511 results about "Short path algorithm" patented technology

This invention extends routing mechanisms that use link metrics for route selection so that: A link metric cross correlation vector is determined for all links, where each element in the vector corresponds to some other link, and reflects the change in the link metric value if a data flow would already use this other link. The invention further describes a specific embodiment where all cross-correlating links are adjacent to each other, i.e., they terminate or originate in a common node. A mechanism is described to create an extended routing graph. This extended graph permits the use of standard polynomial time algorithms that simultaneously construct the optimal route and find the optimal route metric (such as shortest-path algorithms) also for the adjacent link cross-correlating case.

A method for finding shared risk diverse paths is disclosed. The method includes receiving route information at a node and running a shortest path algorithm to identify a first path. A shared risk metric is assigned to links and nodes with the first path. The method further includes running the shortest path algorithm with the shared risk metrics assigned to identify a second path and comparing the first and second paths. New shared risk metrics are assigned to links and nodes in the second path if the first and second paths are not diverse. The second path then becomes the first path and the algorithm is repeated.

The invention relates to a method for evaluating traffic jam, congestion and smooth state of urban roads by using floating vehicle data. Concretely, the method comprises the following steps: analyzing the transmission frequency and the traveling tracks of data based on the prior GPS data by using network state estimation technique based on GPS data of floating vehicles in detail; selecting a comprehensive evaluation value of the calculation result of a time shortest path algorithm as the traveling speed of the road in consideration of the OD characteristics of the urban traffic; and comprehensively evaluating the traffic state of the road by using fuzzy reasoning technique based on the combination of the traveling speed and the use function of the road. The improved evaluation method has the advantages of easily satisfied operation condition, easy implementation, and accurate result.

A sensor network routing is formulated as a joint optimization problem taking into account routing cost and information aggregation. Information gain is used explicitly to optimize the routing path. The optimization approach involves a shortest path algorithm in a modified network graph. A method is provided that routes queries from an arbitrary entry point to high activity network sensor regions using inputs from sensor nodes along the path to refine the message. The multiple step look-ahead approach provides deadlock avoidance and routing around sensor network holes. For point-to-point query routing, a method based on real-time A* (RTA*) search is provided to find a path which takes detours efficiently to maximize information aggregation. Future information expected to be gained along the path from an arbitrary node to an exit node may be estimated to allow the selection of a successor sensor node.

There are provided a system and method for tracing back an attacker by using centroid decomposition technique, the system including: a log data input module collecting log data of an intrusion alarm from an intrusion detection system; a centroid node detection module generating a shortest path tree by applying a shortest path algorithm to network router connection information collected by a network administration server, detecting a centroid node by applying centroid decomposition technique removing a leaf-node to the shortest path tree, and generating a centroid tree whose node of each level is the detected centroid node; and a traceback processing module requesting log data of a router matched with the node of each level of the centroid tree, and tracing back a router identical to the log data of the collected intrusion alarm as a router connected to a source of an attacker by comparing the log data of the router with the log data of the collected intrusion alarm. According to the system and method, an attacker causing a security intrusion event may be quickly detected, a load on the system is reduced, and a passage host exposed to a danger or having weaknesses may be easily recognized, thereby easily coping with an attack.

An apparatus for designing a virtual VLAN network includes a database containing data representing a plurality of VLAN networks in a spanning tree topology, each of the VLAN networks being formed of a plurality of VLAN member nodes interconnected by links. In response to a network configuration request from a communications network, control circuitry determines the costs of the links, and then determines least cost unicast paths by using a shortest path algorithm. A search is made through the least cost unicast paths for detecting a loop. If at least one loop is detected, a link of highest cost of the loop is blocked. All unicast paths of the blocked link are reestablished through links that circumvent the blocked link. A spanning tree built up with all the links accommodating the least cost unicast paths is established. Configuration command is sent to the network for configuring it according to the established spanning tree.

The invention discloses a dynamic road segment division based vehicle route guidance method, which is characterized in that a dynamic rod network connected graph is built through dynamic road segment division for the purpose of searching optimal path search and realizing dynamic navigation. The method specifically comprises the following steps: first, acquiring vehicle real-time information through a vehicle networking technology by the traffic center, and utilizing an algorithm of Density-based Spatial Clustering Of Applications With Noise (DBSCAN) to regularly and dynamically divide the regional rods, so as to generate the dynamic rod network connected graph; secondly, sending the position and destination of a vehicle itself to a traffic information center for asking for the optimal path; and finally, generating the optimal path on the dynamic rod network connected graph through utilizing a shortest path algorithm by the traffic information center according to the position and destination of the vehicle, and sending the information to the vehicle and realizing path guidance. The method has the advantages that the generated dynamic rod network connected graph which is accurate and real-time can provide the optimal path guidance for a traveler, thereby alleviating city traffic jam and improving running efficiency.

Peer to Peer Vehicle Ad Hoc Network is implemented with a distributed P2P model for means of a decentralized model to house data/applications and bonding technologies to reduce collisions, which is extremely high for the accepted VANET standard of 802.11p. The inventive technology provides virtualization of various heterogeneous networks into a single abstract layer of data network, fast soft and hard handoff among various data networks with different link layer characteristics within half RTT plus hardware switching time, a complete load balance of data traffics within and among data networks, optimization of data network resource such as available bandwidths (optimal distributions available resources among the users of networks) with the ability of multi-path unicast for each Internet session, utilization of shortest path algorithm for the adhoc access network routing.

The invention discloses a mobile robot navigation method based on a binocular camera and a two-dimensional laser radar. The mobile robot navigation method includes the steps that a two-dimensional grid map model is built; a mobile-robot pose model is built; a laser radar data model is built; a joint calibration model of the binocular camera and the laser radar is established; route planning and obstacle avoidance navigation are carried out with the Dijkstra algorithm and the A-Star algorithm. According to the mobile robot navigation method, the relative position and the relative orientation ofthe binocular camera and the two-dimensional laser radar can be determined with the triangle joint calibration method; in the known-environment two-dimensional grid map environment, the binocular camera can be used for detecting barriers higher than and lower than the two-dimensional laser radar plane, the barriers can be mapped into an environment map, through the shortest path algorithm and heuristic search optimization, a navigation path line capable of avoiding the barriers is obtained, and a mobile robot can reach the destination along a path capable of avoiding the barriers in the movement process.

In a communication-based navigation system, even when a vehicle deviates from an original guidance route, an in-vehicle terminal device can locate a new guidance route and display the same without receiving another guidance route delivered from a server device. Immediately after searching for a guidance route which is displayed at the start of running, the server device finds data on the shortest route from each node to a destination (direction data to return to the original route) in accordance with a shortest path algorithm, and delivers this data to the in-vehicle terminal device together with delivery map data including the guidance route. When the vehicle deviates from the guidance route, the in-vehicle terminal device locates a new guidance route or a return route from the location at which the vehicle deviates based on the direction data to return to the original route, and displays the guidance route or return route.

The invention discloses an AUV data collection method in an underwater wireless sensor network based on seawater layering. The AUV data collection method comprises: layering of the underwater wirelesssensor network is carried out through an oceanographic model; for different layering, different data collection strategies are adopted; an AUV cruises according to a predetermined path on a surface layer having relatively high mobility; a sensor node performs data forwarding by dynamically selecting a forwarding set at each hop through the factors, such as the forwarding probability and the residual energy, so that the data forwarding reliability of a mobile node is enhanced; simultaneously, in a lower-layer network, the node forms an AUV stop point through initialization operation includingaggregating, and then clustering; an AUV track is planned through a shortest path algorithm; data in the network is collected by utilization of the AUV used as an auxiliary tool; simultaneously, the energy consumption of the AUV is considered; therefore, the whole algorithm accords with a practical condition better; the cruising path of the AUV is reasonably planned; therefore, the data forwardinghop number is reduced; the energy consumption of the network is reduced; the problem that the energy consumption is non-uniform can be partly solved; and thus, the survival time of the network is prolonged.

The invention discloses an urban express delivering method based on a vehicle self-organized network. The method comprises: clustering delivery areas into k blocks by utilizing urban roads and transportation data; calculating link information among blocks by utilizing a historical vehicle track; performing topology modeling according to the blocks and the link information, and establishing a weighted directed graph to draw an urban in-vehicle network; searching the weighted directed graph to obtain a sub-graph of a starting point and an end point of an express piece; obtaining an express delivering path p with minimum weight in the sub-graph by utilizing a Dijkstra shortest path algorithm, wherein the path is an optimum express delivering path; and finally, delivering the express piece according to the path p. According to the delivering mode, the cost of express delivery is greatly reduced; and urban public transport vehicles instead of express transport vehicles are utilized, so that the situation of urban traffic congestion is improved.

A method for searching a car navigation path by using a log file includes the steps of: when a driver selects a new destination, searching a path through a shortest path algorithm, displaying the path to the new destination on a map, map matching the path by following a navigation path, and providing the driver the resulting navigation path guide; when the driver selects an existing registered destination by using an existing registered destination library, reading an already-stored registered destination, displaying a path to the registered destination on a map, map matching the path by following the navigation path, and providing the driver the resulting navigation path guide; and when the driver selects a destination by using a driving path log file library, reading an already-stored driving path log file, displaying the stored driving path on a map, map matching the path by following the navigation path, and providing the driver the resulting navigation path guide. In addition, the driver of a car having a car navigation system can choose an optimal (i.e., shortest) path through the existing navigation algorithm and from the log file strong the shortest path the driver himself found out from experiences.

A method, computer program product, and data processing system for automatically designing routing paths in an integrated circuit is disclosed. The present invention allows for the design of paths that are optimal in terms of the signal delay in circuits that may require registers for signal to travel over multiple clock cycles or in circuits that may contain multiple clock domains.

An integrated circuit die is modeled as a weighted grid graph in which the edges represent wire segments and the weights represent the delays associated with those wire segments. Designing for optimum delay involves finding a shortest path between two vertices in the grid graph using a modified single-source shortest path algorithm. Registers, buffers, and dual-clock domain synchronizers are modeled according to a labeling function that assigns components to selected vertices in the routing path for optimal results.

A system and method to synchronize independent local clocks in multi-core processing system are disclosed. A shared counter or a shared memory/file is provided to establish a partial happened-before relationship (e1<e2 in the happened-before order if we know that the event e1 happened before the event e2) and a synchronizer device is utilized to generate a global time of events in threads or processes. The synchronizer device estimates each clock's start time and approximates elapsed time between events in threads or processes by executing an all-pair shortest-path algorithm.

The invention discloses an indoor positioning and path leading method based on mobile terminal inertial navigation. The indoor positioning and path leading method comprises the following steps: firstly collecting indoor path trajectory data in a subsection manner; performing optimizing processing on history path trajectory data by using a shortest path algorithm to obtain optimal path trajectory data; storing the optimal path trajectory data and uploading the stored optimal path trajectory data to a database; when a place of arrival is set by a user, obtaining corresponding most optimal path trajectory data from the database by mobile equipment, and performing path display and guidance. No extra equipment is needed, indoor inertial navigation and path guidance with relatively high precision can be achieved by just utilizing a built-in sensor of the mobile equipment, and the method has the characteristics of high practicability, high universality and low cost.

The invention provides a virtual network mapping method of an elastic optical network facing an SDN, and mainly solves the problem in the elastic optical network facing the SDN that a network virtualization mode is utilized to realize flexible distribution and scheduling of network resources. The method specifically comprises the steps of: 1, obtaining underlying networking information; 2, receiving virtual network request information; 3, obtaining an alternative programmable physical node set; 4, mapping virtual network nodes; 5, judging whether all virtual node of the current virtual network have been mapped into a physical network; and 6, carrying out virtual network link mapping. According to the invention, the virtual node mapping method based on distance and comprehensive resource sensing, a breadth-first search method and an improved shortest path algorithm based on available space closest matching are utilized, the blocking probability of virtual network mapping is lowered, the bandwidth resource consumption of the physical network is reduced, and the future virtual network business bearing capability of the network is improved.

The invention provides a vehicle positioning and optical band guidance method applied to a parking guidance system. The method generates an optimal path to a designated parking stall by using a shortest path algorithm and controls the switches of optical bands on the way according to vehicle real-time position information fed back by a sensor so that a driver in a parking lot may quickly reach the nearest parking position. The method comprises the following steps of: establishing an abstract model of the parking lot; acquiring the vehicle real-time position information according to the sensor; using the shortest path algorithm to generate an optimal path from the vehicle's current position to a designated position; controlling the switches of the optical bands on the way according to the vehicle position information and the optimal path information, and guiding the vehicle to the designated parking position according to the optical bands. The vehicle positioning and optical band guidance method may quickly guide the vehicle to the designated parking stall according to the optical bands, solves a problem that the driver blindly finds the parking stall in the parking lot, greatly improves parking efficiency, alleviates the traffic jam in the parking lot and reduces manual management cost.

A method for dynamic routing an optical signal in an optical network is provided, including: executing a shortest-path algorithm receiving input concerning a source node, a destination node and the topology of the network, providing a shortest-path tree comprising nodes and arcs connecting the nodes, the shortest-path tree comprising branches along which an effective attenuation is no greater than a predetermined limit, each branch comprising an end node and each end node being associated with a corresponding set of wavelengths; checking, for each end node having no wavelength conversion resources and for each wavelength, if the end node is connected to at least another node external to the branch through the wavelength; excluding, for any end node if the result of the checking is negative for at least one wavelength, the at least one wavelength from the corresponding set of wavelengths, thus updating the topology; and re-executing the shortest-path algorithm.