• 대한기계학회논문집A
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• 제29권1호
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• pp.59-66
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• 2005

In this paper, a robust stationary Kalman filter is designed by minimizing selected performance indices so that it is less sensitive to uncertainties. The uncertainties include not only stochastic factors such as process noise and measurement noise, but also deterministic factors such as unknown initial estimation error, modeling error and sensing bias. To reduce the effect on the uncertainties, three performance indices that should be minimized are selected based on the quantitative error analysis to both the deterministic and the stochastic uncertainties. The selected indices are the size of the observer gain, the condition number of the observer matrix, and the estimation error variance. The observer gain is obtained by optimally solving the multi-objectives optimization problem that minimizes the indices. The robustness of the proposed filter is demonstrated through the comparison with the standard Kalman filter.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.48.3-48
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• 2001

A gain-scheduled autopilot design for a bank-to-turn (BTT) missile is developed by using the Linear Matrix Inequality (LMI) optimization technique and a state-space lineal interpolation method. The missile dynamics are brought to a quasilinear parameter varying (quasi-LPV) form. Robust linear control design method is used to obtain state feedback controllers for the LPV systems with exogenous disturbances at the frozen values of the scheduling parameters. Two gam-scheduled controllers for the pitch axis and the yaw/roll axis are constructed by linearly interpolating the robust state-feedback gains. The designed controller is applied to a nonlinear six-degree-of-freedom (6-DOF) simulations.

• 산업경영시스템학회지
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• 제18권35호
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• pp.61-70
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• 1995

The objective of this study is In develope on productivity improvement program, which named PPM(Participative Productivity Management). This program consists of 3 stages which are Goal setting and sharing. Productivity measurement and evaluation, and Gain sharing. Each concepts of NGT(Nominal Group Technique), Objectives matrix method and Gain sharing was applied to form this frame. This program rewards members of an organization for their contributions to improve business results. It also fits perfectly with today's participative management philosophies. Furthermore, the company and its employees could be partners a win-win situation, and one more barrier to a high-involvement culture should be eliminated.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.586-589
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• 2013

본 논문에서는 무선 데이터 전송에서 데이터 전송의 신뢰성을 얻기 위해 STBC와 컨볼루션 코드를 연계하며 높은 시스템 이득을 취하기 위해 수정된 비터비 알고리즘을 사용한 시스템을 제안한다. 제안한 시스템은 STBC의 다이버시티 이득과 컨볼루션 코드의 부호화 이득을 동시에 얻을 수 있다. 수정된 비터비 알고리즘은 기존의 비터비 알고리즘과 달리 브랜치 매트릭스를 구하기 위해 해밍디스턴스를 사용하지 않고 수신 심볼과 레퍼런스 심볼 사이의 유클리디안 디스턴스를 사용한다. 제안한 시스템을 분석하기 위해 STBC의 송수신 안테나의 개수와 컨볼루션 코드의 구속장을 변경하며 시뮬레이션하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제33권8호
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• pp.1212-1219
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• 2009

본 연구에서는 실용설계의 새로운 도구로써 제어계의 강인성, 성능, 안정성 등의 설계지침을 정량화하기 쉽고 해가 효율적으로 구해져 주목받는 선형행렬부등식을 이용하여 강인한 LMI 제어기를 설계한다. 우선 다층상 구조물의 진동제어를 위해 수학적 모델링을 행하고 적분형 서보계를 적용한 LMI 제어 기법으로 상태 피드백 제어칙을 설계한다. 다음으로 설계한 제어칙으로 시스템 불확실성의 변동에 대해 시간영역의 설계사양을 고려한 경우와 고려하지 않은 경우에 대하여 시뮬레이션을 행하고 실제 적용 가능성을 검토한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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• pp.44-47
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• 1996

An optimal preview controller based on the discrete-time $H_{.inf}$ control is presented. The preview controller is synthesized by considering the bounded unknwon disturbances as well as previewable commands and disturbances. The controller derivation procedure is analogous to the LQ-based scheme. The designed preview gain matrix has a similar structure as the LQ-based one. As the infinity norm .gamma. of the transfer function matrix tends to .inf., the preview gains obtained by $H_{\infty}$ control method approach to the gains by the LQR. The LQ-based preview gains are verified to be subsets of the $H_{.inf}$ -based preview gains..

• 전기학회논문지
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• 제57권10호
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• pp.1708-1712
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• 2008

This paper describes a linear matrix inequality (LMI) approach to the design of robust low-order power system stabilizers (PSSs), which are used to damp out local-mode oscillations of synchronous generators. The performance of a PSS is expressed as the location of the closed-loop poles, and a single fixed-gain pole-placement controller is synthesized for a wide range of operating conditions. The synthesis results in simultaneous regional pole-placement stabilization. and is formulated as an LMI feasibility problem with a rank condition. A penalty method is applied to solve the rank-constrained LMI problem. Numerical experiments with a single-machine connected to an infinite bus system were performed to demonstrate the proposed method.

• International Journal of Precision Engineering and Manufacturing
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• 제3권4호
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• pp.78-86
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• 2002

In this paper, LMI (Linear Matrix Inequality) based on H$\_$$\infty$/ controller for a lire of sight (LOS) stabilization system. It shows that the proposed controller has more excellent stabilization performance than that of the conventional PI-Lead controller. An H$\_$$\infty$/ control has been also applied to the system for reducing modeling errors and the settling time of the system. The LMI-based H$\_$$\infty$/ controller design is more practical in view of reducing a run-time than Riccati-based H$\_$$\infty$/ controller. This H$\_$$\infty$/ controller is available not only to decrease the gain in PI-Lead control, but also to compensate the identifications for the various uncertain parameters. Therefore, this paper, shows that the proposed LMI-based H$\_$$\infty$/ controller had good disturbance attenuation and reference input tracking performance compared with the control performance of the conventional controller under any real disturbances.

• 한국정밀공학회지
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• 제17권3호
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• pp.108-113
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• 2000

An important process for making a new class of polymeric material is called microcellular plastics invented at the Massachusetts Institute of Technology. Many researches for microcellular plastics have been done in various ways and fields. But a research for the polymer which has previous history has not been tried yet. In this paper, weight gain of $CO_2$ was measured in a polymer matrix which had previous history and no history. In each case, experimental data for solubility and diffusivity was shown. A model for $CO_2$ solution process in molecular range was made. The conclusion of this paper is that the previous history has an effect on diffusivity but not solubility and the previous history made by $CO_2$ in supercritical state makes diffusivity of $CO_2$ larger.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 A
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• pp.276-278
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• 1992

This paper presents a method of hierachical optimal control for time invariant large scale systems via Single Term Walsh Series. It is well known that the optimal control of a large scale system with quadratic performance criteria often involves the determination of time varying feedback gain matrix by solving the matrix Riccati differential equation, which is usually quite difficult. Therefore, in order to solve the problem, this paper is introduced to Single Term Walsh Series. The advantages of proposed method are simple and attractive for the control of large scale system in computation.