• Journal of Environmental Science International
• /
• v.30 no.11
• /
• pp.925-936
• /
• 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.

• Journal of Biosystems Engineering
• /
• v.41 no.2
• /
• pp.98-107
• /
• 2016

Purpose: The aim of this study was to find an appropriate polymer film, which could reduce the water condensation for pallet-size modified atmosphere packaging (MAP). Methods: Five different types of films were selected from several commercialized films. Prior to the real food storage test, plastic boxes with wetted plastic balls were used to simulate the high humidity conditions of real food storage. The initial MAP condition was 5% oxygen and 95% nitrogen, and the $O_2$ concentration, the relative humidity and water condensation inside the films were checked on a daily basis. The MAP test for tomatoes was conducted by using the most appropriate film from the five films examined in this study. Results: Every film except Mosspack(R) indicated a similar variation in the $O_2$ concentration over the course of time. The relative humidity near the surfaces of all the films except nylon-6 approached saturation conditions over time. For three kinds of films, namely, low-density polyethylene (LDPE) film, anti-fogging oriented polypropylene (AFOPP) film, and Mosspack(R), the inner surfaces of the films were fully covered with dew after a storage period of a day. Conversely, an area of 4.5% was covered with dew in the case of the poly lactic acid (PLA) film, and there was no dew inside the nylon-6 film. The pallet-size MAP test for tomatoes was conducted by using the nylon-6 film and there was no water condensation inside the nylon-6 film over three weeks of storage. Conclusions: During the pallet scale MAP, water condensation could cause severe fungal infection and wetting of the corrugated box. Hence, it was important to minimize water condensation. This study showed that the MAP films with high WVTR such as nylon-6 and PLA could reduce the water condensation inside the pallet scale MAP.

• The Plant Pathology Journal
• /
• v.19 no.2
• /
• pp.97-101
• /
• 2003

This study was conducted to determine the efficacy of Epicoccosorus nematosporus for the control of Eleocharis kuroguwai and to evaluate the meteorological factors which affect weeding efficacy in field conditions for three years (1996-1998). The best time to control E. kuroguwai with E. nematosporus as a biological control agent in the field was in July, when temperature ranged from 20.4 to $23.4^{\circ}C$; the surface wetness duration was 12.6-16.1 hours, and application time of 6:00 p.m. and 8:00 p.m.; and weeding efficacy was 81-90%. On 10 June 1996 in Milyang area, where the field experiments were performed, mean temperature was $16.5^{\circ}C$ with 11.3 hours of dew duration. Meanwhile, on 20 Aug. 1996 the temperature was $21.3^{\circ}C$ with 15.4 hours of dew duration. During these periods, the weeding efficacy was recorded at 61.8 and 60.8%, respectively. Time required for complete plant death was 25.8 and 25.6 days at application times 10 June and 20 Aug., respectively. At the time of application on 7,18, and 27 July 1996, mean temperature was 20.4-$23.4^{\circ}C$ with 12.6-16.5 hours of dew duration. The weeding efficacies of these periods were very hi일 with 81.4-90.8%. Three years of field observations from 1996 to 1998 showed that infection in the field can occur at any time through the summer season, although total infection rates vary between months and between years. In 1996, plant infection rapidly increased from 56% on 30 June, 82.4% on 15 July, 94.6% on 15 August, and 92.8% on 15 September under favorable meteorological conditions such as minimum temperature of $17.6^{\circ}C$ and maximum temperature of $27.1^{\circ}C$, with 86% relative humidity and 977.5 mm of rainfall during E. kuroguwai growing season. However, in 1997, the disease incidence was very low because of unfavorable weather conditions brought about by the hot temperature and the low amount of rainfall at 321.5 mm. Disease progress was slow from 24.4% on 30 June to 49.2% at the end of the growing season.

• Journal of Conservation Science
• /
• v.34 no.5
• /
• pp.387-396
• /
• 2018

Exposure to the natural environment can cause damage to domestic wooden cultural assets, such as temples. Deterioration is accelerated by biological damage and various environmental factors. In this study, meteorological factors were monitored by equipment installed at Beopjusa temple of Boeun province and Seonamsa temple of Suncheon province. A statistical model was applied to these data to predict the meteorological factors and to compare the predictive performance of each meteorological factor. The resulting correlation coefficient between air and dew point temperatures was highest, at 0.95, while the correlation coefficient for relative humidity had a moderate value(0.65) at both the Beopjusa and Seonamsa temples. Thus, a general linear model was found to be suitable for predicting air and dew point temperatures. An analysis of correlation between meteorological factors showed that there was strong positive correlation between air temperature and dew point temperature, and between solar radiation and evaporation at both sites. There was a weak positive correlation between air temperature and evaporation at Beopjusa temple. Wind speed was negatively correlated with both air temperature and relative humidity at Seonamsa temple. The wind speed at this location is higher than average in winter and lower than average in summer, and it was hypothesized that the low wind speed plays a role in reducing water evaporation in summer, when both air temperature and relative humidity are high. As a result, damage to the wooden buildings of Seonamsa temple is accelerated.

• Korean Journal of Remote Sensing
• /
• v.30 no.5
• /
• pp.571-586
• /
• 2014

Moderate Resolution Imaging Spectroradiometer (MODIS) provides air temperature (Tair) and dew point temperature (Tdew) profiles at a spatial resolution of 5 km. New Collection 6 (C006) MODIS07_L2 atmospheric profile product has been produced since 2012. The Collection 6 algorithm has several modifications from the previous Collection 5 (C005) algorithm. This study evaluated reliabilities of two alternative datasets of surface-level Tair and Tdew derived from C005 and C006 Aqua MODIS07_L2 (MYD07_L2) products using ground measured temperatures from 77 National Weather Stations (NWS). Saturated and actual vapor pressures were calculated using MYD07_L2 Tair and Tdew. The C006 Tair showed lower mean error (ME, -0.76 K) and root mean square error (RMSE, 3.34 K) than the C005 Tair (ME = -1.89 K, RMSE = 4.06 K). In contrasts, ME and RMSE of C006 Tdew were higher than those (ME = -0.39 K, RMSE = 5.65 K) of C005 product. Application of ambient lapse rate for Tair showed appreciable improvements of estimation accuracy for both of C005 and C006, though this modification slightly increased errors in C006 Tdew. The C006 products provided better estimation of vapor pressure datasets than the C005-derived vapor pressure. Our results indicate that, except for Tdew, C006 MYD07_L2 product showed better reliability for the region of South Korea than the C005 products.

• Journal of radiological science and technology
• /
• v.45 no.2
• /
• pp.135-143
• /
• 2022

In SPECT image, scatter count is the cause of quantitative count error and image quality degradation. This study is to evaluate the accuracy of CT based SC(CTSC) and energy window based SC(EWSC) as the comparison with existing Non SC. SPECT/CT images were obtained after filling air in order to acquire a reference image without the influence of scatter count inside the Triple line insert phantom setting hot rod(^99mTc 74.0 MBq) in the middle and each SPECT/CT image was obtained each separately after filling water instead of air in order to derive the influence of scatter count under the same conditions. For EWSC, 9 sub-energy windows were set additionally in addition to main energy window(140 keV, 20%) and then, images were acquired at the same time and five types of EWSC including DPW(dual photo-peak window)10%, DEW(dual energy window)20%, TEW(triple energy window)10%, TEW5.0%, TEW2.5% were used. Under the condition without fluctuations in primary count, total count was measured by drawing volume of interest (VOI) in the images of the two conditions and then, the ratio of scatter count of total counts was calculated as percent scatter fraction(%SF) and the count error with image filled with water was evaluated with percent normalized mean-square error(%NMSE) based on the image filled with air. Based on the image filled with air, %SF of images filled with water to which each SC method was applied is non scatter correction(NSC) 37.44, DPW 27.41, DEW 21.84, TEW10% 19.60, TEW5% 17.02, TEW2.5% 14.68, CTSC 5.57 and the scatter counts were removed the most in CTSC and %NMSE is NSC 35.80, DPW 14.28, DEW 7.81, TEW10% 5.94, TEW5% 4.21, TEW2.5% 2.96, CTSC 0.35 and the error in CTSC was found to be the lowest. In SPECT/CT images, the application of each scatter correction method used in the experiment could improve the quantitative count error caused by the influence of scatter count. In particular, CTSC showed the lowest %NMSE(=0.35) compared to existing EWSC methods, enabling relatively accurate scatter correction.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.230-233
• /
• 1999

The design and implementation of thyristor water cooling control systems in considered in this pape Coolant water is pumped through the thyristor heat sinks where heat is transferred from the thyristo to the water. This water is then pumped through outdoor air-to-water heat exchangers where heat I transferred to the outside air. Since the water must be pure, it is filtered and de-ionized. Also the water temperature must be below dew-point temperature. Redundant pumps, outdoor heat exchangers, power supply system, controller monitoring system are provided for system reliability and availability.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.9 no.1
• /
• pp.19-23
• /
• 1973

The method of forecasting advection fog at Busan area in July is developed using the Spreen's scatter-diagraam technique. The used Parameters are (1) air temperature (2) dew-point temperature, (3) sea surface temperature (4) resultantt wind direction (5) resultant wind speed in Busan. The skill score and the pcr cent correct based on 4 yeare of dependent data are 0.79 and 90.3% respectively.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.269-270
• /
• 2003

이슬은 지표의 물체가 야간복사에 의해 냉각되어 부근의 기온이 노점이하로 떨어지면서 응결되어 생성된 것이다(김광식, 1995). 이슬생성의 세 가지 기본적인 조건은 풍부한 습기와 충분한 야간복사냉각 그리고 지면이나 풀잎사귀 등에 수분이 풍부하여야 한다. 충분한 습기는 주위의 호수 또는 연안으로부터 공급이나 비가 온 후의 습한 토양에서 공급된다고 할 수 있다. 우리나라에 늦여름부터 늦가을까지 이슬이 많이 생기는 이유가 이와 같은 조건을 갖추었기 때문이다. (중략)

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
• /
• 2001.06a
• /
• pp.163-166
• /
• 2001

One of the most important factors influencing the outbreak and severity of foliar diseases is the duration of wetness from dew deposition, rainfall, or irrigation. Models may provide good alternatives for assessing leaf wetness duration (LWD) without the labor, cost, and inconvenience of making measurements with sensors.(omitted)