• Journal of Information Processing Systems
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• v.7 no.3
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• pp.549-560
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• 2011

Vote validity proof and verification is an efficiency bottleneck and privacy drawback in homomorphic e-voting. The existing vote validity proof technique is inefficient and only achieves honest-verifier zero knowledge. In this paper, an efficient proof and verification technique is proposed to guarantee vote validity in homomorphic e-voting. The new proof technique is mainly based on hash function operations that only need a very small number of costly public key cryptographic operations. It can handle untrusted verifiers and achieve stronger zero knowledge privacy. As a result, the efficiency and privacy of homomorphic e-voting applications will be significantly improved.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.569-572
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• 2000

DEA has been effectively applied to various areas which need the evaluation of relative efficiency. We propose a DEA model based on fuzzy LP combined with Genetic Algorithm in order to consider uncertain synergy effects due to M&A of existing organization. We apply the suggested approach to forecasting the efficiency of merged academic departments in a university in Korea. We expect that our approach can be utilized to effectively realign existing departments.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.276-279
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• 2005

Many large organizations that have allocated resources to Data Administration(DA) have DA-context meta data mining. Also meta data is an interesting topic in the data warehouse world. This conceptual view gradually cleared up, and recently we have been talking more confidently about the back-room and front-room meta data. We describe the processes and problems that characterize the general architecture of s meta data mining system to do improve management efficiency that require further research and development.

• IE interfaces
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• v.18 no.2
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• pp.167-177
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• 2005

As the largest shipbuilding company in the world and the leader in the Korean merchant shipbuilding industry, Hyundai Heavy Industries is currently struggling to carry out intensive productivity improvement efforts in order to be the global merchant shipbuilding market leader by surpassing in the competition with Japan and being free from the defiance of China armed with very cheap labor costs. This paper introduces the academy-and-industry collaborative project, a part of the productivity improvement efforts, which has conducted on the steel stockyard operations. As a pilot project that researches for the way of improving the stockyard operations and ignites further projects on the stockyard operations, the project defined the stockyard operations, measured current situations, and analyzed management dilemmas. In addition, the project developed the steel stockyard operations simulator. Besides that the simulator is used by the operations manager who has heavily relied on his work-experienced intuition when making decisions, this paper expects that further projects on the stockyard operations utilize the simulator for their own purposes.

• Journal of the Korea Society of Computer and Information
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• v.3 no.4
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• pp.49-54
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• 1998

AS it takes a considerable time for database operations for processing the condition part of active rule, the operations have an important effect on the efficiency of active database system. The processing time of operations should be minimized in order to improve the efficiency of system. The previous works are limited to basic database operations and the partial aggregate functions. In this paper, the processing technique using the structuralization and the state table of relations is suggested. The processing time for basic database operations can be reduced with the structuralization of relations to classification tree and the introduction of deletion information table. With the introduction of binary search tree and relation state table, the aggregate function which has a big of processing cost can be processed effectively and the function of the active database system can be maximized.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.1
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• pp.127-143
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• 2016

This study applied DEA analysis to measure the relative efficiency of 35 companies that produce automobile body components. First, the input and output, the improvement target value of the calculated variables, and the reference group for benchmarking for inefficient groups to become efficient groups were established through DEA analysis. In addition, whether inefficiency was due to technical inefficiency or size was analyzed in connection with the cases of the actual companies through the measurement of scale efficiency. Second, a route for efficiency improvement was derived through DEA-Tier analysis by defining the possible group for benchmarking in actuality within the production industry of automobile body components where the primary cooperative company belonged. Third, the financial variables that generate the difference between efficient and inefficient groups were derived through logistic regression analysis. Financial strategies that determine the direction the indices should be improved to allow the inefficient group to become an efficient one were recommended. This research is expected to provide diagnostic methods for management efficiency and the direction of improvement to enhance the management efficiency of automotive parts makers by identifying the causes of the inefficiency of domestic automotive parts makers empirically. The study also provides financial strategies together with the target values of efficiency improvement for each individual company.

• Journal of the Korean Operations Research and Management Science Society
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• v.29 no.3
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• pp.79-98
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• 2004

Despite its contribution to the Korean medical service industry the question of how efficiently the Korean public hospitals have operated has been unresolved. This study gauges and analyzes the overall efficiency and the Malmquist productivity index in the industry over the period 1992 through 2001. In addition to cost efficiency. we also measure technical, allocative, pure technical and scale efficiencies. Furthermore. the Malmquist index is decomposed into efficiency and frontier changes. We identify several important factors which seem to have strong relationship with various inefficiency estimates. The results indicate that on average the public hospitals has wasted a significant amount of resources and costs over the period. Unlike many other industries, the low level of cost efficiency of the public hospital industry is mainly due to allocative inefficiency rather than technical inefficiency. The Maimquist productivity indices seem both due to the frontier change and efficiency change, but with more effect by the former. The results also indicate that the turnover of hospital beds has played an important role in determining efficiency and productivity of this important industry.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.53-68
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• 1999

This paper presents a nonparametric method to test if the mean difference of DEA efficiency estimates between two groups statistically exists. A proposed method employs a bootstrapping approach to generation BCC efficiency estimates through Monte Carlo simulation resampling process. For the purpose of demonstration, we empirically apply the proposed method to the korean bank industry and compare its result with the result by the traditional deterministic DEA method. The nonparametric statistical hypothesis testing procedure in this study, which considers not only stochastic variability of the DEA data, but also random radial deviations off the efficient frontier, serves as a useful tool for dbjectively evaluating whether the mean difference of DEA efficiency estimates between groups is statistically significant.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.1
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• pp.57-73
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• 2015

While many previous studies investigated the effect of operations performance on financial performance, most studies considered only a few performance indicators and ignored the characteristics of industries. Therefore, this study intends to analyze the effect of operations performance on financial performance, by selecting a rather comprehensive operations performance indicators from firms' financial data. In doing so, we used operating efficiency and supply chain performance indicators for operations performance and a firm's profitability and future value indicators for financial performance. For the analysis, we collected 544 firms' operations and financial performance data belonging to eight key industries from the 'Forbes Global 2000'. We first analysed the differences in operations and financial performance among high, medium and low supply chain performance groups based on the quantitative criteria of Gartner's 'Supply Chain Top 25' ranking procedure. Then we analysed the effect of operations performance indicators on financial performance for both entire industry and individual industries, using multiple regression. Based on the results, we provided practical insights into key operations performance indicators to focus on and manage in order to improve financial performance.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.1
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• pp.99-111
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• 2016

This paper presents a framework to analyze the change in the research and development (R&D) efficiency of government-funded research institutes (GRIs) in Korea. Cumulative data envelopment analysis/Malmquist index method is utilized to analyze the changes in R&D efficiency of GRIs. Data analysis of the R&D activities of 10 GRIs in Korea Research Council of Fundamental Science & Technology showed that the average R&D efficiency of the 10 GRIs improved from 2009 to 2013. However, the efficiency of a few GRIs decreased in terms of the catch-up index. The proposed framework can help management teams diagnose the current state of R&D activities and determine the efficacy of strategic actions by comparing efficiencies in the past.