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1.
我们考虑在线箱覆盖问题,其中所有被装元素的尺寸不超过1/k(k是正整数).我们给出了该问题的紧上界并证明简单算法NextFit即是最好的.这个结果推广了Csirik与Totik1988年的工作.最后,我们还给出了二维情形的一个非平凡的上界.  相似文献   

2.
本文在实Banach空间的锥上证明了集值映射的随机逼近定理.作为应用,讨论了几个随机的不动点定理.我们的工作推广了Lin,Sehgal和Singh的结果.  相似文献   

3.
关于代数微分方程(f')~n=R(z,f)的亚纯解   总被引:1,自引:0,他引:1  
袁文俊  李叶舟 《数学学报》2001,44(2):277-286
在本文中,我们首先考虑了具有理系数的代数微分方程(f')n=R(z,f)亚 纯解的个数估计问题,并举例说明所得结果是精确的.其次,我们运用 Nevanlinna值 分布论,讨论了具亚纯系数的典型代数微分方程(f')3=a0(f- τ1)2(f- τ2)2(f- τ3)2 的可分解亚纯解.文中的结果推广或改进了高仕安[1],Gundersen G.和LaineI[2]以 及何育赞, LaineI.[3-5]等人的工作.  相似文献   

4.
在本文中,我们首先考虑了具有理系数的代数微分方程(f')n=R(z,f)亚 纯解的个数估计问题,并举例说明所得结果是精确的.其次,我们运用 Nevanlinna值 分布论,讨论了具亚纯系数的典型代数微分方程(f')3=a0(f- τ1)2(f- τ2)2(f- τ3)2 的可分解亚纯解.文中的结果推广或改进了高仕安[1],Gundersen G.和LaineI[2]以 及何育赞, LaineI.[3-5]等人的工作.  相似文献   

5.
Banach空间的上带松弛共强制的广义隐式变分包含组   总被引:1,自引:0,他引:1  
柏传志 《应用数学》2007,20(3):535-540
本文在Banach空间上引入和研究了一类带松弛共强制的广义隐式变分包含组(SNSIVI).使用M增值算子的预解算子技术,我们构造了一类新的迭代算法逼近这类隐式变分包含组,且在q-一致平滑Banach空间上证明了这类迭代算法的收敛性.我们的结果推广和改进了最近的相关工作.  相似文献   

6.
最小二乘法估计通常基于:线性、独立、正态和方差齐性四个基本假定.在实际工作中,这些假定常很难满足,偏离时往往对估计结果带来影响.本文对偏离假定的情况予以讨论并给出发现和处理这些问题的方法;同时结合实例对回归中的影响点和异常点、共线性等问题予以说明.这将对我们实际工作中的数据分析具有指导性意义.  相似文献   

7.
研究具有反馈控制的单种群对数模型.通过构造适当的Lyapunov函数.我们让得系统的正平衡点是无条件全局稳定的.所得结果补充和完善了已有的结果.  相似文献   

8.
柯厚宝 《数学通讯》2010,(10):20-21
三角板是伴随我们成长的最常用、最实用的工具之一.从小学到中学、大学,甚至工作以后,都一直与我们相伴.由于太平常了,所以容易被我们忽视,殊不知它正是我们身边的两颗“珍珠”.  相似文献   

9.
袁秋宝  谭忠 《数学研究》2007,40(3):233-247
本文我们研究的是具有Dini连续性系数的散度形式的非线性椭圆方程组在自然增长条件下的问题.我们证明所用的方法是有Dugaar和Grotowski所引进的调和逼近技巧。这种技窍在证明弱解的局部正则性时非常重要.我们可以用之直接得到最优局部正则性结果.  相似文献   

10.
刘作高老师在这封信中指出本刊上出现了一些失误,这是对我们编审人员的严肃批评,读完信.想到这些失误会对读者产生不良影响我们感到不安和内疚.在此,我们诚恳地向读者们致歉,并向刘作高老师表示衷心的感谢.在今后的工作中,我们一定加强责任心,提高刊物的质量.  相似文献   

11.
In this paper, we prove some common tripled fixed point and tripled coincidence point results for contractive conditions in a cone metric type space. Our results extend, unify and generalize well-known results in the literature, in particular the recent results of Aydi et al. (Fixed Point Theory Appl 2012:134, 2012). Some examples are also presented to validate our obtained results and new concepts.  相似文献   

12.
We establish coupled coincidence point results for mixed g-monotone mappings under general contractive conditions in partially ordered cone metric spaces over solid cones. We also present results on existence and uniqueness of coupled common fixed points. Our results generalize, extend and unify several well known comparable results in the literature. To illustrate our results and to distinguish them from the earlier ones, we equip the paper with examples.  相似文献   

13.
We depict recent developments in the field of positive sectional curvature, mainly, but not exclusively, under the assumption of isometric torus actions. After an elaborate introduction to the field, we shall discuss various classification results, before we provide results on the computation of Euler characteristics. This will be the starting point for an examination of more involved invariants and further techniques. In particular, we shall discuss the Hopf conjectures, related decomposition results like the Wilhelm conjecture, results in differential topology and index theory as well as in rational homotopy theory, geometrically formal metrics in positive curvature and much more. The results we present will be discussed for arbitrary dimensions, but also specified to small dimensions. This survey article features mainly depictions of our own work interest in this area and cites results obtained in different collaborations; full statements and proofs can be found in the respective original research articles.  相似文献   

14.
In this paper, we obtain some stability results in complete convex metric spaces for nonselfmappings satisfying certain general contractivity condition. We prove our results for Jungck-Mann and Jungck-Ishikawa iterations. Our results extend several stability results in the literature.  相似文献   

15.
在锥度量空间中,用压缩性函数代替具体实数,获得了c-距离下的映射的新的不动点定理.所得结果在条件上不要求映射的非减性,且第一个定理去掉了锥的正规性,第二个定理去掉了映射的连续性,改进了原有的许多重要结论,并给出了相应的例子.  相似文献   

16.
Properties of serial kanban systems   总被引:1,自引:0,他引:1  
In this paper we show some structural results of a kanban system by using results about the underlying GSMP. The main results from this connection are: dominance of allocations, optimal partition, upper and lower bounds on throughput, consistency of the IPA derivative, convexity of throughput as a function of service time parameters and concavity of throughput with respect to number of kanbans. Although the dominance and the partition results were obtained previously by sample path arguments, the proofs here are less cumbersome and generalize the earlier results. The second-order properties for kanban lines are new. These results form a basis for results in multi-product lines where proofs by sample paths require extensive notation.  相似文献   

17.
In this paper, the concept of multi-valued weak contraction of Berinde and Berinde [8] for the Picard iteration in a complete metric space is extended to the case of multi-valued weak contraction for the Jungck iteration in a complete b-metric space. While our main results generalize the recent results of Berinde and Berinde [8], they also extend, improve and unify several classical results pertainning to single and multi-valued contractive mappings in the fixed point theory. Our results also improve the recent results of Daffer and Kaneko [16].   相似文献   

18.
In this paper we consider a notion of g-weak contractive mappings in the setting of cone metric spaces and we give results of common fixed points. This results generalize some common fixed points results in metric spaces and some of the results of Huang and Zhang in cone metric spaces. Supported by Universitá degli Studi di Palermo, R. S. ex 60%.  相似文献   

19.
The aim of this paper is to obtain some openness results in terms of normal coderivative for parametric set-valued mappings acting between infinite dimensional spaces. Then, implicit multifunction results are obtained by simply specializing the openness results. Moreover, we study a kind of metric regularity of the implicit multifunction. The results of the paper generalize several recent results in literature.  相似文献   

20.
In this paper, we prove some stability results concerning the generalized quadratic and quartic type functional equation in the context of non-Archimedean fuzzy normed spaces in the spirit of Hyers-Ulam-Rassias. As applications, we establish some results of approximately generalized quadratic and quartic type mapping in non-Archimedean normed spaces. Also, we show that the assumption of the non-Archimedean absolute value of $2$ is less than $1$ cannot be omitted in our corollaries. The results improve and extend some recent results.  相似文献   

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