• Journal of International Academy of Physical Therapy Research
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• v.5 no.1
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• pp.652-660
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• 2014

In the present study, to examine the effects of somatosensory stimulation of the hands on the hand functions and visuomotor coordination of children with developmental disabilities, a total of 24 sessions of experiments were conducted with three children with developmental disabilities for 60 minutes per session, three sessions per week from January 7, 2013 to March 11, 2013. To examine the effects of somatosensory stimulation of the hands on grasping and visuomotor coordination which are sub-areas of PDMS-2, the A-B study design was used which is a single case study method out of single-subject experimental research designs. Somatosensory stimulation of the hands was shown to be effective in improving the hand functions of children with developmental disabilities. Somatosensory stimulation of the hands showed positive effects on the raw scores and standardized scores of grasping and visuomotor coordination in all the three subject children. Visuomotor coordination functions showed higher scores in post-hoc tests in all three children. In particular, ring throws showed high scores at right $90^{\circ}$, right $45^{\circ}$, center, left $45^{\circ}$, and left $90^{\circ}$ among visual directions. In the present study conducted with children with developmental disabilities, ring throws were performed to examine visuomotor coordination. In particular, the numbers of successes of ring throws on the front, left, and right were shown to be high. Therefore, somatosensory stimulation of the hands was effective on the hand functions and visuomotor coordination functions of children with developmental disabilities.

• The Journal of Korean Academy of Sensory Integration
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• v.19 no.2
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• pp.36-45
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• 2021

Purpose : This study aims to identify changes in the visuomotor coordination and fine motor coordination functions caused by the use of a task-oriented intervention in a child with developmental delay. Methods : The participant, who was a 6-year-old girl, was not diagnosed but showed a developmental delay in overall function. The study period was February 5, 2021, to June 4, 2021, and a single-subject A-B study design was used. The baseline (A) was initially evaluated in the first three sessions to identify the child's functions. In the intervention period, 12 session (B), task-oriented intervention was applied; the child engaged in many of the activities in kindergarten, such as painting, writing, making, and cutting with scissors. Visuomotor coordination and fine motor coordination were equally measured during the baseline and intervention periods. Visuomotor coordination was measured via drawing of an oval according to the Korean Developmental Test of Visual Perception 3 (K-DTVP-3), and fine motor coordination was assessed using the finger-nose touching item of the Clinical Observation of Motor and Postural Skills (COMPS). Results : The mean of the baseline of the K-DTVP-3 oval drawing was 23, and the mean of the intervention period was 39.66. The mean of the baseline of the COMPS finger-nose touching was 0, and the mean of the intervention period was 5.08. Conclusion : Task-oriented intervention seems to have a positive effect on the visuomotor coordination and fine motor coordination abilities of children with developmental delay.

• The Journal of Korean Physical Therapy
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• v.26 no.6
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• pp.386-390
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• 2014

Purpose: We aimed to investigate whether visuomotor function would be modulated, when healthy subjects performed tracking task after tDCS application over the primary sensorimotor cortex (SM1) in the non-dominant hemisphere. Methods: Thirty four right-handed healthy participants were enrolled, who randomly and evenly divided into two groups, real tDCS group and sham control group. Direct current with intensity of 1 mA was delivered over SM1 for 15 minutes. After tDCS, tracking task was measured, and their performance was calculated by an accuracy index (AI). Results: No significant difference in AI at the baseline between the two groups was observed. The AI of the real tDCS group was significantly increased after electrical stimulation, compared to the sham control group. Two way ANOVA with repeated measurement showed a significant finding in a large main effects of time and group-by-repeated test interaction. Conclusion: This study indicated that application of the anodal tDCS over the SM1 could facilitate higher visuomotor coordination, compared to sham tDCS group. These findings suggest possibility that tDCS can be used as adjuvant brain modulator for improvement of motor accuracy in healthy individuals as well as patients with brain injury.

• 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.

• The Journal of Korean Physical Therapy
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• v.22 no.6
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• pp.43-51
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• 2010

Purpose: This study examined the influence of visuomotor congruency on learning a relative phase relationship between a single joint movement and an external signal. Methods: Participants (N=5) were required to rhythmically coordinate elbow flexion-extension movements with a continuous sinusoidal wave (0.375 Hz) at a $90^{\circ}$ relative phase relationship. The congruent group was provided online feedback in which the elbow angle decreased (corresponding to elbow flexion) as the angle trajectory was movingup, and vice versa. The incongruent group was provided online feedback in which the elbow angle decreased as the angle trajectory was moving down, and vice versa. There were two practice sessions (day 1 and 2) and each session consisted of 6 trials per block (5 blocks per session). Retention tests were performed 24 hours after session 2, and only the external sinusoidal wave was provided. Repeated ANOVAs were used for statistical analysis. Results: During practice, the congruent group was significantly less variable than the incongruent group. Phase variability in the incongruent group did not significantly change across blocks, while variability decreased significantly in the congruent group. In retention, the congruent group produced the required $90^{\circ}$ relative phase pattern with significantly less phase variability than the incongruent group. Conclusions: Congruent visual feedback facilitates learning. Moreover, the deprivation of online feedback does not affect the congruent group but does affect the incongruent group in retention.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.247-254
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• 1990

Chicken monocular head and eye optokinetic nystagmus (OKN) were observed by coil recordings after intravitreal administration of GABA antagonists (picrotoxin and bicuculline) into the opened and closed eye. Before injection of drugs the chicken displayed an OKN for T-N stimulation being more efficient in evoking this visuomotor reflex than for N-T stimulation. The injection of GABA antagonist into the opened eye provoked a decrease or disappearance of the head and eye OKN. On the other hand, the injection of GABA antagonist into the closed eye, the head and eye OKN augmented. Thus, GABA antagonist abolished the directional asymmetry of the head and eye OKN, indicating the involvement of GABAergic mechanisms in the inhibition of the N-T component of the monocular OKN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.8
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• pp.4241-4254
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• 2019

The efficiency and accuracy of handwriting measurement could be improved by adopting digital image processing. This study developed a computer-based Korean Handwriting Assessment tool. Second graders participated in this study by performing writing tasks of consonants, vowels, words, and sentences. We extracted boundary parameters for each letter using digital image processing and calculated the variables of size, size coefficient of variation (CV), misalignment, inter-letter space, inter-word space, and ratio of inter-letter space to inter-word space. Children were also administered traditional handwriting and visuomotor tests. Digital variables from image processing were correlated with these previous tests. Using these correlations, we established a three-point scoring system that computed test scores for each variable. We analyzed inter-rater reliability between the computer rater and human rater and test-retest reliability between the first and second performances. The validity was examined by analyzing the relationship between the Korean Handwriting Assessment and previous handwriting and visuomotor tests. We suggested the Korean Handwriting Assessment to measure size, size consistency, misalignment, inter-letter space, inter-word space, and space ratio using digital image processing. This Korean Handwriting Assessment tool proved to have reliability and validity. It is expected to be useful for assessing children's handwriting.

• The Journal of Korea Robotics Society
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• v.14 no.1
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• pp.40-49
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• 2019

Reinforcement learning has been applied to various problems in robotics. However, it was still hard to train complex robotic manipulation tasks since there is a few models which can be applicable to general tasks. Such general models require a lot of training episodes. In these reasons, deep neural networks which have shown to be good function approximators have not been actively used for robot manipulation task. Recently, some of these challenges are solved by a set of methods, such as Guided Policy Search, which guide or limit search directions while training of a deep neural network based policy model. These frameworks are already applied to a humanoid robot, PR2. However, in robotics, it is not trivial to adjust existing algorithms designed for one robot to another robot. In this paper, we present our implementation of Guided Policy Search to the robotic arms of the Baxter Research Robot. To meet the goals and needs of the project, we build on an existing implementation of Baxter Agent class for the Guided Policy Search algorithm code using the built-in Python interface. This work is expected to play an important role in popularizing robot manipulation reinforcement learning methods on cost-effective robot platforms.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2001.05a
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• pp.6-9
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• 2001

집중도를 평가하기 위하여 피험자에게 집중을 유발시키는 3가지 task(단기기억작업, Corsi block tapping task, visuomotor task)를 부가하고 주관평가 및 생리신호(뇌파, 심전도, 맥파, 피부온도, 호흡, 피부전도도)를 측정하였다. 뇌파를 mapping하여 평가에 적합한 전극이 위치를 선정하고, task 수행중 집중도 변화와 짐전도의 심박변화와의 관계를 분석하였다. 분석결과 안정과 task 수행시 뇌파 mapping상 전체 power의 변호가 frontal 부분에서 크게 나타났으며, 집중시 R-R 간격의 순간간격변화가 줄어들었다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.393-396
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• 2011

In this paper, we propose a constrained alternating least squares nonnegative matrix factorization algorithm (cALSNMF) to detect active brain regions from single subject's task-related fMRI data. In cALSNMF, we define a new cost function which considers the uncorrelation and noisy problems of fMRI data by adding decorrelation and smoothing constraints in original Euclidean distance cost function. We also generate a novel training procedure by modifying the update rules and combining with optimal brain surgeon (OBS) algorithm. The experimental results on visuomotor task fMRI data show that our cALSNMF fits fMRI data better than original ALSNMF in detecting task-related brain activation from single subject's fMRI data.