Advanced Materials Research Vol. 411

Abstract: Accurate and efficient image-clarity evaluation function which adopts digital image processing technology is the key to achieving automatic focusing. The different evaluation functions are adopted for different images. By converting color images to grayscale, and comparing them with the green component which extract from the color images, it is found that using the gray image can get a much better results and an evaluation function is built which is used for tool images. Experiments prove that the used algorithm has a good single peak, accuracy, stability, and fast speed.

Abstract: It is difficult to separate objects from an image when its background is nonuniform. Traditional methods tend to get obvious targets by using many different algorithms, such as Ostu, morphology, etc. But it frequently fails in extracting objects with different size and shape in nonunfirom background. A new method is proposed for nonuniform image segmentation in this paper. First, on an initial image, grid sample method is performed to reduce data space and prepare for background estimation and an example image is formed by those grids. Then, Gaussian Low Pass Filter (GLPF) is used to filter the noise point in the small image. Then, the next step is to magnify the area of this example image through an interpolation algorithm. Facet Model is used to estimate the background image. Finally, the object image can be acquired by the initial image substracting this estimated background image. Experiments are performed and according to the results, the validity and adaptability of the method is enhanced obviously, compared with conventional image segmentation algorithms.

Abstract: According to the area CCD camera of characteristics, such as high resolution capacity and high frame frequency, this paper puts forward a high speed and parallel image compression system of high integration degree. Firstly, according to the work principle of the area CCD, FPGA is adopted to realize the timing driving and multichannel and parallel analog signal handling to raise the export frame frequency of the area CCD. Secondly, with an image compression scheme based on FPGA embedded processor MicroBlaze and ADV212 compression chip, real time image compression and the high speed area CCD are realized. Finally, by detecting the analog signal of the area CCD output, the real time compression of the big area CCD image is carried out in different compression ratios and the compression performance is analyzed. Experiment result shows that this scheme can realize real time image compression with the biggest data rate of 520Mbps. When compression bit ratio is 0.15, the signal-to-noise ratio of peak value can reach 36 dB. Image collection and image compression are integrated, which reduces the data transmission between them and improves systematic integration degree.

Abstract: In order to improve the performance of FCM clustering segmentation algorithm, a new spatial constrained FCM (SCFCM) algorithm is proposed. The new algorithm computes the membership degree of each pixel according to membership degrees of its neighbor pixels. For the purpose of enhance compute efficiency, two kinds of initial membership matrix creation algorithms are proposed to reduce iteration times. Experiments for a series of images are performed, according to the results, SCFCM clustering segmentation algorithm can restrain the noise effectively.

Abstract: The Bi_0.5Na_0.5TiO₃-xwt%BaTiO₃ compound ceramics were prepared. The influence of different BaTiO3 content on structure was evaluated by scanning electron microscopy and X-ray diffraction analysis. The results show oriented is induced by plate-like BaTiO₃ template. Signficant improvement of the piezoelectric (d33 = 112 pC/N) and dielectric properties ( max ≈ 5500) was observed. The improvement was attested to the apparent alignment of the BaTiO₃ templates and grain oriented growth.

Abstract: With fast development of output, light-weighting and high performance of automobile, 17Cr2Ni2Mo steel, as an important vehicle-used gear steel, has to improve properties to fulfill the development. The performance of 17Cr2Ni2Mo steel is affected by quenching process parameters. In order to investigate the effect of austenitizing temperature and holding time on the quenching hardness and tensile strength, the central composite design (CCD) and response surface method (RSM) are applied to optimize the operating variables viz. austenitizing temperature and holding time. Multi-objective optimization developed for the two responses (quenching hardness and tensile strength) indicates the optimum conditions to be 920.46°C of austenitizing temperature and 0 h of holding time, while the values of quenching hardness, tensile strength are not less than 43.47 HRC and 1616.42 MPa. The gear has advantages with mechanical strength and abrasion resistance energy when 17Cr2Ni2Mo steel is produced using the optimum parameters.

Abstract: The extraction of edge feature is a key technology in the foreign fibers recognition. The traditional algorithm of edge detection operator is more sensitive to noise, which is unable to extract complete edge information. Based on the morphological edge detection, we can get the ideal foreign fibers edge characteristics under the condition of noise for the multi-scale structure elements, combining with inflation and corrosion operator to structure morphology gradient operator, the adjustment of morphology structure elements dimensions. Experiment results show that it has a certain feasibility and effectiveness compared to classic edge detection algorithm in the respect of restraining the noise and improving the testing precision.

Abstract: Under the circumstance of the same parameters as fabric density, yarn type and so on, different fancy openwork could be weaved respectively in which the fabric mesh layout are various. Then in order to get the fabric pore size distribution parameters under the best mechanical strength, the different fancy openwork should be applied in tensile and tear strength tests, which can contribute to analyze the relationship between mesh fabric structure and its mechanical property.

Abstract: Current research on building energy efficiency and the application of the principle of the phase change materials are outlined. Analysis of research regarding phase change materials and their classifications on energy-saving in buildings are analyzed and the main existing issues are summarized. The energy-saving effect is verified with the utilization of paraffin and swelling soil composite phase change materials, the result of which suggests that room temperature can be comparatively stabilized with the utilization of phase change materials and energy efficiency can be critically increased. This demonstrates that phase change materials have a broad potential in engineering endeavors.

Abstract: In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.