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2-median location improvement problems under weighted l_1 norm and l_∞ norm on trees 被引量:1
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作者 杨利平 关秀翠 《Journal of Southeast University(English Edition)》 EI CAS 2013年第3期346-351,共6页
This paper focuses on the 2-median location improvement problem on tree networks and the problem is to modify the weights of edges at the minimum cost such that the overall sum of the weighted distance of the vertices... This paper focuses on the 2-median location improvement problem on tree networks and the problem is to modify the weights of edges at the minimum cost such that the overall sum of the weighted distance of the vertices to the respective closest one of two prescribed vertices in the modified network is upper bounded by a given value.l1 norm and l∞norm are used to measure the total modification cost. These two problems have a strong practical application background and important theoretical research value. It is shown that such problems can be transformed into a series of sum-type and bottleneck-type continuous knapsack problems respectively.Based on the property of the optimal solution two O n2 algorithms for solving the two problems are proposed where n is the number of vertices on the tree. 展开更多
关键词 2-median network improvement problem TREE knapsack problem l1 norm l∞ norm
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针刺联合目偏牵正汤加减治疗2型糖尿病动眼神经麻痹的临床研究
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作者 庞荣 高辉 +4 位作者 徐靖知 李焕丽 路阿慧 杨介川 徐靖知 《辽宁中医杂志》 北大核心 2025年第11期141-144,共4页
目的研究针刺联合目偏牵正汤加减治疗2型糖尿病动眼神经麻痹(dynamic optimization problem,DOP)的疗效。方法将该院收治的102例DOP患者经随机数表法分为51例观察组(常规治疗基础上联合针刺及目偏牵正汤治疗)及51例对照组(常规治疗)。... 目的研究针刺联合目偏牵正汤加减治疗2型糖尿病动眼神经麻痹(dynamic optimization problem,DOP)的疗效。方法将该院收治的102例DOP患者经随机数表法分为51例观察组(常规治疗基础上联合针刺及目偏牵正汤治疗)及51例对照组(常规治疗)。比较两组临床疗效,中医证候积分(主症积分及次症积分),复视角度,瞳孔直径及眼裂高度,血液流变学(红细胞聚集指数、血浆黏度、全血黏度、纤维蛋白原)。结果观察组总有效率高于对照组(P<0.05)。观察组治疗后的中医证候积分低于对照组(P<0.05)。观察组治疗后的复视角度、瞳孔直径小于对照组(P<0.05),眼裂高度高于对照组(P<0.05)。观察组治疗后血液流变学指标低于对照组(P<0.05)。结论针刺联合目偏牵正汤可提高DOP治疗效果,减轻患者症状,改善血液流变学指标。 展开更多
关键词 2型糖尿病 动眼神经麻痹 针刺 目偏牵正汤
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Two Kinds of Contact Problems in Dodecagonal Quasicrystals of Point Group 12 mm 被引量:8
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作者 Xuefen Zhao Xing Li Shenghu Ding 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2016年第2期167-177,共11页
In this paper,two kinds of contact problems in 2-D dodecagonal quasicrystals were discussed using the complex variable function method:one is the finite frictional contact problem,the other is the adhesive contact pr... In this paper,two kinds of contact problems in 2-D dodecagonal quasicrystals were discussed using the complex variable function method:one is the finite frictional contact problem,the other is the adhesive contact problem.The analytic expressions of contact stresses in the phonon and phason fields were obtained for a flat rigid punch,which showed that:(1) for the finite frictional contact problem,the contact stress exhibited power-type singularities at the edge of the contact zone;(2) for the adhesive contact problem,the contact stress exhibited oscillatory singularities at the edge of the contact zone.The distribution regulation of contact stress under punch was illustrated;and the low friction property of quasicrystals was verified graphically. 展开更多
关键词 2-D dodecagonal quasicrystals contact problem singularity Riemann-Hilbert problem
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A 2-PERIODIC TRIGONOMETRIC INTERPOLATION PROBLEM 被引量:3
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作者 孙燮华 《Analysis in Theory and Applications》 1992年第4期1-16,共16页
2-periodic trigonometric interpolation problems on 2n equidistant nodes and 4n+1 equi- distant nodes are considered respectively.Regularity theorems,fundamental polynomials and convergence rate of the corresponding in... 2-periodic trigonometric interpolation problems on 2n equidistant nodes and 4n+1 equi- distant nodes are considered respectively.Regularity theorems,fundamental polynomials and convergence rate of the corresponding interpolations are given here. 展开更多
关键词 ZN A 2-PERIODIC TRIGONOMETRIC INTERPOLATION problem
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Diagonal form fast multipole boundary element method for 2D acoustic problems based on Burton-Miller boundary integral equation formulation and its applications 被引量:1
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作者 吴海军 蒋伟康 Y.J.LIU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第8期981-996,共16页
This paper describes formulation and implementation of the fast multipole boundary element method (FMBEM) for 2D acoustic problems. The kernel function expansion theory is summarized, and four building blocks of the... This paper describes formulation and implementation of the fast multipole boundary element method (FMBEM) for 2D acoustic problems. The kernel function expansion theory is summarized, and four building blocks of the FMBEM are described in details. They are moment calculation, moment to moment translation, moment to local translation, and local to local translation. A data structure for the quad-tree construction is proposed which can facilitate implementation. An analytical moment expression is derived, which is more accurate, stable, and efficient than direct numerical computation. Numerical examples are presented to demonstrate the accuracy and efficiency of the FMBEM, and radiation of a 2D vibration rail mode is simulated using the FMBEM. 展开更多
关键词 2D acoustic wave problem Helmholtz equation fast multipole method boundary element method
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Sodium glucose cotransporter-2 inhibitors: Are we targeting old devil with new problems? 被引量:1
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作者 Venu Gopal Jonnalagadda Kanchan Choudhary Vijay Kranti Matety 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2017年第11期1023-1024,共2页
Dear editor,The advent of modern molecular mechanism’s approach to disease treatment is highly advancing to mitigate/normalize the symptoms of disease i.e.hyperglycemia by targeting at least eight different pathophys... Dear editor,The advent of modern molecular mechanism’s approach to disease treatment is highly advancing to mitigate/normalize the symptoms of disease i.e.hyperglycemia by targeting at least eight different pathophysiological approaches popularly known as omnious octet[1].Importantly,type 2 diabetes is a 展开更多
关键词 Are we targeting old devil with new problems Sodium glucose cotransporter-2 inhibitors
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Application for Superconvergence of Finite Element Approximations for the Elliptic Problem by Global and Local L<sup>2</sup>-Projection Methods 被引量:1
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作者 Rabeea H. Jari Lin Mu 《American Journal of Computational Mathematics》 2012年第4期249-257,共9页
Numerical experiments are given to verify the theoretical results for superconvergence of the elliptic problem by global and local L2-Projection methods.
关键词 FINITE Element Methods SUPERCONVERGENCE L2-Projection ELLIPTIC problem
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ON A PROBLEM OF(O,2)-INTERPOLATION
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作者 Xie Siqing (Wuhan Inst.of Math.Sci.,Academia Sinica,China) 《Analysis in Theory and Applications》 1993年第3期73-88,共16页
The object in this paper is to consider the problem of existence,uniqueness,explicil representation of(0, 2)-interpolation on the zeros of(1-x^2)P~_(n-1)(x)/x when n is odd,where P_(n-1)denotes Legendre polynomial of ... The object in this paper is to consider the problem of existence,uniqueness,explicil representation of(0, 2)-interpolation on the zeros of(1-x^2)P~_(n-1)(x)/x when n is odd,where P_(n-1)denotes Legendre polynomial of degree n-1,and the problem of convergence of interpolatory polynomials. 展开更多
关键词 INTERPOLATION O 2 ON A problem OF
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Enriched Constant Elements in the Boundary Element Method for Solving 2D Acoustic Problems at Higher Frequencies
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作者 Zonglin Li Zhenyu Gao Yijun Liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期2159-2175,共17页
The boundary element method(BEM)is a popular method for solving acoustic wave propagation problems,especially those in exterior domains,owing to its ease in handling radiation conditions at infinity.However,BEM models... The boundary element method(BEM)is a popular method for solving acoustic wave propagation problems,especially those in exterior domains,owing to its ease in handling radiation conditions at infinity.However,BEM models must meet the requirement of 6–10 elements per wavelength,using the conventional constant,linear,or quadratic elements.Therefore,a large storage size of memory and long solution time are often needed in solving higher-frequency problems.In this work,we propose two new types of enriched elements based on conventional constant boundary elements to improve the computational efficiency of the 2D acoustic BEM.The first one uses a plane wave expansion,which can be used to model scattering problems.The second one uses a special plane wave expansion,which can be used tomodel radiation problems.Five examples are investigated to showthe advantages of the enriched elements.Compared with the conventional constant elements,the new enriched elements can deliver results with the same accuracy and in less computational time.This improvement in the computational efficiency is more evident at higher frequencies(with the nondimensional wave numbers exceeding 100).The paper concludes with the potential of our proposed enriched elements and plans for their further improvement. 展开更多
关键词 Enriched boundary elements constant elements 2D acoustic problems higher frequency
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A SISO mixed H2/l1 optimal control problem and its solution
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作者 吴俊 胡协和 褚健 《Journal of Zhejiang University Science》 CSCD 2004年第1期68-74,共7页
Study of the SISO mixed H2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound in l2 norm with solvable suboptima... Study of the SISO mixed H2/l1 problem for discrete time systems showed that there exists a unique optimal solution which can be approximated within any prescribed missing error bound in l2 norm with solvable suboptimal solutions and solvable superoptimal solutions. 展开更多
关键词 Mixed H 2/l 1 problem EXISTENCE UNIQUENESS Approximation
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Quantum algorithm for a set of quantum 2SAT problems
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作者 Yanglin Hu Zhelun Zhang Biao Wu 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第2期59-63,共5页
We present a quantum adiabatic algorithm for a set of quantum 2-satisfiability(Q2SAT)problem,which is a generalization of 2-satisfiability(2SAT)problem.For a Q2SAT problem,we construct the Hamiltonian which is similar... We present a quantum adiabatic algorithm for a set of quantum 2-satisfiability(Q2SAT)problem,which is a generalization of 2-satisfiability(2SAT)problem.For a Q2SAT problem,we construct the Hamiltonian which is similar to that of a Heisenberg chain.All the solutions of the given Q2SAT problem span the subspace of the degenerate ground states.The Hamiltonian is adiabatically evolved so that the system stays in the degenerate subspace.Our numerical results suggest that the time complexity of our algorithm is O(n^(3.9))for yielding non-trivial solutions for problems with the number of clauses m=dn(n-1)/2(d■0.1).We discuss the advantages of our algorithm over the known quantum and classical algorithms. 展开更多
关键词 adiabatic quantum computation quantum Hamiltonian algorithm quantum 2SAT problem
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NONEXISTENCE AND EXISTENCE OF POSITIVE SOLUTIONS FOR 2nTH-ORDER SINGULAR SUPERLINEAR PROBLEMS WITH STRUM-LIOUVILLE BOUNDARY CONDITIONS
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作者 赵增勤 《Acta Mathematica Scientia》 SCIE CSCD 2011年第4期1569-1582,共14页
This paper investigates a class of 2nth-order singular superlinear problems with Strum-Liouville boundary conditions. We obtain a necessary and sufficient condition for the existence of C 2 n- 2 [0, 1] positive soluti... This paper investigates a class of 2nth-order singular superlinear problems with Strum-Liouville boundary conditions. We obtain a necessary and sufficient condition for the existence of C 2 n- 2 [0, 1] positive solutions, and a sufficient condition, a necessary condition for the existence of C 2 n-1 [0, 1] positive solutions. Relations between the positive solutions and the Green’s functions are depicted. The results are used to judge nonexistence or existence of positive solutions for given boundary value problems. 展开更多
关键词 2nth-order differential equation singular boundary value problem fixed point theorem positive solution
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Problems Related to Divers Health and Comfort in Hyperbaric He-O_2 Environment
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作者 Mao Fangguan Senior Engineer, The Naval Medical Research Institute, Chinese People’s Liberation Army, Shanghai, 200433 《China Ocean Engineering》 SCIE EI 1996年第4期495-496,共2页
The Diver Gas Recovery System(DGRS)is an important accessory equipment of the 300m Saturation Dive System. The system facilitates the recycling of the breathing gases for divers,therefore,it has great economic benefit... The Diver Gas Recovery System(DGRS)is an important accessory equipment of the 300m Saturation Dive System. The system facilitates the recycling of the breathing gases for divers,therefore,it has great economic benefits. In April 1995, a 300 m unmanned test and a 100 m manned test on the HY2031 DGRSwere carried out successively.Ten months later,another manned test on the HY2032 DGRS 展开更多
关键词 test problems Related to Divers Health and Comfort in Hyperbaric He-O2 Environment
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SOLVING THE VELOCITY PARAMETER OF THE 2-D WAVE INVERSE PROBLEMS WITH THE INTEGRATION-CHARACTERISTIC METHOD
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作者 金咸熙 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1990年第3期277-284,共8页
For the 2-D wave inverse problems introduced from geophysical exploration, in this paper, the author presents integration-characteristic method to solve the velocity parameter, and then applies it to common shotpoint ... For the 2-D wave inverse problems introduced from geophysical exploration, in this paper, the author presents integration-characteristic method to solve the velocity parameter, and then applies it to common shotpoint model data, in noise-free case. The accuracy is quite good. 展开更多
关键词 SOLVING THE VELOCITY PARAMETER OF THE 2-D WAVE INVERSE problemS WITH THE INTEGRATION-CHARACTERISTIC METHOD LINE
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A Scheme Library-Based Ant Colony Optimization with 2-Opt Local Search for Dynamic Traveling Salesman Problem
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作者 Chuan Wang Ruoyu Zhu +4 位作者 Yi Jiang Weili Liu Sang-Woon Jeon Lin Sun Hua Wang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第5期1209-1228,共20页
The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant... The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant colony optimization(ACO)with a two-optimization(2-opt)strategy to solve the DTSP efficiently.The work is novel and contributes to three aspects:problemmodel,optimization framework,and algorithmdesign.Firstly,in the problem model,traditional DTSP models often consider the change of travel distance between two nodes over time,while this paper focuses on a special DTSP model in that the node locations change dynamically over time.Secondly,in the optimization framework,the ACO algorithm is carried out in an offline optimization and online application framework to efficiently reuse the historical information to help fast respond to the dynamic environment.The framework of offline optimization and online application is proposed due to the fact that the environmental change inDTSPis caused by the change of node location,and therefore the newenvironment is somehowsimilar to certain previous environments.This way,in the offline optimization,the solutions for possible environmental changes are optimized in advance,and are stored in a mode scheme library.In the online application,when an environmental change is detected,the candidate solutions stored in the mode scheme library are reused via ACO to improve search efficiency and reduce computational complexity.Thirdly,in the algorithm design,the ACO cooperates with the 2-opt strategy to enhance search efficiency.To evaluate the performance of ACO with 2-opt,we design two challenging DTSP cases with up to 200 and 1379 nodes and compare them with other ACO and genetic algorithms.The experimental results show that ACO with 2-opt can solve the DTSPs effectively. 展开更多
关键词 Dynamic traveling salesman problem(DTSP) offline optimization and online application ant colony optimization(ACO) two-optimization(2-opt)strategy
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Second Boundary Value Problems for 2n-th Order Nonlinear Differential Equations
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作者 吕显瑞 徐庆 高广学 《Northeastern Mathematical Journal》 CSCD 2002年第1期23-32,共10页
Sufficient conditions for the existence and uniqueness of second boundary value problems of two kinds of even order nonlinear differential equations are obtained. The proofs are based on the lemma on bilinear form, de... Sufficient conditions for the existence and uniqueness of second boundary value problems of two kinds of even order nonlinear differential equations are obtained. The proofs are based on the lemma on bilinear form, developed by A.C.Lazer, Schauder fixed point theorem and the Leray-Schauder degree theory, respectively. 展开更多
关键词 Second boundary value problem 2n-th order differential eauation Existence and uniqueness
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The Problem of Quasiperiodic Photonic Structures Solved by Considering the Cut of 2D Periodic Structure
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作者 Ahmed El Houshy 《Journal of Applied Mathematics and Physics》 2021年第5期864-888,共25页
The physical objective of solving for eigen-modes of a 1D quasiperiodic structure in photonics has been achieved. This was achieved thru considering this structure as a 1D projection or cut of a 2D periodic structure.... The physical objective of solving for eigen-modes of a 1D quasiperiodic structure in photonics has been achieved. This was achieved thru considering this structure as a 1D projection or cut of a 2D periodic structure. And the problem is solved in a manner similar to 2D periodic photonic structures. A mechanical analogy (quasiperiodic orbits) helps to bring conceptual clarity. 展开更多
关键词 1D Quasiperiodic Structure Quasiperiodic Motion 2D Periodic Structure PHOTONICS Mathematical Physics Eigenvalue problem Bloch’s Theorem
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UNIFORM DIFFERENCE SCHEME FOR A SINGULARLY PERTURBED LINEAR 2ND ORDER HYPERBOLIC PROBLEM WITH ZEROTH ORDER REDUCED EQUATION
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作者 苏煜城 林平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1990年第4期301-313,共13页
In this paper a singularly perturbed linear second order hyperbolic problem with zeroth order reduced equation is discussed. Firstly, an energy inequality of the solution and an estimate of the remainder term of the a... In this paper a singularly perturbed linear second order hyperbolic problem with zeroth order reduced equation is discussed. Firstly, an energy inequality of the solution and an estimate of the remainder term of the asymptotic solution are given. Then an exponentially fitted difference scheme is developed in an equidistant mesh. Finally, uniform convergence in small parameter is proved in the sense of discrete energy norm. 展开更多
关键词 UNIFORM DIFFERENCE SCHEME FOR A SINGULARLY PERTURBED LINEAR 2ND ORDER HYPERBOLIC problem WITH ZEROTH ORDER REDUCED EQUATION
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利用融合2-opt的强化学习算法求解TSP问题
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作者 彭俊龙 范静 《计算机科学》 北大核心 2025年第S2期170-177,共8页
旅行售货商问题(Traveling Salesman Problem,TSP)是运筹学中经典的组合优化问题,属于NP难问题。问题的目标是求解旅行商的环游路径,使其在经过每个城市一次后返回起点且路径长度最短。为求解此问题,提出基于指针网络的深度强化学习算法... 旅行售货商问题(Traveling Salesman Problem,TSP)是运筹学中经典的组合优化问题,属于NP难问题。问题的目标是求解旅行商的环游路径,使其在经过每个城市一次后返回起点且路径长度最短。为求解此问题,提出基于指针网络的深度强化学习算法(2+HRL),融合了2-opt算法和图注意力模型。使用图注意力网络提取城市节点的局部和全局结构信息,运用双向LSTM进行路径信息提取,期间利用2-opt策略,通过局部交换改进路径;进而使用REINFORCE算法进行策略网络的梯度优化,结合熵奖励函数避免陷入局部最优解,使用值函数对评价网络参数进行改进。实验结果证明,2+HRL优于传统启发式算法和精确算法,而且与一些深度强化学习算法相比较时,在较低的训练次数下,2+HRL具有更快的计算速度,更准确的计算精度;在增加训练次数后,模型的优化效果也超越了相比较的其他深度强化学习算法。 展开更多
关键词 图注意力网络 旅行售货商问题 深度强化学习 2-opt 组合最优化
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基于改进L1/2正则化的肺部电阻抗断层图像重建研究
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作者 任晓康 张恒 +2 位作者 赵雅晴 李明宇 谢利德 《计算机应用文摘》 2025年第17期134-137,共4页
在肺部电阻抗断层图像重建过程中,病态逆问题会加剧噪声敏感性,导致重建图像精度不高。为此,提出一种基于改进L1/2正则化的肺部电阻抗断层图像重建方法。该方法首先建立描述肺部电阻抗与边界电压关系的数学模型,以增强对肺部电阻抗变化... 在肺部电阻抗断层图像重建过程中,病态逆问题会加剧噪声敏感性,导致重建图像精度不高。为此,提出一种基于改进L1/2正则化的肺部电阻抗断层图像重建方法。该方法首先建立描述肺部电阻抗与边界电压关系的数学模型,以增强对肺部电阻抗变化的捕捉能力;其次利用灵敏度矩阵重建肺部场域的电导率图像。在重建过程中,将改进的L1/2正则化与高斯噪声和拉普拉斯噪声的自适应范数混合模型相结合,有效识别并抑制2类噪声,从而提升图像清晰度与准确性。针对拉普拉斯噪声,引入了专门的滤波方法,并将其嵌入自适应范数混合模型中,以进一步消除该类噪声,优化重建质量。实验结果表明,该方法所生成的肺部电阻抗断层图像与原始真实图像的相似度约为0.95,能够有效降低噪声干扰并显著提升重建精度。 展开更多
关键词 改进L1/2正则化 肺部电阻抗断层 图像重建 正问题 高斯分布 拉普拉斯分布
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