• Journal of Advanced Marine Engineering and Technology
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• 제26권4호
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• pp.472-484
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• 2002

To analyze the characteristics of air flow and $CO_2$ extinguishant transfer when extinguishant is injected into a closed space similar to marine engine room, a numerical simulation on a space was performed. Flow fields and $CO_2$ concentration fields are calculated according with the variation of the location & injection angle of nozzles. The results of simulation showed that the pattern of recirculation flow was affected greatly with the location & injection angle of nozzles and such a recirculation flow accelerated mass transfer of $CO_2$ and greatly affected the diffusion process of $CO_2$ extinguishant. It is considered that this result of this study can be useful to designing the arrangement of nozzles for the $CO_2$ fire fighting equipments in a marine engine room.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제22권4호
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• pp.67-77
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• 2016

Purpose: This paper aimis to analyze the characteristics of ward plan of Korean hospital architecture constructed in each periods and identify the change since 1945. Methods: Literature review was conducted while ward plans for analysis were sellected. And then the important points of ward design were analyzed in each periods. Results: The important points of ward design - type of corridor in ward plan, number of beds per nursing unit, location of nurse station, organization of multi-bed rooms, location of patient toilet, number of day room, concentration and separation of elevator halls for patient and general- were analyzed and the characteristics of change were identified in each periods. Implications: This paper could be a basic data for arranging the history of hospital architecture in Korea.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.405-410
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• 2006

This paper presents a control algorithm of supply and exhaust diffusers by recognizing a contaminant source location. CFD analysis has been conducted to calculate steady state airflow and concentration distributions in a model room, which has two supply and two exhaust openings on the ceiling. Calculations have been performed for five cases out of nine different ventilation modes by combining on/off control of the supply and exhaust openings. Local mean residual life times are obtained and compared at 9 internal points for each ventilation case. Depending on the contaminant source location, the ventilation system is operated at an optimum ventilation mode, which can results in maximum exhaust performance.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2005년도 총회 및 춘계학술발표회
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• pp.304-307
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• 2005

A numerical modelling method using a backward-in-time advection dispersion equation is introduced in assessing the vulnerability of groundwater to contaminants as an alternative to classical vulnerability mapping methods. The flux and resident concentration measurements are normalized by the total contaminants mass released to the system to provide the travel time probability density function and the location probability function. With the results one can predict the expected travel time of a contaminant from up stream location to a well and also the relative concentration of the contaminant at a well. More specific groundwater vulnerability can be mapped by these predicted measurements.

• 한국축산시설환경학회지
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• 제7권1호
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• pp.45-56
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• 2001

The following statistics are the results of a survey that analyzed the classification of livestock area and spatial mobility based upon the number of livestock and an area of 151 towns and cities from 1975 to 1995. 1. As a results of analysis about the degree of location concentration using C.V., Korean native cattles (HanWoo) and swines are becoming more centralized while dairies and chickens are becoming decentralized. 2. 49 regions, that is 32.5%, were classified as growing regions, 30 regions (19.9%) were stagnant regions and 72 regions (47.7%) were withering regions. The classification was based upon the calculation according to the numbers of converted grown animals and growth index. Kyonggi-do and Chungchongnam-do, specifically, took up 26.6% and 24.5% of the developing regions which shows that these two regions are the dominant regions for livestock. 3. Kyongsangbuk-do and Chungchongnam-do play significant roles for overall livestock, and Chollanam-do is considering a transition from swines to Korean native cattles and Kyongsangbuk-do is shifting from Korean native cattles to swines.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 춘계학술발표회요약집
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• pp.187.2-187
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• 2001

• 대한기계학회논문집
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• 제14권2호
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• pp.430-439
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• 1990

Steady state turbulent airflow and unsteady characteristics of generation, transportation, and recovery behavior of contaminate particles in the simplified 2 dimensional Vertical Laminar Flow (VLF) type clean room was numerically simulated using the low Reynolds number k-over bar.epsilon- turbulent model. Characteristics of airflow in VLF type clean room are greatly affected by the recirculation zone around working surface. The recirculation zone must be considered at the time of clean room design because the recirculation zone whose area increases with increment of inlet velocity exerts bad influence upon the performance of clean room in terms of particle contamination. The location of maximum particle concentration changes from the location of particle source to the recirculation zone, while averaged particle concentration is reduced exponentially with time. Recovery time of clean room with spontaneous particle generation source is inversely proportional to inlet velocity. We introduce nondimensionalized recovery time through the dimensional analysis, which can indicates the general performance of clean room with design structure change. It was identified that .tau. is independent of inlet velocity and background concentration. Therefore .tau. can be the simple factor to compare the different structure of clean room in terms of dynamic response to contamination and becomes larger with better structure of clean room.

• 한국안전학회지
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• 제23권6호
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• pp.131-137
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• 2008

SCP(Sand Compaction Pile) method that forms a composite ground by driving compacted sand piles into the soft ground. This method is one of the soil improvement techniques for reinforcing and strengthening soft ground deposits. This thesis describes the investigation on the behavior of soft ground reinforced with SCP by low improvement ratio. Direct shear test and consolidation test carried out to verified behavior of composite ground reinforced with SCP. Test results were discussed with reference to the amount of consolidation settlement, variation of shear resistance with area replacement ratio and effect of the stress concentration. And, laboratory model loading test carried out to verified the effect of the location and failure mode of reinforced embankment. Residual shear strength varies with the area replacement and constrict load in the low replacement ratio. Calculated stress concentration ratio overestimate than proposed valve by experimental, theoretical and analytical method. As regards the location, improving right below of the top of the slope was more effective than below of the toe of the slope. This thesis carried out to obtain fundamental information of behavior of the composit ground. Hereafter, centrifuge test that reproduce stress state of the in-situ must be necessary through the further study about pile penetration, reinforce position and construct time.

• 한국화재소방학회논문지
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• 제18권2호
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• pp.41-48
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• 2004

선박 기관실의 고정식 소화장치로 사용되는 $CO_2 $ 소화장치의 소화효과에 영향을 미칠 수 있는 인자 중 분사노즐위치를 변화시켜 이산화탄소 소화제 전달특성에 대한 전산모이실험을 3차원 비정상상태로 수행하였다. 노즐위치에 따라 유동장과 $CO_2$ 소화제 농도장을 계산하였다 소화제 분사노즐을 공간의 천장 중앙에 매치 한 경우, 천장에 형성되는 대칭 천장 제트가 대칭면에서 서로 부딪혀 저농도 하향 유동을 발생시켜 분사주위에는 규정농도 이하의 농도분포를 형성시킨다. 벽의 모서리에서는 소화제질량전달이 촉진되는 경향으로 인해 농도곡선은 모서리 부근에서 피크를 나타낸다.

• 한국식품저장유통학회지
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• 제2권1호
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• pp.195-202
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• 1995

An experiment was conducted to develop the simple methods of ginger storage which decrease the weight reduction and maintain good quality of ginger during the cellar storage. The stored boxes with volume of 0.03㎥ and ventilator diameter of 3, 4, 5cm was hurried under the ground(60, 80, 100cm) in the green house. During the cellar storage at the 100cm depth the average temperature and relative humidity in the stored box were remained in 11.7~16.3$^{\circ}C$ and 73%, respect. The higher storage amount and smaller size of ventilator size increased the CO2 concentration in the stored box, and the concentration in the stored box with 50% storage quantity rate and 3cm ventilator diameter size was more than 10% for about 2 months from early Feburary. The decay rate of ginger during the cellar storage increased with higher amount of storage quantity and smaller size of ventilator. The CO2 concentration was low and remained relatively constant with the deeper location of stored box under the ground, and the decay rate was lower in the deeper stored box. Germination rate increased with the deeper location of stored box, and with the lower storage quantity and larger ventilator size. The germination rate was low in the higher decay rate box. Weight loss, total sugar and moisture contents of ginger were decreased, while crude fiber and ash were increased during the storage.