• KAPE Magazine
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• s.190
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• pp.6-9
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• 2012

$\blacktriangleright$ 돼지도체 등급판정두수 중 박피도체가 차지하는 비율은 매년 감소하여 '12년 4월말 기준 3.9%임. - 박피 작업장수 및 도매시장 상장두수 감소 $\blacktriangleright$ 돼지도체 등급판정두수 중 상장두수는 매년 감소하여 '12년 4월 현재 9.1%임. - 돼지도체 유통물량 중 9.1%가 전체 돼지도체 거래가격이 결정되는 구조 $\blacktriangleright$ 도매시장 상장두수 중 박피는 '00년 70.0%(2,136천 두)에서 '10년 40.4% (652천 두)로 29.6%P(1,484)가 감소하였으며, '12년 4월 현재 29.8%임. - 탕박 상장두수는 1,200천두 이상까지 증가한 적도 있지만 '10년까지 900천두 이상 수준을 유지하였음 $\blacktriangleright$ 도매시장 상장물량과 일반작업장 물량의 등급별 출현율 비교시 일반작업장물량의 상위등급 출현율이 높음. $\blacktriangleright$ 돼지도체 kg당 경락가격이 3,000원대 이상이 형성된 '04년 이후 박피 탕박간 경락가격 차이는 269~341원/kg로 분석되었음. $\blacktriangleright$ 박피 작업두수(비율) 및 상장 경매물량 감소에 따른 박피 상장 경매물량 변화에 따라 가격 민감성이 커짐. - 탕박은 박피보다 상장물량이 2배 이상이고 상장물량 변화에 따른 가격 민감성이 작아 박피와 탕박의 경락가격의 변동(상승 하락)폭의 차이가 발생하여 박피와 탕박간의 가격 역전현상이 발생.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.883-887
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• 2004

현재 전국적으로 $\blacktriangle$ 전기, 가스, 상수도, 하수도, 열수송관 등을 공동 수용하는 '지하공동구'가 14개 도시 30개소에 160.4km $\blacktriangle$ 보행공간으로 병용되는 '지하도로'가 23개도시 118개소에 63만 $m^2$ $\blacktriangle$ 지하도로내 설치된 지하점포가 1만1천798개소 23만$m^2$이 있다. 이와 같이 현대 도시내에서 지상공간의 과밀도 개발로 인하여 지하공간의 수요가 증대되어 지하공간 구조물이 많이 설치되고 있는 반면, 지하상가, 지하천 등과 같은 지하공간 시설에서 발생할 수 있는 침수피해 대책이 미흡한 실정이다. 본 연구에서는 과거 지하공간의 침수피해 실태를 조사하고 그 사례에서 원인을 분석하여 기술적 해결책을 도출해 내며, 침수방지를 위한 대책으로 국내에서 사용하고 있는 기숙이나 국외(미국, 일본)의 침수방지 기술 및 대책, 침수시 가이드라인 등을 조사하였다. 또한 지하공간이 침수되었을 때 일어날 수 있는 위험성에 대하여 이론적인, 기술적인 조건에 대하여 조사하였다. 이를 토대로 지하공간의 유형 즉, 지하주택, 지하상가, 지하공공시설(지하차도, 지하철, 전철, 지하변전소)에 대한 구체적인 침수방지 기숙에 대한 기준을 제시함으로써 궁극적으로는 지방자치단체, 관련기관, 연구기관에서 지하공간 침수방지대책에 대한 기초자료로 활용할 수 있을 것으로 판단된다.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.911-916
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• 2010

Rice paddy fields and crop residue burning are a major source of methane ($CH_4$) emissions, a potent greenhouse in agriculture. This study was conducted to assess $CH_4$ emissions in Korea cropland sector from 1990 to 2008. Greenhouse gas emissions from the cropland sector are calculated in two categories: 4C (Rice cultivation) and 4F (Field burning). In 4C: Rice Cultivation, methane emissions from paddy fields (continuously flooded and intermittently flooded) cultivated for rice production had decreased from 395 $CH_4$ $10^3$ Mg in 1990 to 297 $CH_4$ $10^3$ Mg in 2008. $CH_4$ emissions converted into $CO_2$ equivalent were 8,303 $CO_2$-eq. $10^3$ Mg in 1990 and 6,229 $CO_2$-eq. $10^3$ Mg in 2008. Greenhouse gas emissions from paddy field in Korea showed that it was gradually going down as the cultivation area decreased. In 4F: Field Burning, methane emissions by burning crop residue increased from 2,502 $CH_4$ Mg in 1990 to 2,726 $CH_4$ Mg in 2008. Emissions converted $CH_4$ into $CO_2$ equivalent were 53 $CO_2$-eq. $10^3$ Mg in 1990 and 57 $CO_2$-eq. $10^3$ Mg in 2008. Total emissions of $CH_4$ from the cropland sector declined from 8,356 $CO_2$-eq. $10^3$ Mg in 1990 to 6,287 $CO_2$-eq. $10^3$ Mg in 2008.

• Journal of Bio-Environment Control
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• v.15 no.3
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• pp.270-276
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• 2006

This experiment was conducted to selecting of oriental melon cultivars suitable for second cropping at summer season. At 20 days after transplanting, 'Supergumssaragi' and 'Gumhwangeunchun' were rapidly growing. Chlorophyll contents of 'Gumgigaeeunchun', 'Gumnodazieunchun', 'Gonggongcheelkkul' and 'Gumboddari' were higher than other cultivars. Days required from transplanting to harvesting of 'Gumboddari', 'Gumdongieunchun', 'Gonggongcheelkkul' and 'Gumgaeeunchun', 'Gumbora' and 'Supergumssaragi', 'Gumssaragieunchun', 'Gumnodazieunchun', 'Gummieunchun' and 'Gumhwangeunchun', 'Diamond' were 51, 52, 53, 55, 56 and 60 days, respectively. The fruit weigh tended to heavy in 'Supergumssaragi' and 'Gumgigaeeunchun'. The flesh thickness was thick a little in 'Gumgigaeeunchun'. The hardness tended to high in 'Gumgigaeeunchun', 'Gumnodazieunchun' and 'Gumgaeeunchun', but it was not difference between treatments. 'L', 'a', 'b' and Y.I. value of the fruit were not difference between the cultivars, but 'a' value was the highest at 'Gumgigaeeunchun', The yield per ha of 'Gumgaeeunchun' and 'Gumgigaeeunchun' increased 8%, 2% than 'Gumssaragieunchun', respectively. From above result, 'Gumgigaeeunchun', 'Gumdongieunchun', 'Gumnodazieunchun' and 'Gumgaeeunchun' cultivars are suitable in summer season.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.163-172
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• 2007

In this study, fish fauna and stream characteristics were surveyed during October-November 2003 in 31 small streams, which are small sub-tributaries of Geum River. The small streams were classified into 4 types of steep mountainous (SM), mountainous-flatland (MF), flat land (FL), and agricultural watercourse (AW) streams, and their types were categorized by features of stream width, water depth, bottom substrate, riparian vegetation, and landuse patterns. The fishes collected during this survey were identified 4 families and 8 species. Dominant family was Cyprinidae, and the most dominant species was Rhynchocypris oxycephalus with 73% (419 individuals) of the total. Only one species of R. oxycephalus was observed in the all five steep mountainous streams, which was surrounded by 100% forest area and had no point-and non-point pollution sources. The observed frequency of R. oxycephalus (as a relative proportion of species) showed a significant positive correlation (r=0.754, p<0.001, n=31) with the substrate composition of bedrock and boulder, indicating that the species prefer the bedrock and boulder rather than the sand or small pebble. Evidently, all five steep mountainous streams were judged as excellent condition (1st rank) according to the criteria of biological water quality, the Ministry of Environment, Korea. This result was accord with a general tendency of the species in most upper stream of the Koreas streams. One family and one species were found at the steep mountainous types and 4 families 6 species were at the mountainous-flatland. Four families 8 species were found at the flat land, which showed most diverse habitat, and 2 families 2 species were collected agricultural watercourse. These study results of 1st-order streams suggest that R. oxycephalus was considered as one of 1st rank ecological indicator species, and that the dominant area should be protected from various pollutions and disturbances.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.492-492
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• 2018

'물발자국(Water Footprint)' 개념은 가상수의 개념이 확장된 것으로 제품 생산과 서비스 전 과정에서 사용된 물의 양을 나타낸다. 따라서 한 국가내의 수자원 총량의 산출 시에 국제 무역을 통해 수출-수입되는 가상수의 양까지 고려하여 국가 물 총합(Water Budget)을 계산한다. 본 연구는 가상수의 수자원 활용에 관한 산업적 차원의 비교를 위하여 산업별 물발자국 산정모델을 구축하고자 하였다. 산업별 물발자국을 산정하기 위하여 첫째, 산업별 용수사용량에 기초하여 물발자국을 산정하였고, 둘째, 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 먼저 산업별 용수사용량에 기초한 물발자국 산정은 하향식 접근법을 적용하였다. 국가 산업별 물발자국을 산정한 결과, 산업 전체 물발자국은 약 330억$m^3$이며 그 중 농업계가 연간 118.8억$m^3$으로 전체 물발자국의 36%를 차지하였다. 그 다음은 생활계로 전체의 34%인 111억 4천만$m^3$이다. 축산계의 물 사용량은 연간 2억 6천 7백만$m^3$ 정도이지만, 오염물질을 정화하는데 필요한 물인 회색수의 양이 많아 물발자국이 73억 $m^3$으로 비교적 높게 산정되었다. 공업계의 가상수량은 연간 26억$m^3$으로 타 산업에 비하여 오염부하량이 높지 않아 회색수량이 작게 나타났다. 다음으로 단위 물발자국에 기초하여 산업별 물발자국을 산정하였다. 단위 물발자국과 생산량을 활용하여 산정하는 상향식 접근법을 활용하였다. 1980년대부터 2014년까지 쌀 외 18개 품목에 대한 농산물 생산의 물발자국을 산정한 결과, 전체 물발자국은 평균 90억$m^3$으로 추정되었다. 한편, 2차 산업의 물발자국은 산업연관분석을 활용하여 산정하였다. 산업연관분석을 위하여 한국은행의 산업연관표와 경제총조사의 용수비 항목을 활용하였다. 2차 산업의 총 물발자국을 산정한 결과, 60억 $m^3$으로 추정되었다. 3차 산업의 물발자국도 이와 동일한 방식으로 산업연관표를 활용하여 산정하였다. 산업연관분석을 활용한 3차 산업의 물발자국 산정한 결과, 숙박 및 음식점업에서의 물발자국이 가장 큰 것으로 산정되었다. 이에 따라 Case Study로서 국내 워터파크 대상으로 물발자국을 산정하였다. 자료가 없는 부분을 제외하고 연간 총 840만 $m^3$의 물발자국을 가지는 것으로 나타났으며, 이 중 직접수는 70만 $m^3$, 간접수는 770만 $m^3$으로 간접수의 비율이 92%를 차지하였다.

• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.179-189
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• 2008

Standard length (SL) and gonadosomatic index (GSI) of Plecoglossus altivelis were investigated from March to October 2007 in Seomjin River and streams flowing to the East Sea, Korea. Water temperatures were $17{\sim}23^{\circ}C$ during the spawning season, which ran from late September to early November in Seomjin River and early August to mid-October in streams flowing to the East Sea. The GSI and HSI variations of ayu population in Seomjin River increased earlier than in populations in streams flowing to the East Sea with similar variation in water temperature. Histological study of ovaries showed that the start of spawning of P. altivelis in Seomjin River was later than in streams flowing to the East Sea. Overall, fecundity increased with increase in SL and not by site specificity. The SL of P. altivelis increased as the river scale increased. Mean length of specimens from Seomjin River (river length: 223.86 km, river area: $4,911.89km^2$) was $194{\pm}15.3mm$, from Osip Stream (55.76 km, $393.78km^2$) $185{\pm}15.5mm$, from Yangyang Namdae Stream (54 km, $474.08km^2$) $142{\pm}11.8mm$, and from Joosoo Stream (21.1 km, $141.47km^2$) $136{\pm}16.7 mm$.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.77-96
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• 2018

We investigated and analyzed three Korean island sites (Bijin-do, Ae-do, and Bogil-do) and one Japanese site (Tachibanayama) of sword-leaf litsea (Actinodaphne lancifolia) forests, known as the climax forest, to discuss the vegetation succession sere of warm-temperature evergreen broad-leaved forests. We then reviewed the literature in Korea, Japan, China, and Taiwan to consider the distribution characteristics of evergreen broad-leaved forests, vegetation succession sere, and climax tree species. Although Mt. Tachibana and Ae-do showed the most advanced vegetation structure, the soil and ordination (CCA) analysis indicated that it was not enough to consider that the sword-leaf litsea forest was at the climax stage in the warm-temperature region. The Actinodaphne lancifolia forest is sparsely distributed in Korea and Japan while the common types of vegetation in the warm temperate zone region in East Asia are Machilus spp., Castanopsis spp., and Cyclobalanopsis spp. The vegetation succession sere of the Korean warm-temperature region is thought to have a secondary succession such as Pinus thunbergii, P. densiflora, Q. serrata (early stage) through Machilus thunbergii, innamomum yabunikkei, Neolitsea sericea, Actinodaphne lancifolia (middle stage) to Castanopsis sieboldii, Q. acuta, Q. salicina (climax stage). However, Machilus thunbergii will be the climax species as an edaphic climax in places where there is a strong influence of the sea wind, or it is difficult to supply the seeds of Castanopsis spp. and Cyclobalanopsis spp.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.1
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• pp.152-159
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• 2010

High power density and power conversion efficiency have been required in the power converters according to the rapid growth of industry. In this context, the next generation High Speed Train(HST) requires power converter which has high-efficiency, high-performance and high-density. In this paper, the new control technique for battery charger used for the next generation HST is proposed. The phase shift ZVZCS converter is classified according to a resonant circuit which is located in the primary or secondary side. In this paper, The PWM switching technique using all-pass filter is proposed to control ZVZCS converter which has resonant circuit in the secondary side. ATmega_128 micro controller based in all-pass filter in substitute for phase shift IC is presented to have digital control. To verify the proposed topology, the simulation and experiment are performed by using PSIM software and 1[kW] experimental set-up.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.325-331
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• 2020

Macromia daimoji nymphs (Endangered Species II) are known to inhabit the Naeseong Stream in Korea. In March 2019, we performed a correlation analysis between sediment particle size and the M. daimoji population using data collected from a 0.2-㎡ area at 37 sites in Naeseong riverbed. Particle size analysis showed different ratios of sediments in the riverbed: Coarse Sand (500-1,000 ㎛) 52.5%; Very Coarse Sand (1,000-2,000 ㎛) 25.6%; Medium Sand (250-500 ㎛) 17.2%; Fine Sand (125-250 ㎛) 3.1%; Very Fine Sand (63-125 ㎛) 1.0%; and Silt (less than 63 ㎛) 0.7%. The number of M. daimoji nymphs showed a positive correlation with Very Fine Sand and Fine Sand and a negative correlation with Coarse Sand, indicating that M. daimoji nymphs inhabit fine sand. These results can be used to monitor changes in the riverbed environment of Naeseong Stream to ensure the conservation of M. daimoji habitat.