Evolution algorithm for water storage forecasting response to climate change with little data sets:the Wolonghu Wetland,China

An attempt of applying a novel genetic programming(GP) technique,a new member of evolution algorithms,has been made to predict the water storage of Wolonghu wetland response to the climate change in northeastern part of China with little data set.Fourteen years(1993-2006) of annual water storage and climatic data set of the wetland were taken for model training and testing.The results of simulations and predictions illustrated a good fit between calculated water storage and observed values(MAPE=9.47,r=0.99).By comparison,a multilayer perceptron(MLP)(a popular artificial neural network model) method and a grey model(GM) with the same data set were applied for performances estimation.It was found that GP technique had better performances than the other two methods both in the simulation step and predicting phase and the results were analyzed and discussed.The case study confirmed that GP method is a promising way for wetland managers to make a quick estimation of fluctuations of water storage in some wetlands under condition of little data set.     

YK58150型齿条插齿机的数控系统的研究

YK58150型数控齿条插齿机的控制系统是采用以可编程控制器为核心的三轴控制两轴联动数控系统，可实现圆周进给、径向进给和分齿运动的精确数字控制。文章对其硬件系统及其软件结构进行了详细的论述。     

HYK58150型数控齿条插齿机硬件系统的研究

HYK58150型数控齿条插齿机采用了以可编程逻辑控制器为核心的数控系统，使用了3个数控轴，可实现圆周进给、径向进给和分齿运动的精确数字控制，其主控单元采用的是模块式结构，各功能部件独立封装，由基本单元、定位单元和显示单元组成。这里对其硬件结构进行了详细的论述。     

单颗磨粒的平面磨削三维动态有限元仿真

将磨粒简化为圆锥形,利用Deform-3D软件,进行了单颗磨粒的平面磨削的三维动态有限元仿真。分析了砂轮与工件表面之间的摩擦系数相同而磨削速度不同时对磨削力产生的影响,以及磨削速度相同而摩擦系数不同时对磨削力产生的影响。结果表明：未变形磨屑厚度不变时,单位磨削力随着砂轮速度的增加而增大,在砂轮速度的低速区,单位磨削力增加较快,而在砂轮速度的高速区,单位磨削力增加得较慢;在磨削速度不变时,单颗磨粒的磨削力随着摩擦系数的增加而增加。     

55钢CBN砂轮平面磨削的磨削力模型研究

本文建立了基于未变形磨屑厚度的磨削力计算模型。根据55号钢的CBN砂轮平面磨削实验,首先采用随机方向搜索法对切向力模型进行优化拟合,再根据拟合的参数对法向力模型进行优化,得出了CBN砂轮与工件之间的摩擦系数和磨粒顶锥角。分析了摩擦力在磨削力中所占比重的影响因素,结果表明:当切深不变时,随着vs/vw比值的增加,磨削力以及摩擦力在磨削力中所占的比重均下降,但当磨粒间距增加时,磨削力减小,而摩擦力在磨削力中所占比重增加。