• Title/Summary/Keyword: Influence Vector

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Magneto-thermo-elastic response of exponentially graded piezoelectric hollow spheres

  • Allam, M.N.M.;Tantawy, R.;Zenkour, A.M.
    • Advances in Computational Design
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    • v.3 no.3
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    • pp.303-318
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    • 2018
  • This article presents a semi-analytical solution for an exponentially graded piezoelectric hollow sphere. The sphere interacts with electric displacement, elastic deformations, electric potentials, magneto-thermo-elasticity, and hygrothermal influences. The hollow sphere may be standing under both mechanical and electric potentials. Electro-magneto-elastic behavior of magnetic field vector can be described in the hollow sphere. All material, thermal and magnetic properties of hollow sphere are supposed to be graded in radial direction. A semi-analytical technique is improved to deduce all fields in which different boundary conditions for radial stress and electric potential are presented. Numerical examples for radial displacement, radial and hoop stresses, and electric potential are investigated. The influence of many parameters is studied. It is seen that the gradation of all material, thermal and magnetic properties has particular effectiveness in many applications of modern technology.

Improved DT Algorithm Based Human Action Features Detection

  • Hu, Zeyuan;Lee, Suk-Hwan;Lee, Eung-Joo
    • Journal of Korea Multimedia Society
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    • v.21 no.4
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    • pp.478-484
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    • 2018
  • The choice of the motion features influences the result of the human action recognition method directly. Many factors often influence the single feature differently, such as appearance of the human body, environment and video camera. So the accuracy of action recognition is restricted. On the bases of studying the representation and recognition of human actions, and giving fully consideration to the advantages and disadvantages of different features, the Dense Trajectories(DT) algorithm is a very classic algorithm in the field of behavior recognition feature extraction, but there are some defects in the use of optical flow images. In this paper, we will use the improved Dense Trajectories(iDT) algorithm to optimize and extract the optical flow features in the movement of human action, then we will combined with Support Vector Machine methods to identify human behavior, and use the image in the KTH database for training and testing.

Simultaneous Estimation of the Speed and the Secondary Resistance under the Transient State of Induction Motor

  • Akatsu, Kan;Kawamura, Atsuo
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.298-303
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    • 1998
  • In the speed sensorless control of the induction motor, the machine parameters (especially the secondary resistance R2) have a strong influence to the speed estimation. It is known that the simultaneous estimation of the speed and R2 is impossible in the slip frequency type vector control, because the secondary flux is constant. But the secondary flux is not always constant in the speed transient state. In this paper the R2 estimation in the transient state without adding any additional signal to the stator current is proposed. This algorithm uses the least mean square algorithm and the adaptive algorithm, and it is possible to estimate the R2 exactly. This algorithm is verified by the digital simulations and the experiments.

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The influence that cup-type shield inner vacuum interrupter causes to electric field distribution (Vacuum Interrupter 내부 End_shield가 전계분포에 미치는 영향)

  • Yoon, Jae-Hun;Kim, Byung-Chul;Her, June;Lim, Kee-Jo;Kim, Seong-Hwa
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.478-479
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    • 2008
  • this paper describes the electric field distribution interpretation along a shield form inner vacuum interrupter(VI). The equipotential line and electric field and field vector in a VI are analysed by a finite element method at various shield form. in result, The equipotential line and electric field distribution was affected to VI shield form. The reason is as it gets distortion of equipotential line done. shield of cup type is how to electric field distribution, finally, this paper recognized whether or not affected, and proposed gap with the most suitable shield length and an external insulation.

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A study on the delay-characteristics and hankel operators of input delay systems (입력 시간지연 시스템의 한켈 연산자와 지연특성에 관한 연구)

  • Ha, Hee-Kwon;Hwang, I-Cheol;Lee, Man-Hyung
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.1
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    • pp.1-7
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    • 2000
  • This paper studies the delay-characteristics using the singular values and vectors of Hankel operators for input delay systems. First, the computational method of Hankel singular values and their corresponding singular vectors are introduced, and then it is analytically provea that all the Hankel singular vlues have a monotone increasing properties as the length of delay time increases. Furthermore, through a simple numerical example, it is shown that the Hankel singular values are dependent only on the ratio of the time constant of a lumped parameter system to the length of delay , and in case that the time constant is relatively larger than the delay time, the lumped parameter characteristic has a great influence on the input delay systems.

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Direct Torque Control of Induction Motor Using Optimal Hysteresis Band Amplitude (최적의 히스테리시스 밴드 크기를 이용한 유도전동기의 직접토크제어)

  • Jeong, Byeong-Ho;Shin, Sa-Hyun;Lim, Byung-Ok;Lee, Kang-Youn;Cho, Geum-Bae;Baek, Hyung-Lae
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1208-1210
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    • 2003
  • Most of all, DTC drive is very simple in its implementation because it needs only two hysteresis comparator and switching vector table for both flux and torque control. The amplitude of hysteresis band greatly influences on the drive performance such as flux and torque ripple and inverter switching frequency. In this paper the influence of the amplitudes of flux and torque hysteresis bands and sampling time of control program on the torque and flux ripples are investigated. Simulation results confirm the superiority of the DTC under the proposed method over the conventional DTC.

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Parametric Analysis and Experimental Testing of Radial Flux Type Synchronous Permanent Magnet Coupling Based on Analytical Torque Calculations

  • Kang, Han-Bit;Choi, Jang-Young
    • Journal of Electrical Engineering and Technology
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    • v.9 no.3
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    • pp.926-931
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    • 2014
  • This paper presents the torque calculation and parametric analysis of synchronous permanent magnet couplings (SPMCs). Based on a magnetic vector potential, we obtained the analytical magnetic field solutions produced by permanent magnets (PMs). Then, the analytical solutions for a magnetic torque were obtained. All analytical results were extensively validated with the non-linear a two-dimensional (2D) finite element analysis (FEA). In particular, test results such as torque measurements are presented that confirm the analysis. Finally, using the derived analytical magnetic torque solutions, we carried out a parametric analysis to determine the influence of the design parameters on the SPMC's behavior.

Calculation of Resistance of Cage Rotor End Ring using 3-D Finite Element Method (3차원 유한요소법을 이용한 농형유도전동기 단락환의 저항계산)

  • Bak, Min-Woo;Lee, Bok-Yong;Jung, Hae-Duk;Lee, Ki-Sik
    • Proceedings of the KIEE Conference
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    • 1995.07a
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    • pp.92-94
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    • 1995
  • This paper is to describe a method for calculating resistance of cage rotor end-ring, based on 3-D finite element method using magnetic vector potential $\vec{A}$ and electric scalar potential ${\phi}$. The induced current of a cage rotor flows through the bars of a cage rotor. The current completes their closed paths by passing around the end-ring. The end-ring may contribute a significant influence to the performance of machine. The resistance under consideration of skin effect is calculate by using Joule's loss equation.

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On Development of Vibration Analysis Algorithm of Beam with Multi-Joints(II) (다관절 보의 진동해석 알고리즘 개발에 관한 연구 II)

  • 문덕홍;최명수;홍승수;강현석
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.203-209
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    • 1996
  • The authors apply the transfer influence coefficient method to the 3-dimensional vibration analysis of beam with multi-joints and formulate a general algorithm to analysis the longitudinal, flexural and torsional coupled forced vibration. In this paper, a structure, which is mainly founded in the robot arms, cranes and so on, has some crooked parts, subsystems and joints but has no closed loop in this system. It is modeled as the beam of a distributed mass system with massless translational, rotational and torsional springs in each node, and joint elements of release or roll at which node the displacement vector is discontinuous. The superiority of the present method to the transfer matrix method in the computation accuracy was confirmed from the numerical computation results. Moreover, we confirmed that boundary and intermediate conditions could be controlled by varying the values of the spring constants.

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A Modified Robust Adaptive Beamformer for Microphone Arrays

  • Lee, Young-Ho;Choi, Su-Young;Park, Jans-Sik;Son, Kyung-Sik
    • Proceedings of the Korea Multimedia Society Conference
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    • 2003.05b
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    • pp.446-449
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    • 2003
  • The conventional GSC is inappropriate in real situation when the target signal is present. The steering vector error cancels the target signal and the target signal misadjusts the weight of the adaptive filter. To prevent the target signal cancellation, the robust GSC using the constrained adaptive filters was already proposed. However, the adaptive weight misadjustment is not settled in robust GSC. This Paper proposes a revised robust sidelobe canceller with adaptive compensator. To compensate the influence of target signal, the adaptive compensator is used in cascade. In computer simulation, we show the performance improvement by comparing the robust GSC with the proposed GSC.

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