In order to detect X-corner (or X-point) features more accurately and apace, this article presents a novel and fast detection method based on block-by-block search strategy. Unlike general pixel-by-pixel searching method, the sampling window is first moved along the image block-by-block to find the X-corner candidates rapidly keeping in view the fourstep and min-step-distance constraints. During the motion, some overlap is kept between the adjacent sampling windows in order to ensure that all X-corners could have a chance to reside inside, avoiding the possibility of that some Xcorners may locate on the edge. Moreover, labeling technology is adopted to prevent duplicate candidates. After the collection of X-corner candidates, the neighborhood variance and centrosymmetry constraints are used to exclude outliers, and the intersection lines is calculated as the sub-pixel position of true X-corner. The experimental results using synthetic and real images show that the presented method approximately takes just about 13 ms to detect 52 X-corners in an image size of 1024 3 768 on a computer having Intel Core i3 CPU at 3.6 GHz and 4GB RAM. The proposed method has faster detection speed compared with the latest methods such as ChESS, SC, and Micron Tracker system while possessing the same or higher detection precision.

An experimental study of the seismic performance of composite frames consisting of reinforced concrete (RC) columns and steel beams (S) is presented in this paper. Three frame specimens-one bare composite RCS frame without slab and two composite RCS frames with slab-were tested under cyclic loading. The test results indicate that two frame specimens with small-scale steel beams exhibited better ductile behavior and dissipated energy, and the strength and stiffness degradation of the postelastic stage was not obvious. The results indicate that using a slab in the frame is not a good way to improve structural bearing capacity when the linear stiffness of steel beams is large. A plastic limit analysis method is proposed to calculate the lateral ultimate bearing capacity of an RCS frame under seismic action. The calculated results agree well with the test. Three RCS frame specimens were simulated using ABAQUS finite element analysis software. A comparison of the results of the numerical study with the experimental results demonstrates that the finite element model can accurately predict the structural behavior.

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The rising of energy demand together with environmental protection awareness have attracted worldwide interest in renewable energy, especially photovoltaic (PV). Meanwhile, with the expansion of transportation infrastructure, solar energy has been employed in roadway construction, called solar road. The technology of Solar road offers an opportunity to capture the vast and dispersed solar energy while maximizing the use of land. A PV power generation assessment method for solar road considering coupled distribution and transportation system is proposed in this paper. The dynamic shading caused by traffic flow on solar road is considered as an effect factor which will influence the PV output in the model. The proposed method is examined on a test system with a transportation and a radial distribution network. The numerical results substantiate that the proposed method is an effective tool for assessing the PV power generation of solar road.

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