• Science of Emotion and Sensibility
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• v.21 no.1
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• pp.177-186
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• 2018

The mechanism of emotion is complex and influenced by a variety of factors, so that it is crucial to analyze emotion in broad and diversified perspectives. In this study, we classified neutral and negative emotions(sadness, fear, surprise) using arousal evaluation, which is one of the psychological evaluation scales, as well as physiological signals. We have not only revealed the difference between physiological signals coupled to the emotions, but also assessed how accurate these emotions can be classified by our emotional recognizer based on neural network algorithm. A total of 146 participants(mean age $20.1{\pm}4.0$, male 41%) were emotionally stimulated while their physiological signals of the electrocardiogram, blood flow, and dermal activity were recorded. In addition, the participants evaluated their psychological states on the emotional rating scale in response to the emotional stimuli. Heart rate(HR), standard deviation(SDNN), blood flow(BVP), pulse wave transmission time(PTT), skin conduction level(SCL) and skin conduction response(SCR) were calculated before and after the emotional stimulation. As a result, the difference between physiological responses was verified corresponding to the emotions, and the highest emotion classification performance of 86.9% was obtained using the combined analysis of arousal and physiological features. This study suggests that negative emotion can be categorized by psychological and physiological evaluation along with the application of machine learning algorithm, which can contribute to the science and technology of detecting human emotion.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.362-370
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• 2019

This study was conducted to investigate effects of 12 weeks of combined exercise training with blood flow restriction (BFR) on body composition (weight, %body fat, lean body mass, body mass index (BMI)) and cardiovascular responses (brachial-ankle pulse wave velocity (ba PWV) and ankle-brachial index (ABI)) in elderly women. Participants (N = 43, Females) were randomly assigned into a combined exercise with BFR (n = 14, BFR), only combined exercise (n =14, EX) or non-exercise control group (n = 15, CON). Two-way repeated measures ANOVA with contrast testing was utilized for data analysis. Alpha was set at p < 0.05. Body composition (weight, %body fat, BMI) in BFR was significantly changed, and %body fat in EX was significantly decreased, but there was no change in the CON. In addition, the right and left ba PWV values in the BFR were significantly decreased, while only the left side ba PWV in EX was significantly decreased and there was no change in the CON. Moreover, the % change and effect size of most variables in the BFR were higher than the EX. Taken together, the results indicate that even though BFR and EX groups performed the same combined exercise training, BFR had additional stimulations of the sympathetic nerve system due to blood flow restriction. Thus, BFR training is more beneficial and has greater effects on body composition and cardiovascular responses in elderly females.

• The Journal of the Acoustical Society of Korea
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• v.13 no.6
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• pp.75-82
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• 1994

The ray paths and travel times of sound wave in the ocean depend on the physical properties of the propagating media. Ocean Acoustic Tomography(OAT), which is inversely estimate the travel time variations between fixed sources and receivers the physical properties of the corresponding media can he understood. To apply ocean survey technology by using the OAT, the tomographic procedure requires forward problem that variation of the travel times be identified with the variability of the medium. Also, received signals must be satisfied the necessary conditions of ray path stability, identification and resolution in order for OAT to work. The canonical ocean has been determined based on the historical data and its travel time and ray path are used as reference values. The sound speed of canonical ocean in the East Sea is about 1523 m/s at the surface and 1458 m/s at the sound channel axis(400m). Sound speeds in the East Sea are perturbed by warm eddy whose horizontal extension is more than 100 km with deeper than 200 m in depth scale. In this study, an acoustic source and receiver are placed at the depth above the sound channel axis, 350 m, and are separated by 200 km range. Ray paths are identified by the ray theory methed in a range dependent medium whose sound speeds are functions of a range and depth. The eigenray information obtained from interpolation between the rays bracketing the receiver are used to simulate the received signal by convolution of source signal with the eigenray informations. The source signal is taken as a 400 Hz rectangular pulse signal, bandwidth is 16 Hz and pulse length is 64 ms. According to the analysis of the received signal and identified ray path by using numerical model of underwater sound propagation, simulated signals satisfy the necessary conditions of OAT, applied in the East Sea.