• 제목/요약/키워드: calculation method

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Intermittent Heating and Cooling Load Calculation Method -Comparing with ISO 13790

  • Lee, Sang-Hoon
    • Architectural research
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    • 제14권1호
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    • pp.11-18
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    • 2012
  • College of Architecture, Georgia Institute of Technology, Atlanta, GA, US Abstract The intermittent heating and cooling energy need calculation of the ISO 13790 monthly method was examined. The current ISO 13790 method applies a reduction factor to the continuous heating and cooling need calculation result to derive the intermittent heating and cooling for each month. This paper proposes a method for the intermittent energy need calculation based on the internal mean temperature calculation. The internal temperature calculation procedure was introduced considering the heat-balance taking into account of heat gain, heat loss, and thermal inertia for reduced heating and cooling period. Then, the calculated internal mean temperature was used for the intermittent heating and cooling energy need calculation. The calculation results from the proposed method were compared to the current ISO 13790 method and validated with a dynamic simulation using EnergyPlus. The study indicates that the intermittent heating and cooling energy need calculation method using the proposed model improves transparency of the current ISO 13790 method and draws more rational outcomes in the monthly heating and cooling energy need calculation.

선박복원력(船舶復原力)의 간이계산법(簡易計算法) (Note on a Simplified Method for Calculation of Stability)

  • 김효철
    • 대한조선학회지
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    • 제15권1호
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    • pp.7-9
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    • 1978
  • In this calculation of statical stability of a ship, mechanical integrator was used most popularly and the direct calculation method such as a Barn's wedge method was also adopted in some cases. Both of the above method was developed for manual calculation which include mechanical integration or drafting procedure on body plan. Therefore, the computerization of stability calculation by the above method is very difficult. In this paper a simplified method for stability calculation is suggested, with based on hydrostatic data and immerged wedged characteristics.

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택시운임 산정방법에 대한 연구 (A Study on the Method of Taxi Fare Calculation)

  • 노경호
    • 경영과정보연구
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    • 제23권
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    • pp.201-231
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    • 2007
  • Taxi is one of the representative transpotation method in Korea. This is the study on the method of taxi fare calculation. So this study tries to find out the resonable method of taxi fare calculation. Many research institutes have tried to find out good method of taxi fare calculation. Until now, there has not been any standard method of taxi fare calculation. So the purpose of this study is to provide the best method of taxi fare calculation. This is the example of the method of taxi fare calculation. Both studies of related literature and empirical investigation have been reviewed to accomplish the purpose of this study.

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상수관망에서 누수탐지를 위한 역추적계산법 (Back Tracing Calculation Method for the Leakage Detection in Water Distribution System)

  • 권혁재
    • 상하수도학회지
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    • 제27권5호
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    • pp.611-619
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    • 2013
  • In this study, Back Tracing Calculation Method was developed to determine the leakage location and leakage amount. Previously developed determination method of monitoring location and newly developed Back Tracing Calculation Method were applied to the sample pipe network and real size pilot plant. After leakage was assumed in the pilot plant, leakage location and leakage amount could be traced by Back Tracing Calculation Method. From the results, it was found that Back Tracing Calculation Method can be applied for the leakage detection in water distribution system. Furthermore, this method can be applied for the pressure management or leakage detection as a pressure control method in water distribution system.

기울기-처짐법에 의한 유조선의 입체 강도 해석 (On the Calculation of 3-Dimensional Strength of Oil Tanker by Slope -Deflection Method)

  • 임상전;김지호
    • 대한조선학회지
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    • 제23권3호
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    • pp.27-38
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    • 1986
  • In the recent years, the finite element method has been a leading method in calculating the strength of ship hull structural members. But such a calculation has many difficulties in constructing data, reducing CPU-time and connecting it with optimal design. This paper describes more efficient method for three dimensional strength calculation of the hull structure of oil tanker by using the slope-deflection method, and the computer program based on this method is developed. The results of the calculation by using this method are compared with those by using the SAP4 program based on the finite element method. Some advantages are obtained from the application of the slop-deflection method described in this paper in the calculation of the hull structure oil tanker.

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녹지의 산출방법이 습도변화에 미치는 영향 (Humidity Variation by Green Space Calculation Method)

  • 윤용한;박헌
    • 아시안잔디학회지
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    • 제16권1호
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    • pp.41-47
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    • 2002
  • 본 연구는 녹지의 계층구조 등이 다양한 도시녹지를 대상으로 그 산출방법이 습도변화에 미치는 영향을 정량적으로 파악하기 위해 녹지내의 습도분포를 관측하였다. 그 데이터를 바탕으로 녹지의 토지피복현황과 습도분포, 식재의 산출방법과 습도, 식재의 계층구조의 산출방법과 습도와의 관련성을 회귀분석 등에 의해 해석하였다. 그 결과, 토지피복현황뿐만 아니라 녹지의 산출방법이 습도변화에 많은 영향을 미치고 있다. 또한, 식재율(평면적) 및 식재량(입체적)의 증가는 습도상승에 효과적이다. 더욱이 계층구조가 다양한 식재를 대상으로 그 산출방법과 습도상승과의 관계를 회귀계수와 상관계수를 통해 비교하면, 식재를 산출할 경우에는 평면적인 방법보다 입체적인 방법이 습도상승에 미치는 효과(수치)가 컸다. 앞으로 습도상승효과의 지표로서 식재의 산출은 입체적인 방법의 활용을 제안한다.

이차함수 근사화를 이용한 가용송전용량과 송전신뢰 및 설비편익 여유도 산정 (Calculation of CBM, TRM and ATC using Quadratic Function Approximation)

  • 이효상;신상헌;신동준;김진오
    • 대한전기학회논문지:전력기술부문A
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    • 제53권5호
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    • pp.296-301
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    • 2004
  • The Available Transfer Capability (ATC) is defined as the measure of the transfer capability remaining in the physical transmission network for further commercial activity above already committed uses. Available Transfer Capability (ATC) calculation is a complicated task, which involves the determination I of total transfer capability (TTC), transmission reliability margin (TRM) and capability benefit margin (CBM). As the electrical power industry is restructured and the electrical power exchange is updated per hour, it is important to accurately and rapidly quantify the available transfer capability (ATC) of the transmission system. In ATC calculation,. the existing CPF method is accurate but it has long calculation time. On the contrary, the method using PTDF is fast but it has relatively a considerable error. This paper proposed QFA method, which can reduce calculation time comparing with CPF method and has few errors in ATC calculation. It proved that the method can calculate ATC more fast and accurately in case study using IEEE 24 bus RTS.

Numerical calculation method for response of friction pendulum system when XY shear keys are sheared asynchronously

  • Wei, Biao;Fu, Yunji;Jiang, Lizhong;Li, Shanshan
    • Structural Engineering and Mechanics
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    • 제81권5호
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    • pp.591-606
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    • 2022
  • When the friction pendulum system and shear keys work together to resist the ground motion, which inclined inputs (non 45°) to the bridge structure, the shear keys in XY direction will be sheared asynchronously, endowed the friction pendulum system with a violent curvilinear motion on the sliding surface during earthquakes. In view of this situation, firstly, this paper abandons the equivalent linearization model of friction and constructs a Spring-Coulomb friction plane isolation system with XY shear keys, and then makes a detailed mechanical analysis of the movement process of friction pendulum system, next, this paper establishes the mathematical model of structural time history response calculation by using the step-by-step integration method, finally, it compiles the corresponding computer program to realize the numerical calculation. The results show that the calculation method in this paper takes advantage of the characteristic that the friction force is always µmg, and creatively uses the "circle making method" to express the change process of the friction force and resultant force of the friction pendulum system in any calculation time step, which can effectively solve the temporal nonlinear action of the plane friction; Compared with the response obtained by the calculation method in this paper, the peak values of acceleration response and displacement response calculated by the unidirectional calculation model, which used in the traditional research of the friction pendulum system, are smaller, so the unidirectional calculation model is not safe.

Development of a magnetic field calculation program for air-core solenoids which can control the precision of a magnetic field

  • Huang, Li;Lee, Sangjin
    • 한국초전도ㆍ저온공학회논문지
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    • 제16권4호
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    • pp.53-56
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    • 2014
  • A numerical method of magnetic field calculation for the air-core solenoid is presented in this paper. In application of the Biot-Savart law, the magnetic field induced from the source current can be obtained by a double integration ormula. The numerical method named composite Simpson's rule for the integration is applied to the program and the adaptive quadrature method is used to adjust the step size in the calculation according to the precision we need. When the target point is in the solenoid and the intergrand's denominator may be zeroin the process of calculation, the method sill can provide an appropriate result. We have developed a program which calculates the magnetic field with at least 1ppm precision and named it as rzBI() to implement this method. The method has been used in the design of an MRI magnet, and the result show it is very flexible and convenient.

Sample Size Comparison for Non-Inferiority Trials

  • Kim, Dong-Wook;Kim, Dong-Jae
    • Journal of the Korean Data and Information Science Society
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    • 제18권2호
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    • pp.411-418
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    • 2007
  • Sample size calculation is very important in clinical trials. In this paper, we propose sample size calculation method for non-inferiority trials using sample size calculation method suggested by Wang et al.(2003) based on Wilcoxon's rank sum test. Also, sample size comparison between parametric method and proposed method are presented.

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