clusters in the Osaka Metropolitan Fringe areas. This paper’s background is the location optimization plan policy formulated by the Japanese MLIT (Ministry of Land, Infrastructure, Transport, and Tourism) in 2015. The methods combined urban ecological analysis, cohort analysis, and Bayesian network analysis. Using the Bayesian network analysis, the causal relationship between the forecasted population change ratio and the urban facility location was analyzed. The results suggest the location of urban facilities for each residential cluster that will prevent a rapid population decline in the future. Specifically, in the sprawl cluster, this study found that residential areas closer to medical facilities will sustain the future population, while in the old new-town cluster, this study found that residential areas closer to train stations will best sustain the future population. However, in the public housing cluster, residential areas more distant from regional resources will best sustain the future population. Therefore, it is worth considering different urban designs in the old new-town and public housing clusters, rather than the location optimization plan policy.

DOI： 10.3390/su13010110

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

This study aimed to clarify the effect of walkability on urban sustainability, according to the types of residential clusters in the Osaka Metropolitan fringe area. For this purpose, this study analyzed the statistical causal relationship between the Walkability Index and the Ecological Footprint to Biocapacity (EF/BC) ratio of each residential cluster. The EF/BC ratio is the ratio of the ecological footprint of the biocapacity of the residential clusters. As a result, the effect of walkability on urban sustainability was clarified depending upon the types of residential clusters in the Osaka Metropolitan fringe area. Specifically, it was found that the Walkability Index negatively affects the EF/BC ratio in the sprawl cluster. This suggests that, in the sprawl cluster, active efforts to improve the Walkability Index can contribute to the realization of SDGs (Sustainable Development Goals of the 2030 Agenda). However, Walkability Index has a strong positive effect on the EF/BC ratio in the old new-town cluster, etc. For the residential clusters, the results of this study suggested that there is a necessity to improve urban sustainability through approaches other than improving Walkability.

DOI： 10.3390/su12219248

Publishing type：Research paper (scientific journal)   Kind of work：Single Work  

DOI： 10.3130/aija.85.1195

Publishing type：Research paper (scientific journal)  

Publishing type：Research paper (scientific journal)  

DOI： 10.3130/aija.85.101

Publishing type：Doctoral thesis  

DOI： 10.14989/doctor.k22154

Publishing type：Research paper (scientific journal)  

DOI： 10.11361/journalcpij.54.10

Publishing type：Research paper (scientific journal)  

DOI： 10.11361/journalcpij.52.1006

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Kind of work：Single Work  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Kind of work：Single Work  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Kind of work：Single Work  

Other URL： http://pub.cpij-kansai.jp/202003-kato/

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Publishing type：Article, review, commentary, editorial, etc. (scientific journal)  

Presentation type：Oral presentation (general)  

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Presentation type：Oral presentation (general)