• The KSFM Journal of Fluid Machinery
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• v.9 no.5 s.38
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• pp.7-13
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• 2006

In the present study, we develop an analysis module to be applicable to design of sliding thrust bearings. The pressure equation is solved by using the finite element method. Average lubricant temperature is obtained from using the energy balance method. The module developed has been applied to three types of thrust bearing, such as tapered-land thrust bearings of angular and diamond types, and tilting-pad thrust bearings. Effects of the dam of the tapered-lad thrust bearings have also been investigated. It has been seen that the tapered-land thrust bearings of angular type result in the highest load capacity, while the tilting pad thrust bearings result in the lowest lubricant temperature. It has also been seen that the dam in the tapered-land thrust bearings increases both the load capacity and lubricant temperature.

• Design & Manufacturing
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• v.13 no.1
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• pp.31-35
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• 2019

For manufacturing upper housing product of mechanical control valve, the progressive drawing process was conducted experimental. Then, the center of the product was cut to measure the thickness of the product. As a result, the following conclusions were obtained. By means of a stand-alone pad provided with sufficient pressure, it is possible to prevent the occurrence of wrinkles in the die pad product of the drawing process. As a result of the experiment, it was considered that the flange bottom of the product and the lower edge of the product are made thick in thickness, the top edge and the top surface are thin. It is considered that this is due to the size and roughness of the entrance edge radius of the die in the drawing process, and the inflow of the material by the die pad.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.11
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• pp.46-56
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• 1996

Planarization technique is rapidly recognized as a critical step in chip fabrication due to the increase in wiring density and the trend towards a three dimensional structure. Global planarity requires the preferential removal of the projecting features. Also, the several materials i.e. Si semiconductor, oxide dielectric and sluminum interconnect on the chip, should be removed simultaneously in order to produce a planar surface. This research has investihgated the development of the chemical mechanical polishing(CMP) machine with uniform pressure and velocity mechanism, and the pad insensitive to pattern topography named hard grooved(HG) pad for global planarization. Finally, a successful result of uniformity less than 5% standard deviation in residual oxide film and planarity less than 15nm in residual step height of 4 inch device wafer, is achieved.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.364-372
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• 1995

Peripheral arterial disease(PAD) is a major health problem in the elderly population, so prevalence of PAD is investigated using Edinburgh claudication questionnaire. Subjects were over 65 years old in the kyeongsan county. The prevalence of PAD was 9.0% in total population(8.5% in men, 9.3% in women). definite claudication was 3.9%, atypical claudication was 5.1%. and, grade 1 was 4.4%, grade 2 was 4.6%. The prevalence of PAD was increased with age but not statistically significant. There was no difference of PAD by gender and smoking. PAD was significantly associated with systolic blood pressure positively. But, unexpectedly, PAD was significantly associated with BMI negatively. PAD are important elderly health problem in the our country. So the etiology and preventive methods of PAD will be researched on our country population.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.458-463
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• 2015

This paper suggests detection system for the movement of patient on bed based on IEEE802.15.4 by using pressure pad and guard sensor. The system is designed to detect ordinary activities of patients on bed as well as patients' falling from the bed while sleeping at night. The node that is installed at bed sends data to gather when the pressure pad and sensor of guard detect patients' activities and falling. These data sent to gather are transmitted to monitor at help desk by TCP/IP communication. To remove unnecessary data that occurred due to switch chattering during tossing and turning, timer of MCU is used. Also, Communication module can change transmission power to apply this system to various environments of hospital room. Therefore, the nurse can take care of patients on bed in real time with data about patients' conditions.

• Tribology and Lubricants
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• v.30 no.1
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• pp.1-8
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• 2014

In this study, a three-pad gas foil journal bearing with a diameter of 40 mm and an axial length of 35 mm was modeled to predict the static and dynamic performances with regard to an increasing mechanical preload. The Reynolds equation for an isothermal and isoviscous ideal gas was coupled with a simple elastic foundation foil model to calculate the hydrodynamic pressure solution iteratively. In the prediction results, the journal eccentricity, journal attitude angle, and minimum film thickness decreased, but the friction torque increased with the preload. A quick comparison implied a lower load capacity but higher stability for a three-pad gas foil bearing compared to a one-pad gas foil journal bearing. The direct stiffness coefficients increased with the preload, but the cross-coupled stiffness coefficients decreased. The direct damping coefficient increased in the horizontal direction but decreased in the vertical direction as the preload increased. These model predictions will be useful as a benchmark against experimental test data.

• Tribology and Lubricants
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• v.27 no.1
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• pp.19-24
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• 2011

Metallic sintered brake pads are often applied to mid/high speed train due to their high strength and thermal characteristics. Imbalance contact between discs and pads can greatly influence the life span, one sided wear, discs attack/crack and threat the safety of the train during operation. In this research, we analyzed pressure/temperature distribution between brake pads and disks. Analyzed data had been verified and modified to conduct further tests of flexible brake pads with small/full-scale dynamo test. Flexible brake pads were installed to high speed train to conduct further tests to identify the differences between rigid brake pads and flexible brake pads. In result, Flexible brake pads showed outstanding disk thermal stability, one sided wear, noise and wear rate than rigid brake pad.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.1
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• pp.194-199
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• 2004

Cheonmabanhwa-tang(CBT) has been used in the Oriental Medicine for many centuries as a therapeutic agent for dizziness due to Poong-Dam. This study was designed to investigate whether CBT has a cytotoxicity in vitro, and affects the cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), and mean arterial blood pressure(MABP)) in normal and cerebral ischemic rats. The changes of rCBF were determinated by laser-doppler f1owmeter(LDF), and the change of PAD was determinated by video-microscopy. The results in normal rats were as follows: CBT had no cytotoxicity in neuronal cells. CBT significantly increased rCBF. MABP and PAD in a dose-dependent manner, respectively. Both rCBF and PAD were significantly and stably increased by CBT(10 mg/kg, i.p.) during the period of cerebral reperfusion. which contrasted with the findings of rapid and marked increase in control group. In conclusion, it is suggested that CBT causes a diverse effect on cerebral hemodynamics thereby has an anti-ischemic action.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1546-1551
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• 2005

This Study was designed to investigate the effects of Nelumbinis Rhizomatis Nodus (NRN) on the change of cerebral hemodynamics [regional cerebral blood flow (rCBF), pial arterial diameter (PAD) and mean arterial blood pressure (MABP)] in normal and cerebral ischemic rats. And, this study was designed to investigate the inhibition of lactate dehydrogenase activity in neuronal cells The results were as follows NRN significantly increased rCBF and PAD in a dose-dependent manner, and NRN increased MABP in a dose-dependent manner. This results suggested that NRN significantly increased rCBF by dilating PAD. Both rCBF and PAD were significantly and stably increased by NRN (10 mg/kg, i.p.) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in control group. NRN significantly inhibited lactate dehydrogenase activity in neuronal cells. This results suggested that NRN prevented the neuronal death. It is suggested that NRN had an anti-ischemic effect through the improvement of cerebral hemodynamics and inhibitive effect on the brain damage.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.3
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• pp.39-44
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• 2015

We investigated the effect of CNT-Ag composite pad on the contact resistance of flip-chip joints, which were formed by flip-chip bonding of Cu/Au chip bumps to Cu substrate metallization using anisotropic conductive adhesive. Lower contact resistances were obtained for the flip-chip joints which contained the CNT-Ag composite pad than the joints without the CNT-Ag composite pad. While the flip-chip joints with the CNT-Ag composite pad exhibited average contact resistances of $164m{\Omega}$, $141m{\Omega}$, and $132m{\Omega}$ at bonding pressures of 25 MPa, 50 MPa, and 100 MPa, the flip-chip joints without the CNT-Ag composite pad had an average contact resistance of $200m{\Omega}$, $150m{\Omega}$, and $140m{\Omega}$ at each bonding pressure.