• 수산해양교육연구
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• 제17권3호
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• pp.340-360
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• 2005

Fishery resource rents(i.e. windfall gains or excess profit), which tend to lead a variety of important economic, social, political problems, have been a fundamental cause of unbalance between fishery resource use and management. Thus, there may exist several sorts of optimal level of resource utilization such as economic maximum sustainable yield, biological maximum sustainable yield, social optimum production, socio-political optimum yield, etc. The fishery resource use level seems to a large extent to be determined by the characteristics of fishermen's rent seeking structure. As well known, fishery resources as common properties have a characteristic of being difficult to establish private property rights. Therefore, their use rights are controlled by the permit and/or the license system. As a result, absolute or differential rents are formed by the changes in institutional arrangements. Rent problems are often transformed into serious socio-political issues when the rent in a given industry is much higher to a socially unacceptable extent than the average of other industries. However, individual fishermen or fishermen's groups tend to behave aggressively to change the existing fishery institutions towards maximizing fishery rents. These rent-seeking behaviors often tend to nullify fishery management schemes. The larger is the relative rent difference between fisheries and other industries, the more aggressive tend to be the rent-seeking behaviors in fisheries.

• 한국초지조사료학회지
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• 제8권2호
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• pp.110-116
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• 1988

1. 분얼수는 3차 예취기에서가장 많았으며, 이시기까지 계속 증가를 하였지만 가을 예취기에서 급격히 감소했다. 엽면적 지수는 3차 예취기에서 가장 높았으며, 보통 예취직후 서서히 증가를 하다가 15~20일부터 빠르게 증가하였다. 2. 各 예취기 건물수량은 1次와 3次 ~예취가 다른 時期에 比하여 높게 나타났으며, 예취기별 건물중 變化는 葉面積 指數의 變化와 비슷한 樣相을 보이고 있었다. 3. LER은 예취후 20-30일l, SLW는 25-30日, CGR은 25~25日 사이에 最大速度에 도달했다. CGR은 1次 빛 3次 예취기에서 비교적 높았다. NAR은 約 20일 정도에 최대에 도달했는데, 棄乾物 重에는 NAR보다 다른 生長指標들이 더욱 크게 作用함을 알 수 있었다. 4. 乾物收量과 가장 높은 相關은 LAI와 CGR 으로서 각각 0.905와 0.962를 보여 고도의 正의 相關을 나타내였고 LER과 LAI 間에도 正의 相關인정되었다. 收量의 추정에 최적식은 LAI와 CGR을 변수로 사용하여 얻어 졌다. 5. LAI와 CGR 및 收量과의 관계로서 결정한 예취의 適期는 各 예취기별로 다르게 나타났으나 32일에서 36일 사이에 존재하였다.

• 한국초지조사료학회지
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• 제8권3호
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• pp.110-116
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• 1988

1. 분얼수는 3차 예취기에서가장 많았으며, 이시기까지 계속 증가를 하였지만 가을 예취기에서 급격히 감소했다. 엽면적 지수는 3차 예취기에서 가장 높았으며, 보통 예취직후 서서히 증가를 하다가 15~20일부터 빠르게 증가하였다. 2. 各 예취기 건물수량은 1次와 3次 ~예취가 다른 時期에 比하여 높게 나타났으며, 예취기별 건물중 變化는 葉面積 指數의 變化와 비슷한 樣相을 보이고 있었다. 3. LER은 예취후 20-30일l, SLW는 25-30日, CGR은 25~25日 사이에 最大速度에 도달했다. CGR은 1次 빛 3次 예취기에서 비교적 높았다. NAR은 約 20일 정도에 최대에 도달했는데, 棄乾物 重에는 NAR보다 다른 生長指標들이 더욱 크게 作用함을 알 수 있었다. 4. 乾物收量과 가장 높은 相關은 LAI와 CGR 으로서 각각 0.905와 0.962를 보여 고도의 正의 相關을 나타내였고 LER과 LAI 間에도 正의 相關인정되었다. 收量의 추정에 최적식은 LAI와 CGR을 변수로 사용하여 얻어 졌다. 5. LAI와 CGR 및 收量과의 관계로서 결정한 예취의 適期는 各 예취기별로 다르게 나타났으나 32일에서 36일 사이에 존재하였다.

• 신재생에너지
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• 제7권4호
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• pp.3-9
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• 2011

Optimization of initial total sugar concentration of sweet sorghum juice, aeration time and aeration rate on ethanol production was performed by response surface methodology (RSM). The optimum conditions for ethanol production from concentrated sweet sorghum juice were determined as follows: initial total sugar concentration, 21.2 Brix; aeration time, 7.66h; aeration rate, 1.22 vvm. At the optimum conditions, the maximum ethanol yield was predicted to be 91.65% by model prediction. Similarly, 92.98% of ethanol yield was obtained by verification experiment using optimum conditions after 48 h of fermentation. This result was in agreement with the model prediction.

• Structural Engineering and Mechanics
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• 제81권6호
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• pp.677-689
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• 2022

Generally, the goal of seismic retrofit design of an existing structure using energy dissipation devices is to determine the optimum design parameters of a retrofit device to satisfy a specified limit state with minimum cost. However, the presence of multiple parameters to be optimized and the computational complexity of performing non-linear analysis make it difficult to find the optimal design parameters in the realistic 3D structure. In this study, genetic algorithm-based optimal seismic retrofit methods for determining the required number, yield strength, and location of steel slit dampers are proposed to retrofit an asymmetric soft first-story structure. These methods use a multi-objective and single-objective evolutionary algorithms, each of which varies in computational complexity and incorporates nonlinear time-history analysis to determine seismic performance. Pareto-optimal solutions of the multi-objective optimization are found using a non-dominated sorting genetic algorithm (NSGA-II). It is demonstrated that the developed multi-objective optimization methods can determine the optimum number, yield strength, and location of dampers that satisfy the given limit state of a three-dimensional asymmetric soft first-story structure. It is also shown that the single-objective distribution method based on minimizing plan-wise stiffness eccentricity turns out to produce similar number of dampers in optimum locations without time consuming nonlinear dynamic analysis.

• 한국환경농학회지
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• 제29권1호
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• pp.1-6
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• 2010

Organic farming system in rice paddy is rapidly expanding in Korea. This study was to find out optimum japonica rice cultivars for organic farming. A field research was conducted to evaluate the characteristics of japonica rice cultivars under no-tillage paddy at Doo-ryangmyeon, Sacheon, Gyeongsangnam-do, Korea. The experimental soil was Juggog series (silty clay loam: 56.0% silt, 31.2% clay and 12.8% sand). In experiment, ten lines of Japanese rice cultivars were tested under no-tillage amended with rye (NTR) and no-tillage without cover crop treatment (NTNT). In addition, two Korean japonica rice cultivars as check cultivars were used in this study. The grain yield in NTR was significantly higher in 6.13 Mg $ha^{-1}$ for Kinuhikari, 5.30 Mg $ha^{-1}$ for Komekogane, 5.25 Mg $ha^{-1}$ for Kosihikari, 5.22 Mg $ha^{-1}$ for Mazizbare and 5.12 Mg $ha^{-1}$ for Akitakomachi compared to two Korean rice cultivars (4.57 Mg $ha^{-1}$ for Hwayoungbyeo and 4.00 Mg $ha^{-1}$ for Ilmibyeo) in that order. While, grain yield in NTNT was significantly higher in 4.90 Mg $ha^{-1}$ for Akitakomachi 3.81 Mg $ha^{-1}$ for Hinohikari, 3.74 Mg $ha^{-1}$ for Umezkusi, 3.67 Mg $ha^{-1}$ for Kosihikari and 3.54 Mg $ha^{-1}$ for Dondokuri compared to 3.02 Mg $ha^{-1}$ for Ilmibyeo and 2.36 Mg $ha^{-1}$ for Hwayoungbyeo, respectively. The number of panicle per $m^2$ and grain number per panicle were indispensible for increasing the yield of rice. These results were able to find out optimum japonica rice cultivar Akitakomachi for organic farming in no-tillage paddy.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.107-112
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• 2004

The combining abilities in the 5 newly evolved thermo tolerant breeds viz., SR6, SR7, SR8 SR9 and SR10 of silkworm Bombyx mori L. and their 15 hybrids were made in a line${\times}$tester crossing programme. Data were analysed for seven quantitative traits i.e., pupation rate, cocoon yield, cocoon weight, cocoon shell weight, cocoon shell ratio, filament length and raw silk percentage under optimum room temperature $(25{\pm}{1^{\circ}C})$ conditions (In case of high temperature $(36{\pm}{1^{\circ}C})$ stress conditions five economic traits except filament length and raw silk percentage) with 3 widely adapted testers i.e., KA, CSR2 and CC1 as lines (females) and testers (males) respectively. The performance at high temperature and low humidity conditions aye only taken into consideration for selecting the best lines/hybrids. Among the lines SR6 exhibited positive General combining ability (GCA) effects for pupation rate, cocoon yield, cocoon weight and cocoon shell ratio traits, followed by SR7 for pupation rate, cocoon yield and cocoon shell weight and cocoon shell ratio. Among testers, KA exhibited positive GCA effects for two quantitative traits cocoon yield, cocoon weight and CSR2 for cocoon shell weight and cocoon shell ratio under adverse temperature conditions. The hybrid SR6${\times}$CC1 and SR7${\times}$CSR2 exhibited significant positive Specific combining ability (SCA) effects for majority of the traits in high temperature stress conditions of rearing. The better parent value of heterosis(Heterobeltiosis) was exhibited by the hybrid SR6${\times}$CC1 for pupation rate, cocoon yield, cocoon weight and cocoon shell weight and SR7${\times}$CSR2 for all the trails evaluated under high temperature conditions. Based on the results, the lines SR6 and SR7 was judged as best combiners and the hybrids SR6${\times}$CC1 and SR7${\times}$CSR2 can be selected for commercial exploitation in tropical climate.

• 한국초지조사료학회지
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• 제14권2호
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• pp.69-75
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• 1994

This experiment was canied out to study the effect of cutting frequencies (3, 4 and 5 cuts per year) and mineral nitrogen fertilization on dry matter yields, in order to estimate optimum level of fertilizing mineral nitrogen in orchardgrass(Dacry1is glomerafa L.). The results are as follows: 1. Dry matter yields were the highest in the 1st cut at 3 cutting frequency and in the 2nd cut at 4 and 5 cutting frequencies, and they shared 49.7, 37.0 and 37.0% of annual dry matter yield respectively. 2. When only phosphorus and potassium were applied, annual dry matter yields were between 9.4 and 11.5 tons per ha and the highest yield was observed at 3 cutting frequency. 3. Dry matter yield in relation to fertilization of mineral nitrogen was highly increased when more nitrogen was applied as 360 kg per ha compared to 240 kg per ha at 3 cutting frequency. At 4 and 5 cutting frequencies, increases in dry matter yield, to large extent, were showed at 120 and 150 kg of nitrogen per ha(30 kg Nlcutlha) compared to no application of nitrogen. The efficiencies of mineral nitrogen fertilization (kg DM/kg N) were 28.0, 22.7 and 20.6 kg dry matter yields per nitrogen(kg) respectively). 4. At 4 and 5 cutting frequencies, dry matter yields were reduced when 360 kg and 300 kg of mineral nitrogen per ha(90 kg and 60 kg Nlcutlha) were applied respectively. 5. Particularly at 4 and 5 cutting frequencies of this study, maximum marginal yields reached at 129.9 kg and 148.0 kg of fertilizing mineral nitrogen per ha, and economical borden of mineral nitrogen fertilization were between 222.4 and 250.0 kg and between 244.8 and 276.8 kg respectively. At the same cutting frequencies, the highest dry matter yields were obtained at 365.4 and 433.8 kg of fertilizing mineral nitrogen respectively.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2001년도 추계정기 학술발표회 초록집
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• pp.43-48
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• 2001

남부지방에서 황금의 맥후작 직파 재배시 재식밀도가 생육과 수량에 미치는 영향을 구명하여 적정 재식밀도를 확립하고자 시험한 결과는 다음과 같다. 1. 경장은 20$\times$10cm의 밀식 일수록 크고, 30$\times$10cm, 40$\times$10cm의 소식일수록 짧아서 재식주수와 경장은 정의상관이 인정되었다. 2. 경직 경은 30$\times$10cm, 40x loom의 소식일수록 크고 20$\times$10cm의 밀식일수록 작았다. 3, 수량구성요소인 주근장과 수량인 건근중은 30$\times$10cm, 40$\times$10cm의 재식주수가 적을수록 높아서 재식주수와는 부의 상관이 인정되었다. 4.이상과 같은 결과로 보아 경직경이 크고 주근장이 길어서 10a당 건근중이 많은 30$\times$10cm(33주/$m^2$)가 알맞은 재식거리였다.

• 한국자원식물학회지
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• 제15권1호
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• pp.77-80
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• 2002

남부지방에서 황금의 맥후작 직파 재배시 재식밀도가 생육과 수량에 미치는 영향을 구명하여 적정재식 밀도를 확립 하고자 시험 한 결과는 다음과 같다. 1. 경장은 20$\times$10cm의 밀식일수록 크고, 30$\times$10cm, 40$\times$l0cm의 소식일수록 짧아서 재식주수와 경장은 정의 상관이 인정 되었다. 2. 경직경은 30$\times$l0cm, 40$\times$l0cm의 소식일수록 크고 20$\times$10cm의 밀식일수록 작았다. 3. 수량구성 요소인 주근장과 수량인 건근중은 30$\times$l0cm, 40$\times$10cm의 재식주수가 적을수록 높아서 재식주수와는 부의 상관이 인정되었다. 4. 이상과 같은 결과로 보아 경직경이 크고 주근장이 길어서 10a당 건근중이 많은 30$\times$10cm(33주/$m^2$)가 알맞은 재식거리였다.