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Equivalent Conditions of Complete Convergence for Weighted Sums of Sequences of i.i.d.Random Variables under Sublinear Expectations
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作者 XU Mingzhou CHENG Kun 《应用概率统计》 北大核心 2025年第3期339-352,共14页
The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the... The complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space is studied.By moment inequality and truncation methods,we establish the equivalent conditions of complete convergence for weighted sums of sequences of independent,identically distributed random variables under sublinear expectation space.The results complement the corresponding results in probability space to those for sequences of independent,identically distributed random variables under sublinear expectation space. 展开更多
关键词 complete convergence weighted sums i.i.d.random variables sublinear expectation
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具有次线性中立项的二阶微分方程的振动性
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作者 赵玉萍 《四川师范大学学报(自然科学版)》 CAS 2025年第1期138-142,共5页
为进一步发展和完善微分方程的振动理论,研究一类具有次线性中立项的二阶非线性微分方程的振动性,利用Riccati变换、不等式技巧和分析性质,获得该类方程振动的充分条件.
关键词 RICCATI变换 振动性 次线性中立项 正解
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一类具次线性中立项的二阶动力方程的振动性
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作者 赵春茹 《许昌学院学报》 2025年第2期6-11,共6页
在非正则条件下研究一类具有次线性中立项的二阶动力方程的振动性,利用时间轴上的微积分理论和广义黎卡提变换以及不等式技巧建立了一些新的振动准则,推广了已有文献中的结果,并给出应用实例加以验证.
关键词 振动性 二阶动力方程 次线性中立项 时间轴
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次线性g-期望的稳健表示及其应用研究
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作者 李敏 纪荣林 +1 位作者 钟文倩 周津名 《哈尔滨商业大学学报(自然科学版)》 2025年第4期474-479,共6页
在关于g-期望定义的基本假设条件下,基于倒向随机微分方程理论,深入探讨了生成元函数在刻画次线性g-期望的稳健表示中的核心作用.通过分析生成元函数的性质,在L^(p)(1<p≤∞)空间中建立了次线性g-期望的稳健表示定理.研究结果表明,... 在关于g-期望定义的基本假设条件下,基于倒向随机微分方程理论,深入探讨了生成元函数在刻画次线性g-期望的稳健表示中的核心作用.通过分析生成元函数的性质,在L^(p)(1<p≤∞)空间中建立了次线性g-期望的稳健表示定理.研究结果表明,在适当的可积性条件下,次线性g-期望可以表示为一类概率测度族上的上确界期望,这一发现本质性地拓展了非线性期望的表示框架.进一步地,获得了g-期望诱导的一致性风险度量的稳健表示模型.该模型满足单调性、平移不变性、次可加性和正齐次性等一致性公理,从而在金融风险管理中具有重要应用. 展开更多
关键词 倒向随机微分方程 G-期望 生成元 次线性g-期望 稳健表示 一致性风险度量
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基于BERTopic主题建模的“Assessing Writing”研究趋势演化分析
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作者 李锦焱 张丹 高慧敏 《河南科技大学学报(自然科学版)》 北大核心 2025年第4期97-104,M0008,共9页
通过深入挖掘期刊研究主题与预测学术发展趋势,研究人员能够更精准地把握学科方向,紧跟前沿动态。然而,期刊摘要作为短文本,其结构化特点、高维稀疏的向量表示、语义结构复杂性以及数据噪声等因素,对传统主题建模方法构成了严峻挑战。... 通过深入挖掘期刊研究主题与预测学术发展趋势,研究人员能够更精准地把握学科方向,紧跟前沿动态。然而,期刊摘要作为短文本,其结构化特点、高维稀疏的向量表示、语义结构复杂性以及数据噪声等因素,对传统主题建模方法构成了严峻挑战。针对这一问题,提出了一种基于BERTopic的主题演化分析模型。模型融合了预训练语言模型在语义表征方面的优势与层次化聚类算法的结构建模能力,同时重构词项加权策略,引入词频的次线性变换机制以优化传统词权计算方法,从而有效削弱高频词的干扰,突出对区分主题具有关键意义的词项,显著提升了模型的主题区分度和语义表征能力。以“Assessing Writing”期刊为研究对象,围绕不同时期写作评估领域的研究成果开展实证分析。通过系统梳理各阶段的研究主题与发展方向,挖掘其动态演化规律。实验结果表明,能够准确捕捉写作评估领域的研究热点变化,清晰揭示其发展脉络,在处理期刊摘要等短文本数据时展现出良好的实用性与有效性,为相关领域的学术研究和趋势预测提供了可靠的技术支撑。 展开更多
关键词 主题建模 BERTopic 语义结构 主题表征 次线性变换
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次线性期望下END随机变量序列的Marcinkiewicz-Zygmund型强大数定律
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作者 魏玉琰 谭希丽 +1 位作者 孙佩宇 郭爽 《北华大学学报(自然科学版)》 2025年第3期281-289,共9页
在次线性期望下利用Chebyshev不等式和Kronecker引理,研究广义负相依(END)随机变量序列的强极限定理,在一般矩条件下得到END随机变量序列的Marcinkiewicz-Zygmund型强大数定律。
关键词 次线性期望 END随机变量序列 强大数定律
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Existence of Multiple Solutions for a Superlinear Sturm Liouville BVPs
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作者 孙伟平 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2000年第1期1-4,共4页
The existence of solutions of a Sturm Liouville boundary value problem(BVP) for u″+g(u)=p(t,u,u′)(0≤t≤1) is studied by using a continuation theorem based on the topological degree theory. Under the condition that... The existence of solutions of a Sturm Liouville boundary value problem(BVP) for u″+g(u)=p(t,u,u′)(0≤t≤1) is studied by using a continuation theorem based on the topological degree theory. Under the condition that g grows superlinearly and p grows with respect to u and u′ linearly at most, the boundary value problem has an infinitude of solutions. 展开更多
关键词 continuation theorem topological degree superlinearity
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AN INEXACT SYMMETRIC PROXIMAL ADMM WITH CONVEX COMBINATION PROXIMAL CENTERS FOR SEPARABLE CONVEX PROGRAMMING
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作者 Xianke TANG Jinbao JIAN +1 位作者 Jianghua YIN Xianzhen JIANG 《Acta Mathematica Scientia》 2025年第4期1701-1722,共22页
In this paper,we develop an inexact symmetric proximal alternating direction method of multipliers(ISPADMM)with two convex combinations(ISPADMM-tcc)for solving two-block separable convex optimization problems with lin... In this paper,we develop an inexact symmetric proximal alternating direction method of multipliers(ISPADMM)with two convex combinations(ISPADMM-tcc)for solving two-block separable convex optimization problems with linear equality constraints.Specifically,the convex combination technique is incorporated into the proximal centers of both subproblems.We then approximately solve these two subproblems based on relative error criteria.The global convergence,and O(1/N)ergodic sublinear convergence rate measured by the function value residual and constraint violation are established under some mild conditions,where N denotes the number of iterations.Finally,numerical experiments on solving the l1-regularized analysis sparse recovery and the elastic net regularization regression problems illustrate the feasibility and effectiveness of the proposed method. 展开更多
关键词 sparable convex optimization convex combination proximal centers relative error criterion ISPADMM ergodic sublinear convergence rate
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超线性收敛的电-气综合能源系统全分布式优化调度方法
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作者 罗清局 朱继忠 +2 位作者 朱浩昊 李盛林 郭泰亨 《电网技术》 北大核心 2025年第5期1816-1825,共10页
电-气综合能源系统分布式优化调度中通常使用线性收敛的交替方向乘子法。但该方法往往需要多次迭代求解子问题,计算效率并不高。此外,交替方向乘子法通常需要协调中心以更新拉格朗日乘子。对此,该文提出了无需协调中心的全分布式超线性... 电-气综合能源系统分布式优化调度中通常使用线性收敛的交替方向乘子法。但该方法往往需要多次迭代求解子问题,计算效率并不高。此外,交替方向乘子法通常需要协调中心以更新拉格朗日乘子。对此,该文提出了无需协调中心的全分布式超线性收敛优化调度方法以应对上述两个问题。所提方法基于全分布式内点共轭梯度法,在内点法的基础上对修正方程进行解耦,继承了内点法的超线性收敛性。该文对解耦后的修正方程进行处理,确保系数矩阵对称正定,使其能被共轭梯度法高效求解。采用分布式共轭梯度法对解耦后的修正方程进行全分布式求解,避免引入协调中心。最后,在3个不同规模的系统中验证了全分布式内点共轭梯度法的高效性。 展开更多
关键词 电-气综合能源系统 分布式优化调度 内点法 共轭梯度法 超线性收敛
原文传递
Positive Periodic Solutions to a Second-order Nonlinear Differential Equation with an Indefinite Singularity
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作者 YUAN Shujing LI Shaowen CHENG Zhibo 《数学理论与应用》 2025年第1期81-93,共13页
In this paper,we provide new sufficient conditions for the existence of positive periodic solutions for a class of indefinite singular differential equation x′′(t)+a(t)x(t)=h(t)/x^(ρ)(t)+g(t)x^(δ)(t)+e(t),whereρ... In this paper,we provide new sufficient conditions for the existence of positive periodic solutions for a class of indefinite singular differential equation x′′(t)+a(t)x(t)=h(t)/x^(ρ)(t)+g(t)x^(δ)(t)+e(t),whereρandδare two positive constants and 0<δ≤1,h,e∈L^(1)(R/TZ),g∈L^(1)(R/TZ)is positive.Our proofs are based on the fixed point theorems(Schauder’s fixed point theorem and Krasnoselskii-Guo fixed point theorem)and the positivity of the associated Green function. 展开更多
关键词 Schauder fixed point theorem Krasnoselskii-Guo fixed point theorem Indefinite singular sublinear and semilinear Positive periodic solution
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一种求解稀疏优化问题的拟牛顿算法
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作者 金环 黎耀成 程万友 《东莞理工学院学报》 2025年第5期17-24,共8页
提出一种求解稀疏优化问题的拟牛顿算法。新算法能利用硬阈值算法识别非零元素,为了加速收敛,在包含非零元素的子空间上使用了拟牛顿法,证明了算法的每个稳定点都是α稳定点。在标准假设下,还证明了新算法具有超线性收敛性,通过数值实... 提出一种求解稀疏优化问题的拟牛顿算法。新算法能利用硬阈值算法识别非零元素,为了加速收敛,在包含非零元素的子空间上使用了拟牛顿法,证明了算法的每个稳定点都是α稳定点。在标准假设下,还证明了新算法具有超线性收敛性,通过数值实验与现有的先进算法进行比较,说明新算法具有优秀数值表现。 展开更多
关键词 稀疏优化 硬阈值算法 拟牛顿法 超线性收敛性
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MULTIPLE POSITIVE SOLUTIONS TO SINGULAR BOUNDARY VALUE PROBLEMS FOR SUPERLINEAR SECOND ORDER ODES 被引量:12
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作者 蒋达清 《Acta Mathematica Scientia》 SCIE CSCD 2002年第2期199-206,共8页
This paper deals with the existence of positive solutions to the singular boundary value problemwhere q(t) may be singular at t = 0 and t = 1, f(t,y) may be superlinear at y =∞ and singular, at y = 0.
关键词 Singular boundary value problem existence superlinear the fixed point theorem
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RELATIVE ENTROPY AND LARGE DEVIATIONS UNDER SUBLINEAR EXPECTATIONS 被引量:6
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作者 高付清 徐明周 《Acta Mathematica Scientia》 SCIE CSCD 2012年第5期1826-1834,共9页
We give a definition of relative entropy with respect to a sublinear expectation and establish large deviation principle for the empirical measures for independent random variables under the sublinear expectation.
关键词 sublinear expectation relative entropy large deviation empirical measure
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EXISTENCE OF SOLUTIONS FOR NON-PERIODIC SUPERLINEAR SCHRDINGER EQUATIONS WITHOUT (AR) CONDITION 被引量:3
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作者 万莉莉 唐春雷 《Acta Mathematica Scientia》 SCIE CSCD 2012年第4期1559-1570,共12页
The existence of solutions is obtained for a class of the non-periodic SchrSdinger equation -△u + V(x)u = f(x,u), x E RN, by the generalized mountain pass theorem, where V is large at infinity and f is superline... The existence of solutions is obtained for a class of the non-periodic SchrSdinger equation -△u + V(x)u = f(x,u), x E RN, by the generalized mountain pass theorem, where V is large at infinity and f is superlinear as |u|→ ∞. 展开更多
关键词 Schroedinger equation superlinear generalized mountain pass theorem
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A QP-FREE AND SUPERLINEARLY CONVERGENT ALGORITHM FOR INEQUALITY CONSTRAINED OPTIMIZATIONS 被引量:3
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作者 徐以凡 王薇 《Acta Mathematica Scientia》 SCIE CSCD 2001年第1期121-130,共10页
In this paper, a new mixed quasi-Newton method for inequality constrained optimization problems is proposed. The feature of the method is that only the systems of linear equations are solved in each iteration, other t... In this paper, a new mixed quasi-Newton method for inequality constrained optimization problems is proposed. The feature of the method is that only the systems of linear equations are solved in each iteration, other than the quadratic programming, which decrease the amount of computations and is also efficient for large scale problem. Under some mild assumptions without the strict complementary condition., the method is globally and superlinearly convergent. 展开更多
关键词 quasi-Newton method strict complementary condition global convergence superlinear convergence
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A SUPERLINEARLY CONVERGENT TRUST REGION ALGORITHM FOR LC^1 CONSTRAINED OPTIMIZATION PROBLEMS 被引量:3
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作者 欧宜贵 侯定丕 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期67-80,共14页
In this paper, a new trust region algorithm for nonlinear equality constrained LC1 optimization problems is given. It obtains a search direction at each iteration not by solving a quadratic programming subprobiem with... In this paper, a new trust region algorithm for nonlinear equality constrained LC1 optimization problems is given. It obtains a search direction at each iteration not by solving a quadratic programming subprobiem with a trust region bound, but by solving a system of linear equations. Since the computational complexity of a QP-Problem is in general much larger than that of a system of linear equations, this method proposed in this paper may reduce the computational complexity and hence improve computational efficiency. Furthermore, it is proved under appropriate assumptions that this algorithm is globally and super-linearly convergent to a solution of the original problem. Some numerical examples are reported, showing the proposed algorithm can be beneficial from a computational point of view. 展开更多
关键词 LC1 optimization ODE methods trust region methods superlinear convergence
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Existence of Positive Solution for Superlinear Semipositone Singular Second-order m-point Boundary Value Problem 被引量:4
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作者 ZHANG Xing-qiu 《Chinese Quarterly Journal of Mathematics》 CSCD 2010年第1期151-158,共8页
By applying fixed point theorem, the existence of positive solution is considered for superlinear semipositone singular m-point boundary value problem -(Lφ)(x)=(p(x)φ′(x))′+q(x)φ(x) and ξi ∈ (0,... By applying fixed point theorem, the existence of positive solution is considered for superlinear semipositone singular m-point boundary value problem -(Lφ)(x)=(p(x)φ′(x))′+q(x)φ(x) and ξi ∈ (0,1)with 0〈ξ1〈ξ2……〈ξm-2〈1,αi ∈ R^+,f ∈C[(0,1)×R^+,R^+],f(x,φ) may be singular at x=0 and x=1,g(x):(0,1)→R is Lebesgue measurable, g may tend to negative infinity and have finitely many singularities. 展开更多
关键词 SEMIPOSITONE superlinear singular m-point boundary value fixed point theo-rem positive solution
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MULTIPLE POSITIVE SOLUTIONS FOR FIRST ORDER IMPULSIVE SUPERLINEAR INTEGRO-DIFFERENTIAL EQUATIONS ON THE HALF LINE 被引量:3
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作者 Guo Dajun 《Acta Mathematica Scientia》 SCIE CSCD 2011年第3期1167-1178,共12页
In this paper, the author discusses the multiple positive solutions for an infinite boundary value problem of first order impulsive superlinear integro-differential equations on the half line by means of the fixed poi... In this paper, the author discusses the multiple positive solutions for an infinite boundary value problem of first order impulsive superlinear integro-differential equations on the half line by means of the fixed point theorem of cone expansion and compression with norm type. 展开更多
关键词 impulsive superlinear integro-differential equation infinite boundary value problem fixed point theorem of cone expansion and compression with norm type
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A GLOBALLY AND SUPERLINEARLY CONVERGENT TRUST REGION METHOD FOR LC^1 OPTIMIZATION PROBLEMS 被引量:1
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作者 Zhang Liping Lai Yanlian Institute of Applied Mathematics,Academia Sinica,Beijing 100080. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2001年第1期72-80,共9页
A new trust region algorithm for solving convex LC 1 optimization problem is presented.It is proved that the algorithm is globally convergent and the rate of convergence is superlinear under some reasonable assum... A new trust region algorithm for solving convex LC 1 optimization problem is presented.It is proved that the algorithm is globally convergent and the rate of convergence is superlinear under some reasonable assumptions. 展开更多
关键词 LC 1 optimization problem global and superlinear convergence trust region method.
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An Oscillation Criterion for Second Order Superlinear Differential Equations 被引量:6
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作者 陈文灯 俞元洪 《Chinese Quarterly Journal of Mathematics》 CSCD 1997年第3期1-6, ,共6页
A new criterion is established for the oscillation of second order superlinear ordinary differential equations of the formx″(t) + p(t)x′(t) + q(t)|x(t)|αsgnx(t) = 0, t ≥ t0,where α>1,p and q are continuous f... A new criterion is established for the oscillation of second order superlinear ordinary differential equations of the formx″(t) + p(t)x′(t) + q(t)|x(t)|αsgnx(t) = 0, t ≥ t0,where α>1,p and q are continuous functions on[t0,∞). This criterion extends and unifies some of the results obtained in [1]- [5]. 展开更多
关键词 superlinearity oscillation criterion second order differential equation
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