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1685 results about "Fitting methods" patented technology

Method for calculating oil saturation of reservoir

ActiveCN102434152ASolve the difficulty of low accuracy in quantitative evaluation of saturationIn line with the actual lawBorehole/well accessoriesElectrical resistance and conductanceNMR - Nuclear magnetic resonance
The invention discloses a method for calculating oil saturation of a reservoir. The method comprises the following steps of: establishing a reservoir oil saturation model including a free fluid porosity phi f, a bound fluid porosity phi b, as well as corresponding macropore bond index mf, micropore bond index mb and micropore bond index characteristic value parameters; measuring a core porosity phi of a selected core sample; carrying out a nuclear magnetic resonance T2 spectrum experiment and an electric petrophysical experiment on the selected core sample to determine the core porosity phi and bound water saturation Swir of the selected core sample, the free fluid porosity phi f and bound fluid porosity phi b, stratum water resistivity Rw of a saturated rock sample, saturated water rock resistivity Ro of each rock sample, and resistivity Rt of each rock under different conditions of water saturation Sw; determining parameters of a reservoir oil saturation model by adopting an optimization data fitting method; establishing a relationship between the core micropore bond index mb and the bound water saturation Swir; classifying reservoir cores according to the bound water saturation; and determining a saturation index n of each type of cores by using the optimization fitting algorithm.
Owner:PETROCHINA CO LTD

Method of constructing fine discrete road grid in urban drainage simulation system

InactiveCN103399990ARealize the expression of micro-topographic featuresBuild accuratelySpecial data processing applicationsTerrainMathematical model
The invention relates to a method of constructing a fine discrete road grid in an urban drainage simulation system and belongs to the cross field of municipal engineering information technology, database technology and geologic information system technology. From the demand on construction of a waterlogging simulation model, under the restraint conditions in road design specifications and on the basis of conventional map measured elevation points, the number and positions of interpolation points are optimized under the drainage simulation system platform by the fitting method of local elevation change curves of cross-longitudinal road section and by road characteristic terrain vector layers according to mathematical model interpolation encryption plane and elevation information of physical road tomography; accordingly, a fine discrete road elevation grid unit is constructed, true tomographic road features are expressed quickly and economically, the demand on precise simulation of waterlogging models is met, especially the dredging and resisting actions of road micro-tomographic features upon waterflow can be correctly expressed, and the method is significant to promotion and application of the drainage simulation technology.
Owner:BEIJING UNIV OF TECH

Apparatus and method for event correlation and problem reporting

An apparatus and method is provided for efficiently determining the source of problems in a complex system based on observable events. By splitting the problem identification process into two separate activities of (1) generating efficient codes for problem identification and (2) decoding the problems at runtime, the efficiency of the problem identification process is significantly increased. Various embodiments of the invention contemplate creating a causality matrix which relates observable symptoms to likely problems in the system, reducing the causality matrix into a minimal codebook by eliminating redundant or unnecessary information, monitoring the observable symptoms, and decoding problems by comparing the observable symptoms against the minimal codebook using various best-fit approaches. The minimal codebook also identifies those observable symptoms for which the greatest benefit will be gained if they were monitored as compared to others.
By defining a distance measure between symptoms and codes in the codebook, the invention can tolerate a loss of symptoms or spurious symptoms without failure. Changing the radius of the codebook allows the ambiguity of problem identification to be adjusted easily. The invention also allows probabilistic and temporal correlations to be monitored. Due to the degree of data reduction prior to runtime, extremely large and complex systems involving many observable events can be efficiently monitored with much smaller computing resources than would otherwise be possible.
Owner:VMWARE INC

Trajectory data-based signal intersection periodic flow estimation method

The invention relates to a trajectory data-based signal intersection periodic flow estimation method. The method comprises the following steps that: 1) the trajectory point data of sampled vehicles are acquired, and the key point information of the vehicles entering and leaving a queue is obtained; 2) a fitting method is adopted to estimate the queuing waves and evanescent waves of vehicle queuing, and the intersection point of the queuing waves and the evanescent waves is taken as the flow estimated value of queuing vehicles; 3) the density distribution function of full-cycle flow is obtainedaccording to the flow estimated value, and the proportion of non-stop vehicles in the full-cycle flow; and 4) a full-cycle flow estimation problem is transformed into a parameter estimation problem based on the Poisson distribution and M3 distribution of the non-queuing vehicles according to the density distribution function of the full-cycle flow, and a maximum likelihood estimation method is used to perform estimation, and the maximum-likelihood expectation-maximization method is adopted to perform solving, and the estimated value of the arrival flow of each cycle can be obtained. Comparedwith the prior art, the method of the present invention has the advantages of the fusion of model analysis and statistical analysis, the full use of trajectory information, wide applicability and thelike.
Owner:TONGJI UNIV

Feeding and press fitting device of clamp spring of clutch booster and press fitting method of clamp spring of clutch booster

The invention relates to the field of assembly of automobile clutch boosters and aims to provide a feeding and press fitting device of a clamp spring of a clutch booster and a press fitting method of the clamp spring of the clutch booster. The feeding and press fitting device of the clamp spring of the clutch booster comprises a machine base, a pressing mechanism, a pre-pressing guiding mechanism and a feeding mechanism, wherein the machine base is provided with a locating assembly, the pressing mechanism is provided with a pressing head opposite to the locating assembly, the prep-pressing guiding mechanism is located between the locating assembly and the pressing mechanism, and the feeding mechanism conveys the clamp spring to the portion below the pressing head. The pre-pressing guiding mechanism can overcome the defects that before press fitting, elements inside the clutch booster are higher than the upper end face of a shell body under the action of the clamp spring, and when a traditional clamping spring press fitting device is applied to press fitting of the clamping spring of the clutch booster, press fitting is difficult and low in efficiency. By the adoption of the feeding and press fitting device of the clamp spring of the clutch booster, press fitting of the clamp spring of the clutch booster is easy and high in efficiency. The press fitting method of the clamp spring of the clutch booster can guarantee that press fitting of the clamp spring of the clutch booster is easy and high in efficiency.
Owner:HANGZHOU WOLEI INTELLIGENT TECH

Correction method used for attitude and course angles of navigation system

The invention declares a correction method used for attitude and course angles of a navigation system. The method comprises the following step of providing an effective method of conducting magnetometer error compensation and attitude angle error secondary modeling and correction, and realizing error correction of a whole system on the basis of an ellipsoid fitting method of improving expanded Kalman filter. The correction method is used for error correction of the attitude and course angles in an inertial integrated navigation and positioning system composed of an inertial measuring unit (IMU), a magnetometer and the like. According to the invention, a magnetic field compensation method is expanded to three-dimensional ellipsoid fitting from two dimensional elliptical fitting; a new ellipsoidal model and an improved extended Kalman filter method are utilized to conduct ellipsoid fitting; through the adoption of the method, the dynamical and real-time compensation for three-dimensional magnetic field interference of a carrier self can be effectively realized, and the accuracy in the measurement of the geomagnetic field is improved, thereby improving the precision of the course angle of the carrier; the error secondary modeling is conducted on the attitude angle information output by the navigation system, and then compensation is conducted on the output attitude angle to improve the precision of the attitude angle in real time.
Owner:SOUTHEAST UNIV

Fitting device and method for special-shaped curved surface cover plate and flexible screen

The invention relates to a fitting device for a special-shaped curved-surface cover plate and a flexible screen. The fitting device comprises a fitting body for pressing a flexible screen, a support body and a tensioning mechanism for elastically connecting the two ends of the flexible screen to the bottom of the support body or the joint body; the fitting body is provided with an air bag shell and an elastic partition wall which is positioned on the inner side; the air bag shell is provided with a flat wall and a curved wall which are used for at least pressing a flat area or an end of an archook area of the special-shaped curved surface cover plate; the flat wall and the curved wall form a flat air cavity and a bending air cavity respectively with the elastic partition wall. The fittingdevice is provided with a flat air cavity and a bending air cavity, and the air cavity can be controlled respectively, on the one hand, the fitting device can effectively control the strength of thewhole fitting body in the non-inflatable state, maintain a good shape, and effectively control the deformation of the fitting body in the inflatable state, which is more conducive to the control of the fitting strength, so as to be more favorable for controlling the bonding force; on the other hand, the different areas of the flexible screen can be attached by step, so that the bonding effect is further improved. The invention also provides a fitting method.
Owner:GUANGZHOU GOVISIONOX TECH CO LTD

Five-axis numerical control machining method based on interpolation of vector of cutting tool

InactiveCN104635619AFlexible control of vector changesImprove machining accuracyNumerical controlNumerical controlKinematics
The invention relates to a five-axis linkage numerical control machining technology, in particular to a five-axis numerical control machining method based on interpolation of a vector of a cutting tool. The five-axis numerical control machining method comprises the following steps of cutting tool track planning: performing interpolation calculation on the vector of the cutting tool under a workpiece coordinate system while the point position of the cutting tool is planned so as to obtain a cutting tool track equation after the vector of the cutting tool is subjected to interpolation and a cutting tool nose point value and a cutting tool vector under the workpiece coordinate system; double-NURBS (non-uniform rational B-spline) curve fitting: performing fitting on a curve formed by a cutting tool nose point and a second point on the axis of the cutting tool by using a double-NURBS curve fitting method; interpolation calculation: performing interpolation on a formed NURBS curve according to a feeding speed so as to obtain corresponding various axis coordinate values in a machine tool coordinate system; and machine tool kinematical modeling and solving: establishing a corresponding machine tool kinematical equation for a specific machine tool mechanism and finishing conversion between two coordinate systems. The five-axis numerical control machining method based on interpolation of the vector of the cutting tool has the advantages of high machining precision and high surface machining quality.
Owner:SHENYANG GOLDING NC & INTELLIGENCE TECH CO LTD

Optimization design method for step stress accelerated degradation test based on Bayesian theory

ActiveCN102622473AAvoid the disadvantage of being prone to large deviationsTaking into account the amount of informationSpecial data processing applicationsAlgorithmOptimal test
The invention discloses an optimization design method for a step stress accelerated degradation test based on a Bayesian theory, and is applied to the technical field of the accelerated degradation test. The optimization design method comprises the steps as follows: firstly, determining product performance degradation and acceleration models, and based on the historical data, giving prior distribution of model parameters; secondly, determining an optimization design space, and forming a test scheme set; thirdly, creating an expected utility function or an expected loss function, determining optimization goals, and based on a Markov Chain Monte Carlo method, determining optimization goal values of designs in the test scheme set; and lastly, finding the optimal test scheme by using a curve fitting method. According to the optimization design method, the shortcoming of high possibility of larger deviation due to the implementation of the traditional (local) test optimization design method when the values of the model parameters are supposed to be known is avoided, and the optimization scheme obtained in the implementation of the test optimization design when the prior distribution of the model parameters is given is more reasonable and more actual.
Owner:BEIHANG UNIV

Method for creating three-dimensional surface model by using perspective sketch

The invention discloses a method for creating a three-dimensional surface model by using a perspective sketch. The method comprises the following steps of: identifying and processing a hand-drawn sketch into a vertex-edge graph consisting of contour sides and articulation points, and identifying closed areas; identifying the symmetric relation of the three-dimensional surface model, and completing hidden contours for the contours according to symmetry and visibility; establishing an object coordinate system of the surface model according to a symmetrical relation, calculating three-dimensional coordinates of the contour sides and the articulation points of the surface model, and recovering the coordinates of three-dimensional space curves among the articulation points according to curve projection between the three-dimensional coordinates of the articulation points and the articulation points; categorizing the three-dimensional closed areas of the model into different closed area pieces according to the characteristics of a level modeling method and a B-spline surface fitting method; and modeling the closed area pieces into sub-surfaces according to the characteristics of the closed area pieces by the level modeling method or the B-spline surface fitting method and jointing the sub-surfaces into a three-dimensional model through dispersing, blending and splicing.
Owner:NANJING UNIV

Bilateral dislocation differential confocal element parameter measuring method

The invention belongs to the technical field of optical imaging and detecting and relates to a bilateral dislocation differential confocal element parameter measuring method. The method includes the steps that dislocation differential subtracting processing is conducted on the two sides of a confocal axial characteristic data set measured by the starting points and the ending points of all various size parameters including the curvature radius, the lens thickness, the refractive rate, the focal distance and the interval, and therefore the positioning precision of the starting points and the ending points of the size parameters is improved, and the measuring precision of optical elements of the curvature radius, the lens thickness, the refractive rate, the focal distance, the interval and the like is improved. According to the bilateral dislocation differential confocal element parameter measuring method, due to the fact that two sections of data, close to the position of the full width at half maximum and very sensitive to axial displacement, of a confocal characteristic curve are used for conducting the dislocation differential subtracting processing, the position, calculated by the data sections, of the extreme point of the confocal characteristic curve is more sensitive and more accurate than the position, calculated through an existing confocal characteristic curve top fitting method, of the extreme point of the confocal characteristic curve, according to the result of the bilateral dislocation differential confocal element parameter measuring method, under the condition that the confocal element parameter system structure is not changed, the axial focusing capability, the signal-to-noise ratio and the like of the system can be obviously improved.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY

Direct calibration method for line structured light vision sensor

The invention relates to a direct calibration method for a line structured light vision sensor. The method comprises the following steps: establishing a target formed through standard gauge blocks and by utilizing a three-dimensional precision translation bench; projecting structured light plane to the target through the line structured light vision sensor to form feature points on the target; establishing a space coordinate system on the target; collecting target images and extracting the feature points; establishing a search index table including establishing a direct mapping relation between image coordinates of the feature points and space coordinate system coordinates of the feature points; carrying out calibration on the line structured light vision sensor; and based on the image coordinate of a point to be calibrated, searching the space coordinate system coordinate, which is obtained directly or obtained by utilizing a least squares fitting method, of the point in the search index table, so that the direct calibration of the line structured light vision sensor can be realized. The calibration method is used for the line structured light vision sensor which belongs to the small vision field high precision measurement application field. The calibration method is simple and direct, easy to realize, high in precision and can meet the need of measurement.
Owner:SHENYANG INST OF AUTOMATION - CHINESE ACAD OF SCI
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