• 한국정보통신학회논문지
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• 제15권7호
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• pp.1517-1524
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• 2011

본 논문은 의미특징과 워드넷 기반의 의사연관피드백을 이용하여 사용자의 질의에 관련 있는 의미 있는 문장을 추출하여 문서요약을 하는 새로운 방법을 제안한다. 제안된 방법은 비음수 행렬 분해로부터 유도된 의미특정이 문서의 잠재의미를 잘 나타나기 때문에 문서요약의 질을 향상할 수 있다. 또한 의미특정과 워드넷기반의 의사연관피드백을 이용하여서 사용자의 요구사항과 제안방법의 요약결과 사이의 의미적 차이를 감소시킨다. 실험결과 제안방법이 유사도, 비음수행렬분해를 이용한 방법들에 비하여 좋은 성능을 보인다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.199-204
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• 2007

This research aimed at to develop a quantitative assesment technique which uses the measured displacements at the excavated plane during tunnel construction. Tunnel structure has a feature with long extents comparing to the excavated section so that the tunnel safety assesment is more effective by using the measured data of displacements. Tunnel structures show different structural behaviors due to the mechanical characteristics of ground and supports themselves, excavation methods and construction methods of supports, etc. From this point of view, it has very important meanings on the practical aspects that the measured data from the construction cite represent the features of the interaction effects between ground and supports as they are. In this study, both the stress state and the properties of surrounding ground are analyzed by newly incorporated feedback analysis technique which can use the measured displacements directly. Then, the stress state and the properties of ground will be used to obtain the strain distribution of surrounding ground. Finally the tunnel safety can be assessed by comparing the estimated strain through the analysis to the allowable strain of ground quantitatively.

• 한국어교육
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• 제25권1호
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• pp.203-234
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• 2014

This paper demonstrates how to incorporate the teaching of communication strategies into a large class of English-speaking learners of the Korean language. The method proposed here was developed to overcome the difficulty of conducting language activities involving communicative interactions amongst students and also between teacher and students in a large classroom. As a way of compensating the minimal opportunities for interactions in the classroom, students are given the task of expressing in Korean the English translations of authentic Korean comics via Twitter, which was later replaced with the feedback feature on Moodle, and then their Korean expressions are collected and projected onto a big screen. These collected expressions by students naturally differ from one another, helping students to realize that it is possible for them to express the same message or meaning in many different ways. The results of two separately conducted questionnaires show that this method is an effective way of providing students with significantly increased chances of producing 'comprehensible output' that requires them to think of how to communicate with their limited knowledge of the Korean language. Many students also commented that the teachers' feedback on errors provides them with the opportunity to learn about common errors as well as their own errors.

• 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.401-404
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• 1996

A new method for the electrostatic suspension of disk-shaped objects is proposed which is based on a switched-voltage control scheme. It operates according to a relay feedback control and deploys only a single high-voltage power supply capable of delivering a dc voltage of positive and/or negative polarity. In addition to the unique feature that no high-voltage amplifiers are needed, this method provides a remarkable system simplification relative to conventional methods. It is shown that despite the inherent limit cycle property of relay feedback based control, an excellent performance in vibration suppression is attained due to the presence of a relatively large squeeze film damping. In this paper, the functional principle of the switched voltage control scheme, numerical analysis, stator electrode design, and a nonlinear dynamic model of the suspension system are described. Experimental results will be presented for a 4-inch silicon wafer that clearly reveal the capability of the proposed control structure to suspend the wafer stably at an airgap length of 50 .mu.m.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.574-578
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• 2004

In this paper, a nonlinear feedback system is analyzed for a surface micromachined resonant accelerometer. For this, a brief illustration of the plant dynamics is given. In the analysis, the periodic signal in the nonlinear feedback loop is obtained by the limit cycle point, which is best approximated via the describing function method. Considering the characteristic feature of plant dynamics, a simple phase shifted relay with finite slope is designed for the nonlinearity implementation. With a describing function for random plus sinusoidal input, we analyzed the effect of a white Gaussian noise on oscillation frequency. Finally, simulation and experimental result is given.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 A
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• pp.247-250
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• 2003

In this paper, we propose a robust controller for motion control of n-link robot manipulators using visual feedback. The desired joint velocity and acceleration is obtained by the feature-based visual systems and is used in the joint velocity control loop for trajectory control of the robot manipulator. We design a robust controller that compensates for bounded parametric uncertainties of robot dynamics. The stability analysis of robust joint velocity control system is shown by Lyapunov Method. The effectiveness of the proposed method is shown by simulation results on the 5-link robot manipulators with two degree of freedom.

• 제어로봇시스템학회논문지
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• 제13권3호
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• pp.268-272
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• 2007

These days many scientists make studies of feedback control system for stability on non-linear state and for the maneuver of flying objects. These feedback control systems have to satisfy trajectory condition and angular conditions, that is to say, controllability and stability simultaneously to achieve mission. In this paper, a design methods using model based control system which consists of spiral predictive model, Q-function included into generalized-work function is shown. It is made a clear that the proposed algorithm using SPM maneuvers for controllability and stability at the same time is successful in attaining our purpose. The feature of the proposed algorithm is illustrated by simulation results. As a conclusion, the proposed algorithm is useful for the control of moving objects.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2445-2447
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• 2002

In this paper, CAN-based feedback control system is proposed for the pressurization system of korean high-speed train. The control performance of the system is evaluated. According to the requirement of the pressurization system A process model considering network delay and an adaptive PID control method based on the process model are proposed here. And it is shown that the proposed adaptive PID control method considering the network delay has on adequate feature compared to some other existing methods consequently it can be considered to be applied the pressurization system of korean high-speed train.

• 대한전기학회논문지
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• 제38권2호
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• pp.83-92
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• 1989

This paper presents a load frequency control by optimal linear tracking, which can be well adapted to practical power systems with successive load disturbances. Conventional Load Frequency Controls (LEC's) have a feedback control scheme of the state error deviated from the post-disturbance steady state. This requires the modification of reference everytime the system encounters load changes. In this study, a new feedback scheme of LEC is developed by using the optimal linear tracking method with a fixed reference. As a result, the proposed LFC, which requires no reference modification, can be efficiently applied to power systems with successive disturbances such as load changes due to the on-off operations of reclosers or feeder switches. Another feature of the proposed LFC is that it adopts an algorithm to calculate an optimal post-fault steady state with the consideration of control input changes. The proposed LFC has been tested for a 2-area power system, which shows that it can be well adapted to successive load disturbances with good frequency response.

• Journal of Advanced Marine Engineering and Technology
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• 제25권4호
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• pp.833-845
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• 2001

Quantitative Feedback Theory(QFT) has been used to design a robust power system stabilizer(PSS) to improve transient and dynamic stabilities of a power system. This design technique is basically accomplished in frequency domain. The most important feature of QFT is that it is able to deal with the design problem of complicated uncertain plants. A basic idea in QFT design is the translation of closed-loop frequency-domain specifications into Nichols chart domains specifying the allowable range of the nominal open-loop response and then to design a controller by using the gain-phase loop shaping technique. This paper introduces a new algorithm to compute QFT bounds more efficiently. The propose QFT design method ensures a satisfactory performance of the PSS under a wide range of power system operating conditions.