• Child Health Nursing Research
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• v.8 no.2
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• pp.164-173
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• 2002

The vision disturbances of school-age children has been recognized as and important school health problem. The purpose of this study is to describe the current status of the visual health and to explore the related factors for the decrease in visual acuity in the elementary school age children. The study subjects were 697 children (Boys: 338, Girls: 359) of 4th to 6th grade in two school in urban area. The visual acuity data of the school health examination in 1999 and 2000 were utilized for analysis. The questionnaire for children and parents was used for survey. The findings were as follows. 1. The prevalance rate of the children with the visual acuity less than 0.7 on the left eye were 26.84％ ( Grade 4), 31.30％ (Grade 5), and 38.39％ (Grade 6). The rate on the right eye were 28.31％ (Grade4), 30.37％ (Grade 5), and 37.92％ (Grade 6). There was a significant difference in the rate of the visual acuity less than 0.7 according to grade (p<.01). 2.The rate of visual acuity decrease was 40.12％. 3. The factors related to the decrease in the visual acuity were grade, sex, genetic factor, posture, and the awareness of the visual acuity. There was more decrease in the visual acuity when the children were in higher grade (O.R= 1.06), girls (O.R=2.29). Children having parents with better vision (Father: O.R=1.26; Mother O.R= 1.25) showed better vision. On the other hand, when the children have siblings with glasses, there was more decrease in the visual acuity (O.R=2.31). Students with good posture during study (sitting on the chair) and watching TV to the lower direction showed less decrease in the visual acuity. Also, when the students know their visual acuity, the rate of decrease were lower. The variables which odds ratio were statistically significant were sex (p<.01), siblings with glasses (p <.01), and awareness of visual acuity (p<.01).

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.10
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• pp.1047-1052
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• 2008

In this paper, we design an image-based robust controller to compensate uncertainties with image Jacobian and robot dynamics due to uncertain depth measurement and load variations. The proposed controller with eye-in-hand structure has separate terms to compensate each of uncertainties. The ultimate boundedness of the closed-loop system is proved by the Lyapunov approach. The performance of the proposed control system is demonstrated by simulation and experimental results a 5-link robot manipulator with two degree of freedom.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.566-571
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• 1994

This paper presents in image-based visual servo control scheme for tracking a workpiece with a hand-eye coordinated robotic system using the fuzzy-neural-network. The goal is to control the relative position and orientation between the end-effector and a moving workpiece using a single camera mounted on the end-effector of robot manipulator. We developed a fuzzy-neural-network that consists of a network-model fuzzy system and supervised learning rules. Fuzzy-neural-network is applied to approximate the nonlinear mapping which transforms the features and theire change into the desired camera motion. In addition a control strategy for real-time relative motion control based on this approximation is presented. Computer simulation results are illustrated to show the effectiveness of the fuzzy-neural-network method for visual servoing of robot manipulator.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.590-593
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• 2001

In this paper we describe the 6-axes robot's position determination using a stereo vision and an image based control method. When use a stereo vision, it need a additional time to compare with mono vision system. So to reduce the time required, we use the stereo vision not image Jacobian matrix estimation but depth estimation. Image based control is not needed the high-precision of camera calibration by using a image Jacobian. The experiment is executed as devide by two part. The first is depth estimation by stereo vision and the second is robot manipulator's positioning.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.510-514
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• 1994

This paper deals with an application of neural network to camera calibration with wide angle lens and 2-D range finding. Wide angle lens has an advantage of having wide view angles for mobile environment recognition ans robot eye in hand system. But, it has severe radial distortion. Multilayer neural network is used for the calibration of the camera considering lens distortion, and is trained it by error back-propagation method. MLP can map between camera image plane and plane the made by structured light. In experiments, Calibration of camers was executed with calibration chart which was printed by using laser printer with 300 d.p.i. resolution. High distortion lens, COSMICAR 4.2mm, was used to see whether the neural network could effectively calibrate camera distortion. 2-D range of several objects well be measured with laser range finding system composed of camera, frame grabber and laser structured light. The performance of 3-D range finding system was evaluated through experiments and analysis of the results.

• Journal of the Ergonomics Society of Korea
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• v.12 no.1
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• pp.25-38
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• 1993

The objective of this study is to collect and analyze the anthropometric data for Korean adults. These data are intended to be used for the product design in industry. Sixty three college students participated in the measurement. One hundred twenty four lengths, thirty circumferences, four strengths, weight, and age data were collected. Descriptions and statistical analysis of the anthropo- metric data are summarized. The results were compared with foreign data available. It was found that forty weven body dimensions were closely correlated each other. It was also found that three dimensions, stature, eye height, and hand length, can be assessed by adding other body dimensions.

• IMMUNE NETWORK
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• v.2 no.3
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• pp.133-136
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• 2002

Background: The costimulatory molecule 4-1BB, a member of nerve growth factor receptor/tumor necrosis factor (NGFR/TNFR) super family, is involved in cell survival and death. Methods: In this study, female C57BL/6 ($H-2^b$) mice were used as a recipient, and DBA/2 ($H-2^d$) as a donor to assess a mixed lymphocyte reaction (MLR) and CTL response in vitro, and skin graft survival. IL-2, IFN level was measured by ELISA. Results: Mixed lymphocyte reaction (MLR) analysis showed that 4-1BB-deficient responder cells showed enhanced cellular proliferation over littermate controls. In contrast, IL-2 production was diminished only in 4-1BB knockout cultures. The IFN expression, on the other hand, was comparable between the groups. When female C57BL/6 ($H-2^b$) mice were grafted with the trunk skin of DBA/2 ($H-2^d$) mice, the in vivo tissue destruction of 4-1BB-deficient mice was not distinct from the normal littermates. Conclusion: These data suggest that 4-1BB is critical for the induction of alloreactive responses in vitro but 4-1BB alone could not change the course of skin rejection in vivo.

• Journal of the Korean Society of Costume
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• v.14
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• pp.167-183
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• 1990

As an attempt to view Chason costume from a aesthetic perspective, the aesthetic values of the Choson people, as expressed through the aesthetic characteristics of costumes, are pursued in this study. To appreciate the beauty of the traditional Korean costume, the following aesthetic characteristics of Choson costumes are investigated: form, color, pattern, material and ornament. From the view point of aesthetics, this study shows that Choson costume had comfortable and voluminous forms with beautiful curved lines and rhythm. The most favored colors were white and natural colors of materials. However unusual combination of colors such as the contrast of black and white, the harmony of the primary and rainbow colors were often used. Patterns revealed two aspects : while subdued patterns generally prevail, at times the unexpected beauty of primary colored patterns draws our attention. Smooth natural materials were preferred. Ornaments both for practical and decorative purposes were used together with certain colors and patterens, indicating wearer's status and warding off the evil's spirits. The aesthetic values in costumes as expressed through the aesthetic characteristics can be classified into the following categories: the beauty of nature, the beauty of personality, the aesthetics of evil's eye and the beauty of tradition. The beauty of nature, as appreciated by the Chason people through their prevailing nature, the "Pung-rew Spirit" and through their Worship of Heaven, produced aesthetic characteristics in harmony with nature. The beauty of personality influenced by the ethical standard of Confucianism produced aesthetic characteristics in costumes, through which the appropriate personality was shown for the appropriate social status. On the other hand, the aesthetics of evil's eye, rooted deeply in Folk religion and Shamanism, contributed to various aesthetic characteristics, which strongly inclined to sorcery and symbolism through choice of patterns, colors and ornaments. Finally, the beauty of tradition, which was based on the ethics of Confucianism and the Choson people's conservative tendencies, demonstrated the strong tendency to adhere to the external characteristics of the Choson costume. These aesthetic values were the yardsticks of the aesthetic judgment of the Choson people. These values influenced Chason people in designing costumes and in appreciating the beauty of costumes. The aesthetic experience and attitudes of the Chason people, which were based on these aesthetic values, represented their aesthetic consciousness and desires.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.165-172
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• 2003

In this paper, we constructed horizontal and vertical virtual spaces using the projection table and the projection wall. We then implemented a system that stereoscopically visualizes three-dimensional (3D) buildings in the virtual environments in accordance with the user's viewing point. The projection table, a kind of horizontal display equipment, is effectively used in reproducing operations on a table or desk as well as in areas that require bird-eye views because its viewing frustum allows to view things from above. On the other hand, the large projection wall, a kind of vertical display equipment, is effectively used in navigating virtual spaces because its viewing frustum allows to take a front view. In this paper, we provided quick interaction between the user and virtual objects by representing major objects as detail 3D models and a background as images. We also augmented the reality by properly integrating models and images with user's locations and viewpoint in different virtual environments.

• Korean Journal of Radiology
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• v.2 no.4
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• pp.197-203
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• 2001

Objective: To compare the clinical utility of contrast-enhanced color Doppler US in the differentiation of retinal detachment (RD) from vitreous membrane (VM) with that of various conventional US modalities, and to analyze the enhancement patterns in cases showing an enhancement effect. Materials and Methods: In 32 eyes examined over a recent two-year period, RD (n=14) and VM (n=18) were confirmed by surgery (n=28) or clinical follow-up (n=4). In all cases, gray-scale, color Doppler, and power Doppler US were performed prior to contrast injection, and after the intravenous injection of Levovist (Schering, Berlin) by hand for 30 seconds at a dose of 2.5 g and a concentration of 300 mg/mL via an antecubital vein, contrast-enhanced color Doppler US was performed. At Doppler US, the diagnostic criterion for RD and VM was whether or not color signals were visualized in membranous structures. Results: Diagnostic accuracy was 78% at gray-scale US, 81% at color Doppler US, 59% at power Doppler US, and 97% at contrast-enhanced color Doppler US. The sensitivity of color Doppler US to color signals in RD increased from 57% to 93% after contrast enhancement. The enhancement patterns observed were signal accentuation (n=3), signal extension (n=2), signal addition (n=3), and new signal visualization (n=5). Conclusion: Contrast-enhanced color Doppler US was the most accurate US modality for differentiating RD from VM, showing a significantly increased signal detection rate in RD.