• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• 제20권8호
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• pp.1-5
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• 2006

We present the method to calculate the phase at each point of the speckle pattern in shearographic system using Polarization components. And, to demonstrate the feasibility of the proposed system, we present the experimental results using polymer specimen.

• Transactions of Materials Processing
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• 제21권2호
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• pp.126-130
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• 2012

Accurate optical texturing of light guide plate over the entire surface area is an important technical issue in LCD TV industry. Injection molding process has the potential to produce large light guide plates having highly efficient optical textures such as micro-prism array. This study is focused on the effect of the degree of replication of the micro texture of the 40" injection molded light guide plates on the overall optical performance of the display panel. Measured replication ratios of the micro-textures formed with three different types of injection molding process were considered in the modeling of prismatic micro segment array. Optical simulation was conducted and results were discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• 제11권5호
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• pp.76-81
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• 2012

The continuing demand for increasingly slimmer and brighter liquid crystal display(LCD) panels has led to an increased focus on the role of the light guide panels(LGPs) or optical films that are used to obtain diffuse, uniform light from the backlight unit(BLU). And the most basic process in the production of such BLU components is the micromachining. LCD BLUs comprise various optical elements such as a LGP, diffuser sheet, prism sheet, and protector sheet with micro patterns. High aspect ratio patterns are required to reduce the number of sheets and enhance light efficiency, but there is a limit to the aspect ratio achievable for a given material and cutting tool. Therefore, this study comprised a series of experimental evaluations conducted to determine the machining feasibility in microcutting various aspect ratio patterns on electroless nickel plated die materials when using single-crystal diamond tools. Cutting performance was evaluated at various cutting speeds and depths of cut using different machining methods and machine tools.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• 제7권4호
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• pp.64-72
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• 1998

This paper a new approach to the design of machine vision technique with a camera modeling that accounts for major sources of geometric distortion, namely, radial, decentering, and thin prism distortion. Radial distortion causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering , that is , the optical centers of lens design and manufacturing as well as camera assembly. It is our propose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing. The performance of proposed vision system is illustrated by simulation and experiment.

• Journal of Educational Research in Mathematics
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• 제9권1호
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• pp.121-132
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• 1999

We have compared Korean and American mathematics curriculums in 5 areas: whole number(concepts and its operations); geometry; pattern and relations; measurements; statistics and probability. We have found significant differences in geometry area. Korean curriculums contain simple planar figures (circles, triangles, rectangles, and squres) and some of the spatial figures until 3rd grades. But in America they learn various planar and spatial fugures(cone, pyramid, triangular prism, etc) since the 1st grade starts. They also start the 1st grade by dealing with topological concepts like open/closed, inside/outside, order, etc. As the grade goes on, students learn other geometrical concepts like congruence, symmetry, 3-dimensional views. We also found that American curriculum focuses on students' activities and courages communication through projects, groupwork, journal writing, etc. It's also superior in respects of motivation, and connections with real life and other subjects. Korean curriculum needs more improvements in these aspects. Furthermore for lower graders reviewing sections need to be enhanced for feedback.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.578-581
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• 1999

Dot pattern print methods composed of a diffusion film and two prism sheets, have been generally used for backlighting systems of LCDs. However, this methods require complex structures and show high power consumption and optical loss. To improve these disadvantages of conventional backlight units, light guides using highly scattering optical transmissions (HSOT) polymer as scatters, have been introduced. In this study we analyzed multiple scattering effect in light guide by means of Monte carlo simulation based on Mie scattering theory and ray tracing method. As a result it was revealed that scattering intensity depends on the size of scatters. On the other hands, it was shown that scattering efficiency depends on the wavelength of fluorescent lamp as well as the size of scatters.

• Journal of Korean Ophthalmic Optics Society
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• 제9권2호
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• pp.361-370
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• 2004

The purpose of this study was to evaluate the outcome and Factors that influence the quantity of Phoria in the low correction and perfect correction. Also the coincidence with the opticenter and the pupillary distance was a principal factor that influence the quantity of Phoria. Thereupon, this study is attributed to promote the perfect Phoria test. The subjects for this study were 120 persons(240 eye) in myopic refractive errors. ISP/WIN program was used for the data analysis. The collected data was analyzed by descriptive statistics and Spearman's correlation coefficient. The results of this study were as follows: 1. The prism pattern was difference between low correction and perfect correction in the Phoria test. The proportion of orthophoria was changed from 10.0% to 12.5%, exophoria was changed from 67.5% to 62.5%, and esophoria was changed from 22.0% to 32.5%, respectively. 2. The average of optical center distance and pupillary distance were 31.70mm and 31.49 mm, respectively. 3. Among the 120 myopic glasses wearers, the distance between optical centers was coincided with the pupillary distance in 37.5%, and discrepant in 62.5%. 4. For the patients who were coincided with the pupillary distance, the proportion of exophoria decreased 53.33%, esophoria increased 20.0%. 5. For the changing of the quantity of Phoria in the low correction, the degree of exophoria decreased 1.11 prism diopters in the perfect correction, esophoria increased 0.39 prism diopters.

• Design & Manufacturing
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• 제2권5호
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• pp.1-4
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• 2008

LCD-BLU (Liquid Crystal Display - Back Light Unit) is one of kernel parts of LCD unit and it consists of several optical sheets(such as prism, diffuser and protector sheets), LCP (Light Guide Plate), light source (CCFL or LED) and mold frame. The LGP of LCD-BLU is usually manufactured by forming numerous dots with $50-200{\mu}m$ in diameter on it by erosion method. But the surface of the erosion dots of LGP is very rough due to the characteristics of the erosion process during the mold fabrication, so that its light loss is high along with the dispersion of light into the surface. Accordingly, there is a limit in raising the luminance of LCD-BLU. Especially, the negative and positive micro-lens pattern fabricated by modified LiGA with thermal reflow process was applied to the optical design of LGP.

• Journal of the Korean Society of Costume
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• 제18권
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• pp.167-181
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• 1992

This study was conducted to clarify the formativeness of Cezanne's painting and it's influence on the Modern Fashion. Recently, fashion was introduced and applied the originality of paintings into the fabric and fashion designing. To go with the current of the times I already discussed about the Modern Fashion under the influence of the color of Impressionism and N대-Impressionism in the previous paper. In this study, Cezanne's painting and it's influence on the Modern fashion was investigated. As one of the original Impressionist, Paul Cez anne had been so adversely affected by the critical attack on his contributions to the 1874 and 1877 exhibitions that he never again showed with the group. That is, he was the first Impressionist to become dissatisfied with the superficial recording of atmospheric effects. When he turned to nature, it was not simply to depict the objects that occupied a given site but rather to consider relationships among those objects. Cezanne attempted to track down the fundamental laws of geometrical prototypes of sphere, prism and corn. Color too, he found, could be employed according to principle, like the tones of a musical scale. Throughout the Modern Fashion, various forms of Bustle style dress and geometrical style dress were reappered under the influence of the Cez anne's painting technique. And the order and the unity of all nature was illuminated on the fashion's pattern.

• Journal of ILASS-Korea
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• 제5권1호
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• pp.49-57
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• 2000

This study presents the flow visualization results, velocity and turbulence intensity measurements made within an air filter cover and entry region of a mass air flow sensor (MAFS) which is used in an induction system of 3.8L engine. Flow structure in two air filter cover assemblies were examined. The first was a clear plastic replica of the production cover while the second was a modified clear plastic cover with a geometry configured to reduce fluctuations. High speed flow visualization and laser doppler velocimetry (LDV) systems were used to reveal and analyze the flow field characteristics encountered in the sensor design process under steady flow conditions. A 40-watt copper vapor laser was used as a light source. Its beam is focused down to a sheet of light approximately 1.5mm thick. The light scattered off the particles was recorded by a 16mm high speed rotating prism camera at 5000 frames per second. A comparison of the flow patterns and LDV measurements in the original and modified air filter covers is presented to illustrate the controlling effect of the cover design on the turbulence structure formation near the bypass and on the sensor output signal. In both axial and radial planes of the main passage it was found that the turbulence flow pattern is remarkably influenced by the air filter cover and main passage configuration.