Jiang Feng Wang’s research while affiliated with Beijing Technology and Business University and other places

Mechanical and deformation characteristics of pile-anchor retaining structure was analyzed by using numerical simulation method. The rationality of numerical model was also verified through comparing measured data in field test and numerical results. On the basis of this numerical model, Mechanical and deformation characteristics of supporting structure under the condition of different soil replacement ratio (m) was analyzed. The results show that: mechanical and deformation characteristics of supporting structure was improved by improving soil which behind retaining pile. The higher the soil replacement rate is, the effect to mechanical and deformation characteristics of supporting structure was more obvious.

This paper describes an architecture of ANFIS (adaptive network based fuzzy inference system), to the prediction of chaotic time series, where the goal is to minimize the prediction error. We consider the stock data as the time series. This paper focuses on how the stock data affect the prediction performance. In the experiments we changed the number of data as input of the ANFIS model, the type of membership functions and the desired goal error, thereby increasing the complexity of the training.

We present a new method to accurately tracking persons indoors by active RFID technology. To deal with nonlinear measurement model, the EKF(extended Kalman filter) is used to estimate the target trajectory. This paper developed the fusion estimation algorithm for the common indoor tracking problem with the reader at any location and fusion estimation with variable number of multi-sensor system. Simulations show the algorithm developed here can adaptively adjust the model parameter while tracking and obtain good estimation performance for indoor RFID tracking.

Mechanical and deformation characteristics of pile-anchor retaining structure was analyzed by using numerical simulation method. The rationality of numerical model was also verified through comparing measured data in field test and numerical results. On the basis of this numerical model, Mechanical and deformation characteristics of pile-anchor retaining structure under three different construction procedures were analyzed individually. The results show that: the maximum horizontal displacement of pile is controlled effectively by applying anchoring force, and the global horizontal displacement of pile increases as well. Forced state of pile is changed from being bended on one side to being bended on both sides, and maximum moment value decreases heavily. Therefore, anchor cable reinforcement should be arranged at the head of construction procedure of pile-anchor retaining structure. The later anchoring force be applied, the closer inflection point nears the pile top.

Constant volume equivalent undrained testing is performed under cyclic loading by the PFC2D model, and the liquefaction behavior of saturated stratified silty sands is discussed from the viewpoint of meso-mechanism. Meso-scale parameters such as co-ordination number, distribution of contact normal and contact forces are studied under cyclic loading. Some results are obtained. The important factors which control the macro-response of saturated stratified silty sands are the average co-ordination number, distribution of contact normal and contact forces at meso-mechanical level. The major characteristics of deformation are stress-induced anisotropy and fabric-induced anisotropy. And the liquefaction behavior of loose saturated stratified silty sands is mainly due to continued and cumulative loss of the co-ordination number under cyclic loading. Numerical simulation can describe the liquefaction behavior of saturated stratified silty sands. The meso-fabric evolutions including co-ordination number, distribution of contact normal and contact forces can be analyzed during liquefaction induced by cyclic loading. Numerical simulation can also be used to illustrate and verify a theoretical relationship between measures of macro- and meso-scopic parameters that describe the anisotropy in contact forces and contact orientations.

The traffic conflict between pedestrian and vehicle is a main factor that influences the intersection safety and capacity. In this paper, a conflict model that simulates the pedestrians and vehicles' crossing behaviors when passing the pedestrian crossing area at signalized intersection is presented based on cellular automata method. Evolution rules for pedestrians, vehicles and conflicts between them are assigned. Four types of traffic conflict events and conflict areas are categorized and defined. On the basis of the simulation results, the pedestrian delay owning to traffic conflicts, the number of pedestrians' conflicts, the conflict event and their relationships with the vehicle density as well as the pedestrian density are analyzed and discussed. This model reproduces realistic pedestrian-related traffic phenomenon effectively and can be used in more complex traffic environments at signalized intersections.

Vehicular ad hoc networks (VANETs) form when vehicles are equipped with devices capable of short-range wireless communication. Realistic vehicle trace modeling for VANETs simulations is a challenging task, which requires the reliable characterization of vehicular mobility. In this study, three different vehicle scenarios are proposed to analyze the difference between vehicle traces in multi-scenarios: city road, expressway and highway. Common trace modeling tools and characters of the scenarios are explored. Furthermore, three experimental scenarios are established using VanetMobiSim to produce vehicle traces. The experimental results show that the trend of the average speed versus the number of vehicles is different, and the vehicular density distribution demonstrates the realism of vehicle trace under multi-scenarios.

Vehicular ad hoc networks (VANETs) form when vehicles are equipped with devices capable of short-range wireless communication. Accurate wireless positioning of VANETs is a challenging task, which requires a robust wireless positioning algorithm. In this study, a quadrilateral positioning algorithm is proposed to estimate the moving vehicle node's position in VANETs based on the wireless signal's "distance-loss" model and geometric relationship. Furthermore, a wireless positioning experimental platform was created to test the positioning algorithm applications in field. The experimental results show that when the moving node is inside the fixed nodes, the positioning accuracy is much higher than the case that the moving node is outside the fixed nodes; when the moving node is located in the middle of the experimental field, the positioning accuracy is higher than located at the corner areas in the test field.

In vehicular ad hoc network(VANETs), it is crucial for obtaining more accurate position information which variation rules between “distance-loss” model influence factors and distance measurement error is analyzed. Based on qualitative analysis of “distance-loss” model, field experimental scene and scheme are proposed. Using experimental sample data, the relation of environmental factor and shelter factor and distance measurement error is studied quantitatively. The experimental results show that distance measurement performance of optimized “distance-loss” model is significantly improved, and 6.7% is the largest reduction proportion of distance measurement error.

based on the finite element method of superstructure-the pile raft foundation-the foundation soil action and interaction are studied. Research shows that the common function is considered, fundamental overall settlement and differential settlement with the increase of floor of a nonlinear trend. The influence of superstructure form is bigger for raft stress, the upper structure existing in secondary stress, and the bending moment and axial force than conventional design method slants big; With the increase of the floors, pile load sharing ratio is reduced gradually,but soil load sharing ratio is increased. Along with the increase of the upper structure stiffness, the load focused on corner and side pile; Increasing thickness of raft, can reduce the certain differential settlement and foundation average settlement, thus reducing the upper structure of secondary stress and improving of foundation soil load sharing ratio, at the same time the distribution of counterforce on the pile head is more uneven under raft, thus requiring more uneven from raft stress, considering the piles under raft and the stress of soils to comprehensive determines a reasonable raft thickness, which makes the design safety economy. As the foundation soil modulus of deformation of foundation soil improvement, sharing the upper loads increases, counterforce on the pile head incline to average, raft maximum bending moment decrease gradually.