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Two-level Bregmanized method for image interpolation with graph regularized sparse coding 被引量:1
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作者 刘且根 张明辉 梁栋 《Journal of Southeast University(English Edition)》 EI CAS 2013年第4期384-388,共5页
A two-level Bregmanized method with graph regularized sparse coding (TBGSC) is presented for image interpolation. The outer-level Bregman iterative procedure enforces the observation data constraints, while the inne... A two-level Bregmanized method with graph regularized sparse coding (TBGSC) is presented for image interpolation. The outer-level Bregman iterative procedure enforces the observation data constraints, while the inner-level Bregmanized method devotes to dictionary updating and sparse represention of small overlapping image patches. The introduced constraint of graph regularized sparse coding can capture local image features effectively, and consequently enables accurate reconstruction from highly undersampled partial data. Furthermore, modified sparse coding and simple dictionary updating applied in the inner minimization make the proposed algorithm converge within a relatively small number of iterations. Experimental results demonstrate that the proposed algorithm can effectively reconstruct images and it outperforms the current state-of-the-art approaches in terms of visual comparisons and quantitative measures. 展开更多
关键词 image interpolation Bregman iterative method graph regularized sparse coding alternating direction method
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Jointly-check iterative decoding algorithm for quantum sparse graph codes 被引量:1
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作者 邵军虎 白宝明 +1 位作者 林伟 周林 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第8期116-122,共7页
For quantum sparse graph codes with stabilizer formalism, the unavoidable girth-four cycles in their Tanner graphs greatly degrade the iterative decoding performance with standard belief-propagation (BP) algorithm. ... For quantum sparse graph codes with stabilizer formalism, the unavoidable girth-four cycles in their Tanner graphs greatly degrade the iterative decoding performance with standard belief-propagation (BP) algorithm. In this paper, we present a jointly-check iterative algorithm suitable for decoding quantum sparse graph codes efficiently. Numerical simulations show that this modified method outperforms standard BP algorithm with an obvious performance improvement. 展开更多
关键词 quantum error correction sparse graph code iterative decoding belief-propagation algorithm
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Graph Regularized Sparse Coding Method for Highly Undersampled MRI Reconstruction 被引量:1
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作者 张明辉 尹子瑞 +2 位作者 卢红阳 吴建华 刘且根 《Journal of Donghua University(English Edition)》 EI CAS 2015年第3期434-441,共8页
The imaging speed is a bottleneck for magnetic resonance imaging( MRI) since it appears. To alleviate this difficulty,a novel graph regularized sparse coding method for highly undersampled MRI reconstruction( GSCMRI) ... The imaging speed is a bottleneck for magnetic resonance imaging( MRI) since it appears. To alleviate this difficulty,a novel graph regularized sparse coding method for highly undersampled MRI reconstruction( GSCMRI) was proposed. The graph regularized sparse coding showed the potential in maintaining the geometrical information of the data. In this study, it was incorporated with two-level Bregman iterative procedure that updated the data term in outer-level and learned dictionary in innerlevel. Moreover,the graph regularized sparse coding and simple dictionary updating stages derived by the inner minimization made the proposed algorithm converge in few iterations, meanwhile achieving superior reconstruction performance. Extensive experimental results have demonstrated GSCMRI can consistently recover both real-valued MR images and complex-valued MR data efficiently,and outperform the current state-of-the-art approaches in terms of higher PSNR and lower HFEN values. 展开更多
关键词 magnetic resonance imaging graph regularized sparse coding Bregman iterative method dictionary updating alternating direction method
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Two-Level Bregman Method for MRI Reconstruction with Graph Regularized Sparse Coding
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作者 刘且根 卢红阳 张明辉 《Transactions of Tianjin University》 EI CAS 2016年第1期24-34,共11页
In this paper, a two-level Bregman method is presented with graph regularized sparse coding for highly undersampled magnetic resonance image reconstruction. The graph regularized sparse coding is incorporated with the... In this paper, a two-level Bregman method is presented with graph regularized sparse coding for highly undersampled magnetic resonance image reconstruction. The graph regularized sparse coding is incorporated with the two-level Bregman iterative procedure which enforces the sampled data constraints in the outer level and updates dictionary and sparse representation in the inner level. Graph regularized sparse coding and simple dictionary updating applied in the inner minimization make the proposed algorithm converge with a relatively small number of iterations. Experimental results demonstrate that the proposed algorithm can consistently reconstruct both simulated MR images and real MR data efficiently, and outperforms the current state-of-the-art approaches in terms of visual comparisons and quantitative measures. 展开更多
关键词 magnetic resonance imaging graph regularized sparse coding dictionary learning Bregman iterative method alternating direction method
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A New Framework for Software Vulnerability Detection Based on an Advanced Computing
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作者 Bui Van Cong Cho Do Xuan 《Computers, Materials & Continua》 SCIE EI 2024年第6期3699-3723,共25页
The detection of software vulnerabilities written in C and C++languages takes a lot of attention and interest today.This paper proposes a new framework called DrCSE to improve software vulnerability detection.It uses ... The detection of software vulnerabilities written in C and C++languages takes a lot of attention and interest today.This paper proposes a new framework called DrCSE to improve software vulnerability detection.It uses an intelligent computation technique based on the combination of two methods:Rebalancing data and representation learning to analyze and evaluate the code property graph(CPG)of the source code for detecting abnormal behavior of software vulnerabilities.To do that,DrCSE performs a combination of 3 main processing techniques:(i)building the source code feature profiles,(ii)rebalancing data,and(iii)contrastive learning.In which,the method(i)extracts the source code’s features based on the vertices and edges of the CPG.The method of rebalancing data has the function of supporting the training process by balancing the experimental dataset.Finally,contrastive learning techniques learn the important features of the source code by finding and pulling similar ones together while pushing the outliers away.The experiment part of this paper demonstrates the superiority of the DrCSE Framework for detecting source code security vulnerabilities using the Verum dataset.As a result,the method proposed in the article has brought a pretty good performance in all metrics,especially the Precision and Recall scores of 39.35%and 69.07%,respectively,proving the efficiency of the DrCSE Framework.It performs better than other approaches,with a 5%boost in Precision and a 5%boost in Recall.Overall,this is considered the best research result for the software vulnerability detection problem using the Verum dataset according to our survey to date. 展开更多
关键词 Source code vulnerability source code vulnerability detection code property graph feature profile contrastive learning data rebalancing
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Dynamic airspace sectorization via improved genetic algorithm 被引量:6
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作者 Yangzhou Chen Hong Bi +1 位作者 Defu Zhang Zhuoxi Song 《Journal of Modern Transportation》 2013年第2期117-124,共8页
This paper deals with dynamic airspace sectorization (DAS) problem by an improved genetic algorithm (iGA). A graph model is first constructed that represents the airspace static structure. Then the DAS problem is ... This paper deals with dynamic airspace sectorization (DAS) problem by an improved genetic algorithm (iGA). A graph model is first constructed that represents the airspace static structure. Then the DAS problem is formulated as a graph-partitioning problem to balance the sector workload under the premise of ensuring safety. In the iGA, multiple populations and hybrid coding are applied to determine the optimal sector number and airspace sectorization. The sector constraints are well satisfied by the improved genetic operators and protect zones. This method is validated by being applied to the airspace of North China in terms of three indexes, which are sector balancing index, coordination workload index and sector average flight time index. The improvement is obvious, as the sector balancing index is reduced by 16.5 %, the coordination workload index is reduced by 11.2 %, and the sector average flight time index is increased by 11.4 % during the peak-hour traffic. 展开更多
关键词 Dynamic airspace sectorization (DAS) Improved genetic algorithm (iGA) graph model Multiple populations Hybrid coding Sector constraints
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Construction of Short-Block Nonbinary LDPC Codes Based on Cyclic Codes 被引量:1
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作者 Hengzhou Xu Baoming Bai +2 位作者 Min Zhu Bo Zhang Yulong Zhang 《China Communications》 SCIE CSCD 2017年第8期1-9,共9页
In this paper, we focus on shortblock nonbinary LDPC(NB-LDPC) codes based on cyclic codes. Based on Tanner graphs' isomorphism, we present an efficient search algorithm for finding non-isomorphic binary cyclic LDP... In this paper, we focus on shortblock nonbinary LDPC(NB-LDPC) codes based on cyclic codes. Based on Tanner graphs' isomorphism, we present an efficient search algorithm for finding non-isomorphic binary cyclic LDPC codes. Notice that the parity-check matrix H of the resulting code is square and not of full rank, and its row weight and column weight are the same. By replacing the ones in the same column of H with a nonzero element of fi nite fi elds GF(q), a class of NB-LDPC codes over GF(q) is obtained. Numerical results show that the constructed codes perform well over the AWGN channel and have fast decoding convergence. Therefore, the proposed NB-LDPC codes provide a promising coding scheme for low-latency and high-reliability communications. 展开更多
关键词 nonbinary LDPC codes tanner graph isomorphism iterative decoding
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On Codes with w-identifiable Parent Property
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作者 马俊 熊瑜 《Journal of Shanghai Jiaotong university(Science)》 EI 2008年第4期487-490,共4页
A code is said to be a w-identifiable parent property code (or w-IPP code for short) if whenever d is a descendant of w (or fewer) codewords, and one can always identify at least one of the parents of d. Let C be an (... A code is said to be a w-identifiable parent property code (or w-IPP code for short) if whenever d is a descendant of w (or fewer) codewords, and one can always identify at least one of the parents of d. Let C be an (N,w + 1,q)-code and C* an (w + 1)-color graph for C. If a graph G is a subgraph of C* and consists of w +1 edges with different colors, then G is called a (w +1)-pattern of C*. In this paper, we proved that C is a w-IPP code if and only if there exists at most one vertex with color degree more than 1 in any (w + 1)-pattern of C*. 展开更多
关键词 w-identifiable parent property graph theory code graph
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