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Fusion Analysis of Resting-State Networks and Its Application to Alzheimer's Disease

Tsinghua Science and Technology 2019年第4期24卷 456-467页

作者： Shengbing Pei Jihong Guan Shuigeng Zhou the Department of Computer Science and Technology Tongji University Shanghai Key Lab of Intelligent Information Processing School of Computer ScienceFudan University

Functional networks are extracted from resting-state functional magnetic resonance imaging data to explore the biomarkers for distinguishing brain disorders in disease diagnosis. Previous works have primarily focused on using a single Resting-State Network(RSN) with various techniques. Here, we apply fusion analysis of RSNs to capturing biomarkers that can combine the complementary information among the RSNs. Experiments are carried out on three groups of subjects, i.e., Cognition Normal(CN), Early Mild Cognitive Impairment(EMCI), and Alzheimer's Disease(AD) groups, which correspond to the three progressing stages of AD; each group contains18 subjects. First, we apply group independent Component Analysis(ICA) to extracting the Default Mode Network(DMN) and Dorsal Attention Network(DAN) for each subject group. Then, by obtaining the common DMN and DAN as templates for each group, we employ the individual ICA to extract the DMN and DAN for each subject.Finally, we fuse the DMNs and DANs to explore the biomarkers. The results show that(1) the templates generated by group ICA can extract the RSN for each subject by individual ICA effectively;(2) the RSNs combined with the fusion analysis can obtain more informative biomarkers than without fusion analysis;(3) the most different regions of DMN and DAN are found between CN and EMCI and between EMCI and AD, which show differences. For the DMN, the difference in the medial prefrontal cortex between the EMCI and AD is smaller than that between CN and EMCI, whereas that in the posterior cingulate between EMCI and AD is larger. As for the DAN, the difference in the intraparietal sulcus is smaller than that between CN and EMCI;(4) extracting DMN and DAN for each subject via the back reconstruction of group ICA is invalid.

关键词： independent Component Analysis(ICA) group analysis fusion analysis Alzheimer’s Disease(AD)

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DYADIC METHOD FOR TENSOR FUNCTIONS

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Acta Mechanica Sinica 2002年第4期18卷 398-406页

作者：黄永念鲁昊 State Key Laboratory of Turbulence Research Department of Mechanics and Engineering SciencePeking UniversityBeijing 100871China

In this paper,we discuss tensor functions by dyadic representation of tensor.Two different cases of scalar invariants and two different cases of tensor invari- ants are calculated.It is concluded that there are six independent scale invariants for a symmetrical tensor and an antisymmetrical tensor,and there are twelve invariants for two symmetrical tensors and an antisymmetrical tensor.And we present a new list of tensor invariants for the tensor-valued isotropic function.

关键词： dyadic scalar invariant tensor invariant independent

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ICM method for topology optimization of multimaterial continuum structure with displacement constraint

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Acta Mechanica Sinica 2019年第3期35卷 552-562页

作者： Hong-Ling Ye Zong-Jie Dai Wei-Wei Wang Yun-Kang Sui College of Mechanical Engineering and Applied Electronics Technology Beijing University of TechnologyBeijing 100124China

A new topology optimization method is formulated for lightweight design of multimaterial structures, using the independent continuous mapping (ICM) method to minimize the weight with a prescribed nodal displacement constraint. Two types of independent topological variable are used to identify the presence of elements and select the material for each phase, to realize the interpolations of the element stiffness matrix and total weight. Furthermore, an explicit expression for the optimized formulation is derived, using approximations of the displacement and weight given by first- and second-order Taylor expansions. The optimization problem is thereby transformed into a standard quadratic programming problem that can be solved using a sequential quadratic programming approach. The feasibility and effectiveness of the proposed multimaterial topology optimization method are demonstrated by determining the best load transfer path for four numerical examples. The results reveal that the topologically optimized configuration of the multimaterial structure varies with the material properties, load conditions, and constraint. Firstly, the weight of the optimized multimaterial structure is found to be lower than that composed of a single material. Secondly, under the precondition of a displacement constraint, the weight of the topologically optimized multimaterial structure decreases as the displacement constraint value is increased. Finally, the topologically optimized multimaterial structures differ depending on the elastic modulus of the materials. Besides, the established optimization formulation is more reliable and suitable for use in practical engineering applications with structural performance parameters as constraint.

关键词： independent continuous mapping method Multimaterial Topology optimization Continuous structure

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RAID 4SMR:RAID Array with Shingled Magnetic Recording Disk for Mass Storage Systems

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Journal of Computer Science & Technology 2019年第4期34卷 854-868页

作者： Quoc Le Ahmed Amer JoAnne Holliday Department of Computer Engineering School of EngineeringSanta Clara UniversitySanta ClaraCA 95053U.S.A.

One way to increase storage density is using a shingled magnetic recording(SMR)disk.We propose a novel use of SMR disks with RAID(redundant array of independent disks)arrays,specifically building upon and compared with a basic RAID 4 arrangement.The proposed scheme(called RAID 4SMR)has the potential to improve the performance of a traditional RAID 4 array with SMR disks.Our evaluation shows that compared with the standard RAID 4,when using update in-place in RAID arrays,RAID 4SMR with garbage collection not just can allow the adoption of SMR disks with a reduced performance penalty,but offers a performance improvement of up to 56%.

关键词： disk array redundant array of independent disks(RAID) shingled magnetic recording(SMR) shingled write

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Engineering stable heterosis

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Journal of Genetics and Genomics 2019年第1期46卷 1-3页

作者： Yingxiang Wang State Key Laboratory of Genetic Engineering and Ministry of Education Key Laboratory of Biodiversity Sciences and Ecological Engineering Institute of Plant Biology School of Life Sciences Fudan University

The ability to fix heterosis or hybrid vigor in crops without crossing holds great potential for crop yield improvement and global food security. Recent studies in Nature and Nature Biotechnology from two independent groups demonstrate the feasibility of clonal propagation of hybrids by engineering changes in meiosis and embryogenesis. These synthetic apomixis technologies represent a watershed moment for both understanding the fundamental basis of heterosis and plant breeding.

关键词： heterosis independent groups technologies represent

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Strong Laws of Large Numbers for Double Sums of Banach Space Valued Random Elements

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Acta Mathematica Sinica,English Series 2019年第5期35卷 583-596页

作者： Robert PARKER Andrew ROSALSKY Department of Biostatistics University of Florida Department of Statistics University of Florida

For a double array {V_(m,n), m ≥ 1, n ≥ 1} of independent, mean 0 random elements in a real separable Rademacher type p(1 ≤ p ≤ 2) Banach space and an increasing double array {b_(m,n), m ≥1, n ≥ 1} of positive constants, the limit law ■ and in L_p as m∨n→∞ is shown to hold if ■ This strong law of large numbers provides a complete characterization of Rademacher type p Banach spaces. Results of this form are also established when 0 < p ≤ 1 where no independence or mean 0 conditions are placed on the random elements and without any geometric conditions placed on the underlying Banach space.

关键词： Real separable Banach space double array of independent random elements strong law of large numbers almost sure convergence Rademacher type p Banach space convergence in Lp

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A high performance gas–liquid two-phase flow meter based on gamma-ray attenuation and scattering

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Nuclear Science and Techniques 2017年第11期28卷 271-279页

作者： G. H. Roshani E. Nazemi Electrical Engineering Department Kermanshah University of Technology Kermanshah Iran Nuclear Science and Technology Research Institute TehranIran Radiation Application Department Shahid Beheshti University Tehran Iran

The ability to precisely estimate the void fraction of multiphase flow in a pipe is very important in the petroleum industry. In this paper, an approach based on our previous works is proposed for predicting the void fraction independent of flow regime and liquid phase density changes in gas–liquid two-phase flows. Implemented technique is a combination of dual modality densitometry and multi-beam gamma-ray attenuation techniques. The detection system is comprised of a single energy fan beam,two transmission detectors, and one scattering detector. In this work, artificial neural network(ANN) was also implemented to predict the void fraction percentage independent of the flow regime and liquid phase density changes. Registered counts in three detectors and void fraction percentage were utilized as the inputs and output of ANN, respectively. By applying the proposed methodology, the void fraction was estimated with a mean relative error of less than just 1.2480%.

关键词： Gamma-ray Transmission and scattering Artificial neural network Density independent Flow regime independent Void fraction

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A polynomial-time algorithm for reducing the number of variables in MAX SAT problem

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Science China(Technological Sciences) 1997年第3期40卷 301-311页

作者：马绍汉梁东敏 Department of Computer Science Shandong University Jinan 250100 China

Maximum satisfiability (MAX SAT) problem is an optimization version of the satisfiability (SAT) problem. This problem arises in certain applications in expert systems and knowledge base revision. MAX SAT problem is NP-hard Some algorithms can solve this problem, but they are not adapted to the special cases where the number of variables is larger than the number of clauses. Usually, the number of variables has great impact on the efficiency of these algorithms. Thus, a polynomial-time algorithm is proposed to reduce the number of variables. Let T be any instance of the MAX SAT problem. The algorithm transforms T into another instance P of which the number of variables is smaller than the number of clauses of T. Using other algorithms, the optimal solution to P can be found, and it can be used to construct the optimal solution of T. Therefore, this algorithm is an efficient preprocessing step.

关键词： MAX SAT problem bipartite graph independent set complexity.

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Uniform dimension results of multi-parameter stable processes

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Science China Mathematics 1999年第9期42卷 932-944页

作者：林火南 Department of Mathematics Fujian Teachers ’ University Fuzhou China

The problem of uniform dimensions for multi-parameter processes, which may not possess the uniform stochastic H(?)lder condition, is investigated. The problem of uniform dimension for multi-parameter stable processes is solved. That is, if Z is a stable (N, d, α)-process and αN≤d, then (?)E(?)R_+~N, dimZ(E)=α·dimE holds with probability 1, where Z(E)={x:(?)t∈E, Z_t=x} is the image set of Z on E. The uniform upper bounds for multi-parameter processes with independent increments under general conditions are also given. Most conclusions about uniform dimension can be considered as special cases of our results.

关键词： uniform dimension processes with independent increments stable (N d α)-process.

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An ICA and EC based approach for blind equalization and channel parameter estimation

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Science China(Technological Sciences) 2000年第1期43卷 1-8页

作者：何振亚刘琚杨绿溪蔚承建 Department of Radio Engineering Southeast University Nanjing 210096 China Department of Radio Engineering Southeast University Nanjing 210096 China Department of Electronic Engineering Shandong University Jinan 250100 China

A new on-line blind equalization approach is proposed. The approach combines over-sampling technique with independent component analysis (ICA) neural network and can give equalized output on-line employing only the received signal. Based on the fourth-order cumulants and the characteristic of the linear system, the parameters of original channel are also estimated using evolutionary computation (EC). Compared to traditional equalization methods, the proposed algorithm is of simple architecture, does not need learning sequences apart from the observation, and can achieve both blind equalization and system identification. Computer simulations show good performance.

关键词： independent component analysis higher-order cumulants. evolutionary computation blind equal-ization .

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