• Title/Summary/Keyword: Dew Point Depression

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Impact of Tidal Effects on Fog Events in the Western Coast of Korea (서해 연안 해역에서의 조석현상이 안개에 미치는 영향)

  • An, Hye Yeon;Jeong, Ju-Hee;Kim, Yoo-Keun
    • Journal of Environmental Science International
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    • v.30 no.11
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    • pp.925-936
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    • 2021
  • The study was aimed to investigate the correlation between tidal effects and fog occurrence in Incheon and Mokpo, which are located in the middle and southern coasts of the West Sea of Korea, respectively. The investigation used meteorological data obtained from the automated synoptic observing systems and automatic weather stations and ocean data from tide stations from 2010 to 2019. Fog occurrence frequency was highest at high tide (Incheon, 41%; Mokpo, 45%). During fog event days at high tide, the dew-point depression was low (Incheon, 0.5℃; Mokpo, 0.4℃) and the relative humidity was high (Incheon, 97%; Mokpo, 98%). The wind speed was 2.4 m/s in Incheon and 2.0 m/s in Mokpo, and the main wind directions were west-southwesterly from Incheon and southwesterly from Mokpo. In the fog case study, tidal flats were covered with water before and after the fog started. During the fog period, both stations experienced negative air-sea temperature differences, low dew-point depression, and high relative humidity were maintained, with weak winds forming from the tidal flats to the shore.

Canopy Microclimate of Water-Seeding Rice during Internode Elongation Period (담수직파 벼의 신장기 군락내 미기후 특성)

  • Yun, Jin-Il;Shin, Jin-Chul;Yun, Yong-Dae;Park, Eun-Woo;Cho, Seong-In;Hwang, Heon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.4
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    • pp.473-482
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    • 1997
  • Temperature, humidity and wetness duration were monitored for fully developed paddy rice canopies with 3 different structures induced by the seeding method(puddled-soil drill seeding, DS ; hand broadcasting, HB ; machine broadcasting, MB). Within-canopy air temperature averaged over "clear sky" hours during the study period(maximum tillering through heading) was lower than the screen temperature at a nearby standard weather station, especially in the night. The same trend was true for "overcast sky" hours except the diurnal distinction. Vapor pressure within the canopy was high during the daytime and low in the night, making the daytime deviation from outside the canopy more significant on clear days. Under the overcast sky, the canopy maintained a steady 5 to 10% higher vapor pressure than the outside regardless of day or night. Daily maximum temperature was observed to be higher within the canopies with more leaf mass, making MB the highest, HB the lowest, and DS in between. Relative humidity was over 90% in the night and dropped to 70% in the mid-afternoon, but vapor pressure within the canopy was highest at around 13:00 LST. Dew point depression was lowest and, combined with the temperature, the relative humidity was highest in HB. Mean period of wetting duration was in the order of DS>HB>MB, while the dew point depression was greatest in DS.

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TOVS retrieved data with the real time synoptic surface data (종관 지상 자료를 이용한 TOVS수치 해석 산출 자료)

  • 주상원;정효상;김금란
    • Korean Journal of Remote Sensing
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    • v.10 no.1
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    • pp.55-67
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    • 1994
  • The International TOVS(TIROS Oprational Vertical Sounders) Process Package(ITPP-VI)is for a global usage, which needs a surface data to generate atmospheric soundings. If the initial input process in the ITPP-VI is not modified, it takes climatic surface data for producing sounding data in general. Korea Meteorological Administration(KMA) is trying to improve the quality of TOVS sounding data using real-time synoptic observations and make a use weather prediction and analysis in various ways. Serval cases in this study show that TOVS retrieved meteolorogical parameters such as atmopheric temperature, dew point depression and geopotential heights used by synoptic surface observations can delineate more detailed atmospheric feature rather than those used by climate surface data. In addition, the collocated comparisons of TOVS synoptic retrieved parameters with radiosonde observations are performed statistically. TOVS retrieved fields with the synoptic surface analyzed data show smaller bias reatively than those with the climatic data and also reduced root mean square differences below 700 hPa as expected.

A Study on the Korea Weather Environment for Icing Airworthiness of Military Helicopter (군용헬기 결빙 감항인증을 위한 국내 기상환경에 관한 연구)

  • Hur, Jangwook;Shin, Baekcheon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.3
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    • pp.304-310
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    • 2014
  • Based on atmosphere weather data by balloon in Osan and Gwangju area, if icing condition occurs in weather environment of altitude range where helicopter is operated was analyzed in quantitative way. Yearly icing occurrence frequency for daytime during recent three years was average 102 days in Osan, average 91 days in Gwangju. Icing weather environment to highly affect operation of helicopter varies a little according to analysis methods but icing intensity at MDT level was calculated in all the methods, and 14.5~38 times was suggested in Osan; 2.5~30 times in Gwangju. Icing at MDT level was calculated in common in all the analysis methods through wide periods such as Jan., Feb., Mar., and Nov. in Osan. In Gwangju, icing at MDT level was suggested focusing on Jan. only. Therefore, military helicopter developed in Korea is required to strive obtaining certificate of airworthiness about icing condition at MDT level for implementation of perfect operational mission and safe operation.

Influence of Local Wind on Occurrence of Fog at Inland Areas (국지풍이 내륙의 안개발생에 미치는 영향)

  • Shim, Hwa-Nam;Lee, Young-Hee
    • Atmosphere
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    • v.27 no.2
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    • pp.213-224
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    • 2017
  • We have examined the influence of local wind on occurrence of fog at two inland areas, Chuncheon and Andong, in Korea. The surrounding topography of two inland areas shows significant difference: Chuncheon is located in the basin surrounded by ridges with north-south axis while Andong is located in the valley between the ridges with east-west axis. Occurrence of fog shows maximum in October at both sites but high occurrence of fog at Chuncheon is also noted in the winter. Occurrence of fog at Andong in October is much larger than that at Chuncheon. High occurrence of fog in October is due to favorable synoptic condition for fog formation such as weak wind, clear day and small depression of the dew-point. Fog occurrence at Chuncheon is closely related to very weak wind condition where wind speed is less than $0.5m\;s^{-1}$. The weak wind at Chuncheon in winter is due that pressure driven channeling wind (southerly) cancels out partly downslope northerly flow during nighttime. On the other hand, fog at Andong occurs well when wind is southeasterly which is thermally forced flow during nighttime. Southeasterly provides cold, moist air from the narrow valley to Andong during nighttime, leading to favorable condition for formation of fog.

Simulation of Local Climate and Crop Productivity in Andong after Multi-Purpose Dam Construction (임하 다목적댐 건설 후 주변지역 기후 및 작물생산력 변화)

  • 윤진일;황재문;이순구
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.5
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    • pp.579-596
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    • 1997
  • A simulation study was carried out to delineate potential effects of the lake-induced climate change on crop productivity around Lake Imha which was formed after a multi-purpose dam construction in Andong, Korea. Twenty seven cropping zones were identified within the 30 km by 25 km study area. Five automated weather stations were installed within the study area and operated for five years after the lake formation. A geostatistical method was used to calculate the monthly climatological normals of daily maximum and minimum temperature, solar radiation and precipitation for each cropping zone before and after the dam construction. Daily weather data sets for 30 years were generated for each cropping zone from the monthly normals data representing "No lake" and "After lake" climatic scenarios, respectively. They were fed into crop models (ORYZA1 for rice, SOYGRO for soybean, CERES-maize for corn) to simulate the yield potential of each cropping zone. Calculated daily maximum temperature was higher after the dam construction for the period of October through March and lower for the remaining months except June and July. Decrease in daily minimum temperature was predicted for the period of April through August. Monthly total radiation was predicted to decrease after the lake formation in all the months except February, June, and September and the largest drop was found in winter. But there was no consistent pattern in precipitation change. According to the model calculation, the number of cropping zones which showed a decreased yield potential was 2 for soybean and 6 for corn out of 27 zones with a 10 to 17% yield drop. Little change in yield potential was found at most cropping zones in the case of paddy rice, but interannual variation was predicted to increase after the lake formation. the lake formation.

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A Clinical Study on the Therapeutic Effects of the Pulsed Nd:YAG Laser on Dentinal Hypersensitivity (상아질지각과민증에 대한 펄스형 Nd: YAG 레이저의 치료효과에 관한 임상적 연구)

  • 최순정;신금백;김문현
    • Journal of Oral Medicine and Pain
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    • v.23 no.1
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    • pp.11-20
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    • 1998
  • 저자는 치과용 레이저를 이용한 상아질지각과민증 치료효과를 임상적으로 평가하고자 상아질지각과민증환자 24명을 대상으로 각 환자마다 상아질 지각과민 치아 중 레이저로 치료 할 치아1개(실험군)와 치료하지 않을 치아 1개(대조군)를 선정하여, 치과용 air-syringe에 의한 냉자극과 치과용 탐침자에 의한 기계적 자극을 가한 후 Visual Analogue Scale(VAS)을 통해 지각과민증 정도를 평가하였으며, 이후 실험군 치아의 치경부 마모면에 광섬유 레이저에너지 전달방식의 펄스형 Nd:YAG 레이저의 일종인 Sunlase Master(Sunrise Technologies Inc., U.S.A., 파장 1064nm, 펄스지속시간 120(sec, 광섬유직경 320(m)를 사용하여, 0.3-1.0W, 10Hz 조건으로 환자의 반응에 따라 1회2분을 초과하지 않는 범위 내에서 비접촉식과 접촉식을 병행하여 3회에 걸쳐(초진 당일, 1일후, 3일후) 레이저를 조사한 후 처음조사 직후, 그리고 초진 1일후, 3일후, 7일후, 14일후 VAS를 채득하여 조사전과 비교, 분석, 평가하였던 바, 상아질 지각과민증이 각각 약 50%, 약36%, 약45%, 약 53% 감소하였으나 (p(0.05) 경시적으로는 유의한 차이를 보이지 않았다. 그리고 24명중 9명에 대해서는 초진 30일 후 까지 레이저조사치료효과를 평가하였던 바, 상아질지각과민증이 처음조사 직후, 감소하였으며 (p(0.05)역시 경시적으로는 유의한 차이를 보이지 않았다. 초진 30일 후 상아질지각과민증이 초진 14일 후에 비해 약간 증가되는 경향을 보여, 레이저조사 치료효과가 약화되는 경향인지 여부에 대해 향후 추가적인 연구가 필요할 것으로 사료된다.안되었다.기란 현실적으로 불가능하므로, 본 연구에서는 이러한 제약점을 극복할 수 있는 근사적인 지체시간을 계산하는 방법을 제시한 점에서 의미를 갖을 수 있다.수들은 직업의 선택이나 소득을 예측하기 위한 요소들로 포함될 수 없었다. 따라서 후속연구에서는 이를 보완해야 할 것이며, 최근 들어 우리 나라에서도 재택근무에 대한 관심이 대두되고 있으나 아직 개념정의나 그 중요성과 가치, 그리고 실태 파악과 같은 연구가 활발히 이루어지지 못하고 있으므로 이에 대한 심층적인 연구가 행해져야 할 것이다.d similar flower proceeding dates in all branches. but "Daepung" showed similar flower proceeding dates in all branches.est in HB. Mean period of wetting duration was in the order of DS>HB>MB, while the dew point depression was greatest in DS.ANCOVA, Pearson correlation을 이용하여 분석하였으며, 그 결과는 다음과 같다. 캠프 프로그램은 소아 당뇨병 환자의 자기 효능을 증진시키고 환자 역할 행위 이행을 높여주는데 효과적 이었다. 소아 당뇨병 환자의 자기 효능은 환자 역할 행위 이행과 순 상관 관계가 있어, 자기 효능이 증진될수록 환자 역할 행위 이행 정도가 높아졌다. 무조건 사주지 않는다(8.0%), 무조건 사준다(3.1%)로 식품광고에 나오는 식품 요구시 부모의 70.3%가 거절하는 것으로 나타났다. 거절 이유는 건강에 나쁘다는 것이 가장 큰 이유였으며 강남과 강북 어린이간에 유의적인 차이가 있었다(p<0.001).

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Development of a Modified Vine Building Shortest Path Algorithm for ATIS (ATIS를 위한 수정형 덩굴망 최단경로 탐색 알고리즘의 개발)

  • 김익기
    • Journal of Korean Society of Transportation
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    • v.16 no.2
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    • pp.157-167
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    • 1998
  • 건설된 도로를 효율적으로 이용하고, 통행자의 편리성을 향상시키기 위해 첨단 여행자 정보체계(ATIS)를 활용할 수 있다. ATIS 체계하에서 노선정보를 통행자에게 제공하기 위해서는 교차로에서의 회전으로 인한 지체를 정확하게 반영할 수 있는 효율적인 최단경로 알고리즘이 필요하다. 하지만 기존의 최단경로탐색 알고리즘은 좌회전 금지, U-turn, P-turn 등 교차로에서의 회전으로 인한 지체를 정확히 반영 못한다는 단점을 갖고 있다. 그러므로 본 논문에서는 이러한 단점을 극복하기 위해 수정형 덩굴망 알고리즘을 재발하였다. 수정형 덩굴망 알고리즘은 노드표지(node labelling) 방법에 있어서는 기존의 덩굴망 알고리즘의 노드표지 방법과 개념적으로 동일하여 이용상의 편리성을 갖도록 하였으며, 최단경로 탐색기능에 있어서는 링크탐색알고리즘(혹은 링크표지기법)이 갖고 있는 장잠을 다 반영할 수 있는 기법으로 개발하였다. 수정형 덩굴망 알고리즘은 노드표지에 있어 특정 노드로 유입하는 방향에 따라 노드표지를 별도로 기록하였다. 따라서 교차로에서의 좌회전, 우회전 및 직진은 물론 U-turn의 경우에도 추가적인 절차 없이 현실적인 최단 경로를 탐색할 수 있도록 하였다. 또한 본 논문은 최단경로의 역추적 방법을 개선하여 좌회전 금지, U-turn, P-turn 및 기타 회전에 의한 지체등을 각 교차로마다 정확히 반영함으로써 비합리적인 최단경로가 추적되는 것을 근본적으로 차단하도록 하였다. 따라서 본 연구에서 개발한 수정형 덩굴망 최단경로탐색 알고리즘은 교차로에서의 회전지체 및 회전금지를 현실적으로 잘 반영함으로써 정확한 노선정보를 요구하는 ATIS체계를 분석하는데 유용하게 활용될 수 있는 기법이다.장자료를 통해 구하기란 현실적으로 불가능하므로, 본 연구에서는 이러한 제약점을 극복할 수 있는 근사적인 지체시간을 계산하는 방법을 제시한 점에서 의미를 갖을 수 있다.수들은 직업의 선택이나 소득을 예측하기 위한 요소들로 포함될 수 없었다. 따라서 후속연구에서는 이를 보완해야 할 것이며, 최근 들어 우리 나라에서도 재택근무에 대한 관심이 대두되고 있으나 아직 개념정의나 그 중요성과 가치, 그리고 실태 파악과 같은 연구가 활발히 이루어지지 못하고 있으므로 이에 대한 심층적인 연구가 행해져야 할 것이다.d similar flower proceeding dates in all branches. but "Daepung" showed similar flower proceeding dates in all branches.est in HB. Mean period of wetting duration was in the order of DS>HB>MB, while the dew point depression was greatest in DS.ANCOVA, Pearson correlation을 이용하여 분석하였으며, 그 결과는 다음과 같다. 캠프 프로그램은 소아 당뇨병 환자의 자기 효능을 증진시키고 환자 역할 행위 이행을 높여주는데 효과적 이었다. 소아 당뇨병 환자의 자기 효능은 환자 역할 행위 이행과 순 상관 관계가 있어, 자기 효능이 증진될수록 환자 역할 행위 이행 정도가 높아졌다. 무조건 사주지 않는다(8.0%), 무조건 사준다(3.1%)로 식품광고에 나오는 식품 요구시 부모의 70.3%가 거절하는 것으로 나타났다. 거절 이유는 건강에 나쁘다는 것이 가장 큰 이유였으며 강남과 강북 어린이간에 유의적인 차이가 있었다

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