• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.259-264
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• 2001

It is necessary to predict the sound pressure level(SPL) in rooms before designing an apartment when exterior noises are produced. In order to predict SPL for an apartment that has some specific exterior noises, the following should be known: the characteristics of outdoor noise, sound insulation performance and sound level differences of each room. The purpose of this study is to find out the possibility of predicting sound pressure level of rooms in an apartment by analysing sound level differences among rooms. Sound sources used in this experiment are construction noise, aircraft noise, railroad noise, road traffic noise and white noise as a reference to compare with the previous four. These noises were recorded and reproduced by speaker. As a result, we found that within the sound reduction pattern, the sound difference level appeared uniform depending on the sound insulation characteristics of the windows installed when facing the noise source. When the windows having the same acoustic performance were installed, the SPL in each room resulted in nearly the same values.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.263-271
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• 2008

Compressor radiated noise is one of the dominant noise for the outdoor unit of the air conditioner. Therefore, air conditioner makers are trying to reduce it continuously. Even though noise absorption and isolation technology are one of the important parts for reducing the noise from the compressor, it is usually treated to the substitute technology when the noise from the compressor is very difficult to reduce by the compressor noise control only. In this paper, we focus on the property of the sound insulation for the cabinet and measure it applying the theory of the sound transmission loss and insertion loss of the simple enclosure. The insertion loss is evaluated by the experiments according to the thickness and the aperture of the partition in the cabinet.

• 대한가정학회지
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• 제43권6호
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• pp.133-144
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• 2005

The purpose of this study was to obtain and offer useful information on innerwear industry through an analysis of consumer purchasing behavior and preference of their between the 20's and 60's. From 310 questionnaires that were distributed, 308 with usable data were coded for further statistical analysis including descriptive statistics(frequency and chi-square test), by using SPSSWIN 10.0. The results were as follows.: It was found that the innerwear for men in their 20's should be developed in an attempt to place greater emphasis on improving functions as an outwear such as impact absorption and protection articulation required for outdoor activities such 3s mountain climbing and in-line skating, rather than the function of thermal insulation. In addition, the development of new materials that improves the hygroscopicity and rapid dryness is needed. For men in their 30's and 40's, the results suggest that innerwear should be designed as thinly as possible without compromising the silhouette of the outwear. For those in their 50's and 60's, it is recommended to intensify the aspects of health and hygiene of the innerwear, while maintaining the function of thermal insulation. Given that a large number of women purchase men's innerwear for their partners, it is important to strengthen the designs and marketing strategy specifically tailored to women's purchasing power.

• 대한건축학회논문집:구조계
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• 제35권10호
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• pp.235-243
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• 2019

In South Korea, millions of poultry have died due to repeated heat waves every year. The purpose of this study is to analyze the characteristics of heating and cooling loads of chicken houses in Korea and to present an effective insulation and ventilation measures to minimize the damage of poultry due to summer heat wave and to save energy in chicken houses in winter. The heating and cooling loads of standard chicken house were calculated. As a result of the calculation of maximum heating load based on the minimum ventilation rate in winter, the outdoor air temperature requiring heating was $6{\sim}7^{\circ}C$ to keep the indoor air temperature of chicken houses as $24^{\circ}C$. The peak cooling load of chicken houses was mostly taken by the heat generated by chickens and the heat gain due to ventilation. The heat gain through building envelopes was as small as neglectable. Most of chicken houses is usually cooled by gigantic forced ventilation in summer in Korea. When the chicken houses are cooled by electric cooling machine such as cooler or air conditioner, it is more effective to keep minimum ventilation rate to reduce the maximum cooling load. To lower the temperature of supplying water to cooling pad, it is recommended to use the underground water below 10 meters from the ground if there is abundant underground water.

• 설비공학논문집
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• 제20권11호
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• pp.718-726
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• 2008

The cooling load in winter is significant in buildings and hotels because of the usage of office equipments and the high efficiency of wall insulation. Hence, the development of a multi-heat pump that can cover heating and cooling simultaneously for each indoor unit is required. In this study, the performance of a simultaneous heating and cooling heat pump was investigated in the heat recovery mode (HR mode). The system adopted a variable speed compressor using R410A with four indoor units and one outdoor unit. In the HR mode, the capacity and COP were improved as compared with those in the cooling or heating mode because the waste heat in the outdoor unit was utilized as useful heat in the indoor units. However, energy imbalance between heating and cooling capacity of each indoor unit was observed in the 2H-1C HR mode. Therefore, the performance of the system in the 2H-1C HR mode was enhanced by controlling refrigerant flow rate through the outdoor unit.

• KIEAE Journal
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• 제16권1호
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• pp.57-65
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• 2016

Purpose: The purpose of this study is to analyze the energy performance by applying new technologies for passive and active control. Method: We selected new technologies for passive and active control which are based on formal study by analyzing technology applied to the High-Performance Buildings in various countries. Also, we analyzed energy saving potential for each technologies by breakdown the result of the energy saving rates in detail. Result: For the wall and roof insulating methods, preceding studies showed that up to 21% energy could be saved by improving roof insulation and applying proper outside insulation compared to non-insulation. For the windows and glazing system, preceding studies showed that Low-E glazing system could save up to 11% energy compared to single glazing system. Studies about solar and daylighting controls revealed that effective daylighting dimming control could save 13% of energy compared to uncontrolled situation. Studies on DOAS (Dedicated Outdoor Air System) showed that about 23% energy could be saved compared to standard VAV system. Studies on the active chilled beam showed that about 25% energy could be saved compared to standard VAV system and studies of applying UFAD (Under Floor Air Distribution) could consume 31% less energy than applying overhead system.

• 청정기술
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• 제29권4호
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• pp.237-243
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• 2023

에어로젤은 지금까지 알려진 가장 단열성이 우수한 소재이지만 유연성이 없고 강도가 매우 낮아 부직포나 섬유에 에어로젤을 담지한 블랭킷이 현실적으로 가장 활용이 가능한 형태이다. 그러나 에어로젤 블랭킷도 분말 발생을 피할 수 없고 유연성이 부족하고 변형 가능성이 있는 문제가 있으므로 아직은 범용으로 사용되지는 못하고 있다. 본 연구에서는 이를 해결하기 위하여 진공 처리, 표면 처리, 복합 소재화 기술을 적용하였고 일부 시제품도 제작하였다. 에어로젤 블랭킷을 알루미늄 시트로 감싼 다음 네 끝을 봉하고 진공을 뽑으면 단열성이 블랭킷 자체보다도 우수한 소재가 될 수 있다. 에어로젤 블랭킷을 수지로 도포하여 표면 처리하면 에어로젤 성형체를 만들 수 있다. 에어로젤 블랭킷에 여러 겹으로 수지나 섬유로 라미네이팅하여 복합체로 만들면 유연성을 지닌 단열소재로 활용할 수 있다. 특히 기공이 조절된 테플론 멤브레인을 활용한 복합체는 투습 및 방수 기능까지 보유하여 의복에 사용할 수 있다. 수지와 섬유의 에어로젤 블랭킷 복합체를 활용하여 방한화용 깔창과 야외용 깔개 시제품도 제작하였다. 에어로젤을 활용하여 제작한 깔창 및 야외 깔개의 열전도는 20 mW m^-1 K^-1 이하로 단열성이 뛰어났으며, 유연성과 내구성도 우수하였다.

• Transactions on Electrical and Electronic Materials
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• 제17권3호
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• pp.155-158
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• 2016

The effect of microsilica content modified with silicone-modified epoxy on electrical and mechanical properties of cycloaliphatic epoxy/microsilica system was investigated. The cycloaliphatic epoxy resin was diglycidyl 1,2-cyclohexanedicarboxylate and curing agent was an anhydride. Surface of microsilica was modified with silicone-modified epoxy. Electrical breakdown strength, the most important property for electrical insulation materials was tested. Tensile and flexural tests were also performed using universal testing machine (UTM). The microcomposite with 60 wt% microsilica shows maximum values in electrical breakdown strength.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.606-608
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• 2005

As the overhead transmission lines are exposed to the outdoor weather, the causes of the transmission lines faults are from natural conditions, and among these faults, the outage rate due to lightning is more than 60%. The lightning causes the damage of power system equipments, the shut down of electricity and the electro-magnetic interference. Therefore, the pertinent insulation design is important, not only to decrease the damage of the facility itself but also to increase the reliability of electric power system. For these reasons, we have to obtain and accumulate the lightning current parameters for the basic lightning research. This paper describes the statistical distribution of lightning current parameters and the IKL map.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 A
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• pp.610-612
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• 2004

Because the overhead transmission lines are exposed to the outdoor weather, the faults of the transmission lines are due to natural conditions, and among these faults, the outage rate by lightning is about $50\%$. Therefore, the insulation design is important to decrease the damage of the facility and to increase the reliability of electric power system. This paper describes the protective method of substation equipments using the Underbuilt Ground Wire and the Guy Wire. This would not only reduce backflashover possibility but also minimize crest and duration of surges entering the substation. EMTP is used to analyze the efficiency of the proposed methods.