• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.120-126
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• 2007

A principal components analysis of the entire median HRIRs in the CIPIC HRTF database reveals that the individual HRIRs can be adequately reconstructed by a linear combination of several orthonormal basis functions. The basis functions cover the inter-individual and inter-elevation variations in median HRIRs. There are elevation-dependent tendencies in the weights of basis functions, and the basis functions can be ordered according to the magnitude of standard deviation of the weights at each elevation. We propose a HRIR customization method via tuning of the weights of 3 dominant basis functions corresponding to the 3 largest standard deviations at each elevation. Subjective listening test results show that both front-back reversal and vertical perception can be improved with the customized HRIRs.

• Structural Engineering and Mechanics
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• v.43 no.3
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• pp.287-309
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• 2012

Precast segmental bridge columns (PSBC) are alternatives for monolithic cast-in-situ concrete columns in bridge substructures, with fast construction speed and structural durability. The analytical tool for common use is demonstrated applicable for seismic performance prediction of PSBCs through experiment conducted earlier. Then the analytical program was used for parameter optimization of PSBC configurations under reversal cyclic loading. Shear strength by pushover analysis was compared with theoretical prediction. Moreover, seismic response of PSBC with energy dissipation (ED) bars was compared with its no ED bar counterpart under three history ground acceleration records. The investigation shows that appropriate ED bar and post-tensioned tendon arrangement is important for higher lateral bearing capacity and good ductility performance of PSBCs.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.12
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• pp.53-58
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• 1996

In this paper, a simple fabrication technique of an air-bridge for interconnection of isolated electrodes of microwave active and passive devices and MMIC's is proposed. The proposed air-bridge proceses are mainly combinations of thermal evaporation, positive photoresist and image reversal processes for easy lift-off of up to 2.0 .mu.m thick metal. According to the resutls of air-birdge processes, it is confirmed that air-gap and thickness of theair-bridge are about 3.5.mu.m, and 2.0.mu.m, respectively. And it is also possible to make the fine air-bridge with widths of 5~60.mu.m and post-intervals of 25~200.mu.m withot collapse. finally, GaAs power MESFET's and rectangular spiral inductors are fabricatd and measured in order to confirm of feasibility of the proposed air-bridge processes. The MAG of the fabricated power MESFET's is 10dB at 10GHz, and the inductance of the (200.mu. * 6 turns) rectangular spiral inductors 4.5 nH inX-band.

• Journal of Magnetics
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• v.15 no.3
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• pp.99-102
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• 2010

We present the fractal properties of the magnetic domain walls in $(5-{\AA}\;Co_{90}Fe_{10}/10-{\AA}\;Pt)_n$ multilayer films with perpendicular magnetic anisotropy for the number of repeats n (1 to 5). In these films, the magnetization reversed due to the domain wall propagation throughout the films with rare nucleations. As n increased, it was observed that the jaggedness of the domain walls increased noticeably, which is possibly due to the accumulation of irregularities at the layer interfaces. The jaggedness of the domain walls was analyzed in terms of the fractal dimension by use of the ruler method, and it was revealed that the fractal dimension significantly changed from $1.0{\pm}0.002$ to $1.3{\pm}0.05$ as n increased from 1 to 5.

• 유체기계공업학회:학술대회논문집
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• 2000.12a
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• pp.110-115
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• 2000

The mean streamline analysis using the empirical loss correlations has been developed for performance prediction of industrial mixed-flow fan impellers in the present study. New simple, but effective, models for the additional Euler input work characteristic and an internal recirculation loss due to internal flow reversal under the low flowrate conditions are proposed in this paper. Comparison of overall performance predictions with six sets of test data of mixed-flow fans is accomplished to demonstrate the accuracy of the proposed models. Predicted performance curves by the present set of loss models agree fairly well with experimental data for a variety of mixed-flow fan impellers over the entire operating conditions. The prediction method presented herein can be used efficiently in the conceptual design phase of mixed-flow fan impellers.

• The Journal of the Acoustical Society of Korea
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• v.19 no.1E
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• pp.38-42
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• 2000

In this paper we studied the reduced subjective timbre space of time-varying tones as well as steady state tones. 45 modified test tones were constructed from the original violin tone in consideration of 4 physical factors: spectrum envelope, inharmonicity, time-varying spectrum and time reversal. The semantic differential (SD) method was used in the listening test. According to the factor analysis, the adjectives can be factorized into 4 groups. The first factor is characterized by the adjectives, 'free', 'broad', 'deep', 'rich', 'strong' and 'reverberant', the second by 'tenor', 'clear', 'bright', 'light' and 'sharp', the third by 'easy', 'smooth', and 'solid', the fourth by 'warm' and 'full'. The first factor, 'richness', seems to be dependent upon the time-varying characteristic of a tone. The second factor, 'sharpness', is shown to play an important role in a time-varying tone as well as in a steady state tone.

• Journal of the Korean Chemical Society
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• v.16 no.2
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• pp.64-69
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• 1972

Nucleophilic reactivities of 1-and 2-phenethyl chlorides have been investigated MO-theoretically using the EHT method. It has been shown that results of population analysis are consistent with the experimental order of relative nucleophilic reactivities and furthermore the reversal of the reactivity order for the less reactive nucleophile, $I^-$, could also be explained satisfactorily.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.317-322
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• 2001

A mathematical modelling technique is proposed for estimating the additional bending stresses of tube(s)-in-tube structures due to tube-tube interaction, which has a significant effects on the shear-lag phenomenon. The proposed method simulates the framed-tube structures with multiple internal tubes as equivalent multiple tubes, each composed of four equivalent orthotropic plate panels. Hence, the tube(s)-in-tube structure can be analysed by using an analogy approach where each tube is individually modelled by a continuous beam that can account for the flexural and shear deformations as well as the shear-lag effects. The numerical analysis is applicable for the structural analysis of framed-tube structures with single and multiple internal tubes, as well as those without internal tubes. The shear-lag phenomenon of such structures is studied with additiona] bending stresses and shear-lag reversal points.

• Journal of Electrochemical Science and Technology
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• v.7 no.4
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• pp.293-297
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• 2016

Here we propose a new equation by which we can estimate the baseline for measuring the peak current of the reverse curve in a cyclic voltammogram. A similar equation already exists, but it is a linear algebraic equation that over-simplifies the voltammetric curve and may cause unpredictable errors when calculating the baseline. In our study, we find a quadratic algebraic equation that acceptably reflects the complexity included in a voltammetric curve. The equation is obtained from a laborious numerical analysis of cyclic voltammetry simulations using the finite element method, and not from the closed form of the mathematical equation. This equation is utilized to provide a virtual baseline current for the reverse peak current. We compare the results obtained using the old linear and new quadratic equations with the theoretical values in terms of errors to ascertain the degree to which accuracy is improved by the new equation. Finally, the equations are applied to practical cyclic voltammograms of ferricyanide in order to confirm the improved accuracy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.4
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• pp.410-418
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• 2004

The multiaxial fatigue test under in-phase and out-of$.$phase load were performed to study what degradation phenomenon affects fatigue life with virgin and 3600 hrs degraded materials. The various kind of fatigue data fur fatigue life prediction were acquired under pure axial and pure torsional load of fully reversal condition. The models which was investigated are: 1) the von Mises equivalent strain range, 2) the critical shear plane approach method of Fatemi-Socie(FS) parameter, 3) the modified Smith-Watson-Topper(SWT) parameter. The result showed that, fatigue life by material degradation are decreased and life prediction which was used the FS parameter is not conservative but the best result.