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991.
宋利梅 《高校应用数学学报(A辑)》2014,29(4)
考虑具有p-Laplace算子的分数阶泛函微分方程边值问题,利用锥上的不动点定理,得到了其正解及多个正解存在的充分条件,所得结果推广了已有的结论,并举例说明了结论的适用性. 相似文献
992.
Global asymptotic stability of a two species competitive system with stage structure and harvesting 总被引:3,自引:0,他引:3
Xinyu SONG Lansun CHEN Department of Mathematics Xinyang Teachers College Henan China Institute of Mathematics Academy of Mathematics System Sciences Chinese Academy of Sciences Beijing China 《Communications in Nonlinear Science & Numerical Simulation》2001,6(2)
Introduction' There have recently appeared in the literature several mathematical models of stagestructured population growth, i. e., models which take into account the faCt that individuals in a population may belong to one of two classes, the immatures and the matureslllZI.Cannibalism has been observed in a great variety of species, including a number of fish species.Cannibalism models of various types have also been investigatedI3"l. In these models, the ageto maturity is represented by a… 相似文献
993.
A differential privacy algorithm DiffPRFs based on random forests was proposed.Exponential mechanism was used to select split point and split attribute in each decision tree building process,and noise was added according to Laplace mechanism.Differential privacy protection requirement was satisfied through overall process.Compared to existed algorithms,the proposed method does not require pre-discretization of continuous attributes which significantly reduces the performance cost of preprocessing in large multi-dimensional dataset.Classification is achieved conveniently and efficiently while maintains the high accuracy.Experimental results demonstrate the effectiveness and superiority of the algorithm compared to other classification algorithms. 相似文献
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本文利用Lovasz局部引理的Spencer形式和对称形式给出r-一致超图Ramsey函数的渐近下界.证明了:对于任意取定的正整数f0,使得当n→∞时,有R~((r))(m~l,n~(k-l))≥(c-o(1))(n~(r-1)/logn)~■.特别地,R~((r))_k(n)≥(1-o(1))n/e k~■(n→∞).对于任意取定的正整数s≥r+1和常数δ>0,α≥0,如果F表示阶为s的r-一致超图,■表示阶为t的r-一致超图,且■的边数满足m(■)≥(δ-o(1))t~r/(logt)α(t→∞),则存在c=c(s,δ,α)>0,使得R~((r))(F,■)≥(c-o(1))(t~(r-1)/(logt)~l+(r-l)α)~(m(F)-l/s-r). 相似文献
1000.
Ultrasonic guided wave becomes one of promising tool for monitoring various types of structures such as large steel plates, vessels, and pipes in oil, chemical or nuclear industry, because guided waves have ability to travel wide range of the target structure in a single position. However, analysis of guided wave signals acquired from structure is difficult on account of low S/N ratio and its dispersive nature. To improve S/N ratio and overcome dispersion effect, focusing techniques for guided waves are needed. Thus, in this study, focusing techniques for guided waves were developed in order to improve long range inspection ability, and performance of the developed techniques was verified by experiments. 相似文献