• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.9
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• pp.873-877
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• 2006

We have fabricated top omission organic light emitting diodes with transparent Ba/Ag double layer cathodes deposited by using thermal evaporation method. The device structure was $glass/Ni(200nm)/2-TNATA(15 nm)/{\alpha}-NPD(15nm)Al_{q3}:C545T\;(1%,\;35nm)/BCP(5nm)/Ba(10nm)/Ag(8nm)$. The optical transmittance of the Ba(10 nm)/Ag(8 nm) layer was over 60 % in the visible wavelength region. The maximum efficiency of the device was $13.7\;cd/A\;at\;0.69\;mA/cm^{2}$ and the efficiency of over 10 cd/A was achieved at wide range of current densities and luminances.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.10a
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• pp.443-453
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• 2011

This study was carried out in order to elucidate effects of types of binder used in pre-coated layer on optical properties and printability of top-coated layer. Coated papers with four different types of SB latex were prepared. Tg, particle size and gel contents of latices were of different. Optical properties and printability of coated paper including print mottle were evaluated. It was confirmed that properties of pre-coated layer distinctively affected final properties of top-coated layer. Tg was found to be the most influencing factor on the print mottle of coated paper: the SB latex with lower Tg and higher particle size resulted in a superior print mottle. These results indicate that final printability and properties of top-coated layer can be controlled by adjusting pre-coated layer.

• International Journal of Precision Engineering and Manufacturing
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• v.8 no.2
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• pp.54-58
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• 2007

This paper describes an atomic force microscope (AFM)-based instrument for measuring the nanoscale cutting edge profiles of diamond cutting tools. The instrument consists of a combined AFM unit and an optical sensor to align the AFM tip with the top of the diamond cutting tool edge over a submicron range. In the optical sensor, a aser beam is emitted from a laser diode along the Y-axis and focused to a small beam spot with a diameter of approximately $10{\mu}m$ at the beam waist, which is then received by a photodiode. The top of the tool edge is first brought into the center of the beam waist by adjusting it in the X-Z-plane while monitoring the variation in the photodiode output. The cutting tool is then withdrawn and its top edge position at the beam center is recorded. The AFM tip can also be positioned at the beam center in a similar manner to align it with the top of the cutting edge. To reduce electronic noise interference on the photodiode output and thereby enhance the alignment accuracy, a technique is applied that can modulate the photodiode output to an AC signal by driving the laser diode with a sinusoidal current. Alignment experiments and edge profile measurements of a diamond cutting tool were carried out to verify the performance of the proposed system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.643-661
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• 2018

This paper proposes a novel algorithm for lane detection based on inverse perspective transformation and Kalman filter. A simple inverse perspective transformation method is presented to remove perspective effects and generate a top-view image. This method does not need to obtain the internal and external parameters of the camera. The Gaussian kernel function is used to convolute the image to highlight the lane lines, and then an iterative threshold method is used to segment the image. A searching method is applied in the top-view image obtained from the inverse perspective transformation to determine the lane points and their positions. Combining with feature voting mechanism, the detected lane points are fitted as a straight line. Kalman filter is then applied to optimize and track the lane lines and improve the detection robustness. The experimental results show that the proposed method works well in various road conditions and meet the real-time requirements.

• Korean Journal of Optics and Photonics
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• v.23 no.3
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• pp.119-123
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• 2012

The structure of an LCD backlight unit (BLU) was simplified by installing a micro reverse-pyramid array (MRPA) or a micro reverse-cone array (MRCA) on the top surface of the light guide panel (LGP) in order to eliminate the conventional diffuser sheet and the prism sheet. The optimum conditions of the MRPA and the MRCA in the new light guide panel were obtained through optical simulation. The change of the luminance and view angle that depend on the side angle, the height, and the length at the top of the MRPA and MRCA were studied. The optimized side angle and the view angle of the MRPA and MRCA were 59 and 57 degrees for the side angles and 68 and 64 degrees for the view angles, respectively.

• Korean Journal of Optics and Photonics
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• v.32 no.6
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• pp.276-285
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• 2021

This paper reports the study of the line-beam optical system of the laser lift-off (LLO) equipment used in the OLED manufacturing process. To obtain both a long process depth and a narrow width of the line beam, even with the poor M² value of the laser source, the research is focused on the optical system, including the beam transformation unit (BTU). We also propose optical configurations for the super-Gaussian distribution and the fiber-based BTU for the flat-top distribution.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.71-76
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• 2006

In this paper, a long gauge Fiber Bragg Grating (FBG) sensor system is described and long gauge FBGs are well, suited for measuring the upper parts of the bridge piers under the extremely severe movement conditions. In the experiments, we used more than 30m long FBG sensors to measure the movement of top part of the bridge piers which are separated from the main bridge by cutting the decks. With the actuator, the deck and girders were pushed and released. We checked the movement of the top of the pier while releasing the pressure of the actuator with the long gauge fiber sensor. In order to measure the movement of the upper part of the pier, the reference point must be outside of the pier. Using the optical fiber sensors, one end of the sensor is attached to the top of the pier and the other end is attached to the bottom of the next pier. The fiber sensors showed good response to the release loading and we could calculate the movement of the top part of the pear.

• Journal of the Korean Society of Costume
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• v.60 no.3
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• pp.1-9
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• 2010

The purpose of this study is to develop Blue-Jean Design for Ideal Body Shape. The final aim of Fashion design is looks beauty of people by optical illusion. This study is based on Gestalt therapy and, is blue jeans design using optical illusion of vertical line for ideal beauty body image. Optical illusion for blue-jean design effect to achieve the ideal body shape. We can accumulate the preceding study for modern clothing from design and the related optical illusion effects. Vertical line stitches have all the advantages especially in pants design. I design blue jeans using optical illusion theory. The results of this study are as follows: First, Vertical line helps that jean has the long body shape effectively. Second, Jeans which have two or more vertical lines is more effective than simple Jean in order to make slim body shape. Third, Appropriate position of horizontal lines can be effective to make long body shape. Fourth, Top stitch, pin-tuck and pleats can be applied to vertical or horizontal lines instead of cutting lines.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.57-58
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• 2008

We have studied an organic layer and semitransparent Al electrode thickness dependent optical properties and microcavity effects for top-emission organic light-emitting diodes. Manufactured top-emission device structure is Al(100nm)/TPD(xnm)/Alq(ynm)/LiF(0.5nm)/Al(25nm). While a thickness of total organic layer was varied from 85nm to 165n, a ratio of those two layers was kept to be about 2:3. Semitransparent Al cathode was varied from 20nm to 30nm for the device with an organic layer total thickness of 140nm. As the thickness of total organic layer increases, the emission spectra show a shift of peak wavelength from 490nm to 580nm, and the full width at half maxima from 90nm to 35nm. The emission spectra show a blue shift as the view angle increases. Emission spectra depending on a transmittance of semitransparent cathode show a shift of peak wavelength from 515nm to 593nm. At this time, the full width at half maximum was about to be a constant of 50nm. With this kind of microcavity effect, we were able to control the emission spectra from the top-emission organic light-emitting diodes.

• Transactions on Electrical and Electronic Materials
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• v.10 no.1
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• pp.28-30
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• 2009

We have studied organic layer-thickness dependent electrical and optical properties of bottom- and top-emission devices. Bottom-emission device was made in a structure of ITO(170 nm)/TPD(x nm)/$Alq_3$(y nm)/LiF(0.5 nm)/Al(100 nm), and a top-emission device in a structure of glass/Al(100 nm)/TPD(x nm)/$Alq_3$(y nm)/LiF(0.5 nm)/Al(25 nm). A hole-transport layer of TPD (N,N'-diphenyl-N,N'-di(m-tolyl)-benzidine) was thermally deposited in a range of 35 nm and 65 nm, and an emissive layer of $Alq_3$ (tris-(8-hydroxyquinoline) aluminum) was successively deposited in a range of 50 nm and 100 nm. Thickness ratio between the hole-transport layer and the emissive layer was maintained to be 2:3, and a whole layer thickness was made to be in a range of 85 and 165 nm. From the current density-luminance-voltage characteristics of the bottom-emission devices, a proper thickness of the organic layer (55 nm thick TPD and 85 nm thick $Alq_3$ layer) was able to be determined. From the view-angle dependent emission spectrum of the bottom-emission device, the peak wavelength of the spectrum does not shift as the view angle increases. However, for the top-emission device, there is a blue shift in peak wavelength as the view angle increases when the total layer thickness is thicker than 140 nm. This blue shift is thought to be due to a microcavity effect in organic light-emitting diodes.