• Title/Summary/Keyword: 성능한계

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A Study about Behavior of Steel Column Members under Varying Axial Force (변동축력에 의한 철골기둥부재의 거동에 관한 연구)

  • Oh, Sang-Hoon;Oh, Young-Suk;Hong, Soon-Jo;Park, Hae-Yong
    • Journal of Korean Society of Steel Construction
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    • v.23 no.2
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    • pp.179-188
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    • 2011
  • The performance-based design is highlighted as an alternative for the current design method, which cannot definitely specify the performance level that a building requires. Research on it is already in progress, however, in developed countries like the United States and Japan, to establish the basis for a performance-based design. Many studies on such design are also being conducted in South Korea, but South Korea still lags behind other countries in all-around technology. On the other hand, the column members, especially the lower external column, are affected by the variation of the axial force by overturning the moments in the case of lateral loads by earthquake. Varying the axial force can affect the time of local buckling and the ultimate behavior. Thus, in this study, the structural performance, such as the time of local buckling and the ultimate behavior, was analyzed through an experimental study on column members under varying axial force. The feasibility of a domestic study proposing a performance level with a story drift angle formed about a structural-performance-based steel structure design was also verified.

Performance measurement of a Communication Kernel on the IXP1200 (IXP1200 네트워크 프로세서를 이용한 Communication Kernel의 성능측정)

  • 박우진;백성찬;황광섭;정영환;안순신
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04a
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    • pp.310-312
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    • 2002
  • 본 논문은 인텔사의 IXP1200 네트워크 프로세서를 사용한 Communication Kernel의 설계 및 구현을 토대로 하여 그것의 타당성을 검증하고, 그것의 성능을 측정하였으며, 이러한 성능측정을 위해 고정된 64바이트 및 1518바이트의 패킷 전송이 가능하도록 IXP1200을 사용하여 packet generator를 구현하였다. 우리의 Communication Kernel의 성능측정 결과는 이론적 한계치의 75%였다.

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Theoretical Analysis of Heat Pipe Thermal Performance According to Nanofluid Properties (나노유체 특성에 따른 히트파이프 성능해석)

  • Lim, Seung Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.39 no.7
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    • pp.599-607
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    • 2015
  • In this study, we theoretically investigate the thermal performances of heat pipes that have different nano-fluid properties. Two different types of nano-particles have been used: $Al_2O_3$ and CuO. The thermal performances of the heat pipes are observed for varying nano-particle aggregations and volume fractions. Both the viscosity and the conductivity increase as the volume fraction and the aggregation increase, respectively. Increasing the volume fraction helps increase the capillary limit in the well-dispersed condition. Whereas, the capillary limit is decreased under the aggregate condition, when the volume fraction increases. The dependence of the heat pipe thermal resistance on the volume fraction, aggregation, and conductivity of the nano-particles is analyzed. The maximum thermal transfer of the heat pipe is highly dependent on the volume fraction because of the high permeability of the heat pipe. For the proposed heat pipe, the optimum volume fraction of the nano-particle can be seen through 3D graphics.

Design of Control Method for ON/OFF Type Actuation System Considering Actuation Limit (구동한계를 고려한 ON/OFF 형식 구동시스템의 구동위치 제어기법 설계)

  • Park, Jungwoo;Park, Iksoo;Park, Dongchang;Hwang, Kiyoung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.19 no.2
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    • pp.17-28
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    • 2015
  • In this paper, it is accomplished to design a control method for such an actuation system of simplified ON/OFF mechanism with actuation command limit. First of all, based on experimental data, the modeling works for nonlinear/linear actuation dynamics are performed, which are govern by PWM command as a control input. Using the linearized model, a classical PI control method is designed to satisfy the aimed control performance requirements, and a control algorithm is proposed to realize the required control performance in the effective control region through resolving the issue for the PWM command limit which reduces the control performance. Finally, through control simulations, the design method is verified and the corresponding control performance improvement is evaluated.

Fragility Contour Method for the Seismic Performance Assessment of Generic Structures (지진 취약성 등고선을 이용한 내진성능 평가 방법)

  • Jeong, Seong-Hoon;Lee, Ki-Hak;Lee, Do-Hyung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.15 no.3
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    • pp.65-72
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    • 2011
  • Extensive computer simulations to account for the randomness in the process of seismic demand estimation have been a serious obstacle to the adoption of probabilistic performance assessments for the decision of applying seismic intervention schemes. In this study, a method for rapid fragility assessments based on a response database and the fragility contour method are presented. By the comparison of response contours in different formats, it is shown that representing maximum responses in ductility demand is better for the investigation of the effect of structural parameter changes on seismic demands than representations in absolute values. The presented fragility contour enables designers to practically investigate the probabilistic performance level of every possible retrofit option in a convenient manner using visualized data sets. This example demonstrates the extreme efficiency of the proposed approach in performing fragility assessments and successful application to the seismic retrofit strategies based on limit state probabilities.