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Applicability of standard forward column/row recurrence equations for ALFs
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作者 Zhang Han-Wei Zhang Hua +1 位作者 Li Xiao-Ling Yang Yong-Qin 《Applied Geophysics》 SCIE CSCD 2022年第3期424-432,472,共10页
Fully normalized associated Legendre functions(fnALFs)are a set of orthogonal basis functions that are usually calculated by using the recurrence equation.This paper presented the applicability and universality of the... Fully normalized associated Legendre functions(fnALFs)are a set of orthogonal basis functions that are usually calculated by using the recurrence equation.This paper presented the applicability and universality of the standard forward column/row recurrence equation based on the isolated singular factor method and extended-range arithmetic.Isolating a singular factor is a special normalization method that can improve the universality of the standard forward row recurrence equation to a certain extent,its universality can up to degree hundreds.However,it is invalid for standard forward column recurrence equation.The extended-range arithmetic expands the double-precision number field to the quad-precision numberfield.The quad-precision numberfield can retain more significant digits in the operation process and express larger and smaller numbers.The extended-range arithmetic can significantly improve the applicability and universality of the standard forward column/row recurrence equations,its universality can up to degree several thousand.However,the quad-precision numberfield operation needs to occupy more storage space,which is why its operation speed is slow and undesirable in practical applications.In this paper,the X-number method is introduced in the standard forward row recurrence equation for thefirst time.With the use of the X-number method,fnALFs can be recursed to 4.2 billion degree by using standard forward column/row recurrence equations. 展开更多
关键词 fnALFs standard forward column recurrence eqution row recurrence equation
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K-Dimensional Optimal Parallel Algorithm for the Solution of a General Class of Recurrence Equations 被引量:1
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作者 高庆狮 刘志勇 《Journal of Computer Science & Technology》 SCIE EI CSCD 1995年第5期417-424,共8页
This paper proposes a parallel algorithm, called KDOP (K-DimensionalOptimal Parallel algorithm), to solve a general class of recurrence equations efficiently. The KDOP algorithm partitions the computation into a serie... This paper proposes a parallel algorithm, called KDOP (K-DimensionalOptimal Parallel algorithm), to solve a general class of recurrence equations efficiently. The KDOP algorithm partitions the computation into a series of sub-computations, each of which is executed in the fashion that all the processors work simultaneously with each one executing an optimal sequential algorithm to solve a subcomputation task. The algorithm solves the equations in O(N/p)steps in EREW PRAM model (Exclusive Read Exclusive Write Parallel Ran-dom Access Machine model) using p<N1-e processors, where N is the size of the problem, and e is a given constant. This is an optimal algorithm (itsspeedup is O(p)) in the case of p<N1-e. Such an optimal speedup for this problem was previously achieved only in the case of p<N0.5. The algorithm can be implemented on machines with multiple processing elements or pipelined vector machines with parallel memory systems. 展开更多
关键词 Parallel algorithm optimal algorithm first-order linear recurrence equations recursive doubling algorithm tridiagonal systems of linear equations
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Understanding the Theory of Karp, Miller and Winograd
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作者 Athanasios I. Margaris 《Journal of Applied Mathematics and Physics》 2024年第4期1203-1236,共34页
The objective of this tutorial is to present the fundamental theory of Karp, Miller and Winograd, whose seminal paper laid the foundations regarding the systematic description of the organization of computations in sy... The objective of this tutorial is to present the fundamental theory of Karp, Miller and Winograd, whose seminal paper laid the foundations regarding the systematic description of the organization of computations in systems of uniform recurrent equations by means of graph structures, via the definition of computability conditions and techniques for the construction of one-dimensional and multi-dimensional scheduling functions. Besides the description of this theory, the paper presents improvements and revisions made by other authors and furthermore, points out the differences regarding the conditions of causality and dependency between the general case of systems of recurrent equations and the special case of multiple nested loops. 展开更多
关键词 COMPUTABILITY SCHEDULING COMPUTATIONS Recurrent equations
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Two-Relaxation-Time Lattice Boltzmann Scheme:About Parametrization,Velocity,Pressure and Mixed Boundary Conditions 被引量:4
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作者 Irina Ginzburg Frederik Verhaeghe Dominique d’Humieres 《Communications in Computational Physics》 SCIE 2008年第2期427-478,共52页
We develop a two-relaxation-time (TRT) Lattice Boltzmann model for hydrodynamicequations with variable source terms based on equivalent equilibriumfunctions. A special parametrization of the free relaxation parameter ... We develop a two-relaxation-time (TRT) Lattice Boltzmann model for hydrodynamicequations with variable source terms based on equivalent equilibriumfunctions. A special parametrization of the free relaxation parameter is derived. Itcontrols, in addition to the non-dimensional hydrodynamic numbers, any TRT macroscopicsteady solution and governs the spatial discretization of transient flows. Inthis framework, the multi-reflection approach [16, 18] is generalized and extended forDirichlet velocity, pressure and mixed (pressure/tangential velocity) boundary conditions.We propose second and third-order accurate boundary schemes and adapt themfor corners. The boundary schemes are analyzed for exactness of the parametrization,uniqueness of their steady solutions, support of staggered invariants and for the effectiveaccuracy in case of time dependent boundary conditions and transient flow.When the boundary scheme obeys the parametrization properly, the derived permeabilityvalues become independent of the selected viscosity for any porous structureand can be computed efficiently. The linear interpolations [5, 46] are improved withrespect to this property. 展开更多
关键词 Lattice Boltzmann equation Dirichlet boundary conditions Chapman-Enskog expansion multiple-relaxation-timemodel BGKmodel TRTmodel Navier-Stokes equation Stokes equation recurrence equations staggered invariants.
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Multistage Uncertain Random Linear Quadratic Optimal Control
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作者 CHEN Xin ZHU Yuanguo 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2020年第6期1847-1872,共26页
In this paper,linear quadratic(LQ)optimal control problems are investigated for two types of uncertain random systems which consider the coefficient of the perturbed term as a constant vector or a vector-valued functi... In this paper,linear quadratic(LQ)optimal control problems are investigated for two types of uncertain random systems which consider the coefficient of the perturbed term as a constant vector or a vector-valued function of state vector and control vector.First,the uncertain random optimal control model is established under expected value criterion.Second,based on Bellman’s principle,recurrence equations are presented for settling such problem.Then by applying the recurrence equations and chance theory,the analytical expressions of the optimal results for the LQ problems are derived.Furthermore,some examples and an application are given to show the effectiveness of our results. 展开更多
关键词 Linear quadratic problem optimal control recurrence equations uncertain random system
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The Proportional Hazards Model for Multiple Type Recurrent Gap Times 被引量:1
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作者 Ji-cai LIU Huan-bin LIU Ri-quan ZHANG 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2016年第1期221-230,共10页
Recurrent events data and gap times between recurrent events are frequently encountered in many clinical and observational studies,and often more than one type of recurrent events is of interest.In this paper,we consi... Recurrent events data and gap times between recurrent events are frequently encountered in many clinical and observational studies,and often more than one type of recurrent events is of interest.In this paper,we consider a proportional hazards model for multiple type recurrent gap times data to assess the effect of covaxiates on the censored event processes of interest.An estimating equation approach is used to obtain the estimators of regression coefficients and baseline cumulative hazard functions.We examine asymptotic properties of the proposed estimators.Finite sample properties of these estimators are demonstrated by simulations. 展开更多
关键词 proportional hazards model estimating equation multiple type recurrent events gap times semiparametric inference
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