91 results about "Numerical precision" patented technology

Embodiments of the present invention provide a method and a device for predicting video image components. The method comprises: obtaining a luminance component value of an image block; obtaining a first numerical value a3 through a linear regression technology based on a luminance component value and a chrominance component value of a sampling point in an application template, changing numerical precision after compensating the first numerical value a3 so as to obtain a first parameter alpha and a third parameter k; obtaining a second parameter beta of a linear model based on the first parameter alpha and the third parameter k; obtaining a predicted value of a chrominance component of the image block through the linear model based on the luminance component value of the image block, the first parameter alpha, the third parameter k and the second parameter beta. The technical solution enhances encoding performance by improving a parameter in the linear model used at the time of predicting the video image components, and meanwhile lowers complexity of the device using the predicting method.

The invention discloses a method for detecting the tire dynamic vertical load during traveling period of a vehicle. The method for detecting the load comprises the steps that vehicle operation speed v is measured through a GPS vehicle speed testing component; tire real-time air pressure Pre is measured through a tire pressure monitoring system; the real-time distance L of a displacement sensor installation datum plane relative to the ground is measured through a displacement sensor; and a controller collects the v, the Pre and the L in real time and processes the v, the Pre and the L through the formulas (1) and (3), and the real-time load Load of a tire is obtained. The speed of vehicle operation and the air pressure of the tire are measured in real time by measuring change of the distance between the specific point on the tire and the ground, thus the real-time load of the tire is obtained, accurate vertical real-time load information is obtained, and the load numerical precision is high.

A non-linear modeling solving method based on matrix index electromagnetic transient simulation comprises the steps that first, under a state analysis frame, electromagnetic transient simulation models of a linear network and a grid-connected non-linear element are established, and then through subsystem interconnection relation, an overall electromagnetic transient simulation model of an electric power system to be studied is formed; after relevant simulation parameters such as simulation step sizes and convergence precision are set, a simulation program is started; in each simulation step size, a fixed point iterative method is used for solving a non-linear equation comprising a matrix index function, and the results are used as a state variable of the current moment; an output vector yn + 1 is obtained through an output equation, output files are written in, and a step size is pushed forward in a simulation mode; and iteration is carried out in sequence until simulation is over. The great numerical precision and the rigidity processing capacity of a matrix index integration method are kept, general modeling and simulation capacity is achieved on the non-linear performance of an electric power system element, and the application range in the electric power system electromagnetic transient simulation field of the matrix index integration method is expanded.

Systems and methods of selecting a solver with appropriate numerical precision in each of a series of hierarchically related engineering simulations are described. According to an exemplary embodiment of the present invention, a series of hierarchically related engineering simulations comprises a sequence of finite element analyses for designing and analyzing a structural product. An input file describing the structural product and type of engineering simulation is received. Each different type of engineering simulations is checked to determine which solver with appropriate numerical precision (i.e., single or double precision) is used. A corresponding executable module (e.g., Finite Element Analysis software module) is then used for performing the analysis of that engineering simulation. The process repeats until all of the engineering simulations have been conducted in the entire sequence.

The invention provides a high-speed aircraft flow transition characteristic obtaining method and system. The method comprises the steps that a full size model of a high-speed aircraft is built, and anoptimal grid corresponding to the full size model is obtained according to shape parameters of the full size model; incoming flow parameters of a high-speed aircraft and boundary condition parametersof the high-speed aircraft are obtained; according to the optimal grid, the incoming flow parameters and the boundary condition parameters, a surface boundary layer flow transition of the high-speedaircraft is simulated through a character-king transition mode based on Reynolds average, a separate flow transition of the high-speed aircraft is simulated through a Reynolds average-large eddy simulation hybrid method, and the transition initiation point of the high-speed aircraft and the transition area length of the high-speed aircraft are obtained. Accordingly, the method and system can be successfully applied to simulation of the flow transition of the aircraft from the subsonic speed to the hypersonic speed, the numerical precision is high, and the result is reliable.

The invention discloses a random playing method which comprises the following steps: grouping multimedia documents to be played according to a predetermined grouping strategy; and playing each group of multimedia documents in a random sequencing mode according to a shuffle algorithm. The invention also discloses a multimedia playing device. By utilizing the scheme of the invention, the calculated amount required for sequencing can be reduced greatly, the hardware requirements for the multimedia playing device can be lowered, and simultaneously the numerical precision of the hardware of the media playing device can satisfy the requirement of random sequencing.

A computer program product, an apparatus, and a method for modeling equivalent surface sources on a closed, arbitrarily shaped object that result from the imposition of an arbitrary time-harmonic incident field (e.g., a radar wave) are provided. An object divided into by a plurality of patches 302 and parameters for the incident field and the properties of the object 304 are provided to the system. Next, the system produces a discretized representation of a well-conditioned boundary integral equation in the form of a well-conditioned matrix equation, modeling the interaction between the incident field and the object 306. The well-conditioned linear system is solved numerically to determine equivalent surface sources on the object 308. The equivalent sources may then be used to determine electromagnetic fields resulting therefrom 310. The invention provides improved computational efficiency as well as increased modeling accuracy by effectively reducing the numerical precision necessary.

The invention discloses a new WENO (Weighted Essentially Non-oscillatory) format construction method under a trigonometric function framework. Compared with a classic essentially non-oscillatory format constructed through utilization of an algebraic polynomial, a weighted essentially non-oscillatory format constructed through utilization of a trigonometric function polynomial has the advantage that the weighted essentially non-oscillatory format is easier to simulate wave or high frequency oscillation problems, can obtain high order numerical precision can be obtained in a smooth area, and keeps essentially non-oscillatory property at shock wave and contact discontinuity locations. Even if the new TWENO format and the classic five-order WENO format employ information at the same five points, according to the new TWENO format, the lower global L<1> and L<infinite> norm truncation errors can be obtained. According to linear weights employed by the new TWENO format, the optimum solutiondoes not need to be obtained through burdensome numerical calculation, the linear weights can be set as any positive numbers satisfying the fact that the sum is 1. Compared with the classic WENO format, the new TWENO format has the advantages that the new TWENO format is simpler, has higher robustness and is easier to popularize to a high-dimensional space. According to the new TWENO format, a plurality of classic Euler problems are effectively and numerically simulated, and the effectiveness is sufficiently verified.

The invention provides a matrix exponent-based parallel calculation method for an electromagnetic transient simulation graphic processor. A to-be-researched overall electromagnetic transient simulation model of a power system is built under a state analysis framework; and electromagnetic transient rapid simulation of the power system is achieved by combining the data parallelism of a matrix exponent algorithm and the performance advantages of parallel calculation of the graphic processor. The matrix exponent-based parallel calculation method reserves good numerical precision and rigid processing capacity of a matrix exponential integration method, has general modeling and simulation capabilities of nonlinear links of power system elements, and achieves high efficiency of a matrix exponential integration algorithm in the field of large-scale electromagnetic transient simulation for the power system by high parallelism characteristic of data of the matrix exponent integration algorithm. Parallel calculation of the simulation graphic processor of the electromagnetic transient model of the general power system is achieved on the basis of the matrix exponential operation under a state analysis framework; and the calculation speed of the matrix exponent-based electromagnetic transient simulation method is improved.

Disclosed is an improved projection integral algorithm based active power distribution system dynamic simulation method. The method includes inputting active power distribution system example power flow data, dynamic element data and fault and operation set information, setting simulation parameters, forming a total system node admittance matrix according to the system example parameters and the dynamic data, simulating initialization calculation, setting simulation time t=0 and an integral step number s=1, perform calculation in time periods of t<n> to t<n+1>, judging whether a system breaks down or is operated, judging whether the simulation time t is larger than the set time T, judging whether an integral step number s in an improved projection integral algorithm is larger than the set step number k+1, judging whether fault or operation exists in the Mh time, setting simulation time t=t+Mh, executing an external integrator correction step in the improved projection integral algorithm, and judging whether the simulation time t reaches the set simulation time T. The improved projection integral algorithm based active power distribution system dynamic simulation method is high in numerical precision, good in numerical stability, high in computational efficiency, and applicable to active power distribution system dynamic simulation with rigid features.

The invention discloses a meshless particle method for analyzing trapped air mass-containing transient pipe flow. The meshless particle method comprises the following steps of (1) initializing relevant variable and particle information; (2) carrying out iterative computation, namely circulating a time variable, circulating particles, calculating pressure information of fluid particles of the initialized particles and updating the pressure information of the fluid particles, the pressure information of upstream virtual particles, speed information of the fluid particles, speeds of upstream and downstream virtual particles, particle positions and corresponding pressure and speed information and the pressure information of downstream virtual particles; and (3) outputting the result. A water hammer equation under a lagrange system is solved by adopting a smoothed particle hydrodynamics method; the influences caused by movement of a gas-liquid interface and weak compressibility of water are fully considered; various errors caused by interpolation and gas-liquid interface tracking technologies are reduced; and the trapped air mass-containing transient pipe flow can be more conveniently simulated on the premise of meeting the numerical precision.

The invention discloses a numerical simulation method for overtopping burst flood of an earth and rockfill dam containing a reservoir area. The reservoir area and the downstream submerged area are subdivided through triangular non-structural grids, and the area where the dam body is located does not participate in subdivision. The outlet flow of the breach serves as the outlet boundary of the reservoir area and the inlet boundary of the downstream submerged area, hydrodynamic evolution calculation of the reservoir area and the downstream submerged area is conducted. The dam front unit and thedam rear unit corresponding to the outlet boundary and the inlet boundary are dynamically adjusted according to the real-time width of the breach. The method not only can provide a downstream submerging form, but also can provide a water flow movement process in the reservoir area. Therefore, the application range of the dam break model is expanded. When breach outflow is calculated, the average water level of the dam front unit directly connected with the breach instead of the average water level of the whole reservoir area is used. The accuracy of the breach outflow process can be remarkablyimproved. Therefore, an existing earth and rockfill dam burst flood calculation method is perfected. The numerical precision of earth and rockfill dam burst flood calculation is improved.

The invention relates to the metering equipment of a chestnut type straight seam welded pipe and the method, the metering equipment of the chestnut type straight seam welded pipe comprises a surveying board (1) and a template (2); the surveying board (1)consists a motherboard (11), a roof (13), a thimble (16), a clamp board (17), and a guidance branch roller (110), wherein, at least 3 guidance slots (14) are arranged on the motherboard (11), a spring (15) and the thimble (16) are arranged in the guidance slot (14), the guidance branch roller(110) is arranged in a branch roller guide slot (113); the template (2) includes a soleplate upper part (22), a soleplate lower part (23), a localization guild hole (26), a standard circular arc (21) is taken as the boundary of the soleplate upper part (22) and the soleplate lower part (23), and the template on (2) is provided with a central graduation line (24). When using the metering equipment of the chestnut type straight seam welded pipe and the method of the invention, the actual anomalous shape can be gathered accurately, the numerical precision of the contrast surveying are high enough, and the operation and the maintenance are also convenient.

The invention discloses an overlapped grid disturbance domain updating method for aircraft multi-body separation simulation. The method comprises the steps that a wall distance algorithm is simplified by employing an implicit assembly method based on the attribute characteristics of a wall distance marking unit, so that the grid assembly efficiency is improved; secondly, under the framework of a disturbance domain updating method, numerical simulation of the overlapped grids is realized, so that only units in a non-convergent disturbed region are subjected to interpolation operation, and the calculation amount of the interpolation operation of the overlapped grids is reduced; and thirdly, a novel overlapping grid information exchange method is established, and the mode that information is transmitted based on grid deformation and encryption in a large flow gradient area and information is transmitted based on flow gradient interpolation in a small flow gradient area is achieved, so that the accuracy of the overlapping area is improved, and the isolated point problem is avoided. According to the method, the calculation efficiency of numerical simulation of the multi-body separation problem of the aircraft can be remarkably improved, and the problems that the numerical precision is lost in a large-flow gradient grid overlapping region, and isolated points exist are solved.

The invention discloses a method for generating and analyzing text files. The method is realized in a way that data sets and data items of a text file are configured in a configuration table; contents including character encoding, fields, field length and field numerical precision defined by text file collecting lines and detail lines, and generating and analyzing text files. Compared with the prior art, the method for generating and analyzing the text file, work load and technical demands for information system and text file analyzing and generation development can be reduced, so developers and implantation workers can focus on business demands.

The invention relates to a house type image automatic processing method and system, and belongs to the technical field of computer aided design. According to the method for automatically generating the house type space area, a designer can automatically generate the area by drawing the wall body, the bottom point of the wall body is the same as the edge point of the area, errors of numerical precision cannot occur, and expansion and use of other functions of home decoration design software are facilitated; meanwhile, the invention further provides an automatic space grouping method suitable for villas or small high-rise apartments, resource investment can be saved, designers can be helped to conduct scheme design like drawing of ordinary flat-floor residences, the grouping relation of floor spaces is automatically calculated, and the working pressure of the designers can be relieved. The invention further provides a method for quickly positioning the local maximum rectangle and the regional center position of the house type space based on deep learning.

The invention relates to the technical field of satellite borne data processing, in particular to a GPS (Global Position System) double-frequency real-time satellite borne data processing method. The method comprises the following steps of: smoothing the motion states of all epoch satellites in the whole window by utilizing an observed value of an epoch position at the tail end of the window; integrating and forecasting a state-transition matrix from a tail end epoch of the window to a next epoch and the motion states of the epoch satellites by utilizing the motion states of all the epoch satellites in the window and a given state-transition matrix by adopting a multistep method; updating the window epoch, i.e. backwards moving the window to a novel epoch; and smoothing the motion states of all the epoch satellites in the window by utilizing novel observing information of forecasted epochs, and the like. In the method, the multistep method is adopted during updating the epochs, and a single-step method is used for intersection, thus the method has high numerical precision and better stability; the calculating times of integrating a right function is fewer, which can effectively improve the calculating speed; and a window moving method is adopted, thus the window length can be changed according to different calculation precision requirements, flexibility and variability are realized and the integrating precision is guaranteed.

The invention discloses a land surface temperature inversion method based on TASI data, which comprises the following steps of S1, acquiring a TASI image of a research area, and successively preprocessing the TASI data by means of relative radiation correction and atmospheric correction; S2, separating the temperature from the surface emissivity; and S3, establishing a temperature inversion modelbased on a surface emissivity spectral curve and an atmospheric upward and downward radiation curve, and using the temperature inversion model to obtain the surface temperature. The land surface temperature inversion method improves the inversion precision by utilizing the relationship characteristics between the intrinsic bands and associated region between the intrinsic bands and the soil emission spectrum feature, thereby improving the surface temperature numerical precision.

The invention provides a rapid and high-precision forward modeling method for the fluctuation stratum frequency domain. An existing calculation method is improved, and the method comprises the steps that firstly, upper and lower interfaces of a field source are unfolded according to the Taylor series on corresponding mean water levels l1 and l2, the absolute fluctuation values of the upper and lower interfaces are converted into relative fluctuation amounts, and the forward modeling algorithm precision is improved; secondly, when rapid Fourier transformation is performed, Gaussian nodes are added so that the integral region is subdivided, the existing rectangular integral is converted into the Gaussian type integral, the problems appearing in boundary vibration effect, forced periodizationand a series of other frequency domain forward modeling processes are effectively solved, and the frequency domain forward modeling numerical precision is improved. According to the method, due to model experimental verification, the good effect on ensuring both calculation efficiency and forward modeling precision is obtained.

The invention relates to the technical field of fluid mechanics, and provides a new method for analyzing a pipeline water hammer, a water hammer equation under a moving coordinate system is solved, and simulation of a water hammer phenomenon in a pipeline is achieved. Meanwhile, the pipeline water hammer problem can be more conveniently simulated on the premise that the numerical precision is met.Therefore, the technical scheme adopted by the invention is as follows: the method comprises the following steps: step 1, initialization: initializing related variables, particles and upstream and downstream virtual particle information; step 2, listing a solving equation and performing iterative computation; and step 3, outputting a result. The method is mainly applied to fluid mechanics engineering design occasions.

The invention relates to a method for mixed explicit implicit integration applicable to random dynamic simulation of an active power distribution network and belongs to the field of active power distribution network simulation. Random characteristics and multi-time scale characteristics in the process of operating the active power distribution network are considered. The method is based on a mixed explicit implicit solving idea, an explicit integration algorithm is adopted to integrate a random disturbance term forming an active power distribution network random dynamic model, and an implicit integration algorithm is adopted to integrate a deterministic model for forming the active power distribution network random dynamic model. According to the method, numerical solution advantages of the explicit integration algorithm and the implicit integration algorithm can be brought into full play, and the method is applicable to random dynamic simulation calculation of a system under malfunction or operation conditions. Compared with a conventional explicit integration algorithm, simulation calculation efficiency and numerical stability are improved while numerical precision needed for simulation is met, and the random dynamic simulation of the active power distribution network under the conditions of considering integrated access of photovoltaic and wind power generation systems is implemented.

The invention discloses a measurement method for a depth measurement device for a sealed groove, and the method comprises the steps: clamping an opening end part of a positioning column on the outer wall of a convex ring of a zero setting boss of a dial indicator; enabling the convex ring to jack a piston body; enabling a spring to shrink; enabling the piston body to drive a moving rod to move upwards, thereby pushing a measuring head of the dial indicator to move; correcting the value of the dial indicator to be zero; clamping the opening end part of the positioning column in a sealed groove of a to-be-measured workpiece; jacking the piston body through an end face of the workpiece; enabling the spring to shrink; enabling the piston body to drive the moving rod to move upwards, thereby pushing the measuring head of the dial indicator to move; reading the value of the dial indicator, wherein the value is the depth of the sealed groove of the workpiece and the deviation value of a standard part. The method is advantageous in that an annular end face of an opening end of the positioning column is enabled to be attached to the plane of the lower end face of the piston rod; the positioning precision is high; the positioning column slides up and down along a measurement cylinder; the method solves problems in the prior art that human factors causes the deflection of the measuring head and the measurement is caused to be inaccurate; the method employs the dial indicator for reading values; and the numerical precision is higher.

The invention discloses an option value calculation system based on a time fractional order option pricing model, and relates to the technical field of option value evaluation. The system comprises aparameter initialization module, a stock price fluctuation ratio calculation module, an option type selection module, an option value calculation module, an adaptive grid generation module and a result output module. According to the system, a stable and effective differential discrete format is constructed on the adaptive grid, the singularity problem of an accurate solution is effectively solved, the problems of low numerical precision and inaccurate calculation result of a classical algorithm are solved, and the calculation precision of the option value is improved.

The invention discloses a shallow underwater acoustic channel model establishment and calculation method, mainly including the following steps: step 1, proposing a geometric model consistent with an actual situation; step 2, proposing a reference model for mathematical analysis, deriving a time-varying channel impulse response of a fading channel reference model, and further deriving a probabilitydensity function of an angle of departure and an angle of arrival as well as an expression of the UWA channel model propagation time and frequency delay; step 3, establishing an SOC random channel simulation model for experimental simulation based on the reference model, and proposing an equal-area scattering method to parameterize the channel simulation model; step 4, adopting a traditional Lp standard method to parameterize the simulation channel model, and comparing the performance of the two methods; and step 5, obtaining a theoretical result, and performing analysis. According to the shallow underwater acoustic channel model establishment and calculation method disclosed by the invention, an MESS parameterization method is adopted, the method is relatively simple in parameter calculation, a function closure analytic expression can be obtained, and compared with the traditional Lp method, the numerical precision is also accurate and efficient.

Provided is a transient simulation multi-time scale output method for matrix exponents. The method includes the steps of determining the structure and parameters of a power system to be simulated, obtaining a transient model in a differential equation mode, initializing and starting a simulation program, forming a state matrix in each simulation step size according to a matrix exponent method, determining the number of available continuous square links of each step size, calculating a Pade approximation matrix of the matrix exponent function, obtaining the approximate value of the state vector of multiple intermediate nodes between discrete time nodes through continuous square operation and matrix vector multiply operation of the approximation matrix, boosting simulation by one step size, and carrying out operations in an iterative manner until simulation is finished. The method achieves decoupling between the simulating calculation step size and the result output step size of a matrix exponent integration method, so that the good numerical precision and the rigid processing capacity of the matrix exponent integration method are brought into full play, and the matrix exponent integration method is applicable to the transient simulation field of power systems with the multi-time scale characteristic.