• 품질경영학회지
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• 제47권1호
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• pp.33-46
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• 2019

Purpose: This study proposed a DEA (Data Envelopment Analysis)-based stepwise benchmarking target selection for inefficient DMU (Decision Making Unit) to improve its efficiency gradually to reach most efficient frontier considering resource (DEA inputs and outputs) improvement preferences. Methods: The proposed method proceeded in two steps. First step evaluates efficiency of DMUs by using DEA, and an evaluated DMU selects benchmarking targets of HCU (Hypothesis Composit Unit) or RU (Real Unit) considering resource improvement preferences. Second step selects stepwise benchmarking targets of the inefficient DMU. To achieve this, this study developed a new DEA model, which can select a benchmarking target of an inefficient DMU in considering inputs or outputs improvement preference, and suggested an algorithm, which can select stepwise benchmarking targets of the inefficient DMU. Results: The proposed method was applied to 34 international ports for validation. In efficiency evaluation, five ports was evaluated as most efficient port, and the remaining 29 ports was evaluated as relative inefficient port. When port 34 was supposed as evaluated DMU, its can select its four stepwise benchmarking targets in assigning the preference weight to inputs (berth length, total area of pier, CFS, number of loading machine) as (0.82, 1.00, 0.41, 0.00). Conclusion: For the validation of the proposed method, it applied to the 34 major ports around the world and selected stepwise benchmarking targets for an inefficient port to improve its efficiency gradually. We can say that the proposed method enables for inefficient DMU to establish more effective and practical benchmarking strategy than the conventional DEA because it considers the resource (inputs or outputs) improvement preference in selecting benchmarking targets gradually.

• 보건행정학회지
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• 제10권4호
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• pp.75-98
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• 2000

This study applied Data Envelopment Analysis(DEA) and Ratio Analysis and Regression Analysis to a set of Korean Public Corporation Medical Centers to evaluate their relative human resource efficiencies. The output measure used in this study was based on health insurance system which was used in both in-patient departments and out-patient departments. Inputs included working time of the doctors, nurses, technicians, and managerial department staff. Based on the data provided on the inputs and outputs, the analysis showed 23 of the 34 hospitals to be relatively inefficient. Each hospital with an efficiency rating of less than 1 was considered relatively inefficient. In addition, managerial strategies based on dual variables were constructed to indicate the manner In which inefficient hospitals may be made efficient. A subsequent analysis of t-test revealed that the bed occupancy rate, medical revenue per 100beds, value added revenue per staff, medical revenue per staff were statistically significant. The results of this study suggest the DEA is a promising tool for evaluating relative human resource efficiency in hospitals which have multiple inputs and outputs and where the efficient production function is not specifiable with any precision. But it is considered that efficiency evaluations may be most effective]y accomplished by Incorporating a combination of methodologies such as ratio analysis and regression analysis.

• 에너지공학
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• 제28권4호
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• pp.61-75
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• 2019

본 논문은 한국의 환경기업 중 R&D를 수행하고 있는 기업들의 자원투입이 경영성과에 미치는 직접적인 영향을 살펴보고, 이어 제품·공정·조직·마케팅 등에서의 혁신이 자원투입과 경영성과의 관계를 매개하고 있는지 간접적인 경로와 영향을 분석하였다. 이를 위해 한국 환경기업을 대상으로 설문조사를 실시하였으며, R&D 조직을 보유한 137개 기업의 응답 자료를 대상으로 SPSS와 Process Macro를 이용하여 매개분석을 실시하였다. 분석의 결과, 첫째, 한국 R&D수행 환경기업의 자원투입은 경영성과에 직접적으로 긍정적인 영향을 미치고 있다. 둘째, 자원투입은 혁신을 매개로 하는 간접적인 경로로 경영성과에 긍정적인 영향을 미치고 있다. 셋째, 혁신 유형 중에서는 유일하게 조직혁신의 매개역할이 검증된 반면, 제품혁신, 공정혁신, 마케팅혁신의 매개효과는 나타나지 않았다. 이에 따른 정책적 시사점으로는 첫째, 한국 R&D수행 환경기업들에서 혁신이 자원투입과 경영성과를 연결하는 중요한 매개체로 분석됨에 따라, 기업이 혁신을 통해 경영성과를 제고할 수 있도록 관련 정책을 강화할 필요가 있다. 둘째, 특히 기업들이 조직혁신을 매개로 경영성과를 높이고 있는 점을 반영하면서, 제품·공정·마케팅 등에 걸친 혁신이 경영성과로 이어질 수 있도록 지원정책을 세심하게 시행할 필요가 있다. 본 연구는 기업의 실질 통계 확보가 어려워 설문을 통해 분석한 점에서 한계가 있으며, 향후 환경산업혁신체제에 대한 추가적인 연구가 필요하다.

• 자원ㆍ환경경제연구
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• 제18권4호
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• pp.745-766
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• 2009

특정 산업의 시장지배력을 측정할 때 일부 생산 투입요소의 시장가격이 존재하지 않을 경우 한계시장비용을 초과한 가격 markup으로 판단한 수치는 현실을 왜곡시킬 수 있다. 투입된 모든 생산요소의 가격들의 함수인 비용함수를 추정하는 데 있어서 총 시장비용에서 이들 투입요소에 대한 지출비용이 누락되면 완전경쟁산업에서의 시장가격이 한계시장비용을 초과하는 상황이 발생한다. 한국 제조업의 경우 원재료의 시장가격이 존재하지 않을 뿐만 아니라 관련 자료의 부족으로 공해저감자본의 가격지수를 산정하는 것이 거의 불가능하다. 본 논문에서는 환경규제를 받는 한국 철강산업의 시장지배력에 대한 가격 markup 추정치의 신뢰성을 제고하기 위하여 최적 수준의 원재료와 공해저감자본의 투입량을 전제로 제약비용함수를 도출한 후 공급관계식과 함께 연립방정식으로 추정하였다. 공급가격에 대한 시장지배력 markup의 비율로 측정한 국내 철강산업의 시장지배도는 1982년부터 2001년까지 연평균 0.49로서, 환경규제를 고려하지 않을 경우 약 8% 과대평가되는 것으로 나타났다.

• 자원ㆍ환경경제연구
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• 제23권3호
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• pp.453-472
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• 2014

2015년부터 도입예정인 탄소 배출권거래제의 파급효과를 분석하는 데 있어서 산업별, 기업별 $CO_2$ 저감비용에 대한 정확한 산정이 요구된다. 기업이 환경규제 등 제약된 환경에서 생산 활동을 할 경우 생산요소의 투입과정에서 비효율적 배분으로 인한 생산비용의 증가가 초래되어 비용최소화 달성에 실패할 개연성이 높아진다. $CO_2$ 암묵가격을 측정한 기존 거리함수접근법은 투입요소 간 비효율적 배분 비용을 반영하지 못함에 따라 $CO_2$ 저감비용을 과소평가할 수 있다. 본 논문에서는 이러한 거리함수접근법의 한계를 극복하기 위하여 국내 철강업을 대상으로 비용함수접근법을 사용하여 1990-2010 기간 동안 투입요소 간 비효율적 배분 여부를 검증하고, $CO_2$ 한계저감비용을 추정하였다. 투입요소 간 배분 효율성 달성은 기각되었으며, 표본기간 동안 $CO_2$ 1톤 감축하는 데 연평균 92,000원의 비용을 지불한 것으로 나타났다.

• 자원ㆍ환경경제연구
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• 제23권1호
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• pp.43-65
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• 2014

본 논문에서는 국내 제조업 가운데 전력 사용량이 상대적으로 많은 화합물 및 화학제품 산업을 대상으로 암묵 (shadow) 비용함수를 사용하여 전력 등의 투입요소 간 효율적 배분 여부를 검증하고 전력의 적정수준 대비 과잉 투입 규모를 조사한다. 기업의 비용최소화 달성을 전제로 각 투입요소에 대한 수요의 가격탄력성을 추정하여 전력요금 인상에 대한 각 요소 수요의 파급효과를 모의실험을 통하여 분석한다. 또한 공급관계식을 비용함수의 방정식체계에 추가하여 동시 추정함으로써 전력요금 10% 인상 시 물가지수에 미치는 영향을 분석한다. 실증분석 결과, 1982-2006년 기간 동안 '투입요소 간 효율적 배분 달성'의 귀무가설은 기각되었으며, 전력은 적정수준 대비 평균적으로 매년 약 98% 과잉 사용되고 있는 것으로 나타났다. 다른 요인들이 불변하다면 전력요금이 10% 인상될 경우 전력 수요는 약 11.4% 감소하였으며, 공급가격은 평균적으로 0.08% 하락하는 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 B
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• pp.1149-1151
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• 1996

In the last several years, considerable attention has been focused on the problem of designing observers for linear systems with unknown inputs. Since UIO(unknown inputs observer) has the derivative of the outputs, it is very sensitive to measurement noises. Therefore this note propose an algebraic approach to UIO design to alleviate the prescribed problems. Since the proposed method has simple form to estimate state and unknown input and robustness to sensor noise, we believe that it is very attractive in practice.

• 한국산림과학회지
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• 제94권5호통권162호
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• pp.302-306
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• 2005

Litterfall and nutrient inputs were measured in even-aged coniferous plantations (a 31-year-old Pinus rigida and a 31-year-old Larix leptolepis) on a similar site condition in the Forest Practice Research Center, Gyeonggi Province. Litterfall was collected monthly from circular littertraps (collecting area: $0.50m^2$) for three years between April 1997 and February 2000. Average total annual litterfall was significantly higher for pine (5,802 kg/ha/yr) than for larch (4,562 kg/ha/yr) plantations. Needle litter in both plantations accounted for about 63% of total litterfall. Litterfall in the larch was distributed as follows: needle > other leaf > branch > miscellaneous > bark, while it was needle > miscellaneous > other leaf > branch > bark in the pine plantation. There was no temporal variation in needle litter, other leaf and bark during the 3 year study period. The concentrations of all nutrients (N, P, K, Ca, Mg) in needle litter were significantly higher in the larch than in the pine plantations. The annual nutrient concentration of needle litter in the larch varied among the years, whereas no year variation of needle litter was in the pine except for phosphorus (P). Nitrogen (N) and P inputs by needle litter were significantly higher for larch than for pine plantations established on a similar soil. The differences in N and P inputs were attributed to lower nutrient concentration in pine needle litter compared with larch needle litter, not to total needle litter mass. Annual inputs of nutrient in both plantations were not significantly different among years except for K of the larch although there was yearly different in needlefall mass and nutrient concentration during the 3-year observed period. The results indicate that the mechanisms of litterfall and nutrient inputs vary considerably between pine and larch plantations established on a similar site condition.

• 산업경영시스템학회지
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• 제41권2호
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• pp.65-73
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• 2018

The dynamic capabilities of sensing market signals, creating new opportunities and reconfiguring resources and capabilities to new opportunities in a rapidly changing economic environment determines the competitiveness of the enterprise to create added value and survival. This study conceptualized a two-stage performance measurement framework based on the casual model of resource (input)-process-performance (output). We have developed a 'Process capability index' that reflect the dynamic capabilities factors as a key intermediary product linking resource inputs and performance outputs in enterprise performance measurement. The process capability index consists of four elements : manpower (level of human resource), operation productivity, structure and risk management. The DEA (Data Envelopment Analysis) model was applied to the developed performance indicators to analyze the branch office performance of a telecom company. Process capability efficiency (stage 1) uses resource inputs to reach a certain level of process capabilities. In performance result efficiency (stage 2), the process capabilities are used to generate sales revenues and subscribers. The two-stage DEA model derives intermediate output values that optimize the individual stages simultaneously. Some branch offices in the telecom company have focused on process capability efficiency or some other branch offices focused on performance result efficiency. Positioning map using two-stage efficiency decomposition and benchmarking can help identify the sources of inefficiencies and visualize strategic directions for performance optimization. Applications of two-stage DEA in conjunction with the case study that are meaningfully used in performance measurement areas have been scarce. In particular, this paper has the contribution to present a new performance measurement model considering the organization theory, the dynamic capabilities.

• 자원ㆍ환경경제연구
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• 제9권2호
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• pp.349-371
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• 2000

Data Envelopment Analysis model is a linear programming based technique for measuring the relative performance of organizational units where the presence of multiple inputs and outputs makes comparison difficult. A common measure for relative efficiency is weighted sum of outputs divided by weighted sum of inputs. DEA model allows each unit to adopt a set of weight that shows it in the most favorable light in comparison to the other unit. In this paper, we present the mathematical background and characteristics of DEA model, and give a short case study where we apply the DEA model to evaluate the relative efficiencies of 51 global electricity companies. The technical efficiency and scale efficiency are also to be investigated. Generating capacity and the number of employees are used for input data, and revenue, net profit and electricity sales are used for output data. We find that the companies with 100% relative efficiency are only 9 among 51 electricity companies. And the technical and scale efficiency of KEPCO is 98.7% and 78.89%, respectively. This means that the inefficiency of KEPCO is caused by the scale inefficiency. The analysis shows that the employees should be decreased by 15% at minimum to get the 100% efficiency. The result suggests that KEPCO needs the structural reform to improve the efficiency.