• 한국토양비료학회지
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• 제1권1호
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• pp.61-71
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• 1968

1. 추낙답토양(秋落畓土壤)에 생육(生育)한 수도(水稻)는 엽(葉)이 아래로 늘어지나 규산물질(珪酸物質)(규산가리(珪酸加里), 규산질비료(珪酸質肥料) 및 규회석(珪灰石))의 시용(施用)으로 수도(水稻)의 엽(葉)은 현저해 직립(直立)되었다. 2. 정조중(精租重)은 규산물질(珪酸物質)의 시용(施用)으로 증가(增加)하며 규회석(珪灰石)의 비효는 규산질비료(珪酸質肥料)보다 못하지 않았다. 3. 규회석(珪灰石)의 비효는 기비(基肥)로 시용(施用)하는 것이 좋으며 질소(窒素)의 증시효과는 규회석(珪灰石)의 증시(增施)에 의(依)하여 현저하다. 4. 수도(水稻)의 규산함량(珪酸含量)은 규산물질(珪酸物質)의 시용(施用)으로 증가(增加)하며 규산물질중(珪酸物質中)에서도 규회석(珪灰石)의 시용(施用)이 수도(水稻)의 규산함량(珪酸含量)을 가장 많이 증가(增加)시켰다. 수도(水稻)의 규산함량(珪酸含量)은 규회석(珪灰石)을 기비(基肥)로 시용(施用)하는 것이 증가(增加)하며 또 규회석(珪灰石)의 시용량(施用量)의 증가(增加)에 따라 증가(增加)하였다. 한편 수도(水稻)의 철(鐵) 및 질소함량(窒素含量)은 규산물질(珪酸物質)의 시용(施用)으로 감소(減少)되었다. 5. 규산물질(珪酸物質)의 시용(施用)은 엽도열병(葉稻熱病), 수수도열병(穗首稻熱病) 및 호마엽고병(胡麻葉枯病)의 발병(發病)을 저하(低下)시키며 규산물질중(珪酸物質中)에서도 규회석(珪灰石)의 효과가 가장 좋았다. 6. 엽도열병(葉稻熱病)의 이병율(罹病率)은 질소(窒素)의 증시(增施)에 비례(比例)하여 증가(增加)하나 규회석(珪灰石)의 시용(施用)으로 현저히 경감(輕減)되며 이 현상(現象)은 만식재배시(晩植栽培時)에 더 현저하다. 7. 호마엽고병(胡麻葉枯病)의 이병율(罹病率)도 규회석(珪灰石)의 시용량(施用量)이 증가(增加)함에 따라 현저히 경감(輕減)하였다.

• 한국응용곤충학회지
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• 제45권3호
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• pp.333-337
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• 2006

담배거세미나방에(Spodoptera litura)에 의한 콩의 피해해석을 하고자 콩 생육기 및 담배거세미나방 유충 밀도를 달리하여 조사한 결과 콩 생육시기별 유충 밀도에 따른 수량감소율과의 관계식은 개화기에는 (1) Y = 1.655X - 6.025 ($R^{2}=0.952$), 착협기에는 (2) Y = 0.725X - 0.475 ($R^{2}=0.986$), 립비대기에는 (3) Y = 0.635X - 1.325 ($R^{2}=0.986$)였다. 이 관계식을 근거로 하여 콩 생육시기별 피해허용수준(수량감소 5% 기준)을 산출한 결과, 주당 2-3령 유충의 밀도는 개화기6.7 마리, 착협기 7.5마리, 립비대기는 10.0마리였다. $28^{\circ}C$에서 1령, 2령, 3령, 4령, 5령 및 6령 유충의 1일 섭식량은 0.3, 0.7, 2.6, 4.0, 20.1 및 $55.8\;cm^{2}$ 이었다.

• 한국응용곤충학회지
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• 제60권3호
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• pp.305-312
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• 2021

2019~2020년 동안 강원도 강릉지역의 아마란스 포장에서 진딧물류 3종(잠두진딧물, 목화진딧물, 복숭아혹진딧물), 노린재류 12종(애긴노린재, 각시장님노린재, 풀밭장님노린재 등), 나방류 4종(흰띠명나방, 파밤나방, 담배거세미나방, 도둑나방) 등 총 7과 18종의 해충을 확인하였다. 이 가운데 발생량이 많아 경제적으로 큰 피해를 주는 종류는 잠두진딧물, 애긴노린재, 각시장님노린재, 파밤나방, 흰띠명나방 등 5종이었다. 진딧물류는 4월 하순부터 발생하기 시작하여 6월 초순에 최대 발생을 보였다. 애긴노린재는 5월 중순부터 발생하여 8월 하순에 최대 발생량을 보이다가 9월 초순부터 밀도가 감소하였고, 각시장님노린재는 9월 중순부터 밀도가 급격히 늘어나서 10월 하순까지 지속적으로 발생하는 경향을 보였다. 흰띠명나방과 파밤나방은 8월 중순부터 유충 발생이 시작되어 10월 중순까지 아마란스에 피해를 주었다. 각각의 해충에 대한 방제구와 무방제구의 수량을 비교한 결과, 진딧물류와 노린재류에 의한 종실 수량 감소율은 각각 51.9%, 69.8%였다. 또한 흰띠명나방과 파밤나방에 의한 잎 생체량 감소율은 각각 72.5%, 36.5%였다.

• Journal of Photoscience
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• 제9권2호
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• pp.162-165
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• 2002

Rice is widely cultivated in various regions throughout Asia. Over a five-year period, we investigated the effects of supplemental UVB radiation on the growth and yield of Japanese rice cultivars in the field. The findings of that study indicated that supplemental UVB radiation has inhibitory effects on the growth and grain development. Furthermore, we investigated the sensitivity to UVB radiation of rice cultivars of 5 Asian rice ecotypes, and found that rice cultivars vary widely in UVB sensitivity. The aim of our study is improving UVB resistance in plants by bioengineering or breeding programs. In order to make it, there is need to find the molecular origin of the sensitivity to UVB. Cyclobutane pyrimidine dimer (CPD) is major UV-induced DNA lesions. Plants possess two mechanisms to cope with such DNA damage. The first is the accumulation of UV-absorbing compounds. Our previous data showed that the steady-state CPD levels in leaves of rice grown under chronic radiation in any culture were not so greatly influenced by the increased UV-absorbing compounds content, although there was a significant positive correlation between the CPD levels induced by challenge UVB exposure and the UV-absorbing compounds content. The other is the repair of DNA damage. Photorepair is the major pathway in plants for repairing CPD. We found that the sensitivity to UVB could seriously correlate with the low ability in CPD photorepair in rice plants. These results suggest that photo lyase might be an excellent candidate for restoration by way of selective breeding or engineering in rice.

• 한국강구조학회 논문집
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• 제9권2호통권31호
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• pp.159-169
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• 1997

최근 중화물 차량의 적재율 증가와 교통량의 증가 등으로 인해 강도로교에서는 반복하중에 의한 피로손상이 많이 발생하고 있으며 이러한 손상은 교량의 안전성에 심각한 영향을 미치고 있다. 따라서 사용기간 동안에 발생하는 피로손상을 합리적으로 반영할 수 있는 피로설계하중을 결정하는 것은 매우 중요하다. 본 연구에서는 먼저 미국 AASHTO의 LRFD 피로설계방법을 고찰하였으며 그 결과 교폭에 관계없이 1대의 피로설계트럭을 재하하여 설계하는 것은 일정한 안전수준을 확보하지 못하는 것으로 분석되었다. 따라서, 교폭에 따라 설계하중 재하방법을 다르게 하는 것이 보다 일관성 있는 안전수준을 가지는 것으로 나타났으며 본 연구에서는 다양한 교량구조형식과 통행특성에 따라 발생하는 피로손상을 합리적으로 반영할 수 있는 피로설계하중의 재하방법과 수준 및 형식을 제시하였다.

• Earthquakes and Structures
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• 제12권6호
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• pp.699-712
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• 2017

This study evaluates the effectiveness of a newly developed retrofitting scheme for masonry-infilled non-ductile RC frames experimentally and by numerical simulation. The technique focuses on modifying the load path and yield mechanism of the infilled frame to enhance the ductility. A vertical gap between the column and the infill panel was strategically introduced so that no shear force is directly transferred to the column. Steel brackets and small vertical steel members were then provided to transfer the interactive forces between the RC frame and the masonry panel. Wire meshes and high-strength mortar were provided in areas with high stress concentration and in the panel to further reduce damage. Cyclic load tests on a large-scale specimen of a single-bay, single-story, masonry-infilled RC frame were carried out. Based on those tests, the retrofitting scheme provided significant improvement, especially in terms of ductility enhancement. All retrofitted specimens clearly exhibited much better performances than those stipulated in building standards for masonry-infilled structures. A macro-scale computer model based on a diagonal-strut concept was also developed for predicting the global behavior of the retrofitted masonry-infilled frames. This proposed model was effectively used to evaluate the global responses of the test specimens with acceptable accuracy, especially in terms of strength, stiffness and damage condition.

• Smart Structures and Systems
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• 제4권1호
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• pp.47-66
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• 2008

The present work utilizes system identification technique for health monitoring of shear building, wherein Parametric State Space modeling has been adopted. The method requires input excitation to the structure and also output acceleration responses of both undamaged and damaged structure obtained from numerically simulated model. Modal parameters like eigen frequencies and eigen vectors have been extracted from the State Space model after introducing appropriate transformation. Least square technique has been utilized for the evaluation of the stiffness matrix after having obtained the modal matrix for the entire structure. Highly accurate values of stiffness of the structure could be evaluated corresponding to both the undamaged as well as damaged state of a structure, while considering noise in the simulated output response analogous to real time scenario. The damaged floor could also be located very conveniently and accurately by this adopted strategy. This method of damage detection can be applied in case of output acceleration responses recorded by sensors from the actual structure. Further, in case of even limited availability of sensors along the height of a multi-storeyed building, the methodology could yield very accurate information related to structural stiffness.

• 한국농공학회논문집
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• 제54권2호
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• pp.87-94
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• 2012

This study is to evaluate flood inundation and to recommend measures of damage reduction on sediment by concentrated torrential rainfall at Gonjiamcheon Watershed (183.4 $km^2$). Firstly, the SWAT (Soil and Water Assessment Tool) was simulated streamflow and sediment at upstream. Then, we produced a map of floodplain boundary by using HEC-RAS (Hydrologic Engineering Centers River Analysis System) at downstream. The SWAT model was calibrated with 2 years (2008~2009) daily streamflow and validated for another years (2010~2011. 7. 31). The SWAT model was simulated with 3 years (2008~2010) by monthly water quality (Sediment) at Gonjiamcheon water quality station. The streamflow and sediment from SWAT model were input as boundary conditions to HEC-RAS. The results of HEC-RAS indicated that mapping of floodplain boundary was Jiwol and Jiwol 2 district. Additionally, inundation area and depth were assessed and applied BMPs scenario for managing the sediment yield.

• Wind and Structures
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• 제7권3호
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• pp.145-158
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• 2004

The evaluation of the accumulation of permanent set for inelastic structures due to wind action is important in establishing a criterion to select a reduced design wind load and in incorporating the beneficial ductile behaviour in wind engineering. A parametric study of the accumulation of the permanent set as well as the ductility demand for bilinear single-degree-of-freedom (SDOF) systems is presented in the present study. The dynamic analysis of the inelastic SDOF system is carried out using the method of Newmark for artificially generated time history of wind speed. Simulation results indicate that the mean of the normalized damage rate is highly dependent on the natural frequency of vibration. This mean value is relatively insensitive to the damping ratio if the damping ratio is larger than 5%. The scatter associated with the accumulation of the permanent set is very significant. The consideration of the postyield stiffness can significantly reduce the accumulation of the permanent set if the ratio of the yield strength to the expected peak response is small. The results also show that the ductility demand due to the wind action over a period of one hour for flexible structures can be much less than that for rigid structures or structures with larger damping ratio if the SDOF systems are designed with a reduced peak response caused by the fluctuating wind.

• Natural Product Sciences
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• 제9권2호
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• pp.83-86
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• 2003

In the present study, Thespesia populnea (Malvaceae) bark was extracted with methanol and water. The extracts were vacuum dried to yield the respective methanol (MET) and aqueous extract (AET). The extracts were evaluated for hepatoprotective activity against carbon tetrachloride $(CCl_{4})$ induced liver damage at 2 dose levels (250 and 500 mg/kg). The biochemical parameters observed in serum were total bilirubin, alkaline phosphatase (ALP), serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT) levels and total protein. Aspartate transaminase (AST), alanine transaminase (ALT) and total protein levels in liver were also evaluated. Histopathological study on the liver tissue was also performed. The extracts exhibited dose dependent reduction in total bilirubin, ALP SGOT, SGPT, AST, ALT and increase in total protein (serum and liver) levels. The extracts also exhibited only mild hepatocytic damage compared to the $CCl_{4}$ Treated group. MET was found to exhibit higher hepatoprotection than AET.