• Korean journal of applied entomology
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• v.31 no.4
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• pp.379-385
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• 1992

Ginseng damage by the African mole cricket (GTyllotalpa africana Palisot de Beauvois) was investigated in the field and laboratory from 1984 to 1991. Ginseng damage by G. africana occurred mainly in the 2nd year ginseng fields during May and June (spring period), and the damage was not nearly recognized in September and October (fall period) when densities of G. africana adults were higher in the field. In the laboratory and field cage, damage of 2nd year ginseng considerably decreased during fall period, which had no relation to ginseng diameter, and 3rd year ginseng was not damaged at all. Soil hardness seemed to influence on ginseng damage by G. africana adults.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2017.11a
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• pp.247-248
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• 2017

교통사고는 인적피해, 물적피해, 사회적피해와 거시적으로는 심리적 피해까지 일으키며 많은 비용을 발생시킨다. 이처럼 교통사고로 인해 발생하는 다양한 피해요소를 비용으로 환산하여 추정하는 것은 교통안전사업의 절감편익을 산정하거나 기타 교통관련사업의 효과를 적용하기 위하여 활용할 수 있다. 하지만 현재까지 이루어진 사고비용 산출에 대한 연구론은 1당사자와 2당사자 구분없이 사고 전체를 아우르는 피해비용을 산출하는 방식의 접근 방법과, 사상자 1인 기준으로 발생되는 피해비용을 산출하는 방식의 접근 방법으로 나뉘며, 두 접근방법 모두 비용분석의 대상을 단일 객체로 간주하고 분석하는 한계를 지니고 있다. 이에 본 연구에서는 특정한 상호작용효과가 있을 것으로 예상되는 고연령 구간을 확인한 뒤 고연령 구간과 전체 연령 구간 사이에서 발생된 사고를 비교분석하여 1당사자와 2당사자가 모두 고연령 구간일 때 추가로 발생되는 사고비용을 산출 및 검정함으로서 고령자 사고감소효과 및 절감편익에 활용될 수 있는 상호작용 효과에 따른 추가 절감편익을 산출하였다.

• Journal of the Korean Geographical Society
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• v.43 no.6
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• pp.843-857
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• 2008

This study analyzed distribution of natural disaster and trend of related climatic elements in mountainous region of Gangwon-do. In mountainous region of Gangwon-do, there have been 27 natural disasters of which heavy rainfall have the leading cause for the last 5 years(16 times in 2003-2007). It has been 9 natural disasters in Jinbu-myeon Pyeongchang-gun, the most frequent area. The mountainous region has been larger natural damage than its surrounding regions and there has been more damage at higher altitudes. While the heavy rainfall have caused damage over the northwest of mountains, most typhoons have damaged southern part of mountains. Most mountainous region suffers from strong wind but damage by snow is small. In mountainous region of Gangwon-do, annual precipitation, intensity of precipitation and heavy rainfall days have been increasing since 2000 and this tendency is significant in its intensity. However, annual snowfall, snowfall days and heavy snowfall days have been clearly decreasing since 2000. In case heavy rainfall accompanies strong wind, the damages are larger in mountainous region of Gangwon-do. Therefore it is important to be prepared for heavy rainfall and strong wind.

• Journal of Korean Society of Forest Science
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• v.96 no.1
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• pp.115-123
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• 2007

We investigated the effects of postfire logging on bird populations and communities through 57 point counts in unburned, burned and logged burned plots of coniferous forests in Samcheok, Korea. We found that lower species richness, abundance, and diversity in logged plots where were controlled by a typical postfire management. As results of guild analysis for nest sites and food resources, postfire logging reduced densities of ground-shrub nesters, primary and secondary cavity nesters, but was also related to reduction in densities of some foraging groups such as timber drillers and foliage searchers. These results suggest that snag-retention is essential for birds in burned forests and that postfire logging is incompatible with the maintenance of bird populations and communities. Consequently we need to develope guidelines of postfire management for snag-retention in burned forests through intensive researches focused on some target species such as Great spotted woodpeckers Dendrocopos major.

• Korean journal of applied entomology
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• v.46 no.3
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• pp.431-435
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• 2007

Control thresholds for the management of beet army worm, Spodoptera exigua (Lepidoptera : Noctuidae) were evaluated on welsh onion of two different planting time. Two inoculation times were tested for each planting and the number of inoculated larva was 5, 10, 20, 40 per twenty plants. The injured rate of leaves was 33.5% to 10.9% at 7th September at 40 to 5 larva inoculation plot on the five days planting. That of leaves was 20.5% at 40 larva on the twenty days planting. The yields of welsh onion on non-inoculation plot were 4,395 kg per 10a. The rate of reduced yields was 49.2%(1,774.2 kg) and 36.5%(2,220.5 kg) at 40 larva inoculation on the 5 and 20 days planting, respectively. The linear relationships between population density and yield reduction were as following; it was Y=-43.474X + 3419.6 ($R^2\;=\;0.9698$) for 5 days and Y=-32.977X + 3518.9 ($R^2\;=\;0.9928$) for 20 days. Based on these results the control threshold level was estimated to be 1.8 larva for 5 days and 4.6 larva for 20 days per 20 plant. The more damaged leaves by S. exigua larva, the more yield reduction on welsh onion.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.289-293
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• 2011

This study was conducted to develop economic injury level (EIL) of onion thrips, Thrips tabaci, on welsh onion (Allium fistulosum L. var) in the early transplanting stage. The changes of welsh onion biomass, yield loss, and T. tabaci density were investigated according to the inoculation periods of T. tabaci. In the early transplanting stage of welsh onion, the yield loss (%) increased with increasing inoculation periods: 17.0, 53.3, 38.4, and 80.8% yield loss in 5, 10, 15, and 20 d inoculation periods, respectively. The relationship between Cumulative Insect Days (CID) of T. tabaci and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL of T. tabaci on welsh onion was estimated to 30 CID per plant based on the yield loss 12% (an empirical gain threshold 5% + marketable rate 93% of welsh onion). ET was calculated to 24 CID, which corresponds to 80% of EIL. Until a more defined EIL-model is developed, the present results should be useful for T. tabaci management in early growth stage of welsh onion. The effect of T. tabaci attack on the yield of welsh onion in late growing season (120 days after transplanting) was also examined. The yield of welsh onion increased at a low population density of T. tabaci and decreased at higher densities, showing a typical over-compensatory response.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.81-86
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• 2009

Economic injury level and control thresholds for the management of beet army worm, Spodoptera exigua (Lepidoptera: Noctuidae) were evaluated on chinese cabbage of two different planting time. Two inoculation times were tested for each planting and the number of inoculated larva was 10, 20, 40, 80, respectively. Damages of leaves by first inoculation were 63.2% after eight days planting on 80 larva inoculation plot. By the second inoculation, those were below 50% after 20 days planting on the end of September. The linear relationships between population density and yield reduction were as following; Y = -10.62x + 867.9 ($R^2\;=\;0.643$) for 5 days and Y=-6.432x + 1074 ($R^2\;=\;0.720$) for 20 days. Based on these results the economic injury level was 5.4 larva for five days and 9.0 larva for 20 days per 20 chinese cabbage. The control thresholds calculated by 80% level of economic injury level were 4.3 and 7.2 larva, respectively.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.299-306
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• 2005

Soybean seed injury was analyzed in the experiments that soybean pods were allowed to be sucked by adults of the bean bug, R. clavatus, and were picked with a specimen pin. While attack by the bean bug at podding stage of soybean caused the increase of empty pods and completely-undeveloped seeds, attack at full seed stage caused the increase of seeds wi distinct injury mark on seed-coat. The ratio of deformed seed was lower than those of injury-marked seed and undeveloped seed when attacked during all stages. In at full bloom stage hardly produced injury-marked seeds and deformed seeds. When the injured seeds were dyed with acid-fuchsine solution, stylet sheaths of R. clavatus formed on seed-coat were observed in 83% of undeveloped seeds formed under attack during podding stage and in 91% of injury-marked seeds formed during full seed stage. In pods injured with a specimen pin at full seed and full maturity stages, no healthy seeds could be obtained from the pods. And the more picked at full seed stage, the more deformed seeds were produced and the higher weight reduction of injury-marked seed occurred. However, pin-injury at full maturity stage didn't give rise to weight reduction of seeds.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2015.11a
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• pp.287-289
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• 2015

최근 기후변화로 인하여 태풍 및 집중호우로 인한 극한 강우사상의 발생빈도가 증가하고 있으며, 급격한 도시화로 인한 유역 내 불 투수 면적이 늘어나고 있다. 이로 인해 재산피해가 증가하고 있어 기후 변화를 고려한 미래 하천범람 등 홍수피해를 경감시키기 위한 홍수저감 대안 선정이 필요하다. 따라서 본 연구에서는 기후변화를 고려하여 목표기간별로(기준년도 : 1971~2010년, 목표기간 I : 2011~2040년, 목표기간 II : 2041~2070년, 목표기간 III : 2071~2100년) HEC-HMS모형을 이용하여 기후변화에 따른 홍수량을 산정하였다. 또한, 배수펌프(A~E)와 저류지(A~E)를 홍수저감 대안으로 설정하여 HEC-RAS모형을 통해 대안별 홍수위를 산정하였다. 지형자료 및 홍수위를 이용하여 홍수범람도를 도시하였으며, 다차원 홍수피해액산정법(Multi dimension - Flood Damage Analysis, MD-FDA)을 이용하여 홍수피해 저감을 위한 대안별 경제성분석을 실시하였다. 홍수저감효과를 분석한 결과 배수펌프를 설치했을 경우 홍수위는 최소0.06m, 최대0.44m 감소하였고, 저류지는 최소0.01m, 최대1.86m 감소하였으며, 침수면적은 최소 0.3%, 최대 32.64% 감소되는 것을 확인할 수 있었다. 또한, 경제성분석을 실시하여 대안별 편익 비용비를 비교한 결과 목표기간I에서는 저류지 E, 목표기간II, 목표기간III에서는 배수펌프D가 기후변화를 적응을 위해 타당한 홍수저감 대안으로 판단되었다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 1998.10a
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• pp.195-196
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• 1998

MTBE는 미국에서 1970년대부터 휘발유의 옥탄가를 높이고 배기가스중 NOx, VOC, 일산화탄소의 방출을 감소시키기 위해 휘발유에 첨가되어 사용하기 시작하였다. 그 동안 MTBE의 사용은 자동차 배기가스에 의한 오존의 발생을 감소시키는 등 대도시내 대기오염감소에 많은 공헌을 한 것으로 알려져 왔다. 그러나 최근 미국등에서 이 물질의 사용으로 인한 인체가 입는 건강피해에 대한 우려가 조심스럽게 제기되고 있다. 우리나라에서도 시중휘발유에 많은 경우 부피비로 15 % 가량 MTBE가 첨가하여 사용하는 것으로 알려져 있다. 따라서 이 물질의 사용시 도시주민피해가 염려되는 대도시 지역에 대해서는 MTBE에 의한 대기오염감소에 의한 이점 등을 종합적으로 고려하는 종합적인 평가가 필요하다고 본다.