79 results about "Knapsack problem" patented technology

The invention discloses a method for islanding an electric power system into a plurality of subsystems. The method comprises the following steps: dividing an electric power system islanding model into a first electric power submodel and a second electric power submodel; for the two submodels, using a staging solving strategy which is searching+adjusting: a first stage: searching the first electric power submodel based on a knapsack problem restrained by a connected graph so as to acquire each isolated subsystem; a second stage: carrying out optimization and adjustment to the each isolated subsystem based on the second electric power submodel. According to the each subsystem obtained through the islanding method, specific coherent generator groups are in the same subsystem, the subsystems are connected, voltages of the each isolated subsystem and an equipment capacity constraint are all in a bound, and a total load of safe power supply of the each isolated subsystem is greatest. Because of employing a decomposition solving strategy, a calculating speed can be accepted by engineering by using the islanding method.

A method of determining allocations in a business operation to maximize profit includes: collecting profit data for a plurality of classes in the business operation, where each class includes an allocation having a cost function and each allocation belongs to the group consisting of physical allocations and economic allocations; determining profit functions for the allocations from the profit data; formulating a Multiple Choice Knapsack Problem to maximize profit from the profit functions, the cost functions, and a cost constraint; and solving the Multiple Choice Knapsack Problem to determine values for the allocations.

The invention discloses a multichannel diversity-based cognitive medium access control realizing method, which is designed on the basis of multichannel diversity. In the method, source nodes and target nodes compete for the right of use of a data channel through exchange control packets on a public control channel, node pairs wining the competition determine data channels and corresponding power allocation for the transmission according to power/channel combined allocation and are shifted to corresponding data channels to transmit a plurality of data packets continuously. The invention also provides a method for resolving power/channel combined allocation, which is to resolve the power/channel combined allocation by converting the power/channel combined allocation into a multi-choice knapsack problem and by dynamic planning. Simulation results show that the cognitive MAC protocol can effectively improve intra-node pair data transmission rate and network throughput under a condition that the total transmission power is limited compared with an opportunistic multiradio MAC (OMMAC) protocol.

The invention discloses an electric system splitting fracture surface searching method based on master-slave problem alternating optimization. A complete active splitting model is transformed to a master-slave problem based on the connected graph constrained Knapsack problem (CGKP) theory. The master problem is the graph optimal balanced dividing problem and solution is performed with the CGKP technology adopted. The slave problem is that the solution is performed with the optimal power flow (OPF) technology adopted and based on the scheduling problem of the OPF problem. The coupling between the master problem and the slave problem is achieved through regulation variable of node load. A more excellent splitting scheme is obtained through alternating iteration between the master problem and the slave problem. Compared with the prior art, a novel strategy based on the a master-slave problem alternating solving electric system optimal active splitting section is proposed, and meanwhile, the splitting scheme is enabled to be closer to an optimal solution of the complete model. Therefore, a greater load is generated after splitting to achieve power supply.

The invention provides a method for network flow scheduling suitable for a distributed network environment. A network flow prediction method based on Kalman filtering is adopted in the flow scheduling process to predict flow collected by a distributed network flow center; due to the fact that a flow scheduling model in the distributed network environment is a multi-dimensional knapsack problem which is an NP problem, by the combination with factors such as predicted flow and each network time delay, the NP problem is solved, an optimized scheduling result obtained; after flow scheduling, the distributed network can access a server in a maximum ratio within the bearing capacity range of the server, message spreading time delay and the hop count are minimized, the goal of load balance is achieved, and the flow scheduling effect is optimal. Efficient prediction of the distributed network flow and flow scheduling high in utilization rate and low in consumption can be achieved by applying the method.

The invention relates to a recognition method for components of Chinese character pictures and belongs to the field of image processing and pattern recognition. The method includes firstly pre-processing Chinese character component pictures with specific fonts, performing skeleton extracting, forming initial sections according to endpoints and intersections which are detected out, and merging some sections in an artificial interactive mode; next, performing statistical modeling on the marked sections and describing directional information of the sections by using a four-dimensional vector; then constructing section neighbor relations to complete the component modeling process according to the maximum spinning tree principle; for an input Chinese character, firstly decomposing the character into sections, then generating a group of section sets with the maximum similarity by contrasting each component in a library, finally obtaining recognition results of components of the input Chinese character through the optimum selection strategy, namely, obtaining the optimum solution through solution of the variety knapsack problem. Local features are introduced, the optimum combination strategy is adopted, the complete recognition method for the components of the Chinese character pictures is formed, and the recognition rate can be improved effectively.

The invention discloses an underwater multi-sensor cooperative passive tracking method based on a dynamic cluster. According to the method, a distribution type fusion estimation process with feedbackis introduced into a target tracking process, and a linear minimum variance fusion criterion weighted by a scalar quantity is used for minimizing a trace of fusion error covariance by utilizing components, and the optimal fusion state estimation is achieved. A dynamic clustering process selected based on adaptive nodes is used for dynamically selecting cluster head nodes and cluster member nodes which are involved in the passive target tracking process, wherein the selection of the cluster head nodes is mainly started from the view of energy; and the selection of the cluster member nodes is that an objective function is constructed by using utility functions and cost functions, the node selection problem is classified as a knapsack problem in mathematics, and finally a dynamic programmingmethod is used for selecting an optimal node combination to achieve the maximization of the objective function. By adopting the method, the convergence of the accuracy of the passive target tracking can be guaranteed and the energy consumption of the network in the passive tracking process can be effectively reduced.

The invention provides a three-dimensional encasement scheme generating method based on a three-step dynamic programming. A three-dimensional encasement problem is decomposed into three 01 knapsack problems which are conducted in sequence. The generating process of a three-dimensional encasement scheme is converted into a solution of the three 01 knapsack problems. According to the three-dimensional encasement scheme generating method based on the three-step dynamic programming, compared with existing methods, the encasement rate and the encasement scheme generating speed are improved; the container space use rate is further increased through the three-dimensional encasement scheme generating method, the container freight cost is reduced, and the corporate profits are increased.

The invention discloses a resource allocation method applicable to a multi-hop wireless mesh network. The method includes the steps that the parameter of each node on a multi-hop path is acquired, and the characteristic parameters of each hop of link in the multi-hop path at different rates and different frame lengths are calculated and comprise media access time slot numbers and packet error rates; with minimum time slot occupation as an optimization target, a multi-choice knapsack problem mathematic model is established with the end-to-end PER as the constraint condition; the solution of a multi-choice knapsack problem is converted into the solution of a multistage decision diagram according to a dynamic planning method; the multistage decision diagram is solved according to a Dijkstra algorithm so that an optimal resource allocation result can be obtained. Compared with the prior art, the method is applicable to resource allocation of the multi-hop WMN, resource allocation is performed by source nodes, a graph theory is used for simplifying the algorithm, the resource allocation complexity is reduced, and a feasible optimal allocation result can be obtained.

The invention provides an intelligent asset matching method comprising the following steps: S1, calculating the characteristic value of an asset target to be matched; S2, selecting a real asset target of which the characteristic value matches the characteristic value of the asset target to be matched from an asset pool; S3, comparing the characteristic value of the real asset target with the characteristic value of the asset target to be matched, completing matching if the characteristic value of the real asset target is greater than or equal to the characteristic value of the asset target to be matched, and going to S4 if the characteristic value of the real asset target is smaller than the characteristic value of the asset target to be matched; and calculating the characteristic values of remaining asset targets to be matched, and going to S2. According to the method, by calculating the characteristic values of asset targets and conducting asset matching according to the characteristic values and based on a knapsack problem, intelligent matching of assets is realized, asset matching can be optimized as much as possible, and users' money can be utilized effectively.

A resource management method in SVC multicast based on NOMA in a heterogeneous wireless network is characterized in that the resource management is joint resource management including wireless spectrum allocation and transmitting power division, a joint resource management problem is decomposed into sub-problems, then the sub-problems are solved respectively. The method comprises the following steps: 1) converting a joint resource management problem into a mixed integer nonlinear programming problem, and decoupling the mixed integer nonlinear programming problem P0 into two sub-problems: a multicast group internal transmitting power division problem P1; inter-base station spectrum resource segmentation and multi-group spectrum resource allocation problem P2 in the base station; 2) solvingthe problem P1, solving all possible power distribution schemes, wherein the group with the highest overall video quality is the optimal solution; and 3) solving the problem P2, modeling the spectrumresource segmentation between the base stations and the resource allocation problem between the multicast groups into a knapsack problem, and solving the knapsack problem.

The embodiment of the invention discloses a service providing method and device, electronic equipment and a computer-readable storage medium. The method comprises the steps of pre-estimating a total service quantity required by a current user according to attribute information of the current user; determining different service weights corresponding to different feature label service sets accordingto the total service quantity, wherein each feature label service set comprises one or more services with same feature labels, and the sum of different service weights is smaller than or equal to thetotal service quantity; determining one or more services from different feature label service sets according to a solution algorithm of a knapsack problem, service feedback attributes and the serviceweights; providing the determined services for the current user. According to the service providing method, the possible bearing range of the user for the demanded service quantity is taken into consideration, the suitable services are selected from the service sets with different feature labels and provided for the user, and therefore matching of finally-obtained services can meet the service requirements of the user in all aspects.

The invention discloses an efficient improved FSPSO (Particle Swarm Optimization based on prey behavior of Fish Schooling). According to the efficient improved FSPSO, an intelligent behavior is simulated, and current globally-optimal particles search for current globally-superior positions through own optimal position information provided by a minority of other random particles. When fish schooling is attacked by other predators, weak fish which cannot escape quickly is eaten. The behaviors are simulated, weak particles close to current globally-worst particles are replaced with particles which are generated randomly, so that the diversity of the schooling is improved, and a local optimum can be effectively avoided by the FSPSO. The efficient improved FSPSO can be particularly applied to the solving process of complicated optimization problems such as function optimization and knapsack problems, traveling salesman problems, assembly line work problems and graph and image processing problems.

The invention discloses a method for link self-adaption of video sensing in an HSDPA network. The method comprises the steps of first calculating video transmission utility of a video packet for the video packet of a terminal user; dynamically calculating transmission capability and a corresponding link self-adaption scheme and transmission error probability according to reporting conditions of wireless channel quality signal interference noise ratio (SINR) of the terminal user; finally utilizing a dynamic programming mathematical method to convert a link self-adaption utility maximum restricted problem to a standard mathematical Knapsack problem, and solving a video transmission utility maximum link self-adaption scheme through limited mathematic iteration. According to the method, factors such as video packet transmission utility, user wireless transmission capability and user wireless transmission error probability are considered comprehensively, and simulation experiments show that the wireless transmission capability of video users in an HSDPA system can be effectively improved.

The invention discloses a wireless heterogeneous network file cache updating method based on multicast. The method comprises the steps of 1, establishing a network topology which comprises small basestation distribution, user distribution, and distribution of connection relationships between small base stations and users; 2, establishing a current popular file set popularity distribution model; 3, establishing an energy consumption model for updating files in a multicast mode; 4, inferring a target function and a limiting condition for maximizing a system cache hit rate, and establishing an optimization model; 5, converting an optimization problem into a multi-choice knapsack problem, and carrying out solution to obtain cache file updating schemes of all small base stations; 6, sending afile to the small base stations in a multicast mode; and 7, periodically carrying out cache updating on all small base stations in the system through adoption of the steps 2-6 when a popular file setis changed. According to the method provided by the invention, popular files can be reasonably updated to different small base stations, so the possibility of directly obtaining video data from the small base stations by the users is improved, and the data of a network backhaul link is reduced.

The invention provides a method for automatic material interchange in urgent specification change of a hot rolling production line. When a three-level computer receives a second-level specification change telegraph text, virtual slabs which are not brought into a rolling mill operating plan yet and meet contract matching conditions are searched for interchange. Model constraint conditions include that the width and thickness of hot rolling materials are identical to the target width and target thickness of an order, actual steel codes of the slabs are identical to representative steel codes or nominal steel code of the order, the nominal width of the slabs minus the maximum side pressure quantity of the slabs is smaller than or equal to a target width value of a hot rolling procedure outlet, the nominal width of the slabs minus the minimum side pressure quantity of the slabs is larger than or equal to the target width value of the hot rolling procedure outlet, checking weight is larger than or equal to a minimum inlet piece weight and smaller than or equal to a maximum inlet piece weight, and solution can be worked out by translating matching between the contract and the slabs into a 0-1 knapsack problem. Using the method can improve operating efficiency, shorten delivery time for users, reduce overstocked products, quicken logistic circulation and reduce coil surplus and capital employment rate.

The invention belongs to the technical field of power supply management, in particular to a method for quickly distinguishing transformer area user-transformer relations. The line loss electric quantity and the user electric quantity are analyzed by using a Pearson correlation coefficient method; particularly, correlation analysis is carried out on a negative loss transformer area, abnormal userscan be quickly found, the number of field check users is reduced, a user marking unit is designated as a unit, the unit is a meter box (generally one meter box represents the same power supply point,namely the same transformer area), the daily power consumption of the meter box is calculated according to the relationship between the meter box and the users, and then the transformer area relationship of the user meter box is checked; a 'genetic algorithm' is adopted to solve a 'combination problem', one population has a plurality of individuals, and each individual has a chromosome and a corresponding gene and is similar to a knapsack problem in the genetic algorithm.

The invention discloses a classical combinatorial optimization problem in the field of operational research, i.e., the multi-scale quantum resonance solving algorithm for a multi-choice and multi-dimensional knapsack problem, firstly, the Lagrange relaxation dual model is established for the original problem model, which greatly reduces the constraint conditions and evaluates the value of the items in the group by using Lagrange value. On this basis, the MMKP approximate kernel problem is introduced, which is heuristic to find the optimal solution and reduces the scale of the problem. In addition, based on the approximate kernel problem, a mixed Gaussian sampling model is constructed to guide the algorithm to intensify the search in the trusted region and to uniformly search in the untrusted region, which improves the solution accuracy and convergence speed.