• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.6
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• pp.606-615
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• 2003

This study examined the effects of exposure to the electromagnetic field emitted by mobile phone on human cognitive function. Total volunteers were twenty and volunteers were separated in two groups. One is teenager group, and the other is adult group. Test was performed in the counterbalanced order(sham-real, real-sham). Subject remained blind to mobile phone status during the exam. The result showed that the exposure to the electromagnetic field significantly speeded up response time fur teenager group. This results suggest that exposure to the electromagnetic field emitted by cellular phones may have a mild facilitating effect on cognitive function in teenager group.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.131-131
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• 2002

목적： 인간의 뇌는 감각기관이 지속적으로 시각적, 청각적 자극을 받음으로 인해 영향을 받는다. 현재 이러한 이론을 실용화하여 몇 가지 상업적인 뇌 자극장치가 개발되어 시판 중이다 본 실험에서는 시중에 판매 중인 뇌 자극장치를 이용하여 실험을 하여 실제 인간의 뇌에 영향을 주는 지를 확인한다.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.253-260
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• 2020

This study was performed to evaluate the effects of Visual feed-back ankle training combined with Ankle joint Functional electrical stimulation on balance, gait ability on patient with Chronic Stroke. A total of 22 chronic stroke patients were divided into VFAF Group, CON group. Each group performed 60 minutes a day 5 times a week for 8 weeks. VFAF group revealed significant differences in balance and gait ability as compared to the CON groups(p<.05). The exercises were conducted for 60 min per day, five, per week for eight weeks. Balance and gait ability were examined at 0 week and after 8 weeks of intervention. Our results showed that VFAF was more effective on balance ability and gait ability in chronic stroke patients. We suggest that this study will be able to be used as an clinical intervention data for recovering balance and gait ability in chronic stroke patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3353-3357
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• 2010

The purpose of this study is to investigate the effect of visual rhythmic stimulation in gait ability and proprioception in chronic stroke patients. Twenty-one persons after six months post stroke participated in pre and post test control. The subjects were randomly assigned to a rhythmic visual stimulation(RVS) group (n=10) and control group (n=11). Training process was practiced with exercise on thirty minutes a day, three days a week for four weeks. To find out the effect, inspected the proprioception test and gait characteristics by gait analysis. In gait characteristics, the walking speed, cadence and the TUG time were significantly different from RVS group. The proprioception were significantly different RVS and control group. This study showed that the RVS training increased better functional activity by postural adjustment and gait learning of chronic stroke patients than that of control group. And so, the RVS training of hemiplegic patients was very important to successive rehabilitation. A continuous examination of RVS training could be practical use of physical therapy with exercise.

• Journal of the Korea Computer Graphics Society
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• v.28 no.3
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• pp.1-11
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• 2022

Body ownership illusion (BOI), which means 'the illusion that a non-bodily object feels like my body', has been actively studied since the Rubber-hand Illusion showed that a person can feel a rubber hand like one's own hand. It has been proven that BOI can be elicited for virtual bodies in virtual reality. Although many studies have been examined the effect of visuomotor (VM) and visuotactile (VT) stimuli, which are mainly used for the elicitation of BOI, there were very limited studies that delivered both stimuli to the whole body at the same time. In this paper, we investigated how each stimulus affects BOI when delivering VM and VT stimulisimultaneously to the virtual avatar, and examined user experience that appears as presence, emotion, and virtual motion sickness. The results showed that BOI was high when VM is synchronous, but there was no significant difference according to VT levels. In the case of presence, it was confirmed that VT affects only when VM is synchronous, and in the case of emotion, both VM and VT affect valence, and in the case of virtual motion sickness, a statistical difference is not found.These results suggest that overall synchrony of VM is important factor in BOI with virtual avatars, but that the matching VT affects subjective experience such as presence when VM is synchronous.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 1999.03a
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• pp.261-264
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• 1999

복합 감각 자극하의 감성정보를 도출하기 위한 기초연구로서 시각과 청각자극에 따른 주관적 평가 및 생리신호를 계측하였다. 심리적 평가와 생리신호 계측으로 단일 자극에 더하여 동적, 정적감성의 심화를 유도하는 결과를 보였고, 부가된 자극을 반영하는 생리신호로 HRV가 유용함을 발견하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.11
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• pp.2143-2149
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• 2007

Visual Cortex Stimulator is among artificial retina prosthesis for blind man, is the method that stimulate the brain cell directly without processing the information from retina to visual cortex. In this paper, we propose image construction and recognition model that is similar to human visual processing by recognizing the feature data with orientation information, that is, the characteristics of visual cortex. Back propagation algorithm based on Delta-bar delta is used to recognize after extracting image feature by Kirsh edge detector. Various numerical patterns are used to analyze the performance of proposed method. In experiment, the proposed recognition model to extract image characteristics with the orientation of information from retinal cells to visual cortex makes a little difference in a recognition rate but shows that it is not sensitive in a variety of learning rates similar to human vision system.

• Science of Emotion and Sensibility
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• v.18 no.1
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• pp.15-26
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• 2015

In this paper, amplitude and phase difference patterns for theta and alpha bands of the Evoked Potential(EP) in relation to perform a task at visual stimulus were analyzed using the Empirical mode decomposition(EMD). The EMD is applied to decompose EP signals with task-related sub-frequency band signals. Intrinsic mode function was implied in Hilbert transform and instantaneous amplitude and phase differences of theta and alpha were derived from Hilbert transformed EP. In a task status, large amplitude for both bands was observed at P2, N2, and P3 points as well as maximum phase difference was observed at N1 and P2. We confirmed that both bands are associated with a task at visual stimulus, and less associated with fixation. The proposed method enhances the time and frequency resolution in comparison with band-pass filter method which observed different phase results according to conditions.

• Investigative Magnetic Resonance Imaging
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• v.15 no.2
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• pp.130-138
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• 2011

Purpose : To compare fMRIs of visual and auditory word generation tasks, and to evaluate the difference of its activated areas and lateralization according to the mode of stimuli. Materials and Methods : Eight male normal volunteers were included and all were right handed. Functional maps were obtained during auditory and visual word generation tasks in all. Normalized group analysis were performed in each task and the threshold for significance was set at p<0.05. Activated areas in each task were compared visually and statistically. Results : In both tasks, left dominant activations were demonstrated and were more lateralized in visual task. Both frontal lobes (Broca's area, premotor area, and SMA) and left posterior middle temporal gyrus were activated in both tasks. Extensive bilateral temporal activations were noted in auditory task. Both occipital and parietal activations were demonstrated in visual task. Conclusion : Modality independent areas could be interpreted as a core area of language function. Modality specific areas may be associated with processing of stimuli. Visual task induced more lateralized activation and could be a more useful in language study than auditory task.

• Journal of Broadcast Engineering
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• v.27 no.4
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• pp.569-580
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• 2022

In this study, we investigated the effect of peripheral blur on binocular fusion to resolve binocular fusion failure which is one of the 3D visual fatigues in the perspective of human visual system. With stimulus having discrete disparity change, binocular fusion failure rate for target stimulus having crossed and uncrossed disparity decreased. And target stimulus having continuous disparity also required relatively larger binocular disparity when peripheral blur was presented with target stimulus rather than when peripheral blur was not presented. These results imply that peripheral blur facilitated binocular fusion in the situation of binocular disparity change, and suggest that considering the characteristics of human three-dimensional visual systems, manipulating 3D contents can improve visual discomfort caused by binocular displays at low costs.