• 한국군사과학기술학회지
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• 제13권4호
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• pp.708-715
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• 2010

In Strapdown Inertial Navigation System, alignment accuracy is the most important factor to determine the performance of navigation. However by an existing self-alignment method, it takes a long time to acquire the alignment accuracy that we want. So, to attain the desired alignment accuracy in as little as $\bigcirc$ minutes, we have developed the precise multi-position alignment method. In this paper, it is proposed a inertial measurement matching transfer alignment method among alignment methods to minimize the alignment error in a short time. It is based on a mixed velocity-DCM matching method be suitable to the operating environment of vertical launching system. The compensation methods to reduce misalign error, especially azimuth angle error incurred by measurement time-delay error and body flexure error are analyzed and evaluated with simulation. This simulation results are finally confirmed by experimentations using FMS(Flight Motion Simulator) in Lab and the integration test to follow the fire control mission.

• 대한전기학회논문지:전력기술부문A
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• 제48권2호
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• pp.97-106
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• 1999

This paper proposes the structure and the algorithm of the Fuzzy-Neural Controller(FNNC) which is able to adapt itself to unknown plant and the change of circumstances at the Fuzzy Logic Controller(FLC) with the Neural Network. This Learning Fuzzy Logic Controller is made up of Fuzzy Logic controller in charge of a main role and Neural Network of an adaptation in variable circumstances. This construct optimal fuzzy controller applied to the 2-area load frequency control of power system, and then it would examine fitness about parameter variation of plant or variation of circumstances. And it proposes the optimal Scale factor method wsint three preformance functions( E, , U) of system dynamics of load frequency control with error back-propagation learning algorithm. Applying the controller to the model of load frequency control, it is shown that the FNNC method has better rapidity for load disturbance, reduces load frequency maximum deviation and tie line power flow deviation and minimizes reaching and settling time compared to the Optimal Fuzzy Logic Controller(OFLC) and the Optimal Control for optimzation of performance index in past control techniques.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국제학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.764-769
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• 1988

In this paper the failure possibility and the error possibility are used to represent reliability of a technical component and that of a human operator, respectively. The failure possibility and the error possibility are fuzzy sets on the interval [0,1]. In a man-machine system, reliability of the technical component and that of the human operator are usually affected by many factors, e.g., the environment in which a machine is operated, psychological stress of the human operator, etc. The possibility is derived from not only the failure or the error rate but also estimates of these factors. The fuzzy reasoning plays an important role in the derivation. The reliability analysis is performed by the use of the possibility obtained by the present method. Moreover this paper discusses the sensitivity analysis which evaluates what extent the change of the estimation of each factor has an influence on reliability of a man-machine system. The important factors to be ameliorated are shown through the sensitivity analysis.

• 대한산업공학회지
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• 제7권1호
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• pp.21-31
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• 1981

This paper develops a short term forecasting model for household electric power consumption in Seoul, which can be used for the effective planning and control of utility management. The model developed is based on exponentially weighted moving average model and incorporates monthly average temperature as an exogeneous factor so as to enhance its forecasting accuracy. The model is empirically compared with the Winters' three parameter model which is widely used in practice and the Box-Jenkins model known to be one of the most accurate short term forecasting techniques. The result indicates that the developed hybrid exponential model is better in terms of accuracy measured by average forecast error, mean squared error, and autocorrelated error.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.537-540
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• 1998

This thesis deals with the design problem of the state estimator for digital servo system. Digital servo system has input time delay, which depends on the size of control algorithm. The delayed input is a factor that brings out the state estimation error. So, in order to reduce this state estimation error of the system, we proposes a state estimator in which the delayed input of the system is considered. At first, a discrete-time state-space model is established accounting for the delayed input. Next, the state estimator is designed based on this model. we employ Kalman filter algorithm in design of the state estimator. The performance of proposed state estimator is exemplified via some simulations and experiment for servo system. And robustness of the proposed estimator to modelling error by variation of the system parameter is also shown in these simulations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.64.2-64
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• 2001

In this paper, fabricated is a motion capture and attitude detection system for Head Mounted Display HMD composed of three low-price and low-grade micro gyroscopes and a micro-controller, To calculate attitude of a body, modified INS algorithm is used. Because the micro gyroscope has much bias drift error, scale factor error, and run-to-run bias error, the motion of a body can not be measured exactly if the general INS algorithm and micro gyroscopes are used. To reduce the errors, three accelerometers can be used. In this case, however, the size and power consumption become too large to use in HMD system. The modified INS algorithm use the grid map and the characteristics of the human motions.

• 한국철도학회논문집
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• 제10권1호
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• pp.51-56
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• 2007

In this paper, control schemes are developed for a propulsion system(Converter/Inverter) in electrical train. A robust controller for PWM converter is proposed. The converter controller consists of a PI controller for DC output voltage and a current controller using error-space approach for maintaining the sinusoidal current waveform and unity power factor. This proposed method is based on characteristic ratio assignment(CRA) method which has the advantage to design the optimal gain to meet the referenced response and overshoot within the limit range. Inverter system is controlled by vector control and slip frequency control. At low speed region, vector control scheme is applied to control instantaneous torque and slip frequency control is performed under overmodulation region and one pulse mode. Because output voltage of converter contains harmonics ripple at twice input ac line frequency, control scheme is developed to reduce the pulsating torque current. The performance of propulsion system will be verified by simulation and prototype experimental results.

• 한국가스학회지
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• 제18권4호
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• pp.68-75
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• 2014

독성가스시설에서 대형사고로 인한 손실을 감소시키기 위해서는 인적요소를 제어하고, 평가하는 것이 필요하다. 기존의 안전성 평가는 기계적 결함이나 시스템의 위험이 주로 강조되어 왔으며, 인적오류를 관리하는 평가방법이 부족하여 본 연구에서는 독성가스시설의 사고관리 상황에서 인적오류를 구성하는 수행영향인자 분류체계를 제안하고자 하였다. 이를 위해 주요 수행영향인자 분류체계의 유형을 수집하여 검토와 분석을 한 후 4가지(작업자 특성, 시스템, 직무특성 및 직무환경)로 나누고, 독성가스시설의 상황적 특성과 직무특성 및 작업환경을 고려하여 수행영향인자를 선택하였다. 이로 부터 인적오류의 평가에 사용하기 적절한 수행영향인자 체계를 구축하고, 구축한 수행영향인자 분류체계를 독성가스시설에서 발생하였던 사고 사례분석을 통해 적용성을 검토하였다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2007년도 춘계학술발표회 논문집
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• pp.3-6
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• 2007

The GPS baseline processing and the network adjustment was required a preliminary classification and check for effective work because the observation data of GPS $3^{rd}$ order control points are enormous attain to about 12,000 points. Particularly, in baseline processing and network adjustment a inaccuracy GPS antenna heights and point names yield a gross error or a S/W computation error. For the baseline processing of observation data, the related all materials were collected and were required a final check. The factor occurring a error, in GPS the baseline processing, were inspected variously after a checking observation data. Also, baseline processing method of GPS $3^{rd}$ order control points were commented and the analysis carry out a results with a experiment. The ellipsoidal distance and height of duplication baseline was compared between adjoin campaign areas for a accuracy analysis of baseline processing. According to the result, the mean is about 1cm for horizontal direction and about 2cm for vertical direction.

• 한국항행학회논문지
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• 제15권2호
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• pp.241-247
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• 2011

유선네트워크 환경에서의 Transmission Control Protocol(TCP) 패킷 손실은 대부분 네트워크의 혼잡에 의해서 발생한다. 하지만, 무선네트워크 환경에서는 무선 네트워크의 특징 중 하나인 높은 Bit Error Rate (BER)에 의한 손실이 대부분 일어난다. 네트워크는 무선 신호 품질에 의한 패킷 손실을 혼잡제어에 의한 손실로 판단하여, 혼잡제어 메커니즘이 빈번하게 수행된다. 무선 환경의 패킷 손실율을 이용하여 Explicit Wireless Loss Notification (EWLN) 알고리즘에서 발생될 수 있는 비효율적인 Congestion Window의 크기를 보다 효율적으로 재조정함으로써, 기존의 EWLN 알고리즘을 개선하는 알고리즘을 제안한다.