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线性相关计算法形成数字剪切散斑相关条纹图 总被引:8,自引:0,他引:8
本文提出了用线性相关计算法形成数字剪切散斑干涉条纹的新方法,从理论分析和实验研究均证明,用该方法所获得的数字剪切散斑相关条纹图在图象监视器上易于观看,条纹图象光强无直流分量影响且可见度较减模式要高,该新方法的采用为今后的条纹图象分析奠定了基础。 相似文献
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Ming-Fei Chen Yu-Pin Chen Wen-Tse Hsiao Shi-Yuan Wu Chun-Wei Hu Zhi-Peng Gu 《Optics and Lasers in Engineering》2008,46(5):410-418
Laser marking is an important branch of laser processing technology, and has been widely used in many fields of industry. Digital signal processor (DSP) is an incredibly fast and powerful microprocessor that can deal with signals in real time. Not only it is portable but has the ability to integrate the processing signals of subsystems. In this research, it is emphasized that we designed a scribing laser marking system based on a DSP in galvanometric marking method. To control the rotating angle of the galvanometric scanning mirrors more accurately, we combine the D/A converter of the DSP with the human–machine interface successfully. The whole marking system is not only inexpensive, but also miniaturized. 相似文献
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以相位光栅为实验对象,开展了基于数字显微全息技术的相位物体三维显微结构信息的再现研究.在Mach-Zender透射式实验系统的基础上,分别采用显微物镜和无透镜放大方式,对相位光栅进行放大,以提高系统横向分辨率.在显微物镜放大系统中,菲涅耳近似数值再现算法与双波长技术相结合,抑制主要系统噪音,获得相位光栅的显微结构三维分布.在无透镜放大数字显微全息系统中,分别利用菲涅耳近似法和卷积方法再现原始物波前,并提出相减法消除系统主要球面误差,获得相位光栅的深度信息.实验结果与Veeco干涉仪测试结果比对表明,光栅周期和深度结构与干涉仪测试数据相符. 相似文献
106.
Use of rigid-body motion for the investigation and estimation of the measurement errors related to digital image correlation technique 总被引:1,自引:1,他引:1
The aim of this work is to investigate the sources of errors related to digital image correlation (DIC) technique applied to strain measurements. The knowledge of such information is important before the measured kinematic fields can be exploited. After recalling the principle of DIC, some sources of errors related to this technique are listed. Both numerical and experimental tests, based on rigid-body motion, are proposed. These tests are simple and easy-to-implement. They permit to quickly assess the errors related to lighting, the optical lens (distortion), the CCD sensor, the out-of-plane displacement, the speckle pattern, the grid pitch, the size of the subset and the correlation algorithm. The errors sources that cannot be uncoupled were estimated by amplifying their contribution to the global error. The obtained results permit to address a classification of the error related to the used equipment. The paper ends by some suggestions proposed in order to minimize the errors. 相似文献
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Carmen Camarero Izquierdo Javier Rodríguez Pinto Rebeca San José-Cabezudo 《Telematics and Informatics》2018,35(5):1176-1189
This research explores how digital publications may be turned into something more than just a meeting point for people who are seeking information and may become a latent community. The paper proposes that the network of editors, followers, and advertisers of digital publications determine the user sense of community towards the publication. While the pattern of connections among editors and followers reinforces the sense of community, advertisers act as intruders who weaken the feasibility of building a community. Data were collected from followers of digital publications. The dynamics of the sense of community is described as a process in which informational value and identification are essential to nurturing readers’ soft or hard commitment. Findings indicate that the strong ties between editors and followers as well as the diversity positively impacts on informational value and identification, whereas advertising intrusiveness diminishes the informational value. 相似文献
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Smart cities are built upon information and communication technologies (ICTs) to enable a broad range of advanced services. Through a comprehensive literature review, this study identified four pitfalls brought by the pervasive application of ICT, including information insecurity, privacy leakage, information islands, and digital divide. Therefore, a questionnaire survey together with 27 interviews was conducted in Hong Kong to investigate how the public perceived these pitfalls within the context of mobile apps providing real-time parking information which form a major part of smart mobility. System insecurity and privacy leakage were found to arouse worries among the app-users while their awareness of protecting personal data was found to have room for improvement. Islands of real-time parking information occur as a result of the lack of collaboration among private carpark operators. Digital divide existed widely among the disadvantaged groups and the problem cannot be solved by mere provision of ICT facilities. Overall, technologies alone cannot make a city smart or smarter. It is the suitable way in which ICTs are used to serve all citizens that matters. 相似文献
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Material databases of plastics are becoming more and more the focus of applied science and commercial use in industry. Material properties of material manufacturers are often provided in publicly accessible material databases, which usually contain processing and mechanical properties under static loadings. Fatigue strength values are usually not accessible. The fatigue data for thermoplastics is of particular interest, as these materials have a particularly high lightweight construction potential and can be processed with a high degree of automation and reproducibility.Individual fatigue strength parameters for a specific material, environmental condition, geometry and loadings have been investigated in numerous publications. However, no work has been found in which fundamental interactions of different materials, environmental conditions, geometries and loadings on the course of the S/N-Curve have been investigated.In this paper, different effect relationships between temperature, filler type and filler content, fiber orientation and load ratio will be presented for the material Polypropylene (PP). A fatigue strength database of 11 different material manufacturers, from 71 different S/N-Curves with 606 tested samples, serves as a basis. The fatigue database enables a digital twin, which is used for the design of structural components to add a third dimension with artificial intelligence, and which is trained by an engineer. From the determined effect relationships, fatigue factors are to be derived and can be used to evaluate the fatigue strength of a component in the design process and to train the digital twin. The fatigue-strength values from the database also allow a statistical consideration of the slope k and the scattering of the S/N-Curve. The different S/N-Curves are transferred into a Haigh diagram, from which the functional course of the mean stress is determined. 相似文献