期刊文献+
共找到401篇文章
< 1 2 21 >
每页显示 20 50 100
Geometry Theorem Proving by Decomposing Polynomial System into Strong Regular Sets 被引量:1
1
作者 Yong-BinLi WuLiu] Xiao-LinXiang 《Journal of Computer Science & Technology》 SCIE EI CSCD 2004年第6期820-827,共8页
This paper presents a complete method to prove geometric theorem by decomposing the corresponding polynomial system. into strong regular sets, by which one can compute some components for which the geometry theorem is... This paper presents a complete method to prove geometric theorem by decomposing the corresponding polynomial system. into strong regular sets, by which one can compute some components for which the geometry theorem is true and exclude other components for which the geometry theorem is false. Two examples are given to show that the geometry theorems are conditionally true for some components which are excluded by other methods. 展开更多
关键词 zero decomposition strong regular set automated geometry theorem proving subsidiary condition
原文传递
Characteristic Decomposition: From Regular Sets to Normal Sets 被引量:1
2
作者 MOU Chenqi WANG Dongming 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2019年第1期37-46,共10页
In this paper it is shown how to transform a regular triangular set into a normal triangular set by computing the W-characteristic set of their saturated ideal and an algorithm is proposed for decomposing any polynomi... In this paper it is shown how to transform a regular triangular set into a normal triangular set by computing the W-characteristic set of their saturated ideal and an algorithm is proposed for decomposing any polynomial set into ?nitely many strong characteristic pairs, each of which is formed with the reduced lexicographic Gr?bner basis and the normal W-characteristic set of a characterizable ideal. 展开更多
关键词 CHARACTERISTIC DECOMPOSITION CHARACTERISTIC PAIR NORMAL set regular set W-characteristic set
原文传递
A POLYNOMIAL ALGORITHM FOR FINDING THEMINIMUM FEEDBACK VERTEX SET OF A3-REGULAR SIMPLE GRAPH 被引量:2
3
作者 李德明 刘彦佩 《Acta Mathematica Scientia》 SCIE CSCD 1999年第4期375-381,共7页
A subset of the vertex set of a graph is a feedback vertex set of the graph if the resulting graph is a forest after removed the vertex subset from the graph. A polynomial algorithm for finding a minimum feedback vert... A subset of the vertex set of a graph is a feedback vertex set of the graph if the resulting graph is a forest after removed the vertex subset from the graph. A polynomial algorithm for finding a minimum feedback vertex set of a 3-regular simple graph is provided. 展开更多
关键词 maximum genus nonseparating independent number feedback vertex set 3-regular graph adjacency matching
在线阅读 下载PDF
REGULARIZATION OF PLANAR VORTICES FOR THE INCOMPRESSIBLE FLOW 被引量:2
4
作者 Daomin CAO Shuangjie PENG Shusen YAN 《Acta Mathematica Scientia》 SCIE CSCD 2018年第5期1443-1467,共25页
In this paper, we continue to construct stationary classical solutions for the incompressible planar flows approximating singular stationary solutions of this problem. This procedure is carried out by constructing sol... In this paper, we continue to construct stationary classical solutions for the incompressible planar flows approximating singular stationary solutions of this problem. This procedure is carried out by constructing solutions for the following elliptic equations{-△u=λ∑1Bδ(x0,j)(u-kj)p+,in Ω,u=0,onΩ is a bounded simply-connected smooth domain, ki (i = 1,… , k) is prescribed positive constant. The result we prove is that for any given non-degenerate critical pointX0=(x0,1,…,x0,k of the Kirchhoff-Routh function defined on Ωk corresponding to ( k1,……kk )there exists a stationary classical solution approximating stationary k points vortex solution. Moreover, as λ→+∞ shrinks to {x05}, and the local vorticity strength near each x0,j approaches kj, j = 1,… , k. This result makes the study of the above problem with p _〉 0 complete since the cases p 〉 1, p = 1, p = 0 have already been studied in [11, 12] and [13] respectively. 展开更多
关键词 regularIZATION planar vortices vorticity sets REDUCTION
在线阅读 下载PDF
Assessment of Contingent Liabilities for Risk Assets Evolutions Built on Brownian Motion
5
作者 Nicholas Simon Gonchar 《Advances in Pure Mathematics》 2020年第5期259-296,共38页
This paper is a generalization of the results of the previous papers. Using these results a class of evolutions of risk assets based on the geometric Brownian motion is constructed. Among these evolutions of risk asse... This paper is a generalization of the results of the previous papers. Using these results a class of evolutions of risk assets based on the geometric Brownian motion is constructed. Among these evolutions of risk assets, the important class of the random processes is the random processes with parameters built on the basis of the discrete geometric Brownian motion. For this class of random processes the interval of non-arbitrage prices are found for the wide class of contingent liabilities. In particular, for the payoff functions of standard options call and put of the European type the fair prices of super-hedge are obtained. Analogous results are obtained for the put and call of arithmetical options of Asian type. For the parameters entering in the definition of random process the description of all statistical estimates is presented. Statistical estimate for which the fair price of super-hedge for the payoff functions of standard call and put options of European type is minimal is indicated. From the formulas found it follows that the fair price of super-hedge can be less than the price of the underlying asset. In terms of estimates the simple formula for the fair price of super-hedge is found. Every estimates can be realized in the reality. This depends on the distribution function of the observed dates in the financial market. 展开更多
关键词 Random Process regular set of Measures Optional Doob Decomposition Local regular Super-Martingale MARTINGALE ASSESSMENT of DERIVATIVES
在线阅读 下载PDF
Description of Incomplete Financial Markets for Time Evolution of Risk Assets
6
作者 Nicholas S. Gonchar 《Advances in Pure Mathematics》 2019年第6期567-610,共44页
In the paper, a class of discrete evolutions of risk assets having the memory is considered. For such evolutions the description of all martingale measures is presented. It is proved that every martingale measure is a... In the paper, a class of discrete evolutions of risk assets having the memory is considered. For such evolutions the description of all martingale measures is presented. It is proved that every martingale measure is an integral on the set of extreme points relative to some measure on it. For such a set of evolutions of risk assets, the contraction of the set of martingale measures on the filtration is described and the representation for it is found. The inequality for the integrals from a nonnegative random value relative to the contraction of the set of martingale measure on the filtration which is dominated by one is obtained. Using these inequalities a new proof of the optional decomposition theorem for super-martingales is presented. The description of all local regular super-martingales relative to the regular set of measures is presented. The applications of the results obtained to mathematical finance are presented. In the case, as evolution of a risk asset is given by the discrete geometric Brownian motion, the financial market is incomplete and a new formula for the fair price of super-hedge is founded. 展开更多
关键词 Random Process regular set of Measures Optional Doob Decomposition Local regular Super-Martingale MARTINGALE DISCRETE GEOMETRIC BROWNIAN Motion
在线阅读 下载PDF
Convergence Analysis of General Version of Gauss-Type Proximal Point Method for Metrically Regular Mappings 被引量:2
7
作者 Md. Asraful Alom Mohammed Harunor Rashid Kalyan Kumer Dey 《Applied Mathematics》 2016年第11期1248-1259,共12页
We introduce and study in the present paper the general version of Gauss-type proximal point algorithm (in short GG-PPA) for solving the inclusion , where T is a set-valued mapping which is not necessarily monotone ac... We introduce and study in the present paper the general version of Gauss-type proximal point algorithm (in short GG-PPA) for solving the inclusion , where T is a set-valued mapping which is not necessarily monotone acting from a Banach space X to a subset of a Banach space Y with locally closed graph. The convergence of the GG-PPA is present here by choosing a sequence of functions with , which is Lipschitz continuous in a neighbourhood O of the origin and when T is metrically regular. More precisely, semi-local and local convergence of GG-PPA are analyzed. Moreover, we present a numerical example to validate the convergence result of GG-PPA. 展开更多
关键词 set-Valued Mappings Metrically regular Mappings Lipschitz-Like Mapping Local and Semi-Local Convergence
在线阅读 下载PDF
Einstein’s Dark Energy via Similarity Equivalence, ‘tHooft Dimensional Regularization and Lie Symmetry Groups 被引量:4
8
作者 Mohamed S. El Naschie 《International Journal of Astronomy and Astrophysics》 2016年第1期56-81,共26页
Realizing the physical reality of ‘tHooft’s self similar and dimensionaly regularized fractal-like spacetime as well as being inspired by a note worthy anecdote involving the great mathematician of Alexandria, Pytha... Realizing the physical reality of ‘tHooft’s self similar and dimensionaly regularized fractal-like spacetime as well as being inspired by a note worthy anecdote involving the great mathematician of Alexandria, Pythagoras and the larger than life man of theoretical physics Einstein, we utilize some deep mathematical connections between equivalence classes of equivalence relations and E-infinity theory quotient space. We started from the basic principles of self similarity which came to prominence in science with the advent of the modern theory of nonlinear dynamical systems, deterministic chaos and fractals. This fundamental logico-mathematical thread related to partially ordered sets is then applied to show how the classical Newton’s kinetic energy E = 1/2mv<sup>2</sup> leads to Einstein’s celebrated maximal energy equation E = mc<sup>2</sup> and how in turn this can be dissected into the ordinary energy density E(O) = mc<sup>2</sup>/22 and the dark energy density E(D) = mc<sup>2</sup>(21/22) of the cosmos where m is the mass;v is the velocity and c is the speed of light. The important role of the exceptional Lie symmetry groups and ‘tHooft-Veltman-Wilson dimensional regularization in fractal spacetime played in the above is also highlighted. The author hopes that the unusual character of the analysis and presentation of the present work may be taken in a positive vein as seriously attempting to propose a different and new way of doing theoretical physics by treating number theory, set theory, group theory, experimental physics as well as conventional theoretical physics on the same footing and letting all these diverse tools lead us to the answer of fundamental questions without fear of being labelled in one way or another. 展开更多
关键词 Equivalence Relation SCALING Intermediate Asymptotic Golden Mean Scaling Einstein Self Similarity Fractal Scaling E-INFINITY Special Relativity Random Cantor sets ‘tHooft regularization Fractal Quantum Field Quantum Gravity Exceptional Lie Symmetry Groups
在线阅读 下载PDF
Uniformly Bounded Set-Valued Composition Operators in the Spaces of Functions of Bounded Variation in the Sense of Riesz
9
作者 Wadie Aziz Nelson Merentes 《International Journal of Modern Nonlinear Theory and Application》 2015年第4期226-233,共8页
We show that the lateral regularizations of the generator of any uniformly bounded set-valued composition Nemytskij operator acting in the spaces of functions of bounded variation in the sense of Riesz, with nonempty ... We show that the lateral regularizations of the generator of any uniformly bounded set-valued composition Nemytskij operator acting in the spaces of functions of bounded variation in the sense of Riesz, with nonempty bounded closed and convex values, are an affine function. 展开更多
关键词 j-Variation in the SENSE of RIESZ set-VALUED Functions Left and Right regularizations UNIFORMLY BOUNDED OPERATOR Composition (Nemytskij) OPERATOR Jensen Equation
在线阅读 下载PDF
Martingales and Super-Martingales Relative to a Convex Set of Equivalent Measures
10
作者 Nicholas S. Gonchar 《Advances in Pure Mathematics》 2018年第4期428-462,共35页
In the paper, the martingales and super-martingales relative to a convex set of equivalent measures are systematically studied. The notion of local regular super-martingale relative to a convex set of equivalent measu... In the paper, the martingales and super-martingales relative to a convex set of equivalent measures are systematically studied. The notion of local regular super-martingale relative to a convex set of equivalent measures is introduced and the necessary and sufficient conditions of the local regularity of it in the discrete case are founded. The description of all local regular super-martingales relative to a convex set of equivalent measures is presented. The notion of the complete set of equivalent measures is introduced. We prove that every bounded in some sense super-martingale relative to the complete set of equivalent measures is local regular. A new definition of the fair price of contingent claim in an incomplete market is given and the formula for the fair price of Standard Option of European type is found. The proved Theorems are the generalization of the famous Doob decomposition for super-martingale onto the case of super-martingales relative to a convex set of equivalent measures. 展开更多
关键词 Random Process CONVEX set of EQUIVALENT Measures Optional Doob Decomposition Local regular Super-Martingale MARTINGALE Fair Price of CONTINGENT CLAIM
在线阅读 下载PDF
Gap Functions and Error Bounds for Set-Valued Vector Quasi Variational Inequality Problems
11
作者 Rachana Gupta Aparna Mehra 《Applied Mathematics》 2017年第12期1903-1917,共15页
One of the classical approaches in the analysis of a variational inequality problem is to transform it into an equivalent optimization problem via the notion of gap function. The gap functions are useful tools in deri... One of the classical approaches in the analysis of a variational inequality problem is to transform it into an equivalent optimization problem via the notion of gap function. The gap functions are useful tools in deriving the error bounds which provide an estimated distance between a specific point and the exact solution of variational inequality problem. In this paper, we follow a similar approach for set-valued vector quasi variational inequality problems and define the gap functions based on scalarization scheme as well as the one with no scalar parameter. The error bounds results are obtained under fixed point symmetric and locally α-Holder assumptions on the set-valued map describing the domain of solution space of a set-valued vector quasi variational inequality problem. 展开更多
关键词 set-VALUED VECTOR QUASI Variational Inequality Problem GAP FUNCTION regularized GAP FUNCTION Error Bounds Fixed Point Symmetric MAP α-Holder MAP
在线阅读 下载PDF
基于模糊隶属度的自适应复合正则化图像复原
12
作者 唐利明 《工程数学学报》 北大核心 2025年第3期554-576,共23页
从退化图像中恢复原始干净图像是一个经典的病态反问题,正则化技术是解决此问题的主流方法之一。它将解图像限定在一个正则空间中,复原图像即是退化图像在正则空间中的投影,但是针对不同图像选择合适的正则空间是一个难点。为提高正则... 从退化图像中恢复原始干净图像是一个经典的病态反问题,正则化技术是解决此问题的主流方法之一。它将解图像限定在一个正则空间中,复原图像即是退化图像在正则空间中的投影,但是针对不同图像选择合适的正则空间是一个难点。为提高正则化模型的适应性,更为精细地建模不同特征图像,基于模糊集理论,提出了一个自适应复合正则化模型。首先采用学习算法计算图像对于不同正则空间的隶属度,然后选择隶属度最大的前s个空间,以隶属度为权重建立自适应复合正则化模型,最后采用ADMM(Alternating Direction Method of Multipliers)算法对模型进行求解。实验结果表明,对于不同的图像,模型可以很好地选择合适的正则空间,得到满意的复原效果。 展开更多
关键词 正则化 模糊集 隶属度 图像复原 自适应
在线阅读 下载PDF
基于DRLSE和梯度流优化的红外目标分割方法
13
作者 周斌 李传真 +1 位作者 闫宁 赵琳琳 《激光与红外》 北大核心 2025年第8期1259-1265,共7页
针对电力设备红外图像受复杂背景、噪声干扰及目标形状多样性影响,导致目标分割效果不理想的问题,提出一种改进距离正则化水平集演变(DRLSE)的红外目标分割方法。利用DRLSE模型构建水平集函数,通过引入距离正则化项保持函数的规律性,避... 针对电力设备红外图像受复杂背景、噪声干扰及目标形状多样性影响,导致目标分割效果不理想的问题,提出一种改进距离正则化水平集演变(DRLSE)的红外目标分割方法。利用DRLSE模型构建水平集函数,通过引入距离正则化项保持函数的规律性,避免重新初始化需求,以提高数值稳定性和计算效率;结合梯度流优化技术,根据图像梯度信息指导水平集函数演变,使轮廓逐渐逼近目标真实边界,从而实现对电力设备红外目标的有效分割。实验结果表明,该模型较其他常用的五种方法表现更为出色,平均分割准确率为93.48%,平均重叠率(IoU)为0.922,平均Dice相似系数为0.924,该方法对提升智能电网设备故障诊断的准确性与可靠性具有重要应用价值。 展开更多
关键词 红外目标分割 DRLSE模型 正则水平集 局部梯度流
在线阅读 下载PDF
关于二重极限的极坐标变换法
14
作者 汪继林 马迪 曹怀信 《文山学院学报》 2025年第5期60-66,共7页
极坐标变换法在讨论函数的二重极限时经常使用,但在一般教材中并未给出使用该方法的条件与相应证明,使得解题者在使用该方法时导致困惑。基于二重极限的定义,提出了关于二重极限的极坐标变换定理,并进行了理论证明与应用举例,明晰了二... 极坐标变换法在讨论函数的二重极限时经常使用,但在一般教材中并未给出使用该方法的条件与相应证明,使得解题者在使用该方法时导致困惑。基于二重极限的定义,提出了关于二重极限的极坐标变换定理,并进行了理论证明与应用举例,明晰了二重极限与方向极限有关系。 展开更多
关键词 平面点集 局部星凸性 正则性 二重极限 极坐标变换法
在线阅读 下载PDF
基于综合云的移动自组织网络信息安全评估
15
作者 程华福 郑越峰 +1 位作者 邹凯 陈彦龙 《自动化技术与应用》 2025年第5期66-69,172,共5页
大数据的复杂性让以单一权重为主的信息安全评估过程,易受信息差异性、不均衡性等问题的干扰,评估效率较低,为此提出基于综合云的移动自组织网络信息安全评估方法。采用改进k均值聚类算法对移动自组织网络信息实行聚类处理,降低信息之... 大数据的复杂性让以单一权重为主的信息安全评估过程,易受信息差异性、不均衡性等问题的干扰,评估效率较低,为此提出基于综合云的移动自组织网络信息安全评估方法。采用改进k均值聚类算法对移动自组织网络信息实行聚类处理,降低信息之间的差异性;采用组合权重算法得到网络信息的综合权重,解决单一权重不均衡的问题;将综合权重与云模型生成的逆向云相结合得到综合云,通过计算相似性,完成移动自组织网络信息的安全评估。测试结果显示,设计的信息安全评估方法的评估时间短、评估误差小。 展开更多
关键词 信息聚类 判断矩阵 评估指标 正则化运算 信任数字特征集 风险值
在线阅读 下载PDF
基于非零水平集保凸算法的左心室MRI分割
16
作者 李季 刘艾汶 秦柳 《山东大学学报(理学版)》 北大核心 2025年第7期32-47,共16页
心脏左心室分割临床应用要求是分割的左心室保持凸形且包含左心室腔、小梁和乳头肌,提出一个包含改进距离正则项和非零水平集保凸项的心脏核磁共振成像分割模型,其利用水平集轮廓的曲率来保持凸性,从而使轮廓最终演化为凸形。使用ACDC M... 心脏左心室分割临床应用要求是分割的左心室保持凸形且包含左心室腔、小梁和乳头肌,提出一个包含改进距离正则项和非零水平集保凸项的心脏核磁共振成像分割模型,其利用水平集轮廓的曲率来保持凸性,从而使轮廓最终演化为凸形。使用ACDC MICCAI 2017数据集进行模型评估,该模型在心脏舒张末期和收缩末期阶段的平均Dice系数分别为0.961和0.936,平均豪斯多夫距离分别为4.89和5.79。同时该模型无需对训练数据进行人工标注和学习,分割精度和鲁棒性均可以达到与基于深度学习的左心室分割模型相同的分割性能。 展开更多
关键词 非零水平集 保凸 水平集方法 左心室分割 距离正则化 双阱势函数
原文传递
基于三维规则数据场的快速光线投射法 被引量:6
17
作者 洪歧 张树生 +2 位作者 杨敏 伍新中 王飞 《计算机工程与应用》 CSCD 北大核心 2007年第5期39-40,123,共3页
光线投射法是体绘制技术中的经典算法。该算法原理简单、明了,并能产生高质量的显示图像,但由于所有体素参与了图像绘制,运行速度慢,从而极大制约了其在交互可视化中的运用。论文利用光线穿过三维规则数据场时与某一方向平面簇交点的快... 光线投射法是体绘制技术中的经典算法。该算法原理简单、明了,并能产生高质量的显示图像,但由于所有体素参与了图像绘制,运行速度慢,从而极大制约了其在交互可视化中的运用。论文利用光线穿过三维规则数据场时与某一方向平面簇交点的快速确定及光线投射方向确定后两相邻平面间所截取线段为定长的特点,简化了光线亮度积分公式,从而在图像质量不减低的情况下,快速进行图像绘制。 展开更多
关键词 三维规则数据场 光线投射 变密度云 不透明度
在线阅读 下载PDF
LF拓扑空间的正则闭分离性 被引量:6
18
作者 苏淑华 许兆龙 杨淑群 《模糊系统与数学》 CSCD 北大核心 2008年第1期85-90,共6页
利用正则闭集概念在LF拓扑空间中引入了正则闭分离性Tirc(i=-1,0),次Torc概念,给出了它们的刻画,证明了正则闭Tirc(i=-1,0)分离性、次Torc分离性为拓扑性质,在LF拓扑空间的半正则化中Tric分离性与Ti分离性是等价的。
关键词 正则闭集 正则闭分离性 半正则化
在线阅读 下载PDF
基于水平集和视觉显著性的植物病害叶片图像分割 被引量:7
19
作者 周强强 王志成 +1 位作者 赵卫东 陈宇飞 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第9期1406-1413,共8页
为了提高植物病害叶片图像分割的准确性和效率,提出了一种基于水平集和视觉显著性的彩色图像分割方法.首先采用基于小波变换的显著性检测算法得到活动轮廓模型中曲线演化的初始位置,并构造一个基于显著区域的图像活动轮廓模型,再设计一... 为了提高植物病害叶片图像分割的准确性和效率,提出了一种基于水平集和视觉显著性的彩色图像分割方法.首先采用基于小波变换的显著性检测算法得到活动轮廓模型中曲线演化的初始位置,并构造一个基于显著区域的图像活动轮廓模型,再设计一个向量值图像的边界检测算子,引入到距离正则化水平集演化的改造中,以构造一个初始化轮廓更灵活,演化速度更快,目标分割更精确的新的水平集能量泛函.最后的实验对比表明,该方法具有较好的叶片病害部位分割效果. 展开更多
关键词 植物病害叶片 图像分割 显著性检测 距离正则化水平集演化(DRLSE)
在线阅读 下载PDF
基于水平集的前列腺磁共振图像分割方法研究 被引量:22
20
作者 张永德 彭景春 +2 位作者 刘罡 姜金刚 赵燕江 《仪器仪表学报》 EI CAS CSCD 北大核心 2017年第2期416-424,共9页
基于前列腺磁共振图像(MRI)特征信息及其病变好发特定区域等先验知识,针对前列腺内外轮廓全分割问题,提出基于边缘距离调整水平集演化(DRLSE)的前列腺MRI两步分割方法。在构建统一水平集能量函数的基础上,第1步基于前列腺MR的T1(纵向弛... 基于前列腺磁共振图像(MRI)特征信息及其病变好发特定区域等先验知识,针对前列腺内外轮廓全分割问题,提出基于边缘距离调整水平集演化(DRLSE)的前列腺MRI两步分割方法。在构建统一水平集能量函数的基础上,第1步基于前列腺MR的T1(纵向弛豫时间)图像实现其外轮廓分割,第2步在外轮廓约束限定条件下,基于前列腺MR的T2(横向弛豫时间)图像实现前列腺的内部轮廓分割,进而完成前列腺内外轮廓的全面有效分割。设计了前列腺分割的人机交互界面,对10个前列腺病例MR图像(含正常、增生和癌变共30幅)进行了分割实验研究,并采用Dice相似性系数(DSC)对分割结果进行评价分析,DSC值达到90%以上。实验结果表明,所提出的基于边缘DRLSE的前列腺MRI两步分割方法能够有效地实现前列腺内外轮廓的全面分割,非常接近于临床专家手动分割的理想结果,对前列腺疾病的临床诊断和治疗有较好的参考价值。 展开更多
关键词 图像分割 前列腺磁共振图像分割 边缘距离调整水平集演化 活动轮廓模型 水平集
在线阅读 下载PDF
上一页 1 2 21 下一页 到第
使用帮助 返回顶部