To achieve high measurement accuracy with less computational time in phase shifting interferometry, a random phase retrieval approach based on difference map normalization and fast iterative algorithm (DN&FIA) is ...
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To achieve high measurement accuracy with less computational time in phase shifting interferometry, a random phase retrieval approach based on difference map normalization and fast iterative algorithm (DN&FIA) is proposed, it doesn't need pre-filtering, and has the advantage of the iterative algorithms-high accuracy, moreover, it also has the advantage of non-iterative algorithms-timesaving, it only needs three randomly phase shifted interferograms, and the initial phase shifts of the iteration can be random, last but not least, it is effective for the circular, straight or complex fringes. The simulations and experiments verify the correctness and feasibility of DN&FIA.
The present work proposes a finite iterative algorithm to find the least squares solutions of periodic matrix equations over symmetric -periodic matrices. By this algorithm, for any initial symmetric -periodic matrice...
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The present work proposes a finite iterative algorithm to find the least squares solutions of periodic matrix equations over symmetric -periodic matrices. By this algorithm, for any initial symmetric -periodic matrices, the solution group can be obtained in finite iterative steps in the absence of round-off errors, and the solution group with least Frobenius norm can be obtained by choosing a special kind of initial matrices. Furthermore, in the solution set of the above problem, the unique optimal approximation solution group to a given matrix group in the Frobenius norm can be derived by finding the least Frobenius norm symmetric -periodic solution of a new corresponding minimum Frobenius norm problem. Finally, numerical examples are provided to illustrate the efficiency of the proposed algorithm and testify the conclusions suggested in this paper.
In this paper, we use the dual variable to propose a self-adaptive iterative algorithm for solving the split common fixed point problems of averaged mappings in real Hilbert spaces. Under suitable conditions, we get t...
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In this paper, we use the dual variable to propose a self-adaptive iterative algorithm for solving the split common fixed point problems of averaged mappings in real Hilbert spaces. Under suitable conditions, we get the weak convergence of the proposed algorithm and give applications in the split feasibility problem and the split equality problem. Some numerical experiments are given to illustrate the efficiency of the proposed iterative algorithm. Our results improve and extend the corresponding results announced by many others.
In this paper, an iterative algorithm that approximates solutions of split equality fixed point problems (SEFPP) for quasi-phi-nonexpansive mappings is constructed. Weak convergence of the sequence generated by this a...
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In this paper, an iterative algorithm that approximates solutions of split equality fixed point problems (SEFPP) for quasi-phi-nonexpansive mappings is constructed. Weak convergence of the sequence generated by this algorithm is established in certain real Banach spaces. The theorem proved is applied to solve split equality problem, split equality variational inclusion problem, and split equality equilibrium problem. Finally, some numerical examples are given to demonstrate the convergence of the algorithm. The theorems proved improve and complement a host of important recent results.
In this paper, the convergence characterization of a special implicit iterative algorithm with a tuning parameter for continuous coupled Markov jump Lyapunov matrix equation is investigated. First, a necessary conditi...
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ISBN:
(纸本)9789881563972
In this paper, the convergence characterization of a special implicit iterative algorithm with a tuning parameter for continuous coupled Markov jump Lyapunov matrix equation is investigated. First, a necessary condition for the convergence of the iterative algorithm is given. Then, a necessary and sufficient condition is proposed and the optimal tuning parameter such that the algorithm has the fastest convergence rate is analyzed in two cases according to the distribution of eigenvalues. Finally, a numerical example is given to illustrate the effectiveness of the algorithm and the effects of different tuning parameters.
In this paper, the mixed-norm optimization is investigated for sparse signal reconstruction. Furthermore, an iterative optimization algorithm based on the projection method is presented for face recognition. From the ...
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ISBN:
(纸本)9783030228088;9783030228071
In this paper, the mixed-norm optimization is investigated for sparse signal reconstruction. Furthermore, an iterative optimization algorithm based on the projection method is presented for face recognition. From the theoretical point of view, the optimality and convergence of the proposed algorithm is strictly proved. And from the application point of view, the mixed norm combines the L-1 and L-2 norms to give a sparse and collaborative representation for pattern recognition, which has higher recognition rate than sparse representation algorithms. The algorithm is designed by combining the projection operator onto a box set with the projection matrix, which is effective to guarantee the feasibility of the optimal solution. Moreover, numerical experiments on randomly generated signals and three face image data sets are presented to show that the mixed-norm minimization is a combination of sparse representation and collaborative representation for pattern classification.
In this work, we present a new iterative exact solution algorithm for a recently introduced NP-hard sequencing problem. In the problem we are given an upper bound on the allowed solution sequence length and a list of ...
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In this work, we present a new iterative exact solution algorithm for a recently introduced NP-hard sequencing problem. In the problem we are given an upper bound on the allowed solution sequence length and a list of symbols. For each symbol, there is a positive weight and a number, which gives the minimum amount of times the symbol has to occur in a feasible solution sequence. The goal is to find a feasible sequence, which minimizes the maximum weight-distance product, which is calculated for each consecutive appearance of each symbol in the sequence, including the last and first appearance in the sequence, i.e., the sequence is considered to be circular for the calculation of the objective function. Our proposed solution algorithm is based on a new mixed-integer programming model for the problem with a fixed sequence length. We also present various enhancements for our algorithm. We conduct a computational study on the instances from literature to assess the efficiency of our newly proposed solution *** approach solves 404 of 440 instances to optimality within the given time limit, most of them within five minutes. The previous best existing solution approach for the problem only solves 229 of these instances and its exactness depends on an unproven conjecture. Moreover, our approach is up to two orders of magnitude faster compared to this best existing solution approach.
Electron paramagnetic resonance (EPR) imaging is an advanced oxygen imaging modality for oxygen -image guided radiation. The iterative reconstruction algorithm is the research hot-point in image recon-struction for EP...
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Electron paramagnetic resonance (EPR) imaging is an advanced oxygen imaging modality for oxygen -image guided radiation. The iterative reconstruction algorithm is the research hot-point in image recon-struction for EPR imaging (EPRI) for this type of algorithm may incorporate image-prior information to construct advanced optimization model to achieve accurate reconstruction from sparse-view projections and/or noisy projections. However, the system matrix in the iterative algorithm needs complicated cal-culation and needs huge memory-space if it is stored in memory. In this work, we propose an iterative reconstruction algorithm without system matrix for EPRI to simplify the whole iterative reconstruction process. The function of the system matrix is to calculate the projections, whereas the function of the transpose of the system matrix is to perform backprojection. The existing projection and backprojection methods are all based on the configuration that the imaged-object remains stationary and the scanning device rotates. Here, we implement the projection and backprojection operations by fixing the scanning device and rotating the object. Thus, the core algorithm is only the commonly-used image-rotation algo-rithm, while the calculation and store of the system matrix are avoided. Based on the idea of image rota-tion, we design a specific iterative reconstruction algorithm for EPRI, total variation constrained data divergence minimization (TVcDM) algorithm without system matrix, and named it as image-rotation based TVcDM (R-TVcDM). Through a series of comparisons with the original TVcDM via real projection data, we find that the proposed algorithm may achieve similar reconstruction accuracy with the original one. But it avoids the complicated calculation and store of the system matrix. The insights gained in this work may be also applied to other imaging modalities, for example computed tomography and positron emission tomography. (c) 2022 Elsevier Inc. All rights r
Traveling salesman problem (TSP) is one of the extensively studied NP-hard problems. The recent research showed that the TSP on sparse graphs could be resolved in the relatively shorter computation time than that on t...
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Traveling salesman problem (TSP) is one of the extensively studied NP-hard problems. The recent research showed that the TSP on sparse graphs could be resolved in the relatively shorter computation time than that on the complete graph K-n. This paper updates a previous probability model for the optimal Hamiltonian cycle edges according to the frequency quadrilaterals in Kn. A new binomial distribution for TSP is rebuilt to show the probability that an edge e has the frequency 5 in a frequency quadrilateral. Based on the binomial distribution, an iterative algorithm is designed to compute the sparse graphs for TSP. There are two steps at each computation cycle. Firstly, N frequency quadrilaterals containing an edge e in the input graph is chosen to compute the average frequency (f) over bar (e) with the frequency quadrilaterals where e has the frequency 5. Secondly, half edges with the small values (f) over bar (e) are eliminated. The two steps are repeated until a sparse graph is computed. The computation time of the algorithm is O(Nn(2)). For the TSP instances in the TSPLIB, the experimental results illustrated that the sparse graphs with the O(n log(2)n) edges are computed and the original optimal solution is preserved. The experiments means the optimal Hamiltonian cycle edges have the bigger average frequency (f) over bar (e) in K-n and the subgraphs of K-n so they are preserved in the computation process.
In this paper, a variational Bayesian (VB)-based iterative algorithm for ARX models with random missing outputs is proposed. The distributions of missing outputs can be estimated in the VB-E step, and the distribution...
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In this paper, a variational Bayesian (VB)-based iterative algorithm for ARX models with random missing outputs is proposed. The distributions of missing outputs can be estimated in the VB-E step, and the distributions of unknown parameters can be estimated in the VB-M step by the estimated missing outputs and the available outputs. Compared with the expectation-maximization-based iterative algorithm, this algorithm computes the latent variable and the parameter distributions at each iteration. Therefore, it is more accurate. The simulation results demonstrate the advantages of the proposed algorithm.
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