• 한국농촌건축학회논문집
• /
• 제16권1호
• /
• pp.35-42
• /
• 2014

Due to the development of civilization, the humans is privileged the rich of technologies for housing thermal environment. But, this kind of technological development caused enough trouble of energy excessive consumption. For solve this problem, many researchers strive to exploit the low energy sustainable techniques. For such a reason, the eco-friendly techniques of vernacular house are resurfacing. These traditional techniques are applied to a development of eco-friendly modern housing. They are no longer recognized as outdated products. On this context, this study proposes an scientific analysis on the thermal environment characteristics of Neolithic thatched-roof dugout hut(Um house). So far the several studies have been carried out in viewpoint of the history and structural compositions of the Um house which has been used as the normal housing for about 1000 years in the Neolithic era, however the thermal characteristics analysis of the Um house has never been studied. Um house is not a housing which has been composed by the scientific analysis or architectural design technology, but evolved empirically over a long period. This study on the thermal environment characteristics of Um house would provide basic information for the development of korean eco-friendly rural housing by korean climate characteristics. In this study, the thermal environmental characteristics of the Um house in the Neolithic era was analysed experimentally. The results of this study could be summarized as follows: 1. When the solar insolation and the ambient temperature in the daytime were $420W/m^2$ and $17^{\circ}C$ respectively, the surface temperature of the Um house roof covered with the rice straw was $37^{\circ}C$ and that in the roof $32^{\circ}C$, and in the conditions above the air temperature in the room was $15^{\circ}C$. 2. When the ambient relative humidity was 40%, that in the room of the Um house 50%, and at the ambient relative humidity of 90~100%, that in the room was 60%. 3. Through the experimental analysis, it was verified that the enthalpy and relative humidity is in an inverse relationship. 4. In general the comfort degree in the living space is changed with the seasonal climate, also in this study, the comfort degree in the room of the Um house in October and November was higher than that in May and June.

• 한국산업융합학회 논문집
• /
• 제9권1호
• /
• pp.61-66
• /
• 2006

In perspective of saving natural resource and energy, today's automobiles are in process of regenerating by smaller and lighter. In order to achieve the sufficiency on the consumption of the fuel, new mechanism and new assembly are required. Therefore the expectations on the new materials are very high. Especially, AI materials are widely used to reduce the weight. AI that is used in automobiles is mostly casting material, and according to the innovation of technique is in rapid development. AI Die casting is an important field as today's trend of lightweight on automobiles. One of the parts in steering system, Valve Housing plays a role of reduce the operating effort of drivers. Unfortunately, the Valve Housing which is widely reliable to the most automobiles are not developed at this moment in our automobile industry. Therefore, they are produced by casting method which cost three times or even more expensive in production. If Valve Housing, which is a part of steering system is produced by Gravity Casting, the space that manufacturing equipment will be increased, and more time and workers would be brought into service. For such reason, Die Casting would replace Gravity Casting in order to minimize cost of time, manpower, and working space.

• 설비공학논문집
• /
• 제22권7호
• /
• pp.460-467
• /
• 2010

In housing units constructed recently in Korea, the length of ondol coil is different in each room, so the flow rate of hot water is adjusted by setting valve opening. If the flow rate is not appropriate for heating load, the room temperature seriously deviates from the set temperature range for comfort. In particular, too small valve opening can induce a noise by cavitation. In order to adjust the valve opening, two methods by zone area and a new method by return temperature rise were modelled and simulated using TRNSYS and EES. As a result, heating energy consumption during one week was the same on three methods, but the room temperature of the new method minimally deviated from the range of set temperature with a low possibility of noise.

• Asian-Australasian Journal of Animal Sciences
• /
• 제29권12호
• /
• pp.1756-1760
• /
• 2016

Estimation of feed intake (FI) for individual animals within a pen is needed in situations where more than one animal share a feeder during feeding trials. A partitioning method (PM) was previously published as a model to estimate the individual FI (IFI). Briefly, the IFI of a pig within the pen was calculated by partitioning IFI into IFI for maintenance ($IFI_m$) and IFI for growth. In the PM, $IFI_m$ is determined based on the metabolic body weight (BW), which is calculated using the coefficient of 106 and exponent of 0.75. Two simulation studies were conducted to test the hypothesis that the use of different coefficients and exponents for metabolic BW to calculate $IFI_m$ improves the accuracy of the estimates of IFI for pigs, and that PM is applied to pigs fed in group-housing systems. The accuracy of prediction represented by difference between actual and estimated IFI was compared using PM, ratio (RM), or averaging method (AM). In simulation studies 1 and 2, the PM estimated IFI better than the AM and RM during most of the periods (p<0.05). The use of 0.60 as the exponent and the coefficient of 197 to calculate metabolic BW did not improve the accuracy of the IFI estimates in both simulation studies 1 and 2. The results imply that the use of $197kcal{\times}kg\;BW^{0.60}$ as metabolizable energy for maintenance in PM does not improve the accuracy of IFI estimations compared with the use of $106kcal{\times}kg\;BW^{0.75}$ and that the PM estimates the IFI of pigs with greater accuracy compared with the averaging or ratio methods in group-housing systems.

• 한국지열·수열에너지학회논문집
• /
• 제7권1호
• /
• pp.51-58
• /
• 2011

Due to enhanced sealing and insulation of buildings, extensive use of glasses for building envelopes and increased use of heat generating office equipments, energy consumption of modem buildings for cooling is steadily increasing. With outdoor air cooling(ODAC) system, cooling load can be reduced by exchanging indoor air with the cold outdoor air during spring and fall seasons. If ODAC is operated based only on temperature, total cooling load may virtually increase if the outdoor humidity is high. To overcome this problem, ODAC should be controlled based on enthalpy. In this work energy saving characteristics of enthalpy controlled ODAC is studied using dynamic simulation. The result shows that cooling load can be reduced by 27% by adopting ODAC.

• 한국지열·수열에너지학회논문집
• /
• 제7권2호
• /
• pp.37-42
• /
• 2011

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional Cooling + reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 50% less equivalent energy than the conventional system. The on-site performance test of a prototype shows that the coefficient of performance(COP) of the DOA system is 37% higher than the conventional system.

• 설비공학논문집
• /
• 제20권4호
• /
• pp.274-279
• /
• 2008

In the perspective of saving energy in buildings, high performance of insulation and air tightness for improving the heating and the cooling efficiency has brought the positive effect in an economical view. However, these building energy saving technologies cause the lack of ventilation, which is the direct cause of increasing the indoor contaminants, and it is also very harmful to residents because they spend over 90% of their time in the indoor area. Therefore, the ventilation is important to keep indoor environment clean and it can also save energy consumption. In this study, a HEPA type breathing wall is designed as a passive ventilation system to collect airborne particles and to supply fresh outdoor air. To make fine porous structures, polymer nano fibers which were made by electro spinning method are used as a precursor. The nano fibers are coated with SiO2 nano particles and finally the HEPA type breathing wall is made by sintering in the electric furnace at $300\sim500^{\circ}C$. The pressure drops of nano ceramic structure are 8.2, 25.5 and 44.9 mmAq at the face velocity of 2.0, 5.9 and 8.8 cm/s, respectively. Also the water vapor permeability is $3.6g/m^2{\cdot}h{\cdot}mmHg$. In this research, the porous nano ceramic structures are obtained and the possibility for the usage of a material for HEPA type breathing wall can be obtained.

• 토지주택연구
• /
• 제14권3호
• /
• pp.77-92
• /
• 2023

본 연구는 건축물에서 발생하는 탄소배출량에 영향을 미치는 도시특성 요인을 분석하였다. 2021년 서울시 에너지정보 플랫폼에서 구득한 건축물에서 사용된 에너지와 탄소배출량을 이용하여 424개 행정동 단위의 분석을 실시하였다. 종로와 강남, 구로와 목동 등지에서 단위 건물면적당 탄소배출량이 큰 것으로 나타났다. 공간시차모형(SLM)을 이용하여 회귀분석을 실시한 결과, 건물의 탄소배출량에 영향을 미치는 변수는 건조환경요인의 상업, 교육, 업무, 공업시설 변수와 인구요인의 생활인구, 교통시설 요인의 통행량, 버스노선 수, 지하철역 수, 환경요인의 녹지면적과 하천면적으로 파악되었다.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2011년도 춘계학술발표대회 논문집
• /
• pp.261-266
• /
• 2011

The purpose of this study was to identify the perception of residents on green home and their green residential life. For this study, a questionnaire survey was conducted and the items consisted of whether green home was perceived and how well green residential life was maintained in 6 types of environments. A total 118 responses of residents living in apartments of Seoul Metropolitan Area were used for data analysis. Using statistical program SPSS Win 18.0, frequency analysis, t-test, One-way ANOVA, and factor analysis was employed. The major findings were as follows: 1) slightly more than half of the respondents were aware of green home, and the vast majority were in favor of the green home policy; 2) most of the respondents carried out guidelines of green residential life, and in particular, green living on air environment was well done, followed by consumption, waste, energy, traffic and water; 3) the six kinds of environments were subcategorized by using factor analysis, and 3 to 5 factors were included in each category of environment. Also, it was found that age, educational level, employment status of respondents, housing tenure and duration were related to the degree of green residential life. In midst of global movement toward sustainability, environmentally friendly living is not optional but mandatory, so it's important to change each individual's value on the relation between people and environment and to facilitate more environmentally conscious behaviors.

• 설비공학논문집
• /
• 제21권8호
• /
• pp.456-461
• /
• 2009

Recently, an increasing interest in district heating system has emerged rapidly, In this paper, the physical measurements and data to be monitoring through the internet were carried out with regard to hot water heating energy consumption at the three apartment housings with district heating system in Sang-am district of Seoul, Korea, Measurements were made of the thermal factors such as the pressure of heating pipe, flow rates, hot water temperature and etc, The objective of this study is to compare the design capacity of reheat exchanger with that of preheat exchanger in order to evaluate for the number of plates of two exchangers to be distributed properly.