期刊文献+
共找到2,887篇文章
< 1 2 145 >
每页显示 20 50 100
The Equivalence between the Mann and Ishikawa Iterations for Generalized Contraction Mappings in a Cone 被引量:3
1
作者 L. Jones Tarcius Doss T. Esakkiappan 《Applied Mathematics》 2011年第11期1369-1371,共3页
In this paper, equivalence between the Mann and Ishikawa iterations for a generalized contraction mapping in cone subset of a real Banach space is discussed.
关键词 MANN ITERATION ISHIKAWA iterations Generalized CONTRACTION CONE
在线阅读 下载PDF
The Equivalence between Orthogonal Iterations and Alternating Least Squares 被引量:1
2
作者 Achiya Dax 《Advances in Linear Algebra & Matrix Theory》 2020年第2期7-21,共15页
This note explores the relations between two different methods. The first one is the Alternating Least Squares (ALS) method for calculating a rank<em>-k</em> approximation of a real <em>m</em>&... This note explores the relations between two different methods. The first one is the Alternating Least Squares (ALS) method for calculating a rank<em>-k</em> approximation of a real <em>m</em>×<em>n</em> matrix, <em>A</em>. This method has important applications in nonnegative matrix factorizations, in matrix completion problems, and in tensor approximations. The second method is called Orthogonal Iterations. Other names of this method are Subspace Iterations, Simultaneous Iterations, and block-Power method. Given a real symmetric matrix, <em>G</em>, this method computes<em> k</em> dominant eigenvectors of <em>G</em>. To see the relation between these methods we assume that <em>G </em>=<em> A</em><sup>T</sup> <em>A</em>. It is shown that in this case the two methods generate the same sequence of subspaces, and the same sequence of low-rank approximations. This equivalence provides new insight into the convergence properties of both methods. 展开更多
关键词 Alternating Least Squares (ALS) Orthogonal iterations Equivalence Relations Low-Rank Approximations
在线阅读 下载PDF
Research on a novel restoration algorithm of turbulence-degraded images with alternant iterations
3
作者 Liu Chunsheng Hong Hanyu Zhang Tianxu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第3期477-482,共6页
A new restoration algorithm based on double loops and alternant iterations is proposed to restore the object image effectively from a few frames of turbulence-degraded images, Based on the double loops, the iterative ... A new restoration algorithm based on double loops and alternant iterations is proposed to restore the object image effectively from a few frames of turbulence-degraded images, Based on the double loops, the iterative relations for estimating the turbulent point spread function PSF and object image alternately are derived. The restoration experiments have been made on computers, showing that the proposed algorithm can obtain the optimal estimations of the object and the point spread function, with the feasibility and practicality of the proposed algorithm being convincing. 展开更多
关键词 turbulence-degraded image image restoration double loops alternant iterations.
在线阅读 下载PDF
Higher Order Aitken Extrapolation with Application to Converging and Diverging Gauss-Seidel Iterations 被引量:3
4
作者 Ababu Teklemariam Tiruneh 《Journal of Applied Mathematics and Physics》 2013年第5期128-143,共16页
In this paper, Aitken’s extrapolation normally applied to convergent fixed point iteration is extended to extrapolate the solution of a divergent iteration. In addition, higher order Aitken extrapolation is introduce... In this paper, Aitken’s extrapolation normally applied to convergent fixed point iteration is extended to extrapolate the solution of a divergent iteration. In addition, higher order Aitken extrapolation is introduced that enables successive decomposition of high Eigen values of the iteration matrix to enable convergence. While extrapolation of a convergent fixed point iteration using a geometric series sum is a known form of Aitken acceleration, it is shown that in this paper, the same formula can be used to estimate the solution of sets of linear equations from diverging Gauss-Seidel iterations. In both convergent and divergent iterations, the ratios of differences among the consecutive values of iteration eventually form a convergent (divergent) series with a factor equal to the largest Eigen value of the iteration matrix. Higher order Aitken extrapolation is shown to eliminate the influence of dominant Eigen values of the iteration matrix in successive order until the iteration is determined by the lowest possible Eigen values. For the convergent part of the Gauss-Seidel iteration, further acceleration is made possible by coupling of the extrapolation technique with the successive over relaxation (SOR) method. Application examples from both convergent and divergent iterations have been provided. Coupling of the extrapolation with the SOR technique is also illustrated for a steady state two dimensional heat flow problem which was solved using MATLAB programming. 展开更多
关键词 Linear EQUATIONS GAUSS-SEIDEL ITERATION Aitken EXTRAPOLATION ACCELERATION Technique ITERATION Matrix Fixed Point ITERATION
在线阅读 下载PDF
Application of a simultaneous iterations reconstruction technique for a 3-D water vapor tomography system 被引量:1
5
作者 Wang Wei Ye Biwen Wang Jiexian 《Geodesy and Geodynamics》 2013年第1期41-45,共5页
The simultaneous iterations rithms of the ART family. It is used reconstruction technique (SIRT) widely in tomography because of is one of several reconstruction algoits convenience in dealing with large sparse matr... The simultaneous iterations rithms of the ART family. It is used reconstruction technique (SIRT) widely in tomography because of is one of several reconstruction algoits convenience in dealing with large sparse matrices. Its theoretical background and iteration model are discussed at the beginning of this paper. Then, the implementation of the SIRT to reconstruct the three-dimensional distribution of water vapor by simulation is discussed. The results show that the SIRT can function effectively in water vapor tomography, obtain rapid convergence, and be implemented more easily than inversion. 展开更多
关键词 SIRT reconstruction water vapor TOMOGRAPHY ITERATION
原文传递
CONVERGENCE BALL OF ITERATIONS WITH ONE PARAMETER 被引量:1
6
作者 Guo Xueping 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2005年第4期462-468,共7页
Under the weak Lipschitz condition about the solution of the equation, convergence theorems for a family of iterations with one parameter are obtained. An estimation of the radius of the attraction ball is shown. At l... Under the weak Lipschitz condition about the solution of the equation, convergence theorems for a family of iterations with one parameter are obtained. An estimation of the radius of the attraction ball is shown. At last two examples are given. 展开更多
关键词 ITERATION convergence ball parameter.
在线阅读 下载PDF
Parallel finite element computation of incompressible magnetohydrodynamics based on three iterations 被引量:1
7
作者 Qili TANG Yunqing HUANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2022年第1期141-154,共14页
Based on local algorithms,some parallel finite element(FE)iterative methods for stationary incompressible magnetohydrodynamics(MHD)are presented.These approaches are on account of two-grid skill include two major phas... Based on local algorithms,some parallel finite element(FE)iterative methods for stationary incompressible magnetohydrodynamics(MHD)are presented.These approaches are on account of two-grid skill include two major phases:find the FE solution by solving the nonlinear system on a globally coarse mesh to seize the low frequency component of the solution,and then locally solve linearized residual subproblems by one of three iterations(Stokes-type,Newton,and Oseen-type)on subdomains with fine grid in parallel to approximate the high frequency component.Optimal error estimates with regard to two mesh sizes and iterative steps of the proposed algorithms are given.Some numerical examples are implemented to verify the algorithm. 展开更多
关键词 local and parallel algorithm finite element(FE)method ITERATION stationary incompressible magnetohydrodynamics(MHD)
在线阅读 下载PDF
Non-Linear Localization Algorithm Based on Newton Iterations 被引量:1
8
作者 Jianfeng Lu Guirong Fei 《Journal on Internet of Things》 2020年第4期129-134,共6页
In order to improve the performance of time difference of arrival(TDOA)localization,a nonlinear least squares algorithm is proposed in this paper.Firstly,based on the criterion of the minimized sum of square error of ... In order to improve the performance of time difference of arrival(TDOA)localization,a nonlinear least squares algorithm is proposed in this paper.Firstly,based on the criterion of the minimized sum of square error of time difference of arrival,the location estimation is expressed as an optimal problem of a non-linear programming.Then,an initial point is obtained using the semi-definite programming.And finally,the location is extracted from the local optimal solution acquired by Newton iterations.Simulation results show that when the number of anchor nodes is large,the performance of the proposed algorithm will be significantly better than that of semi-definite programming approach with the increase of measurement noise. 展开更多
关键词 Wireless localization non-linear programming time difference of arrival newton Iteration
在线阅读 下载PDF
New conditions of stability and convergence of Stokes and Newton iterations for Navier-Stokes equations
9
作者 Guodong ZHANG Xiaojing DONG +1 位作者 Yongzheng AN Hong LIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2015年第7期863-872,共10页
This paper considers Stokes and Newton iterations to solve stationary Navier- Stokes equations based on the finite element discretization. We obtain new sufficient conditions of stability and convergence for the two i... This paper considers Stokes and Newton iterations to solve stationary Navier- Stokes equations based on the finite element discretization. We obtain new sufficient conditions of stability and convergence for the two iterations. Specifically, when 0 〈 σ =N||f||-1/v2≤1/√2+1 , the Stokes iteration is stable and convergent, where N is defined in the paper. When 0 〈 σ ≤5/11, the Newton iteration is stable and convergent. This work gives a more accurate admissible range of data for stability and convergence of the two schemes, which improves the previous results. A numerical test is given to verify the theory. 展开更多
关键词 Navier-Stokes equation Stokes iteration Newton iteration stability convergence
在线阅读 下载PDF
Common Fixed Point Iterations of Generalized Asymptotically Quasi-Nonexpansive Mappings in Hyperbolic Spaces
10
作者 A. R. Khan H. Fukhar-ud-din 《Journal of Applied Mathematics and Physics》 2014年第5期170-175,共6页
We introduce a general iterative method for a finite family of generalized asymptotically quasi- nonexpansive mappings in a hyperbolic space and study its strong convergence. The new iterative method includes multi-st... We introduce a general iterative method for a finite family of generalized asymptotically quasi- nonexpansive mappings in a hyperbolic space and study its strong convergence. The new iterative method includes multi-step iterative method of Khan et al. [1] as a special case. Our results are new in hyperbolic spaces and generalize many known results in Banach spaces and CAT(0) spaces, simultaneously. 展开更多
关键词 HYPERBOLIC Space General ITERATIVE Method Generalized ASYMPTOTICALLY Quasi-Nonexpansive Mapping Common Fixed Point Strong Convergence
在线阅读 下载PDF
基于栅元嵌套网格的停堆剂量率方法初步验证及应用
11
作者 郑征 夏春梅 +4 位作者 梅其良 解均涵 史涛 高静 王梦琪 《强激光与粒子束》 北大核心 2025年第9期118-124,共7页
停堆剂量率计算分析是核反应堆辐射安全的重要内容。为了分析车载微型移动核电源的停堆剂量率,研究了基于栅元嵌套网格的停堆剂量率计算方法。该方法在严格两步法的计算框架下,对活化光子源的抽样方法进行了改进。通过构建几何简单的包... 停堆剂量率计算分析是核反应堆辐射安全的重要内容。为了分析车载微型移动核电源的停堆剂量率,研究了基于栅元嵌套网格的停堆剂量率计算方法。该方法在严格两步法的计算框架下,对活化光子源的抽样方法进行了改进。通过构建几何简单的包围盒,抽样得到源栅元内的粒子分布,从而提高了抽样效率和精度。在国际热核聚变实验堆(ITER)停堆剂量率基准题中进行了验证,该方法与参考解符合较好。基于该方法开展了兆瓦级车载微型移动核电源Megapower的停堆剂量率分析,计算结果表明热管贯穿端剂量率水平相对较高。该方法可用于反应堆停堆剂量率的计算分析,能够准确评估结构材料活化源及其产生的剂量率,对于反应堆屏蔽设计、维修计划的制定及退役具有重要的参考意义。 展开更多
关键词 停堆剂量率 严格两步法 源粒子抽样 ITER基准题 Megapower
在线阅读 下载PDF
Consequences of Invariant Functions for the Riemann Hypothesis
12
作者 Michael Mark Anthony 《Advances in Pure Mathematics》 2025年第1期36-72,共37页
This paper attempts to form a bridge between a sum of the divisors function and the gamma function, proposing a novel approach that could have significant implications for classical problems in number theory, specific... This paper attempts to form a bridge between a sum of the divisors function and the gamma function, proposing a novel approach that could have significant implications for classical problems in number theory, specifically the Robin inequality and the Riemann hypothesis. The exploration of using invariant properties of these functions to derive insights into twin primes and sequential primes is a potentially innovative concept that deserves careful consideration by the mathematical community. 展开更多
关键词 LambertW Function Principal Branch Riemann Hypothesis iterations Robin Inequality Robin Integers INVARIANCE Gauss Gamma Function Li-Function Prime Counting Function Sums of Divisors INVARIANCE PRIMES Twin Primes
在线阅读 下载PDF
Convergence of iterations of Euler family under weak condition 被引量:5
13
作者 王兴华 《Science China Mathematics》 SCIE 2000年第9期958-962,共5页
The iteration maps of Euler family for finding zeros of an operatorf in Banach spaces is defined as the partial sum of Taylor expansion of the local inversef z -1 off atz. The unified convergence theorem is establishe... The iteration maps of Euler family for finding zeros of an operatorf in Banach spaces is defined as the partial sum of Taylor expansion of the local inversef z -1 off atz. The unified convergence theorem is established for the iterations of Euler family under the assumption that $\alpha \leqslant 3 - 2\sqrt 2 $ , while the strong condition thatf is analytic in Smale’s criterion α is replaced by the weak condition thatf is of finite order derivative. 展开更多
关键词 Banach space zero of operator iterations of Euler family criterion α under weak condition universal constant unified convergence theorem
原文传递
Local Rate of Convergence in the Functional Limit Theorem for Increments of a Fractional Brownian Motion 被引量:1
14
作者 LIU Yonghong DING Ding ZHOU Xia 《数学进展》 北大核心 2025年第1期197-211,共15页
In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):104... In this paper,we present local functional law of the iterated logarithm for Cs?rg?-Révész type increments of fractional Brownian motion.The results obtained extend works of Gantert[Ann.Probab.,1993,21(2):1045-1049]and Monrad and Rootzén[Probab.Theory Related Fields,1995,101(2):173-192]. 展开更多
关键词 fractional Brownian motion INCREMENT local functional law of the iterated logarithm large deviation small deviation
原文传递
MODELS OF ASYNCHRONOUS MRALLEL NONLINEAR MULTISPLITTING RELAXED ITERATIONS 被引量:2
15
作者 Z.Z. Bai(Institute of Computational Mathematics and Scientific/Engineering Computing,Chinese Academy of Sciences, Beijing, China)D.R. Wang(Depariment of Mathematics, Shanghai University of Science and Technology,Shanghai, China)D.J. Evans(Parallel Algorit 《Journal of Computational Mathematics》 SCIE CSCD 1995年第4期369-386,共18页
In the sense of the nonlinear multisplitting and based on the principle of suffi-ciently using the delayed information, we propose models of asynchronous parallelaccelerated overrelaxation iteration methods for solvin... In the sense of the nonlinear multisplitting and based on the principle of suffi-ciently using the delayed information, we propose models of asynchronous parallelaccelerated overrelaxation iteration methods for solving large scale system of non-linear equations. Under proper conditions, we set up the local convergence theoriesof these new method models. 展开更多
关键词 NoC Wang MODELS OF ASYNCHRONOUS MRALLEL NONLINEAR MULTISPLITTING RELAXED iterations EN DCR
原文传递
Optimal Production Capacity Matching for Blockchain-Enabled Manufacturing Collaboration With the Iterative Double Auction Method 被引量:1
16
作者 Ying Chen Feilong Lin +2 位作者 Zhongyu Chen Changbing Tang Cailian Chen 《IEEE/CAA Journal of Automatica Sinica》 2025年第3期550-562,共13页
The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a block... The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises. 展开更多
关键词 Blockchain iterative double auction manufacturing collaboration production capacity matching
在线阅读 下载PDF
Improved algorithm of multi-mainlobe interference suppression under uncorrelated and coherent conditions 被引量:1
17
作者 CAI Miaohong CHENG Qiang +1 位作者 MENG Jinli ZHAO Dehua 《Journal of Southeast University(English Edition)》 2025年第1期84-90,共7页
A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the s... A new method based on the iterative adaptive algorithm(IAA)and blocking matrix preprocessing(BMP)is proposed to study the suppression of multi-mainlobe interference.The algorithm is applied to precisely estimate the spatial spectrum and the directions of arrival(DOA)of interferences to overcome the drawbacks associated with conventional adaptive beamforming(ABF)methods.The mainlobe interferences are identified by calculating the correlation coefficients between direction steering vectors(SVs)and rejected by the BMP pretreatment.Then,IAA is subsequently employed to reconstruct a sidelobe interference-plus-noise covariance matrix for the preferable ABF and residual interference suppression.Simulation results demonstrate the excellence of the proposed method over normal methods based on BMP and eigen-projection matrix perprocessing(EMP)under both uncorrelated and coherent circumstances. 展开更多
关键词 mainlobe interference suppression adaptive beamforming spatial spectral estimation iterative adaptive algorithm blocking matrix preprocessing
在线阅读 下载PDF
Fault-observer-based iterative learning model predictive controller for trajectory tracking of hypersonic vehicles 被引量:1
18
作者 CUI Peng GAO Changsheng AN Ruoming 《Journal of Systems Engineering and Electronics》 2025年第3期803-813,共11页
This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hype... This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller. 展开更多
关键词 hypersonic vehicle actuator fault tracking control iterative learning control(ILC) model predictive control(MPC) fault observer
在线阅读 下载PDF
An Iterated Greedy Algorithm with Memory and Learning Mechanisms for the Distributed Permutation Flow Shop Scheduling Problem
19
作者 Binhui Wang Hongfeng Wang 《Computers, Materials & Continua》 SCIE EI 2025年第1期371-388,共18页
The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent years.The iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because o... The distributed permutation flow shop scheduling problem(DPFSP)has received increasing attention in recent years.The iterated greedy algorithm(IGA)serves as a powerful optimizer for addressing such a problem because of its straightforward,single-solution evolution framework.However,a potential draw-back of IGA is the lack of utilization of historical information,which could lead to an imbalance between exploration and exploitation,especially in large-scale DPFSPs.As a consequence,this paper develops an IGA with memory and learning mechanisms(MLIGA)to efficiently solve the DPFSP targeted at the mini-malmakespan.InMLIGA,we incorporate a memory mechanism to make a more informed selection of the initial solution at each stage of the search,by extending,reconstructing,and reinforcing the information from previous solutions.In addition,we design a twolayer cooperative reinforcement learning approach to intelligently determine the key parameters of IGA and the operations of the memory mechanism.Meanwhile,to ensure that the experience generated by each perturbation operator is fully learned and to reduce the prior parameters of MLIGA,a probability curve-based acceptance criterion is proposed by combining a cube root function with custom rules.At last,a discrete adaptive learning rate is employed to enhance the stability of the memory and learningmechanisms.Complete ablation experiments are utilized to verify the effectiveness of the memory mechanism,and the results show that this mechanism is capable of improving the performance of IGA to a large extent.Furthermore,through comparative experiments involving MLIGA and five state-of-the-art algorithms on 720 benchmarks,we have discovered that MLI-GA demonstrates significant potential for solving large-scale DPFSPs.This indicates that MLIGA is well-suited for real-world distributed flow shop scheduling. 展开更多
关键词 Distributed permutation flow shop scheduling MAKESPAN iterated greedy algorithm memory mechanism cooperative reinforcement learning
在线阅读 下载PDF
Multiplicity and Stability of Closed Characteristics on Compact Convex Hypersurfaces in R^(2n)
20
作者 WANG Wei 《数学进展》 北大核心 2025年第4期673-686,共14页
A survey of recent progress on the multiplicity and stability problems for closed characteristics on compact convex hypersurfaces in R^(2n) is given.
关键词 compact convex hypersurface closed characteristic Hamiltonian system Morse theory index iteration theory
原文传递
上一页 1 2 145 下一页 到第
使用帮助 返回顶部