As it is commonly known,the estimation of physical and mechanical characteristics of rocks is very important issue in various geotechnical projects.The characteristics are mainly influenced by the microfabric-texture ...As it is commonly known,the estimation of physical and mechanical characteristics of rocks is very important issue in various geotechnical projects.The characteristics are mainly influenced by the microfabric-texture features of rocks.In this research,dry unit weight,effective porosity,point load index,Schmidt rebound hardness,uniaxial compressive strength,and texture coefficient were measured with the aim of correlating the physical and mechanical properties to the texture coefficient.For this purpose,a comprehensive laboratory testing program was conducted after collecting twenty sedimentary block samples including nine limestones and eleven mudstones,taken from Kalidromo(central Greece)in accordance with ASTM and ISRM standards.Also,mineralogical and petrographic properties,textural characteristics as well as X-ray diffractions were studied and the obtained results were statistically described and analysed.The maximum and minimum values of the texture coefficient were 0.13 and 0.50,respectively.The highest value was obtained for the rocks with a large amount of grains.Regression analyses were used to investigate the relationships between the texture coefficient and the engineering properties.Thus,empirical equations were developed and because of the good determination coefficients,they showed that all of the engineering properties were well correlated to the texture coefficient.展开更多
To analyze the influence of surface texture on friction properties of Crl2MoV＇, ordinary grinder and spinning technology were adopted to obtain the grooved surface morphology of samples, and then the impact of spindl...To analyze the influence of surface texture on friction properties of Crl2MoV＇, ordinary grinder and spinning technology were adopted to obtain the grooved surface morphology of samples, and then the impact of spindle speed and feed in z-direction on surface morphology in the process of spinning was studied. In addition, the corresponding friction coefficient of sample was obtained through friction and wear tests. The results show that the peak clipping and the valley filling were conducted on the grinding surface, which could improve the surface roughness effectively and make the grinding trench-type wear scar more uniform. Both the area ratio of groove and groove spacing increased initially and then decreased with the increase of the spindle speed or the feed in z-direction. As a kind of micro-process, the groove could influence the friction coefficient of sample surface, whose distribution was beneficial to the reduction of friction coefficient. Compared with the surface obtained through ordinary grinding, grooved surface morphology through spinning technology was more conductive to reduce the friction coefficient, which could be reduced by 25%. When the friction coefficient of sample was reduced to the minimum, the texture of groove corresponded had an optimal area ratio and an optimal groove spacing, 37.5% and 27.5 μm, respectively.展开更多
An adaptive digital image watermark algorithm with strong robustness based on gray-scale morphology is proposed in this paper.The embedded strategies include:The algorithm seeks and extracts adaptively the image stron...An adaptive digital image watermark algorithm with strong robustness based on gray-scale morphology is proposed in this paper.The embedded strategies include:The algorithm seeks and extracts adaptively the image strong texture regions.The algorithm maps the image strong texture region to the wavelet tree structures, and embeds adaptively watermark into the wavelet coefficients corresponding to the image's strong texture regions.According to the visual masking features, the algorithm adjusts adaptively the watermark-embedding intensity.Experimental results show the algorithm is robust to compression, filtering, noise as well as strong shear attacks.The algorithm is blind watermark scheme.The image strong texture region extraction method based on morphology in this algorithm is simple and effective and adaptive to various images.展开更多
Biometric techniques require critical operations of digital processing for identification of individuals. In this context, this paper aims to develop a system for automatic processing of fingerprint identification by ...Biometric techniques require critical operations of digital processing for identification of individuals. In this context, this paper aims to develop a system for automatic processing of fingerprint identification by their minutiae using Artificial Neural Networks （ANN）, which reveals to be highly effective. The ANN method implemented is a based on Multi-Layer Perceptron （MLP） model, which utilizes the algorithm of retro-propagation of gradient during the learning process. In such a process, the mean square error generated represents the specific parameter for the identification phase by comparing a fingerprint taken from a crime scene with those of a reference database.展开更多
文摘As it is commonly known,the estimation of physical and mechanical characteristics of rocks is very important issue in various geotechnical projects.The characteristics are mainly influenced by the microfabric-texture features of rocks.In this research,dry unit weight,effective porosity,point load index,Schmidt rebound hardness,uniaxial compressive strength,and texture coefficient were measured with the aim of correlating the physical and mechanical properties to the texture coefficient.For this purpose,a comprehensive laboratory testing program was conducted after collecting twenty sedimentary block samples including nine limestones and eleven mudstones,taken from Kalidromo(central Greece)in accordance with ASTM and ISRM standards.Also,mineralogical and petrographic properties,textural characteristics as well as X-ray diffractions were studied and the obtained results were statistically described and analysed.The maximum and minimum values of the texture coefficient were 0.13 and 0.50,respectively.The highest value was obtained for the rocks with a large amount of grains.Regression analyses were used to investigate the relationships between the texture coefficient and the engineering properties.Thus,empirical equations were developed and because of the good determination coefficients,they showed that all of the engineering properties were well correlated to the texture coefficient.
基金Project(51275543)supported by the National Natural Science Foundation,ChinaProject(KJ1603804)supported by the Research Projects of Chongqing Commission of Science and Technology,China
文摘To analyze the influence of surface texture on friction properties of Crl2MoV＇, ordinary grinder and spinning technology were adopted to obtain the grooved surface morphology of samples, and then the impact of spindle speed and feed in z-direction on surface morphology in the process of spinning was studied. In addition, the corresponding friction coefficient of sample was obtained through friction and wear tests. The results show that the peak clipping and the valley filling were conducted on the grinding surface, which could improve the surface roughness effectively and make the grinding trench-type wear scar more uniform. Both the area ratio of groove and groove spacing increased initially and then decreased with the increase of the spindle speed or the feed in z-direction. As a kind of micro-process, the groove could influence the friction coefficient of sample surface, whose distribution was beneficial to the reduction of friction coefficient. Compared with the surface obtained through ordinary grinding, grooved surface morphology through spinning technology was more conductive to reduce the friction coefficient, which could be reduced by 25%. When the friction coefficient of sample was reduced to the minimum, the texture of groove corresponded had an optimal area ratio and an optimal groove spacing, 37.5% and 27.5 μm, respectively.
基金Supported by the Technology Key Project of Shanxi Province (2007K04-13)the Application Development and Research Project of Xi’an (YF07017)
文摘An adaptive digital image watermark algorithm with strong robustness based on gray-scale morphology is proposed in this paper.The embedded strategies include:The algorithm seeks and extracts adaptively the image strong texture regions.The algorithm maps the image strong texture region to the wavelet tree structures, and embeds adaptively watermark into the wavelet coefficients corresponding to the image's strong texture regions.According to the visual masking features, the algorithm adjusts adaptively the watermark-embedding intensity.Experimental results show the algorithm is robust to compression, filtering, noise as well as strong shear attacks.The algorithm is blind watermark scheme.The image strong texture region extraction method based on morphology in this algorithm is simple and effective and adaptive to various images.
文摘Biometric techniques require critical operations of digital processing for identification of individuals. In this context, this paper aims to develop a system for automatic processing of fingerprint identification by their minutiae using Artificial Neural Networks （ANN）, which reveals to be highly effective. The ANN method implemented is a based on Multi-Layer Perceptron （MLP） model, which utilizes the algorithm of retro-propagation of gradient during the learning process. In such a process, the mean square error generated represents the specific parameter for the identification phase by comparing a fingerprint taken from a crime scene with those of a reference database.
