基于n次型正定性的多元函数极值判别法

针对多元函数稳定点处二阶偏导数全为0的情况,提出了有效的极值判别法.定义了广义n维方阵、n次型及其正定性;提出了更具普遍意义的极值充分条件;得到了利用n次型的正定性判断n元函数极值的方法并举例验证了结论的正确性和有效性.     

Smarandache函数在两数列上的下界估计

设S(n)是Smarandache函数,其中n是一正整数.讨论Smarandache函数S(n)在数列F((2k),1)=F(n,1)=n2n+1(n=2k)与数列G(2n,1)=(2n)2n+1上的下界估计.基于初等方法证明了:当偶数n≥6时,有S(F((2k),1))=S(F(n,1))≥6×2n+1;当n≥4时,有S(G(2n,1))≥6×2n+1.     

一个包含Z（n）和D（n）函数的方程及其它的正整数解

对于任意正整数n,著名的伪Smarandache函数Z（n）定义为最小的正整数m使得n｜m（m＋1）／2．而数论函数D（n）定义为最小的正整数m使得n｜d（1）d（2）d（3）…d（m）,其中d（n）为Dirichlet除数函数．本文的主要目的是利用初等方法研究一类包含伪Smarandache函数Z（n）和数论函数D（n）的方程2^z（n）=D（n）的可解性,并获得了该方程的所有正整数解．     

关于位数函数高次均值的计算

针对1993年美国数论专家Smarandache提出了初等数论及集合论中的105个未解决的问题中的5个关于自然数列的性质问题,就自然数列的位数函数问题进行了研究,给出了在一个正整数的n进制表示中的位数函数定义,采用了归纳、猜想的方法得出了位数函数a（m,n）的高次均值的精确计算公式.     

高阶可微函数Ostrowski型不等式

研究了一类n阶可微函数,利用其n阶导数上、下界以及Cruis不等式,给出了n阶可微函数Ostrowski型不等式,从而推广二阶可微函数Ostrowski型不等式.     

关于n进制及其有关计数函数

给出了n进制中数字之和函数均值A（N）的一个精确的计算公式。     

基于矩阵初等变换的n元函数极值的快速判别法

给出了 n元函数极值的一个充分条件 ,并结合矩阵的初等变换建立了 n元函数极值的一种快速判别法 ,最后给出了一个例子     

关于Smarandache函数S(n)与除数函数d(n)的混合均值

对于任意的正整数n,著名的Smarandache函数S(n)定义为最小的正整数m,使得n|m!,即就是S(n)=min{m:n|m!,m ∈N).本文的主要目的是应用初等方法研究S(n)与除数函数d(n)的加权均值问题,并获得一个有趣的渐进公式.     

有界正则函数的导数估计

在这篇文章中,主要讨论了n阶导数的估计式,即对有界正则函数φ（z)=c0 c1z … cnz^n …(在│z│1内正则）,从已知的三阶、四阶导数估计式,利用归纳法原理及有界正则函数的性质推出n阶导数的一般估计式,并推出在│z│＜1内正则的正实部函数的n阶导数的一般估计式。     

(n+1)重周期和准周期Riemann边值问题

该文首先考虑了Rⁿ⁺¹维欧氏空间中(n+1)重周期正则函数和(n+1)重准周期正则函数的一些性质, 然后分别讨论了n+1重周期和准周期Riemann边值问题, 分别给出了两种边值问题 解的显式表达式和可解条件.     

Min–Max vs. Min–Sum Vehicle Routing: A worst-case analysis

The classical objective function of the Vehicle Routing Problem (VRP) is to minimize the total distance traveled by all vehicles (Min–Sum). In several situations, such as disaster relief efforts, computer networks, and workload balance, the minimization of the longest route (Min–Max) is a better objective function. In this paper, we compare the optimal solution of several variants of the Min–Sum and the Min–Max VRP, from the worst-case point of view. Our aim is two-fold. First, we seek to motivate the design of heuristic, metaheuristic, and matheuristic algorithms for the Min–Max VRP, as even the optimal solution of the classical Min–Sum VRP can be very poor if used to solve the Min–Max VRP. Second, we aim to show that the Min–Max approach should be adopted only when it is well-justified, because the corresponding total distance can be very large with respect to the one obtained by optimally solving the classical Min–Sum VRP.     

Vectorization of set-valued maps with respect to total ordering cones and its applications to set-valued optimization problems

As a result of our previous studies on finding the minimal element of a set in n-dimensional Euclidean space with respect to a total ordering cone, we introduced a method which we call “The Successive Weighted Sum Method” (Küçük et al., 2011 [1], [2]). In this study, we compare the Weighted Sum Method to the Successive Weighted Sum Method. A vector-valued function is derived from the special type of set-valued function by using a total ordering cone, which is a process we called vectorization, and some properties of the given vector-valued function are presented. We also prove that this vector-valued function can be used instead of the set-valued map as an objective function of a set-valued optimization problem. Moreover, by giving two examples we show that there is no relationship between the continuity of set-valued map and the continuity of the vector-valued function derived from this set-valued map.     

关于KAPLAN-MEIER估计的二阶EDGEWORTH展开

定义F={t>0,F(t)=1},设t<τ     

PERIODIC SOLUTIONS OF LINEAR NEUTRAL INTEGRO-DIFFERENTIAL EQUATIONS

Consider the linear neutral FDEd/dt[x(t) Ax(t - r)] = R [dL(s)]x(t s) f(t)where x and / are ra-dimensional vectors; A is an n x n constant matrix and L(s) is an n x n matrix function with bounded total variation. Some necessary and sufficient conditions are given which guarantee the existence and uniqueness of periodic solutions to the above equation.     

具有拟周期系数的schrodinger方程的可约化与平衡点的线性稳定性

对Schrodinger方程(A):iut-uxx+c(t)u=0u(t,0)=u(t,2π)=0,u(t,x)=∑∞n=1qn(t)n(x)进行讨论.n(x)是特征方程y″+λy=0y(0)=y(2π)=0中特征值对应的特征函数,c(t)=a+εc1(t),其中a是常数,c1(t)是以ω为频率的拟周期函数.直接判断方程的稳定性十分困难,把方程中的c(t)约化为常数,然后利用约化后的结果来判断方程(A)的平衡点的线性稳定性,方法简单实用.     

半参数回归模型中二阶段估计的渐近性质

给定半参数回归模型Y＝X′β g(T) e,其中β∈R^p是未知参数向量,g(t)是定义在[0,1]上的未知函数,e是随机误差,本文研究了β,,g(t)和σ2的估计量βn,gn(t)和σn^2,在适当的条件下证明了它们的渐近正态性,并给出了gn(t)的最优收敛速度。     

Maximal inequalities for a continuous semimartingale

Let X =( X t ) t S 0 be a continuous semimartingale given by d X t = f ( t ) w ( X t )d d M ¢ t + f ( t ) σ ( X t )d M t , X 0 =0, where M =( M t , F t ) t S 0 is a continuous local martingale starting at zero with quadratic variation d M ¢ and f ( t ) is a positive, bounded continuous function on [0, X ), and w , σ both are continuous on R and σ ( x )>0 if x p 0. Denote X 𝜏 * =sup 0 h t h 𝜏 | X t | and J t = Z 0 t f ( s ) } ( X s )d d M ¢ s ( t S 0) for a nonnegative continuous function } . If w ( x ) h 0 ( x S 0) and K 1 | x | n σ 2 ( x ) h | w ( x )| h K 2 | x | n σ 2 ( x ) ( x ] R , n >0) with two fixed constants K 2 S K 1 >0, then under suitable conditions for } we show that the maximal inequalities c p , n log 1 n +1 (1+ J 𝜏 ) p h Á X 𝜏 * Á p h C p , n log 1 n +1 (1+ J 𝜏 ) p (0< p < n +1) hold for all stopping times 𝜏 .     

Best rational function approximation to Laplace transform inversion using a window function

The best rational function approximation for Laplace transform inversion due to Longman is modified by the introduction of an appropriate “window” function. This window function enables one to approximate the inverse transform f(t) by a linear combination g_n(t) of n exponential functions accurately in a given interval about a given point along the t-axis. It is proved that the sequence of approximants {g_n(t)}_{n = 1}^∞ converges to f(t) in the mean. The method is illustrated by some numerical examples.     

广义时滞Hopfield型神经网络系统的平稳周期振荡

本文利用重合度理论和 V-泛函研究了一类具有周期输入的广义时滞 Hopfield型连续神经网络系统的平稳周期振荡问题 ,得到了其周期解存在、唯一和全局吸引的充分条件 .     

一個多元函數的內插公式

本文介绍一个新型多元函数结构.它在一定条件下: 1)可根据一定的已知数值决定函数的其他近似值, 2)可作为构成经验公式的骨架.