For microseisimic monitoring it is difficult to determine wave modes and their propagation velocity. In this paper, we propose a new method for automatically inverting in real time the source characteristics of micros...For microseisimic monitoring it is difficult to determine wave modes and their propagation velocity. In this paper, we propose a new method for automatically inverting in real time the source characteristics of microseismic events in mine engineering without wave mode identification and velocities. Based on the wave equation in a spherical coordinate system, we derive a tomographic imaging equation and formulate a scanning parameter selection criterion by which the microseisimic event maximum energy and corresponding parameters can be determined. By determining the maximum energy positions inside a given risk district, we can indentify microseismic events inside or outside the risk districts. The synthetic and field examples demonstrate that the proposed tomographic imaging method can automatically position microseismic events by only knowing the risk district dimensions and range of velocities without identifying the wavefield modes and accurate velocities. Therefore, the new method utilizes the full wavefields to automatically monitor microseismic events.展开更多
A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism prop...A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism proposed to calculate the samples＇ weights; the convergence and veracity of the sample set are guaranteed by the designed resampling and scattering process. The proposed serf-localization algorithm is fully implemented on a specific mobile robot system, and experimental results illustrate that it provides an efficient solution for the kidnapped problem.展开更多
An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the c...An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.展开更多
The use of AVL （automatic vehicle locator） systems has increased considerably. By using an AVL system, it is possible to know vehicle positions at the dispatch center, which allows the use of several applications, s...The use of AVL （automatic vehicle locator） systems has increased considerably. By using an AVL system, it is possible to know vehicle positions at the dispatch center, which allows the use of several applications, such as safety and security, logistics, and emergency response. High communication and data storage costs, however, lead to a low position update rate with the AVL products available, causing poor track representation, and making the route determined by the vehicle in urban areas almost illegible. This paper proposes a new approach by using intelligent techniques to choose the best position update moment to improve track representations. The principle underlying these techniques is based on vehicle status analysis （speed, direction and timing）, which tries to determine when a position update is required, in order to better represent the path that a vehicle has traced, thus avoiding excessive communication and data storage. Therefore, the better the correspondence between the traced track and the real track followed by the vehicle, the greater the added value offered by system applications. This enhancement to the representation of the track allows the creation of new applications in the realm of AVL systems, particularly for situations where accuracy plays an important role.展开更多
Energy is the determinant factor for the survival of Mobile Sensor Networks(MSN).Based on the analysis of the energy distribution in this paper,a two-phase relocation algorithm is proposed based on the balance between...Energy is the determinant factor for the survival of Mobile Sensor Networks(MSN).Based on the analysis of the energy distribution in this paper,a two-phase relocation algorithm is proposed based on the balance between the energy provision and energy consumption distribution.Our main objectives are to maximize the coverage percentage and to minimize the total distance of node movements.This algorithm is designed to meet the requirement of non-uniform distribution network applications,to extend the lifetime of MSN and to simplify the design of the routing protocol.In ad-dition,test results show the feasibility of our proposed relocation algorithm.展开更多
基金support jointly by projects of the National Natural Science Fund Project (40674017 and 50774012)the National Key Basic Research and Development Plan 973 (2010CB226803)
文摘For microseisimic monitoring it is difficult to determine wave modes and their propagation velocity. In this paper, we propose a new method for automatically inverting in real time the source characteristics of microseismic events in mine engineering without wave mode identification and velocities. Based on the wave equation in a spherical coordinate system, we derive a tomographic imaging equation and formulate a scanning parameter selection criterion by which the microseisimic event maximum energy and corresponding parameters can be determined. By determining the maximum energy positions inside a given risk district, we can indentify microseismic events inside or outside the risk districts. The synthetic and field examples demonstrate that the proposed tomographic imaging method can automatically position microseismic events by only knowing the risk district dimensions and range of velocities without identifying the wavefield modes and accurate velocities. Therefore, the new method utilizes the full wavefields to automatically monitor microseismic events.
基金Supported by the National Natural Science Foundation of China (No. 60875055)Natural Science Foundation of Tianjin (No. 07JCY-BJC05400)Program for New Century Excellent Talents in University (No. NCET-06-0210)
文摘A practical serf-localization scheme for mobile robots is proposed and implemented by utilizing sonar sensors. Specifically, the localization problem is solved by employing Monte Carlo method with a new mechanism proposed to calculate the samples＇ weights; the convergence and veracity of the sample set are guaranteed by the designed resampling and scattering process. The proposed serf-localization algorithm is fully implemented on a specific mobile robot system, and experimental results illustrate that it provides an efficient solution for the kidnapped problem.
基金Supported by the National Natural Science Foundation of China （60974061）.
文摘An integrated method for identifying the propagation of multi-loop process oscillations and their source location is proposed in this paper. Oscillatory process loop variables are automatically selected based on the component-related ratio index and a mixing matrix, both of which are obtained in data preprocessing by spectral independent component analysis. The complex causality among oscillatory process variables is then revealed by Granger causality test and is visualized in the form of causality diagram. The simplification of causal connectivity in the diagram is performed according to the understanding of process knowledge and the final simplest causality diagram, which represents the main oscillation propagation paths, is achieved by the automated cutting-off thresh-old search, with which less significant causality pathways are filtered out. The source of the oscillation disturbance can be identified intuitively through the final causality diagram. Both simulated and real plant data tests are presented to demonstrate the effectiveness and feasibility of the proposed method.
文摘The use of AVL （automatic vehicle locator） systems has increased considerably. By using an AVL system, it is possible to know vehicle positions at the dispatch center, which allows the use of several applications, such as safety and security, logistics, and emergency response. High communication and data storage costs, however, lead to a low position update rate with the AVL products available, causing poor track representation, and making the route determined by the vehicle in urban areas almost illegible. This paper proposes a new approach by using intelligent techniques to choose the best position update moment to improve track representations. The principle underlying these techniques is based on vehicle status analysis （speed, direction and timing）, which tries to determine when a position update is required, in order to better represent the path that a vehicle has traced, thus avoiding excessive communication and data storage. Therefore, the better the correspondence between the traced track and the real track followed by the vehicle, the greater the added value offered by system applications. This enhancement to the representation of the track allows the creation of new applications in the realm of AVL systems, particularly for situations where accuracy plays an important role.
文摘Energy is the determinant factor for the survival of Mobile Sensor Networks(MSN).Based on the analysis of the energy distribution in this paper,a two-phase relocation algorithm is proposed based on the balance between the energy provision and energy consumption distribution.Our main objectives are to maximize the coverage percentage and to minimize the total distance of node movements.This algorithm is designed to meet the requirement of non-uniform distribution network applications,to extend the lifetime of MSN and to simplify the design of the routing protocol.In ad-dition,test results show the feasibility of our proposed relocation algorithm.
