• Title/Summary/Keyword: load computation

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Wind Load Analysis owing to the Computation Fluid Dynamics and Wind Tunnel Test of a Container Crane (컨테이너 크레인의 전산유동해석과 풍동실험에 의한 풍하중 분석)

  • Lee, Su-Hong;Han, Dong-Seop;Han, Geun-Jo
    • Journal of Navigation and Port Research
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    • v.33 no.3
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    • pp.215-220
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    • 2009
  • Container cranes are vulnerable structure to difficult weather conditions bemuse there is no shielding facility to protect them from strong wind. This study was carried out to analyze the effect of wind load on the structure of a container crane according to the change of the boom shape using wind tunnel test and computation fluid dynamics. And we provide a container crane designer with data which am be used in a wind resistance design of a container crane assuming that a wind load 75m/s wind velocity is applied in a container crane. In this study, we applied mean wind load conformed to 'Design Criteria of Wind Load' in 'Load Criteria of Building Structures' and an external fluid field was divided as interval of 10 degrees to analyze the effect according to a wind direction. In this conditions, we carried out the wind tunnel test and the computation fluid dynamic analysis and than we analyzed the wind load which was needed to design the container crane.

An Efficient Correlation Scheme for the GPS Software Receiver

  • Lim, Deok-Won;Cho, Deuk-Jae;Park, Chan-Sik;Lee, Sang-Jeong
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1216-1221
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    • 2005
  • The GPS software receiver based on the SDR(Software Defined Radio) technology provides the ability to easily adopt other signal processing algorithms without changing or modifying the hardware of the GPS receiver. However, it is difficult to implement the GPS software receiver using a commercial processor because of heavy computation load for processing the GPS signals in real time. This paper proposes an efficient GPS signal processing scheme and correlator structure to reduce the computation load for processing the GPS signal in the GPS software receiver, which uses a patterned look-up table method to generate the correlation value between the GPS signals and the replica signals. In this paper, it is explained that the computation load of the proposed scheme is much smaller than that of the previous GPS signal processing scheme. Finally, the processing time of the proposed scheme is compared with that of the previous scheme, and the improvement is shown from the viewpoint of the computation load.

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Optimal Distributed Computation with Communication Delays (통신지연이 있는 분산처리의 최적화)

  • Kim, Hyoung-Joong;Jee, Gyu-In;Lee, Jang-Gyu
    • Proceedings of the KIEE Conference
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    • 1991.07a
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    • pp.748-752
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    • 1991
  • Tree network consisting of communicating processors is considered. The objective is to minimize the computation time by distributing the processing load to other nodes. The effect of the order of load distribution on the processing time is addressed. An algorithm which optimally determines the order of load distribution is developed. It is shown that the order depends only on the channel capacity between nodes but not on the computing capability of each node.

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Wind Load Analysis of 61ton-class Container Crane using the Computation Fluid Dynamics (61ton 컨테이너 크레인의 전산유동해석을 통한 풍하중 분석)

  • Lee, Su-Hong;Lee, Seong-Wook;Han, Dong-Seop;Kim, Tae-Hyung;Han, Geun-Jo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2007.12a
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    • pp.228-229
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    • 2007
  • Container cranes are vulnerable structure to difficult weather conditions because there is no shielding facility to protect them from high wind This study carried out to analyze the wind load have an effect on container crane according to a wind direction variation The container crane for this research is a model of a 61-ton class tint used broadly in the current ports. The dimension of an external fluid field set up 500m ${\times}$ 200m. In this study, Mean wind load conformed to the 'Design Criteria of Wind Load' in 'Load Criteria of Building Structures' and an external fluid field divided in interval of 10 degrees to analyze effect according to a wind direction From there, we carried out to the computation fluid dynamic analysis using a CFX-10 Therefore as consequence of computation fluid dynamic analysis and wind velocity experiment make a comparative study, we analyzed a wind load for construction design if container crane.

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Wind Load Analysis of 61ton-class Container Crane using the Computation Fluid Dynamics (61ton 컨테이너 크레인의 전산유동해석을 통한 풍하중 분석)

  • Lee, Su-Hong;Lee, Seong-Wook;Han, Dong-Seop;Kim, Tae-Hyung;Han, Geun-Jo
    • Journal of Navigation and Port Research
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    • v.32 no.3
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    • pp.251-255
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    • 2008
  • Container cranes are vulnerable structure about difficult weather conditions bemuse there is no shielding facility to protect them from the strong wind. This study was carried out to analyze the wind load which have an effect on container crane according to the various wind direction. The container crane is a model of a 61-ton class that used broadly in the current ports. The external fluid field was figured as a cylinder which was set up $500m{\times}200m$. In this study, we applied mean wind load conformed to 'Design Criteria of Wind Load' in 'Load Criteria of Building Structures' and an external fluid field was divided as interval of 10 degrees to analyze effect according to a wind direction In this conditions, we carried out the computation fluid dynamic analysis using the CFX-10. As we compared computation fluid dynamic analysis with wind tunnel test, we analyzed the wind load which was needed to design the container crane.

Estimation of load and resistance factors based on the fourth moment method

  • Lu, Zhao-Hui;Zhao, Yan-Gang;Ang, Alfredo H.S.
    • Structural Engineering and Mechanics
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    • v.36 no.1
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    • pp.19-36
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    • 2010
  • The load and resistance factors are generally obtained using the First Order Reliability Method (FORM), in which the design point should be determined and derivative-based iterations have to be used. In this paper, a simple method for estimating the load and resistance factors using the first four moments of the basic random variables is proposed and a simple formula for the target mean resistance is also proposed to avoid iteration computation. Unlike the currently used method, the load and resistance factors can be determined using the proposed method even when the probability density functions (PDFs) of the basic random variables are not available. Moreover, the proposed method does not need either the iterative computation of derivatives or any design points. Thus, the present method provides a more convenient and effective way to estimate the load and resistance factors in practical engineering. Numerical examples are presented to demonstrate the advantages of the proposed fourth moment method for determining the load and resistance factors.

Penalty Factor Computation Algorithms for Economic Load Dispatch Based on B-Coefficient and AC Load Flow and their Performance Comparison (경제급전을 위한 B-계수와 조류계산에 의한 페널티계수 산정법의 개발 및 성능비교)

  • Nam, H.K.;Moon, Y.H.;Choi, H.K.;NamKung, J.Y.
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.206-209
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    • 1999
  • This paper presents an improved method of calculating the penalty factors for economic load dispatch based on B-coefficient and AC load flow and their performance comparison. The algorithm for calculating B-coefficients by Meyer is improved and its performance is compared with that of AC load flow. The B-coefficient method is superior to the load flow method in its simplicity and computation speed. However accuracy of the B-coefficient method is not satisfactory when it is applied to the ill-conditioned systems where generators produce excessive reactive power.

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Verification Experiment and Calculation of Heating Load for a Test Space (시험공간에 대한 난방부하 실증실험 및 계산)

  • 현석균;홍희기;유호선
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.14 no.2
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    • pp.153-160
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    • 2002
  • As a way to assess the reliability of programs for building energy analysis, verification experiment and calculation of heating load are simultaneously conducted for a well-defined test space. Experimental conditions are carefully set to minimize uncertainties associated with radiation heating, air change, infiltration, and room-to-room interaction. Dyna- mic load calculations using TRNSYS, which are performed for two different computation domains, rely on the energy rate control that represents inherent load characteristics of a space. The predicted instantaneous heating load favorably simulates the overall behavior the measured one, though the latter fluctuates much more rapidly than the former Comparison of the accumulative load between the experiment and calculations shows a close agreement within an engineering tolerance, regardless of the computation model. It is deduced from such findings that the present experimental results along with weather information can serve as a set of reference data for validating load calculation softwares from the users'standpoint. In order to enhance the completeness of this work, a complementary study on the cooling load for the same test space is highly recommended.

The Analysis of a Wind Load on a Container Crane Using a Computation Fluid Dynamics

  • Kwon, Soon-Kyu;Lee, Seong-Wook;Han, Dong-Seop;Han, Geun-Jo
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.325-328
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    • 2006
  • This study analyzed the fluid state around a container crane according to a wind direction when a wind load was applied to a container crane. The container crane for this research is a model of a 50-ton class used broadly in the current ports. The dimension of an external fluid field is $500m{\times}200m$. This study considered the change of a wind velocity according to an altitude in a criterion of a wind velocity, 50m/s, applying a power series law. An incident angle applied to an interval of 30 degrees in $0^{\circ}C$ ${\sim}$ $180^{\circ}C$ and this study carried out a computation fluid dynamics using a CFX 10. In this study, we indicate the wind pressure and coefficient according to the height and section figure of each member. In addition, we suggest the wind load according to a wind direction.

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