Journal of Architecture and Planning (Transactions of AIJ)
Online ISSN : 1881-8161
Print ISSN : 1340-4210
ISSN-L : 1340-4210
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Showing 1-17 articles out of 17 articles from the selected issue
  • Jiefang LIAO, Akihiko HOKUGO, Kazuyoshi OHNISHI, Nobuhito OHTSU, Abel ...
    2021 Volume 86 Issue 786 Pages 2032-2042
    Published: August 30, 2021
    Released: August 30, 2021

     This exploratory study investigates the evacuation process of elderly facilities during the Great West Japan Flood. Based on the actual lifting up conditions and the measurement data, we scrutinized the evacuation time and configured its scenario to explain the vertical evacuation. The results highlight the following points:

    (1) About evacuation responses of the three elderly facilities:

    ・ Flood experience and horizontal evacuation drills have played a key role in responding to evacuation. However, with the absence of the agreement on the evacuation starting time among the three elderly facilities, there were differences in the criteria for determining evacuation at the affiliated facilities.

    ・ In the horizontal evacuation, Facility A took more than two hours to prepare for evacuation (including a support request), and Facility B took one hour to transport luggage. The residents' travel time by the vehicle (TH ) is "50 minutes" for Facility A and "70 minutes" for Facility B.

    ・ Despite frequent unexpected events such as nighttime, explosion, evacuees from outside, etc., self-help, mutual assistance, and public assistance were well balanced. However, the efforts such as emergency food stockpiles need to be further promoted.

    ・ Horizontal evacuation by using vehicles was useful for a large number of elderly people at the facilities in case the support system was set up early.

    ・ Vertical evacuation by lifting vulnerable people upstairs took a lot of time when the elevator in Facility C stopped accidentally. Evacuation time (TV ) is "about 80 minutes" from the 1st floor to the 2nd floor and "52 minutes" from the 2nd floor to the 3rd floor.

    (2) About the vertical evacuation process at Facility C:

    ・ Based on the results for the time spent on vertical evacuation, the evacuation time per resident on each floor (T1 ) is "2 minutes 56.6 seconds to 4 minutes 16.6 seconds" in the case of being carried on a wheelchair by four supporters, "1 minute 7.6 seconds to 2 minute 27.6 seconds" in the case of being carried on one supporter’s back, and "1 minute to 2 minutes " in the case of walking with a supporter.

    ・ In the case of being carried by a wheelchair and being carried on the back were cyclic lifting up process, and by comparing the capacity between two means, the evacuation time(TV ) is determined by the total time in the case of being carried by a wheelchair.

    ・ The wheelchair residents were not carried separately with the wheelchair during the vertical evacuation, even though the capacity of being carried on the back is four times that of being carried by a wheelchair.

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  • -Considering the ease of moving to a neighborhood and reconstruction costs-
    Kouya INADA, Ken MIURA
    2021 Volume 86 Issue 786 Pages 2043-2051
    Published: August 30, 2021
    Released: August 30, 2021

     In recent years, large cities have a large number of aging public housing units and the number of vacant public housing units is increasing. In this paper, a rational reorganization method of public housing is discussed based on the data of public housing units (generally owned by local governments). The information was obtained with the cooperation of the Kobe City Housing Bureau, Hyogo Prefecture Housing Management Division, and Kyoto City Housing Policy Division.

     The first thing we considered was how to statistically derive the priority of reorganization of residential buildings. This method evaluates each residential building on two axes: overall problem level and ease of relocation. The effectiveness of the method was confirmed by applying it to all the public housing in Kobe City. Furthermore, based on the comparison with Kyoto City, the items used in this statistical processing may be useful in large cities where public housing is constructed at high density. On the other hand, in municipalities with a low density of public housing, it was considered necessary to select a separate item for statistical processing.

     Even after identifying a priority candidate public housing project, it is very difficult to derive an appropriate restructuring plan from the vast number of combinations of housing units in the project. For example, there are 29 buildings in Oshibedani housing, but it is virtually impossible for the government officials to consider all of them because there are more than 500 million combinations of buildings.

     In this study, a program was developed, using the open-source programming language Python3, to automatically rank all combinations of residential buildings that are candidates for reorganization in terms of cost of reconstruction, number of buildings that can be reduced, and number of units.

     When the program was applied to the area under consideration for reorganization by Kobe City, it led to a combination of buildings that could reorganize more units at a lower cost than the possible combinations of reorganization proposals.

     The last thing we considered was how much easier it would be to draw up a reorganization plan by making both municipal and prefectural housing in the same area candidates for reorganization at the same time.

     The study was applied to the Outuka area in Kobe City. The results show that in the Outuka area, the variation of possible combinations for restructuring increased by 50% at the present time, and the variation increases significantly as the year progresses. Thus, in order to be able to develop a more rational reorganization plan, it was found to be effective for public housing managers to cooperate with each other to develop a coordinated reorganization plan for municipal and prefectural housing.

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  • Haoyuan CHENG, Misao KAWAI, Shuji FUNO, Naoyuki HIROTA
    2021 Volume 86 Issue 786 Pages 2052-2062
    Published: August 30, 2021
    Released: August 30, 2021

     In this research, authors will clarify the transformation process and the present condition of the historical block of Beijing Inner Castle as a series of researches on urban fabric. The objective of this article is to evaluate living environment of Xintaicang district, focusing on the space formation of ‘da-za-yuan’ (a large miscellaneous house) based on field studies. Xintaicang district is designated for ‘Conservation Area of Historic Cultural’. The district still maintains the traditional house type called si-he-yuan, but most of them is occupied by several families.

     The major points which this article clarifies are the following.

    1. Although Xintaicang district is designated for ‘Conservation Area of Historic Cultural’, the change from si-he-yuan to ‘da-za-yuan’ and the illegal occupation of hu-tong is progressing in this district, and the living environment improvement is required immediately.

    2. There are many short streets with various directions and bends in the northern area of Xintaicang district, where many storages were located. On the other hand, the southern area of the district, where most of the streets are straight, follows the basic block model of Inner Castle of Beijing presented by Funo and Deng (1999).

    3. The streets are divided into 3 levels. This street system plays a role in maintaining the daily use of residents and the sense of unity of ‘she-qu’ (community).

    4. The Xintaicang district is crowded with ‘da-za-yuan’ and many of the daily activities are carried out in the streets. Various stalls, food stalls, and rear cars are placed on the street.

    5. Parking spaces and public trash cans have been set up on the streets of the Xintaicang district and there are many private storages.

    6. There are 558 si-he-yuan. 16 types were distinguished by the number of ‘yuan-zi’ (courtyard) in the depth direction and the frontage direction. However, since the establishment of the People's Republic of China in 1949, many people have flowed into the city, and si-he-yuan has become ‘da-za-yuan’ where multiple families live together.

    7. In the Xintaicang district, the same street network was established in 1750, and the entire area was almost completely built. Comparing the current situation, there is almost no change in the blocks and streets, but in the dead end, many of them are narrow, straight and long, which shows that the district is overcrowded. In addition, there are several cases that residential lots are integrated into one residential lot.

    8. According to the interviews, the extension of si-he-yuan that added in the courtyard began in the 1970s, and the storage area, sink, laundry, etc. Inside the house are gradually overflowing, and the living environment becomes extremely deteriorated. Looking at the composition of each dwelling unit, the facilities necessary for daily life are not enough, and external shared facilities are used.

     Currently, there is an urgent need to improve the living environment where ‘da-zai-yuan’ are crowded. However, the area proves impractical with traditional remodeling methods because of the need for historical protection and the lack of commercial gain. The architecture of the Xintaicang is diverse in many respects, including its use, location, structure, number of soreys, and form. In order to revitalize the district, it seems necessary to maintain the texture, scale, and altitude of the current district, while narrowing down the development target and making the construction open.

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  • A case study on birth centers, which provide childcare support programs to regional mothers giving birth elsewhere
    Sachi IZAWA, Yoshiro KODAMA
    2021 Volume 86 Issue 786 Pages 2063-2074
    Published: August 30, 2021
    Released: August 30, 2021

     In this study, the management methods practiced in birth centers, how to use space and their assessment by participant mothers are analyzed through case studies. The aim was to investigate the factors that guide regional mothers to participate in birth centers’childcare support programs.

     A public and a private birth center (Birth Centers E and F, respectively), where mothers who gave birth elsewhere received childcare support, were examined. Birth Center E was established in 1963 as a public birth center, whereas Birth Center F was established in 2002 as a private birth center, comprising two beds.

     The survey was conducted by collecting drawings and activity-guide material as well as questionnaires and interviews with mothers. The questionnaire handed out was answered by 27 (Birth Center E) and 12 (Birth Center F) mothers, respectively. Interviews were conducted with mothers of five (Birth Center E) and four (Birth Center F) children, respectively.

     Yoga and meetings were held at Birth Center E, and programs, which continued before and after childbirth, were prepared. Additionally, the same person served as an instructor before and after childbirth. A foot-training course and baby massage were held at Birth Center F, whereas an exchange meeting was held at a nearby community center.

     59.3% at Birth Center E and 91.7% at Birth Center F of the participants were mothers who gave birth elsewhere. The living area of the participants at Birth Center E was small. At Birth Center F, mothers who gave birth elsewhere were invited by a midwife to visit a newborn baby.

     The data collected from nine interviewing participants were classified into 12 categories; these were further divided into four groups. In the first group, mothers evaluated the facilities and operations of birth centers, such as easy access and a good familiar atmosphere with the use of a dual-purpose room, regardless of where they gave birth. In the second group, mothers who gave birth at the birth centers reported that they were provided with support at the time of delivery, which established a connection. In the third group, mothers who gave birth elsewhere appreciated their midwives’expertise and free exchange. Finally, in the fourth group, mothers who gave birth elsewhere expressed their opinion to reconsider the place they gave birth.

     In conclusion, the following factors are considered important for the participation of regional mothers in childcare support at birth centers:

     The following three factors are considered relevant to mothers living in the region: 1) Transmission of reliable information. 2) Continuation of prenatal and postnatal programs. 3) Potential support from the midwives’expertise.

     The following three factors are common to both regional mothers and mothers who gave birth at birth centers: 1) Easy participation in activity places. 2) Free interaction with parents and children. 3) Activity programs that meet mothers’ needs.

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  • Psychological effects of changes in the work environment by office relocation
    2021 Volume 86 Issue 786 Pages 2075-2082
    Published: August 30, 2021
    Released: August 30, 2021

     “Work environment” where individuals and organizations carry out various activities has become even more important. As it stands, it is generally accepted that the development of a creative working environment has a better effect. On the other hand, it has been proposed internationally that the importance of balancing health, work, and economic growth. Therefore, it is important for organizations to give a positive "work mind" to worker, such as job satisfaction and meaningful work motivation. Indicators for determining these are widely developed. However, the knowledge is limited to a specific field, and is not applied across the entire "work environment".

     This paper discusses the relationship between "work environment" as an organization's activity base and "work mind". Therefore, the goal of this study is to explore the effects and limitations involved in this relationship by Work Engagement (WE) scale as a starting point.

     Survey 1: "Influence on WE due to difference in work environment" and Survey 2: "Influence on WE due to changes in work environment" were examined and dealt with in Chapters 2 and 3.

     First, a survey of workers in Japan revealed some differences in WE due to differences in worker attributes and differences in awareness of the work environment. We conducted a survey of employees aged 20 to 65 who live in Japan and work in an organization to which more than 5 people belong. Utrecht Work Engagement Scale-9, 24 items "items that define the work environment" and 6 items "items that evaluate the work environment", were selected as appropriate items to describe the work environment, were used as the survey item. As a result, differences in WE were recognized due to differences in worker age and annual income. It was shown that the emotional value, the ease of communication, and the appeal of the work environment, called Workplace Engagement (Attachment to one’s own office), had an influence on personal WE. At the same time, it was shown that a better work environment for workers affects WE.

     Next, questionnaire surveys were conducted before/after the office relocation of the organization. In addition to the items used in survey 1, time consumptions of knowledge creation behavior corresponding to the SECI model were used as an alternative indicator of changes in work style. Through a comparison of the surveys before/after, it was examined the changes in WE due to changes in the work environment. With the office relocation, positive changes were observed in physical components of work environment. However, most items had no significant effect on WE. Organizations with a high WE originally have little impact on WE due to office relocation. For workers whose work styles are changing, changes in the work environment affect WE. It was found that it was necessary to change not only the work environment but also the work styles in order to influence WE.

     The results of the present study partially show the relationship between work environment and work mind by WE scale. However, the second survey lacks generality. Further studies are needed in order to classify the elements that define the work environment, and effects of other work minds.

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  • - Transition of floor plan, structure, and materials from 1879~1972 -
    Shogo OMI, Juan Jose CASTRO
    2021 Volume 86 Issue 786 Pages 2083-2092
    Published: August 30, 2021
    Released: August 30, 2021

     This research aims to clarify the transition from the Ryukyu's Kingdom to the post-war period of the traditional wooden houses, based on the information of 122 traditional houses. Among them, eight are considered important cultural properties (ICP), and the other 114 are classified as ordinary houses. The parameters considered in this study were period of construction, location, wood materials, construction systems, structural elements joints, type of walls, floor layout, and roof characteristics.

     The study considers four construction periods 1) up to 1879 when the Kingdom of the Ryukyus become Okinawa Prefecture, 2) from 1879 up to 1911 when the Japanese government enforced the National Forest Law in Okinawa, and 3) from 1911 up to 1945 when World War II (WWII) ended and 4) from 1945 to 1972 when Okinawa was restored to Japan from the United States Army.

     Location considers three zones, 1) the Northern part of the main island, 2) the Central and Southern part of the main island, and 3) Remote islands. The structural elements are divided into five categories, 1) Flooring, 2) Columns, 3) Horizontal elements, 4) Roof and 5) Walls.

     The results showed no changes in the room layout (front and backside) of the houses, including the Amahaji corridor located in the house's outer part. No changes are observed in the structural elements joints regardless of the construction period. On the other hand, after WWII, some traditional living rooms were skipped from the house's plan, probably because of the social changes produced by the reconstruction process after the war and the American building regulations.

     The results showed that after 1879 there was a steady increment of wood materials such as Sugi, coming from the mainland, especially in the central-southern part of the main island.

     There are some differences in the wood materials used for those houses classified as ICP and ordinary houses. For ICP houses, Inumaki and Mokkoku, which are considered high-class wood types in Okinawa, were used for structural elements and floors. Itaji and Sugi were for the thin plate used in the walls. On the other hand, for ordinary houses, Sugi was the most popular structural wood material, except for those elements with decorative functions, where Inumaki was used because of its high-quality appearance.

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  • Takayuki KUMAZAWA, Daisuke SHIMIZU
    2021 Volume 86 Issue 786 Pages 2093-2103
    Published: August 30, 2021
    Released: August 30, 2021

     In a previous study, no study has to date evaluated the effect of light color on human perception and impression evaluation during rainfall. In this study, the effect of light color during rainfall was evaluated, and the knowledge about creating attractive landscapes was investigated. Field experiments were carried out depending on the combination of changes in rainfall and light color. Then, the visual effect of light color during rainfall on human perception and impression evaluation was quantitatively assessed by rainfall simulation experiments.

     The factors evaluated were rainfall, light color, vertical illuminance, and stimulus purity. Three levels for rainfall (0 mm/h, 14 mm/h, 36 mm/h), four levels for light color (yellow, red, blue, green), and two levels for vertical illuminance (0.05 lx, 5 lx), and four levels of chroma (low, Low-mid., mid.-high, high) were set. Ninety-six presentation spaces constructed in all experiments were combined by factors and levels.

     As a result, the following became clear:

     1. Even if the amount of rainfall changes, the perception of Y system does not change in the low and medium chroma.

     2. When it rains, the chroma of the R system is perceived as low.

     3. When it rains, the chroma of B system is perceived as low.

     4. When it rains, the medium chroma and high chroma of the G system are perceived as low. On the other hands, when it rains, the low chroma of the G system is perceived as high.

     5. When there was a lot of rainfall, the light color signboards made a positive impression in terms of attractiveness, strength, flashiness, and beauty, and a negative impression in terms of stability, compared to when there was no rainfall.

     6. The attractiveness of the light color signboard in the night view during rainfall consisted of flashiness, beauty, and brightness. The attractive impression was enhanced in the case of G and Y system series, medium and high chroma, and rainfall of 36 (mm / h).

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  • Akira TAKAHASHI, Kensuke YASUFUKU, Hirokazu ABE
    2021 Volume 86 Issue 786 Pages 2104-2114
    Published: August 30, 2021
    Released: August 30, 2021

     Underground spaces are widely developed in many large cities in Japan. Therefore, social and economic risk management of underground mall against tsunamis caused by major earthquakes is required. When the Great East Japan Earthquake struck in 2011, a tsunami of greater-than-expected proportions caused extensive flooding in large areas, and then forcing a fundamental review of disaster prevention measures. Administrators of underground malls and other facilities in the Tsunami Hazard Area were obliged to prepare and publish Tsunami Evacuation Plans (Act on Development of Areas Resilient to Tsunami Disasters,2011). Predicting the behavior of evacuees during a disaster is important to evaluate the safety of such evacuation plans. However, there are challenges in predicting evacuee behavior and verifying the safety of evacuation plans for various disaster situations.

     This study aims to quantitatively evaluate the improvement of evacuation safety following the revision of the evacuation plan for tsunami disaster in a large underground space. Several scenarios developed by the management company (under consideration) were simulated at the most congested time of day (18:00 on weekdays), and a comparative study was conducted. The main findings are as follows.

    1) Evacuees chose the shortest staircase to evacuate by themselves or were guided to evacuate in groups by the management company, and both scenarios were completed within the target time of 120 minutes.

    2) Simulations of a scenario in which evacuees choose the shortest staircase and evacuate on themselves revealed a bottleneck staircase.

    3) the Plan for dispersed evacuation through evacuation guidance and the plan to direct people to the widest staircase even if the distance was disadvantageous were more effective than the plan to select the staircase at the shortest distance. And then the time and amount of the effect were quantitatively shown by simulation.

    4) In the case of a group evacuation, the efficiency of evacuation to the ground was better if there were more evacuation stairs due to the dispersion effect. However, there are still some points to be noted regarding the safety of the overall evacuation, such as the choice of the evacuation movement routes on the ground and the capacity of the walkways.

    5) The visualization of the distribution of evacuee retention revealed the location and time of evacuee retention for each evacuation scenario, demonstrating the potential use of the simulation to support evacuation guidance planning.

    6) We were able to visualize the bottlenecks that occur when dividing up areas that are difficult to identify by numerical analysis.

     In summary, we were able to evaluate part of the evacuation safety from the perspective of evacuation guidance by comparing each scenario (evacuation timeline) considered by the management company by using evacuation simulation.

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  • Focusing on the policy and actual conditions of maintenance (1968-2007)
    Arisa UTSUMI, Daisuke ABE
    2021 Volume 86 Issue 786 Pages 2115-2124
    Published: August 30, 2021
    Released: August 30, 2021

     In the 1960s, many municipalities set up children's playground because of the high number of traffic accidents in which children playing on the road were victims. Amagasaki city, the study site, also established children's playground (Kodomo Hiroba)to prevent children's accidents. This project was started in 1968. There were 216 children's playground in the city as of 2017. One of the characteristics of these playground is that the municipalities set the outline for their installation and proceeded with the installation. Therefore, the project can be developed in accordance with the actual situation of the municipality.

     The purposes of this study are to clarify the outline and transformation of the projects for establishing children's playground in Amagasaki City by organizing the project policies and actual conditions of the development of children's playground and to exam the characteristics and policy significance of the projects

     Amagasaki city at the time of the project is the lack of land for parks due to geographical and social conditions. Therefore, it was difficult to establish a city park.

     Through the research, following were identified. First of all, it is about the project of installing Children’s playground.1) Amagasaki city set up a variety of ways to secure children's playground quickly and in large numbers. The children's playground was set up in three ways: (1) the installation of children's playground on low or unused land (2) the installation of children's playground in the corner of the playground equipment that had already been installed (3) Entrusting the installation to a private operator. As a result, many playgrounds of different characteristics in different locations and areas were established in the city. 2)The installation was entrusted to the private sector. Around 1980, children's playground was shifted from the " Neighborhood type" (where the city leased land to the owner of the land and set up the playground) to the "apartment type" (where the private sector set up the playground at the time of development). 3) There was no reasonable standard to evaluate the projects established in children's playground when the project was reviewed. Amagasaki City explains that the reason for their abolition is that few people use children’s playground by a decrease in the youth population. However, block parks are used on a daily basis by a wide range of age groups, and so are the playground. The decision to review the project of the children's playground on such weak grounds is not reasonable.

     In addition to the above, the characteristic of the project for children's playground in Amagasaki city is that it was established on low and unused land obtained in cooperation with various sectors. The policy significance of the project to establish children's playground in Amagasaki City provided citizens with a variety of options for places to relax by constructing. Children's playground is not only served as a complement to city parks for residents in areas where city parks are not yet established, but also as a place of relaxation for residents in areas where city parks have been established.

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  • -Through analysis of the narratives of Korean repeat tourists-
    Miyuu MURAMATSU, Haruhiko GOTO, Shu YAMAMURA, Chungmin RHEEM
    2021 Volume 86 Issue 786 Pages 2125-2135
    Published: August 30, 2021
    Released: August 30, 2021

     In Japan, during the post-war reconstruction and the period of high economic growth, land use prioritized short-term economy and efficiency. As a result, urban space has been fragmented by the incessant insertion of landscapes devoid of connection with others, greatly undermining the meaning and richness of the spatial experience.

     As a new means of landscape formation in such urban spaces, there is a demand for a perspective on the "Lifescape" that is unconsciously generated in our daily lives. In this study, we define "Nameless Landscapes" as unobtrusive and unnamed landscapes that are not eye-catching landscapes such as landmarks and historical monuments, but rather familiar living environments and activities in them, and focus on their value and approach the real picture.

     The "Nameless Landscape" , that is unconsciously created in our daily lives and whose value is difficult for the people themselves to recognize and evaluate, is analyzed from the perspective of a "stranger = traveler". This study targets Korean repeat tourists who have stayed in Tokyo under the hypothesis that repeat tourists have an excellent eye for the "Nameless Landscape" through multiple experiences. By analyzing the process of discovering and interpreting "Nameless Landscapes" , including social aspects of life and culture, this study aims to clarify the structure of the semantic interpretation that appears between the landscape and the foreign traveler (hereinafter, this is called "observer") and the nature, the value of the "Nameless landscapes" . The main results obtained are as follows:


    1) When an observer perceives a landscape, he or she first momentarily draws out prior knowledge related to the object from the knowledge stores within the self in an instant, and then "interprets" the meaning of the object being viewed by combining such knowledge with the visual information of the landscape. Interpretation means capturing the invisible elements of the landscape as information, such as the context and localities that it possesses. Through interpretation, the landscape is contextualized and a 'depth' of meaning is brought to it. The "Nameless Landscape" as interpreted by the observer is stored and accumulated as new knowledge, sometimes accompanied by "knowledge updates" such as reinforcement or overwriting of prior knowledge.


    2) A "structural model of semantic interpretation" was derived that appears between the "Nameless Landscape" and the observer. This indicates that the landscape as fragmentary information becomes "three-dimensional" as it is given meaning by the observer, and the process of establishing it as a "landscape" is also a process of "knowledge circulation" that involves the knowledge of information.


    3) It is considered that the "Nameless Landscape" that emerges endogenously from the local environment and requires a conscious interpretation by the observer is particularly strong in the above characteristics, and the experience of the "Nameless Landscape" can be found to be valuable as an opportunity for the observer to "learn" and cultivate his or her observational eyes.

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  • A study on the estimation method of spatial distribution of vacant houses using municipal public data (Part 3)
    Yuki AKIYAMA, Hiroki BABA, Yoshiya ONO, Hideo TAKAOKA
    2021 Volume 86 Issue 786 Pages 2136-2146
    Published: August 30, 2021
    Released: August 30, 2021

     This study resolved the problem of Part 2 and refined the method for estimating the spatial distribution of vacant houses using public municipal data by addressing the following issues.

     1) This study realized a more reliable method for estimating the distribution of vacant houses without concern for the simplicity of the method used in Part 2

     2) We applied the method developed in this study to the entire area of Kagoshima City and Asakura City covered by Part 2, clarifying the method’s practicality and versatility.

     3) By comparing the results of Part 2 and this study, we demonstrated the extent to which the reliability of this paper’s estimation method was improved.

     4) The correct answer rate on a building-by-building basis was also revealed, and the results of estimating vacant and non-vacant houses per building could be obtained.

     Chapter 2 introduced the database for analyzing the characteristics of vacant houses: the vacant house database, developed by combining several public municipal data: the basic resident register (BRR), Hydrant consumption amount information (HCI), and the building registration information (BRI) and the results of a field survey of vacant houses, as used in Part 2. Chapter 3 introduced the method for estimating the distribution of vacant houses in Part 2 and its challenges.

     Chapter 4 proposed a method for estimating the distribution of vacant houses. In this study, XGBoost, a decision tree-based machine learning model for dealing with missing values and setting optimal thresholds, was applied to estimate the vacant house probability of each building. XGBoost iterated the decision tree until there was no improvement in predictions, and then summed the results of each decision tree to estimate the vacancy probability per building.

     Chapter 5 verified the reliability of the method proposed in this study, comparing it with the method developed in Part 2. Results show that the correct answer rate for the vacant or non-vacant judgments for each building reached 97.81% in Kagoshima City and 97.25% in Asakura City. Even when we aggregated by the 250-m square grid as in Part 2, the accuracy of this study’s methods exceeded that of Part 2. In addition, when we determined whether a building was vacant or not using the method of Part 2, the determination accuracy of vacant houses was particularly low. However, the method used in this study significantly improved this problem and could estimate both vacant and non-vacant buildings with high accuracy.

     Finally, Chapter 6 showed the estimated number of vacant houses and the vacant house rate aggregated by a 500-m square grid for Kagoshima and Asakura. Compared to the results of Part 2, the estimated number of vacant houses in Kagoshima City increased from 7,361 to 9,856, while the number of vacant houses in Asakura City remained almost the same. In addition, vacant house rates were higher in the central city and mountainous areas and lower in the suburbs than in Part 2 for both cities. This indicates that it is possible to estimate the distribution of the number of vacant houses accurately.

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  • Analysis based on a web-based questionnaire survey carried out in Tokyo and three prefectures during the spread of COVID-19
    Takashi YAMADA, Yume NOBUSADA
    2021 Volume 86 Issue 786 Pages 2147-2157
    Published: August 30, 2021
    Released: August 30, 2021

    The purpose of this study is to investigate how people's outing behavior changed before, during, and after the state of emergency declaration in April-May 2020, and also how their health satisfaction and stress levels changed. In this study, we analyzed the differences between respondents' attributes, such as differences in attitudes toward emergency declarations by gender, age, employment status, and other personal attributes, and the changes in their relationship with their children. In addition, we conducted a model analysis of health satisfaction during the period of emergency to acquire knowledge of the personal attributes, lifestyle behaviors, and attitudes that are associated with health satisfaction during the period of emergency. In the past, there have been studies that have investigated and analyzed the relationship between outing behavior and health. However, there have been no studies that have investigated the changes in outing behavior and the attitude toward health during and after the state of emergency declaration.

    The survey was conducted in Tokyo, Kanagawa, Chiba, and Saitama prefectures, which had the longest period of emergencies in Japan. The survey targeted men and women who are in the 20s to 70s age group. The survey was conducted in July 2020 using an online questionnaire. The survey items are categorized into "respondent attributes," "means of transportation before, during, and after the state of emergency declaration," "outing behavior, time use, and health before, during, and after the state of emergency declaration," and "behavior, health, and post-declaration awareness during the state of emergency declaration. " Note that the period before the state of emergency declaration is before April 6, the period during the state of emergency declaration is from April 7 to May 25, and the period after the state of emergency declaration is the period of response.

    The findings of this study are as follows:

    (1) There was a tendency for major behavioral changes to occur during the state of emergency declaration, and a tendency to return to the situation before the declaration, with the effects of the period remaining even after its passing.

    (2) A majority of people refrained from going out, and when some people did go out, they wore masks and were conscious of not going into crowds. There were a certain number of people who did not have any awareness of what is considered to be effective in preventing the spread of infection.

    (3) During the period of emergency, there was a decrease in the use of trains and buses. The number of people who only walked or who did not go out increased.

    (4) During the period of emergency, the time spent outside the office became shorter and less frequent, and telecommuting increased. While some people increased their workload, a certain number of people decreased their workload.

    (5) During the period of emergency, changes in parents’ relationship with their children were more common among younger parents and children. There was also a significant difference in employment status.

    (6) A model analysis of health satisfaction during the period of the emergency showed that health satisfaction was significantly related to stress levels, time spent on housework, and employment status.

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  • -Based on interviews with persons in charge-
    Riho ABE, Yuki SAITOU, Kazuya SHIDE
    2021 Volume 86 Issue 786 Pages 2158-2167
    Published: August 30, 2021
    Released: August 30, 2021

     Construction delivery systems have become more diverse in recent years due to the increasing complexity of building use, building owner needs, and construction technology. In addition, due to a lack of in-house engineers, the scope and responsibilities of each project stakeholder have become unclear. This paper clarifies the effects and problems of early entry of general contractors into projects and utilization of external project managers, based on interviews with building owners, architects, general contractors, and external project managers, and considers countermeasures.

    (1) Early entry of general contractors into projects

     Many of the building owners, architects, and general contractors answered that it was effective in rationalizing and improving the construction period, planning of temporary works, and structural types, etc. And private building owners were positive about early entry of general contractors because value engineering proposals and cost reductions could be expected. On the other hand, public building owners are reluctant to involve general contractors in early phase of project unless special technology is required because transparency and accountability are difficult to achieve.

     Therefore, in order to involve general contractors in public works from an early stage of projects, it is necessary to take measures to ensure transparency of the general contractor selection process and construction costs. In addition, by utilizing an external project manager to promote operations from requirements arrangement to order support, it is possible to ensure the explanatory adequacy. However, in order to utilize project managers in public projects, it is necessary to establish a system that can correctly evaluate the effect of introducing them.

    (2) Expectations for project managers

     This paper clarifies that there are cases in which accuracy is insufficient when the building owner arranges design requirements by themselves, and that there are cases in which an appropriate fee is not obtained when the architect arranges requirements. Building owners who have in-house engineers and who place orders on a daily basis answered that they organize design requirements internally. On the other hand, it is not clear whether the Contractor feels that the work has been sufficiently completed.

     If the project manager supports the requirements organization, the project will be more efficient, the level of deliverables will be maintained, and architects will be able to focus on their own work. In addition, there were responses from architects and general contractors requesting the project managers to acquire specialized knowledge and skills related to design and construction. On the other hand, there were responses from building owners that they wanted project managers to have knowledge and experience specific to their core business and building type. Project managers with such knowledge and experience can help organize useful design requirements.

     This paper shows the possibility of supplementing the problem by the coexistence of early entry of general contractors to the project and utilization of project managers. And the characteristics of the role of the project manager expected in Japan are described.

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  • - In case of Aichi, Gifu, Mie, and Shizuoka prefecture -
    Hideki NOZAWA, Kazuhisa TSUNEKAWA
    2021 Volume 86 Issue 786 Pages 2168-2179
    Published: August 30, 2021
    Released: August 30, 2021

     In this study, the following contents were clarified.

    ・ Social education and community activity facilities account for about half, which are often managed by local governments.

    ・ There are differences in reuse depending on the prefecture due to the characteristics of location, regional requirements, and school type.

    ・ It is considered that the policy of reuse, set by local governments, is one of the factors affecting the number of cases of actual reuse.

    ・ Social education and community facilities are often located in urban or central region of the mountainous areas. They are reused as the core facilities for regional education and activity.

    ・ School facilities for other purposes are located, where a certain number of children and students are expected. Due to consolidation and abolition, relatively large-scale facilities with high seismic performance are required.

    ・ Small-scale closed schools located in mountainous areas are reused as physical education and accommodation facilities with the richness of nature.

    ・ Medical/welfare facilities, nursery schools, and kindergartens are often found in mountainous and agricultural/ fishing village areas, where many of small-scale closed schools are located. In these areas, due to the shortage of such facilities, active utilization is expected.

    ・ Although warehouses are often found in Mie and Shizuoka prefectures, they are considered to be used temporarily, and have little effect on regional revitalization.

    ・ Business, training, and commercial facilities are often located in mountainous areas with abundance of nature. They are expected to make use of this characteristic in training facilities and restaurants with local ingredients.

    ・ Cultural facilities are located in mountainous areas, and are expected to be a core of new area by integrating a theme of local culture and history.

    ・ Other facilities are used in a wide range of purposes, such as hot springs and factories. This means that closed schools are facilities with a high possibility of diversion.

    ・ The percentage of cases which continue to reuse the facilities is high. From this, there are many cases, where stable operation has been achieved to some extent.

    ・ The percentage of cases which was changed from unused to reused was as low as 40%, due to insufficient development of reuse policies, and time required for coordination with related parties.

    ・ About 50% of new facility were constructed after the demolition. The location of closed schools tends to be in the vast and center of the area, and is considered to be a factor that makes it easier to utilize effectively.

    ・ Although there are cases of reuse from unused, there are also some cases of being demolished from reuse/unused, due to insufficient seismic performance.

    ・ Municipalities with financial strength are likely to continue to reuse the unused closed schools. When the proportion of young generation is low, it is difficult to maintain reuse closed schools, and tends to be demolished.


     From the above, it was possible to understand that regional attributes and building specifications are factors that influence the determination of reuse. When selecting the purpose of reuse, it is important to consider the characteristics of the regional attributes, including the location and the building specifications such as the scale and structural reliability of the facility.

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    2021 Volume 86 Issue 786 Pages 2180-2188
    Published: August 30, 2021
    Released: August 30, 2021

     The author has examined the fact that Japanese nails and Western nails were used together in the latter half of the Meiji era, and the price transition of Western nails during the Meiji era. For the import and price of Western nails at the end of the early modern period, the import and price of Western nails in 1864 can be confirmed using the European newspaper published in Japan. The earliest imports into the country during this period were "Nail-rod", the material for Japanese nails called nail paddles. Then, from the mid-10's to the mid-20's of the Meiji era, "Yotetsu Wakugi" were manufactured by Nail-rod, and in the early 10's of the Meiji era, this production expanded and the price was reduced. In late 10's of the Meiji era, it was shown that the import of Western nails increased sharply, and the combination period in which both Japanese nails and Western nails were used was reached. In addition, Western nails called “maru kugi” have been confirmed to be imported from the early Meiji era at the latest, and the price fluctuations of Wire Nail imported throughout the Meiji era have already been clarified, but the country of importing Western nails to Japan, the transition of the port of unloading, and various problems related to these are not clear. Therefore, the purpose of this paper is to clarify the current state of nail imports in Europe and the United States after middle of the Meiji era by using "Dai-nihon gaikoku boeki nempyo" and "Gaikoku boeki gairan", which indicate the actual state of trade in Japan after this era.

     Based on the statistical data after 1883, the country where Japan initially imported the most iron nails was the United Kingdom, Germany after 1887, and the United States after 1897. Immediately after World War I, imports from Germany ceased, but they revived after 1921, after which imports from the United States and Germany accounted for the majority. Quality was one of the reasons for the change of importing countries, but price reduction was the main factor. However, in terms of imports from the United States, transportation from the west coast served as an advantage for imports to Japan in terms of delivery dates. Yokohama Port accounted for about half of the total unloading of iron nail imports. The changes in the amount of iron nails imported were well correlated with Yokohama Port and Kobe Port. However, it can be considered that the decrease in imports in Kobe after the Taisho era is due to the direct unloading to Osaka Port and the production of iron nails in the Kansai region. From 1902 to 1908, Yasuda Kogyo imported more than half of the iron nails in the Kanto area, which affected the price of iron nails at that time.

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  • Sara GOTO, Shingo SUEKANE, Ryo MASUOKA
    2021 Volume 86 Issue 786 Pages 2189-2200
    Published: August 30, 2021
    Released: August 30, 2021

     This paper is a part of the researches to characterize and identify the architectural theory of Jun Itami (1937-2011) through all the currently available articles written by him. The keywords of the subjects were sorted out as a number of items and examined from the viewpoint of hierarchy of composition of the meaning by extracting important sentence. As the first level of his architectural thought, three items of 【Joseon period】, 【Korea】, 【Contemporary Japan】 were extracted. This paper is examining 《Nature》,《Human Spirit》, and 《City》 that make up【Contemporary Japan】. 《Nature》consists of the third level of three items of[Natural objects], [Natural environment], and [The role of nature]. [Natural objects] consists of the 4th level of four items of 〈Water〉, 〈Wood〉, 〈Stone〉, and〈Soil〉. [Natural environment] consists of the 4th level of seven items of 〈Magnificence〉, 〈Environment〉, 〈Face〉, 〈Light〉, 〈Wind〉, 〈Sound〉, and 〈Sky〉. [The role of nature] consists of the 4th level of five items of 〈Harmony〉, 〈Antagonist〉, 〈Fusion〉, 〈Coexistence〉, and 〈Multi-layered〉. 《Human spirit》 consists of the third level of five items of [Perceptual structure], [Changing to the line of sight], [Art], [Drawing], and [Parthenon temple]. [Drawing] consists of the 4th level of five items of 〈Physicality〉, 〈Layering and blocking〉, 〈Primitive experience〉, 〈Tuning〉, and 〈The significance of contemporary drawing〉. 《City》 consists of the third level of two items of [Life in the city], and [Architecture in the city].

     In 【Contemporary Japan】, industrialization and internationalization are progressing, various spatial and temporal boundaries are fading, everyday life and 《Architecture》 itself continue to change day by day. Human beings are being isolated from 《Nature》, 《Architecture》, and 《City》.

     While presenting an awareness of the problem of 《City》, he examined various ways of the relationship between 《Nature》 and 《Architecture》, and found and explained the concept of 〈Face〉and[Perceptual structure] in his own word.

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  • Youngeun YU, Nobuhito OHTSU, Akihiko HOKUGO, Yuying ZHANG
    2021 Volume 86 Issue 786 Pages 2201-2211
    Published: August 30, 2021
    Released: August 30, 2021

     Japan's declining birthrate and aging population are advancing at a rapid pace, and the number of young and middle-aged people who should be playing a central role in supporting the evacuation of the elderly is decreasing, making support even more difficult. Therefore, it is necessary to be able to ensure safety for individuals even in an unavoidable situation when evacuation support cannot be received, but in the case of elder people, there are various problems due to social, environmental and physical factors. Meanwhile, in recent years, from the viewpoint of linking disaster prevention and welfare, the number of areas that support the evacuation of vulnerable people in the event of disasters are increasing. Unlike existing studies that provide direct support when evacuating, the purpose of this study was to clarify the factors that can be incorporated into the care plan, including how the care managers are involved in daily lives, so that vulnerable people such as the elderly can evacuate on their own. Therefore, in this study, we measured the evacuation speed and observed an evacuation drill conducted in Kainan City, and examined them separately into four phases: preparation, evacuation start time, evacuation action time, and evacuation spare time.

     As a result, it was found that non-structural support such as physical training should be reflected in the care plan, excluding structural support such as installation of handrails and installation of individual receivers. During evacuation drills, vulnerable people tend to have anxiety about physical factors, and in order to eliminate this, it is considered necessary to conduct training aimed at maintaining and improving physical strength.

     In addition, welfare personnel such as care managers who are closely involved on a daily basis not only directly support the evacuation behavior of the elderly in the event of a disaster, but also support in preparation phase, such as recognition, initial response behavior, and the selection of evacuation means and evacuation routes. It is considered necessary for supporters to participate in evacuation drills with vulnerable people.

     In the future, it will be necessary to verify whether maintaining and improving the physical strength of vulnerable people through training will lead to improved evacuation safety. Further research will be focusing on the evacuation ability of vulnerable people based on local welfare and disaster prevention.

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