• Structural Engineering and Mechanics
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• 제6권4호
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• pp.439-455
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• 1998

A three-dimensional static nonlinear finite element analysis was performed on the NUPEC large-scale flanged shear wall, which was the subject of an international study program. Details of the constitutive models and analysis procedures used are provided, and the results of the analysis are presented and discussed. The analytical results are compared to the experimentally observed behaviour, and reasonable correlation is observed. Deficiencies in the modelling are identified. In addition, a parametric study is undertaken to investigate factors and mechanisms influencing both the observed behaviour and the calculated response. Finally, a cyclic load analysis of the wall is described and discussed. The paper serves to point out aspects in modelling that are critical to both producing realistic results, and correctly interpreting those results.

• Advances in nano research
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• 제13권1호
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• pp.63-75
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• 2022

The nonlinear dynamic behavior of a nonuniform small-scale nonlocal beam is investigated in this work. The nanobeam is theoretically modeled using the nonlocal Eringen theory, as well as a few of Von-nonlinear Kármán's theories and the classical beam theory. The Hamilton principle extracts partial differential equations (PDE) of an axially functionally graded (AFG) nano-scale beam consisting of SUS304 and Si₃N₄ throughout its length, and an elastic Winkler-Pasternak substrate supports the tapered AFG nanobeam. The beam thickness is a function of beam length, and it constantly varies throughout the length of the beam. The numerical solution strategy employs an iteration methodology connected with the generalized differential quadratic method (GDQM) to calculate the nonlinear outcomes. The nonlinear numerical results are presented in detail to examine the impact of various parameters such as nonlinear amplitude, nonlocal parameter, the component of the elastic foundation, rate of cross-section change, and volume fraction parameter on the linear and nonlinear free vibration characteristics of AFG nanobeam.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2827-2830
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• 2003

Tele manipulator is distingushed from industrial robot by iterating same specified work. Manipulator operator is included in control loop for controlling the telemanipulator because he decide directly during the work and order controllabily reducing the modelling error of telemanipulator which depend on the PID controller. But position-force control method of bidirectional control impose unsafety of vibiration and Analytic Hierachy Method can stabilize for reducing nonlinear modelling error by expert operator because of transformation empirical control rule to linear model.

• 대한전자공학회논문지
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• 제25권2호
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• pp.162-167
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• 1988

In this note, we present some sufficient conditions on the structure of modelling uncertainties for output regualtion of uncertain systems. It turns out that these conditions include as special cases the ordinary matching conditions for stage regulation of uncertain systems and the disturbance decoupling condition. the previous restrictions on the structure of modelling uncertainties can be considerably relaxed in the case of output regulation. The significance of out result is illuminated through a simple example.

• Computers and Concrete
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• 제1권1호
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• pp.99-113
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• 2004

The article reports data on, and numerical modelling of, beams exhibiting points of inflection and subjected to sequential loading. Both tests and analysis point to inadequacies in current codes of practice. An alternative design methodology, which is strongly associated with the notion that contraflexure points should be designed as "internal supports", is shown to produce superior performance even though it requires significantly less secondary reinforcement than that advocated by codes.

• 대한치과보철학회:학술대회논문집
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• 대한치과보철학회 2002년도 추계학술대회
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• pp.92-92
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• 2002

• Structural Engineering and Mechanics
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• 제61권5호
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• pp.593-603
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• 2017

A high-efficiency simplified modelling approach is proposed for investigating the nonlinear responses of reinforced concrete linings of shield tunnels. Material and geometric nonlinearities are considered in the analysis of the lining structures undergoing large deformation before ultimately losing the load-carrying capacity. A beam-spring element model is developed to capture the force-transfer mechanism between lining segments and radial joints. The developed model is validated by comparing analyzed results to experimental results of a single-ring lining structure under two loading conditions: the ground overloading and the lateral unloading respectively. The results show that the lining structure under the lateral unloading due to excavation on the both sides of the tunnel is more vulnerable compared to the case of ground overloading on the top of the tunnel. A parameter study is conducted and results indicate that the lateral pressure coefficient has the greatest influence on the behaviour of the lining structure.

• 한국정보통신학회논문지
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• 제7권8호
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• pp.1612-1620
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• 2003

본 논문에서는 GaAsFET 전력증폭기를 다중반송 통신시스템에서 적용시키고자 설계한 PA증폭기의 측정된 전달함수를 비선형 모델링 한 결과를 제시하였으며 모델링 한 결과를 가지고 설계한 RF 증폭기의 AM­AM 및 AM­PM 비선형 특성을 추정하였다. 추정된 비선형특성 의하여 다중반송전송시스템에서의 증폭기의 근접채널간섭특성(ACPR), QPSK 및 64­QAM과 같은 디지털 변조 신호에 대하여 성상도에서의 데이터 오차벡터의 크기(EVM) 및 BER 관계를 분석하였다. 본 연구에서 제시한 RF GaAs FET의 비선형 모델링은 OFDM을 이용하는 무선 다중반송전송시스템 설계에 적용할 수 있으며 전력증폭기와 디지털 변조 신호에 따른 비선형 관계를 정확하게 추정할 수 있다.

• 대한전기학회논문지:시스템및제어부문D
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• 제51권12호
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• pp.562-570
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• 2002

The Purpose of this paper is to design and manufacture an educational system in order to demonstrate the causes and effects of electromagnetic induction.'rho educational system described in this study is a "jumping ring apparatus". This system demonstrates the principle of electromagnetic induction, a force from AC sources, Lenz's law of repulsion and transformer. The educational system is composed of a jumping ring apparatus, a sensor array, encoder, A/D converter, D/A converter and nonlinear controller. The educational system is controlled by 586 PC using Turbo C program. The sensor array is composed of 20 optical sensors. The nonlinear controller consists of nonlinear control algorithm and control board included SCR, FET and phase controller. The A/D converter is used to show the height of ring position to analog for an education purpose. The control signal calculated from the nonlinear control of algorithm send control board through 8 bit D/A convertor. Experiment results are given to verify that Proposed nonlinear controller is useful in on line control of the educational system.al system.

• 전기학회논문지
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• 제59권5호
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• pp.1001-1004
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• 2010

Acoustic feedback and background noise variation can degrade the performance of an active noise control (ANC) system. In this paper, nonlinear ANC using a non-parametric VSS-NLMS (or NPVSS-NLMS) algorithm and online feedback path modeling is proposed, whereby the conventional linear ANC with online acoustic feedback-path modeling is further extended to nonlinear Volterra ANC with a linear acoustic feedback path. In particular, the step-size of the NPVSS-NLMS algorithm is controlled to reduce the effect of background noise variation in the ANC system. Simulation results demonstrate that the proposed approach yields better nonlinear ANC performance compared with the conventional nonlinear ANC method.