• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2082-2087
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• 2008

The heat transfer process from steam to web through the cylinder drum consists of the thermal resistance by condensate thickness. thickness of shell, and the contact resistance between cylinder and web. The most thermal resistance in conventional cylinder drum dryer is generated by condensate, which is increased by the increase on revolution per minute(RPM). Therefore, the increase of RPM for the production enhancement results in the more thermal resistance, and eventually RPM is restricted. In this study, the theoretical analysis on the characteristics of heat transfer in cylinder drum for paper dryer was performed in the stationary state of steam in drum. The overall heat transfer coefficient, steam quantity and heat transfer quantity were predicted by diameter and length of drum, condensate thickness, revolution per minute and steam temperature for experimental apparatus design.

• Tribology and Lubricants
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• v.11 no.4
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• pp.53-57
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• 1995

The contact pressure behavior is examined by means of a finite element analysis. The oil film between the piston ring and cylinder liner is analyzed on the basis that it behaves like a polymer material. The calculated results indicate that a shape of sloping edge with a straight line, which is designated as a Model III, shows a good performance on the contact pressure behavior for the increased speed. Obviously, the ring face profiles play an important role on the contact pressure between compression ring and oil film.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1549-1550
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• 2011

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.499-502
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• 2001

In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using cylinder type reactor and packed-bed reactor. An experimental investigation has been conducted for NO concentration of 50[ppm], 100[ppm], 200[ppm] balanced with air, a gas flow rate of 5[1/min]. Ac voltage to discharge the gases was supplied. In the result, NOx removal rate in packed bed reactor is higher than that in cylinder type reactor. it is thought that plasma density in contact point of BaTiO$_3$ is significantly higher than that in cylinder reactor.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.3
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• pp.1-11
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• 2000

Instantaneous temperature probes were manufactured by pressing method. By using these probes, the instantaneous surface temperature and unsteady heat flux in the cylinder liner of DOHC engine were measured. The main results are as follows; ⅰ) the instantaneous surface temperature of cylinder liner are affected by the contact of piston ring as well as burning gas. ⅱ) the wall temperature of the siamese portion is much higher than other parts. ⅲ) it was shown that the rising trend of heat flux by burning gas are nearly limited to the 1/2-stroke distance from the top of cylinder liner.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1018-1023
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• 2005

A new MR cylinder with built-in valves using MR fluid (MR valve) is suggested and fabricated for fluid control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. The MR cylinder is composed of cylinder with small clearance and piston with electromagnet. The differential pressure is controlled by the applied magnetic field intensity. It has the characteristics of simple, compact and reliable structure. The size of MR cylinder and piston has ${\varphi}30mm{\times}300mm\;and\;{\varphi}28.5mm{\times}120mm$ in face size, respectively and 0.8mm in gap length. Through experiments, it was found that the differential pressure is controlled by the applied magnetic field intensity under little influence of the flow rate, which corresponds to a pressure control valve. The differential pressure of 0.47MPa and contact force of 320N were obtained with the input current of 1.5A. The rising time of force was 1.1s in step response of a manipulator using the MR cylinder. The effectiveness of the MR cylinder was also demonstrated through the force control.

• Transactions of the Korean hydrogen and new energy society
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• v.20 no.2
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• pp.125-132
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• 2009

Cylinder shaped air-breathing PEMFC has been developed to have small volume, low contact resistance and better air accessibility to the open cathode. This cylinder shaped design consists of an anode cylinder with helical flow channel and a cathode current collector with slits. The pressure distribution measurement according to the shapes was performed. The test result indicated that cylinder shaped fuel cell has better pressure distribution compared with the planar shaped fuel cell. The better pressure distribution was connected to the higher performance. The maximum power density of cylinder shaped fuel cell was about 20% higher than the planar shaped fuel cell. The maximum power density of the developed cylinder shaped air-breathing PEMFC with dry hydrogen was $220\;mW/cm^2$ and with humidified hydrogen was $293\;mW/cm^2$.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.627-646
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• 1997

In order to find the degree of osseointegration at bone-implant interface of clinically successful implants, models including the 3.75mm wide, 10mm long screw type $Br{\aa}nemark$ implant as a standard and cylinder, 15mm long, 5.0mm wide, two splinted implants, and implants installed in various cancellous bone density were designed. Also, the amount of load and material of prostheses were changed. The stress and minimum contact fraction were analyzed on each model using three-dimensional finite element method(I-DEAS and ABAQUS version 5.5). The results of this study were as follows. 1. 10mm long, 3.75mm diameter-screw type implant had $36.5{\sim}43.7%$ of minimum contact fraction. 2. Cylinder type implant showed inferior stress distribution and higher minimum contact fraction than screw type. 3. As implant length was increased, minimum contact fraction was increased a little, however, maximum principal stress was decreased. 4. Implants with a large diameter had lower stress value with slightly higher minimum contact fraction than standard screw type. 5. Two splinted implants showed no change of minimum contact fraction. 6. The higher bone density, the lower stress value. 7. The material of occlusal surface had no effect on the stress of the bone-implant interface.

• Journal of Technologic Dentistry
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• v.35 no.4
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• pp.303-312
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• 2013

Purpose: In this research, non-linear three dimensional finite element models with contact elements were constructed. For the investigations of the distributions of contact stresses, 3 units fixed partial dentures model were studied, especially on the interface of the gold screw and cylinder, abutment screw. Methods: 3 types of models were constructed ; the basic fixed partial denture in molar region with 3 units and 3 implants, the intermediate pontic fixed partial denture model with 3 units and 2 implants, and the extension pontic fixed partial denture model with 3 units and 2 implants. For all types, the external loading due to chewing was simulated by applying $45^{\circ}$ linguo-buccal loading of 300 N to the medial crown. For the simulation of the clamping force which clinically occurs due to the torque, thermal expansion was provided to the cylinder as a preload. Results: Under 300 N concentrated loading to the medial crown, the maximum contact stress between abutment screw and gold screw was 86.85~175.86MPa without preload, while the maximum contact stress on the same area was 25.59~57.84MPa with preload. Conclusion: The preloading affected the outcomes of the finite element stress analysis. Reflecting the clinical conditions, the preloading conditions should be considered for other practical study utilizing FEA. For the study of the contact stresses and related motions, various conditions, such as frictional coefficient changes, gap between contact surfaces, were also varied and analyzed.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2001.11a
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• pp.356-363
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• 2001

Piston seal is a device designed to prevent leakage in split connecctions or between relatively moving part. Contact force, critical pressure at which extrusion occurs, leakage rate, fluid film thickness and friction force have been analyzed for some design parameter such as clearance between cylinder wall piston, depth of rectangular groove and pressure of sealed hydraulic fluid. In this paper, we analyze displacement and stress of Wearing by finite element analysis to understand Contact Behaviour Characters.