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Research shows that multi-fractal can not only exhibit the singular probability distribution form of the fractal signal completely, but also increase the fine level of signal geometrical characteristics and local scaling behavior. Based on multi fractal dimension calculation of time frequency matrix of vibration signal of rolling bearing in this paper, energy distribution characteristics of time-frequency...
In the operation of bulldozer, the working device bears various complex loads, which raise higher demands on the rationality of the structural design, the convenience of the operation, the durability and the reliability of the working device. The finite element method is used to analysis the structural strength and the fatigue life of the working device. The dangerous points, stress, strain distribution...
A fault diagnosis approach based on empirical mode decomposition(EMD), Hilbert envelope spectrum and Kurtosis criterion is proposed, by considering the nonlinear and non-stationary characteristic of fault signal for rolling bearing. The fault signals are decomposed into a sum of intrinsic mode functions(IMFs) with EMD decomposing process. Also, some of the IMFs are selected to reconstruct the signal...
In all the security issues in wireless sensor networks (WSNs), session key exchange is fundamental one with a great challenge. Owning to the semi-group property and one-way trapped characteristic of Chebyshev polynomials, an enhanced key exchange scheme based on Chebyshev chaotic map for WSNs was proposed in this paper. Our scheme aims at increasing the security of the session key between nodes. According...
In the wharf structure health monitoring systems, the systems exit low efficiency of data transmission and no effective data processing problems, which result in less effective reflecting the health status of the wharf structure. In order to improve the data transmission efficiency and make a better use of the data, an intelligent wireless sensor network (WSN) method and multi-sensor information fusion...
Probabilistic tracking algorithms typically using linear structure to update the learning model. Such linear structure is not appropriate for long-term robust tracking as the occlusion and other challenging factors may interfere the processing of incoming frames. Recently a spatio-temporal context (STC) algorithm based on Bayesian framework has using the context information between the target and...
In order to meet the current requirement of low voltage apparatus protection function test, a design of three phase high current generator based on virtual instrument technology is proposed. The coarse-fine tuning voltage regulator with the compensation transformer structure is used in the main circuit of the current generator, which not only could extend the range of current regulation, improve current...
Based on the existing research of Chinese text clustering, this paper proposes an improved algorithm for the optimization of short term semantic clustering based on social media. The method of weighted factor is introduced to optimize text distance formula and related mathematical proof, the calculation process optimization design from text, written text distance calculation algorithm, the simulation...
Tri-axial magnetometers used to calculate the heading information of vehicles. In this paper, a method of determining attitude variations using only one tri-axial magnetometer was proposed. The condition is that the vehicle has only four degrees of freedom (moving pitch and roll). In addition, the attitude changing process was decomposed. Therefore, the attitude was calculated with the data of current...
Wind power and solar energy are representatives of renewable resources, and their volatility and randomization make power grid regard wind power and solar energy as negative load in daily dispatch. The increase of wind power and solar energy in the system may lead to the increase of uncontrollable factors, so the abilities for power grid to receive wind power and solar energy might be limited. Limiting...
In this paper, the fast field program based on propagator matrix is used to model the acoustic field of airborne source in the air and underwater. The main characteristic distributions and the changing law of the airborne source radiated noise through the air-sea interface is analyzed in vertical direction at a certain distance and in level direction at a certain depth. It is of significance to further...
The forging handling robot is one of the key pieces of equipment in the integrated forging operation unit. The robot is characterized by heavy loading ability, high velocity and high positioning accuracy. According to these characteristics, this work proposes a new scheme for the hybrid structure. The scheme can complete 5-DOF motion, which contains body rotation, clamp expansion, clamp lifting, clamp...
In order to overcome the drawbacks of the traditional frame-difference method that is used in moving target detection, and to achieve both accurate and robust detection result, a novel approach for moving objects detection based on improved Canny edge detection and adaptive frame difference method is proposed in this paper. Firstly, select the threshold value of three-frame difference method adaptively...
Based on the deficiencies for risk indicators of fault probability and consequence's application in distribution systems, the strategy of risk assessment for system operation based on health and importance indices is proposed. The health index oriented to system running states and importance index geared to the user diversity are defined, by comprehensively thinking about the development situation...
The working principle of the electro-hydrostatic actuator(EHA) is described, and its mathematical model is deduced. To further improve the robustness of the EHA system, a fuzzy adaptive PID control model is proposed, simulation using MATLAB /Simulink. The results show that the system step response is fast, sport smoothness is better.
With the gradual advance of transmission and distribution price reform, the operating mode and profit model of power grid enterprises will be completely changed. By strengthening the supervision of transmission and distribution costs of power grid enterprises, the government has mobilized the power grid to reduce operating costs and improve the quality of customer service. At the same time, it also...
With an increase in acceptance of face recognition systems, the desire for accurate biometric authentication — face recognition, has increased. Nowadays, the fundamental limitations of existing systems are, the vulnerabilities of false verification via a picture or simple video of a person. In this paper, it is inspired by how humans can perform reliable spoofing detection only based on the available...
The protection of important nodes in Large-scale software network has been the focus of software engineering. Large-scale software network is a kind of complex network, therefore, we can identify influential nodes in large-scale software networks in the view of complex networks. This paper proposes a method for measure the importance of nodes based on the duplicato-degree and the neighbor clustering...
Recent years, many researchers are focus on personalized recommendation in the area of knowledge discovery. Due to the user privacy, a recommender system finds it is hard to help individual user to find the items which the user prefers quickly and precisely. So, we combine domain features with AHP model to help us solve the problem. In this paper, we introduce a new recommendation method named AHP-Based...
Process monitoring and controlling system is essentially a data monitoring event transmission system, they are usually developed based on the procedure languange C with high cost and in low maintainability. functional reactive programming is a time-saving, bug-preventing programming paradigm worthy of control system to implement. In this paper the implementing the new kind of functional reactive programming...
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