• Korean journal of applied entomology
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• v.29 no.4
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• pp.222-229
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• 1990

The flight activities of Holotrichia morosa Watershouse and H. diomphaia Bates adults were monitored by blacklight traps for six years from 1984 to 1989. The flight activity of H. morosa adults was most prominent from late June to early August with a peak flight in mid July, and that of H. diomphalia adults mainly occurred from early May to late June of odd years with the peak flight dates varying year by year. The flight activities of the two species during the fight period became vigorous after moderate to heavy rainfalls. The overwintered adults of H. diomphalia seemed to begin flying when the daily mean temperature rose above $15^{\circ}C$. The ratios of the females to the total adults collected by the blacklight traps were 53.3% for H. morosa and 0% for H. diomphalia, although the female sex ratio of the latter species was 57.4% in the field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.1
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• pp.65-69
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• 1991

In order for investigating the factors related to decrease of seedling vigor in the naked barley lines, two naked lines and a covered variety were sprouted with 20 mm rainfall in the natural condition, dried and the sprouted seeds were threshed by hand and small machine thresher, Chiyota. In the case of hand-threshing of the sprouted seeds, the germination rate index (GRI), germination rate, and TTC test value of the different varieties were not different due to the different sprouting degrees, but emergence rate index (ERI) became decreased with stronger sprouting damage. In comparison with hand-threshing, the embryos of sprouted seeds from machine threshing with 700 rpm were partially damaged, and the traits related to seedling vigor were decreased highly significantly. However, the diastatic activity was sharply increased by stronger sprouting and machine threshing. The sprouting degree in the hand-threshing plot was significantly correlated with the diastatic activity(r=0.931＊＊, 0.951＊＊) and GRI(r=0.461), respectively.

• Economic and Environmental Geology
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• v.31 no.6
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• pp.499-508
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• 1998

The Imgok Creek is located in the Gangreung coal field, which has been known that sulfides are more abundant than other coal fields in Korea, and it has been severly contaminated by acid mine drainage (AMD) discharging from the abandoned coal mines, such as the Youngdong, the Dongduk and the Waryong coal mines. The purposes of this study are to synthetically assess the contamination of natural water, stream sediment and cultivated soils, and to provide the basic data for AMD treatment. Geochemical samples were collected in December, 1996 (dry season) and April, 1997 (after three day's rainfall). TDS of the Youngdong mine water was remarkably higher than those of other mine waters. In the Imgok Creek, concentrations of most elements, except Fe decreased with distance by dilution caused by the inflow of uncontaminated tributaries. From the results of NAMDI and $I_{geo}$ calculation, the Youngdong coal mine was the main contamination source of the study area. Groundwater pollution was not yet confirmed in this study and the paddy and farm land soils were also not yet contaminated by mining activity based on the pollution index ranging from 0.27 to 0.47.

• Atmosphere
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• v.27 no.1
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• pp.17-28
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• 2017

The sensitivity of the typhoon track and intensity simulation to physics schemes of the global model are examined for the typhoon Bolaven and Tembin cases by using the Global/Regional Integrated Model System-Global Model Program (GRIMs-GMP) with the physics package version 2.0 of the Korea Institute of Atmospheric Prediction Systems. Microphysics, Cloudiness, and Planetary boundary Layer (PBL) parameterizations are changed and the impact of each scheme change to typhoon simulation is compared with the control simulation and observation. It is found that change of microphysics scheme from WRF Single-Moment 5-class (WSM5) to 1-class (WSM1) affects to the typhoon simulation significantly, showing the intensified typhoon activity and increased precipitation amount, while the effect of the prognostic cloudiness and PBL enhanced mixing scheme is not noticeable. It appears that WSM1 simulates relatively unstable and drier atmospheric structure than WSM5, which is induced by the latent heat change and the associated radiative effect due to not considering ice cloud. And WSM1 results the enhanced typhoon intensity and heavy rainfall simulation. It suggests that the microphysics is important to improve the capability for typhoon simulation of a global model and to increase the predictability of medium range forecast.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.691-693
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• 2015

Radio sources are very weak, as they can travel through large distances. Radio sources also have photons with low energies compared to others electromagnetic waves (EM). Microwave photons have a little more energy than radio waves, infrared photons have still more, then visible, ultraviolet, X-rays, and the most energetic electromagnetic wave is gamma-rays. Radio astronomy studies are restricted due to radio frequency interference (RFI) produced by people. If this disturbance is not minimized, it poses critical problems for astrophysical studies. The purpose of this paper is to profile RFI maps in Peninsular Malaysia with a minimum mapping technique for RFI interference. Decision-making processes using GIS (Geographical Information System) for the selection requires gathering information for a variety of parameters. These factors affecting the selection process are also taken into account. In this study, various factors or parameters are involved, such as the availability of telecommunications transmission (including radio and television), rainfall, water lines and human activity. This mapping step must be followed by RFI site testing in order to identify areas of low RFI. This study will benefit radio astronomy research, especially regarding the RFI profile.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4629-4634
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• 2010

Most prevention efforts have been made for relatively large watersheds near to channel flow. However, as economical development and the expansion of leisure areas to mountainous region, human casualty by flash flood occurs frequently, requiring additional prevention activity. Therefore, to minimize the damage of human lives and property by flash flood, we develop a methodology to assess the risk of flash flood occurrence for mountainous areas considering various factors involving it. For accomplishing the task, we selected the assessment indexes such as the characteristics of region, rainfall and land in mountainous area. And considering the characteristics of these indexes, the assessment method was suggested to assess and select the reasonable points for flash flood warning system. The suggested method was applied to BongHwa region and the application process of this method was explained.

• Atmosphere
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• v.32 no.1
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• pp.17-25
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• 2022

As climate change due to global warming continues to be accelerated, various extreme events become more intense, more likely to occur and longer-lasting on a much larger scale. Recent studies show that global warming acts as the primary driver of extreme events and that heat-related extreme events should be attributed to anthropogenic global warming. Among them, both terrestrial and marine heat waves are great concerns for human beings as well as ecosystems. Taking place around the world, one of those events appeared over East Sea in July 2021 with record-breaking high temperature. Meanwhile, climate condition around East Sea was favorable for anomalous warming with less total cloud cover, more incoming solar radiation, and shorter period of Changma rainfall. According to the results of wave activity flux analysis, highly activated meridional mode of teleconnection that links western North Pacific to East Asia caused localized warming over East Sea to become stronger.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.381-389
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• 2009

Confined spaces are inherently dangerous workplace and many fatal and nonfatal accidents have been reported. Even though these accidents occur in various kinds of confined spaces, there has rarely been reported on the health hazard agent, i.e., the types of gases and their concentration ranges. Therefore in this study, we evaluated several toxic and asphyxiating gas concentrations in various confined spaces. We surveyed 57 manholes, 3 sewage treatment plants, 2 yellow radish manufacturing companies and 7 barges to measure the concentrations of oxygen($O_2$), hydrogen sulfide($H_2S$), carbon monoxide(CO), ammonia($NH_3$). Lower Explosion Limits(LEL) and Volatile Organic Compounds (VOCs). Those four types of confined spaces occupies 56% of accidents during last 9 years in Korea. In 57 manholes, the concentration varied according to the types of manholes; rainfall and sewage, and by location; residential and industrial areas. Sewage manhole in industrial area was evaluated as the most hazardous than other types of manhole like rainfall manholes, residential sewage manholes. The highest $H_2S$ concentration and the lowest $O_2$ concentration at sewage manhole in industrial area were 300 ppm, 8.7% respectively. In 3 sewage treatment plants, $H_2S$ and $NH_3$ concentrations were reached up to the 500 ppm and 200 ppm respectively. Two yellow radish manufacturing companies showed the concentrations of 316 ppm, 505.2 ppm, 90 ppm and 15.7% for $H_2S$, CO, VOCs and $O_2$, respectively. Seven barges showed 15.9%~20.9% oxygen concentration. Gas species and concentration ranges varied by the types and location of confined spaces; CO, $H_2S$, $O_2$ could be hazardous in manhole, especially manhole connected to sewage plants. CO, $H_2S$, LEL, $O_2$, $NH_3$ should be controlled in sludge silo and sluge pumping confined spaces in sewage treatment plant. The activity of lifting out radish from the storage tank was evaluated more hazardous rather than the other activities in yellow radish manufacturing industry. The employers must conduct the survey to identify all possible confined spaces in their local workplace prior to performing the tasks. At the national level to reduce the accidents in the confined spaces, we suggest that systemic approach and active education program including possible hazards, standard operation procedures, ventilation plan, and personal protective equipment in confined spaces should be implemented.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.3
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• pp.189-197
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• 2022

This study investigated the antioxidant and yield properties of eight adzuki bean (Vigna angularis L.) cultivars grown under different mean temperatures and sunshine hours in 2020 and 2021. Compared to 2021, which had a normal mean temperature, 2020 showed a lower mean temperature during the pod-extension and grain-filling periods. In addition, due to frequent rainfall during the vegetative period in 2020, there were fewer hours of sunshine in 2020 than in 2021. The adzuki bean yield was approximately 13% lower in 2020 than in 2021 due to the decreased number of pods per plant and 100-seeds weight. 'Hongda' and 'Hongjin' cultivars showed more stable yields than the 'Arari' variety, which is the most commonly cultivated variety in Korea. Moreover, the 'Hongda' and 'Hongjin' cultivars had higher yields than the 'Arari' variety in both years. Compared to 2021, in 2020, when the weather conditions were unfavorable, both antioxidant levels and activity were higher. 'Hongda' had higher antioxidant levels and activity than the other cultivars over the 2 years. These results suggest that the antioxidant levels and activity were good in 2020, with an approximately 13% decrease in yield compared to 2021, which was a normal year with respect to mean temperature and sunshine hours.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.1-12
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• 2006

Distributions of water temperature and DO profiles were investigated in Andong Reservoir from 1992 to 2004. Thermal stratification began to form from May of every year. Increasing water temperature of epilimnion, temperature difference between epilimnion and hypolimnion increased until August. Lower oxygen layer was formed at metalimnion from June or July of every year and there were 2 layers depending on each year. The two lower oxygen layers were affected by rainfall and inflow between July and September when thermal stratification was formed. The metalimnetic oxygen minima strongly formed at 2 layers, upper and lower part, when the average rainfall and inflow were ${\geqq}$ 170 mm, ${\geqq}$ 50 $m^3\;sec^{-1}$, respectively. It formed weakly when they were > 400 mm and > 200 $m^3\;sec^{-1}$ for one month. The upper part of low oxygen layers formed on the interface of epilimnion and metalimnion showed larger decreasing rate of DO than temperature and it disappeared around November. The lower part of those farmed on interface of metalimnion and hypolimnion existed until December and disappeared in January, this layer showed larger decreasing rate of temperature than DO. DO increased between the upper and lower part of the low oxygen layers. DO on hypolimnion increased under metalimnion and dramatically decreased near the bottom of the reservoir. Temperature of the inflow during rainy season was similar to that of the reservoir's metalimnion, DO was similar or higher and BOD, COD and SS increased. Density layer caused by turbidity was formed in metalimnion, and turbidity increased under the upper part (oxygen increasing layer) of metalimnetic DO minima layers reaching the maximum at the direct upper part of the lower DO minima layer. The upper part of DO minima layers formed on the interface of epilimnion and metalimnion is related to organic activity on the surface, and the lower part of those was considered to be the result of turbid water inflow to metalimnion during rainy season.