Some aspects of polaritons and plasmons in materials

We have studied the interaction of optical phonons with photons. So, we have calculated the coupled modes of photons and transverse optical phonons and likewise, the dielectric function. We have found an alternative relation of the splitting between the frequencies of the longitudinal optical (LO) and transverse optical (TO) phonons in crystals. Likewise, we have studied the plasmon resonance frequency. We have determined the phonon–photon and the plasmon–photon coupling constant in ionic crystals and in metals, respectively, which is very close to the elastic force constant, and we have evaluated the bulk modulus. Further we have applied these results to tetrahedrally bonded III–V semiconductors.     

Eigenvalue approach to study the effect of rotation and relaxation time in generalized magneto-thermo-viscoelastic medium in one dimension

The fundamental equations of the problems of generalized thermoelasticity with one relaxation parameter including heat sources in infinite rotating magneto-thermo-viscoelastic media have been derived in the form of a vector matrix differential equation in the Laplace transform domain for a one dimensional problem. These equations have been solved by the eigenvalue approach to determine deformations, stress, and temperature. The results have been compared to those available in the existing literature. The graphs have been drawn to show the effect of rotation in the medium.     

An algebraic theory of strong power in negatively connected exchange networks

Various extensions of the model are proposed to deal with a wider variety of conditions than are normally examined in experiments on exchange networks. With little or no modification, the model can predict power when exchange relations are unequal in value, when positions vary in the number of exchanges in which they can participate, and when three or more participants are required for a transaction to occur.

A structural and algebraic theory of power in negatively connected exchange networks can be deduced from a few simple and plausible assumptions about how individuals make decisions. The model generates a set of equations. A typology of exchange networks follows from characteristics of the solution to these equations. There are four possibilities: the equations have a unique solution in which some positions have all the power; the equations have a unique solution in which all positions have equal power; the equations have an infinity of solutions, in which case power is undetermined by structural considerations; the equations have no solution, in which case power should be unstable.     

A computational study on different penalty approaches for solving constrained global optimization problems with the electromagnetism-like method

In this article, the application of the electromagnetism-like method (EM) for solving constrained optimization problems is investigated. A number of penalty functions have been tested with EM in this investigation, and their merits and demerits have been discussed. We have also provided motivations for such an investigation. Finally, we have compared EM with two recent global optimization algorithms from the literature. We have shown that EM is a suitable alternative to these methods and that it has a role to play in solving constrained global optimization problems.     

热弹性理论准静态问题解的一般公式及其应用

本文利用分解定理［１］求得热弹性理论的准静态问题在无限空间中的Ｇｒｅｅｎ函数组．从而，借助于文［２］中的互易定理建立了该问题解的一般公式．     

Analysis of the escape in systems with four exit channels

In this paper, we have performed a numerical investigation of the escape of a particle from two different dynamical systems with the same number of exit channels. We have chosen specific values of the parameters of the systems so that the openings of the potential well in both systems are approximately of the same size. We have found that, in the galactic system, the distribution of the times of escape follows a sequential pattern that has never been detected before. Moreover, we have proved that this pattern is directly related to the geometry of the stable manifolds to the Lyapunov orbits located at the openings of the potential. Finally, we have shown that the different nature of the two systems affects the way the escape occurs, due to the difference in the geometry of the manifolds to the Lyapunov orbits in both systems.     

CEO早年经历与企业诉讼风险——基于上市公司的实证研究

本文基于高层梯队理论,选取中国A股上市公司作为样本,以实证分析的方式探究了CEO个人能否有效降低上市公司面临的诉讼风险。我们发现,婴儿-幼儿期、童年-青少年期经历过困难时期的CEO所在的上市公司的诉讼风险水平更低,且童年-青少年期经历困难时期的影响更为明显。利用CEO在不同省份经历困难时期的严重程度差异构造双重差分模型、将被解释变量前置一期控制潜在的内生性之后,因果关系仍保持稳健。进一步研究表明,经历过困难时期的CEO因为具有更高的风险厌恶程度而降低了企业运营中整体的风险水平,没有改变企业的内部控制水平。     

自然数幂和公式的另一种计算机实现方法

自然数幂和问题,许多文献给出不同算法,借助M ATLAB系统,利用自然数幂和的矩阵算法,给出可计算所有小于任意指定自然数m的自然数幂和公式的计算机实现方法.     

Using digital stories to reduce misconceptions and mistakes about fractions: an action study

The aim of this study is to determine the mistakes and misconceptions about fractions of the fourth-grade students in a primary school and to eliminate these mistakes and misconceptions through digital stories. The study has been conducted with a total of 25 students in the fourth-grade of a private primary school in Turkey. An action research method based on qualitative research approach has been used in the study. In the preparation of activities related to digital stories, the mistakes and misconceptions that students have regarding fractions are taken into account. As a data collection tool, the Determination of Misconceptions Form consisting of 30 open ended questions about the fractions prepared by the researchers and the observation notes taken during the implementation process have been used. In addition, semi-structured interviews have been conducted to identify views of teachers and students about activities designed with digital stories. The implementation has been carried out for 5 weeks. Qualitative data analysis techniques have been used in analysing the data. As a result of the research, it has emerged that teaching implementations designed with digital stories have eliminated the mistakes and misconceptions that a large majority of students have about fractions. Most of the students who had a limited perception about the concept of fraction before implementation have fully perceived the definition of fractions after the activities designed with digital stories. Likewise, most of the students who incorrectly modelled the operations with fractions before the implementation, have been able to use the correct model for the operations with fractions after the-implementation fractions. When opinions about the activities designed with digital stories have been examined, it has been found that most students’ express positive opinions on digital story use in lessons and found digital stories fun, instructive and constructive.     

A multiple times scale solution for non-linear vibration of mass grounded system

In this paper, the vibration of a mass grounded system which includes two linear and non-linear springs in series has been considered. Since this system, depending on its parameters can oscillate symmetrically and asymmetrically, both cases have been solved using multiple times scales (MTS) method and some analytical relations have been obtained for natural frequency of oscillations. The results have been compared with previous work and good agreement has been obtained. Also forced vibrations of system in primary and secondary resonances have been studied for the first time and the effects of different parameters on the frequency-response have been investigated.     

Numerical analysis for bulk-arrival queueing systems: Root-finding and steady-state probabilities inGI r /M/1 queues

Queueing theorists have presented, as solutions to many queueing models, probability generating functions in which state probabilities are expressed as functions of the roots of characteristic equations, evaluation of the roots in particular cases being left to the reader. Many users have complained that such solutions are inadequate. Some queueing theorists, in particular Neuts [6], rather than use Rouché's theorem to count roots and an equation-solver to find them, have developed new algorithms to solve queueing problems numerically, without explicit calculation of roots. Powell [7] has shown that in many bulk service queues arising in transportation models, characteristic equations can be solved and state probabilities can be found without serious difficulty, even when the number of roots to be found is large. We have slightly modified Powell's method, and have extended his work to cover a number of bulk-service queues discussed by Chaudhry et al. [1] and a number of bulk-arrival queues discussed in the present paper.     

Home Care optimization: impact of pattern generation policies on scheduling and routing decisions

In Home Care optimization, operators have to be assigned to patients by taking into account compatibility skill constraints, and patient visits have to be scheduled in a given planning horizon. Moreover, operator tours have to be determined. Integer Linear Programming models have been proposed which use the concept of patterns, i.e. a priori scheduling profiles, to combine the diverse decision levels. Computational results on real instances show that pattern generation policies are crucial to address scheduling and routing in large Home Care instances.     

On the finiteness property for rational matrices

We analyze the periodicity of optimal long products of matrices. A set of matrices is said to have the finiteness property if the maximal rate of growth of long products of matrices taken from the set can be obtained by a periodic product. It was conjectured a decade ago that all finite sets of real matrices have the finiteness property. This “finiteness conjecture” is now known to be false but no explicit counterexample is available and in particular it is unclear if a counterexample is possible whose matrices have rational or binary entries. In this paper, we prove that all finite sets of nonnegative rational matrices have the finiteness property if and only if pairs of binary matrices do and we state a similar result when negative entries are allowed. We also show that all pairs of 2×2 binary matrices have the finiteness property. These results have direct implications for the stability problem for sets of matrices. Stability is algorithmically decidable for sets of matrices that have the finiteness property and so it follows from our results that if all pairs of binary matrices have the finiteness property then stability is decidable for nonnegative rational matrices. This would be in sharp contrast with the fact that the related problem of boundedness is known to be undecidable for sets of nonnegative rational matrices.     

Dissipative Nonlinear Evolution Equations and Chaos

In this article we have studied the nonlinear interaction between ellipticity and dissipation in a set of model equations (1.1) and established the relation between this interaction and chaos. In addition to theoretical investigations, extensive numerical simulations with these equations have been made, and different routes to chaos have been found. The numerical studies have revealed the chaotic nature of the solutions.     

Analyzing on stability of HIV-PI model with general incidence rate

In this article, we have constructed a PI model with general incidence rate and humoral immunity. We have analyzed about the equilibrium points in general case. Using appropriate Lyapunov functional and Lasalle’s invariance principle, the global stability of the newly constructed model have been discussed. Using patient data we have discussed about the model numerically.     

模糊共生结构的加细及其性质

介绍模糊拓扑,模糊邻近,模糊拟一致框架下的模糊(半)拓扑序、模糊共生结构的概念,研究模糊(半)拓扑序,模糊共生结构的加细,得到一些重要性质。     

明渠中变密度变粘度牛顿流体紊动基本方程式

本文利用Navier－Stokes方程及雷诺时均法则,导出了变密度变粘度牛顿流体的紊动微分方程式,并进一步导出了变密度变粘度牛顿流体在明渠中紊流流动时的运动微分方程式.文中首次提出了密度紊动应力与粘度紊动应力的概念.     

新形势下高等数学分级教学模式的探索

突破以前按照不同专业分层次教学的模式,根据学生不同的学习目的,采用一种新的分级教学模式,针对相同专业学生不同的学习要求,给予不同层次的培养.通过对教育观念的新认识和培养目标的再确定,在高等数学的课程体系,课程内容,教学方法,教学手段等方面进行改革和调整,因材施教,使各层次的学生真正受益,提高整体教学质量,也使基础课教育更有针对性.     

一类由一维概率密度函数构造多维概率密度函数的方法

将文献[1]给出的由一维连续型随机变量的概率密度函数构造二维连续型随机变量的概率密度函数的方法,推广为由一维连续型随机变量的概率密度函数构造三维连续型随机变量的概率密度函数的情况,并作出了证明和举例说明.说明利用本文的方法构造多维概率密度函数,其方法简单易行.     

具弱色散误差的单调差分格式

本文基于[1]、[2]的理论分析,分别给出了计算(一维、二维)非线性双曲方程组的两类具弱色散误差的单调格式。§2针对一维气动力学方程组,通过数值结果。就激波的逼近问题,与已有的格式进行了比较。