• 건축역사연구
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• 제10권2호
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• pp.55-71
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• 2001

This study reviewed the preservation status of the Early Western Style Architecture in Korea based on the on-site research of church buildings which are registered as National Cultural Properties. I have investigated 21 church buildings regarding the frequency, content and concept of restoration. The results are summarized as follows First, the churches have been restored extensively in every 17 years on the average. Second, the main restorations are replacement of bricks, painting, waterproofing, repair of roof and timber. And the main changes are extension of plan, removal of Interior posts, and replacement of floor. Third, the main concept of restorations are historical restoration(62%), critical restoration(23%), stylistic restoration(14%). Forth, the category of restoration have been changed, that is extending of incompletion (1st stage), functional improvement and extension of the span of life(2nd stage), improvement of facilities(3rd stage), restoration to the original state and conservation(4th stage). Fifth, the issues of repairing techniques are revival and replacement of weathered bricks, the removal of painting, and structural reinforcement. This study will be able to be used as the fundamental materials to improve the techniques of restoration of Early Western style masonry buildings.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.283-288
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• 2010

The characteristics of a condenser dryer and a vented dryer that are common types of domestic clothes dryers for home use are predicted and compared in an effort to improve the efficiency and to overcome economical and environmental problems due to its inefficient power consumption. In the present study, a drying system is simplified by assuming the mechanism is composed of several elements such as heater and drum and mathematical models using the mass and energy conservation of moisture and air through each element are defined. Based on this mathematical model, the computational tool is developed to predict temperature, humidity and enthalpy of moisture and air in a drum and remained moisture contents (RMC) in drying materials. The computational results are verified by comparing with experimental results from existing studies. In addition, the efficiency of a dryer is calculated using these predicted results for a given condition and the drying characteristics of a condenser dryer and a vented dryer are compared and analyzed.

• 한국발생생물학회지:발생과생식
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• 제21권1호
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• pp.79-91
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• 2017

The aim of this study was to compare the efficacy of cryopreservation methods for ex situ conservation of spermatozoa from far eastern catfish, Silurus asotus. The spermatozoa activity index (SAI) and hatching rates were higher in spermatozoa stored in Alserver's solution than those of spermatozoa stored in glucose solution. The SAI and hatching rates in all experimental groups gradually decreased with increasing duration of storage. Additionally, the SAI and hatching rates gradually decreased with increasing thawing temperatures at all storage durations (P<0.05). Based on the SAI and hatching rates, our results suggest that the optimal cryopreservation conditions of catfish spermatozoa involve storage in Alserver's solution with 15% ethylene glycol, and thawing at $25^{\circ}C$. Cryopreservation of spermatozoa is a useful and reliable technique for conserving gene resources and for artificial propagation of far eastern catfish.

• 한국수소및신에너지학회논문집
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• 제24권5호
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• pp.401-412
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• 2013

The paper is to study on the simulation of the micro/macroscale thermo-electrochemical model of a single cell of anode-supported SOFC with direct internal reforming. The coupled heat and mass transport, electrochemical and reforming reactions, and fluid flow were simultaneously simulated based on mass, energy, charge conservation. The micro/macroscale model first calculates the detailed electrochemical and direct internal reforming processes in porous electrodes based on the comprehensive microscale model and then solve the macroscale processes such as heat and mass transport, and fluid flow in SOFCs with assumption of fully-developed flow in gas channel. The simulation results evaluate the overall performance by analyzing distributions of mole fraction, current density, temperature and microstructural design in co/counter flow configurations.

• 대한기계학회논문집A
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• 제20권1호
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• pp.189-205
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• 1996

The twin-roll type strip continuous casting process(or direct rolling process) of steel materials is characterized by two rotating water cooled rolls receiving a steady supply of molten metal which solidifies onto the rolls. A solidification analysis of molten metal considering phase transformation and thermofluid is performed using finite diffefence method with curvilinear coordinate to reduce computing time and molten region analysis with arbitrary shape. An enthalpy-specific heat method is used to determine the temperatures inthe roll and the steel. The temperature distribution of cooling roll is calculated using two dimensional finite element method, because of complex roll shape due to cooling hole in rolls and improvemnt accuracy of calculation result. The energy equaiton of cooling roll is solved simultanuously with the conservation equaiton of molten metal in order to consider heat transfer through the cooling roll. The calculated roll temperature is compared to experimental results and the heat transfer coefficient between cooling roll surface and rolling material(steel) is also determined from comparison of measured roll temperature and calculated temperature.

• 한국농촌건축학회논문집
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• 제16권1호
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• pp.1-8
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• 2014

This study investigated the characteristics of the establishment of an architectural guideline which is an important element of a urbanscape plan in basic landscape plans established by four local governments(a county level) in Jeollanam-do since the enactment of the landscape law. The results were as follows. The guideline for landscape plan elements was closely associated with shapes, materials, harmony, and coherence. For the detailed guideline for landscape plan elements, an architectural guideline on the arrangement, height, facade, and roof shapes of buildings, which is one of important elements related to urbanscape, was similar in local governments, showing a standard and uniform tendency. It indicates the limitation of forming urbanscape to enhance local identity and unique features and complementary contents are needed. The color guideline was classified into base color, sub color, and accent color in consideration of local features. In particular, natural material color was commonly used for base and sub color in all local governments. Therefore, it is necessary to develop unique material color and distinctive local color for each region.

• Environmental Engineering Research
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• 제18권2호
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• pp.91-94
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• 2013

Recently Ibadan in southwestern Nigeria has been facing severe water shortage due to the increase of population, social and economic activities. In order to meet the shortfall, attempts to utilize rainwater harvesting (RWH) have been made to provide an alternative source of water supply. A desk study was conducted to review various RWH technologies locally, regionally and globally. A hydrological analysis was also carried out using rainfall data for 30 years from two meteorological stations, with the aim of providing a more sustainable RWH system for water supply to private individuals, organizations, and government agencies. RWH is found to be technically feasible based on the prevailing rainfall pattern with over 90% of households having a rooftop constructed from technically appropriate materials. Results of the study indicate that an average roof of $80m^2$ will collect 82,835 L/yr (45 L/person/day) for a family of five people which is about the required water demand for drinking and cooking purposes. Hence, the capacity of storage tanks and the catchment area required for an all-purpose water supply system based on RWH are quite large. These can be reduced to affordable sizes, by collecting and storing water for cooking and drinking only while non-potable uses are supplemented by water from other sources. However, it must be highlighted that due to the type of roofing material, rainwater should go through proper treatment in order to be used for potable purposes. This study clearly shows that Ibadan city has a good rainwater harvesting potential.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.760-765
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• 2013

Eco-friendly material applied to building would be one of the materials which is must developed for global environmental conservation and reduction of carbon dioxide. For development of eco-friendly material, a cellulose sound-absorbing material has been developed with waste paper through adjustment of various mix proportions. The developed cellulose sound-absorbing material has been tested for its acoustic properties such as acoustic absorptivity and dynamic elastic modulus. The absorptivity was evaluated by developing six samples and using impedance tube and reverberation chamber. As a result of the evaluation, 0.64(NRC) was secured in absorptivity and $4.7MN/m^3$ was indicated in dynamic elastic modulus. Also, for practical use of developed sound-absorbing material as inner heartwood in drywall, comparison test of sound reduction index was performed with existing glass wool sound-absorbing material and constructed drywall of gybsum board. The results have shown 55dB(Rw) of sound reduction index in glass-wool wall and 46dB(Rw) in cellulose.

• 한국소음진동공학회논문집
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• 제23권5호
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• pp.456-462
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• 2013

Eco-friendly material applied to building would be one of the materials which is must developed for global environmental conservation and reduction of carbon dioxide. For development of eco-friendly material, a cellulose absorber has been developed with waste paper through adjustment of various mix proportions. The developed cellulose absorber has been tested for its acoustic properties such as absorption coefficient and dynamic stiffness. The absorption coefficient was evaluated by developing six samples and using impedance tube and reverberation chamber. As a result of the evaluation, 0.64(NRC) was secured in absorption coefficient and 4.7 $MN/m^3$ was indicated in dynamic stiffness. Also, for practical use of developed absorbers as inner heartwood in drywall, comparison test of sound reduction index was performed with existing glass wool absorbers and constructed drywall of gypsum board. The results have shown 55 dB(Rw) of sound reduction index in glass-wool wall and 46 dB(Rw) in cellulose.

• 한국농공학회지
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• 제16권2호
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• pp.3395-3409
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• 1974

The purpose of this study is to test and compare the efficiency of heating-system for materials and construction of the wall, ceiling and window in soil brick house, cement house and boulder house respectively, in order to construct ideal farm houses in rural area. The results obtained were as follows: 1. In heat conservation due to construction of walls the thermal efficiency of cement brick house was equivalent to 66.3% of that of soil brick house, and boulder house 60.3% 2. In the case of ceiling, the thermal efficiency of paper ceiling was amounted to 84.2% of that of the composite ceiling (thickness 6mm veneer+thickness. l0m chaffs), and the common ceiling putting on soil above the ceiling, 76% of the composite while the efficiency of the ceiling putting on chaffs above them was 15.8% higher than that of the paper. 3. In the case of improving the window, the double type was 12% higher than. the efficiency of single type. 4. The warming velocity of conventional house was slower but the velocity of radiation was quicker than that of experimental one. It was thought to be due to unscietific constructions of the room bottom, fire inlet and chimney, 5. The temperature gradient line was not dependad upon the amount of throwing into fuel in the rural farm house. 6. It was concluded that the final thermal efficiency of the conventional farm house was 10.6% lower than that of experimental farm house.