Motor Function in School-Aged Children with Attention-Deficit/Hyperactivity Disorder in Korea

Hyunjin Cho,Seokyeon Ji,Sungho Chung,Meesun Kim,YooSook Joung 대한신경정신의학회 2014 PSYCHIATRY INVESTIGATION Vol.11 No.3

Objective-Motor function critically influences daily activities and academic performance. We compared motor function in schoolaged children with Attention-Deficit/ Hyperactivity Disorder (ADHD) to that of normal children. Methods-Participants were 58 children with ADHD [51 males, 7 females; mean age 9 years 6 months±2 years 0 months (SD)] and 70 normal controls [56 males, 14 females; mean age 9 years 2 months±1 years 7 months (SD)]. We assessed motor function with the Bruininks- Oseretsky Test of Motor Proficiency, Second Edition. Results-The ADHD group had a significantly lower total motor composite score (t=-9.32, p<0.001) than that of the control group. Standard scores of four motor-area composites such as fine manual control (t=-3.76, p<0.001), manual coordination (t=-6.87, p<0.001), body coordination (t=-7.14, p<0.001), and strength and agility (t=-8.54, p<0.1) were significantly lower in the ADHD group than those in the control group. Among the subtests, scores on fine motor precision, fine motor integration, manual dexterity, bilateral coordination, balance, running speed and agility, and strength were significantly lower in the ADHD group than those in the controls, whereas upper-limb coordination was not significantly different between the groups. Conclusion-School-aged children with ADHD in Korea had significantly lower motor function compared to that of controls. Thus, it is suggested that appropriate target intervention for motor function is important in children with motor impairment in addition to pharmacotherapy or psychosocial therapy for improving the core symptoms.

전기모터 효율 시험의 조기중단 결정 알고리즘

최병호 ( Byoungho Choi ),김민규 ( Minkyu Kim ),김흥섭 ( Heungseob Kim ) 사단법인 한국빅데이터서비스학회 2023 빅데이터서비스학회 논문집 Vol.1 No.2

전기모터는 산업 전반에 광범위하게 사용되는 핵심 자원이며, 산업용 모터는 국내 전력소비량의 절반 이상을 소비하고 있어 에너지 소비 효율성에 대한 문제가 중요하게 다루어지고 있다. 더불어, 전세계적인 탄소 중립정책 추진으로 고효율 전기모터에 관심이 매우 높아지고 있다. 이에 따라 모터 효율 검정을 위한 시험이 증가하고 있으며, 시험을 위한 전력소비량도 증가하고 있는 추세이다. 그러나 기존의 연구들은 주로 모터의 성능을 개량하기 위한 연구이며 모터시험에 관한 연구는 미흡한 상황이다. 따라서 본 연구는 전기모터 효율 측정 시험의 전력소비량 감소를 위해 모터 효율의 포화 값을 예측하여 시험의 조기중단을 결정하기 위한 알고리즘을 제안한다. 후보 곡선모형에 대해 비선형 모형의 경우 변수변환을 통해 선형 모형으로 변환하였으며 최소제곱법을 통해 곡선모형의 계수를 추정하여 적합하고 다수의 미래 시점의 효율을 예측하였다. 예측값과 실제값의 평균제곱오차를 통해 후보 곡선모형을 평가하였으며, 모터 규격별 적절한 모형을 선정하였다. 적합한 모형의 잔차들과 종료 시점의 효율 예측값 및 최저효율 기준을 토대로 표준정규분포를 계산하고 효율 측정 시험 불합격 확률을 도출한다. Electric motors are an essential resource widely utilized across industries, and industrial motors consume more than half of domestic electricity consumption, making energy efficiency a critical issue. In addition, the global push for carbon neutrality drives interest in high-efficiency electric motors. Accordingly, the number of tests for motor efficiency verification is increasing, and the power consumption for such tests is also growing. Therefore, this study proposes an algorithm for predicting the saturation value of the motor efficiency to determine the early termination of the test to reduce the power consumption of the electric motor efficiency measurement test. However, existing studies are mainly aimed at improving the performance of motors, and there is a lack of research on motor testing. Therefore, this study proposes an algorithm for predict the saturation value of motor efficiency to determine the early termination of the test in order to reduce the power consumption of electric motor efficiency measurement test. For the candidate curve model, the nonlinear model was converted into a linear model through variable transformation, and the coefficients of the curve model were estimated through the method of least squares to fit and predict the efficiency at multiple future time points. Candidate curve models were evaluated using the mean square error between predicted and actual values, and the appropriate model for each motor standard was selected. Based on the residuals of the fitted model, the predicted efficiency at the end of the test and the minimum energy performance standard, a standard normal distribution was calculated and the probability of failing the efficiency measurement test was derived.

구강운동촉진기술: 2 부-개념적 위계 및 핵심 기법

민경철(Min, Kyoung Chul),서상민(Seo, Sang Min),우희순(Woo, Hee-soon) 대한신경계작업치료학회 2021 재활치료과학 Vol.10 No.1

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) 준비기법: 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. Introduction : OMFT is a therapeutic technique based on sensorimotor, motor control and motor learning, and its major goal is to improve oral motor function. The oral motor conceptual hierarchical development is divided into 5 steps: 1) sensorimotor, 2) movement integration, 3) structural movement, 4) functional oral motor, and 5) comprehensive oral motor. Discussion : The OMFT consists of 3 techniques, 10 categories, and 50 sub-item. 1) Warming up technique: 2 categories, 12 sub-item, warming up by sensory awareness and adaptation, therapy situation adaptation, neck movement; 2) Key point technique: 7 categories, 30 sub-item, oral motor facilitation and increasing chewing skill by direct stroke of oral structures such as the face, lips, cheeks, gum, jaws, and tongue; 3) Application technique: 1 category, 8 sub-item, facilitate food intake and swallowing. Conclusion : The goal of this article is to introduce 3 techniques, 50 sub-item of OMFT, as a comprehensive oral motor therapy method, for application to clients. This article provides information that will help oral motor specialists in treating clients with oral motor problems more effectively and professionally.

초소형차용 후륜 인휠모터 시스템개발

김영렬(Youngryul Kim),김종수(Jongsu Kim),이준호(Junho Lee),이호영(Hoyoung Lee),권순오(Soono kwon) 한국자동차공학회 2020 한국자동차공학회 학술대회 및 전시회 Vol.2020 No.11

When the in-wheel motor is applied to the vehicle, the differential gear and the drive shaft are removed, thereby increasing the spatial design freedom in the vehicle layout, and can also be used to control vehicle motion through independent torque control of the in-wheel motor. The point of design of the in-wheel motor is the harmonious and concise packaging of the surrounding components, such as suspension, brake, hub, and reduction gear, in a given space within the wheel. In particular, the inherent performance of the surrounding components shall not be reduced due to the mounting of the in-wheel motor. This study is about the design of the in-wheel motor for the rear wheels of a ultra-small electric truck, and the design of the in-wheel motor for vehicles with disc brake and torsion beam axle suspension. where the in-wheel motor was designed based on the excellent buried permanent magnetic motor motor in efficiency and size, and the reduction gear was applied with the planetary gear. In the primary design and manufacture of the motor, a motor with a small outer diameter and a long length in the axial direction of the motor was designed, but in the secondary design, the motor was able to increase the outer diameter of the motor and shorten the axial length of the motor by improving the packaging design with the brake caliper and packaging the reduction gear into the rotor of the motor.

Induction Motor Torque Prediction Using Dual Function Radar Received Polarised Signals and Machine Learning Algorithm

Chinthamani B.,Kavitha S.,Bhuvaneswari N. S.,Shanker N. R. 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

Induction motor is used for different applications in industries such as grinding, milling, mining and automation. Induction motor performance degrades over time due to continuous operation, over load, transient unbalanced supply voltage and current. Hence, induction motor performance and efficiency are evaluated through measurement of motor torque. The torque measurement using various sensors such as acoustic, mems-vibration, strain gauge, in line sensors, never provides the inaccurate results due to contact type sensors and improper mounting of sensor on the motor. Moreover, existing methods never provides inaccurate torque measurement for different types of motor duty cycle such as continuous duty, intermittent periodic duties, short-time duty and continuous operation with intermittent load. In this paper, novel non-contact method measures torque with Dual-function ultra-wide band (UWB) (DFR) Radar sensor. DFR acquires polarized signal reflected from air gap of motor magnetic flux. Moreover, air gap magnetic flux radiation through motor ventilator is directly proportional to motor torque. In this paper, motor torque is measured through air gap magnetic flux radiation and DFR sensor. The electromagnetic waves from DFR is reflected by the air gap magnetic flux emitted from motor and the reflected waves are polarized. The reflected DFR sensor signal from air gap magnetic flux has high polarity charge and resonance. From received polarized signal, Instantaneous Frequency (IF) is obtained through Multi-Synchro Squeezing Transform (MSST) algorithm. The motor torque is measured with IF and Gaussian regression algorithm. Torque spikes in Induction motor is analyzed during frequent change in heavy, low load, and induced transient Torque prediction through MSST IF frequency and Gaussian Regression is compared with Torque predicted through different transform such as Discrete Wavelet Transform (DWT), Stationary Wavelet Transform (SWT), Dyadic Wavelet Transform (DyWT). The MSST based torque measurement provides 96% of accuracy, when compared with traditional strain gauge torque measuring instrument. Initial review.

선외기 구동을 위한 BLDC 전기모터 개발

신철기,김진사,Shin, Cheol-Gi,Kim, Jin-Sa 한국전기전자재료학회 2013 전기전자재료학회논문지 Vol.26 No.10

This paper tried to develop a BLDC electric motor securing the 800 W-level watertight structure for driving the outboard motor. For this purpose, this paper developed a high-efficient controller-integrating BLDC electric motor system for underwater propulsion and designed and developed a triple watertight structure. Besides, this study developed a outboard motor integrating motor, propeller and controller based on the production of a controller for BLDC motor which can the speed control by selecting low-voltage, high-current power element. The characteristics of developed outboard motor were 24 V input voltage, over 800 W motor output, and max. 3,000 rpm motor, and 84.9% motor efficiency, and the developed outboard motor could secure the watertight structure in 5 m in water depth.

고밀도 토크를 가지는 5상 영구자석형 전동기의 약계자 제어

김남훈 전력전자학회 2007 전력전자학회 논문지 Vol.12 No.4

This paper investigates the field weakening operation of a five-phase permanent magnet motor. The proposed motor has concentrated windings such that the produced back-EMF is almost trapezoidal and is supplied with the combined sinusoidal plus third harmonic of currents to produce trapezoidal current. Therefore this motor, while generating the same average torque as an equivalent permanent magnet brushless dc motor, overcomes its disadvantages. It is shown that torque producing and flux producing components of current for this motor can be decoupled by using multiple reference frame transformation. Therefore, Vector control is easily applicable to the motor. This motor has benefits such as high torque density of a BLDC motor below the rated speed and controllability of PMSM above the rated speed and during the field weakening region and simulation and experimental results are provided to prove the validity of the superior performance of this drive. 본 논문에서는 영구자석형 5상 전동기(Five-phase permanent magnet motor)의 약계자 제어에 대한 연구를 수행한다. 제안된 전동기는 집중권 방식의 권선분포를 가지고 있고 사다리꼴 형태의 역기전력을 나타내고 있으며, 사다리꼴 형태의 전류를 인가하기 위하여 사인파의 기본파 성분에 3고조파 성분을 첨가하였다. 따라서 BLDC 전동기(Brushless dc motor)와 등가적으로 같은 평균토크를 발생시키면서 BLDC 전동기의 단점을 극복할 수 있었다. 전동기 전류의 토크성분과 자속성분은 다중 레퍼런스 프래임을 이용하여 분리할 수 있었으며, 결과적으로 쉽게 벡터제어가 이루어질 수 있었다. 사용된 전동기는 고속영역에서부터 저속영역까지 BLDC 전동기와 같이 높은 토크 밀도를 가지며, 약계자 영역이나 고속영역에서 영구자석형 전동기와 같이 제어의 용이함을 가진다는 장점을 가지고 있으며 실험결과를 통하여 제안된 전동기와 알고리즘을 검증하였다.

근전도 신호와 BLDC모터 제어를 통한 무릎재활시스템

권형기,고형규,송윤오,손의성,이붕주 한국전자통신학회 2019 한국전자통신학회 논문지 Vol.14 No.5

This research is the design and implementation of a rehabilitation medical device based on a EMG measurement. Rehabilitation systems are controlled using BLDC motors and motor drives. The BLDC motor drive controls the operation and the speed controls the drive through the external servo motor. The potentionmeter coupled to the outside of the motor transmits information about the position of the load being rotated by the motor. The rehabilitation algorithm executes the periodic contraction relief rehabilitation at a certain angle range by speed stage and controls the maximum angle of 0-120 using the motor according to the user setup stage during the rehabilitation exercise. The walking algorithm compensates motor control for legs with low avionics signal by motor control using differential values of signals obtained by EMG measurement attached to both innermost roots and controls the maximum angle of 0 to 88 using motor and EMG measurement during walking motion. In addition, the application implements a more convenient knee rehabilitation system to confirm the feasibility of the application. 본 연구에서는 표면근전도 측정기 기반의 재활 의료기기의 설계 및 구현에 관한 내용을 기술한다. 재활시스템은 BLDC모터와 모터 드라이브를 이용하여 제어된다. BLDC모터 드라이브는 동작 제어를 하며, 속도는 외부 서보모터를 통해 드라이브를 제어한다. 모터 외부에 결합된 포텐쇼미터는 모터에 의해 회전하는 부하 위치 정보를 전달한다. 재활 알고리즘은 환자가 일정 각도 범위에서 주기적인 수축⋅이완 재활운동을 속도단계별로 실행하며 재활운동 시 사용자 설정 단계에 따른 모터를 활용하여 0∼120[]의 최대각도를 제어한다. 보행 알고리즘은 양쪽 안쪽넓은근에 부착된 표면근전도 측정기로 획득한 신호의 차이 값을 이용하여 근전도 신호가 낮은 다리에 모터제어로 보상해주며 보행운동 시 모터와 표면근전도 측정기를 활용하여 0~88[]의 최대각도를 제어한다. 또한, 어플리케이션으로 보다 편리한 무릎재활시스템을 구현하여 실용화 가능성을 확인하였다.

Sensorless control of printed permanent magnet synchronous motor

Xianming Deng,Maolin Li,Min Xu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.1

As a special disc motor, a printed permanent magnet synchronous motor (PMSM) uses a PCB printed board as the stator, which has the advantages of simple assembly, short axial distance, no stator slot, low eddy current loss, etc. Due to the stator-less core structure and the small number of winding turns, the inductance of the motor is very small. When vector control technology is used to drive the motor, the motor current pulse vibration is intense, there is a large number of integer multiples of the switching frequency high-frequency harmonics, there is also torque output pulse vibration, and it cannot be sampled to obtain the actual working state of the motor stator current, which affects the sliding mode sensorless control algorithm in terms of stator current estimation. Then it affects the motor speed and position estimation. In this paper, a solution involving high switching frequency control is proposed to obtain the characteristics of this kind of motor. In addition, the sensorless control of the motor based on the super-twisting sliding mode is realized. Simulation and experiments show the stability and effectiveness of the motor position free control system, and solve the problems related to severe motor stator current oscillation, motor output electromagnetic torque oscillation, and poor control performance of the sensorless algorithm caused by a small motor stator inductance.

직류전동기 제어기법을 적용한 3상 BLDC 모터 제어에 관한 연구

김진만,남택근 해양환경안전학회 2023 해양환경안전학회지 Vol.29 No.6

본 논문은 직류전동기(DC motor)와 전기적인 특성은 유사하지만, 수명과 신뢰성이 향상된 BLDC 모터의 제어기법에 대해 언급하고 있다. BLDC모터는 회전자의 위치 정보를 사용하여 직류전동기의 기계적인 접촉에 의한 정류 장치를 제거함으로써 내구성과 속도 안정성을 향상시킬 수 있다. 본 연구에서는 BLDC모터의 권선에 흐르는 전류가 직류전동기의 전기자에 흐르는 구형파 형태의 전류인 것에 착안하여 직류전동기에 대한 제어기를 설계하고, 설계된 제어기를 3상 BLDC모터에 적용하여 제어기의 유효성을 확인하였다. 이를 위해 3상 BLDC모터의 전기적인 파라미터 값을 가지는 단상 직류전동기의 모델링을 실시하였고, 도출된 시스템에 대해 근궤적법을 적용하여 전동기의 속도제어를 위한 PI 제어기를 설계하였다. DC 전동기의 속도제어 시뮬레이션을 시행하여 제어기의 성능을 확인하였고, 동일한 제어기를 MATLAB으로 구현한 3상 BLDC모터의 속도제어에 적용하였다. DC 전동기와 유사한 제어 결과를 3상 BLDC모터에서 얻을 수 있었고, 이를 통해 연구에서 제안한 제어기법의 유용성을 확인할 수 있었다. This paper discusses the control method of BLDC(Brushless Direct Current) motor that has similar electrical characteristics with DC motor but has improved its lifespan and reliability. The BLDC motor can improve durability and speed stability by using rotor position information to eliminate commutators that require mechanical contact with DC motors. In this study, a controller for a DC motor was designed based on the fact that the current in the windings of a BLDC motor is a square-wave current like the current flowing in the armature of a DC motor. Next, the designed controller was applied to a 3-phase BLDC motor to confirm the effectiveness of the controller. In detail, a single-phase DC motor with electrical parameter values ​​of a three-phase BLDC motor was modeled and a PI controller for motor speed control was designed by applying the root locus method to the derived system. The speed control simulation of the DC motor was performed to confirm the validity of the controller, and the same controller was applied to the speed control of the 3-phase BLDC motor implemented in MATLAB. From the simulation, similar results of the DC motor were obtained in the 3 phase BLDC motor and confirmed the usefulness of the proposed control scheme.