• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2005년도 전력전자학술대회 논문집
• /
• pp.417-420
• /
• 2005

In this paper proposes a very simple method to estimate the rotor position of a switched reluctance motor. By on-line estimating the self-inductance of the motor, the rotor position of the SR motor is obtained, and a closed-loop drive system can be achieved. Proposed methods can easy implement to application with sensorless SR motor drive system. Speed 2000rpm SR motor simulation executed with self inductance estimation and result represented. Simulation result verified the rotor position using the proposed self-inductance estimation method.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
• /
• pp.1441-1443
• /
• 2005

In this paper proposes a very simple method to estimate the rotor position of a switched reluctance motor. By on-line estimating the self-inductance of the motor, the rotor position of the SR motor is obtained, and a closed-loop drive system can be achieved. Proposed methods can easy implement to application with sensorless SR motor drive system. SR motor simulation executed with self inductance estimation and result represented. Simulation result verified the rotor position using the proposed self-inductance estimation method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제5B권1호
• /
• pp.13-19
• /
• 2005

The performance of two designs of permanent magnet brushless motor, by having self-shielding magnetized magnets or sinusoidally shaped parallel-magnetized magnets with essentially sinusoidal airgap flux distributions, are compared. It is shown that the parallel-magnetized motor with shaped sintered NdFeB magnets can result in a higher airgap flux density and torque density than that of a self-shielding magnetized motor equipped with an anisotropic injection moulded NdFeB ring magnet.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 B
• /
• pp.1137-1139
• /
• 2002

In this paper, recurrent artificial neural network (RNN) based self tuning speed controller is proposed for the high performance drives of induction motor. RNN provides a nonlinear modeling of motor drive system and could give the information of the load variation, system noise and parameter variation of induction motor to the controller through the on-line estimated weights of corresponding RNN. Thus, proposed self tuning controller can change gains of the controller according to system conditions. The gain is composed with the weights of RNN. For the on-line estimation of the weights of RNN, extended kalman filter (EKF) algorithm is used. Self tuning controller that is adequate for the speed control of induction motor is designed. The availability of the proposed controller is verified through the MATLAB simulation with the comparison of conventional PI controller.

• 한국산학기술학회논문지
• /
• 제9권6호
• /
• pp.1560-1564
• /
• 2008

산업 자동화의 고정밀도에 따라 직류 전동기는 강인제어가 요구되고 있다. 하지만 PID 제어기를 갖는 전동기 제어 시스템이 부하 외란의 영향을 받게되면 제어 시스템의 강인제어는 어렵게 된다. 이에 대한 보완적인 한 방법으로 본 논문에서는 전동기 제어시스템을 위한 PID-자기동조 제어기법을 제시하였다. 만약 오차가 구속영역 내에 있고, 시스템이 안정한 상태에 있다면 자기동조는 사용되지 않고 PID 제어기만 동작한다. 자기동조 제어기는 오차가 구속 경계에 도달하게 되면 오차를 구속 영역내로 들어가도록 제어를 시작한다. PID-자기동조 제어 시스템의 오차가 시스템 설계자의 허용한도 내에서 유지되고 전체적으로 안정함을 증명하였다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 B
• /
• pp.1111-1113
• /
• 2003

This paper proposes an effective self-turning algorithm based on Artificial Neural Network (ANN) for fuzzy speed control of the indirect vector controlled induction motor. Indirect vector control method divides and controls stator current by the flux and the torque producing current so that the dynamic characteristic of induction motor may be superior. However, if motor parameter changes, the flux current and the torque producing one's coupling happens and deteriorates the dynamic characteristic. The fuzzy speed controller of an induction motor has the robustness over the effect of this parameter variation than a conventional PI speed controller in some degree. This paper improves its adaptability by adding the self-tuning mechanism to the fuzzy controller. For tracking the speed command, its membership functions are adjusted using ANN adaptation mechanism. This adaptability could be embodied by moving the center positions of the membership functions. Proposed self-tuning method has wide adaptability than existent fuzzy controller or PI controller and is proved robust about parameter variation through Matlab/Simulink simulation.

• 가정과삶의질연구
• /
• 제23권4호
• /
• pp.17-26
• /
• 2005

The purpose of the this study was to identify the relations among intelligence, parenting environment and self-regulation of preschool children. The subjects were 81 children between the ages 3 and 6 and their mothers from one day-care center in Seoul. T-test, correlation analysis, multiple regression analysis were used for data analysis. First, the result of this study showed that children's self-regulation ability by sex difference was significant to only girls and children's self-regulation ability by no was not significant. Parents who had higher educational background were positively related to children's intelligence and children's self-regulation ability was significant to mothers' educational background. Second, the preschool children who got higher scores in intelligence scale were higher self-regulation ability. Third, the young children's self-regulation ability showed significance only in motor intelligence which was one of the subscales of intelligence scale. Fourth, the effect of children's intelligence and parenting environment on preschoolers' self-regulation were relatively presented as intelligence($\beta$=.34, p<.01), trauma state($\beta$=0.31, p<.05) and development state($\beta$ =.23, p<0.5) which were subscales of parenting environment.

• 한국소음진동공학회논문집
• /
• 제16권12호
• /
• pp.1201-1207
• /
• 2006

This paper introduces a step motor with a passively levitated rotor which comprises a homopolar step motor and a passive magnetic bearing. Compared with conventional self-bearing motors which are mostly based on the active magnetic bearing technology, the proposed motor has a very simple structure and operating principle. For the levitation, it works just like passive magnetic bearings which use the repulsive force between permanent magnets. Halbach array is used to increase the bearing stiffness. On the other hand, its rotation principle is just the same with that of conventional motors. In this paper, we introduce the design scheme to avoid the flux interference possibly produced by electromagnets and permanent magnets, and show some results of FEM analysis to predict the performance of the proposed motor.

• 대한간호학회지
• /
• 제48권2호
• /
• pp.195-207
• /
• 2018

Purpose: The purpose of the study was to develop and test a model for predicting problem gambling in speculative game users based on Blaszczynski and Nower's pathways model of problem and pathological gambling. Methods: The participants were 262 speculative game users recruited from seven speculative gambling places located in Seoul, Gangwon, and Gyeonggi, Korea. They completed a structured self-report questionnaire comprising measures of problem gambling, negative emotions, attentional impulsivity, motor impulsivity, non-planning impulsivity, gambler's fallacy, and gambling self-efficacy. Structural Equation Modeling was used to test the hypothesized model and to examine the direct and indirect effects on problem gambling in speculative game users using SPSS 22.0 and AMOS 20.0 programs. Results: The hypothetical research model provided a reasonable fit to the data. Negative emotions, motor impulsivity, gambler's fallacy, and gambling self-efficacy had direct effects on problem gambling in speculative game users, while indirect effects were reported for negative emotions, motor impulsivity, and gambler's fallacy. These predictors explained 75.2% problem gambling in speculative game users. Conclusion: The findings suggest that developing intervention programs to reduce negative emotions, motor impulsivity, and gambler's fallacy, and to increase gambling self-efficacy in speculative game users are needed to prevent their problem gambling.

• 한국융합학회논문지
• /
• 제12권2호
• /
• pp.67-75
• /
• 2021

본 연구는 초등학교 1학년 부적응 아동을 대상으로 감각과 운동 중심의 융합 활동으로 구성 된 그룹 작업치료 프로그램을 실시하여 자기조절능력, 실행 기능에 미치는 영향을 알아보고자 하였다. 연구 설계는 사전-사후 검사를 통한 사례 연구이며 대상자는 총 3명이다. 사전-사후 검사로 자기 조절 능력 척도와 실행 기능을 알아보기 위해서 운동적 합성 검사를 실시하였다. 감각-운동 중심의 그룹 작업치료 프로그램은 전정 감각, 고유 감각, 촉각이 기초 한 움직임 활동을 하였으며 아동의 활동에 대한 선호도를 조사하여 과제를 선정하였다. 그 결과 대상자 1과 대상자 2 아동은 자기조절 능력, 실행 기능의 향상이 나타났다. 본 연구의 결과를 근거로 하여 교육 현장과 임상이 연계되어 학교의 부적응을 보이는 아동들에게 그룹 중심의 감각-운동 프로그램을 제공하여 학교의 적응 능력 향상을 기대할 수 있을 것을 사료된다.