• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.441-452
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• 2012

Recently, various researches have been attempted to effectively display pseudo-aural senses to the hearing-impaired or the deaf, using vibro-tactile stimulus as well as visual sense. Particularly, it is reported that as complementary senses to support the visual sense, tactile senses displayed by either speakers or vibration motors improve the reality sense significantly but do not nearly improve the emotional sense. Thus, in this study, the thermal sense is selected as another complementary sense to support the pseudo-aural sense display and it is investigated whether the thermal sense could generate a pseudo-aural sense or not. For this purpose, a thermal display module which could effectively display the desired thermal sense is implemented. Then, experiments have been conducted to subjects, which provide them with various types of stimuli combined with the aural, the vibrotactile, and the thermal stimuli along with the visual information. It can be confirmed, through statistical analysis on the data collected from experiments, that subjects could feel a pseudo-thermal sense closer to the real thermal sense which the normal subject feel from both the visual and the aural information, particularly either i) with the thermal stimulus along with the visual information or ii) with both the thermal and the vibrotactile stimuli along with the visual information than only with the visual information. Conclusively, it can be confirmed that the thermal stimulus applied to the skin of the subjects could play a role of effectively displaying pseudo-aural sense related to the thermal sense, as an complementary media for the pseudo-aural display.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.6
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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.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.27-36
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• 2019

In this study, experiments on the improvement of the emotion classification, analysis and accuracy of EEG data were proceeded, which applied DEAP (a Database for Emotion Analysis using Physiological signals) dataset. In the experiment, total 32 of EEG channel data measured from 32 of subjects were applied. In pre-processing step, 256Hz sampling tasks of the EEG data were conducted, each wave range of the frequency (Hz); Theta, Slow-alpha, Alpha, Beta and Gamma were then extracted by using Finite Impulse Response Filter. After the extracted data were classified through Time-frequency transform, the data were purified through Independent Component Analysis to delete artifacts. The purified data were converted into CSV file format in order to conduct experiments of Machine learning algorithm and Arousal-Valence plane was used in the criteria of the emotion classification. The emotions were categorized into three-sections; 'Positive', 'Negative' and 'Neutral' meaning the tranquil (neutral) emotional condition. Data of 'Neutral' condition were classified by using Cz(Central zero) channel configured as Reference channel. To enhance the accuracy ratio, the experiment was performed by applying the attributes selected by ASC(Attribute Selected Classifier). In "Arousal" sector, the accuracy of this study's experiments was higher at "32.48%" than Koelstra's results. And the result of ASC showed higher accuracy at "8.13%" compare to the Liu's results in "Valence". In the experiment of Random Forest Classifier adapting ASC to improve accuracy, the higher accuracy rate at "2.68%" was confirmed than Total mean as the criterion compare to the existing researches.

• Journal of The Korean Association For Science Education
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• v.14 no.2
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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.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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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.

• Korean Journal of Applied Biomechanics
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• v.31 no.2
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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.

• Journal of the Ergonomics Society of Korea
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• v.32 no.6
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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.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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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.

• Journal of Korean Elementary Science Education
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• v.27 no.1
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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.

• Journal of Society of Preventive Korean Medicine
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• v.12 no.3
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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