• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.648-651
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• 2004

This paper compares the efficiency of the banking systems of 8 countries during 1996-2002 period. When to estimate the efficiency for each country only, the efficiency levels are more than $85\%$ that shows the production functions of all banks in a single county are similar. But the estimation for all countries shows that the banking systems of some countries are not so efficient compared to other countries' production functions.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.4
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• pp.83-100
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• 2008

We propose a new aggressive formulation of cross-efficiency in Data Envelopment Analysis(DEA). In the traditional aggressive formulation, the efficiency score of a test DMU is maximized as the first goal while an average of efficiency scores of peer DMUs is minimized as the second goal. The proposed model replaces the second goal with the minimization of the best efficiency score of peer DMUs. We showed the model is a quasi-convex optimization problem, and for a solution method we developed a bisection method whose computational complexity is polynomial-time. We tested the model on 200 randomly generated DEA problems, and compared it with the traditional model in terms of various criteria. The experimental results confirmed the effectiveness and usefulness of the proposed model.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.39-52
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• 2001

Recently, the assessment of a bank efficiency focusing on its branches has been conceived as important in developing a competitive strategy. DEA (Data Envelopment Analysis) model can be employed as an effective analysis model for such an assessment. Therefore, this paper proposes an analysis process using DEA model to conduct an efficiency assessment of bank branches. The proposed process includes a segmentation of branches considering their competitive environment and strategy for target market : this approach can help to develop effective strategies for each group of branches. The proposed DEA model can analyze efficiency in terms of not only cost but also marketing. Finally, a real case is analyzed, demonstrating the effectiveness of the proposed model and process.

• Journal of the Korea Safety Management & Science
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• v.9 no.5
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• pp.17-25
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• 2007

All of the city gas companies in Korea must employ the gas safety patrols by law. The gas safety patrols are responsible for the various tasks including daily gas pipeline patrol to prevent gas accidents. Since the size of jurisdiction varies among the city gas companies, it is very difficult to compare their efficiency for the operations of the safety patrol each other directly. The objective of this research is to develop the methodology to analyze and compare the efficiency of the safety patrol's operations among various city gas companies. Several factors that are related to the safety patrol's duty on the gas safety factors were identified and DEA(Data Envelopment Analysis) model for efficiency analysis was developed. Finally, the DEA model was applied to the collected data from six city gas companies. The less efficient city gas companies can benchmark the higher efficient city gas companies in order to improve the safety control systems.

• Journal of the Korean Operations Research and Management Science Society
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• v.37 no.4
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• pp.125-138
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• 2012

Health care that is considered to be one of the major factors for the quality of life is nowadays receiving a great deal of attention, and thus there is a growing need in Korea to identify the efficiency of national medical service and enhance the competitiveness. Although there exist studies on the medical service efficiency about general hospitals and local hospitals, they mostly deal with the efficiency problems from a domestic and regional perspective. In response, this paper analyzes the competitive efficiency of national medical service with respect to 16 OECD countries, by exploiting Data Envelopment Analysis (DEA) and Malmquist Productivity Index (MPI). Building on the DEA and MPI analysis results, this paper identifies the competitive position of Korean national medical service and suggests implications for the medical service improvement.

• Journal of the Korean Operations Research and Management Science Society
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• v.35 no.3
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• pp.59-68
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• 2010

Improving productive efficiency is important for strengthening a competitiveness of coastal fisheries. This paper examines the productive efficiency of a sample of coastal gillnet fishing business units by estimating a stochastic frontier analysis (SFA) and a data envelopment analysis (DEA) approaches and compares those estimates obtained from two approaches. The estimated mean productive efficiency by SFA is 77.6% and the mean productive efficiencies obtained for the VRS and CRS DEA are 75.9% and 45.7%, respectively. The joint use of SFA and DEA for estimating efficiency is also discussed.

• Proceedings of the Korean Magnestics Society Conference
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• 1994.10a
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• pp.78-79
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• 1994

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.139-143
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• 2014

This paper proposes a simplified DC calculation method for simplified depth coding (SDC) mode of 3D High Efficiency Video Coding (3D-HEVC) to reduce the computational complexity. For the computational complexity reduction, the current reference software of 3D-HEVC employs reference samples sub-sampling method. However, accumulation, branch, and division operations are still utilized and these operations increase computational complexity. The proposed method calculates DC value without those operations. The experimental results show that the proposed method achieves 0.1% coding gain for synthesized views in common test condition (CTC) with the significantly reduced number of computing operations.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.3
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• pp.75-85
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• 2024

Airpower is a crucial force for suppressing military threats and achieving victory in wars. This study evaluates newly introduced fighter forces, considering factors such as fighter performance and power index, operational environment, capacity of each airbase, survivability, and force sustainment capability to determine the optimal deployment plan that maximizes operational effectiveness and efficiency. Research methods include optimization techniques such as MIP(mixed integer programming), allocation problems, and experimental design. This optimal allocation mathematical model is constructed based on various constraints such as survivability, mission criticality, and aircraft's performance data. The scope of the study focuses the fighter force and their operational radius is limited to major Air Force and joint operations, such as air interdiction, defensive counter-air operations, close air support, maritime operations and so on. This study aims to maximize the operational efficiency and effectiveness of fighter aircraft operations. The results of proposed model through experiments showed that it was for superior to the existing deployment plan in terms of operation and sustainment aspects when considering both wartime and peacetime.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.4
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• pp.95-109
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• 1999

We propose a series of methodologies that can evaluate relative efficiency of logistics units(centers) in three categories; managerial, cost, and operational efficiency. Inputs and outputs of logistics systems are first defined. Appropriate quantitative and qualitative measures for the three categories are then selected. Employed also are Analytic Hierarchy Process, Weighted Scoring Method, Stochastic Frontier Model, and Data Envelopment Analysis for the development of a comprehensive assessment scheme. Our scheme not only assesses the degree of relative efficiency of logistics units but also identify the sources of inefficiency in each unit The methodologies are applied to a large telecommunications company which operates 12 distribution centers nation wide. Relative efficiencies of the centers are compared using 1995-1997 performance data. Summarized are the level of efficiency of each distribution center for each of the three categories. The degree and sources of inefficiency of each distribution center are also discussed.