形态学和最大熵图像分割的城市路面裂缝检测

针对路面检测过程中后期处理数据工作量大、城市路面图像噪声多等特点,提出利用形态学和最大熵图像分割的城市路面裂缝检测方法.路面图像经过初始分类后,利用数学形态学变换对路面裂缝图像预处理,采用不同尺度、不同方位的结构元素对灰度图像做开运算重构,以提高图像中裂缝目标与路面背景之间的灰度差异;利用最大熵法进行图像分割,并对二值化后的裂缝图像进一步精细化处理;利用投影分析方法进行裂缝分类.研究结果表明:该方法能够在抑制噪声干扰的同时,实现快速、准确地检测路面裂缝边缘,并准确完成裂缝分类.     

基于爬壁机器人的桥梁裂缝图像检测与分类方法

针对传统的桥梁裂缝检测方法成本高、工作环境危险的现状,提出一种基于爬壁机器人的桥梁裂缝图像检测与分类方法,即利用安装在爬壁机器人上的微型摄像镜头获取桥梁的壁面裂纹,通过图像处理和分析方法识别并对裂缝分类.首先对获取的图片去除运动模糊;然后运用小波变换对图像中的裂缝目标进行增强,再用二值图像面形态学分析提取裂缝目标,运用KD树对裂缝进行连接完成对裂缝图像的识别;最后运用支持向量机方法对裂缝实现分类,并与几何特征分类方法和基于BP神经网络的分类方法比较,结果表明,该方法对裂缝分类效果较好.     

基于分数域加窗和对比度增强的路面裂缝检测

针对传统人工路面裂缝检测的效率和精度低以及耗费大量人力物力等问题,提出了一种基于分数域加窗和对比度增强的路面裂缝检测方法。首先,使用分数阶傅里叶变换将裂缝图像转化到分数域,利用最优窗函数对频谱进行加窗处理达到去噪效果。然后,使用分数阶同态滤波算法对去噪图像进行对比度增强,并通过迭代的方法获取最佳阶次下对比度最高的图像。最后,使用Canny算法和Otsu算法分别对增强图像做边缘检测和阈值分割,通过对两者结果做或运算和图像形态学运算来有效提取裂缝图像中的裂缝特征。将检测结果与分数频域处理法和改进HC显著法对比,该方法的准确率分别提升了5.84%和4.5%,召回率分别提升了5.58%和3.52%,表明该方法在路面裂缝检测上具有更好的检测效果和更高的识别率。     

基于图像处理技术的管道裂缝检测方法研究

提出了一种新的管道裂缝检测方法,基于OpenCV开源平台开发了一个方便用户使用的图像处理系统,实现了管道缺陷检测。该方法首先利用中值滤波法去除图像中的噪声;然后使用形态学梯度算法检测裂缝图像边缘轮廓;最后通过Otsu算法自适应地选取阈值分割图像得到管道裂缝的二值图像。对管道裂缝的检测实验结果表明本文提出的方法检测效果优于DEE(dou-edge evaluation)方法。     

基于上限定理的含裂缝边坡稳定性图表分析方法

大量地灾现场勘测发现,滑坡外表面广泛分布着裂缝,在地震、静水压力、边坡超载等条件下均会加剧裂缝边坡失稳.为详细分析含裂缝边坡在不同条件下的安全性能,文章通过强度折减法结合极限分析上限定理,建立了综合性分析任意深度、位置的临界裂缝边坡稳定性的评估方法,推导得到安全系数求解方程,并优化了算法:将随机搜索法与非线性序列二次规划法相结合,解决计算中的大量迭代问题和易陷入局部最优解等问题;还原了裂缝边坡的形态并与经典结构、有限元计算结果对比验证.结果表明:与经典解相比,优化后算法显著提高计算稳定性与准确性;不同的工况条件会对边坡稳定性产生较大的影响;相同参数设计下,不利的工况易产生更深的裂缝.最后利用研究结论绘制了一系列的安全性图表,可作为工程师进行边坡安全性初步快速评估的依据.     

嵌入式FRP抗剪增强梁斜裂缝水平投影长度计算

为计算嵌入式FRP抗剪增强梁在四点加载作用下的斜裂缝水平投影长度,利用投影长度经验公式和变角空间桁架模型分别研究了剪跨比和纵筋-箍筋强度比对投影长度的影响,在此基础上综合考虑两者的相互关系,同时根据9根FRP嵌入式增强梁的实测试验数据,采用最小二乘法拟合斜裂缝投影长度计算公式.分析结果表明,单独考虑剪跨比和纵筋-箍筋强度比都不能很好地预测斜裂缝水平投影长度,而将两者结合能够较好地反应斜裂缝出现和发展的全过程,从而准确地计算斜裂缝水平投影长度.推导公式的计算结果和试验实测值取得了很好的吻合,误差小,离散程度低,同时还表明剪跨比是影响斜裂缝投影长度的主导因素.     

饱和开裂混凝土氯离子二维扩散的数值模拟

对饱和状态下开裂混凝土裂缝附近区域氯离子的二维扩散进行了数值模拟.以Fick第二扩散定律(FSDL)修正模型及二维氯离子扩散理论模型为基础,建立了开裂混凝土氯离子扩散有限差分数值模型,并编制了计算程序.通过与试验结果的对比,证明了模型的有效性.利用建立的模型分析了裂缝、水胶比、衰减系数和时间因素对氯离子扩散的影响,提出了裂缝影响区的概念.在裂缝影响区内,氯离子呈二维扩散,在其外,氯离子呈一维扩散;在时间上,氯离子扩散存在快速期、过渡期与缓慢期;从长期来看,裂缝深度对氯离子的扩散影响显著,而裂缝宽度几乎对其无影响.     

纤维硅灰水泥基复合材料渗透性与腐蚀行为

利用试验法探讨钢纤维与硅灰的混合添加对于水泥基复合材料渗透性与腐蚀行为的影响,采用开路电位法与直流极化法来评估水泥基复合材料中钢筋腐蚀程度;并通过快速移动试验与浸盐试验推求氯离子扩散系数来评估水泥基复合材料的渗透性,并与快速氯离子试验、压汞试验与电阻率试验相比较.试验结果显示,使用钢纤维除可抑制裂缝成长外,还能降低水泥基复合材料氯离子的渗透性及提高材料耐久性.当钢纤维用量达2%并混合10%硅灰的双重增强效应下试体有最佳的抗腐蚀能力,从快速移动试验与浸盐试验可知纤维硅灰水泥基复合材料的氯离子扩散系数为控制组的1/10,显示纤维与硅灰混合使用能有效减少氯离子渗透性.     

沥青混合料Ⅰ型疲劳开裂虚拟离散元试验

采用离散单元法对Arcan I型开裂试验进行了虚拟试验.根据现实试验中的沥青混凝土试件集料-集料和集料-黏结料之间的力学关系,在虚拟试验中利用Burgers模型建模,并在电子扫描图像基础上使用Particle Flow Code3D软件建立虚拟试件.在虚拟试验过程中实时监测试件应力分布变化及观测点应变变化.结果表明:虚拟试验结果与实际试验符合良好;应力监测结果表明裂缝发展全程符合裂缝尖端应力集中现象,且初始微裂缝会沿尖端方向继续发展成为大裂缝;Arcan I型开裂试验中试件直接受拉,应力分布简单直观,应力-应变分析对比其他试验方法更为直观.     

基于动态最短路径识别水泥路面裂缝的方法

针对水泥路面图像裂缝识别过程中刻槽带来的干扰问题,利用频域滤波消除水泥路面刻槽,并使用动态最短路径提取路面裂缝识别结果.首先用频域滤波消除水泥路面刻槽,并将频域滤波后图像划分为不重叠的16*16小方块,再运用动态最短路径判断方块中是否含有裂缝,经过后续二值化、裂缝拼接等处理,最后得到裂缝图像.实验结果表明,该方法可以很好地去除刻槽的影响,具有良好的识别效果.     

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.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

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.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

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