• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.3
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• pp.232-238
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• 2011

In the present study, Taguchi method is used to determine the rough region first, followed by RSM technique to determine the exact optimum value during milling on a machining center. A region reducing algorithm is applied to narrow down the region of the Taguchi method for RSM. The result from the Taguchi method is fed to train the artificial neural network (ANN), whose optimum value is used to drive the region reducing algorithm. The proposed algorithm is tested under different cutting condition and results show that the introduced algorithm works well during milling process. It is also shown that theoretically obtained optimal cutting condition is very close to experimentally obtained result.

• The Journal of the Acoustical Society of Korea
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• v.34 no.2
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• pp.91-97
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• 2015

In this paper, wireless communication from a smart phone to a hearing aid using audible frequency band sound was considered. 1kHz single channel carrier frequency was applied for amplitude shift keying (ASK) binary data modulation, and the result of the transmission and reception was tested. The overall system process was precisely explained and experimentally evaluated. The result will be applied for realizing a digital hearing aid with remote control feature by a smart phone.

• Structural Engineering and Mechanics
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• v.12 no.6
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• pp.633-656
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• 2001

In this paper, modal control with direct output feedback is formulated in a systematic manner for easy implementation. Its application to the seismic protection of structural systems is verified by a shaking table test, which involves a full-scale building model and an active bracing system as the control device. Two modal control cases, namely, one full-state feedback and one direct output feedback control were tested and compared. The experimental result shows that in mitigating the seismic response of building structures, modal control with direct output feedback can be as effective and efficient as that with full-state feedback control. For practical concerns, the control performance of the proposed method in the presence of sensor noise and stiffness modeling error was also investigated. The numerical result shows that although the control force may be increased, the maximum floor displacements of the controlled structure are very insensitive to sensor noise and modeling error.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.771-775
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• 1999

The antimutagenic activities of the total extract and several fractions of starfish, Asterina pectinifera (Asteriidae), were investigated in vitro by SOS chromotest with Escherichia coli PQ37 and Ames test with Salmonella typhimurium TA100. When various fractions was tested, the chloroform and butanol fractions showed low induction factors, which means both fractions increased antigenotoxicity against the base substitution mutagen MNNG. Even though higher antigenotoxic effect of the chloroform fraction, no effective result of Ames test was found in revertant formation of S. typhimurium TA100. The most effective antigenotoxic and antimutagenic fraction was a butanol one: i.e., When 0.5 mg/tube of butanol fraction was applied, the induction factor was 0.68. As the concentration of the fraction was increased the formation of revertants of S. typhimurium TA100 by about 81%. There was no cytotoxic effect of butanol fraction against S.typhimurium TA100. This result might be useful for further study to search a possible anticancer agent from the starfish, Asterina pectinifera.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.281-283
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• 1993

A new method of EEG spindle waveform detection i s presented. The method combines the signal conditioning in the time-domin and the analysis of local spectrum in the frequency-domain. Fast computation methods, utilizing some effective approximations, are also suggested for the desist and implementation of the filter as well as for the computation of the local spectrum. The presented approach is especially useful for the real-time implementation of the waveform detection system under a general purpose microcomputer environment. The overall detection system is implemented and tested on-line with the total 24 hour data of selected four subjects. The result show the average agreement of 86.7% with the visually inspected result.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.2
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• pp.365-369
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• 2016

The 350[km/h] catenary system was successfully opened in Honam high speed line. This 350[km/h] catenary system is firstly constructed in South Korea. Therefore the current collection performance of this system should be tested and evaluated by the authority. This paper describes the testings by running of HEMU-430X train and the evaluation criteria and result analysis to determine whether the performance of the catenary is good or not as a verification of catenary-pantograph interface. In detail, the contact force by pantograph, arcs by loss of contact and uplift amount of the catenary support were measured and discussed as a category of the current collection performance.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.215-216
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• 2005

To decrease and remove of much noises that is detected in PD (partial discharge) measuring test. we forced on detection of those. We made W-LC filter for measuring PD. which adapted that to field test. We tested after design laboratory circumstances like field line. and then the phase change properties of detected signal in UHF sensor were measured by Lemke Probe and oscilloscope (TDS-3054. Tektronix). Eventually we checked decrement of noises from experimental result. Also from experimental result at the joint box of 22.9[kV] distribution line. we obtained reasonable data which enable noises to decrease. Hereafter those results will be adapted at ultra-high voltage for trouble prevention and on-line cable watch. diagnosis of those.

• Journal of the Optical Society of Korea
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• v.4 no.1
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• pp.30-36
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• 2000

In this paper, a method based on the Genetic Algorithm(GA) for phase optimization is proposed. The programmable hybrid optical interconnection system implemented by the spatial light modula-tor is tested for a near-real-time optical processing. Designed diffractive grating has a 74.7[%] high diffraction efficiency and a $1.73 {\times}10^{-1}$ uniformity quantitatively. The dependence of characteris-tics on several parameters in the grating design are analyzed. Also, as a result of the geometrical transformation to obtain quantitative data for $3 {\times} 3$ spot beams, an objective optical experiment using CCD array detector produces the mean of beam intensity as a gray level of 202, the maximum value is 225, the minimum value is 186, and uniformity is quantitatively $1.93 {\times} 10^{-1}$, similar to the simulation result.

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.886-900
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• 1989

The purpose of this paper is to obtain the effect of blankholding force in deep drawing process. Flange deformation is analysed by theoretical approach in order to apply the optimum blankholding force to the blank. As the result, the upper and lower blankholding force is determined in terms of variables in deep drawing process. Experiment are carried out with the high stiffness spring-type blankholder system. Theoretical upper blankholding force are relatively good agreement with experimental result and the range of initial blankholding forces for various materials tested are found by experiment.

• Journal of KSNVE
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• v.10 no.1
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• pp.82-96
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• 2000

The purpose of this study is to figure out the relationship between the mini-laboratory and the reverberation room for the domestic floor structures which are practically constructed in apartment houses. For this purpose, seven specimen which were varied in structures and thicknesses were tested in Chonnam National University reverberation room and in the artificial mini-laboratory which is the $\farc{1}{3}$ scale model of the former. From the result of this study, it was proved that there is a good correlation between the mini-laboratory and the reverberation room for the apartment floor structures as well as floorcovering PVC. The result of this study could save the labor and the time, etc.