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Search Results: 1 - 10 of 74009 matches for " Zhi-Hui Xiao "
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Efficient and Effective Total Variation Image Super-Resolution: A Preconditioned Operator Splitting Approach
Li-Li Huang,Liang Xiao,Zhi-Hui Wei
Mathematical Problems in Engineering , 2011, DOI: 10.1155/2011/380807
Abstract: Super-resolution is a fusion process for reconstructing a high-resolution image from a set of low-resolution images. This paper proposes a novel approach to image super-resolution based on total variation (TV) regularization. We applied the Douglas-Rachford splitting technique to the constrained TV-based variational SR model which is separated into three subproblems that are easy to solve. Then, we derive an efficient and effective iterative scheme, which includes a fast iterative shrinkage/thresholding algorithm for denoising problem, a very simple noniterative algorithm for fusion part, and linear equation systems for deblurring process. Moreover, to speed up convergence, we provide an accelerated scheme based on precondition design of initial guess and forward-backward splitting technique which yields linear systems of equations with a nice structure. The proposed algorithm shares a remarkable simplicity together with a proven global rate of convergence which is significantly better than currently known lagged diffusivity fixed point iteration algorithm and fast decoupling algorithm by exploiting the alternating minimizing approach. Experimental results are presented to illustrate the effectiveness of the proposed algorithm.
Multiplicative Noise Removal via a Novel Variational Model
Huang Li-Li,Xiao Liang,Wei Zhi-Hui
EURASIP Journal on Image and Video Processing , 2010,
Abstract: Multiplicative noise appears in various image processing applications, such as synthetic aperture radar, ultrasound imaging, single particle emission-computed tomography, and positron emission tomography. Hence multiplicative noise removal is of momentous significance in coherent imaging systems and various image processing applications. This paper proposes a nonconvex Bayesian type variational model for multiplicative noise removal which includes the total variation (TV) and the Weberized TV as regularizer. We study the issues of existence and uniqueness of a minimizer for this variational model. Moreover, we develop a linearized gradient method to solve the associated Euler-Lagrange equation via a fixed-point iteration. Our experimental results show that the proposed model has good performance.
Multiplicative Noise Removal via a Novel Variational Model
Li-Li Huang,Liang Xiao,Zhi-Hui Wei
EURASIP Journal on Image and Video Processing , 2010, DOI: 10.1155/2010/250768
Abstract: Multiplicative noise appears in various image processing applications, such as synthetic aperture radar, ultrasound imaging, single particle emission-computed tomography, and positron emission tomography. Hence multiplicative noise removal is of momentous significance in coherent imaging systems and various image processing applications. This paper proposes a nonconvex Bayesian type variational model for multiplicative noise removal which includes the total variation (TV) and the Weberized TV as regularizer. We study the issues of existence and uniqueness of a minimizer for this variational model. Moreover, we develop a linearized gradient method to solve the associated Euler-Lagrange equation via a fixed-point iteration. Our experimental results show that the proposed model has good performance.
A Weberized Total Variation Regularization-Based Image Multiplicative Noise Removal Algorithm
Xiao Liang,Huang Li-Li,Wei Zhi-Hui
EURASIP Journal on Advances in Signal Processing , 2010,
Abstract: Multiplicative noise removal is of momentous significance in coherent imaging systems and various image processing applications. This paper proposes a new nonconvex variational model for multiplicative noise removal under the Weberized total variation (TV) regularization framework. Then, we propose and investigate another surrogate strictly convex objective function for Weberized TV regularization-based multiplicative noise removal model. Finally, we propose and design a novel way of fast alternating optimizing algorithm which contains three subminimizing parts and each of them permits a closed-form solution. Our experimental results show that our algorithm is effective and efficient to filter out multiplicative noise while well preserving the feature details.
A Weberized Total Variation Regularization-Based Image Multiplicative Noise Removal Algorithm
Liang Xiao,Li-Li Huang,Zhi-Hui Wei
EURASIP Journal on Advances in Signal Processing , 2010, DOI: 10.1155/2010/490384
Abstract: Multiplicative noise removal is of momentous significance in coherent imaging systems and various image processing applications. This paper proposes a new nonconvex variational model for multiplicative noise removal under the Weberized total variation (TV) regularization framework. Then, we propose and investigate another surrogate strictly convex objective function for Weberized TV regularization-based multiplicative noise removal model. Finally, we propose and design a novel way of fast alternating optimizing algorithm which contains three subminimizing parts and each of them permits a closed-form solution. Our experimental results show that our algorithm is effective and efficient to filter out multiplicative noise while well preserving the feature details.
Performance Analysis and Optimization for Cluster System Based on HPL Benchmark
基于HPL测试的集群系统性能分析与优化

WANG Xiao-Ying,DU Zhi-Hui,
王晓英
,都志辉

计算机科学 , 2005,
Abstract: Cluster system has become increasingly significant in High Performance Computing(HPC) research field be- cause of its high performance/cost ratio and good scalability. How to evaluate and optimize the performance of cluster system becomes a key issue in this field. The World TOP500 computer rank list uses HPL as a standard benchmark, from which the optimized performance of clusters on floating-point operations can be obtained. Specific tests are carried out for a typical cluster system, and then some most important factors which affect the performance of the whole sys- tem are studied. With the analysis of these factors in detail, this article proposed some methods of optimization for cluster systems, which have both practical significance and researching value.
Genetic mutation analysis of HBV covalently closed circular DNA in peripheral blood mononuclear cells from chronic hepatitis B patients with nucleos(t)ide analog-resistant mutations in serum virions
Zhong-bin LI,Xiao-qiang REN,Yan LIU,Zhi-hui XU
Medical Journal of Chinese People's Liberation Army , 2012,
Abstract: Objective  To analyze the characteristics of genetic mutations in reverse-transcriptase (RT) domain of HBV covalently closed circular DNA (cccDNA) in peripheral blood mononuclear cells (PBMCs) obtained from chronic hepatitis B (CHB) patients with drug-resistant mutations in serum virions during nucleoside/nucleotide analog (NA) therapy. Methods  A total of 30 CHB patients admitted to 302 Hospital of PLA from July 2010 to August 2011 were included in this study. All the patients were confirmed to harbor the drug-resistant mutations in serum virions during an NA therapy longer than 6 months. Total DNA was extracted from PBMCs isolated from 30 whole blood samples at the same time point as that of serum analysis. Plasmid-safe ATP-dependent DNase (PSAD) digestion in combination with rolling circle amplification and gap-spanning semi-nested PCR were used to amplify the RT region of HBV cccDNA. NA-resistant-associated mutations were analyzed at nine sites. Results  HBV cccDNA was efficiently amplified in 16 out of 30 (53.3%) PBMC samples, and the detection rate was not correlated with HBeAg-positive rate, serum ALT level or HBV DNA load. Five of 16 (31.3%) patients were sustained to have genotype B HBV infection, and 11 of 16 (68.8%) were of genotype C HBV infection, and the result was consistent with the genotyping results using serum HBV. Different from drug-resistant mutations detected in the serum virions, the viruses detected in HBV cccDNA of 16 PBMC samples were all wild-type viruses without NA-resistant-associated mutations in RT region. Conclusions  During NA antiviral treatment, if drug-resistant mutations occur in serum HBV DNA of CHB patients, the dominant species of HBV cccDNA in PBMCs from the same patient is still the original wild-type strains. It is speculated that PBMCs might be the potential "repository" of HBV wild-type strain in vivo.
Up-regulation effect of hepatitis B virus genome A1846T mutation on viral replication and core promoter activity
Ling JIANG,Zhi-hui XU,Yan LIU,Xiao-dong LI
Medical Journal of Chinese People's Liberation Army , 2013,
Abstract: Objective  To evaluate the influence of hepatitis B virus (HBV) genome nucleotide A1846T mutation on the viral replication capacity and the transcription activity of HBV core promoter (CP) in vitro. Methods  A total of 385 patients with hepatitis B admitted to the 302 Hospital of PLA were enrolled in the study, including 116 with moderate chronic hepatitis B (CHB-M), 123 with severe chronic hepatitis B (CHB-S), and 146 with acute-on-chronic liver failure (ACLF). Serum HBV DNA was isolated and full-length HBV genome was amplified. The incidence of A1846T was analyzed. Full-length HBV genomes containing 1846T mutation were cloned into pGEM-T easy vector, and the counterpart wild-type 1846A plasmids were obtained by site-directed mutagenesis. The full-length HBV genome was released from recombinant plasmid by BspQ Ⅰ/Sca Ⅰ digestion, and then transfected into HepG2 cells. Secreted HBsAg level and intracellular HBV core particles were measured 72 hours post-transfection to analyze the replication capacity (a 1.0-fold HBV genome model). 1846 mutant and wild-type full-length HBV genomes were extracted to amplify the fragment of HBV CP region, and the dual luciferase reporter of the pGL3-CP was constructed. The luciferase activity was detected 48 hours post-transfection. Results  The incidence of A1846T mutation gradually increased with the severity of hepatitis B, reaching 31.03%, 42.27%, and 55.48% in CHB-M, CHB-S and ACLF patients respectively (P<0.01). The replication capacity of 1846T mutants, level of secreted HBsAg, and transcriptional activity of CP promoter were increased by 320%, 28% and 85% respectively, compared with 1846A wild-type strains. While the more common double mutation A1762T/G1764A in CP region was increased by 67%, 9% and 72% respectively, compared with its counterpart wild-type strains. A1846T had a greater influence on viral replication capacity in vitro. Conclusions A1846T mutation could significantly increase the replication capacity of hepatitis B virus, secretion of HBsAg and transcription activity of CP promoter, and cis-activate the downstream gene transcription. The finding indicates that HBV genome A1846T mutation might play a role in liver disease progression.
Update analysis of tau- --> V P- nu(tau): Theory and Experiment
Guo, Zhi-Hui
High Energy Physics - Phenomenology , 2008, DOI: 10.1016/j.nuclphysbps.2008.12.041
Abstract: Within the resonance chiral theory, we have studied the process of a tau lepton decaying into a vector resonance plus a pseudo-Goldstone meson and a tau neutrino. Two kinds of processes are discussed: (a) tau- --> (rho pi-,omega pi-, phi pi-, K*0 K-) nu(tau), belonging to Delta S=0 processes and (b) Delta S = 1 processes, such as tau- --> (rho K-, omega K-,phi K-,\bar{K*0} pi-) nu(tau). To fit the tau- --> omega pi- nu(tau) spectral function and the decay distribution of tau- --> omega K- nu(tau) to get unknown resonance couplings, we then make a prediction for branching ratios of all channels.
Research of Image Content Based Digital Watermarking Model and Algorithm in Ridgelet Transform Domain
基于图像内容的脊波变换域数字水印模型和算法研究

Xiao Liang,Wei Zhi-hui,Wu Hui-zhong,
肖亮
,韦志辉,吴慧中

电子与信息学报 , 2004,
Abstract: In this paper, an image content based perceptual watermarking model using ridgelet transform is presented. It provides a new visual model, which can exactly evaluate the Just Noticeable Distortion (JND) tolerance of human visual system. The watermarking algorithm is designed to address the issue of how to improve the robustness and the security of the embedded watermark according to the image content. In order to improve the robustness and transparency, the watermark bits are inserted in the visual significant ridgelet coefficients without exceeding the maximum strength of JND. With the spread spectrum technique and the secret key protection, the security of the embedded watermark is also guaranteed very well. Through analyzing the statistical property of the watermarked image, a threshold selection method based on Neymann-Pearson principle is presented and then the embedded watermark can be blindly detected by correlation coefficients between the original image and the watermark sequence. Experiments show that the proposed method can achieve a better tradeoff between the robustness and transparency.
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