• Title/Summary/Keyword: Dynamic Process

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Design of Time-varying Stochastic Process with Dynamic Bayesian Networks

  • Cho, Hyun-Cheol;Fadali, M.Sami;Lee, Kwon-Soon
    • Journal of Electrical Engineering and Technology
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    • 제2권4호
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    • pp.543-548
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    • 2007
  • We present a dynamic Bayesian network (DBN) model of a generalized class of nonstationary birth-death processes. The model includes birth and death rate parameters that are randomly selected from a known discrete set of values. We present an on-line algorithm to obtain optimal estimates of the parameters. We provide a simulation of real-time characterization of load traffic estimation using our DBN approach.

Subjective Point Prediction Algorithm for Decision Analysis

  • Kim, Soung-Hie
    • 한국경영과학회지
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    • 제8권1호
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    • pp.31-40
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    • 1983
  • An uncertain dynamic evolving process has been a continuing challenge to decision problems. The dynamic random variable (drv) changes which characterize such a process are very important for the decision-maker in selecting a course of action in a world that is perceived as uncertain, complex, and dynamic. Using this subjective point prediction algorithm based on a modified recursive filter, the decision-maker becomes to have periodically changing plausible points with the passage of time.

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Nonlinear PLS Monitoring Applied to An Wastewater Treatment Process

  • Bang, Yoon-Ho;Yoo, Chang-Kyoo;Park, Sang-Wook;Lee, In-Beum
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.102.1-102
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    • 2001
  • In this work, extensions to partial least squares (PLS) for wastewater treatment (WWT) process monitoring are discussed. Conventional data gathered by monitoring WWT systems are usually time varying, high dimensional, correlated and nonlinear, PLS has been shown to be an efficient approach in modeling and monitoring high dimensional and correlated data. To represent dynamic and nonlinear features of the data several kinds of dynamic nonlinear PLS (DNLPLS) models have been proposed. However, the complexity and ambiguity of the models make them unsuitable for WWT monitoring, Recently, dynamic fuzzy PLS (DFPLS) was proposed ...

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고온성형중 동적재결정에 의한 하중감소의 정략적 해석 (Quantitative Analysis of Hot Forming with Stress Compensation to Dynamic Recrystallization)

  • 장영원
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.203-206
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    • 1999
  • The shift of flow behavior due to dynamic recrystallization during hot forming process is investigated, A series of load relaxation and compression tests has been conducted at various temperatures Constitutive relations and recrystallization behaviors were formulated from the mechanical test results, The consideration of dynamic recrystallization during a specific forming process was implemented to commercial FEM package by conditioned remeshing and remapping of state variables. Improvement of Load-Stroke prediction was validated by comparison with experimental results.

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Rotor Dynamics의 현황과 문제점

  • 김폴영일
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 추계학술대회논문집; 한국과학기술회관; 6 Nov. 1997
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    • pp.11-19
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    • 1997
  • 이 글의 내용은 다음과 같다 1.서론 2.Rotor Dynamics에서의 Quotes & Misquotes/역사 바로 세우기 3.Rotor Dynamics는 이대로 좋은가\ulcorner 3.1.Rotor Dynamics와 Balancing 3.2.Balancing은 ultra-precision process 3.3.Unbalance response의 현황과 문제점 3.4.Jeffcott Rotor[Jeffcott 1919] 3.5.National Rotor Dynamics Test Facility의 필요성 4.결론

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HMM-Based Transient Identification in Dynamic Process

  • Kwon, Kee-Choon
    • Transactions on Control, Automation and Systems Engineering
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    • 제2권1호
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    • pp.40-46
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    • 2000
  • In this paper, a transient identification based on a Hidden Markov Model (HMM) has been suggested and evaluated experimentally for the classification of transients in the dynamic process. The transient can be identified by its unique time dependent patterns related to the principal variables. The HMM, a double stochastic process, can be applied to transient identification which is a spatial and temporal classification problem under a statistical pattern recognition framework. The HMM is created for each transient from a set of training data by the maximum-likelihood estimation method. The transient identification is determined by calculating which model has the highest probability for the given test data. Several experimental tests have been performed with normalization methods, clustering algorithms, and a number of states in HMM. Several experimental tests have been performed including superimposing random noise, adding systematic error, and untrained transients. The proposed real-time transient identification system has many advantages, however, there are still a lot of problems that should be solved to apply to a real dynamic process. Further efforts are being made to improve the system performance and robustness to demonstrate reliability and accuracy to the required level.

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NI LabVIEW를 이용한 동적 제어용 FCM 제어기 (Fuzzy Cognitive Maps built in NI LabVIEW for control of dynamic process)

  • 바딤;다랴;최성주;조현찬
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 2007년도 춘계학술대회 학술발표 논문집 제17권 제1호
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    • pp.217-220
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    • 2007
  • This paper studies method of controlling dynamic process with Fuzzy Cognitive Map (FCM) built in NI LabVIEW software. FCM is the hybrid methodology that combines fuzzy logic and neural networks. A FCM will be developed using NI LabVIEW software to model and control a process of dynamic system. Nowadays more autonomous and intelligent systems are very useful in many areas of people lives especially related with Complex Systems.

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Dynamic Response Behavior of Femtosecond Laser-Annealed Indium Zinc Oxide Thin-Film Transistors

  • Shan, Fei;Kim, Sung-Jin
    • Journal of Electrical Engineering and Technology
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    • 제12권6호
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    • pp.2353-2358
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    • 2017
  • A femtosecond laser pre-annealing process based on indium zinc oxide (IZO) thin-film transistors (TFTs) is fabricated. We demonstrate a stable pre-annealing process to analyze surface structure change of thin films, and we maintain electrical stability and improve electrical performance. Furthermore, dynamic electrical characteristics of the IZO TFTs were investigated. Femtosecond laser pre-annealing process-based IZO TFTs exhibit a field-effect mobility of $3.75cm^2/Vs$, an $I_{on}/I_{off}$ ratio of $1.77{\times}10^5$, a threshold voltage of 1.13 V, and a subthreshold swing of 1.21 V/dec. And the IZO-based inverter shows a fast switching behavior response. From this study, IZO TFTs from using the femtosecond laser annealing technique were found to strongly affect the electrical performance and charge transport dynamics in electronic devices.

Impact of gate protection silicon nitride film on the sub-quarter micron transistor performances in dynamic random access memory devices

  • Choy, J.-H.
    • 한국결정성장학회지
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    • 제14권2호
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    • pp.47-49
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    • 2004
  • Gate protection $SiN_x$ as an alternative to a conventional re-oxidation process in Dynamic Random Access Memory devices is investigated. This process can not only protect the gate electrode tungsten against oxidation, but also save the thermal budget due to the re-oxidation. The protection $SiN_x$ process is applied to the poly-Si gate, and its device performance is measured and compared with the re-oxidation processed poly-Si gate. The results on the gate dielectric integrity show that etch damage-curing capability of protection $SiN_x$ is comparable to the re-oxidation process. In addition, the hot carrier immunity of the $SiN_x$ deposited gate is superior to that of re-oxidation processed gate.

FPSO Cargo Pumping 시스템 가상운전 시스템 개발

  • 남기일;한기훈;장광필;오태영;장대준;송석용
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2006년도 전기학술대회논문집
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    • pp.251-252
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    • 2006
  • This study developed the virtual operation system for the hydraulic pump system for marine usage. The scope of this study is to develop a process dynamic simulation model for the hydraulic pump system for marine usage, to investigate the process dynamic characteristics using the models, to accomplish the logic diagram for the PLC control and to achieve a human-machine interface (HMI) for the convenience of operators to monitor and control the process. The virtual operation system provides a virtual operation environment for the pumping system, enabling the operators to simulate the change of process variables. The system will assist in developing advanced control logics and then optimal design of the system.

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