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Yoshida Y.,A1288 Project Team | Nakagawa S.,A1288 Project Team | Yoshida A.,Digital Systems | Yoshiyama K.,A1288 Project Team | Furukawa H.,Corporate Research and Development Division
Shapu Giho/Sharp Technical Journal | Year: 2015

In this paper, we analyze the resolution characteristics of multi-primary color (MPC) display systems. We demonstrate that four-primary (4 PC) displays can increase the effective resolution for achromatic images in the luminance domain by a factor of two as compared to conventional RGB-based displays with MPC-specialized sub-pixel rendering, which we propose in this paper. Five- and six-primary color (5PC and 6PC) display system can reproduce denser luminance data than conventional RGB-based display systems and solve a problem of MPC displays, viz. increase of production costs and decrease of the aperture ratio caused by increasing the number of sub-pixels in one pixel. This is an essential advantage of MPC display systems, which is related to the combination of our proposed color filter architecture and image processing: so, we propose a completely new advantage of MPC display systems in addition to their well-known capabilities of color reproduction and power-saving. Source

Lee S.-Y.,Korea Institute of Science and Technology | Kim H.-J.,Korea Institute of Science and Technology | Cho E.,Korea Institute of Science and Technology | Lee K.-S.,Korea Institute of Science and Technology | And 3 more authors.
International Journal of Hydrogen Energy | Year: 2010

When the temperature of a fuel cell vehicle is repeatedly reduced to subzero temperatures, volume changes by water/ice transformations and frost heave mechanism can cause microstructural changes in membrane-electrode assemblies (MEA), and a resultant permanent decrease in the performance of fuel cell stacks. In this study, five MEAs manufactured by different methods, were tested under repeated freeze-thaw (F-T) cycles between -20 °C and 10 °C, and the variations in their electrochemical and microstructural characteristics were analyzed according to the initial microstructures. When the MEAs were prepared by spraying catalyst inks on polymer membranes, no significant microstructural changes were observed. In the case of two supplied MEAs, void formations at the electrolyte/electrode interface or vertical cracks within the catalyst layers were observed after 120 F-T cycles. Void formation seems to be responsible for performance degradation as a result of ohmic loss, but the effect of cracks in the catalyst layers was not confirmed. In 120 F-T cycles, activation overpotentials and concentration overpotentials did not increase significantly for any of the MEAs, even although gradual decreases in the electrochemically active surface area of the platinum catalysts and changes in the porous structure were observed. © 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. Source

Lim M.-S.,Hanyang University | Chai S.-H.,Hanyang University | Yang J.-S.,Corporate Research and Development Division | Hong J.-P.,Hanyang University
IEEE Transactions on Industrial Electronics | Year: 2015

This paper proposes the design process of a 2.62-kW 150-krpm high-speed surface-mounted permanent-magnet synchronous motor. To meet the required specifications, the numbers of poles and slots were determined by considering the maximum speed and the rotary stability affected by the vibration of the rotor. In addition, this paper describes not only the appropriate material selection method but also the appropriate geometry design method based on analytic approaches. Furthermore, to precisely evaluate the bearing and windage losses at a high speed, a method that combines the finite-element method and the experiment results of the prototype was used. As a result, an improved motor was designed, which had higher maximum power and speed than the prototype and a lower mass moment of inertia. Finally, tests were conducted to verify the validity of the proposed design process and the effectiveness of the motor. © 1982-2012 IEEE. Source

Kim D.W.,Seoul National University | Cho I.-S.,Seoul National University | Lee S.,Seoul National University | Bae S.-T.,Corporate Research and Development Division | And 4 more authors.
Journal of the American Ceramic Society | Year: 2010

Ag-based oxides, Ag2M2O7 (M=Mo, W) with a triclinic structure, were prepared using a conventional solid-state reaction method, and their band structures and photocatalytic properties were investigated. From the electronic band structure calculations, Ag 2Mo2O7 had an indirect band gap of 2.65 eV, whereas Ag2W2O7 had a direct band gap of 3.18 eV. Moreover, the calculated electron affinities were 4.75 eV for Ag 2Mo2O7 and 4.62 eV for Ag2W 2O7. The smaller band gap and higher electron affinity of Ag2Mo2O7 than those of Ag2W 2O7 originated from the contribution of the unoccupied Mo 4d orbital to the conduction band, which was positioned at a lower energy level than the W 5d orbital. The effects of the different band structure characteristics in Ag2M2O7 (M=Mo, W) on the photocatalytic activity were investigated by the degradation of a Rhodamine B dye solution under visible light irradiation. The results showed that the photocatalytic activity of Ag2Mo2O7 was much higher than that of Ag2W2O7 and comparable with a well-known WO3 powder. The higher photocatalytic property of Ag2Mo2O7 was attributed to its higher optical absorption ability and lower charge recombination rate. © 2010 The American Ceramic Society. Source

Noh Y.,Corporate Research and Development Division | Byun G.,Hongik University | Ahn S.,Hongik University | Choo H.,Hongik University
SAE 2011 World Congress and Exhibition | Year: 2011

We propose an on-glass antenna with vertical lines for FM radio reception in a commercial sedan. The proposed antenna consists of vertical lines and multiple horizontal lines that are also used as defroster lines. The proposed antenna structure is optimized with the GA algorithm in conjunction with the FEKO EM simulator. The optimized antenna was built and installed on an Azera test vehicle (Korean model: TG Grandure 270) from Hyndai-Kia Motors and antenna performances such as reflection coefficients, and bore-sight gain are measured in an anechoic chamber. The optimized antenna shows a half power matching bandwidth of 26 % at the center frequency of the FM radio band and an average bore-sight gain of about -10.37 dBi. Then, we take a field test to measure actual received power of FM radio signals. The field test result shows the antenna's minimum received power level of about -80 dBm. The overall measured data show that the optimized antenna can be used as a FM antenna for vehicles. © 2011 SAE International. Source

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