查询词典 discontinuous variable

Local discontinuous Galerkin method for convection-dominated diffusion problems with periodic boundary conditions is constructed. To deal with the derivative of second order, an auxiliary variable is introduced. The stability and error estimations are presented simultaneously.

针对具有周期性边界条件对流占优的扩散问题中的二阶导数，引入辅助变量，构造了局部间断Galerkin方法，并给出了方法的稳定性结果和误差估计式。

Monitoring data of rock slope collapse is a sort of uncertain and incomplete information, Furthermore, it is a discontinuous deformation system, which will branch off or be in critical state with the continuous change of dominant variable parameter, the Gray theory and catastrophic theory are more effective to predict time of collapse occurrence.

由于崩塌的监测数据存在信息不完全和不确知性，同时，崩塌的发生存在有突跳性，采用灰色理论和突变理论能够有效地预测预报边坡崩塌发生的时间，为崩塌防治提供及时的决策依据。

The experiments of neuronal pacemaker show typical bifurcations from period 1 to period 5 with stochastic bursting patterns. A discontinuous map of the slow variable in Chay model which captures the essential characters of the period-adding bifurcation scenario is constructed in this thesis.

在神经起步点实验中展示了伴有随机簇放电的从周期1到周期5的典型分岔，本文在把握加周期分岔的根本特征的基础上构造了Chay模型中慢变量的不连续映射。

We firstly look back thebirth of SD method,and then present the SD scheme presented by Johnson et.al.forlinear problem to explain the basic idea and implementation:At step 1,we change the testfunctionwhere(1,β)t is the streamline or character direction decidedby hyperbolic operator of the continuous problem,therefore the SD method belongs tothe Petrov-Galerkin method;At step 2,we adopt time-space finite element space,whoseelement is only continuous in space variables x but discontinuous in time variable t.

首先回顾了SD方法的产生过程，然后以线性问题为模型，描述了SD方法的基本思想和具体实现：第一步，将标准有限元方法的检验函数ν改成其中(1，β)t是连续问题的双曲算子部分所确定的流线方向。换言之，SD方法是一种Peterov-Galerkin有限元方法；第二步，采用时空有限元空间，其元素关于空间变量x是连续的，但关于时间变量t仅分段连续。

In a'variable structure system', the control law is a discontinuous function of the state variables when the trajectory crosses a prescribed hypersurface in the state space.

在一个变结构系统中，控制律是当状态轨迹经过规定的超平面时状态变量的不连续函数。

In order to meet the required simulation precision and meet the real-time simulation in ballistic simulation calculation,this paper analyzes the selection method of the simulation step,and then introduces variable step integration methods in Runge-Kutta to Adams and educes Adams variable step integral formulas,and then put forwards a method by seeking zero of condition function in discontinuous nonlinear system of the ballistic simulation.

在弹道仿真计算中，为了既达到要求的仿真精度又能满足实时仿真，分析了仿真步长的选择方法，然后在龙格－库塔转阿当姆斯法中引入变步长积分方法，推导了阿当姆斯变步长积分公式，同时对弹道仿真中的间断非线性系统提出条件函数求零的方法来解算弹道。

In order to assist Boost converter design, the working process of the converter at discontinuous current mode was analyzed and a nonlinear mathematical model was estabilished as well. Case study on Matlab/ Simulink was performed with binary logical variable used, the simulation result was consistent with the theoretical analysis which proveed the validitd and feasibility of the proposed model. The model could be used to assist Boost circuit design effectively and supplie a basis for parameter optimization.

为了辅助升压变换器在应用中的设计，分析了电流断续状态下Boost变换器的工作过程，建立了这种状态下的Boost变换器非线性数学模型，在结合二进制逻辑变量，建立了Simulink模块下的变换器仿真模型，研究表明仿真结果与理论分析结果一致，证实了模型的准确性和可行性，这种逻辑与模拟结合的简明通用的模型可以高效辅助Boost电路设计并为参数优选打下了基础。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。