共查询到20条相似文献,搜索用时 250 毫秒
1.
张隆辉 《数学的实践与认识》2013,43(6)
证明了一类n阶(n=P_1P_2…p_m,p_i(i=1,2,…,m)互异为素数)环是有限循环环,并讨论了他们的结构及相关性质,最后给出了这类n阶环有零因子或有子域的充要条件.主要结果:P_1P_2…P_m阶环共有2m个,它们是(p_(1m个,它们是(p_(1k_1) p_(2k_1) p_(2k_2)…p_(mk_2)…p_(mk_m)Z)/(p_(1k_m)Z)/(p_(1k_1+1)p_(2k_1+1)p_(2k_2+1)…p_(mk_2+1)…p_(mk_m+1)Z),其中k_i=0或1,1≤i≤m;阶是n=P_1P_2…p_m的环R可唯一分解为m个素数阶理想的直和,即R=〈α〉=(?);含pi(1≤i≤m)阶子域的P_1P_2…P_m阶环共有2k_m+1)Z),其中k_i=0或1,1≤i≤m;阶是n=P_1P_2…p_m的环R可唯一分解为m个素数阶理想的直和,即R=〈α〉=(?);含pi(1≤i≤m)阶子域的P_1P_2…P_m阶环共有2(m-1)个,它们是p_(1(m-1)个,它们是p_(1k_1) p_(2k_1) p_(2k_2)…p_(mk_2)…p_(mk_m)Z)/(p_(1k_m)Z)/(p_(1k_1+1)p_(2k_1+1)p_(2k_2+1)…p_(mk_2+1)…p_(mk_m+1)Z),其.中k_i=0,k_j=0或1,1≤j≤m,j≠i. 相似文献
2.
THEDISCRETEDYNAMICSFORCOMPETITIVEPOPULATIONSOFLOTKA-VOLTERRATYPELIULAIFUANDGONGBINAbstract:Thediscretedynamicsforcompetitionp... 相似文献
3.
On the analysis of a simple evolutionary algorithm on quadratic pseudo-boolean functions 总被引:2,自引:0,他引:2
Evolutionary algorithms are randomized search heuristics, which are often used as function optimizers. In this paper the well-known (1+1) Evolutionary Algorithm ((1+1) EA) and its multistart variants are studied. Several results on the expected runtime of the (1+1) EA on linear or unimodal functions have already been presented by other authors. This paper is focused on quadratic pseudo-boolean functions, i.e., polynomials of degree 2, a class of functions containing NP-hard optimization problems. Subclasses of the class of all quadratic functions are identified where the (1+1) EA is efficient, for other subclasses the (1+1) EA has exponential expected runtime, but a large enough success probability within polynomial time such that a multistart variant of the (1+1) EA is efficient. Finally, a particular quadratic function is identified where the EA and its multistart variants fail in polynomial time with overwhelming probability. 相似文献
4.
关于正定厄米特矩阵的一个不等式的推广 总被引:2,自引:0,他引:2
本文推广了正定厄米特矩阵的一个不等式 ,得到以下结果 :设 A( i) ,B( i) ,… ,C( i) ( i=1 ,2 ,… ,m)都是 n阶正定厄米特矩阵 ,A( i)11,B( i)11,… ,C( i)11为其相应矩阵的 k阶顺序主子阵 ,1≤ k≤ n-1 ,α,β,… ,γ都是正实数 ,且 α+β+… +γ=p≥ 1 ,则有∑mi=1|A( i) |α|A( i)11|α,|B( i) |β|B( i)11|β… |C( i) |γ|C( i)11|γ) <∑mi=1A( i) α∑mi=1A( i)11α.∑mi=1B( i) β∑mi=1B( i)11β…∑mi=1C( i) γ∑mi=1C( i)11γ 相似文献
5.
Spatial autoregressive and moving average Hilbertian processes 总被引:1,自引:0,他引:1
M.D. Ruiz-Medina 《Journal of multivariate analysis》2011,102(2):292-305
This paper addresses the introduction and study of structural properties of Hilbert-valued spatial autoregressive processes (SARH(1) processes), and Hilbert-valued spatial moving average processes (SMAH(1) processes), with innovations given by two-parameter (spatial) matingale differences. For inference purposes, the conditions under which the tensorial product of standard autoregressive Hilbertian (ARH(1)) processes (respectively, of standard moving average Hilbertian (MAH(1)) processes) is a standard SARH(1) process (respectively, it is a standard SMAH(1) process) are studied. Examples related to the spatial functional observation of two-parameter Markov and diffusion processes are provided. Some open research lines are described in relation to the formulation of SARMAH processes, as well as General Spatial Linear Processes in Functional Spaces. 相似文献
6.
针对在现实生活中, 经典GM(1,1)模型预测精度不稳定, 且以往的优化方法大部分具有片面性的缺点, 文章对经典GM(1,1)模型背景值与初始值进行改进, 提出了一种组合优化方法:根据动态寻优原则, 将背景值设为变量, 其参数以及时间响应式由MRE取最小值时确定;同时, 采用差分方程取代以x(1)(1)为固定点的静态方程。将初始值和背景值看作变量, 以系统地减少模型误差。结合国内石油年消费量数据, 分别应用经典和改进后的GM(1,1)模型进行计算和误差对比, 验证了改进后的模型精度要显著优于经典模型。 相似文献
7.
8.
<正> 在文章[2],[3],[4],[5]中已对任何N>n>1及0≤δ≤1/2(以下总假设上列不等式满足)研究了最优分批问题的满足[2]中定理5.1的条件组 相似文献
9.
Evolutionary algorithms are applied as problem-independent optimization algorithms. They are quite efficient in many situations. However, it is difficult to analyze even the behavior of simple variants of evolutionary algorithms like the (1+1) EA on rather simple functions. Nevertheless, only the analysis of the expected run time and the success probability within a given number of steps can guide the choice of the free parameters of the algorithms. Here static (1+1) EAs with a fixed mutation probability are compared with dynamic (1+1) EAs with a simple schedule for the variation of the mutation probability. The dynamic variant is first analyzed for functions typically chosen as example-functions for evolutionary algorithms. Afterwards, it is shown that it can be essential to choose the suitable variant of the (1+1) EA. More precisely, functions are presented where each static (1+1) EA has exponential expected run time while the dynamic variant has polynomial expected run time. For other functions it is shown that the dynamic (1+1) EA has exponential expected run time while a static (1+1) EA with a good choice of the mutation probability has polynomial run time with overwhelming probability. 相似文献
10.
11.
王婧敏 《数学的实践与认识》2010,40(23)
讨论了θ-型Calderón-Zygmund算子T与b=(b_1,b_2,…,b_m)(b_j∈Osc_(exp L~Tj),1≤j≤m)生成的多线性交换子(?)的加权估计.当0
相似文献
12.
<正> §1.引言 采用Kendall的記号,所謂GI/E_k/1是指由下述条件規定的一个排队过程: (i)若用t_n表第n个顾客来到服务系统的时刻,而用ui=ti-t_(i-1)山表示相紕两顾客到达时刻間的間隔(簡称到达間隔),則这些u互相独立,并且服从同一分布 相似文献
13.
对于正整数n=a10~kn+…a,称a,a是n的位数码,记s(n)=a+ +a_0,sm(n)=(a)m+ +(a_0)~m,称1~m2~m3~m4~m5~m6~m7~m8~m9~m1~m0~m1~m1~m1~m2~m1~m3~m1~m4~m是m阶位数码列,定义函数fm(x)=1~m+2~mx~1+ +9~mx~8+1~mx~9+0x~10+1~mx~11+1~mx12+…. 相似文献
14.
本文讨论了将分式环S-1R上的模归约到R上的模时包(hull)、类(class)、界(bound)、秩(rank)的保持性,证明了:1)NR是A在MR中的包当且仅当NS-1R是A在MS-1R中的包;2)还讨论了分式模(S-1M)S-1R与MR之间上述性质存在单向或双向保持性的条件. 相似文献
15.
研究了通过矩阵A的顺序主子矩阵A_((k))=(aij)_(i,j=1)(n-k+1)的特征值{λ_i(n-k+1)的特征值{λ_i((k)))}_(i=1)((k)))}_(i=1)(n-k+1)k=1,2,…,r+1来构造一个带比例关系的实带状矩阵的特征值反问题.对当特征值{λ_i(n-k+1)k=1,2,…,r+1来构造一个带比例关系的实带状矩阵的特征值反问题.对当特征值{λ_i((k))}_(i=1)((k))}_(i=1)(n-k+1)中有多重特征值出现时,应当如何来构造这类矩阵进行了讨论,并给出了问题的具体算法及数值例子. 相似文献
16.
本文讨论了关于以下内积的正交多项式 :〈p(x) ,r(x)〉( u0 ,u(α,β) ) =∑∞k=0p(qk) r(qk) (qk-c) ak(b) k(q) k +λ∑∞k=0(Dqp) (qk) (Dqr) (qk) (aq) k(bq) k(q) k给出了它的一些代数性质以及和小 q-Jacobi多项式的关系 ,得到了在 C\([0 ,1 ]∪ H )的紧子集上Qn(x)P(α- 1,β- 1)n (x) n和 Pn(x)P(α- 1,β- 1)n (x) n的相对渐近性质 .其中 Qn(x)是 n次的小 q -Jacobi-Sobolev正交多项式 ,P(α- 1,β- 1)n (x)和 Pn(x)分别是关于线性泛函 u(α- 1,β- 1)和 u0 的首一的 n次正交多项式 . 相似文献
17.
研究三维微分系统:u′1=a1(t)|u2|λ1sgn u2,u′2=a2(t)|u3|λ2sgn u3,u′3=-a3(t)|u1|λ3sgn u1.假设λi(i=1,2,3)是正的常数,ai(t)(i=1,2,3)在区间[0,∞)上是正的连续函数,根据u的分量ui的特殊渐近条件定义了正值解的几种类型。系统满足条件∫0∞ai(t)dt=∞,i=1,2. 相似文献
18.
Teoman Özer 《Chaos, solitons, and fractals》2009,39(3):1371-1385
New exact soliton solutions to the Cologero–Degasperies–Fokas (CDF) equations in (1+1)-dimension and (2+1)-dimension by using the improved tanh method are investigated. First, the (1+1)-dimensional CDF equation is analyzed. By the improved tanh method, the corresponding nonlinear partial differential equation is reduced to the nonlinear ordinary differential equations and then the different types of exact solutions to the original equation are obtained based on the solutions of the Riccati equation. For the case of (2+1)-dimensional CDF equation the same computation procedure is carried out. It is presented that one could obtain new exact explicit solutions, which are traveling wave solutions, to (2+1)-dimensional CDF equation. Additionally, some graphical representations of the solitary and periodic solutions are presented. 相似文献
19.
讨论二阶四点微分方程组边值问题u″+p(t)f(t,u(t),v(t))=0,0 t 1,v″+q(t)g(t,u(t),v(t))=0,0 t 1,u(0)=a1x(ξ1),u(1)=b1x(η1)v(0)=a2x(ξ2),v(1)=b2x(η2)如果函数f,g:[0,1]×[0,∞)×[0,∞)→[0,∞)是连续的,并赋予f、g一定的增长条件,利用Leggett-Williama不动点定理,证明了上述边值问题至少存在三对正解. 相似文献