通过关键词查论文: Imaging


作者: M.A.A. Mohd Salleh, A. Sugiyama, Hideyuki Yasuda, Stuart D. McDonald, Kazuhiro Nogita
摘要: This paper demonstrates the development of an experimental technique of in-situ observation for soldering of Sn-0.7wt%Cu lead-free solder on a Cu substrate which was achieved for the first time by synchrotron X-ray imaging. Reactions between liquid solder and Cu substrate during a soldering process were able to be recorded in real-time. Individual stages of the soldering process consisted of flux activation in removal of Cu oxide, solder melting and contact with the Cu substrate (wetting) and intermetallic compound (IMC) and void formation between the solder and Cu substrate. The technique development which includes experimental setup with calculated optimum beam energy in the range of 20 – 30 keV appears to result in a clear observation of real-time X-ray imaging of the soldering process. This technique provides a key method to understand the mechanism of formation of micro-electronic inter-connects for future electronic packaging applications.
作者: Horst Meier, H. Ermert, P. Knoll, Oliver Keitmann-Curdes
摘要: With fluid forming processes getting more and more common in industrial application a lot of research is carried out to analyze the forming behavior of sheet metal within these processes. In order to gather experimental information about the forming behavior of the workpiece, an imaging system is presented, that will allow determining the actual shape within the forming process. The system has to be functional in liquid media as well as in a high pressure environment. Therefore an ultrasonic based system has been chosen, consisting of a small number of transducers which are alternately used as transmitter and receiver. It is possible to cover 100 by 100 mm² with only 10 by 10 transducers by the use of special algorithms. The reconstruction of the echographic images from the recorded data is done by a SAFTalgorithm (synthetic aperture focusing technique) followed by an analysis with special contourdetection algorithms, which are able to scan the image for contour data. It can be shown that the accuracy of the reconstruction is quite good in the 2.5-dimensional domain, if appropriate contour models for the description are used. Because of the small number of transducers and the specular reflection of the signals, the quality of the image can be improved significantly by the extension of the SAFT algorithm with an angle-weighted factor. The three dimensional reconstruction is also possible and will be demonstrated for simple geometries. The ability for sampling more complex geometries and enhancing the accuracy will be achieved by the integration of three dimensional contour models and three dimensional angle-weighting.
作者: Zong Yao Li, Lu Zhang, Hong Zhao, Bing Kong, Nian Ling Yao
摘要: An elaborated mechanism for sheath flow forming includes flow cell, vacuum pool, sample pool, syringes, valves, and tubes. Firstly the sample is drawn into the sample inlet of flow cell through vacuum generated with one syringe. Then, the sample and buffer are driven to pass the flow cell to form sheath flow by other two syringes. To visualize and evaluate the sheath flow, black ink is used as sample, and optical imaging system is adopted to capture the formed sheath flow. Sheath flows with sample width of 21μm and 37μm in diameter are formed in a flow cell with micro-square hole of the size 0.2mm×0.2mm when the syringes run in different speed.
作者: Cong Yao Zhang, De Quan Guo, Dong C. Liu
摘要: Ultrasound elastography is a technique of imaging information about tissue elastic moduli, which plays an important role in early diagnosis of several kinds of tumor. Usually, elastograms display only axial displacement and corresponding tissue strain. In lateral direction, however, there is no phase information and the precision of data is lacking too. In this paper, a spline based method for lateral displacement and the corresponding strain estimation is proposed. SSE, which is computed based on lateral data lines in pre-and post-ultrasound signal, was used as a pattern-matching function to estimate lateral displacement. With this method, we can obtain directly continuous estimates with lower computational cost. The SNRe and CNRe of elastograms have been evaluated using simulated data.
作者: Lei Chen, Dian Ren Chen, Ying Liu, Ze Chuan Lv
摘要: In this paper,it is established the geometric and radar echo model of the rotating target with the Forward-looking synthetic aperture radar firstly,then the Doppler frequency History Formula is Deduced and Pointed out that the Formula has a sinusoidal characteristics. It is simulated the imaging of the stationary target and the rotating target with different rotation speed, the imaging result can be expressed as the forms of curve and the curve circle nomadic type, when these features appear in the imaging results, it can initially determine that the rotating target is presence.
作者: Fábio Henrique Antunes Vieira, Carlos Affonso, Manoel Cléber de Sampaio Alves
摘要: Searching for systems with intelligent, flexible, and self-adjusting solutions on imaging, which could provide the contraction of the human operators’ presence, a range of techniques is found. Each one of them can control the process through the assistance of autonomous systems, either software or hardware. Therefore, modeling by traditional computational techniques is quite difficult, considering the complexity and non-linearity of image systems. Compared to traditional models, the approach with Artificial Neural Networks (ANN) behaves well as noise elimination and non-linear data treatment. Consequently, the challenges in the wood industry justify the use of ANN as a tool for process improvement and, therefore, add value to the final product. Additionally, the Artificial Intelligence techniques, such as Neuro-Fuzzy Networks (NFN), have shown efficient, since they combine the ability to learn from examples and to generalize the learned information from the ANNs with the capacity of Fuzzy Logic, in order to transform linguistic variables in rules. Then, ANFIS plays active roles in an effort to reach a specific goal.
作者: Jun Tang
摘要: On the basis of explaining the basis theory on transient electromagnetic sounding, wavelet theory and imaging principle of differential conductivity for transient electromagnetic sounding data, this thesis proposes rapid imaging technology of electromagnetic sounding based on wavelet analysis, describes the characteristics of noises under wavelet decomposition, and employs wavelet packet analysis to eliminate noise of signals, at last, introduces wavelet analysis into transient electromagnetic sounding on the platform of MATLAB wavelet function toolbox and deals with differential conductivity imaging processing steps of transient electromagnetic sounding.
作者: Ying Lan Jiang, Ruo Yu Zhang, Jie Yu, Wan Chao Hu, Zhang Tao Yin
摘要: Agricultural products quality which included intrinsic attribute and extrinsic characteristic, closely related to the health of consumer and the exported cost. Now, imaging (machine vision) and spectrum are two main nondestructive inspection technologies to be applied. Hyperspectral imaging, a new emerging technology developed for detecting quality of the food and agricultural products in recent years, combined techniques of conventional imaging and spectroscopy to obtain both spatial and spectral information from an objective simultaneously. This paper compared the advantage and disadvantage of imaging, spectrum and hyperspectral imaging technique, and provided a description to basic principle, feature of hyperspectral imaging system and calibration of hyperspectral reflectance images. In addition, the recent advances for the application of hyperspectral imaging to agricultural products quality inspection were reviewed in other countries and China.
作者: Bo Xue, Hong Li, Yun Fen Shi
摘要: EuPO4 nanoparticle was synthesized using chitosan induced mechanism. The nanoparticles were formed after calcination inside a fiber template. The nanoparticles were characterized by Transmission Electron Microscopy (TEM), X-ray Diffraction (XRD) and Fluorespectrometer. The synthesized EuPO4 nanoparticles with nano-pore structures presented the excitation peaks located at about 375nm and 500nm and the emission peaks located at 590-620nm and 750nm, respectively. Live imaging was performed in in-vitro cell culture. The nanoparticles were biocompatible and could be intake by cells. Cells with nanoparticles showed fluorescent signals for imaging, which indicate the potential application of these particles for live imaging.
作者: Jun Wang, Xiao Hong Meng, Fang Li, Jun Jie Zhou
摘要: With the continuing growth in influence of near surface geophysics, the research of the subsurface structure is of great significance. Geophysical imaging is one of the efficient computer tools that can be applied. This paper utilize the inversion of potential field data to do the subsurface imaging. Here, gravity data and magnetic data are inverted together with structural coupled inversion algorithm. The subspace (model space) is divided into a set of rectangular cells by an orthogonal 2D mesh and assume a constant property (density and magnetic susceptibility) value within each cell. The inversion matrix equation is solved as an unconstrained optimization problem with conjugate gradient method (CG). This imaging method is applied to synthetic data for typical models of gravity and magnetic anomalies and is tested on field data.