• 대기
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• 제29권5호
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• pp.639-658
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• 2019

The classification of fog type and the characteristics of fog based on fog events over South Korea were investigated using a 3-year (2015~2017) visibility meter data. One-minute visibility meter data were used to identify fog with present weather codes and surface observation data. The concept of fog events was adopted for the better definition of fog properties and more objective classification through the detailed investigation of life cycle of fog. Decision tree method was used to classify the fog types and the final fog types were radiation fog, advection fog, precipitation fog, cloud base lowering fog and morning evaporation fog. We enhanced objectivity in classifying the types of fog by adding the satellite and the buoy observations to the conventional usage of AWS and ceilometer data. Radiation fog, the most common type in South Korea, frequently occurs in inland during autumn. A considerable number of advection fogs occur in island area in summer, especially in July. Precipitation fog accounts for more than a quarter of the total fog events and frequently occurs in islands and coastal areas. Cloud base lowering fog, classified using ceilometer, occurs occasionally for all areas but the occurrence rate is relatively high in east and west coastal area. Morning evaporation fog type is rarely observed in inland. The occurrence rate of thick fog with visibility less than 100 meters is amount to 21% of total fog events. Although advection fog develops into thick fog frequently, radiation fog shows the minimum visibility, in some cases.

• 설비공학논문집
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• 제24권4호
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• pp.297-305
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• 2012

In recent large-scale semiconductor manufacturing clean rooms, the energy consumption of outdoor air conditioning systems to heat, humidify, cool and dehumidify incoming outdoor air represents about 45% of the total air conditioning load required to maintain a clean room environment. Therefore, the energy performance evaluation and analysis of outdoor air conditioning systems is useful for reducing the outdoor air conditioning load for a clean room. In the present study, an experiment was conducted to compare the energy consumption of outdoor air conditioning systems with a simple air washer, an exhaust air heat recovery type air washer and a DCC return water heat recovery type air washer. It was shown from the present lab-scale experiment with an outdoor air flow of 1,000 $m^3/h$ that the exhaust air heat recovery type and DCC return water heat recovery type air washer outdoor air conditioning systems were more energy-efficient for the summer and winter operations than the simple air washer outdoor air conditioning system and furthermore, the DCC return water heat recovery type one was the most energy-efficient in the winter operation.

• 한국환경과학회지
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• 제16권3호
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• pp.323-331
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• 2007

Polycyclic aromatic hydrocarbons (PAHs) are well known for strong carcinogen. However, the human exposure analysis of PAHs is quite difficult and unreliable because of hard for estimation of actual expose dose. Then urinary 1-hydroxypyrene (1-OHP) has been a biological marker of exposure to PAHs. The purpose of this study was to investigate total amount from exposure to PAHs soused by indoor occupational exposure, and residence at Seoul metropolitan area and Kyeonggi province in Korea. Thirty-five housewives were included in this study from April 2003 through February 2004. Dietary habit and general characteristics such as age, type of building, existence of passive smoking, period of residence, fuel type for heating and ventilation type were obtained by self administered questionnaire. Urine samples were collected at morning and freeze quickly. Urinary creatinine was measured for converting into 24 hr urine. Concentration of the indoor PAHs was examined by NIOSH method number 5506. Urinary 1-OHP and PAHs were analysed by HPLC. Correlation coefficient between urinary 1-OHP levels and pyrene concentration of indoor air was 0.66 and statistically significant(P<0.01). The difference of urinary 1-OHP level due to dietary habits were not significant. Urinary 1-OHP level of Spring, Summer, Autumn, and Winter were $0.21{\pm}0.12,\;0.10{\pm}0.17,\;0.16{\pm}0.12,\;0.17{\pm}0.14{\mu}g/g$ cr, respectively. The arithmetic means of urinary 1-OHP for four season tee $0.16{\pm}0.14 {\mu}g/g$ cr. There was a trend that urinary 1-OHP level of residents who dwelling in apartment were higher compared with detached home, Comparison of 1-OHP level between heating by kerosene and LPG, Much higher gas heating type than kerosene type (P<0.05). This result implies that the urinary 1-OHP can be applied as the PAHs exposure indices.

• 한국환경과학회지
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• 제27권7호
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• pp.489-497
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• 2018

In this study, the ion index characteristics of small and medium urban land use types were investigated in the city of Chungju. The average temperature for each land use type was in the order: general commercial district ($29.59^{\circ}C$) > general residential district ($28.34^{\circ}C$) > productive green district ($28.31^{\circ}C$). The average relative humidity was in the order: productive green district (70.12%) > general residential district (69.93%) > general commercial district (66.48%). The average wind speed was in the order: productive green district (0.95 m/s) > general commercial district (0.87 m/s) > general residential district (0.54 m/s). Positive and negative ions were investigated to determine the ion index by land use type. The average amount of positive ion generated was in the order: general commercial district ($737ea/cm^3$) > general residential district ($492ea/cm^3$) > productive green district ($445ea/cm^3$). The average negative ion production decreased in the order: productive green district ($930ea/cm^3$) > general residential district ($754ea/cm^3$) > general commercial district ($744ea/cm^3$). The ion index calculated from measured data can be arranged in the order: productive green district (2.09) > general residential district (1.53) > general commercial district (1.01). These results confirm the state of positive and negative ion generation in each land use type. Further, the differences in the ion index by land use type were confirmed. However, a limitation of this study is that simple summer measurements were conducted, and seasonal characteristics were not considered. Therefore, any future investigation and research should consider seasonal variation characteristics.

• 대한가정학회지
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• 제26권4호
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• pp.87-100
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• 1988

The purpose of this study was to investigate the dweller's housing needs through the connection between dwellers' living pattern and space usage. The objectives were (1) to examine how to eat and cook in the eating and cooking spaces, (2) to examine how to alter the original housing, (3) to research the dwellers' housing needs for the eating and cooking spaces, and the changing process of dwellers' housing needs, and (4) to classify the type of eating and cooking spcaces. The results of this study were (1) there were changed in eating pattern of space usage according to the season. The eating activities were a Korean living pattern : sitting on the floor and eating at the BAB SANG. (2) There was a difference in the pattern of space usage and the activity for main cooking and KIM CHI. (3) AN BANG (eating space for winter) as well as MARU (eating space for summer) has changed to a larger space. (4) By the changing of living patterns, BU AUK (a main cooking space ) has showed a various alternations: function, dimension of space, facilities, floor materials and floor level. (5) The dwellers' housing needs for eating space were a multipurpose room, and a dining kitchen of western living pattern (using a dining table and chairs) with the present changing life styles. (6) The dwellers' housing needs for cooking space were a multipurpose room of working area, a seperation of heating area, a western living pattern, a plan of flat fllor level and a dining kitchen. (7) BU AUK of eating and cooking spaces was classified into 4 types: a traditional type, a mixing type, a modernized type, and a western type.

• 한국초지조사료학회지
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• 제20권4호
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• pp.237-242
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• 2000

This study was conducted to investigate the effects of cutting frequency on dry matter yield and nutritive value between heading and headless varieties of sorghumxsudangrass hybrid in 1998. Treatments were var. TE hay grazer(heading type) and Jumbo(headless type) as main plot, and 1, 2, and 3 cutting times per a year as sub plot. Although plant height of sorghumxsudangrass hybrid was no significant difference among treatments, headless type was very slightly higher than that of heading type, and both of variety decreased with 1, 2, and 3 cutting times in order. Also, dry matter yield of sorghum~sudangrass hybrid was no significant difference between heading and headless type. Dry matter yield of first cutting plot in heading type and in headless type was the higher than those of second and third cutting plot. Acid detergent fiber and neutral detergent fiber of headless type were slightly higher than that of heading type. Acid detergent fiber of sorghumxsudangrass hybrid was highest at first cutting plot in both varieties. Neutral detergent fiber of second cutting plot in heading type and first cutting plot in headless type were the highest respectively. In vitro dry matter digestibility of headless type was very slightly higher than that of heading type. And in vitro dry matter digestibility of second cutting plot was the highest in both varieties. In vitro digestible dry matter of sorghumxsudangrass hybrid was no significant difference among treatments. The results demonstrated that although there was not significant difference, cultivation of headless type and first cutting plot per a year were very good for nutritive value and DM yield of sorghumxsudangrass hybrid as summer forage crops in Korea. (Key words : Heading, Headless type, Cutting frequency, Sorghum X Sudangrass Hybrid)

• 한국가금학회지
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• 제17권1호
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• pp.33-44
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• 1990

본 연구는 육계와 육용오리의 도체특성을 비교하고 육계의 성, 사육형질, 계절 및 절식시간에 따른 도체율과 복강지방축적률을 조사하기 위하여 육계 240수와 육용오리 20수에 대한 도체조사기록을 이용하여 연구하였는바 그 결과를 요약하면 다음과 같다. 1. 육계와 육용오리의 도체률은 각각 65.43%와 66.79%였으며, 복강지방축적률은 육계가 육용오리가 비하여 현저하게 높았다. 2. 육계와 육용오리의 부분육 생산비율은 현저한 차이가 있었으며, 육계의 경우 부분육 생산비율은 다리, 가슴, 등, 날개 및 목의 순서로 높았다. 3. 육계의 도체율은 성별에 따라 차이가 없었으나 복강지방축적율은 암컷이 수컷에 비하여 현저하게 높았다. 4. 사육형태간에 도체율은 차이가 없었으나 복강지방축적율은 케이지가 평사에 비하여 다소 높은 경향이었다. 5. 사육계절간에도 도체율은 차이가 없었으나 복강지방축적률은 하계에 가장 높았고 동계에 가장 낮았다. 6. 절식ㆍ절수시간이 1시간 경과함에 따라 육계의 체중은 약0.28365%씩 감소하였으며, 도체율은 절식 6시간 후 가장 높았다.

• 한국환경과학회지
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• 제23권10호
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• pp.1673-1691
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• 2014

Although most natural disaster related studies conducted in Korea recently have been related to typhoons or severe rainstorms, the occurrence frequency of disasters due to windstorms or rainstorms is also high. To reduce the strong wind damage caused by strong windstorms due to climate change, basic studies of strong winds are necessary. Therefore, in this study, the types and representative cases of windstorms that were observed to have been higher than 14 m/s, which is the criterion for strong-wind warnings from the Korea Meteorological Administration, were selected from among those windstorm cases that occurred on the Korean Peninsula for 10 years to conduct a statistical analysis of them and determine their synoptic meteorological characteristics. The cases of windstorms occurring on the Korean Peninsula were divided into six weather patterns according to the locations of the anticyclones/cyclones. Among these types, the SH type, which occurs when Siberian Highs expand into the Korean Peninsula, showed the highest occurrence frequency, accounting for at least the majority of the entire occurrence frequency of windstorms together with that of the EC type, which occurs when cyclones develop on the East Sea, and there was no clear yearly trend of the occurrence frequencies of windstorms. The monthly occurrence frequencies of windstorms were formed mainly by typhoons in the summer and the Siberian Highs in the winter, and the months with the highest windstorm occurrence frequencies were December and January, in which mainly the SH and EC type windstorms occurred. March showed the next highest occurrence frequency with10 times, and SH windstorms occurred the most frequently in March, followed by the CC, SC, and EC types of windstorms, in order of precedence. Therefore, attention to these types of windstorms is required. Countermeasures against storm and flood damage in Korea targeting the summer should be re-reviewed together with pre-disaster prevention plans, because cases of storm and flood damage due to windstorms occur more frequently than those due to typhoons, and they occur throughout the year.

• 한국환경복원기술학회지
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• 제11권1호
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• pp.23-32
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• 2008

In order to discern the development of technology in creating, properly managing, and characterizing the types used in facade greening, this article examines the instances of facade greening of Bulgaria, Greece and Turkey which is not only located in the latitude similar to South Korea's but also influenced by the both continental and oceanic climate. The study was carried out for 11 months from October 2002 to September 2003. The total 242 places were researched and they were 83 sites in Athens, 77 sites in Istanbul, and 82 sites in Sofia. Varieties, usage, configuration, foundation and characteristics of plants were studied. The goals of greening, and building's surface roughness and thickness, direction of the wall were also researched. The result of survey are as follows; 17 families and 33 species of climbing plants were found in Athens, Istanbul, and Sofia. Thickness of facade greening in the three cities is 46cm in Athens, 39cm in Istanbul, and 53cm in Sofia. The possible facade greening size per a climbing plant, Parthenocissus tricupidata takes up the largest portion of the wall in the three cities similarly followed by Vitis vinifera and Wistaria spp. By its diversity it can be assumed that these plants are most practical for large scale of facade greening and full covering. Evergreen climbing plants such as Hedera helix and Ficus niponica are useful plants for relatively large scale of facade greening area. In the facade greening types, the climbing type is the most dominant in the three cities and most of the climbing type was planted on the natural foundation but the hanging and combination types were planted on an artificial foundation located on the balcony or on the roof of the building. In the directions of the walls for facade greening, the west direction are most popular which is for the improvement of sun shading in summer season. In Sofia the apartments were most applied with facade greening but In Istanbul and Athens the residential buildings and the public buildings were adapted with facade greening actively as well as residential building. The purpose of lowering summer heat took up the highest portion followed by the purpose of ornamentation and maintaining privacy in all surveyed cities.

• 한국가스학회지
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• 제13권4호
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• pp.33-39
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• 2009

이 연구는 천연가스버스에 장착된 용기가 국부화염에 집중적으로 노출되었을 때나 외기온도가 높은 여름철 충전과정에서 과 충전되었을 때 용기파열을 방지하기 위한 방안으로 압력방출장치의 성능을 확인하고 확대 적용할 목적으로 의도되었다. 열사이클링 실험결과, $-40^{\circ}C{\sim}82^{\circ}C$ 인증기준에서 가스누출요건을 모두 충족하였지만 $-45^{\circ}C{\sim}135^{\circ}C$의 가속조건에서는 3개사 시험편중 2개사 시험편의 오링이 손상되었다. 또한 온도감응형 PRD의 평균작동시간은 액체봉입식이 1분 39초가 걸렸고, 가용합금식이 2분 31초가 소요되어 액체봉입식이 가용합금식보다 약 1분 정도 빠름을 나타내었다. 또한 압력감응형 PRD의 작동압력은 가속조건에서 약 32.1 MPa을 나타내었고 인증기준에서의 압력감응형 PRD의 파열압력은 $30.7{\sim}32.1\;MPa$를 기록하였다. 이상의 실험을 통해서 압력방출장치의 성능은 온도감응형 PRD의 경우, 액체봉입식이 가용합금식보다 화염에 더 효과적이며, 압력 감응형 PRD의 파열압력은 외부온도 및 반복가압이 파열판의 작동압력에 크게 영향을 미치지 않음을 확인할 수 있었다.