• Plant Journal
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• v.10 no.3
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• pp.39-44
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• 2014

The gas turbine thermal efficiency has been predicted when the compressor pressure ratio increases from the previously set 13.5. Thermal efficiency has been predicted from 14.2 up to 18.2 at which the turbine work reaches its maximum value on the assumption that isentropic efficiency of the compressor and the turbine are constant using the operating data at the pressure ratio of 13.5. 35.11% of thermal efficiency has been acquired by the performance test when the pressure ratio increased to 16.2 since replacing the compressor low pressure stages. It's been approved that predicting thermal efficiency using the operating data at the pressure ratio of 13.5 is useful within 7.86% of tolerance as the figure measured by the performance test.

• Defense and Technology
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• no.1 s.167
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• pp.18-19
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• 1993

군사비가 경제발전에 미치는 영향을 분석해 보면 군사비나 경제개발 투자비의 문제가 아니라 군사비를 포함한 국가재정이 얼마나 효율성 있고 생산성 있게 쓰여졌는가가 중요한 문제입니다. 앞으로의 군사력 건설은 기술집약적 방위에의 방향으로 나아가면서 국방비 사용의 효율성(비용효율성)을 극대화하고, 동시에 경제적으로 파급효과도 크게끔 하는것이 요구된다 하겠습니다

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.41-49
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• 2008

According to the demand for services. a single point contract between a user and provider spreads over the industry, and the relationship between them is a main issue. The user wants to make a deal with the contributor which can provide the effective services to the user. This study is to estimate the efficiency of global logistics industry with Data Envelopment Analysis, by nations from 2001 to 2005. Furthermore, it tries to estimate the inefficiency affected by macro factors, and proves the association between them using Tobit model. Global logistics industry has made growth both externally and internally more than doubled for the last 5years. Technical inefficiency of global logistics industry is more influenced by pure technical inefficiency than inefficiency of scale. Therefore technical efficiency can be increased by decreasing pure technical inefficiency. Through this study, it found that the logistics industry got influenced to its efficiency by high price of oil, and courier and transportation service market is formed stably. Furthermore, it advocates policy planners to consider effectiveness and clearness of policy which influence to inefficiency of logistics industry. Also, it found that labor and financial support can give critical effect.

• The Journal of the Korea Contents Association
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• v.15 no.5
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• pp.475-487
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• 2015

This study measures the managerial efficiency of Korea's 14 public enterprises using bootstrap DEA in 2013. In addition, it examines the factors that affect on the bootstrap bias-corrected efficiency using truncated regression analysis. The results and implications of this study are as follows. First, using bootstrap DEA model analysis, the results showed that the mean technical efficiency was 0.3182, the mean pure technical efficiency was 0.4994 and the mean scale efficiency was 0.6585. The main cause of technical inefficiency was due to pure technical inefficiency. Second, rank test between technical efficiency of general DEA model and bootstrap DEA model was no significant difference under CRS and VRS assumption. Third, the main cause of the inefficiency in 11 DMUs among 14 DMUs were mainly due to the pure technology and three DMUs were because of the scale efficiency. Finally, in the truncated regression analysis, cost of labor, profit, sales, return of equity, and the number of employees appeared as factors affecting the scale efficiency at the 10% significance level.

• Environmental and Resource Economics Review
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• v.14 no.3
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• pp.595-626
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• 2005

The purpose of this paper is to estimate technical efficiency, scale efficiency, and environmental efficiency by income level of Korean farms, and analyze the factors to decide three efficiencies. Depending on the non-parametric methods, we estimate technical using inputs and outputs of total farms without assuming of goods or behavior of optimization. The average technical efficiency of total firms under constant return to scale and strong disposability is 0.437. The technical inefficiency was caused by 47.7% in pure technical inefficiency, 11.3% in scale failure, and 3.2% in environmental inefficiency. The number of firms under increasing return to scale occupied almost 70% and 27% of total firms respectively. Higher are income class, middle debt & long debt per asset, and N effluents per cultural land, higher technical efficiency. The increases of BOD discharges per cultural land and machines per cultural land deteriorate environmental efficiency.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.99-100
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• 2015

본 논문에서는 연속모드로 동작하는 차지펌프가 적용된 부스트 플라이백 셀 밸런싱 회로의 권선비에 따른 효율을 다룬다. 기존의 플라이백 보다 승압 시 적은 권선비를 사용하기 때문에 효율이 좋은 차지펌프가 적용된 부스트 플라이백 셀 밸런싱 회로에서 권선비에 따른 전력 손실을 예상함으로써 전력 효율을 가장 높게 하는 권선비를 선택 할 수 있다. 제안된 회로의 동작원리를 설명하고 82w 하드웨어로 설계를 하여서 검증하였다.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2005.10a
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• pp.521-532
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• 2005

IT 기업의 기술적 효율성의 정도를 추정하고, 그 결정요인을 알아보기 위해 Coelli(1995)의 확률적프론티어(Stochastic Frontier model) 중 초월대수 변경생산함수(translog stochastic frontier production function)를 설정한다. 분석견과 연구개발투자, 기업의 재무구조, 설비투자효율, 노동소득분배율 등은 기업의 비효율을 감소시키는 역할을 하는 반면, 기업규모, 재고자산증가율, 자기자본증가율 등은 기업의 비효율성을 더 높여주는 것으로 나타났다. 1990년부터 2004년까지 국내 제조업 전체의 생산의 기술적 효율성은 평균 0.5311로 이는 생산효율성이 $53.11\%$임을 의미하고, 비효율성은 $46.89\%$에 달한다고 볼 수 있다. IT 기업의 기술적 효율성은 0.5337회 제조업과 비슷하지만, IT 대기업은 0.61, IT 중소기업은 0.511로 대기업과 중소기업의 격차가 크게 발생하고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.145-147
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• 2006

최근 차세대 메모리 기술이 급격히 발전하여 FeRAM과 PRAM같은 비휘발성 메모리의 상품화가 진행중 이다. 이러한 차세대 비휘발성 메모리는 메모리와 저장장치의 속성을 모두 만족시켜 주지만, 용량/가격 면에서 비효율적이다. 따라서 다양한 크기의 객체를 효율적으로 표현하고 네이밍과 같은 영속성을 제공하면서 공간 효율성이 뛰어난 관리기법이 필요하다. 비휘발성 메모리에서 공간 효율성을 높이기 위하여 새로운 메모리 파일시스템을 설계하였으며, 본 논문에서는 파일 시스템을 설계하면서 파일 시스템의 공간 효율성을 측정하기 위한 공간 비용 분석 모델과 그 결과를 제시한다. 분석 모델은 다양한 파일 시스템의 공간효율성을 수치로 제시하여 파일 시스템 설계 단계부터 공간 효율성을 예측하고 설계를 구체화하는데 매우 큰 도움이 되었다. 또한 분석 모델은 파일 시스템의 공간 효율을 최대화하는 블록 크기를 결정하는 데 근거를 제시하였으며 아울러 공간 효율을 최대화하는 블록 크기는 파일 시스템에 존재하는 파일의 평균 크기에 의존적임을 보여주었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.61-69
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• 2020

This paper examined the operational efficiency of the new rice variety "Sindongjin" farmed by the Rural Development Administration. Thirty farmers were surveyed in the survey area--Jeonbuk-do Province. The operational efficiency was analyzed by studying the data of these 30 farmers. The operational efficiency of the farmers was analyzed through a survey using the DEA model for analysis. DEA analysis was performed to obtain the technical efficiency of the farmers. The results showed that the DEA technical efficiencies of 12 farmers were efficient, and 18 farmers were inefficient. Farmers No. 13 and No. 25 were representative of inefficiency, and the results show that the cost of input elements was high. An analysis of the determinants of efficiency through the Tobit model found that the operating efficiency increased with decreasing variable costs (Seed costs, By-product fertilizer costs, General fertilizer cost, Pesticides cost, Cost of water, electricity, gas, and Cost of small farm implements) and fixed costs (Repair cost and Other costs). There is a problem of excess input from farmers, and these input costs need to be reduced.

• Management & Information Systems Review
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• v.31 no.1
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• pp.273-292
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• 2012

This paper attempts to analyze the efficiency of Korean Materials and Components Industry. 48 sample companies are extracted and efficiency analysis for them are accomplished by using DEA model. We use both CCR-I model and BCC-I model and classify the 48 companies into two groups; efficient and inefficient companies. We find the reference set which inefficient companies should benchmark in order to achieve efficiency and present the improving values for input and output variables. We analyze whether the inefficiencies come from scale or inefficient operation by measuring the scale efficiency. Finally the ranking among the efficient companies is derived through the super-efficiency analysis.