检索结果-内蒙古大学图书馆

Comparative analysis of vector algorithms for statistical modelling of polarized radiative transfer process

RUSSIAN JOURNAL OF NUMERICAL ANALYSIS AND MATHEMATICAL MODELLING 2018年第4期33卷 253-263页

作者： Mikhailov, Gennadya Prigarin, Sergei M. Rozhenko, Sergey A. RAS Siberian Branch Inst Computat Math & Math Geophys Novosibirsk 630090 Russia Novosibirsk State Univ Novosibirsk 630090 Russia

The comparative efficiency of different algorithms of statistical modelling of polarized radiation transfer process is studied for the problem with molecular matrix of scattering. The vector illumination and brightness are calculated for passing and reflected radiation. A statistical nuclear estimator is developed for evaluation of the corresponding angular distributions taking into account the weights of registered quanta.

关键词： Polarized radiation transfer process Stokes vector statistical modelling vector algorithms statistical error integral transfer equation kernel density estimation Legendre polynomial

来源：评论

学校读者我要写书评

暂无评论

From Texts to Knowledge Graph in the Semantic Library LibMeta

引用

LOBACHEVSKII JOURNAL OF MATHEMATICS 2024年第5期45卷 2211-2219页

作者： Ataeva, O. M. Serebryakov, V. A. Tuchkova, N. P. Russian Acad Sci Fed Res Ctr Comp Sci & Control Moscow 119333 Russia

The problem of constructing a knowledge graph for previously unprocessed scientific texts is studied. The task is to analyze the use of various machine processing methods for extracting text semantics using the example of an interdisciplinary subject area. The goal of the research is to create a semantic model of the subject area of an interdisciplinary scientific journal and use a knowledge graph to navigate through data. The semantic model is based on the ontology of the LibMeta library. Texts and metadata receive connections due to the processing procedure and become part of the ontology of the semantic library. The interdisciplinary subject area is integrated into the library content as a related area of the ''mathematics'' ontology of the LibMeta library. A comparison of texts is carried out according to different characteristics, thematic proximity, commonality of research methods and approaches, problem setting and their symbolic representation. The results of preliminary text processing and the results in the form of a knowledge graph integrated into the library content are presented. The formulation of the problem of constructing an ontology and a knowledge graph for an interdisciplinary subject area adjacent to mathematics is considered by the authors as part of the general problem of managing mathematical knowledge.

关键词： ontology design semantic relationships subject ontology vector algorithms knowledge graph

来源：评论

学校读者我要写书评

暂无评论

Development of vector algorithm using CUDA technology for three-dimensional retinal laser coagulation process modeling

COMPUTER OPTICS

引用

COMPUTER OPTICS 2021年第3期45卷 427-+页

作者： Shirokanev, A. S. Andriyanov, N. A. Ilyasova, N. Y. Samara National Research University Moskovskoye Shosse 34 Samara 443086 Russian Federation IPSI RAS – Branch of the FSRC “Crystallography and Photonics” RAS Molodogvardeyskaya 151 Samara 443001 Russian Federation Financial University under the Government of the Russian Federation Leningradskii prospekt 49 Moscow 125167 Russian Federation

For diabetic retinopathy treatment, laser coagulation is used in modern practice. During the laser surgery process, the parameters of laser exposure are selected manually by a doctor, which requires the doctor to have sufficient experience and knowledge to achieve a therapeutic effect. On the basis of mathematical modeling of the laser coagulation process, it is possible to estimate the crucial parameters without performing an operation. However, the retina has a rather complex structure, and when even low-cost numerical methods are used for modeling, it takes a long time to obtain a result. In this regard, the development of time-efficient algorithms for three-dimensional modeling is an urgent task, since the use of such algorithms will provide a comprehensive study within a limited time. In this paper, we study the execution time of algorithms that implement various variations in the application of the splitting method and the finite difference method, adapted to the set problem of heat conduction. The study reveals the most efficient algorithm, which is then vectorized and implemented using the CUDA technology. The study was carried out using Intel Core i7-10875H and Nvidia RTX 2080 MAX Q and showed that an analog of the vector algorithm, focused on solving a multidimensional heat conduction problem, provides an acceleration of no more than 1.5 times compared to the sequential version. The developed vector-based algorithm, focused on the application of the sweep method in all directions of the three-dimensional problem, significantly reduces the time spent on copying into the memory of the video card and provides a 40-fold acceleration in comparison with the sequential three-dimensional modeling algorithm. On the basis of the same approach, a parallel algorithm of mathematical modeling was developed, which provided a 20-fold acceleration at full processor load.

关键词： diabetic retinopathy laser coagulation mathematical modeling heat conduction equation parallel algorithms vector algorithms CUDA

来源：评论

学校读者我要写书评

暂无评论

DIFFERENCE SOLUTIONS OF THE WAVE EQUATION ON GPU WITH REUSE OF PAIRWISE SUMS OF THE DIFFERENTIAL TEMPLATE

COMPUTER OPTICS

引用

COMPUTER OPTICS 2017年第1期41卷 134-138页

作者： Vorotnikova, D. G. Golovashkin, D. L. RAS Image Proc Syst Inst Branch FSRC Crystallog & Photon Samara Russia Samara Natl Res Univ Samara Russia

This work proposes a technique for constructing vector algorithms for solving the diffraction problem using a finite difference scheme on GPUs. The use of an approach based on the reuse of sums of the differential pattern when solving the D' Alembert equation allowed up to a three-fold reduction in the running time in comparison with the known algorithms.

关键词： vector algorithms wave equation acceleration of computing

来源：评论

学校读者我要写书评

暂无评论

vector algorithms FOR APPROXIMATE STRING MATCHING

引用

International Journal of Foundations of Computer Science 2002年第1期13卷 53-65页

作者： ANNE BERGERON SYLVIE HAMEL LACIM Université du Québec à Montréal C.P. 8888 Succursale Centre-Ville Montréal Québec Canada H3C 3P8 Canada

vector algorithms allow the computation of an output vector r = r1 r2 ⋯ rm given an input vector e = e1 e2 ⋯ em in a bounded number of operations, independent of m the length of the vectors. The allowable operations are usually restricted to bit-wise operations available in processors, including shifts and binary addition with carry. These restrictions imple that the existence of a vector algorithm for a particular problem opens the way to extremely fast implementations, using the inherent parallelism of bit-wise operations. This paper presents general results on the existence and construction of vertor algorithms, with a particular focus on problems arising from computational biology. We show that efficient vector algorithms exist for the problem of approximate string matching with arbitrary weighted distances, generalizing a previous result by G. Myers. We also characterize a class of automata for which vector algorithms can be automatically derived from the transition table of the automata.

关键词： vector algorithms computational biology string matching

来源：评论

学校读者我要写书评

暂无评论

A vectorIZABLE RANDOM LATTICE

引用

JOURNAL OF STATISTICAL PHYSICS 1992年第5-6期68卷 911-923页

作者： MOUKARZEL, C HERRMANN, HJ HLRZ c/o KFA Jülich Germany

We describe a family of random lattices in which the connectivity is determined by the Voronoi construction while the vectorizability is not lost. We can continuously vary the degree of randomness so in a certain limit a regular lattice is recovered. Several statistical properties of the cells and bonds of these lattices are measured. We also study anisotropy effects on the numerical solution of the Laplace equation for varying degrees of randomness.

关键词： RANDOM LATTICES vector algorithms

来源：评论

学校读者我要写书评

暂无评论

MAPPING ENTHALPY-BASED SOLIDIFICATION algorithms ONTO vector AND PARALLEL ARCHITECTURES

引用

APPLIED MATHEMATICAL MODELLING 1989年第12期13卷 702-709页

作者： CROSS, M JOHNSON, S CHOW, P Centre for Numerical Modelling and Process Analysis Thames Polytechnic London UK

Effective methods are required to solve three-dimensional solidification problems with fine meshes. This paper considers some of the problems associated with mapping control volume-based enthalpy algorithms onto vector processors and transputer-based parallel networks. Although vector processors may bring speedups of a factor of 5 or so, it appears that transputer-based networks have the facility to yield speedups that increase linearly with the number of transputer chips used.

关键词： solidification vector algorithms parallel algorithms

来源：评论

学校读者我要写书评

暂无评论

ITERATIVE algorithms FOR GRAM-SCHMIDT ORTHOGONALIZATION

引用

COMPUTING 1989年第4期41卷 335-348页

作者： HOFFMANN, W Department of Computer Systems University of Amsterdam Amsterdam The Netherlands

The algorithms that are treated in this paper are based on the classical and the modified Gram-Schmidt algorithms. It is shown that Gram-Schmidt orthogonalization for constructing aQR factorization should be carried out iteratively to obtain a matrixQ that is orthogonal in almost full working precision. In the formulation of the algorithms, the parts that express manipulations with matrices or vectors are clearly identified to enable an optimal implementation of the algorithms on parallel and/or vector machines. An extensive error analysis is presented. It shows, for instance, that the iterative classical algorithm is not inferior to the iterative modified algorithm when full precision ofQ is required. Experiments are reported to support the outcomes of the analysis.

关键词： AMS Subject Classifications: 65F25, 65G05, 15A23 Gram-Schmidt orthogonalization QR factorization vector algorithms

来源：评论

学校读者我要写书评

暂无评论

AN ESTIMATE FOR THE SPECTRAL NORM OF THE INVERSE OF A MATRIX WITH THE GAUSS-JORDAN ALGORITHM

引用

JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 1989年第3期27卷 421-428页

作者： HOFFMANN, W Universiteit van Amsterdam Vakgroep Computersystemen Kruislaan 409 1098 SJ Amsterdam The Netherlands

In this paper an algorithm is presented for calculating an estimate for the spectral norm of the inverse of a matrix. This algorithm is to be used in combination with solving a linear system by means of the Gauss—Jordan algorithm. The norm of the inverse is needed for the condition number of that matrix. The algorithm exploits the effect the Gauss—Jordan elimination is equivalent with writing the matrix as a product of n elementary matrices. These elementary matrices are sequentially used to maximize (locally) the norm of a solution vector that matches a right-hand side vector under construction. In n steps this produces a satisfactory estimate. Our algorithm uses 5 n 2 +O( n ) extra floating-point multiplications for the calculation of the required estimate and is tested for a multitude of matrices on the CYBER 205 vector computer of the Academic Computer Centre, SARA, in Amsterdam.

关键词： Gauss—Jordan algorithm condition estimation vector algorithms

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：