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Fully Coupled Fluid-Structure Interaction Model Based on Distributed Lagrange Multiplier/Fictitious Domain Method
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作者 及春宁 董晓强 +1 位作者 赵冲久 王元战 《China Ocean Engineering》 SCIE EI 2007年第3期439-450,共12页
This paper, with a finite element method, studies the interaction of a coupled incompressible fluid-rigid structure system with a free surface subjected to external wave excitations. With this fully coupled model, the... This paper, with a finite element method, studies the interaction of a coupled incompressible fluid-rigid structure system with a free surface subjected to external wave excitations. With this fully coupled model, the rigid structure is taken as "fictitious" fluid with zero strain rate. Both fluid and structure are described by velocity and pressure. The whole domain, including fluid region and structure region, is modeled by the incompressible Navier-Stokes equations which are discretized with fixed Eulerian mesh. However, to keep the structure' s rigid body shape and behavior, a rigid body constraint is enforced on the "fictitious" fluid domain by use of the Distributed Lagrange Multipher/Fictitious Domain (DLM/ FD) method which is originally introduced to solve particulate flow problems by Glowinski et al. For the verification of the model presented herein, a 2D numerical wave tank is established to simulate small amplitude wave propagations, and then numerical results are compared with analytical solutions. Finally, a 2D example of fluid-structure interaction under wave dynamic forces provides convincing evidences for the method excellent solution quality and fidelity. 展开更多
关键词 fluid-structure interaction fully coupled model distributed Lagrange multiplier/fictitious domain method numerical wave tank
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Distributed Lagrange Multiplier/Fictitious Domain Finite Element Method for a Transient Stokes Interface Problem with Jump Coefficients 被引量:2
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作者 Andrew Lundberg Pengtao Sun +1 位作者 Cheng Wang Chen-song Zhang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2019年第4期35-62,共28页
The distributed Lagrange multiplier/fictitious domain(DLM/FD)-mixed finite element method is developed and analyzed in this paper for a transient Stokes interface problem with jump coefficients.The semi-and fully disc... The distributed Lagrange multiplier/fictitious domain(DLM/FD)-mixed finite element method is developed and analyzed in this paper for a transient Stokes interface problem with jump coefficients.The semi-and fully discrete DLM/FD-mixed finite element scheme are developed for the first time for this problem with a moving interface,where the arbitrary Lagrangian-Eulerian(ALE)technique is employed to deal with the moving and immersed subdomain.Stability and optimal convergence properties are obtained for both schemes.Numerical experiments are carried out for different scenarios of jump coefficients,and all theoretical results are validated. 展开更多
关键词 TRANSIENT STOKES interface problem JUMP COEFFICIENTS DISTRIBUTED LAGRANGE multiplier fictitious domain method mixed finite element an optimal error estimate stability
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Development of a ceramic gas-electron-multiplier neutron detector prototype with a large sensitive area
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作者 Lin Zhu Jianrong Zhou +13 位作者 Xiaojuan Zhou Lixin Zeng Liang Xiao Hong Xu Fei Jia Chaoyue Zhang Yezhao Yang Dingfu Li Hao Xiong Yuguang Xie Yubin Zhao Yadong Wei Zhijia Sun Yuanbo Chen 《Chinese Physics B》 2025年第9期135-141,共7页
The rapid growth of neutron flux has driven the development of^(3)He-free neutron detectors to satisfy the requirements of the neutron scattering instruments under construction or planned at the China Spallation Neutr... The rapid growth of neutron flux has driven the development of^(3)He-free neutron detectors to satisfy the requirements of the neutron scattering instruments under construction or planned at the China Spallation Neutron Source(CSNS).Position-sensitive neutron detectors with a high counting rate and large area play an important role in the instruments performing neutron measurements in or close to the direct beam.The ceramic gas-electron-multiplier(GEM)detector serves as a promising solution,and considerable work has been done using the small-area GEM neutron detectors.In this article,we designed and constructed a detector prototype utilizing ceramic GEM foils with an effective area of about307 mm×307 mm.To evaluate and investigate their basic characteristics,the Monte Carlo(MC)tool FLUKA was employed and several neutron beam tests were conducted at CSNS.The simulated spatial resolution was basically in agreement with the measured value of 2.50±0.01 mm(FWHM).The wavelength spectra measurement was verified through comparisons with a commercial beam monitor.In addition,a detection efficiency of 4.7±0.1%was achieved for monoenergetic neutrons of 1.59 A wavelength.This is consistent with the simulated result.The results indicate that the large-area ceramic GEM detector is a good candidate to implement neutron beam measurements.Its efficiency can be improved in a cascading manner to approach that reached by traditional^(3)He detectors. 展开更多
关键词 neutron detector counting rate gas electron multiplier spatial resolution detection efficiency
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Highly Accurate Golden Section Search Algorithms and Fictitious Time Integration Method for Solving Nonlinear Eigenvalue Problems
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作者 Chein-Shan Liu Jian-Hung Shen +1 位作者 Chung-Lun Kuo Yung-Wei Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1317-1335,共19页
This study sets up two new merit functions,which are minimized for the detection of real eigenvalue and complex eigenvalue to address nonlinear eigenvalue problems.For each eigen-parameter the vector variable is solve... This study sets up two new merit functions,which are minimized for the detection of real eigenvalue and complex eigenvalue to address nonlinear eigenvalue problems.For each eigen-parameter the vector variable is solved from a nonhomogeneous linear system obtained by reducing the number of eigen-equation one less,where one of the nonzero components of the eigenvector is normalized to the unit and moves the column containing that component to the right-hand side as a nonzero input vector.1D and 2D golden section search algorithms are employed to minimize the merit functions to locate real and complex eigenvalues.Simultaneously,the real and complex eigenvectors can be computed very accurately.A simpler approach to the nonlinear eigenvalue problems is proposed,which implements a normalization condition for the uniqueness of the eigenvector into the eigenequation directly.The real eigenvalues can be computed by the fictitious time integration method(FTIM),which saves computational costs compared to the one-dimensional golden section search algorithm(1D GSSA).The simpler method is also combined with the Newton iterationmethod,which is convergent very fast.All the proposed methods are easily programmed to compute the eigenvalue and eigenvector with high accuracy and efficiency. 展开更多
关键词 Nonlinear eigenvalue problem quadratic eigenvalue problem two new merit functions golden section search algorithm fictitious time integration method
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Optimal Shape Factor and Fictitious Radius in the MQ-RBF:Solving Ill-Posed Laplacian Problems
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作者 Chein-Shan Liu Chung-Lun Kuo Chih-Wen Chang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期3189-3208,共20页
To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection techniq... To solve the Laplacian problems,we adopt a meshless method with the multiquadric radial basis function(MQRBF)as a basis whose center is distributed inside a circle with a fictitious radius.A maximal projection technique is developed to identify the optimal shape factor and fictitious radius by minimizing a merit function.A sample function is interpolated by theMQ-RBF to provide a trial coefficient vector to compute the merit function.We can quickly determine the optimal values of the parameters within a preferred rage using the golden section search algorithm.The novel method provides the optimal values of parameters and,hence,an optimal MQ-RBF;the performance of the method is validated in numerical examples.Moreover,nonharmonic problems are transformed to the Poisson equation endowed with a homogeneous boundary condition;this can overcome the problem of these problems being ill-posed.The optimal MQ-RBF is extremely accurate.We further propose a novel optimal polynomial method to solve the nonharmonic problems,which achieves high precision up to an order of 10^(−11). 展开更多
关键词 Laplace equation nonharmonic boundary value problem Ill-posed problem maximal projection optimal shape factor and fictitious radius optimal MQ-RBF optimal polynomial method
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The Multiplier Algebra of a Ternary Algebra 被引量:1
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作者 许天周 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第2期6-11,共6页
In this article, we have given the definition of the relative double multiplier (quasi-multiplier) on a ternary algebra,and studied the isomorphic problem of the multiplier algebra M(A,e) of a ternary algerbra A.
关键词 multiplier algebra ternary algebra relative arens product
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Fast alternating direction method of multipliers for total-variation-based image restoration 被引量:1
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作者 陶敏 《Journal of Southeast University(English Edition)》 EI CAS 2011年第4期379-383,共5页
A novel algorithm, i.e. the fast alternating direction method of multipliers (ADMM), is applied to solve the classical total-variation ( TV )-based model for image reconstruction. First, the TV-based model is refo... A novel algorithm, i.e. the fast alternating direction method of multipliers (ADMM), is applied to solve the classical total-variation ( TV )-based model for image reconstruction. First, the TV-based model is reformulated as a linear equality constrained problem where the objective function is separable. Then, by introducing the augmented Lagrangian function, the two variables are alternatively minimized by the Gauss-Seidel idea. Finally, the dual variable is updated. Because the approach makes full use of the special structure of the problem and decomposes the original problem into several low-dimensional sub-problems, the per iteration computational complexity of the approach is dominated by two fast Fourier transforms. Elementary experimental results indicate that the proposed approach is more stable and efficient compared with some state-of-the-art algorithms. 展开更多
关键词 total variation DECONVOLUTION alternating direction method of multiplier
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OTA MACROMODEL AND QUARTER-SQUARE MULTIPLIER
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作者 程泽 刘建猷 +1 位作者 刘艳莉 程明 《Transactions of Tianjin University》 EI CAS 1999年第2期49-54,共6页
This paper presents a new kind of macromodel of OTA,which can be used to solve the problem in which the two port macromodel couldnt reflect some functions of the OTA.The new model also opens up a new way for the simu... This paper presents a new kind of macromodel of OTA,which can be used to solve the problem in which the two port macromodel couldnt reflect some functions of the OTA.The new model also opens up a new way for the simulation of the OTA circuit.This paper discusses the way of designing this model and simulating it in SPICE.The result proves its reasonable design and its simplicity in structure.In the application of this model,we design a complete symmetric double differential quarter square OTA multiplying unit by using four three port OTA macromodels.It successfully solved the problem of the unsymmetry of two input ports in an OTA multiplying unit.This result fully agrees with the experiment. 展开更多
关键词 OTA macromodel nonlinear application multiplier
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A FICTITIOUS DOMAIN METHOD FOR DIRICHLET PROBLEM AND ITS APPLICATIONS TO GENER ALIZED STOKES PROBLEM
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作者 周春华 唐海敏 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2001年第1期22-28,共7页
This paper discusses a fictitious domain method for the linear Dirichlet problem and its applications to the generalized Stokes problem. This method treats Dirichlet boundary condit ion via a Lagrange multiplier tec... This paper discusses a fictitious domain method for the linear Dirichlet problem and its applications to the generalized Stokes problem. This method treats Dirichlet boundary condit ion via a Lagrange multiplier technique and is well suited to the no-slip bound ary condition in viscous flow problems. In order to improve the accuracy of solu tions, meshes are refined according to the a posteriori error estimate. The mini -element discretization is applied to solve the generalized Stokes problem. Fin ally, some numerical results to validate this method are presented for partial d ifferential equations with Dirichlet boundary condition. 展开更多
关键词 fictitious domain Diri chlet problem finite element generalized Stokes problem Lagrange multiplier
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Multipliers of Hardy Spaces
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作者 郭继东 娄增建 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期69-73,共5页
本文刻划了Hardy空间H^p(1≤p≤∞)到Bloch空间的乘子,推广了前人的结果。
关键词 multiplier Hardy space BMOA Bloch space
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π-quasitriangular group-cograded multiplier Hopf algebras
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作者 杨涛 王栓宏 《Journal of Southeast University(English Edition)》 EI CAS 2009年第4期552-556,共5页
Let G be a group and (A, B) be a pair of multiplier Hopf algebras, where B is regular G-cograded. Let π be a crossing action of G on B, D^π=A^cop∝B=+p∈GDπ^p with Dπ^p=A^cop∝Bp, is the Drinfeld double of the ... Let G be a group and (A, B) be a pair of multiplier Hopf algebras, where B is regular G-cograded. Let π be a crossing action of G on B, D^π=A^cop∝B=+p∈GDπ^p with Dπ^p=A^cop∝Bp, is the Drinfeld double of the pair (A, B), and then the deformation D^π becomes a multiplier Hopf algebra. B×A can be considered as a subalgebra of M(D^π×D^π), the image of element b×a in B×A is (1∝b)×(a∝1) in M(D^π×D^π). Let W =∑αWα∈ M(B×A) be a π-canonical multiplier for the pair (A, B) with Wα∈M(Bα×A) for all α∈G. The image of W in M(D^π×D^π)is a π-quasitriangular structure over D^π. 展开更多
关键词 multiplier Hopf algebra group-cograded Drinfeld double quasitriangular
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Coefficient Multipliers for Polynomials
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作者 申大维 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期113-118,共6页
Let Q n denote the class of all polynomials p(z) nonvanishing in the unit disk with deg p≤n and p (0)=1, and let W n denote the class of all polynomials s(z) satisfying deg s≤n and for all... Let Q n denote the class of all polynomials p(z) nonvanishing in the unit disk with deg p≤n and p (0)=1, and let W n denote the class of all polynomials s(z) satisfying deg s≤n and for all p∈Q n, s*p∈Q n , where * denotes the Hadamard product. Some properties for W n and Q n are obtained. 展开更多
关键词 POLYNOMIALS COEFFICIENTS multiplierS
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Multipliers on Weighted Hardy Spaces over Locally Compact Vilenkin Groups
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作者 朱月萍 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第4期18-26,共9页
This paper is devoted to study the atomic decomposition of the weighted Hardy space on Vilenkin groups and a weighted Hp multiplier theorem.
关键词 multiplierS Vilenkin group atom-decomposition
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Longitudinal vibration of pile in layered soil based on Rayleigh-Love rod theory and fictitious soil-pile model 被引量:6
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作者 吕述晖 王奎华 +1 位作者 吴文兵 C.J.LEO 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第5期1909-1918,共10页
The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect.Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between... The dynamic response of pile in layered soil is theoretically investigated when considering the transverse inertia effect.Firstly, the fictitious soil-pile model is employed to simulate the dynamic interaction between the pile and the soil layers beneath pile toe. The dynamic interactions of adjacent soil layers along the vertical direction are simplified as distributed Voigt models.Meanwhile, the pile and fictitious soil-pile are assumed to be viscoelastic Rayleigh-Love rods, and both the radial and vertical displacement continuity conditions at the soil-pile interface are taken into consideration. On this basis, the analytical solution for dynamic response at the pile head is derived in the frequency domain and the corresponding quasi-analytical solution in the time domain is then obtained by means of the convolution theorem. Following this, the accuracy and parameter value of the hypothetical boundaries for soil-layer interfaces are discussed. Comparisons with published solution and measured data are carried out to verify the rationality of the present solution. Parametric analyses are further conducted by using the present solution to investigate the relationships between the transverse inertia effects and soil-pile parameters. 展开更多
关键词 viscoelastic pile layered soil longitudinal vibration fictitious soil-pile transverse inertia effect
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Images of triple gas electron multiplier with pixel-pads 被引量:4
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作者 董静 胡碧涛 +1 位作者 陈元柏 谢一冈 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第10期4229-4233,共5页
Testing of a triple gas electron multiplier (GEM) with pixel-pads is described. Images by scanning and suspending radioactive sources were obtained by using 96 channels digital data acquisition (DAQ) system which ... Testing of a triple gas electron multiplier (GEM) with pixel-pads is described. Images by scanning and suspending radioactive sources were obtained by using 96 channels digital data acquisition (DAQ) system which was composed of 96 8×8 mm2 pads and associated electronics channels. 展开更多
关键词 gas electron multiplier IMAGES digital data acquisition system
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ON SOME GENERALIZED DIFFERENCE PARANORMED SEQUENCE SPACES ASSOCIATED WITH MULTIPLIER SEQUENCE DEFINED BY MODULUS FUNCTION 被引量:5
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作者 Binod Chandra Tripathy Prabhat Chandra 《Analysis in Theory and Applications》 2011年第1期21-27,共7页
In this article we introduce the paranormed sequence spaces (f,A, Am,p), c0(f,A,Am,p) and L00(f,A, Am,p), associated with the multiplier sequence ∧ = (hk), defined by a modulus function f. We study their diff... In this article we introduce the paranormed sequence spaces (f,A, Am,p), c0(f,A,Am,p) and L00(f,A, Am,p), associated with the multiplier sequence ∧ = (hk), defined by a modulus function f. We study their different properties like solidness, symmetricity, completeness etc. and prove some inclusion results. 展开更多
关键词 paranorm solid space symmetric space difference sequence modulus function multiplier seuence
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Convergence of Generalized Alternating Direction Method of Multipliers for Nonseparable Nonconvex Objective with Linear Constraints 被引量:5
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作者 Ke GUO Xin WANG 《Journal of Mathematical Research with Applications》 CSCD 2018年第5期523-540,共18页
In this paper, we consider the convergence of the generalized alternating direction method of multipliers(GADMM) for solving linearly constrained nonconvex minimization model whose objective contains coupled functio... In this paper, we consider the convergence of the generalized alternating direction method of multipliers(GADMM) for solving linearly constrained nonconvex minimization model whose objective contains coupled functions. Under the assumption that the augmented Lagrangian function satisfies the Kurdyka-Lojasiewicz inequality, we prove that the sequence generated by the GADMM converges to a critical point of the augmented Lagrangian function when the penalty parameter in the augmented Lagrangian function is sufficiently large. Moreover, we also present some sufficient conditions guaranteeing the sublinear and linear rate of convergence of the algorithm. 展开更多
关键词 generalized alternating direction method of multipliers Kurdyka Lojasiewicz in-equality nonconvex optimization
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Missile robust gain scheduling autopilot design using full block multipliers 被引量:3
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作者 Jianqiao Yu Guanchen Luo Wentao Yin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第5期883-891,共9页
Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying(LPV) con... Reduction of conservatism is one of the key and difficult problems in missile robust gain scheduling autopilot design based on multipliers.This article presents a scheme of adopting linear parameter-varying(LPV) control approach with full block multipliers to design a missile robust gain scheduling autopilot in order to eliminate conservatism.A model matching design structure with a high demand on matching precision is constructed based on the missile linear fractional transformation(LFT) model.By applying full block S-procedure and elimination lemma,a convex feasibility problem with an infinite number of constraints is formulated to satisfy robust quadratic performance specifications.Then a grid method is adopted to transform the infinite-dimensional convex feasibility problem into a solvable finite-dimensional convex feasibility problem,based on which a gain scheduling controller with linear fractional dependence on the flight Mach number and altitude is derived.Static and dynamic simulation results show the effectiveness and feasibility of the proposed scheme. 展开更多
关键词 full block multiplier gain scheduling control robust control model matching autopilot.
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CHARACTERIZATION OF MULTIPLIER SPACES WITH DAUBECHIES WAVELETS 被引量:2
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作者 杨奇祥 《Acta Mathematica Scientia》 SCIE CSCD 2012年第6期2315-2321,共7页
We characterize the multiplier spaces from Sobolev spaces to L2 with Daubechles wavelets without using capacity.
关键词 Daubechies wavelet multiplier spaces Morrey spaces
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MULTIPLIERS ON HERZ TYPE HARDY SPACES OVER LOCAL FIELDS 被引量:2
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作者 Zhu Yueping(Department of Mathematics Nantong Teachers College Nantong, 226007 PRC) 《Analysis in Theory and Applications》 2000年第1期66-72,共7页
In this paper, we establish two multiplier theorems for Herz type Hardy spaces, and as an application, we discuss the boundedness of pseudo-differential operators in these spaces.
关键词 oscillatory integral operator multiplier SINGULARITY
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