15results about How to "Guaranteed numerical stability" patented technology

The application discloses a VCSEL cold cavity three-dimensional vector mode solving method based on a transmission matrix-finite element hybrid. The method firstly constructs a complete epitaxial structure transmission matrix model containing an oxidation limiting layer to search for a resonance wavelength, and calculates DBR surface admittance at the resonance wavelength; then only the core active region is subjected to three-dimensional structured grid division and Nédélec edge element vector finite element discretization, and the DBR surface admittance is embedded into the weak form of Maxwell equation as an impedance boundary condition; a generalized non-hermitian eigenvalue problem is solved to obtain a cold cavity mode; finally, LP mode automatic classification is realized through a three-level algorithm of aperture restriction factor screening, azimuth angle Fourier decomposition and radial node counting. The application equivalently processes the DBR by the transmission matrix method, reduces the FEM calculation domain by one to two orders of magnitude, greatly improves the calculation efficiency while maintaining the three-dimensional vector precision, and correctly describes the influence of the longitudinal position of the oxide on the resonance condition.

The application provides a polymer material life prediction method and system considering bidirectional coupling, and aims to solve the problem that the permeability of the polymer material suddenly increases due to hydrogen-induced damage accumulation under a high-pressure hydrogen environment. The method obtains material parameters and service boundary conditions, converts pressure into surface concentration, alternately performs mechanical and diffusion-damage evolution solving in a finite element increment step, modifies the stiffness by using the damage variable of the last step to calculate the hydrostatic stress of the current step, modifies the effective diffusion coefficient by using the stress and the damage variable of the last step, solves the hydrogen diffusion equation and updates the damage variable of the current step, and constructs a bidirectional positive feedback coupling closed loop. Finally, the residual life is output based on the permeation threshold or the damage critical value. The application is mainly used for life evaluation of polymer materials in high-pressure hydrogen storage and transportation equipment.

The invention discloses an industrial control system anomaly detection method based on digital twinborn and reinforcement learning, and aims to solve the problems that in the prior art, abnormal samples are scarce, the false alarm rate is high under a dynamic working condition, and the generalization ability of a single detection model is insufficient. Generating synthetic data by simulating anomalies in the twinborn body, and mixing the synthetic data with normal data to form a training set after space-time and distribution alignment; based on the real-time data, generating a time sequence prediction residual error, a distribution reconstruction error and classification confidence multi-source evidence in parallel; constructing a reinforcement learning environment, constructing a state through multi-source evidence and the like, and guiding an agent to learn a fusion strategy through an asymmetric reward function; and training the intelligent agent to obtain a detection model and performing online deployment. According to the method, the multi-source evidence is adaptively fused through the reinforcement learning agent, so that the robustness, the accuracy and the adaptive capability of anomaly detection under the dynamic working condition are remarkably improved, and missing report and false report are effectively reduced.

The invention discloses a full-process simulation and blasting pressure prediction method for a weak-rigidity core mold composite material shell, and belongs to the technical field of solid rocket engine integrated explosive forming shell design. The method comprises the following steps: designing an equal residual stress tension system based on a fiber winding layer stress theory; constructing a finite element model in the shell winding process, iteratively optimizing a tension system and determining a stress field and a strain field after winding; taking the stress field and the strain field as predefined fields, constructing a finite element model in the curing process, and calculating the stress field and the strain field after curing; and based on the stress field and the strain field after curing, progressive damage analysis is realized through a three-dimensional Hashin criterion, and the maximum blasting pressure of the shell with the powder is predicted. The problems that in the prior art, a tension system lacks collaborative optimization, simulation cannot cover the whole process, and blasting prediction deviation is large are solved, precise coupling prediction of the process and performance is achieved, and theoretical support is provided for optimization of the integrated forming process.

The application belongs to the technical field of the cross of artificial intelligence and computational mechanics, and particularly relates to a bagged sand cofferdam MPM simulation method and system based on artificial intelligence, a three-dimensional simulation system of the bagged sand cofferdam is constructed by combining the MPM method, a penetration state of the sand and the geotextile is detected by using a penetration tracking algorithm and a space hash acceleration, an artificial intelligence algorithm is introduced to design a reward function with the minimum penetration depth and penetration times as the target, penetration prediction of the bagged sand MPM particle is driven, further based on the predicted contact model and the artificial intelligence algorithm, the MPM particle velocity and stress are dynamically regulated to prevent penetration and ensure numerical stability, and the implicit integration and gradient descent method are adopted to improve the calculation precision, and the two-way coupling of the sand and the geotextile is realized through a visualization module. The problems of low coupling simulation efficiency, easy penetration and numerical instability of the sand and the flexible structure in the traditional method are solved, and the accuracy and reliability of the simulation analysis of the bagged sand cofferdam structure under complex working conditions are significantly improved.

This invention discloses a method and system for anti-interference multi-tag webpage recognition under encrypted traffic conditions. The method includes: constructing a dynamic association graph using the burst transmission structure of encrypted traffic; accurately deconstructing aliased traffic and outputting independent sub-stream sequences through an entropy weight penalty mechanism and node aggregation algorithm; extracting non-stationary time-frequency features from the sub-streams and fusing them with graph topological features extracted based on graph structure in the tangent space; generating perturbation samples using an adversarial training environment; adjusting feature weights to generate a composite fingerprint; performing long-term time-series modeling on a Lie group manifold using a Bi-Mamba network and reserving a modulation interface to output a preliminary recognition probability; auditing causal consistency through a webpage loading logic state machine, converting abnormal states into geodesic correction quantities in the Lie algebra tangent space, and correcting network parameters online through the reserved interface. This invention solves the problems of difficult deconstruction of aliased traffic, insufficient fingerprint robustness, and lack of logical consistency constraints in the recognition results.

The application relates to the technical field of electric digital data processing, and discloses a train ice melting simulation optimization method of an electromagnetic heat coupling model fused with a deep learning method, which comprises the following steps: inputting a geometric characterization tensor and a physical working condition parameter vector containing an electromagnetic excitation frequency and a reference environment temperature into a feature mapping neural network, outputting a double-channel space source term tensor containing a basic heat source power density and a heat source temperature change sensitivity distribution matrix through nonlinear convolution operation; constructing a heat conduction discrete numerical evolution operator configured with a source term linear correction interface; performing time step operation in a heat conduction time scale, and correcting the basic heat source in real time by using Hadamard product of the sensitivity distribution matrix and a temperature deviation, and substituting the basic heat source into the operator for solving; and the mixed architecture of neural network static mapping and numerical operator dynamic correction is adopted, time scale decoupling is realized under the premise of retaining electromagnetic-heat nonlinear coupling characteristics, and the calculation efficiency in high-frequency physical field simulation is effectively solved.

The invention belongs to the technical field of geophysical signal processing, and relates to a nuclear magnetic resonance adaptive transverse constraint inversion method for a complex geological environment. According to the method, an inversion objective function is constructed through a Tikhonov regularization algorithm, an LM iteration framework is deeply fused, and the numerical stability of an inversion process in an ill-conditioned matrix environment is ensured by utilizing the cooperative adjustment of a damping factor and a unit matrix. According to the method, the limitation that only the correlation coefficient of the simple adjacent measuring points is constructed in the prior art is abandoned, and the self-smoothing correlation coefficient is combined with the Pearson correlation coefficient. Linear correlation of measuring point data is accurately captured through a Pearson coefficient, and a self-smoothing mechanism based on weighted moving average is introduced, so that environmental noise interference is effectively reduced, and continuity of an inversion model in space is enhanced. According to the method, the constraint force can be adaptively adjusted according to the continuity of the underground geologic structure. The anti-noise capability is obviously improved, and the transverse resolution of the nuclear magnetic resonance signal is effectively improved.

This invention discloses a simulation method and related apparatus for a power system. The method includes: dividing the main power grid of the power system into sub-networks, dividing the sub-networks into converter subsystems, and dividing the converter subsystems into switching sub-circuits; simulating the sub-networks and converter subsystems using a large-step simulation method, simulating the switching sub-circuits within the critical window of switching action using a small-step simulation method, and simulating the switching sub-circuits in other time periods using a large-step simulation method; wherein the large step size is an integer multiple of the small step size; the critical window of switching action is determined based on the simulation results of the switching sub-circuits of the current simulation time step and the historical simulation time steps, and the small step size is determined based on the step-coupling stability judgment of the switching sub-circuits within the critical window of switching action. This invention separates the transient process of switching from the slow dynamic process of the main power grid through three-level topology decoupling. It uses small-step fine-grained solution for local switching subcircuits only within a very short window before and after the switching action, while using large-step solution for the entire system in the remaining time domain. This eliminates the computational redundancy caused by small-step solution for the entire system, effectively compressing computational overhead and reducing simulation resource consumption. Furthermore, this invention uses a hybrid simulation strategy to balance the numerical stability of slow dynamic processes with the solution efficiency of fast dynamic processes. It can ensure the simulation efficiency of electromagnetic transients with a high proportion of power electronics connected to the power system while maintaining the accuracy of switching transient simulation and long-term time domain numerical stability.

This invention provides a method and system for updating the personality parameters of a digital avatar based on implicit user feedback. The method includes: extracting implicit feedback signals from user-digital avatar interaction logs; performing weighted linear fusion and smoothing on the implicit feedback signals to obtain a smoothed reward value; calculating the policy gradient using a proximal policy optimization algorithm based on the smoothed reward value, and limiting the single-step update amplitude with a pruning objective function to perform gradient ascent, obtaining candidate updated personality parameter vectors; calculating a deviation metric by combining the baseline personality parameter vector, and comparing it with a preset drift threshold; when the deviation metric is greater than the drift threshold, projecting the personality parameter vector to the feasible region boundary and outputting the target personality parameter vector; otherwise, using the candidate updated personality parameter vector as the target personality parameter vector. This invention significantly reduces the feedback acquisition threshold, ensures the numerical stability of the personality parameter update process, and avoids personality drift in reinforcement learning.

The invention discloses a method and system for triggering the sound effect of automobile simulation sound, and relates to the technical field of active sound production of new energy automobiles, and the method comprises the following steps: collecting an input vector of a vehicle physical signal generation system; updating a virtual tension state variable reflecting mechanical stress memory, wherein the virtual tension state variable comprises starting tension injection and driving time domain attenuation; meanwhile, the virtual torque gradient for quantifying the driving intention and the virtual inertia saturation for representing the rotating speed approximation degree are calculated; the torque gradient and the tension variable are fused to synthesize a dynamic gear shifting threshold value, and the dynamic gear shifting threshold value is compared with inertia saturation to generate a gear shifting trigger instruction; and outputting a sound effect modulated by tension in response to the instruction, and executing energy dissipation operation to deduct a tension value to complete closed-loop control. According to the method, the virtual transmission chain tension model and the power state observer are constructed, the physical logic relation between the starting condition and the driving condition is established, self-adaptive adjustment of the triggering threshold value is achieved, and the problems that in the prior art, sound effect triggering logic is rigid, and physical reality is lacked are solved.

This invention discloses a method for modeling the vertical vibration dynamics of a hub motor-driven wheel system considering the effect of the vehicle body articulated beam. It constructs a four-degree-of-freedom lumped-parameter vertical dynamic equation model of the hub motor-driven wheel system, including tire vertical displacement, hub motor drive system vertical displacement, sprung mass vertical displacement, and the rotation angle of the lower control arm around the vehicle body articulation point. The method reads the S-K and V-C characteristic curves of the air spring and the S-F characteristic curve of the tire from external experimental data files. Using the suspension geometric mapping as the independent variable, it calculates the nonlinear suspension stiffness and damping in real time through spline interpolation. Using tire deflection as the independent variable, it calculates the nonlinear tire elastic force, and applies soft saturation limiting to ensure numerical robustness. Based on the ISO 8608 standard, it establishes road surface excitations for three conditions: high speed, climbing, and off-road, using a filtered white noise time-domain method. The equations are transformed into a first-order state-space form and solved using an adaptive step-size numerical integration method. This invention accurately describes the multi-body coupled vibration transmission relationship after the introduction of the hub motor, providing a precise and reliable modeling foundation for vibration reduction design and dynamic analysis.

This invention provides a method, apparatus, and electronic device for improving the fluidity of porous media using pulsating flow. The method includes: determining a critical threshold and a subcritical baseline; applying a steady-state displacement with a displacement intensity equal to the subcritical baseline, and superimposing a pulsating drive; using a solution framework to advance the interfacial motion of droplets under pulsating drive over time, adaptively controlling the time step during the advancement process, the time step being jointly limited by multiple physical constraints; determining the truncated axial net displacement of the droplet within the pore throat contraction structure within a fixed observation time window; obtaining the fluidity index corresponding to the pulsating drive based on the truncated axial net displacement; keeping the amplitude of the pulsating drive constant, changing the frequency of the pulsating drive to obtain a first curve of the fluidity index changing with frequency, and determining a cutoff frequency based on the first curve; changing the amplitude of the pulsating drive to obtain a second curve of the cutoff frequency changing with amplitude. This method is suitable for engineering parameter design and selection and is reproducible.

The invention discloses a multi-variable-speed ship adaptive space-time step length coordination method, a state updating method and a collision risk prediction method. The method comprises the following steps: acquiring real-time states of a ship and all target ships; calculating the recent meeting time among all ship pairs, finding out the minimum positive PAT value, and carrying out time interval calculation by adopting a time urgency constraint function; the minimum Euclidean distance between all ship pairs is calculated, and a spatial proximity constraint coordination function is adopted to carry out spatial proximity constraint step length calculation; the maximum absolute value of acceleration changes in all ships is calculated, and a self-adaptive step length is obtained through calculation based on a speed change feature constraint function; according to the method, the numerical integration of the ship motion state is updated, then the ship collision risk is predicted based on the collision risk potential field model, and the method aims at solving the limitation of a fixed step size algorithm and achieving the effects of high-risk speed change stage fine analysis and low-risk constant-speed stage efficient propulsion.

The application discloses a kind of slope and river channel confluence coupling parallel computing method and related device, method includes: the cumulative confluence area of each cell is calculated based on the flow direction relationship between each cell to identify slope cell and river channel cell;Based on the flow direction relationship between each cell, simulate the slope confluence movement of study area, and calculate the hydrological flow data of each slope cell and river channel cell in parallel;Simulate the river channel confluence movement of study area, according to the hydrological flow data, calculate the inflow data of each river channel cell at the current time step in parallel;According to inflow data, update the water storage of each river channel cell at the next time step in parallel based on linear storage confluence method;Based on water storage, update the outflow data of each river channel cell at the next time step in parallel.The application realizes the coupling simulation of slope and river channel confluence;Through linear storage, the water quantity of each cell is updated, and the river channel confluence does not need sequential iteration, so as to realize the synchronous update of whole watershed cell.