This paper proposes a reliability based design for limiting floor slab vibration due to human walk. The reliability index β can predict the stochastic vibration performance of any floor slabs, independent of the dynamic characteristics of the slabs. Then the reliability design method was applied to an actual floor slab design and its validity was confirmed by hammering tests and a one person walking test using the actual building floor slabs. The second moment method was used in formulating the reliability based design. The serviceability limit state was defined based on previous experimental data by other researchers. The serviceability limit is one at which acceleration “isn't unpleasant“. This was deemed as a log-normal distribution with the median of 4cm/s2 (or mean 5.28cm/s2) and coefficient of variance 0.8. From this work, “the walking vibration V-value response spectrum” is proposed first as the loading effect. A relationship between the reliability index β based on formulation, V-value (the corrected response acceleration considering human perception) and the perception probability mentioned above, was formulated using a single degree of freedom system. It was shown that a relationship between reliability index β and V-value is almost independent of the dynamic characteristics of the floor slab. Finally, the reliability based design was applied to an actual floor slab with an intention of realizing a certain value of β against one person walking. The effectiveness of the design was verified through the fact the targeted β and experimentally obtained one were almost identical. The latter value of β was estimated using the data from a hammering tests and a one person walking tests on a slab in an actual building. The following conclusions were obtained. 1 Formulation of the reliability based design method for limiting floor slab vibration due to human walking was proposed using the authors' walking vibration V-value response spectrum. 2 This reliability based design method considered the effects of prediction errors in the vibration characteristics of the floor slab, such as the first natural frequency, damping coefficient, modal mass and individuality of walkers. It was also expanded to the multi degree of freedom system. 3 The reliability index β could almost uniquely determine a stochastic behavior of habitability performance for any floor slabs. This fact was empirically reduced, through various calculation model cases, where various combinations of reliability index β and vibration characteristics of the floor slabs were tried. 4 An application example of the reliability based design of floor vibration due to human walking was shown, and design objectives were verified based on the field experiment including hammering tests and a one person walking test on the designed actual slabs.
There are many people involved when planning lighting. In addition, consideration of users is crucial when planning in retail. Most of the lighting “How to” books refer to lighting method or lighting equipment (lamps) based on the typical pattern used in that certain industry sector. In reality, the impression created by lighting differs not only by industry sectors, but also with the main target and concept of the shop. Therefore, it is difficult to generalize based on industry sectors. The aim of lighting is to lighten the visual target and to create a favorable atmosphere suited for its action and behavior of the space16). Illuminance is often used for planning lighting, yet many admit that creating favorable atmosphere involves more than that. The objective of this research is to make a chart for lighting planning of retail. This focuses on the favorable evaluation of the lighting environment as in visual environmental index and lighting environmental factors that form it. Finding the relationship between the visual environmental index and lighting environmental factors will help why that lighting environment created by that lighting method ends up to be evaluated in that certain way. Considering the visual environmental factors, the point of view is taken into account. First, where and when it is evaluated, in fact, evaluator's behavior and its chronical change is categorized into three steps and named accordingly; a) exterior evaluation, b) interior evaluation, c) integrated evaluation. Next, what is being evaluated, in other words, visual target and move of focus point are divided into three categories and named accordingly; a) objective evaluation, b) spatial evaluation, c) behavioral evaluation. As a whole, evaluation is divided into nine categories. Lighting environmental factors are information taken from the environment (what people see) to create the evaluation (visual environmental index). Therefore, the category of the factors are based on 4 attributes of perception and lighting equipment properties; 1) quality of light ( a) color rendering properties, b) light color), 2) intensity of light ( c) luminous flux, d) reflection rate), 3) extension of light ( e) irradiation angle, f) flux distribution, g) equivalence area), 4) endurance of light ( h) on/off/timing), 5) lighting equipment properties ( i) design, j) number, k) placement, l) efficiency). In total, factors are divided into 12 categories. Visual environmental index and lighting environmental factors are picked up from the previous books and researches written on lighting planning of retail and basic perception of brightness, and arranged based on its categories. In total, 72 visual lighting index and its lighting environmental factors are organized in a matrix, and 69 of them is shown in Table 4. This chart is then used to create the lighting plan for retrofit of retail. First, by investigating and interviewing, 4 problems arose; 1) dark, 2) doesn’t look like open, 3) glare at nighttime, 4) no atmospheric lighting according to areas. Visual environmental index related to solving those problems were chosen, and lighting plan was formed. By comparing the result of impression experiment using visual environmental index before and after the retrofit, the validity of the renovation was shown. To enhance the effect of lighting renovation, the manual that indicates the position of the products, lighting patterns and explanation of automatic adjustment by exterior brightness was created. This example shows the usage of the chart and possibility of application to commissioning in the field of lighting.
It is important to retain enough visibility of the opposite passenger's face on the street at nighttime for the passengers to walk with feeling of security. There are several previous studies identifying the effects of street lighting on visibility of the opposite passenger's face using scale models. However in those studies, the effects of the light except for the street lighting such as headlight of cars or motorbikes, spilled light from shops or houses and etc., that exist in actual situations, were not considered. Recently, the number of LED street lighting is increasing rapidly. It is necessary to evaluate the effects of LED street lighting on the passengers' visual environment properly in actual situations. In this study, subjective experiment was conducted to identify the effects of changing the light source of the street lighting on the passengers' visual environment at nighttime in an actual situation. Three different streets within the distance of 500 m from the south exit of JR Tsudanuma station were chosen to be evaluated. The light source of the street lighting on the two of them was changed from high pressure mercury lamp to LED, and there was no street lighting on the other one (only security lighting illuminated the street). The experiments were conducted three times. Each experiment was conducted on the same day of the week with almost the same age of the moon. University age young people with no visual impairment nor eye diseases were chosen as the subjects. The number of the subjects ranged from 41 to 60. The experiment was started at 8 p. m. and finished before 10 p.m. In the beginning of the experiment the subjects were instructed about the experiment, and after the instruction a subject started to walk alone after another at intervals of 2 minutes. After enough walking to adjust their eyes, he/she reached to the target street. He/she evaluated the impression of the light environment of the street with eight items, such as brightness of the street, visibility of steps, feeling of security and etc., at the entrance of the street. Then he/she went forward the street and judged visibility of the opposite passenger's face, preference of color appearance and easiness for distinguishing colors at two points on the street, the point with the highest road illuminance and that with the lowest road illuminance. After the evaluation at the two points, he/she went through the street and answered whether the light environment of the street was suitable or not as the street for walking at night. Continuously, the subjects walked and evaluated the light environment on the other two target streets in the same way. From the results of the measurement, it was identified that average color rendering index Ra and S/P ratio became higher by changing the light source of the street lighting from high pressure mercury lamp to LED. The results of the subjective experiment showed that spacious brightness of the street at nighttime was related stronger to mesopic luminance than to photopic luminance, i.e. spacious brightness at nighttime was effected by spectral power distribution much or less. In addition, visibility of the opposite passenger's face was improved by changing the light source of the street lighting from high pressure mercury lamp to LED. It was also identified that LED street lighting caused significantly higher glare than high pressure mercury lamp street lighting. However, there was no significant difference in the impression of the light environment of the street or the suitability as the light environment for walking at night between the two kinds of light sources.
Decline in the quality of sleep increases the morbidity and risk of lifestyle diseases. In addition, daytime sleepiness causes traffic accidents and decreased work efficiency. According to a survey conducted by the Japanese Ministry of Health, Labour and Welfare, 20% of people experience sleep problems, and decline in sleep quality in particular is serious. One factor that has been linked to decline in sleep quality is high heat and humidity in summer. Against this background, some studies have examined the effects of thermal environment control on sleep. Appropriate use of air conditioning has been shown to improve sleep quality; however, maintaining a good indoor thermal environment using air conditioning increases energy consumption. Given the present state of climate change, the reduction of energy consumption in the Japanese residential sector is a pressing issue. However, an excessive reduction in air conditioning use for the purpose of saving energy could create a poor sleep environment. The effects of thermal environment control using air conditioning on sleep quality and energy consumption have been independently investigated in several previous studies. In this research, we elucidate the impact of thermal environment control on both sleep and energy consumption during the summer. The effect of thermal environment control on sleep and energy saving was unified as a monetary value. Increase in energy consumption can be estimated as an increase in air conditioning costs. Conversely, because reduced sleep efficiency translates to reduced working efficiency, improved sleep efficiency was converted into monetary value as a reduction in wages. Eight healthy male university students participated in this study. The study was performed in a two-story maisonette room in an apartment building with high environmental performance. Experiments were conducted in August 2013 and 2014. In the 2013 experiments, we examined the effect of thermal environment control on sleep and energy consumption. Three thermal environmental control scenarios were used: an air conditioner set at continuous operation at 26.0 °C (Case I); an air conditioner set at continuous operation at 28.0 °C (Case II); and natural draft only (Case III). The increase in air conditioner temperature setting from 26.0 to 28.0 °C used in this study resulted in a 0.03 kWh/day/m2 reduction in 8-h energy consumption (Fig. 6). Sleep efficiency was significantly higher for Case II (average SET* during sleep, 27.4 °C) (Fig. 8). Low SET* caused by excessive air conditioner use and high SET* caused by not using an air conditioner adversely affected sleep efficiency. The relationship between sleep efficiency and work efficiency was verified in the experiments conducted in August 2014, confirming that the economic impact of decreased sleep efficiency could be converted to a monetary value. Working efficiency decreased by 1.1% per 1% decrease in sleep efficiency (p<0.01) (Fig. 13). The combined economic impact of energy saving and sleep quality was calculated. The economic impact of improved sleep quality was much greater than that of energy saving, and the economic value of Case II (average SET* during sleep, 27.4 °C) was the highest (Fig. 14). This study found that sleep quality influences work efficiency, demonstrating the importance of improving sleep. To create a comfortable sleeping environment, further verification of thermal environment control in more detail is necessary.
This paper reports the summertime measurement results of the indoor thermal environment at the head office of S Company. On the subject of air conditioning system, the perimeter zone supplies cold water to a perimeter chilled beam and it processes the perimeter cooling load. The interior zone adopts a task and ambient air conditioning system. Ambient air conditioning supplies cold water to an interior radiation ceiling panel and processes the internal heat generated by human bodies, lighting, OA equipment, and so on. In addition, the air carried out during latent heat processing with the desiccant air conditioning system is supplied from the personal floor outlet installed under the desk. The current from a personal floor air outlet provides air conditioning and it can be adjusted to an individual’s preference. This study aims to evaluate the thermal comfort of an indoor environment in office from physical quantity and psychological state. Moreover, this study aims to assess the thermal conditions of an indoor environment deemed unacceptable by workers that it is impossibility to evaluate from conventional method. For this purpose, the acceptability voting device “Ostracon” was developed, which can record the physical environment when workers express a complaint. Workers can push a button on Ostracon to vote when they feel that the thermal environment is unacceptable. In this study, Ostracon was used to measure whether 25 workers felt that the thermal environment was acceptable in the office S during the summer. The results showed that the mean radiant temperature was lower than room temperature. Moreover, up-and-down temperature distribution was very small. In addition, the temperature difference to every time is smaller during the up-and-down temperature distribution. Distribution stability throughout the day should be confirmed. For this reason, it was determined that the radiation ceiling panel was effective. Regarding questionnaire about satisfaction with the room environment, the many of respondents said they were "comfort" overall. The result showed a very high level of satisfaction. Regarding the survey of Ostracon, subjects expressed that the environment was unacceptable even when the temperature and humidity were within an acceptable range. Therefore, the authors consider that thermal environmental acceptability is not determined simply by temperature and humidity. However, it was observed that the workers' complaints were often expressed moments after returning from tasks performed outside the office, suggesting that their complaints were influenced by factors other than the office environment, such as changes in metabolic rate and the individual's thermal history.
Introduction: Appropriate use of air-conditioner will not only lead comfortable indoor air but also prevent from heat stroke. We can see these information on Guidelines or weather forecast. On the other hand, we know the use of air-conditioner is a cause of high electricity bills. Parent/child, age and sex have effect on these decisions such as on/off or set temperature. For example, metabolism of elders is lower than that of younger people. This is the reason why elders set lower temperature than the younger people. Many and complex functions are loaded on the air-conditioner. That is also the one of the reason why elderly do not like to use of air-conditioner. In a past, a lot of researches were done about the relationship between use of air-conditioning and age, sex. They were based on physiological and psychological knowledge. This study aims to analyze the relationship between behavior of use of air-conditioner and physiological and psychological differences. Method: I commissioned a private school to distribute questionnaires. In the questionnaire, a respondent requested to choice room type, age range, set temperature, reasons why you use air-conditioner and why not. As the reason why you use air-conditioner, I showed several reasons such as “Hot” “Humid” and “No wind”. As the reason why you do not use air-conditioner, I showed several reasons such as “Not hot” “Not humid” “Wind” “High electricity expense”. Also I asked to answer the set temperature that respondent usually use. I commissioned a private school to distribute 100 questionnaires to households where teenagers are living. Questionnaires were distributed in July or August and that were collected in August or September. Result and Discussion: 77% of distributed questionnaire were collected. These questionnaire included 203 air-conditioner units. About the half of air-conditioner was mainly used by male or female. Room type had no influence to the set temperature. “Hot” is the main reason why the air-conditioner was used. “Humid” is the next. “Not hot” was the main reason why air-conditioner was not used. “Not humid” was the next. Average set temperature was about 26.7°C. Air-conditioner users decides to use AC at the temperature of 30.2°C. Air-conditioner users set temperature at 26.4°C. Conclusion: Survey about actual condition of use of air-conditioners was analyzed on following 3 aspects. 1. There were no-difference on the set temperature between male/female and types of the room. 2. Average set temperature was about 26.7°C. 3. Air-conditioner users decides to use AC at the temperature of 30.2°C. Air-conditioner users set temperature at 26.4°C. 4. The main factors of the use of AC is high temperature and humidity. The main factors of the not-use of AC is bearable temperature/humidity, airflow and high electric bill.
In recent years, the “compact city” concept is gaining popularity as a suitable urban structure for a depopulation society in Japan. Many studies using scenario analysis methods have evaluated ideal compact city scenarios from various points of view including aspects of CO2 emissions, infrastructure maintenance costs, and traffic accessibility. However, actual forms of the compact cities have not been clarified to date. Therefore, it is also necessary to build compact urban scenarios based on residents' intentions. Consequently, this study was undertaken to clarify residents' intentions and preferences for future living environments using a questionnaire survey. Based on those results, one can produce urban structure scenarios incorporating those residents' intentions. This study specifically examines four points of residents' intentions for future life using questionnaire survey results as described below. (1) Place where residents want to live in the future: downtown vs. suburbs More residents want to live in downtown areas than in suburbs. However, differences in preferences are apparent by sex, age, and the place of current residence. Overall, many residents intend to live in downtown areas in the future. However, elderly men who currently live in the suburb are more likely to want to live there in the future. Therefore, one must consider not only future living environments in the downtown area, but also those in suburbs to build a compact city based on residents' intentions. (2) Centrally located facilities of the future Many residents hope that shopping centers will be located in the city center. Some survey respondents also selected the stations and shopping streets. Such facilities that are used frequently can form the center of a compact city. (3) Daily transportation of the future First, the number of retained cars per household and the frequency of present car use were analyzed. Results show that residents in this study area routinely depend on personal automobiles. Second, the desired frequency of cars and transportation use in the future were also analyzed. Age strongly affects the preferred frequency of automobile use. Older respondents show lower rates of intended car use in the future. Among transportation modes, cars are expected to be the most used, followed by “on foot”. Particularly, the response rate for “on foot” was higher among responses of residents who do not expect to use cars in the future. (4) Necessary nearby facilities Residents who want to live in the suburbs expect to need no facilities near their homes in the future. In contrast, residents wanting to live in the downtown area require the several facilities nearby. As basic information for designing a compact city, population densities near some facilities such as supermarkets and clinics were analyzed. Results show that facilities cited for their high necessity are built in areas where the population density is 20-50 persons/ha.
Penumbra is an important factor for three dimensional Computer Graphics in order to represent realistic images especially at interior views. Point light represents images with sharp-edge shadow that is far from reality. On the other hand, area light casts penumbra at the situation where occluders prevent some part of light area from reaching calculation points. Although path tracing and radiosity are technologies that handle area light, both of them take so enormous times for processing that they are not suitable to use at the stage of reviewing designs which are weighed with turnaround time. Therefore, this paper proposes a new high-speed algorithm that represents high resolution penumbra casted from psuedo area light by applying ray tracing that handles point light only. It is inevitable that the previous technologies, namely percentage closer filtering (PCF) and variance shadow maps (VSM), generate low quality penumbra because they are algorithms based on shadow maps that include aliasing problem. We name this new algorithm “light obstacle depth”. Light obstacle depth calculates intensity of shadow by point light at each calculation point at first and subsequently blends shadow around the calculation point according to the distance between the nearest occluder and the point. Ray tracing produces shadow with shading at a time which contains textures, reflection, transparency, and refraction, etc. However, light obstacle depth separates shadow calculation process from other shading process, calculates shadow intensity independently, stores them at each pixel to make shadow buffer, and at last combines the shadow buffer and other shading together after blending shadow buffer. Blending problems around occluders occur when we apply the basic blending technique, so we propose an enhanced blending technique to solve the problem. In addition, we show the equation that estimates blending area using size, direction, and distance of an area light simulated. We also propose a technique to estimate blending area on image with perspective transformation. To validate quality and speed of the new algorithm, we used two different types of models, namely a model with scattered polygons and a model crowded in small area. Compared with images generated accurately by area light, images by our new algorithm show that light obstacle depth is able to simulate penumbra of area light with practically sufficient quality. In terms of the calculation time, our new algorithm is capable to generate penumbra at almost the same time as point light calculation and several tens of times faster than normal area light calculation. Furthermore, we show that calculation speed of our new algorithm becomes more efficient for more complex data. We aim that light obstacle depth is processed using GPGPU (general purpose GPU) technology. As GPGPU processing is expected to be several tens of times acceleration, real time penumbra generation will come true after GPGPU application to light obstacle depth is realized.