• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1394-1397
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• 1987

It is difficult to detect edge segments from a noisy image since the image have a noise in piratical applications which utilize some type of visual input capability. Hence, the proposed algorithm consists of the modality tests based on parallel statistical tests without a noise removal preprocessing or postprocessing, and the edge detection technique With one-Pixel edge segments in this paper. The algorithm is very reliable and effective in the case of those situations where the Picture is poor quality and low resolution. And it does'nt require thinning operation and thresholding in hand. Experimental comparision With the more conventional techniques when applied to typical low-quality Pictures confirms good capabilities of the algorithm.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.791-796
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• 2000

The cavitation-induced fluctuating pressure of the container ship named "Sydney Express" is measured in Samsung Large Cavitation Tunnel(SCAT). In the measurements, a complete ship model is employed. The effects of thrust coefficient and cavitation number on cavity pattern and cavitation-induced fluctuating pressure were investigated experimentally. It is demonstrated that the fluctuating pressure coefficient is very sensitive to the cavitation number. The results of cavitation and pressure fluctuations are compared with those of ITTC and HSVA, which shows fairly good agreement. It is exhibited that the removal of rudder can significantly change the loading condition of a propeller, and can reduce the fluctuating pressure coefficient almost by half.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.345-349
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• 2003

The dynamic behavior of CANDU nuclear fuel channel was analyzed by the use of 3-dimensional finite element method, under the various fault conditions such as a fault in the end fitting support and the removal/migration of the garter spring in the fuel channel, in order to predict the dynamic behavior for a degraded symptoms of CANDU nuclear fuel channel. Moreover, the frequency response analysis for possible fault conditions was also peformed considering the effects of the pressure tube vibration and flow-induced vibration by the coolant flow. From the analysis of the frequency responses, defects in the garter spring have influenced the changes of 2nd and 3rd modes and all the important modes are varied for the failure in the journal bearing in the end fitting body.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.363-364
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• 2014

국내 에너지의 장기적인 수요상황을 볼 때 원자력 발전의 비중이 확대되는 것은 불가피 하므로 환경 친화적인 사용 후 핵연료의 관리 및 고준위 폐기물의 처분방안의 마련은 원자력의 개발만큼이나 중요하다. 이에 본 연구에서는 방사성 폐기물의 효율적인 관리와 저장 및 열제거를 위하여 최적 환기시스템을 적용한 처분장 설계를 목적으로 여러 환기시스템 설계안을 비교 분석하였다. 분석결과, 8가지 중 case 4(병렬회로)와 case 6(혼합 Diagonal 회로)의 환기효율이 우수한 결과를 나타냈으며, 이와 같은 연구를 통해 환경 친화적인 처분장의 건설이 가능할 것이다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.8-9
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• 2019

Euro forms and aluminum forms, which are currently used in formwork construction sites are limited by their heavy weight and the use of environmentally hazardous form oils. Therefore, in this study, 'eco-friendly light weight form' was developed, which does not require form oils during the removal process of form. In addition, the superiority of the developed form was verified by comparison with Euro forms and aluminum forms in terms of noise generation and weight. Application of the eco-friendly light weight form in construction sites is expected to reduce the noise level, and increase workers' convenience. The productivity of formwork is also increased.

• ETRI Journal
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• v.37 no.3
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• pp.637-645
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• 2015

Common-mode noise (CMN) is an unresolved problem in wireless capsule endoscopy (WCE) systems. In a WCE system, CMN originates from various electric currents found within the human body or external interference sources and causes critical demodulation performance degradation. The differential operation, a typical method for the removal of CMN rejection, can remove CMN by subtracting two signals simultaneously received by two reception sensors attached to a human body. However, when there is impedance mismatching between the two reception sensors, the differential operation method cannot completely remove CMN. Therefore, to overcome this problem, we propose an enhanced CMN rejection method. The proposed method performs not only subtraction but also addition between two received signals. Then a CMN ratio can be estimated by sufficient accumulation of division operation outcomes between the subtraction and addition outputs during the guard period. Finally, we can reject the residual CMN by combining the subtraction and addition outputs.

• Proceedings of the IEEK Conference
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• 2007.07a
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• pp.413-414
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• 2007

Successful speech recognition in noisy environments for intelligent robots depends on the performance of preprocessing elements employed. We propose an architecture that effectively combines adaptive beamforming (ABF) and blind source separation (BSS) algorithms in the spatial domain to avoid permutation ambiguity and heavy computational complexity. We evaluated the structure and assessed its performance with a DSP module. The experimental results of speech recognition test shows that the proposed combined system guarantees high speech recognition rate in the noisy environment and better performance than the ABF and BSS system.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.11
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• pp.268-272
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• 1996

The removal of impulsive noise terms which occur in interventricular pressure (IVP) signals of a Korean-type total artificial heart is essential for estimation of atrial pressure change. We compared various order statistic filters and conclude that median filter with sidelength L = 1 is the most appropriate filter for IVP signals in the perspectives of operation cost, detail preserving (peak value), and waveform.

• Communications for Statistical Applications and Methods
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• v.29 no.1
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• pp.27-40
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• 2022

In this paper, the focus on the removal noise in the binary image based on the variational Bayesian method with the Ising model. The observation and the latent variable are the degraded image and the original image, respectively. The posterior distribution is built using the Markov random field and the Ising model. Estimating the posterior distribution is the same as reconstructing a degraded image. MCMC and variational Bayesian inference are two methods for estimating the posterior distribution. However, for the sake of computing efficiency, we adapt the variational technique. When the image is restored, the iterative method is used to solve the recursive problem. Since there are three model parameters in this paper, restoration is implemented using the VECM algorithm to find appropriate parameters in the current state. Finally, the restoration results are shown which have maximum peak signal-to-noise ratio (PSNR) and evidence lower bound (ELBO).

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.57-59
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• 2020

본 논문에서는 컨볼루션 신경망을 이용하여 다시점 비디오의 중간 시점 양자화 노이즈를 제거하는 방안을 제안한다. 다시점 비디오에서 중간 시점의 화질을 개선하기 위한 방안으로 인접 시점의 정보를 활용하였다. 제안하는 알고리즘을 적용하여 중간 시정에서의 양자화 노이즈를 제거할 수 있으며, 화질 (PSNR, peak-to-noise ratio)를 개선할 수 있다. 인접 시접의 정보를 활용할 경우, 일반적인 양자화 노이즈에 대해서 학습한 결과 대비 성능 향상을 제공한다.