查询词典 stochastic dynamic model

The Adolph accurate dynamic model cannot describe the movement of the reciprocating pump valve at the moment of opening, thereby a new accurate dynamic model for describing the motion law of an automatic conical valve is set up, in consideration of the condensability of the fluid, the Westphal's effect, the condition of the continuous flow of fluid and the dynamic characteristic of pump valve's motion.

针对阿道尔夫往复泵泵阀精确运动微分方程在泵阀开启瞬间存在奇点的不足，综合考虑液体可压缩性、魏氏效应、液体连续流条件及泵阀运动的动力特性，建立了描述往复泵自动锥形阀运动规律的精确运动微分方程。

This paper analyzed conveyor belt dynamic propertie s which would influence the results of dynamic design of belt conveyor,common dyn amic model was introduced,and the rule about how to choose dynamic model when de sign was put forward.

文摘：对影响带式输送机动态设计结果的输送带的动力学特性进行了分析，介绍了常见输送带的动力学模型，并指出在带式输送机动态设计中输送带动力学模型的选取原则。

Based on water-entry dynamic and water-entry ballistic theories, the oblique water-entry process of disk ogive is simplified and a wetted correction factor is introduced in order to accord with the true water pile phenomena, and an oblique water-entry impact model coupled with ballistic and dynamic models are established. According to the exact geometric shape of the wetted body surface, the dynamic model is established.

以冲击体入水动力学和入水弹道学理论为基础，针对平头尖拱体入水冲击这个复杂物理现象，引入体现液面隆起现象的沾湿因子，用等效液面代替自由水平液面，建立了斜入水高速冲击的运动学和动力学冲击模型，其中动力学模型是根据平头尖拱体沾湿面的具体几何形状而建立。

In this paper, the author sets up the dynamic model of the vibratory extracting-driving piling machine, and carries out the dynamic analysis, parameter calculation and Matlab's simulation for this model. Using the equation reciprocity law to carry out the calculation of soil parameter and simulation, and using the genetic algorithm to make optimization of the machine on the basis of the simulation, the author gets the optimum self-induced vibration frequencies of the machine changing with the depth of the pile and the optimization result of other parameters, thus reaching the conclusion that along with the increase of pile sinking depth, the optimum self-induced vibration frequency becomes bigger, and the vibration mass becomes smaller, hence deepening the knowledge of the dynamic performance of this system.

本文建立了振动沉拔桩机的动力学模型并对这一模型进行了动力学分析、参数计算和Matlab仿真，并利用方程对等法进行土壤参数的计算和仿真，又在仿真的基础上使用遗传算法对桩机进行了优化，从而得出了路基加固振动沉拔桩机随沉桩深度变化而改变的最佳激振频率以及其它参数的优化结果，并得出了随沉桩深度的增加，桩机的最佳激振频率由小变大，最佳参振质量由大变小的结论，深化了对该系统动力学性能规律的认识。

In this paper, the author sets up the dynamic model of the vibratory extracting-driving piling machine, and carries out the dynamic analysis, parameter calculation and Matlabs simulation for this model. Using the equation reciprocity law to carry out the calculation of soil parameter and simulation, and using the genetic algorithm to make optimization of the machine on the basis of the simulation, the author gets the optimum self-induced vibration frequencies of the machine changing with the depth of the pile and the optimization result of other parameters, thus reaching the conclusion that along with the increase of pile sinking depth, the optimum self-induced vibration frequency becomes bigger, and the vibration mass becomes smaller, hence deepening the knowledge of the dynamic performance of this system.

本文建立了振动沉拔桩机的动力学模型并对这一模型进行了动力学分析、参数计算和Matlab仿真，并利用方程对等法进行土壤参数的计算和仿真，又在仿真的基础上使用遗传算法对桩机进行了优化，从而得出了路基加固振动沉拔桩机随沉桩深度变化而改变的最佳激振频率以及其它参数的优化结果，并得出了随沉桩深度的增加，桩机的最佳激振频率由小变大，最佳参振质量由大变小的结论，深化了对该系统动力学性能规律的认识。

Dump truck has a propensity to roll over in certain situations. Variable soil conditions, high winds, significant ground slope, and shifting loads contribute to a high risk of rollover for dump trucks, In this study, a dynamic simulation model of a dump truck with triangle rod assembly lifting mechanism was established to study the dumping stability of the dump truck. Through the dynamic simulation of the dump truck model in several typical situations, the dynamic rollover threshold values were determined.

本文主要针对自卸汽车在作业卸载时容易失稳发生侧翻的现象，以某厂三角臂组合式举升机构的自卸汽车为研究对象，建立自卸汽车整车虚拟样机模型，综合考虑影响自卸汽车作业稳定性的各种主要因素，对自卸汽车的作业稳定性进行仿真分析，找出了自卸汽车侧翻的临界值。

The separation of the dynamic principal stresses in the model is completed by solving the dynamic Poisson's equation with the transient dynamic isochromatics and isoclinics of the model combined ...

并采用落锤冲击－维模型求出了光弹性材料的动态力学特性。文章系统总结了动态光弹性方法，并将该方法引入生物力学的研究领域，研究结果在医学、军事、体育等方面均具有实际的意义。

With CAE analysis, multi-body dynamic model of the loader is established with multi-body dynamics software of finite element NAS-TRAN and MSC Adams/View during design period. Various curve functions are added in dynamic analysis model to simulate the terrain excitation on tires and conduct dynamic calculation and analysis. Stress change vs. time of each part is easily obtained when a loader travels on rough terrain. Compared with test results of the physical prototype, the calculation results are relatively consistent.

利用CAE分析手段，在产品的设计阶段，利用有限元NASTRAN和MSC Adams/View多体动力学软件建立装载机的多体动力学模型，通过在动力学分析模型上加入各种曲线函数来模拟路面对轮胎的激励，进行动力计算分析，很容易获得装载机在通过不平路面时各部件应力随时间的变化值，并将其计算结果与物理样机的测试结果进行对比，两者的结果比较一致。

Among used machine learning methods, the gradient descent method is widely used to train various classifiers, such as Back-propagation neural network and linear text classifier. However, the gradient descent method is easily trapped into a local minimum and slowly converges. Thus, this study presents a gradient forecasting search method based on prediction methods to enhance the performance of the gradient descent method in order to develop a more efficient and precise machine learning method for Web mining.However, a prediction method with few sample data items and precise forecasting ability is a key issue to the gradient forecasting search method. Applying statistic-based prediction methods to implement GFSM is unsuitable because they require a large number of data items to model a prediction model. In the contrast with statistic-based prediction methods, GM(1,1) grey prediction model does not need a large number of data items to build a prediction model, and it has low computational load. However, the original GM(1,1) grey prediction model uses a mathematical hypothesis and approximation to transform a continuous differential equation into a discrete difference equation in order to model a forecasting model.

其中梯度法是一个最常被使用来实现机器学习的方法之一，然而梯度法具有学习速度慢以及容易陷入局部最佳解的缺点，因此，本研究提出一个梯度预测搜寻法则(gradient forecasting search method， GFSM)来改善传统梯度法的缺点，用来提升一些以梯度学习法则为基础的分类器在资讯探勘上的效率与正确性；而一个所需资料量少、计算复杂度低且精确的预测模型是梯度预测搜寻法能否有效进行最佳解搜寻之关键因素，传统统计为基础之预测方法的缺点是需要较大量的数据进行预测，因此计算复杂度高，灰色预测模型具有建模资料少且计算复杂度低等优点，然而灰色预测理论以连续之微分方程式为基础，并且透过一些数学上的假设与近似，将连续之微分方程式转换成离散之差分方程式来对离散型资料进行建模及预测，这样的作法不尽合理，且缺乏数学理论上的完备性，因为在转换过程中已经造成建模上的误差，且建模过程仅考虑相邻的两个资料点关系，无法正确反应数列未来的变化趋势。

Based on the energy sensing, there are cooperative spectrum detection algorithms such as AND model, OR model, counting model, double threshold model, likelihood ratio model, linear cooperation model, and Distributed Wireless Communications System model.

基于能量检测，协作频谱检测的算法主要有：与算法、或算法、计数算法、分区算法、似然比算法、线性加权算法和分布式无线通信系统算法。

Connectors are lines that can be anchored to particular places, called glue points , on the graphic object.

连接符，可固定在图形对象的特定的地方的线条。

Another way of putting it, too many agents have a say in each other's work, and bureaucratic rigor mortis sets in.

另一种表达是，太多的作用物在彼此的工作里都有话语权，官僚的僵尸开始抬头。