• 한국과학교육학회지
• /
• 제33권7호
• /
• pp.1450-1470
• /
• 2013

본 연구는 다수준 포함 교수법(multi-level instruction)을 적용한 초등과학 프로그램을 개발하고, 이를 적용한 수업 과정에서 나타나는 학생들 간의 언어적 상호작용을 분석한 것이다. 이러한 연구 목적을 달성하기 위하여 경기도 H시의 B초등학교 5학년 27명을 대상으로 이질적인 4명의 학생으로 소집단을 구성하였고, 매 차시마다 2개 소집단의 수업 과정을 녹화하였다. 5학년 2학기 '1. 우리의 몸' 단원을 대상으로 다수준 포함 교수법을 적용한 초등과학 프로그램을 개발하였다. 언어적 상호작용은 크게 인지적 영역과 정의적 영역 두 가지 측면으로 분석하였다. 인지적 영역은 응답, 질문, 의견제시, 의견받기로 정의적 영역은 행동참여, 분위기 조절로 세분화하여 분석하였다. 다수준 포함 교수법을 적용한 초등과학 프로그램에서 학생들의 언어적 상호작용 분석 결과는 다음과 같다. 첫째, 인지적 영역과 관련된 언어적 상호작용이 정의적 영역과 관련된 상호작용에 비해 많이 일어났다. 둘째, 인지적 영역에서는 중위수준 아동의 언어적 상호작용 빈도가 가장 높았고, 정의적 영역에서는 상위수준 아동의 빈도가 가장 높았다. 인지적, 정의적 영역에서 모두 하위수준 아동의 빈도가 가장 낮게 나타났다. 셋째, 인지적, 정의적 영역에서 상위-중위수준 아동 사이에는 언어적 상호작용의 빈도에 차이가 없었다. 그리고 상위-하위수준 아동보다 중위-하위수준 아동에게서 유의하게 차이가 있는 상호작용 유형이 더 많았다. 중위-하위수준 아동은 행동 참여를 제외한 모든 영역에서 유의한 차이가 있었다. 넷째, 시간이 지날수록 전반적으로 아동들의 언어적 상호작용의 빈도가 증가하고 있었다. 또한 성취수준에 관계없이 활발한 상호작용이 일어나고 있음을 알 수 있었다.

• 대한의용생체공학회:의공학회지
• /
• 제17권2호
• /
• pp.155-164
• /
• 1996

In the clinical environment, measurements of some characteristics of the skeletal muscle are currently used to assess the severity of a neuromuscular disease or in some cases to assist in making a diagnosis. But a quantitative method of evaluation has not yet been introduced satisfactorily. In this paper, the skeletal EMG(biceps muscle, masseter muscle) analysis has been processed both in the time and in the frequency domain by designing the digital signal processing system based on pentium PC and transputer (IMS 7805). The experiment have been performed in five normal subjects, and various parameters have been statistically tested and compare4 As a results, the effective parameters obtained for the evaluation of skeletal EMG electrical activity are turn analysis, MiTi, MiTa, IEMG, PDF in the time domain, and are mean frequency, median frequency, skewness, kurtosis, muscle fatigue slope in the frequency domain. The designed H/W and S/W in this study can be used effectively for the establishment of EMG data base and for clinical research.

• 한국자동차공학회논문집
• /
• 제11권4호
• /
• pp.165-172
• /
• 2003

This study aims to find frequency weighting curves for the evaluation of drivers' discomfort by vertical and rotational steering wheel vibration. Equal sensation curves, inverse of frequency weighting curves, were determined for the two kinds of vibrations respectively by using the sinusoidal signals with reference amplitudes from 0.2 to 0.4 m/s2 in the frequency range from 5 to 100 ㎐. Twelve subjects joined at the tests, and median values of the twelve judgments were used to determine the equal sensation curves. An experiment was followed to compare the relative sensation magnitude between the two kinds of equal sensation curves, which showed discomfort by the rotational vibration was 1.5 times of that by the vertical vibration at 50 ㎐.

• 한국정보통신학회논문지
• /
• 제7권7호
• /
• pp.1575-1581
• /
• 2003

사회가 고도의 디지털 정보화 시대로 급속히 발전함에 따라 영상 및 음성 데이터의 획득, 전송, 저장을 위한 멀티 미디어 통신 서비스가 상용화 되어가고 있다. 그러나, 여전히 데이터를 디지털화하거나 전송하는 과정에서 여러 가지 원인에 의해 노이즈가 발생하고 있으며, 이러한 노이즈를 제거하기 위한 연구는 지금까지 계속되고 있다. 노이즈를 제거하기 위해 기존에 FFT와 STFT 등이 있었으나, 신호에 대한 시간정보를 알 수 없고 시간-주파수 국부성이 상충관계를 갖는다. 따라서, 이러한 한계를 극복하기 위해 신호처리 분야의 새로운 기법으로 제시된 웨이브렛 변환은 시간-주파수 국부성을 가지므로, 다양한 신호를 해석하는데 용이할 뿐만 아니라, 다중 해상도 해석이 가능하므로 최근 여러 분야에 응용되고 있다. 그리고, 두 개의 웨이브렛 기저가 힐버트 변환쌍을 형성하도록 설계될 때, 웨이브렛 쌍은 데이터 특징 검출에서 기존의 DWT보다 우수한 성능을 갖는다. 따라서, 본 연구에서는 절단된 계수 벡터에 의해 설계된 두 개의 dyadic 웨이브렛 기저와 적응-길이 메디안 필터를 사용하여 임펄스 노이즈를 제거하였다.

• 한국정보전자통신기술학회논문지
• /
• 제5권1호
• /
• pp.20-25
• /
• 2012

표면근전도의 중앙주파수 특징을 이용하여 근지구력시간에 대한 남녀 성별차별을 구분할 수가 있다. 중앙주파수는 근육의 피로속도를 측정하는데 주로 사용하는 인자이다. 본 연구에서는 상완이두근의 등장성 운동을 통한 근전도의 성별차이를 알아보았다. 등장성운동은 피실험자가 근육피로가 피곤해 질 때까지를 측정하였다. 남녀 성별차이는 근지구력시간에 대한 중앙주파수의 선형회귀선의 기울기로 구분되어지는 특성을 보였다.

• 제어로봇시스템학회논문지
• /
• 제21권5호
• /
• pp.427-433
• /
• 2015

Hot forging industry workers are prone to encounter several health risks due to lack of automation and poor working environment conditions. These workers particularly suffer from muscle fatigue owing to the constant handling of heavy products during the forging process. Thus we developed an assistant robot for workers who carry out hot forging tasks. The purpose of a robot is to compensate gravity-loads for heavy products. To verify the functionality of a robot, we performed a muscle fatigue analysis using Electromyography (EMG) signals. Four muscles of the upper extremity were chosen to measure muscle activity. And experiment conditions were setup to imitate the hot forging process. Post experimental analysis of the captured muscle activity revealed a reduction in the median frequency of the EMG signals, which means clear fatigue reduction due to a robot's assistance. The developed assist robot with compact and economical components can be efficiently utilized at forging work sites to create better working conditions for operators.

• 대한통합의학회지
• /
• 제6권2호
• /
• pp.117-123
• /
• 2018

Purpose : The purpose of this study was to investigate the effect of increased brain activity on the muscle endurance and the effect of brain activation through the combination of transcranial direct current stimulation and aerobic exercise on elderly woman. Methods : To investigate the effect of the muscle endurance on right leg, muscle endurance was evaluated by measuring the surface EMG of the muscles of the rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius muscle. Results : There was a significant difference in the pre and post comparisons of muscle endurance on rectus femoris, biceps femoris, tibialis anterior muscle (p<.05). Difference of Combination of transcranial direct current stimulation and aerobic exercise group median frequency was smaller than control group (p<.05). There was not a significant difference in the pre and post comparisons of muscle endurance on biceps femoris, and gastrocnemius muscle. Difference of Combination of transcranial direct current stimulation and aerobic exercise group median frequency was showed a similar pattern. Conclusion : Through these results, It was found that increasing the brain activity by the transcranial direct current stimulation improves the exercise capacity on the elderly women. Combination of transcranial direct current stimulation and aerobic exercise maybe applied as an effective treatment for improving muscular endurance.

• The Journal of Korean Physical Therapy
• /
• 제19권3호
• /
• pp.11-17
• /
• 2007

Purpose: The purpose of this study were to analyze fatigue patterns of the rectus femoris muscle by isometric contraction. Methods: Twenty healthy subjects(10 male, 10 female) participated in this study. Maximal voluntary isometric contraction(MVIC) was measured by the dynamometer. Muscle activity was recorded from the rectus femoris muscle. During the experiment, the subject was seated in the chair. The measured items, median frequency(MDF) and root mean square (RMS), were collected from the surface EMG. All data were analyzed using repeated measures ANOVA. Results: There was significant difference of MVIC between male and female. Endurance time was significant difference by the level of MVIC but no significant in the main effect(sex) and interaction effect. The MDF and fatigue index were significant differences in the interaction effect. The RMS was not significant difference in both of main and interaction effect. The muscle fatigue patterns of female was greater than male after 60% MVIC. Conclusion: This study showed that sex differences of muscle fatigue were started from 60% MVIC.

• Korean Journal of Acupuncture
• /
• 제28권4호
• /
• pp.59-66
• /
• 2011

Objectives : This study is aimed to evaluate and objectify the therapeutic effect of moxibustion on muscle fatigue recovery. Methods : To evaluate the therapeutic effect on the muscle fatigue recovery, we compared the fatigue recovery of two groups (non-stimulation group and moxibustion group) by analyzing the EMG and peak torque after strenuous knee exercise of isokinetic contraction. Results : The median frequency (MF) of the moxibustion group was recovered faster than that of the non-stimulation group. However, the peak torques of both groups were not restored until after 20 minutes. Nevertheless, the moxibustion group's peak torque was regained higher than that of the non-stimulation group. Conclusions : We confirmed the therapeutic effect of moxibustion and found that the moxibustion can used as prevention method for musculoskeletal disease.

• 대한인간공학회지
• /
• 제32권6호
• /
• pp.541-547
• /
• 2013

Objective: The aim of this study is to find the influence on muscle fatigue by changing an angle of neck while Shaker exercise. Background: Shaker exercise is commonly applied to dysphagia patients for strengthen suprahyoid muscle(SHM) and relaxing upper esophageal sphincter. Method: Experiments were conducted by measuring muscle fatigue with surface electromyography(SEMG) in case of neck $15^{\circ}$ and $50^{\circ}$ flexion, in addition to original method. For the study 30 undergraduate students were participated as subjects. Muscle fatigue was measured with variations of median frequency(MF) and median frequency slope(MFS) by attaching SEMG to 3 muscles. At the same time, perceived exertion was measured by using Borg's rating of perceived exertion(RPE). Results: A MF was increased when low angle in SHM, both male and female. It means that muscle fatigue was significantly decreased(p<.05). RPE was significantly increased when low angle(p<.01). Perceived exertion explained 15.2% of the variation of MF in SHM. And regression equation was, MF in SHM = 59.918 + (4,910 * RPE). Conclusion: The outcome shows that it is possible to use the efficient method which makes muscle fatigue decrease by reducing the angle of neck flexion. Application: The results might contribute to develop the effective Shaker exercise method.