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In this paper, a novel method for face recognition, called two-dimensional weighted and locality preserved discriminant analysis (2D-WLPDA) is proposed. The new algorithm is developed based on three techniques: (1) locality preserved embedding, by embedding nearest-neighbor graphs which characterize the within-class compactness of the same class samples, 2D-WLPDA discovers the submanifold of images space; (2) image based projection which can avoids the small sample problem and improves the computation efficiency;(3) weighting contributions of individual class pairs which alleviates the overlap of neighboring classes in Fisher criterion for a k-class problem with k>2. We experimentally compare 2D-WLPDA to other feature extraction methods, such as 2D-LDA, 2D-PCA and 2D-DLPP, 2D-WLPDA has better recognition performance.

Concrete plate is mainly anti-seepage structure for rockfill dam and essential to avoid dam destruction. Cooling shrinkage will be effectively compensated by mix MgO, as a result, it have been widely used in hydraulic structure. However, with large radiating surface, uniform heat exchange and small bottom restriction, stress characteristic of concrete plates is much different from conventional massive concrete structure. Therefore, impact of MgO on stress characteristic of concrete plates is unclear. In view of this, construction process using MgO concrete and ordinary concrete are simulated based on practical project data. Conclusions indicate that tensile stress of concrete plates in cooling stage can be reduced by adding MgO.

For virtue of small volume and fast speed of construction, arch dam is the most suitable dam type in cold region, where construction period is relatively short each year. Low average value and large amplitude of atmospheric temperature make temperature stress distribution of arch affect directly by thickness of permanent insulation material as while as the time of thermal insulation. Extreme climate lead to stricter external insulation requirement for cold region arch than these in common district, however, thermal insulation will increase the burden of artificial cooling and extend the construction period. Therefore, it is complicated and critical for arch dam crack prevention to study on permanent thermal insulation. In view of this, finite element method was applied for simulation of construction processes of a practical project in cold region. Influence of permanent thermal insulation layer thickness and selection of insulation time is analyzed, in order to provide basis for permanent thermal insulation optimization.

Some cracks are observed in a heightening project of a concrete gravity. In order to investigate and solve this problem, the three-dimensional finite element simulation and nonlinear cracking analysis are implemented in this paper to analyze the causes of cracks and their propagation trends. This work is helpful to design the proper crack controlling plans. The research shows that large tensile stress has accumulated during construction, especially after an early air temperature sudden drop in November, the tensile stress increases 3MPa in general on the concrete surface, which exceeds the tensile strength of concrete and causes cracking. Therefore, the crack is the result of both the accumulated temperature stress during construction and temperature sudden drop. The crack will further propagate during another temperature sudden drop, but extended range is limited. If concrete tensile strength is greater than 2.5MPa, the cracks will not penetrate throughout the dam body along the water flow direction.

Under the action of annual change and sudden drop of air temperature, thermal induced cracking will occur in concrete dam during the operation period. For exploring the temperature control measures for crack prevention, taking a concrete gravity dam section as the research object, sensitivity analyses to the factors which affecting the water-cooling effect are conducted with 3D FEM, some significant suggestions for the water cooling are presented. The results show that, the stresses of the dam surface will decrease to a certain extent after water cooling in the operation period using the cooling water pipe which embedded during construction period, and the cracking risk of the dam will reduce. The study provides a new train of thought for the temperature control and crack prevention of the mass concrete during the operation period.

Maximum Scatter Difference (MSD) aims to preserve discriminant information of sample space, but it fails to find the essential structure of the samples with nonlinear distribution. To overcome this problem, an efficient feature extraction method named as Locality Preserving Maximum Scatter Difference (LPMSD) projection is proposed in this paper. The new algorithm is developed based on locality preserved embedding and MSD criterion. Thus, the proposed LPMSD not only preserves discriminant information of sample space but also captures the intrinsic submanifold of sample space. Experimental results on ORL, Yale and CAS-PEAL face database indicate that the LPMSD method outperforms the MSD, MMSD and LDA methods under various experimental conditions.

Gate pier may cause damaged by construction joints under inappropriate pouring in Pengshui Hydropower Station. Based on nonlinear FEM, a contact algorithm is adopted to simulate interaction of construction joints between the overflow dam surface and gate pier. With different contact type and loading, the deformation and stress are analyzed comparatively in detail in order to evaluate the strength and safety of the gate pier. The results show that existence of construction joints reduces the stiffness of the structure, but satisfies the requirements of original reinforcement project, which have a little effect on safety of the gate pier.

The spiral case with combinatorial embedding manner is a novel design and inherits the advantage of the general types of embedding manners of embedded with cushion layers and embedded directly, which is progressively used in hydro projects. In the present paper, the mechanical behavior of a larger spiral case with combinatorial embedding manner is analyzed by using 3-D non-linear finite element method. The deformation of the spiral case structure and crack analysis of outer reinforced concrete structure are carried out. The strengthening measures under the engineering control criterion are also discussed. The results show that the penetrating crack will appear in the concrete and the relative rising displacement of generator pedestal structure is out of the control criterion if no strengthening measures implemented. Increasing the quantity of reinforcement only is not able to hold back the penetrating cracks. The enhancement of the tensile strength of concrete is an effective way to decrease the range of crack propagation, resist the penetrating and decrease the rising displacement of generator pedestal structure. It also indicated that extending the laying length of cushion is another effective way to decrease the rising displacement of generator pedestal structure

Based on Numerical Manifold Method (NMM), a novel method is presented for computing Stress Intensity Factor (SIF) of cracks. The Williams expansions are employed as the analytical solutions in the mesh containing the crack tip. And high-order polynomial functions are used as the numerical solutions in the surrounding meshes. Then the SIFs are computed via combination of the numerical solutions and the analytical solutions. Meanwhile, the meshes in NMM need not conform to the physical boundaries including the crack edges, allowing the cracks arbitrarily align within the meshes. The given example shows the validity of the method.