• Title, Summary, Keyword: process parameter

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An Approximation Theorem for Two-Parameter Wiener Process

  • Kim, Yoon-Tae
    • Journal of the Korean Statistical Society
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    • v.26 no.1
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    • pp.75-88
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    • 1997
  • In this paper, a two-parameter version of Ikeda-Watanabe's mollifiers approximation of the Brownian motion is considered, and an approximation theorem corresponding to the one parameter case is proved. Using this approximation, we formulate Wong-Zakai type theorem is a Stochastic Differential Equation (SDE) driven by a two-parameter Wiener process.

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A Simulation Method of PID Tuning with Process Modeling in Operating Nuclear Power Plants (가동원전에서 공정모델링을 통한 PID 튜닝 시뮬레이션 방법)

  • Min, Moon-Gi;Jung, Chang-Gyu;Lee, Kwang-Hyun;Lee, Jae-Ki;Kim, Hee-Je
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.4
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    • pp.290-294
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    • 2014
  • PID(Proportional, Integral, Derivative) controller is the most popular process controllers in nuclear power plants. The optimized parameter setting of the process controller contributes to the stable operation and the efficiency of the operating nuclear power plants. PID parameter setting is tuned when new process control systems are installed or current process control systems are changed. When the nuclear plant is shut down, a lot of PID tuning methods such as the Trial and Error method, Ultimate Oscillation method operation, Ziegler-Nichols method, frequency method are used to tune the PID values. But inadequate PID parameter setting can be the cause of the unstable process of the operating nuclear power plant. Therefore the results of PID parameter setting should be simulated, optimized and finally verified. This paper introduces the simulation method of PID tuning to optimize the PID parameter setting and confirms them of the actual PID controller in the operating nuclear power plants. The simulation method provides the accurate process modeling and optimized PID parameter setting of the multi-loop control process in particular.

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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Parameter Study of Roller Leveling Process of Steel Cord Using Finite Element Analysis (유한요소해석을 이용한 스틸코드 롤러교정공정의 영향인자 분석)

  • Bae, G.H.;Lee, J.S.;Huh, H.;Lee, J.W.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.245-248
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    • 2008
  • This paper deals with the parameter study of roller leveling process of steel cord using finite element analysis. A simplified model of roller leveling process is constructed for the efficient numerical simulation considering the computing time. Using the constructed simulation scheme, the parameter study of main process parameters, such as back-tension and intermesh, is carried out in order to evaluate elastic recovery angle and roller force quantitatively. The effect of the initial shape of steel cord is also evaluated during the parameter study. And the mechanism of roller leveling process is verified by investigating the residual stress distribution.

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A Study on the Optimization of Deburring Process for the Micro Channel using EP-MAP Hybrid Process (전해-자기 복합 가공을 이용한 마이크로 채널 디버링공정 최적화)

  • Lee, Sung-Ho;Kwak, Jae-Seob
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.22 no.2
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    • pp.298-303
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    • 2013
  • Magnetic abrasive polishing is one of the most promising finishing methods applicable to complex surfaces. Nevertheless this process has a low efficiency when applied to very hardened materials. For this reason, EP-MAP hybrid process was developed. EP-MAP process is expected to machine complex and hardened materials. In this research, deburring process using EP-MAP hybrid process was proposed. EP-MAP deburring process is applied to micro channel, thereby it can obtain both deburring process and polishing process. EP-MAP deburring process on the micro channel was performed. Through design of experiment method, error of height in this process according to process parameter is analyzed. When the level 1 parameter A(magnetic flux density) and level 2 parameter B(electric potential), C(working gap) and level 3 parameter D(feed rate) are applied in the deburring process using EP-MAP hybrid process, it provides optimum result of EP-MAP hybrid deburring process.

Characteristics of Fabricated Devices and Process Parameter Extraction by DTC (DTC에 의한 공정 파라메터 추출 및 제작된 소자의 특성)

  • 서용진;이철인;최현식;김태형;최동진;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.29-34
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    • 1993
  • In this paper, we used one-dimensional process simulator, SUPREM-II, and two-dimensional device simulator, MINIMOS 4.0 to extract optimal process parameter that can minimize degradation of device characteristics caused by process parameter variation in the case of short channel nMOSFET and pMOSFET device. From this simulation, we have derieved the relationship between process parameter and device characteristics. Here we have presented a method to extract process parameters from design trend curve(DTC) obtained by process and device simulations. We parameters to verify the validity of the DTC method. The experimental result of 0.8 $\mu\textrm{m}$ channel length devices that have been fabricated with optimal that reduces short channel effects, that is, good drain current-voltage characteristics, low body effects and threshold voltage of 1.0 V, high punchthrough and breakdown voltage of 12 V, low subthreshold swing(S.S) values of 105 mV/decade.

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Modeling of Electrical Characteristics in Poly Silicon Thin Film Transistor with Process Parameter (다결정 실리콘 박막 트랜지스터에서 공정 파라미터에 따른 전기적 특성의 모델링)

  • Jung, Eun-Sik;Choi, Young-Sik;Lee, Yong-Jae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.201-204
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    • 2001
  • In this paper, for modeling of electrical characteristics in Poly Silicon Thin Film Transistors with process parameters set up optimum values, So, the I-V characteristics of poly silicon TFT parameters are examined and simulated in terms of the variations in process parameter. And these results compared and analyzed simulation values with examination value. The simulation program for characteristic analysis used SUPREM IV for processing, Matlab for modeling by mathematics, and SPICE for electric characteristic of devices. Input parameter for simulation characteristics is like condition of device process sequence, these electric characteristic of $I_D-V_D$ $I_D-V_G$, variations of grain size. The Gate oxide thickness of poly silicon are showed similar results between real device characteristics and simulation characteristics.

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Multiresponse Optimization Through A New Desirability Function Considering Process Parameter Fluctuation (공정변수의 변동을 고려한 호감도 함수를 통한 다중반응표면 최적화)

  • Kwon Jun-Bum;Lee Jong-Seok;Lee Sang-Ho;Jun Chi-Hyuck;Kim Kwang-Jae
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.1
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    • pp.95-104
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    • 2005
  • A desirability function approach to a multiresponse problem is proposed considering process parameter fluctuation which may amplify the variance of response. It is called POE (propagation of error), which is defined as the standard deviation of the transmitted variability in the response as a function of process parameters. In order to obtain more robust process parameter setting, a new desirability function is proposed by considering POE as well as distance-to-target of response and response variance. The proposed method is illustrated using a rubber product case in Ribeiro et al. (2000).

ON THE LARGE AND SMALL INCREMENTS OF GAUSSIAN RANDOM FIELDS

  • Zhengyan Lin;Park, Yong-Kab
    • Journal of the Korean Mathematical Society
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    • v.38 no.3
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    • pp.577-594
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    • 2001
  • In this paper we establish limit theorems on the large and small increments of a two-parameter Gaussian random process on rectangles in the Euclidean plane via estimating upper bounds of large deviation probabilities on suprema of the two-parameter Gaussian random process.

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