• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2325-2334
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• 2023

To study the lubrication performance of tilting-pad thrust bearing (TPTBs) during start-up in nuclear pump, a hydrodynamic lubrication model of TPTBs was established based on the computational fluid dynamics (CFD) method and the fluid-structure interaction (FSI) technique. Further, a mesh motion algorithm for the transient calculation of thrust bearings was developed based on the user defined function (UDF). The result demonstrated that minimum film thickness increases first and then decreases with the rotational speed under start-up condition. The influence of pad tilt on minimum film thickness is greater than that of collar movement at low speed, and the establishment of dynamic pressure mainly depends on pad tilt and minimum film thickness increases. As the increase of rotational speed, the influence of pad tilt was abated, where the influence of the moving of the collar dominated gradually, and minimum film thickness decreases. For TPTBs, the circumferential angle of the pad is always greater than the radial angle. When the rotational speed is constant, the change rate of radial angle is greater than that of circumferential angle with the increase of loading forces. This study can provide reference for improving bearing wear resistance.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.1892-1894
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• 2004

We have suggested the moxa-pad cauterizer especially for knee arthralgia. We have researched the variation on knee heat generating by the moxa-pad moxibustion cauterizer. The experimental demonstrations have been made by the stimulating the spots which are G-34(Gall-bladder Meridian 34), Sp-9(Spleen Meridian 9), and Liv-3(Liver Meridian 3) acupuncture points. And stimulating time was one hour with moxa-pad cauterizer.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.04a
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• pp.235-240
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• 1998

The inlet pressure build-up at the leading edge of bearings and its effects on the static performances are investigated theoretically. The performance analyses of air-lubricated tilting pad bearings are carried out considering the inlet pressure which is obtained by means of momentum conservation method. The results show that inlet pressure is above atmosphere pressure in front of leading edge of tilting pad bearing and there is a significant influence of the inlet pressure on the performance of bearings.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.311-318
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• 2000

In this paper, the process of development of resilient sleepers, which improves the train safety, passenger comport and reduces the noise and vibration, is discussed. To determine the required material properties of elastic pad, static and dynamic simulations are performed and is applied in manufacturing. From the experiment results, it is investigated that the displacement is less for sleeper with elastic pad than that in ordinary PC form. The rate of displacement is also shown In be less for the sleeper with elastic pad. These results indicate that the elastic pad can reduce possibility of rail-corrugations and thus resulting in the reduction of maintenance costs.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.3
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• pp.302-307
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• 1988

A noble interconnection line capacitance measurement method to be able to remove the measurement errors from the probe pad to substrate stray capacitance has been proposed and verified. The measurement errors in the capacitance measurement, which usually be involved from the probe pad to substrate stray capacitance, can easily be removed by isolating the metal probe pad from the substrate with a grounded shield plate between the probe pad the substrate. The measurement results by using this improved capacitance measurement method were compared with the calculations by two-dimensional computer simulations.

• Tribology and Lubricants
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• v.17 no.2
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• pp.116-123
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• 2001

A theoretical analysis has been undertaken to show the influence of bearing geometry on the steady state characteristics of air lubricated spherical tilting pad bearings. The geometry variations considered are the number of pads, the eccentricity ratio, the direction of load, and the preloading. Dynamic characteristic equations are derived with pad assembly method.

• 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 the Korean Society of Clothing and Textiles
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• v.15 no.2 s.38
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• pp.139-150
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• 1991

The purpose of this study is to do the Somatotype classification according to the type of shoulder-neck and to give the thinkness of shoulder pad according to them. Therefore this study was measurement body size of 201 and the somatotypes were classified as their plumb line. The standard somatotype of this measurement was classified as 9 type according to its angle of shoulder inclination and neck length. Pads which have different thickness (1 cm, 1.5 cm, 2 cm) were attached to the 9 body type and the set-in sleeve blouse and raglan sleeve blouse were made and tring test and sensory test were accomplished. The results of this study were as follows: 1 . Classification of shoulder-neck relationship. Angles of shoulder inclination ($15^{\circ},\;21^{\circ},\;27^{\circ}$), lock lenaths (10 cm, 12.5 cm, 15 cm) were classi- fied as 3 type each and these types were combined as 9 types. II . The result of angle difference of shoulder inclination according to pad thickness. 1) In case of set-in pad. angle is increased $5.75^{\circ}$ per 1 cm of pad thickness. 2) In case of raglan pad. angle is increased $6.45^{\circ}$ per 1 cm of pad thickness. III. The most fit pad thickness to the 9 types. In case of set-in sleeve blouse. 1) High shoulder-long neck, Standard shoulder-long neck Low shoulder-long neck, Stan-dard shoulder·standard neck. Low shoulder-standard neck: 1.5 cm. 2) High shoulder-standard neck, Standard shoulder-short neck, Low shoulder-short neck: 1 cm. 3) High shoulder-short neck: 0 cm(without pad) In case of raglan sleeve blouse. 4) High shoulder-long neck, Standard shoulder-long neck, Low shoulder·long neck, Stan-dard shoulder-standard neck, Low shoulder-standard neck: 1.5 cm. 5) High shoulder-standard neck, Standard shoulder-short neck, Low-shoulder-short neck: 1 cm. 6) High shoulder-short neck: 0 cm(without pad)

• Tribology and Lubricants
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• v.33 no.3
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• pp.85-91
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• 2017

This work studies the flow behaviors in the gap between the friction pad and separator in wet-clutch systems. The fluid volume of the lubricant is modeled using the entire system of wet-clutch pack of a dual clutch transmission that has larger outer radius of odd gear shifts and smaller inner radius of even gear shifts. Flow behaviors in the gap of the clutch pad are computed using the gear shift modes that consider the real relative velocities between the friction pad and separator. Flow behaviors in the gap of the disengaged clutch pad are mainly investigated for the wet-clutch system, whereas the engaged clutch pad is modeled with no fluid rate through the contacting surfaces. The developed hydrodynamic fluid pressures and velocity fields in the clutch pad gap are computed to obtain the relevant information for managing flow rates in wet-clutch packs under dual operating conditions during gear shifts. These hydrodynamic pressures and velocity fields are compared on the basis of each gear level and gap location, which is necessary to determine the effects of groove patterns on the friction pad. Shear stresses in the gap locations are also computed on the basis of the gear level for the inner and outer clutch pads. The computed results are compared and used for the design of cooling capacity against frictional heat generation in wet-clutch pack systems.

• Tribology and Lubricants
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• v.36 no.1
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• pp.27-33
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• 2020

Self-equalizing tilting pad thrust bearings are usually employed in turbomachines to achieve high stability and reliability. A tilting pad bearing can incorporate self-equalizing links to handle the misalignment between the bearing and the thrust collar. In this popular design method, the pads sit on the upper-level plates and the lower-level plates stay on the retainer base. With misalignment, the pads that are heavily loaded are pushed down. Consequently, the link pushes up the pads on the opposite side, keeping the bearing surface parallel to the thrust collar surface. The self-equalizing link is used to handle the misalignment from the thermal and mechanical effects. In this study, the experimental investigation deals with the performance of self-equalizing tilting pad thrust bearings. The test rig for evaluating the performance of bearing is developed which can control the misalignment angle. Simultaneous measurements are taken for the force acting on each pad. Pad metal temperature and oil film thickness are functions of the shaft speed, bearing load, misalignment angle, and design of leveling plates. The effect of misalignment on bearing performance is discussed. The results demonstrate that the load on each pad depends on the test conditions(especially misalignment angle), and the load influences the performance of bearings.