• 수산경영론집
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• 제43권2호
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• pp.67-77
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• 2012

Based on the survey on aquaculture management status in Nohwa-eup, Bogil-myeon, Wando-eup in Wando region, this study aimed to estimate productive efficiencies of abalone aquaculture production using a stochastic frontier approach (SFA) and to find out their determinants. In the analysis, a Cobb-Douglas production function with an inefficiency term that follows an halfnormal distribution was assumed for the estimation of productive efficiencies. Then, based on the outcomes of productive efficiencies, determinants of productive efficiency were investigated using a tobit regression model. Results showed that the average inefficiency was estimated to be 10% and the production size would be a statistically significant variable for the production. In addition, it was shown that the cage installing method would be an important factor affecting to the level of productive efficiency.

• 수산경영론집
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• 제43권2호
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• pp.79-94
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• 2012

The purpose of this study is to investigate the production efficiencies of the Korean aquaculture fishery with respect to species and methods using a Data Envelopment Analysis. The study extracted the 8 fishes in each of the sea cage culture, aquarium basin, and enclosed aquaculture for the analytical purposes. First, the study estimated the technical, pure technical, and scale efficiencies of the total of 24 aquaculture fishes based on the traditional DEA under the assumptions of both CRS and VRS. 2 fishes were identified as the efficient DMUs under the CCR-model, and 6 fishes under the BCC-model. Second, we tested to see if there was any difference in production efficiencies regarding those three different methods of aquaculture. we could not find any evidence of the differences in efficiency using a rank sum test based on the traditional DEA. However, we could do find that the pure technical efficiency in the sea cage culture was lower than others at 1% level of significance and the pure technical efficiency in enclosed aquaculture was also lower than others at 5% level of significance using Bilateral-DEA, which could explicitly consider the heterogeneity in the 3 production methods of aquaculture. Finally, the study obtained the 95% confidence intervals of the efficiency scores for the 24 fishes under our study using the smoothed bootstraping method in the process of the re-sampling in cooperation with both a kernel density estimation and a reflection method. At the same time, we could estimate the bias-corrected efficiency scores while the traditionally estimated efficiency scores suffered from the biases in the process of solving a linear programming with the deterministic nature of a production frontier. And hence, we could distinguish the differences in production efficiencies of the 8 fishes with respect to those 3 methods of aquaculture.

• 농업과학연구
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• 제48권1호
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• pp.59-71
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• 2021

This study investigated the extent to which rice producers from the Ayeyarwaddy Region of Myanmar could improve their productivity if inputs were used efficiently in rice cultivation. To achieve this objective, simple random sampling was used to collect data from 300 rice growers in the study area. Data were analyzed with the translog stochastic frontier approach to understand the production efficiencies. The study further estimated the influencing factors that affect the efficiency levels of rice farmers. The empirical result reveals that the average technical, allocative, and economic efficiencies were at 76.11, 47.85, and 34.15%, respectively. This suggests that there is considerable room for improving rice production by better utilization of the available resources at the current level of technology. This study suggests that strenthening agricultural training programs and adoption of improved rice varieties may reduce overall inefficiencies among rice farmers in Myanmar. Factors like age, household size, education, farming experience, farm size, rice variety, training, and off-farm income have a significant impact on increasing/decreasing farmer's efficiency. Efficiency can be improved by establishing farmer field school programs to increase the scale of operations. The government should encourage young educated people to participate in paddy production and also intervene to reduce input prices and control the quality of seeds.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2000년도 국제심포지움
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• pp.7-8
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• 2000

Transgenic animals are very useful for scientific, pharmaceutical, and agricultural purposes. In livestock, transgenic technology has been used forthe genetic alteration of farm animals, the production of human proteins inlarge quantities in the milk of transgenic farm animals, and the generation of animals with organs suitable for xenotransplantation. To date, the transfer of foreign genes into farm animals has been performed mainly by microinjection of DNA into the pronuclei of fertilized eggs. However, the overall success rate of transgenic animals in livestock so far has been disappointingly low, eg., the efficiency is 0∼5% in swine, and less than 1% in sheep and cattle, compared with the rate in mice where 5% microinjected develop into transgenic animals. Recently, McGreath et al. (2000) have succeeded in producing the gene targeted sheep by the use of nuclear transfer from cultured somatic cells transfected with a foreign gene in vitro. However, we may need plenty of time until currently employ this method for gene transfer to farm animals. We have been studying to exploit the method for improving production efficiencies of transgenic animals with emphasis of its application to farm animals. The present paper describes three approaches that we have made in our laboratory to improve production efficiencies of transgenic animals, based on the DNA microinjection method. 1. Co-injection of restriction enzyme with foreign DNA into the pronucleus for elevating production efficiencies of transgenic animals. 2. Efficient selection of transgenic mouse embryos using EGFP as a marker gene. 3. Phenotypes of tansgenic mice expressing WAP/hGH-CAG/EGFP fusion gene produced by selecting transgenic embryos. 4. Efficient site-specific integration of the transgene targeting an endogenous lox like site in early mouse embryos.

• Asian-Australasian Journal of Animal Sciences
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• 제11권2호
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• pp.192-195
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• 1998

Biomass conversion efficiencies (B.C.E) of six fish species viz, Catla catla, Labeo, rohita, Cirrhina mrigala, Hypophthalmicthys molitrix, Ctenopharyngodon idella and Cyprinus carpio cultured under artificial feed (T1), broiler manure (T2), buffalo manure (T3), N:P:K (25:25:0) (T4) and control pond (T5) have been determined for the period of one year. The overall biomass conversion efficiencies under the influence of T2, T3, and T4 were statistically similar. However, the best (0.40) efficiency was determined under feed supplement-ation (T1).

• 한국문헌정보학회지
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• 제38권2호
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• pp.137-160
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• 2004

본 연구의 목적은 대학도서관의 다양한 활동을 평가하기 위하여 정보서비스의 생산 및 이용의 과정 속에서 2년(1999-2000) 동안의 효율성을 평가하고자 하였다. 효율성 평가에 있어서는 자료포락분석(Data Envelopment Analysis)기법을 사용하였으며, 프랑스의 대학도서관이 가진 환경적 요소는 외생변수로 고려되었다. 실증분석은 서비스의 생산과 이용의 두 측면에서 독립적으로 실시하였으며, 도서관의 효율성 정도는 평가 년도에 따라, 평가 영역에 따라 그리고 도서관의 특성에 따라 다르게 나타났다. 특히, 주제화된 도서관이라 할 수 있는 CADSIT 대학도서관이 일반대학도서관에 비해 서비스의 이용측면에서 보다 효율적으로 나타났다. 그리고 비효율적인 도서관의 비효율성은 투입량의 비효율적 사용보다는 산출량의 생산 부족에서 비롯된 것으로 나타났다.

• 자원ㆍ환경경제연구
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• 제23권3호
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• pp.365-408
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• 2014

본 연구의 목적은 전통적 접근의 한계를 지적하고 물질균형 접근의 생산효율을 도입하여 두 생산효율의 차이와 2단계 효율, 오염규제의 경제성장에 미치는 영향 등을 비교하고자 함이다. 특히 상이한 국가들을 대상으로 세 그룹으로 구분하여 이들의 결과를 비교한다. 본 연구에서는 화석연료 투입물을 직접 연계된 $CO_2$와 산출물과 연결시킴으로써 보다 현실에 가까운 생산효율을 측정하였다. 전통적 생산효율과 물질균형 효율비교에서 효율의 측정치는 세부적으로 살펴보면 상당한 차이가 있다. 특히 투입물인 화석연료를 고려하지 않을 경우 저소득국은 생산효율의 성과가 나쁘고 OECD와 중고소득이 보다 좋은 성과를 보인 것으로 나타나고 있어서 현실을 제대로 반영하지 못하고 있다. 물질흐름접근에 기초할 경우 저소득국의 성과가 OECD보다 높고 환경적 요인이 경제에 미치는 영향도 보다 완화된 것으로 확인된다.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1285-1289
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• 2016

A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance the photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of the SC-PBRs were compared with a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, and the photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance the production of astaxanthin.

• Journal of Ecology and Environment
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• 제31권2호
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• pp.125-129
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• 2008

To predict Daphnia secondary productivity along a trophic gradient indexed as total phosphorus (TP) concentration, we estimated energy transfer efficiencies from food quality for Daphnia such as eicosa-pentaenoic acid (EPA) or docosahexaenoic acid (DHA) content. Eleven flow-through Daphnia magna growth experiments were conducted with seston from 9 lakes, ponds and river waters. Primary productivities were estimated from food supply rates in the flow-through experiments, producing energy transfer efficiencies from seston to D. magna. We found DHA content was the best predictor of energy transfer efficiencies among the essential fatty acids. An asymptotic saturation model explained 79.6% of the variability In energy transfer efficiencies. Based on empirical data in this study and empirical models from literature, we predict that Daphnia productivity would peak in mesotrophic systems by decreasing food quality and Increasing food quantity along trophic gradient.

• 한국버섯학회지
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• 제20권4호
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• pp.193-198
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• 2022

The biological efficiencies of promising Pleurotus spp. were evaluated. Pleurotus ostreatus, Pleurotus tuberregium,and Pleurotus sajor-cajuwere investigated at temperatures of 22℃, 20℃, and 18℃ to determine their ability to adapt to temperatures that are likely to be found in subtropical regions. The experiment was conducted using a substrate comprising Popular sawdust 60% + cotton seed 20% + beet pulp 20% under a relative humidity of 65%. The results indicated that there were significant differences in terms of biological efficiency between the species: P. tuber regium 128.84% at 22℃, P. ostreatus 108.41% at 22℃, and P. sajor-caju is 80% at 20℃. The common temperatures at which all species showed the highest biological efficiencies were 22℃ and 20℃. Therefore, the production of the evaluated species was equal to or surpassed biological efficiencies reported in tropical environments, thereby demonstrating a potential opportunity to adapt to tropical environments without compromising quality standards.