• Title/Summary/Keyword: Validity Check

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A Study on Investment Evaluation of Transportation Facilities (교통시설물 투자평가에 관한 연구 -충주시를 중심으로-)

  • 김용범;김용래
    • Journal of the Korea Safety Management & Science
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    • v.5 no.1
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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.

An Experimental Study on Validation of Nonlinear Critical Speed (비선형 임계속도 검증을 위한 실험적 연구)

  • 정우진;김성원
    • Journal of the Korean Society for Railway
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    • v.3 no.1
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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.

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Evaluation of Ultimate Strength of Reinforced Concrete Deep Beams Using Grid Strut-Tie Model Approach (격자 스트럿-타이 모델 방법을 이용한 철근콘크리트 깊은 보의 극한강도 평가)

  • Kim, Byung-Hun;Lee, Won-Seok;Yun, Young-Mook
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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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.

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Evaluation of the Current Seismic Design Procedures Based on the Seismic Performance of the Building Located in the Same Seismic Area (동일한 지진구역에 위치한 건축 구조물의 내진거동을 기초로한 기존 내진설계 평가)

  • 한상환;이리형
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.04a
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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.

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Free vibration analysis of composite conical shells using the discrete singular convolution algorithm

  • Civalek, Omer
    • Steel and Composite Structures
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    • v.6 no.4
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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.

Indeterminate Strut-Tie Model for Rational Design of Continuous RC Deep Beams (연속지지 RC 깊은 보의 합리적인 설계를 위한부정정 스트럿-타이 모델의 제안)

  • Chae, Hyun-Soo;Kim, Byung-Hun;Yun, Young-Mook
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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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.

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Experimental Study and Numerical Simulation of Cavity Oscillation in a Conical Diffuser

  • Chen, Chang-Kun;Nicolet, Christophe;Yonezawa, Koichi;Farhat, Mohamed;Avellan, Francois;Miyazawa, Kazuyoshi;Tsujimoto, Yoshinobu
    • International Journal of Fluid Machinery and Systems
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    • v.3 no.1
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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.

Numerical Evaluation of MoM Diagonal and Off-diagonal Elements for the Analysis of a General Microstrip Structures (마이크로스트립 구조의 해석을 위한 MoM 대각 및 비대각 행렬요소들의 수치계산)

  • 김의중;오병희;이영순;조영기
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.1
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    • pp.26-32
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    • 2002
  • When a spatial method of moments(MoM) is used in conjunction with closed-form Greens functions for the analysis of a general microstrip structures of thin or thick substrate, an efficient technique fur the evaluation of MeM off-diagonal matrix elements as well as diagonal elements is proposed. In order to check the validity of the present method, performance is demonstrated for the example of a coaxially-fed microstrip antenna and the present results are compared with the previous results.

Reliability Analysis of Arcing Measurement System Between Pantograph and Contact Wire (팬터그래프-전차선간 아크 검측 장치의 신뢰성 분석)

  • Park, Young;Kwon, Sam-Young;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.8
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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.

The Band-Broadening Design of the Rotary Joint Transition for the X-Band Microwave Channel (X밴드 고주파 채널용 로터리 조인트 천이구조의 대역확장 설계)

  • Kim, Siok;Lee, Changhyeong;Han, Dajung;Roh, Donsuk;Kahng, Sungtek
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.3
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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.