Applied Mechanics and Materials Vol. 577

Abstract: In order to meet the measuring performance requirement of both high accuracy and large range when measuring the large-scale space angle formed by non-uniplanar lines quantitatively based on the engineering background of ammunition assembly angle test, we propose a measurement method that uses line structured laser as a common measurement reference and combined with vision inspection technique to achieve the measurement of large-scale space angle formed by non-uniplanar axes. Ammunition assembly angle have been measured accurately by using this method which provides a scientific approach for quality evaluation of that type of ammunition.

Abstract: The stress distribution of the coating interface in measuring bonding strength of revolution body coating was emulated. The stress curves of coating bonding interface were obtained. The abscission characteristics of coating were analyzed. It showed that Stress concentration occurred in the symmetric centre of the coating bonding interface. The coating peeled off from the symmetric centre to both sides of the sample interface in the measuring process. Avoiding shearing stress was a method to promote the measuring test of bonding strength of revolution body coating.

Abstract: A new method has been developed for the detection of broken rotor bars fault in squirrel cage induction motor during startup regimes. The incipient detection of fault is made by using DWT analysis of FIR low pass filtered original startup transient current signal. The extracted particular characteristic evolution of the time-varying signal is used as a fault index. The method was tested using healthy and damaged 3.0kW squirrel cage induction motors under no-load conditions. The results indicate that the method yields a high degree of performance in fault identification.

Abstract: The usability and reliability of conventional vehicle carrying system is not always satisfy when customers were using it, bugs occur occasionally. To solve the problem, this paper presented a series of field experiment plan to find and modify bugs so that its stability and usability would be guarantee. This paper introduced from the sensor calibration, Static floor check, vibrate test, braking test, long trip test to signal analysis, the high reliability of vehicle carrying system based on Compactrio is proved.

Abstract: Fish-eye lens is a special wide angle lens shooting all of the information within 185 degrees at the same time, but the image taken by it cause distortion. In order to fit for people's visual habits, the images need a correction. This article proposes a correction method of fish-eye lens based on projective reconstruction and verified the effectiveness of the method by the experiment.

Abstract: A new algorithm based on fractional lower order statistics (FLOS) is presented to joint estimate the range and direction of arrival (DOA) parameters of near-field sources. The proposed algorithm adopts centra-symmetric uniform linear array, and constructs three fractional lower order statistics matrixes by the received array data, and utilizes TLS method to estimate the two dimension parameters, the algorithm has high estimation accuracy, only need a parameters pairing easily. The performance of proposed method is verified by computer simulations.

Abstract: HLLC is a monotonous high resolution scheme, which can capture shock, contact discontinuity and rarefaction wave accurately. But when we use it to calculate the multidimensional problem, the phenomenon of shock instability will appear near the strong shock. Compared with the HLLC, the FORCE scheme can present a good stability near the strong shock, and the dissipation is lower than HLL. This paper analyzes the stability of HLLC and FORCE, and proposes a hybrid scheme which can not only present good stability but also retain the high resolution of HLLC.

Abstract: In this paper we proposed a secure image watermarking algorithm for digital image using the visual cryptography (VC) and discrete fractional Fourier transform (DFRFT). We use the visual secret sharing scheme to construct two shares, namely, master share and ownership share. Features of the original image are extracted using Non-Negative Matrix Factorization (NMF), and are used to generate the master share. Ownership share is generated with the help of secret image (watermark) and the master share, using VC technique. In case of any dispute, the master shares and ownership shares can be stacked together to give the copyright image verifying the ownership about the host image. In order to achieve the robustness and security, the properties of VC, DFRFT and NMF are used in our scheme. The experimental results show that the proposed scheme is strong enough to resist various signal processing operations.

Abstract: Parameter estimation of chirp signal is analyzed using Pei algorithm of FRFT (Fractional Fourier Transform). Firstly, the model of parameter estimation has been made. Secondly, the factors influencing the estimation accuracy have been analyzed. Finally, the simulation has been made to verify the conclusions.

Abstract: This paper analyzes the data got in two Monte Carlo simulations, namely, extensive air shower simulation and detector simulation. Then, based on the data from experimental arrays, some physical problems have been analyzed and illustrated. Those problems include the distribution of energy spectrum of secondary particles, the distribution of zenith angle, of azimuths, of background noises, and that of strip pattern, as well as the atmospheric absorption.