• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.29-34
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• 1998

An efficient 3-dimensional compressible solver is developed using the second-order upwind TVD scheme and the multigrid diagonalized ADI method. The multigrid method is improved so that the present DADI algorithm obtains better convergence rates. Results are computed on Cray C90 computer for transonic unsaperated flows past ONERA-M6 wing to demonstrate the accuracy and efficiency. The results show good agreement with experimetal data. A reduction of four orders of residual for 3-dimensional transonic flow is obtained about 99 seconds.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.991-994
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• 2009

This paper reports of camera detection of Mura. The type, location, size, orientation and amplitude are found. As the luminance variation in Mura is down to less than app. 0.3 %, measurement apparatus, techniques and algorithms are developed to measure low noise data and to extract the Mura from data with the residual noise in the same magnitude as the Mura.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권2호
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• pp.168-172
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• 2005

A novel cogging torque reduction algorithm is presented for 2-pole permanent magnet DC motor. While the shape of the permanent magnet is changed in the conventional method, the pole shape of the magnetizing yoke is optimized in the presented algorithm. In order to parameterize the shape of the yoke, and the distribution of the residual magnetization of the permanent magnet, the Bezier spline is used. The shape of the magnetizing yoke is optimized using the design sensitivity analysis incorporated with the finite element method and Bezier spline.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(4)
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• pp.106-109
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• 2000

There have been proposed two types of low bit rate vocoder upto now : One is MBE type using the spectrum modeling and another is CELP type using the hybrid coding method. CELP type vocoder has mainly studied between them. Specially, much of intensity is concentrated in CELP vocoder due to the emergence of Internet Phone and PCS in a domestic. In order to improve the speech quality in CELP vocoder, in this paper, we proposed a new spectrum analysis algorithm with variable window, In CELP vocoder, the spectrum of the synthesised speech signal is distorted because the fixed size windows is used for spectrum analysis. So we have measured the spectral leakage and in order to minimize the spectral leakage have adjusted the window size. Applying this method G.723.1 ACELP, we can get SD(Spectral Distortion) reduction 0.084(dB), residual energy reduction 6.3% and MOS(Mean Opinion Score) improvement 0.1.

• ETRI Journal
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• 제36권1호
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• pp.167-170
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• 2014

In this letter, we propose an unsupervised framework for speech noise reduction based on the recent development of low-rank and sparse matrix decomposition. The proposed framework directly separates the speech signal from noisy speech by decomposing the noisy speech spectrogram into three submatrices: the noise structure matrix, the clean speech structure matrix, and the residual noise matrix. Evaluations on the Noisex-92 dataset show that the proposed method achieves a signal-to-distortion ratio approximately 2.48 dB and 3.23 dB higher than that of the robust principal component analysis method and the non-negative matrix factorization method, respectively, when the input SNR is -5 dB.

• Journal of Information Display
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• 제9권4호
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• pp.39-44
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• 2008

This paper investigates the effects of the existing sealing methods, such as the conventional atmospheric-pressure sealing method and vacuum sealing, on temporal bright-image sticking. To produce a residual image caused by temporal brightimage sticking, the entire region of a 42-in panel with an Xe-(11%)-He(35%) gas mixture was abruptly changed to a full-white background image after displaying a square-type image at peak luminance for about 60s. From the monitoring of the difference in the display luminance, infrared emission, color temperature, and disappearing time between the cells with and without temporal bright-image sticking, it was observed that the vacuum sealing method contributes to the reduction of temporal bright-image sticking.

• The Journal of the Acoustical Society of Korea
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• 제25권2E호
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• pp.36-42
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• 2006

In this paper, a novel post processing using Wiener filtering technique is proposed to p rm further interference reduction in FDICA. Using the proposed method, the target signal components are remained with little attenuation while the interference components are drastically suppressed. The results of experiments show that the proposed method achieves a reduction of the residual crosstalk. Compared to the NLMS method, the proposed method has slightly better separation performance in SIR, and even requires much less computational complexity.

• Structural Engineering and Mechanics
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• 제24권1호
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• pp.91-105
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• 2006

In this paper, post-earthquake capacity evaluation method of reinforced concrete buildings was studied. Substructure pseudo-dynamic test and static loading test of first story column in a four-story R/C building was carried out in order to investigate the validity of the evaluation method proposed in the Damage Assessment Guideline (JBDPA 2001). In pseudo-dynamic test, different levels of damage were induced in the specimens by pre-loading, and input levels of seismic motion, at which the specimens reached to the ultimate stage, were examined. From the experimental result, no significant difference in damage levels such as residual crack width between the specimens under static and pseudo-dynamic loading was found. It is shown that the seismic capacity reduction factors ${\eta}$ can provide a reasonable estimation of post-earthquake seismic capacity of R/C buildings suffered earthquakes.

• 한국세라믹학회지
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• 제33권8호
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• pp.871-876
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• 1996

It is believed that fly ash could be suitable for preparing the sialon by carbothermal reduction method because the total amount of SiO2 and Al2O3 is above 80% and the unburned residual carbon is above 5% within the fly ash. The effects of reaction temperature (1350, 1400, 145$0^{\circ}C$) reaction time (1, 5, 10 hours) and the amount of carbon additions (C/SiO2=2, 3, 4 mole) on the $\beta$-sialon synthesis were obserbed, It was conformed that $\beta$-sialon (Z=2.15~2.18) was formed as major phase under all of the synthesis conditions and small amount of Si2ON2 SiC, AlN and Si3N4 was formed depending on the synthesis conditions. FeSix intermetal-lic compound was formed above 140$0^{\circ}C$ reaction temperature due to the large amount of iron oxides within the raw fly ash.

• International Journal of Precision Engineering and Manufacturing
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• 제1권2호
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• pp.105-114
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• 2000

An output feedback control (OFC) is presented for a linear stochastic system with known disturbance and applied to a flexible spacecraft for the reduction of residual vibration while allowing the natural deflection during operation. By converting the tracking problem into regulator problem, the OFC minimizes the expected value of a guadratic objective function composing of error stats which always remain on the intersection of sliding hypersurfaces. For the numerical evaluation with a flexible spacecraft, a large slewing maneuver strategy is devised with a tracking model for nominal trajectory and start-cost-stop strategy for economical maneuver in conjunction with the input shaping technique. The performance and efficacy of the proposed control scheme are illustrated with the comparison of different maneuver strategies.