基于区域围绕追踪的激光雕刻新算法

针对激光雕刻中所出现的边缘锯齿现象，提出一种基于围线追踪的激光雕刻算法，该算法 在于围线的“侵蚀”策略，通过地图像中各个连通区域不断追踪围线而得到的“侵蚀”路径完成激光雕刻在实践中取得了效果。     

一种基于像素标记的二值图像区域围线追踪方法

在研究了多种二值图像连通区域围线追踪算法的基础上,提出了一种改进型的二值图像连通区域围线追踪算法。该算法在已有围线追踪算法的基础上,通过定义特定追踪方向,使得追踪过程始终按照逆时针或顺时针方向沿着连通区域边缘进行。在追踪过程中对像素点进行多次标记,通过在按照追踪方向确定的像素点基础上判断像素标记值来确定下一次待追踪像素点的选取。由于对像素点进行多次标记,有效区分了一次追踪像素点和二次追踪像素点,解决了追踪过程中出现的追踪间断现象,使得追踪结果呈现一条完整围线。实验结果表明,此方法可以快速有效地完成二值图像连通区域的围线追踪和提取。     

应用模式识别自动追踪地震剖面同相轴

将模式识别技术应用于自动追踪地震剖面同相轴．追踪过程用迭代法来实现，第一次迭代时追踪到强同相轴，在其后的迭代中追踪到弱同相轴．每次迭代中的追踪范围限制在前一次迭代已得到同相轴所勾划出的区域内，采用相关相邻地震道的方法追踪同相轴，一种称为双态相容性检测法ＢＣＣ的算法可以同时相关三个道．追踪完同相轴后自动编辑同相轴，提供描述同相轴的有关参数．迭代法和ＢＣＣ算法的结合在模拟人工解释以及将“地质趋势”加入最终结果方面是有效的．     

面向手语自动翻译的基于Kinect的手势识别

提出了一种基于3D体感摄像机Kinect设备实现面向手语自动翻译的手势识别方法,利用Kinect体感外设提供的深度图像实现手的检测,并通过OpenNI+NITE框架中函数获得手掌质心在三维空间中的位置,然后通过等值线追踪算法(又称围线追踪算法)和三点定位算法识别出手指实现了手势跟踪,最后通过矢量匹配方法识别手指名字,并设计了三层分类器来实现静态手势语的识别.相较于传统的基于数据手套和单目摄像机的方法,本方法识别的更准确.基于上述方法,实现了一个手势识别系统.实验结果显示,本文提出的方法更加简洁且行之有效.     

NURBS图形激光雕刻算法及其嵌入式实现

为了实现非均匀有理B样条(NURBS)图形的激光雕刻,推导了显式有理多项式的NURBS表达式,并在此基础上研究了NURBS图形激光雕刻算法,然后在基于DSP/BIOS的实时嵌入式平台上实现了NURBS图形激光雕刻控制系统.实验结果表明,高性能嵌入式平台能够满足算法的空间和时间需求,实现复杂NURBS图形激光雕刻.     

基于边缘矩阵的链编码追踪算法

提出了一种基于边缘矩阵的链编码追踪算法,并引入“边缘矩阵”的数据结构,记录像素边缘的一些信息,以此辅助链编码追踪算法的运行。该算法不仅能追踪任意形状复杂区域的链编码,而且它的计算复杂性是线性的。该算法还可为给出表示链编码之间包含关系的树结构和其它分析打下了基础。     

一种改进的图像中连通体边界freeman链码的获取算法

本文介绍了一种基于边界追踪的freeman链码获取算法，算法可以快速获取二值图像中连通体边界线的freeman链码，不仅适用于单连通的简单区域，对于多连通的孔洞区域同样有效．     

基于DSP的嵌入式运动控制系统开发

本文介绍了一种基于TMS320F2812BIOS内核的运动控制系统设计方法,该方法利用DSP／BIOS内核基于任务优先级的多线程机制,实现对伺服电机运动控制的实时处理,包括运动系统的任务调度、运动轨迹算法以及与硬件设备的通信等,使得程序结构分配合理,调试、修改程序非常方便．经过在激光雕刻切割机机床平台上的验证,结果表明本文提出的控制系统完成了包括直线、圆弧等各种运动轨迹,最大加工速度达64000mm／min,定位精度≤±0．01mm／min。它完全满足高精度激光雕刻机加工的实时性要求,在性能和功能上达到了预期效果．     

口腔预备体颈缘线快速提取技术研究

由于高质量的全瓷冠、桥体制作的需要，在过去的16年里，基于CAD/CAM的口腔修复体制作技术成为研究的热点。预备体颈缘线的自动提取技术是口腔CAD/CAM修复工艺边缘密合的关键环节，修复冠的边缘密合性将对患者的牙龈健康有重要影响。本文提出了半自动颈缘线提取算法，首先，采用二次曲面拟合估算网格点的曲率；接着，利用“方向”追踪方法快速提取初始特征线；然后，利用“曲率”吸引策略保持能量最小的方法优化网格表面的特征线。最后的应用实例证实本文算法是有效的、可行的，满足临床应用要求。     

理想材料零件实体模型自动添加支撑技术研究

在一些RP工艺中,给各种形状的零件添加支撑对于完成零件的制造和保证零件的精度非常重要,但目前尚无很好的自动添加支撑算法能够应用于一般的情况．为此提出两种自动添加支撑算法：曲线追踪法和标志位追踪法．前者主要是在切片前基于追踪得到的采样点利用蒙面法重构支撑面片;而后者则是在切片后通过多边形的布尔运算逐层计算各切层端面的实际轮廓和综合轮廓．这两种算法形成了一种新的自动添加支撑方案．实例证明了这种方案的有效性和便利性．     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with