关于平方三角数及相关定理的证明

研究的对象为既是三角数，又是平方数的“三角平方数”．利用Ferma的无穷下降法证明了平方三角数定理，从而说明了平方三角数存在无穷多个这一事实，并且给出了平方三角数的表示方法．     

Exponential estimates for stochastic delay equations with norm-bounded uncertainties

This paper presents the sufficient conditions for the exponential stability of linear or semilinear stochastic delay equations with time-varying norm bounded parameter uncertainties. Exponential estimates for the solutions are also obtained by using a modified Lyapunov-Krasovski functional. These conditions can be tested numerically using interior point algorithms. This work is Supported by the National Natural Science Foundation of China under Grant Nos. 10801056 and 10826095.     

延迟期权在大型基建项目风险决策中的应用

不确定性条件下,净现值法（NPV）在对基建设施项目进行价值评估时忽略了项目管理柔性特征.本文基于实物期权理论分析基建设施项目的特点,指出分阶段投资的基建设施项目中存在的延迟期权,并运用二叉树期权定价模型对其进行评价.文章通过案例分析对基建设施项目进行价值评估,对影响延迟期权的各种因素进行敏感性分析,说明运用实物期权方法进行投资决策的优越性.     

对毫秒延期电雷管延期元件秒量精度影响因素的研究

作为起爆器材的毫秒延期电雷管，其秒量精度的问题一直是爆破工程界关注的焦点问题，而毫秒延期电雷管的秒量精度主要取决于延期元件。通过对延期元件加工工艺及贮存过程中，秒量精度影响因素的分析和研究，找出了提高该延期元件秒量精度的工艺技术途径，为更好地生产该产品奠定基础。     

GOP-Level Bit Allocation Using Reverse Dynamic Programming

An efficient adaptive group of pictures(GOP)-Ievel bit allocation algorithm was developed based on reverse dynamic programming(RDP).The algorithm gives the initial delay and sequence distortion curve with just one iteration of the algorithm.A simple GOP-level rate and distortion model was then developed for two-level constant quality rate control.The initial delay values and the corresponding optimal GOP-level bit allocation scheme can be obtained for video streaming along with the proper initial delay f...     

无穷格子系统的新型周期行波解

研究了无穷格子系统q（n）＋f＇（g（n））=V^t（g（n＋1）-g（n））-V^t（g（n）-g（n-1）），n∈Z周期行波解的存在性．其中：q（n）=q（n，t）是第n个质点在t时刻的坐标；f表示质点的位势函数；V表示相邻2个质点间的相互作用函数．应用山路定理和环绕定理，获得了该系统新型周期行波解的存在性定理．     

基于锚点拟合的宽带短波信道修正ITS模型

构建仿真系统时,仿真模型直接关系到仿真系统能否实现。针对宽带短波信道ITS模型存在的功率延迟剖面函数不能拟合各种信道条件且计算量较大的问题,提出了修正参考模型,并证明了其有效性与正确性。首先定义锚点,将模型中功率剖面延迟函数的锚点与特定分布中的锚点锁定,再利用拟合的方法根据特定分布确定延迟剖面上的其它点。仿真结果表明:锚点拟合法缩短了信道模型参量的求解时间,且理论上能够拟合短波信道各种延迟分布,验证了修正模型的正确性。修正后的模型通过锁定关键的锚点能灵活拟合真实信道且计算量较小,能够有效地应用于宽带短波信道模拟系统中。     

二阶非线性时滞微分方程边值问题正解的存在性

给出非线性二阶时滞微分方程边值问题存在正解的一些条件,并利用锥上的Guo-Krasonselskii不动点定理证明这些条件是成立的.     

Role of different system delays on ecological food chain dynamics: Mathematical modelling and analysis

<正> This paper studies a three tier ecological food chain model consisting of nutrient,autotroph,and herbivore populations.Regeneration of nutrient from dead autotroph and herbivore biomass bydecomposers present in the soil is included.The time required for maturation of the herbivore populationis incorporated as a distributed time delay.Next,the authors introduce the time lag requiredfor regeneration of nutrient from the dead herbivore as a discrete time delay.Stability and bifurcationbehavior of the one-and two-delay models are carried out and a comparative study of the significanceof these delays in controlling the system dynamics is performed.Numerical simulations are done tojustify analytical results.