438 results about "Numerical computing" patented technology

A source code inspection method and system. The method includes receiving by a computing system, source code files associated with a specified project. The computing system retrieves metrics data comprising software metrics associated with the source code files. The computing system generates first evaluation scores associated with the source code files. The computing system generates and presents to a user, a graph displaying the first evaluation scores. The computing system calculates parameter values associated with an evaluation function used to calculate second evaluation scores associated with the source code files. The computing system calculates the second evaluation scores by enabling the evaluation function using the parameter values. The computing system generates and presents to the user, a second graph displaying the second evaluation scores.

The invention discloses a fitting eccentric error compensating method based on a CNC (Computerized Numerical Control) gear measuring center, belonging to the technical field of measurement and solving the problem that the measurement precision is influenced in the traditional gear measuring process because the geometric center of a gear deviates from an instrument center of gyration. The fitting eccentric error compensating method comprises the following steps of: firstly, establishing a workpiece coordinate system and an instrument coordinate system; acquiring an expression of a fitting eccentric vector by means of a transformational relation between the two coordinate systems in an eccentric measurement state; setting an initial eccentric parameter of a workpiece to be detected, and acquiring an expression of a polar angle of the deviation of an original point of the workpiece coordinate system from the original point of the instrument coordinate system; establishing the transformational relation between the two original points of the two coordinate systems in the fitting eccentric measuring state; transforming a measurement value of the workpiece to be detected into a spatial coordinate value in the instrument coordinate system; calculating the initial eccentric parameter value of the workpiece to be detected; calculating a fitting eccentric vector value; and compensating the measurement value for error evaluation. The fitting eccentric error compensating method disclosed by the invention is used for error compensation in the gear measuring process.

The invention relates to a method for determining air-leakage rate of an oxidized zone of goaf, and belongs to the technical field of coal mine downhole spontaneous combustion disaster prevention. The method includes firstly, determining nitrogen injection flow rate; secondly, burying beam tubes for gas component measurement in the goaf to determine change of concentration of oxygen; thirdly, establishing a numerical computing module, and determining concentration distribution of oxygen in the goaf and the air-leakage rate on the condition without nitrogen injection by a numerical simulation process; fourthly, performing a thermogravimetric experiment to coal samples sampled from the work face, acquiring oxygen concentration on the condition without weight gaining, and serving the oxygen concentration as an inerting fireproof index of the goaf; fifthly, dividing the spontaneous combustion three-zone of the goaf; sixthly, selecting the widest section of the oxidized zone in the goaf, simulating dividing results of the spontaneous combustion three-zone of the goaf to determine the boundary according to a fitted equation of field real-time measured oxygen concentration distribution results, and solving the average oxygen concentration of the section in the oxidized zone; seventhly, determining nitrogen purity in an actual nitrogen injection process of the work face; and eighthly, determining the air-leakage rate of the oxidized zone of the goaf according to a nitrogen injection quantity calculation formula.

The invention discloses a simulation method of an MMC (modular multilevel converter). The simulation method comprises the following steps: (1) obtaining operation parameters of an SM (Submodule); (2) construction an equivalent circuit of SM; (3) establishing an artificial circuit of SM; and (4) establishing a simulation system of MMC and simulating the system. According to the simulation method provided by the invention, by the utilization of numerical calculation and electromagnetic simulation internal mechanism, the SM in the MMC can be equivalent to a simple branch formed by a controlled voltage source and an adjustable resistor effectively, and the number of nodes of the system and the corresponding simulation calculation can be greatly reduced, so that on the premise that the simulation precision is ensured, the simulation speed of the MMC is greatly promoted, and the method is applied for MMC design.

A verification tool receives a finite precision definition for an approximation of an infinite precision numerical function implemented in a processor in the form of a polynomial of bounded functions. The verification tool receives a domain for verifying outputs of segments associated with the infinite precision numerical function. The verification tool splits the domain into at least two segments, wherein each segment is non-overlapping with any other segment and converts, for each segment, a polynomial of bounded functions for the segment to a simplified formula comprising a polynomial, an inequality, and a constant for a selected segment. The verification tool calculates upper bounds of the polynomial for the at least two segments, beginning with the selected segment and reports the segments that violate a bounding condition.

The invention discloses a double-volute hydraulic design method based on an RSM model. The design method comprises the steps of 1) solving double-volute initial hydraulic geometric parameters based on a velocity coefficient method; 2) performing optimization solving on double-volute key geometric parameters by adopting an RSM-based adaptive sequence algorithm; 3) performing parameterization automatic modeling based on a CATIA macroprogram, and outputting to obtain a three-dimensional double-volute model; 4) by adopting a GridPro script file to output a grid file used for numerical value calculation; 5) automatically completing grid loading and boundary condition setting based on a CFX CCL language drive program to complete calculation of related data, and outputting a calculation result; 6) repeatedly executing the steps 3) to 5) to obtain a double-volute scheme with the minimum total pressure loss coefficient; and 7) taking the data obtained in the steps 1) to 6) as the double-volute design parameters to manufacture a double-volute centrifugal pump. By adoption of the double-volute hydraulic design method, the double-volute hydraulic optimization design can be realized.

The invention discloses a real-time inversion method for creep parameters of a surrounding rock mass. The real-time inversion method comprises the following steps: determining creep parameters of thesurrounding rock mass to be inversed; establishing a surrounding rock body numerical calculation model; constructing a creep parameter inversion recurrent neural network agent model data set; trainingan optimal creep parameter inversion recurrent neural network agent model; and optimizing and determining the creep parameters of the surrounding rock mass to be inverted by utilizing the creep parameter inversion recurrent neural network agent model and a random global optimization algorithm according to the field actual measurement mechanical response. The real-time inversion method solves theproblem of large calculation time consumption of a traditional inversion method, also solves the bottleneck problems that the time effect of creep surrounding rock mass mechanical response cannot be considered and the creep parameter of the surrounding rock mass cannot be predicted and adjusted in real time, has the advantages of small workload, low cost, high precision, high reliability and the like, can greatly improve the inversion efficiency of the creep parameter of the surrounding rock mass, and is high in universality.

The risk measures of a portfolio are calculated with speed. Concerning a loss for each of the sectors to which the companies constituting the portfolio belong, the Laplace transform of a conditional probability distribution in which factors affecting management indexes are respective values is calculated in advance and stored in a storage unit as data. The stored data is retrieved as an approximate value and used when a numerical calculation of an integral is performed, to perform the integration. Consequently, as it becomes possible to quickly calculate the Laplace transform of a density function and a distribution function, it is possible to calculate the density function and the distribution function by Laplace inversion and calculate the risk measures of the portfolio.

The invention relates to a method for measuring a grounded resistance of a grounded screen by a short range measuring method, which comprises the following steps: selecting the position of an current electrode; carrying out simulation calculation on the ground potential distribution of an earth screen without the current electrode and an earth screen with the current electrode according to the true form of the grounded screen to be measured by a numerical computing method so as to determine the position of a compensation point, i.e. the measuring position of a voltage electrode; and finally carrying out measurement to obtain the value of the ground resistance. The method for measuring the grounded resistance of a transformer substation by the short range measuring method provided by the invention adopts a shorter current electrode and a voltage electrode lead to realize measuring the grounded resistance by the short range measuring method according to the potential compensation principle, saves manpower and material resources, and has important project practical value.

The invention discloses a numerical simulation method for a cable fire caused by an electrical fault in a tunnel. The method includes the following steps of , according to the structure of a cable tunnel and the laying condition of cables in the tunnel, establishing a physical model of the cable tunnel; determining an initial fire source model causing a cable tunnel fire according to the positionand the fault type of the fault cable in the cable tunnel; inputting the initial fire source model, the laying condition of the cable in the cable tunnel and the like into a FLASH-CAT model; the real-time heat release rate of the fire source in the tunnel can be obtained; establishing a fire source model of the cable tunnel fire; directly importing the fire source model into fluid dynamics calculation software FDS; and setting material characteristics and boundary conditions of the cable tunnel model in the FDS, dividing grids, and performing numerical calculation to obtain time-varying rulesof temperature, smoke concentration, flame propagation, CO concentration and the like in the cable tunnel, thereby realizing risk assessment of the cable tunnel fire.

The invention discloses an ice boat contact process numerical calculation method, and belongs to the field of ice region ship navigation performance calculation. The method is characterized by carrying out the numerical simulation and calculation of the ice boat contact process by combining a near-field dynamics method and an ice boat contact area recognition method, firstly, dispersing an ice field solid structure into a series of ice substance points, and initializing the density, volume, speed and acceleration parameters of all the ice substance points; dispersing the ship body three-dimensional model needing to be calculated into a series of quadrilateral surface element forms; adopting an ice-boat contact area recognition algorithm to carry out the contact judgment on all ice materialpoints and a ship body structure at the current moment and the calculation of an ice load; calculating the crushing condition of the sea ice particles under the contact action at the current moment based on a near-field dynamics method; and calculating sea ice breaking by using an ice boat contact area and a near-field dynamics method in each time step until the maximum time step is reached. Theice boat contact detection method can effectively carry out the contact identification on the ice particles and the boat body and calculate the transient ice load.

The invention discloses a multi-objective-based building scheme stage energy-saving optimization design mode construction method, and belongs to the field of building design. The method sequentially comprises the steps of integrating a building body and environment information, determining an optimization target and a design variable, establishing a building multi-target prediction model, coupling the prediction model and executing operation, and constructing an energy-saving optimization design mode. According to the method, the building energy consumption, the thermal comfort index and the initial investment cost are considered at the same time in the scheme stage, the support vector machine algorithm in machine learning is adopted to construct the multi-target prediction model, compared with software simulation, target prediction can be converted into a numerical calculation process from a performance simulation process, the prediction efficiency of the performance index is improved, And the synchronism of multi-target prediction can be ensured. The algorithm is specially proposed for the small sample problem, so that a large number of redundant samples can be eliminated, the optimal model is obtained under the condition of limited samples, and the construction efficiency of the prediction model is improved.

The invention relates to a method for predicting the energy performance of a pump through an adjustable guide vane on the basis of computational fluid dynamics (CFD), and belongs to the technical field of water conservancy projects and mechanical engineering. The method is characterized by specifically including the following steps of firstly, establishing an energy performance database of a pump at different adjustable guide vane installation angles by calculating the numerical value of the CFD; secondly, drawing the comprehensive characteristic curve of the pump at different adjustable guide vane installation angles and outputting a number of energy performance data of the pump at different adjustable guide vane installation angles during calculation of the numerical value of the CFD on the basis of a Visual Fortran program; thirdly, establishing a mathematical model for predicting the energy performance of the pump through the adjustable guide vane. The method is easy and convenient to implement and reliable.

The invention discloses a method for calculating pneumatic parameters of a two-dimension trajectory correction projectile with a fixed rudder. The method comprises the steps of constructing the two-dimension trajectory correction projectile; building an entity model of the two-dimension trajectory correction projectile; building a mesh model of the two-dimension trajectory correction projectile; importing the mesh model of the two-dimension trajectory correction projectile into Fluent software; and performing Fluent software setting and numerical calculation. By utilizing the method for calculating the pneumatic parameters, the relatively accurate pneumatic parameters of the correction projectile can be quickly obtained, and a wind tunnel test does not need to be carried out for verifying the accuracy of pneumatic calculation data, so that a large amount of time and project funds can be saved; and it is verified that the accuracy of a calculation result can be ensured through wind tunnel test data.

The invention discloses a vane pump cavitation numerical simulation automatic operation method based on ANSYS-CFX software. The ANSYS-CFX software is used for setting a vane pump cavitation-free numerical calculation file which comprises initial modeling and mesh division of a flow field zone, boundary condition setting, calculation model selection and convergence condition judgment; a cavitation numerical calculation file is set and comprises vapor-phase physical property material addition, inlet two-phase component boundary condition setting, initial inlet pressure boundary condition setting and cavitation model selection; the ANSYS-CFX software is used for automatically operating a required file with a name suffix of ccl; a batch file capable of realizing cavitation numerical simulation automatic operation is established; and the file is double-clicked and operated, so that the automatic operation for vane pump cavitation numerical simulation can be realized. According to the method, the whole numerical calculation process can be guaranteed to operate continuously and automatically, so that the time spent in the whole numerical calculation process is shortened to the greatest extent.

The invention disclose a method for designing the configuration of a big supercooling water droplet icing detector based on a numerical computation method of movement and knock-on effect of supercooling water droplets. The existing icing detector can analyze whether an ice-formation condition exists or not through detecting the information such as liquid water content and temperature in the atmosphere. The invention aims to solve the problem that the conventional detecting method is only sensitive to the liquid water content, cannot differentiate water droplet sizes, and cannot be used for SLD icing detection. The detector comprises a first bulge and a rear part, wherein the first bulge is connected with the rear part through a groove. According to the invention, the configuration of the detector with curvature change is designed, so that in the conventional water dropping condition, water droplets all strike the front part of the configuration, so that only one continuous striking area is formed in the detector; while under the condition of SLD, the supercooling water droplets strike both the front part and the rear part, therefore, a plurality of incontinuous icing areas are formed in the detector.

The invention discloses a random dynamic allocation method for frequency domain simulation calculation tasks of a super-large-scale integrated circuit. An operation program is divided into a pluralityof parallel coarse particles which are not overlapped with one another and execute independent operation; layout projection, triangulation operation, grid alignment, layer information superposition,parallel flat plate field domain recognition and parallel flat plate field domain adaptive grid subdivision processing are carried out; all parallel flat plate field domains can be quickly identifiedat one time. The problem that gaps cannot be formed between the parallel plate field domains which should be mutually coupled due to errors of numerical calculation is avoided. Meanwhile, different parallel coarse particles are used for calculating at different levels, so that the communication between processes and the waiting time caused by synchronization are reduced, and the hard disk read-write bottleneck caused by virtual memory access due to an overhigh peak memory is also avoided.

The die cushion force setting apparatus according to an aspect of the present invention allows die cushion forces (component forces) acting on plural driving shafts to be set easily, makes it easy to apply strong or weak die cushion forces to a complex-shaped drawn part in a plane of a cushion pad, and provides a smooth die cushion force distribution. An operator manually enters a total die cushion force, axial component force of a left front hydraulic cylinder, and center-of-force position by operating an input device. Based on the information entered via the input device, the numerical computing device B1 calculates axial component forces of three hydraulic cylinders through numerical computations. The one axial component force thus entered and three axial component forces thus computed numerically are set as the axial component forces of four hydraulic cylinders.

The invention discloses a method for establishing a numerical model of a shell-and-tube heat exchanger of a nuclear power system under a motion condition. The method is suitable for establishing a three-dimensional numerical calculation model of large heat exchange equipment of the nuclear power system under the motion condition that different forms are generated under certain external force. Thethree-dimensional numerical calculation model is mainly based on a three-dimensional thermal hydraulic numerical calculation model of the shell-and-tube heat exchanger in static operation. According to the motion forms and the stress characteristics under different motion conditions, the stress is uniform; motion decomposition, stress analysis and decomposition of a single motion, establishment ofan additional force source item acting on a momentum equation under the single motion, and a composite motion additional force source item synthesis process are carried out on a shell-and-tube heat exchanger under a composite motion condition; and finally, establishing a set of numerical calculation model capable of accurately describing the thermal hydraulic characteristics of the shell-and-tubeheat exchanger of the nuclear power system under the composite motion condition.

The invention provides a multi-time-step unsteady icing calculation method and system and a storage medium. The method comprises the steps that S1, flow field and cloud and mist field information is read in; S2, the relative inflow wind speed and the relative inflow angle of attack alpha re1 of blades extending to different section positions are calculated; S3, a two-dimensional wing-shaped localliquid water collection coefficient is calculated; S4, liquid film icing phase change is calculated; S5, according to the icing configuration, through grid deformation calculation, a numerical calculation grid is updated, and icing calculation of the next time step is started, wherein the wind wheel plane induction speed updating time step is delta T1, the local wing-shaped icing flow field updating time step is delta T2, the local icing wing-shaped collection coefficient updating time step is delta T3, and delta T1>delta T2> delta T3. According to the method, different icing calculation updating step lengths are formulated in the step S5 for different icing time scales, the icing calculation efficiency of a wind turbine can be improved to the maximum extent, and therefore ultra-long icingcalculation of a large wind turbine becomes possible.

The invention discloses a high-resolution radar target echo signal generating method. According to the high-resolution radar target echo signal generating method, the characteristic that subtle features of radio-frequency signals can be reserved completely through a DRMF technology is utilized, and a radar transmitting signal sampling sequence is obtained through down-conversion and A/D sampling; a target feature response model is obtained through experiments or an electromagnetic field numerical computing method; convolution is carried out on the radar transmitting signal sampling sequence and the target feature response model, a data sequence after the convolution is reverted to the radio-frequency signals through D/A and up-conversion, and the radio-frequency signals serve as high-resolution radar simulation target echo signals and are output. The simulation target echo signals generated by adopting the technology reserve phase information of transmitting signals and also contain feature information of a target to be detected, and the high-resolution radar target echo signal generating method can be used for high-resolution radar tests. The high-resolution radar target echo signal generating method is already applied in certain equipment developed by the institute, and the effectiveness and the correctness of the method are verified.

The invention discloses a calculation method for hydrodynamic numerical value of a natural circulation hot-water boiler. The method carries out a hydrodynamic equivalent calculation on single lines of the natural circulation hot-water boiler. A equations set is listed for the water circulation loop of the boiler on the base of that, in a pipeline network, a working medium flow flowing into any node certainly equals to the working medium flow flowing out of such a node and that the algebraic sum of working medium pressure differential of all pipelines in any loop equals to zero. The working medium flow can be obtained by resolving the equations set. The invention provides a hydrodynamic equivalent pipeline chart, a mathematic calculation equations set and relative resolution methods for water wall of the natural circulation hot-water boiler and the circulation loop of convection bank and introduces a calculation method and mathematical steps for the hydrodynamic operating points of a whole boiler. The adoption of the method has important meaning for guaranteeing the hydrodynamic safety of the hot-water boiler. As the method adopts computer numerical value for resolution, the calculation efficiency is improved obviously and the method can be used as the basic hydrodynamic calculation method of a thermal pipeline network and a hydrodynamic pipeline network.

The invention relates to a real-time dynamic prediction method for a leakage process of a hazardous medium based on UAV (Unmanned Aerial Vehicle) detection, and belongs to the field of diffusion process of continuous leakage of the hazardous medium. After the hazardous medium is continuously leaked, a Gaussian model original algorithm is improved by using numerical computation methods such as a Taylor formula and a polynomial expansion method under the condition that the size of a leakage source is unknown, and further a novel prediction method which is based on UAV detection data and can dynamically display prediction results is obtained. By using the method, the leakage range of the hazardous medium can be predicted in real time according to the medium concentration of any two points inthe leaking range space and three-dimensional coordinate position data, which are detected by the UAV.