• 대한안전경영과학회지
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• 제15권1호
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• pp.249-258
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• 2013

Data Envelopment Analysis (DEA) is a useful tool to analyze the relative efficiency of decision making units (DMU) characterized by multiple inputs and multiple outputs. This method has been popularly used as an analytical tool to suggest some strategic improvement. To do this, the results of DEA provide decision makers with a single efficiency score, efficient frontier, return to scale, benchmarking decision making units, etc. The purpose of this paper is to evaluate research performance of 38 universities and provide an inefficient university with the way of organizational changes to be an efficient university by using DEA. Various input and output variables are used to identify technical and scale inefficiency. Additionally, we analyze how an inefficient DMU could be changed an efficient DMU based on a case university. This result will give an insight of constructive directions for increasing of research performance to university decision makers.

• 자원ㆍ환경경제연구
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• 제15권2호
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• pp.177-200
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• 2006

최근 수확불변 하에서의 오염처리비용회피활동(pollution haven activities)에 대한 연구는 많이 진행되어 왔으나 수확체증 하에서의 연구는 미미한 실정이다. 1990년대 이후 수확체증 하에서의 교역이론이 산업 재배치에 대한 문제를 다루면서 수확체증과 오염처리비용회피활동 간의 관계를 살피는 것은 의미 있는 일이다. Davis (1998)가 발표한 수확체증 하에서의 자국시장효과(home market effect)에 대한 모형을 응용하여 환경정책이 산업 재배치에 주는 효과를 분석한 결과 시장규모가 적은 지역에서 오염물처리에 대한 책임을 생산자가 담당하는 지역과 시장규모가 크면서 오염물로 인한 비효용을 거주자가 감내하는 지역과의 교역상황에서 교역장벽이 높을 때 일부 공해산업에 대해 오염처리비용회피효과가 존재하나 교역장벽이 낮아지면서 공해산업뿐만 아니라 저공해산업에서도 산업의 지역이탈이 관찰되어 오염처리비용회피활동에 대한 식별이 힘들어지며 오염처리비용회피효과(pollution haven effect)뿐만 아니라 오염처리비용회피가설(pollution haven hypothesis)이 동시에 성립됨을 보일 수 있었다. 따라서 시장규모가 작으나 환경보전가치가 높아 환경규제가 강한 지역에서 환경보전과 지역경제발전을 동시에 도모하기 위해서는 오염처리기술의 생산성을 높이기 위한 활동이 필수적이다.

• 농업과학연구
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• 제39권2호
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• pp.279-289
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• 2012

This study was conducted to survey and diagnose operation status of the agricultural machinery rental service, analyse and compare operational efficiency among 82 city and county ATDEC (agricultural technology development and extension center) using the DEA (Data Envelopment Analysis) method, and recommend future direction, for improvement of the business. Input variables were invested budget and labor, and output variable was rental return. Percentages of return to investment on the rental service were calculated as 68.3% and 63.9% when analyzed with CCR (Charnes, Cooper and Rhodes) and BCC (Banker, Charnes and Cooper) models, respectively, indicating inefficiency of the service operation. Increase of rental charge would increase efficiency by 63.9~68.3% depending on models, and decrease of financial and labor investment would improve the efficiency by about 11.3%. Technical efficiency would be more important than scale efficiency, therefore adjustment of over-invested budget and labor needed to be made together with increase of rental charge to improve the operation. Among the ATDECs providing the rental service, 6 (7.3%), 43 (52.4%), and 33 (40.2%) were in state of CRS (constant return to scale), IRS (increasing return to scale), and DRS (decreasing return to scale), respectively. These indicated public aspects of the rental system, over-investment, lack of output component for input component, meaning that scale income would be increased by qualitative expand of rental charge. Efficiency analysis of the rental system by region showed that efficient ATDECs to be benchmarked by others were in the order of DMU-70, DMU-54, DMU-29, DMU-5, DMU-22, DMU-2, and DMU-61. More comprehensive and extensive survey and analyses would be necessary in the future.

• 한국유기농업학회지
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• 제24권3호
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• pp.337-353
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• 2016

The objective of this study is to analyze the DEA efficiency of the environment-friendly agricultural districts and zones. There are political inefficiency in districts and zones with 45.3% and 85.0%. It mainly results from scale efficiency than pure technical efficiency. There are 10 efficient zones, while 34 decreasing return to scale ones. Meanwhile, districts mostly have increasing return to scale with 97.9%. The results of this study is meaningful to re-construct the project based on the environment-friendly agricultural production.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.548-551
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• 2004

Magnetostrictive actuators have seen increasing use in fine positioning system because it has many advantages such as friction free, resolution of ${\mu}{\textrm}{m}$ or nm scale, and powerful output force. Usually, the magnetic circuit of magnetostrictive actuator has components which are flux return path, coil, and magnetostrictive material. It is classified in two types according to existence of the permanent magnet. The magnetic circuit having optimal performances transfer magnetic field which is obtained by providing input current at coil without energy loss. This paper described mathematical model of magnetic circuit for getting design variables. The modeling equation is obtained from the relations between flux and reluctance of the magnetic equivalent circuit. Also, finite element analysis has been used to study the performance of magnetic circuit according to change of design variables such as existence and shape of the permanent magnet, flux return path etc. The modification of dimensions enables us to optimize magnetic circuit.

• 한국시스템다이내믹스연구
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• 제8권2호
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• pp.5-23
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• 2007

According to the system dynamics model of this study, if there is a significant network effect on vehicle operating costs, it is difficult to achieve the shift to AFV even in the long term without a policy intervention because the car market is locked in to the current structure. Network effect can be caused by an increasing return to scale in fuel supply sector as well as in maintenance service sector. It is also related to the fact that the reliability and awareness of consumers on new products increases with the growth of the market share of the new products. There are several possible policy options to break the 'locked in' structure of car market, such as subsidy on vehicle price (capital cost), subsidy on fuel (operating cost) and niche management policy. Combined policy options would be more effective than relying on a single policy option to increase the market share of AFV.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 추계학술대회
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• pp.191-196
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• 2004

본 연구는 우리나라 RCC/RSC의 효율성을 전체 기술적 효율성, 순수 기술적 효율성과 규모의 효율성으로 구분하여 측정 평가하였다. RCC/RSC의 전체 기술적 효율성은 평균 $91.03\%$ 수준이었으며, 순수 기술적 효율성은 $96.80\%$로 나타났고 규모의 효율성은 $93.83\%$로 전체 기술적 비효율성이 가장 높게 나타났으며 이것은 생산규모에 따른 비효율성보다는 자원의 비효율적인 운영에 따른 효율성에 큰 문제가 있는 것으로 판단된다. 또한 규모에 대한 수익체감은 통영RSC, 수익체증은 인천, 태안, 군산, 여수, 울산, 동해 등의 RCC/RSC로 나타났다. 그리고 비효율적인 RCC/RSC는 준거집단을 참조하여 벤치마킹올 해야 한다.

• 한국항해항만학회지
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• 제29권3호
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• pp.215-220
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• 2005

본 연구는 우리나라 RCC/RSC의 효율성은 전체 기술적 효율성, 순수 기술적 효율성과 규모의 효율성으로 구분하여 측정 평가하였다. RCC/RSC의 전체 기술적 효율성은 평균 $91.03{\%}$ 수준이었으며, 순수 기술적 효율성은 $96.80{\%}$로 나타났고 규모의 효율성은 $93.83{\%}$로 전체 기술적 비효율성이 가장 높게 나타났으며 이것은 생산규모에 따른 비효율성보다는 자원의 비효율적인 운영에 따른 효율성에 큰 문제가 있는 것으로 판단된다. 또한 규모에 대한 수익체감은 통영RSC, 수익체증은 인천, 태안, 군산, 여수, 울산, 동해 등의 RCC/RSC로 나타났다. 따라서 효율성이 낮은 RCC/RSC는 효율성이 높은 준거집단을 참조하여 벤치마킹을 해야 한다.

• 자원ㆍ환경경제연구
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• 제14권3호
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• pp.595-626
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• 2005

본 연구의 목적은 투입물 효율함수를 이용하여 한국농가의 소득계층을 대상으로 기술효율, 환경효율, 규모효율을 측정하고, Tobit 모형으로 그 결정요인을 분석하는 것이다. 본 연구는 비모수적(nonparametric) 방법에 의존하여 재화의 가격이나 최적화 행동에 관한 가정없이 투입요소와 산출량에 의존하여 기술효율을 계측한다. 생산기술은 바람직한 재화와 바람직하지 못한 오염물의 결합생산을 모형화한다. 규모불변과 강처분 하에서 평균 기술효율 수준은 0.437 이었다. 기술비효율의 원인은 순수기술비효율이 47.7%, 규모비효율은 11.3%, 환경비효율 3.2%의 순이다. 규모체증 상태에서 생산농가는 전체농가의 70%를 점유하고 규모체감 상태에서 생산농기는 전체농가의 27%에 이른다. 효율성을 결정하는 요인으로 소득계층이 높을수록 중장기 부채가 높을수록 단위면적당 질소배출량이 높을수록 기술효율은 높았고, 경지면적당 농업경영비가 높을수록 기술효율은 저하되었다. 환경효율에서는 BOD 배출량, 단위면적당 기계도입, 자본의 생산성 유의적이고 음(-)으로 나타나, 청정기술이 아닌 단순한 기계화의 확대는 환경효율을 악화시키는데 영향을 주고 있음을 시사한다.

• 한국항해항만학회지
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• 제34권9호
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• pp.719-726
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• 2010

As the competition among the container terminals in Korea has become increasingly fierce, every terminal is striving to increase its investments constantly and lower its operational costs in order to maintain the competitive edge and provide satisfactory services to terminal users. The unreasoning behavior, however, has induced that substantial waste and inefficiency exists in container terminal production. Therefore, it is of great importance for the terminal to know whether it has fully used its existing infrastructures and that output has been maximized given the input. From this perspective, data envelopment analysis (DEA) provides a more appropriate benchmark. This study applies three models of DEA to acquire a variety of analytical results about the operational efficiency to the Korean container terminals. According to efficiency value analysis, this study first finds the reason of inefficiency. It is followed by identification of the potential areas of improvement for inefficient terminals by applying slack variable method and giving the projection results. Finally, return to scale approach is used to assess whether each terminal is in a state of increasing, decreasing, or constant return to scale. The results of this study can provide terminal managers with insight into resource allocation and optimization of the operating performance.