• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.344-349
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• 2013

This paper proposes a simulation algorithm to assess the gradual yellowing vision of the elderly, which refers to the predominance of yellowness in their vision due to aging of the ocular optic media. This algorithm employed the spectral transmittance property of a yellow filter to represent the color appearance perceived by elderly people with yellow vision, and modeled the changes in the color space through a spectrum change in light using the yellow filter effect. The spectral reflectivity data of 1269 Munsell matte color chips were used as reference data. Under the standard conditions of a D65 illuminant and a $10^{\circ}$ observer of 1964 CIE, the spectrum of the 1269 Munsell colors were processed through the yellow filter effect to simulate yellow vision. Various degrees of yellow vision were modeled according to the transmittance percentage of the yellow filter. The color differences before and after the yellow filter effect were calculated using the DE2000 formula, and the color pairs were selected based on the color difference function. These color pairs are distinguishable through normal vision, but the color difference diminishes as the degree of yellow vision increases. Assuming 80% of yellow vision effect, 17 color pairs out of $(1269{\times}1268)/2$ pairs were selected, and for the 90% of yellow vision effect, only 3 color pairs were selected. The result of this study can be utilized for the diagnosis system of gradual yellow vision, making various types of test charts with selected color pairs.

• International Journal of Korean Welding Society
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• v.3 no.2
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• pp.53-59
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• 2003

Visual inspection using laser vision sensor was proposed for fast and economic inspection and was verified experimentally. Welding is one of the most important manufacturing processes for automotive and electronics industries as well as heavy industries. The weld zone influences the reliability of the products. There are two kinds of weld inspection tests, destructive and non­destructive test. Even though the destructive test is much more reliable, the product should be destroyed, and hence the non­destructive test such as ultrasonic or X­ray test was used to overcome this problem. However, these tests are not used for real time inspection.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.12
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• pp.1209-1216
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• 2009

This paper presents the pose estimation of a small UAV utilizing visual information from low cost cameras installed indoor. To overcome the limitation of the outside flight experiment, the indoor flight test environment based on multi-camera systems is proposed. Computer vision algorithms for the proposed system include camera calibration, color marker detection, and pose estimation. The well-known extended Kalman filter is used to obtain an accurate position and pose estimation for the small UAV. This paper finishes with several experiment results illustrating the performance and properties of the proposed vision-based indoor flight test environment.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.4
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• pp.95-99
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• 2007

This study performed apreliminary test with male high school students in Gwangju metropolitan city in order to determine visual function information of high school students. For the items in this preliminary test, there were inquiry, test for long distance unaided visual acuity, pinhole visual acuity test, colour vision test, cover test and stereo test. Most complaint related to eye was about blurred vision (28.4%) and over 90% of subjects had one or more, and among them, over 50% appealed two or more complaints. 76.1% of all subjects showed less than 0.7 in unaided distance visual acuity. In pinhole visual acuity test, 98% had an improved unaided pinhole visual acuity and most of them experienced an improvement and 2% had no change or dropped. The students with normal stereoscopic vision test were 85.6% and the students under normal range were 14.4%. In colour vision test, 7.9% of them were protanomaly and deuteranomaly and none of them had trichromasy and total color blindness. In cover test, it showed 30.2% of orthophoria, 8.2% of esophoria and 61.5% of exophoria, and none of them had strabismus.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.569-577
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• 2018

Purpose : The study looked at how effective each group wearing MyoVison lens, MC lens, and Single Vision lensdepending on their parents' myopia condition. Methods : The study observed the changeof spherical equivalent among customers, who visited between January 2010 and December 2016,of an optical shop in Incheon Metropolitan City. And we observed MyoVision 152 eyes, MC Lens 86 eyes and Single Vision lens 270 eyes. This study was conducted using SPSS ver18, which analyzes the changes in average values of MyoVision, MC Lens, and Single Vision for a year.In each group, the differences in the group were compared using the Paired T-test and then one-way ANOVA (post-hoc; Bonferroni) Results : Group-to-group comparisons showed that MyoVision and MC Lens have a shorterinhibition than Single Vision. In particular, MyoVisionand MC Lens showed different relief effects depending on the degree of refraction of parents.When both parents had normal refractive, the change between MyoVision and Single Vision lens was $-0.35{\pm}0.05D$. When the father had a refraction MC lens were $-0.36{\pm}0.14D$ more effective than Single Vision. When only the mother had refraction, the mean value between MyoVision and Single Vision lens was $-0.37{\pm}0.06D$, and the mean between MC lens and Single Vision lens was $-0.38{\pm}0.08D$. And when both parents had refraction problems, the mean value change between MyoVision and Single Vision lens was $-0.28{\pm}0.07D$, and $-0.31{\pm}0.07D$, respectively. Conclusion : MyoVision and MC Lens appeared to have no effect on the functions of mitigating myopia in within group comparisons, but MyoVision and MC Lens showed reducing myopia than Single Vision in between group.

• Journal of Korean Ophthalmic Optics Society
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• v.12 no.3
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• pp.111-115
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• 2007

Purpose: The aim of this study was to assess vision-related quality of life and modes of refractive error correction. We administered NEI-VFQ (National Eye Institute Visual Function Questionnaire) to 137 subjects in two modes of refractive error correction: spectacles and contact lens wearers. The NEL-VFQ was developed to assess vision-related quality of life with respect to 1) visual symptoms 2) social function as well as difficulty with tasks and symptoms 3) economic issues and health concerns 4) psychological well-being. The NEL-VFQ was translated from English into Korean. Methods: All data were analyzed using SAS 8.0. Student's T-test was conducted to determine significant differences in each of the subscale (${\alpha}=0.05$). Result: The Peripheral Vision subscale score ($mean{\pm}SD$) was $52.2{\pm}32.7$ for the spectacle wearers, $88.6{\pm}18.1$ for contact lens wearers; the spectacle wearers' Peripheral Vision score was significantly lower than contact lens wearers (p=0.0001). There were also significant differences between two groups detected in Color Vision (p=0.001), General Vision (p=0.01) and Health Perception (p=0.01). Conclusion: Contact lens wearers and spectacle wearers were mostly high vision-related quality of life except General Vision and Health Perception. Especially, contact lens wearers were higher vision-related quality of life than spectacle wearers. Further studies on developing of good quality of contact lens will be needed to improve quality of life in ametropia.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.731-736
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• 2011

On this paper, we propose how to apply the vision system for monitoring a platform safety. The vision system is tested in real platform in a deagu subway station. According to the result of field test, we propose how to use vision system for monitoring a platform safety. The result showed that it had a high performance to detecting ratio.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1367-1370
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• 1997

This paper presents a vision algorithm for finding the centers of steam generator tubes using the generalized symmetry transform, which is used for ECT(Eddy Current Test) of steam generator tubes in nuclear power plants. The geometrical properties of the image representing steam generator tubes shows that they have amost circular or somewhat elliptic appearances and each tube has strong symmetry about its center. So we apply the generalized symmetry transform to finding centers of steam geneator tubes. But applying the generalized symmetry transform itself without any modification gives difficulties in obtaining the exact centers of steam generator tubes. But applying the generalized symmetry transform itself without any modification gives difficulties in obtaining the exact centers of tubes due to the shadow effect generated by the local light installed inside steam generator. Therefore we make the generalized symmetry transform modified, which uses a modified phase weight function in getting the symmetry magnitude in order to overcome the misleading effect by the local light. The experimental results indicate that the proposed vision algorithm efficiently recongnizes centers of steam generator tubes.

• Journal of Biosystems Engineering
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• v.32 no.1 s.120
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• pp.44-49
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• 2007

A stereo vision system was developed for robot milking system (RMS) using two monochromatic cameras. An algorithm for inverse perspective transformation was developed for the 3-D information acquisition of all teats. To verify performance of the algorithm in the stereo vision system, indoor tests were carried out using a test-board and model teats. A real cow and a model cow were used to measure distance errors. The maximum distance errors of test-board, model teats and real teats were 0.5 mm, 4.9 mm and 6 mm, respectively. The average distance errors of model teats and real teats were 2.9 mm and 4.43 mm, respectively. Therefore, it was concluded that this algorithm was sufficient for the RMS to be applied.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.2
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• pp.191-198
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• 2015

In this paper, six-degree-of-freedom (DoF). Displacement measurement technique using a compact stereo-vision system is proposed. The measuring system consists of a camera, an optical prism, two plane mirrors, and a planar marker on a target. The target was attached on an object so that its six-DoF displacement can be calculated using a proposed coordinates estimating algorithm and stereo images of the marker. A prototype was designed and fabricated for performance test. From the test results, it can be confirmed that the proposed measuring technique can be applied to monitoring and control of various manipulators.