• Journal of Korean Society of Transportation
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• v.16 no.3
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• pp.7-14
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• 1998

터널의 경우 도로교통용량이 일반구간에 비해 감소하는 것으로 나타나고 있다. 그러나 연속되는 터널의 경우에 있어 도로교통용량감소에 대한 연구는 아직 이루어지지 않고 있다. 본 연구에서는 고속도로의 2지점에서 연속되는 터널의 도로교통용량의 감소특성을 이용한 터널보정계수를 산정하여 다음과 같은 결과를 도출하였다. (1) 터널을 통과하는 경우의 도로교통용량은 통과전보다 감소하는 것을 알 수 있으며, 연속되는 터널을 통과하는 경우 감소량은 이보다 큰 것으로 나타났다. (2) 터널보정계수$(f_{tu})$를 도출한 결과 하나의 터널을 통과하는 경우의 터널보정계수$(f_{tu1})$는 0.95, 연속되는 터널을 통과하는 경우의 터널보정 계수$(f_{tu2})$는 0.90으로 산정되었다.

• YAKHAK HOEJI
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• v.39 no.5
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• pp.541-547
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• 1995

In order to investigate the usability of PALMIWON as antidiabetic immuno-modulating prescription for Insulin-dependent diabetes, we studies the effects of PALMIWON on immune cell and ${\beta}-cell$. U937 was used as the model of immune cell and RINm5F as the model of ${\beta}-cell$. The effects of PALMIWON was measured by cell viability in terms of MIT assay. As a result, PALMIWON and the compositional drugs showed the different effects m immune cell and ${\beta}-cell$. Cell viability of U937 was significantly decreased wheras that of RINm5F was no significantly difference between drug treated group and control, or significantly less reduction compared with U937. It implies that PALMIWON is useful as immunotherapeutic agents in the prevention and therapy of type 1 diabetes.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.287.1-287.1
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• 2003

F$_2$-isoprostanes are derived in vivo principally from the formation of positional peroxyl radicals of arachidonic acid, endocyclization to prostaglandin G$_2$-like structures, and reduction to PGF$_2$-like compounds. F$_2$-isoprostanes have been proposed as biomarkers of lipid peroxidation, oxidative stress status, and oxidation of low density lipoprotein (LDL) in atherogenesis. Especially, elevated 8-iso-PGF$\sub$2a/ is known as a useful clinical biomarker of oxidative stress in-end stage renal disease (ESRD) patients receiving hemodialysis (HD). (omitted)

• Proceedings of the Korean Society of Laser Processing Conference
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• 2006.11a
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• pp.21-24
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• 2006

• International Journal of Automotive Technology
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• v.3 no.1
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• pp.41-46
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• 2002

Effect of secondary air injection (SAI) on hydrocarbon reduction has been investigated in a single cylinder Sl engine operating at cold-steady/cold-start conditions. The hydrocarbon emission and exhaust gas temperature with and without catalytic converter were compared with continuous and synchronized SAIs, which injected secondary air intermittently into exhaust port. Effects of SAI location, SAI pressure, SAI timing, and location of catalytic converter have been investigated and the results are compared for both SAls with base condition. At cold-steady condition, the rate of HC reduction increased as the location of SAI was closer to the exhaust valve for both synchronized and continuous SAls. The emission of HC decreased with increasing exhaust-A/F when it was rich, and was relatively insensitive when it was lean. The timing of SAI in synchronized SAI had significant effect on HC reduction and exhaust gas temperature and the synchronized SAI was found to be more effective in HC reduction and exhaust gas temperature compared to the continuous SAI . At cold-start condition, when the catalytic converter was located 20 cm downstream from the exhaust port exit, the catalytic converter warm-up period for both SAls decreased by about 50%, and the accumulated hydrocarbon emission during the first 120 s decreased about by 56% and 22% with the synchronized and continuous SAIs, respectively, compared to that of the base condition.

• Journal of the Korean Electrochemical Society
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• v.8 no.2
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• pp.106-114
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• 2005

This article covers the theoretical ac-impedance models for the analysis of oxygen reduction on the porous cathode electrode f3r solid oxide fuel cell (SOFC). Firstly, ac-impedance models were explained on the basis of the mechanism of oxygen reduction, which were classified into the rate-determining steps; (i) adsorption of oxygen atom on the electrode surface, (ii) diffusion of adsorbed oxygen atom along the electrode surface towards the three-phase (electrode/electrolyte/gas) boundaries, (iii) surface diffusion of adsorbed oxygen atom m ixed with the adsorption reaction of oxygen atom on the electrode surface and (iv) diffusion of oxygen vacancy through the electrode coupled with the charge transfer reaction at the electrode/gas interface. In each section for ac-impedance model, the representative impedance plots and the interpretation of important parameters attributed to the oxygen reduction reaction were explained. Finally, we discussed in detail the applications of the proposed theoretical ac-impedance models to the real electrode of SOFC system.

• Wind and Structures
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• v.4 no.6
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• pp.505-518
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• 2001

Shantou Bay Bridge is the first long-span suspension bridge in China. Because of its location near the Shantou Seaport and its exposure to high typhoon winds, wind-resistant studies are necessary to be made. In this paper, critical flutter wind speeds and buffeting responses of this bridge at its operation and main construction stages are investigated. The Buffeting Response Spectrum method is first briefly presented. Then the sectional model test is carried out to directly obtain the critical flutter wind speed and to identify the flutter derivatives, which are adopted for the later analysis of the buffeting responses using the Buffeting Response Spectrum method. Finally the aeroelastic full bridge model is tested to further investigate the dynamic effects of the bridge. The results from the tests and the computations indicate that the flutter and buffeting behaviors of the Shantou Bay Bridge are satisfied.

• The Journal of the Acoustical Society of Korea
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• v.26 no.3E
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• pp.87-96
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• 2007

In this paper we propose a new noise reduction algorithm for stationary and nonstationary noisy environments. Our algorithm classifies the speech and noise signal contributions in time-frequency bins, and is not based on a spectral algorithm or a minimum statistics approach. It relies on calculating the ratio of the standard deviation of the noisy power spectrum in time-frequency bins to its normalized time-frequency average. We show that good quality can be achieved for enhancement speech signal by choosing appropriate values for ${\delta}_t\;and\;{\delta}_f$. The proposed method greatly reduces the noise while providing enhanced speech with lower residual noise and somewhat higher mean opinion score (MOS), background intrusiveness (BAK) and signal distortion (SIG) scores than conventional methods.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.4
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• pp.651-656
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• 1999

In current animal production in Japan, a large surplus of nitrogen and phosphorus is given to animals as their feed which are mostly imported from outside of our own country. Today, an excess of nitrogen and phosphorus from animal manure has been spread out of the area of animal production and the surroundings. These components have become the major reason for eutrophication of ground, surface and inland water. Nutritional studies for the reduction of nitrogen and phosphorus from animal waste has been done by many researchers. The reduction of excess protein in animal feed and the supplementation of deficient essential amino acids to feed have a possibility to increase the biological value of feed and to reduce nitrogen excretion, especially, via urine. The use of phytase activity to degrade phytate and to release utilizable inorganic phosphorus make it possible to cut an excess supply of feed additive inorganic phosphorus and to reduce phosphorus excretion from animal waste.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.52 no.12
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• pp.608-615
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• 2003

This paper describes an implementation of a DSP (Digital Signal Processor) controlled random carrier frequency modulation for the PWM inverter for acoustic noise reduction of induction motors. Real-time generation of the random variable and RPWM(Random PWM) along with the speed control was achieved by DSP TMS320C31. The experimental results show that the voltage and current harmonics are spread to a wide band area and the power spectrum of the acoustic switching noise was spread to create a more appealing, less annoying sound. Also, the speed response of the implemented method and the conventional method is nearly similar to each other from the viewpoint of the v/f constant control.