72 results about "Control variates" patented technology

The invention provides a method for identifying a hyperspectral material. First a standard light source spectrum database is established, a spectral material standard database is established, and standard light source spectra are obtained through a difference method and a control variable method; spectral data information is shot for a material needing to be identified; through preprocessing and intrinsic material information extraction, spectral characteristics of the material are obtained, and then the spectral characteristics are matched with data in the spectral material standard database, so as to perform high-precision identification of the material. According to the method, the interference to spectral information of the material caused by complex factors such as different illumination conditions and material shape changes and the like can be resisted, the problems of metamerism and homogeneity and heterochrome which cannot be solved through conventional red green blue (RGB) and RGBD cameras are solved, and the identification precision rate is high.

The invention discloses a multi-relay cooperation system based on vehicle assistance in a parking lot and a communication method, and belongs to the field of vehicle networking. According to an established multi-relay cooperation system for parking vehicles in a parking lot, on the basis of a vehicle arrival model and a vehicle expected parking duration model, a probability model of vehicle leaving behaviors are given. In the invention, a segment of two-hop point-to-point communication in the multi-relay cooperation system is selected, the influence of leaving behaviors is introduced, the breakout probability of the communication link is calculated, a control variable method is used to obtain the influence of each parameter in the leaving probability model on the breakout probability, andthe parameter with the greater influence is used as a reference factor in the relay selection of the system, so as to improve the stability of the relay network in the parking lot. The invention proposes the influence of the vehicle leaving behaviors on the network system in the parking lot, so that a theoretical basis and specific performance evaluation are available for applying vehicle parkingto the relaying.

The invention discloses a method for precisely measuring the shoe length and stride of target person in video. The method comprises the following steps: (1) selecting and performing screenshot storage to an original video including the target person, wherein tips and heels of feet of the target person can be seen in the screenshot, two feet of the target person are contacted with the ground and one foot is stepped onto the ground firmly; (2) selecting at least two reference persons which are required that the sizes of shoes of each person are different and close to the size of feet of the target person as far as possible; (3) by adopting a variable control method and a variable method, accurately positioning the position of two feet and position of shoes of the target person by utilizing the original video screenshot including the target person; (4) conducting scene restoration experiment; and (5) measuring the video images obtained from the scene restoration experiment. Images are recovered by adopting a computer image processing technology, especially the difficulty that the feature data of the target person cannot be measured after the video shooting space is changed can be solved.

The invention belongs to the field of the reliability of a power generation system, and discloses a method for evaluating the reliability of a large-scale wind power plant based on control variable sampling. The method is particularly suitable for evaluating the reliability of the large-scale wind power plant. The method includes the steps that a control variable method is used for sampling the power generation system including the large-scale wind power plant, a K-means method is used for establishing a new load model, the reliability index of conventional set sampling is used as a new state function constructed by control variables, and an analytical method is used for calculating the reliability index of a conventional set; the conventional set and a wind generation set are sequentially sampled, the reliability index of the conventional set and the reliability indexes of all sets are calculated, and the system reliability index of the sampling at this time can be calculated according to the new state function; through repeated cyclic sampling, the final reliability index of the calculation system can be counted. According to the method, the advantage of being accurate in analytical method and the advantage of being easy to model in a simulation method are combined; compared with a traditional analytical method, the modeling process is simple and visual; compared with a conventional Monte Carlo method, the precision of the obtained reliability index is high, and sampling efficiency is greatly improved.

The invention provides a flapping wing aerodynamic characteristic analysis method based on two-dimensional plane hovering. The aerodynamic characteristic analysis method comprises the following stepsof step 1 determining a research scheme; step 2 modeling of a two-dimensional airfoil: selecting a standard airfoil in a low-speed airfoil series; step 3 setting a user-defined function UDF: on the basis of the step 2, compiling a plurality of groups of different UDF functions by adopting a control variable method according to the phase angle of the primarily-selected flapping wing and the frequency of the primarily-selected flapping wing; 4 calculating a lift coefficient and a resistance coefficient; 5 calculating a mean value and analyzing a numerical simulation result. According to the two-dimensional plane hovering flapping wing aerodynamic characteristic analysis method provided by the invention, the aerodynamic characteristics of a real high-frequency vibration biological thin wing during hovering can be simulated; the relation between the average lift-drag coefficient and the frequency and phase angle is analyzed through numerical calculation, so that the most appropriate flapping wing frequency and phase angle are preferably selected, and the method has the meanings of an unpredictable for the design of the bionic flapping wing aircraft at present.

The invention discloses an improved laser micropore manufacturing experiment method based on the penetration detection technology. The method includes the steps of S1, using the penetration detection technology to obtain a pulse number needed when through holes are formed during laser micropore manufacturing and a pulse number threshold; S2, using the pulse number threshold as the pulse number used under different parameter combinations in an experiment so as to improve a control variable method and an orthogonal experiment method; S3, using the improved control variable method and the improved orthogonal experiment method to research the influence of various influence factors on laser micropore manufacturing quality and improve laser micropore manufacturing process parameters. The improved laser micropore manufacturing experiment method has the advantages that the pulse number threshold which can exactly penetrate a material is obtained through the penetration detection technology, the pulse number threshold is used as the laser drilling pulse number in the experiment, influence of pulse laser on through hole taper after the through holes are formed, heat influence is reduced, research reliability is increased, laser drilling efficiency is increased, and defects of a traditional control variable method and a traditional orthogonal experiment method are overcome.

The invention provides a shared bicycle analysis and scheduling method based on a stochastic Petri net model. A K-means algorithm and an MeanShift algorithm cluster and analyze the shared bicycle dataof a certain day in a certain area. According to the scheduling situation of each shared bicycle virtual station and each station, the pre-scheduling stochastic Petri net model is established. Basedon the natural flow of shared bicycles, the variables in the dispatching process are set and a stochastic Petri net model is established. The variables include a scheduling path, the scheduling time and a scheduling quantity. Based on the stochastic Petri net model, the optimal frequency of shared bicycles is obtained by adjusting the number of shared bicycles in each dispatching path according tothe control variable method, and the optimal dispatching strategy of shared bicycles is determined, so that the number of shared bicycles in each virtual station is stabilized in the initial state. The invention has the advantages of alleviating the problems of chaotic parking and disorderly distribution of shared bicycles.

According to the optimal installation point selection method for the active filter in the power distribution network, a plurality of basic buses are primarily selected as alternative installation points according to experience; APFs capable of separately compensating active power and reactive power of harmonic waves are mounted on the plurality of alternative mounting points; the method of controlling variables is adopted to control the APF to compensate a harmonic current each time to enable the harmonic current distortion rate of the total bus to reach the same value and obtain a compensation curve corresponding to each basic bus, and an injection compensation current value on each corresponding alternative mounting point is calculated when the harmonic current distortion rate of the total bus reaches the same value according to the compensation curve; and the alternative installation point with the minimum injection compensation current value is selected as an optimal installation point. According to the invention, the optimal installation point is selected by adopting the method, the harmonic current distortion rate of the total bus meets the grid-connected requirement, and thecompensation effect of the active filter on the power distribution network can be improved. The method has universal applicability and is suitable for networks with various nonlinear loads.

The invention discloses a loudspeaker mesh cover design method based on a finite element method. The loudspeaker mesh cover is simulated and designed by the finite element method, and the loudspeakermesh cover shape can be optimized in the prophase of the design to adjust the loudspeaker performance, speed up the loudspeaker design and development progress, and reduce the development cost. A loudspeaker mesh cover design method based on finite element method comprises the following steps: S1, making a three-dimensional model of the loudspeaker with the mesh cover; 2, establishing a finite element model of that loudspeaker with a mesh cover accord to the three-dimensional model; S3, exciting the loudspeaker to the finite element model; S4, setting the parameters of the screen cover; S5, solving the finite element model by the control variable method and the parameterized scanning model, calculating the frequency response curves corresponding to the screen covers with different parameters, and comparing and selecting the optimal solution.

The invention discloses a method for obtaining an electromagnetic forming coil capable of realizing uniform deformation of plates. The method comprises the following steps: acquiring a deformation amount specific to flat plate blanks formed by means of repeated electromagnetic forming, and selecting matched electromagnetic forming coils according to the deformation amount; acquiring the skin depths of the electromagnetic forming coils according to the electrical conductivities of plates to be formed, the discharge frequency of electromagnetic equipment and vacuum permeability; acquiring the parameter ranges of the electromagnetic forming coils according to the skin depths; selecting the structural parameters of multiple groups of electromagnetic forming coils within the parameter range by adopting a control variable method; performing deformation simulation on the multiple groups of electromagnetic forming coils and matched plates respectively, selecting an optimal structural parameter according to plate deformation results, and obtaining the electromagnetic forming coil according to the optimal structural parameter. By adopting the electromagnetic forming coil provided by the invention, metal plates which are deformed uniformly can be obtained, and further forming of the plates is facilitated.

The invention discloses a construction method and device of a multi-spraying-head flow control model. The construction method comprises the steps: the pipeline pressure and the PWM control signal frequency of a solenoid valve are obtained; based on a control variable method, according to the pipeline pressure and the PWM control signal frequency of the solenoid valve, the PWM control signal duty ratio of the solenoid valve is adjusted to enable the solenoid valve to be opened and closed for multiple times so as to control the work flow; flow data are fed back in real time through a flow sensorto obtain a flow dataset; according to the duty ratio and the flow dataset, a fitting curve is obtained through polynomial fitting, and a dynamic function of a multi-spraying-head flow about the PWMcontrol signal duty ratio of the solenoid valve is generated; the dynamic function is analyzed and processed through the polynomial fitting curve; and a PWM control signal duty ratio function, takingthe multi-spraying-head flow as a variable, of the solenoid valve is calculated, and the multi-spraying-head flow control model is constructed. The multi-spraying-head flow control model provides a dynamic adjustment strategy for the multi-spraying-head flow, and can be applied to multi-spraying-head working scenes.

The invention relates to a research method for conducting low-frequency noise processing by using COMSOL and resonant cavity models. The method includes the steps that firstly, resonant cavity modelsof different specifications are made; secondly, first detection groups are placed in B&K type 4206 impedance tubes respectively for sound reduction index testing, and second detection groups are placed in B&K type 4206 impedance tubes respectively for sound reduction index testing; thirdly, theoretical simulation of resonant cavity sound absorption is conducted by using COMSOL software until theoretical data fitted by the COMSOL software is basically consistent with experimental data in the second step; fourthly, expansion simulation of resonant cavity sound absorption continues to be conducted through a control variable method by using the COMSOL software, and finally an influence curve of film thickness and diameter on the sound absorption effect is determined. According to the film typeresonant cavity with adjustable parameters, the absorption frequency and absorption coefficient of the peak value are adjusted by changing the size of the models and the thickness of elastic films, theoretical simulation is conducted by using the COMSOL software, and specific absorption at a specific frequency is realized with the least space, the minimum material consumption and the lowest cost.

The invention discloses an establishment method for an ultrasonic power supply power adjustment model of an ultrasonic-assisted processing acoustic system. The method includes the specific steps that firstly, the theoretical relation between parameters related to the amplitude of the ultrasonic acoustic system and the amplitude is theoretically analyzed based on an amplitude-parameter relational expression and ABAQUS finite element simulation harmonic response analysis; secondly, an ultrasonic-assisted processing amplitude test experiment platform is designed and built based on theoretical analysis, the single-factor influence and comprehensive influence of the parameters on the amplitude are analyzed through the control variable method, and sample data is acquired; thirdly, regression analysis and optimization are conducted on the sample data through the multiple linear regression analysis method by means of the MATLAB, and then a guidance model with the amplitude as the dependent variable is established; fourthly, reverse deduction is conducted based on the guidance model with the amplitude as the dependent variable to obtain the ultrasonic power supply power adjustment model of constant-amplitude output of the ultrasonic-assisted processing acoustic system; fifthly, any pointed tool is selected to conduct experimental verification on the ultrasonic power supply power adjustment model.

The invention discloses a method for reducing data remanence in a nonvolatile memory. The method comprises the steps of: carrying out structural modeling and electrical characteristic modeling on a non-volatile memory cell by Silvaco TCAD; determining model parameters corresponding to the factors affecting the data remanence in the non-volatile memory in a structural model and an electrical characteristic model; by use of the control variate method, determining the influence of any influence factor on the data remanence in the non-volatile memory according to a 0.18micron standard CMOS technology and calculating the quantity of floating gate electrons corresponding to floating gate charges; and reducing the quantity of the floating gate electrons by reducing the thickness of a tunnel oxide layer or increasing source voltage in an erasure operation or prolonging the erasure operation time, and selecting a model parameter value of the minimum quantity of the floating gate electrons to apply to the technical manufacturing process and the working process of a device, so that an attacker guesses stored data more difficultly according to the quantity of the floating gate electrons, namely the probability of restoring the data is effectively reduced.

The invention provides a bearing idling operation analysis and detection device, belongs to the technical field of bearing detection, and is used for solving the problems of incomplete bearing idlingdetection and analysis and complicated operation. The device includes a platform; a tensioning assembly is arranged in the middle of the platform; an air injection assembly, a vibration assembly, a rotating speed assembly, an operation display platform and a micro air pump are arranged at the upper end of the platform; a plurality of elastic clamping grooves are fixed to the upper end of the platform; a vibration detection probe and a rotation speed detection probe are arranged on the vibration assembly and the rotation speed assembly respectively; a temperature detection probe and a noise detection probe are clamped in the elastic clamping grooves; and a vibration detector, a rotation speed detector, a noise detector and a temperature detector are installed in the operation display platform. Different idling rotating speeds are controlled through a control variate method, vibration, noise, temperature and the like of the bearing are efficiently and conveniently detected in an all-around mode, errors are small, efficiency is high, and the tensioning assembly, the air injection assembly, the vibration assembly and the rotating speed assembly are matched to meet detection of bearingsof different sizes.

The invention provides a spectrum form librating constructing method of a pendulum impact tester. The method comprises the following steps that influential factors of an impact spectrum form of the pendulum impact tester are determined; major influential factors are combined and arranged via a multi-factor complete factorial experiment, and for minor influential factors, a control variable method is used to implement impact test; curve fitting is carried out to obtain an optimal fitting curve, and a corresponding standard spectrum form is obtained by fitting; and standard spectrum forms are concluded and gathered to obtain a standard spectrum form debugging database. The methods have the advantages that the standard spectrum form debugging database which is convenient to retrieve and easy to analyze is established on the basis of a curve fitting algorithm, the validity and convenience of the database are verified by test of different engineering models, influence of change of different influential factors on the impact response spectrum form is analyzed to obtain a debugging rule of the pendulum impact response tester, a control spectrum form of the impact response spectrum test of a spaceflight product can be guided to establish rapidly, debugging time is shortened, and the test risk is reduced.

The invention discloses a method for evaluating filling characteristics of filling coal mining hydraulic supports, and belongs to solid filling coal mining evaluating systems. The method particularly includes steps of A, analyzing geological data and geological conditions; B, initially selecting frame types of the hydraulic supports; C, determining initial selection schemes for foundations; D, determining indexes for evaluating the filling characteristics of the filling coal mining hydraulic supports; E, constructing framework models by the aid of Pro/E, Solidworks or CATIA three-dimensional software and simulating movement to obtain matrixes for evaluating the filling characteristics; F, comprehensively evaluating the filling characteristics of the filling coal mining hydraulic supports by the aid of the multiple indexes and determining the optimal schemes. The method has the advantages that each filling coal mining hydraulic support is one of important solid filling coal mining devices, the initial schemes are determined and optimized by the aid of computer technologies by control variable processes, the optimal schemes are determined by analytic hierarchy processes, accordingly, a scientific and reasonable evaluation system and specific, feasible, comprehensive and simple support optimization processes can be provided for extensive related personnel such as scientific research workers and engineers who engage in filling coal mining hydraulic support optimization, and the design, research and development time can be shortened to a great extent.

The invention discloses a method for testing the optimal spring stiffness coefficient of an elastic hydrofoil of a wave glider. A vertical excitation trolley, an underwater tractor model of a wave glider, a pull wire and a water tank form a test device, the vertical excitation trolley is used for replacing a wave glider water surface mother ship to apply heaving excitation to the underwater tractor model, thus he influence of water surface waves on the underwater tractor caused by the size limitation of the test device is eliminated, and the optimal spring stiffness coefficient of the wave glider in a specified working environment is researched by comparing the average movement speed of the vertical excitation trolley and applying a control variable method. The method is simple and easy toimplement, capable of carrying out simulation experiments on the wave glider more accurately and truly, high in accuracy and convenient to position.

The invention discloses a test judgment method of influence on coexistence among multiple groups of systems by a wireless power transmission system parameter. The method comprises the following steps:selecting the own parameters of a wireless power transmission system and parameters among multiple groups of systems, and analyzing test ranges of the parameters; testing magnetic field strength change of the wireless power transmission system in a certain range and the self-inductance and mutual-inductance parameters of the own primary secondary side coil of the wireless power transmission system through a control variable method, and testing magnetic field change when the inter-system distance is changed by changing the distance between a measurement point and the wireless power transmission system; and combining the magnetic field strength and the own coupling coefficient of the wireless system to obtain a new coefficient Q, and judging the influence on the inter-system coexistence bythe parameters; and selecting the parameter with low Q value as an advantage parameter so as to determine the wireless power transmission system with the minimum influence on the coexistence among multiple groups of systems. Through the method disclosed by the invention, the wireless power transmission system most suitable for the inter-system coexistence can be judged, and the model reference andthe method basis are provided for the construction of multiple wireless power transmission systems or large-scale wireless power transmission regions in the future.

The invention discloses a ceramic material laser scribing process method. The ceramic material laser scribing process method comprises following steps that firstly, a ceramic material to be machined is placed on an absorbing platform of an optical fiber laser cutting machine, and positioning is carried out; secondly, a cutting path is preset, and the designed cutting path is input to software; thirdly, laser machining parameters are set, wherein under the focus exact position state, the scribing speed ranges from 180 to 220 mm/s, the pulse width is 0.1 ms, the peak power is 36 to 45 W, and therepeated frequency is 2400 to 2800 Hz; fourthly, the optical fiber laser cutting machine is started, and a ceramic material is subject to laser scribing. An optical fiber laser device is adopted to precisely scribe ceramic, under different process parameters of the control variate method, the machining technology is subject to experiment operation, through adjusting and optimizing of process parameter setting, the proper ceramic material laser scribing depth is obtained, product machining quality is improved, the process stability is good, market needs are met, and the good practical value isachieved.

The invention relates to the oil gas storage and transportation technology field and especially relates to the method of the three-dimensional physical model of a large-scale underground water sealingstone cave depot water curtain water supplementing system. The method comprises the following steps of (1) making the device of the three-dimensional physical model of the large-scale underground water sealing stone cave depot water curtain water supplementing system; (2) changing the water injection structure of a water curtain system, measuring a water supplementing effect and water discharge,and acquiring an optimum water injection structure; and (3) through a constant speed or constant voltage feed liquid device, changing the water injection parameter of the water curtain system, measuring the water supplementing effect and the water discharge, and acquiring an optimum water injection parameter. In the invention, through a three-dimensional visual physical model, the large-scale underground water sealing stone cave depot water curtain water supplementing system can be visually simulated, and the water supplementing effect of the cave depot water supplementing system is visually known; and a control variable method is used to accurately analyze, a result is accurate and reliable, and the method has important guiding significance for mine construction designing and parameter adjustment.

The invention discloses an optimization method for gas injection parameters of a carbonate reservoir. The method comprises the steps of 1) determining N gas injection parameters affecting the gas injection yield increase range of the carbonate reservoir and range of values of the N gas injection parameters; 2) using a BBD design method, and designing M numerical simulation schemes for the yield increase range based on the N gas injection parameters; 3) determining the type of a response surface regression model based on the variance of the yield increase range results calculated by M numericalsimulation schemes; 4) based on the discriminant result of step 3), establishing a response surface regression model equation, and establishing the relationship between the increase yield range and the N gas injection parameters; 5) conducting global optimization based on the response surface regression model, and obtaining optimal combination of gas injection parameter values which satisfy a convergence condition. The method avoids the problem that a control variable method or an orthogonal design method has too many experimental design schemes, and avoids the problem that a current method numerical simulation optimization workload is large and an obtained result is not a global optimal solution.

The invention discloses a quantitative analysis method for a situation that bottomland wavebreak forest planting is unfavorable for river channel flood. The method comprises the following steps of a,obtaining terrain and structure conditions of a research region through reconnaissance and data collection, performing data processing to generate a three-dimensional terrain file, and obtaining a non-structure terrain grid of the research region through processing and correction; b, building a two-dimensional unsteady flow numerical model, and performing parameter setting and verification on themodel; c, performing structure simplification on a wavebreak forest, thereby simplifying each tree into a bridge pier; and d, by adopting a control variable method, simulating the influence of different wavebreak forest schemes on the river channel flood under different water inflow conditions. According to the method, the hydrologic characteristics of an actual river channel can be really and objectively reflected; and the negative influence of the wavebreak forest planting on the river channel flood, and the influence degree can be analyzed more accurately and scientifically, so that the wavebreak forest planting is reasonably planned and the river channel flood safety is ensured; and the method has relatively high practicality and wide applicability.