• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.100-107
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• 2014

Currently, there are many power transmission devices, including gears, friction wheels, chains, and belts. Because the power transmission of gears is most certainin these devices, gears are widely used in different power transmission fields and environments. In accordance with the gear shape, gears can be classified as cylindrical gears and conical gears. A cylindrical gear, which provides a means of power transmission under parallel axis and skewed axis conditions, contains a spur gear, a helical gear and a worm gear. A conical gear, which can be used on a skewed axis as well as parallel and crossed axes, includes a bevel gear(e.g., straight bevel, spiral bevel, hypoid gear) and a conical involute gear(or a bevel oid gear). In this paper, a conical involute gear which utilizes the fabrication method of other involute gears such as spur and helical gears using a CNC hobbing machine is discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.293-296
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• 2007

Gamma curve is one of the most important optical performance characteristics of a liquid crystal display. we present investigations on the relationship between gamma and polarizer. The gamma curve is affected by the angle of the polarizer absorption axis. When the crossed angle between the two polarizers turns larger, gamma values will decrease. The gamma variation caused from each polarizer variation could be improved by monitoring and controlling the axial direction of the polarizers.

• Journal of The Korean Digital Architecture Interior Association
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• v.8 no.2
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• pp.57-64
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• 2008

The walls of art museums become the background of exhibits, and they form a unit space depending on the of each exhibit. In addition, the walls are configured and presented depending on the rhythm of space, or the structure of an axis. In this study, according to the axis composed for each unit space, the presentation methods of walls were classified as follows: The central type, the skewed type, the crossed type, the one-side corridor type, and the two-way corridor type. By analyzing visual configurations formed by the arrangement of each unit space, the value and the hierarchy of walls are discussed To analyze the classified types with the physical change of unit space, the factors of visual integration, connectivity, depth, and visual axis are compared, and various configurations of walls and space change are applied.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.809-813
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• 2006

We have studied the optical properties of the biaxial film such as fast axis, retardance and the change of polarization state between crossed polarizer using dual rotating retarder polarimeter. We have developed a novel simulation model, which could explain well the experimental results, and found that it could be used to optimize the compensation film in LCD for improving wide-viewing property.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1197-1199
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to the high transmittance, the low operating voltage and wide viewing angle simultaneously.

• Proceedings of the Optical Society of Korea Conference
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• 1990.02a
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• pp.162-166
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• 1990

Photoinduced anisotropy (PIA) in amorphous As2S3 (a-As2S3 ) thin film, deposited by vacuum evaporation, is investigated. PIA is induced by linearly polarized Ar+ laser beam (λ=514.5nm) and probed by weak Ar+ laser (λ=514.5nm) and He-Ne laser (λ=632.8nm) beam through the crossed analyzer. Keeping pump beam intensity constantly, rotation of pump beam polarization direction induces reorientation phenomina of anisotropic axis. Introducing directional factor into simplified 3-level system, which is used to analyze photodarkening phenomina, an analytical expression of PIA is derived. Temporal behavior of PIAand its reorientation phenomina are investigated andcompared with theory. In the experiment pump beam intensity is 100mW/$\textrm{cm}^2$ and thickness of a-As2S3 thin film is 3${\mu}{\textrm}{m}$. In those condition, time constant of photoinduced anisotropy obtained by method of least square curve fitting is 4.0$\times$10-2sec-1. The time constant of PIA we obtained is larger than that of photodarkening, 2.8$\times$10-2sec-1.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05a
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• pp.157-160
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• 2004

We have studied an optically compensated splay (OCS) mode driven by fringe electric field. The OCS LC configuration obtained by applying voltage to vertically aligned LCs shows a dark state when an optic axis of the OCS cell coincides with one of crossed polarizer axis. When the fringe electric field is applied, the LC director rotates in plane above whole electrode surface, giving rise to high transmittance and wide viewing angle simultaneously.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.716-725
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• 2007

In this paper we describe a motion tracking algorithm for 3D human animation using stereo vision system. This allows us to extract the motion data of the end effectors of human body by following the movement through segmentation process in HIS or RGB color model, and then blob analysis is used to detect robust shape. When two hands or two foots are crossed at any position and become disjointed, an adaptive algorithm is presented to recognize whether it is left or right one. And the real motion is the 3-D coordinate motion. A mono image data is a data of 2D coordinate. This data doesn't acquire distance from a camera. By stereo vision like human vision, we can acquire a data of 3D motion such as left, right motion from bottom and distance of objects from camera. This requests a depth value including x axis and y axis coordinate in mono image for transforming 3D coordinate. This depth value(z axis) is calculated by disparity of stereo vision by using only end-effectors of images. The position of the inner joints is calculated and 3D character can be visualized using inverse kinematics.

• The Korean Journal of Applied Statistics
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• v.26 no.6
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• pp.873-887
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• 2013

The axis of rotation in biomechanics is a major tool to investigate joint function; therefore, many methods to estimate the axis of rotation have been developed. However, there exist several problems to describe, estimate, and test the axis statistically. The axis is directional data(axial data) and it should not be analyzed with traditional statistics. A proper comparative method should be considered to compare axis estimating methods for the same given data ANOVA (analysis of variance) is a frequently used statistical method to compare treatment means in experimental designs. In case of the axial data response assumed to come from Watson distribution, there are a few ANOVA method options. This study constructed ANOVA models for within-subjects designs of axial data. Two models (one within-subjects factor and two within-subjects factors crossed design) were considered. The empirical data used in this study were instantaneous axes of rotation of flexion/extension at the knee joint and the flexion/extension and pronation/supination at the elbow joint. The results of this study can be further applied to the various analysis of experimental designs.

• Journal of the Optical Society of Korea
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• v.12 no.1
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• pp.25-30
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• 2008

The optical performances of 15-inch edge-lit backlight were simulated by using a Monte Carlo ray-tracing technique. The backlight model was built by combining a wedge-type light guide plate, a diffuser sheet, a tubular fluorescent lamp with a lamp reflector, and two crossed prism sheets. Angular distributions of the luminance on each optical component obtained from simulation were consistent with those obtained from experiments on a real 15-inch backlight. The constructed backlight model was used to evaluate the optical performances of a micro-pyramid film. It was found that the on-axis luminance gain on the pyramid film is higher than that on one prism film but much lower than that on the two crossed prism films. These results suggest that a reliable simulation model can be used to develop new hybrid films and to optimize the optical structure of edge-lit backlight in order to reduce the developmental period.