2D Minimum Compliance Topology Optimization Based on a Region Partitioning Strategy

This paper presents an extended sequential element rejection and admission(SERA)topology optimizationmethod with a region partitioning strategy.Based on the partitioning of a design domain into solid regions and weak regions,the proposed optimizationmethod sequentially implements finite element analysis(FEA)in these regions.After standard FEA in the solid regions,the boundary displacement of the weak regions is constrained using the numerical solution of the solid regions as Dirichlet boundary conditions.This treatment can alleviate the negative effect of the material interpolation model of the topology optimization method in the weak regions,such as the condition number of the structural global stiffness matrix.For optimization,in which the forward problem requires nonlinear structural analysis,a linear solver can be applied in weak regions to avoid numerical singularities caused by the over-deformedmesh.To enhance the robustness of the proposedmethod,the nonmanifold point and island are identified and handled separately.The performance of the proposed method is verified by three 2D minimum compliance examples.

Highly Available Hypercube Tokenized Sequential Matrix Partitioned Data Sharing in Large P2P Networks

Peer-to-peer (P2P) networking is a distributed architecture that partitions tasks or data between peer nodes. In this paper, an efficient Hypercube Sequential Matrix Partition (HS-MP) for efficient data sharing in P2P Networks using tokenizer method is proposed to resolve the problems of the larger P2P networks. The availability of data is first measured by the tokenizer using Dynamic Hypercube Organization. By applying Dynamic Hypercube Organization, that efficiently coordinates and assists the peers in P2P network ensuring data availability at many locations. Each data in peer is then assigned with valid ID by the tokenizer using Sequential Self-Organizing (SSO) ID generation model. This ensures data sharing with other nodes in large P2P network at minimum time interval which is obtained through proximity of data availability. To validate the framework HS-MP, the performance is evaluated using traffic traces collected from data sharing applications. Simulations conducting using Network simulator-2 show that the proposed framework outperforms the conventional streaming models. The performance of the proposed system is analyzed using energy consumption, average latency and average data availability rate with respect to the number of peer nodes, data size, amount of data shared and execution time. The proposed method reduces the energy consumption 43.35% to transpose traffic, 35.29% to bitrev traffic and 25% to bitcomp traffic patterns.

THE SUPERIORITY OF EMPIRICAL BAYES ESTIMATION OF PARAMETERS IN PARTITIONED NORMAL LINEAR MODEL

In this article,the empirical Bayes（EB）estimators are constructed for the estimable functions of the parameters in partitioned normal linear model.The superiorities of the EB estimators over ordinary least-squares（LS）estimator are investigated under mean square error matrix（MSEM）criterion.

Adaptive partition intuitionistic fuzzy time series forecasting model

To enhance the accuracy of intuitionistic fuzzy time series forecasting model, this paper analyses the influence of universe of discourse partition and compares with relevant literature. Traditional models usually partition the global universe of discourse, which is not appropriate for all objectives. For example, the universe of the secular trend model is continuously variational. In addition, most forecasting methods rely on prior information, i.e., fuzzy relationship groups (FRG). Numerous relationship groups lead to the explosive growth of relationship library in a linear model and increase the computational complexity. To overcome problems above and ascertain an appropriate order, an intuitionistic fuzzy time series forecasting model based on order decision and adaptive partition algorithm is proposed. By forecasting the vector operator matrix, the proposed model can adjust partitions and intervals adaptively. The proposed model is tested on student enrollments of Alabama dataset, typical seasonal dataset Taiwan Stock Exchange Capitalization Weighted Stock Index (TAIEX) and a secular trend dataset of total retail sales for social consumer goods in China. Experimental results illustrate the validity and applicability of the proposed method for different patterns of dataset.

套代数上的一类非线性中心化子

为了推广算子代数中的基本理论,对一类非线性映射成为套代数上的可加中心化子的条件进行了研究。首先,基于Hilbert空间上的非平凡套定义与该套有关的套代数,并定义套代数上的一个非线性映射;其次,采用矩阵分块方法获得关于此映射的几个性质;最后,证明套代数上满足某种条件的非线性映射为可加中心化子,给出刻画该映射的具体形式。结果表明,套代数上满足某种条件的非线性映射为可加中心化子,且可完全刻画。研究结果推广了非线性映射成为套代数上可加中心化子的结论,丰富了算子代数拓扑结构的分类问题,为套代数上其他类型非线性映射问题的刻画提供了借鉴与参考。

基于无功源控制空间的自动电压控制系统聚类分区方法及关键节点选择

自动电压控制(AVC)系统在降低电网损耗、维护电网稳定等方面发挥重要作用。在应用AVC系统时,需要对电网进行分区控制从而达到全局最优的控制目标。该文提出一种基于无功源控制空间的AVC系统聚类分区方法,在构建节点导纳矩阵、建立无功源控制空间的基础上,实现聚类分区。在完成分区后,选择中枢节点和临界节点作为子分区的关键节点。通过保证关键节点的电压水平稳定,实现输电网的可靠运行。

惯性定理的矩阵证明

本文总结了惯性定理的矩阵证明方法,并给出了一种新的矩阵分块证明.

具有鲁棒性的正交约束多视图子空间聚类算法

通过直接处理原始数据的每个视图,多视图子空间聚类算法通常可以获得潜在的子空间表示矩阵.然而,这些方法往往低估了冗余数据的影响,因此在潜在子空间表示中准确捕捉精确的聚类结果具有挑战性.此外,用于产生聚类结果的K-means算法很容易忽略子空间内数据的局部结构,导致结果不稳定.针对上述问题,本文提出了一种多视图子空间方法来获取高质量的子空间表示.具体来说,首先通过特征分解方法获得鲁棒性表示.然后,为多个视图构建一个联合潜在子空间表示.接下来,使用谱旋转来获得聚类结果,并对划分矩阵采用正交约束来重构子空间,从而提高聚类性能.最后,使用迭代优化算法来解决相关的优化问题.本文在5个基准数据集上进行了实验,结果表明,与最近的多视图聚类算法相比,本文的算法更加有效.

基于截断核范数和PM算子的稀疏面阵角度估计算法

与均匀阵列相比,稀疏阵列可以使天线阵列成本降低,减少数据处理,同时带来更大的阵列孔径提高信号解析能力,在信号处理中有着广泛的应用。但是由于其排布的不规则性,计算量较大,二维面阵合成协方差矩阵存在空洞,对角度估计的准确性造成负面影响,增强了系统对噪声的敏感度。为了克服这些问题,本文提出了一种新的角度估计方法,采用截断核范数以降低噪声的影响,并通过ℓ_(p)范数优化提升信号的稀疏表示,利用交替方向乘子法(Alternating Direction Method of Multipliers,ADMM)算法构造子问题恢复出完整的阵列信号。随后采用子阵划分技术和基于最小二乘的传播算子模型(Propagator Method,PM)对恢复的信号处理,精确估计信号源的方位和俯仰角。仿真结果表明,所提出的角度估计算法在角度精度和时间复杂度方面具有优越性。

Microstructure,mechanical properties,and wear resistance of VCp-reinforced Fe-matrix composites treated by Q&P process

A quenching and partitioning(Q&P) process was applied to vanadium carbide particle(VCp)-reinforced Fe-matrix composites(VC-Fe-MCs) to obtain a multiphase microstructure comprising VC, V8 C7, M3 C, α-Fe, and γ-Fe. The effects of the austenitizing temperature and the quenching temperature on the microstructure, mechanical properties, and wear resistance of the VC-Fe-MCs were studied. The results show that the size of the carbide became coarse and that the shape of some particles began to transform from diffused graininess into a chrysanthemum-shaped structure with increasing austenitizing temperature. The microhardness decreased with increasing austenitizing temperature but substantially increased after wear testing compared with the microhardness before wear testing; the microhardness values improved by 20.0% ± 2.5%. Retained austenite enhanced the impact toughness and promoted the transformation-induced plasticity(TRIP) effect to improve wear resistance under certain load conditions.

Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators

Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators （BEQPO＇s）I we present the analytic expression of arbitrary matrix elements for BEQPO＇s. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO＇s.

Solve Goldbach Conjecture with Chandra Matrix Computation

This paper shows a fairly simple method of lifting Chandra matrices to explain Goldbach conjecture,by lifting we mean to add a nature number to every element of the matrix,in this way we constructed a set of Chandra matrices,which are equivalent to a modulo operations for a prime check.The advantage of this method is that it offers a quick computation of large prime partition for encryption key application.In this paper,it shows that all positive even integers n≥40 can be expressed as the sum of two primes,those n<40 are trivial cases.We computed for n=40 to 400000 selectively with Matlab program.From which,we can verify that the conjecture is correct,and we can use it to construct the pseudo random key for encryption key exchanges.

一种矩阵分块的GNSS相位模糊度快速解算方法

为解决GNSS模糊度解算中最小二乘模糊度去相关(least-square ambiguity decorrelation adjustment,LAMBDA)算法涉及大量矩阵运算、降相关耗时较长等问题,提出一种对条件方差矩阵进行分块的最小二乘模糊度去相关(blocking in least-square ambiguity decorrelation adjustment,BLAMBDA)算法。该算法对条件方差矩阵进行分块,减少条件方差排序次数,并在此基础上对Cholesky分解公式进行整合,减少Cholesky分解过程中的数乘运算。仿真实验和实测结果表明,与LAMBDA算法相比,BLAMBDA算法的整体解算效率提升显著,且更加稳定。

分块矩阵特征值估计的Ostrowski-Brauer定理

推广了分块矩阵特征值估计的Brauer定理和Ostrowski定理,得到了更精确的特征值估计的Ostrowski-Brauer定理,给出具体例子,证明了结果的有效性。

路矩阵相关谱半径和路谱展的界及其应用

由于图谱能够很好地反映图的结构性质且便于计算,本文通过图的矩阵,建立图谱与图的拓扑性质之间的联系,更好地反应图的结构和研究图的相关性质;利用矩阵论和图论的理论和方法,证明路谱半径的下界和路无符号拉普拉斯谱半径的上下界;定义路谱展并得到其上下界;最后作为应用,研究完全r-部图的路谱、路拉普拉斯谱和路无符号拉普拉斯谱并得到了图K_(p,p,…,p)的相关能量。

平行线路感应电压电流的矩阵精确计算

平行线路间的感应电压、电流数值是线路接地开关选型的重要依据,目前采用的近似理论方法结果不够准确。为提升计算结果的准确性,以同塔双回线路为研究对象,基于相模变换原理、传输线方程和分块矩阵理论,提出了一种可准确计算平行线路感应电压、电流的新方法。该方法考虑线路首末端及各相感应电压、电流的差异,其基本原理同样适用于多回平行线路。采用所提方法计算某330 kV同塔双回线路的感应电压、电流,并与ATP仿真结果进行比较,结果表明,所提方法能够从技术、经济层面为平行线路选择合适的接地开关。

基于DNA局域结构和统计物理模型识别核小体定位

核小体是真核生物染色质的基本单位。核小体的精确定位影响了基因组序列对结合蛋白的可及性、转录、遗传复制和重组。了解核小体在基因组的准确位置对理解真核生物的生命活动过程有重要作用。本文基于核小体的序列和结构特征及统计物理理论,用统计物理模型预测了核小体的定位。利用统计物理和信息论原理计算了酿酒酵母(S.cerevisiae)、人类(H.sapiens)、秀丽隐杆线虫(C.elegans)和黑腹果蝇(D.melanogaster)数据集中序列片段的DNA局部结构的总能量,基于核小体序列与非核小体序列的总能量差异进行分类,通过10倍交叉验证进行了性能评估。结果显示该模型具有较好的识别效能。

关于分块半正定矩阵的Everitt不等式的注记

在矩阵分析中,分块半正定矩阵是一类具有较好性质的矩阵。分块半正定矩阵相关的理论研究一般都是从2×2分块半正定矩阵开始,因此2×2分块半正定矩阵性质的研究是矩阵分析中基本的研究课题之一。鉴于此,基于已有的分块半正定矩阵的相关性质,通过2×2分块半正定矩阵来研究分块半正定矩阵行列式的Everitt不等式。利用矩阵分块的技巧,文章不仅给出了它的一个新的证明,同时给出了等号成立的一个新的刻画。

有向符号网络的边能控性研究

符号网络是一类具有正负符号特征的网络.在多智能体系统中,符号网络能够描述智能体之间的合作与对抗交互关系,因此受到学者的广泛关注.本文主要研究有向符号网络的边能控性.首先,对具有符号网络的多智能体系统边动力学进行建模,得到边能控性模型.其次,从网络拓扑结构角度对边能控子空间进行定量刻画,利用有向符号网络的距离和等价划分得到能控子空间的上下界估计.进一步,讨论了符号网络边能控性与顶点能控性的关系.所得结果表明:当顶点符号图为结构非平衡时,符号网络的边能控性与顶点能控性等价.最后,通过仿真结果验证所得理论的有效性.

矩阵的分块初等变换在求秩中的应用

利用分块矩阵的初等变换和分块初等矩阵证明了分块矩阵秩的一些性质,结合几道全国研究生入学考试线性代数试题,讨论了分块矩阵的初等变换在矩阵秩中的应用,并对相关结果作了推广。