• KSBB Journal
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• v.16 no.4
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• pp.381-388
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• 2001

A program for integrated gene expression profile analysis such as hierarchical clustering, K-means, fuzzy c-means, self-organizing map(SOM), principal component analysis(PCA), and singular value decomposition(SVD) was made for DNA chip data anlysis by using Matlab. It also contained the normalization method of gene expression input data. The integrated data anlysis program could be effectively used in DNA chip data analysis and help researchers to get more comprehensive analysis view on gene expression data of their own.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2015.11a
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• pp.173-175
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• 2015

We proposed a blind watermarking scheme using singular vectors based on Discrete Wavelet Transform (DWT) and Redundant Discrete Wavelet Transform (RDWT) combined with Singular Value Decomposition (SVD) for copyright protection application. We replaced the 1st left and right singular vectors decomposed from cover image with the corresponding ones from watermark image to overcome the false-positive problem in current watermark systems using SVD. The proposed scheme realizes the watermarking system without a false positive problem, and shows high fidelity and robustness.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.5
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• pp.1041-1046
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• 2009

In this paper, we proposed a robust watermark scheme for image based on SVD(Singular Value Transform) and Triplet. First, the original image is decomposed by using 3-level DWT, and then used the singular values changed for embedding and extracting of the watermark sequence in LL3 band. Since the matrix of singular values is not easily altered with various signal processing noises, the embedded watermark sequence has the ability to withstand various signal processing noise attacks. Nevertheless, this method does not guarantee geometric transformation(such as rotation, cropping, etc.) because the geometric transformation changes the matrix size. In this case, the watermark sequence cannot be extracted. To compensate for the above weaknesses, a method which uses the triplet for embedding a barcode image watermark in the middle of frequency band is proposed. In order to generate the barcode image watermark, the pattern of the watermark sequence embedded in a LL3 band is used. According to this method, the watermark information can be extracted from attacked images.

• Journal of Information Processing Systems
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• v.11 no.3
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• pp.406-420
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• 2015

We present a secure and robust image watermarking scheme that uses combined reversible DWT-DCT-SVD transformations to increase integrity, authentication, and confidentiality. The proposed scheme uses two different kinds of watermarking images: a reversible watermark, $W_1$, which is used for verification (ensuring integrity and authentication aspects); and a second one, $W_2$, which is defined by a logo image that provides confidentiality. Our proposed scheme is shown to be robust, while its performances are evaluated with respect to the peak signal-to-noise ratio (PSNR), signal-to-noise ratio (SNR), normalized cross-correlation (NCC), and running time. The robustness of the scheme is also evaluated against different attacks, including a compression attack and Salt & Pepper attack.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.03a
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• pp.97-104
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• 2008

Most of engine control systems for helicopter turboshaft engines are equipped with dual sensors. For the system with dual redundancy, analytic methods are used to detect faults based on the system dynamical model. Helicopter engine dynamics are affected by aerodynamic torque induced from the dynamics of the main rotor. In this paper an engine model including the rotor dynamics is constructed for the T700-GE-700 turboshaft engine powering UH-60 helicopter. The singular value decomposition(SVD) method is applied to the developed model in order to detect sensor faults. The SVD method which do not need an additional computation to generate residual uses the characteristics that the system outputs in direction of the left singular vector if an input is applied in direction of the right singular vector. Simulations show that the SVD method works well in detecting and isolating the sensor faults.

• Journal of Information Processing Systems
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• v.19 no.3
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• pp.275-288
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• 2023

Many image edge details are easily lost in the image denoising process, and the smooth image regions are prone to produce jagged. In this paper, we propose a wavelet-based image global k- singular value decomposition variational method to remove image noise. A layer of wavelet decomposition is applied to the noisy image first. Then, the image global k-singular value decomposition (IGK-SVD) method is used to remove the random noise of low-frequency components. Furthermore, a constructed variational denoising method (VDM) removes the random noise in the high-frequency component. Finally, the denoised image is obtained by wavelet reconstruction. The experimental results show that the proposed method's peak signal-to-noise ratio (PSNR) value is higher than other methods, and its structural similarity (SSIM) value is closer to one, indicating that the proposed method can effectively suppress image noise while retaining more image edge details. The denoised image has better denoising effects.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.963-965
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• 2021

본 논문에서는 위성 영상과 같은 원격 센싱 영상 등의 저 대비 영상의 화질을 개선하기 위하여 SVD (singular value decomposition)를 이용한 적응적 히스토그램 평활화 기법을 제안한다. 저 대비 영상의 특이값과 히스토그램 평활화 영상의 특이값을 결합하되, 사용자 파라미터를 통해 영상의 화질을 조절할 수 있도록 적응적 화질 개선 기법을 제안한다. 위성 영상을 비롯한 다양한 영상을 대상으로 실험한 결과 제안하는 방법이 기존의 히스토그램 평활화 기법 및 이를 개선한 방법에 비해 GSD (global standard deviation)으로 측정한 객관적 수치 측면에서 우수한 성능을 나타내고, 주관적 화질 측면에서 자연스럽고 영상의 어두운 영역 및 밝은 영역에서의 디테일 보존 성능이 우수함을 확인할 수 있다.

• Journal of Chest Surgery
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• v.41 no.6
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• pp.695-702
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• 2008

Background: The choice between a bioprosthetic and a mechanical valve is an important decision in cardiac valve surgery, and the durability of the tissue valve is a major decision factor. We retrospectively evaluated the midterm results of bioprosthetic valve replacement in the mitral position. Material and Method: The subjects were all patients who had undergone mitral bioprosthesis replacement between July 1989 and August 200.7. Among the 216 patients, there were 236 surgical cases. The mean age was $63{\pm}15$ years, and the male to female ratio was 1 : 3. We retrospectively analyzed hospital and outpatient records such that the total follow-up duration amounted to 760.2 patient-years, and the mean follow-up duration was $41.9{\pm}40.7$ months (range $0{\sim}212$ months). Result: Early death occurred in 18 patients (8.3%), and 13 of these underwent concomitant cardiac procedures. The survival rate after 5 years was $79.9{\pm}3.5%$, and the survival rate after 8 years was $65.5{\pm}5.5%$, while freedom from structural valve deterioration (SVD) was $96.2{\pm}2.2%$ at 5 years and $85.9{\pm}5.3%$ at 8 years. Freedom from reoperation was $90.6{\pm}1.7%$ at 5 years and $90.4{\pm}4.2%$ at 8 years, while freedom from reoperation for SVD was $98.1{\pm}1.2%$ at 5 years and $92.3{\pm}4.1%$ at 8 years. On multivariate analysis of preoperative risk factors, small valve size (between 25mm and 27mm) was a significant risk factor for reoperation, and low LV ejection fraction (<40%) was a significant risk factor for SVD and mortality. Conclusion: Survival and freedom from reoperation for SVD in mitral bioprosthesis replacement had acceptable midterm results, but freedom from SVD Was relatively low. In particular, since SVD increased sharply at the eighth postoperative year, frequent follow-up and echocardiograms around that time will be helpful for the early detection of SVD. It will be necessary to conduct further studies involving long-term follow-up and more patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2393-2399
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• 2013

In this paper, we proposed a method to screening of Alzheimer's disease (AD) from Raman spectra of platelet with synthesis of basis spectra using singular value decomposition (SVD). Raman spectra of platelet from AD transgenic mice are preprocessed with denoising, removal background and normalization method. The column vectors of each data matrix consist of Raman spectrum of AD and normal (NR). The matrix is factorized using SVD algorithm and then the basis spectra of AD and NR are determined by 12 column vectors of each matrix. The classification process is completed by select the class that minimized the root-mean-square error between the validation spectrum and the linear synthesized spectrum of the basis spectra. According to the experiments involving 278 Raman spectra, the proposed method gave about 97.6% classification rate, which is better performance about 6.1% than multi-layer perceptron (MLP) with extracted features using principle components analysis (PCA). The results show that the basis spectra using SVD is well suited for the diagnosis of AD by Raman spectra from platelet.

• The Journal of the Petrological Society of Korea
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• v.4 no.1
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• pp.49-58
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• 1995

Staurolite-biotite-andalusite-garnet (SBAG) assemblage and its sub-assemblages (SBA and SBG) commonly occur in the Dueumri Formation near the Chunyang granite, belonging to andalusite and sillimanite zones. The occurrence of the SBAG mineral assemblage is unusual because it is univariant in the $K_2O-FeO-MgO-Al_2O_3-SiO_2-H_2O$ (KFMASH) model system. We used projection and singular value decomposition (SVD) methods to investigate the equilibrium relationship between SBAG and its sub-assemblage. The SVD modelling of single specimen containing the SBAG assemblage suggests no reaction relationship with respect to mass-balance. Thus, the SBAG assemblages are stabilized by non-KFMASH component. On the other hand, the AFM-Mn projection suggests a reaction relationship between SBAG and its sub-assemblage because they intersect each other in this composition space. The SVD modelling, however, suggests no reaction relationship between these assemblages. Thus, the SBAG assemblages are likely to be stabilized by the variation in bulk-rock composition and/or 1.1~2,. The stable occurrence of staurolite in the sillimanite zone is compatible with pressure estimates from the garnet-plagioclase-biotite-muscovite geobarometer.