• 감성과학
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• 제15권4호
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• pp.441-452
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• 2012

최근 들어 청각 장애인들에게 정상인들이 소리로부터의 느끼는 청감과 유사한 느낌을 전달하기 위한 방안으로써 시각은 물론 진동감과 같은 촉감을 활용하는 연구가 시도되고 있다. 특히 시각 정보의 보조 감각으로써 스피커나 진동 모터를 이용한 촉감이 제공되는 경우 생동감은 상당히 개선되는 측면이 있으나 정서감 측면에서는 그 효과가 거의 없는 것으로 보고되었다. 따라서 본 연구에서는 유사 청감을 재현할 수 있는 또 하나의 보조 감각으로서 열감을 설정하고 열감이 유사 청감 재현 효과를 가질 수 있는가에 관하여 조사하였다. 이를 위해 열감을 효과적으로 재현할 수 있는 열감 재현 모듈을 구현하였다. 그리고 실험 대상자들에게 시각 정보와 더불어 청각 정보, 진동 촉감, 그리고 열감을 혼합한 다양한 형태의 자극을 제공한 실험을 수행하였다. 실험에서 얻어진 데이터 통계 분석을 통하여 i) 영상과 함께 열감 자극을 제공하거나 또는 ii) 영상과 함께 열감 자극과 진동 자극을 동시에 제공하는 경우가 영상만을 제공하는 경우보다 실험 대상자들이 영상과 소리로부터 느끼는 실제 열감에 더 가까운 유사 열감을 느낄 수 있다는 사실을 확인하였다. 결론적으로 실험 대상자의 피부에 제공되는 열감이 유사 청감 재현 보조 매체로서의 활용 가능성이 있음을 확인할 수 있었다.

• 한국정밀공학회지
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• 제27권6호
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• pp.82-89
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• 2010

Ankle-foot orthosis with an artificial pneumatic muscle which is intended for the assistance of plantarfelxion torque was developed. In this study, power pattern of the device in the various pneumatics and the effectiveness of the system were investigated. The pneumatic power was provided by ankle-foot orthosis controlled by user‘s physiological signal, that is, muscular stiffness in soleus muscle. This pneumatic power can assist plantarflexion torque of ankle joint. The subjects performed maximal voluntary isokinetic plantarflexion motion on a biodexdynamometer in different pneumatics, and they completed three conditions: 1) without wearing the orthosis, 2) wearing the orthosis with artificial muscles turned off, 3) wearing the orthosis activated under muscular stiffness control. Through these experiments, we confirmed the effectiveness of the orthosis and muscular stiffness control using the analyzing isokinetic plantarflexion torque. The experimental results showed that isokinetic torques of plantarflexion motion of the ankle joints gradually increased in incremental pneumatic. The effectiveness of the orthosis was -7.26% and the effectiveness of the muscular stiffness control was 17.83% in normalized isokinetic plantarflexion torque. Subjects generated the less isokinetic torques of the ankle joints in wearing the orthosis with artificial muscles turned off, but isokinetic torques were appropriately reinforced in condition of wearing the orthosis activated under muscular stiffness control(17.83%) compared to wearing the orthosis(-7.26%). Therefore, we respect that developed powered orthosis is applied in the elderly that has weak muscular power as the rehabilitation equipment.

• 인터넷정보학회논문지
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• 제20권5호
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• pp.27-36
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• 2019

본 연구에서는 공개된 뇌파 데이터인 DEAP(A Database for Emotion Analysis using Physiological Signals) 데이터 세트를 활용한 감정분류 분석 및 정확도 향상에 대한 실험을 진행하였다. 실험에는 32명에 대한 32개의 뇌파측정 채널 데이터가 모두 사용되었다. 전처리과정에서는 뇌파 데이터에 대한 256Hz 샘플링작업을 진행하였고, 유한 임펄스 응답 필터를 사용하여 주파수 대역별로 쎄타(4-8Hz), 슬로 알파(8-10Hz), 알파(8-12Hz), 베타(12-30Hz), 감마(31-45Hz) 파형에 대한 데이터를 추출하였다. 추출한 데이터는 시간-주파수 변형을 통하여 데이터의 상태를 구분한 후에, 독립성분분석방법을 통해 잡음(Artifact)을 제거하여 데이터를 정제했다. 도출된 데이터는 분류기 기계학습 알고리즘 실험을 시행할 수 있도록 CSV 파일로 변형 하였으며, 감정분류에는 Arousal-Valence 평면을 사용하였다. 감정은 "긍정적(Positive)", "부정적(Negative)" 이외에 평온한 상태로 존재하는 "중립적(Neutral)"의 3가지 상태로 분류하였다. 정확도를 개선하기 위해서 랜덤 포레스트(Random Forest) 알고리즘에 속성 선택적 분류기(Attribute Selected Classifier: ASC) 방식에 의해 선택된 속성을 적용하여 실험하였다. 정확도는 "각성(Arousal)" 부분에서 Koelstra의 결과보다 "32.48%" 높은 결과가 도출되었고, Liu의 실험의 "정서가(Valence)"와 비교해보면 ASC(Random Forest) 결과가 "8.13%" 더 높은 결과를 도출하였다. 정확도를 개선하기 위해 ASC 방식을 적용한 랜덤 포레스트 분류기 실험결과에서는 전체평균을 기준으로 기존 연구 결과와 대비하여 "2.68%" 높은 정확도가 도출되었다.

• 한국과학교육학회지
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• 제14권2호
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• pp.199-213
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• 1994

The quality of science teachers is one of the most important factors to improve the science education in secondary schools. In this study the current status of preservice education of secondary science teachers was surveyed and the directions for the improvement were suggested as follows: 1. The purposes of departments of science education have to be partially revised to include other education programs related to science education than preservice training courses of science teachers. 2. Training courses of integrated science teacher should be organized differently from those of physics, chemistry, biology or earth science teachers because their requirements are different. 3. Strict standards of curricula for training science teacher have to be established and applied practically. 4. The curricula of departments of science education have to reflect the contents and the changes of secondary science education. 5. More credits to subjects on the science education, the nature of science, and the laboratory experiments should be taken in the preservice courses of science teachers. 6. Professors at the department of science education have to use various methods to teach inquiry lab and evaluation techniques so that students can experience them at the training courses. 7. The number of professors majoring in science education at the department of sciece education should be increased. 8. Enough research funds have to be supported to activate the researches in science education.

• 대한의용생체공학회:의공학회지
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• 제30권6호
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• pp.495-502
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• 2009

This paper investigated the effects of dynamic postural control for maintaining upright standing on a support surface during continuous sinusoidal horizontal translation in anterior-posterior direction. 15 healthy young subjects participated in this experiment. The analysis of body movement was analyzed using Ariel Performance Analysis System. Motion pattern was analyzed by seven markers on subject's body. Position of markers were head, chest, hip, right knee, left knee, right ankle and left ankle. Seven different frequencies of support surface were employed ; 0.1, 0.25, 0.5, 0.75, 1, 1.5 and 2Hz at 2cm of moving path of motionbase. The experiments were performed dynamic postural reponses at the condition of eye open. The results showed that median frequency of the knee, ankle were increased in all frequency bands. Following the frequency of perturbation increased, postural control strategy was changed from ankle strategy to combined strategy. The experiment results could be applied to the dynamic postural training for the elderly and the rehabilitation training for the patients to improving the ability of postural control.

• 한국운동역학회지
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• 제31권2호
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• pp.104-112
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• 2021

Objective: This study aimed to analyze the effects of consecutive whole body vibration through heel raise posture on the center of pressure and electromyography of anterior tibial muscle, lateral gastrocnemius and soleus muscles during single-leg stance. Method: The subjects of this study included 30 healthy males in their 20's, with the following inclusion criteria: no history of orthopaedic medical history, no participation in regular exercises, no history of whole body vibration exercise, and right leg being the dominant leg. The experimental procedure involved pretreatment measurement of eye open single-leg stance, application of whole body vibration for 30 seconds, post-treatment measurement (3 measurements in total). Static and dynamic movements have been measured over 2 separate experiments, with 72 hours gap between the experiments. Static movement involved maintaining single-leg heel raise posture for 30 seconds while applying whole body vibration, and dynamic movement involved heel raise (15 repetitions over 30 seconds) while applying whole body vibration. The strength of applied whole body vibration was 35 Hz frequency and 2~4 mm amplitude. Results: As the single-leg posture after static heel raise posture, mediolateral velocity of the center of pressure at post 2 and post 3 were significantly reduced compared to the pre-treatment measurement. In addition, the percentage for reference voluntary contraction in anterior tibial muscle and soleus and median frequency at anterior tibial muscle and lateral gastrocnemius muscle at post 3 were significantly decreased compared to the pre-treatment value. As the single-leg posture after dynamic heel raise posture, the mediolateral 95% edge frequency of the center of pressure and median frequency at anterior tibial muscle, lateral gastrocnemius muscle, and soleus muscle at post 3 were significantly reduced compared to the pre-treatment value. Conclusion: Acute whole body vibration via static and dynamic heel raise posture have positive effect on mediolateral posture control during single-leg stance.

• 대한인간공학회지
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• 제32권6호
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• pp.541-547
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• 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.

• 대한의용생체공학회:의공학회지
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• 제28권6호
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• pp.832-839
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• 2007

In this study, a new bicycle system was developed to improve muscular strength using the Magneto-Rheological(MR) rotary brake. The friction load of the MR rotary brake is adjusted according to muscle strength of the subjects. The characteristic of muscular strength was studied with various friction loads of MR rotary brake. The friction load was occurred with the current, applied to the MR. rotary brake. Experiments was composed of several cycling trials for various friction loads. In training programs involving muscle improvement, it is necessary to confirm muscle activity and fatigue. To measure the muscle activity and fatigue, EMG signals of rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastus lateralis (VL), vastus medialis (VAS), gastrocnemius (GAS), tibialis anterior (TA) and soleus (SOL) muscles were collected with surface electromyography and analyzed into time and frequency domain. The experimental results showed that the muscle activity according to the applied current to the MR rotary brake was significantly different. The more the current was applied, the higher value of the integrated EMG (IEMG) was obtained. Especially, the magnitude of IEMG of the RF, BF, TFL and VL varied in direct proportion to the current. However, there was not significant in the median frequency as the cycling time continue.

• 한국초등과학교육학회지:초등과학교육
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• 제27권1호
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• pp.49-59
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• 2008

The purpose of this study was to invent a quotient equation which could quantitatively evaluate individual's hypothesis evaluating ability. The equation was induced by the analysis of the classification types about hypothesis evaluation knowledges generated by 15 pre-service elementary school teachers and the construction of the quotient equation on hypothesis evaluating ability. The hypothesis evaluation task administered to subjects was dealt with the woodpecker behavior. The task was initiated by generating hypothesis on the following question: 'Why don't woodpecker have brain damage after pecking wood?' Subjects then were asked to design and perform experiments for testing hypothesis. Finally they were asked to evaluate their own hypothesis based on the collected, analyzed and interpreted data. The knowledges generated from their evaluating hypothesis were analyzed by 4 major categories (richness, type, level and accuracy). Then, a general equation which could quantitatively and systematically evaluate individual's hypothesis evaluating ability was invented by an inductive process. After combining all the categories the following quotient equation was proposed; '$VQ\;=\;{\sum}(TE_n\;{\times}\;AE_n)\;{\times}\;LE$'. According to this results, woodpecker task and hypothesis evaluating ability quotient equation (VQ) which invented in this study could be applied to a practical use of measuring students' ability of scientific hypothesis evaluation.

• 대한예방한의학회지
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• 제12권3호
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• pp.129-139
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• 2008

The purpose of this study was to investigate the effect of aqua exercise on women 50 years of age or older with knee degenerative arthritis, and then examining the therapeutic value of aqua exercise in degenerative arthritis of the knee. The subjects of the study were 115 residents 50 years of age or older who had been diagnosed as degenerative arthritis of the knee by doctors from medical institutions and applied for the aqua exercise program in the Public Health Care Center in Suseong-gu in 2006 and 2007. Experiments were conducted to all the subjects with the application of the 8-week aqua exercise program (2 times a week, 50 minutes a time), designed in the study, and the differences before and after the aqua exercise were compared through questionnaires for measuring the state of the body such as the knee extension angles, weight, body fat, and abdominal obesity. The data was analyzed by t-test and the Wilcoxon method through SPSS 14.0 and the statistical significance level ${\alpha}$ was set at 0.05 and 0.01. The results of the study are as the following. First, In comparison of before and after the aqua exercise, there was improvement in the extension angle of the right knee(p<0.01), while there was some improvement in the extension angle of the left knee, it was not significant. Second, In comparison of before and after the aqua exercise there were statistically significant differences in weight(p<0.05), body fat ratio, and abdominal obesity(p<0.01). The results of this study showed that the aqua exercise program to female patients with knee degenerative arthritis significantly increased the extension angle of the knee. Therefore it is thought that aqua exercise is an effective meditating method to improve their symptoms of female patients 50 years of age or older