• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.361-363
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• 1997

Rated frequency of inverter driven induction motor for a traction system can be chosen lower or higher. Traction motor with higher rated frequency can be lighter than the lower. But the maximum torque must be checked, because it is very important for starting and acceleration and it should be reduced with high frequency operation. In the paper, two motors with different rated frequency are designed and compared.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 D
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• pp.2277-2279
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• 2001

This paper describes a vision-based steering control method for AGV which use dual motor drive. We suggest an algorithm which can be detect the guideline quickly and exactly for real time vision processing, and control the steering through an assign the CP (Control - Point) of input image. This method is tested via a IAGV which dual motor drive with a single camera in laboratory environment.

• 재활치료과학
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• 제10권1호
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• pp.53-61
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• 2021

서론 : 구강운동촉진기술(OMFT)은 감각-운동, 운동 조절, 운동 학습의 이론적 배경을 바탕으로 한 치료기법으로 주요 목표는 구강 운동 기능 증진이다. OMFT에서는 구강 운동 기능의 개념적 위계 및 발달 단계는 5단계이며, 1) 감각-운동 단계, 2) 운동요소 통합 단계, 3) 구조적 움직임 단계, 4) 기능적 구강 운동 단계, 5) 통합적 구강 운동 단계로 구분하였다. 본론 : OMFT는 총 3개의 기법, 10개 범주, 50개 하위 항목으로 구성되어 있다. 자세히 살펴보면, 1) 준비 기법: 감각 인식 및 적응, 치료 적응과 목의 움직임을 통한 준비 과정으로 2범주, 12하위 항목, 2) 핵심기법: 얼굴, 입술, 볼, 잇몸, 혀, 턱 등의 구강 구조물에 치료사의 직접적인 자극을 통한 구강 운동 기술 촉진과 씹기 기능 증진을 목적으로 7개 범주, 30개 하위 항목, 3) 응용기법: 음식 섭취와 삼킬 때 도움을 줄 수 있는 치료적 접근법 1개 범주, 8개 하위 항목으로 구성된다. 결론 : 본 논문은 OMFT의 실제적 적용을 위한 구강 관련 구조물의 기능 증진을 목표로 하는 준비 기법과 핵심 기법 및 섭식을 포함한 구강 기능의 종합적인 접근을 고려한 응용 기법에 대하여 소개하는 것을 목적으로 한다.

• Journal of Power Electronics
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• 제11권5호
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• pp.743-750
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• 2011

This article deals with the sensor-less control of a DC Motor via a SEPIC Converter-Full Bridge combination powered through solar panels. We simultaneously regulate, both, the output voltage of the SEPIC-converter to a value larger than the solar panel output voltage, and the shaft angular velocity, in any of the turning senses, so that it tracks a pre-specified constant reference. The main result of our proposed control scheme is an efficient linear controller obtained via Lyapunov. This controller is based on measurements of the converter currents and voltages, and the DC motor armature current. The control law is derived using an exact stabilization error dynamics model, from which a static linear passive feedback control law is derived. All values of the constant references are parameterized in terms of the equilibrium point of the multivariable system: the SEPIC converter desired output voltage, the solar panel output voltage at its Maximun Power Point (MPP), and the DC motor desired constant angular velocity. The switched control realization of the designed average continuous feedback control law is accomplished by means of a, discrete-valued, Pulse Width Modulation (PWM). Experimental results are presented demonstrating the viability of our proposal.

• 산업기술연구
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• 제21권B호
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• pp.117-123
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• 2001

In a modern control field, a control engineer who has theoretical backgrounds with some practical knowledge is demanded. That is to say, an engineer who can understand and operate the various parts such as modeling, simulation, system analysis, signal processing, statistics, and hardware is required. In order to prove the theoretical backgrounds and operate various hardwares, a lot of experimental devices for students are designed in universities. Since the conventional experimental devices are manufactured abroad and the prices of the devices are too high, it is difficult to have. If a low cost experimental device can be developed, it will be very useful for a control engineering education. In Ibis paper, an experimental rig which has two control inputs and three sensor outputs to control the end point of a flexible beam is designed and manufactured. This rig can be used for a control field education.

• The Journal of Korean Physical Therapy
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• 제14권1호
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• pp.159-167
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• 2002

The Halliwick concept was developed by James McMillan over 50 years ago, and began as a method for teaching swimming to children with physical disables. After that the Halliwcik concept was developed as a specific strategy(called the Ten-Point Program) for teaching swimming to children with disabilities. Soon after the changes in the physical and emotional behavior were attributed to a unique teaching/learning philosophy and a psycho-sensory-motor learning program that is enhanced by hydrodynamics. Recognizing the therapeutic effects of the Ten-Pont Program adapted the program as a therapeutic intervention called Water Specific Therapy or the Logic Approach to Therapy in Water.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.654-658
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• 2003

In this study a control system with variable gain schedule using real speed and moving direction is proposed to control a Permanent Magnet Linear Synchronous Motor (PMLSM) with Z-axis operation structure. The implementation of the controller is designed on the DSP TMS320C32 board. PMLSM is operated by using 4-point absolute positions profile with each velocity, acceleration and deceleration. The direction of the initial angle action for starting is set from the lower limit point to the upper limit point on PMLSM operation stroke. The effectiveness of a control system with variable gain schedule is demonstrated by some experimental results.

• 대한전기학회논문지
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• 제41권6호
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• pp.588-599
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• 1992

This paper describes the variable speed drive of an induction motor by the line commutated inverter, which is operated in the forced commutation mode from start-up to operating point of load commutation. A novel forced-commutation circuit is proposed in this paper. The selection range of leading condenser to decide load commutation starting point is simulated by the sampling data of a general purpose IM and a high speed IM. The experiment to drive IM by a line commutated inverter with the proposed forced commutated circuits is performed. There was no problem in driving IM from standstill to starting point of load commutation by a line commutated inverter with forced commutation.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.82.6-82
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• 2001

This paper presents the control X-Y table being the precise movement by point-to-point in the x-y plane. The dual modulus technique is used for our system to control the frequency of pulse supplied to the motors. Such technique is used to stop motor of both axes accurately as the desired target point in the same period. Both motors are stepping motor. To Improve steps per revolution, we employ ministep form to drive motors. In system, personal computer, using parallel port, is used for computing algorithm in open-loop form to control motors. In experiment, our system applies on the X-Y table for drawing to test system performance.

• 대한전기학회논문지
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• 제36권12호
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• pp.874-887
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• 1987

The efficiency of a synchronous motor can be substantially improved by controlling armature voltage, field excitation, and load angle on optimum values which yield minimum input power at any specified torque and speed. This improvement is particularly noticeable in the case of light loads. In addition, the control of armature input voltage improves the power factor at which the motor operates. Employed in the analysis is a new equivalent circuit model of the motor which incorporates the frequency dependent nature of the motor parameters and the effects of iron loss. The stability of synchronous motor operation is studied by applying the Nyquist stability criterion to the linearized equations which describe the behavior of the motor as the motor loads perturb about a steady-state operating point. This investigation reveals that, in some cases, the stable region of the motor is delineated from the results of a computer simulation. With a view to reducing harmonic loss and improving torque pulsation from harmonic components, a very poweful pulse amplitude modulation (PAM) method using an 16-bit microcomputer has been developed. This method has the advantages of simplicity of control algorithms and requires small memory space for storing thyristor trigger angles for a three-phase PAM inverter. The method can be used for smooth control of both modulation depth and frequency over a wide range.