• The Pure and Applied Mathematics
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• v.8 no.2
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• pp.153-162
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• 2001

In this Paper, the notion of $\varepsilon$-Birkhoff orthogonality introduced by Dragomir [An. Univ. Timisoara Ser. Stiint. Mat. 29(1991), no. 1, 51-58] in normed linear spaces has been extended to metric linear spaces and a decomposition theorem has been proved. Some results of Kainen, Kurkova and Vogt [J. Approx. Theory 105 (2000), no. 2, 252-262] proved on e-near best approximation in normed linear spaces have also been extended to metric linear spaces. It is shown that if (X, d) is a convex metric linear space which is pseudo strictly convex and M a boundedly compact closed subset of X such that for each $\varepsilon$>0 there exists a continuous $\varepsilon$-near best approximation $\phi$ : X → M of X by M then M is a chebyshev set .

• KIEE International Transactions on Power Engineering
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• v.4A no.2
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• pp.84-90
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• 2004

This paper presents a new method for choosing the best line for transmission system expansion planning considering the highest reliability level of the transmission system. Conventional methodologies for transmission system expansion planning have been mainly focused on economics, which is the minimization of construction costs. However, quantitative evaluation of transmission system reliability is important because successful operation and planning of an electric power system under the deregulated electricity market depends on transmission system reliability management. Therefore, it is expected that the development of methodology for choosing the best lines considering the highest transmission system reliability level while taking into account uncertainties of transmission system equipment is useful for the future. The characteristics and effectiveness of the proposed methodology are illustrated by the case study using a MRBTS.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.475-478
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• 2019

웹어플리케이션의 발전에 따라 자바스크립트 런타임 플랫폼인 Node.js 의 사용도 증가하고 있다. 개발자들은 Node.js 의 다양한 모듈을 활용하여 프로그래밍을 하게 되는데, Node.js 모듈 보안의 중요성에 비하여 모듈 취약점 분석은 충분히 이루어지지 않고 있다. 본 논문에서는 소스코드의 구조를 트리 형태로 표현하는 Abstract Syntax Tree 와 소스코드의 실행 흐름 및 변수의 흐름을 그래프로 나타내는 Control Flow Graph/Data Flow Graph 가 Node.js 모듈 취약점 분석에 효율적으로 활용될 수 있음을 서술하고자 한다. Node.js 모듈은 여러 스크립트 파일로 나누어져 있다는 점과 사용자의 입력이 분명하다는 특징이 있다. 또한 자바스크립트 언어를 사용하므로 선언된 변수들의 타입에 따라 적용되는 범위인 scope 가 다르게 적용된다는 특징이 있다. 본 논문에서는 이러한 Node.js 모듈의 특징을 고려하여 Abstract Syntax Tree 및 Control Flow Graph/Data Flow Graph 을 어떻게 생성하고 취약점 분석에 활용할 것인지에 대한 방법론을 제안하고, 실제 분석에 활용할 수 있는 코드 구현을 통하여 구체화시키고자 한다.

• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.30-36
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• 2014

BACKGROUND: Best management practices are often implemented to control nonpoint source pollutants. Best management practices need to be simulated and analyzed for effective Best management practices implementations. Filter strip is one of effective Best management practices in agricultural areas. METHODS AND RESULTS: Soil and Water Assessment Tool model was selected to explore the effectiveness of filter strip to control total phosphorous in Golji watershed. Soil and Water Assessment Tool model was calibrated for flow and total phosphorous by Sequential Uncertainty Fittin ver.2 algorithm provided in Soil and Water Assessment Tool-Calibration and Uncertainty Procedures. Three scenarios defined by filter strip width were applied. The filter strip width of 5 m was able to reduce the most amount of total phosphorous. In other words, the total phosphorous reduction by filter strip of 5 m was 28.0%, while the reduction was 17.5% by filter strip of 1 m. However, the reduction per unit filter strip width were 17.4%, 8.0%, and 4.5% for 1 m, 3 m, and 5 m of filter strips, respectively. CONCLUSION: Best management practices need to be simulated and analyzed so that the BMP scenario can be cost-effective. A large size of BMP might be able to control large amount of pollutants, however it would not be indicated as a cost-effective strategy.

• Journal of the Korean Solar Energy Society
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• v.31 no.5
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• pp.60-66
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• 2011

Selecting optimal wind turbine generators for wind farm sites in the capacity factor point of view is performed in this study. A program to determine the best wind turbine generator for the maximum capacity factor for a site was developed. The program uses both the wind characteristics of the site of interest and the power curves of the wind turbines. The program developed was applied to find out optimal wind turbine generators of three different sites in complex terrain and successfully yielded the best site dependent wind turbine generators. It was also used to determine the best wind turbine generator of the wind farm currently operating in Korea and proved its usefulness. The program and methodology developed in this study considered to be very useful at the initial design stage of the wind farm to determine the best wind turbine generators for the site of interest.

• IE interfaces
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• v.16 no.2
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• pp.125-139
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• 2003

This paper reports an empirical study on assessment of R&D best practices. The principles of quality management and their tools such as best practices or benchmarking have been so prevailing in the operational process that the R&D management recently consider extensive use of them for their innovation process. However, characteristics of the two processes may be different each other. Are the principles or the tools that were effective in the operational field still going to be effective in the innovative field? In order to answer the question, we statistically examine how R&D best practices contribute to the innovative performance. Upon literature review on technological innovation, we present a R&D process model whereby we set forth research hypotheses. Using data from 66 successful R&D efforts carried out among Korean firms mostly between 1999-2001, regression analyses reveal that best practices used in most stages throughout the R&D process are found not to significantly contribute to the innovative performance. Only those in technology strategy and prototyping stages are proven effective for technical and commercial performance respectively. Interestingly, efforts in a problem solving and improvement stage are counterproductive in the case of the innovation process. Discussions on our empirical observations are presented followed by some managerial implications.

• Journal of Energy Engineering
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• v.26 no.1
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• pp.45-53
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• 2017

The best practices of energy efficiency were selected by reviewing cases collected from the results of IEA research and prior studies, and then by evaluating the correspondence of each case for four attributes including economic performance, synergy, political adjustment, and marketability. The selected best practices included 36 cases in 6 fields such as governance, finance, utility, home, transportation, and industry/small and medium-sized businesses. The reduction of energy costs has brought countries implementing best practices of energy efficiency a variety of benefits, including higher rate of return, the reduction of incidental expenses, the increase of productivity, and the improvement of accessibility to energy. To have similar effects, other countries need to adjust these best practices before applying to their situations.

• Proceedings of the KIEE Conference
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• 1992.07a
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• pp.93-95
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• 1992

A planner have to consider many uncertain factors in best generation mix problem. To solve those problems, fuzzy theory is applied in this paper. Using fuzzy measure and Sugeno's fuzzy integral, the planner can choose the best alternative. By applying the proposed algorithm to KEPCO data, the validity of the proposed method is verified.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1518-1520
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• 2002

Purpose of this research compares best transfer speed about applied frequency and voltage using characteristic of $L_1-B_4$ mode and $L_1-B_8$ mode linear ultrasonic motor that use piezoelectric effect. By method of study, analyzed best transfer speed measuring and comparison load status that use actuality telephone card in $L_1-B_4$ mode linear ultrasonic motor and no-load status of $L_1-B_8$ mode linear ultrasonic motor. Experiment result is applied frequency(58.4Hz) in $L_1-B_4$ mode linear ultrasonic motor (load state) and the best transfer speed by 19.8[cm/s] at applied voltage(56V) point. Also, $L_1-B_8$ mode linear ultrasonic motor (no-load state) is best transfer speed by applied frequency(27.9kHz) and 32.96[cm/s] at applied voltage (50V) point.

• Journal of Korean Society for Quality Management
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• v.45 no.4
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• pp.829-846
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• 2017

Purpose: This paper compares the effectiveness of typical selective assembly criteria and suggests the most promising one. Based on the result of a computer simulation, the key issues of selective assembly are examined and the best criterion is recommended from the effectiveness perspective. Methods: Using JAVA program, production of ten thousand units for each pair of components are simulated for selective assembly of the two types. And the number of mismatching and the fraction nonconforming for each criterion are determined. Results: The best match criterion appeared to be most promising from the perspectives of both mismatching and nonconforming problems. Its effectiveness appears to be also good even when the precision of one component is different from that of the other. Conclusion: For designing an optimal method for selective assembly, the best match criterion is recommendable as the base criterion.