• IE interfaces
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• v.24 no.3
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• pp.220-230
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• 2011

The multi-reservoir operation problem for efficient utilization of water resources involves conflicting objectives, and the problem can be solved by varying weight coefficient on objective functions. Accordingly, decision makers need to choose appropriate weight coefficients balancing the trade-offs among multiple objectives. Although the appropriateness of the weight coefficients may depend on the total amount of water inflow, reservoir operating policy may not be changed to a certain degree for different hydrological conditions on inflow. Therefore, we propose to use fuzzy Data Envelopment Analysis (DEA) to rank the weight coefficients in consideration of the inflow variation. In this approach, we generate a set of Paretooptimal solutions by applying different weight coefficients on Coordinated Multi-reservoir Operating Model. Then, we rank the Pareto-optimal solutions or the corresponding weight coefficients by using Fuzzy DEA model. With the proposed approach, we can suggest the best weight coefficients that can produce the appropriate Pareto-optimal solution considering the uncertainty of inflow, whereas the general DEA model cannot pinpoint the best weight coefficients.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.15-23
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• 2016

Objectives : The purpose of this study was to evaluate the productivity changes of 18 public health centers in Gangwon-do from 2006 to 2013 using the Malmquist Productivity Index(MPI). Methods : Data were collected from Statistics Korea from 2006 to 2013. The input variables were the numbers of medical, nursing and administrative personnels. The output variables were the performances of health promotion programs. Along with the traditional input-oriented DEA analysis, the MPI was calculated. Results : First, among the 18 public health centers, the productivity index of 14 public health centers was increased. Second, the annual productivity showed a 6% increase. Third, the productivity improvements were mainly caused by Scale Efficiency Change. Conclusions : Improving the productivity of public health centers requires the support and external policies of the national and local government. Internally, public health centers need to maintain scale optimization of the center. Additionally, efforts should be made to effectively use limited resources.

• Korean Management Science Review
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• v.29 no.1
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• pp.33-56
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• 2012

Domestic LCD TV market is composed of two groups of products produced by major firms and small and medium enterprises. The major companies make the price relatively high, but the other makes lower in the same sizes. The model of the low price products does not make consumers choice when they choose LCD TV. This makes the questions of capability between difference price products. The reason above mentioned, the firms that include group of comparatively lower price, are worried about not increasing sale because of prejudice. This study is to find any interrelationship and evaluate the efficiency between the products using performance, exterior and brand power of product. In order to do this, a hybrid AHP/DEA evaluation model for comparison/valuation of LCD TV products is developed. The proposed process is; first, to derive hierarchy structure of LCD TV evaluation criteria using axiomatic design, second, to calculate the score of each LCD TV product through AHP analysis including weight calculation of evaluation criteria, and last, to evaluate the efficiency of LCD TV product by applying DEA by defining product scores as output and prices as input. It concludes that the high price products shows good efficiency, but there are some products with good exterior and brand power, not performance, also presenting good efficiency.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.1106-1110
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• 2001

The parasporal biogenesis of crystal inclusion during the sporulation of Bacillus sphaericus strain 1593 was observed using transmission electron microscopy. The crystal biogenesis and sporulation process involved a sequence of events talking about 10 h. The sporulation Precesses were found to be similar to previous findings. The crystal biogenesis of B. sphaericus was initiated at the start of engulfment and nearly completed by the time of exosporium formation. The crystal formation was clearly associated with the outer forespore membrane from stages III through VI, and the crystals grew from polypeptide-like chains originated from the outer forespore membrane. These observations are different from previous findings, which report no association with the forespore membrane. The crystals were located adjacent to the outer membrane of the spore until the release stage. The axes size of the bipyramidal crystal was approximately $0.25{\mu}m{\times}42{\mu}m$. During crystal biogenesis, the crystal development could be classified into four stages; initiation stage Cl (sporulation stage . III), growth stage C2 (sporulation III to V), envelopment and maturation C3 (sporulation V to V), and finally release stage C4 (sporulation Vll).

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.3
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• pp.23-40
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• 2014

This paper measures the operational efficiency of domestic online game companies and analyze its trends and patterns by using data envelopment analysis (DEA). DEA is a non-parametric approach to measuring the relative efficiency of decision-making units (DMUs) with multiple inputs and outputs. 14 online game companies are selected as DMUs and three inputs (number of employees, capital and asset) and three outputs (sales, operating profit and net profit) are selected as DEA variables. First, the output-oriented BCC model and super-efficiency model are employed to measure the static operational efficiency of the online game companies from 2003 to 2012. We also conduct the dynamic analysis with DEA window model to capture the trends of their operational efficiency influenced by internal and external environmental changes. The results are expected to provide fruitful implications for strategic decision making of online game companies and policy making for the online game industry.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.405-420
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• 2013

The purpose of this paper is to develop an evaluation model for e-government system in Korea which is one of world best practices of e-government systems. We have presented a method to perform an efficiency analysis of each e-government service which in a component of e-government system in Korea and to establish a benchmark target for each e-government service. To do this, the output-oriented DEA(Data Envelopment Analysis) CCR model was performed for the selected 12 e-government public services of Korean e-government system in this paper. As a result of DEA analysis, first the internet civil appeal support service, the employment comprehensive information service, and the company support information service were evaluated as the efficient solutions among the 12 e-government public services. Second the remaining 9 e-government public services were evaluated as the inefficient information services which should be improved in terms of their service levels. Finally the benchmark targets for the inefficient e-government services were suggested to improve those inefficient systems through DEA analysis.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.485-492
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• 2008

To propose proper vessel characteristics for sustainable fisheries in Korean waters, we analyzed the fishing capacity, scale efficiency and utilization of large pair-trawl vessels based on the database of catch, effort and vessel characteristics (gross tonnage and engine power) in 1990 by applying data envelopment analysis (DEA). The input factors were gross tonnage, horse power and days operated; whereas the output factor was expected catch by vessel characteristics. The optimal vessel types, selected based on the input-oriented technical efficiency and gross tonnages, was 100 GT with engine power <600 HP. The output-oriented unbiased estimate of capacity utilization (CD) decreased with increasing vessel tonnage. For the same tonnage vessels, the CD decreased with increasing engine power.

• Journal of Navigation and Port Research
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• v.29 no.6 s.102
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• pp.495-500
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• 2005

This paper presents an approach to the measurement of efficiency which is trunk route of global liners. Data envelopment analysis(DEA), as it is called, has particular applicability in the service sector. Applying mathematical programming techniques, DEA enables relative efficiency ratings to be derived within a set of analysed units(Iine services). This paper investigates the efficiency employing DEA Model of line services classified into routes( ex. America-asia line, Europe-asia line, Pendulum line etc). Results of this paper, suggests to some plans for improving the performance in the side of operating global liners.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.3
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• pp.51-63
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• 2014

Because of the changing educational environments, Korean universities have to stand up to the challenge of enhancing their performances in educational activities. Therefore, Korean universities should seek ways to improve its competitiveness. The evaluation of Korean universities has been conducted by the Government and other media agencies like JoongAng's Daily to promote the development of universities. The purpose of this study is to evaluate and compare the relative efficiency of Korean universities using DEA (Data Envelopment Analysis) and AHP (Analytic Hierarchy Process) models. To produce reasonable results, major input and output variables have been determined in a step using a Profiling method, Spearman correlation analysis and AHP model. Also, this study shows that the relative efficiency for Korean universities is obtained not only based on quantity of output, but also on the basis of the quality of the output. Drawing upon the results of the analysis, this study provides a comprehensive and practical method for evaluating the performance of universities in terms of efficiency.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.121-126
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• 2009

This study analyzed the standard school's energy usage and patterns as the zero-energy goal of primary school building, and proposed the energy reduction process of school building using energy analysis computing simulation tool. As a analysis simulation tool, Visual DOE 4.0 is used. For analysis of actual energy usage, selected primary school that is standard in the nation's energy consumption. Standard of the school's energy consumption analysis were devided into electric and gas energy. Input parameters of the simulation program based on the literature material and field survey material. after, but it was calibrated to comparison with the standard school's energy consumption. Finally, its energy usage analyzed by component and made the priority order of energy saving. Applied energy saving technologies are envelopment insulation, high efficiency lighting, high performance HAVC system and used active equipment system of solar collector and photovoltaic generation for additional savings.