• Title/Summary/Keyword: closed model

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Assessments of baroreflex sensitivity through the closed-loop feedback model between RR fluctuation and arterial blood pressure fluctuation (RR간격변동과 열합변동간의 폐루프 귀환 모델을 통한 압수용체반사감도의 평가)

  • 신건수;최석준;이명호
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1643-1646
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    • 1997
  • In this study, the method is proposed, which enable us to noninvasively assess baroreflex sensitivity through the closed-loop feedback modle between RR flucturarion and arterial blood pressure fluctuation. The proposed indexes of baroreflex sensitivity, BRS$_{LF}$와 BRS$_{HF}$ are calculated by the modulus (or gain) of the transfer function between fluctuatuons in blood pressure and RR interval in the LF band HF band, where the coherence is more than 0.5 to evaluate the performance of the proposed method, it is applied to various cardiovascular variability signals obtained form subjects under the submaximal ecericse on bicycle ergometner. In result it is concluded that the proposed method can noninvasively assess the baroreflex sensitivity.ty.

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A Simple Beam Model for Thin-Walled Composite Blades with Closed, Two-Cell Sections (폐쇄형 이중세포로 된 박벽 복합재료 블레이드의 단순화 해석 모델)

  • Jung, Sung-Nam;Park, Il-Ju;Lee, Ju-Young;Lee, Jung-Jin
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.04a
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    • pp.187-190
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    • 2005
  • A simple beam model based on a mixed method is proposed for the analysis of thin-walled composite blades with a two-cell airfoil section. A semi-complementary energy functional is used to obtain the beam force-displacement relations. The theory accounts for the effects of elastic couplings, shell wall thickness, warping, and warping restraint. All the kinematic relations as well as the cross-section stiffnesses are evaluated in a closed-form through the current beam formulation. The theory has been applied to two-cell composite blades with extension-torsion couplings and fairly good correlation has been observed in comparison with a detailed analysis and other literature.

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Thiele Small Parameters Estimation for Pseudo Loudspeaker within 10 mm Grade Circular-type Microspeaker (10 mm급 원형 마이크로스피커의 가상 스피커 TS 매개변수 규명)

  • Park, Seok-Tae
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.17 no.11
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    • pp.1112-1118
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    • 2007
  • It was discussed to identify Thiele Small Parameters for Pseudo loudspeaker within 10mm grade microspeaker attached to closed-box using known dynamic mass of moving parts. Also, enhanced circuit model for vented-box micro speaker system was used to more accurately simulate electrical impedance curves for real vented-box microspeaker system and compared to test results. Consequently, it showed that micro speaker could be modeled by pseudo loudspeaker TS parameters similar to general loudspeaker. Vented-box microspeaker model with pseudo loudspeaker TS parameters was well suited to describe real microspeaker. Also, it was proposed to estimate volume of rear closed-box of microspeaker without design specifications.

Sampled-Data Observer-Based Decentralized Fuzzy Control for Nonlinear Large-Scale Systems

  • Koo, Geun Bum;Park, Jin Bae;Joo, Young Hoon
    • Journal of Electrical Engineering and Technology
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    • v.11 no.3
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    • pp.724-732
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    • 2016
  • In this paper, a sampled-data observer-based decentralized fuzzy control technique is proposed for a class of nonlinear large-scale systems, which can be represented to a Takagi-Sugeno fuzzy system. The premise variable is assumed to be measurable for the design of the observer-based fuzzy controller, and the closed-loop system is obtained. Based on an exact discretized model of the closed-loop system, the stability condition is derived for the closed-loop system. Also, the stability condition is converted into the linear matrix inequality (LMI) format. Finally, an example is provided to verify the effectiveness of the proposed techniques.

Performance analysis ofthe improved reverse link closed loop powercontrol with the variable step size for the mobile transmit power (이동국 가변증감량 조정방법에 의한 역방향 폐쇄회로 전력제어 성능개선 연구)

  • 원석호;정인명;임덕채;김환우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.6
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    • pp.1567-1575
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    • 1996
  • This paper presents a new power control method for compensating the short term fading of the reverse link channel in the CDMA mobile telephone system. The fixed step closed loop power control which is now adopted in IS-95, is very simple in structure. However, the step size in the closed loop power control is too big for the channel with a small variation or too big for the channel with a small variation or too small for the channel with a large variation. The method presented in this paper has a simple structure and shows a new model employing the combination of the fixed step size method and variable step size method which results in compensatingthe disadvantages mentioned above. This paper also evaluates the performance inthe fundamental channel model.

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Intelligent Digital Redesign for Nonlinear Interconnected Systems using Decentralized Fuzzy Control

  • Koo, Geun-Bum;Park, Jin-Bae;Joo, Young-Hoon
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.420-428
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    • 2012
  • In this paper, a novel intelligent digital redesign (IDR) technique is proposed for the nonlinear interconnected systems which can be represented by a Takagi-Sugeno (T-S) fuzzy model. The IDR technique is to convert a pre-designed analog controller into an equivalent digital one. To develop this method, the discretized models of the analog and digital closed-loop system with the decentralized controller are presented, respectively. Using these discretized models, the digital decentralized control gain is obtained to minimize the norm between the state variables of the analog and digital closed-loop systems and stabilize the digital closed-loop system. Its sufficient conditions are derived in terms of linear matrix inequalities (LMIs). Finally, a numerical example is provided to verify the effectiveness of the proposed technique.

Improvement of Tidal Circulation in a Closed Bay using Variation of Bottom Roughness (해저조도 변화를 이용한 폐쇄성 만의 해수순환 개선)

  • BOO SUNG YOUN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.1 s.62
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    • pp.1-7
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    • 2005
  • Tidal circulation in a closed bay using a variation of bottom roughness was investigated through the numerical experiments based on a finite difference multi-level model. Various distributions of bottom roughness in the bay were implemented to determine their effects. It hadbeen determined that residual currents can be generated from the differences of the bottom roughness between streaming and reverse flow directions. The magnitude of residual currents and volume flow rate increase when the relative ratio of bottom roughness between streaming and reverse flow directions increase. Circulation in the closed bay is also improved by the employment of the change of bottom roughness.

A Design of Fuzzy Controller with Optimal Rule Using Genetic Algorithm (유전 알고리듬을 이용한 최적의 룰 맵핑을 가지는 퍼지 제어기 설계)

  • Lee, Young-Seog;Kim, Sung-Sik;Seo, Bo-Hyeok
    • Proceedings of the KIEE Conference
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    • 1996.11a
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    • pp.68-70
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    • 1996
  • A fuzzy network using genetic algorithm is investigated in the context of control for finite dimensional nonlinear discrete systems. The proposed FN(Fuzzy Network) constructed to identify various parameter of fuzzy control is used for the nonlinear system control. Each of two FN, presented FN control system is based on a framework of closed loop control. A proposed FNN model trains using the modeling error and the closed loop error. That case study shows that the presented FN model and closed loop control system is very useful in practical sense.

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Analysis of Heat Loss Effect of Combustion in Closed Vessel (정적 연소실에서의 열 손실 해석 모델)

  • Lee, Dae-Hoon;Kwon, Se-Jin
    • Journal of the Korean Society of Combustion
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    • v.6 no.1
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    • pp.14-19
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    • 2001
  • Interests and importance of down-scale combustor is increasing with the emerging need for miniaturized power source which is now a bottleneck of micro system development. But in down scaled combustor increased heat loss compared to thermal energy generation inhibits the usability and application of the device, so as a preliminary work of down scaled combustor fabrication. Modeling tool for the device should be established, in this study modeling approach of closed vessel combustion phenomena that can express heat loss effect and resulting quenching is proposed and the result is compared with experiment data. From this model heat loss effect following combustor scale down can be further understood, and further more design parameter and analysis tool can be obtained.

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