• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.289-297
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• 2014

This article surveys the control theoretic study on time delay systems. Since time delay systems are infinite dimensional, there are not analytic but numerical solutions on almost analysis and synthesis problems, which implies that there are a tremendous number of approximated solutions. To show how to find such solutions, several results are summarized in terms of two different axes: 1) theoretic tools like integral inequality associated with the derivative of delay terms, Jensen inequality, lower bound lemma for reciprocal convexity, and Wirtinger-based inequality and 2) various candidates for Laypunov-Krasovskii functionals.

• The tire
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• s.61
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• pp.16-19
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• 1975

무우니이점도 30에서 70까지의 천연고무(이하 NR이라고 약)와 합성 시스-1,4-포리이소프렌(이하 IR이라고 약)의 완화탄성률에 대해서 검토했다. 완화탄성률은 -50℃로부터 90℃이며 시간 3초로부터 3,000초에 긍해서 측정했다. 동일한 무우니이점도로서 어느 온도에 있어서도 IR의 완화탄성률은 NR에 비하면 작으며 따라서 IR은 부드럽게 촉감된다고 생각된다. NR과 IR의 각종온도에서의 완화탄성률과 시간의 관계는 같은 환산계수를 사용해서 중합이 가능했었다. 얻어진 합성곡선에 대해서 특히 종단역에 있어서 NR의 완화탄성률이 IR에 비해서 크다. 이것은 같은 무우니이점도로서 NR쪽이 IR에 비하여 높은 평균분자량과 넓은 분자량분포를 가지기 때문이라고 생각된다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.307-313
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• 2008

In this paper, we propose a novel defects inspection algorithm for TFT-LCD panels. We first compensate the distorted image caused by the camera distortion and the uneven illumination environment using the least squares method and the bezier surface. We find a starting point of each pattern for restricting each pattern. A clean image is compared to each pattern to find defects using modified PCSR-G algorithm. The simulation example shows that our algorithm not only inspects the defects well, but also is robust to the 1-pixel error.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.149-151
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• 2007

For several decades, VSC has gained much attention as one of the useful design tools for handling the practical system with uncertainties or disturbances. Generally, the disturbances in the matching condition can be perfectly rejected via VSC; however, these in the mismatching condition are known to be hardly rejected. There have been some trials on it, in which the resulting controls in fact belong to the class of robust control guaranteeing disturbance ${\gamma}$-attenuation. Therefore, in this paper, we propose a new Variable Structure Control (VSC) for a system with mismatched disturbances. The proposed controller is composed of linear and nonlinear parts; the former plays a role in stabilizing the system and the latter takes care of attenuating the disturbances. The main contribution is to introduce the concept of switching-zone, rather than switching-surface, that is designed through piece-wise Lyapunov functions. The resulting non-convex conditions are formulated with an iterative linear programming algorithm, which provides an excellent performance of almost rejecting the disturbances.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.364-367
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• 2001

In this paper, an analysis of electromagnetic repulsion force is presented using 3D FEM considering eddy current. It is important for the optimum design of switching device to analysis electromagnetic repulsion forces generated by the interaction of the electric current and its own magnetic field on the closed electric contacts flowing over current. The validity of our analysis is confirmed by comparing analytic and experimental results.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.295-296
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• 2018

본 논문은 입 출차를 하는 주차타워의 원리를 바탕으로 NFC를 활용하여 신발을 반 출입하고, IoT 센서를 이용하여 신발의 관리를 편리하게 도와주는 자동 신발타워이다. 수동으로 번호를 입력하던 주차타워와는 다르게 제안한 신발타워는 NFC에 있는 고유ID값을 활용하여 인증된 사용자가 신발장의 센서 터치로 본인의 신발을 반 출입하도록 한다. 신발장 관리 시스템은 신발의 임의적인 반출을 가능하게 하며, IoT센서를 탑재하여 신발장 내부에 향균, 건조, 온도 조절 등의 효과를 탑재하여 신발의 관리를 편리하게 도와주는 기능들을 제공한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.785-788
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• 2017

우리나라의 차량 범죄율은 국민들의 소득 증가와 더불어 계속해서 증가 중인 추세이다. 현재 상용화 된 차량 번호판 인식은 시스템은 특정 우치에 고정되어 있고, 화면의 특정 영역에 물체가 들어와야만 번호판을 인식할 수 있다. 단순히 그 영역에 들어오지 못하면 번호판을 인식하지 못하고 지나치게 된다. 본 연구는 특정 영역에 구애받지 않고 장소, 화면 어디에서든 차량 번호판을 인식할 수 있게 딥 러닝 기술을 응용하여 범죄차량을 찾아내는 기법을 제안한다. 또한 서버와 연동시켜 실시간으로 범죄차량의 위치를 파악, 주변 경찰들에게 연락을 주어 빠르게 범죄차량을 검거하는 서비스를 제공한다.

• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.475-484
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• 2004

In this paper, we present a dynamic output-feedback receding horizon $H_{\infty}$controller for linear discrete-time systems with disturbance. The controller is obtained numerically from the finite horizon output-feedback $H_{\infty}$optimization problem, which is, in fact, hardly solved analytically. Under a matrix inequality condition on the terminal weighting matrix, the monotonic decreasing property of the cost is shown. This property guarantees both the closed-loop stability and the $H_{\infty}$norm bound. Then, we extend the proposed design method to a reference tracking problem and a problem for time-varying systems. Numerical examples are given to illustrate the performance of the proposed controller.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.55-56
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• 2007

In this paper, a delay-dependent stability criterion for time-delayed linear parameter varying (LPV) systems is considered. Stability criterion has been developed on the basis of including x(t-h) and x(t) and introducing free variables to eliminate model dynamics. Since the resultant criterion is formed parameterized linear matrix inequalities (PLMIs), we propose a relaxation technique that allows to find an LMI formulation. Examples demonstrate the efficiency of the criterion over the existing results.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.149-150
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• 2007

In this paper, we propose a novel defects inspection algorithm for TFT-LCD panels. We first compensate the distorted image caused by the camera distortion and the uneven illumination environment using the least squares method and the bezier surface. We find a starting point of each pattern. The reference frame, made by subtract method using several clean patterns, is compared to each pattern to find defects. The simulation example shows that our algorithm not only inspects the defects well, but also is robust to the 1-pixel error.