• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.64-70
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• 2003

Jaeumgenby-tang(JGT) have been used in oriental medicine for many centuries as a therapeutic agent of vertigo caused by deficiency of qi(氣) and blood(血). Effect of Aurantii Fructus(AF) take off the phlegm by promoting the circulation of qi, Gastrodae Rhizoma(GR) has effects treating for headache, vertigo by calming the liver and suppressing hyperactivity of the liver-yang(陽). And, I designed to investigate whether injection of JGT adding AFㆍGR extract(JGTAG) affects cytotoxicity in vitro, cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP)] in normal and cerebral ischemia rats by MCA occlusion method. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. The results were as follows in normal rats; JGTAG was not cytotoxicity in brain cells. And JGTAG was significantly increased rCBF, PAD and MABP. This results suggest that JGTAG increased significantly rCBF by dilating PAD. And the results were as follows in cerebral ischemic rats; The changes of rCBF and PAD were increased stably by treatment with JGTAG(10mg/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with propranolol and indomethacin were increased JGT AG induced increase of rCBF and PAD during the period of cerebral reperfusion. We suggest that JGTAG has an anti-ischemic effect through the improvement of cerebral hemodynamics.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.5
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• pp.1063-1070
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• 1988

The influence of the inlet pressure on bearing performance of tilting pad bearings in laminar regime is examined. A simple flow model is presented to calculate the inlet pressure in inlet flow that occurs at a short distance ahead of the bearing inlet. The bearing performances are obtained, load capacity, friction torque and lubricated flow-rate, etc, numerically for the inlet pressure boundary conditions with and without pressure jump. The computed results of both cases show that bearing performance and the optimum pivot position changes remarkably according to the bearing operating conditions. The influence of the inlet pressure on bearing performance must be considered to analyze the bearing performance precisely.

• Tribology and Lubricants
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• v.27 no.5
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• pp.269-274
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• 2011

The purpose of this paper is to study and analyze the improvement method for the failure examples including the vehicle brake system in actual field. It was verified that the indicator plate of pad wear scratched the brake disk because of wearing after displacement of non- identification parts pad. The caliper of other vehicle was installed with brake system verified the phenomenon produced groove in center point because of one side wear when the pad was not fully contacted with the rub disk by other action surface pressure and pad action condition. It verified that the crack phenomenon fatigue was produced by brake thermal deformation because of decreasing the thickness by grinding to modify the non-uniformed wear of brake disk. It verified that the friction sound was produced by the friction phenomenon because of non-uniformed contact of lining and an alien substance with inner of the drum and lining braking by crack phenomenon with brake drum surface.

• The Journal of Internal Korean Medicine
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• v.26 no.3
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• pp.596-604
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• 2005

Objectives : Geopungjeseub-tang(Gufengchushi-tang) has been used in oriental medicine for many centuries as a therapeutic agent for hemiplegia caused by deficiency of qi(氣虛) and damp phlegm(濕痰). This study was performed to evaluate effects of Geopungjeseub-tang extract(GJT) on hemodynamics[regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure(MABP), heart rate(HR)] in normal rats and in rats with cerebral ischemia by middle cerebral artery(MCA) occlusion. Also, effects of adrenergic ${\beta}-receptor$, cyclooxygenase on response to GJT were evaluated. Methods : Laser-doppler flowmetry(LDF) measured changes of rCBF, MABP and HR. Video microscope and width analyzer measured changes in PAD. Results : rCBF and PAD increased after treatment with GJT(10mg/kg, i.v.) during the period of cerebral reperfusion, and pretreatment with indomethacin raised rCBF and PAD increased after treatment with GJT during the same period as above. Pretreatment with propranolol decreased rCBF, but increased after GJT treatment, but raised PAD increased after GJT treatment during this period of reperfusion. Conclusion : CR caused diverse responses were observed in rCBF and PAD after treatment with GJT. ACF action is mediated by adrenergic ${\beta}-receptor$ and cyclooxygenase. Result suggest that GJT has an anti-ischemic effect through the improvement of cerebral hemodynamics and has theraputic potential for cerebral apoplexy.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.86-89
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• 2003

Chemical Mechanical Planarization(CMP) has been accepted as the most effective processes for ultra large scale integrated (ULSI) chip manufacturing. However, as the polishing process continues, pad pores get to be glazed by polishing residues, which hinder the supply of new slurry. And pad surface is ununiformly deformed as real contact distance. These defects make material removal rate(MRR) decrease with a number of polishied wafer. Also the desired within-chip planarity, within wafer non-uniformity(WIWNU) and wafer to wafer non-uniformity(WTWNU) arc unable to be achieved. So, pad conditioning in CMP Process is essential to overcome these defects. The eletroplated or brazed diamond conditioner is used as the conventional conditioning. And. allumina long fiber, the jet power of high pressure deionized water, vacuum compression. ultrasonic conditioner aided by cavitation effect and ceramic plate conditioner are once used or under investigation. But. these methods arc not sufficient for ununiformly deformed pad surface and the limits of conditioning effect. So this paper focuses on the characteristics of diamond conditioner which reopens glazed pores and removes ununiformly deformed pad away.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.179-184
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• 2000

Chemical Mechanical Polishing (CMP) refers to a material removal process done by rubbing a work piece against a polishing pad under load in the presence of chemically active and abrasive containing slurry. CMP process is a combination of chemical dissolution and mechanical action. The mechanical action of CMP involves hydrodynamic behavior. The liquid slurry is trapped between the work piece and pad forming a hydrodynamic film. For the first step to understand material removal mechanism of the CMP process, the hydrodynamic analysis is done with semiconductor wafer. Three-dimensional Reynolds equation is applied to get pressure distribution of the slurry film. Shear stress distributions on the wafer surface are also analyzed

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.1
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• pp.77-87
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• 2012

In this paper, the method and its effectiveness to decrease the uneven wear of the brake pad were proposed. A finite element analysis was performed to analyze the pressure distributions on the contact surfaces. The optimum brake pad shape was determined by a robust design using the Taguchi method. The effectiveness of the optimum design was clarified by the wear tests with a dynamometer.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.22 no.12
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• pp.1206-1212
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• 2012

The brake squeal propensity due to the friction-velocity curve is numerically investigated. The finite element models for the disc and pad are correlated with the modal test. In the friction-engaged system modeling, the friction function is linearized at the equilibrium. The damping term induced by friction-velocity slope is incorporated into the equations of motion. In the complex eigenvalue analysis, it is found that the pad shear mode is very sensitive to the friction curve. The results shows that the squeal propensity of the pad shear mode can be controlled by the design parameters such as pressure and stiffness.

• Tribology and Lubricants
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• v.22 no.4
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• pp.173-181
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• 2006

In the present study, we developed a numerical analysis software to predict performance of tilting-pad thrust bearings. The finite element method was adopted to compute lubricant film pressure and temperature. Three-dimensional heat transfer equations were solved simultaneously for the lubricant film, pad, and runner. Groove temperature was assumed with two different models. From application of the software to a thrust bearing, it has been seen that the three-dimensional analysis predicts higher temperature than the average temperature analysis. It has also been found that the groove model with a hot-oil-carry-over factor predicts higher temperature.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.5
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• pp.107-115
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• 2008

In this paper, we have proposed a wear growth prediction method on the surface of rubber pad of track assembly installed in high-speed battle tank i.e. the automatic model updating code interfacing with commercial finite element simulation software. Also, simple and resonable geometrical, material finite element model was established to be easily updated based on the empirical threshold value of contact pressure on the contact surface. From the iterative model update and analysis results, we discovered a weak point on rubber pad surface and suggested a new design concept for improving the wear performance of track assembly.