• 한국농공학회지
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• 제33권2호
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• pp.94-103
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• 1991

This study was carried out to investigate the engineering characteristics of the R.C circular ring sector plate with various boundary conditions and then to propose a rational and paraical method for application of finite element method to R.C structures. The stiffness matrix of the circular ring sector plate was obtained by using the multi-base coordinate system in which the base-coordinate systems were constructed for each nodal point of the quadrilateral element in order to reflect the complicated boundary conditions conveniently and correctly. The R.C element stiffness matrix was constructed by adding the stiffness coefficients of the steel-bar element into the plate bending element stiffness matrix. Herein, the steel-bar element was treated as the common beam element. Using the above method, the effects of steel-bar can be considered without increasing of the numbers of element and nodal points.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.381-383
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• 2003

The authors have developed a solution method based on the incremental algorithm. The optimal load balance between feeders is found through the incremental algorithm with allowing the loop configuration. Therefore loops can be configured in the resulting configuration, and then we must eliminate all loops to satisfy radiality of distribution system because the distribution system is operated under radial status. But the optimal load balance through incremental algorithm is deteriorated when the loops are eliminated. In this paper, authors propose a new method which is to improve the searching procedure of path in the incremental algorithm, that is, so as not to make loop in the path configuration.

• 한국결정성장학회지
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• 제9권4호
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• pp.432-436
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• 1999

Fiber growth of $Al_{2}O_{3}/R-Al-O$ (R = Y, Gd, Dy, Ho, Er) eutectic by the micro-pulling down method is described. The thermal stability and strength at elevated temperature of each materials is evaluated in relation to the microstructure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 A
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• pp.312-314
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• 1999

This paper describes the general formulation for free vibration analysis of rotor by the transfer matrix method. For solving structural dynamics problems, it is used the transfer matrix method. The rotor of the induction motor for main coolant pump is regarded as a distributed mass system.

• 자원ㆍ환경경제연구
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• 제13권3호
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• pp.469-497
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• 2004

환경 R&D 예산의 효율성 제고 방안의 연구를 위해 전주기방법에 입각하여 환경 R&D 사업의 운영체계에 대한 문제점과 개선방안을 제시하였다. 연구결과 크게 네 가지 부문의 개선 노력이 요구되는 바, 첫째, 기술현황에 관한 기초자료를 축적 관리하는 전담조직의 운영, 둘째, 주기적 기술수요조사를 통한 과업선정체계의 강화, 셋째, 국가연구개발사업으로 추진된 개발기술의 상용화 자금지원제도에 대한 홍보 알선 업무의 강화, 그리고 마지막으로 이전기술의 사업화를 위한 지원기관, 대상사업 및 재정지원의 확대가 가장 필요한 것으로 결론지어졌다. 그러나 R&D 지원사업의 운영체계에만 국한하여 분석한 본 연구의 한계를 극복하기 위해서는 R&D 사업의 전반에 관한 포괄적인 추후 연구를 추진할 필요가 있다.

• Archives of Plastic Surgery
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• 제37권3호
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• pp.213-219
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• 2010

Purpose: Iodine has been used for the prevention or management of wound infection as a topical agent. Although iodine was widely used mainly by Betadine$^{(R)}$ and cadexomer iodine, there was no comparative study on the efficacies of dressing methods of iodine. And also it's wound healing effect was not yet clear. The purpose of this study is to compare antibacterial effects and wound healing effects associated with various dressing methods of iodine on infected full thickness skin defect in the mouse. Methods: One full thickness skin defects in the mice (n=60) were developed on the back and left open for twenty-four hours. Sixty mice were divided into four groups : group S (dressing with Betadine$^{(R)}$ soaking, n=15), group T (dressing with Betadine$^{(R)}$ topping, n=15), group I (dressing with Iodosorb$^{(R)}$, n=15), group G (control group, dressing with dry gauze, n=15). The size of the wound defects and the grades of wound healing were evaluated in 4, 7, 10 days, and antibacterial effect was evaluated with restricted zone in Mueller Hinton agar by disk diffusion method. Results: After the wound was left open for twenty-four hours, many Staphylococcus aureus were cultured. The wound defect size was decreased in order of Betadine$^{(R)}$ soaking, Iodosorb$^{(R)}$, Betadine$^{(R)}$ topping and gauze dressing group in all days, but difference among experimental groups was not statistically significant. The grade score of wound healing was increased in order of Betadine$^{(R)}$ soaking, Iodosorb$^{(R)}$, Betadine$^{(R)}$ topping and gauze dressing group, and the difference was statistically significant. Antibacterial effect for S. aureus was increased in order of Iodosorb$^{(R)}$, Betadine$^{(R)}$ soaking, Betadine$^{(R)}$ topping and gauze dressing group, and the difference was statistically significant. Conclusion: Selection of the effective dressing method of iodine for infected wounds remains a controversial decision. According to this study, Iodosorb$^{(R)}$ may be most effective method for antibacterial effect and Betadine$^{(R)}$ soaking may be most effective method for infected wound healing. However, further study is necessary to evaluate the clinical efficacy of dressing methods of iodine and to search for the mechanisms that explain their effects.

• 통합자연과학논문집
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• 제7권3호
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• pp.200-207
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• 2014

Average number of samples to signal (ANSS) and average time to signal (ATS) are the most widely used criterion for comparing the efficiencies of the quality control charts. In this study the method of evaluating ANSS and ATS values of the multivariate exponentially weighted moving average (EWMA) control charts with Markov chain approach was presented when the production process is in control state or out of control state. Through numerical results, it is found that when the number of transient state r is less than 50, the calculated ANSS and ATS values are unstable; and ATS(r) tends to be stabilized when r is greater than 100; in addition, when the properties of multivariate EWMA control chart is evaluated using Markov chain method, the number of transient state r requires bigger values when the smoothing constatnt ${\lambda}$ becomes smaller.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1994년도 봄 학술발표회 논문집
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• pp.17-24
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• 1994

In the analysis pre-cast large panel structures, we can use the new discrete analyzing method to be consisted of rigid bodies. Because the pre-cast panels we still more rigid than the connection, the rigid element method is more efficient numerical method than F. E. M. The characteristics of R. E. M. is that strains in element are not occurred by external loadings and the deformation of the structures by external loadings is transmitted through springs around elements. In this study, we focus on the comparison of the results from the R. E. M. and the F. E. M. in order to establish the validity of the R. E. M. to analysis of pre-cast panel structures.

• 대한기계학회논문집B
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• 제21권2호
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• pp.202-212
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• 1997

In this study, performance of the multi-stage explicit methods for numerical computation of the unsteady Navier-Stokes equations is investigated. Three methods under consideration are 1 st-, 2 nd-, and 4 th-order Runge-Kutta (R-K) methods. Compared in this estimation is stability, accuracy, and CPU time of each method. The computational codes developed are applied to the two-dimensional flow in a square cavity driven by an oscillating lid. It turned out that at Reynolds number 400, the 1 st-order R-K method is the best, while at 3200 the 2 nd-order R-K is recommended. At higher Reynolds numbers, it is conjectured that the 4 th-order R-K method will be the best algorithm among three due to its highest stability.

• 한국국방경영분석학회지
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• 제2권1호
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• pp.111-125
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• 1976

This paper is to explore technological forecasting methodologies and their application to military R&D programming. Among a number of forecasting methodologies, eight frequently used methods are explained. They are; Delphi method, analogy, growth curve, trend extrapolation, analytical model, breakthrough, normative method, and combined method. Due to the characteristic situation of a developing country, the application of technological forecasting to the Korean military R&D programming is limited. Therefore, only two forecasting methods such as Delphi and normative method are utilized in the development of a decision model for the military R&D programming. The model consists of a dynamic programming using decision tree model, which optimizes the total cost to equip a certain military item under a given range of risk during a given period. Some pitfalls in forecasting methodologies and of the model are discussed.