• Composites Research
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• v.14 no.1
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• pp.15-21
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• 2001

The pressing roller was designed and manufactured with high modulus carbon fiber composite material to exploit the high specific stiffness of the composite material. the optimal stacking sequence for the pressing roller was obtained from the FE analysis and the shape of the rubber coating layer was determined based on the calculated deflection for the uniform pressure on the film along the axial length of the pressing roller. Then the static deflection of the manufactured composite pressing roller was experimentally evaluated in comparison with analysis result and dynamic characteristics were measured through vibrational test.

• Tribology and Lubricants
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• v.25 no.6
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• pp.427-431
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• 2009

When a bearing roller is in contact with race ways. excessive pressure peaks occur at the ends of the contact region. They are called edge loading. In this study, a method to determinate crowning quantity of the tapered roller bearing which considers tilting. This method is based on contact analysis.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.6
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• pp.913-922
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• 1987

In this paper the solidification phenomena at the molten pool has been modeled and simulated in terms with the one dimensional unsteady-state heat transfer of the solid and molten phase and the pressure distribution in the solid phase for the twin-roller continuous casting of Sn-15% Pb. The further purpose of this study was to effectively analyze the thermal and mechanical deformation of roll applying the results of the heat transfer and the pressure distribution to the boundary conditions. The strip thickness of rapidly solidified metallic strip decreases with increasing angular velocity of the roller and with increasing initial roll gap. For this reason the roll spacing and angular velocity of the rolls are considered to be main variables. The recommended optimal casting regimes for continuous strip dimensions is near 0.8mm-1.0mm in thickness at the given angular velocity .omega.=2.0 rad/sec. Results of the experiment using Sn-15% Pb are compared with model predictions. The calculated roll deformation has been in good agreement with the observed value of roll deformatiion. All the deformation. All the deformation of the roller is within the elastic range, the plastic yielding are not occured. However, these elastic stresses are sufficient to take place of the shortened roller life by the thermal fatigue and a notch fatigue. The higher cooling rates were obtained by a twin-roller quenching technique. Also the quenched microstructure of the rapidly solidified shell was verified.

• Tribology and Lubricants
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• v.29 no.1
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• pp.27-32
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• 2013

This study examined the effects of surface roughness in the mixed lubrication regime of smooth and rough surfaces for roller bearings. The average flow model was adopted for interaction between the flow rheology of the lubricant and the surface roughness. The average Reynolds equation and related flow factor that describes the coupled effects of surface roughness and flow rheology, the viscosity-pressure and density-pressure equations, the elastic deformation equation, and the force balance equation were solved simultaneously. The results showed that the effects of surface roughness on the film thickness and pressure distribution should be considered, especially in elastohydrodynamic lubrication contact problems.

• Journal of International Academy of Physical Therapy Research
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• v.10 no.4
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• pp.1879-1888
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• 2019

Background: The treatment of pain in the iliotibial band friction syndrome has been difficult to determine, according to studies to date. However, recent studies have suggested that flexibility in the subacute stage of pain in the iliotibial band friction syndrome may help reduce pain. Objective: To investigate the immediate effect on pressure pain threshold and flexibility of the tensor fascia latae and iliotibial band by applying static and dynamic myofascial release foam rolling and self-stretching to adults with shortening iliotibial band. Design: Randomized controlled trial Methods: In this study, 50 subjects who were selected in advance as a randomized controlled trial were randomly allocated using a R Studio program. The included subjects were randomly allocated to three intervention groups. The static self-myofascial release 18 people, dynamic self-myofascial release group 16 people separated the self-stretching group 16 people and conducted a homogeneity check in advance. Before the start of the experiment, after of the experiment, 5 minutes after the end of the experiment, the pressure pain threshold and flexibility change for each part were measured. Results: The results of this study showed that the static self-myofascial release showed a significant difference in the pressure pain threshold in the tensor fascia latae and middle, lower part of the iliotibial band, compared with the other intervention groups (p<.05). In change of flexibility, the static self-myofascial release was significantly different than the other intervention groups (p<.05). Conclusion: The result of this study suggest that static self-myofascial release using foam roller may help to improve the pain and flexibility of the iliotibial band and to apply it as a more discerning intervention.

• Textile Coloration and Finishing
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• v.17 no.5 s.84
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• pp.53-60
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• 2005

Fusing press m/c is used for heating and pressing the specimens that are fed into between the two moving belts. Therefore the belt movement, belt temperature, and the pressure between belts must be kept constant. Especially, the belts should move in a limited operation range. When the belts run far out of the operation point, the machine has to be stopped, which results in a product defect because the fusing conditions, e.g., temperature and pressure, change during the transient process time period. It is important to avoid the belt stopping by maintaining the belt movement in a limited range. This study reports about the movement of the endless fusing belt in a long-span roller fusing m/c. The belt position changes as the 1st-order system does; if the roller axes are slanting each other with a certain angle, the belt running around the two rolls shows a dynamic behavior with the time that deviates fastly at the beginning from the initial condion and slows down. Then it reaches at a final position. The skewer the axes, the greater the position change. The inital change rate of the belt becomes large as the skewness of the axes between the two rollers increases.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.10
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• pp.887-894
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• 2016

The CNG pressure vessel is manufactured by a deep drawing and ironing (D.D.I) process for forming cylinder parts, followed by a spinning process for formation of the dome part. However, studies on the buckling phenomenon of the dome part and formation of the inlet part have not been performed yet, and the CNG pressure vessel is produced by the experience of the field engineers and the trial and error method. In this study, buckling phenomenon during the spinning process was predicted by comparing critical buckling loads obtained through theoretical analysis with axial loads from the FEA, and a method for preventing buckling of the dome part was proposed by employing commercial software (Forge NxT 1.0.2). Also, to form the inlet part, forming loads of the roller at contact point between the roller and the dome part were analyzed according to radii of the dome part, and the inlet part was formed by controlling the radius of the dome part.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.2
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• pp.86-94
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• 2004

The flash temperature distribution on the contact surfaces between cam and roller-follower mechanism was analysed numerically. The elasto-hydrodynamic lubrication pressure and film thickness were used to get the accurate analysis results. The temperature distribution was obtained by numerical integration by making use of Carslaw and Jaeger's formulation to the whole contact surfaces. The maximum flash temperature was increased with both the increasing slip ratio of the contact surface and increasing external load Profile of the temperature distribution was affected by the sliding velocity of the surface.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.71-76
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• 2008

This paper is concerned with the active vibration control of elevator by means of the active roller guide. To this end, a dynamic model for the horizontal vibration of the elevator consisting of a supporting frame, cage and active roller guides was derived using the energy method. Free vibration analysis was then carried out based on the equations of motion. Active vibration controller was designed based on the equations of motion using the LQR theory and applied to the numerical model. Rail irregularity and wind pressure variation were considered as external disturbance in the numerical simulations. The numerical results show that the active vibration control of elevator is possible.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.8 s.197
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• pp.74-80
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• 2007

The distortion of printed pattern is frequently observed in gravure offset printing process, which can be a serious problem in printing process for printed electronics. The mechanism of pattern distortion is studied and the factors which affect the amount and shape of distortion are found using FEM. The amount and shape of distortion is influenced by material properties of the roller, thickness of roller, applied load, and so on. As the printing pressure increases and Possion ratio increases, the degree of the image distortion increases. And the increase of the thickness of rubber roller brings a large distortion of image, too. In some cases, the distortion of printed pattern can reach a few hundred micromillimeters. The comparison of the experiment result and the simulation result shows good agreement in their quantitative tendency.