• Journal of Welding and Joining
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• v.7 no.4
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• pp.22-29
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• 1989

In this paper weld distortion both in butt and fillet welds by flux cored arc welding has been investigated by changing welding parameters such as heat input and plate thickness, and the weld distortion was expressed as a function of welding parameters adopting the inherent strain theory as proposed by Watanabe and Satoh in 1961. As results of the research it is proposed that transverse shrinkage in root pass butt welds in proportional to ln[(Q/t_-tan.theta.] where Q is heat input(cal/mm), t is plate thickness(mm), and 2.theta. is groove angle(degree), and angular distortion .phi.(radian) in one pass of fillet welds has the following relationship: .phi..var.(Q/ $t^{1.5}$)$^{3}$exp[-(Q/ $t^{1.5}$ )$^{2}$3/] These equations provide us with basic tools to predict the amount of weld distortion in welded structures.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2075-2076
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• 2011

The stator winding faults diagnosis technique based on MCSA is as follows. Firstly, collecting the 3 phase motor currents, that signal is transformed by (d-q transform, $i_d$, $i_q$). Park's vector pattern, the circle that is down by d-q transformed currents($i_d$, $i_q$). The circle is widely used for stator winding faults detection. The current distortion ratio(DR), defined by the ratio of max-axis and min-axis of ellipse of Park's vector's pattern. In this study, distortion ratio of Park's vector pattern is suggested for Auto diagnosis of stator winding short fault and usefulness of distortion ratio is verified through simulation using LabVIEW program.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.335-336
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• 2008

We observe the distortion of the back scattered Stokes pulse and the complementary distortion of the transmitted pulse by the stimulated Brillouin scattering when a Q-switched Nd:YAG laser pulse injected into a single mode optical fiber. We determine the constant required energy for the SBS by comparing their temporal shapes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.4
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• pp.643-649
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• 2012

The diagnosis technique of stator winding faults based on Motor Current Signature Analysis(MCSA) was suggested. Park's vector pattern, the circle that is drawn by d-q transformed currents($i_d$, $i_q$), is widely used for stator winding faults detection. The current Distortion Ratio(DR), defined by the ratio of max axis and min axis of ellipse of Park's vector's pattern, was more simple and powerful method than the Park's vector pattern. In this study, a calculation method of distortion ratio of Park's vector pattern was suggested for auto diagnosis of stator winding short fault and usefulness of suggested calculation method of distortion ratio was verified through simulation using LabVIEW program.

• The Journal of the Acoustical Society of Korea
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• v.19 no.3
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• pp.63-71
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• 2000

A new type of second-order digital peaking filters for professional-quality digital audio system is proposed whose frequency response can be elaborately controlled throughout the composite structure of a standard band-pass filter and a 0-dB bypass gain. The proposed method for designing the peaking filter uses the Q-compensation technique to prevent the Q-distortion caused by the variation of the gain factor and is reduced into a compact form which is proper to the real-time implementation. Methods are examined for computing its coefficients, which are exact and very straightforward to compute with small amount of the system resources.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1391-1392
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• 2008

The modulation quality of the I/Q modulator in a wireless transmitter usually affects system performance and it mostly depends on both a nonlinearity and a distortion, from the third order intermodulation(IM3) signal and the imperfection features such as an input amplitude error and a local phase error, respectively. This paper focused on how much the Single Sideband Ratio(SSR), which indicates the signal distortion, changes according to the variation of the imperfection features. Since a desired signal, side band and IM3 signals at the I/Q modulator output are also represented with those power series coefficients and the imperfection features, the effects of the imperfection features on SSR can be clearly analyzed.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.234-236
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• 2004

The purpose of this study is to establish the predictive equation of welding distortion at the thick AA5083 alloy weldment. In order to do it, the extensive FE analysis was peformed to identify the principal factor controlling welding distortion. Based on the results, the predictive equations of transverse shrinkage and angular distortion at the thick AA5083 alloy weldment were formulated as the function of heat intensity (Q), in-plane(Di) and bending(Db) rigidity.

• Electrical & Electronic Materials
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• v.7 no.5
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• pp.403-408
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• 1994

Dielectric and structural properties of $Ba_{1-x}$(Z $n_{1}$3/T $a_{2}$3/) $O_{3}$+1 mol% Mn $O_{2}$ (x=0, 0.01, 0.02, 0.03, 0.04) ceramics was investigated at microwave frequencies. With $Ba_{+2}$ shortage, the sinterability and the unloaded Q( $Q_{u}$) were much improved, and the ordering in B site and the lattice distortion was greatly enhanced and the structure approached the completely ordered structure. $Q_{u}$ was strongly correlated with these factors such as ordering ratio, lattice distortion and sinterability, and had the maximum value of 7500 at x=0.01. The dielectric constant was near 30 and the temperature coefficient of the resonant frequency was 2 ppm/.deg. C at x=0.01.1.1.1.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.6C
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• pp.384-390
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• 2011

The paper derives formulas for the mean-squared error distortion and resulting signal-to-noise (SNR) ratio of a fixed-rate scalar quantizer designed optimally in the minimum mean-squared error sense for a Gaussian density with the standard deviation ${\sigma}_q$ when it is mismatched to a Laplacian density with the standard deviation ${\sigma}_q$. The SNR formulas, based on the key parameter and Bennett's integral, are found accurate for a wide range of $p\({\equiv}\frac{\sigma_p}{\sigma_q}\){\geqq}0.25$. Also an upper bound to the SNR is derived, which becomes tighter with increasing rate R and indicates that the SNR behaves asymptotically as $\frac{20\sqrt{3{\ln}2}}{{\rho}{\ln}10}\;{\sqrt{R}}$ dB.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.570-572
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• 2008

The modulation quality of the I/Q modulator in a wireless transmitter usually affects system performance and it mostly depends on both a nonlinearity and a distortion, from the third order intermodulation($IM_3$) signal and the error components such as an input amplitude error and a local phase error, respectively. This paper focused on how much the Single Sideband Ratio(SSR), which indicates the signal distortion, changes according to the variation of the error components. Consequently, since a desired signal, side band signal at the I/Q modulator output are also represented with those power series coefficients and the error components, the effects of the error components on SSR to meet the EVM specification of the WPAN can be clearly analyzed.