Description of shape characteristics through Fourier and wavelet analysis

来源 :Chinese Journal of Aeronautics | 被引量 : 0次 | 上传用户:lbtx368
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
In this paper,Fourier and Wavelet transformation were adopted to analyze shape characteristics,with twelve simple shapes and two types of second phases from real microstructure morphology. According to the results of Fast Fourier transformation(FFT),the Fourier descriptors can be used to characterize the shape from the aspects of the first eight Normalization amplitudes,the number of the largest amplitudes to inverse reconstruction,similarity of shapes and profile roughness. And the Diepenbroek Roughness was rewritten by Normalization amplitudes of FFT results. Moreover,Sum Square of Relative Errors(SSRE) of Wavelet transformation(WT) signal sequence,including approximation signals and detail signals,was introduced to evaluate the similarity and relative orientation among shapes. As a complement to FFT results,the WT results can retain more detailed information of shapes including their orientations. Besides,the geometric signatures of the second phases were extracted by image processing and then were analyzed by means of FFT and WT. In this paper, Fourier and Wavelet transformation were adopted to analyze shape characteristics, with twelve simple shapes and two types of second phases from real microstructure morphology. According to the results of Fast Fourier transformation (FFT), the Fourier descriptors can be used to characterize the shape from the aspects of the first eight Normalization amplitudes, the number of the largest amplitudes to inverse reconstruction, similarity of shapes and profile roughness. And the Diepenbroek Roughness was rewritten by Normalization Amplitudes of FFT results. Moreover, Sum Square of Relative Errors ( SSRE) of Wavelet transformation (WT) signal sequence, including approximation signals and detail signals, was introduced to evaluate the similarity and relative orientation among shapes. As a complement to FFT results, the WT results can retain more detailed information of shapes including their orientations Besides, the geometric signatures of the second phases were extracted by image processi ng and then were analyzed by means of FFT and WT.
其他文献
学位
对内河航道而言,伴随着经济的快速发展,航道上也趋于更加繁忙,来往的船舶也越来越多,这就给有限的航道空间造成了拥堵,增加了船舶撞击桥梁的风险,轻则桥梁受损,重则桥梁垮塌,
他是一名普通的供电员工,却给每一个服务客户带来不一样的感动:他身穿红色马甲,指挥队员安装路灯,照亮了联建社区黑暗的角落,也照亮了社区居民的心;他手捧“爱心卡”,为孤寡老人家更
在初中美术教育教学中,教师不但要向学生传授画的基本技能,首先,教师必须重视对学生的审美素质教育,通过创设美的情境,激发学生学习兴趣,实现审美教育目的.其次,教师必须通过
数字化和信息化技术如今已广泛地应用到了各行各业,迅速推进了世界新军事变革和中国特色军事变革,成为现代军工产业方兴未艾的时代潮流。作为20世纪五六十年代应时而生的中国
资本结构是财务理论中一个十分重要而复杂的问题,亦是财务领域中最具有争议的古老而热门的课题之一。资本结构的决策问题不仅是一个财务决策问题,更是一个公司治理问题,因此本文
上市公司的代理问题一直是公司治理的研究重点。国内外学者的研究成果表明,公司经营权与管理权的分离引发了代理问题,此外公司其他参与者之间的利益冲突以及信息的不对称情况也
学前阶段是教育教学的启蒙阶段,也是人成长过程的重要阶段,做好学前阶段教育至关重要。基于多媒体视角,探讨学前教育中,如何运用多媒体来突破教学重难点,锻炼和培养幼儿语言
期刊
湖北美术学院陶艺本科专业依托学院“通识造型”这一学术概念,在“宽口径、厚基础、重能力、求创新”的办学指导下,陶艺本科专业的办学理念逐步在“内引外联”的办学形式中,