Applied Mechanics and Materials Vols. 668-669

Abstract: Industrial frequency and its harmonious waves are one of the main interferences in electronic measurement, which will cause severe influence on test accuracy. Digital filter is better than analog filter at resolution; furthermore multi-band stop digital filter design is unrealizable for analog filter design method. This paper designs an FIR(Finite Impulse Response) multi-band stop digital filter to reject the noise of 50 Hz and its harmonic waves from power network, whose stop bands are respectively as 48~52 Hz, 98~102 Hz and 148~152 Hz. Simulation results prove that the noise can be depressed to 30 dB. To analyze the filtered signal can improve accuracy of the test system. The whole course includes two parts, which are filter mathematical modeling and filter algorithm implementation on worksite data.

Abstract: This paper presents a Fast display Algorithm of large Map File based on memory mapping file technique, designing for reducing the number of pointer moves and the data in memory scheduling ,The algorithm uses a memory-mapped file access operation of a large-scale map file to resolve the problem of traditional file processing methods, which can not read more than 2G map image file; combined image pyramid technology to apply different resolutions depending on the display requirements map image, in order to achieve the purpose of roaming quickly. The experiment and analysis results show that the algorithm is able to achieve the best resolution real-time roaming of large-scale digital map.

Abstract: This paper studies on the eigenvalue^[1-5] of the a class of upper triangular matrix with linear relation. It discusses the feature of existence and uniqueness of matrix via two given two characteristic pairs(λ,χ),(μ,γ) . Solutions and expressions are provided under satisfied conditions. The possibilities are exanimated by numerical example.

Abstract: In traditional target tracking methods, the target number, target states and target class can not be estimated in same time. This paper investigated the joint target detection, tracking and classification method which is based on finite-set statistics theory. First, the random set and finite-set statistics theory are introduced for theoretic analysis. Second, the finite-set model for target tracking is given to construct a generalized nonlinear fusion framework. Finally, the finite-set based Bayesian filter is developed to track the targets in surveillance region. By recursively calculating the probabilistic hypothesis density, the target number, target states and target class can be evaluated simultaneously.

Abstract: The measurement data of the marine gravity contains a lot of noise, the low frequency part of which have a similar frequency with the gravity signal. It’s difficult to inhibit the noise of the measurement data and extract the gravity signal by classical algorithms. Therefore, in order to effectively eliminate the noise of the measurement gravity data and improve the accuracy of the extracted signal, based on algorithms of wavelet and Empirical Mode Decomposition (EMD), a novel method to extract the sea gravity anomaly signal is proposed. Firstly, the measurement gravity signal is decomposed into detail signals and approximate signals. Secondly, the algorithm EMD is used to extract the low-frequency part of the decomposed signals, and the estimation of the gravity anomaly is reconstructed by inverse wavelet transform. The de-noising experiment has been emulated based on the measurement gravity data. Results of theoretical analysis and emulation experiments indicate that the proposed method can effectively eliminate the noise of the measurement gravity and recovery the wave form of gravity signal, the accuracy of the signal can be approximately increased 40% than classical algorithms.

Abstract: Mass distribution of floating structures will change due to such factors as ballast water management during ship sailing or inward and outward port, crane movement during construction, and the loading and unloading of cargoes on the offshore platform structures, which will then make its natural frequency change with time. While traditional modal identification cannot deal with the issues of non-stationary of time-varying system, Hilbert-Huang transform is quite effective for the processing and analysis of non-stationary signal. Therefore, this paper investigates the identification of linear time-varying system using the Hilbert-Huang transform, and conducts a numerical simulation of the two degrees-of-freedom time-varying system. In addition, this paper designs a cantilever beam subjected to a moving mass, and then makes a comparison of the identification results between the present identification method and those from finite element method (FEM) and eigensystem realization algorithm (ERA), which shows a higher accuracy of the present method for modal identification of time-varying system.

Abstract: This paper aims at the difficulty that lack of observation model and high-dimensional sampling in video tooning, proposes a method based on key frame matching and dual-directional Markov chain Monte Carlo sampling of video motion redirection. At first, after extracting the key frame of a given video, By affine transformation and linear superposition, the subject initializes the video’s space-time parameters and forms the observation model; Secondly, in each space-time, based on the bi-directional Markov property of each frame, This paper proposed a dual-directional Markov chain Monte Carlo sampling particle filter structure and takes full advantage of the relationship of the front and back frame of the parameters to estimate motion redirection parameters. At the same time, for high-dimensional sampling problem, the subject according to the directional parameters’ correlation implements classification of skeleton parameters-morphological parameters-physical parameters, proposes a hierarchical genetic strategy to optimize the output parameters and improves the efficiency of the algorithm. The research of this paper will produce an efficient and prominent animation expressive video motion redirection method and play an important role on video animation of the development.

Abstract: Fuzzy integral has been widely used in multi-attribution classification when the interactions exist between the attributions. Because the fuzzy measure defined on the attributions represents the weights of all the attributions and the interactions between them. The lower integral is a type of fuzzy integral with respect to fuzzy measures, which represents the minimum potential of efficiency for a group of attributions with interaction. The value of lower integrals can be evaluated through solving a linear programming problem. Considering the lower integral as a classifier, this paper investigates its implementation and performance. The difficult step in the implementation is how to learn the non-additive set function used in lower integrals. And Genetic algorithm is used to solve the problem. Finally, numerical simulations on some benchmark data sets are given.

Abstract: We consider one axisymmetric problem of the equilibrium position of a soft rotation shell. Generalized statement of this problem is formulated in the form of variational inequality with a pseudo-monotone operator in Banach space. To solve this variational inequality, we suggest the iterative method. This method was realized numerically. The numerical experiments made for the model problems confirmed the efficiency of the iterative method.

Abstract: Catadioptric panoramic vision system has been widely used in many fields, and also plays a very important role in environment perception of unmanned platform especially. However, the resolution of system is not very high, usually less than 5 million pixels at present. Even if the resolution is high, but the unwrapping and rectification of panoramic video is carried out off-line. Further, the system is also applied in stationary state or low stationary moving. This paper proposes an unwrapping and rectification method based on high-resolution catadioptric panoramic vision system used during non-stationary moving. It can segment dynamic circular mark region accurately and get the coordinates of center of circular image real-timely, shorten the time of image processing, meanwhile the coordinates of center and radius of the circular mark region would be obtained, so the image distortion caused by inaccurate center coordinates can be reduced. During image rectification, after achieving radial distortions parameters (K₁, K₂, K₃), decentering distortions parameters (P₁, P₂), and the correction factor that has no physical meanings, we can used those for fitting the rectification polynomial, so the panoramic video can be rectified without distortion.