• 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.

• Journal of the Ergonomics Society of Korea
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• v.30 no.5
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• pp.629-636
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• 2011

Objective: The aim of this study is developing an elderly automatic showering system by optimizing nozzle position and angle of water injection on ergonomics approach. Background: The elderly living in nursing home or hospital were increased by an aging population. Helping the elderly on showering is so hard. In addition, the existing showering/bathing systems are not effective because shower pattern of the elderly and washed range of nozzle were not considered. Method: Firstly, basic specification were determined by anthropometric approach. Secondly, position of nozzle and angle of water injection were determined through observation of elderly behavior on showering. And, finally, they were optimized by washing test and showering simulation. Results: On showering importance of body parts were able to analysis through observation of elderly behavior. The position of nozzle and angle of water injection was able to optimize by showering simulation. The automatic showering system was developed by considering their results. Conclusion: The most important technology of developing a showering system is the determining position of nozzle and angle of water injection, number of nozzle. It was developed by applying its results through user centered-research. Application: The user centered-research of developing products was able to apply directly to develop automatic bath, showering products etc. Further more it was available to apply senior friendly products.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.11
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• pp.1227-1232
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• 2014

This paper relates 10% shrink from $0.13{\mu}m$ design for core devices as well as input and output (I/O) devices different from previous poly length shrink size only. We analyzed body effect with different channel length and doping profile simulation. After fixing the gate oxide module process, LDD implant conditions were optimized such as decoupled plasma nitridation of gate oxide, TEOS oxide $100{\AA}$ before LDD implant and 22o tilt-angle(45o twist-angle) LDD implant respectively to match the spice DC parameters of pre-shrink and finally matched them within 5%.

• Korean Journal of Remote Sensing
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• v.18 no.2
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• pp.91-96
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• 2002

The performance characteristics of a satellite imager using a Time Delay and Integration(TDI) Charge Coupled Device (CCD) with fixed integration time is investigated for the variation of satellite altitude and tilt angle. In consequence of the investigation TDI synchronization using tilt imaging is proposed as a solution to compensate geometric performance degradation due to altitude decrease. The tilt angle optimized for the TDI synchronization at decreased altitude is presented. This result can be used for a TDI CCD imager with variable integration time in a certain range as well.

• Journal of the Korea Society for Simulation
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• v.28 no.3
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• pp.83-89
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• 2019

This research describes quantitative effects of initial dispersion conditions upon the dispersion randomness of Magnus rotor bomblets. Ratios of the missile spin rate to the missile velocity, a, flight path angles, ${\gamma}$ and altitudes, h, were changed to investigate their effects on dispersion randomness. Dispersion was analyzed through calculation of 6 degree of freedom motion equation with aerodynamic coefficients from wind tunnel experiments. In order to analyze the randomness, regression analysis is adopted to calculate the coefficient of determination. The optimized ratio of the missile spin rate to the missile velocity and flight path angle were obtained and the dispersion altitudes had more effect on the dispersion diameter and had less effect on dispersion than other parameters.

• Journal of Korea Multimedia Society
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• v.23 no.12
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• pp.1565-1575
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• 2020

This study examines the game balance of the MOBA game genre, which was selected as a model item for the Asian Games. The "bird-eye view" was used for a more efficient representation of 3D modeling. Based on that, statistical analysis was conducted to present appropriate game camera settings and camera balance to match the competitive structure of the MOBA game. A review of the game camera settings reveals that 64° to 70° is the angle that minimizes the difference in vision between the two-player teams the most. Through a one-way ANOVA analysis, we found that the user ranking level and SVB value are closely related. Therefore, the factor of the regression equation using the SVB value must have a user ranking level. As a result of the optimized camera focus analysis of , the camera setting methods were classified into 3 types. For main action games, the recommended camera angle is 64°~66°, and the recommended camera focus is 11.2 mm~19.3 mm. For action and strategy games, the camera angle is 66°~68°, camera focus - 19.3 mm~27.3 mm. And lastly, for the main strategy game, the recommended camera angle is 68°~70°, and the camera focus is 27.3 mm~35.3 mm.

• Aerospace Engineering and Technology
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• v.9 no.1
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• pp.78-83
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• 2010

In the present paper, a flap was optimized to maximize the lift. A 2-element fowler flap system was utilized for optimization with an initial shape of general aviation airfoil and a flap shape designed by Wentz. Response surface method and Hicks-Henne shape function were implemented for optimization. 2-D Navier-Stokes method was used to solve flow field around aGA(W)-1 airfoil with a fowler flap. Commercial programs including Visual-Doc, Gambit/Tgridand Fluent were used. Upper surface shape and the flap gap were optimized and lift for landing condition was improved considerably. The original and optimized flaps were tested in the KARI's 1-m low speed wind tunnel to examine changes in aerodynamic characteristics. For optimized flap tests, the similar trend to prediction could be seen but stall angle of attack was lower than what was expected. Also, less gap than optimized design delayed stall and produced better lift characteristics. This is believed to be the effect of turbulence model.

• Journal of Photoscience
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• v.7 no.2
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• pp.67-71
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• 2000

A quantum-chemical investigation on the conformations and electronic properties of trans(diphenyl-diheterocyclic) ethenes(t-PHEs) as building block for fully $\pi$-conjuated polymer are performed in order to display the effects of heterocyclic ring substitution. Structures for the molecules, t-PHEs were fully optimized by using semiempirical AM1, PM3 methods, and ab initio HF methods, with 6-31G basic set. The potential energy curves with respect to the change of single are obtained by using ab initio HF/6-31G basic set. The curves are not similar shapes in the molecules with respect to heterocyclic rings. It is shown that the steric repulsion interactions between phenyl ring and heterocyclic ring are subjected to different type with the respect to each heterocyclic ring. Electronic properties of the molecules were molecules were obtained by applying the optimized structures and selected geometries to the extended Huckel method. To investigate the change of HOMO-LUMO gap with respedt to the torsion angle, we select the optimized structures. By using the results, the dependency of conjugation for the energy gaps is analyzed. For t-PHE the energy gap increase up to 0.52 eV compared with its planar structure. In the cases of t-PHE and t-PHE, the energy gap increase by 1.29 and 1.15 eV, respectively, compared with its planar structure.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.397-400
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• 2011

MDO Optimization for a low pressure axial compressor rotor has been carried out to improve aerodynamic performance and structural stability. Global optimized solution was obtained from an artificial neural network model with genetic algorithm. Optimized rotor model has a high blade loading near hub and near zero incidence flow angle near tip region to reduce the incidence loss and flow separation at trailing edge region. Also the rotor shape is converged to a trapezoid shape to reduce the maximum stress occurred at the root of the blade. Numerical simulation results show that rotor has 87.6% rotor efficiency and safety factor over than 3.

• ETRI Journal
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• v.45 no.6
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• pp.1056-1064
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• 2023

The optical properties of the materials composing organic light-emitting diodes (OLEDs) are considered when designing the optical structure of OLEDs. Optical design is related to the optical properties, such as the efficiency, emission spectra, and color coordinates of OLED devices because of the microcavity effect in top-emitting OLEDs. In this study, the properties of top-emitting blue OLEDs were optimized by adjusting the thicknesses of the thin metal layer and capping layer (CPL). Deep blue emission was achieved in an OLED structure with a second cavity length, even when the transmittance of the thin metal layer was high. The thin metal film thickness ranges applicable to OLEDs with a second microcavity structure are wide. Instead, the thickness of the thin metal layer determines the optimized thickness of the CPL for high efficiency. A thinner metal layer means that higher efficiency can be obtained in OLED devices with a second microcavity structure. In addition, OLEDs with a thinner metal layer showed less color change as a function of the viewing angle.