32 results about "Multivariate optimization" patented technology

The invention discloses a robust resource allocation algorithm of a cognitive heterogeneous wireless network and belongs to the technical field of communication cognitive heterogeneous wireless networks. The robust resource allocation algorithm is characterized by considering a robust resource allocation algorithm in a cognitive heterogeneous multi-network environment influenced by channel parameter perturbation, considering cross-layer interference constraint and bounded channel uncertainty and interference power uncertainty in an objective function, converting the original infinite dimensional multivariate optimization problem into the convex optimization problem of certainty by using a robust optimization theory, obtaining a robust power control algorithm by using a lagrangian duality method, and achieving sharing of the robust resource of the cognitive heterogeneous wireless network. Simulation results show that the algorithm can effectively protect the performance of users of a macro-cellular network and has stronger robustness.

The invention discloses a PSO (Particle Swarm Optimization)-based maximum wind energy capturing method of a VSVF (Variable-speed Variable-frequency) wind power system. Aiming at the VSVF wind power system which is formed by a variable-frequency transformer and multiple parallel-running permanent magnetic synchronous wind power generation units, cooperative optimization can be carried out on the rotating speed of the variable-frequency transformer and the pitch angles of all permanent magnetic synchronous wind power generation units through PSO, so that the capturing of maximum wind energy of the VSVF wind power system is realized. Compared with a univariate optimization method aiming at the rotating speed of the variable-frequency transformer, a PSO-based multivariate optimization method provided by the invention is capable of obtaining more wind energy.

The invention discloses an externally meshed gear pair which comprises two external gears. In polar coordinates, a single figure of the external gear I is sequentially composed of a cosine base compound curve which is composed of a line segment I, a cosine curve I, a line segment II and a cosine curve II. The line segment I, the cosine curve I, the line segment II and the cosine curve II meet first order continuity. A single conjugate figure of the external gear II corresponding to the single figure of the external gear I is obtained through a meshing principle and a conjugate gear pair is formed. A complete conjugate gear pair is obtained as the single figures of the external gear I and the external gear II respectively rotate around the center of the conjugate gear pair and evenly distributed according to the number of teeth of the conjugate gear pair. An asymmetric gear pump figure is obtained by adjusting symmetrical coefficients of the gear figure so that long sides in two gear sides of the gear are suitable for transmission, while short sides are suitable for seal. Separation of functions of transmission and seal are benefited and transmission and seal performance is enhanced. Fairness between the gear pairs can reach first order continuity and a mathematical model is set up for multivariate optimization of the gear pair.

Disclosed is a cold-rolling mill multivariate strip shape control method based on a constrained optimization algorithm. The method includes the steps that a multivariate optimization model used for solving an optimal regulating quantity of each strip shape regulating mechanism is designed; the multivariate optimization model is converted into a standard form of an optimization problem; an initial searching point for solving the multivariate optimization problem of the standard form is designed; a searching mechanism in the direction of each coordinate axis is designed; searching is performed in the direction of each coordinate axis, and a candidate value of an optimal point is calculated; a searching termination criterion is designed; and a cold-rolling mill multivariate strip shape control system model is established. By means of the cold-rolling mill multivariate strip shape control method based on the constrained optimization algorithm, the multivariate strip shape optimization model can be converted into a series of univariate optimization problems, and the method has the advantages of being high in calculation efficiency, saving the storage space of a controller and being capable of achieving concurrent computation and the like, and is quite suitable for development of a cold-rolling strip shape control system with the multiple strip shape regulating mechanisms.

The present disclosure relates to a method and an ad decision sever for determining personalized messages during a provisioning of digital content. The method comprises to provide a set of personalized messages candidates by executing a relevance algorithm, which matches message metadata and content metadata. The method continues with receiving calculated network costs for the set of personalized message candidates in order to determine a set of personalized messages, which are optimized with respect to the received network costs by applying a multivariate optimization algorithm.

The invention relates to the technical field of logistics freight, and relates to a railway freight intelligent assembly method, which comprises the steps that basic data of goods are input into a railway freight intelligent assembly system, the basic data comprise the shape, the size and the number of the goods, and the railway freight intelligent assembly system calculates and analyzes constraint conditions of the goods according to the basic data of the goods; during assembly, according to the vehicle body condition of the transport vehicle, the vehicle body is assembled; vehicle body stowage constraint conditions in the railway freight intelligent assembly system are called; and according to the constraint conditions of the goods and the vehicle body stowage constraint conditions, utilizing a multivariate optimization algorithm to calculate a stowage plan of the goods in the transport vehicle, and according to the stowage scheme, generating a stowage graph of the goods loaded on the transport vehicle. The method has the advantages that reasonable and efficient loading and stowage are calculated according to cargo attributes and vehicle body specifications, the stowage efficiency is improved, and the work of bag overturning after manual loading is reduced.

The invention discloses a closed-loop control method of cold-rolled sheet shape based on lag compensation. The closed-loop control method comprises the specific steps of manufacturing a structure of a sheet shape closed-loop control system based on a multivariate optimization model; designing the multivariate optimization model of the sheet shape closed-loop control system; manufacturing PID control models of all sheet shape regulating mechanisms; manufacturing PID+Smith predictor control models of all the sheet shape regulating mechanisms; determining process models of control circuits of all the sheet shape regulating mechanisms, and setting corresponding PID parameters; and establishing control modes of the sheet shape closed-loop control system. The closed-loop control method has the advantages that the influence of measurement lag to the stability of the sheet shape closed-loop control system during sheet shape control process can be removed through switching the sheet shape closed-loop control modes according to the rolling speed change, the structure is simple, the calculation efficiency is high, the control real time performance is relatively high, the stability of the sheet shape closed-loop control system is not influenced by measurement lag, and relatively high homeostatic control accuracy is achieved.

A method for minimizing system energy consumption of non-orthogonal multiple access narrowband Internet of Things based on mobile edge computing, which is realized by jointly optimizing transmit power, computing resource allocation, and decoding sequencing in a narrowband Internet of Things network with both MEC and NOMA technologies System energy consumption minimization, the optimization problem is described as a multivariate optimization; P1 is decomposed into two sub-optimization problems: optimizing resource allocation and optimizing decoding sorting, wherein, for the optimization of resource allocation, firstly, according to the one-to-one logarithmic transformation Transform the P1 problem into a P2 convex problem, and then use the gradient descent algorithm to optimize the problem of transmission power and computing resource allocation; secondly, for the optimization of device decoding sorting, the tabu search algorithm is used to optimize variables. The present invention provides a method for minimizing energy consumption of the entire system by designing an optimization algorithm for joint transmission power, computing resource allocation, and device decoding and sorting in the narrowband Internet of Things with both MEC and NOMA technologies.