• 한국태양에너지학회 논문집
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• 제38권3호
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• pp.29-36
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• 2018

The goal of this study is to retrofit the windows of residential buildings and to activate the green remodeling by verifying energy saving and indoor thermal environment. As a result of analysis of the energy saving effect of 458 units window retrofits, it was possible to reduce the energy requirement by 48.20% ~ 54.97%. According to the improvement on indoor environment, it was possible to operate by reducing heating temperature and supply time. The actual gas consumption of the heating period was reduced by 25% compared with that of the window retarder to save 28,968 thousand won of heating energy cost. Resident's satisfaction surveys were conducted one year after window retrofit. More than 80% of the respondents answered that they satisfied the improvement on window performance, indoor thermal environment and indoor sound environment. As a result, we verified the energy saving effect and the improvement on the indoor environment through window retrofits.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.9-17
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• 2022

As the COVID-19 pandemic situation worsens, the time spent indoors increases, and the exposure to indoor environmental pollution such as indoor air pollution and noise also increases, causing problems such as deterioration of human health, stress, and discord between neighbors. This paper designs and implements a system that measures and monitors indoor air quality and noise, which are representative evaluation criteria of the indoor environment. The system proposed in this paper consists of a particulate matter measurement subsystem that measures and corrects the concentration of particulate matters to monitor indoor air quality, and a noise measurement subsystem that detects changes in sound and converts it to a sound pressure level. The concentration of indoor particulate matters is measured using a laser-based light scattering method, and an error caused by temperature and humidity is compensated in this paper. For indoor noise measurement, the voltage measured through a microphone is basically measured, Fourier transform is performed to classify it by frequency, and then A-weighting is performed to correct loudness equality. Then, the RMS value is obtained, high-frequency noise is removed by performing time-weighting, and then SPL is obtained. Finally, the equivalent noise level for 1 minute and 5 minutes are calculated to show the indoor noise level. In order to classify noise into direct impact sound and air transmission noise, a piezo vibration sensors is mounted to determine the presence or absence of direct impact transmitted through the wall. For performance evaluation, the error of particulate matter measurement is analyzed through TSI's AM510 instrument. and compare the noise error with CEM's noise measurement system.

• KIEAE Journal
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• 제11권1호
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• pp.3-8
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• 2011

Sound absorbing materials used for lightweight panels and interior material are mainly made of fibroid material such as glass wool or rock wool. However these fiber type sound absorbing materials have some problems such that sound absorption could be decreased as time goes by because of durability. In addition, dust scattering from fiber type material can cause another problem in health. In this point of view, this study aims to develop environment friendly sound absorbing material using Hwangto(so called loess or yellow soil), a traditional housing material. Hwangto is natural housing material in Korea and generally known for improving indoor air quality. Hwangto panel is made to construct on the floor, wall and ceiling, and expected that there is not enough absorption. Present study tried to develop environment friendly sound absorbing material that has high sound absorption performance with good environment performance in terms of air quality. Pore rate was designed to maximize the absorption in the specific frequency bands, and two kinds of backing space were applied in order to see the effect of backing space. As a result peak frequency that has maximum absorption is going high as the pore rate is increased. The backing space provides more absorption and makes the peak frequency down to low.

• KIEAE Journal
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• 제10권4호
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• pp.39-44
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• 2010

Reading room in the university is one of necessary facilities that university student must use. It is, therefore, very important to make reading room comfortable acoustically not only to minimize the annoyance to the users but also to provide efficiency in studying. Present study aims to investigate the current situation of reading room in terms of acoustics and moreover to find out the relationship between the indoor noise and users' satisfaction through questionnaire survey. As a result, the indoor noise level is quite higher than the 1st grade, 35 dB(A), that the Ministry of land, transport and maritime affairs suggests as certificate regulation for environment friendly building and there were lots of noise sources that can provoke users in studying or concentrating. Questionnaire survey illustrates that the sound when opening and closing door, and airborne sound from outdoor transmitted through window are most annoying, which affected users' dissatisfaction.

• 교육녹색환경연구
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• 제19권2호
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• pp.21-31
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• 2020

본 연구는 교육품질에 직·간접적인 영향을 미치는 다양한 환경요소 중 음환경에 대한 내용을 W대학 인문대 소공연장의 리모델링 사례를 통해 분석하고자 하였다. 본 연구의 대상인 W대학 인문관의 소공연장은 강의전용 공간으로 리모델링하기에 앞서 적당한 울림이 필요한 공연장과 상대적으로 음성의 명료성이 중요한 강의실의 음향성능 차이를 인지하고 강의전용 공간에 적합한 실내 음환경을 조성하고자 하였다. 따라서 본 연구에서는 리모델링 전 음향성능 측정, 음향 시뮬레이션을 통한 마감재료 변경안 제시, 리모델링 후 음향성능 측정의 단계를 거쳐 리모델링에 따른 강의전용공간의 음향성능 개선안의 사례를 제시하고자 하였다. 이러한 과정은 추후 마감재 변경을 통한 강의전용 공간 등 교육공간에 적합한 실내 음향성능 확보의 사례로 활용될 수 있을 것으로 사료된다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.1738-1741
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• 1997

This paper addresses the issue fo target classification and localization with a SONAR for mobiler robot indoor navigation. In particular, multiple refetions of SONAR sound are used actively and interntionally. As for the SONAR sensor, the multiple reflection has been generally considered as one of the noisy phenomena, which is inevitable in the indoor environments. However, these multiple reflections can be a clue for classifying and localizing targets in the indoor environment if those can be controlled and used well. This paper develops a new SONAR sensor module with a reflection plane which can actively create the multiple refection. This paper also intends to suggest a new target classification emthod which uses the multiple refectiions. We approximate the world as being two dimensional and assume that the targets consisting of the indoor environment are pland, corner, and edge. Multiple reflection paths of an acoustic bean by a SONAR are analyzed, by simulations and the patterns of the TOPs (Time Of Flight) and angles of multiple reflections from each target are also analyzed. In addition, a new algorithm for target classification and localization is proposed.

• 한국실내디자인학회논문집
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• 제15권4호
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• pp.21-28
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• 2006

To promote environmentally responsible architectural practice, many nations have established their own green building rating system. Among other criteria, recently the indoor environmental quality section has been paid great attention due to Sick Building Syndrome, as this believed to caused by polluted indoor environment. In this context, indoor environmental quality is one of very important sections of each green building rating system and closely related to the very happiness of building users. The goal of this research is to compare and analyze the indoor environmental sections of three green building rating systems, GBCC, LEED v2.1, and BREEAM Office 2005, and find a direction for the improvement of GBCC. First, the three rating systems are analyzed in general to compare the importance of indoor environmental factors in each system. Second, the indoor environmental factors are reclassified within related sub-categories for the comparable analysis. Finally, based upon the comparable analysis, directions for the improvement of GBCC are as follows: 1. GBCC's h4r Environment Section needs to clarify its VOCs criteria based upon types of finish materials. 2. Sound Environment Section's noise control criteria needs to be revised based upon types of building usages and application method. 3. An indoor lighting related section needs to be included in GBCC, as even though light is the one of the most important factors in indoor environment, it has not been included in GBCC yet. 4. The sub-section of Confortable Indoor Environment Section related to the resting space and the universal accessibility are not in accord with the goal of green building rating system. These items need to be dealt within general building codes. 5. The rating evaluation structure and process need to be streamlined.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.332-339
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• 2007

As the economy has grown and the main industry in Korea has been changed from secondary industry to tertiary industry, the importance of indoor environment has been a matter of common concern, in which one of the main concerns is to improve the indoor acoustic conditions. However, even though this is required more than before, there are no measures to protect the human being from the noise of electric home appliances. This is owing to the absence of the data about sound power level of electric home appliances. So, we investigate the sound power level of them and analyze the acoustical characteristics of each one. First, we tried to investigate the sound power measurement method of each electric home appliance. After it we test the sound power level of them. From the survey, we can know that the vacuum cleaner is the most noisy electric home appliance, and the refrigerator is the least noisy one. The noise of a range hood is distributed over a wide range frequency. Lastly, we intented to propose the proper method measuring sound power level on each electric home appliance.

• 한국실내디자인학회논문집
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• 제14권3호
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• pp.191-198
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• 2005

The present study is a preliminary research improving the dwelling quality of one-room type multi-family housings around the university campus. The purpose of the study is to investigate the present condition of Indoor noise level using · residents' responses and field measurements. The respondents are 104 residents living in one-room type multi-family housings. The field measurements on equivalent noise level of indoor and outdoor were carried out in 6 subject house units during the $26th\~28th$ of November 2002. The results are as follows. 1) The residents show relatively non-positive responses at evening and night on the present condition of indoor noise. 2) They answer 'living equipment foise' and 'water hammer' as major types of indoor noise of house unit. 3) Outdoor noise levels, basic factor of noise environment in 6 subject buildings were distributed $52.8\~65.3dB(A)Leq_{5min}$ and were inappropriate to the standard for environmental noise, $55 dB(A)Leq_{5min}$. 4) Indoor noise levels of subject house units were measured as $27.5\~63.5dB(A)Leq_{5min}$, the average of each house unit except one house unit was higher than the level feeling as noise, 40dB(A). 5) It was found that the differences of indoor noise levels between subject house units were caused by 'residents' living noise', 'living equipment noise', 'water hammer', and 'walking and talking noise in stairs and corridors'. 6) Therefore, it is required to plan for improving the quality of noise environment in one-room type multi-family housing around the campus. For example, soundproof construction (including double window with pair glass and balcony), outdoor garden with trees and water for increasing natural sound, interior materials with sound absorbing power to absorb living noise, soundproof pipe or double surface pipe for decreasing 'water hammer', and noiseproof floors, etc. are required.

• KIEAE Journal
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• 제16권6호
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• pp.135-142
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• 2016

Purpose: The purposes of this paper are to investigate effects of indoor thermal environment on acoustical perception and effects of acoustics on indoor thermal perception, and to understand basic human perception on indoor environment. Method: Subjective assessment was performed in an indoor environmental chamber with 24 university students. Thermal conditions with PMV -1.53, 0.03, 1.53, 1.83 were simulated with a VRF system, a humidifier, a dehumidifier, and a ventilation system. Six noise sources - Cafe, Fan, Traffic, Birds, Music, Water- with sound levels of 45, 50, 55, 60 dBA were played for 2 minutes in random order. Temperature sensation, temperature preference, humidity sensation, humidity preference, noisiness, loudness, annoyance, and acoustic preference were assessed using bipolar visual analogue scales. The ANOVA and Turkey's post hoc test were used for data analysis. Result: Thermal environmental perceptions were not altered through 2 minutes noise exposure. Acoustical perceptions were altered by thermal conditions. The results were consistent with previous papers, however, the noise exposure time should be carefully considered for further development.