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144results about How to "Slow convergence" patented technology

Short-term prediction method for occupancy of effective parking space of parking lot

The invention discloses a short-term prediction method for occupancy of an effective parking space of a parking lot. The short-term prediction method comprises the steps as follows: 1) determining a time sequence of the occupancy of the effective parking space of the parking lot; 2) carrying out wavelet decomposition to the time sequence of the occupancy of the effective parking space through a wavelet function, thus obtaining a low-frequency coefficient vector and a high-frequency coefficient vector; implementing the wavelet reconstruction to the low-frequency coefficient vector and high-frequency coefficient vector, so as to obtain the time sequence of N+1 reconstructions; 3) establishing a wavelet neural network model to the time sequence of the N+1 reconstructions for predicting, thus obtaining N+1 prediction results; and 4) accumulating the N+1 prediction results, so as to obtain the prediction results corresponding to the time sequence of the occupancy of the effective parking space. According to the short-term prediction method disclosed by the invention, a wavelet analysis-wavelet neural network combinational prediction model is raised to perform short-term prediction to the occupancy of the effective parking space of the parking lot according to the short-term variation characteristic of the occupancy of the effective parking space of the parking lot, therefore, the prediction accuracy and the stability are improved.
Owner:SOUTHEAST UNIV

Determination method of initial completion initial cable force of cable-stayed bridge

The invention relates to a determination method based on an ANSYS second development platform of the initial completion initial cable force of a cable-stayed bridge. The method uses the design cable force as the target value, considers the geometric non-linear effect and performs iteration for solving and correcting the cable initial strain under the action of dead load. The method comprises the following specific steps: any group of cable forces is assumed to be added on the stay cable in the mode of initial strain, dead load is added to calculate, the *do-loop command language is used to extract the calculated cable force of the stay cable and check whether the error between the cable force and the target completion cable force is within an available limit; if the error is large, the indifference method is used to correct the stay cable initial strain, then the error is calculated again until the error is within the available limit; and the initial completion initial cable force can be obtained by multiplying the last calculated group of stay cable initial strains by the elastic modulus of the stay cable which is corrected by considering the vertical effect. By using the method, the solving time of the completion initial cable force of the cable-stayed bridge can be reduced and the precision can be increased, thus the method has large practical engineering application value.
Owner:WUHAN UNIV OF TECH

Driving motor system performance evaluation method for electric vehicle

The invention discloses a driving motor system performance evaluation method for an electric vehicle. The driving motor system performance evaluation method analyzes from different dimensions such as motor control performance, motor body design and enterprise qualification and ability of the driving motor system according to performance characteristics of a driving motor used for the electric vehicle, adopts an analytic hierarchy process to determine a driving motor performance evaluation index system and index weights thereof, establishes a BP neural network model for driving motor system performance evaluation, organically integrates a bat algorithm with a particle swarm algorithm to form a bat-particle particle swarm hybrid algorithm, and optimizes parameters of the neural network structural model by adopting the bat-particle particle swarm hybrid algorithm. Simulation examples show that, through training and testing data samples, the driving motor system performance evaluation method which optimizes the neural network based on the analytic hierarchy process and the bat-particle particle swarm hybrid algorithm has the advantages of fast evaluation speed and high accuracy rate, achieves satisfying evaluation results, and has certain promotion value in evaluation, selection and application of a driving motor system for the electric vehicle.
Owner:WUXI OPEN UNIV

Field programmable gate array (FPGA) implementation equipment and method for self-adaptive clutter suppression of external radiation source radar

The invention discloses field programmable gate array (FPGA) implementation equipment and an FPGA implementation method for self-adaptive clutter suppression of external radiation source radar. The method comprises the following steps of inputting four paths of channelized data to be processed into a finite impulse response (FIR) filter module through a first in first out (FIFO) memory inside a self-adaptive clutter suppression module of an FPGA chip; inputting two paths of data, channelized by an auxiliary antenna, into a step length calculation module through the FIFO memory, and calculating the step length through the step length calculation module; simultaneously inputting the output of the step length calculation module and two paths of output of the FIR filter module into a weight updating module; inputting an updated weight into the FIR filter module; and performing synchronous parallel output on clutter suppression results through in-phase/quadrature (I/Q) channels. The self-adaptive clutter suppression is controlled by five global clocks with the same rate and different phases. The self-adaptive clutter suppression of the external radiation source radar can be better realized. The problem of difficulty in meeting of a requirement on real-time performance caused by large conventional clutter suppression equipment amount is solved. The equipment and the method are high in processing efficiency, high in calculation speed and low in equipment complexity, and are used for implementing the self-adaptive clutter suppression of the external radiation source radar.
Owner:XIDIAN UNIV

AUV (Autonomous Underwater Vehicle) track deviation estimation method based on multi-point terrain matching and positioning

The invention provides an AUV (Autonomous Underwater Vehicle) track deviation estimation method based on multi-point terrain matching and positioning. The AUV track deviation estimation method comprises the following steps: (1) estimating a searching region of the terrain matching and positioning; (2) carrying out terrain matching and positioning under unknown tidal difference and measurement error conditions; (3) estimating measurement errors and estimating a positioning confidence interval; (4) estimating positioning errors; (5) estimating multi-point terrain matching and positioning initial track deviation; (6) carrying out track correlation and eliminating an incorrect positioning point; (7) carrying out secondary fitting of a track. The AUV track deviation estimation method provided by the invention has the advantages that characteristics that reckoning navigation is slowly changed in a time domain and an airspace and a terrain matching and positioning result has no diffusivity in the time domain and the airspace are combined, and a plurality of dense terrain matching and positioning points are obtained on a track line; track line of the reckoning navigation is fitted with multi-point positioning information so that the positioning precision and the positioning reliability are greatly increased.
Owner:HARBIN ENG UNIV

Active factor set membership proportional sub band self-adaption echo cancellation method

Disclosed is an active factor set membership proportional sub band self-adaption echo cancellation method. The method comprises the steps: A, dividing an adaptive echo cancellation sub band filter input vector X(n) formed by a discrete value of a far-end signal into a sub band signal X(n), B, performing N extraction on an input sub band signal X(n) and a near-end sub band signal d(n) to obtain a signal X(k) after the extraction and a d(k), C, obtaining a filtering value y(k) of the signal X(k) after the extraction via an adaptive echo cancellation sub band filter, D, subtracting a filtering value y(k) from the near-end sub band signal d(k), with an echo, after the extraction and then sending a different value to a far end, E, obtaining a sub band filter step length u(k) through calculation of an active factor f<l>(k) and a proportional matrix G(k) by utilizing a set membership filtering algorithm, and updating a weight coefficient vector W(k), and F, enabling k to meet an expression k=k+1, and repeating A-E steps until an end of a call. The method has the rapid convergence speed and the low steady-state error at one aspect, and has the rapid tracking capability at the other aspect; and the method has the good cancellation effect on an acoustic echo of a communication system.
Owner:SOUTHWEST JIAOTONG UNIV

Method for controlling component and thermal treatment technological process of pre-hardening plastic die steel

The invention discloses a method for controlling the component and thermal treatment technological process of pre-hardening plastic die steel. The method includes the steps that firstly, an orthogonal test is designed according to structure characteristics and performance requirements of the pre-hardening plastic die steel, and thermal treatment technological parameters which have obvious influences on performance are found out through the test; then chemical components, the thermal treatment technological parameters and performance indexes are collected; an artificial neural network model is built, the model is trained, input of the model is the chemical components and the thermal treatment technological parameters, and output of the model is the performance indexes; the trained artificial neural network model is used for predicting steel performance and studying influence laws of input to output according to the chemical components and the thermal treatment technological parameters. According to the method, the complicated non-linear relationship between the chemical components, the thermal treatment technological parameters and mechanical properties is built, therefore, the component and thermal treatment technological process can be effectively controlled, the pre-hardening plastic die steel with excellent performance can be generated, and the service life of dies can be prolonged.
Owner:ZHENGZHOU UNIV

Method for optimizing linear array antenna radiation pattern

The invention discloses a method for optimizing a linear array antenna radiation pattern, which mainly solves the problems of low shaping and optimizing speed, low accuracy and low flexibility of the conventional antenna radiation pattern. The method comprises the following steps of: (1) setting parameters given by a system and a radiation pattern level value required by the system; (2) generating a level restraining fitness function, a level filling fitness function and a lower inclination angle fitness function according to the radiation pattern level value required by the system; (3) initializing excitation amplitude, an excitation phase and a unit distance parameter, and performing iterative optimization according to an optimizing formula until the requirement that the sum of values of the three fitness functions is equal to zero can be met; and (4) generating an antenna radiation pattern from the optimized excitation amplitude and / or the optimized excitation phase and / or the unit distance according to the theory of the array antenna radiation pattern so as to finish optimization on the radiation pattern. The method has advantages of high calculation speed, high accuracy and strong flexibility, and the optimized design, meeting the various system requirements, of the linear array antenna radiation pattern can be achieved.
Owner:西安新海天通信有限公司

Satellite video dynamic target tracking method fusing correlation filter and motion estimation

ActiveCN110956653AAccurate satellite video dynamic target trackingImprove accuracyImage enhancementImage analysisImaging FeatureKalman filter
The invention discloses a satellite video dynamic target tracking method fusing a correlation filter and motion estimation, and relates to the field of spaceflight earth observation information processing and analysis. The satellite video dynamic target tracking method comprises the steps: obtaining a satellite video, and segmenting the satellite video into continuous single-frame images; selecting a to-be-tracked target from the single-frame image, constructing image features of the target, and inputting the image features into a related filter to obtain the position of the target; performingmotion estimation processing on the position of the target through a trajectory average algorithm and a Kalman filter, and when the Kalman filter is not stable, taking the processing result of the trajectory average algorithm as a motion estimation result; and when the Kalman filter is stable, taking a processing result of the Kalman filter as a motion estimation result. The satellite video dynamic target tracking method is suitable for satellite video ground target tracking, especially when the target is shielded, can still effectively track the target, and can complete multiple applicationssuch as target high-precision tracking, sensitive target real-time positioning and traffic flow monitoring.
Owner:TECH & ENG CENT FOR SPACE UTILIZATION CHINESE ACAD OF SCI

Training method of deep convolutional neural network for face recognition

The invention discloses a training method of a deep convolutional neural network for face recognition. The method comprises the following steps: 1) preparing a face image data set, dividing the face image data set into a training set and a verification set, and selecting the type, the structure, the hyper-parameter and the magnitude of a deep convolutional neural network model according to the scale and the complexity of the training set and the performance index of face recognition which should be achieved; 2) extracting features of face pictures input by the training set by using the model,and taking the features as input in the step 3); 3) constructing a loss layer, and iteratively calculating a loss value for the training; 4) comparing the loss value calculated in the step 3) with a preset threshold value, judging whether training is stopped or the gradient is calculated, and updating model parameters; and 5) verifying the model performance, and determining whether to stop training. According to the method, the human face features can be constrained by using a multivariate acting force from two aspects of an Euclidean space and an angle space during training, so that the deepconvolutional neural network model can learn the human face features with higher discrimination and robustness.
Owner:SOUTH CHINA UNIV OF TECH +1

High-precision numerical simulation calculation method for carrying out static characteristic analysis on concrete gravity dam based on h-p type finite element method

The invention relates to a high-precision numerical simulation calculation method for carrying out static characteristic analysis on concrete gravity dam based on h-p type finite element method, and belongs to the technical field of simulation. The high-precision numerical simulation calculation method for carrying out static characteristic analysis on concrete gravity dam based on h-p type finiteelement method comprises the following steps of building a calculation model of the hydraulic concrete gravity dam; calculating a displacement field and a stress field of the hydraulic concrete gravity dam model by a h-p type finite element method; judging whether the obtained displacement field and stress field meet the precision requirement or not, if the obtained displacement field and stressfield do not meet the precision requirement, encrypting the grid again, improving the order of the interpolation polynomial, and repeating the steps until a satisfactory result is obtained. The invention provides a novel high-precision finite element calculation and analysis method for a concrete gravity dam in order to solve the problems that an existing concrete gravity dam model based on traditional finite element static analysis is too long in calculation time, too large in error and low in precision.
Owner:KUNMING UNIV OF SCI & TECH
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