• Journal of Ocean Engineering and Technology
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• v.23 no.6
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• pp.23-31
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• 2009

The interaction of incident monochromatic waves with a bottom-mounted vertical porous circular cylinder is investigated using the framework of the three-dimensional linear potential theory. The porosity of the circular cylinder is uniform vertically but varies in the circumferential direction. By adjusting the porosities of the circular cylinder, both the wave blocking performance of a porous semi-circular breakwater and the wave responses inside a circular harbor with an entrance are applied as calculation examples. It is found that the reflected waves, wave run-up, and wave forces are significantly reduced due to wall porosity, which are positive factors for a breakwater, and the amplification factor of a circular harbor at resonant frequencies is greatly reduced by a porous sidewall.

• Journal of Ocean Engineering and Technology
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• v.30 no.3
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• pp.151-160
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• 2016

The diffraction and radiation of linear waves by an array of truncated floating multiple buoys are solved using the interaction theory based on a matched eigenfunction expansion method (MEEM). The interaction processes between multiple buoys are very complex and numerous, because the scattered and radiated waves from each buoy affect the others in the array. Our primary aim is therefore to construct the rigorous wave exciting forces and hydrodynamic forces to deal with the problem of multiple interactions. This present method is applied to a square array of four buoys with two incidence angles, and the results are given for the wave excitation forces on each buoy, heave RAO for each buoy heaving independently, and wave elevations around the buoys and wave run-up. The analytical solutions are in good agreement with the numerical solutions obtained from commercial code (WAMIT).

• Knowledge Management Research
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• v.9 no.4
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• pp.35-49
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• 2008

The purpose of the study is to develop and validate an instructional design model from the perspective of the knowledge creation. To serve the purpose, the researcher conducted 1) literature review to find causal relationship model among knowledge creation factors and to propose a hypothetical instructional design model, 2) data analysis with 50 senior level e-Learning instructional designers, and 3) testing the fitness of the proposed model and relevant causal-relational hypotheses. Results indicate; 1) the proposed model fit to the empirical evidence, 2) 6 hypotheses among 11 were validated. A typical instructional designer's personal competency was evidenced as the most powerful independent variable that predicted knowledge acquisition, knowledge sharing, and the application of the instructional models. However, the expected effect of instructional design models toward other dependent variable was not be found. In addition, further suggestions for the future research are addressed.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 1997.05a
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• pp.67-75
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• 1997

To establish testing method for ignition energy of explosive powders caused by electrostatic discharge, one testing method using a very small quantity of tested powders ( Frima ) was proposed, and the influence of discharge - limiting resistance connected in series into a capacitive discharge circuit on ignition energies of explosive powders was investigated using, as tested powders. As a result the minimum ignition energy was 9 mJ when discharge-limiting resistance was 300 k$\Omega$. The reason for the dependence of ignition energy on discharge-limiting resistance was thought to the difference in the type of electrostatic discharge, such as arc or glow discharge, from the observation of discharging wave forms.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.5 no.4
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• pp.350-356
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• 1993

We carry out a numerical calculation to understand the nonlinear wave deformation around breakwaters using the Boussinesq equation, which is weakly nonlinear and weakly dispersive shallow water equation. A numerical method based on a finite element scheme and fourth order Runge-Kutta algorithm is employed to investigate the diffraction of incident waves by the breakwater. As a computational model, two-dimensional wave flume is treated. The breakwaters is perpendicular to the side wall of a channel. From the numerical results, the wave deformations according to the change of the length and the thickness of breakwaters are investigated. We also investigate the effect of the nonlinearity by comparing the results with the linear solutions.

• Bulletin of the Korean Space Science Society
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• 2008.04a
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• pp.28.2-28.2
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• 2008

• Proceedings of the Korean Information Science Society Conference
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• 2008.06b
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• pp.146-149
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• 2008

유비쿼터스 컴퓨팅 시대가 도래함에 따라 크고 작은 수많은 컴퓨팅 장치들이 집, 사무실, 자동차 등 도처에서 지원되고 있으며, 손목시계형, 목걸이형 등 소형 액세서리 웨어러블 컴퓨터도 다수 출현하여 사용자에게 보다 편리하게 정보를 제공하고자 하는 연구들이 진행되고 있다. 웨어러블 컴퓨팅 장치는 사용자를 위해 정보를 제공하는 입력 장치로도 사용되고 있으나, 정보를 표현하고 제공하는 좋은 출력 장치이기도 하다. 본 논문에서는 다수의 입출력 장치들과 연동하여 다중 피드백을 효과적으로 지원할 수 있는 피드백 인터페이스 프레임워크를 제안하고, 손목밴드형 시스템에서 구현한 결과에 대해 논의한다.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.3 no.1
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• pp.207-219
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• 1997

We experienced a case of postobstructive pneumonia in lung cancer patient by orinetal medical treatment(Herbal medication, Acupuncture therapy, Moxa therapy, Aqua-acupuncture therapy, Carbon radiotherapy), and through it we got a good result to report. According to the above results, it could be suggested that Jukyeopseokgo-tanggagambang extract has indirect autitumor effects by strengthening the effects of MMC on tumor cells.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.271-272
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• 2015

정부의 ICT R&D는 전체산업 관점과 거시적 목적 지향적인 R&D 추진체계에서 필요한 R&D 목적달성을 위해 R&D투자재원의 효율적 배분이 매우 중요한 기능이 된다. 즉, R&D재원배분에 대한 다양한 기준들이 존재할 수 있으며, 이러한 상충적 배분기준들 사이에 객관적이고 효율적인 재원투자의 우선순위와 가중치가 기본적으로 필요하게 된다. R&D계획수립과 지원 분야선정을 위한 방법론으로 보편적으로 사용되고, 현장적용에 객관성을 확보하고 있는 AHP(Analytic Hierarchy Process) 모형을 통해 상충적 다중의사결정에 발생하는 기준의 선호에 대한 쌍대비교를 통해 객관적 선택기준과 대안적 선택에 대한 의사결정 프레임워크를 제공해준다. 따라서 본 연구에서는 정부의 ICT산업경쟁력 제고 목적달성을 위한 투자부문과 기술분야에 대한 실증적인 의사결정구조와 재원배분안을 제시하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.8
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• pp.828-835
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• 1990

A new state feedback control scheme is proposed to improve the stability and dynamic performances of the series resonant converter (SRC). The proposed scheme can be easily implemented without speed limitation. Design parameter of the proposed control is the ratio of the state feedback gains. A closed loop dynamic modeling for the SRC with the proposed control law is derived. Parametric curves which can be used to select the design parameter in the control system are presented. The experimental results show that the excellent dynamic performance of the converter can be obtained by properly selecting the design parameter. The results are further compared with both the theoretical analysis and the frequency control.