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Application of Sturm Theorem in the Global Controllability of a Class of High Dimensional Polynomial Systems
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作者 XU Xueli LI Qianqian SUN Yimin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2015年第5期1049-1057,共9页
In this paper, the global controllability for a class of high dimensional polynomial systems has been investigated and a constructive algebraic criterion algorithm for their global controllability has been obtained. B... In this paper, the global controllability for a class of high dimensional polynomial systems has been investigated and a constructive algebraic criterion algorithm for their global controllability has been obtained. By the criterion algorithm, the global controllability can be determined in finite steps of arithmetic operations. The algorithm is imposed on the coefficients of the polynomials only and the analysis technique is based on Sturm Theorem in real algebraic geometry and its modern progress. Finally, the authors will give some examples to show the application of our results. 展开更多
关键词 Global controllability high dimensional systems number of sign variations polynomial Sturm theorem.
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The Counterintuitive Increase of Information Due to Extra Spacetime Dimensions of a Black Hole and Dvoretzky’s Theorem 被引量:2
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作者 Mohamed S. El Naschie 《Natural Science》 2015年第10期483-487,共5页
As per Hawking and Bekenstein’s work on black holes, information resides on the surface and there is a limit on it amounting to a bit for every Planck area. It would seem therefore that extra dimensions would logical... As per Hawking and Bekenstein’s work on black holes, information resides on the surface and there is a limit on it amounting to a bit for every Planck area. It would seem therefore that extra dimensions would logically lead to a hyper-surface for a black hole and consequently a reduction of the corresponding information density due to the dilution effect of these additional dimensions. The present paper argues that the counterintuitive opposite of the above is what should be expected. This surprising result is a consequence of a well known theorem on measure concentration due to I. Dvoretzky. 展开更多
关键词 Higher dimensional BLACK HOLES Dvoretzky’s theorem INFORMATION PARADOX E-INFINITY Theory Counterintuitive Geometry Bekenstein Limit Hawking Radiation 'tHooft-Susskind BLACK HOLES
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The Coxeter Trisection and the Hadwiger Conjecture in Multidimensional Spaces
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作者 István Lénárt 《Journal of Applied Mathematics and Physics》 2024年第12期4301-4321,共21页
In this article, I consider the right triangle as the simplex in the Euclidean plane, and extend this definition to higher dimensions. The n-dimensional simplex has one hypotenuse and (n−1)legs (catheti). The (n−1)leg... In this article, I consider the right triangle as the simplex in the Euclidean plane, and extend this definition to higher dimensions. The n-dimensional simplex has one hypotenuse and (n−1)legs (catheti). The (n−1)legs define an orthogonal path of edges in the solid with perpendicular adjacent edges along the path. The length of the hypotenuse and the volume of the solid can be calculated without the Cayley-Menger determinant, by direct extension of the corresponding right triangle formulas. I give a proof of the existence of these shapes, describe the distribution of right angles in them, give an algebraic proof of the Coxeter trisection of a right tetrahedron into three smaller right tetrahedra, and generalize this construction to n-dimensional spaces. Finally, I investigate the connection between the Coxeter partition and the Hadwiger conjecture on the partition of the simplex into orthoschemes, which I call Pythagorean simplexes. 展开更多
关键词 Generalized Pythagoras theorem Description of a Pythagorean Simplex Pythagorean Unit Simplex Coxeter Partition of a Simplex in -dimensional Space Relation to the Hadwiger Conjecture
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Effective and Efficient Feature Selection for Large-scale Data Using Bayes' Theorem 被引量:7
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作者 Subramanian Appavu Alias Balamurugan Ramasamy Rajaram 《International Journal of Automation and computing》 EI 2009年第1期62-71,共10页
This paper proposes one method of feature selection by using Bayes' theorem. The purpose of the proposed method is to reduce the computational complexity and increase the classification accuracy of the selected featu... This paper proposes one method of feature selection by using Bayes' theorem. The purpose of the proposed method is to reduce the computational complexity and increase the classification accuracy of the selected feature subsets. The dependence between two attributes (binary) is determined based on the probabilities of their joint values that contribute to positive and negative classification decisions. If opposing sets of attribute values do not lead to opposing classification decisions (zero probability), then the two attributes are considered independent of each other, otherwise dependent, and one of them can be removed and thus the number of attributes is reduced. The process must be repeated on all combinations of attributes. The paper also evaluates the approach by comparing it with existing feature selection algorithms over 8 datasets from University of California, Irvine (UCI) machine learning databases. The proposed method shows better results in terms of number of selected features, classification accuracy, and running time than most existing algorithms. 展开更多
关键词 Data mining CLASSIFICATION feature selection dimensionality reduction Bayes' theorem.
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The symplectic eigenfunction expansion theorem and its application to the plate bending equation 被引量:5
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作者 黄俊杰 阿拉坦仓 王华 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第9期3616-3623,共8页
This paper deals with the bending problem of rectangular plates with two opposite edges simply supported. It is proved that there exists no normed symplectic orthogonal eigenfunction system for the associated infinite... This paper deals with the bending problem of rectangular plates with two opposite edges simply supported. It is proved that there exists no normed symplectic orthogonal eigenfunction system for the associated infinite-dimensional Hamiltonian operator H and that the two block operators belonging to Hamiltonian operator H possess two normed symplectic orthogonal eigenfunction systems in some space. It is demonstrated by using the properties of the block operators that the above bending problem can be solved by the symplectic eigenfunction expansion theorem, thereby obtaining analytical solutions of rectangular plates with two opposite edges simply supported and the other two edges supported in any manner. 展开更多
关键词 plate bending equation symplectic eigenfunction expansion theorem infinite dimensional Hamiltonian operator analytical solution
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GALIN’S THEOREM HOLDS FOR MOVING PUNCH 被引量:2
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《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1991年第1期82-87,共6页
This paper presents a formulation for solving three-dimensional moving punch problem. It proves that Galin's theorem holds for the punch. As an example, the study offers some results (including numerical data) of ... This paper presents a formulation for solving three-dimensional moving punch problem. It proves that Galin's theorem holds for the punch. As an example, the study offers some results (including numerical data) of dynamic displacement over an ellipse contact region. 展开更多
关键词 three-dimensional moving contact Lame potentials double Fourier transform influence functions Galin's theorem
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On Gorenstein Homological Dimensions of Groups
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作者 Yueming XIANG 《Journal of Mathematical Research with Applications》 CSCD 2023年第2期191-203,共13页
Let k be a commutative ring with finite weak dimension and let G be a group. In this paper, we explore the criterion that a group G has finite Gorenstein homological dimension.It is shown that the finiteness of the Go... Let k be a commutative ring with finite weak dimension and let G be a group. In this paper, we explore the criterion that a group G has finite Gorenstein homological dimension.It is shown that the finiteness of the Gorenstein homological dimension of G coincides with the finiteness of the Gorenstein weak dimension of the group ring kG. Furthermore, we give a Gorenstein analogy of the Serre's theorem. Some well-known results for the Gorenstein homological dimension of G over the integer ring are also extended. 展开更多
关键词 Gorenstein homological dimension Serre's theorem group ring
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The Generalized Sine Theorem for Mixed Vertex Angle of Two Simplices and Applications
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作者 WANG Wen YANG Shi-guo QI Ji-bing 《Chinese Quarterly Journal of Mathematics》 2015年第2期190-198,共9页
Some related problems of two n-dimensional simplices which are on an(n- 1)-dimensional hypersphere are investigated and a sine theorem of the k-dimensional mixed vertex angles which are defined in this paper is given.... Some related problems of two n-dimensional simplices which are on an(n- 1)-dimensional hypersphere are investigated and a sine theorem of the k-dimensional mixed vertex angles which are defined in this paper is given. This result is a generalization of the sine theorem established. By using the generalized sine theorem, we present some new interesting geometric inequalities involving the k-dimensional vertex angles of each n-simplex and the k-dimensional mixed vertex angle of two n-simplices. These results can improve some recent results. 展开更多
关键词 simplex k-dimensional vertex angle k-dimensional mixed vertex angle the sine theorem geometric inequalities
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On the Far Field Pattern for Acoustic Scattering by a Piecewise Homogeneous Obstacle in Two Dimensions
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作者 Evagelia S. Athanasiadou Paraskevi Roupa 《Journal of Applied Mathematics and Physics》 2022年第10期2951-2964,共14页
A time-harmonic plane acoustic wave is scattered by a piecewise homogeneous obstacle with a penetrable or impenetrable core. We construct in the close form an integral representation for the far field pattern in which... A time-harmonic plane acoustic wave is scattered by a piecewise homogeneous obstacle with a penetrable or impenetrable core. We construct in the close form an integral representation for the far field pattern in which we have incorporated the physical and geometrical characteristics of the scatterer. Through this representation, we obtain the far field pattern for this scatterer. We prove scattering relations between the far field patterns of two scattering problems due to two distinct incident waves on the same scatterer. In particular, we prove reciprocity and general scattering theorems. The optical theorem, connecting the total power that the scatterer extracts from the incident plane wave either by radiation or by absorption with the corresponding far field pattern of an incident plane wave, is recovered as a corollary of the general scattering theorem. Moreover, if we consider incident waves to be both a plane and a spherical, we derive a mixed reciprocity theorem. We define the corresponding far field operators and using these relations, we prove some properties that can be used for solving inverse scattering problems. 展开更多
关键词 Two-dimensional Electromagnetic Scattering Piecewise Obstacle Reciprocity Principle Optical theorem
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三维稳态MHD模型和三维稳态Hall-MHD模型在混合Lebesgue空间中的Liouville型定理
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作者 周艳平 桂萍萍 范漪涵 《华南师范大学学报(自然科学版)》 北大核心 2025年第2期65-70,共6页
在混合Lebesgue空间框架下,突破传统有限Dirichlet积分条件的限制,研究三维稳态情形下的磁流体动力学(Magnetohydrodynamics,MHD)模型和具Hall效应的磁流体动力学(Hall-MHD)模型的平凡解的唯一性。通过解决压力项估计这一关键难点,建立... 在混合Lebesgue空间框架下,突破传统有限Dirichlet积分条件的限制,研究三维稳态情形下的磁流体动力学(Magnetohydrodynamics,MHD)模型和具Hall效应的磁流体动力学(Hall-MHD)模型的平凡解的唯一性。通过解决压力项估计这一关键难点,建立了这两类模型的Liouville型定理,即若光滑解(u,b)属于混合Lebesgue空间L^(p)(R^(3)),p=(p_(1),p_(2),p_(3)),1/p_(1)+1/p_(2)+1/p_(3)≥2/3,且对于三维稳态MHD模型满足p_(1),p_(2),p_(3)∈[3,+∞),对于三维稳态Hall-MHD模型满足p_(1),p_(2),p_(3)∈[4,+∞),则u=b=0。 展开更多
关键词 三维稳态MHD模型 三维稳态Hall-MHD模型 LIOUVILLE型定理 混合Lebesgue空间
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引力对不确定度关系修正带来的效应
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作者 刘昊迪 李宇轩 衣学喜 《物理与工程》 2025年第2期9-14,共6页
引力的引入使量子系统具有了许多奇异的性质,无引力时给出不确定度关系下限的状态在引力的扰动下可能发生变化。利用简单的物理系统(如一维无限深势阱和一维谐振子)对这些奇异性质进行研究,可以拓展我们对量子力学的理解,体会引力带来... 引力的引入使量子系统具有了许多奇异的性质,无引力时给出不确定度关系下限的状态在引力的扰动下可能发生变化。利用简单的物理系统(如一维无限深势阱和一维谐振子)对这些奇异性质进行研究,可以拓展我们对量子力学的理解,体会引力带来的物理效应。本文将广义不确定性关系引入一维无限深势阱和一维谐振子,将引力看作一个微扰势场,计算微扰下系统能量本征值和本征态发生的变化,展示引力引起的奇异效应。结果表明,在考虑引力的影响后,一级近似下能量本征值没有发生变化,但能量的本征态发生了改变。我们还计算了引力对位力定理的修正,得出了引力修正给位力定理带来的影响。 展开更多
关键词 不确定度关系 引力修正 一维无限深势阱 一维谐振子 位力定理
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Functional Limit Theorems for C-R Increments of k-Dimensional Brownian Motion in Holder Norm 被引量:11
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作者 Qicai Wei School fo Economics, Zhejiang University. Hangzhou 310028. P. R. China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2000年第4期637-654,共18页
In this paper. based on large deviation formulas established in stronger topology generated by Hlder norm, we obtain the functional limit theorems for C-R increments of k-dimensional Brownian motion in Hlder norm
关键词 Large deviation formulas k-dimensional Brownian motion Functional limit theorems C-R increments Holder norm
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Functional Limit Theorems for d-dimensional FBM in H lder Norm 被引量:2
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作者 Zheng Yan LIN Wen Sheng WANG Kyo Shin HWANG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2006年第6期1767-1780,共14页
In this paper, we obtain functional limit theorems for d-dimensional FBM in HSlder norm via estimating large deviation probabilities for d-dimensional FBM in HSlder norm.
关键词 large deviation probability Holder norm functional limit theorem d-dimensional fractional Brownian motion Gaussian random vector
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立方体绕对角线轴转动惯量的解法分析
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作者 刘玉丽 王钰茹 《物理通报》 2025年第11期17-19,共3页
转动惯量是刚体转动惯性大小的量度,就像质量是平动物体惯性大小的量度一样.在刚体力学中,转动惯量的计算非常重要,分别应用积分法和量纲分析法,结合转动惯量的平行轴定理,计算了立方体绕对角线轴的转动惯量.通过计算表明,量纲分析法比... 转动惯量是刚体转动惯性大小的量度,就像质量是平动物体惯性大小的量度一样.在刚体力学中,转动惯量的计算非常重要,分别应用积分法和量纲分析法,结合转动惯量的平行轴定理,计算了立方体绕对角线轴的转动惯量.通过计算表明,量纲分析法比通常所用的积分法运算简便,物理意义明确.当所求转动惯量的几何形体具有某种对称性时,量纲分析法具有其独特的优越性. 展开更多
关键词 转动惯量 平行轴定理 量纲分析
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AN INFINITE DIMENSIONAL ANALOGUE OF THE ALBEVERIO-RCKNER'S THEOREM ON FUKUSHIMA'S CONJECTURE
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作者 宋士奇 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 1993年第2期115-124,共10页
Let X be the solution of the SDE:dX_t=σ(X_t)dB_t+b(X_t)dt,with σ and b ∈C_B~∞(R) such that σ≥λ>0 for some constant λ,and B a real Brownian motion.Let μ be the law of X on E=C([0,1],R)and k ∈E~*-{0},where ... Let X be the solution of the SDE:dX_t=σ(X_t)dB_t+b(X_t)dt,with σ and b ∈C_B~∞(R) such that σ≥λ>0 for some constant λ,and B a real Brownian motion.Let μ be the law of X on E=C([0,1],R)and k ∈E~*-{0},where E~* is the topological dual space of E.Consider the classical form:where u and v are smooth functions on E.We prove that,if is closable for any k in a dense subset of E~* and if the smooth functions are contained in the domain of the generator of the closure of ε_k,σ must be a constant function. 展开更多
关键词 CKNER’S theorem ON FUKUSHIMA’S CONJECTURE AN INFINITE dimensional ANALOGUE OF THE ALBEVERIO-R SDE
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On the k-dimensional Piatetski-Shapiro prime number theorem
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作者 翟文广 《Science China Mathematics》 SCIE 1999年第11期1173-1183,共11页
Thek-dimensional Piatetski-Shapiro prime number problem fork?3 is studied. Let π(x 1 c 1,?,c k ) denote the number of primesp withp?x, $p = [n_1^{c_1 } ] = \cdots [n_k^{c_k } ]$ , where 1<c 1<?<c k are fixed... Thek-dimensional Piatetski-Shapiro prime number problem fork?3 is studied. Let π(x 1 c 1,?,c k ) denote the number of primesp withp?x, $p = [n_1^{c_1 } ] = \cdots [n_k^{c_k } ]$ , where 1<c 1<?<c k are fixed constants. It is proved that π(x;c 1,?,c k ) has an asymptotic formula ifc 1 ?1 +?+c k ?1 >k?k/(4k 2+2). 展开更多
关键词 k-dimensional Piatetski-Shapiro prime number theorem onential sum mptotic formula
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二维PSD的结构和性能分析 被引量:17
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作者 唐九耀 黄梅珍 陈钰清 《功能材料与器件学报》 CAS CSCD 2000年第3期301-304,共4页
从二维PSD的结构和性能的比较出发,对枕型结构PSD的性能作了理论上的推导和分析,由此得到的结论和现有的实验结果相符。
关键词 二维PSD 横向光电效应 Gear定理 位置敏感探测器
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铁矿粉烧结液相流动性能的特征数方程的建立 被引量:8
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作者 吴铿 申威 +3 位作者 杜瑞岭 闫广 门正朝 员晓 《重庆大学学报(自然科学版)》 EI CAS CSCD 北大核心 2015年第5期26-31,45,共7页
为解决在研究铁矿粉烧结液相流动性能时通常只考虑面积增长率这一终点信息,而没有考虑过程信息的缺陷以及采用多个指标来表征流动性能在使用上的不便,对影响流动性的因素进行了分析,结合量纲分析和白金汉定理推导出了能定量表征流动性... 为解决在研究铁矿粉烧结液相流动性能时通常只考虑面积增长率这一终点信息,而没有考虑过程信息的缺陷以及采用多个指标来表征流动性能在使用上的不便,对影响流动性的因素进行了分析,结合量纲分析和白金汉定理推导出了能定量表征流动性强弱的流动性特征数(LD),简化特征数方程后得到等效流动性特征数(LdΘ)。试验采用了可视卧式高温炉,记录了铁矿粉烧结液相流动的整个过程信息,通过基础实验和对照实验确定液相流动的起点和终点之后,可以得到每一种矿粉相应的等效流动性特征数数值。测量5种铁矿粉在两种方法下的流动性指标,当只考虑面积增长率时的流动性强弱顺序为A>C≈D>B>E,新方法下为LdΘA>LdΘD>LdΘC≈LdΘE>LdΘB,两种方法下的指标相近,但是综合了各种重要信息的新指标能进一步区分出各个因素对流动性能的影响程度。 展开更多
关键词 铁矿粉 烧结 流动性 量纲分析 白金汉定理
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量纲分析法在土工模型试验中的应用 被引量:6
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作者 杨宇友 张钦喜 +2 位作者 张在明 刘艳 李聪 《北京工业大学学报》 EI CAS CSCD 北大核心 2009年第6期785-789,共5页
量纲分析对试验设计和试验结果的简明表达十分有用,有效的量纲分析可以产生一组无量纲成果.以地基承载力为例说明了Buckingham的π定理及Butterfield对其计算方法的改进.通过数值计算的方法对岸坡虹吸排水模型试验进行了分析,初步验证... 量纲分析对试验设计和试验结果的简明表达十分有用,有效的量纲分析可以产生一组无量纲成果.以地基承载力为例说明了Buckingham的π定理及Butterfield对其计算方法的改进.通过数值计算的方法对岸坡虹吸排水模型试验进行了分析,初步验证了量纲分析的成果,对模型试验的关键参数选取提出了一些建议. 展开更多
关键词 量纲分析 模型试验 π定理 数值模拟 相似常数
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一种改进的纳米压入测试方法 被引量:7
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作者 宋仲康 马德军 +1 位作者 郭俊宏 陈伟 《中国有色金属学报》 EI CAS CSCD 北大核心 2012年第2期520-525,共6页
利用过量纲理论和有限元模拟分析了Oliver-Pharr方法识别材料折合弹性模量的精度。结果表明:理论测试误差明显依赖于卸载后的残余深度与最大压入深度的比值(hf/hm)和材料的应变硬化指数n。当hf/hm>0.7、n=0时,Oliver-Pharr方法计算... 利用过量纲理论和有限元模拟分析了Oliver-Pharr方法识别材料折合弹性模量的精度。结果表明:理论测试误差明显依赖于卸载后的残余深度与最大压入深度的比值(hf/hm)和材料的应变硬化指数n。当hf/hm>0.7、n=0时,Oliver-Pharr方法计算的折合弹性模量最大测试误差将近32%,其原因是由于估算得到的接触深度明显低于真实的接触深度。在此基础上,提出一种改进的计算方法,对接触深度的估算进行修正,应用改进方法确定材料折合弹性模量时,最大误差可控制在±15%以内。两种铝合金材料的压入试验也证明了此结论。 展开更多
关键词 纳米压入 弹性模量 量纲分析 有限元方法 硬化指数
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