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Discrete gap breathers in a two-dimensional diatomic face-centered square lattice 被引量:1
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作者 吕彬彬 田强 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第10期4393-4406,共14页
In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site pot... In this paper we study the existence and stability of two-dimensional discrete gap breathers in a two-dimensional diatomic face-centered square lattice consisting of alternating light and heavy atoms, with on-site potential and coupling potential. This study is focused on two-dimensional breathers with their frequency in the gap that separates the acoustic and optical bands of the phonon spectrum. We demonstrate the possibility of the existence of two-dimensional gap breathers by using a numerical method. Six types of two-dimensional gap breathers are obtained, i.e., symmetric, mirror-symmetric and asymmetric, whether the center of the breather is on a light or a heavy atom. The difference between one-dimensional discrete gap breathers and two-dimensional discrete gap breathers is also discussed. We use Aubry's theory to analyze the stability of discrete gap breathers in the two-dimensional diatomic face-centered square lattice. 展开更多
关键词 discrete gap breathers two-dimensional diatomic face-centered square lattice linear stability coupling parameters
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Effect of interaction and temperature on quantum phase transition in anisotropic square-octagon lattice 被引量:1
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作者 保安 张雪峰 章晓中 《Chinese Physics B》 SCIE EI CAS CSCD 2015年第5期257-261,共5页
We investigate the effect of interaction, temperature, and anisotropic parameter on the quantum phase transitions in an anisotropic square-octagon lattice with fermions under the framework of the single band Hubbard m... We investigate the effect of interaction, temperature, and anisotropic parameter on the quantum phase transitions in an anisotropic square-octagon lattice with fermions under the framework of the single band Hubbard model through using the combination of cellular dynamical mean field theory and a continuous time Monte Carlo algorithm. The competition between interaction and temperature shows that with the increase of the anisotropic parameter, the critical on-site repulsive interaction for the metal-insulator transition increases for fixed temperature. The interaction-anisotropic parameter phase diagram reveals that with the decrease of temperature, the critical anisotropic parameter for the Mott transition will increase for fixed interaction cases. 展开更多
关键词 anisotropic square-octagon lattice FERMIONS quantum phase transition cellular dynamical mean field theory
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Spin-correlation function of the fully frustrated Ising model and ±J Ising spin glass on a square lattice
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作者 M Y Ali J Poulter 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第6期549-552,共4页
In this work we study the correlation function of the ground state of a two-dimensional fully frustrated Ising model as well as spin glass. The Pfaffian method is used to calculate free energy and entropy as well as t... In this work we study the correlation function of the ground state of a two-dimensional fully frustrated Ising model as well as spin glass. The Pfaffian method is used to calculate free energy and entropy as well as the correlation function. We estimate the exponent of spin correlation function for the fully frustrated model and spin glass. In this paper an overview of the latest results on the spin correlation function is presented. 展开更多
关键词 spin glass correlation function EXPONENT square lattice
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Nonlinear Waves in Two-Dimensional (2D) Square Lattice Frenkel-Kontorova (FK) System
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作者 WANG Cang-Long HAN Jiu-Ning GAO Xiu-Yun DUAN Wen-Shant 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期90-96,共7页
A 2D square lattice is studied. By using the continuum approximation, we set up the differential equations of motion for an arbitrary particle in the square lattice which subjects to an external periodic substrate pot... A 2D square lattice is studied. By using the continuum approximation, we set up the differential equations of motion for an arbitrary particle in the square lattice which subjects to an external periodic substrate potential. The exact solitary waves of the system are found for special cases. We conclude that the adhesive force f and the angle between propagation directions of upper and lower layers can affect these waves. 展开更多
关键词 FK model square lattice solitary waves
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Coexistence and Extinction Pattern of Asymmetric Cyclic Game Species in a Square Lattice
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作者 董林荣 李永明 杨光参 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1201-1204,共4页
The co-evolutionary dynamics of a cyclic game system is investigated in a two-dimensional square lattice with the asymmetrical rates for three species. Different with the well-mixed system, coexistence and extinction ... The co-evolutionary dynamics of a cyclic game system is investigated in a two-dimensional square lattice with the asymmetrical rates for three species. Different with the well-mixed system, coexistence and extinction emerge alternately in the system, where a "zero-one" behavior is robust for a small population size, whereas, the system is predominated by coexistence for a big population one. We study in detail the influence about the fluctuation to the change of the state, and find that the difference between the maximal amplitude about the fluctuation and the average intensity determines which state the system is ultimately. In addition, we introduce Ports energy to explain the reason of the "zero-one" behavior. It is shown that the average Ports energy per site is the distance to the "zero-one" behavior in the model. 展开更多
关键词 co-evolutionary dynamics "zero-one" behavior asymmetrical rates a square lattice average Ports energy
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Effect of Strategy-Homogeneity on the Prisoner’s Dilemma Game in a Square Lattice
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作者 Mengqin Yang Hedong Xu +1 位作者 Cong Li Suohai Fan 《Journal of Applied Mathematics and Physics》 2021年第2期295-305,共11页
We investigate the effect of strategy-homogeneity on the prisoner’s dilemma game in a square lattice. Strategy-homogeneity means that the population contains at least one connected group in which individuals maintain... We investigate the effect of strategy-homogeneity on the prisoner’s dilemma game in a square lattice. Strategy-homogeneity means that the population contains at least one connected group in which individuals maintain the same strategy at each iteration and may update according to updating rule at next iteration. The simulation results show that the introduction of strategy-homogeneity increases the cooperation in the evolutionary stable state. For any value of temptation to defect, the density of cooperators in equilibrium state increases firstly and then decreases as the level of strategy-homogeneity increases constantly, and there exists an appropriate level of strategy-homogeneity, maximizing the density of cooperators. The results may be favorable for comprehending cooperative behaviors in societies composed of connected groups with coherent strategy. 展开更多
关键词 Strategy-Homogeneity Prisoner’s Dilemma Game square lattice Cooperative Behavior
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Magnetization of Nano-Size Subsystem in a Two-Dimensional Ising Square Lattice
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作者 Liang-Ming He Rong Wang +2 位作者 Cai-Liu Yin San-Jun Peng Dong Qian 《World Journal of Condensed Matter Physics》 2012年第4期175-180,共6页
A two-dimensional Ising square lattice is modeled as a nano-size block array to study by Monte Carlo simulation the magnetic thermal stability of nano-structure magnetic media for data storage, thereon in the blocks J... A two-dimensional Ising square lattice is modeled as a nano-size block array to study by Monte Carlo simulation the magnetic thermal stability of nano-structure magnetic media for data storage, thereon in the blocks J1 > 0 is assigned for the interaction of a pair of nearest-neighbor spins, while 0 J0 J1 for that in regions between the blocks and (J0 + J1)/2 for the nearest-neighbor pairs with one in the block and the other one out of but near-most the block. We show that the magnetic thermal stability of the block accrues with the increase of J1 and with the decrease of J1 - J0 for a given J1, but contrarily, the anchoring ability for the initial magnetic orientation in nano-size block trails off as J1 - J0 diminish. This phenomena and size dependence of such anchoring ability are discussed in detail. 展开更多
关键词 MAGNETIZATION ISING square lattice NANO-SIZE SUBSYSTEM
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Propagation and Interaction of Edge Dislocation(Kink) in the Square Lattice
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作者 贾利平 Jasmina Teki 段文山 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第4期21-24,共4页
The propagation of kink or edge dislocations in the underdamped generalized two-dimensional Frenkel-Kontorova model with harmonic interaction is studied with numerical simulations. The obtained results show that exact... The propagation of kink or edge dislocations in the underdamped generalized two-dimensional Frenkel-Kontorova model with harmonic interaction is studied with numerical simulations. The obtained results show that exactly one line of atoms can be inserted into the lattice, which remains at standstill However, if more than one line of atoms are inserted into the lattice, then they will split into several lines with α= 1, where a presents the atoms inserted. In other words, only the kink with α= 1 is stable, while the other kinks are unstable, and will split into α =1 kinks, which remain at standstill. 展开更多
关键词 in the square lattice
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Lattice Boltzmann simulation of a laminar square jet in cross flows
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作者 Guoneng Li Youqu Zheng +2 位作者 Huawen Yang Wenwen Guo Yousheng Xu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第11期1505-1512,共8页
A three-dimensional, nineteen-velocity(D3Q19) Lattice Boltzmann Method(LBM) model was developed to simulate the fluid flow of a laminar square jet in cross flows based on the single relaxation time algorithm. The code... A three-dimensional, nineteen-velocity(D3Q19) Lattice Boltzmann Method(LBM) model was developed to simulate the fluid flow of a laminar square jet in cross flows based on the single relaxation time algorithm. The code was validated by the mathematic solution of the Poiseuille flow in a square channel, and was further validated with a previous well studied empirical correlation for the central trajectory of a jet in cross flows. The developed LBM model was found to be able to capture the dominant vortex, i.e. the Counter-rotating Vortex Pair(CVP) and the upright wake vortex. Results show that the incoming fluid in the cross flow channel was entrained into the leeside of the jet fluid, which contributes to the blending of the jet. That the spread width of the transverse jet decreases with the velocity ratio. A layer-organized entrainment pattern was found indicating that the incoming fluid at the lower position is firstly entrained into the leeside of the jet, and followed by the incoming fluid at the upper position. 展开更多
关键词 lattice Boltzmann method square jet Cross flow Laminar flow
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Crystal growth of CeMn_(0.85)Sb_(2):Absence of magnetic order of Ce-sublattice
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作者 李勇 苗杉杉 +2 位作者 冯海 杨槐馨 石友国 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第6期569-575,共7页
Single crystals of CeMn_(0.85)Sb_(2) have been successfully synthesized by using the Bi as flux.Analysis of single crystal x-ray diffraction data confirms that CeMn_(0.85)Sb_(2) crystallizes in the HfCuSi_(2)-type str... Single crystals of CeMn_(0.85)Sb_(2) have been successfully synthesized by using the Bi as flux.Analysis of single crystal x-ray diffraction data confirms that CeMn_(0.85)Sb_(2) crystallizes in the HfCuSi_(2)-type structure with the space group P4/nmm(No.129).In the case of H‖c,CeMn_(0.85)Sb_(2) displays a robust antiferromagnetic transition at~160 K for Mn-sublattice,and there is no sign of magnetic order regarding Ce-sublattice.In the case of the Mn-sublattice shows signs of magnetic order at 160 K and 116 K,indicating a possible spin reorientation.There is no sign of magnetic order for the Cesublattice either,but,alternating current magnetic susceptibility measurements reveal a spin glass state below 18 K in the case of H⊥c.Isothermal magnetization curves measured below magnetic order with H⊥c show saturation and even large hysteresis at 2 K,indicating the presence of a ferromagnetic component.In addition,a field-induced spin-flop transition is observed in the case of H⊥c,indicating a field-induced spin reorientation of Mn spins.Electrical resistivity measurements indicate a metallic nature for CeMn_(0.85)Sb_(2) and large anisotropy which is consistent with its quasi-two-dimensional layered structure. 展开更多
关键词 CeMn_(0.85)Sb_(2) MAGNETISM spin glass layered structure square lattice
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Amplitude and Period Effect on Heat Transfer in an Enclosure with Sinusoidal Heating from Below Using Lattice Boltzmann Method
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作者 Noureddine Abouricha Chouaib Ennawaoui Mustapha El Alami 《Frontiers in Heat and Mass Transfer》 EI 2023年第1期523-537,共15页
This work presents a simulation of the phenomena of natural convection in an enclosure with a variable heating regime by the lattice Boltzmann method(LBM).We consider a square enclosure of side H filled with air(Pr=0.... This work presents a simulation of the phenomena of natural convection in an enclosure with a variable heating regime by the lattice Boltzmann method(LBM).We consider a square enclosure of side H filled with air(Pr=0.71)and heated from below,with a hot portion of length L=0.8 H,by imposing a sinusoidal temperature.The unheated segments of the bottom wall are treated as adiabatic,and one of the vertical walls features a cold region,while the remaining walls remain adiabatic.The outcomes of the two-dimensional(2D)problem are depicted through isotherms,streamlines,the temperature evolution within the enclosure,and the Nusselt number.These visualizations span various amplitude values“a”in the interval[0.2,0.8],and of the period T0 for Ra=107.The amplitude and period effect on the results is evaluated and discussed.The amplitude of the temperature at the heart of the enclosure increases with the increase in amplitude.This also increases with the period(T0)of the imposed temperature,something that is not observable on the global Nusselt number. 展开更多
关键词 Sinusoidal heating square cavity lattice Boltzmann method natural convection heat transfer under floor heating
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用Lattice Boltzmann方法模拟方柱绕流 被引量:10
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作者 王兴勇 索丽生 +1 位作者 程永光 刘德有 《河海大学学报(自然科学版)》 CAS CSCD 北大核心 2003年第3期259-263,共5页
用LatticeBoltzmann方法模拟了两种情况下的方柱绕流:方柱位于流场的边壁和方柱位于流场的中央.在第1种情况中,分析了流场的流线、速度矢量分布以及方柱后面绕流形成的回流区长度随Reynolds数的变化曲线;在第2种情况中,除了给出稳定时... 用LatticeBoltzmann方法模拟了两种情况下的方柱绕流:方柱位于流场的边壁和方柱位于流场的中央.在第1种情况中,分析了流场的流线、速度矢量分布以及方柱后面绕流形成的回流区长度随Reynolds数的变化曲线;在第2种情况中,除了给出稳定时流场的流线、速度矢量分布和压力分布以外,还模拟了Re=150时方柱后面形成的周期旋涡现象.两种情况下的计算结果与其他文献中的计算数值和试验数据是一致的. 展开更多
关键词 latticeBoltzmann方法 方柱绕流 流场 流线 压力
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基于Lattice Boltzmann方法的方柱绕流模拟 被引量:8
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作者 刘天成 葛耀君 +1 位作者 曹丰产 刘高 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2008年第8期1028-1033,共6页
从分子动力论出发,探讨了模拟不可压缩粘性流动的Lattice Boltzmann(LB)方法.根据粒子平衡分布函数和非平衡反弹思想,提出了高效的出口边界条件处理格式.结合区域分裂技术设计了适合集群计算机运算的LB并行算法,并用C++程序语言开发了L... 从分子动力论出发,探讨了模拟不可压缩粘性流动的Lattice Boltzmann(LB)方法.根据粒子平衡分布函数和非平衡反弹思想,提出了高效的出口边界条件处理格式.结合区域分裂技术设计了适合集群计算机运算的LB并行算法,并用C++程序语言开发了LB并行计算程序.通过对不同雷诺数时的方柱绕流模拟,验证了本文方法的有效性,同时详细分析了雷诺数对方柱绕流特性的影响. 展开更多
关键词 方柱绕流 lattice BOLTZMANN方法 区域分裂 出口边界
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并列双方柱绕流的Lattice Boltzmann模拟分析 被引量:10
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作者 饶勇 倪玉山 刘超峰 《应用力学学报》 EI CAS CSCD 北大核心 2008年第2期192-197,共6页
采用Lattice Boltzmann方法对并列双方柱绕流问题进行数值模拟。对方柱间距比s/D=0.2、0.3、0.4、0.5、1.0、1.4、1.5、1.6、1.8、2.0、2.5共11种情况下的流场分别进行计算,给出了对应的流线图、方柱的升力图及阻力图,同时计算了方柱各... 采用Lattice Boltzmann方法对并列双方柱绕流问题进行数值模拟。对方柱间距比s/D=0.2、0.3、0.4、0.5、1.0、1.4、1.5、1.6、1.8、2.0、2.5共11种情况下的流场分别进行计算,给出了对应的流线图、方柱的升力图及阻力图,同时计算了方柱各边中点的压力,给出了压力与间距比的变化曲线,并对各个流线图、升力图、阻力图及压力图进行了分析讨论。结果表明:当s/D≤1.5时,流动呈偏流型,形成周期漩涡;当s/D>1.5时,流动呈对称型,形成对称漩涡;s/D=1.5为流动从偏流型向对称型转换的临界间距比。该结果对工程中建筑物位置的安排及其安全系数的提高有一定的参考价值。 展开更多
关键词 lattice Bo[tzmann 方柱绕流 流场模拟 间距比
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二维正方形介质柱Square格子光子晶体的能带研究
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作者 李秀杰 杨毅彪 +3 位作者 韩培德 王拴锋 王云才 梁伟 《太原理工大学学报》 CAS 北大核心 2010年第6期689-691,695,共4页
利用平面波展开法计算了两种不同介质材料(GaAs,Ge)构建的二维正方形介质柱Square格子光子晶体的能带结构,研究了介质柱旋转角度、填充比及介质折射率对二维光子晶体禁带结构的影响。结果发现,介质柱旋转角度为0°时,完全光子禁带最... 利用平面波展开法计算了两种不同介质材料(GaAs,Ge)构建的二维正方形介质柱Square格子光子晶体的能带结构,研究了介质柱旋转角度、填充比及介质折射率对二维光子晶体禁带结构的影响。结果发现,介质柱旋转角度为0°时,完全光子禁带最大;由不同折射率材料构建的该结构光子晶体,在折射率n=2.57时,即有完全光子禁带产生,为实现用较低折射率材料构建完全禁带光子晶体提供了便利;n=4.10时,完全光子禁带达到最大,禁带宽度Δ=0.048(ωa/2πc)。该研究结果为二维光子晶体应用提供了理论依据。 展开更多
关键词 二维光子晶体 完全光子禁带 平面波展开法 square格子
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A Solvable Decorated Ising Lattice Model 被引量:3
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作者 SUN Chun-Feng KONG Xiang-Mu YIN Xun-Chang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期555-557,共3页
A decorated lattice is suggested and the Ising model on it with three kinds of interactions K1, K2, and K3 is studied. Using an equivalent transformation, the square decorated Ising lattice is transformed into a regul... A decorated lattice is suggested and the Ising model on it with three kinds of interactions K1, K2, and K3 is studied. Using an equivalent transformation, the square decorated Ising lattice is transformed into a regular square Ising lattice with nearest-neighbor, next-nearest-nelghbor, and four-spin interactions, and the critical fixed point is found at K1 = 0.5769, K2= -0.0671, and K3 = 0.3428, which determines the critical temperature of the system. It is also found that this system and the regular square Ising lattice, and the eight-vertex model belong to the same universality class. 展开更多
关键词 Ising model square decorated lattice critical point universality class
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Simulation on Cavitation Bubble Collapsing with Lattice Boltzmann Method 被引量:3
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作者 Jia Yang Zhuangzhi Shen +1 位作者 Xia Zheng Li Li 《Journal of Applied Mathematics and Physics》 2015年第8期947-955,共9页
We consider a pressure (density) in a square flume solid boundaries and no-slip format condition formulation are introduced to investigate cavitation bubble for the two-dimensional lattice Boltz- mann method (LBM). Us... We consider a pressure (density) in a square flume solid boundaries and no-slip format condition formulation are introduced to investigate cavitation bubble for the two-dimensional lattice Boltz- mann method (LBM). Using the coupling Carnahan-Starling equation of state (C-S EOS) and exact difference method (EDM) based on modified Shan-Chen model, the whole process of bubble collapse was observed complete and visual with equilibrium distribution function and rebound format. This paper analyzes the bubble form evolution, collapse time and dynamic character under the two dimensional press fields. 展开更多
关键词 lattice BOLTZMANN Method square FLUME Solid Boundaries BUBBLE Form
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L(1, 2)-edge-labelings for lattices
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作者 HE Dan LIN Wen-song 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第2期230-240,共11页
For a graph G and two positive integers j and k, an m-L(j, k)-edge-labeling of G is an assignment on the edges to the set {0, 1, 2,..., m}, such that adjacent edges which receive labels differ at least by j, and edg... For a graph G and two positive integers j and k, an m-L(j, k)-edge-labeling of G is an assignment on the edges to the set {0, 1, 2,..., m}, such that adjacent edges which receive labels differ at least by j, and edges which are distance two apart receive labels differ at least by k. The λj,k-number of G is the minimum m such that an m-L(j, k)-edge-labeling is admitted by G. In this article, the L(1, 2)-edge-labeling for the hexagonal lattice, the square lattice and the triangular lattice are studied, and the bounds for λj,k-numbers of these graphs are obtained. 展开更多
关键词 L(j k)-edge-labeling line graph triangular lattice square lattice hexagonal lattice.
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QRD-BASED MULTICHANNEL ADAPTIVE LATTICEALGORITHMS FOR THE PARAMETERIDENTIFICATION PROBLEM
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作者 Ouyang Shan Fang Huijun(Guilin Institute of EJectronic TechnoJogy, Guilin 541004) 《Journal of Electronics(China)》 1996年第3期201-210,共10页
A pair of multichannel recursive least squares (RLS) adaptive lattice algorithms based on the order recursive of lattice filters and the superior numerical properties of Givens algorithms is derived in this paper. The... A pair of multichannel recursive least squares (RLS) adaptive lattice algorithms based on the order recursive of lattice filters and the superior numerical properties of Givens algorithms is derived in this paper. The derivation of the first algorithm is based on QR decomposition of the input data matrix directly, and the Givens rotations approach is used to compute the QR decomposition. Using first a prerotation of the input data matrix and then a repetition of the single channel Givens lattice algorithm, the second algorithm can be obtained. Both algorithms have superior numerical properties, particularly the robustness to wordlength limitations. The parameter vector to be estimated can be extracted directly from internal variables in the present algorithms without a backsolve operation with an extra triangular array. The results of computer simulation of the parameter identification of a two-channel system are presented to confirm efficiently the derivation. 展开更多
关键词 RECURSIVE least squareS lattice algorithm QR decomposition MULTICHANNEL signals Adaptive PARAMETER identification
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Hydrodynamic Characteristics of Square Heaving Plates with Opening Under Forced Oscillation 被引量:1
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作者 CONG Long-fei TENG Bin 《China Ocean Engineering》 SCIE EI CSCD 2019年第6期637-648,共12页
The existence of the heaving plates can improve the heaving motion performance of an offshore structure significantly by providing both extra added mass and damping.In the current research,numerical investigation is c... The existence of the heaving plates can improve the heaving motion performance of an offshore structure significantly by providing both extra added mass and damping.In the current research,numerical investigation is carried out on the hydrodynamic characteristics of both isolated square heaving plate and double square heaving plates with opening by an immersed boundary-lattice Boltzmann method.The effects on hydrodynamic performance of plates due to Keulegan-Carpenter(KC)number,frequency number,opening ratio,opening distribution and spacing of plates are examined.It is found that the heaving plates with optimized opening ratio can provide additional damping compared with the plates without opening.Better hydrodynamic characteristics of double plates can be obtained with the increase of plate spacing. 展开更多
关键词 immersed boundary-lattice Boltzmann method square heaving plate opening shape opening ratio opening distribution plate spacing
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