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Alternating minimization for data-driven computational elasticity from experimental data: kernel method for learning constitutive manifold
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作者 Yoshihiro Kanno 《Theoretical & Applied Mechanics Letters》 CSCD 2021年第5期260-265,共6页
Data-driven computing in elasticity attempts to directly use experimental data on material,without constructing an empirical model of the constitutive relation,to predict an equilibrium state of a structure subjected ... Data-driven computing in elasticity attempts to directly use experimental data on material,without constructing an empirical model of the constitutive relation,to predict an equilibrium state of a structure subjected to a specified external load.Provided that a data set comprising stress-strain pairs of material is available,a data-driven method using the kernel method and the regularized least-squares was developed to extract a manifold on which the points in the data set approximately lie(Kanno 2021,Jpn.J.Ind.Appl.Math.).From the perspective of physical experiments,stress field cannot be directly measured,while displacement and force fields are measurable.In this study,we extend the previous kernel method to the situation that pairs of displacement and force,instead of pairs of stress and strain,are available as an input data set.A new regularized least-squares problem is formulated in this problem setting,and an alternating minimization algorithm is proposed to solve the problem. 展开更多
关键词 alternating minimization Regularized least-squares Kernel method Manifold learning Data-driven computing
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A TRUST-REGION-BASED ALTERNATING LEAST-SQUARES ALGORITHM FOR TENSOR DECOMPOSITIONS
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作者 Fan Jiang Deren Han Xiaofei Zhang 《Journal of Computational Mathematics》 SCIE CSCD 2018年第3期351-373,共23页
Tensor canonical decomposition (shorted as CANDECOMP/PARAFAC or CP) decomposes a tensor as a sum of rank-one tensors, which finds numerous applications in signal processing, hypergraph analysis, data analysis, etc. ... Tensor canonical decomposition (shorted as CANDECOMP/PARAFAC or CP) decomposes a tensor as a sum of rank-one tensors, which finds numerous applications in signal processing, hypergraph analysis, data analysis, etc. Alternating least-squares (ALS) is one of the most popular numerical algorithms for solving it. While there have been lots of efforts for enhancing its efficiency, in general its convergence can not been guaranteed. In this paper, we cooperate the ALS and the trust-region technique from optimization field to generate a trust-region-based alternating least-squares (TRALS) method for CP. Under mild assumptions, we prove that the whole iterative sequence generated by TRALS converges to a stationary point of CP. This thus provides a reasonable way to alleviate the swamps, the notorious phenomena of ALS that slow down the speed of the algorithm. Moreover, the trust region itself, in contrast to the regularization alternating least-squares (RALS) method, provides a self-adaptive way in choosing the parameter, which is essential for the efficiency of the algorithm. Our theoretical result is thus stronger than that of RALS in [26], which only proved the cluster point of the iterative sequence generated by RALS is a stationary point. In order to accelerate the new algorithm, we adopt an extrapolation scheme. We apply our algorithm to the amino acid fluorescence data decomposition from chemometrics, BCM decomposition and rank-(Lr, Lr, 1) decomposition arising from signal processing, and compare it with ALS and RALS. The numerical results show that TRALS is superior to ALS and RALS, both from the number of iterations and CPU time perspectives. 展开更多
关键词 Tensor decompositions Trust region method alternating least-squares Ex-trapolation scheme Global convergence Regularization.
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Proximal Support Matrix Machine
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作者 Wan Zhang Yulan Liu 《Journal of Applied Mathematics and Physics》 2022年第7期2268-2291,共24页
In this paper, we have proposed a novel model called proximal support matrix machine (PSMM), which is mainly based on the models of proximal support vector machine (PSVM) and low rank support matrix machine (LRSMM). I... In this paper, we have proposed a novel model called proximal support matrix machine (PSMM), which is mainly based on the models of proximal support vector machine (PSVM) and low rank support matrix machine (LRSMM). In design, the PSMM model has comprehensively considered both the relationship between samples of the same class and the structure of rows or columns of matrix data. To a certain extent, our novel model can be regarded as a synthesis of the PSVM model and the LRSMM model. Since the PSMM model is an unconstrained convex problem in essence, we have established an alternating direction method of multipliers algorithm to deal with the proposed model. Finally, since a great deal of experiments on the minst digital database show that the PSMM classifier has a good ability to distinguish two digits with little difference, it encourages us to conduct more complex experiments on MIT face database, INRIA person database, the students face database and Japan female facial expression database. Meanwhile, the final experimental results show that PSMM performs better than PSVM, twin support vector machine, LRSMM and linear twin multiple rank support matrix machine in the demanding image classification tasks. 展开更多
关键词 PSMM PSVM LRSMM The alternating Direction method of Multipliers al-gorithm Image Classification Tasks
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退火温度对ITO/Cu/AZO透明导电薄膜结构及性能的影响
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作者 孙冰成 张健 +1 位作者 张贤旺 于尉 《微纳电子技术》 CAS 2024年第11期155-162,共8页
采用射频与直流磁控交替溅射法在石英玻璃载玻片上制备了氧化铟锡(ITO)/Cu/Al掺杂ZnO(AZO)(45 nm/10 nm/45 nm)组合结构的透明导电薄膜,并在不同退火温度下对薄膜进行真空热处理。利用X射线衍射仪(XRD)、紫外-可见分光光度计、四探针电... 采用射频与直流磁控交替溅射法在石英玻璃载玻片上制备了氧化铟锡(ITO)/Cu/Al掺杂ZnO(AZO)(45 nm/10 nm/45 nm)组合结构的透明导电薄膜,并在不同退火温度下对薄膜进行真空热处理。利用X射线衍射仪(XRD)、紫外-可见分光光度计、四探针电阻测试仪等表征手段,系统地研究了退火温度对ITO/Cu/AZO复合薄膜晶体结构和光电性能的影响。结果显示,经过不同温度的真空退火处理,薄膜的晶体结构和导电性能得到显著改善和提高,薄膜可见光平均透过率随着退火温度的升高先增加后降低。对比发现,在气压5×10^(-3)Pa、温度150℃下退火制备的ITO/Cu/AZO结构薄膜表现出最佳的综合性能,薄膜具有较强的(222)和(440)晶面衍射峰,在400~800 nm光波范围平均透过率约为80.5%,电导率约为1.76×10^(3) S/cm,综合品质因数达到约2.12×10^(-3)/Ω。 展开更多
关键词 磁控溅射 真空热处理 氧化铟锡(ITO)薄膜 al掺杂ZnO(AZO)薄膜 交替溅射法
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铝阳极脉冲电化学法处理难降解印染废水的实验研究 被引量:10
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作者 罗亚田 梅建辉 《环境技术》 2004年第6期34-36,共3页
研究铝阳极脉冲电化学法处理印染废水的可行性及处理效果。试验结果表明:电絮凝法对废水的色度和COD具有良好的去除效果。实验确定的电絮凝法处理条件为:电流强度2A,电解时间90min,色度和COD的去除率最高分别为95%和92%。
关键词 电絮凝 铝电极 电化学 印染废水
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基于投影梯度的非负矩阵分解盲信号分离算法 被引量:7
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作者 李煜 何世钧 《计算机工程》 CAS CSCD 北大核心 2016年第2期104-107,112,共5页
在盲信号分离过程中,基于乘性迭代的非负矩阵分解(NMF)存在运算量大、收敛速度慢等问题。为此,在投影梯度法的基础上提出一种新的NMF盲信号分离算法。通过增加行列式约束、稀疏度约束和相关性约束条件,将最优化问题转化为交替的最小二... 在盲信号分离过程中,基于乘性迭代的非负矩阵分解(NMF)存在运算量大、收敛速度慢等问题。为此,在投影梯度法的基础上提出一种新的NMF盲信号分离算法。通过增加行列式约束、稀疏度约束和相关性约束条件,将最优化问题转化为交替的最小二乘问题,将投影梯度法应用于基于约束的NMF盲信号分离过程。仿真结果表明,该算法能减小重构误差,在维持源分离信号稀疏性的基础上实现混合信号的唯一分解。与经典NMF算法和NMFDSC算法相比,其收敛和分解速度更快,重构信号的信噪比更高。 展开更多
关键词 盲信号分离 非负矩阵分解 乘性迭代 交替最小二乘法 投影梯度
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基于Spark平台的推荐算法研究 被引量:3
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作者 陈干 肖博 《国外电子测量技术》 2020年第3期71-74,共4页
传统的推荐系统无论是在处理效率还是推荐准确度上都有一些不足之处,Spark作为新一代的数据处理的分布式框架,在数据处理效率上相较于hadoop有飞速的提升。主要针对Spark平台上的主流推荐算法ALS算法只考虑隐含信息而忽略了相似度信息... 传统的推荐系统无论是在处理效率还是推荐准确度上都有一些不足之处,Spark作为新一代的数据处理的分布式框架,在数据处理效率上相较于hadoop有飞速的提升。主要针对Spark平台上的主流推荐算法ALS算法只考虑隐含信息而忽略了相似度信息的缺点展开研究,目的是进一步提高ALS算法的推荐精确度。通过将用户的相似度信息加权到ALS算法评分预测的公式中对ALS算法进行改进,并在Spark平台上使用MovieLens数据集验证改进前后的ALS算法的均方根误差(RMSE)值。实验证明,改进后的ALS算法的RMSE值更小,推荐的精度更高。 展开更多
关键词 als 矩阵分解 SPARK 最小交替二乘法
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基于交替投影算法求解单变量线性约束矩阵方程问题 被引量:1
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作者 李姣芬 张晓宁 +1 位作者 彭振赟 彭靖静 《计算数学》 CSCD 北大核心 2014年第2期143-162,共20页
研究如下线性约束矩阵方程求解问题:给定A∈R^(m×n),B∈R^(n×p)和C∈R^(m×p),求矩阵X∈R(?)R^(n×n)"使得A×B=C以及相应的最佳逼近问题,其中集合R为如对称阵,Toeplitz阵等构成的线性子空间,或者对称半(ε... 研究如下线性约束矩阵方程求解问题:给定A∈R^(m×n),B∈R^(n×p)和C∈R^(m×p),求矩阵X∈R(?)R^(n×n)"使得A×B=C以及相应的最佳逼近问题,其中集合R为如对称阵,Toeplitz阵等构成的线性子空间,或者对称半(ε)正定阵,(对称)非负阵等构成的闭凸集.给出了在相容条件下求解该问题的交替投影算法及算法收敛性分析.通过大量数值算例说明该算法的可行性和高效性,以及该算法较传统的矩阵形式的Krylov子空间方法(可行前提下)在迭代效率上的明显优势,本文也通过寻求加速技巧进一步提高算法的收敛速度. 展开更多
关键词 线性矩阵方程 交替投影算法 Dykstra’s交替投影算法 最佳逼近问题 KRYLOV子空间方法
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Multivariate Curve Resolution Combined with On-line Infrared Spectroscopy for Researching the Synthesis Mechanism of 3,4-Bis(4 '-aminofurazano-3 ') fu roxa n
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作者 WU Nan SUN Kun-lun +2 位作者 LIU Yu YANG Xiao-feng LI Hua 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2013年第4期759-764,共6页
3,4-Bis(4'-aminofurazano-3')furoxan(DATF), one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior deton... 3,4-Bis(4'-aminofurazano-3')furoxan(DATF), one of a new generation of high energy density materials, shows lots of interesting properties such as lower sensitivity, excellent thermal stability and superior detonation perfor- mance in chemistry and physics. In this paper, on-line infrared(IR) spectroscopy was used to monitor the synthesis process of DATF. The concentration profiles and IR spectra of the components were determined by analyzing the IR data via principal component analysis(PCA), evolving factor analysis(EFA) and multivariate curve resolution-alternating least squares(MCR-ALS). The geometric configurations of reactant, intermediates and product were optimized with the density functional theory(DFT) at B3LYP/6-3 l+G(d, p) level. Their vibrational frequencies and IR spectra were obtained on the basis of vibrational analysis. The result obtained by the chemometric resolution methods agreed well with that obtained by quantum chemical calculation method, which demonstrated the reliability of the proposed chemometric resolution methods. The unstable intermediate 3-amino-4-oxycyanofurazan(AOF) was confirmed via comparing the IR spectra resloved by chemometric resolution methods with those calculated by B3LYP/6-3 l+G(d,p) and analyzed by MCR-ALS. Finally, the possible synthesis mechanism of DATF was deduced by analyzing the above IR spectra. 展开更多
关键词 Evolving factor analysis(EFA) Multivariate curve resolution-alternating least square(MCR-als) On-line infrared spectrum Quantum chemical calculation method Synthesis mechanism
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