• Journal of IKEEE
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• v.22 no.4
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• pp.1109-1114
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• 2018

Electroencephalogram (EEG) is a tool used to study brain activity caused by external stimuli. In this process, artifacts are mixed and it is easy to distort the signal, so post-processing is necessary to remove it. Independent Component Analysis (ICA) is a widely used method for removing artifact. This method has a disadvantage in that it has excellent performance but some loss of brain wave information. In this paper, we propose a method to reduce EEG information loss by restricting the filter coverage using eye blink information obtained from Eyetracker. We then compared the results of the proposed method with the conventional method using quantization methods such as Signal to Noise Ratio (SNR) and Spectral Coherence (SC).

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.729-736
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• 2019

In this paper, we propose a method to improve the background sound separation performance by adding a Wiener filter to the end of the non - negative matrix factorization method. In the case of a mixed voice signal with background sound, a part that has not yet been completely separated may remain in the signal that separated first by the non-negative matrix factorization method. In this case, it can be reduced in proportion to the size of the residual signal due to the Wiener filter, so that the background sound separation or reduction effect can be expected. Experimental results show that the addition of the Wiener filter is more effective than the case of applying the non-negative matrix factorization method.

• The Magazine of the IEIE
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• v.42 no.7
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• pp.45-53
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• 2015

Power 소자 기술은 digital & mixed signal device와 on-chip 구현을 위해서 CMOS 공정에 대한 기본 이해가 필요하다. CMOS 공정 기반 위에 power device 공정을 추가하면서 다양한 operation voltage의 power 소자를 구현하고, passive device 들을 동일 공정에서 구현하여 다양한 components 들로 power IC 제품을 design 할 수 있도록 modular process를 제공하는 것이 중요하다. 또한 power device로 주로 사용되는 LDMOS 소자에 대한 performance 개선을 위해 simulation을 통해 key device parameter들의 특성을 예측하고, 구조를 설계하는 것이 Si process 전에 중요한 일 중의 하나이다. 아울러 power management가 potable power, consumer electronics 및 green energy에서 가장 빠르게 성장하는 분야이므로, 차별화된 power 소자 기술을 확보하여 급변하는 시장 환경에 대응하는 것이 필요하다.

• Proceedings of the IEEK Conference
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• 2002.06b
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• pp.149-152
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• 2002

The performance of a 1-bit DAC depends on that of the analog circuits. The mixed SC-CT (switched capacitor-continuous time) architecture is an effective design methodology for the analog circuits. This paper Proposes a new buffer scheme for the 1-bit digital-to-analog subconverter and a new SF-DSC(smoothing filter and differential-to-sig le converter) which performs both the smoothing filter and the differential-to-single convertor simultaneously.

• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.3
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• pp.226-232
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• 2002

This paper explains a technique to improve the fault coverage of oscillation-test [1-5] for linear analog circuits. The transient behavior of the virtual ground is monitored during oscillation to extract information of the circuit. The limitation of the oscillation-test is analyzed, and an efficient signature analysis technique is proposed to maximize the fault coverage. The experimental result proves that the parametric fault coverage can be significantly increased by the proposed technique.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1983.10a
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• pp.102-104
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• 1983

This paper analyzes the patterns of Toneburst Waveform that generated Volumetarily in Broadband, as various Parameters, and applicate in the case that it is mixed Random Noise. As a result, it prooves that auto correlation function is Optimal parameter in analysis of Tone Burst wave form but reference signal.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.31-31
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• 2014

I provide an observer's view on the recent BICEP2 results. I begin with giving background information on the instrument and CMB polarization measurements. Based on a survey of the current debate, I will provide an overview on the conclusions to be drawn from the BICEP2 measurements which are actually mixed: on the hand, there is no doubt that the results are very important and exciting; on the other hand, it is probably premature to conclude that the observed signal is indeed cosmological.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.296-301
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• 1999

Background: Generally, it is difficult to differentiate uterine malignant mixed M$\ddot{u}$ llerian tumor(MMMT) from endometrial carcinom in radiological and clinical aspects. Our purpose is to investigate MR findings that distinguishes MMMT from endometrial carcinoma. Materials and Methods: We retrogradely evaluated the magnetic resonance imaging findings of pathologically proven 5 cases of malignant mixed M$\ddot{u}$llerian tumor(MMMT) and 14 endometrial carcinomas to know the differential points of these two tumors originating in the endometrial cavity. The size of the mass, presence or absence of myometrial or uterine cervical invasion, growth pattern of the mass, signal intensity and degree and pattern of contrast enhancement were analyzed and compared. Results: The length of the long axis of the MMMT was 1.5-9.0cm(average, 5.7cm) but that of the endometrial carcinoma was 0.5-6.0cm(average, 2.5cm). Invasion of uterine cervix which was found in 3 MMMT cases, dilated the endometrial cavity and the lumen of the uterine cervix and showed the pattern of growing into the external os. Invasion of uterine cervix was found in only one case of endometrial carcinoma. The presence or absence of myometrial invasion, the signal intensity and homogeneity on T1- and T2-weighted images, and the degree and patterns of contrast enhancement showed no significant difference. Conclusion: Any specific finding to differentiate MMMT from endometrial carcinoma was not ascertained. However, MMMT can be suspected if the size of the endometrial mass is greater than 5cm and if the mass dilates the enocervical canal and invades the uterine cervix.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.1
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• pp.139-145
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• 2015

This paper compare the VSCA (Variable stepsize Square Contour Algorithm) and VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSCA and VSDA, it is possible to the improving the equalization performance by varing the stepsize using the concept of distance adjusted approach for constellation matching. We compare the performance of the VSCA and VSDA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSCA algorithm has better than the VSDA in every performance index.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.1
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• pp.85-91
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• 2014

This paper relates with the VSDA (Variable stepsize Square contour Decision directed Algorithm) adaptive equalization algorithm that is used for the minimization of the intersymbol interference due to the distortion which occurs in the time dispersive channel for the transmission of 16-QAM signal.. In the conventional SCA, it is possible to compensates the amplitude and phase in the received signal that are mixed with the intersymbol interference by the constellatin dependent constant by using the 2nd order statistics of the transmitted signal. But in the VSDA, it is possible to the increasing the equalization performance by adding the concept of distance adjusted approach for constellation matching and the cost function of decision directed. We compare the performance of VSDA and SCA algorithm by the computer simulation. For this, the equalizer output signal constellation, residual isi, maximum distortion and MSE were used in the performace index. As a result of computer simulation, the VSDA algorithm has better than the SCA in convergence speed, but it gives nearly same equalization performance in other index.