• Journal of Institute of Control, Robotics and Systems
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• v.15 no.11
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• pp.1122-1129
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• 2009

Recently taping robot with smart recognition function have been studied in the coil manufacturing field. Due to the difficulty of 3D surface processing from the complicated working environment, it is not easy to accomplish smart tape attachment motion with non-contact sensor. To solve these problems the applicable surface recognition algorithm and a flexible sensing device has been recommended. In this research, the fusion method between 1D displacement and 3D laser scanner is applied for robust tape attachment about cold rolled coil. With these sensors we develop a two-step exploration and the smart algorithm for the awareness of non-aligned coil's information. In the proposed robot system for tape attachment, the problem is reduced to coil's radius searching with laser displacement sensor at first, and then position and orientation detection with 3D laser scanner. To get the movement at the robot's base frame, the hand-eye compensation between robot's end effector and sensing device should be also carried out respectively. In this paper, we examine the auto-coordinate transformation method in the calibration step for the real environment usage. From the experimental results, it was shown that the taping motion of robot had a robust under the non-aligned cold rolled coil.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.25-30
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• 2007

In this paper, we proposed a new burst-mode optical transmitter structure which is suitable for high data rate operation such as Gb/s operation. With this structure we made a 1.25Gb/s burst-mode optical transmitter including a digitally controlled APC circuit for EPON systems using commercial 0.8m BiCMOS technology. It well functioned at 1.25Gb/s and showed good eye patterns with 53.3ps jitter, 191ps rise time and 258ps fall time. To characterize the APC function we measured optical output power as increasing external voltage VREF. The optical power is linearlyproportional to VREF at the rate of 0.293mW/V.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.3037-3040
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• 2000

Real-Time object tracking has emerged as an important component in several application areas including machine vision. surveillance. Human-Computer Interaction. image-based control. and so on. And there has been developed various algorithms for a long time. But in many cases. they have showed limited results under uncontrolled situation such as illumination changes or cluttered background. In this paper. we present a novel. computationally efficient algorithm for tracking human face robustly under illumination changes and cluttered backgrounds. Previous algorithms usually defines color model as a 2D membership function in a color space without consideration for illumination changes. Our new algorithm developed here. however. constructs a 3D color model by analysing plenty of images acquired under various illumination conditions. The algorithm described is applied to a mobile head-eye robot and experimented under various uncontrolled environments. It can track an human face more than 100 frames per second excluding image acquisition time.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.428-429
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• 2011

3D 디스플레이 장치는 디스플레이 장치의 시점 수에 따라 다시점 디스플레이 장치 및 스테레오 디스플레이 장치로 구분할 수 있다. 스테레오 디스플레이 장치는 좌우 두 개의 영상을 디스플레이 방식에 따라 영상포맷을 변경하여 디스플레이에 보여지고 다시점 디스플레이는 두 개 이상의 영상 데이터를 포함하는 것으로 구분할 수 있다. 영상의 화질문제로 인하여 최근 3DTV는 스테레오 방식을 사용하고 있으며 대기업에서 양산하고 있는 기술이다. 스테레오 방식에서는 개인용 단말의 경우 사용자의 위치 및 눈의 위치에 따라 깊이감을 달리 보여주는 장치가 개발되고 있어 이에 대한 연구를 진행하였다. 이와같은 기술의 흐름에 맞춰 3D 디스플레이 장치를 위한 눈 추적 알고리즘을 구현하였다. 본 논문에는 카메라에서 입력되는 영상에서 얼굴영역을 Haar training 방법을 통하여 추출하였으며 PCA 방법을 통하여 눈 영역을 추출하였다. 알고리즘의 복잡도로 인하여 연산량을 줄이기 위하여 Downsampling 방법을 활용하여 연산량을 약 26% 감소시켰다. 본 연구 결과를 통하여 얼굴 및 눈 추적 알고리즘 구현시 최적화를 위하여 필요한 프로세스를 예측할 수 있다.

• Journal of The Korean Ophthalmological Society
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• v.59 no.12
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• pp.1152-1159
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• 2018

Purpose: We prospectively investigated clinical changes and long-term outcomes after administration of the drugs recommended by the Age-Related Eye Disease Study-2 to patients with intermediate age-related macular degeneration (AMD). Methods: This prospective multicenter study enrolled 79 eyes of 55 patients taking lutein and zeaxanthin. The primary endpoint was contrast sensitivity; this was checked every 12 months for a total of 36 months after treatment commenced. The secondary endpoints were visual acuity, central macular thickness, and drusen volume; the latter two parameters were assessed using spectral domain optical coherence tomography. Results: The mean patient age was $72.46{\pm}7.16years$. Contrast sensitivity gradually improved at both three and six cycles per degree. The corrected visual acuity was $0.13{\pm}0.14logMAR$ and did not change significantly over the 36 months. Neither the central macular thickness nor drusen volume changed significantly. Conclusions: Contrast sensitivity markedly improved after treatment, improving vision and patient satisfaction. Visual acuity, central retinal thickness, and drusen volume did not deteriorate. Therefore, progression of AMD and visual function deterioration were halted.

• Journal of Korea Entertainment Industry Association
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• v.15 no.1
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• pp.221-228
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• 2021

This study aims to provide basic data for developing hand functional training programs using a keyboard to see if there is a relationship between the smart keyboard input speed using both hands, the Dexterity of the hand and the eye-hand coordination ability. The smartphone keyboard input speed, Purdue Pegboard, Grooved Pegboard Test, and Korean-Developmental-Test of Visual Perception-Adolescent were evaluated for 40 university students Province. An independent sample t-test and one-way ANOVA were conducted to identify differences in smartphone keyboard input speed, dexterity, eye-hand coordination ability and visual-motion using both hands according to the general characteristics of the subjects. Pearson correlation was also conducted to find out the relationship between hand-used smartphone keyboard input speed, hand dexterity, eye-hand coordination ability and visual-motor. As a result, the smartphone keyboard input speed using both hands showed a correlation with the dominant hand in the Purdue Pegboard Test (r=-.313, p<.05). In addition, the input speed of the smartphone keyboard is Copying(r=-.333, p<.05), Visual Motor Search(r=.455, p<.01), Visual Motor speed(r=-.453, p<.01) and Form Constancy (r=-.341, p<.05) in the item of K-DTVP-A. Therefore, it is believed that it will be helpful in the development of a treatment program using a smartphone, and it is expected that the effectiveness of a treatment program using a smartphone will be proven through additional experimental studies in the future.

• Korean Journal of Cognitive Science
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• v.35 no.2
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• pp.129-159
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• 2024

In the process of reading, readers can process information not only within the fixated region, known as the fovea, but also in the parafoveal region to the right of the fovea. While the parafoveal semantic preview effect has been confirmed in eye-tracking experiments using boundary techniques, research on how the parafoveal preview effects differ depending on the degree of semantic relatedness is still limited. This study investigates the parafoveal preview effects as a function of semantic relatedness with the target word. The experiment utilized Korean-Chinese bilinguals and presented mixed-language sentences as experimental stimuli. Four parafoveal preview conditions were applied to the target words in each sentence: (1) Korean identical condition, where the parafoveal word was the same as the target word (e.g., "나라," meaning "country" in English), (2) Chinese synonymous condition, where the parafoveal word had the same meaning as the target word (e.g., "国家," also meaning "country" in English), (3) Chinese semantically related condition, where the parafoveal word was semantically related to the target word (e.g., "政权," meaning "political power" in English), and (4) Chinese unrelated condition, where the parafoveal word was semantically unrelated to the target word (e.g., "围裙," meaning "apron" in English). The study explored the parafoveal preview effect in terms of the degree of semantic association with the target word. We found the most pronounced preview effect in conditions where the preview and the target word shared the same meaning, and we also observed preview effects in conditions where the semantic relatedness with the target word was relatively weak. This study suggests that the degree of semantic relatedness between the parafoveal preview word and the target word can influence readers' reading processes. It contributes to a better understanding of readers' eye movements and comprehension processes, with potential implications for the development of effective reading strategies and educational methods.

• Sleep Medicine and Psychophysiology
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• v.28 no.2
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• pp.78-85
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• 2021

Objectives: When elderly patients show depressive symptoms, discrimination between depressive disorder and prodromal phase of Alzheimer's disease is important. We tested whether a quantitative electroencephalogram (qEEG) marker was associated with cerebral amyloid-β (Aβ) deposition in older adults with depression. Methods: Non-demented older individuals (≥ 55years) diagnosed with depression were included in the analyses (n = 63; 76.2% female; mean age ± standard deviation 73.7 ± 6.87 years). The participants were divided into Aβ+ (n = 32) and Aβ- (n = 31) groups based on amyloid PET assessment. EEG was recorded during the 7min eye-closed (EC) phase and 3min eye-open (EO) phase, and all EEG data were analyzed using Fourier transform spectral analysis. We tested interaction effects among Aβ positivity, condition (EC vs. EO), laterality (left, midline, or right), and polarity (frontal, central, or posterior) for EEG alpha band power. Then, the EC-to-EO alpha reactivity index (ARI) was examined as a neurophysiological marker for predicting Aβ+ in depressed older adults. Results: The mean power spectral density of the alpha band in EO phase showed a significant difference between the Aβ+ and Aβ- groups (F = 6.258, p = 0.015). A significant 3-way interaction was observed among Aβ positivity, condition, and laterality on alpha-band power after adjusting for age, sex, educational years, global cognitive function, medication use, and white matter hyperintensities on MRI (F = 3.720, p = 0.030). However, post-hoc analyses showed no significant difference in ARI according to Aβ status in any regions of interest. Conclusion: Among older adults with depression, increased power in EO phase alpha band was associated with Aβ positivity. However, EC-to-EO ARI was not confirmed as a predictor for Aβ+ in depressed older individuals. Future studies with larger samples are needed to confirm our results.

• Therapeutic Science for Rehabilitation
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• v.12 no.2
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• pp.55-68
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• 2023

Objective : This study aims to analyze the effects of visual perception intervention by systematically reviewing the studies that applied visual perception intervention to children with cerebral palsy. Methods : The databases used were PubMed, EMbase, Science Direct, ProQuest, Koreanstudies Information Service System (KISS), Research Information Sharing Service (RISS), and the National Assembly Library. The keywords used were cerebral palsy, CP, and visual perception. According to the PRISMA flowchart, 10 studies were selected from among studies published from January 1, 2012 to March 30, 2022. The quality level of the selected studies, the demographic characteristics of study participants, the effectiveness of interventions, area and strategies of intervention, assessment tools to measure the effectiveness of interventions, and risk of bias were analyzed. Results : All selected studies confirmed that visual perception intervention was effective in improving visual perception function. In addition, positive results were shown in upper extremity function, activities of daily living, posture control, goal achievement, and psychosocial areas as well as visual perception function. The eye-hand coordination area was intervened in all studies. Conclusion : In visual perception intervention, It is necessary to evaluate the visual perception function by area, and apply systematically graded customized interventions for each individual.

• BMB Reports
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• v.39 no.4
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• pp.339-345
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• 2006

The blood-neural barrier (BNB), including blood-brain barrier (BBB) and blood-retinal barrier (BRB), is an endothelial barrier constructed by an extensive network of endothelial cells, astrocytes and neurons to form functional 'neurovascular units', which has an important role in maintaining a precisely regulated microenvironment for reliable neuronal activity. Although failure of the BNB may be a precipitating event or a consequence, the breakdown of BNB is closely related with the development and progression of CNS diseases. Therefore, BNB is most essential in the regulation of microenvironment of the CNS. The BNB is a selective diffusion barrier characterized by tight junctions between endothelial cells, lack of fenestrations, and specific BNB transporters. The BNB have been shown to be astrocyte dependent, for it is formed by the CNS capillary endothelial cells, surrounded by astrocytic end-foot processes. Given the anatomical associations with endothelial cells, it could be supposed that astrocytes play a role in the development, maintenance, and breakdown of the BNB. Therefore, astrocytes-endothelial cells interaction influences the BNB in both physiological and pathological conditions. If we better understand mutual interactions between astrocytes and endothelial cells, in the near future, we could provide a critical solution to the BNB problems and create new opportunities for future success of treating CNS diseases. Here, we focused astrocyte-endothelial cell interaction in the formation and function of the BNB.