Tracklet-Global Track Fusion Using Support Degree Function in Sensor Networks

Xiaobin Li,En Fan,Changhong Yuan,Pengfei Li 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.10

For the situation with unknown qualities of local tracks in sensor networks, a new tracklet-global track fusion method using the support degree function (SDF-T2GTF) is proposed. According to the characteristic of actual transmission modes, two local estimates of a moving target in adjacent interval transmitted by the same local node are defined as a tracklet, and subsequently tracklet-global track (T2GT) fusion can replace the traditional track fusion in the global node, namely local track-global track (LT2GT) fusion. Considered the advantage of the fuzzy track association (TA) method for unknown prior information of local tracks, it is used in T2GT association. Then all correlated tracklets in the same interval can be mapped into a set of points in parameter space by the Hough transform (HT) algorithm. The support degree function of these points is utilized to dynamically estimate the qualities of tracklets and reasonably allocates the weights of local estimates in fusion results. Hence, the proposed method can realize T2GT fusion without the prior information of local tracks. The experimental result illustrates that the proposed method can satisfy the requirement of data transmission in real systems, and can realize T2GT fusion; on the other, it can improve the performance of track fusion in accuracy compared with the traditional methods.

Dynamic stiffness matrix of an axially loaded slender double-beam element

Li Jun,Hua Hongxing,Li Xiaobin 국제구조공학회 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

Dynamic stiffness matrix of an axially loaded slenderdouble-beam element

Jun, Li,Hongxing, Hua,Xiaobin, Li Techno-Press 2010 Structural Engineering and Mechanics, An Int'l Jou Vol.35 No.6

The dynamic stiffness matrix is formulated for an axially loaded slender double-beam element in which both beams are homogeneous, prismatic and of the same length by directly solving the governing differential equations of motion of the double-beam element. The Bernoulli-Euler beam theory is used to define the dynamic behaviors of the beams and the effects of the mass of springs and axial force are taken into account in the formulation. The dynamic stiffness method is used for calculation of the exact natural frequencies and mode shapes of the double-beam systems. Numerical results are given for a particular example of axially loaded double-beam system under a variety of boundary conditions, and the exact numerical solutions are shown for the natural frequencies and normal mode shapes. The effects of the axial force and boundary conditions are extensively discussed.

Hydraulic regenerative braking system studies based on a nonlinear dynamic model of a full vehicle

Ning Li,Xiaobin Ning,Qiucheng Wang,Jiliang Li 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.6

To obtain a reasonable match of the main parameters of a hydraulic regenerative braking system and to improve the energy recovery efficiency, this paper establishes the corresponding mathematical models and testbed for a hydraulic regenerative braking system. The proposed system is analysed and verified through simulation and experiments. Then, the linear and nonlinear mathematical models of a full vehicle are built, with joint simulation of the hydraulic regenerative braking system, and the influence of the hydraulic regenerative braking system on braking performance under different running conditions is discussed. The results indicate that the deviations in the simulation results between the linear and nonlinear dynamic models are very small. When the brake deceleration and road adhesion coefficient are 0.2, deviations are within 1.38 %. With an increase in the braking deceleration and road adhesion coefficient, the deviations in braking time and distance between the systems become larger and larger. When the braking deceleration and road adhesion coefficient are 0.7, the deviation reaches 30 %. Finally, with braking energy recovery efficiency and braking distance as the optimization objectives, the nonlinear braking energy recovery system parameters are optimized. After optimization, the energy recovery efficiency of the nonlinear system reaches 76.3 %, and the braking distance is 22.8 m.

Event-triggered Non-fragile State Estimation for Discrete Nonlinear Markov Jump Neural Networks with Sensor Failures

Jianning Li,Zhujian Li,Yufei Xu,Kaiyang Gu,Wendong Bao,Xiaobin Xu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.5

This paper investigates the non-fragile state estimation problem for discrete nonlinear Markov jump neural networks(MJNNs) with sensor failures. Due to the limit communication resource, we adopt a kind of eventtriggered mechanism to determine whether the sensor sampling information is sent or not. By selecting suitable Lyapunov functions, a sufficient condition is obtained to guarantee the mean-square exponential stability of the augmented system. Finally, a numerical example is given to show the effectiveness of the proposed method.

Dynamic stiffness analysis of steel-concrete composite beams

Jun Li,Qiji Huo,Xiaobin Li,Xiangshao Kong,Weiguo Wu 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.16 No.6

An exact dynamic stiffness method is introduced for investigating the free vibration characteristics of the steel-concrete composite beams consisting of a reinforced concrete slab and a steel beam which are connected by using the stud connectors. The elementary beam theory is used to define the dynamic behaviors of the two beams and the relative transverse deformation of the connectors is included in the formulation. The dynamic stiffness matrix is formulated from the exact analytical solutions of the governing differential equations of the composite beams in undamped free vibration. The application of the derived dynamic stiffness matrix is illustrated to predict the natural frequencies and mode shapes of the steel-concrete composite beams with seven boundary conditions. The present results are compared to the available solutions in the literature whenever possible.

Free vibration of a steel-concrete composite beam with coupled longitudinal and bending motions

Jun Li,Li Jiang,Xiaobin Li 국제구조공학회 2017 Steel and Composite Structures, An International J Vol.24 No.1

Free vibrations of steel-concrete composite beams are analyzed by using the dynamic stiffness approach. The coupled equations of motion of the composite beams are derived with help of the Hamilton's principle. The effects of the shear deformation and rotary inertia of the two beams as well as the transverse and axial deformations of the stud connectors are included in the formulation. The dynamic stiffness matrix is developed on the basis of the exact general solutions of the homogeneous governing differential equations of the composite beams. The use of the dynamic stiffness method to determine the natural frequencies and mode shapes of a particular steel-concrete composite beam with various boundary conditions is demonstrated. The accuracy and effectiveness of the present model and formulation are validated by comparison of the present results with the available solutions in literature.

Background Error Statistics for Aerosol Variables from WRF/Chem Predictions in Southern California

Zengliang Zang,Zilong Hao,Xiaobin Pan,Zhijin Li,Dan Chen,Li Zhang,Qinbin Li 한국기상학회 2015 Asia-Pacific Journal of Atmospheric Sciences Vol.51 No.2

Background error covariance (BEC) is crucial in data assimilation. This paper addresses the multivariate BEC associated with black carbon, organic carbon, nitrates, sulfates, and other constituents of aerosol species. These aerosol species are modeled and predicted using the Model for Simulating Aerosol Interactions and Chemistry scheme (MOSAIC) in the Weather Research and Forecasting/Chemistry (WRF/Chem) model at a resolution of 4 km in Southern California. The BEC is estimated from the differences between the 36-hour and 12-hour forecasts using the NMC method. The results indicated that the maximum background error standard deviation is associated with nitrate and is larger than that of black carbon, organic carbon, and sulfate. The horizontal and vertical scale of the correlation of nitrate is much smaller than that of other species. A significant cross-correlation is found between the species of black carbon and organic carbon. The cross-correlations between nitrate and other variables are relatively smaller and exhibit a relatively smaller length scale. Single observation data assimilation experiments are performed to illustrate the effect of the BEC on analysis increments.

Risk Assessment of Power System Security based on a Hybrid Optimization GP Method

Xiaobin Wu,Hui Li,Xiaolu Chen 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.12

In this paper, we propose a hybrid optimization algorithm based on Improved Differential Evolution (IDE) algorithm and Gaussian Process (GP). Firstly, the paper constructs the assessment index system using Fault Tree Analysis (FTA) based on the summary and classification of the factors that could affect the power system security. Secondly, establish the risk assessment model of power system security based on the hybrid optimization GP algorithm. Hyper-parameter of GP has a great influence on construction of evaluation model, while conjugate gradient method which is usually used has strong dependence on initial values and is easy to fall into local optimal solution. So the paper uses the IDE algorithm for the traditional Hyper-parameter optimization, then the optimal Hyper-parameter is used to construct evaluation model for power grid security risk assessment. In the process of improvement, this paper adds the local search (Bees accelerated evolution operation) and global search (Bees scout operation) thought of ABC algorithm into the DE algorithm to reduce the population size required by the algorithm. After that, do the risk assessment of power system by using the established assessment model. Finally, do the simulation experiments using the standard data IEEE-39 and IEEE-118 bus example, and besides compare the IDE-GP with other optimization model like ABC-GP, DE-GP, MA-GP, GA-GP, and the experimental results show that hybrid optimization algorithm has better performance in accuracy while the time-consuming difference is minor. The validity of the proposed method is also demonstrated.

Synergetics based damage detection of frame structures using piezoceramic patches

Xiaobin Hong,Jiaobiao Ruan,Guixiong Liu,Tao Wang,Youyong Li,Gangbing Song 국제구조공학회 2016 Smart Structures and Systems, An International Jou Vol.17 No.2

This paper investigates the Synergetics based Damage Detection Method (SDDM) for frame structures by using surface-bonded PZT (Lead Zirconate Titanate) patches. After analyzing the mechanism of pattern recognition from Synergetics, the operating framework with cooperation-competition-update process of SDDM was proposed. First, the dynamic identification equation of structural conditions was established and the adjoint vector (AV) set of original vector (OV) set was obtained by Generalized Inverse Matrix (GIM).Then, the order parameter equation and its evolution process were deduced through the strict mathematics ratiocination. Moreover, in order to complete online structural condition update feature, the iterative update algorithm was presented. Subsequently, the pathway in which SDDM was realized through the modified Synergetic Neural Network (SNN) was introduced and its assessment indices were confirmed. Finally, the experimental platform with a two-story frame structure was set up. The performances of the proposed methodology were tested for damage identifications by loosening various screw nuts group scenarios. The experiments were conducted in different damage degrees, the disturbance environment and the noisy environment, respectively. The results show the feasibility of SDDM using piezoceramic sensors and actuators, and demonstrate a strong ability of anti-disturbance and anti-noise in frame structure applications. This proposed approach can be extended to the similar structures for damage identification.