37 results about "Relaxation factor" patented technology

A system and method for designing a progressive lens. Mean power is specified at points distributed over the entire surface of the lens and lens height is specified around the edge of the lens. Lens height is determined at the points consistent with the specified mean power and the lens edge height in part by solving a partial differential equation of the elliptic type subject to the lens edge height as a boundary condition. A successive over-relaxation technique may be employed to converge on the solution to the partial differential equation, and an over-relaxation factor may be determined to most efficiently relax the equation.

The invention discloses a method for estimating a 20-kilovolt medium-voltage distribution scheme, which belongs to the technical field of the application of electric industry. In the method, an estimation index system of the 20-kilovolt distribution scheme is established by an analytic hierarchy process (AHP), and a data envelopment analysis (DEA) estimation model with an AHP preference cone is improved, wherein the provided AHP/DEA model is used for solving the weight of an index. By the method, the problem that 9 comparison objects cannot be exceeded in the conventional method is solved and the problem of combining subjectivity and objectivity reasonably in estimation by introducing a relaxation factor is also solved properly.

The invention discloses a method for predicting the relaxation life of a spiral spring on the basis of the stress relaxation theory of a temperature accelerating material. The method comprises the following steps of: testing stress relaxation data of the spiral spring at test temperature and drawing a relaxation curve; drawing a semilogarithmic curve of load loss rate and time and fitting a regression equation; drawing a relation curve of relaxation factors A and B and temperature and fitting a regression equation; and calculating relaxation factors A (actual) and B (actual) of the spiral spring at an actual use temperature and calculating the relaxation life of the spiral spring. Compared with the traditional compression loading and unloading method, the method has the advantages that due to adoption of an RDL10 spring stress relaxation testing machine, errors are reduced and the accuracy is improved; and since a temperature accelerating mode is adopted for predicting the relaxation life of the spiral spring, the predication accuracy is higher, simultaneously the test period is greatly reduced, the efficiency is improved and the cost is lowered.

The invention discloses a water chilling unit fault detection method based on an improved FastICA. The water chilling unit fault detection method introduces relaxation factors on the basis of the traditional FastICA, changes the original iterative manner, and effectively reduces the dependence of the algorithm on initial values. The water chilling unit fault detection method comprises two stages of ''offline modeling'' and ''online detection''. The ''offline modeling'' stage comprises the steps of: firstly, carrying out steady state treatment on a normal data sample; then extracting independent component information of the data by adopting the FastICA algorithm which introduces the relaxation factors; and finally calculating statistics I2 and SPE, and determining control limits by adopting a kernel density estimation method. The ''online detection'' stage comprises the steps of processing newly acquired refrigeration process data according to a model, calculating statistics and comparing the statistics with the control limits to judge whether the refrigeration process operates normally. The water chilling unit fault detection method based on the improved FastICA reduces the dependence of the FastICA algorithm on initial values, and ensures the safety and stability of the water chilling unit in the refrigeration process.

The invention provides a non-stretch cloth simulation oriented mass-spring model constraint method. By adopting the method, deformation repair of a structural spring in a mass-spring model can be realized by correcting the mass point position of the mass-spring model. The mass-spring model constraint method specifically comprises the following steps: in order to accelerate the convergence speed of constraint implementation, giving an optimal relaxation factor based on a topological structure and deformation of the structural spring and the like in the mass-spring model; according to deformation of a single structural spring, calculating components of position correction quantity of mass points at two endpoints along the spring direction; superposing the components of the position correction quantity of the same mass point; multiplying the superposition sum by the optimal relaxation factor, and taking the result as the position correction quantity of the mass point; and finally updating the mass point position so as to realize deformation repair of the structural spring. The mass-spring model constraint method has the beneficial effects that conservation between linear momentum andangular momentum of cloth can be ensured and the non-stretch cloth can be efficiently and stably simulated during the constraint implementation process, thus the method can be widely applied to non-stretch cloth simulation in virtual reality systems for film and video production, digital entertainment and other purposes.

The invention discloses a hydraulic status optimization scheduling method for a multi-heat source annular centralized heat supply pipe network. The method comprises the steps of (1) giving user flow demands Gsub, n of heating stations; (2) setting an initial iterative point f0 of the frequency of a heat source pump, calculating flow G0 of branches and valve opening x0 of the heating stations, andsetting a step length relaxation factor defined in the specification; (3) calculating a generalized reduced gradient, defined in the specification, of total power consumption WT of the heat source pump under k working conditions, and improving the frequency fk+1 of the heat source pump along the reduced gradient; (4) performing Newton iterative calculation on valve opening xk+1 of the heating stations when the frequency of the heat source pump is fk+1 and the user flow demands are Gsub, n; and (5) calculating total power, defined in the specification, of the heat source pump, and judging whether a condition is met or not. According to the method, the water pump rotating speed and the valve opening of the multi-heat source annular network can be optimized online in real time; the problems of hydraulic disorder and transmission and distribution energy consumption optimization in a scheduling process of the multi-heat source annular network can be solved; the transmission and distributioncapability of the multi-heat source annular network is brought into full play; and the operation of the multi-heat source annular network is more reliable, efficient and energy-saving.

The invention relates to a method for eliminating an EEG signal noise artifact. The method comprises the steps of performing independent component separation on an EEG signal after denoising processing, then selecting an independent component with an artifact, and finally reconstructing the independent component which does not comprise the artifact for obtaining the EEG signal after noise artifactelimination, wherein independent component separation is based on an improved five-order FastICA algorithm. The improvement of the method is characterized in that an improved updating formula is usedfor updating the separated vectors and the relaxation factor of the independent component; and the independent component which comprises the artifact is selected based on a multi-domain adaptive threshold signal selecting method. According to the method for eliminating the EEG signal noise artifact, not only can a plurality of ocular artifacts be automatically identified and eliminated, but alsoa large amount of EEG information can be reserved. Furthermore the method can well improve the signal-to-noise ratio of the EEG signal and reduce the mean square error of the signal.

The invention discloses a fault classification method based on an improved fuzzy support vector machine. The method comprises the steps that sample data of a switch cabinet are acquired, an optimization model is established for the sample data by introducing a relaxation factor, and the minimum radius of the hyper-sphere of the optimization module is calculated; the membership degree of the sample data inside and outside the boundary of the hyper-sphere is calculated by using a segmented half-time normal cloud model with the minimum radius of the hyper-sphere acting as the boundary of the hyper-sphere; the sample data of the switch cabinet, fault classification marks and the membership degree form a sample set of the fault types, and the optimal segmented function of the improved FSVM is acquired by using the sample set of the fault types; and the classifier of the improved FSVM is established by using the optimal segmented function of the improved FSVM, and the sample data pass through the classifier of the improved FSVM in turn so that the fault type of each sample data is acquired. The effect of fault classification of the switch cabinet can be enhanced by the method.

The present invention discloses a symmetry analysis method for a three-dimensional face model. The method comprises: sampling an input face model, and pairing sampling results so as to obtain symmetrical features; and extracting and clustering the obtained symmetrical features, so as to obtain a symmetry relation of the model. According to the method, a PCA constraint is added during feature extraction, which effectively increase the maximum number of initial sampling points when computing resources are limited; by improving the extraction method for the symmetrical feature, the validity of the clustering result is enhanced; and by adding a relaxation factor during feature-grid reassignment, stability of results is ensured and the matching is extended to the whole model. A test is performed on a face model that is acquired at Kinect and reconstructed using KinectFusion, and the validity of the method is verified.

The invention provides a method for predicting a reservoir by relaxation factor pre-stack seismic inversion. The method comprises the following steps of: A, acquiring pre-stack seismic angle gather data and corresponding logging data in a seismic work area; B, generating an initial model of longitudinal wave velocity, transverse wave velocity and density according to a prior geological layer and the logging data; C, superposing the pre-stack seismic angle gather data to form n superposed seismic angle gathers at different angles; D, extracting corresponding n subwaves according to the n superposed seismic angle gathers; and E, gradually extracting a superposed seismic angle gather, the corresponding subwave and the like from the n superposed seismic angle gathers and the corresponding n subwaves. A relaxation factor generated by the longitudinal wave velocity, the transverse wave velocity and the density is added into the inversion process to predict the reservoir, so that the accuracy of predicting the reservoir is improved, and the advantageous position of oil and gas is more obviously indicated.

The invention discloses a method for determining the leakage pollution range of a hazardous chemical substance, and the method comprises the following steps: s1, determining a simulation scene, and obtaining the meteorological and hydrological information, geographic feature information and leakage source information of a leakage accident generation region; s2, establishing a three-dimensional geometric model of an area near the leakage source, and performing mesh generation; s3, importing the grid into a fluid flow module in finite element analysis software; s4, setting material characteristics and boundary conditions in finite element analysis software according to the information acquired in the step s1, meanwhile, judging whether the leaked substances have phase change or not, and setting an inter-phase mass transfer model according to the phase change type; s5, selecting an appropriate convergence condition and a sub-relaxation factor, calculating a step length, and carrying out numerical calculation; and s6, after calculation is finished, analyzing a result to obtain concentration field distribution, diffusion velocity field distribution and diffusion path data of the leakedsubstances. According to the method, the diffusion ranges of the liquid-phase hazardous chemical substance and the vapor cloud thereof can be determined at the same time, and a hazardous chemical substance concentration distribution cloud chart is provided.

The invention relates to a method for numerical simulation of a drop flow tongue. The method comprises the following steps: 1, establishing an overflow weir model, subdividing a structural grid and setting boundary conditions; 2, establishing a drop flow tongue iterative calculation model which comprises establishing a turbulence equation, a two-phase flow model, an initial condition and a relaxation factor; and 3, establishing a numerical simulation result processing model, wherein the numerical simulation result processing model comprises color strip parameter setting, water volume fractionsetting and two-phase display parameter setting. According to the invention, the motion state of the drop tongue can be simulated quickly and accurately, and reference is provided for basic mechanismdevelopment and practical engineering application of the drop tongue diffusion rule.

The invention provides a road marking accurate extraction method driven by a vehicle-mounted laser radar point cloud. According to the method, the method comprises the following steps: firstly, generating a plane histogram by utilizing point intensity values; segmenting the point cloud data according to the point densities and the point intensity values to obtain grouped data with different pointdensities; threshold segmentation is carried out by using a plane histogram to maximize the between-class variance, an intensity grade critical value at the maximum between-class variance is obtained,and road markings in the data are extracted by using the intensity grade critical value and the relaxation factor; and finally, generating a research and judgment graph of the extraction result by utilizing the point density, and performing density aggregation on the extraction result according to the research and judgment graph to obtain a guest road marking result. The method is good in effectiveness and feasibility, the problem that it is difficult to rapidly and completely extract the road markings from the vehicle-mounted laser radar point cloud data with intensity noise and uneven intensity distribution is solved, and rapid and objective extraction of the road markings in the massive vehicle-mounted laser radar point cloud data is achieved.

The invention belongs to the technical field of communication and relates to a method for selecting a relaxation factor of a massive MIMO detector. The method is extended to obtain a relaxation factoronly related to the number of transmitting and receiving antennae according to approximation of characteristic values of a filter matrix on the basis of an existing optimal factor under a certain condition. The relaxation factor is easy to calculate. A simulation result shows that, compared with performance achieved by a successive over-relaxation (SOR) method and symmetric successive over-relaxation (SSOR) method based on an existing relaxation factor, performance achieved by the SOR and SSOR methods based on the relaxation factor obtained by the method is greatly improved. Performance gainsof the SOR and SSOR methods based on the relaxation factor are more remarkable when an NB/NU ratio is relatively small, and are still obvious in case of high NB/NU ratio. Particularly in case of lowNB/NU ratio, the SOR and SSOR methods based on the existing relaxation factor cannot be converged, but performance of an MMSE algorithm is achieved by the methods based on the relaxation factor afterfour iterations.

The invention provides a service combination-oriented global QoS (Quality of Service) constraint decomposition method for constraint intensity perception. A measurement method of user constraint strength is defined, a relaxation factor self-adaptive adjustment method based on a fuzzy inference rule is designed, and a QoS constraint decomposition model of constraint strength perception for servicecombination is constructed. By using the model, in a constraint decomposition stage, when the user constraint strength is relatively weak, candidate services of each task can be effectively eliminated, so that the size of a solution space when a global optimization method is adopted is reduced; when the user constraint strength is high, a certain number of candidate services can be reserved for each task, so that the probability that a feasible combination scheme can be found during service combination is increased.

The invention discloses a boundary-free swimming pool water drop flow calculation method. The method comprises the following steps: A, establishing a boundary-free swimming pool model through gambit software; B, importing the established boundary-free swimming pool model into Fluent software, and selecting an RNG mode of a k-[epsilon] model, adjusting an under-relaxation factor and an initial condition, and starting iterative computation after initialization; C, after iterative computation is stable and convergent, extracting mass effective data of all nodes of the middle section, importing the mass effective data into graph processing software Tecplot, adjusting a water volume fraction to 0.95, and adjusting and displaying cloud picture indexes to obtain minimum unit width flow which is the minimum flow when the model water film is not attached to the wall and is not broken; and D, fitting the height and the flow velocity value of the effective node into a curve, and finding out the minimum flow of the water film which is not attached to the wall but not broken when the boundary-free swimming pool with the fixed width runs from the curve. The relation between the width of the swimming pool and the water falling flow when the water tongue is not attached to the wall and is not broken is determined through a numerical simulation technology.