Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 86, Issue 782
Displaying 1-6 of 6 articles from this issue
  • Kunihito TOBITA
    2021 Volume 86 Issue 782 Pages 348-356
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    Conflicts between developers and residents often arise when building skyscrapers, wind turbines, and solar power facilities. One of the reasons residents oppose the development plan is that the new additions to the existing landscape will pollute the landscape and make the residents feel that something is strange (FSS). FSS landscapes would seem to lower liking for the landscape, but it has not been experimentally verified. Additionally, residents see that landscape again and again because it is part of their daily lives. Mere Exposure Effect is a known phenomenon in which repeated exposure to a stimulus increases or decreases the liking for that stimulus. Therefore, liking of the FSS landscape may also change with repeated exposure. So, this study aimed to reveal the effect of repeated exposure to visual pollution in the landscape on liking rates.

     

    In preliminary experiment I, 100 participants rated their preferences of the 100 Non-FSS landscape photographs.

    Twelve of the one hundred landscapes were selected to use in preliminary experiment II and the main experiment. In preliminary experiment II, twelve FSS landscapes were produced by adding a skyscraper or other object to the Non-FSS landscapes. Fifty participants evaluated the oddness and pleasantness of the landscapes on the FSS scale. Welch’s t-test was performed for each pair of FSS and Non-FSS landscape scores and found that the FSS landscape showed a greater score than the Non-FSS landscape in oddness, pleasantness, and total scores.

     

    Thirty-two participants took part in the main experiment which consisted of 9 sessions. During sessions 1, 3, 5, and 9, participants evaluated their liking of the landscapes on a 7-point scale. Participants were shown 6 FSS and 6 Non-FSS landscapes in each session. For sessions 2, 4, 6, 7, and 8, participants tackled the recognition task as a filler task and were asked if each landscape was previously presented (“old”) or not presented before (“new”). Twelve landscapes, the same ones as used in the liking rating task, and 30 novel landscapes were used in the recognition task.

     

    Welch’s t-test was applied for the liking rates on the first viewing and the results were that the FSS landscape was evaluated significantly lower than the Non-FSS landscape. ANOVA was conducted to compare the effect of the exposure frequency on the liking. The mere exposure effect was found in the FSS condition and the repeated exposure to the FSS landscape resulted in decreased liking for the stimulus. In contrast, the mere exposure effect was not shown in the Non-FSS landscape.

     

    Even as residents became accustomed to seeing visual landscape pollution, it was clear that their evaluation did not increase, but rather decreased. A decrease of the liking on the landscape would then lead to the formation of the impression that the area is inhibited in some way and residents may desire to move to another property. If the attraction of the area as a tourist destination is also reduced, the economic conditions of the area would eventually deteriorate.

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  • Ryuta TOMITA, Katsuo INOUE, Toru MATSUDA
    2021 Volume 86 Issue 782 Pages 357-367
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    We reported that the degree of discomfort increased as the vibration perception time increased. Moreover, it was shown that LVeq,h,Th + kV* 10log 10 Th corresponded to the degree of discomfort. Furthermore, it was shown that the time correction coefficient kv changes with time. However, the time correction coefficient kv was a value that discretely changed for each time segment in four stages of 1 second or less, 1 to 5 seconds, 5 to 50 seconds, and 50 seconds or more.

    Hermann Ebbinghaus, a German psychologist, is studying the memory of humans and is investigating the retention of memory during repeated learning. It is shown that the amount of retained memory is proportional to the logarithm of the repeated period when the learning is repeated.

    This result can also be applied to the vibration sensation of a person exposed to vibration.

    In this report, in order to study the effect of vibration perception time on human vibration sensation, a new time correction coefficient is proposed as a continuous function.

    In addition, in order to verify the practicality of the proposed time correction coefficient, we also examined the applicability of actual vibrations such as traffic vibration in addition to impact vibrations caused by rubber balls.

    As a result, the following findings were obtained.

    (1) 0.5*10logTh (20logTh1/4 ), which is the time correction term, was added too much when the vibration perception time became long, and the response was poor.

    (2) Discomfort scale is held and becomes constant when the vibration perception time exceeds a certain time. In the range of this study, it became constant when the vibration perception time exceeded about 1 5 seconds.

    (3) kC2 in Eq. (9) had the best correspondenc e with the time correction coefficient as a continuous function.

    LVeq,h,Th + kC2 ’*10log 10 Th was used as the evaluation index for discomfort scale, and the response was improved.

    (4) The time correction coefficient k C2 was applicable not only to impact vibrat ion but also to actual traffic vibration.

    However, this report is an experimental study, and the correspondence between the actual resident reaction and the reaction in the laboratory or field experiment, as well as the setting of evaluation scales, evalua tion methods, and performance ranks are left for future study.

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  • Yuta MOTOMI, Koki KIKUTA, Naoki KOBAYASHI
    2021 Volume 86 Issue 782 Pages 368-376
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    Recently, the heat source renewal in existing office building has increased. In addition, many simulations have clarified that downsizing at the heat source renewal is effective in terms of both primary energy consumption and life cycle cost. Nevertheless, in most cases, the careful consideration is not clear at the heat source renewal, and the same equipment capacity as before the heat source renewal is selected. Probably, many engineers recognize the importance of selecting an appropriate equipment capacity based on their knowledge and practical experience. However, it is difficult to propose heat source downsizing, considering risk when a complaint occurs due to lack of capacity.

    Therefore, to make it easier to propose heat source downsizing at the heat source renewal while suppressing risk of indoor environment deterioration, it is important to examine the feasibility due to heat source downsizing and envelope performance improvement in terms of both primary energy consumption and life cycle cost. The aim of this study is to the suppress selection of excessive heat source capacity and to promote the envelope performance improvement at the renewal. The results are as follows:

    1) In the simulation model of existing office building that has reached at the heat source renewal in snowy cold cities, the building specifications were set from the previous investigation, and the air conditioning equipment specifications were set from the equipment selection by the peak heat load. Through this process, it was confirmed that the finally selected equipment capacity was more than 30 % higher than the peak heat load.

    2) In the feasibility study by indoor environment evaluation by PMV, the heat source capacity that could maintain the indoor environment almost the same as before the heat source renewal was selected. Alternatively, it was clarified that there were more possible to size down for two size of BH and 1 size of GAR after envelope performance improvement.

    3) Through this simulation, compared to before the renewal, it was confirmed that about half of refurbishment cost could be covered by the reduction in initial cost, against the increase in cost after envelope performance improvement. As a result, it was clarified that the reduction effect is 33 % in terms of primary energy consumption and 28 % in terms of life cycle cost at the maximum.

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  • En KOBAYASHI, Yasuyuki ISHIDA, Miki HOMMA, Hikaru ISHIDU, Jun TESHIROG ...
    2021 Volume 86 Issue 782 Pages 377-387
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    The latent heat transfer associated with tree transpiration is one of the influences of trees on the surrounding physical environment and it is important to predict the transpiration rate of trees correctly in order to predict and evaluate the urban heat and water budgets. When trees are planted as a countermeasure against urban warming in street canyon design, it is necessary to predict the influence of commonly planted trees on typical summer days accurately rather than that of a particular tree on a certain day. Various prediction models for transpiration rate and stomatal conductance have been proposed. In this study, in order to predict the transpiration rate of trees widely planted as road side trees on a typical summer day at a certain time with high accuracy, transpiration rate is predicted with the Penman Monteith method incorporating the Jarvis type stomatal conductance model. Penman Monteith method is one of the transpiration models tha t can predict the time variation of transpiration rate on a single tree scale and Jarvis type stomatal conductance model is one of the most widely used stomatal conductance models today. In this study, the time variation of transpiration rate of Zelkova serrata, one of the species widely planted as roadside trees in Japan, on typical summer days was clarified using long term measurement result. Based on the result, model parameters in the Jarvis type stomatal conductance model proposed by Ward et al 23,24) were identified for the prediction of transpiration rate on typical summer days.

     

    The influences of solar radiation (condition of cloud cover), soil water content and vapor pressure deficit on the transpiration rate were analyzed. As for the solar radia tion (condition of cloud cover), the peak of the transpiration rate tended to appear earlier in sunny mornings than cloudy mornings. As for the soil water content, decrease in the transpiration rate was observed due to the continuous decrease of the soil w ater content for three days when the time variation of the vapor pressure deficit and the solar radiation was almost equal. As for the vapor pressure deficit, the increase in the daily total transpiration rate associated with the increase in the daily mean vapor pressure deficit was hardly observed, suggesting that the stomat a of the water stressed tree were closed to prevent excessive drying. As a result of these analyses, the time variation of transpiration rate of Zelkova serrata on typical summer days was clarified, and model parameters in the stomatal conductance model were identified based on the data.

     

    The accuracy of transpiration rate and leaf surface temperature prediction using the model which incorporates the stomatal conductance model with the identified parameters into the Penman Monteith method was validated . The model reproduced the tendency that the transpiration rate of the whole single tree peaked in the morning and then decreased . The tendency that the transpiration rate in the tree crown is the highest at the top of the crown, where it receives the most solar radiation, followed by the bottom part, where it receives less solar radiation, and the lowest at the middle part, where it receives little solar radiation was also reproduced. As for the leaf surface temperature, the tendency that the leaf surface temperature varies little at each point in the crown was also reproduced.

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  • Analysis based on field survey and development of a unit-conversion database
    Kensuke KOBAYASHI, Kazuki SHIMOKAWA, Rei MATSUZAKI, Yoshiyuki SUZUKI, ...
    2021 Volume 86 Issue 782 Pages 388-398
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    The use of LCAs related to buildings and building materials is increasing. When implementing LCA, the analyst should collect all input data and output data. However, because data collection requires significant effort, the analyst normally concentrates on collecting the foreground data. In contrast, background data is normally collected from a background database. Consequently, differences between the functional units of the foreground and the background data are frequently required commonly a need for unit conversion.

     

    We assert that the promulgation of LCA in the building industry is hindered by the scale of the variety among materials utilized in construction; consequently, LCA data analysts are frequently overwhelmed. To ameliorate this situation, it is indispensable not only to enhance the content of the background data but also to provide proper means of unit conversion. Based on the above, our study clarified as follows:

     

    1) We examined 11 building (LCA) cases and selected materials requiring unit conversion, based either on the scale of data or environmental loads. As a result, the proportion of items requiring unit conversion was required from approximately 70 to 90 percent in the former to 50 to 80 percent in the latter.

     

    2) Assuming several stages in the design of the building, a list of used items was created by researching various documents and examining expert opinions. The list consists of approximately 1000 items.

     

    3) Through a questionnaire survey of experts and the analysis of 11 buildings, we selected the data to be examined in this work with a priority for items from the list proposed in 2).

     

    4) We propose a method to create unit conversion database. This method refers to the descriptors utilized when creating inventory database (IDEA). We scrutinized the information that should be recorded when creating a unit conversion database. The descriptor for each item in the unit conversion database includes our proposed descriptors.

     

    5) Based on the above contents, a unit conversion database was developed from documents, statistics, and public information on the Internet. This database is a compilation of unit conversion values for more than 100 high priority items and was published on the website of the Architectural Institute of Japan.

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  • Emiri MIYAZAKI, Shintaro ANDO, Toshiharu IKAGA
    2021 Volume 86 Issue 782 Pages 399-408
    Published: April 30, 2021
    Released on J-STAGE: April 30, 2021
    JOURNAL FREE ACCESS

    In Japan, healthcare and nursing care expenses for the elderly are increasing year by year, and extending healthy life expectancy is therefore desirable. Social capital (SC) is a measure of the degree of social interaction and has been gaining attention as a health-related Previous studies have shown that few people have poor subjective health in areas with good SC scores. Thus, a living environment that fosters SC might facilitate the improvement and maintenance of health status. The purpose of this study was to clarify the effects of living environment, such as facilities and community outreach efforts, on nursing care risk as mediated by SC. A questionnaire survey was carried out for 3 weeks from September to October 2018.Participants were adults in three elementary school districts in Niihama City, Ehime Prefecture, Japan Survey contents included SC, neighborhood environment, residential environment, and health status. A total of 7,220 questionnaires were distributed, and 2,693 were correctly completed (valid response rate = 37.3%) The number of samples used for analysis was 2,053.

    Of respondents over 65 years of age, 26.8% were at high risk of needing long-term care. Mann-Whitney U test was performed to verify the impact of SC on risk of needing long-term care. Logistic regression analysis was performed using participant attributes such as sex and household composition as moderator effects. The aim was to clarify the effects of living environment such as facilities and community outreach on the risk of needing long-term care via SC.

    The analysis model considered factors including age, sex, educational attainment, and length of residence in the area.

    The odds ratio (OR) of requiring long-term care for low SC compared with high SC was 1.91 (p <0.01). Next, I examined the relationship between SC and the living environment based on the “Facilities” and “Activity participation,” or “Communication” items of living environment. The OR of SC for neighborhood environment factors ranged from 1.3 to 2.4 (p <0.05), and the OR of SC for housing environment factors ranged from 1.3 to 3.0 (p <0.05).

    Finally, path analysis was performed. An index for the housing and neighborhood environments was determined as the total score of the items that showed the relationships between SC and the housing and neighborhood environments, as analyzed previously. The determination coefficient for the risk of needing long-term care was 0.19.

    In summary, the facilities of the living environment affected SC directly or via the community items and finally affected the risk of needing long-term care. A study limitation is that the results were based solely on data that covered one target area. In the future, we plan to conduct questionnaire surveys in other regions using statistical data and to analyze responses considering regional characteristics.

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