34 results about "Maximal independent set" patented technology

A method allocates resources in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations (BSs), and a set of mobile stations (MSs) for each BS. Each cell includes a center and edge zone. A node weighted constraint graph is constructed for the network. Maximal independent sets in the graph are searched as sub-channels are allocated to the MSs in edge zones. Remaining bandwidth is allocated to the MSs in the center zones. Power is assigned to the sub-channels so that inter-cell interference is minimized and traffic load is maximized.

This invention discloses a method for scheduling efficient resource of a minisatellite network based on earth observation tasks, and solves the problems that the end-to-end throughput capacity is low and the utilization efficiency of the network resource is low because the network resource is not fully considered during the scheduling process in the earth observation scene of the resource-limited minisatellite network. The method comprises the implementation processes of: according to an initial network topology, determining a node number; at the same time, initializing a network resource scheduling planning time set; according to current network state and resource scheduling conflict restraint, constructing a link scheduling conflict graph by a ground control center; solving a maximal independent set corresponding to the conflict graph to acquire a network conflict-free scheduling link set; by using the link set and a linear programming, solving a resource allocation scheme and a data transmission method capable of mostly optimizing the network efficiency till a time slot is ended. The method improves the resource utilization ratio, increases the returning efficiency of important task data, improves the earth observation network performance of the minisatellite, and is used for scheduling the efficiently transmitted resource of earth observation system data.

A frequency spectrum distribution method based on a system revenue in cognitive radio, which relates to the frequency spectrum distribution technology in the cognitive radio technology, is disclosed. By using the method of the invention, system communication costs can be reduced; a problem of a low total system revenue caused by frequency spectrum revenue differences which are ignored by a current algorithm can be solved. The frequency spectrum distribution method is characterized by: dividing a topological graph into a plurality of connected components and calculating all maximal independent sets in the each connected components; carrying out frequency spectrum distribution to nodes one by one in the each maximal independent set of the each connected component; after the frequency spectrum distribution of the all maximal independent sets in one connected component is completed, detecting whether there is the node that is not distributed with the frequency spectrum and the available frequency spectrum in the connected component, carrying out the frequency spectrum distribution to the node that is not distributed with the frequency spectrum and distributing the available frequency spectrum to the nodes continuously till available frequency spectrum lists of all the nodes are empty which means that the frequency spectrum distribution of the connected component is completed. By using the method of the invention, a distribution speed is fast and costs are low. And the high total system frequency spectrum revenue can be obtained.

The objective of the invention is to provide a method for post-routing redundant via insertion. The method is to construct a conflict graph from a post-routing design first, to find a maximal independent set (MIS) of the conflict graph, and to replace a single via with a double via for each vertex in the maximal independent set. Furthermore, since redundant vias can be classified into on-track and off-track ones and since on-track ones have better electrical properties, the invention also presents two methods to increase the amount of on-track redundant vias while a redundant via insertion solution is given.

The invention discloses a link allocation method for a multi-channel wireless network. The method comprises the following steps of: (1) dividing the wireless network into m sub-networks with the same available channel number m of the multi-channel wireless network; (2) acquiring a network conflict graph G according to a topological graph of the multi-channel wireless network; (3) acquiring the maximum independent set sequence I of the network according to the network conflict graph G acquired in the step (2); and (4) allocating the maximum independent set sequence I acquired in the step (3) into various sub-networks which are divided in the step (1). The link allocation method for the multi-channel wireless network can be used for a single network interface multi-channel condition and a multi-network interface multi-channel condition and is simple in execution process and easy to implement; and so long as the network topology is not changed, the network does not need nodes to negotiate in the working process, channels are allocated for links, and load and delay brought by channel negotiation of the network are reduced.

The invention discloses a distributed graph coloring algorithm based on Pregel. The distributed graph coloring algorithm comprises the following steps that a random number as a weight value is respectively assigned to all points in a graph G; a color value of 1 is assigned to a vertex with a degree of 0, that is, the vertex has no edge to be connected with other vertices; the current color value is initialized to 1; the Pregel model is used for finding an independent set S, and three schemes are included; the current color value is assigned to any vertex v in the independent set; the colored vertices are removed from the graph G, and the color value is increased by 1; the step 4) to the step 6) are executed again until all points in the graph G are colored. The distributed graph coloring algorithm adopts the Pregel model suitable for large-scale graph calculation to improve efficiency of a parallel graph coloring algorithm. Based on an idea of finding the maximum independent set, graphcoloring processing is performed on large-scale graph data, and the purposes for reduction of graph coloring algorithm time and the number of colors required for coloring are achieved by means of introduction of optimization strategies.

The invention discloses a centralized link scheduling method for a multi-channel wireless network. The method comprises the following steps of: 1, numbering links in a network topology based on a wireless network topology consisting of n links, recording the number as 1,2, ..., and n and acquiring a corresponding network conflict graph G through the network topology; 2, acquiring a maximum independent set sequence Iseq of the network conflict graph according to the network conflict graph G in the step 1; and 3, acquiring a maximum group sequence Cseq of the network conflict graph according to the network conflict graph G in the step 1, recording number of elements in the maximum group sequence Cseq as m, wherein each element in the sequence corresponds to a maximum group, and numbering the elements according to a sequence from 1 to m to be recorded as Ci, wherein i is more than and equal to 1 and less than or equal to m. The centralized link scheduling method utilizes space diversity to the greatest degree, maximizes links which are transmitted simultaneously, improves the network capacity and is a conflict-free link scheduling method.

The invention discloses a graph theory based multi-cell two-layer network spectrum allocation method. According to the method based on a multi-cell scene in long term evolution (LTE), a macro base station and a family base station coexist and share a platform of a frequency spectrum, a maximum independent set of a graph is obtained by a genetic algorithm, and the frequency spectrum is distributed for macro users to obtain a resource block proportion occupied by the macro users. The macro base stations on different resource blocks and small-scale fading have influence on family users, so that a plurality of interference patterns are established, and a good scheme dynamic allocation frequency spectrum is provided. The method has the advantages that the cross-layer interference and co-layer interference are reduced, the requirement of service quality of the macro users can be met, the total handling capacity of a system is increased, and the compromise between the handling capacity of edge family users and the total handling capacity of the family users is achieved.

The invention discloses an authorization channel switching probability-based maximal independent set frequency spectrum distribution method in cognitive radio, relating to a frequency spectrum allocation method. The method can be used for improving fairness of a cognitive system and solving the problem of no consideration of negative effects of the working state of an authorization channel to system property in a process of periodically allocating frequency spectrum in the traditional graph theory frequency spectrum allocation method. The authorization channel switching probability-based maximal independent set frequency spectrum distribution method comprises the steps of: if frequency spectrum allocation of all subgraphs is not completed, selecting one subgraph which does not complete the allocation, figuring out all maximal independent sets of all subgraphs one by one; simultaneously allocating same frequency spectrums of parallel maximal independent sets; if the subgraphs have un-allocated frequency spectrums, allocating the frequency spectrums for nodes according to the sequence of the allocated expected frequency spectrums and the interference expected frequency spectrums from small to large; and updating node frequency spectrum lists and obtained frequency spectrum mean values of nodes of corresponding independent sets. The method is suitable for frequency spectrum allocation.

A quantum mechanical arithmetic operation method for machine vision, based on quantum dots is performed by a quantum processing processor. The quantum mechanical arithmetic operation method comprises, obtaining a first labeled graph connecting between feature points of the first image and a second labeled graph connecting feature points of the second image, generating a point-to-point combination by matching the feature points of the first image with the feature points the second image, generating a conflict graph by adding the largest point-to-point combination by comparing the point-to-point combinations with the threshold, generating non-constrained binary optimization equation for finding a maximum independent set of conflict graphs, converting the non-constrained binary optimization equation into Ising model of the quantum system, and calculating the Hamiltonian of Ising model based on the quantum dots to obtain solution of the non-constrained binary optimization equation.

A quantum mechanical arithmetic operation method for machine vision, based on orbital qubit is performed by a quantum processing processor. The quantum mechanical arithmetic operation method comprises, obtaining a first labeled graph connecting between feature points of the first image and a second labeled graph connecting feature points of the second image, generating a point-to-point combination by matching the feature points of the first image with the feature points the second image, generating a conflict graph by adding the largest point-to-point combination by comparing the point-to-point combinations with the threshold, generating non-constrained binary optimization equation for finding a maximum independent set of conflict graphs, converting the non-constrained binary optimization equation into Ising model of the quantum system, and calculating the Hamiltonian of Ising model based on an orbital qubit to obtain solution of the non-constrained binary optimization equation.

A method allocates resources in an orthogonal frequency-division multiple access (OFDMA) network including a set of base stations (BSs), and a set of mobile stations (MSs) for each BS. Each cell includes a center and edge zone. A node weighted constraint graph is constructed for the network. Maximal independent sets in the graph are searched as sub-channels are allocated to the MSs in edge zones. Remaining bandwidth is allocated to the MSs in the center zones. Power is assigned to the sub-channels so that inter-cell interference is minimized and traffic load is maximized.

The invention relates to the field of graph data mining and graph matching, in particular to a method for mining similar frequent graphs in a single graph. The method comprises the steps of calculating a size upper limit of each frequent sub-graph of the single graph according to a given single graph size, given similarity and a given frequent degree; according to the size upper limit of each frequent sub-graph, traversing the single graph, and searching for all sub-graphs of the single graph; for the sub-graphs of the single graph, searching for all similar sub-graphs of the sub-graphs; for the similar sub-graphs of the sub-graphs, performing matching in the single graph, and searching for all matching graphs of the similar sub-graphs; forming matching graph sets by the matching graphs ofall the similar sub-graphs of the sub-graphs, and calculating the quantity of the matching graphs of the maximum independent set in the matching graph sets; and comparing the quantity of the matchinggraphs of the maximum independent set and the frequent degree, and if the quantity of the matching graphs of the maximum independent set is greater than or equal to the frequent degree, outputting the sub-graphs. The invention furthermore relates to an apparatus and a system for mining the similar frequent graphs in the single graph, a device and a medium.

The present invention discloses an extension method for Latin hypercube sampling. An LHS (Latin hypercube sampling) of which a sample size is n is supposed to exist, the extension method aims to obtain a new LHS sampling of which the sampling size is n+m, and meanwhile, the novel sampling contains a maximum number of existing sampling points. According to the method provided by the present invention, a relationship between the LHS sampling points is transformed into a simple undirected acyclic graph, an adjacent matrix is obtained, and a maximum individual set is solved to retain a maximum number of existing sampling points. The method comprises the implementation steps of: calculating distribution of the existing sampling points in a novel sampling structure; calculating a matrix of the sampling points that need to be retained; calculating a matrix of newly added sampling points; and finally, calculating a Latin hypercube sampling matrix after extension. According to the extension method for the Latin hypercube sampling, which is provided by the present invention, the existing sampling points can be deleted as few as possible, so that sampling cost is conserved; and meanwhile, the novel sampling points are generated, so that a sampling sample formed by the novel sampling points and the retained sampling points still meets an LHS structure.

The invention discloses a spatial information network task planning method based on resource exchange. The method comprises the following steps: 1) initializing basic parameters of a spatial information network; 2) dividing the planning period into K equal-length time slots, wherein the length of each time slot is tau, and constructing a space information network resource time-varying graph GK (V,A); 3) sampling a feasible resource combination space of each task omi belonging to OM, and taking a resource combination set Pi of which the independence is greater than or equal to n as an alternative resource set; 4) calculating a conflict relationship among the resource combinations, and constructing a resource combination conflict graph RCG (PC, EC); 5) solving the maximum independent set inthe resource combination conflict graph to obtain a global planning result; and (6) the neighborhood of the global planning result is searched, then local adjustment of the task planning scheme is completed in a resource exchange mode, task planning based on the resource exchange characteristic is completed, and by means of the method, the calculation complexity of task planning can be reduced while the task completion rate is increased.

The invention belongs to the technical field of wireless communication, and discloses a non-orthogonal multiple access-based edge computing system control joint optimization method and application. The method comprises: initializing parameters; performing unloading decision and local computing resource allocation optimization according to the feasibility of local execution and the maximum delay limit of task processing; performing access control optimization; sorting all users; using a maximum independent set MWIS method in a graph theory to carry out joint user pairing, subcarrier distribution and sending power control: all feasible user pairs and subcarrier distribution forming a graph, and each node in the graph being a combination of one feasible user pair and one subcarrier; wherein the sending power of each user is distributed according to the maximum time delay requirement; generating a maximum independent set of graphs. According to the invention, as many user tasks as possible are executed, and as much energy consumption as possible is saved for users; the method can be applied to various Internet of Things scenes requiring large capacity and low energy consumption.

The invention discloses a graph theory based multi-cell two-layer network spectrum allocation method. According to the method based on a multi-cell scene in long term evolution (LTE), a macro base station and a family base station coexist and share a platform of a frequency spectrum, a maximum independent set of a graph is obtained by a genetic algorithm, and the frequency spectrum is distributed for macro users to obtain a resource block proportion occupied by the macro users. The macro base stations on different resource blocks and small-scale fading have influence on family users, so that a plurality of interference patterns are established, and a good scheme dynamic allocation frequency spectrum is provided. The method has the advantages that the cross-layer interference and co-layer interference are reduced, the requirement of service quality of the macro users can be met, the total handling capacity of a system is increased, and the compromise between the handling capacity of edge family users and the total handling capacity of the family users is achieved.

The invention provides a method for constructing a feature database. The method comprises the steps that third-party account information and network information released within preset time are acquired; interactive information between third-party accounts is analyzed so that an information transmission network based on the interactive information is generated; all maximal strongly connected components based on the information transmission network and all the maximal independent sets in each maximal strongly connected component are acquired; the least maximal independent sets are selected from all the maximal independent sets in each maximal strongly connected component; de-duplication is performed on points included in all the least maximal independent sets of all the maximal strongly connected components and then a vertex set is formed through merging; and the third-party account information and vertex set information are merged so that a feature information base is generated. The invention also provides a system and a device corresponding to the method. Marketing of different types of projects or activities can be flexibly supported so that marketing resource is saved and construction cost of a marketing model is reduced, and selection of new users of the operation level is also facilitated.

The invention discloses an approximate solving method for a maximum independent set on a unit disk graph. The method comprises the following steps: 1, designing an optimal solution solving method fora maximum vertex independent set of an adjacent vertex set induction sub-graph of unit disc vertexes by utilizing a dynamic programming method, and giving an optimal solution for a maximum vertex independent set of a union set induction sub-graph of any two vertex adjacent vertex sets; 2, for a general unit disk graph, firstly calculating a vertex dominating independent set; then independently checking members in the vertex dominated independent set, and judging whether a result can be optimized or not to obtain an intermediate solution; and finally, performing joint inspection on members in the intermediate solution, and judging whether a result can be optimized or not to obtain a final solution. According to the method, the approximate solution with the approximate ratio of 1.5 is obtained according to the calculation time complexity of O (delta 2n3), delta is the vertex maximum degree. Compared with an existing approximate algorithm for solving the problem through the maximum independent set on a unit disc graph, the approximate ratio is increased, and higher efficiency is achieved.

The invention discloses a high bandwidth data transmission method in a wireless ad hoc network. The high bandwidth data transmission method in the wireless ad hoc network comprises: in the process of data transmission in the wireless ad hoc network, a synchronous CSMA / CA(Carrier Sense Multiple Access with Collision Avoidance) protocol is adopted in an MAC sublayer, and in a LLC (Logical Link Control) sublayer, links are scheduled according to a distribution type MIS (Maximal Independent Set) algorithm of a diagram. The high bandwidth data transmission method enables the convergence time of the link scheduling algorithm in the process of data transmission in the wireless ad hoc network to be shorter, and compared with a conventional link layer which merely adopts the CSMA / CA protocol, the bandwidth performance is improved.

The invention discloses a method and device for detecting wormhole attacks on wireless networks and delay-tolerant networks in a three-dimensional space. The method first responds to received wormhole detection requests by nodes in the network to obtain some topological information in the adjacent areas maintained in advance. Calculate the largest independent set in the graph, and then compare the actual size of the largest independent set with the size of these largest independent sets in the predefined network to determine whether there is an illegal subgraph structure in the network; if there is an illegal subgraph structure in the network, It means that there is a wormhole attack in the network. The invention is a lightweight and distributed algorithm, which can not only efficiently identify wormhole attacks, but also facilitates the realization and deployment of wormhole attack detection devices. The present invention does not need any preconditions and assumptions, does not need to know the initial state of the network, global clock synchronization, protection nodes and special hardware devices, and has no false detection rate.

The invention relates to the field of RFID, in particular to a performance evaluation method for an RFID reader anti-collision protocol. Firstly, under the control of a server, an RFID reader sends aspecified signal to detect the collision condition with surrounding readers. Then, the server performs graph theory modeling according to the collision information of all the readers, and calculates amaximum independent set. Meanwhile, all the RFID readers are provided with the same RFID reader anti-collision protocol, and start to execute and record state information at the same time. Finally, the server compares the state information of all the readers with the maximum independent set, and calculates the closeness degree of the state information and the maximum independent set. The RFID reader anti-collision protocol is selected with the optimal performance according to the closeness degree. From the perspectives of simple deployment and rapid evaluation, performance evaluation can be carried out on multiple RFID reader anti-collision protocols according to the graph theory principle and RFID system characteristics, and the protocol with the optimal performance can be selected.

The present invention relates to the technical field of wireless mesh (Mesh) networks, in particular to a method for solving a conflict-free node set of a wireless mesh network, comprising steps: S1: establishing a conflict graph model G(V,E) of a wireless mesh network; S2: Select the node set S of the conflict graph model G(V,E) that does not conflict with node A A , then the node set S3 that conflicts with node A: Obtain all maximal independent sets T including node A of the conflict graph model G(V,E) A ; S4: Obtain the union of all maximal independent sets including each node in the node set S5: Obtain all the maximal independent sets, that is, the conflict-free node set. The method of the present invention establishes a 4D conflict graph model , and based on the Hasse graph traversal method to obtain all the maximum independent sets of the 4D conflict graph model, that is, the conflict-free node set, which is much simpler than the existing method of traversing all feasible combinations to obtain all maximum independent sets.

The invention discloses a three dimensional sensor network surface skeleton extraction method. The three dimensional sensor network surface skeleton extraction method includes the steps: every internal node calculates the feature point thereof; a restrictive broadcast mode is used to enable the feature points of the nodes to form a plurality of feature connected components; surface skeleton points are identified; a maximum independent set of the surface skeleton points is constructed; the surface skeleton nodes in the maximum independent set are used to obtain a Voronoi graph; and based on the Voronoi graph, triangularization of the dual graph Delaunay can be obtained so as to obtain a three dimensional sensor network surface skeleton. The surface skeleton point identifying method has no use for depending on a special grid structure and cannot be influenced by network noise, distance round-off error and sparse network, and can obtain a steady surface skeleton.

The invention discloses a centralized link scheduling method for a multi-channel wireless network. The method comprises the following steps of: 1, numbering links in a network topology based on a wireless network topology consisting of n links, recording the number as 1,2, ..., and n and acquiring a corresponding network conflict graph G through the network topology; 2, acquiring a maximum independent set sequence Iseq of the network conflict graph according to the network conflict graph G in the step 1; and 3, acquiring a maximum group sequence Cseq of the network conflict graph according to the network conflict graph G in the step 1, recording number of elements in the maximum group sequence Cseq as m, wherein each element in the sequence corresponds to a maximum group, and numbering the elements according to a sequence from 1 to m to be recorded as Ci, wherein i is more than and equal to 1 and less than or equal to m. The centralized link scheduling method utilizes space diversity to the greatest degree, maximizes links which are transmitted simultaneously, improves the network capacity and is a conflict-free link scheduling method.

A channel allocation method based on mobility prediction in a cognitive radio network relates to a channel allocation technology in a cognitive radio technology in a communication system. It is to solve the problem of low effective channel utilization and poor system fairness caused by traditional channel static spectrum allocation method without considering the mobility characteristics of cognitive users. This method first sets the available channel probability threshold α and the interference edge probability threshold β, predicts each subgraph according to the interference relationship between mobile cognitive users, and predicts each cognitive subgraph in the subgraph according to the interference relationship between mobile cognitive users and authorized users. The user's available channel list, so as to obtain the predicted topology map of the entire network and the predicted available channel list of each cognitive user. Then, from the perspective of fairness, channel allocation is performed for each predicted subgraph one by one. The allocation of each subgraph is to solve the maximum independent set first, and then uniformly allocate channels to the nodes in the subgraph. The present invention is applicable to channel allocation in cognitive radio networks.

This invention discloses a method for scheduling efficient resource of a minisatellite network based on earth observation tasks, and solves the problems that the end-to-end throughput capacity is low and the utilization efficiency of the network resource is low because the network resource is not fully considered during the scheduling process in the earth observation scene of the resource-limited minisatellite network. The method comprises the implementation processes of: according to an initial network topology, determining a node number; at the same time, initializing a network resource scheduling planning time set; according to current network state and resource scheduling conflict restraint, constructing a link scheduling conflict graph by a ground control center; solving a maximal independent set corresponding to the conflict graph to acquire a network conflict-free scheduling link set; by using the link set and a linear programming, solving a resource allocation scheme and a data transmission method capable of mostly optimizing the network efficiency till a time slot is ended. The method improves the resource utilization ratio, increases the returning efficiency of important task data, improves the earth observation network performance of the minisatellite, and is used for scheduling the efficiently transmitted resource of earth observation system data.