Optimal Control for Age Distribution and Weighted Size Competitive Species in a Polluted Environment

In the paper,we study an optimal control for a system representing a competitive species model with fertility and mortality depending on a weighted size in a polluted environment.A fixed point theorem is applied to obtain the existence and uniqueness exhibited by a non-negative solution of above mentioned model.A maximum principle helps to carefully verify the existence of the optimal control policy,and tangent-normal cone techniques help to obtain the optimal condition specific to control issue.

右π—逆半群的最小群同余

本文具体给出了右逆半群的最小群同余的最简表达形式.

颗粒群组方法中关键参数的选取

为了深入了解颗粒群组方法的特点,提出了修正最大群组数方法,研究了颗粒群组方法中的两个关键参数(体积增量和最大群组数)对数量密度和体积分数的影响.结果表明:传统最大群组数在计算颗粒数量密度时比较准确,修正最大群组数在计算颗粒体积分数时比较准确.随着颗粒体积增量的增加,传统最大群组数得到的颗粒数量密度的预测值降低,而颗粒体积分数的预测值增加.随着颗粒体积增量的增加,修正最大群组数得到的颗粒数量密度的预测值下降,而颗粒体积分数的预测值呈振荡趋势.

域D＝｛z＝（z_1，z_2）∈C^2：｜z_1｜＋｜z_2｜＜1｝的解析自同

给出了域Ｄ＝｛ｚ＝（ｚ＿１，ｚ＿２）∈Ｃ＿２：｜ｚ＿１｜＋｜ｚ＿２｜＜１｝上的Ｂｅｒｇｍａｎ核函数及其解析自同构最大群。

GV－逆半群的局部化及应用

证明了ＧＶ－逆半群Ｓ在其正则元集合ＫｅｇＳ所生成的子半群（ＲｅｇＳ）上的局部化在同构意义下存在唯一，且为其最大群同态象。由此又可得到Ｓ的最小群同余．

Ad Hoc网络中最大最小公平性算法的改进

Ad Hoc网络的信道资源非常有限,且相邻节点之间竞争网络资源,公平有效的分配带宽成为Ad Hoc网络的重要研究方向。本文在已有的最大最小公平算法基础上,采用加权的最大群算法,并利用节点的代价值作为权值进行调节,保证了带宽的公平分配,而且有效的提高了网络资源的利用率。

E-稠密半群的局部化

半群S称为E-反演半群,如果对于S中的每一个元素a,存在x∈S,使得ax是S的幂等元。半群S称为E-稠密半群,如果S是E-反演半群并且幂等元相乘可交换。研究了E-稠密半群的局部化,证明了E-稠密半群在其幂等元半格上的局部化存在并且在同构意义下唯一。作为局部化的应用,证明了局部化同构于其最大群同态象,这推广了强π-逆半群和逆半群的相应结论。

E-稠密半群上的最小群同余

半群S称为E-反演半群,如果对于S中的每一个元素a,存在x∈S,使得ax是S的幂等元。半群S称为E-稠密半群,如果S是E-反演半群并且幂等元相乘可交换。利用E-稠密半群局部化的结论,给出了E-稠密半群上的最小群同余的一个表示及若干等价刻画。在对强π-逆半群和逆半群上一些结果进行推广的同时,也获得了强π-逆半群和逆半群上最小群同余的一些新的结论。

Lower bound estimation of the maximum allowable initial error and its numerical calculation

In the numerical prediction of weather or climate events,the uncertainty of the initial values and/or prediction models can bring the forecast result’s uncertainty.Due to the absence of true states,studies on this problem mainly focus on the three subproblems of predictability,i.e.,the lower bound of the maximum predictable time,the upper bound of the prediction error,and the lower bound of the maximum allowable initial error.Aimed at the problem of the lower bound estimation of the maximum allowable initial error,this study first illustrates the shortcoming of the existing estimation,and then presents a new estimation based on the initial observation precision and proves it theoretically.Furthermore,the new lower bound estimations of both the two-dimensional ikeda model and lorenz96 model are obtained by using the cnop(conditional nonlinear optimal perturbation)method and a pso(particle swarm optimization)algorithm,and the estimated precisions are also analyzed.Besides,the estimations yielded by the existing and new formulas are compared;the results show that the estimations produced by the existing formula are often incorrect.

Effects of Channelization on Fish Biomass in River Ecosystems

Channel straightening in a naturally meandering river is a common historical trigger of channel incision which typically results in stream bank destabilization. Several of the larger river systems in the upland portion of the Yazoo River Basin have subjected channelization resulting in profound changes in the physical and geomorphological characteristics of these systems. Fish were sampled using electroshocking gear and hoop nets to evaluate the impact of stream bank destabilization and loss of habitat heterogeneity resulting from channelization on fish communities. While distinct differences in the fish communities were evident, only the Skuna appeared to have characteristics of a damaged system. More than 95% of the biomass was comprised of species reaching an adult length of less than 300 mm. The lotic omnivorous fishes that dominated the biomass from Skuna are often associated with smaller streams rather than rivers. Furthermore, 72% of the catch consisted of fish preferring littoral zone habitats. The shallow depth and lack of woody debris in Skuna provided a selective advantage for smaller species of fish that could use shoreline habitats as protection from the current. Based on results from the Skuna River, channel straightening that leads to channel incision, bank failure and over widening provide habitats too shallow to support a community of fishes typical of northern Mississippi riverine system. This information may be useful in making comparison of damaged riverine ecosystems and assist managers in determining impairment and success in the TMDL （Total Maximum Daily Load） process.

Simulating Particle Swarm Optimization Algorithm to Estimate Likelihood Function of ARMA（1, 1） Model

This paper present a simulation study of an evolutionary algorithms, Particle Swarm Optimization PSO algorithm to optimize likelihood function of ARMA（1, 1） model, where maximizing likelihood function is equivalent to maximizing its logarithm, so the objective function ＇obj.fun＇ is maximizing log-likelihood function. Monte Carlo method adapted for implementing and designing the experiments of this simulation. This study including a comparison among three versions of PSO algorithm “Constriction coefficient CCPSO, Inertia weight IWPSO, and Fully Informed FIPSO”, the experiments designed by setting different values of model parameters al, bs sample size n, moreover the parameters of PSO algorithms. MSE used as test statistic to measure the efficiency PSO to estimate model. The results show the ability of PSO to estimate ARMA＇ s parameters, and the minimum values of MSE getting for COPSO.

Graphs of nonsolvable groups with four degree-vertices

Let G be a finite group. The degree(vertex) graph Γ(G) attached to G is a character degree graph.Its vertices are the degrees of the nonlinear irreducible complex characters of G, and different vertices m, n are adjacent if the greatest common divisor(m, n) > 1. In this paper, we classify all graphs with four vertices that occur as Γ(G) for nonsolvable groups G.

Consensus of Flocks under M-Nearest-Neighbor Rules

This paper investigates a class of flocks with an M-nearest-neighbor rule,where each agent's neighbors are determined according to M nearest agents with M being a given integer,rather than all the agents within a fixed metric distance as in the well-known Vicsek's model.Such a neighbor rule has been validated by biologists through experiments and the authors will prove that,similar to the Vicsek's model,such a new neighbor rule can also achieve consensus under some conditions imposed only on the system's speed and the number M,n,without resorting to any priori connectivity assumptions on the trajectory of the system.In particular,the authors will prove that if the number M is proportional to the population size n,then for any speed v,the system will achieve consensus with large probability if the population size is large enough.

The Riemannian Manifolds with Boundary and Large Symmetry

Seventy years ago, Myers and Steenrod showed that the isometry group of a Riemannian manifold without boundary has a structure of Lie group. In 2007, Bagaev and Zhukova proved the same result for a Riemannian orbifold. In this paper, the authors first show that the isometry group of a Riemannian manifold M with boundary has dimension at most 1/2 dim M（dim M - 1）. Then such Riemannian manifolds with boundary that their isometry groups attain the preceding maximal dimension are completely classified.

OPTIMAL BIRTH CONTROL FOR AN AGE-DEPENDENT COMPETITION SYSTEM OF N SPECIES

In this paper, we investigate optimal policies for an age-dependent n-dimensional competition system, which is controlled by fertility. By using Dubovitskii-Milyutin＇s general theory, the maximum principles are obtained for the problems with free terminal states, infinite horizon, and target sets, respectively.

STABILIZATION OF UNITARY GROUPSOVER POLYNOMIAL RINGS

The author studies the stabilization for the unitary groups over polynomial rings and obtainsfor them some results analogous to the results of linear groups and symplectic groups.It isespecially proved that K1 U(A) = K1 U(R) where A = R[X1,…, Xm], R is a ring of algebraicintegers in a quadratic field Q().

FURTHER RESEARCH OF A NEW KIND OF SERIES REPAIRABLE SYSTEM

This paper is devoted to studying the uniqueness and existence of the system dynamic solution by using C0-semigroup theory and discussing its exponential stability by analyzing the spectrul distribution of system operator and its quasi-compactness. Some primary reliability indices are discussed with the eigenfunction of system operator and the optimal vacation time to get the maximum system profit is analyzed at the end of paper.