Journal of Environmental Engineering (Transactions of AIJ)
Online ISSN : 1881-817X
Print ISSN : 1348-0685
ISSN-L : 1348-0685
Volume 85, Issue 774
Displaying 1-8 of 8 articles from this issue
  • Ayako MATSUO, Takeshi AKITA, Takaya KOJIMA, Naoko SANO, Hanui YU
    2020 Volume 85 Issue 774 Pages 557-567
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     Many of the previous studies in the fields of architectural acoustics concerning concert hall have mainly focused on examination and evaluation of better acoustic characteristics by the audience. On the other hand, several studies have been made from the viewpoint of evaluating sonic field by music players in the field of architectural acoustics associated with music performance. Gade [1989] considered physical parameters of a player's response to the acoustic properties of a concert hall based on subjective parameters. Ueno et al. [2005, 2010] have proposed a performer's cognitive model from the viewpoint of acoustics of the hall, the performer and the audience. In particular, they reported that “performance experience” affects the background of the control process of auditory cognition and performance behavior for “perception, cognition, and judgment” for sounds input from the sound field. Additionally, in the field of music education and psychology of music, it is stated that there are stages in the learning process of that performance (Roger Chaffin, 2001).

     From the above studies, we considered that “Proficiency Level of a Music piece (PLM)” has an effect on performance behavior as much as the "performance experience", when music players perform in a certain sound field. In the present research, we analyzed proficiency process as the period from the time that piano players who have regular skills start reading scores of music pieces to the time that they come to be able to play the piano in public performance on the basis of the cognitive model. Two questionnaires in order to clarify the relationship between the contents of “Practice and Performance Behavior (PPB)” and “Consciousness to sound field” were carried out. In the first research, we made a questionnaire investigation in order to classify PLM. Subjects are asked to answer about “Implementing period” of PPB.

     As a result, PLM was classified into four groups. The four groups are named, I : Reading score of the music piece and understanding the format and composition, II : Understanding the knowledge of the music piece and fixing of the performance, III : Deepening of expression and performance and fixing to memory, IV : Consciousness of unity sense of performance and consideration of objective evaluation.

     In the second research, subjects were asked to evaluate the importance level of PPB at each PLM obtained in the first research by means of questionnaire. Causality analysis were made in order to reveal the relationship among practice, performance behavior and consciousness of the sound field from the viewpoint of PLM. As a result, the practice and performance behavior contents were constituted by five factors. Its contents were mainly “F1 : Reading score / Basics”, “F2 : Technique”, “F3 : Understanding / Fixing”, “F4 : Expression / Quality of timbre”, “F5 : Objectivity / Performance venue”. Results show that F1, F2 and F5 are affected directly by the progress of PLMs, on the other hand, F3 and F4 receive indirect effects from them. They also show that F2, F3 and F5 have significant effect on F4. Considering the characteristics of four PLMs and the relations among the five factors, it is supposed that consciousness of the sound field is low in the first half of PLM and it increases in the latter half of it.

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  • Marina NISHIKAWA, Ye MA, Jaeyoung HEO, Kotaroh HIRATE, Yoshiki IKEDA, ...
    2020 Volume 85 Issue 774 Pages 569-577
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     A sign is a means of conveying information such as directions to destinations, usage information and advertisements for products and services, in a space where many people gather.

     Public spaces need to provide information that can be used easily on the spot to various people, and it is considered essential to show information constantly. In order for the user to obtain the necessary information from signs, they must be found and recognized.

     In this study, other signs and decorations were focused as elements of contrast with the surroundings. The real space (a concourse at a major terminal station in Tokyo) was reproduced by 3DCG and presented on a screen or VR space showed by head-mounted display for experiments.

     In Experiment 1, evaluation of the conspicuity of the target sign by stationary subjects was conducted using adjustment method. It was suggested that when a subject did not move his / her line of sight, it is mainly based on the range of 6 degree from the center of the sight as judging the conspicuity of the target signs and ease of finding them. Moreover, it was suggested that the area of “attractant” around the target signs disturbed the conspicuity of the target signs. In this study, “attractant” refers to other signs, decorations, or other things that contain information that being in the field of view.

     In Experiment 2, the relationship between the area of “attractant” around the target signs and the time to find the target signs was examined by a sign search experiment with looking around in the VR space. It was suggested that it is based on the range of 10 degree from the center of the sight as judging the conspicuity of the target signs and ease of finding them with looking around.

     The area of “attractant” had a major impact on the ease of finding signs. The same was true for colors used on the signboard surface. In particular, if a high contrast combination such as white and black is not used, it is considered that signs will easily blend into background.

     In Experiment 3, the subjects walked and searched the target signs in the VR space, and the relationship between advertisement display conditions, age group, and ease of finding the sign (time to search, distance to find) was examined. The time to search and the color code did not affect the search time, it was suggested that the signs could be easily found by preventing them from blending into the surrounding visual environment. It was shown that the influence of the advertisement display condition on the distance to find is limited. In order to be able to find the sign from a long distance, it is considered necessary to change the conditions of the sign itself more than the presence of “attractant” such as surrounding advertisements.

     In future research, in order to be able to predict the ease of finding from the state of the attractant in the actual space, it is necessary to increase the pattern such as the type of “attractant” and the positional relationship with the sign, and conduct a more detailed examination.

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  • Ryuta TOMITA, Katsuo INOUE, Toru MATSUDA
    2020 Volume 85 Issue 774 Pages 579-589
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     Various studies on both vertical and horizontal vibration have been reported on the effect of vibration duration on vibration sensation both in Japan and overseas.

     However, almost reports are targeted at vibration generation times of about 30 seconds. As a result, the time correction term is 20 log10 (T1/4) and the index is constant. However, in an actual living space, the vibration generation time of about 30 seconds is short and occurs for a long time.

     In addition, since human vibration sensation is highly dependent on the time to perceive vibration, it is considered necessary to study when the time to perceive vibration is extended for a long time.

     In this report, vibration sensation evaluation experiments were conducted for vertical vibrations of buildings using internal vibration sources by the rubber ball and external vibration sources by traffic. We focused on the number of vibrations, the duration of vibration, and the perception time of vibration, and examined the evaluation methods for magnitude and discomfort.

     As a result, the following knowledge was obtained.

     (1) Magnitude scale corresponds to LVmax (10ms) even if the number of impacts increases.

     (2) In the case of impact vibration, discomfort scale increases exponentially with increasing number of impacts.

     (3) Discomfort scale is improved by setting the vibration perception time as the evaluation range.

     (4) The integral dependence of discomfort scale becomes dull as the sensory amount corrected for time changes as the vibration perception time increases.

     (5) From the result of (4), discomfort scale corresponds to LVeq, h, Th + kv*10log10Th.

     However, since this paper was experimentally studied, the evaluation scale and evaluation method corresponding to the actual resident reaction will be left as a future issue. In addition, since the sensory correction coefficient k is supposed to change continuously instead of changing in a stepwise manner, a method of evaluating it as a continuous function will be a future subject.

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  • Aging of heating and cooling loads in office buildings and energy saving by blind control
    Kyoichiro ISOZAKI, Hitoshi TAKEDA, Takashi AKIMOTO
    2020 Volume 85 Issue 774 Pages 591-601
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     Using the heat load calculation program (LESCOM) developed by the authors, we conducted a thermal load simulation using the weather data of the recent Japan Meteorological Agency in Tokyo for 60 years, captured the annual heating and cooling load, the instantaneous peak load, and predict the heating and cooling load in the near future.

     In addition, we examined the correspondence in the blind control of the opening to decrease the cooling load, and the following conclusions were obtained.

     (1) The annual cooling load in offices in Tokyo has been decreasing from 1960 to 1969, and has been on an increasing trend since 1972.The most recent building standard level estimated increase is 0.58GJ/year.

     (2) Tokyo's office annual heating load has decreased since 1960. It tends to be small. The estimated decrease in the most recent building standard level is 0.47GJ/year.

     (3) Office instantaneous cooling load in Tokyo is on a declining trend from 1960 to 1969, It has been on an increasing trend since 1972.The estimate of the most recent is 0.31kW/year.

     (4) The annual cooling load of the window is decreasing from 1960 to 1969, and has been on an increasing trend since 1972. The estimated increase in the most recent is 0.07GL/year.

     (5) The annual cooling load of the out air incorporation is decreasing from 1960 to 1969, and has been increasing since 1972. Similarly the estimated increase is 0.17GJ/year.

     (6) The annual cooling load of the outside wall incorporation is decreasing from 1960 to 1969, and has been increasing since 1972. Similarly the estimated increase is 0.003GJ/year.

     (7) Office instantaneous heating load in Tokyo has been decreasing since 1960 to the present day. The estimated decrease in the most recent is 0.150kW/year.

     (8) The annual heating load of the opening has been decreasing since 1960 to the present day. The estimated decrease in the most recent is 0.06GJ/year.

     (9) The annual heating load of the outside air intake has been decreasing since 1960 to the present day.

     (10) As a way to deal with the increasing cooling load, it is found that the minimum thermal heat gain control is effective in reducing the cooling load.

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  • Kahori GENJO
    2020 Volume 85 Issue 774 Pages 603-613
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     To determine the comfort temperature in houses in warm climatic regions and examine the locality of adaptive model of houses, a thermal comfort field survey, integrated with measurements and questionnaires, was conducted in 12 houses of the Nagasaki Prefecture, which has a warm climate, in summer, autumn, and winter seasons from 2015 to 2018. The 12 houses comprised 6 detached houses and 6 apartment houses. Most of the houses had minimal insulation and airtightness.

     Here, the thermal environment measurements were carried out. These included the temperature and relative humidity in living room and bathroom at 1.1 m above the floor surface; the temperature in living room at 0.1 m above the floor surface; the globe temperature in living room; and the outdoor temperature. Each item was measured every 10 min by a small data logger. During the measurement, the occupants were asked to assess their living environment for thermal sensation, preference, thermal acceptability, humidity sensation, draft sensation, sweat sensation, general comfort, activity 15 min before, window and door openings, heating and cooling systems’ operation, electric fan operation, and clothing, and they were asked to vote up to three times a day when their thermal sensations were neutral. To evaluate the thermal sensation, two scales, i.e., the ASHRAE seven-point thermal sensation scale (TSV) and the modified seven-point TSV (mTSV), were employed. The collected voting sheet was classified into three modes: free running (FR), cooling (CL), and heating (HT) modes. In this survey, the thermal sensation based on mTSV was used because their correlation coefficients with thermal preference vote, indoor temperature, and globe temperature were higher than those of TSV. In this survey, the indoor temperature at which an occupant voted the thermal sensation as ‘neutral’ was defined as the “comfort temperature,”, and the indoor temperature at which an occupant voted the thermal sensation as ‘slightly cold,’ ‘neutral,’ or ‘slightly hot’ was defined as the “semi-comfort temperature.” In addition to this, the comfort temperature was calculated and examined using another method, the Griffiths’ method.

     It was found that the comfort temperature extracted from the voting sheet was approximately same as that calculated using the Griffiths’ method. Therefore, an adaptive model with the comfort temperature, calculated using the Griffiths’ method in this study, was proposed for houses in the Nagasaki Prefecture for comparison with other areas. On comparison based on building type, structure, age, gender, and temperature preference, some differences were observed in the adaptive models depending on the building type and occupant attributes. Although the adaptive model also considered the running mean outdoor humidity ratio in addition to the running mean outdoor temperature in this study, it was confirmed that the accuracy of the model did not change when only the running mean outdoor temperature was used as an explanatory variable. The adaptive model in the Nagasaki Prefecture was then compared with that in the Kanto region. Based on this comparison, it was observed that the regression equations used to calculate the comfort temperature from the running mean outdoor temperature were approximately similar, except that the regression coefficients in FR mode tended to be slightly different. Consequently, it is thought that it is necessary to set the target of the housing adaptation model in detail by region and by housing and occupant attribute in order to achieve efficient energy saving for houses.

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  • Yuki KIYOKAWA, Daisuke NARUMI
    2020 Volume 85 Issue 774 Pages 615-624
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     Recently, increasing urban temperatures due to the Urban Heat Island (UHI) effect and Global Warming (GW) have been remarkable in some Japanese metropolises. The UHI effect and GW not only cause temperatures to rise, they also have other diverse impacts on urban dwellers. Therefore, it is important to understand the effect of temperature increase on urban dwellers to take action for preventing the occurrence of adverse impact. In this regard, the authors have shown the overall perspective of the effect of temperature change on urban dwellers by relation diagram, and evaluated the influence on energy, resources, health, air pollution etc. as much as possible quantitatively.

     This paper aims to comprehensively and quantitatively evaluate the impact of urban outdoor temperature change on energy consumption in Osaka Prefecture, based on the data by authors and Japanese government, energy supply company and so on. In this paper, annual evaluations concerning electric power and city gas, oils, vehicle fuel were conducted. The evaluation time was set 2000 as the past, 2015 as the present, 2040 as the future.

     The results of this research are described below.

     1) Regarding the temperature sensitivity of each energy source, the electric power showed a V-shaped tendency for all building use. City gas for residential showed a year-round sensitivity that drew a loop. Business and commercial showed V-shaped, but very weak in both summer and winter. Residential oil was sensitive only in winter. Business and commercial oils and vehicle fuel were negligible.

     2) Regarding the temperature effect of energy consumption in 2015, the total amount of electric power changes was positive, with the change in summer exceeding winter. Since the city gas changed greatly for residential, the total showed a large negative value. The oils showed a negative in all uses, with the residential being dominant. The vehicle fuel was positive for both gasoline and diesel, with gasoline being dominant.

     3) Regarding the overall evaluation in 2015, the total changes in all energy resources were almost zero. In other words, the overall energy consumption hardly changed when the outside air temperature rose 1 °C uniformly in Osaka in 2015.

     4) Regarding the future changes of the influential factors, outside temperature in Osaka was predicted to rise by 1.1 °C for annual average from 2015 to 2040.

     5) Regarding the effect of temperature on energy consumption in 2040, the amount of electric power change in summer greatly exceeded winter, and the total showed positive. City gas became negative due to the dominant of residential use. Oils had a negative change in all use, and residential use were particularly dominant. Regarding the total evaluation in 2040, the total change of each energy resources showed positive value.

     6) Concerning the secular change, the impact of outdoor air temperature change (°C) on the total change of all energy consumption was 2.2 PJ in 2000, 0.0 PJ in 2015, 3.9 PJ in 2040, and there was no constant rising trend from the past to the future. From 2000 to 2015, the overall change was offset by an increase in negative changes in city gas. On the other hand, from 2015 to 2040, the overall change increased due to temperature rise.

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  • Yuto ONUMA, Taro MORI, Yusuke IWAMA
    2020 Volume 85 Issue 774 Pages 625-632
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     Introduction

     In recent years, many researchers research a relationship between indoor environments and health in older people because an aging society is rapidly progressing all over the world. In Japanese cases, the researches mentioned that the strong relationship between cold indoor environments and health problems such as heart disease and brain disease caused by high blood pressure. However, there are still a few previous studies dealing with the correlation between indoor thermal environment and chronic diseases in cold and snowy Hokkaido. The purpose of this study is to analyze the influence of the cold indoor environment on the health of older people in Hokkaido.

     Method

     Table 1 shows the outline of the survey. We conducted the questionnaire, medical examinations, and indoor climate measurement on older people who are over 70 years old without a care in the local cities of Hokkaido, such as Tomamae, Otofuke, Higashikawa, Higashi Kagura, Biei, and Yoichi. We conducted a questionnaire survey on personal attributes and a health condition such as current symptoms, drinking, smoking, sleeping habits. Also, we collected the data for housing information to estimates building energy efficiency. At the same time, we measured indoor temperatures and humidity in the living room and the dressing room as an indoor climate for 14 days from December 2017 to March 2018. The number of respondents was 574, but there were 95 respondents with a miss-measurement of temperature and humidity, and seven respondents whose questionnaires were invalidated. Then 472 respondents were eligible for analysis. We calculated the average temperature, the 1/4 temperature, and the average temperature during the sleeping of the living room and dressing room and the average of the temperature difference between the living room and dressing. Three temperature group, a warm group, a semi-cold group, and a cold group were considered for the logistic analysis. The objective variables of the analysis were high blood pressure, stroke, heart disease, and musculoskeletal symptoms.

     Discussion

     The adjusted odds ratio (AOR) was 15.23 (p<0.05) in the comparison of the cold group with the warm group on 1/4 temperature of a living room and dressing room when the objective variable is a stroke. It indicates that the lowest temperature during the winter season is an important index on stroke in a cold climate area.

     The AOR was 2.99 (p<0.05) in the comparison of the semi-cold group with the warm group on average temperature during a sleeping time when the objective variable is musculoskeletal symptoms. Also, COR and AOR were 3.17 (p<0.05) and 3.44 (p<0.05), respectively, on sleeping habits. The high odds ratio among musculoskeletal symptoms, sleeping temperature, and sleeping habits indicates that keeping an indoor environment during sleep effects on good health. AOR was 2.84 (p<0.05) in the comparison of the cold group with the warm group on 1/4 temperature of a living room and dressing room when the objective variable is heart disease. Previous researches found the relationship between heart disease and hypertension. But in this research, we are not able to find the relationship. The reason is that the analysis method was insufficiently considered.

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  • Cost reduction measures considering the amount of larch and sakhalin fir lumber resources and transportation costs
    Yoshio ISHIKAWA, Takahiro CHIBA, Akira FUKUSHIMA
    2020 Volume 85 Issue 774 Pages 633-643
    Published: 2020
    Released on J-STAGE: August 30, 2020
    JOURNAL FREE ACCESS

     This research is aimed at promoting the use of regional materials for structural materials made of larch wood, which is low in use for building applications, and structural laminated wood made of Sakhalin fir wood, which is expected to increase in the amount of resources.

     The purpose is to clarify the possibility of cost reduction.

     As cost-cutting measures, it is conceivable to use biomass fuel (sawdust and chip) as a fuel for drying wood, and to expand the production scale by taking advantage of scale merit. On the other hand, when the production scale is expanded, a large amount of raw wood is required, so the range of raw wood collection is expanded, and it is assumed that the product price will be improved due to the increase in transportation costs.

     Therefore, in this study, the price of the product was estimated based on the production scale of the larch structural material and Sakhalin fir glulam and the impact of fuel when drying wood. The product price of larch structural materials was reduced by approximately 18-28% by increasing the production scale from 10,000 m3 log consumption to 70,000 m3/year. In addition, by using biomass fuel, a reduction effect of about 11-16% was seen compared to factories of the same scale.

     The production volume is 5,623 m3 square timber and 6,158 m3 flat square timber.

     These structural materials correspond to about 700 houses.

     The product price of Sakhalin fir Glulam has been reduced by about 44-52% by increasing the production scale from 3,000 m3 to 61,000 m3/year.

     In addition, the use of biomass fuel resulted in a reduction of about 1 to 3% compared to factories of the same scale.

     The production volume is 29,280 m3 square timber and 31,720 m3 flat square timber.

     These structural materials correspond to about 3,660 houses.

     As a result of the trial calculation, the possibility of reducing the product price due to the cost reduction effect was found.

     It was clarified that if a certain level of demand could be secured, it would be possible to sell at a price that could compete with imported and laminated timber.

     In the future, in order to realize the cost reduction measures described in this paper, it will be necessary to comprehensively consider the supply system and procurement range of raw wood commensurate with production, and labor saving of production due to difficulty in securing human resources.

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