• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.6
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• pp.1576-1586
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• 1996

The subject of this paper is the analysis of a Wire-TEM cell(W-TEM cell) which has an inner wire array rather than a metallic septum;its basic structure is similiar to a NBS TEM cell. To verify improved performances of this W-TEM cell as a standard EM field generator, well-known quasi-static approximations are employed and their resultant ingegral equations are numerically analyzed by moment method. Although the electric field strength of a W-TEM cell is 1.4 dB lower than tht of a NBS TEM cell, the uniformity of EM field patterns in a W-TEM cell is improved. It is also shown that the EM field distortions resulting from loading by the conditing objects under test(loading effects), are decreased considerably. This paper also deals with the investigations about relationship between the EM field distributions and the number of wire composing the inner conductor. Finally, the experimental analysis is performed on the practical model which is built on the basis of the design variables brought out by the theoretical andnumerical analysis.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.1
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• pp.65-70
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• 2013

A 0.18-${\mu}m$ 3.3 V grounded-gate NMOS (GGNMOS) I/O cell array for timing controller (TCON) application is proposed for improving electrical overstress (EOS) robustness. The improved cell array consists of 20 GGNMOS, 4 inserted well taps, 2 end-well taps and shallow trench isolation (STI). Technology computer-aided design (TCAD) simulation results show that the inserted well taps and extended drain contact gate spacing (DCGS) is effective in preventing EOS failure, e.g. local burnout. Thermodynamic models for device simulation enable us to obtain lattice temperature distributions inside the cells. The peak value of the maximum lattice temperature in the improved GGNMOS cell array is lower than that in a conventional GGNMOS cell array. The inserted well taps also improve the uniformity of turn-on of GGNMOS cells. EOS test results show the validity of the simulation results on improvement of EOS robustness of the new GGNMOS I/O cell array.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.132-145
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• 1991

Experimental studies are made of the characteristics of turbulent flow around the propeller shaft in Cavitation Tunnel using a 2-component LDV system. First the flow uniformity and turbulence levels at the test section are measured. The turbulent boundary layer around the propelle shaft and the wakes behind the propeller shaft are also measured. It is shown that the former represents the general turbulent boundary layer around the propeller shaft but the latter represents the complicated flows behind it.

• Korean Journal of Optics and Photonics
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• v.10 no.3
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• pp.259-264
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• 1999

The relationship is derived for color CRT display system between the spectral radian existence emitted and digital inputs. The amount of spectral radiant existence depends on the characteristics of the video board, electric circuits, and CRT as well as digital inputs. Especially, the function of this relationship changes as the amplifier gain and offset voltage of electric circuits. In this study, we set the test display system on the optimum state which satisfies gun independence characteristics by using the contrast and the brightness controls of display. Temporal stability, special uniformity, and color distinction of CRT display system are evaluated at the optimum state. Also contrasts in dark room and illuminated room are compared.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.24-31
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• 1999

The MPI engine becomes increasingly popular because it meets two requirements of stringent pollutant emission and the lower fuel consumption. Even though supplies the same amount of fuel to each cylinder , it is hard to precisely control the air-duel ration due to the different amount of air flowing into each cylinder. The uniformity of air-fuel ration in each cylinder is considerably affected by the plenum chamber configuration . This study is focused on experimentally analyzing the flow characteristics within the plenum chamber In the present experiment , steady and valve dynamic state flow tests are performed and the flow field inside the plenum chamber is visualized and measured by utilizing a laser sheet visualization technique and a PTV method. These measured results indicate that the flow structure in the plenum chamber is highly influenced by the plenum chamber configurations, suction flow rates, crank speeds and so on.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2221-2226
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• 2009

This paper presents the design of the LED sign board system installed on the exterior of a building and powered by a photovoltaic system. A grid connected photovoltaic system has been designed with the capacity estimate of the load, battery and power. After the luminance and uniformity of LED load has been checked, the sign board and the solar cell modules have been installed. The performance and problems occurred during the field test for the photovoltaic LED sign board system have been analyzed.

• Current Optics and Photonics
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• v.2 no.5
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• pp.407-412
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• 2018

An optimal matching approach is proposed to maximally ensure the output power uniformity of the cascaded encoder in the passive optical network (PON) monitoring system based on a remote coding scheme. The calculation results show that the optimum arrangement can effectively reduce the difference of the total insertion loss in comparison to the random arrangement (i.e., 0.07 dB vs 2.67 dB in the cascaded encoder with 16 output ports). The proposed approach realizes the optimum configuration for the $1{\times}2$ optical splitters used without adding any extra components. The test results of the fabricated cascaded encoder with 32 output ports prove the feasibility of the proposed approach.

• Journal of the Korean institute of surface engineering
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• v.53 no.6
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• pp.322-329
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• 2020

The utilization of aluminum scrap is a subject of great importance in terms of reducing energy consumption and environmental protection. However, aluminum scrap contains impurities, which can degrade the properties of aluminum alloy, especially corrosion resistance. This study examines the effect of scrap charge rate of aluminum alloys about microstructures and corrosion characteristics. According to the metallographic examinations, Mg2Si tended to become coarser and its uniformity was decreased by increasing aluminum scrap charge rate. The immersion test exhibited corrosion progressed through the eutectic areas due to micro-galvanic interactions. Electrochemical measurements revealed that excess aluminum scrap could reduce the intergranular corrosion resistance of aluminum alloys. Results showed that the scrap charge rate is important factor in the design of corrosion resistance of aluminum die casting alloys.

• Culinary science and hospitality research
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• v.24 no.1
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• pp.96-104
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• 2018

The purpose of this study was to promote consumption of rice through production of jeungpyun added with blueberry attracting attention as a functional food material and to develop a functional blueberry supplement suited to the preference of Westernized consumers. For that pupose, we performed physicochemical quality test and sensory test after preparing the jeungpyun added with blueberry powder based on a ratio of 1%, 2%, 3%, and 4% of rice flour. The results of this experiment can be summarized as follows. When the addition of blueberry powder increased, the moisture content in jeungpyun decreased, but there was no significant difference between the samples. The lightness and the yellowness related to chromaticity decreased and redness increased when the addition of blueberry powder increased. The pH of the dough in jeungpyun increased significantly (p<0.001) when addition of blueberry powder increased. As the fermentation progressed, the pH tended to decline. The volume of dough decreased when addition of blueberry powder increased. The volume was the highest after the first fermentation, and decreased after the second fermentation. Viscosity decreased significantly as the addition of blueberry powder increased, and increased as fermentation time increased, and decreased after the third fermentation. A test was conducted to determine difference in characteristics, and the results showed that the color intensity, cell uniformity, blueberry flavor and sweetness were strong when the addition of blueberry powder increased. The results of preference test showed that JB3 containing 3% blueberry powder had the best appearance, flavor and overall acceptance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.96-99
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• 1993

Electrical properties of the Thin Film Transistor(TFT) electrode metal films were investigated through the Test Elements Group(TEG) experiment. The main purpose of this investigation was to characterize the electrical resistance properties of patterned metal films with respect to the variations of film thickness and TEG metal line width. Aluminum(Al), Tantalum(Ta) and Chromium(Cr) that are currently used as TFT electrode films were selected as the probed metal films. To date, no work in the electrical characterizations of patterned electrodes of a-Si TFT was accomplished. Bulk resistance$(R_b)$, sheet resistance$(R_s)$, and resistivities($\rho$) of TEG patterned metal lines were obtained. Electrical continuity test of metal film lines was also performed in order to investigate the stability of metallization process. Almost uniform-linear variations of the electrical properties with respect to the metal line displacements was also observed.