• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.970-975
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• 2008

This study considers indoor thermal comfort in an ondol space by supply vent configurations to prevent cold draft in winter. A specially-designed vent cap has been investigated in comparison with a round pan-type vent and a simple opening without a cap. Numerical simulations have been conducted using CFD to analyze thermal comfort indices such as Predicted Mean Vote (PMV) and Effective Draft Temperature (EDT) as well as air distribution index i.e. Air Diffusion Performance Index (ADPI). Results show the new vent cap provides improved thermal comfort conditions especially near ondol heated floor, as the cold outdoor air spreads upwards along the vertical wall before reaching occupant region near floor. This paper includes discussions on the flow and comfort distributions created by the thermal jets from the vents.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.489-494
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• 2016

There have been many cases when an air curtain installed in the apartment could not remove the gases well, such as carbon dioxide and particles like as smoke, oils, and vapors generated during cooking to disperse pollutants into the room. This study used a numerical analysis to show how the pollutant-removing performance of the range hood is changed when the air curtain is installed front of the kitchen table. The result of this study was that when the air amount supplied by an air curtain through the slot was about 50% of the exhaust amount, the capturing efficiency of the range hood for pollutants increased 90% more than without an air curtain. Even when the amount of supplied air was small, the capturing efficiency improved markedly with the use of an upward air curtain. In case that the air flow rate of the slot was greater than 60%, the capturing efficiency decreased.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.321-326
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• 2002

To design mechanical ventilation for bathroom of apartment houses where air supply and exhaust are taken Into consideration, mock-ups of ventilation systems, widely used in bathroom of apartment houses with an area of 100$m^2$, were made and installed in a laboratory, These ventilation mock-ups were available for control of air supply and exhaust, and the size of supply openings were 40cm$\times$1cm, 40cm$\times$3cm, 40cm$\times$5cm. They were installed at five positions, spaced 40cm at a height of 25cm from the floor. and the position of exhaust fans were four corners and center Exhaust fan established each one on corner of the ceiling and one in center. As result that measure ventilation effect by each condition, size of hole that supply air is big, and ventilation effect took effect to be good establishment location is low, Also, distance of exhaust fan is far with hole that supply air, ventilation effect took effect by superior thing.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.06a
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• pp.231-235
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• 2001

This paper has been presented the dynamic effect by the journal speed. eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from previous investigations in the side of pressure distribution of air film by the wedge effects. These optimal chooses of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high speed spindle. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high speed milling.

• Journal of Korean Medical classics
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• v.19 no.3
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• pp.47-64
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• 2006

籬위제고화가심대청대정골추나요법적인식화이해(爲提高和加深對淸代正骨推拿寮法的認識和理解), 특선어차방면의의교심차유의사문환가치적(特選於此方面意義較深且有醫史文歡價値的) ${\ulcorner}$의종금감(醫宗金鑑) 정골심법요지(正骨心法要旨)${\lrcorner}$ 중적(中的) ${\ulcorner}$외치법(外治法)${\lrcorner}$ 진행료연구(進行了硏究), 획득여하연구결과(獲得如下硏究結果). 기수법총론부분(其手法總論部分), 파요지규정료정골수법적정의급기중요성(擺要地規定了正骨手法的定義及其重要性), 후유증적예방(後遺症的預防), 안환자원기강약이수요주의적사항(按患者元氣强弱而需要注意的事項), 정골의생적기본공화심이소질등문제(正骨醫生的基本功和心理素質等問題). 기정골수법부분(其正骨手法部分), 포괄모(包括模) 접(接) 단(端) 제(提) 접(按) 나(摩) 추(推) 나등팔법(拿等八法), 각법지적응증용현대용어해석여하(各法之適應症用現代用語解釋如下): 모법용어촉진(模法用於觸診), 접법용어골절치료(接法用於骨折治療), 단법용어탈위치료(端法用於脫位治療), 제법용어견인법(提法用於牽引法), 안마법용어연조직손상화골착건적치료(按摩法用於軟組織損傷和骨錯鍵的治療), 추나법용어절적운동(推拿法用於節的運動) 부리화관절적부완전결합적치료(不利和關節的不完全結合的治療). 기기구총론부분(其器具總論部分), 개소료십종정골치료용기구(介紹了十種正骨治療用器具), 각종기구적적응증급기효능용현대용어해석여하(各種器具的適應症及其效能用現代用語解釋如下): 이렴구유보호환부적효과(裏簾具有保護患部的效果), 진정용어동통(振挺用於疼痛) 부종(浮鍾) 경결적치료(硬結的治療), 피견용어견관절탈구적고정료법(被肩用於肩關節脫臼的固定療法), 격색속어리용자아체중적견인료법(擊索屬於利用自我體重的牽引療法), 루관속어분부동계단이용자아체중진행견인적료법(壘觀屬於分不同階段利用自我體重進行牽引的療法), 통목속어포추지압축성골절적래목치료용구(通木屬於胞推之壓縮性骨折的來木治療用具), 요주구유대요추골급기근육이상적부가보호대효과(腰柱具有對腰推骨及其筋肉異常的附加保護帶效果), 죽렴용어골절적고정치료(竹簾用於骨折的固定治療), 삼리구유대골절적쌍중고정효과(杉籬具有對骨折的雙重固定效果), 포슬구유대슬관절적고정효과(抱膝具有對膝關節的固定效果).

• Fire Science and Engineering
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• v.23 no.5
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• pp.117-124
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• 2009

The objective of this research is to analyze the ventilation performance of mechanical ventilation systems to enhance removal efficiency of indoor hamful gases. The ventilation performance is evaluated using a step-down method based on ASTM Standard E741-83. The ventilation performance is evaluated as a function of the ventilation rate and supply/extract locations using a tracer gas ($CO_2$) technique. As a result, the $CO_2$ concentration as a function of time is decayed exponentially and the ventilation performance is found to increase with increased the ventilation rate. The ventilation performance of the second type ventilation system is better than that of the first type or the third type. The ventilation performance without human occupancy increases up to 55% and the ventilation performance with one person increases up to 25% at the supply air of 570Lpm comparing with a natural reduction after one hour in the test chamber. The ventilation performance is better than 15% comparing with natural decay at the supply of 570Lpm in an office room.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.243-249
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• 2001

This paper has been presented the hydrodynamic effect by the journal speed, eccentricity and source positions in order to overcome the defects of air bearing such as low stiffness and damping coefficient. Choosing the two row source position of air bearing is different from existed investigations in the side of pressure distribution of air film because of the high speed of journal and the wedge effects by the eccentricity. These optimal chooses of the two row source positions enable us to improve the performance of the film reaction force and loading force as making the high speed spindle. In this paper, the pressure behavior in theory of air film according to the eccentricity of journal and the source positions analyzed. The theoretical analysis have been identified by experiments. The results of investigated characteristics may be applied to precision devices like ultra-precision grinding machine and ultra high speed milling.

• Fire Science and Engineering
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• v.24 no.6
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• pp.20-27
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• 2010

In smoke control systems the amount of air supply is almost the same as that of smoke exhaust. This study analyzed the effect of supply air velocity on the smoke exhaust behavior using FDS tool. The results showed that fire plume can be disheveled by the rapid air velocities developed when the air supply inlet is located near the fire plume. Disheveled smoke caused the rapid descent of smoke layer level and the reduced visibility. To increase the efficiency of smoke exhaust systems supply air inlet should be located sufficiently far from the location of the fire plume.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.148-153
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• 2009

This paper considers the age of air in a ventilated space with multiple supply inlets. The local mean age of air at a point from one supply inlet is different from those from the other supply inlets. It is the purpose of the present paper to investigate theoretically the relations between the LMA's from each supply and overall combined LMA whether or not to trace the origins of supply air. Transient concentration distributions are calculated with a step-up injection of tracer gas at each supply inlet, and at both inlets simultaneously. The steady state concentration with a continuous tracer injection at a supply inlet works as a weighting factor for the corresponding LMA in calculating the average overall LMA from multiple inlets.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.662-668
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• 2018

Most electric rooms are located in the underground spaces of buildings. When a fire occurs in electrical equipment, the fire expands to cable insulation material, resulting in toxic smoke and combustion products. If the smoke and combustion products quickly move vertically and horizontally, the evacuation of occupants and firefighting activities will be hindered. Therefore, it is necessary to design optimal equipment for smoke control in cases of fires in electric rooms. This study analyzes the characteristics of smoke and combustion products in fires in a cubicle-type switchboard in an electric room using PyroSim, which is based on the program Fire Dynamics Simulator (FDS). The fire modeling consists of four scenarios according to the operation mode of the mechanical ventilation equipment, the amount of air supply and exhaust, and the location of the air supply slot. The analysis shows that the mechanical ventilation equipment improves the smoke density, visibility, carbon monoxide concentration, and temperature characteristics. The visibility and temperature characteristics were improved when the air flow rate and the location of the air supply slot from fire defense regulations were applied.