期刊文献+
共找到488篇文章
< 1 2 25 >
每页显示 20 50 100
A RANDOM FUNCTIONAL CENTRAL LIMIT THEOREM FOR PROCESSES OF PRODUCT SUMS OF LINEAR PROCESSES GENERATED BY MARTINGALE DIFFERENCES 被引量:2
1
作者 WANG YUEBAO YANG YANG ZHOU HAIYANG Department of Mathematics, Suzhou University, Suzhou 215006, Jiangsu, China. Department of Mathematics, Suzhou University, Suzhou 215006, Jiangsu, China. 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2003年第4期449-456,共8页
A random functional central limit theorem is obtained for processes of partial sums andproduct sums of linear processes generated by non-stationary martingale differences. It devel-ops and improves some corresponding ... A random functional central limit theorem is obtained for processes of partial sums andproduct sums of linear processes generated by non-stationary martingale differences. It devel-ops and improves some corresponding results on processes of partial sums of linear processesgenerated by strictly stationary martingale differences, which can be found in [5]. 展开更多
关键词 Ilandom functional central limit theorem Processes of product sums
原文传递
Sum-Product Networks模型的研究及其在文本分类的应用 被引量:1
2
作者 李俊 《电子设计工程》 2016年第24期42-45,共4页
图模型在机器学习有着广泛的应用。相比图模型,Sum-Product Networks模型具有更强表达能力和更快的推理速度,所以其在对文本和图像数据建模有着广泛的应用。本文总结Sum-Product Networks这一新的深度概率模型的研究进展,先介绍了固定... 图模型在机器学习有着广泛的应用。相比图模型,Sum-Product Networks模型具有更强表达能力和更快的推理速度,所以其在对文本和图像数据建模有着广泛的应用。本文总结Sum-Product Networks这一新的深度概率模型的研究进展,先介绍了固定结构的Sum-Product Networks的参数学习方法,再介绍了根据不同的输入数据而进行的结构和参数学习方法。并且介绍了判别式和生成模型的Sum-Product Networks,最后介绍了Sum-Product Networks在文本分类上的应用。 展开更多
关键词 sum-product Networks模型 概率模型 数据挖掘算法 文本分类
下载PDF
Almost sure central limit theory for products of sums of partial sums 被引量:6
3
作者 WU Qun-ying 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2012年第2期169-180,共12页
Consider a sequence of i.i.d.positive random variables.An universal result in almost sure limit theorem for products of sums of partial sums is established.We will show that the almost sure limit theorem holds under a... Consider a sequence of i.i.d.positive random variables.An universal result in almost sure limit theorem for products of sums of partial sums is established.We will show that the almost sure limit theorem holds under a fairly general condition on the weight dk= k-1 exp(lnβk),0≤β〈1.And in a sense,our results have reached the optimal form. 展开更多
关键词 almost sure central limit theorem WEIGHT product of sums of partial sums.
下载PDF
Rearrangement Inequality and Chebyshev's Sum Inequality on Positive Tensor Products of Orlicz Sequence Space with Banach Lattice 被引量:1
4
作者 Wei-Kai Lai 《Journal of Mathematics and System Science》 2014年第8期574-578,共5页
Let φ be an Orlicz function that has a complementary function φ* and let lφ be an Orlicz sequence space. We prove a similar version of Rearrangement Inequality and Chebyshev's Sum Inequality in lφ FX, the Freml... Let φ be an Orlicz function that has a complementary function φ* and let lφ be an Orlicz sequence space. We prove a similar version of Rearrangement Inequality and Chebyshev's Sum Inequality in lφ FX, the Fremlin projective tensor product of lφ with a Banach lattice X, and in lφ iX, the Wittstock injective tensor product of lφ with a Banach lattice X. 展开更多
关键词 Rearrangement inequality Chebyshev's sum inequality injective tensor product projective tensor product Orlicz sequence space
下载PDF
On the Product of Integro Differential Equations and Their Solutions in Direct Sum Spaces
5
作者 Sobhy El-sayed Ibrahim 《Journal of Mathematics and System Science》 2013年第5期231-245,共15页
In this paper, we consider a general quasi-differential expressions t1,t2 Tn, each of order n with complex coefficients and their formal adjoints are t1+,t2+- x+ on [0, b) respectively. We show in the direct sum s... In this paper, we consider a general quasi-differential expressions t1,t2 Tn, each of order n with complex coefficients and their formal adjoints are t1+,t2+- x+ on [0, b) respectively. We show in the direct sum spaces LZ(Ip), p = 1,2 N of functions defined on each of the separate intervals with the case of one singular end-points and under suitable conditions on the function F that all solutions of the product quasi-integro differential equations are bounded and LZw -bounded on [0,b). 展开更多
关键词 Quasi-integro differential equation product differential expressions direct sum spaces bounded and square integrablesolutions.
下载PDF
Parallel Computation of Disjoint Products Approach
6
作者 刘景森 李捷 《Chinese Quarterly Journal of Mathematics》 CSCD 2002年第3期41-48,共8页
In this paper, extracting parallelizatio n from the sum of disjoint products approach is discussed. A general framework of parallelizing disjoint products approach is presented. And a parallel version of the newest... In this paper, extracting parallelizatio n from the sum of disjoint products approach is discussed. A general framework of parallelizing disjoint products approach is presented. And a parallel version of the newest disjoint products algorithm is implemented. The results of testing s how the effect is so good to get linear speedups. 展开更多
关键词 sum of disjoint products PARALLELIZATION relia bility evaluation
下载PDF
lim n→∞ sum n^kf[i^q/n^p] from i=1 to n型极限的计算公式及其应用 被引量:1
7
作者 杜秀清 《南通职业大学学报》 2014年第3期86-88,共3页
对p>q≥0情形下,形如lim n→∞ sum n^kf[i^q/n^p] from i=1 to n的一类和式极限,给出并证明了其计算公式。该公式在求解这类极限时具有计算简便、适用面宽等优点,进一步还可运用于可化为这类和式极限的积式极限的计算。
关键词 和式极限 积式极限 函数 可导
下载PDF
Estimation of Two-Dimensional Correction Factors for Min-Sum Decoding of Regular LDPC Code
8
作者 Ahmed A. Hamad 《Wireless Engineering and Technology》 2013年第4期181-187,共7页
In this paper, two-dimensional (2-D) correction scheme is proposed to improve the performance of conventional Min-Sum (MS) decoding of regular low density parity check codes. The adopted algorithm to obtain the correc... In this paper, two-dimensional (2-D) correction scheme is proposed to improve the performance of conventional Min-Sum (MS) decoding of regular low density parity check codes. The adopted algorithm to obtain the correction factors is simply based on estimating the mean square difference (MSD) between the transmitted codeword and the posteriori information of both bit and check node that produced at the MS decoder. Semi-practical tests using software-defined radio (SDR) and specific code simulations show that the proposed quasi-optimal algorithm provides a comparable error performance as Sum-Product (SP) decoding while requiring less complexity. 展开更多
关键词 LDPC Code sum-product Min-sum 2-D CORRECTION Factors Software-Defined RADIO (SDR)
下载PDF
A General Law of Precise Asymptotics for Products of Sums under Dependence 被引量:6
9
作者 Yong ZHANG Xiao Yun YANG Zhi Shan DONG 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2010年第1期107-116,共10页
Let {Xn,n ≥ 1} be a strictly stationary LNQD (LPQD) sequence of positive random variables with EX1 = μ 〉 0, and VarX1 = σ^2 〈 ∞. Denote by Sn = ∑i=1^n Xi and γ = σ/μ the coefficients of variation. In this ... Let {Xn,n ≥ 1} be a strictly stationary LNQD (LPQD) sequence of positive random variables with EX1 = μ 〉 0, and VarX1 = σ^2 〈 ∞. Denote by Sn = ∑i=1^n Xi and γ = σ/μ the coefficients of variation. In this paper, under some suitable conditions, we show that a general law of precise asymptotics for products of sums holds. It can describe the relations among the boundary function, weighted function, convergence rate and limit value in the study of complete convergence. 展开更多
关键词 general law precise asymptotics products of sums NA (PA) LNQD (LPQD)
原文传递
An Improved Result in Almost Sure Central Limit Theory for Products of Partial Sums with Stable Distribution 被引量:1
10
作者 Qunying WU 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2012年第6期919-930,共12页
Consider a sequence of i.i.d.positive random variables with the underlying distribution in the domain of attraction of a stable distribution with an exponent in (1,2].A universal result in the almost sure limit theore... Consider a sequence of i.i.d.positive random variables with the underlying distribution in the domain of attraction of a stable distribution with an exponent in (1,2].A universal result in the almost sure limit theorem for products of partial sums is established. Our results significantly generalize and improve those on the almost sure central limit theory previously obtained by Gonchigdanzan and Rempale and by Gonchigdanzan.In a sense,our results reach the optimal form. 展开更多
关键词 Almost sure central limit theorem product of partial sums Stable distribution
原文传递
Moderate deviations principle for products of sums of random variables
11
作者 MIAO Yu MU JianYong 《Science China Mathematics》 SCIE 2011年第4期769-784,共16页
Let(Xn)n≥1 be a sequence of independent identically distributed(i.i.d.) positive random variables with EX1 = μ,Var(X1) = σ2.In the present paper,we establish the moderate deviations principle for the products of pa... Let(Xn)n≥1 be a sequence of independent identically distributed(i.i.d.) positive random variables with EX1 = μ,Var(X1) = σ2.In the present paper,we establish the moderate deviations principle for the products of partial sums(πnk=1Sk/n!μn)1/(γbn√(2n))1where γ = σ/μ denotes the coefficient of variation and(bn) is the moderate deviations scale. 展开更多
关键词 moderate deviations principle products of sums independent identically distribution positive random variables
原文传递
On a Certain Sum-product Estimate in Fields of Prime Order
12
作者 Bo Qing XUE 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2014年第11期1861-1866,共6页
Let Fp be the finite field of p elements with p prime.If A is a subset of Fp and g is an element of F*p with order ν,then max{|A + g·A|,|A·A|} (ν/(ν + |A|2) )1/12|A|13/12.
关键词 sum-product estimate different sets fields of prime order
原文传递
基于强乘积运算下图的广义和连通度指标上下界
13
作者 李志豪 朱焱 《运筹学学报(中英文)》 CSCD 北大核心 2024年第1期141-152,共12页
对于图G,令E(G)表示G的边集,令V(G)表示G的点集,d_(G)(v)表示v的度。对于边e=uv,定义广义和连通度指标χ_(α)(e)=(d_(G)(u)+d_(G)(v))^(α),其中α为任一实数。本文先介绍了图的S,R,Q,T四种运算,然后给出了四种运算下的强乘积,并利用... 对于图G,令E(G)表示G的边集,令V(G)表示G的点集,d_(G)(v)表示v的度。对于边e=uv,定义广义和连通度指标χ_(α)(e)=(d_(G)(u)+d_(G)(v))^(α),其中α为任一实数。本文先介绍了图的S,R,Q,T四种运算,然后给出了四种运算下的强乘积,并利用最大度最小度确定了其四种图的广义和连通度指标的上下界。 展开更多
关键词 广义和连通度指标 强乘积 四种运算 F-和
下载PDF
健壮且自适应的学习型近似查询处理方法研究
14
作者 乔艺萌 荆一楠 张寒冰 《计算机工程》 CSCD 北大核心 2024年第1期30-38,共9页
由于在大规模数据集上执行精确查询耗时较长,因此近似查询处理(AQP)技术常被用于在线分析处理,目的是以较短的交互延迟返回查询结果,并尽可能地降低查询误差。现有的学习型AQP方法与底层数据解耦,将I/O密集型计算转化为CPU密集型计算,... 由于在大规模数据集上执行精确查询耗时较长,因此近似查询处理(AQP)技术常被用于在线分析处理,目的是以较短的交互延迟返回查询结果,并尽可能地降低查询误差。现有的学习型AQP方法与底层数据解耦,将I/O密集型计算转化为CPU密集型计算,但是由于计算资源的限制,该类方法通常基于随机的数据样本进行模型训练,此类训练数据会引起稀有群组缺失问题,导致模型预测准确性不高。针对上述问题,提出一种基于分层样本学习的混合型和积网络模型,并基于该模型设计一种AQP框架。分层样本能够有效避免稀有群组缺失现象,基于该样本训练的模型预测准确性大幅提升。此外,针对数据动态更新的情况,提出一种模型自适应更新策略,使得模型能够及时检测数据偏移现象并自适应地执行更新。实验结果表明,与基于抽样和基于机器学习的AQP方法相比,该模型在真实数据集和合成数据集上的平均相对误差分别约降低18.3%和2.2%,在数据动态更新的场景下,其准确性和查询时延均呈现出良好的稳定性。 展开更多
关键词 近似查询处理 和积网络 分层抽样 数据偏移 自适应更新
下载PDF
Nullors, and Nullor Circuits;There Applications in Symbolic Circuit Analysis and Design
15
作者 Reza Hashemian 《Applied Mathematics》 2024年第1期33-45,共13页
The objective in this presentation is to introduce some of the unique properties and applications of nullors in active circuit analysis and designs. The emphasis is to discuss the role nullors can play in symbolic rep... The objective in this presentation is to introduce some of the unique properties and applications of nullors in active circuit analysis and designs. The emphasis is to discuss the role nullors can play in symbolic representation of transfer functions. To show this we adopt the topological platform for the circuit analysis and use a recently developed Admittance Method (AM) to achieve the Sum of Tree Products (STP), replacing the determinant and cofactors of the Nodal Admittance Matrix (NAM) of the circuit. To construct a transfer function, we start with a given active circuit and convert all its controlled sources and I/O-ports to nullors. Now, with a solid nullor circuit (passive elements and nullors) we first eliminate the passive elements through AM operations. This produces the STPs. Second, the all-nullor circuit is then used to find the signs or the STPs. Finally, the transfer function (in symbolic, if chosen) is obtained from the ratio between the STPs. 展开更多
关键词 Admittance Method Analog Circuits Nullors Nullor Circuits sum of Tree products Transfer Functions
下载PDF
基于DEA-Malmquist指数方法及秩和比法的我国城乡居民医疗保险基金动态效率分析
16
作者 刘畅 杨慧兰 《中国医药导报》 CAS 2024年第3期187-191,共5页
目的 以2017—2021年度全国31个省(区、市)的城乡居民医保基金面上数据为基础,对城乡居民医保基金进行动态效率评价。方法 从《中国统计年鉴》收集2017—2021年度全国31个省(区、市)的城乡居民医保基金的参保人数、基金收入、基金支出... 目的 以2017—2021年度全国31个省(区、市)的城乡居民医保基金面上数据为基础,对城乡居民医保基金进行动态效率评价。方法 从《中国统计年鉴》收集2017—2021年度全国31个省(区、市)的城乡居民医保基金的参保人数、基金收入、基金支出、基金累计结余和人均补偿金额相关统计数据,利用DEA-Malmquist指数方法和秩和比法(RSR)综合评价城乡居民医保基金运行效率。结果 2017—2021年全国居民医保基金全要素生产率均值为0.894,东部>中部>西部,技术进步变化指数均值为0.875(<1),技术效率指数均值为1.021。RSR法排序分档结果为好、中、差三档,其中,北京、陕西、海南、安徽和贵州的居民医保基金综合水平最高,黑龙江、广西、西藏和青海的医保基金综合水平最低,大部分省(区、市)医保基金运行水平分档等级处于中档。回归结果显示,回归方程y=-0.329+0.156×Probit(F=473.94,P<0.05,R2=0.942),模型表现较为优秀。结论 技术进步指数下降是导致居民医保基金全要素生产率低的主要原因,且居民医保基金运行效率存在较大的区域差异。应提高医疗保险基金管理的专业化、规范化水平,提高基金运行的整体效益。 展开更多
关键词 城乡居民医保基金 动态效率 全要素生产率 秩和比法
下载PDF
Performance and Complexity Trade-Off between Short-Length Regular and Irregular LDPC
17
作者 Ziyuan Peng Ruizhe Yang 《Journal of Computer and Communications》 2024年第9期208-215,共8页
In this paper, both the high-complexity near-ML list decoding and the low-complexity belief propagation decoding are tested for some well-known regular and irregular LDPC codes. The complexity and performance trade-of... In this paper, both the high-complexity near-ML list decoding and the low-complexity belief propagation decoding are tested for some well-known regular and irregular LDPC codes. The complexity and performance trade-off is shown clearly and demonstrated with the paradigm of hybrid decoding. For regular LDPC code, the SNR-threshold performance and error-floor performance could be improved to the optimal level of ML decoding if the decoding complexity is progressively increased, usually corresponding to the near-ML decoding with progressively increased size of list. For irregular LDPC code, the SNR-threshold performance and error-floor performance could only be improved to a bottle-neck even with unlimited decoding complexity. However, with the technique of CRC-aided hybrid decoding, the ML performance could be greatly improved and approached with reasonable complexity thanks to the improved code-weight distribution from the concatenation of CRC and irregular LDPC code. Finally, CRC-aided 5GNR-LDPC code is evaluated and the capacity-approaching capability is shown. 展开更多
关键词 Regular LDPC Irregular LDPC Near-ML Decoding List Decoding Belief Propagation Algorithm sum-product Algorithm CRC-Aided Hybrid Decoding
下载PDF
关于不同分布两两NQD列的Jamison型加权乘积和的强稳定性 被引量:42
18
作者 王岳宝 严继高 +1 位作者 成凤旸 蔡新中 《数学年刊(A辑)》 CSCD 北大核心 2001年第6期701-706,共6页
本文讨论了不同分布两两NQD列的Jamison型加权乘积和的强稳定性及乘积和的Marcinkiewicz型强大数律,推广并改进了Etemadi[1]关于不同分布两两独立列部分和的工作及Matula[2],王岳宝等[3... 本文讨论了不同分布两两NQD列的Jamison型加权乘积和的强稳定性及乘积和的Marcinkiewicz型强大数律,推广并改进了Etemadi[1]关于不同分布两两独立列部分和的工作及Matula[2],王岳宝等[3]关于同分布两两NQD列部分和的工作. 展开更多
关键词 两两NQD列 乘积和 强稳定性 强大数律 部分和
下载PDF
两类模糊有限状态机积的交换性 被引量:8
19
作者 谢正卫 翟莹 +2 位作者 黄飞丹 易忠 邓培民 《计算机研究与发展》 EI CSCD 北大核心 2014年第9期2130-2136,共7页
利用代数工具矩阵、半群等对两类模糊有限状态机的交换性作了进一步的研究.首先给出了模糊有限状态机是可交换的几个等价刻画,即模糊有限状态机交换与其状态转移矩阵关于模糊矩阵乘法交换等价,与其输入集上字符串关于同余关系构成的乘... 利用代数工具矩阵、半群等对两类模糊有限状态机的交换性作了进一步的研究.首先给出了模糊有限状态机是可交换的几个等价刻画,即模糊有限状态机交换与其状态转移矩阵关于模糊矩阵乘法交换等价,与其输入集上字符串关于同余关系构成的乘法半群交换等价,并讨论了模糊有限状态机的直积、级联积、圈积以及和的交换性.其次提出了Mealy-型模糊有限状态机是可交换的概念,同时在新的概念下详细地研究了Mealy-型模糊有限状态机的直积、级联积、圈积以及和、商的交换性.得到了两个(Mealy-型)模糊有限状态机的完全直积、和交换的充要条件;得到两个(Mealy-型)模糊有限状态机的圈积、级联积交换的一个充分条件;证明了商Mealy-型模糊有限状态机保持原Mealy-型模糊有限状态机的交换性.最后给出判别模糊有限状态机交换性的算法. 展开更多
关键词 (Mealy-型)模糊有限状态机 交换 直积 级联积 圈积
下载PDF
Fibonacci数奇数次方的积和式 被引量:23
20
作者 刘端森 李超 杨存典 《纺织高校基础科学学报》 CAS 2004年第3期187-189,193,共4页
利用第二类Chebyshev多项式的性质以及其与Fibonacci数的关系得到了关于Fibonacci数奇数次方的积和式.
关键词 CHEBYSHEV多项式 FIBONACCI数 LUCAS数 积和式
下载PDF
上一页 1 2 25 下一页 到第
使用帮助 返回顶部