The purpose of this paper is to present an in-flight initial alignment method for the guided projectiles, obtained after launching, and utilizing the characteristic of the inertial device of a strapdown inertial navigation system. This method uses an Elman neural network algorithm, optimized by genetic algorithm in the initial alignment calculation. The algorithm is discussed in details and applied to the initial alignment process of the proposed guided projectile. Simulation results show the advantages of the optimized Elman neural network algorithm for the initial alignment problem of the strapdown inertial navigation system. It can not only obtain the same high-precision alignment as the traditional Kalman filter but also improve the real-time performance of the system.

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The traveling wave and slope amplification effects should be considered in the shaking table test of large-span structures in mountain areas. Based on the structural characteristics and site conditions of a large-span structure in a mountain area, this paper designed a high-rise steel frame structure with viscous dampers through finite element analysis to amplify seismic waves with a time delay. Then, the original structure and steel frame models with a similarity ratio of 1/40 were made for shaking table tests. The test results showed that a high-rise steel frame structure with reasonable viscous dampers could delay and amplify seismic waves, and the scaled model of the structure could play the same role in shaking table tests. Meanwhile, by comparing the seismic responses of large-span structural models in mountain areas before and after the amplification of seismic wave delays, it was found that the delay and amplification of seismic waves had little impact on the acceleration response of the structure. In contrast, the seismic wave delay played a dominant role in the change in the structural displacement response.

In order to solve the problem of the linear measurement of arch ring for the detection of bridge,a new method is presented that measures the arch ring using a reflectorless total station on the side of the arch bridge and the detail operations are given. Taking account of weakness of edge suveying using a reflectorless total station,some formulas on the 3d coordinates calculation of the above and down edge of the arch ring based on the arch ring points are deduced.According to the law of error propagation, the accuracy of the X and Z axial coordinates are analysed.It is helpful for calculating lateral and vertical deformation and biridges elevation map that the transformation from free-station coordianates to the birdge axis coordinate by programming using EXCEL software is achieved.The method is used for bridges arch ring axial measurement in Qingcheng town,Yuzhong county,Gansu province,and its deformation is consistent with the measured results of the dial indicator,which satisfies the requirement of bridge detecton accuracy.So it is showed that the method is a good way of linear measuring of bridges arch ring.