• 한국유기농업학회지
• /
• 제31권4호
• /
• pp.357-380
• /
• 2023

This study analyzed the management efficiency of jujube, bitter persimmon, and chestnut farms using data envelopment analysis (DEA). And this study analyzed causes affecting management inefficiency of those farms using the two-step method. The main findings are as follows. First, as self and employment labor costs are increased, it is important to reduce labor costs which account for 60~70% of the total production cost. Second, efforts to improve management efficiency are needed as overall efficiency of farms were decreased. Third, a pesticide cost per 10a representing a level of pesticide had a negative effect or did not have a statistically significant effect on the management efficiency. This implies that expanding environment-friendly production by reducing pesticides is effective for improving the management efficiency. Fourth, as leading farms were more efficient than general farms, technology dissemination and education through leading farms are important for improving efficiency, and efforts are needed to promote exchange between leading and general farms.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.784-791
• /
• 2007

Most operational organization and railway authority which conduct scheduled maintenance(SM) have carried out the preventive maintenance(PM) based on the information provided from supplier and manufacturer of railway system. However these activities are far away from reality and low the efficiency, it is because an appropriate methods for system selection didn't take into account for improving maintenance efficiency. Therefore, the current SM tasks and maintenance activities lead to lots of spend on the cost and time. To solve the above problem, this thesis presents new approach methodology. This proposes the criteria for reliability centered maintenance(RCM) system selection through level of quantification of each parameter, i.e, frequency, severity and maintenance cost, etc. To do this, the field operation data and information of maintenance cost are essential. As applying this methodology, we can look forward to improving efficiency of PM/SM, and reducing cost.

• Asian Journal of Atmospheric Environment
• /
• 제5권4호
• /
• pp.228-236
• /
• 2011

Since most Green House Gases (GHGs) and air pollutants are generated from the same sources, it will be cost-effective to develop a GHGs reduction plan in combination with simultaneous removal of air pollutants. However, effects on air pollutants reduction according to implementing any GHG abatement plans have been rarely studied. Reflecting simultaneous removal of air pollutants along with the GHGs emission reduction, this study investigated relative cost effectiveness among GHGs reduction action plans in Busan Metropolitan City. We employed the Data Envelopment Analysis (DEA), a methodology that evaluates relative efficiency of decision-making units (DMUs) producing multiple outputs with multiple inputs, for the investigation. Assigning each GHGs reduction action plan to a DMU, implementation cost of each GHGs reduction action plan to an input, and reduction potential of GHGs and air pollutants by each GHGs reduction action plan to an output, we calculated efficiency scores for each GHGs reduction action plan. When the simultaneous removal of air pollutants with the GHGs reduction were considered, green house supply-insulation improvement and intelligent transportation system (ITS) projects had high efficiency scores for cost-positive action plans. For cost-negative action plans, green start network formation and running, and daily car use control program had high efficiency scores. When only the GHGs reduction was considered, project priority orders based on efficiency scores were somewhat different from those when both the removal of air pollutants and GHGs reduction were considered at the same time. The expected action plan priority difference is attributed to great difference of air pollutants reduction potential according to types of energy sources to be reduced.

• 대한간호학회지
• /
• 제41권4호
• /
• pp.500-509
• /
• 2011

Purpose: Time-driven activity-based costing was applied to analyze the nursing activity cost and efficiency of a medical unit. Methods: Data were collected at a medical unit of a general hospital. Nursing activities were measured using a nursing activities inventory and classified as 6 domains using Easley-Storfjell Instrument. Descriptive statistics were used to identify general characteristics of the unit, nursing activities and activity time, and stochastic frontier model was adopted to estimate true activity time. Results: The average efficiency of the medical unit using theoretical resource capacity was 77%, however the efficiency using practical resource capacity was 96%. According to these results, the portion of non-added value time was estimated 23% and 4% each. The sums of total nursing activity costs were estimated 109,860,977 won in traditional activity-based costing and 84,427,126 won in time-driven activity-based costing. The difference in the two cost calculating methods was 25,433,851 won. Conclusion: These results indicate that the time-driven activity-based costing provides useful and more realistic information about the efficiency of unit operation compared to traditional activity-based costing. So time-driven activity-based costing is recommended as a performance evaluation framework for nursing departments based on cost management.

• 한국산학기술학회논문지
• /
• 제12권6호
• /
• pp.2500-2505
• /
• 2011

본 연구는 Farrell_Debreu방식과 Tone방식에 의해 제시된 DEA모형을 원가효율성 관점에서 비교 분석하고 이 한계를 극복하기 위한 방안을 제시하였다. 전통적인 접근법인 Farrell_Debreu 방식과 최근에 연구된 Tone 방식의 공통점과 차이점을 알아보고 각 접근법에 따른 DEA모형을 구축하였다. 또한 두 모형의 결과를 비교하기 위해 분석 사례를 구축하고 두 모형에 따른 분석과 결과치의 차이를 살펴봄으로써 두 모형의 장단점을 비교할 수 있었다. 두 접근법은 동일한 자료를 사용하더라도 자료의 분석 방식이 상이하고 효율성의 값, 각 단위의 효율성 순위, 참조집합에 있어 차이를 나타냈다. 전통적인 모형에 비해 Tone의 방식은 동일한 투입량이라 하더라도 보다 낮은 가격으로 조달 가능한 투입물에 강조점을 둠으로써 원가효율성 측면에서는 현실 설명력이 높지만 기술적 효율성 측면에서는 Farrell_Debreu방식에 의한 DEA모형이 더 합리적인 것으로 나타났다.

• 환경정책연구
• /
• 제10권2호
• /
• pp.61-92
• /
• 2011

제조업을 중심으로 분석한 환경관련투자 효율성의 주요 연구 결과는 다음과 같다. 내부수익률과 편익의 현재가치를 가변비용절감부문, 투자비용절감부문, 임대수입부문으로 분해함으로써 기존 연구의 범위를 확장했다. 그리고 단기총비용과 임대수입의 역할을 탐구하여 편익의 현재가치는 편익의 크기만을 나타내는 반면, 내부수익률은 효율성의 존재여부를 나타냄을 발견했다. 그리고 내부수익률과 시장이자율을 비교하는 투자효율성 방법론으로 환경관련투자와 관련된 투자효율성과 편익을 분석함으로써 사후 비용편익분석을 수행했다. 그 결과 환경투자, 공해방지투자 모두 비효율적인데, 공해방지투자가 환경투자보다 더 비효율적임을 발견했다.

• 한국BIM학회 논문집
• /
• 제10권2호
• /
• pp.12-20
• /
• 2020

Recently, interest in BIM technology has been growing in the domestic construction market as the number of construction projects requiring the application of BIM technology has increased. The use of BIM allows the use of various visualization functions through 3D models as well as drawing interference review, quantity calculation and integrated management of information. In particular, estimates of construction costs based on BIM can increase work efficiency by reducing the burden of calculating construction costs and managing them. In order to increase the efficiency of BIM-based cost estimates, it is necessary to improve the correlation between the BoQ(Bill of Quantity) information and the BIM model. For this purpose, the ratio of the amount and item to the detailed construction of the current BoQ was analyzed, especially the problem of the calculation of construction cost in the window work in this study. In addition, we would like to suggest a method for systematically linking the BoQ information with the BIM model by improving the BoQ information structure of the window work. It is expected that this will increase the efficiency of the quantity calculation and analysis work of construction cost of window work. In addition, it is expected that this method will help to analyze and predict changes in construction cost of windows and doors by facility characteristics and type.

• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2009년도 하계학술발표대회 논문집
• /
• pp.1197-1202
• /
• 2009

Cost allocation on cogeneration is a methodology dividing the input of common cost to electricity cost and heat cost. In the cost allocation methodology of the electricity and heat on a cogeneration, there are energy method, work method, proportional method, benefit distribution method, reversible work method, various exergetic methods, and so on. In previous study, various cost allocation methodologies have been applied and analyzed on a gas-turbine cogeneration producing the 33.1 MW of electricity and the 32.2 Gcal/h of heat, a steam-turbine cogeneration producing the 22.2 MW of electricity and the 44.3 Gcal/h of heat, and combined-cycle cogeneration producing the 314.1 MW of electricity and the 279.4 Gcal/h of heat. In this study, we integrately analyze the results of previous studies and examine the generality and rationality each methodology. Additionally, a new point of view on the values of alternative electricity efficiency and alternative heat efficiency in the previous methodologies was proposed. As the integrated result, we conclude that reversible work method of various common cost allocation methodologies is most rational.

• ETRI Journal
• /
• 제42권1호
• /
• pp.118-128
• /
• 2020

A semitransparent photovoltaic-thermal (PV/T) air collector can produce electricity and heat simultaneously. To maximize the thermal and overall efficiency of the semitransparent PV/T air collector, its availability should be maximum; this can be determined through a Markov analysis. In this paper, a Markov model is developed to select an optimized number of semitransparent PV modules in service with five states and two states by considering two parameters, namely failure rate (λ) and repair rate (μ). Three artificial neural network (ANN) models are developed to obtain the minimum cost, minimum temperature, and maximum thermal efficiency of the semitransparent PV/T air collector by setting its type appropriately and optimizing the number of photovoltaic modules and cost. An attempt is also made to achieve maximum thermal and overall efficiency for the semitransparent PV/T air collector by using ANN after obtaining its minimum temperature and available solar radiation.

• 한국IT서비스학회지
• /
• 제12권4호
• /
• pp.255-265
• /
• 2013

This paper proposes a DEA-AR model for the efficiency evaluation of the iron ore brands in an integrated steel mill. The input factor is defined as unit cost of each brand based on CIF and two output factors are chosen as Fe and Al which are the important ingredients of iron ore. The relative importance between two output factors is determined by several experts using AHP model. The efficiency of each brand is determined using DEA and DEA-AR models. The negative correlation between the DEA-AR efficiency and the unit cost (CIF) is shown as significant whereas no significant correlation exist between the efficiency and the output factors. Also, the Kruskal Wallis rank sum test shows that there exist efficiency differences among the iron ore types whereas no difference is shown among the countries. The result could be utilized in selecting good brands of iron ores based on the DEA-AR efficiency in an integrated steel mill.