3 results about "Mathematical theory" patented technology

This invention discloses a method for constructing QC-LDPC codes that minimizes the number of short loops, comprising the following steps: Step 1: Randomly generate the initial QC-LDPC code base matrix according to the construction requirements; Step 2: Count the number of short loops passing through each element in the base matrix; Step 3: Sort all elements in the base matrix according to the number of short loops; Step 4: Iterate through each element sequentially, calculate the number of short loops corresponding to all values ​​of the element, select the value with the fewest short loops as the new value of the element, if the element value changes, return to Step 2 for the next round of optimization, otherwise continue to traverse the next element; Step 5: Replace each element in the base matrix with a CPM (Current Minimum Quantity). This invention performs global optimization on all elements in the entire matrix, which can approach the global optimum solution, and does not rely on mathematical theories such as finite fields, has no restrictions on parameters, and has great flexibility.

The application is based on the unmanned ship formation encounter risk space-time analytic method of quantum field theory, including the following steps: constructing the initial quantum state of the ship, accurately characterizing the uncertainty distribution of the ship position through the Gaussian wave packet model; calculating the probability density of the ship at a certain state at a certain time; superposition calculation of the sum of the probabilities of all position pairs of two ships satisfying the geometric collision condition; based on the sum of the probabilities of all position pairs of two ships satisfying the geometric collision condition, the total value of the risk potential field of the encounter risk of two ships is calculated; the total value of the risk potential field of the encounter risk of two ships is compared with the risk threshold value, and whether the two ships exist the risk of collision is judged, the method of the application realizes the fundamental paradigm conversion from the classical trajectory description to the quantum field operator description by establishing the multi-level calculation framework under the quantum mechanics form system, and provides a new mathematical theoretical basis for the ship navigation risk analysis.

This invention discloses a relative acoustic impedance prediction method for composite microperforated plate structures based on a surrogate model, belonging to the field of vibration and noise control technology. This invention considers the structural parameters of variable cross-section series-parallel composite microperforated plate structures and uses Latin hypercube sampling to generate parameter samples. Relative acoustic impedance data for different structures are obtained through numerical simulation. Fourier series functions are constructed using the relative acoustic impedance data to solve for the fitting coefficients, thus achieving a fit to the relative acoustic impedance. A multi-input / output multilayer perceptron neural network is built to predict the fitting coefficients based on the structural parameters, forming a relative acoustic impedance prediction surrogate model with the fitting coefficients as an intermediate bridge. The relative acoustic impedance prediction method of this invention effectively solves the contradictory problems of high accuracy but long time consumption in numerical simulation of acoustic superstructures, and high requirements for mathematical theory and low accuracy in analytical solution derivation, thus balancing the accuracy and efficiency of acoustic superstructure design.