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基于平均差异度的改进k-prototypes聚类算法 被引量:4
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作者 石鸿雁 徐明明 《沈阳工业大学学报》 EI CAS 北大核心 2019年第5期555-559,共5页
针对k-prototypes聚类算法随机选取初始聚类中心导致聚类结果不稳定,以及现有的大多数混合属性数据聚类算法聚类质量不高等问题,提出了基于平均差异度的改进k-prototypes聚类算法.通过利用平均差异度选取初始聚类中心,避免了初始聚类中... 针对k-prototypes聚类算法随机选取初始聚类中心导致聚类结果不稳定,以及现有的大多数混合属性数据聚类算法聚类质量不高等问题,提出了基于平均差异度的改进k-prototypes聚类算法.通过利用平均差异度选取初始聚类中心,避免了初始聚类中心点选取的随机性,同时利用信息熵确定数值数据的属性权重,并对分类属性度量公式进行改进,给出了一种混合属性数据度量公式.结果表明,改进后的算法具有较高的准确率,能够有效处理混合属性数据. 展开更多
关键词 k-prototypes算法 聚类 初始聚类中心 混合属性数据 平均差异度 信息熵 属性权重 度量公式
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Cosmology Should Directly Use the Doppler’s Formula to Calculate the Red Shift of Ia Supernova<br />—The Proofs That Metric Red Shift Is Inapplicable and Dark Energy Does Not Exist 被引量:1
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作者 Xiaochun Mei Ping Yu 《International Journal of Astronomy and Astrophysics》 2013年第3期303-317,共15页
The Doppler formula should be used directly to calculate red shift of Cosmology. The first is gravity, the second is the Doppler’s effect and the third is the Compton scattering. The red shift of cosmology is conside... The Doppler formula should be used directly to calculate red shift of Cosmology. The first is gravity, the second is the Doppler’s effect and the third is the Compton scattering. The red shift of cosmology is considered to be caused by the receding motions of celestial bodies, of which essence is the Doppler’s effect. However, the basic formula used to calculate the relationship between red shift and distance for Ia supernova in cosmology is z+1= R(t0)/R(t1)which is based on the R-W metric and related to the scalar factor R(t). This is different from the Doppler formula which is related to speed factor R(t). Because the R-W metric is only a mathematical structure of space, the metric red shift is not an independent law of physics, this inconsistence is not allowed in physics. It is proved strictly in this paper that the formula of metric red shift is only the result of the first order approximation. If higher order approximations are considered, we can obtain a restrict condition R(t). It indicates that if the formula of metric red shift holds, it can only be suitable to describe the spatial uniform expansion, unsuitable for the practical universal process with acceleration. The further study reveals that the R-W metric violates the invariability principle of light’s speed in vacuum. The time delay caused by 展开更多
关键词 COSMOLOGY Doppler formula R-W metric HUBBLE Law SUPERNOVA DARK Energy DARK Material
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The Formula to Calculate the Red Shift-Distance Relation of Ia Supernova in Cosmology Has Essential Mistakes —The Calculation of Cosmological Red Shift Should Use the Doppler Formula Directly
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作者 Xiaochun Mei Ping Yu 《International Journal of Astronomy and Astrophysics》 2012年第3期183-193,共11页
There are three main mechanisms to cause the red shift of spectrum in physics. The first is gravity which is related to mass. The second is the Compton scattering which is related to the energy transformation of photo... There are three main mechanisms to cause the red shift of spectrum in physics. The first is gravity which is related to mass. The second is the Compton scattering which is related to the energy transformation of photon. The third is the Doppler’s effect which is related to velocity. The basic formula used to calculate the relation of red shift and distance of Ia supernova in cosmology is which is related to the scalar factor of the R-W metric. It is completely different from the Doppler formula of red shift which is related to velocity factor . This kind of inconsistency is not allowed in physics. Because of , when became larger and larger with time increase, z became smaller and smaller, means that space expansion leads to red shift becoming smaller. At present time, we have and , means that there is no red shift for the light emitted from distance celestial bodies at present. The results obviously violate the Hubble law! It is proved strictly in mathematics that the formula is untenable unless constant and . The further study reveals that the essential reason of the mistake is that the R-W metric violates the principle of light’s speed invariable. The time delay caused by relativity velocity between light’s source and observer is neglected. Besides, there exists the problem of time misalignment between theoretical calculation and practical observations in the original documents of Ia supernova projects. So the formula used to calculate the relation between red shift and distance of Ia supernova is wrong and the deduced conclusion about dark energy and the accelerating expansion of the universe are incredible. It is proved in this paper that based on the Doppler’s formula and the method of numerical calculation, the relation of red shift and distance of Ia supernova can be explained well. The hypotheses of dark energy and the accelerating expansion of the universe are completely unnecessary in cosmology. 展开更多
关键词 COSMOLOGY DOPPLER formula HUBBLE Law SUPERNOVA Dark Energy R-W metric
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The Study on the Differential and Integral Calculus in Pseudoeuclidean Space
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作者 Gennady Tarabrin 《Journal of Applied Mathematics and Physics》 2017年第9期1739-1749,共11页
In the vector space of real vectors, comparison was executed of the multilinear forms, covariant derivatives, the total differentials and derivatives in the direction which are calculated with different metrics—with ... In the vector space of real vectors, comparison was executed of the multilinear forms, covariant derivatives, the total differentials and derivatives in the direction which are calculated with different metrics—with Euclidean metric and with pseudoeuclidean metric of a zero index. Comparison was executed of the Taylor’s formulas to different metrics. What is established by us is that multilinear forms of different metrics have different values;covariant derivatives have identical values;the total differentials and derivatives in the direction have different values. In Euclidean space, Taylor’s formula with any order of accuracy assigned in advance is equal, but in pseudoeuclidean space Taylor’s formula is not equal with any order of accuracy. It is concluded that in space with a pseudoeuclidean metric, the computing sense of the differential and integral calculus created in Euclidean space is lost and the possibility of mathematical model operation of real physical processes in vector space with pseudoeuclidean metric is called into question. 展开更多
关键词 The Vector SPACES Taylor’s formula Pseudoeuclidean metric
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关于区间向量空间上的度量及其完备性 被引量:1
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作者 包玉娥 赵博 郭丽 《模糊系统与数学》 CSCD 北大核心 2015年第3期108-113,共6页
首先,利用度量的公理化定义,讨论了区间向量空间的度量化问题,给出了区间向量空间中度量的一般表示形式;其次,分析区间向量空间中度量的一般表示形式的同时举例说明了根据一般表示形式构造具体度量公式的方法;然后,讨论了区间向量空间... 首先,利用度量的公理化定义,讨论了区间向量空间的度量化问题,给出了区间向量空间中度量的一般表示形式;其次,分析区间向量空间中度量的一般表示形式的同时举例说明了根据一般表示形式构造具体度量公式的方法;然后,讨论了区间向量空间上度量的完备性问题,给出了几种刻画完备性的定理。 展开更多
关键词 区间向量空间 度量化 度量公式 完备性
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Cartan-Hartogs域上Khler-Einstein度量的显表达式问题
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作者 邓义华 肖娟 阳志锋 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2011年第6期20-22,29,共4页
讨论了Cartan-Hartogs域上Khler-Einstein度量的显表达式以及该度量与Bergman度量的等价性问题。得到了Cartan-Hartogs域上Khler-Einstein度量显表达式的统一公式。运用该公式与连续函数的性质以及Bergman度量显表达式的一个统一公... 讨论了Cartan-Hartogs域上Khler-Einstein度量的显表达式以及该度量与Bergman度量的等价性问题。得到了Cartan-Hartogs域上Khler-Einstein度量显表达式的统一公式。运用该公式与连续函数的性质以及Bergman度量显表达式的一个统一公式,得到了这类域上Khler-Einstein度量和Bergman度量等价性的统一证明。 展开更多
关键词 CARTAN-HARTOGS域 Khler-Einstein度量 BERGMAN度量 显表达式
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光瞳半径对纯位相调制激光束整形系统的影响
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作者 何杰铃 魏凌 +3 位作者 杨金生 李喜琪 何益 张雨东 《物理学报》 SCIE EI CAS CSCD 北大核心 2016年第4期339-348,共10页
光瞳截断作用对纯位相调制激光束整形系统的性能有重要影响.本文提出了一种关于光瞳半径对近场调制位相和远场系统评价函数影响的定量分析方法.通过拉格朗日乘数法等方法分析光瞳半径对近场调制位相的影响,发现近场调制位相随光瞳半径... 光瞳截断作用对纯位相调制激光束整形系统的性能有重要影响.本文提出了一种关于光瞳半径对近场调制位相和远场系统评价函数影响的定量分析方法.通过拉格朗日乘数法等方法分析光瞳半径对近场调制位相的影响,发现近场调制位相随光瞳半径近似线性增加.通过建立数学模型,拟合分析光瞳半径对系统评价函数的影响.结果表明:对方形目标光强,系统评价函数拟合精度确定系数达到99%左右,光瞳半径为2.5倍高斯光束束腰半径时,相关系数达到0.997,光强偏离残差平方均值达到0.0004左右,光瞳截断作用趋于最小;对圆形目标光强,系统评价函数拟合精度确定系数达到97%,光瞳半径为3倍高斯光束束腰半径时,相关系数与光强偏离残差平方均值变化幅度均在10^(-3)量级,系统评价函数趋于收敛,光瞳截断作用趋于最小. 展开更多
关键词 激光束整形 评价函数 拟合公式 光瞳半径
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Ruin Probabilities in the Risk Process with Random Income 被引量:2
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作者 Zhen-hua Bao Zhong-xing Ye 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2008年第2期195-202,共8页
We extend the classical risk model to the case in which the premium income process, modelled as a Poisson process, is no longer a linear function. We derive an analog of the Beekman convolution formula for the ultimat... We extend the classical risk model to the case in which the premium income process, modelled as a Poisson process, is no longer a linear function. We derive an analog of the Beekman convolution formula for the ultimate ruin probability when the inter-claim times are exponentially distributed. A defective renewal equation satisfied by the ultimate ruin probability is then given. For the general inter-claim times with zero-truncated geometrically distributed claim sizes, the explicit expression for the ultimate ruin probability is derived. 展开更多
关键词 Beekman convolution formula Defective renewal equation Ruin probability Zero-truncated geo-metric distribution
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Broyden族校正公式的另一种推导方法 被引量:1
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作者 柳力 柳毅 《北华大学学报(自然科学版)》 CAS 2011年第3期279-281,共3页
给出了Broyden族校正公式的另一种推导方法,从另一角度表现了Broyden族各校正公式之间的关系,证明了Hoshino校正公式是Broyden凸族中唯一自对偶校正公式.
关键词 非线性规划 变尺度法 BROYDEN族 校正公式
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Lukasiewicz三值逻辑度量空间中的反射变换
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作者 程红梅 王国俊 《云南师范大学学报(自然科学版)》 2011年第4期50-53,共4页
在Lukasiewicz三值逻辑度量空间中定义了反射变换φ和(准)对称逻辑公式,探讨了反射变换φ的性质,证明了φ保持逻辑等价关系和(准)对称逻辑公式,且为同态变换.研究了φ在商代数——Lindenbaum代数上诱导的反射变换φ*的性质.证明了φ*是... 在Lukasiewicz三值逻辑度量空间中定义了反射变换φ和(准)对称逻辑公式,探讨了反射变换φ的性质,证明了φ保持逻辑等价关系和(准)对称逻辑公式,且为同态变换.研究了φ在商代数——Lindenbaum代数上诱导的反射变换φ*的性质.证明了φ*是自同构的等距变换,进而讨论了φ*的不动点的性态,得到了4类特殊的不动点形式[A]∨φ*([A]),[A]∧φ*([A]),[A]φ*([A])和[A]φ*([A]). 展开更多
关键词 Lukasiewicz三值逻辑度量空间 反射变换 (准)对称逻辑公式 LINDENBAUM代数 不动点
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一个结构简单的约束变尺度算法
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作者 曾庆光 《应用数学与计算数学学报》 1995年第1期89-96,共8页
本文我们考虑具有线性约束凹函数的最优化问题。利用我们的算法和变尺度修正公式,提出了一个结构简单的组合算法。并在[2],[3]和[4]同样的假设条件下,证明了该算法的收敛性和超线性收敛速度,从而使该算法比原有各算法更具实用性。
关键词 线性约束优化 收敛性 最优化 变尺度算法
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用区间方法解积分方程
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作者 马少青 王海燕 《沈阳大学学报》 CAS 1994年第2期91-94,共4页
本文证明了积分方程解存在且唯一的一个充分条件、区间迭代法收敛的一个充分条件、在解存里且唯一的前提下保证区间迭代收敛的一个具体办法.然后讨论了度量空间M的取法.
关键词 度量空间 积分方程解 迭代公式
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