• Journal of the Institute of Electronics Engineers of Korea TC
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• v.38 no.12
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• pp.49-57
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• 2001

In this paper, equivalent circuit model and novel model parameter extraction method of a silicon(Si) substrate are presented. Substrate coupling through Si-substrate is quantitatively investigated by analyzing equivalent circuit with operating frequency and characteristic frequencies (i.e., pole and zero frequency) of a system. For the experimental verification of the equivalent circuit and parameter extraction method, test patterns are designed and fabricated in standard CMOS technology with various isolation distances, substrate resistivity, and guard-ring structures. Then, these are measured in l00MHz-20GHz frequency range by using vector network analyzer. It is shown that the equivalent-circuit-based HSPICE simulation results using extracted parameters have excellent agreement with the experimental results. Thus, the proposed equivalent circuit and parameter extraction methodology can be usefully employed in mixed-signal circuit design and verification of a circuit performance.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.2
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• pp.127-136
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• 2008

This paper proposes the efficient system for automatic design of FSS(Frequency Selective Surface) with periodic pattern and frequency characteristics specified by operator. The proposed system derives optimal design parameters through tool for analysis of FSS with arbitrary pattern, DB(Data Base) implemented from limited simulation and measurement data of FSS, and GA(Genetic Algorithm) for optimizing design parameters. FSS analysis tool consists of two analysis tools. One is the simulator for analysis of monolayer FSS that using moment method, another is the tool with approximated analysis method of FSS with dielectric layer. Given pattern configuration and characteristics specified by operators, the DB system searches the best matching FSS, and provides initial genes to GA from the searched parameters, which drastically reduces running time of GA for finding the FSS design parameters. In this paper, the proposed design system is verified through simulation and measurement about FSS with various patterns.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2421-2427
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• 2012

This paper is discussed the design on non-linear adaptive attitude controller for quadrotor UAV. Quadrotor UAV featured to have four rotor, required the special controller to compensate for the model parameter uncertainties as the unstable nonlinear system. In this research, we designed the adaptive controller to compensate for the payload changes even though it is changed with industrial applications. Especially, based on the mathematical model of UAV, non-linear adaptive controller is suggested and the stability is verified using the Lyapunov function and finally proved its performance and effectiveness of update laws with various payload by simulation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.04a
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• pp.126-128
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• 2009

• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.528-531
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• 2009

본 연구에서는 두 스프링으로 지지된 강체가 회전하는 Timoshenko 축을 따라 이동할 때, 그 계의 동적응답 특성을 해석하였다. 운동방정식은 Hamilton의 원리에 따라 유도되었다. 유도된 운동방정식을 이용하여 주요 설계 파라미터 변화에 따른 응답특성을 해석하였다. 해석시 설계파라미터를 무차원 변수화 하여 속도비, 질량비, 회전수비 등 그 변화에 따른 응답특성을 비교 분석하였다.

• Magazine of the Korean Society of Agricultural Engineers
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• v.32 no.1
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• pp.7-16
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• 1990

불규칙파(不規則波)의 피습(被襲)에 의한 사석제(捨石堤)의 호안공(護岸工)이나 방파제(防波堤)에 대하여 화란(和蘭)이 Delft수이시험소(水理試驗所)에서 종합적(綜合的)인 모형연구(模型硏究)를 실시(實施)한 결과(結果) 새로운 안정도(安定度) 공식(公式)을 수립(樹立)하였다. 이들 공식(公式)은 파랑주기(波浪週期), 폭풍지속기간(暴風持續期間) 및 구조물(構造物) 투수성(透水性) 등의 파라미터(媒介變數)가 포함(包含)되어 있으므로 파손(破損)의 정도(程度)가 분명(分明)하여 Hudson형(型) 공식(公式)의 주(主)된 단점(短點)을 해결(解決)하였다. 이들 신공식(新公式)의 개발(開發)은 이전(以前)에도 기술(記述)된바 있으며 본론설(本論說)에는 재론(再論)하지 않는다. 안정도공식(安定度公式)은 파라미터로서 적용(適用)이 가능(可能)한 범위(範圍)가 부여(附與)되었으며, 이들 공식(公式)은 결정론(決定論) 및 확률론적(確率論的) 양자(兩者) 다같이 사용(使用) 방법(方法)이 제시(提示)되어 있다. 결정론적(決定論的) 설계절차(設計節次)는 여러가지지 파라미터의 영향(影響)을 곡선(曲線)으로 나타내어 졌으며 확률론적(確率論的) 설계(設計)는 구조물(構造物)의 내구연수기간내(耐久年數期間內)에 파손도(破損度)의 초과확률(超過確率)을 나타낸 곡선(曲線)으로 되어있다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.40 no.4
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• pp.251-263
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• 2003

This paper presents matrix inequality conditions for Η$_2$control and Η$_2$controller design method of linear time-invariant descriptor systems with parameter uncertainties in continuous and discrete time cases, respectively. First, the necessary and sufficient condition for Η$_2$control and Η$_2$ controller design method are expressed in terms of LMI(linear matrix inequality) with no equality constraints in continuous time case. Next, the sufficient condition for Hi control and Η$_2$controller design method are proposed by matrix inequality approach in discrete time case. Based on these conditions, we develop the robust Η$_2$controller design method for parameter uncertain descriptor systems and give a numerical example in each case.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.11
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• pp.22-33
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• 1999

This paper presents the method for the automatic tuning of a design weighting polynomial parameters of a generalized minimum-variance stochastic ultivariable self-tuning controller which adapts to changes in the higher order nonminimum phase system parameters with time delays and noises. The self-tuning effect is achieved through the recursive least square algorithm at the parameter estimation stage and also through the Robbins-Monro algorithm at the stage of optimizing the design weighting polynomial parameters of the controller. The proposed multivariable self-tuning method is simple and effective compared with pole restriction method. The computer simulation results are presented to adapt the higher order multivariable system with nonminimum phase and with changeable system parameters.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.3
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• pp.87-95
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• 1998

This paper presents the method for the automatic tuning of a design weighting polynomial parameter of a generalized minimum-variance stochastic self tuning controller which adapts to changes in the system parameters with time delays and noises. The self tuning effect is achieved through the recursive least square algorithm at the parameter estimation stage and also through the Robbins-Monro algorithm at the stage of optimizing a design weighting polynomial parameters. The proposed self tuning method is simple and effective compared with other existing self tuning methods. The computer simulation results are presented to illustrate the procedure and to show the performance of the control system.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.4
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• pp.125-132
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• 2015

PCI Express is high-speed point-to-point serial protocol, the system is designed by analysing loss and jitter through Eye Diagram. It is necessarily analyzing high speed serial signals when the PCI Express Gen3 which has 8Gbps physical signal speed is designed especially. This paper deals with topology extraction, channel analysis, extraction of s-parameters and system signal integrity simulation within transceiver buffer models through PCI Express Gen3 server connecting switch system design. Optimal parameters of transmitter buffer equalizer are found through solution space simulation of de-emphasis and preshoot parameters to compensate channel loss.