38 results about "Maximum weight matching" patented technology

The invention provides a video clip retrieval method and a system, and the method comprises the following steps: original video clips are frame-sampled; sample frames selected from each original video clip are clustered, a frame of image is selected from each cluster as a representative frame, and the proportion value of the representative frame is calculated according to the quantity of intraframe images in each cluster; a weighted bipartite graph is built according to the representative frames of two video clips to be compared, and the weight of the weighted bipartite graph is determined by similarity between the representative frames and the proportion value of the representative frame in the corresponding cluster; maximum weight matching is carried out on the weighted ratio bipartite graph so that the similarity between the two video clips is obtained; and the video clips similar to the input video clips are searched in a database by the analysis of the similarity of the video clips. The video clip retrieval method and the system can accurately give similarity between video clips even in case of greater changes in video clip duration, and provide effective video retrieval results.

The invention discloses an optimal relay selection method based on a two-way auction model. The method includes the steps of firstly, informing beginning of action through an auctioneer, determining a respective offer or a respective asked price through each node according to a respective resource condition, then, defining an energy efficiency function between contracting parties according to an actual situation, setting up a complete weight pre-matching bipartite graph; obtaining a maximum energy efficiency matching relationship between nodes by utilizing a maximum weight matching algorithm; and finally, deleting a virtual paring relationship according to an actual relationship, and obtaining finally successful trade. The two-way auction model is utilized to achieve the optimal relay selection method which aims at the optimal relay mode selection of an edge user to obtain high energy efficiency and expand a communication range. Energy consumption of a system and nodes is effectively reduced, the maximum weight matching algorithm is utilized to help the system to select an optimal energy efficiency matching combination and obtain the final deal matching relationship through deletion of virtual matching. Energy consumption of an individual user and even the whole system is effectively reduced, and network performance is improved.

The invention is applicable to the technical field of offline map matching, and provides an offline map matching method. The method models an offline map matching problem into a shortest path problemtaking minimization of a total matching difference value between moving track data and a matching path as an optimization target, so that on one hand, the problem of arc crossing in offline map matching is solved, and on the other hand, the problem of arc crossing in offline map matching is solved; on the other hand, compared with an incremental matching method which only considers the informationof the adjacent GPS positioning points or the adjacent track segments to match the current GPS positioning points or the track segments, the offline map matching method provided by the embodiment ofthe invention has the advantages that a driving path with the minimum total matching difference value with the moving track data is found from the global perspective, a high matching precision is obtained, and in the process, a plurality of candidate matching positions do not need to be set for each GPS positioning point, and only one shortest path from the starting node to the destination node needs to be calculated, so that compared with a global maximum weight matching method, the method of the invention omits a large amount of shortest path calculation and greatly improves the map matchingefficiency.

The invention provides an energy consumption and user fairness combined content delivery method in a D2D (Device-to-Device) cache network and belongs to the technical field of wireless communication.The method comprises the realization steps of simulating a two-way selection process between request users and cache users in a content delivery process into the maximum weight matching problem in a bipartite graph; and carrying out content delivery through D2D, assuming that at the same time, a file f<k> in a network has M request users and N cache users, and when the content delivery is carriedout, carrying out the following condition that when the M is smaller than or equal to the N, M users are selected from the cache users for matching with the requests users, when the M is greater thanthe N, N users are selected form the request users for matching with the cache users, and it is ensured that weight sum of the matching users is the maximum. According to the method, in the content delivery process of a cellular and D2D network based on cache, energy consumption resulting from unsuccessful transmission is taken into consideration, and fairness for the users to obtain content is also taken into consideration, so energy consumption can be reduced, and the fairness for the users to obtain the content also can be ensured.

The invention discloses an event discovery and display method based on a knowledge graph. The method comprises the following steps: S100, preprocessing each piece of government service hotline data; s200, dividing the government service hotline data in the time period selected by the user into data frames according to a time interval specified by the user, and performing event detection on the government service hotline data in each frame through a community discovery algorithm to obtain each city event; and S300, based on a bipartite graph maximum weight matching algorithm, matching events of front and back frames, establishing an event chain of each city event evolution, analyzing z-score values of each city event in the event chain, determining emergencies and emergency degrees of each city event, and performing early warning and multi-dimensional visualization on the city emergencies therein. According to the invention, various events occurring in a city can be clearly known, and detection and early warning can be carried out on emergencies in the city.

The invention discloses an in-vehicle heterogeneous network resource collaborative optimization method based on a graph theory. The method comprises the following steps: determining whether communication between a vehicle and a base station is single-hop communication or two-hop communication, and performing classified collection to form a single-hop communication set and a two-hop communication set; combining the single-hop communication set and the two-hop communication set into a bipartite graph according to the graph theory, calculating amount of service of each single-hop communication and two-hop communication, and then, ranking the amount of service of links in the single-hop communication set according to size; selecting vehicle nodes with minimum value of the amount of service toform a DV vehicle set, forming a RV vehicle set with the other vehicles, and taking the DV vehicle set and the RV vehicle set as peaks to form a weighted bipartite graph; calculating weight of each side between the peaks of the weighted bipartite graph, further looking for an overall maximum weight matching scheme of the weighted bipartite graph through a KM algorithm, and setting a delay-limitingconstraint condition in a matching process; and performing iterative updating for the number of the DV vehicles through a binary search method, and according to an iterative updating result, judgingwhether an optimal collaborative scheme of communication between the vehicle and the base station is found.

The invention belongs to video search technique area especially, related to the new method for searching video based on a segment of video. Aim at disadvantages of current technique such as low searches precision and slow searches speed, the invention puts forward and solves two difficult problems under frame of optimal matching in graph theory: automatic obtaining similar segments and evaluating degree of similarity between two segments. Model of weighted bipartite graph is built. Examining continuity of similar frames obtains similar segments in preliminary. Maximum weighted matching between these segments and queried segment is calculated out by using Kuhn_Munkres method. The match determines whether two segments are similar or not as well as boundary of similar segments. Maximum weight shows degree of similarity between two segments. Comparing with prior art, experimental result indicates the invention obtains higher precision ratio, recall ratio and quicker searching speed.

The invention discloses an optimal relay selection method based on a two-way auction model. The method includes the steps of firstly, informing beginning of action through an auctioneer, determining a respective offer or a respective asked price through each node according to a respective resource condition, then, defining an energy efficiency function between contracting parties according to an actual situation, setting up a complete weight pre-matching bipartite graph; obtaining a maximum energy efficiency matching relationship between nodes by utilizing a maximum weight matching algorithm; and finally, deleting a virtual paring relationship according to an actual relationship, and obtaining finally successful trade. The two-way auction model is utilized to achieve the optimal relay selection method which aims at the optimal relay mode selection of an edge user to obtain high energy efficiency and expand a communication range. Energy consumption of a system and nodes is effectively reduced, the maximum weight matching algorithm is utilized to help the system to select an optimal energy efficiency matching combination and obtain the final deal matching relationship through deletion of virtual matching. Energy consumption of an individual user and even the whole system is effectively reduced, and network performance is improved.

The invention provides a disjoint-view object matching method based on a corrected weighted bipartite graph. The method relates to the field of computer vision. The method expresses a disjoint-view object matching problem as a maximum posterior probability problem, so that an object observation model and time-space constraints of a surveillance network are combined, and the maximum posterior probability problem is resolved through solving the maximum weight matching of a weighted bipartite graph. To solve the problem that construction of a common weighted bipartite graph is liable to introduction of incorrect matching, the method provides a corrected weighted bipartite graph construction method based on an adaptive threshold, so that incorrect matching is prevented from being introduced during construction of the weighted bipartite graph as much as possible. Aimed at the defect of a conventional KM method that the amount of computation is too large during large-scale weighted bipartite graph matching problem solving, the method brings forward a MH sampling-based method for approximating and solving the maximum weight matching of the weighted bipartite graph, so that a disjoint-view object matching relationship is obtained.

The invention discloses a link priority virtual network mapping method based on maximum weighted matching, relates to the technical field of computer networks, in particular to virtual network mapping, and the method can effectively reduce the number of physical links of virtual links. On the basis of the link priority mapping method, the present invention changes the random link mapping into a mapping method with the goal of minimizing the link distance, and defines a new link comprehensive bandwidth measurement index, which comprehensively considers the bandwidth of the link itself And the bandwidth of the adjacent link, and then map the first virtual link in the maximum weighted matching to the physical link with the largest comprehensive bandwidth metric, so as to improve the success probability of subsequent mapping. Through the above solution, the present invention can effectively reduce the average number of physical links of the virtual links in the virtual network mapping result, and improve the acceptance rate of the virtual network.

The invention proposes a content distribution method combining energy consumption and user fairness under a D2D cache network, which belongs to the technical field of wireless communication. The implementation steps include: first, simulate the two-way selection process between the requesting user and the cache user in the content distribution process as a maximum weight matching problem in a bipartite graph; then, carry out content distribution through D2D. file k There are M requesting users and N cached users; including the following situations: when M≤N, select M users from the cached users to match the requesting users; when M>N, first select N from the requesting users The user is matched with the cached user; the sum of the weights of the matched users is guaranteed to be the largest. In the content distribution process based on the cached cellular and D2D network, the present invention considers the energy consumption caused by the transmission failure, and also considers the fairness of the content obtained by the user, which can not only save energy consumption, but also ensure the fairness of the content obtained by the user.

The present invention requests protection of a resource allocation method based on full-duplex D2D communication in a cellular network. The introduction of full-duplex (Full Duplex, FD) D2D (Device-to-Device) communication in the cellular network can reduce the burden on the base station, reduce the energy consumption of the terminal, and expand the coverage of the cell. However, sharing resources between D2D users and cellular users brings certain co-channel interference to the system, and the mutual interference can be reduced through reasonable resource allocation. A resource allocation algorithm based on maximum weight matching is proposed in this paper. Under the premise that the algorithm can guarantee the quality of service requirements of cellular users, it also guarantees the minimum requirements for D2D link communication. The resource allocation relationship between cellular users and D2D users in the system is equivalent to the vertex pairing relationship in graph theory. The maximum weight matching algorithm in the algorithm reasonably allocates wireless resources between D2D user pairs and cellular users, effectively reduces the interference between cellular users and D2D users, obtains better fairness, and maximizes the throughput of the system at the same time.

The invention discloses a D2D resource allocation method based on uplink and downlink spectrum joint multiplexing, and belongs to the technical field of wireless communication. The invention firstly models the D2D channel allocation variables and related constraints; respectively models the transmission rates of the D2D users and the cellular users in the multiplexing mode, aiming at maximizing the throughput of the D2D network, the D2D resources are allocated The problem is constructed as a mixed integer nonlinear programming problem Φ; the problem Φ is decomposed into a power allocation problem Φ 1 and the channel assignment problem Φ 2 ; use Lagrange duality theory to convert the problem Φ 1 Converted to a convex optimization problem; the problem Φ 1 Substitute the solution into Φ to get the problem Φ 2 , transform it into a bipartite graph maximum weight matching problem, and then use the Hopcroft-Karp algorithm to solve until the optimal channel resource allocation for all D2D users is achieved, thereby maximizing the throughput of the D2D network.