• 대한안전경영과학회지
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• 제5권1호
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• pp.13-31
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• 2003

This provided a basic frame to analyze the investment effect on the road, railroad, airport and port as a national dimension but it still has a limitation to analyze the specific economic and financial validities to consider the characteristics of the traffic facilities within the area. Conclusively, the aims of this study provide the reasonable evaluation guidelines effectively to the local automatic groups, especially Chungju in the frame of the present evaluation guidelines. We provide the adaptive alternatives on the present systems which are difficult to adapt to the present investment evaluation guidelines; the estimation method of the social economic index and the estimation method of the traffic demand. Additionally, we discuss the research method of the passage actual state for a reasonable estimation of the traffic demand. The result of this study will be activated for the validity check and construction plan of the reasonable traffic investment plan of Chungju city.

• 한국철도학회논문집
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• 제3권1호
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• pp.12-18
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• 2000

This paper addresses the experimental study on the nonlinear critical speed and the validity of simple prediction formulation. The experiment on nonlinear critical speed is carried out using roller rigs, which has been impossible on track because of a possibility of an accident. In addition, experiment for a bogie is performed to check the difference in modeling a full railway vehicle and a bogie. It is found that nonlinear critical speed proves to be an inherent phenomenon of a railway vehicle itself and the difference of test results between a full railway vehicle and a bogie is comparatively negligible. Finally. the accuracy of simple prediction formulation for outbreak velocity and response frequency in hunting is investigated.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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• pp.179-182
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• 2005

Recently, many design codes including ACI 318-02 recommend the use of a strut-tie model approach for design of structural concrete with D-region(s). However, there are several unclear problems and shortcomings in the codes' strut-tie model approach. A grid strut-tie model approach was proposed to resolve these problems. In this study, the ultimate strengths of 17 deep beams, the most familiar type of D-regions, were evaluated for the validity check of the grid strut-tie model approach. The analytical results obtained by the approach are compared with those by the strut-tie model approach presented by CEB-FIP, AASHTO LRFD, and ACI 318-02.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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• pp.160-166
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• 1997

Current Seismic Design Procedure has been developed and improved mostly based on the experiences of the past earthquakes. Many engineers and researchers believe that the seismic codes and provisions are adequate for the basic objective of the code which is "life-safe". However they doubt the performance of the structure during the earthquake. The seismic code seems the black box for the designers which means it is not transparent since the designer can not predict the level of the damage of the structure under future earthquakes. This purpose of this study is to check the validity of the current seismic design procedures. Two structures with different heights are designed and their seismic performances are evaluated for this purpose. Both structures are assumed to be located at the same strong seismic zone.

• Steel and Composite Structures
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• 제6권4호
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• pp.353-366
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• 2006

The discrete singular convolution (DSC) algorithm for determining the frequencies of the free vibration of single isotropic and orthotropic laminated conical shells is developed by using a numerical solution of the governing differential equations of motion based on Love's first approximation thin shell theory. By applying the discrete singular convolution method, the free vibration equations of motion of the composite laminated conical shell are transformed to a set of algebraic equations. Convergence and comparison studies are carried out to check the validity and accuracy of the DSC method. The obtained results are in excellent agreement with those in the literature.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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• pp.265-268
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• 2006

Recently, many design standards recommend the use of a strut-tie model approach for design of structural concrete with D-region(s). However, since the design standards of the conventional strut-tie model approaches are suggested on the assumption of using a determinate strut-tie model, it is difficult to apply an indeterminate strut-tie model in the design of continuous deep beams. In this study, an indeterminate strut-tie model for continuous deep beams is proposed to resolve the problem, and the ultimate strengths of 35 continuous deep beams tested to failure are evaluated for the validity check of the proposed indeterminate strut-tie model. The analytical results by the proposed model are compared with those by the conventional approaches of ACI 318-99 and ACI 318-05.

• International Journal of Fluid Machinery and Systems
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• 제3권1호
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• pp.91-101
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• 2010

Based on the one-dimensional stability analysis, the self-excited oscillation in hydraulic power generating systems was studied by a simple experiment and numerical simulation. It was shown that a cavity in a conical diffuser can cause surge. With the diffuser, a high amplitude and low frequency oscillation occurs at low cavitation number. This oscillation was not observed with the straight pipe. It was confirmed that the diffuser effect of the draft tube can be the cause of the full load surge in hydraulic power system. Numerical results were also analyzed to check the validity of the one-dimensional stability analysis.

• 한국전자파학회논문지
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• 제13권1호
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• pp.26-32
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• 2002

일반적인 마이크로스트립 구조의 해석을 위해 closed-form 그린함수를 이용한 공간영역 모멘트법을 사용하는 경우, 모멘트 행렬의 대각 및 비대각 요소들을 계산하기에 보다 효율적인 기법을 제안하고자 한다. 본 논문에서 제안된 기법의 타당성 확인을 위해 동축선 급전된 마이크로스트립 안테나를 해석한 결과를 기존 논문들의 결과와 비교 제시하였다.

• 전기학회논문지
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• 제61권8호
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• pp.1216-1220
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• 2012

The current collection between pantograph and contact wire is a more critical component for need to train speed up in electric railway. The basic purpose of this paper is to establish a measure of determining arc by developing an arc detector assessment system. The system was designed under conditions of EN 50317 and simulations were conducted using the developed device. According to the results, it was possible to conduct certification tests following regulations of international standards. To check the validity of our approach for the intended application, we analysis contact loss of catenary system using developed arcing measurement system in Korea. The proposed arcing measurement system is expected to enhance precision of current collection quality performance assessment methods at high-speed lines and conventional lines.

• 전기학회논문지
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• 제66권3호
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• pp.557-562
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• 2017

In this paper, we show the design of a rotary joint transition for the X-band channel in a rotatable microwave communication system. The transition seems complicated to make a channel between two coaxial cables through a cylindrical waveguide. To make a broad-band performance in the X-band with low insertion loss and return loss given the constraint on the length and radius of this complicated-looking cylindrical structure, Genetic Algorithm optimization is adopted to check the validity of an intensive parametric study in the design. The structure is fabricated and tested to show how valid the design method is as well as good frequency responses.