• 한국산학기술학회논문지
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• 제10권6호
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• pp.1304-1316
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• 2009

본 연구는 효율성에 기초한 환산지수의 도입 가능성을 알아보기 위한 기초 연구로 시도되었다. DEA 효율성지표와 환산지수가 전공의 수련교육을 실시하고 있는 60 개 병원을 그룹화하는데 얼마나 유용하게 사용될 수 있는가를 고찰하였다. 이러한 목적을 달성하기 위해 자료수집이 가능한 표본병원의 환산지수와 AHP 개념을 도입해 DEA 모형의 투입변수와 산출변수를 선정하였다. 그 결과 병상규모가 클수록 규모적 비효율성이 큰 것으로 나타났으며 기술적으로 또는 규모적으로 비효율적인 병원일수록 환산지수가 더 큰 것으로 나타났다. 환산지수와 효율성지표는 수련병원을 병원의 종별에 따라 종합전문병원과 종합병원으로 구분하는데 유용하게 사용될 수 있었다. 또한 DEA 효율성을 구하는 과정에서 독립변수로 사용된 투입 산출변수를 판별함수에 도입하였음에도 불구하고 환산지수와 효율성지표는 판별함수를 구성하는 주요 변수로 작용함을 확인하였다. 따라서 만약 모집단을 대표할 수 있는 많은 표본을 기초로 보다 명확한 결과를 얻을 수 있다면 건강보험의 수가계약제 하에서 효율성 개념을 바탕으로 한 환산지수계약의 도입을 신중하게 고려해 볼 수 있다.

• Safety and Health at Work
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• 제1권2호
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• pp.175-182
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• 2010

Objectives: This study examined how ethanolamines (EAs) with the same functional alcohol group ($HOCH_2CH_2$), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. Methods: Two types of experimental apparatus were manufactured to achieve these objectives. Results: Vaporization tests using a water bath showed that the vaporization rate increased markedly from $0.19\;mg/m^2{\cdot}min$ at $23.5^{\circ}C$ to $8.04\;mg/m^2{\cdot}min$ at $60^{\circ}C$. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was $0.45\;mg/m^3$ in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. Conclusion: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

• 한국항만경제학회지
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• 제38권2호
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• pp.123-138
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• 2022

우리나라는 동북아지역에서 아시아 허브항만의 위상을 유지하기 위해 항만시스템의 업그레이드에 막대한 예산을 투입하고 있다. 그 결과로 우리나라 대표항만인 부산항은 세계 5위 수준의 컨테이너 물동량 처리 수준을 보이고 있다. 그러나 부산항을 제외한 다른 항만은 낮은 순위에 자리하고 있다. 이 연구는 자료포락분석(DEA) 모델과 Malmquist 생산성지수(MPI)를 이용하여 국내 주요 항만의 효율성과 생산성을 분석하는데 목적이 있다. 특히 변수의 수가 의사결정단위(DMU) 수를 초과할 경우 판별력이 약해지는 DEA모델을 보완하기 주성분분석(PCA, Principal Component Analysis)을 DEA모델에 결합한 PCA-DEA모델을 이용하였다. 그리고 MPI는 다년간의 항만의 생산성을 측정하기 위하여 적용하였다. 그 결과로 우리나라 주요항만의 효율성과 생산성 순위를 결정할 수 있었으며, 광양항과 울산항 2010년과 2018년 비교시 효율성 측면에서 상위권을 보였으며, 생산성 분석 결과에 있어서 대산항과 목포항이 다른 항만에 비해 상대적으로 높게 나타났다. 이 연구결과는 항만별 경쟁력을 객관적으로 평가하고 전략을 마련하는데 활용될 수 있다.

• Korean Chemical Engineering Research
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• 제48권1호
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• pp.121-127
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• 2010

본 연구의 목적은 효소법을 이용한 바이오디젤의 생산에서의 효소(lipase) 활성화를 최적화함에 있다. 효과적인 방법으로 효소를 고정하기 위해 방사선 그라프트 중합법을 이용한 부직포에 음이온 교환기인 ethanolamine과 diethylamine을 도입시켜 음이온 교환 부직포(이때 얻어진 부직포는 EtA, DEA-EtA 부직포라 함)를 합성하였다. 기존에 사용하던 다공성 중공사막의 경우 시간이 지남에 따라 막힘 현상에 따라 유속이 현저하게 줄어드는 점을 보완하고자 기공(pore size)이 $300{\mu}m$인 부직포를 선택하였다. 이 부직포에 음이온 교환기가 도입된 EtA, DEA-EtA 부직포의 최적효소 흡착 특성과 효소 활성도에 대하여 고찰하였다. 그 결과 효소 흡착량은 EtA, DEA-EtA 부직포가 비슷하였으나(EtA non-woven fabric: 15.69 mg/g, DEA-EtA non-woven fabric: 14.45 mg/g) 기름을 투과시킨 결과 효소 활성화는 DEA-EtA 부직포가 EtA 부직포에 비해 현저히 떨어짐(EtA non-woven fabric: $3.50mol/h{\cdot}kg$, DEA-EtA non-woven fabric: $0.38mol/h{\cdot}kg$)을 알 수 있었다. 이 음이온교환기를 이용해 효율적인 바이오디젤 생산을 위한 온도, 효소고정량, 기름과 알코올과의 관계 등의 최적의 조건을 도출하였다.

• 산업공학
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• 제21권1호
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• pp.75-84
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• 2008

It is a difficult task for decision makers(DMs) to choose an appropriate release plan which balances the conflicts between water storage and hydro-electric energy generation in a multi-reservoir operation problem. In this study, we proposed a DEA-based ranking procedure by which the DM can rank the potential alternatives and select the best solution among the Pareto-optimal solutions. The proposed procedure can resolve the problem of mix inefficiency that may cause errors in measuring the efficiency of alternatives. We applied the proposed procedure to the multi-reservoir operation problem for the Geum-River basin and could choose the best efficient solution from the Pareto-set which were generated by the Coordinated Multi-Reservoir Operating Model.

• 대한산업공학회지
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• 제43권3호
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• pp.203-212
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• 2017

Emissions Trading System (ETS) is utilized in many countries, including South Korea, as an efficient policy to abate GHG (Greenhouse Gas) emissions. Grandfathering on the basis of historic emissions is used as the way to allocate permits in South Korea. It, however, has caused an increase in the emission permits and lack of equity. To overcome these drawbacks, we propose an alternative DEA model for centralized allocation of emission abatement to evaluate the amount of emissions abatement by company based on the energy efficiency. In addition, an empirical analysis of 36 assigned companies for ETS in Korean metal industry is conducted to validate the feasibility of the proposed model. The result of the analysis shows that energy-efficient companies achieve reduced target of the emissions abatement and companies with low energy efficiency score are turned out to have contrary outcome, against the result of applying Grandfathering.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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• pp.289-293
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• 2005

변화하는 사회에 대응하기 위한 교육 패러다임은 급속하게 변화하고 있지만 이의 실천적 도구인 ICT 활용 교육은 아직 충분하지 않은 상태이며, 효율적인 교수 학습 방법에 대한 연구가 요청된다. 따라서, 본 연구에서는 초급자의 ICT 활용 교육을 목적으로 웹 기반 문제중심학습 시스템을 설계하였다.

• International Journal of Quality Innovation
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• 제10권1호
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• pp.25-36
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• 2009

The purpose of this study is to analyze the efficiency of the service quality activity itself by using the DEA Model, in contrast to previous quality evaluation methods, as an attempt to evaluate the service quality activities of the distribution industry. Furthermore, by complementing the shortfalls of the weighted value of the DEA Model, it recommends a DEA/PS Model that is appropriate in the evaluation of service quality activities. Based on this model, the study proposes the SQAE Model, an evaluation tool to complement the traditional measuring method. According to the results of the analysis of 18 sample distribution businesses, there was a discrepancy by business in the results of the Traditional Scoring System and the Evaluation Measuring System. Therefore, it is most desirable to not only be active in service quality activities but also increase efficiency at the same time.

• 산업경영시스템학회지
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• 제28권2호
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• pp.18-26
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• 2005

The balanced scorecard(BSC) overcomes the limit of traditional financial statement that focuses on only financial performance. BSC is widely used in government and industry because of the clear representation of the relationship and logic between the key performance indicators(KPI) of 4 perspectives - financial, customer, internal process, and loaming and growth. However, traditional BSC does not consider evaluating the difference between the results measured by BSC. By using relatively small number of inputs and outputs In comparing decision-making units, data envelopment analysis(DEA) can aggregate multiple performance measures. In this research, we propose a methodology named CDB(Combined DEA and BSC) to evaluate the performance of organization considering financial and non-financial perspectives. CDB uses KPI of cause-and-effect relationship on BSC as inputs and outputs of DEA method. In addition, this research proposes a method of converting the KPI of BSC to the input and output variables of DEA, and enhancing discrimination power using the limit number of variables. We illustrate the methodology by giving an example of evaluating aquisition-unit efficiency in a supply chain.

• Journal of information and communication convergence engineering
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• 제6권3호
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• pp.323-326
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• 2008

Data Envelopment Analysis (DEA) is a theoretically sound framework for performance analysis that offers many advantages over traditional methods such as performance ratios and regression analysis. Largely the result of multidisciplinary research during the last three decades in economics, engineering and management, DEA is best described as an effective new way of visualizing and analyzing performance data. Besides, overseas information technology companies have aggressively tried to enter the domestic market. In the age of globalization and high competition, it is imperative that the system integration (SI) companies need to introduce the performance evaluation models of SI projects, including Capability Maturity Model and Software Process Improvement and Capability Determination, to gain a competitive advantage. Therefore, it makes our research regarding evaluation of SI projects very opportune. The purpose of the study is not only to evaluate efficiency of each project by DEA but also to gain insight into various factors such as project complexity, team members' man-months structure, and process index(project management index) that link to the projects performance.