基于断点分类和方向差异的等高线分级补断方法

扫描地图等高线的自动识别是当前GIS领域的研究热点,但图像分割后提取的等高线上往往存在着各种断点.现有的等高线断点连接方法不能有效连接断裂过大的等高线,并且容易造成近似平行的等高线处断点的错连.针对以上两个问题,本文提出了一种高效的补断策略:首先根据等高线断点的特征将其分成三类,然后再针对每类断点采用不同的匹配方法.其中,对于最常见的中间断点,引入了改进的方向差异计算方法,以解决平行等高线间的错连问题;结合分级补断的思想,能有效地对等高线断裂过大处进行连接.实验结果表明,相比于常规最小点对法,该算法在时间效率和连接准确率方面具有较大的优势.     

连接刚体的三维结构和运动参数估计

根据连接刚体的结构和运动属性，提出了一种基于单目图像序列点对应元的连接刚体三维运动估计新方法．该方法首先利用相邻两个连杆的运动连接关系，由2幅图像估计连接刚体的初始位姿，即确定连接点的空间位置．其次在初始位姿估计的基础上，将各个连杆的运动用螺旋和指数映射表示．最后利用图像点对应元的运动约束方程，求得连接刚体的运动参数．实验结果表明，连接刚体的各个连杆的相互关联性被充分利用。降低了问题的复杂度，提高了算法稳健性．     

路面病害检测中的背景处理和断点连接算法

在基于机器视觉的路面病害检测中,如何进行背景均匀化以及对二值图像中存在的断点问题处理是其中的技术难点.针对该问题,提出一种自适应的倍乘因子不均匀背景去除法来对不一致路面背景进行修正,该方法具有自适应性,可以通过调节自适应因子σ修正背景;然后使用一种基于区域搜寻的断点连接算法对非连续裂缝像素进行连接,它主要基于深度优先原则进行裂缝邻域搜索,然后根据联通性原理去除断点.仿真结果表明,这两种方法对目前的路面检测技术是很好的补充.     

等高线自动矢量化的后处理

为了更好的实现等高线自动矢量化的后处理工作,包括数据预处理(剔除毛刺和矢量数据压缩)、断点连接、接边检查和等高线赋值等.对于等高线数据压缩问题,采用了一种较好的压缩方法--Douglas-Peucker 算法.通过解决断点连接问题,提出了端点趋势连接方法,建立矩形框缓冲区、趋势比较和距离判断进行层层筛选,将符合要求的等高线进行连接处理的方法,提高了连接的速度和效率,为等高线后处理工作提供了指导和帮助.     

三相变压器12种连接组规律探析

三相变压器连接组问题分为两类：第一类是已知三相变压器的连接方法，判定其组号；第二类是给定了组号，确定三相变压器的连接，通过分析得出了三相变压器12种连接组的连接规律，该规律能用来解决上述两类问题。     

解计算机网络连接增强性问题的若干方法

为解决现有计算机网络中一些间接相连的结点添加额外的连接问题，提高整个网络系统的强健性和存活力。综述了线性搜索法、ＣＲＣＳ方法和遗传算法在解决这一问题时的基本思路和实现过程、并提出了模拟退火算法解决方案。通过两个实例，比较了它们的运行结果，最后对各方法的性能进行了综合分析和评价。     

两封闭弹性长方体连接结构的声辐射建模与分析

利用汉密尔顿函数和瑞利－李兹方法,建立了分别由１块四边弹性支承的弹性板及５块刚性板构成 的两连接封闭矩形腔外的辐射声场模型,推导了腔体外辐射声场的解析解。模型在两个弹性长方体结构的连接 处施加假想的弹簧系统模拟不同连接条件,同时考虑了两弹性结构连接点之间以及弹性板与腔体内声场之间的 耦合。通过算例表明,间接力通过连接结构对弹性板辐射声场的影响明显小于弹性板在同样直接力作用下的辐 射声场;弹性结构连接点处线弹簧的刚度变化对辐射声场的影响较旋转弹簧大。     

铆压重塑形工艺的铆钉优化与试验研究

为解决传统机械变形压力连接存在较高凸起的问题并增加连接强度,提出了一种采用特制铆钉的铆压重塑形工艺。该工艺在无铆连接工艺后将铆钉置于连接点的凹坑内,然后压缩凸起处使凸起高度降低。采用DEFORM-2D软件对铆压重塑形工艺进行有限元分析,得到了连接点的最大拉伸强度;采用正交试验方法对铆钉尺寸进行了设计优化,得到了能实现最大拉伸强度的铆钉尺寸。在铆压重塑形试验中,连接点的凸起高度从1.6 mm降低到了1.1 mm;平均拉伸强度从950.6N提高到1 130.7N,即重塑形后的拉伸强度比重塑形前提高了18.9%;平均剪切强度从1 168.6N提高到2 636.1N,即重塑形后的剪切强度比重塑形前提高了125.6%。由此证明,铆压重塑形工艺可有效降低凸起高度,并且能提高连接点的强度。     

一种复合材料螺栓连接强度三维分析方法

本文的重点就是分析一种特征曲线法,一种基于复合材料三维的应力分析,目的就是为了计算复合材料螺栓连接件的迁都问题。该方法与基于二维应力分析的特征曲线法相比,可以考虑螺栓拧紧力矩对接头强度的影响。通过对算例的分析及与试验结果的对比,证明本文提出三维特征曲线法是可用于复合材料螺栓连接强度分析,是一种适合工程计算的有效方法。     

大规模网络边分解的一种新算法

针对最小化边连接集分解法所存在的问题，提出了一种新的ＢＢＤ（加边对角）形式的边分解法。它包括相对最小化边连接集概念及其判别与判别定理，以及新的边分解方法两部分。与原分解方法比较，分解结果更为合理，分解速度更快。还给出了改进的数据结构、程序框图和分解实例。     

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.     

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     

Journal of Donghua University ( English Edition) Contents of Volume 31

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