The application of a proportional difference type iterative learning control in active vibration control

Active vibration control is used to instead passive solutions in order to increase the performance at low frequencies, in a variety of different engineering systems. This method has improved the performance specifically. The paper will propose a proportional difference type iterative learning control algorithm to deal with the periodic sources and to investigate the active solution as the three degrees of freedom ＂mass spring damping＂ mount. Simulation shows that this method could get a better tracking performance, also the displacement could converge to zero with a fast speed.     

基于三层网络架构及DOM的XML系统模型

本文阐述如何在三层网络架构上运用XML以构造XML文档支持系统,提出了基于三层网络架构及DOM的XML系统的模型,该系统与传统的客户／服务器应用或是应用一般的数据传输方式如HTML等系统相比具有减少了网络流量、更有利于检索、可从多种不同的数据源集成数据、开放性、可扩充性、可重用性等一系列特点。     

三维管道系统CAD中二维视图自动生成技术探讨

文中结合开发供热管路系统CAD的实践,介绍了在MDT3下由三维模型生成符合行业制图标准的二维视图的总体思路和具体实现方法,包括设计信息的传递、设备、阀门的投影以及对管道重叠、转向、交叉等的处理。     

对重催I/A'S系统三冲量控制回路的探讨

本文主要对广州石油化工总厂重油催化裂化装置的复杂回路——三冲量控制在I/A'S系统的实现进行探讨和实施。     

基于二维雷达组网目标高度计算算法

根据雷达兵作战需要,探讨了传统二维雷达组网目标高度计算算法.针对传统算法需要目标方位信息或三站处于同一水平面的不足,提出一种基于Matlab solve函数的二维雷达网目标高度计算算法.该方法只利用目标距离信息来实现目标的高度计算以及三维定位.仿真结果表明:该方法的高度计算误差小于150m,高于一般雷达测高精度,具有一定的参考价值.     

A segmentation algorithm for automated tracking of fast swimming unlabelled cells in three dimensions

Recent advances in microscopy and cytolabelling methods enable the real time imaging of cells as they move and interact in their real physiological environment. Scenarios in which multiple cells move autonomously in all directions are not uncommon in biology. A remarkable example is the swimming of marine spermatozoa in search of the conspecific oocyte. Imaging cells in these scenarios, particularly when they move fast and are poorly labelled or even unlabelled requires very fast three-dimensional time-lapse (3D+t) imaging. This 3D+t imaging poses challenges not only to the acquisition systems but also to the image analysis algorithms. It is in this context that this work describes an original automated multiparticle segmentation method to analyse motile translucent cells in 3D microscopical volumes. The proposed segmentation technique takes advantage of the way the cell appearance changes with the distance to the focal plane position. The cells translucent properties and their interaction with light produce a specific pattern: when the cell is within or close to the focal plane, its two-dimensional (2D) appearance matches a bright spot surrounded by a dark ring, whereas when it is farther from the focal plane the cell contrast is inverted looking like a dark spot surrounded by a bright ring. The proposed method analyses the acquired video sequence frame-by-frame taking advantage of 2D image segmentation algorithms to identify and select candidate cellular sections. The crux of the method is in the sequential filtering of the candidate sections, first by template matching of the in-focus and out-of-focus templates and second by considering adjacent candidates sections in 3D. These sequential filters effectively narrow down the number of segmented candidate sections making the automatic tracking of cells in three dimensions a straightforward operation.     

电网电压不平衡条件下并网逆变器的研究

采用一种具有双参数控制的结构实现并网运行和负序电流的消除,直流侧的电压控制环作为并网的基础控制,同时提取电网电压和逆变器输出电压的负序分量并加以控制,当两者相等时就可以达到消除负序电流的目的,然后对负序电压的获取以及电流的跟踪控制作了分析。最后利用Matlab/Simulink对系统进行仿真,验证了系统的可行性。     

高校公共体育课程体系优化的研究——以浙江工业大学体育课程改革为例

文章通过资料、访谈、问卷调查和统计分析方法对浙江工业大学公共体育课程体系的操作现状进行调查与分析,针对调查中发现的问题,从优化课程资源、构建课内外一体化的课程模式、优化课程评价体系以及加强以长跑为特色的校园体育文化建设角度提出了课程体系的优化策略,以期为高校体育课程改革的理论研究和实践操作提供一定的参考。     

土木工程专业课程教学改革与实践

基于“以学生为主体,以教师为主导”的理念,针对目前土木工程专业课程教学的现状和存在的问题,提出了广义的课程教学“传授知识、建立思想、培养能力”的三要素,建立了“理论教学、实践教学、自主研学”三位一体的教学模式,对专业课程教学方法及手段进行了深入探讨和全面改革.实践证明,该方法不仅提高了课堂教学的效率,还大大激发了学生的学习热情,取得了良好的教学效果.     

基于三网融合的数字机顶盒的设计与应用

数字电视机顶盒是随着电视系统的更新而推出的家庭数字终端产品,其功能是把各种数字信号通过电视终端展示出来。结合实际说明了现有的数字机顶盒的设计方法,并从三网融合最新的业务需求出发,分析了新业务需求对数字机顶盒的功能要求,提出了基于三网融合的数字机顶盒的设计方案,并讨论了三网融合数字机顶盒的应用方向。