• Journal of Communications and Networks
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• v.7 no.3
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• pp.248-257
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• 2005

In this paper, we develop design procedures for carrier tracking loop for orthogonal frequency division multiplexing (OFDM) systems or other systems of blocked data. In such communication systems, phase error measurements are made infrequent enough to invalidate the traditional loop design methodology which is based on analog loop design. We analyze the degradation in the OFDM schemes caused by the tracking loop and show how the performance is dependent on the rms phase error, where we distinguished between the effect of the variance in the average phase over the symbol and the effect of the phase change over the symbol. We derive the optimal tracking loop including optional delay in the loop caused by processing time. Our solution is general and includes arbitrary phase noise apd additive noise spectrums. In order to guarantee a well behaved solution, we have to check the design against margin constraints subject to uncertainties. In case the optimal loop does not meet the required margin constraints subjected to uncertainties, it is shown how to apply a method taken from control theory to find a controller. Alternatively, if we restrict the solution to first or second order loops, we give a simple loop design procedure which may be sufficient in many cases. Extensions of the method are shown for using both pilot symbols and data symbols in the OFDM receiver for phase tracking. We compare our results to other methods commonly used in OFDM receivers and we show that a large improvement can be gained.

• Biomedical Science Letters
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• v.20 no.3
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• pp.124-128
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• 2014

Alcoholism is a significant global health problem. Alcohol dehydrogenase and aldehyde dehydrogenase play important roles in the metabolism of alcohol and aldehyde. In this study, we aimed to investigate the eliminatory effects of a fruit extract drink on alcohol metabolism in drunken Sprague-Dawley (SD) rats. Male SD rats were given a fruit extract drink or a commercial product (10 mL/kg) 30 min prior to 40% (5 g/kg) ethanol ingestion. To assay the effect of the fruit extract drink on blood ethanol concentration, blood samples were taken from the saphenous vein at 3 and 5 h after ethanol ingestion. The blood concentrations of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase were significantly lower in the fruit extract drink group than in the control group, in a time-dependent manner. However, the alanine aminotransferase and aspartate aminotransferase activities of all experimental groups were unaltered compared to those of the control group. These results suggested that fruit extract drink intake can have a positive effect on the reduction of alcohol, alcohol dehydrogenase, and aldehyde dehydrogenase concentrations in the blood and may alleviate acute ethanol-induced hepatotoxicity by altering alcohol metabolic enzyme activities.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.99-102
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• 2002

The present study describes a numerical analysis for simulation of the sloshing of flows with free-surface which contained in a rectangular tank The SOLA-VOF (Volume of fluid) method uses a fixed mesh for calculating the motion of flow and the free-surface. This Eulerian approach enables the VOF method to use only a small amount of computer memory for simulating sloshing problems with complicated free-surface contours. The VOF function, representing the volume fraction of a cell occupied by the fluid, is calculated for each cells, which gives the locating of the free-surface filling any some fraction of cells with fluid. Using SOLA-VOF method, the study describes visualization about simulation of the sloshing of flows and damping effect by baffle. Translation and pitching motion of the forms have been investigated The time-dependent changes of free-surface height are used for visualization subject to several conditions such as fluid height horizontal acceleration, sinusoidal motion, and viscosity. The free-surface heights were used for comparing wall-force, which is caused by sloshing of flows. Baffle was Installed to reduce the force on the wall by sloshing of flows. Damping effects was extensively expressed under the conditions such as baffle shape and position.

• Advances in Traditional Medicine
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• v.7 no.4
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• pp.390-394
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• 2007

The present study was conducted to evaluate the analgesic activity of ethanolic extract of Andrographis paniculata (AP) in mice. The analgesic investigations were carried out using the acetic acid-induced abdominal writhing and the hot-plate tests. It was demonstrated that intraperitoneal (i.p.) administration of the extract at a dose of 30, 100, 300, 500 mg/kg, produced significant inhibition of abdominal constriction induced with 0.6% (v/v) acetic acid in dosedependent manner. It also demonstrated that the extract produced significant dose-dependent increase in the time of latency to a discomfort reaction in the hot-plate model. In addition, the analgesic effect of the ethanolic extract of AP was significantly reversed by a non-specific opioid receptor antagonist, naloxone. These results indicate that AP has an analgesic effect that was mediated through opioid receptors.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1125-1131
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• 2006

This study was undertaken to elucidate the effect of diallyl disulfide (DADS), an oil-soluble organosulfur compound found in garlic, in suppressing human nasopharyngeal carcinoma cells. A potent increase (of at least 9-fold) in apoptotic cells has accompanied 1) a decrease in cell viability, 2) a increase of the fraction of S-phase cells by up to 63.8%, and 3) a transient increase of the phospho-p38 and phospho-p42/44 (phosphorylated p38 MAPK and phosphorylated p42/44 MAPK) in a time-and concentration-dependent manner. These results indicate that DADS can induce apoptosis in human nasopharyngeal carcinoma cells via, at least partly, S-phase block of the cell cycle, related to a rise in MAPK phosphorylation.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.1220-1225
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• 2009

A manipulator is operated for the motion of mechanical hands or arms. When a cup including liquid inside is shifted by a manipulator, it is important to know how a free surface of the liquid moves. In this study, non dimensional parameters have been found that affect the rise of the free surface in a cup moving with constant acceleration. The non-dimensional parameters are the dimensionless time, the ratio of inertia effect to viscous effect (the Reynolds number), aspect ratio of the liquid inside the cup and the acceleration ratio (the Froude number). Through this study, the height of the free surface rise in a cup has been predicted and the detailed velocities in the liquid have been examined. Generally, the maximum rise of the free surface is dependent on the Reynolds number and Froude number strongly, but on the aspect ratio weakly. However, the influence of the aspect ratio on the maximum rise of the free surface is not negligible in the range of 10 < Re < 100.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.172-172
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• 1999

Perovskite Manganese Oxide has been intensively investigated since the discovery of the colossal magnetoresistive(CMR) effect. In this paper, we studied the effect of temperature dependence and various doping dependence of rare earth site ions of La0.7-xPrxCa0.3MnO3 series using Ultraviolet Photoelectron spectroscopy(UPS). They show unusual temperature dependent features and the doped rare earth ions seem to affect the electron-phonon coupling strongly. We found clear evidence of metal-insulator transition from the spectral density at the Fermi level. but the transition temperature is lower than that deduced from transport measurements. Also we found that the spectral features change as time goes on implying that the surface of these materials is somewhat unstable in the vacuum. We can conclude from these results that the surface oxygen atoms correlated to the hopping electrons can escape from the material into the vacuum and that the surface state of these material is different from the bulk state.

• Journal of Hydrogen and New Energy
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• v.24 no.6
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• pp.495-509
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• 2013

In this study, we develop a one-dimensional (1-D), two-phase, transient-thermal DMFC model to investigate the effect of methanol concentration fluctuation that usually occurs in active-type direct methanol fuel cell (DMFC) systems. 1-D transient simulations are conducted and time-dependent behaviors of DMFCs are analyzed under various DMFC operating conditions such as anode/cathode stoichiometry, cell temperature, and cathode inlet humidification. The simulation results indicate that the effect of methanol concentration fluctuation on DMFC performance can be mitigated by proper control of anode/cathode stoichiometry, providing a guideline to optimize operating conditions of active DMFC systems.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.15
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• pp.6075-6080
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• 2014

Lung cancer is the leading cause of cancer-related death worldwide. Here we investigated the antitumor effect and mechanism of Zhejiang (Huzhou and Jiande) saffron against lung cancer cell lines, A549 and H446. Using high performance liquid chromatography (HPLC), the contents of crocin I and II were determined. In vitro, MTT assay and annexin-V FITC/PI staining showed cell proliferation activity and apoptosis to be changed in a dose- and time-dependent manner. The inhibition effect of Jiande saffron was the strongest. In vivo, when mice were orally administered saffron extracts at dose of 100mg/kg/d for 28 days, xenograft tumor size was reduced, and ELISA and Western blotting analysis of caspase-3, -8 and -9 exhibited stronger expression and activity than in the control. In summary, saffron from Zhejiang has significant antitumor effects in vitro and in vivo through caspase-8-caspase-9-caspase-3 mediated cell apoptosis. It thus appears to have more potential as a therapeutic agent.

• Polymer(Korea)
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• v.24 no.1
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• pp.23-28
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• 2000

Autoadhesion strength of PS/PS Interfaces in solvent welding was determined as a function of processing conditions by butt joint test. It was verified that the chain mobility and surface roughness at PS/PS interface were enhanced by the applied solvent having a similar solubility parameter as PS and resulted in the dramatic improvement of autoadhesion strength at PS/PS interface. It was found that the mechanism of solvent welding is dependent upon the chain mobility due to the diffusion of solvent to PS interface and the contact area at interface. When the welding temperature is lower than the boiling point of applied solvent, the effect of chain mobility on autoadhesion strength was dominated, while contact area took more important role when welding temperature is above the boiling point of solvent. Autoadhesion strength increased with increasing contact time and contact temperature but :he effect of solvent on autoadhesion strength became smaller.