• Environmental Engineering Research
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• 제25권2호
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• pp.222-229
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• 2020

Membrane assisted condenser is an innovative membrane operation that exploits the hydrophobic nature of microporous membranes to promote water vapor condensation and recovery. It can be used for water and chemicals recovery from waste gaseous streams. In this work, the testing of membrane condenser for water and ammonia recovery from synthetic streams (i.e., a saturated air stream with ammonia) simulating the plume of cooling tower is illustrated. The modeling of the process was carried out for predicting the membrane-based process performance and for identifying the minimum operating conditions for effectively recovering liquid water. The experimental data were compared with the results achieved through the simulations showing good agreement and confirming the validity of the model. It was found that the recovery of water can be increased growing the temperature difference between the plume and the membrane module (DT), the relative humidity of the plume (RH^plume) and the feed flow rate on membrane area ratio. Moreover, the concentration of NH₃ in the recovered liquid water increased with the growing DT, at increasing NH₃ concentration in the fed gaseous stream and at growing relative humidity of the feed.

• 농업생명과학연구
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• 제45권4호
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• pp.29-35
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• 2011

본 연구에서는 2005년부터 2009년까지 전라남도 지역의 기상변화와 산불특성과의 관련성을 파악하기 위해 기상요소와 산불 발생자료 (시간, 원인)를 분석한 결과, 최고온도 상승과 상대습도 감소로 인해 산불발생의 위험성이 높은 기후조건이 형성되었으며, 산불은 최고기온 $10{\sim}20^{\circ}C$에서, 상대습도 40~60% 에서, 평균풍속 2 m/s이하에서 주로 발생하였다. 이러한 기상조건은 강우 후에 2~3일이면 산불발생 위험이 높은 기상조건이 형성되었다.

• 한국측량학회지
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• 제30권6_2호
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• pp.673-680
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• 2012

Long-term GPS data analysis was performed in order to analyze the seasonal variation of tropospheric delay and the success rate of the ambiguity resolution. For this analysis, a total of 57 stations including 10 IGS stations in East Asia were processed together with double-differenced observables using Bernese GPS Software V5.0. The time span for this study ranges from 2002.0 to 2012.5 (10.5 years). The average baseline length is 339.0 km and the maximum reaches up to 2,000 km. The analysis is focused on two things: the annual variation of the tropospheric delay and the ambiguity resolution rate. The tropospheric delay is closely related to the weather condition, especially relative humidity, therefore it was estimated that the maximum would be in summer, while reaching its minimum in winter with the apparent seasonal variations. On the contrary, however, the success rate of the ambiguity resolution shows the opposite pattern: its maximum was in winter and minimum in summer. The fact seems to be induced by the surrounding conditions; that is, the trees thick with leaves near the GPS antenna interfere with GPS signals in summer. This seems to confirm partly that there is a distinct trend in the decreasing success rate since 2006 because the trees are growing every year. It is necessary to eliminate the factors that degrade the GPS quality and the tropospheric modeling for Korea needs to be studied further.

• 대한기계학회논문집B
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• 제38권3호
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• pp.219-225
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• 2014

본 연구에서는 NACA0012/14/15 천음속 에어포일 유동에서 비평형 응축이 충격파 진동에 미치는 영향을 TVD 수치해석을 통하여 연구하였다. 주류 마하수 0.81-0.90에 대해, 정체점 상대습도 및 에어포일의 기하학적 형상이 유동 특성에 미치는 영향이 구명되었다. 받음각 ${\alpha}=0^{\circ}$, 정체점 온도(288K) 및 주류 마하수가 0.87인 경우, 정체점 상대습도의 증가는 Terminating Shock의 충격파 강도를 약화시킨다. 정체점 상대습도가 30%인 경우 961Hz이던 충격파의 진동수가 60%일 때는 912Hz로 약 5% 감소한다. 정체점 상대습도가 동일한 경우는 주류 마하수가 클수록 충격파의 진동수 및 이동거리는 크게 된다. 또, 진동의 한 주기에 대해 항력계수의 변화도 구명되었다. 정체점 상대습도가 높을수록 최대 항력 계수는 작고, 항력계수의 변화폭 또한 감소한다. 한편 에어포일의 최대 두께가 두꺼울수록 초음속 영역의 크기는 증가하며 충격파의 진동수 및 이동거리도 증가한다.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권1호
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• pp.1-7
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• 2007

At present, multivoltine silkworm races reared five times per year involving huge manpower and rearing expenditure. Egg diapausing behavior is facultative in multivoltine and egg diapause was induced in selected multivoltine races by regulating temperature at $18^{\circ}C$, relative humidity 80% and photoperiod (6L:18D) in the late stage silkworm rearing. The maximum percentage of egg diapause induction was recorded in Rong Diazo, Diazo and MW13 showed 94%, 93% and 92% respectively, whereas the races A14DY and OS-616 showed minimum diapause induction 15% and 18% respectively. The diapause induced multivoltine eggs were preserved up to six months by cold preservation schedule normally adopted for bivoltine. After three and six months egg preservation, the diapause induced layings were released and observed for hatching percentage, all races showed above 82 % of hatching except the race AP12, which showed only 78 % of hatching. This methods reduce the crop cycle, gives strong safety backup and preventing the genetic erosion. This study helps formulating a new conservation method for multivoltine silkworm germplasm.

• Mycobiology
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• 제42권1호
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• pp.27-33
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• 2014

From April 2009 to October 2011, we surveyed the higher fungi in the Byeonsanbando National Park, Korea. In total, we identified 2 kingdoms, 3 divisions, 7 classes, 22 orders, 63 families, 149 genera, and 313 species (including 6 undocumented taxa: 2 families, 2 genera, and 2 species). Seventeen 17 orders, 49 families, 128 genera, and 286 species belonged to Basidiomycota; 7 orders, 9 families, 15 genera, and 21 species were of Ascomycota; and 4 orders, 5 families, 6 genera, and 6 species of primordial fungi. Among the Basidiomycota, Agaricomycetes were represented by 47 families, 126 genera, and 282 species. The most common fungi were Boletaceae (33 species), followed by Russulaceae (30), Agaricaceae (27), and Amanitaceae (24). Various species of most of the higher fungi occurred during periods with average temperatures of $23{\sim}24.9^{\circ}C$, maximum temperatures of $28{\sim}31.9^{\circ}C$, minimum temperatures of $22{\sim}22.9^{\circ}C$, > 82% relative humidity, and > 200 mm precipitation.

• 한국환경과학회지
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• 제8권3호
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• pp.287-292
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• 1999

This study was performed to investigate the characteristics of nocturnal maxiumu ozone occurrence and the meteorological relevance using to hourly ozone data and meteorological data for 1995~1996 in Pusan coastal area. Kwangbokdong showed the highest occurrence of nocturnal maximum ozone as 36.9%, and Deokcheondong showed the lowest occurrence(9.2%) for research period in Pusan. The occurrence rates of nocturnal maximum ozone concentration were decreased toward land area. The low maximum temperature, high minimum temperature, low diurnal range, high relative humidity, high wind speed, high could amount, low sunshine and low radiation were closely related to the main meteorological characteristics occuring the nocturnal maximum concnetration of ozone. It was shown that normal daily variation of ozone concentration by strong photochemical reaction at the before day of nocturnal maximum ozone. The concnetration of nocturnal maximum ozone were occured by entrainment of ozone from the upper layer of developed mixing layer. There are no ozone sources near the ground at night, so that the nighttime ozone should be entrained from the upper layer by forced convection.

• Water Engineering Research
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• 제4권3호
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• pp.111-126
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• 2003

Meteorological data are often needed to evaluate the long-term effects of proposed hydrologic changes. The evaluation is frequently undertaken using deterministic mathematical models that require daily weather data as input including precipitation amount, maximum and minimum temperature, relative humidity, solar radiation and wind speed. Stochastic generation of the required weather data offers alternative to the use of observed weather records. The precipitation is modeled by a Markov Chain-exponential model. The other variables are generated by multivariate model with means and standard deviations of the variables conditioned on the wet or dry status of the day as determined by the precipitation model. Ultimately, the objective of this paper is to compare Richardson's model and the improved weather generation model in their ability to provide daily weather data for the crop model to study potential impacts of climate change on the irrigation needs and crop yield. However this paper does not refer to the improved weather generation model and the crop model. The new weather generation model improved will be introduced in the Journal of KWRA.

• 한국환경과학회지
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• 제7권6호
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• pp.827-831
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• 1998

Statistical $SO_2$ forecasting technique by multiple regression analysis was designed and developed to predict $SO_2$ concentration in Wonju City. $SO_2$ concentration data measured from air pollution monitoring system and meteorological factors data such as : wind speed, atmospheric stability, surface temperature, relative humidity and precipitation were used in Wonju City during the 1996~1997. As the results, correlation model for forecasting was well fitted with some parameters including minimum temperature, wind speed and the $SO_2$ concentration of the previous day.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2000년도 춘계 학술대회 및 국제 감성공학 심포지움 논문집 Proceeding of the 2000 Spring Conference of KOSES and International Sensibility Ergonomics Symposium
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• pp.62-66
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• 2000

This study investigated the effects of certain specific wavelengths of lighting on the autonomic nervous system (ANS) using the heart rate variability (HRV) as an index. Six subjects with normal color vision participated n this study between 15:00 and 17:00 hr to neutralize any visual differences arising from circadian rhythm. The environmental conditions of the laboratory were maintained in complete darkness and the temperature was equilibrated at 24$\Box$ with a relative humidity of 60%. Subjects were only subjected to light stimulation when the pupil of dyes attained a minimum size of 2 mm by projecting illumination equalized with the same spectral radiance of 500-700 nm with 50-nm internal radiance. HRV was calculated from electrocardiogram (ECG) with systematic respiratory control at 0.35 Hz. The results suggest that illumination with certain wavelengths may induce ANS activation.