• Title/Summary/Keyword: parameter variation

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A study on process parameter extraction and device characteristics of nMOSFET using DTC method (DTC방법을 사용한 nMOSFET의 공정파라메터 추출 및 소자특성에 관한 연구)

  • 이철인;장의구
    • Electrical & Electronic Materials
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    • v.9 no.8
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    • pp.799-805
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    • 1996
  • In short channel MOSFET, it is very important to establish optimal process conditions because of variation of device characteristics due to the process parameters. In this paper, we used process simulator and device characteristics caused by process parameter variation. From this simulation, it has been ' derived to the dependence relations between process parameters and device characteristics. The experimental result of fabricated short channel device according to the optimal process parameters demonstrate good device characteristics.

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Regularization Parameter Selection for Total Variation Model Based on Local Spectral Response

  • Zheng, Yuhui;Ma, Kai;Yu, Qiqiong;Zhang, Jianwei;Wang, Jin
    • Journal of Information Processing Systems
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    • v.13 no.5
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    • pp.1168-1182
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    • 2017
  • In the past decades, various image regularization methods have been introduced. Among them, total variation model has drawn much attention for the reason of its low computational complexity and well-understood mathematical behavior. However, regularization parameter estimation of total variation model is still an open problem. To deal with this problem, a novel adaptive regularization parameter selection scheme is proposed in this paper, by means of using the local spectral response, which has the capability of locally selecting the regularization parameters in a content-aware way and therefore adaptively adjusting the weights between the two terms of the total variation model. Experiment results on simulated and real noisy image show the good performance of our proposed method, in visual improvement and peak signal to noise ratio value.

LPD(Linear Parameter Dependent) System Modeling and Control of Mobile Soccer Robot

  • Kang, Jin-Shik;Rhim, Chul-Woo
    • International Journal of Control, Automation, and Systems
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    • v.1 no.2
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    • pp.243-251
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    • 2003
  • In this paper, a new model for mobile soccer robot, a type of linear system, is presented. A controller, consisting of two loops the one of which is the inner state feedback loop designed for stability and plant be well conditioned and the outer loop is a well-known PI controller designed for tracking the reference input, is suggested. Because the plant, the soccer robot, is parameter dependent, it requires the controller to be insensitive to the parameter variation. To achieve this objective, the pole-sensitivity as a pole-variation with respect to the parameter variation is defined and design algorithms for state-feedback controllers are suggested, consisting of two matrices one of which is for general pole-placement and other for parameter insensitive. This paper shows that the PI controller is equivalent to the state feedback and the cost function for reference tracking is equivalent to the LQ cost. By using these properties, we suggest a tuning procedure for the PI controller. We that the control algorithm in this paper, based on the linear system theory, is well work by simulation, and the LPD system modeling and control are more easy treatment for soccer robot.

Alternative Optimization Procedure to Parameter Design (파라미터 설계에 대한 최적화 대체방안)

  • Kwon, Yong-Man;Chang, Duk-Soon
    • Journal of the Korean Data and Information Science Society
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    • v.12 no.1
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    • pp.11-18
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    • 2001
  • Taguchi parameter design is an approach to reducing performance variation of quality characteristic value in products and processes. Taguchi has used signal-to-noise(SN) ratio to achieve the appropriate set of operating conditions where variability around target is low in the Taguchi parameter design. Many statisticians criticize the Taguchi techniques of analysis, particularly those based on SN ratio. In this paper we propose a substantially simpler optimization procedure for parameter design without resorting to SN ratio.

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Flow of casson nanofluid along permeable exponentially stretching cylinder: Variation of mass concentration profile

  • Iqbal, Waheed;Jalil, Mudassar;Khadimallah, Mohamed A.;Hussain, Muzamal;Naeem, Muhammad N.;Naim, Abdullah F. Al;Mahmoud, S.R.;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.38 no.1
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    • pp.33-45
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    • 2021
  • The Runge-Kutta method of 6th-order has been employed in this paper to analyze the flow of Casson nanofluid along permeable exponentially stretching cylinder. The modeled PDEs are changed into nonlinear ODEs through appropriate nonlinear transformations. The aim of the paper is to investigate the effects of different parameters such as Casson fluid parameter, slip parameter, suction parameter, Prandtl number, Lewis number, Brownian motion parameter, and thermophoresis parameter, with the variation of mass concentration profile. Numerical results are attained using a renowned numerical scheme shooting technique and for the authenticity of present methodlogy, the results are verified with earlier open text.

Instantaneous Current Control for Parallel Inverter with a Current Share Bus (전류공유버스를 이용한 병렬 인버터 순시 제어기 설계)

  • 이창석;김시경
    • Proceedings of the KIPE Conference
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    • 1998.07a
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    • pp.90-94
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    • 1998
  • The parallel inverter is popularly used because of its fault-tolerance capability, high-current outputs at constant voltages and system modularity. The conventional parallel inverter usually employes active and reactive power control or frequency and voltage droop control. However, these approaches have the disadvantages that the response time of parallel inverter control is slow against load and system parameter variation to calculate active, reactive power, frequency and voltage. This paper describes a novel control scheme for power equalization in parallel connected inverter. The proposed scheme has a fast power balance control response, a simplicity of implementation, and inherent peak current limiting capability since it employes a instantaneous current/voltage control with output voltage and current balance and output voltage regulation. A design procedure for the proposed parallel inverter controller is presented. Futhermore, the proposed control scheme is verified through the simulation in various cases such as the system parameter variation, the control parameter variation and the nonlinear load condition.

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A Current Sharing Circuit for the Parallel Inverter

  • Lee, Chang-Seok;Kim, Si-Kyung
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.176-181
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    • 1998
  • The parallel inverter is popularly used because of its fault-tolerance capability, high-current outputs at constant voltages and system modularity. The conventional parallel inverter usually employs active and reactive power control of frequency and voltage droop control. However, these approaches have the disadvantages that the response time of parallel inverter control is slow against load and system parameter variation to calculate active, reactive power, frequency and voltage. This paper describes a novel control scheme for power equalization in parallel-connected inverter. The proposed scheme has a fast power balance control response, a simplicity of implementation, and inherent peak current limiting capability since it employees an instantaneous current/voltage control with output voltage and current balance and output voltage regulation. A design procedure for the proposed parallel inverter controller is presented. Furthermore, the proposed control scheme is verified through the experiment in various cases such as the system parameter variation, the control parameter variation and the nonlinear load condition.

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Analysis of Nonlinear Control Characteristic for the Parameter Variation of Vector Control-Fed Induction Motors (벡터제어-구동 유도전동기의 파라미터 변동에 대한 비선형 제어특성의 해석)

  • Shon, Jin-Geun;Suk, Won-Yeob;Song, Yang-Hoi;Jeon, Hee-Jong
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.53 no.2
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    • pp.51-57
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    • 2004
  • Vector control schemes are used in inverter-fed induction motor drives to obtain high performance. Crucial to the success of the vector control scheme is the knowledge of the instantaneous position of the rotor flux. However, the position of the rotor flux change with temperature and magnetic saturation of the motor. This variation cause deterioration of both steady state and dynamic operation of the motor drives. Performance degradation is in the form of input-output torque nonlinearity and saturation of the motor. Analytic expressions are derived to evaluate the effects due to parameter sensitivity. Also, dynamic response is shown by speed command with the variation of stator and rotor resistance.

Structural detection of variation in Poisson's ratio: Monitoring system for zigzag double walled carbon nanotubes

  • Hussain, Muzamal;Asghar, Sehar;Ayed, Hamdi;Khadimallah, Mohamed A.;Alshoaibi, Adil;Tounsi, Abdelouahed
    • Advances in nano research
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    • v.12 no.4
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    • pp.345-352
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    • 2022
  • In this paper, natural frequency curves are presented for three specific end supports considering distinct values of nonlocal parameter. The vibrational behavior of zigzag double walled carbon nanotubes is investigated using wave propagation with nonlocal effect. Frequency spectra of zigzag (12, 0) double walled carbon nanotubes have been analyzed with proposed model. Effects of nonlocal parameters have been fully investigated on the natural frequency against against variation of Poisson's ratio. A slow increase in frequencies against variation of Poisson's ratio also indicates insensitivity of it for suggested nonlocal model. Moreover, decrease in frequencies with increase in nonlocal parameter authenticates the applicability of nonlocal Love shell model. Also the frequency curves for C-F are lower throughout the computation than that of C-C curves.

A Study on the Analysis of Posture Balance Based on Multi-parameter in Time Variation (시간변화에 따른 다중파라미터기반에서 자세균형의 분석 연구)

  • Kim, Jeong-Lae;Lee, Kyoung-Joung
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.11 no.5
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    • pp.151-157
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    • 2011
  • This study analyzed the posture balance of time variation for exercising body a period of time. Posture balance measured output values for the posture balance system of body moving in the multi-parameter. Posture moving variation had three methods such as open and closed eye, head moving and upper body moving. There were checked a parameter that measured vision, vestibular, somatosensory, CNS. This system was evaluated a data through the stability. This system has catched a signal for physical condition of body data such as a data acquisition system, data signal processing and feedback system. The output signal was generated Fourier analysis that using frequency of 0.1Hz, 0.1-0.5Hz, 0.5-1Hz and 1Hz over. The posture balance system will be used to support assessment for body moving the posture balance of time variation. It was expected to monitor a physical parameter for health verification system.