• The Journal of the Korea Contents Association
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• v.16 no.12
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• pp.132-142
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• 2016

The study aimed to examine the state of visual acuity tests in preschoolers and determine the factors affecting the deterioration of their vision. A total of 172 pair, child aged 5-7 years and either one of their parents, were recruited from childcare centers or kindergarten between August 2015 and January 2016. Questionnaires were administered to the parents, and the children's visual acuities were measured. Using forward selection in logistics regression analysis, factors affecting vision deterioration were elucidated. Of 172 children, 128 (74.4%) had undergone a visual acuity test previously and 77 (44.8%) showed a deterioration in their vision. Children who had undergone their first visual acuity test after the age of 7 years (OR=7.425, CI=2.844- 19.385) and showed more abnormal eye symptoms, such as squinting or tilting the head to see or falling down frequently (OR=3.084, CI=1.202-7.914) and whose age was younger (OR=10.335, CI=3.252-32.848), were more likely to develop deterioration of vision. Children who had a posture such that they looked up at the computer monitor from below (OR=.075, CI=.022-.255), were less likely to show deterioration of vision. It can be inferred that early visual acuity tests is essential to detect deteriorated vision of preschoolers. Therefore, it is necessary to educate parents, personnels in day care center, and health clinics about the importance of early visual acuity tests and close observation of specific behaviors related to vision deterioration. Development of precautionary intervention program of vision deterioration in preschoolers and examination of its effects are needed.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1634-1637
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• 2004

We developed a communication device for person with serious disability to use slight movement. This device is developed mainly for patients suffering from ALS or a cerebral infarction. They often have communication difficulty because of deterioration of muscle functions. A feature of this device is that slight movements of user's finger, eyes or lips can be detected by using a vision sensor. Due to the features of the vision sensor, it is quite easy even for person with serious disability to use a communication device. By the field test it is confirmed that the vision sensors have superior performances as an input device for communication device. Experiments to use an EMG (electromyography) sensor and a rotary sensor are also tested to compare the performances.

• Journal of Korean Clinical Health Science
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• v.5 no.3
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• pp.888-896
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• 2017

Purpose. The purpose of this study was to investigate the effect of visual field training on visual function, visual perception and attention enhancement. Methods. We examined the changes of visual function and visual perception tests for children with mild developmental disabilities through vision therapy. Results. At the time of the initial visit of the child, the ability to control not only distant and near visual function, but also accommodation, was also very limited. Also, the visual perception score was measured at 80 points. Through vision therapy, it was confirmed that the improvement of control ability as well as the visual function and visual perception function test results were also improved to 108 points. Conclusion. It was confirmed that vision therapy results in an improvement of visual function, improved visual perception ability, as well as visual perception ability, It was concluded that visual function affected visual perception, and that vision therapy used in order to prevent visual function deterioration was found to be very helpful.

• International Journal of Korean Welding Society
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• v.2 no.1
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• pp.45-51
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• 2002

In the multi-pass welding of pressure vessels or ships, the mechanical touch sensor system is generally used together with a manipulator to measure the gap and depth of the narrow gap to perform seam tracking. Unfortunately, such mechanical touch sensors may commit measuring errors caused by the deterioration of the measuring device. An automation system of narrow gap multi-pass welding using a laser vision system which can track the seam line of narrow gap and which can control welding power has been developed. The joint profile of the narrow gap, with 250mm depth and 28mm width, can be captured by laser vision camera. The image is then processed for defining tracking positions of the torch during welding. Then, the real-time correction of lateral and vertical position of the torch can be done by the laser vision system. The adaptive control of welding conditions like welding currents and welding speeds, can also be performed by the laser vision system, which cannot be done by conventional mechanical touch systems. The developed automation system will be adopted to reduce the idle time of welders, which happens frequently in conventional long welding processes, and to improve the reliability of the weld quality as well.

• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.1
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• pp.1-10
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• 2015

In urban area, since multipath and signal attenuations frequently occur due to street trees, street lights and buildings, it is difficult to obtain accurate navigation solution using GPS. As these problems also impact negatively on the INS/GPS coupled system, implementing advanced transportation systems such as autonomous navigation system and Intelligent Transportation System (ITS) become quite hard. For this reason, to alleviate deterioration of navigation system performance in urban area, direction information extraction algorithm using vision system is proposed in this paper. 2D Finite Rate of Innovation (FRI) technique is applied to extract lane edges. The proposed technique is simulated using road images and feasibility of proposed technique is analyzed through the simulation results.

• Journal of Korea Multimedia Society
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• v.23 no.11
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• pp.1383-1387
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• 2020

Recently, a 4-col 7-row LED Screen that provides various information of major roads and local governments has been installed and operated. However, due to deterioration due to changes in temperature and humidity, deterioration due to static electricity, and mechanical stress, partial module failure of the display may occur, which is a major cause of missing information of vitally given to citizens. However, there have been frequent cases where the 4-col and 7-row LED Screen that have failed due to reasons such as installed location where the signboards are installed on the road and outdoor, the lack of monitoring means at all times, and the lack of manpower is often neglected for a long time. Following this flow, this paper proposes a method to detect defective modules by analyzing the images collected through the camera fixed to the front part of the LED display.

• Architectural research
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• v.18 no.3
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• pp.83-90
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• 2016

Senescent effects are the gradual deterioration of function caused by biological aging. Senescent effects on color vision are not clearly understood even after considerable researches. Part of the reason is that the color vision is a complex phenomenon resulting from various factors such as organic systems, and the physical (neuro-optical) and the psychological (experiential) processes of color perception. We performed a field experiment on color perceptional differences due to aging vision. Our experiment was applied to two different groups in South Korea: an experimental group (46 subjects of over the age of 61 years) and a control group (49 subjects in their twenties). The experimental tools are comprised of (1) six gradual yellowing detector board (40%, 50%, 60%, 70%, 80%, 90%); (2) pairs of vivid-strong, vivid-deep, grayish-deep, deep-dull, and bright-light tones of Blue (B) and Purple (P) colors; (3) Red (R), Yellow (Y), Green (G), Blue (B), and Purple (P) colors of dull-tones and pale-tones; and (4) a questionnaire on the semantic differential scales of the color images and color differences. A diagnosis system of gradual yellow vision, developed by the authors for this study, was adapted to generate the color detecting boards. The results are as follows. (1) There are significant differences between the two groups in detecting colors that simulate 40% and 50% of yellow vision. (2) As to the color difference detecting ability between similar tones, the experimental group shows difficulties in pairs of vivid-strong tones and deep-dull tones of the B color. And (3), the emotional responses to the dull tone and the pale tone are not stable in the red, the yellow, blue, and purple. Thus, we empirically demonstrate the specific differences in color perception between the old and young groups.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.06a
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• pp.34-39
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• 2006

An automated surface-strain measurement system, named ASIAS, was developed by using the image processing and stereo vision techniques in the previous studies by the corresponding author and his coworkers. This system has been upgraded mainly to improve the accuracy through image enhancement, sub-pixel measurement, surface smoothing, etc., since the first version was released. The present study has still more improved the convenience of users as well as the accuracy of measurement by processing high resolution images 8 mega pixels or more which can be easily obtained from a portable digital steal camera. It is proved that high resolution image processing greatly decreases the measurement error and gives strain data without considerable deterioration of accuracy even when the deformed grids to be measured and the master grids for camera calibration are captured together in the same image, making the whole process of strain measurement much simpler.

• Structural Monitoring and Maintenance
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• v.2 no.1
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• pp.19-34
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• 2015

One of the main causes of a limited use of nondestructive evaluation (NDE) technologies in bridge deck assessment is the speed of data collection and analysis. The paper describes development and implementation of the RABIT (Robotics Assisted Bridge Inspection Tool) for data collection using multiple NDE technologies. The system is designed to characterize three most common deterioration types in concrete bridge decks: rebar corrosion, delamination, and concrete degradation. It implements four NDE technologies: electrical resistivity (ER), impact echo (IE), ground-penetrating radar (GPR), and ultrasonic surface waves (USW) method. The technologies are used in a complementary way to enhance the interpretation. In addition, the system utilizes advanced vision to complement traditional visual inspection. Finally, the RABIT collects data at a significantly higher speed than it is done using traditional NDE equipment. The robotic system is complemented by an advanced data interpretation. The associated platform for the enhanced interpretation of condition assessment in concrete bridge decks utilizes data integration, fusion, and deterioration and defect visualization. This paper concentrates on the validation and field implementation of two NDE technologies. The first one is IE used in the delamination detection and characterization, while the second one is the USW method used in the assessment of concrete quality. The validation of performance of the two methods was conducted on a 9 m long and 3.6 m wide fabricated bridge structure with numerous artificial defects embedded in the deck.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.3
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• pp.51-58
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• 2008

This paper is a study of a prevention of power folding controller's thermal degradation. Power folding technology has been applied for many fields such as side rear vision mirror of vehicles, windshield wiper, antenna, power window. These controllers have been comprised with traditional DC moors, Switching electronic devices, and relays. But this methods have a limitation to overcome such problems of product reliability, endurance, noise margins. Therefore on this paper, to detect the movement of motor, sensing motor brush noise on a load sensing part has been used and controlling a precise RC timing control minimizes the thermal deterioration of motor. And using MOS FETs as a electronic switching device increases life-time and liability of control circuit. After testing such circuit and control method, repetition of operating time, cut-off time, wide operation voltage, power noise margin ware increased over eleven-fold.