• Journal of the Korean Society for Precision Engineering
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• v.18 no.9
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• pp.140-146
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• 2001

Seals in a universal joint bearing are important components reinforcing lubrication performance by holding lubricant and preventing infiltration of dust, moisture, etc.. There is a great difference in seal performance according to seal shape and bonding position. Therefore, in this study, as for both the lip type seal and the O-ring type seal, FE analysis is conducted using Mooned-Rivlin Model. The results show that O-ring type seal does not have any effect of misalignment angle compared with lib type seal, which is more profitable.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.17-19
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• 2008

An advanced TFT-LCD structure was proposed to increase aperture ratio (AR). In this structure, metal layers formed below the data lines are used as light-blocking layers, achieving higher AR ratio than that of a conventional structure. Since average misalignment between the metal light-blocking layers and pixel electrodes is smaller than that of black matrixes on color filter glass, substantially less light-blocking areas are needed to achieve misalignment margin. The AR of the LCD panel fabricated by using proposed structure was enhanced by 18.7 % over that of the conventionally structured panel.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.8 s.179
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• pp.2059-2064
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• 2000

The measurement of residual stresses by the hole-drilling method has been commonly used to evaluate residual stresses in structural members. In this method, one of the source of error is due to the misalignment between the drilling hole and strain gage center. This paper presents a finite element analysis of the influence of such misalignment for the uniaxial residual stress field. The stress error increases proportionally to hole eccentricity. The correction equations which easily obtain the residual stress taking account of the hole eccentricity are derived. The stress error due to the hole eccentricity decreases by approximately one percent using this equations.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.564-566
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• 1992

It is tragic that the Korean Airline Boing 747, KE007, wandered hundreds of miles off course into Soviet airspace and was shot down on September 1, 1983. The exact cuases are not known yet. Thus, speculation centers on human error or faulty procedure of three Litton LTN-72R inertial navigation systems(INS) with which the KAL KE007 was equipped. The inertial platform must be aligned before the INS can be used as a precision inertial navigation system. This analysis checks a possibility that the navigation errors are caused by a wrong INS alignment procedure assuming it is done at Anchorage. Possible causes for the navigational position error, such as alignment errors and gyro drift errors, are analyzed through inertial navigation system error prapagation simulations. A set of misalignment angle is estimated to determine what degree of alignment errors are required to cause the navigation error assuming that the accident is caused by the INS misalignment.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.12
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• pp.1565-1571
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• 1995

Misalignment of recording head position results in inter-track interference (ITI), which is a primary factor limiting radial(track) density in current digital magnetic channels. This paper proposes a multi- channel adaptive PRML for digital high-density recording channels, and compares it with the conventional single-channel PRML in the presence of ITI for the per- formance evaluation. Simulation results show that the proposed method removes ITI effectively when heal-misalignment occurs, then improving its performance significantly as compared with the single- channel PRML. As a result, it is confirmed that multi-channel adaptive PRML is well suited for high-density recording in digital magnetic channels.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1366-1370
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• 2010

This paper supposes the vector control algorithm to estimate the rotor position of permanent magnet synchronous traction motor using the hall-effect sensor. The hall-effect provides 60 electrical degrees resolution in rotor position sensing and it is very low resolution. The algorithm makes resolution high as optical encoders or electromagnetic resolver. If necessary, the reference rotor position angle is controlled by adjusting the variable. When a rotor position sensor such as either a optical encoder or a electromagnetic resolver is misalignment, it is useful to align with those. The method on adjusting the reference rotor position angle can compensate for misalignment error degrees by 60 electrical degrees.

• Journal of the Optical Society of Korea
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• v.11 no.1
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• pp.40-43
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• 2007

We propose a taper-underlaid spot-size converter (TU-SSC) with an offset which consists of two vertically stacked taper layers. The designed TU-SSC reduces coupling loss of a high index-contrast waveguide with $1.5%{\Delta}$ to a single mode fiber from 1.5 dB to 0.27 dB. We also considered the effects of mask misalignment in the fabrication process of TU-SSC, and optimized the design of TU-SSC so that the additional loss of TU-SSC for the mask misalignment of $3{\mu}m$ in the photo-lithography process was as low as 0.13 dB.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.107-112
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• 2012

All chemical processes are centered in the chemical reactor. Chemical reactions are often accompanied by mixing. Mixing can influence not just reaction rate but also product distribution if more than one product is possible. So, reactor agitator is more critical in industrial reactions. High vibration was occurred on reactor agitator which is critical equipment in HDPE plant. This paper describes analysis and diagnosis for agitator vibration throughout some tests. High vibration has been occurred by misalignment and resonance. Through the correction it could be stable.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.99-104
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• 2012

This paper analyzes the pitting's cause of elevator's worm gear type traction machine. To find a cause of pitting problem, we analyzed vibration, a proper design allowance and lubrication. We brought a conclusion that the cause of pitting is not a simple vibration problem, such as misalignment of worm reducer and rail, but mostly related to a designed allowance. In this case, the allowance is tight. In general, the allowance of traction machine and lubrication is varied by manufacturers. When the allowance is tight, a proper lubrication can diminish the pitting problem.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.2
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• pp.59-68
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• 1995

In this study, the effects of the power transmission units on the rotational accuracy are investigated experimentally in a hydrostatic spindle. The effects of warm up time, unbalancing and the position of measuring sensor are pre-examined for the determination of measuring conditions. The misalignment of the power transmission units and the vibration excited by the fluctuation of belt are considered as the dominant parameters of error motion. The variation and scatter of run out at the range of 0 to 3,000rpm in rotational speed are appropriated for the camparison of availabilities of the transmission units to precision spin- dles.