• 한국공간구조학회논문집
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• 제13권1호
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• pp.69-77
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• 2013

This study is the research appling the representative Displacement-Based Design which is the basic concept of Direct Displacement Based Design proposed by Chopra and Goel to original Reinforced Concrete moment frame and determining the thickness of retrofit Steel Jacket about the Maximum design ground acceleration, and developing the more improved Algorithm as well as program by the Retrofit Design method and Nonlinear analysis by the Performance design method before and after reinforcement appling the determined retrofit thickness. It also shows the result of the seismic performance improvement which is the ratio of seismic performance appreciation result yield displacement 19%, yield strength ratio 24%, displace ductility ratio the maximum 27% comparing Multi degree of freedom, column member of Reinforced Concrete with the performance improvement column member considering the thickness of the determined Steel Jacket. The developed Algorithm and program are easy to apply seismic design and application to the original Reinforced Concrete building, at the same time, it applicate to display well the design result of Target displacement performance level about nonlinear behavior.

• 한국산학기술학회논문지
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• 제12권5호
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• pp.2285-2290
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• 2011

본 논문은 광 통신용 송수신기의 핵심 부품인 DFB 레이저의 SMSR 수율 향상에 관한 연구이다. 광 송수신기는 주로 1310, 1490 및 1550 nm 파장의 DFB 레이저를 사용하고 있는데, 변조된 DFB 레이저의 SMSR 특성에 따라 전송효율이 결정되므로, 변조된 DFB 레이저의 SMSR 특성을 확보하는 것이 매우 중요하다. 하지만, 대량 생산시변조된 상태의 광 송수신기 제품이 SMSR 사양에 만족하기가 어려울 경우, 불량률이 높아지는데, 불량률을 감소시키기 위해 광 송수신기의 광 파워 출력과 소광비를 조정하여 SMSR을 개선할 수 있는 연구를 하였고, 이를 실제 적용하여 SMSR 불량률을 감소시켰다.

• 한국식품영양학회지
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• 제12권5호
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• pp.484-489
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• 1999

Rosting conditions for improvement of viscosity and sensory properties of sea tangle extracts were investigated. The supernatant % solid yield and crude protein yield were increased by increasing of roasting temperature and times. The highest contents of algin was obtained in roasting temperature of 175$^{\circ}C$ ash contents were increased by roasting temperature increasing. Viscosities of sea tangle extract were significantly decreased by increasing of roasting temperature and time upto 175$^{\circ}C$ and 10 mins more than further roasting conditions. The pH of sea tangle extracts slightly decreased from 5.94 to 5.83 in the roasting of 15$0^{\circ}C$ however at temperature more than 175$^{\circ}C$ its pH was increased by increasing of temperature and time. According to increase of roasting temperature and time Lightness (L value) were significantly decreased and redness (a value) and yellowness (b value) reached the highest value in the roasting of 20$0^{\circ}C$ 15 min. or 175$^{\circ}C$ 30 min and after that its value were decreased. The odor characteristics showed that sea tangle extract prepared by roasting of 175$^{\circ}C$ 10mins was slightly reduced in intensity of savory and seaweed taste but significantly low in intensity of nauseous taste and high in intensity of roasted taste and accetability. Overall data suggested 175$^{\circ}C$ 10min was the most effective roasting conditions for improvement of viscosity and sensory properties of sea tangle extract.

• 한국토양비료학회지
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• 제14권3호
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• pp.157-162
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• 1981

농작물(農作物)에 대(對)한 불화수소(弗化水素)가스의 피해(被害)를 경감(輕減)시키기 위(爲)하여 피해경감제(被害輕減制)로서 소석회(消石灰) 규회석(硅灰石), 인산질(燐酸質)을 토양(土壤)에 시용(施用)하여 수도(水稻)를 재배(裁培)하고 $0.1g/m^3$의 불화수소(弗化水素)가스를 1시간(時間)씩 접촉(接觸)한후(后) 수량감소정도(收量減少程度), 피해엽율(被害葉率), 식물체중(植物體中)의 불소함량(弗素含量) 및 규산함량(珪酸含量)을 조사(調査)한 결과(結果)는 다음과 같다. 1. 불화수소(弗化水素)가스 피해경감효과(被害輕減效果)는 소석회(消石灰) 및 규회석(硅灰石)이 가장 좋았다. 2. 불화수소(弗化水素)가스를 접촉(接觸)하지 않은 구(區)에서는 개량제처리간(改良劑處理間)에 수량착이(收量着異)가 없었으나 불화수소(弗化水素)가스를 접촉(接觸)하므로서 개량제간(改良劑間)에 유의성(有意性) 있는 수량 수량착이(收量着異)가 있었다. 3. 식물체내(植物體內) 불소함량(弗素含量)은 감수율(減收率) 및 피해엽율(被害葉率)과 각각(各各) 정(正)의 상관(相關)이 있었다.

• 한국토양비료학회지
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• 제34권2호
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• pp.92-97
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• 2001

염류가 집적된 시설재배지의 강서 미사질 양토에서 1999년부터 2년간 무처리, 심토반전, 심토파쇄, 폭기식 심토파쉐 및 암거배수 등 5개 처리를 하여 토양의 물리적 성질과 작물 생산성을 비교시험하였다. 1. 심토의 물리성 개선효과는 심토반전 > 암거배수 > 심토파쇄 > 무처리 순으로 높았고 2년차까지 잔효가 인정되었으며 토양물리성 개선처리는 통기성을 높이고 근권을 확대시켰다. 2. 심토의 토양수분함량은 심토반전 > 암거배수 > 심토파쇄 > 무처리 순으로 높았으나 큰 차이는 없었다. 또한 토양물리성 개선처리는 무처리구에 비하여 토층내 시기별 토양수분함량 변동폭을 크게 하였다. 3. 토양물리성 개선처리에 의한 토층내 염농도 저하효과는 적었으며 토양물리성 개선구의 수량증대는 염농도 저하나 토층내 양수분 분포개선 보다는 물리성 개선효과가 더 높은 것으로 판단되었다. 4. 토양물리성 개선처리에 의한 평균수량 증대효과는 10~20%정도 이었다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권7호
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• pp.1049-1054
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• 2003

A group of Hanwoo (Korean cattle) steers (n=14,386) was sampled from a commercial abattoir located in Seoul over one year period (spring, summer, autumn and winter) and their carcass traits were collected. Carcass traits assessed by an official meat grader comprised degree of marbling, meat color, fat color, texture and maturity for quality grade, and back fat thickness, ribeye area and carcass weight for yield grade. A heavier carcass with a higher marbling score, more red meat color and white fat color received better quality grade (p<0.05). Regression analysis showed that the marbling score was the strongest attribute (partial $R^2=0.88$) for quality grade. Lighter carcasses with a thinner back fat and larger ribeye area received higher yield grade score. The back fat thickness was the most negative determinant of yield grade (Partial $R^2=-0.66$). The slaughter season had a little effect on quality and yield grades. As slaughter weight increased, back fat thickness and ribeye area increased linearly, whereas marbling score reached its asymptotic level at approximately 570 kg. As a consequence, quality grade showed a considerable improvement up to 570 kg, but increases in slaughter weight afterward showed a little benefit on quality grade. There was a clear curvilinear relationship between slaughter weight and yield grade in that the yield grade reached its highest point at approximately 490 kg and decreased afterward. These results suggested that 570kg at the age of 24 months might be the economic slaughter weight for quality grade but 490 kg for yield grade.

• 한국화재소방학회논문지
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• 제22권3호
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• pp.300-304
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• 2008

고분자 물질의 화재 위험성 및 화재시 인명 피해의 감소를 위한 기초자료로 제시하고자 점토질의 첨가에 의한 난연성 평가를 수행하였다. 본 연구에서는 에폭시 수지의 난연성 향상과 연기의 발생량을 감소시키기 위하여 점토질의 montmorillonite(MMT)와 같은 천연 물질을 삽입하여 연소 특성을 살펴보았다. 이 연구를 위하여 한계산소지수(limiting oxygen index, LOI), 탄화층 생성량(char yield), 연기 밀도(smoke density) 측정 둥의 난연성 실험을 실시하였다. Epoxy/MMT의 복합재료는 MMT의 농도가 증가할수록 한계산소지수 및 탄화층 생성량이 증가하여 난연성이 향상되었으나 연기 밀도는 오히려 증가하는 결과를 나타내었다.

• Asian-Australasian Journal of Animal Sciences
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• 제10권3호
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• pp.265-273
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• 1997

The minimum amounts of leucaena (Leucaena leucocephala) required to improve the performance of cattle on a straw diet has been studied. Four levels of leucaena, namely 0 (0%), 2 kg (10%), 4 kg (18%) and 6 kg (27% of dietary dry matter intake) were supplied to 4 adult indigenous bulls ($355{\pm}21.5kg$ weight) fed rice straw alone, in a $4{\times}4$ latin square design. Measurements were made on intake, digestibility, N balance and microbial N yield. Up to 10% level of leucaena supplementation, there were no significant improvement on intake, digestibility, microbial N yield and N balance. Both straw and total dry matter intake showed diminishing return to increasing levels of leucaena supplementation and the maximum intake was observed at around 20% level. However, dietary N and digestible organic matter intake, the microbial N yield and the N balance increased linearly to the increasing levels of leucaena supplementation. On a rice straw based diet, the minimum level of leucaena required to improve the animal performance would probably be at around 20% of the dietary intake.

• 한국초지조사료학회지
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• 제17권1호
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• pp.75-81
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• 1997

This study was wnducte to investigate the effects of treatment level and seasons of sluny hm bovine feces on the productivity of rye, N efficiency and improvement of soil fertility under the Korean climate condition. The results obtained fiom this study summarized as follows ; 1. The highest dry matter yield of rye was obtained in the partial fertilization of sluny in spring or autumn. There is no differences of dry matter yield between spring and autumn application. 2. With increasing the amount of slurry-N, the dry matter yield of rye was signigicantly increased up to 100Kg sluny Nha. As the level of slurry-N rises above about 100Kg N/ha, the maximal yield of dry matter was unchanged or declined. 3. As the level of sluny fertilization rises, the crude protein content of rye increases significantly. However the contents of crude protein was less affected by the application seasons. 4. The amount of nitrogen which produced 6om rye is dependent upon the level of slurry-N. The highest nitrogen yield of rye was obtained by the partial fertilization of sluny-N. 5. The season or amount of slurry treatments did not affect the organic matter content in soil. N-content in soil was the lowest by the partial fertilization of slurry in spring or autumn. However, N-content was increased with the higher level of sluny-N.

• Asian-Australasian Journal of Animal Sciences
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• 제32권3호
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• pp.334-340
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• 2019

Objective: The objective of this study was to investigate the genetic components of daily milk yield and to re-rank bulls in South Korea by estimated breeding value (EBV) under heat stress using the temperature-humidity index (THI). Methods: This study was conducted using 125,312 monthly test-day records, collected from January 2000 to February 2017 for 19,889 Holstein cows from 647 farms in South Korea. Milk production data were collected from two agencies, the Dairy Cattle Genetic Improvement Center and the Korea Animal Improvement Association, and meteorological data were obtained from 41 regional weather stations using the Automated Surface Observing System (ASOS) installed throughout South Korea. A random regression model using the THI was applied to estimate genetic parameters of heat tolerance based on the test-day records. The model included herd-year-season, calving age, and days-in-milk as fixed effects, as well as heat tolerance as an additive genetic effect, permanent environmental effect, and direct additive and permanent environmental effect. Results: Below the THI threshold (${\leq}72$; no heat stress), the variance in heat tolerance was zero. However, the heat tolerance variance began to increase as THI exceeded the threshold. The covariance between the genetic additive effect and the heat tolerance effect was -0.33. Heritability estimates of milk yield ranged from 0.111 to 0.176 (average: 0.128). Heritability decreased slightly as THI increased, and began to increase at a THI of 79. The predicted bull EBV ranking varied with THI. Conclusion: We conclude that genetic evaluation using the THI function could be useful for selecting bulls for heat tolerance in South Korea.