面向对象轮廓约束GGVF Snake的建筑物边界优化方法

分析高分辨率遥感影像中建筑物的特征和常用方法提取建筑物存在边界漏检误检导致的边界不规则等问题,提出面向对象轮廓约束广义梯度矢量流（GGVF）Snake模型的建筑物边界优化方法. 在利用分类法获取建筑物轮廓的初始结果基础上,自动提取每个建筑物轮廓线作为GGVF Snake的初始轮廓线,获取各轮廓外接矩形进行对象裁剪,提取每个建筑物的子图对象. 对每个子图对象进行Canny边缘检测,结合Hough变换提取直线特征,输入到广义梯度矢量流模型的迭代求解中快速最小化能量函数,实现对象级建筑物轮廓的精确优化. 实验结果表明,利用提出的方法能够自动获取初始建筑物的轮廓信息,提高优化的自动化程度;基于对象级的边缘检测与直线特征的加入,有助于GGVF Snake快速拟合,准确地平滑建筑物边缘且准确度高. 相对于其他对比方法,本文方法的轮廓优化总体精度和综合值均有提升,可以作为有效提升分类原理获取的建筑物轮廓的优化后处理手段,提高了建筑物提取的精度.     

一种针对灰度非均匀图像的混合分割框架

该文将基于区域的局部和全局活动轮廓技术有机结合起来,给出了一种针对灰度非均匀图像的分割框架。考虑到灰度非均匀特性对图像非轮廓象素点影响较大而对图像轮廓象素点影响较小这一事实,在该框架中引入了图像边缘停止函数来平衡局部和全局灰度信息之间的相互影响。基于该框架,给出了一个具体的实例模型,运用快速的模糊对偶算法获取实例模型的全局最优解。用一组图像进行实验,并通过对实验结果的定量分析,验证了该模型的合理性。     

Design and Machining of Combination Gear Cutter Hob

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Unsteady-State Model for Continuous Moving-Bed Chromatography

Abstract

Mathematical equations have been formulated to predict the longitudinal concentration distribution in the case of instantaneous behavior of a continuous chromatographic system. Partial differential equations are initially obtained from mass balance on the differential element of column height. The formulated equations are solved by Lap lace transformation and the contour integration method. Two equations are obtained, one for the column section above the feed point and the second for the column section below the feed. Both of these equations give the concentration distribution along the appropriate section of the column. The model predicts the instantaneous and steady-state behavior of the continuous moving-bed chromatographic system. The model can also be used as a tool for the design of new continuous chromatographic columns.     

Optimization of physical and mechanical properties of rubber compounds by a response surface methodological approach

Response surface methodology was used for optimizing the ratio of vegetable oil and carbon black and occluded volume fraction of rubber in the compound. Central composite design for two variables was chosen as the experimental design. The data obtained from measurement of properties was fitted as a two variable second-order equation, and were plotted as contours using software developed from MATLAB v.5.1. From contours it is observed that at the ratio of 0.06 of vegetable oil and carbon black, there is maximum coupling, and a further increment in vegetable oil and carbon black ratio shows less coupling and more plasticizing effect. The ultimate failure properties like tensile and tear strength and elongation decreases with an increase in occluded volume fraction, reaches a minima at the central region, followed by an increase, whereas 300% modulus and hardness decreases throughout.© 2001 John Wiley & Sons, Inc, J Appl Polym Sci 82: 997-1005, 2001     

采用石墨电极制备多孔硅工艺研究

采用石墨电极作为阴极,通过向腐蚀溶液中添加适量65％(质量分数wt％,下同)浓硝酸,以电化学腐蚀法在单晶硅片表面制备出多孔硅微结构.实验表明,随着腐蚀时间的增加,衡量多孔硅表面形貌的粗糙度和颗粒度指标值呈周期性增减变化;在电流密度为10 mA/cm2的阳极腐蚀参数下,将单晶硅片腐蚀1875秒制备的多孔硅样品的粗糙度和颗粒度值相对较大,原子力显微镜(AFM)和扫描电子显微镜(SEM)检测结果表明其硅柱最大高度、颗粒最大直径和平均直径分别达到470 nm、1693.590nm、489.954nm.     

50Mn钢凸轮轴的中频感应淬火

凸轮轴是柴油机的重要传动件之一,要求根据所采用的材料进行渗碳淬火或表面淬火,以提高其表面硬度和耐磨性。50Mn钢凸轮轴采用BVH-1000双工位中频淬火机床、仿形感应器和专用夹具等设备,以及10％～15％AQ251聚合物水溶液进行感应淬火。结果,凸轮轴的表面硬度、硬化层深度分布和显微组织均达到了要求,生产成本明显低于进行渗碳淬火的20Cr钢凸轮轴。     

FANUC系统Cs轮廓控制功能在数控机床中的应用

本文阐述了Cs轮廓控制功能基本原理、硬件配置,梯形图编写,参数设置以及调试中的注意事项。对FANUC数控系统在扩展功能方面进行实际应用作了介绍,对其他数控系统在数控机床应用有指导作用。     

基于激光传感器的弧焊机器人焊缝跟踪研究

采用激光扫描式传感器,设计了一套机器人焊缝自动跟踪系统。开发了相应的焊缝跟踪算法,包括直线、圆弧和直线圆弧组合连续焊缝的跟踪算法。探讨实现这些算法的相关技术问题。计算机仿真结果表明,该算法合理有效,可用于弧焊机器人焊缝在线跟踪作业,改善和提高机器人的焊接精度和质量。