搜索结果: 1-15 共查到“知识库 连续问题离散化方法”相关记录20条 . 查询时间(1.875 秒)
基于波束标记的M2M业务建模及性能优化
5G M2M 基于波束标记的不连续接收(M-DRX) 节能 时延
2022/3/23
采用离散元算法模拟了石英玻璃圆环受到外加动态载荷时的力学行为. 首先基于flat-jointed粘结模型,通过标准的单轴拉压、三点弯曲等数值实验来标定了石英玻璃的微观参数. 在此模型基础上,数值模拟再现了石英玻璃圆环在不同应变率下的膨胀碎裂过程. 为定量分析数值模拟结果,需要准确确定圆环的碎裂发生时刻. 模拟发现:伴随着石英玻璃圆环的断裂,圆环外表面粒子径向膨胀速度的时程曲线会发生突然升高然后下降...
水平井压裂技术已经成为开发低渗透油气藏、页岩气藏和致密气场等非常规油气藏的关键技术。基于离散裂缝模型,对裂缝进行简化,建立了二维多段压裂水平井有限导流数值试井模型,利用有限元方法求解模型,获得多段压裂水平井试井理论曲线和压力场特征。分析表明:多段压裂水平井的试井理论曲线一共分为七个阶段:井筒储存段、裂缝线性流段、裂缝-地层双线性流段、裂缝干扰段、地层线性流段、系统径向流段和边界作用段,其中裂缝-地...
离散达芬映射中由边界激变所诱发的复杂的张弛振荡
离散达芬系统 边界激变 张弛振荡 延迟倍周期分岔
2019/1/3
多时间尺度问题具有广泛的工程与科学研究背景,慢变参数则是多时间尺度问题的典型标志之一.然而现有文献所报道的慢变参数问题,其展现出的振荡形式及内部分岔结构,大多较为单一,此外少有文献涉及到混沌激变的现象.本文以含慢变周期激励的达芬映射为例,探讨了一类具有复杂分岔结构的张弛振荡.快子系统的分岔表现为S形不动点曲线,其上、下稳定支可经由倍周期分岔通向混沌.而在一定的参数条件下,存在着导致混沌吸引子突然消...
簇发振荡是多时间尺度系统复杂动力学行为的典型代表,簇发振荡的动力学机制与分类问题是簇发研究的重要问题之一,但当前学者们所揭示的簇发振荡的结构大多较为简单.研究以非自治离散Duffing系统为例,探讨具有复杂分岔结构的新型簇发振荡模式,并将其分为两大类,一类经由Fold分岔所诱发的对称式簇发,另一类经由延迟倍周期分岔所诱发的非对称式簇发.快子系统的分岔表现为典型的含有两个Fold分岔点的S形不动点曲...
对于具有复杂几何形态的多面体单元,线性接触模型不能准确地计算不同接触模式下的作用力,且接触变形和作用力方向也不易判断.基于闵可夫斯基和(Minkowski sum)方法的扩展多面体单元能够准确描述非规则颗粒单元的几何形态,并可精确计算单元间的接触碰撞作用.该方法具有接触判断简单、计算效率高的特点.它将基本多面体和扩展球体相叠加以形成具有光滑棱边和角点的扩展多面体单元.考虑扩展多面体单元相互作用过程...
利用离散控制理论, 针对结构动力学方程时间积分提出了一种新的无条件稳定的显式算法. 新算法采用CR 算法的速度和位移递推格式, 同时利用Z变换获得算法对应的传递函数, 进而根据极点条件推导了递推格式系数的具体表达式. 然后, 在其系数中引入了一个控制周期延长率的变量s, 从而调节新算法的精度. 理论分析表明无条件稳定显式新算法具有二阶精度、零振幅衰减率、无超调和自起步特性, 且周期延长率可以用变量...
该文提出一种基于概率接触算法,并嵌入到球形颗粒离散元程序中,在保持原有颗粒接触检索效率的基础上,实现了非球形颗粒模拟。以椭球颗粒为例给出了算法推导过程,进行了球形西米、椭球形绿豆和长米的料仓卸料过程模拟,对颗粒体系的流态和流量进行了研究,并开展了相应的试验加以验证。结果表明:基于概率接触算法的非球形颗粒离散元法适用于在椭球颗粒流动特性方面的研究,可以较精确的模拟卸料过程,且计算效率较高。
On the continuity and regularity of convex extensions
continuity regularity of convex extensions
2011/2/28
We study continuity and regularity of convex extensions of functions from a compact set C to its convex hull K = co(C). We show that if C contains the relative boundary of K, and f is a continuous con...
The mean value for infinite volume measures, infinite products and heuristic infinite dimensional Lebesgue measures
The mean value for infinite volume measures infinite products heuristic infinite dimensional Lebesgue measures
2011/1/20
The goal of this article is to define the mean value of a function defined on an infinite product of measured spaces with infinite measure. As a preliminary approach, the mean value of a map defined o...
Equation-Free Multiscale Computational Analysis of Individual-Based Epidemic Dynamics on Networks
Computational Epidemiology Individual-based models Networks
2010/12/28
The surveillance, analysis and ultimately the efficient long-term prediction and control of epidemic dynamics appear to be one of the major challenges nowadays. Detailed atomistic mathematical models ...
Adaptive Set Observers Design for Nonlinear Continuous-Time Systems: Application to Fault Detection and Diagnosis
Adaptive observers nonlinear continuous-time systems fault detection interval residuals
2011/3/2
The paper deals with joint state and parameter estimation for nonlinear continuous-time systems.
An Algorithm for Computing the Ratliff-Rush Closure
Algorithm Computing the Ratliff-Rush Closure
2010/11/30
Let I ⊂ K[x, y] be a hx, yi-primary monomial ideal where K is a field. This paper produces an algorithm for computing the Ratliff-Rush closure eI for the ideal I =hm0, . . . ,mni whenever mi is ...
"Explosive Percolation" Transition is Actually Continuous
"Explosive Percolation" Transition Continuous
2010/12/15
The basic notion of percolation in physics assumes the emergence of a giant connected (percolation) cluster in a large disordered system when the density of connections exceeds some critical value.
Idempotents in representation rings of quivers
Idempotents representation rings of quivers
2010/11/26
For an acyclic quiver Q, we solve the Clebsch-Gordan problem for the projective representations by computing the mul-tiplicity of a given indecomposable projective in the tensor product of two indecom...