• 디지털융복합연구
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• 제17권9호
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• pp.259-269
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• 2019

본 연구는 토익을 학습 하는 보건계열 신입여대생의 셀프리더쉽에 대한 융복합적인 관련 요인들을 분석하였다. 2019년 4월 29일부터 2019년 5월 10일까지 J시에 위치한 대학의 토익학습반에서 무작위로 추출된 보건계열 신입여대생 201명에 대하여 무기명 자기기입식 질문지를 사용하여 설문조사를 수행하였다. 위계적 다중회귀분석 결과, 자기유능감이 높을수록, 자기효능감이 하위영역인 과업효능감 및 대처효능감이 높을수록, 통제위치의 하위영역인 우연통제 위치가 낮을수록, 셀프리더쉽이 높았으며 이들의 설명력은 49.7%이었다. 연구결과를 볼 때, 토익을 학습하는 보건계열 신입여대생의 셀프리더쉽을 높이기 위해서는 자기유능감, 자기효능감 및 통제위치를 관리하는 학습상담지도가 필요하다. 이러한 결과는 토익학습을 하는 보건계열 신입여대생의 셀프리더쉽을 높이는 학습상담지도에 활용될 수 있다. 향후 연구에서는 토익을 학습하는 보건계열 남녀 대학생과 셀프리더쉽의 관련요인 탐색과 셀프리더쉽에 영향을 미치는 구조방정식 모형의 수립 및 분석이 필요하다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.136-144
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• 2014

The existing conventional motion controller does not perform well in the presence of nonlinear properties, uncertain factors, and servo lag phenomena of industrial actuators. Hence, a feasible and effective fuzzy self-tuning proportional integral derivative (PID) and feed-forward control scheme is introduced to overcome these problems. In this design, a fuzzy tuner is used to tune the PID parameters resulting in the rejection of the disturbance, which achieves better performance. Then, both velocity and acceleration feed-forward units are added to considerably reduce the tracking error due to servo lag. To verify the capability and effectiveness of the proposed control scheme, the hardware configuration includes digital signal processing (DSP) which plays the main role, dual-port RAM (DPRAM) to guarantee rapid and reliable communication with the host, field-programmable gate array (FPGA) to handle the task of the address decoder and receive the feed-back encoder signal, and several peripheral logic circuits. The results from the experiments show that the proposed motion controller has a smooth profile, with high tracking precision and real-time performance, which are applicable in various manufacturing fields.

• 한국정보처리학회논문지
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• 제7권12호
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• pp.3848-3854
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• 2000

제어 시스템에서 요구되는 특성과 제공되는 하드웨어들의 기능을 유지하는 것은 만족할만한 제어기를 설계하는데 있어서 중요하다. 제어시스템의 하드웨어들 중에서 센서는 내·외부 외란에 가장 취약하지만, 정확하고 신뢰성있는 센서값을 유지하는 것은 좋은 제어기 성능을 위해 꼭 필요하다. 센서에 오류가 발생했을 경우, 센서 출려과 제어기 출력 같은 값을 사용하여 이를 검출하고, 오류 증상을 분석하여 오류 요인을 판단한다. 오류 요인에 따라 원래 센서값 대신 Self-Validating 센서값을 사용한다. 본 논문에서는 유연 링크 시스템에서 광센서 모듈의 오류 문제들에 Self-Validating 센서를 응용하여 이의 유효성을 보이고, 센서 오류가 발생하였을 때 만족할만한 성능을 제공할 수 있는 디지털 제어기를 제안한다.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 추계학술발표회논문집(1)
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• pp.85-90
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• 1996

In this paper, the self-organizing fuzzy logic controller is developed for water level control of steam generator. In comparison with conventional fuzzy logic controllers, this controller performs control task with no control rules at initial and creates control rules as control behavior goes on, and also modifies its control structure when uncertain disturbance is suspected. Selected parameters in the fuzzy logic controller are updated on-line by the gradient descent loaming algorithm based on the performance cost function. This control algorithm is applied to water level control of steam generator model developed by Lee, et al. The computer simulation results confirm good performance of this control algorithm in all power ranges. This control algorithm can be expected to be used for automatic control of feedwater control system in the nuclear power plant with digital instrumentation and control systems.

• 전기의세계
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• 제22권4호
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• pp.11-16
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• 1973

This paper presents an optimum control of the field resistance for the self-excited DC shunt generator to keep a constant terminal voltage in case of the load change or the torque variation in the system. The non-linearity of the system is linearized by applying the small signal technique and the linearized equation is solved by the maximum principle with the digital computer. The optimal control value of the field resistance for the step error of the generator output voltage is obtained and the transient voltage characteristics in the system are investigated.

• 한국지구과학회지
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• 제39권1호
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• pp.46-52
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• 2018

이 논문은 자체 개발된 드론을 이용하여 사진측량기술을 적용하여 3차원 수치지표면모델(DSM)개발 연구를 수행하였다. 이 DSM을 개발하기 위하여 제주도 지역을 선정하여 24장의 사진을 개발된 드론으로 직접 촬영을 수행하였다. 촬영된 사진의 정확한 3차원 좌표를 부여하기 위하여, 10개의 지표기준점(GCP)점을 선정하여 상대측위 지구위치시스템(DGPS)측량을 실시하였다. 사진의 정확도를 평가하기 위하여 3개의 GCP점을 선정하여 사진상의 좌표와 지상점의 좌표의 정확도를 비교하였다. 사진좌표계과 지상좌표계의 정확도를 평가한 결과 수평오차는 8.8-14.7 cm로 나타났으며, 연직오차는 12.4 cm로 나타났다. 이 정확도는 국토지리정보원(NGII)이 인정하는 1/1,000 수치지도의 정확도를 가지는 측량결과이다. 이 연구를 통하여 본 연구에서 개발된 드론과 사진측량기법이 제주지역에서 우리가 원하는 DSM자료를 얻는데 유용한 기술임을 알 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.332-335
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• 1990

A digital phase-locked loop speed control system of a self-controlled permanent magnet synchronous mortar fed by a voltage source inverter is presented. This paper discribes the hardware and software design of the system. Variable speed control system for self-controlled permanent magnet synchronous motor is proposed. Simulation results demonstrate the validity of proposed methods. This proposed control technique is implemented by using a microprocessor-based system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2349-2351
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• 2003

This paper reports a novel microfluidic system, by which microfluidic delivery, transport and control can be digitally realized in femtoliter scale. Microelectronic grade $N_2$ from a pressurized canister was passed through HPLC tubing into a micro injector. The micro injector was driven and controlled digitally by the control system that can apply various control parameters such as pulse frequencies. A front-end of micro nozzle was inserted the dyed oil to collect droplets injected. The diameter of a droplet was measured by a microscope and a CCD camera, and then its volume can be calculated on the assumption that the droplet is spherical. The micro nozzles were simply pulled in glass capillary tubes by the micro puller self-made, and the geometry parameters of the micro nozzles can be adjusted easily. Experiments have successfully been carried out, and the results demonstrated that the proposed digital micro injector possesses three significant advantages : precise ultra-small liquid volume in femtoliter scale, digital microfluidic control and micro devices fabricated by simple glass process, not based on IC process.

• Journal of Power Electronics
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• 제16권3호
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• pp.915-924
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• 2016

A digital self-sustained phase shift modulation (DSSPSM) strategy that allows for good soft switching and dynamic response performance in the presence of step variations is presented in this paper. The working principle, soft switching characteristics, and voltage gain formulae of a LLC converter with DSSPSM have been provided separately. Furthermore, the method for realizing DSSPSM is proposed. Specifically, some key components of the proposed DSSPSM are carefully investigated, including a parameter variation analysis, the start-up process, and the zero-crossing capture of the resonant current. The simulation and experiment results verify the feasibility of the proposed control method. It is observed that the zero voltage switching of the switches and the zero current switching of the rectifier diodes can be easily realized in presence of step load variations.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.987-992
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• 1992

In recent years, induction motor is applied for several industrial actuatung parts instead of direct current motor because of the robust construction, nonexpensive and maintenance-free actuator etc. and having capability of speed control according to development of power electrounics and microprocessor techniques. In the paper, a microprocessor-based digital control approach for spped control of induction motor system is presented by considering a simple modelling equation as the system expression equation of induction motor and using the self tuning control and torque effdforward control method. As the model equation of the induction motor system, we use a second order differential equation which is well known in the modeling equation is induced form the control theory stand point such tath we can describe usually the motor system connected by inverter, generator and load etc. The effectiveness of the control system composed by the above mentioned design concept is illustrated by the expermental result in the presence of step reference change and generator load variation.