• 제목/요약/키워드: back calculation

검색결과 272건 처리시간 0.034초

청소년 수련관의 열원설비 대안별 생애주기 비용에 관한 연구 (Analysis of Life Cycle Cost for Heat Source Equipments in Buildings for Adolescent Trainees)

  • 안창환;방승기;백용규
    • KIEAE Journal
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    • 제5권3호
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    • pp.25-31
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    • 2005
  • Computer simulations were performed for Heating Ventilating and Air-Conditioning (HVAC) systems to figure out more efficient maintenance methods for the building used for adolescent trainees. This study aims at suggesting design alternatives for optimum operation and performing life cycle cost (LCC) for each alternative. First, the capacity of the heat source equipment was determined using annual maximum heating and cooling loads. Annual loads were calculated and applied to the alternative for the purpose of calculating annual energy cost. Second, several types of data were collected to predict energy cost. Finally, the pay back period for each alternative was calculated using total cost estimation during standard duration period. This study indicates that the absorption chiller that does not occupy most part of a mechanical room, and does not need much operation cost was most economical.

PI속도제어기에서의 새로운 적분누적 방지기법 (New Anti-windup Strategy for PI-type Speed Controller)

  • 최종우;이상철
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제54권12호
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    • pp.629-637
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    • 2005
  • This paper proposes a new anti-windup strategy to suppress integrator windup for PI speed controller and to be implemented on the existing system with minimal modification. When the speed control mode is changed from P controller to PI controller. an appropriate initial value for integrator is assigned. This value restricts overshoot and high settling time. Also, the proposed method guarantees the designed performance independent on operating conditions, i.e. different set-point change and load torque. Simulation and experimental results for PMSM speed controller have shown its superior performance compared with the conditional integration and tracking back calculation.

Magnetic charge를 이용한 Axial-gap 전동기의 특성해석 (Characteristic Analysis of Axial-gap Motor using Magnetic Charge)

  • 이상호;김도진;홍정표
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2007년도 제38회 하계학술대회
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    • pp.997-998
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    • 2007
  • This paper deals with analytical solution concerning the image method using the magnetic charge instead of 3D FEA(finite element analysis) in the slotless single air-gap motor. The theory of analytical method and the design procedures are introduced. The reliability and validity of proposed analytical solution are verified through the comparison with the results of commercial 3D FE software. In addition, calculation time between proposed analytical solution and 3D FEA is compared. Finally, characteristics, such as Back-EMF and phase resistance, between calculated and experimental results are compared. From the verification with 3D FEA and experimental results, it is proved that presented analytical method provided very effective and precise results.

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타원 곡선 암호 알고리즘의 네배점 스칼라 연산 (Point Quadruple Operation on Elliptic Curve Cryptography Algorithm)

  • 문상국;허창우;유광열
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2004년도 춘계종합학술대회
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    • pp.784-787
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    • 2004
  • 타원곡선 암호시스템에서의 가장 줄기가 되는 연산은 스칼라 곱셈 연산이다. 본 논문에서는 기존의 두배점-덧셈 (double-and-add) 알고리즘으로 처리하였던 스칼라 곱셈 연산을 개선하여 네배점-덧셈(fund-and-add) 알고리즘을 사용하기 위하여 네배점 (point quadruple) 연산을 유도한다. 유도된 식은 C 프로그램을 사용하여 실제 계산에 응용하여 증명하였다. 네배점 스칼라 연산은 타원곡선 암호시스템의 효율적이고 빠른 연산을 처리하는데 응용될 수 있다.

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등호제약조건을 이용한 계통 해석 및 고장판단 계산 구현 (Calculation of Network Analysis and Fault Decision using Equality Constraint Condition with MATLAB)

  • 양민욱;김건중;황인준
    • 전기학회논문지
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    • 제58권11호
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    • pp.2101-2106
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    • 2009
  • The power system state estimation and prediction are very important for operation. Because that accidents of the Power system are the cause that many devices and etc are damaged. Currently, almost every power systems have 2nd,3rd back-upsystem for prevention of accident. But prevention of accident by miss-operation, due to operator or miss data, has not acounter plan. Because, we need to estimate the power system for correcting miss data and preventing miss operation by operator. We suggest algorithm for integrity of power system network data.

전기품질 진단 시스템 개발을 위한 인공 신경망 적용에 관한 연구 (A Study on Power Quality Diagnosis System using Neural NetWorks)

  • 김진수;김영일;김광순;박기주
    • 전기학회논문지
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    • 제56권8호
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    • pp.1351-1359
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    • 2007
  • In this paper, we have studied the power quality(PQ) diagnosis system with the two methods for PQ diagnosis. One to Apply a regulation value in compliance with mathematics calculation, and the other Automatic identification using Neural network algorithm. Neural network algorithm is used for an automatic diagnosis of the PQ. The regulation proposed by IEEE 1159 Working group is applied for the precision of the diagnosis. In order to divide accurate segmentation, the algorithm for a computer training used the back propagation out of several neural network algorithms. We have configured the proto-type sample by using Labview and a programmed Neural Networks Algorithm using with C. And arbitrary electric Signal generated by OMICRON Company's CMC 256-6 for an efficiency test.

BLDC 전동기 파라메터 산정에 관한 연구 (Study for Calculation of BLDC Motor Parameter)

  • 한경희;백수현;김용;윤신용;김철진
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.134-136
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    • 2001
  • In this paper, using equivalent circuit of BLDC motor in the 30W class, process of modeling the BLDC motor and calculating the parameter is shown. Through run-down-test and measuring back EMF, torque, speed and ampere, parameter that transfer function requires was gotten. In this result, for step response of BLDC motor, comparing the actual result obtained by circuit experiment with the simulation result obtained by substituting this parameter into the transfer function, it was established that process calculating parameters in this study is proper.

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Dynamic analysis of a cable-stayed bridge using continuous formulation of 1-D linear member

  • Yu, Chih-Peng;Cheng, Chia-Chi
    • Earthquakes and Structures
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    • 제3권3_4호
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    • pp.271-295
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    • 2012
  • This paper presents the solution scheme of using the continuous formulation of 1-D linear member for the dynamic analysis of structures consisting of axially loaded members. The context describes specific applications of such scheme to the verification of experimental data obtained from field test of bridges carried out by a microwave interferometer system and velocimeters. Attention is focused on analysis outlines that may be applicable to in-situ assessment for cable-stayed bridges. The derivation of the dynamic stiffness matrix of a prismatic member with distributed properties is briefly reviewed. A back calculation formula using frequencies of two arbitrary modes of vibration is next proposed to compute the tension force in cables. Derivation of the proposed formula is based on the formulation of an axially loaded flexural member. The applications of the formulation and the proposed formula are illustrated with a series of realistic examples.

슬랙스 설계를 위한 하지동작에 따른 체표선 변화 2 (Changes in Body Surface Lines Caused By Lower Limb Movements in Designing Slacks (II))

  • 조성희
    • 한국가정과학회지
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    • 제7권3호
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    • pp.35-48
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    • 2004
  • In this study, by determining lower limb movements which cause significant changes in body surface lines, body parts with the greatest maximum expansion and contraction rate respectively were illustrated in descending order. Using unmarried female university students aged 18 - 24 as subjects, a total of 32 body surface categories (15 body surface lines and 17 body surface segment lines) were measured in one static and 9 movement poses. In particular, expansion and contraction levels and rates were measured and used in the analysis. The analysis first involved the calculation of the average measurement per body part in body surface line in static pose as well as of the average expansion and contraction levels and rates in 9 lower limb movements. Two-way MANOVA and multiple comparison analysis (Tukey) were conducted on movements and individual somatotypes regarding measurement per body part and expansion and contraction rates. Movements which cause measurements of body surface lines differed significantly in body surface line in static pose versus in movement were then identified. Among average expansion and contraction rates in such movements, maximum average expansion and contraction levels, maximum average expansion and contraction rate, and classes of expansion and contraction rate were determined per body part. The results of this study are as follows. First, 5 lower limb movements; F2, F5, F6, F7, F8, which caused significant changes in body surface lines were determined and illustrated in table 4. Second, the levels, rates, and classes of expansion and contraction rate per body part are illustrated in Tables 5 and 6. Body parts with the greatest maximum expansion rate were, in descending order: upper segment of center back leg line, upper segment of inner leg line, middle segment of center front leg line, posterior crotch length, anterior knee girth, anterior thigh girth, center back leg line, girth at crotch height, anterior midway thigh girth, hip girth, anterior crotch length, knee girth, waist girth, inner leg line, thigh girth, and crotch length. Those with the greatest maximum contraction rate were, in descending order: anterior crotch length, upper segment of center front leg line, lower segment of center back leg line, center front leg line, and posterior thigh girth. The maximum expansion rates and maximum contraction rates, which ranged from 2.05 to $35.95\%$ and from -0.20 to $-30.16\%$ respectively, were classified per body part into 4 ABCD classes. The body part with maximum expansion was the upper segment of the center back leg line at vertical body surface line, expanding by $35.95\%$ or 16.03cm in F5 flexion movement. In contrast, the body part with maximum contraction was the anterior crotch length at vertical body surface line, contracting by $-30.16\%$ or -10.54cm in F5 flexion movement. Both, however, were the body parts to expand or contract the most among all horizontal and vertical body surface lines.

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FWD 처짐곡선을 이용한 아스팔트 포장구조체의 탄성계수 추정 모형 개발 (Development of a Model for Predicting Modulus on Asphalt Pavements Using FWD Deflection Basins)

  • 박성완;황정준;황규영;박희문
    • 대한토목학회논문집
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    • 제26권5D호
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    • pp.797-804
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    • 2006
  • 본 연구에서는 비파괴 시험 장비인 FWD(Falling Weight Deflectometer)에 의한 처짐곡선을 활용하여 아스팔트 포장구조체의 물성을 합리적으로 추정할 수 있는 방법을 개발하였다. 2004년 국도 PMS(Pavement Management System)의 FWD 자료로 다층탄성이론에 근거한 역산프로그램을 사용하여 역해석을 실시하였다. 3층 포장구조체로 기반암을 고려하여 역해석을 실시하였으며, 통계분석을 통하여 각 층 탄성계수의 95% 신뢰구간을 선정하였다. 이 신뢰구간의 범위와 기존 문헌상의 범위를 비교한 결과 차이가 없었으며, 그 결과를 바탕으로 회귀분석을 실시하여 탄성계수를 직접 추정할 수 있는 회귀 분석 모델을 제시하였다. 회귀 분석모델의 적합성 및 유의성 검증, 다중공선성 분석, 잔차 분석 그리고 분산 분석을 통하여 본 연구에서 제시한 회귀 분석모델이 유의하며 높은 적합성을 갖고 있음을 증명하였다. 따라서, 본 연구에서 제시한 회귀 분석 모델을 통해 FWD 시험시 현장에서 역해석을 실시하지 않고도 직접 탄성계수를 추정하여 포장구조체의 상태평가를 할 수 있을 것으로 판단된다. 또한, 아스팔트층의 탄성계수는 온도변화에 따라 많은 차이를 나타내므로 기준온도로 온도보정을 실시하였으며 그 결과를 토대로 현재 공용중인 국도 아스팔트 포장구조체 각 층의 탄성계수와 95%신뢰구간의 탄성계수를 제시하였다.