• Title/Summary/Keyword: Equivalent linear method

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Dynamic Characteristics Analysis of Linear DC Motor Using 3D Equivalent Magnetic Circuit Network Method by Voltage Driven (전압구동 3차원 등가자기회로망법을 이용한 선형 직류전동기의 동특성 해석)

  • Yeom, Sang-Bu;Ha, Kyung-Ho;Hong, Jung-Pyo;Hur, Jin
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.271-273
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    • 2000
  • This paper presents the dynamic characteristics Linear DC Motor(LDM) using 3 Dimensional Equivalent Magnetic Circuit Network Method(3-D EMCN) by voltage driven. The movement of mover substitutes for the movement of magnetization in permanent magnet expressed by Fourier series. The Dynamic characteristics are carried out from coupling the electrical circuit equation and mechanical kinetic equation.

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Characteristics Analysis of Permanent Magnet Linear Synchronous Motor in case of Skew of Permanent Magnet (영구자석형 선형 동기전동기의 영구자석 Skew시의 특성해석)

  • Jung, In-Soung;Hur, Jin;Hyun, Dong-Seok
    • Proceedings of the KIEE Conference
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    • 1998.11a
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    • pp.19-21
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    • 1998
  • The problem in improving the positioning precision of a Permanent Magnet Linear Synchronous Motor (PMLSM) is the detent force caused by the interaction of the magnets with the teeth of stator. This paper presents 3-Dimensional Equivalent Magnetic Circuit Network Method (3-D EMCN) for the analysis of PMLSM. 3-D EMCN is a numerical analysis method which supplements magnetic equivalent circuit by using numerical technique. We analyzed the fields and forces of PMLSM in case of skewed magnet and axially segmented magnet construction.

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Application of the Equivalent Frequency Response Method to Runoff Analysis

  • Mutsuhiro Fujita;Ruai Hamouda;Gaku Tanaka
    • Proceedings of the Korea Water Resources Association Conference
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    • 2000.05a
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    • pp.1-2
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    • 2000
  • This paper introduces the equivalent frequency response method (EFRM) into runoff analysis. This EFRM originally had been developed to analyze dynamic behavior of nonlinear elements such as threshold and saturation in control engineering. Many runoff models are described by nonlinear ordinary or partial differential equations. This paper presents that these nonlinear differential equations can be converted into semi-linear ones based on EFRM. The word of “a semi-linear equation” means that the coefficients of derived equations depend on average rainfall

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Development of equivalent linear algorithm procedure that accounts for the loading frequency dependent soil behavior (하중의 주파수에 지배받는 흙의 동적거동을 고려하는 등가선형해석방법 개발)

  • Park, Du-Hee;Lee, Hyun-Woo;Lee, Seung-Chan;Kim, Jae-Yeon;Chun, Byung-Sik
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.617-624
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    • 2006
  • Site response analysis is widely used in estimating local seismic site effects. The soil behavior in the analysis is assumed to be Independent of the rate of the seismic loading laboratory results, however, indicate that cohesive soil behavior is greatly influenced by the rate of loading. A new equivalent linear analysis method is developed that accounts for the rate-dependence of soil behavior and used to perform a series of one dimensional site response analyses. Results indicate that while rate-dependent shear modulus has limited influence on computed site response, rate-dependent soil damping greatly filters out high frequency components of the ground motion and thus results in lower response.

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Ductility inverse-mapping method for SDOF systems including passive dampers for varying input level of ground motion

  • Kim, Hyeong-Gook;Yoshitomi, Shinta;Tsuji, Masaaki;Takewaki, Izuru
    • Earthquakes and Structures
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    • v.3 no.1
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    • pp.59-81
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    • 2012
  • A ductility inverse-mapping method for SDOF systems including passive dampers is proposed which enables one to find the maximum acceleration of ground motion for the prescribed maximum response deformation. In the conventional capacity spectrum method, the maximum response deformation is computed through iterative procedures for the prescribed maximum acceleration of ground motion. This is because the equivalent linear model for response evaluation is described in terms of unknown maximum deformation. While successive calculations are needed, no numerically unstable iterative procedure is required in the proposed method. This ductility inverse-mapping method is applied to an SDOF model of bilinear hysteresis. The SDOF models without and with passive dampers (viscous, viscoelastic and hysteretic dampers) are taken into account to investigate the effectiveness of passive dampers for seismic retrofitting of building structures. Since the maximum response deformation is the principal parameter and specified sequentially, the proposed ductility inverse-mapping method is suitable for the implementation of the performance-based design.

Case Study of Estimate the Response Displacement for the Seismic Design of Shaft Cable Tunnel (수직전력구 내진설계를 위한 응답변위 산정에 대한 사례 조사)

  • Kim, Yong-Min;Jeong, Sang-Seom;Kim, Young-Ho;Kwon, Young-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.634-639
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    • 2009
  • The response displacement method is the most frequently used method for the seismic design of underground structures. Underground structures under seismic loading will tend to deform with the surrounding ground, and thus the structure is designed to accommodate the free-field deformation without loss of its structural integrity. This method is pseudo-static method, and response displacement of surrounding ground are most important steps. In this study, the single cosine method and the equivalent linear analysis are applied to estimate the response displacement of the real sites, and the results of the each method are compared. Response analysis was also performed with respect to bedrock depth. As a results, Equivalent linear analysis result was larger than single cosine method. And, the relative displacement becomes lager according to depth of the bedrock.

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Estimation of Smoothing Constant of Minimum Variance and Its Application to Shipping Data with Trend Removal Method

  • Takeyasu, Kazuhiro;Nagata, Keiko;Higuchi, Yuki
    • Industrial Engineering and Management Systems
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    • v.8 no.4
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    • pp.257-263
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    • 2009
  • Focusing on the idea that the equation of exponential smoothing method (ESM) is equivalent to (1, 1) order ARMA model equation, new method of estimation of smoothing constant in exponential smoothing method is proposed before by us which satisfies minimum variance of forecasting error. Theoretical solution was derived in a simple way. Mere application of ESM does not make good forecasting accuracy for the time series which has non-linear trend and/or trend by month. A new method to cope with this issue is required. In this paper, combining the trend removal method with this method, we aim to improve forecasting accuracy. An approach to this method is executed in the following method. Trend removal by a linear function is applied to the original shipping data of consumer goods. The combination of linear and non-linear function is also introduced in trend removal. For the comparison, monthly trend is removed after that. Theoretical solution of smoothing constant of ESM is calculated for both of the monthly trend removing data and the non monthly trend removing data. Then forecasting is executed on these data. The new method shows that it is useful especially for the time series that has stable characteristics and has rather strong seasonal trend and also the case that has non-linear trend. The effectiveness of this method should be examined in various cases.

Force Characteristic Analysis of Linear Switched Reluctance Motor using Dynamic Simulation (동특성 시뮬레이션을 이용한 리니어 스위치드 릴럭턴스 전동기의 힘 특성 해석)

  • Jang, Seok-Myeong;Park, Ji-Hoon;Park, Yu-Seop;Kim, Jin-Soon;Choi, Ji-Hwan
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.58-60
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    • 2009
  • This paper deals with force characteristic analysis of linear switched reluctance motor using dynamic simulation. First, we calculated flux density of linear switched reluctance motor according to position. Second, analyzed normal force from flux density of linear switched reluctance motor according to position. Also, analysis result compares with data that is derived through a finite element analysis, and proved validity. However, linear switched reluctance motor has non linear characteristic, hence, analysis of propulsion force do not easy using analytical method. Therefore, we presented dynamic characteristic analysis model which is consisted at motor and sensor signal part, etc., and substitute circuit constant that get using magnetic equivalent circuit method, we confirmed propulsion force.

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Crushing study for interlocked armor layers of unbonded flexible risers with a modified equivalent stiffness method

  • Ren, Shaofei;Liu, Wencheng;Song, Ying;Geng, Hang;Wu, Fangguang
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.11 no.1
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    • pp.521-529
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    • 2019
  • Interlocked armor layers of unbonded flexible risers may crush when risers are being launched. In order to predict the behavior of interlocked armor layers, they are usually simplified as rings with geometric and contact nonlinearity ignored in the open-literature. However, the equivalent thickness of the interlocked armor layer has not been addressed yet. In the present paper, a geometric coefficient ${\gamma}$ is introduced to the equivalent stiffness method, and a linear relationship between ${\gamma}$ and geometric parameters of interlocked armor layers is validated by analytical and finite element models. Radial stiffness and equivalent thickness of interlocked armor layers are compared with experiments and different equivalent methods, which show that the present method has a higher accuracy. Furthermore, hoop stress distribution of interlocked armor layer under crushing is predicted, which indicates the interlocked armor layer can be divided into two compression and two expansion zones by four symmetrically distributed singular points.

Statistical Analysis of Random Ship Rolling Using Equivalent Linearization Method (등가선형화방법을 이용한 선체의 불규칙 횡동요 운동의 통계적 해석)

  • Dong-Soo Kim;Won-Kyoung Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.30 no.4
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    • pp.39-45
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    • 1993
  • In order to analyze the rolling motion of a ship in random beam waves we have used the equivalent linearization method. The quadratic nonlinear damping, the cubic and quintic nonlinear restoring moments were added to a single degree of freedom linear equation of roll motion. The irregular excitation moment was assumed to be the Gaussian white noise. The statistical characteristic of the response by the equivalent linearization method was compared with the simulation result.

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