• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.327-331
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• 2006

This study was carried out to determine the economic injury level of the rice leaffolder,Cnaphalocrocis medinalis G.. The damage aspects of rice plant (at tilling stage) by leaf folders at different larval density per plant were studied in pot experiment (24 cm in diameter, 18 cm in height). One leaf folder consumed 6-7 leaves during larval stage. The damage by leaf folders was simulated by cutting off 0, 10, 30, 50, 70, and 90% of leaves before and after heading stage July 15th (at panicle initiation stage) and August 15th (at milk stage), respectively. When leaves were cut before the heading of rice, the linear relationships between the leaf cutting rate (X) and each factors of yield (Y) were as following; for grain maturity it was Y = -9.379X + 83.630 ($R^{2}=0.493$),\;Y = 0.139X + 0.490 ($R^{2}=0.925$) for yield, and Y = -4.880X + 81.116 ($R^{2}=0.665$) for head rice. When leaves were cut after the heading of rice, it was Y = -23.0l4X + 83.589 ($R{2}=0.915$), for grain maturity, Y=0.141X + 3.466 ($R^{2}=0.842$) for yield, and Y = -13.795X + 81.964 ($R^{2}=0.898$) for head rice. We found that when leaf cutting after the heading stage caused more damage than before the heading in terms of yield and yield components. Based on theses results the economic threshold level was estimated to be 30% and 7% leaf loss before and after heading stage.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.132-140
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• 2008

Two different sensitivity classes of black cherry (Prunus serotina) under the natural growing environmental conditions were assessed adjacent to Air Monitoring Station located at Horton research center in Giles County, Virginia, USA. Ambient ozone concentrations, leaf gas exchange, and visible foliar injury were measured on-site during the growing seasons of 2000, 2001, and 2002. Ambient ozone exposures were sufficient to induce typical foliar visible injury corresponding with the reduction in photosynthetic activities only in sensitive black cherry. There were positive correlations between increasing cumulative ozone concentration and percent reduction in maximum net photosynthetic rates ($Pn_{MAX}$) under saturating light conditions and in quantum yield for carbon reduction (${\Phi}CO_2$) of sensitive black cherry compared to tolerant black cherry. There was a negative correlation between chlorophyll content and percent leaf injury in sensitive black cherry. Furthermore, $Pn_{MAX}$ was inversely related to percent leaf injury.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.139-145
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• 1987

This study was carried out to find out the effects of ammonia gas on the leaf destruction of vegetable crops, and nitrogen contents in their leaves. Radish, chinese cabbage, tomato and cucumber were fumigated with 0.05, 0.1, $0.2mg/{\ell}$ ammonia gas for 2 hrs under different exposure time, light and soil water condition at vegetative growth stage. The results obtained were as follows. The crop damages measured by percentage of leaf destruction were more severe at the night time fumigation than treatment during the day, at the full sun condition than the shading, and at the higher soil water contents. Cucumber plant showed higher resistance to ammonia gas than tomato plant. The chrolophyll contents in leaves of each crops were remarkably decreased by increment of ammonia concentration from $0.05mg/{\ell}$ to $0.2mg/{\ell}$, but the N content in them was increased.

• Korean Journal of Soil Science and Fertilizer
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• v.12 no.2
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• pp.109-116
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• 1979

This experiment was conducted to find out the effects on soybean plant exposed with various concentration and different fumigation periods of ammonia gas ($0.2mg/{\ell}$). The yield of soybean, nitrogen and, chlorophyll contents in leaves, and percentage of destroyed leaf area were investigated. The results were summarized as: 1. The soybean yield losses and percentage of destroyed leaf area were positively correlated with concentration of inflicting ammonia gas respectively. The yield losses was higher at noon exposure time than at night exposure time. 2. The soybean yield was negatively correlated with the percentage of destroyed leaf area. 3. The highest percentage of destroyed leaf area had at afternoon exposure time (14:00-15:00 o'clock) by $0.2mg/{\ell}$ ammonia gas fumigation, and the lowest one had at midnight exposure time (22:00-23:00 o'clock). 4. According to the increasing concentration of ammonia gas, the total and water soluble nitrogen contents in soybean leaves were increased, but the contents of chlorphyll b on decreasing rate. 5. The nitrogen contents in plant were higher in the afternoon exposure than in the morning, but the contents of chlorophyll were higher at night time exposure than at day time. 6. The highest decreasing of absorption spectra of chlorohpyll in chloroplast had at 10:00-11:00 o'clock on fumigation time and the lowest one had at 22:00-23:00 o'clock.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.483-488
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• 1993

This study was conducted to obtain the basic information for easily judgement to level of salinity stress of the reclaimed land. Rice varieties used were Nakdongbyeo and Chilsungbyeo. In seedling stage, 13 day-old seedlings were subjected to salt solution (0, 30, 60, 90mM) for 8 days. In reproductive stage, 30 day-old seedlings were transplanted 3 hills(3 seedlings /hill) per plastic pot (diameter 28${\times}$depth 30cm). Salinity stress was given by immersing pot in the salt solution(sea water) with 4 concentrations(0, 30, 60, 90mM)for 8 days at booting stage. The stomatal resistance was increased with salinity concentrations. Salinity stress appeared to be more sensitive in seedling stage than in reproductive stage in each concentrations. The photosynthesis was decreased in salinity treatment. Salt-treated periods influenced unfavorably stomatal resistance in each stages. The leaf chlorophyll content was remarkably decreased by increasing salt concentrations. The absorption of Na+ and Cl￣ were increased as salt concentration in the culturing medium became higher, but there was no appearent difference in the absorption of K+, Mg++, and Ca++. The plant height and root length were decreased in salinity treatment. The inhibitory effect of salinity stress on root growth was more severe than in shoot growth. The stomatal resistance could have been used as bio-information.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.534-545
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• 2010

To examine 1) rainfall pattern (i.e., type and intensity) regulating surface erosion on hillslopes in postwildfire area and 2) its effect on variation in sediment yield along the gradient of severity wildfire regimes and elapsed years, we surveyed the amount of sediment yield with respect to daily or net-effective rainfall in 9 plots in eastern coastal region, Republic of Korea. Before field investigation, all plots classified into three groups: low-, mixed- and high-severity wildfire regimes (3 plots in each group). We found that, with decreasing wildfire regimes and increasing elapsed years, the rainfall type regulating surface erosion changed from daily rainfall to net-effective rainfall (considering rainfall continuity) and its intensity increased continuously. In general, wildfires can destroy the stabilized forest floors, and thus rainfall interception by vegetation and litter layer should be reduced. Wildfires can also decrease soil pores in forest floors, and thus infiltration rates of soil are reduced. These two processes lead to frequent occurrence of overland flows required to surface erosion, and sediment yields in post-wildfire areas should increase linearly with increasing rainfall events. With the decreasing severity wildfire regimes and the increasing elapsed years, these processes should be stabilized, and therefore their sediment yields also decreased. Our findings on variations in sediment yields caused by the wildfire regimes and the elapsed years suggest understanding of hydrogeomorphic and ecologic diversities in post-wildfire areas, and these should be carefully examined for both watershed management and disaster prevention.

• Korean Security Journal
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• no.36
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• pp.469-492
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• 2013

While the average age of population increases, so as the number elderly workers employed in the private security in Korea. However, not many studies have examined the issues related to elderly security guards so far, especially regarding the experience of workplace violence victimization even though they are quite vulnerable. The current study surveyed elderly private security guards across the nation in an attempt to ask about their workplace violence victimization experience, including both physical and verbal ones. The researchers investigated if victimization experiences affect the elderly security guards' perception of occupational stress. The result indicated that the respondents experienced verbal violence more than physical violence, and perpetrators were usually customers, not their supervisor or coworkers. In addition, those who experienced verbal violence in the workplace, perceived a higher level of occupational stress. The experience of physical violence did not make a significant impact. Policies are discussed in order to decrease workplace violence towards elderly security guards.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.168-168
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• 2011

최근 한반도는 과거 최대 강우량의 기록을 갱신하는 집중호우가 지속적으로 발생하고 있으며, 2000년대 들어 기상재해에 대한 피해 규모가 수조원에 달한다. 자연재해를 예방하여 피해를 최소화하기 위해서는 미래에 발생 가능성이 있는 재해를 사전에 예측하고, 재난발생 가능성을 감소시키며, 발생한 재난의 피해를 최소화시키기 위한 활동이 필요하다. 따라서 본 연구에서는 2003년도에 발생한 태풍 'Maemi'의 영향으로 부산과 경남지역에 발생 가능한 최대 풍피해의 정도를 예측해보고자 하였다. 이를 위해서 태풍의 중심기압과 태풍의 이동경로와 대상지역의 거리를 이용하여 3-second gust를 산정하였고, 이를 이용하여 시 군 구 단위의 주택에 대한 최대 풍피해 분포 특성을 파악하였다. 태풍 Meami에 의한 부산 경남지방의 3-second gust를 산정한 결과 풍속이 25m/s 이상의 폭풍영역에 해당되는 지역은 김해시, 강서구, 남해군, 고성군, 창원시, 사상구, 북구, 함안군, 통영시, 하동군, 거제시, 사천시이고, 강풍영역에는 대부분의 지역이 포함되었다. 그 중에서 3-second gust가 가장 높았던 지역은 북구와 사상구였고, 다음으로 강서구 창원시 사천시, 함안군 이였으며, 마산시, 김해시, 거제시 그리고 양산시가 다음으로 높게 나타났다. 고성군은 3-second gust가 가장 낮게 나타났다. 부산과 경남지방의 집 한 채 피해액은 북구와 강서구, 사상구가 가장 높게나왔고, 다음으로 사천시와 창원시 순으로 높게 나타났다. 거창군은 부산 경남지방 중에서 가장 낮은 피해액이 나타났다. 이러한 결과에는 그 지역에서 발생 가능한 3-second gust의 영향이 크게 작용한 것으로 판단된다. 본 연구에서는 태풍의 특성 자료를 제외한 자료의 경우 국내 자료의 한계로 인해 국외 자료를 이용하거나, 가정을 통해 계산을 진행하였다. 그러나 향후 보다 정확한 최대 풍피해를 평가하기 위해서는 기초자료의 마련이 반드시 이루어져야한다.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.154-159
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• 2000

This study was carried out to elucidate the symptom of leaf injury to ozone and to determine varietal difference to ozone injury in rice and soybean plant. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. The rice leaves were spotted red and rolling leaf edge, discolored to reddish brown or yellowish white in response to ozone, and the leaves that were severely stressed were withered from the tip of leaf. The soybean ones were also discolored to lemon yellow, yellow or dark brown. The leaf injury in both rice and soybean was clearly appeared at the reverse side of leaf and in lower leaves. Milyang 23 and Nonganbyeo among rice cultivars tested were resistant to ozone, but Chucheongbyeo was resistant to it. The ratio of leaf injury was increased and chlorophyll content was decreased as the extension of ozone exposure from 2 to 8 hours in rice. Keunolkong and Danyeopkong among soybean cultivars tested showed resistant reaction to ozone, but Kwangankong and Muhankong were susceptible to it. It was observed that the soybean plants grown for 45 days after seeding were severely damaged by ozone than those of other growth stages.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.50-50
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• 2017

도시홍수의 잠재적 위험은 홍수경감계획이 발전됨에 따라 감소하지만, 침수피해 가능성은 도시화와 도시 확장에 따라 증가한다. 침수피해 가능성에 대한 사전 파악 및 위험도 분석은 대규모 침수재해 발생 시의 위기관리에도 도움을 준다. 또한, 경제적 피해에 대한 예측은 재해발생 후 복구 및 복원 작업에 필요한 자원 할당에 매우 유용하며, 잠재적 홍수 피해에 대한 예측은 장기적인 홍수경감계획과 재해관리에 필요하다. 본 연구에서는 다차원 침수해석 모형의 결과로 산정 가능한 침수심, 유속 등의 지표들을 복합적으로 고려하여 침수위험도를 산정하고, 침수 발생 위험이 있는 지역의 인문 사회 경제적 지표를 통해 피해 저감 및 복구성을 반영하기 위한 재해 취약인자를 선정하여 해당 지역에 대한 취약도를 산정하였다. 또한, 분석된 위험도와 취약도의 연산으로 통합리스크 분석을 실시하여 침수 발생 시 해당지역에 대한 피해 예상과 지역별 상대평가가 가능하도록 하였다. 위험도와 취약도 및 리스크 분석은 다양한 인자를 동시에 고려하기 위해 여러 개의 기준에 대한 선호도를 결정하거나 최적 대안을 선택하는 다기준의사결정(MCDM)기법을 적용하였으며, MCDM기법 중 보편적으로 많이 이용되는 TOPSIS기법을 적용하였다. 이러한 리스크 분석은 우리나라 전체, 특정 시도, 시군구, 읍면동 간의 침수피해와 관련한 상대적 비교 평가가 가능하며, 대응 및 대비의 관점에서 저감 대책 수립의 우선 지역을 도출하는 데 활용될 수 있을 것이며, 침수피해 발생 후, 리스크가 큰 지역에 대해 우선적으로 복구 조치가 이뤄질 수 있을 것이다. 또한, 한정된 지자체 예산 안에서 도시홍수 피해 경감 대책 수립을 위한 의사결정에 활용될 수 있을 것으로 판단된다.