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开发等式比较SQL查询语句的一种模型推理方法 被引量:1
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作者 杨波 薛锦云 《计算机工程与应用》 CSCD 北大核心 2007年第22期99-102,164,共5页
尝试将模型推理引入一类典型的SQL查询语句(等式比较SQL查询语句)的开发过程中;以便使这类SQL查询语句的开发过程有章可循,减少盲目的直觉推理尝试,保证SQL查询语句的正确性。提出了一种固定形式的一阶谓词逻辑表达式,描述了这种一阶谓... 尝试将模型推理引入一类典型的SQL查询语句(等式比较SQL查询语句)的开发过程中;以便使这类SQL查询语句的开发过程有章可循,减少盲目的直觉推理尝试,保证SQL查询语句的正确性。提出了一种固定形式的一阶谓词逻辑表达式,描述了这种一阶谓词逻辑表达式与等式比较SQL查询语句的对应关系;总结了开发过程的三个步骤;形成了一种开发等式比较SQL查询语句的模型推理方法;并且按照由简单到复杂的顺序给出了两个应用实例。 展开更多
关键词 等式比较 SQL查询语句 模型推理 一阶谓词逻辑
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奇异半线性反应扩散方程组的Blow-up问题 被引量:2
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作者 雷学红 杨凤藻 黄永霞 《昆明理工大学学报(自然科学版)》 CAS 北大核心 2011年第2期75-78,共4页
利用算子半群理论和压缩映射原理,对一类奇异半线性反应扩散方程组解的问题进行讨论,得到其解在有限时间内爆破.
关键词 反应扩散方程组 算子半群 比较等式
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Comparison of two approximal proximal point algorithms for monotone variational inequalities 被引量:1
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作者 TAO Min 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第6期969-977,共9页
Proximal point algorithms (PPA) are attractive methods for solving monotone variational inequalities (MVI). Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approx... Proximal point algorithms (PPA) are attractive methods for solving monotone variational inequalities (MVI). Since solving the sub-problem exactly in each iteration is costly or sometimes impossible, various approximate versions ofPPA (APPA) are developed for practical applications. In this paper, we compare two APPA methods, both of which can be viewed as prediction-correction methods. The only difference is that they use different search directions in the correction-step. By extending the general forward-backward splitting methods, we obtain Algorithm Ⅰ; in the same way, Algorithm Ⅱ is proposed by spreading the general extra-gradient methods. Our analysis explains theoretically why Algorithm Ⅱ usually outperforms Algorithm Ⅰ. For computation practice, we consider a class of MVI with a special structure, and choose the extending Algorithm Ⅱ to implement, which is inspired by the idea of Gauss-Seidel iteration method making full use of information about the latest iteration. And in particular, self-adaptive techniques are adopted to adjust relevant parameters for faster convergence. Finally, some numerical experiments are reported on the separated MVI. Numerical results showed that the extending Algorithm II is feasible and easy to implement with relatively low computation load. 展开更多
关键词 Projection and contraction methods Proximal point algorithm (PPA) Approximate PPA (APPA) Monotone variational inequality (MVI) Prediction and correction
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对数平均和双参数广义Muirhead平均之间的比较 被引量:1
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作者 赵铁洪 褚玉明 《中国科学:数学》 CSCD 北大核心 2015年第3期233-244,共12页
本文讨论了两个不同正实数x和y的对数平均L(x,y)=(x-y)/(logx-logy)与双参数广义Muirhead平均M(a,b;x,y)=[(x^ay^b+x^by^a)/2]^(1/(a+b))之间的比较,得到了如下三个结论:(11)若(a,b)∈D_1∪E_1∪L_0,则M(a,b;x,y)<L(x,y);(2)若(a,b)... 本文讨论了两个不同正实数x和y的对数平均L(x,y)=(x-y)/(logx-logy)与双参数广义Muirhead平均M(a,b;x,y)=[(x^ay^b+x^by^a)/2]^(1/(a+b))之间的比较,得到了如下三个结论:(11)若(a,b)∈D_1∪E_1∪L_0,则M(a,b;x,y)<L(x,y);(2)若(a,b)∈D_2∪E_2,则M(a,b;x,y)>L(x,y);(3)若(a,b)∈D_3∪E_3,则存在x_1,y_1,x_2,y_2,使得M(a,b;x_1;y_1)<L(x_1,y_1)和M(a,b;x_2,y_2)>L(x_2,y_2).其中D_1={(a,b)∈R^2:a+b≠0,b>a,ω_1(a,b)≤0,ω_2(a,b)≤0},E_1={(a,b)∈R^2:a+b≠0,b<a,ω_1(a,b)≤0,ω_2(a,b)≤0},D_2={(a,b)∈R^2:ab≤0,b>a,ω_1(a,b)≥0},E_2={(a,b)∈R^2:ab≤0,b<a,ω_1(a,b)≥0},D_3={(a,b)∈R^2:b>a>0,ω_1(a,b)>0)∪{(a,b)∈R^2:b>a>0,ω_1(a,b)=0,ω_2(a,b)>0}∪{(a,b)∈R^2:b>a,ab≤0,ω_1(a,b)<0,ω_2(a,b)>0},E_3={(a,b)∈R^2:a>b>0,ω_1(a,b)>0}∪{(a,b)∈R^2:a>b>0,ω_1(a,b)=0,ω_2(a,b)>0}∪{(a,b)∈R^2:a>b,ab≤0,ω_1(a,b)<0,ω_2(a,b)>0},L_0={(a,b)∈R^2:a=b≠0},ω_1(a,b)=(a+b)[3(a-b)~2-(a+b)],ω_2(a,b)=(a+b)[2(a-b)~2+1]-3(a^2+b^2). 展开更多
关键词 比较等式 广义Muirhead平均 对数平均
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Comparison of Some Means
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作者 刘证 《Journal of Mathematical Research and Exposition》 CSCD 北大核心 2002年第4期583-588,共6页
The known results on comparison of extended mean values are used to compare power means, Stolarsky means and Heron mean. Some proofs of well known results are simplified with several new results obtained.
关键词 extended mean value power mean Stolarsky mean Heron mean
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ON JENSEN'S INEQUALITY FOR g-EXPECTATION 被引量:26
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作者 JIANG LONG CHEN ZENGJING School of Mathematics and System Sciences, Shandong University, Jinan 250100, China. Department of Mathematics, China University of Mining and Technology, Xuzhou 221008, Jiangsu,China. E-mail: jianglong@math.sdu.edu.cn School of Mathematics and System Sciences, Shandong University, Jinan 250100, China. 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2004年第3期401-412,共12页
Briand et al. gave a counterexample showing that given g, Jensen's inequality for g-expectation usually does not hold in general This paper proves that Jensen's inequality for g-expectation holds in general if... Briand et al. gave a counterexample showing that given g, Jensen's inequality for g-expectation usually does not hold in general This paper proves that Jensen's inequality for g-expectation holds in general if and only if the generator g (t, z) is super-homogeneous in z. In particular, g is not necessarily convex in z. 展开更多
关键词 Backward stochastic differential equation Jensen's inequality g-expectaation Conditional g-expectation Comparison theorem
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COMPARISON,SYMMETRY AND MONOTONICITY RESULTS FOR SOME DEGENERATE ELLIPTIC OPERATORS IN CARNOT-CARATHEODORY SPACES 被引量:1
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作者 GEYUXIN YEDONG ZHOUFENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2002年第3期361-372,共12页
This paper studies the properties of solutions of quasilinear equations involving the p-laplacian type operator in general Carnot-Caratheodory spaces. The authors show some comparison results for solutions of the rele... This paper studies the properties of solutions of quasilinear equations involving the p-laplacian type operator in general Carnot-Caratheodory spaces. The authors show some comparison results for solutions of the relevant differential inequalities and use them to get some symmetry and monotonicity properties of solutions, in bounded or unbounded domains. 展开更多
关键词 Carnot-Caratheodory space SYMMETRY MONOTONICITY Degenerate elliptic operator
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Eigenvalue Comparison Theorems on Finsler Manifolds 被引量:1
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作者 Songting YIN Qun HE 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2015年第1期31-44,共14页
Cheng-type inequality, Cheeger-type inequality and Faber-Krahn-type inequality are generalized to Finsler manifolds. For a compact Finsler manifold with the weighted Ricci curvature bounded from below by a negative co... Cheng-type inequality, Cheeger-type inequality and Faber-Krahn-type inequality are generalized to Finsler manifolds. For a compact Finsler manifold with the weighted Ricci curvature bounded from below by a negative constant, Li-Yau's estimation of the first eigenvalue is also given. 展开更多
关键词 The first eigenvalue Finsler-Laplacian Ricci curvature S-CURVATURE
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THEORETICAL AND NUMERICAL COMPARISON ON DOUBLE-PROJECTION METHODS FOR VARIATIONAL INEQUALITIES
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作者 WANGYiju SUNWenyu 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2003年第2期268-274,共7页
Recently, double projection methods for solving variational inequalities havereceived much attention due to their fewer projection times at each iteration. In this paper, weunify these double projection methods within... Recently, double projection methods for solving variational inequalities havereceived much attention due to their fewer projection times at each iteration. In this paper, weunify these double projection methods within two unified frameworks, which contain the existingdouble projection methods as special cases. On the basis of this unification, theoretical andnumerical comparison between these double projection methods is presented. 展开更多
关键词 double-projection method variational inequalities COMPARISON
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