The methane monitoring system for coal mines is capable of detecting apparent changes in the value of the mine gas composition. It could provide guidance for coal miners to escape following the safest and fastest rout...
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ISBN:
(纸本)9781479913909
The methane monitoring system for coal mines is capable of detecting apparent changes in the value of the mine gas composition. It could provide guidance for coal miners to escape following the safest and fastest route while a mine disaster was occurring. In this paper, the coal mine network topology model was established. Furthermore, it is desirable to apply XML-based mechanism for data storage in order to enhance the interoperability. In following, Gaussian puff model was built for the sake of simulating the process of methane gas diffusion with model parameters adjusted according to the coal mine network topology. Application of this model was of great significance for realizing the Markov-chain based simulation engine. The escape routes for coal miners were generated and optimized using the dijkstra algorithm. The experiment results suggest that the methane gas concentration proved to be the major precursor indicating the gas emission hazard. In addition, the correctness and validity of the proposed model was verified though modeling and simulation of the Daping coal mine in China.
The airspace for the activities of light-sport aircraft in Taiwan is strongly restricted due to mountainous terrains and populated areas. This study intends to investigate the feasible sky-lanes for light-sport aircra...
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The airspace for the activities of light-sport aircraft in Taiwan is strongly restricted due to mountainous terrains and populated areas. This study intends to investigate the feasible sky-lanes for light-sport aircraft by minimize the impact to populated area and the threats from terrain obstacles to the aircraft. The terrain obstacles and populated area is considered and segmented in the two-dimensional structure through the graph theory. The shortest path problem between the aerodrome and the training area is established to minimize the impact to population and threats to the aircraft. The dijkstra algorithm is adopted to resolve the planning of feasible sky lanes and gives the possibility of the augmentation of airspace for the activities of light-sport aircraft.
Effective path planning has been identified as an important requirement for route navigation in Intelligent Transportation Systems (ITS). However, the paths computed by the conventional path planning algorithms are us...
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Effective path planning has been identified as an important requirement for route navigation in Intelligent Transportation Systems (ITS). However, the paths computed by the conventional path planning algorithms are usually not optimal because they ignore the drivers’ experience and the characteristics of the local road network. Routes chosen by taxi drivers are believed to be more representative, so it can be significant to take advantage of the taxi drivers’ experience to support the path planning. We present a hierarchical path planning method based on the experiential routes of taxis. The algorithm consists of three steps. Firstly, routes are extracted from original taxi trajectories. Secondly, all roads are categorized according to the track data and then the road network is classified into two grades using travel frequency for road segments. Thirdly, combined with dijkstra algorithm, a hierarchical path planning method which searches paths by traversing the hierarchy is proposed. Guangzhou, China is chosen for the study because of the availability of taxi GPS data. This study compares the paths planned by the proposed approach with the conventional algorithm's results from the aspects such as travel time and route length. The experimental results show that the method proposed incurs much lower costs in travel time than the traditional ITS path planning using dijkstra or hierarchical dijkstra algorithms.
The optimal path algorithm analysis of GPS navigation in taxi management system based on A* algorithm was introduced in this paper. Through improving the traditional dijkstra algorithm and avoiding problems such as ...
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The optimal path algorithm analysis of GPS navigation in taxi management system based on A* algorithm was introduced in this paper. Through improving the traditional dijkstra algorithm and avoiding problems such as "time-consuming and low efficiency" in dijkstra algorithm with traversal search for each node, A* algorithm could help the taxi find the optimal path and bring convenience for traffic management.
GPS positioning system is installed in taxis and most mobile phones support GPS positioning function at present. GPS phones are used in the taxi to achieving intelligent scheduling based on this basis. The taxi intell...
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GPS positioning system is installed in taxis and most mobile phones support GPS positioning function at present. GPS phones are used in the taxi to achieving intelligent scheduling based on this basis. The taxi intelligent dispatch system based on GPS is proposed, improve the traditional dijkstra scheduling algorithms by setting taxi maximum reasonable scheduling range, experimental results show that improved algorithms reduce the time complexity and improve scheduling efficiency. Meanwhile the traffic jam information can be sent to the dispatch center and make scheduling algorithm more reasonable by combined with above information.
Generator start-up sequence is critical to power system restoration. A new algorithm to optimize the start-up sequence of generators based on dijkstra method is proposed in this paper. First, a combined weight is prop...
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ISBN:
(纸本)9781479913022
Generator start-up sequence is critical to power system restoration. A new algorithm to optimize the start-up sequence of generators based on dijkstra method is proposed in this paper. First, a combined weight is proposed for the dijkstra method to balance various optimization objects. Based on the modified weights, a priority index considering the branch weight, generator start-up requirement and ramping rate is proposed to optimize the generator start-up sequence. Second, we analyze the backtracking algorithm in detail and found its limitation and disadvantages, which leads a large amount of calculation and start-up failure. A new algorithm to calculate the start-up sequence is proposed. It can avoid the repetition calculation of dijkstra and reduce the computation cost by avoiding backtracking. Finally, the IEEE 30-Bus system and Guangdong power grid system are used to validate the proposed algorithm. Simulation results show that the proposed method is efficiency and it can decrease the restoration time significantly.
In this figure, it finds a vertex to another vertex k shortest path algorithm. Provided there are n vertices and edges in the diagram. If the path loops, the time complexity of the algorithm is allowed O(w+nlog n +kw...
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In this figure, it finds a vertex to another vertex k shortest path algorithm. Provided there are n vertices and edges in the diagram. If the path loops, the time complexity of the algorithm is allowed O(w+nlog n +kwlogk). If the request path does not contain the loop, the time complexity of the algorithm O(kn(w +nlogn) +kwlogk). The algorithm utilizes a simple extension of the dijkstra algorithm determined the end of the length of the shortest path to the other vertices, and then, based on these data, branch and bound method to identify the required path. Experimental results show that the actual running time has relations with the structure of FIG.
In this study a modified Live-Wire approach is presented. A Fuzzy C-Means (FCM) clustering procedure has been implemented before the wavelet transform cost map function is defined. This shrinks the area to be searched...
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In this study a modified Live-Wire approach is presented. A Fuzzy C-Means (FCM) clustering procedure has been implemented before the wavelet transform cost map function is defined. This shrinks the area to be searched resulting in a significant reduction of the computational complexity. The method has been employed to computed tomography (CT) and magnetic resonance (MR) studies. The 2D segmentation of lungs, abdominal structures and knee joint has been performed in order to evaluate the method. Significant numerical complexity reduction of the Live-Wire algorithm as well as improvement of the object delineation with a decreased number of user interactions have been obtained. (C) 2012 Elsevier Ltd. All rights reserved.
This study is motivated by the need for a micro-geographic information system (GIS) to represent and analyze 3D spatial data for the plotting of fire-fighting search and rescue routes within buildings. The GIS uses a ...
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This study is motivated by the need for a micro-geographic information system (GIS) to represent and analyze 3D spatial data for the plotting of fire-fighting search and rescue routes within buildings. The GIS uses a 3D geometric network model (GNM) and the dijkstra algorithm to consider smoke movement during different times of a building fire. Therefore, the route calculation algorithm can avoid routes through heavy smoke within buildings. In addition, when firefighters must search an area to find victims, the GNM and Ant Colony Optimization are applied to find the shortest path that passes through each room of the area. Finally, the GNM is implemented to perform a search and rescue route analysis from an actual underground station. The proposed method can not only provide the shortest safe route within a building but can also minimize the time required to search for potential victims. (C) 2011 Elsevier Ltd. All rights reserved.
The authors study the issues on distributed geographical packet forwarding in wireless sensor and actuator networks (WSANs) using a stochastic optimal control approach. First, a distributed geographic-informed forward...
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The authors study the issues on distributed geographical packet forwarding in wireless sensor and actuator networks (WSANs) using a stochastic optimal control approach. First, a distributed geographic-informed forwarding (DGIF) scheme is proposed that defines a set of distributed routing policies. Then, the distributed WSAN packet forwarding problem is modelled and analysed from the perspective of stochastic optimal control. The WSAN is viewed as a controlled stochastic system. The routing procedure is determined by the routing policy and system disturbance (e. g. the position uncertainty of remote nodes) jointly. An improved value iteration method is presented to accelerate the convergence of the optimal routing strategy. The reliability-driven routing algorithm (called DGIF-RRP) for emergency applications and the quality-of-serviceaware routing algorithm (called DGIF-QRP) for real-time applications are proposed. Simulations are carried out to evaluate the proposed routing algorithms. The results show that DGIF-RRP and DGIF-QRP significantly outperform two enhanced versions of the dijkstra's algorithm in emergency and real-time applications, respectively.
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