• 제목/요약/키워드: Linear

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선형 공정계획 모델의 작업 관계성 적용 방법 (A Method of Applying Work Relationships for a Linear Scheduling Model)

  • 류한국
    • 한국건축시공학회지
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    • 제10권4호
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    • pp.31-39
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    • 2010
  • 선형 공정계획 방법은 1929년 엠파이어 스테이트 빌딩에서 그래픽한 용도로 사용되면서 현재는 다양한 작업 공간, 현장 작업과 조립 작업에 적용되고 있다. 선형 공정계획 상에 동시적인 크리티칼 패스가 발생하면 자원 관리는 작업흐름의 최적화 문제로 연결되어 유연한 작업생산성과 지속적인 자원의 할당을 하기 위해 적용되고 있다. 그러나 선형 공정계획 모델 연구에서 간과하고 있는 선형 공정계획 모델의 작업 관계성을 고려하는 것이 필요하다. 이에 본 연구는 선형 공정계획 모델에 관한 기존 연구를 분석하여 네트워크 공정표의 관계성을 선형 공정표에 적용할 수 있는 방법을 제시한다. 네트워크 공정표를 선형공정표로 변환 시에 발생하는 작업의 관계성을 고찰하고 건축물의 물리적 층수 변화와 같이 작업공간의 변화에 따라 선형 공정표에 반영되어야 할 선형 공정표상의 액티비티의 이동 문제를 고찰하여 네트워크 공정표를 선형 공정표로 호환할 수 있는 시스템 개발을 위한 기초연구를 제공하는 것이 본 연구의 목적이다.

Design of PM Excited Transverse Flux Linear Motor of Inner Mover Type

  • Kang Do-Hyun;Ahn Jong-Bo;Kim Ji-Won;Chang Jung-Hwan;Jung Soo-Jin
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제5B권2호
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    • pp.137-141
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    • 2005
  • A transverse flux, PM-exited linear motor (TFM-LM) with inner mover was designed and built. Its output power density is higher and its weight is lower than those of the conventional PM exited linear synchronous motors (PM LSM). To obtain the maximum thrust force under the given volume, the thrust force density with respect to the ratio of the slot width and the length of pole pitch is analyzed by the 3-dimension finite element method (FEM). Finally, calculated static thrust forces was compared with the experimental values. The calculated and measured performance of the transverse flux, PM-exited linear motor with inner mover revealed great potential for system improvements by reducing the mass of the linear motor. For examples, when this motor was applied to a ropeless elevator, it was possible to increase the power density by more than 400% over the conventional PM-LSM. The results of this study recommend this type of motor for the ropeless elevator or gearless direct linear driving system.

How to Improve Classical Estimators via Linear Bayes Method?

  • Wang, Lichun
    • Communications for Statistical Applications and Methods
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    • 제22권6호
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    • pp.531-542
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    • 2015
  • In this survey, we use the normal linear model to demonstrate the use of the linear Bayes method. The superiorities of linear Bayes estimator (LBE) over the classical UMVUE and MLE are established in terms of the mean squared error matrix (MSEM) criterion. Compared with the usual Bayes estimator (obtained by the MCMC method) the proposed LBE is simple and easy to use with numerical results presented to illustrate its performance. We also examine the applications of linear Bayes method to some other distributions including two-parameter exponential family, uniform distribution and inverse Gaussian distribution, and finally make some remarks.

회로 시뮬레이션을 위한 영역 분할식 구분적 선형 다이오드 모델 (Piecewise Linear Diode Models by Region Division for Circuit Simulations)

  • 박인규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.106-109
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    • 2008
  • Piecewise linear diode models are widely used for large-signal circuit analyses, especially power electronic circuit simulations. When using a piecewise linear diode model for simulation, a switching method to select a proper one among linear models is needed. The conventional switching method keeps the previous ON, OFF state information, and applies different switching conditions according to the state. However, this method has difficulties especially in extending to multi-piecewise linear models. This paper presents a switching method which appropriately divides the v-i plane into regions and select a linear model according to the region where the operating point(the voltage and the current of the diode) belongs. This switching method is easily extended to multi-Piecewise linear models. An example using the tableau analysis and the backward Euler integration is presented for verification.

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NC선반의 직선 사이클 평면 위치결정 정도 측정에 관한 연구 (A Study on Measurement of Linear Cycle Plane Positioning Accuracy of NC Lathe)

  • 김영석;송인석;정정표;한지희;윤원주
    • 한국공작기계학회논문집
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    • 제12권2호
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    • pp.53-58
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    • 2003
  • It is very important to measure linear cycle plane positioning accuracy of NC lathe as it effects all other parts of machines machined by them in industries. If the plane positioning accuracy of NC lathe is bad, the dimension accuracy and the change-ability of works will be bad in the assembly of machine parts. In this paper, computer software systems are organized to measure linear cycle plane positioning displacement of ATC(Automatic tool changer) on zx plane of NC lathe using two linear scales. And each sets of error data obtained from the test is descriptions to plots and the results of linear cycle plane positioning errors are expressed as nutriments by computer treatment.

선형 모터의 동특성 분석 (Analysis of the Dynamic Characteristics of the Linear Motors)

  • 설진수;임경화
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.258-263
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    • 2005
  • The nearest variety of the industrial world requires using the high precision and resolution positioning technology to do a semi-conductor, information field , and measurement field. It is especially important for the positioning technology that makes up a proper controller, is affected by the minimal heat and vibration, and can control a structurally generated non-linear friction factor to determine the efficiency of the system. The paper is to analyze the vibration characteristic according to the speed of linear motor and grasp the dynamic characteristic through the modal test and show the verification of the experimental result and design parameters by using FEM(Finite Element Method). Also, it shows the optimum standard analyzed the acceleration patterns of the moving part that lead to the vibration source in linear motor. It presents the analyzed dynamic of linear motor in compliance with a change of the non-linear factor.

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Linear Motor 위치 제어 성능 시험을 위한 장치 연구 (Study on a Linear Motor Dynamometer for Positioning Performance Test)

  • 노창열;김주경;노명환;이응석
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.305-308
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    • 2005
  • Linear motor has been developed for linear motion of machine tools. Linear motor is useful to design the linear motion, high speed and high accuracy, because of the simple system not required the additional mechanical part such as coupling and ballscrew. This paper tested performance of linear motor such as velocity response, position tracing performance, subordinate Traction force change and positional accuracy.

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자율이동로봇 이동음원 추적센서 개발을 위한 의사선형 도래각 추정기법 (Acoustic Source Tracker Based on Pseudo-Linear DOA Estimator for Autonomous Robots)

  • 임재일;나원상
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1788-1789
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    • 2011
  • In order to develop a one-axis gimbaled acoustic source tracker for mobile robots, a pseudo-linear direction of arrival(DOA) estimator is proposed using a linear ultrasonic sensor array. Under the assumption that the sensor measurement errors are negligible, a linear measurement model is derived using the linear prediction relation of the received sinusoidal acoustic signals. Applying the Kalman filtering technique for this model, the linear recursive DOA estimator is designed. For its linear recursive filter structure, it is preferable for real-time implementation on a commercial DSP. Through the experiments, the effectiveness of the suggested method is demonstrated.

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Nonlinear vibration of Euler-Bernoulli beams resting on linear elastic foundation

  • Javanmard, Mehran;Bayat, Mahdi;Ardakani, Alireza
    • Steel and Composite Structures
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    • 제15권4호
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    • pp.439-449
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    • 2013
  • In this study simply supported nonlinear Euler-Bernoulli beams resting on linear elastic foundation and subjected to the axial loads is investigated. A new kind of analytical technique for a non-linear problem called He's Energy Balance Method (EBM) is used to obtain the analytical solution for non-linear vibration behavior of the problem. Analytical expressions for geometrically non-linear vibration of Euler-Bernoulli beams resting on linear elastic foundation and subjected to the axial loads are provided. The effect of vibration amplitude on the non-linear frequency and buckling load is discussed. The variation of different parameter to the nonlinear frequency is considered completely in this study. The nonlinear vibration equation is analyzed numerically using Runge-Kutta $4^{th}$ technique. Comparison of Energy Balance Method (EBM) with Runge-Kutta $4^{th}$ leads to highly accurate solutions.

A SECOND ORDER UPWIND METHOD FOR LINEAR HYPERBOLIC SYSTEMS

  • Sohn, Sung-Ik;Shin, Jun-Yong
    • 대한수학회논문집
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    • 제17권1호
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    • pp.103-120
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    • 2002
  • A second order upwind method for linear hyperbolic systems is studied in this paper. The method approximates solutions as piecewise linear functions, and state variables and slopes of the linear functions for next time step are computed separately. We present a new method for the computation of slopes, derived from an upwinding difference for a derivative. For nonoscillatory solutions, a monotonicity algorithm is also proposed by modifying an existing algorithm. To validate our second order upwind method, numerical results for linear advection equations and linear systems for elastic and acoustic waves are given.