基于点云截面数据点的多轮廓排序算法

针对使用切片技术提取的点云截面数据点的多轮廓排序问题,提出了一种简便有效的算法.该算法分为两步,首先通过最近邻域搜索,根据距离阈值依次生成各个轮廓的闭合多边形,完成多轮廓截面数据点的粗排序和轮廓分离,然后将剩余数据点依照最小夹角原则插入到相应的轮廓闭合多边形中,达成截面数据点的精确排序.实验证明,该算法可对逆向工程中各种复杂的截面数据点实现精确排序和轮廓分离,将无序数据点转化为有序数据点,排序结果稳定、准确.     

自适应尺度的形状表示与匹配方法

提出了一种基于轮廓的形状特征描述方法,以及基于此形状特征的相似度度量方法.将轮廓形状的质心作为极点,在极坐标系中对轮廓等角间距采样获得轮廓点,并将相邻两采样轮廓点的极径所围面积比值作为轮廓特征向量.将改进后的归一化欧式距离作为轮廓特征向量之间的相似度距离.实验表明,基于轮廓的形状特征描述方法,仅用少量数据来表示原始轮廓信息而保留了原始轮廓信息的主要特征,且对于形状的缩放、旋转、翻转等形变操作具有尺度不变性;同时,也可以获得轮廓向量之间的相似度距离和旋转角度.实验证明了此方法可行、有效.     

TrueType字体自动打标机软件设计

通过分析TrueType字体文件结构和提取出字符轮廓信息,实现了对字符的无失真任意放大和缩小以及旋转等特效,曲线轮廓可以进行填充.将二次Bezier曲线构成的字符轮廓,通过最小二分法转换成一组能够保持曲线轮廓形状的小折线,将原有的字体轮廓数据从用曲线轮廓表示转变为用多边形顶点控制,用一组点及其先后顺序来描述轮廓.研完了字形交叉的消隐处理方法,解决了笔画重叠的问题.打标机将得到的多边形顶点信息准确打标.     

融合轮廓和区域特征的形状描述子

提出了一种融合轮廓和区域信息的新的形状描述子。首先提取图像的轮廓,并对轮廓进行采样,形成描述形状轮廓的有序点列表。之后对每个采样点分别顺时针和逆时针等距离跟踪获得两个邻点,计算相邻点距离、拱高以及质心距离三个函数的均值、方差和极差。然后获取由拱高和质心距离组成的复函数的傅里叶描述子。组合统计值与傅里叶描述子形成轮廓特征。最后对区域进行采样形成形状矩阵,获得低频傅里叶系数作为区域特征。对MPEG—7标准图形库的检索实验显示,该描述子的检索性能显著优于三角形面积函数、质心距离函数、拱高半径复函数和Hu不变矩等同类描述子。     

一种基于双平面镜的相机标定算法

为了从物体的二维图像得到三维重构模型,需要通过相机内部参数,建立已知物点、像点对应的关系模型.提出一种基于双平面镜的相机标定算法,用两个普通平面镜取得物体5个不同角度的二维图像,通过基于颜色信息和基于区域背景差的方法获取目标轮廓,用多边形动态规划算法获取轮廓的特征点以确定各个物体轮廓的对应点,最后根据特征点得到相机内部参数.多边形动态规划算法将时间复杂度从O(n3)降低到O(n2),算法的效率得到提高.     

TrueType字体自动打标机软件设计

通过分析TrueType字体文件结构和提取出字符轮廓信息,实现了对字符的无失真任意放大和缩小以及旋转等特效,曲线轮廓可以进行填充。将二次Bezier曲线构成的字符轮廓,通过最小二分法转换成一组能够保持曲线轮廓形状的小折线,将原有的字体轮廓数据从用曲线轮廓表示转变为用多边形顶点控制,用一组点及其先后顺序来描述轮廓。研究了字形交叉的消隐处理方法,解决了笔画重叠的问题。打标机将得到的多边形顶点信息准确打标。     

粒子群优化算法实现仿射不变性形状识别

针对形状识别过程中,轮廓图像会因为视点改变发生仿射变换的问题,提出了一种新的仿射不变特征提取方法及匹配策略。首先,对所有边界点计算其与质心的距离及方向角,并在给定的角度邻域内进行平均以消除噪声干扰;然后,计算方向角相差180°的边界点质心距离之比作为形状特征,该特征具有仿射不变性。由于仿射变换图像间各轮廓点的方向角具有非线性变化特征,质心距离比需要重采样以建立对应关系,笔者将其转化为一个路径规划问题,并用粒子群优化算法得以解决。实验表明该方法对形状识别中的平移、旋转、缩放、拉伸和噪声干扰具有良好的效果。     

基于最小误差逼近的轮廓特征点提取

针对轮廓曲线的多边形近似和特征点提取,提出了多边形逼近误差和局部最小误差逼近特征点的定义和相应的实现算法.该特征点对轮廓曲线进行树状递归划分,并最大限度地减小逼近误差.使得在给定特征点数目情况下,多边形逼近误差为最小.在给定逼近误差的情况下,特征点数目为最少.对于轮廓线的特征提取、优化多边形逼近、压缩表示具有一定的意义.     

基于小波变换的物体轮廓缺陷图像检测研究

提出将二维物体的轮廓图像坐标信息转换成基于质心距离的一维向量信息来进行检测.并设计了基于双正交对称小波的去噪算法.实验结果表明,这种算法可以有效地去除噪声信号和缓变信号,保留缺陷的突变信息,是一种有效和实用的轮廓缺陷检测算法.     

一种基于重心计算的角点检测算法

提出了一种基于重心计算的轮廓曲线角点提取算法.针对图像的数字化轮廓曲线,首先,以等曲线长为特征点检测邻域,通过插值法得到精确的支持区域端点;接着,采用分割多边形法计算支持区域重心,避免了重心近似引起的误差;最后,以曲线上的点到其对应支持区域重心距离为特征值,依据该特征值区域最大化方法实现角点提取.实验证明,本算法具有较强的抗噪声、干扰能力,且运行速度快,角点寻找准确.     

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.     

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.     

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.     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

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.