• Title/Summary/Keyword: Linear response

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Nonlinear response of laterally loaded rigid piles in sand

  • Qin, Hongyu;Guo, Wei Dong
    • Geomechanics and Engineering
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    • v.7 no.6
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    • pp.679-703
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    • 2014
  • This paper investigates nonlinear response of 51 laterally loaded rigid piles in sand. Measured response of each pile test was used to deduce input parameters of modulus of subgrade reaction and the gradient of the linear limiting force profile using elastic-plastic solutions. Normalised load - displacement and/or moment - rotation curves and in some cases bending moment and displacement distributions with depth are provided for all the pile tests, to show the effect of load eccentricity on the nonlinear pile response and pile capacity. The values of modulus of subgrade reaction and the gradient of the linear limiting force profile may be used in the design of laterally loaded rigid piles in sand.

Dynamic Characteristic Identification on Steel Column bases Installed in Pendulum-type Earthquake Response Observatory

  • Choi, Jae-Hyouk;Ohi, Kenichi
    • Journal of Mechanical Science and Technology
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    • v.18 no.12
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    • pp.2225-2235
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    • 2004
  • An observatory termed 'Steel Swing' has been developed, where a 15000 kg pendulum is hanged from a stiff steel frame. A building element can be tested after inserted between the pendulum and the frame. Free vibration, forced vibration tests and earthquake monitoring were performed on an exposed-type steel column base. The response records monitored during natural earthquakes were used to identify the vibration property of the specimen. Identified system gain was approximated by a theoretical gain of linear SDOF system, and the response calculated based on such a linear system agrees with the monitored response fairly well. This research technique can be applied to check the behaviors of new materials and new details of connections and the safety of non-structural elements as well.

Transient Response Analysis of DC Voltage Regulating System with Amplidyne Saturation Effect (Amplidyne의 포화현상을 고려한 직류정전압계통의 과도응답 해석)

  • 이승원;김남호
    • 전기의세계
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    • v.26 no.6
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    • pp.55-58
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    • 1977
  • This paper deals with the transient analysis of an amplidyne dc voltage regulating system under the following conditions: (1) assuming all the components of the system to be linear, (2) considering the effect of amplidyne saturation. The mathematical technique employed is state variables method. The calculated response curves are compared with the experimental results obtained on a practical system. The main results can be summerized as follows: 1) The effect of amplidyne saturation on the transient response of a dc voltage regulating system is to reduce the overshoot and setting time. 2) With the increase in level of the step reference voltage, the system response becomes apesiodic. 3) The steady output voltage is reduced appreciably compared to the linear case.

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Identification of Dynamic Characteristics of Gimbals for Line-of-Sight Stabilization Using Signal Compression Method (신호 압축법을 이용한 시선안정화 제어용 짐벌의 동특성 규명)

  • Kim, Moon-Sik;Yoo, Gi-Sung;Yun, Jung-Joo;Lee, Min-Cheol
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.7
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    • pp.72-78
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    • 2008
  • The line-of-sight(LOS) stabilization system is a precision electro-mechanical gimbals assembly for suppressing vibration due to its environment and tracking the target in a desired direction. This paper describes the design of gimbals system to reject the disturbance and to improve stabilization. The controller consists of a DSP with transducer and actuator interfaces. Unknown parameters of the gimbals are estimated by the signal compression method. The cross-correlation coefficient between the impulse response from the assumed model and the one from model of the gimbals is used to obtain the better estimation. The quasi-impulse response through linear element included in the gimbals could be obtained by the signal compression method. The unknown parameter of the linear element could be estimated as comparing the bode plots for impulse response from gimbals with them from model's response.

Optimal Design of Permanent Magnet Linear Synchronous Motor(PMLSM) Considering Multiple Response by Response Surface Methodology(RSM) (영구자석 선형 동기전동기(PMLSM)의 반응표면법(RSM)을 이용한 다중 반응 최적설계)

  • Kim Sung-Il;Nam Hyuk;Kim Young-Kyoun;Hong Jung-Pyo;Cho Han-Ik
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.1097-1099
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    • 2004
  • This paper deals with the optimal design of a slotless type of permanent magnet linear synchronous motor (PMLSM). Response surface methodology, one of the optimization methods, is used to consider multiple response of the PMLSM. That is, it is applied to obtain more average thrust and less thrust ripple than prototype PMLSM. To analyze quickly, characteristic analysis of the PMLSM is performed by space harmonic method and final results of optimized PMLSM are compare with those of prototype PMLSM through finite element analysis.

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Vibration Analysis on the Ground by 2D FEM (2차원 유한요소법을 이용한 지반의 진동에 대한 동적응답해석)

  • 황성춘;박춘식;정성교
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.10a
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    • pp.365-370
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    • 1999
  • In this paper, dynamic response analysis on the ground movement applied traffic load by 2D finite element procedure has been studied. In particular, The paper deal with pointing acceleration method that applied AFIMEX Code as like 2D-FLUSH using equivalent linear method. As the result, it is found that dynamic response analysis by pointing acceleration method expressed ground movement by traffic load exactly.

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Flow Prediction by Analytical Response Function (해석적 해법에 의한 흐름의 예측)

  • 윤태훈
    • Water for future
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    • v.8 no.2
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    • pp.93-99
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    • 1975
  • A linear and optimum linear systems have been reviewed in some detail. The procedure of the solution of the Wiener-Hopf equation analytically in time domain is given and the prediction of downstream outflow for given upstream inflow are made. The predicted results are fairly satisfaotory. The intended physical interpretation of the analytical solution could be descriptable but it was found that the evaluation of the parameters of the response function is rather difficult due to complicacy and a great deal of works.

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Robust FIR filter for Linear Discrete-time System

  • Quan, Zhong-Hua;Han, Soo-Hee;Kwon, Wook-Hyun
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2548-2551
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    • 2005
  • In this paper, a robust receding horizon finite impulse response(FIR) filter is proposed for a class of linear discrete time systems with uncertainty satisfying an integral quadratic constraint. The robust state estimation problem involves constructing the set of all possible states at the current time consistent with given system input, output measurements and the integral quadratic constraint.

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Optimal Design and Development of Electromagnetic Linear Actuator for Mass Flow Controller

  • Chung, Myung-Jin;Gweon, Dae-Gab
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.40-47
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    • 2003
  • In this paper, we constructed the analytic model of control valve as a function of electric and geometric parameters, and analyzed the influence of the design parameters on the dynamic characteristics. For improving the dynamic characteristics, optimal design is conducted by applying sequential quadratic programming method to the analytic model. This optimal design aims to minimize the response time and maximize force efficiency. By this procedure, control valve can be designed to have fast response in motion.

Modelling Count Responses with Overdispersion

  • Jeong, Kwang Mo
    • Communications for Statistical Applications and Methods
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    • v.19 no.6
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    • pp.761-770
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    • 2012
  • We frequently encounter outcomes of count that have extra variation. This paper considers several alternative models for overdispersed count responses such as a quasi-Poisson model, zero-inflated Poisson model and a negative binomial model with a special focus on a generalized linear mixed model. We also explain various goodness-of-fit criteria by discussing their appropriateness of applicability and cautions on misuses according to the patterns of response categories. The overdispersion models for counts data have been explained through two examples with different response patterns.