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Composition Analysis and Identification of Ancient Glass Products Based on L1 Regularization Logistic Regression
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作者 Yuqiao Zhou Xinyang Xu Wenjing Ma 《Applied Mathematics》 2024年第1期51-64,共14页
In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluste... In view of the composition analysis and identification of ancient glass products, L1 regularization, K-Means cluster analysis, elbow rule and other methods were comprehensively used to build logical regression, cluster analysis, hyper-parameter test and other models, and SPSS, Python and other tools were used to obtain the classification rules of glass products under different fluxes, sub classification under different chemical compositions, hyper-parameter K value test and rationality analysis. Research can provide theoretical support for the protection and restoration of ancient glass relics. 展开更多
关键词 Glass Composition L1 regularization Logistic Regression Model K-Means Clustering Analysis Elbow Rule Parameter Verification
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Convergent Data-Driven Regularizations for CT Reconstruction
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作者 Samira Kabri Alexander Auras +4 位作者 Danilo Riccio Hartmut Bauermeister Martin Benning Michael Moeller Martin Burger 《Communications on Applied Mathematics and Computation》 EI 2024年第2期1342-1368,共27页
The reconstruction of images from their corresponding noisy Radon transform is a typical example of an ill-posed linear inverse problem as arising in the application of computerized tomography(CT).As the(naive)solutio... The reconstruction of images from their corresponding noisy Radon transform is a typical example of an ill-posed linear inverse problem as arising in the application of computerized tomography(CT).As the(naive)solution does not depend on the measured data continuously,regularization is needed to reestablish a continuous dependence.In this work,we investigate simple,but yet still provably convergent approaches to learning linear regularization methods from data.More specifically,we analyze two approaches:one generic linear regularization that learns how to manipulate the singular values of the linear operator in an extension of our previous work,and one tailored approach in the Fourier domain that is specific to CT-reconstruction.We prove that such approaches become convergent regularization methods as well as the fact that the reconstructions they provide are typically much smoother than the training data they were trained on.Finally,we compare the spectral as well as the Fourier-based approaches for CT-reconstruction numerically,discuss their advantages and disadvantages and investigate the effect of discretization errors at differentresolutions. 展开更多
关键词 Inverse problems regularization Computerized tomography(CT) Machine learning
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Impact Force Localization and Reconstruction via ADMM-based Sparse Regularization Method
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作者 Yanan Wang Lin Chen +3 位作者 Junjiang Liu Baijie Qiao Weifeng He Xuefeng Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期170-188,共19页
In practice,simultaneous impact localization and time history reconstruction can hardly be achieved,due to the illposed and under-determined problems induced by the constrained and harsh measuring conditions.Although ... In practice,simultaneous impact localization and time history reconstruction can hardly be achieved,due to the illposed and under-determined problems induced by the constrained and harsh measuring conditions.Although l_(1) regularization can be used to obtain sparse solutions,it tends to underestimate solution amplitudes as a biased estimator.To address this issue,a novel impact force identification method with l_(p) regularization is proposed in this paper,using the alternating direction method of multipliers(ADMM).By decomposing the complex primal problem into sub-problems solvable in parallel via proximal operators,ADMM can address the challenge effectively.To mitigate the sensitivity to regularization parameters,an adaptive regularization parameter is derived based on the K-sparsity strategy.Then,an ADMM-based sparse regularization method is developed,which is capable of handling l_(p) regularization with arbitrary p values using adaptively-updated parameters.The effectiveness and performance of the proposed method are validated on an aircraft skin-like composite structure.Additionally,an investigation into the optimal p value for achieving high-accuracy solutions via l_(p) regularization is conducted.It turns out that l_(0.6)regularization consistently yields sparser and more accurate solutions for impact force identification compared to the classic l_(1) regularization method.The impact force identification method proposed in this paper can simultaneously reconstruct impact time history with high accuracy and accurately localize the impact using an under-determined sensor configuration. 展开更多
关键词 Impact force identification Non-convex sparse regularization Alternating direction method of multipliers Proximal operators
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Enhanced Differentiable Architecture Search Based on Asymptotic Regularization
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作者 Cong Jin Jinjie Huang +1 位作者 Yuanjian Chen Yuqing Gong 《Computers, Materials & Continua》 SCIE EI 2024年第2期1547-1568,共22页
In differentiable search architecture search methods,a more efficient search space design can significantly improve the performance of the searched architecture,thus requiring people to carefully define the search spa... In differentiable search architecture search methods,a more efficient search space design can significantly improve the performance of the searched architecture,thus requiring people to carefully define the search space with different complexity according to various operations.Meanwhile rationalizing the search strategies to explore the well-defined search space will further improve the speed and efficiency of architecture search.With this in mind,we propose a faster and more efficient differentiable architecture search method,AllegroNAS.Firstly,we introduce a more efficient search space enriched by the introduction of two redefined convolution modules.Secondly,we utilize a more efficient architectural parameter regularization method,mitigating the overfitting problem during the search process and reducing the error brought about by gradient approximation.Meanwhile,we introduce a natural exponential cosine annealing method to make the learning rate of the neural network training process more suitable for the search procedure.Moreover,group convolution and data augmentation are employed to reduce the computational cost.Finally,through extensive experiments on several public datasets,we demonstrate that our method can more swiftly search for better-performing neural network architectures in a more efficient search space,thus validating the effectiveness of our approach. 展开更多
关键词 Differentiable architecture search allegro search space asymptotic regularization natural exponential cosine annealing
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Trigonometric Regularization and Continuation Method Based Time-Optimal Control of Hypersonic Vehicles
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作者 LIN Yujie HAN Yanhua 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第S01期52-59,共8页
Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analy... Aiming at the time-optimal control problem of hypersonic vehicles(HSV)in ascending stage,a trigonometric regularization method(TRM)is introduced based on the indirect method of optimal control.This method avoids analyzing the switching function and distinguishing between singular control and bang-bang control,where the singular control problem is more complicated.While in bang-bang control,the costate variables are unsmooth due to the control jumping,resulting in difficulty in solving the two-point boundary value problem(TPBVP)induced by the indirect method.Aiming at the easy divergence when solving the TPBVP,the continuation method is introduced.This method uses the solution of the simplified problem as the initial value of the iteration.Then through solving a series of TPBVP,it approximates to the solution of the original complex problem.The calculation results show that through the above two methods,the time-optimal control problem of HSV in ascending stage under the complex model can be solved conveniently. 展开更多
关键词 hypersonic vehicle(HSV) optimal control trigonometric regularization method(TRM) continuation method
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Low-Rank Multi-View Subspace Clustering Based on Sparse Regularization
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作者 Yan Sun Fanlong Zhang 《Journal of Computer and Communications》 2024年第4期14-30,共17页
Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The signif... Multi-view Subspace Clustering (MVSC) emerges as an advanced clustering method, designed to integrate diverse views to uncover a common subspace, enhancing the accuracy and robustness of clustering results. The significance of low-rank prior in MVSC is emphasized, highlighting its role in capturing the global data structure across views for improved performance. However, it faces challenges with outlier sensitivity due to its reliance on the Frobenius norm for error measurement. Addressing this, our paper proposes a Low-Rank Multi-view Subspace Clustering Based on Sparse Regularization (LMVSC- Sparse) approach. Sparse regularization helps in selecting the most relevant features or views for clustering while ignoring irrelevant or noisy ones. This leads to a more efficient and effective representation of the data, improving the clustering accuracy and robustness, especially in the presence of outliers or noisy data. By incorporating sparse regularization, LMVSC-Sparse can effectively handle outlier sensitivity, which is a common challenge in traditional MVSC methods relying solely on low-rank priors. Then Alternating Direction Method of Multipliers (ADMM) algorithm is employed to solve the proposed optimization problems. Our comprehensive experiments demonstrate the efficiency and effectiveness of LMVSC-Sparse, offering a robust alternative to traditional MVSC methods. 展开更多
关键词 CLUSTERING Multi-View Subspace Clustering Low-Rank Prior Sparse regularization
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A Hybrid Regularization-Based Multi-Frame Super-Resolution Using Bayesian Framework 被引量:1
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作者 Mahmoud M.Khattab Akram M.Zeki +3 位作者 Ali A.Alwan Belgacem Bouallegue Safaa S.Matter Abdelmoty M.Ahmed 《Computer Systems Science & Engineering》 SCIE EI 2023年第1期35-54,共20页
The prime purpose for the image reconstruction of a multi-frame super-resolution is to reconstruct a higher-resolution image through incorporating the knowledge obtained from a series of relevant low-resolution images... The prime purpose for the image reconstruction of a multi-frame super-resolution is to reconstruct a higher-resolution image through incorporating the knowledge obtained from a series of relevant low-resolution images,which is useful in numerousfields.Nevertheless,super-resolution image reconstruction methods are usually damaged by undesirable restorative artifacts,which include blurring distortion,noises,and stair-casing effects.Consequently,it is always challenging to achieve balancing between image smoothness and preservation of the edges inside the image.In this research work,we seek to increase the effectiveness of multi-frame super-resolution image reconstruction by increasing the visual information and improving the automated machine perception,which improves human analysis and interpretation processes.Accordingly,we propose a new approach to the image reconstruction of multi-frame super-resolution,so that it is created through the use of the regularization framework.In the proposed approach,the bilateral edge preserving and bilateral total variation regularizations are employed to approximate a high-resolution image generated from a sequence of corresponding images with low-resolution to protect significant features of an image,including sharp image edges and texture details while preventing artifacts.The experimental results of the synthesized image demonstrate that the new proposed approach has improved efficacy both visually and numerically more than other approaches. 展开更多
关键词 SUPER-RESOLUTION regularized framework bilateral total variation bilateral edge preserving
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Regularization by Multiple Dual Frames for Compressed Sensing Magnetic Resonance Imaging With Convergence Analysis 被引量:1
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作者 Baoshun Shi Kexun Liu 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第11期2136-2153,共18页
Plug-and-play priors are popular for solving illposed imaging inverse problems. Recent efforts indicate that the convergence guarantee of the imaging algorithms using plug-andplay priors relies on the assumption of bo... Plug-and-play priors are popular for solving illposed imaging inverse problems. Recent efforts indicate that the convergence guarantee of the imaging algorithms using plug-andplay priors relies on the assumption of bounded denoisers. However, the bounded properties of existing plugged Gaussian denoisers have not been proven explicitly. To bridge this gap, we detail a novel provable bounded denoiser termed as BMDual,which combines a trainable denoiser using dual tight frames and the well-known block-matching and 3D filtering(BM3D)denoiser. We incorporate multiple dual frames utilized by BMDual into a novel regularization model induced by a solver. The proposed regularization model is utilized for compressed sensing magnetic resonance imaging(CSMRI). We theoretically show the bound of the BMDual denoiser, the bounded gradient of the CSMRI data-fidelity function, and further demonstrate that the proposed CSMRI algorithm converges. Experimental results also demonstrate that the proposed algorithm has a good convergence behavior, and show the effectiveness of the proposed algorithm. 展开更多
关键词 Bounded denoiser compressed sensing magnetic resonance imaging(CSMRI) dual frames plug-and-play priors regularization
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Distributed Optimal Formation Control for Unmanned Surface Vessels by a Regularized Game-Based Approach 被引量:1
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作者 Jun Shi Maojiao Ye 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第1期276-278,共3页
Dear Editor,This letter explores optimal formation control for a network of unmanned surface vessels(USVs).By designing an individual objective function for each USV,the optimal formation problem is transformed into a... Dear Editor,This letter explores optimal formation control for a network of unmanned surface vessels(USVs).By designing an individual objective function for each USV,the optimal formation problem is transformed into a noncooperative game.Under this game theoretic framework,the optimal formation is achieved by seeking the Nash equilibrium of the regularized game.A modular structure consisting of a distributed Nash equilibrium seeker and a regulator is proposed. 展开更多
关键词 regular SEEKING OPTIMAL
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Echo State Network With Probabilistic Regularization for Time Series Prediction
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作者 Xiufang Chen Mei Liu Shuai Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第8期1743-1753,共11页
Recent decades have witnessed a trend that the echo state network(ESN)is widely utilized in field of time series prediction due to its powerful computational abilities.However,most of the existing research on ESN is c... Recent decades have witnessed a trend that the echo state network(ESN)is widely utilized in field of time series prediction due to its powerful computational abilities.However,most of the existing research on ESN is conducted under the assumption that data is free of noise or polluted by the Gaussian noise,which lacks robustness or even fails to solve real-world tasks.This work handles this issue by proposing a probabilistic regularized ESN(PRESN)with robustness guaranteed.Specifically,we design a novel objective function for minimizing both the mean and variance of modeling error,and then a scheme is derived for getting output weights of the PRESN.Furthermore,generalization performance,robustness,and unbiased estimation abilities of the PRESN are revealed by theoretical analyses.Finally,experiments on a benchmark dataset and two real-world datasets are conducted to verify the performance of the proposed PRESN.The source code is publicly available at https://github.com/LongJinlab/probabilistic-regularized-echo-state-network. 展开更多
关键词 Echo state network(ESN) noise probabilistic regularization ROBUSTNESS
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Comparisons between Isotropic and Anisotropic TV Regularizations in Inverse Acoustic Scattering
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作者 Ping Liu 《Engineering(科研)》 CAS 2023年第2期106-113,共8页
This article compares the isotropic and anisotropic TV regularizations used in inverse acoustic scattering. It is observed that compared with the traditional Tikhonov regularization, isotropic and anisotropic TV regul... This article compares the isotropic and anisotropic TV regularizations used in inverse acoustic scattering. It is observed that compared with the traditional Tikhonov regularization, isotropic and anisotropic TV regularizations perform better in the sense of edge preserving. While anisotropic TV regularization will cause distortions along axes. To minimize the energy function with isotropic and anisotropic regularization terms, we use split Bregman scheme. We do several 2D numerical experiments to validate the above arguments. 展开更多
关键词 Inverse Acoustic Scattering Problem regularization Isotropic TV Anisotropic TV ILL-POSEDNESS
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Regularization Methods to Approximate Solutions of Variational Inequalities
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作者 Nguyen Van Kinh 《Open Journal of Optimization》 2023年第2期34-60,共27页
In this paper, we study the regularization methods to approximate the solutions of the variational inequalities with monotone hemi-continuous operator having perturbed operators arbitrary. Detail, we shall study regul... In this paper, we study the regularization methods to approximate the solutions of the variational inequalities with monotone hemi-continuous operator having perturbed operators arbitrary. Detail, we shall study regularization methods to approximate solutions of following variational inequalities: and with operator A being monotone hemi-continuous form real Banach reflexive X into its dual space X*, but instead of knowing the exact data (y<sub>0</sub>, A), we only know its approximate data  satisfying certain specified conditions and D is a nonempty convex closed subset of X;the real function f defined on X is assumed to be lower semi-continuous, convex and is not identical to infinity. At the same time, we will evaluate the convergence rate of the approximate solution. The regularization methods here are different from the previous ones. 展开更多
关键词 Ill-Posed Problem Variational Inequality regularization Method Monotone Operator Hemi-Continuous Operator Lower Semi-Continuous Function
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Diverse Deep Matrix Factorization With Hypergraph Regularization for Multi-View Data Representation
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作者 Haonan Huang Guoxu Zhou +2 位作者 Naiyao Liang Qibin Zhao Shengli Xie 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第11期2154-2167,共14页
Deep matrix factorization(DMF)has been demonstrated to be a powerful tool to take in the complex hierarchical information of multi-view data(MDR).However,existing multiview DMF methods mainly explore the consistency o... Deep matrix factorization(DMF)has been demonstrated to be a powerful tool to take in the complex hierarchical information of multi-view data(MDR).However,existing multiview DMF methods mainly explore the consistency of multi-view data,while neglecting the diversity among different views as well as the high-order relationships of data,resulting in the loss of valuable complementary information.In this paper,we design a hypergraph regularized diverse deep matrix factorization(HDDMF)model for multi-view data representation,to jointly utilize multi-view diversity and a high-order manifold in a multilayer factorization framework.A novel diversity enhancement term is designed to exploit the structural complementarity between different views of data.Hypergraph regularization is utilized to preserve the high-order geometry structure of data in each view.An efficient iterative optimization algorithm is developed to solve the proposed model with theoretical convergence analysis.Experimental results on five real-world data sets demonstrate that the proposed method significantly outperforms stateof-the-art multi-view learning approaches. 展开更多
关键词 Deep matrix factorization(DMF) diversity hypergraph regularization multi-view data representation(MDR)
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Brain Functional Networks with Dynamic Hypergraph Manifold Regularization for Classification of End-Stage Renal Disease Associated with Mild Cognitive Impairment
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作者 Zhengtao Xi Chaofan Song +2 位作者 Jiahui Zheng Haifeng Shi Zhuqing Jiao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第6期2243-2266,共24页
The structure and function of brain networks have been altered in patients with end-stage renal disease(ESRD).Manifold regularization(MR)only considers the pairing relationship between two brain regions and cannot rep... The structure and function of brain networks have been altered in patients with end-stage renal disease(ESRD).Manifold regularization(MR)only considers the pairing relationship between two brain regions and cannot represent functional interactions or higher-order relationships between multiple brain regions.To solve this issue,we developed a method to construct a dynamic brain functional network(DBFN)based on dynamic hypergraph MR(DHMR)and applied it to the classification of ESRD associated with mild cognitive impairment(ESRDaMCI).The construction of DBFN with Pearson’s correlation(PC)was transformed into an optimization model.Node convolution and hyperedge convolution superposition were adopted to dynamically modify the hypergraph structure,and then got the dynamic hypergraph to form the manifold regular terms of the dynamic hypergraph.The DHMR and L_(1) norm regularization were introduced into the PC-based optimization model to obtain the final DHMR-based DBFN(DDBFN).Experiment results demonstrated the validity of the DDBFN method by comparing the classification results with several related brain functional network construction methods.Our work not only improves better classification performance but also reveals the discriminative regions of ESRDaMCI,providing a reference for clinical research and auxiliary diagnosis of concomitant cognitive impairments. 展开更多
关键词 End-stage renal disease mild cognitive impairment brain functional network dynamic hypergraph manifold regularization CLASSIFICATION
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An improved four-dimensional variation source term inversion model with observation error regularization
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作者 Chao-shuai Han Xue-zheng Zhu +3 位作者 Jin Gu Guo-hui Yan Xiao-hui Gao Qin-wen Zuo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第6期349-360,共12页
Aiming at the Four-Dimensional Variation source term inversion algorithm proposed earlier,the observation error regularization factor is introduced to improve the prediction accuracy of the diffusion model,and an impr... Aiming at the Four-Dimensional Variation source term inversion algorithm proposed earlier,the observation error regularization factor is introduced to improve the prediction accuracy of the diffusion model,and an improved Four-Dimensional Variation source term inversion algorithm with observation error regularization(OER-4DVAR STI model)is formed.Firstly,by constructing the inversion process and basic model of OER-4DVAR STI model,its basic principle and logical structure are studied.Secondly,the observation error regularization factor estimation method based on Bayesian optimization is proposed,and the error factor is separated and optimized by two parameters:error statistical time and deviation degree.Finally,the scientific,feasible and advanced nature of the OER-4DVAR STI model are verified by numerical simulation and tracer test data.The experimental results show that OER-4DVAR STI model can better reverse calculate the hazard source term information under the conditions of high atmospheric stability and flat underlying surface.Compared with the previous inversion algorithm,the source intensity estimation accuracy of OER-4DVAR STI model is improved by about 46.97%,and the source location estimation accuracy is improved by about 26.72%. 展开更多
关键词 Source term inversion Four dimensional variation Observation error regularization factor Bayesian optimization SF6 tracer test
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A Formulation of the Porous Medium Equation with Time-Dependent Porosity: A Priori Estimates and Regularity Results
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作者 Koffi B. Fadimba 《Applied Mathematics》 2024年第10期745-763,共19页
We consider a generalized form of the porous medium equation where the porosity ϕis a function of time t: ϕ=ϕ(x,t): ∂(ϕS)∂t−∇⋅(k(S)∇S)=Q(S).In many works, the porosity ϕis either assumed to be independent of (or to de... We consider a generalized form of the porous medium equation where the porosity ϕis a function of time t: ϕ=ϕ(x,t): ∂(ϕS)∂t−∇⋅(k(S)∇S)=Q(S).In many works, the porosity ϕis either assumed to be independent of (or to depend very little of) the time variable t. In this work, we want to study the case where it does depend on t(and xas well). For this purpose, we make a change of unknown function V=ϕSin order to obtain a saturation-like (advection-diffusion) equation. A priori estimates and regularity results are established for the new equation based in part on what is known from the saturation equation, when ϕis independent of the time t. These results are then extended to the full saturation equation with time-dependent porosity ϕ=ϕ(x,t). In this analysis, we make explicitly the dependence of the various constants in the estimates on the porosity ϕby the introduced transport vector w, through the change of unknown function. Also we do not assume zero-flux boundary, but we carry the analysis for the case Q≡0. 展开更多
关键词 Porous Medium Equation POROSITY Saturation Equation A Priori Estimates regularity Results
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Alternative Methods of Regular and Singular Perturbation Problems
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作者 Boampong Asare Manohar Sah Ram Krishna Hona 《Applied Mathematics》 2024年第10期687-708,共22页
Making exact approximations to solve equations distinguishes applied mathematicians from pure mathematicians, physicists, and engineers. Perturbation problems, both regular and singular, are pervasive in diverse field... Making exact approximations to solve equations distinguishes applied mathematicians from pure mathematicians, physicists, and engineers. Perturbation problems, both regular and singular, are pervasive in diverse fields of applied mathematics and engineering. This research paper provides a comprehensive overview of algebraic methods for solving perturbation problems, featuring a comparative analysis of their strengths and limitations. Serving as a valuable resource for researchers and practitioners, it offers insights and guidance for tackling perturbation problems in various disciplines, facilitating the advancement of applied mathematics and engineering. 展开更多
关键词 PERTURBATION regular Perturbation Singular Perturbation Asymptotic Expansion Matched Asymptotic Strained Coordinates Multiple Scales
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THE GLOBAL EXISTENCE AND ANALYTICITY OF A MILD SOLUTION TO THE 3D REGULARIZED MHD EQUATIONS
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作者 肖存涛 邱华 姚正安 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期973-983,共11页
In this paper,we study the three-dimensional regularized MHD equations with fractional Laplacians in the dissipative and diffusive terms.We establish the global existence of mild solutions to this system with small in... In this paper,we study the three-dimensional regularized MHD equations with fractional Laplacians in the dissipative and diffusive terms.We establish the global existence of mild solutions to this system with small initial data.In addition,we also obtain the Gevrey class regularity and the temporal decay rate of the solution. 展开更多
关键词 regularized MHD equations fractional Laplacian global well-posedness ANALYTICITY decay rate
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SHARP MORREY REGULARITY THEORY FOR A FOURTH ORDER GEOMETRICAL EQUATION
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作者 向长林 郑高峰 《Acta Mathematica Scientia》 SCIE CSCD 2024年第2期420-430,共11页
This paper is a continuation of recent work by Guo-Xiang-Zheng[10].We deduce the sharp Morrey regularity theory for weak solutions to the fourth order nonhomogeneous Lamm-Rivière equation △^{2}u=△(V▽u)+div(w▽... This paper is a continuation of recent work by Guo-Xiang-Zheng[10].We deduce the sharp Morrey regularity theory for weak solutions to the fourth order nonhomogeneous Lamm-Rivière equation △^{2}u=△(V▽u)+div(w▽u)+(▽ω+F)·▽u+f in B^(4),under the smallest regularity assumptions of V,ω,ω,F,where f belongs to some Morrey spaces.This work was motivated by many geometrical problems such as the flow of biharmonic mappings.Our results deepens the Lp type regularity theory of[10],and generalizes the work of Du,Kang and Wang[4]on a second order problem to our fourth order problems. 展开更多
关键词 fourth order elliptic equation regularity theory Morrey space decay estimates Riesz potential
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Impact of Regular Blood Donation on Body Iron Stores at Saudi Blood Donors
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作者 Mohammed Qassadi Saleh Mohammed Abdullah 《Open Journal of Blood Diseases》 2024年第3期65-80,共16页
Introduction: One of the most frequent observations in long-term blood donation is chronic iron deficiency, which can develop into anaemia. The majority of blood screening methods employed by blood banks do not incorp... Introduction: One of the most frequent observations in long-term blood donation is chronic iron deficiency, which can develop into anaemia. The majority of blood screening methods employed by blood banks do not incorporate iron-status markers, which may result in potential subclinical iron deficiency. The aim of this study was to evaluate the effects of repeated blood donation on the levels of iron in the body and to guide blood donors in preventing the depletion of iron stores. Methods: Regular blood donors were categorised into distinct groups according to the number of donations they gave, and then the correlation between these groups and their bodies’ iron levels was examined. Different parameters were employed to identify iron deficiency and iron depletion in blood donors: serum ferritin, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), total iron-binding capacity (TIBC), and serum iron. Results: The study included 300 individuals who regularly and willingly donated blood. There were no iron insufficiency cases among those donating blood for the first time (Group I). However, 15.5% of individuals who had donated once before (Group II) had ferritin levels of 15 - 30 μg/dl (ng/ml), indicating reduced iron stores. The rate increased to 18% (37 out of 206 individuals) among regular blood donors (Groups III, IV, and V). Iron deficiency (depletion) prevalence among regular blood donors in Groups III, IV, and V was 5.9% (12 out of 206) and 50.4% (100 out of 206). Donors who had donated blood most frequently had the lowest levels of haematological markers MCH, MCHC, and TIBC. Provide the p-values representing the differences between the means of MCV, MCH, iron, TIBC, and ferritin levels when comparing donor groups with the control group (Group I) based on the frequency of donations. Indicate statistically significant differences where the p-value is less than 0.0125. This significance level is adjusted based on the Bonferroni method, considering multiple independent tests. The result shows that the Iron parameter for the comparison between Group I and Group III and Group I and Group IV suggests a statistically significant difference in iron levels between these donor groups. Conclusion: The findings of this study show that a higher times of donations lads to a higher occurrence of depleted iron stores and subsequent erythropoiesis with iron deficiency by one donor from every three healthy donors. The iron and ferritin concentrations were within the normal range in group one (Control group) and reduced in the other four groups (G-2 to G-5). However, the level of haemoglobin remained within an acceptable range for blood donation. This outcome suggests that it may be necessary to reassess the criteria for accepting blood donors. The average serum ferritin levels were examined in all five groups (G-1 to G-5), both for males and females, and significant variations were seen among the groups under study. This study found that 35% of the individuals who regularly donate blood have iron-deficient anaemia (sideropenia). This suggests that it would be beneficial to test for serum ferritin at an earlier stage, ideally after three donations. 展开更多
关键词 Iron Deficiency Anaemia regular Blood Donors ANAEMIA Volunteer Blood Donor Blood Donation
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