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156 results about "Radial distribution function" patented technology

In statistical mechanics, the radial distribution function, (or pair correlation function) g(r) in a system of particles (atoms, molecules, colloids, etc.), describes how density varies as a function of distance from a reference particle. If a given particle is taken to be at the origin O, and if ρ=N/V is the average number density of particles, then the local time-averaged density at a distance r from O is ρg(r).

Copula function-based multivariate hydrologic uncertainty processing method

ActiveCN107423546ACapture non-linearitySnap featureSpecial data processing applicationsInformaticsQuantitative precipitation forecastNormal density
The invention provides a Copula function-based multivariate hydrologic uncertainty processing method. The method can be used for hydrologic forecasting, and is characterized by comprising the following steps: step 1, collecting hydrometeorological basic data and quantitative precipitation forecast data of a basin; step 2, establishing a hydrologic model to obtain forecast discharge processes of different forecast periods; step 3, determining marginal distribution functions of actually measured flow and forecast flow; step 4, utilizing a Copula function to construct a joint probability distribution function of the actually measured flow and the forecast flow; step 5, solving a Bayesian posterior transition probability density function of the actually measured flow of the different forecast periods according to the marginal distribution functions estimated in the step 3 and the joint probability distribution function constructed in the step 4; and step 6, acquiring a Bayesian posterior joint probability density function of the actually measured discharge processes through a total probability formula according to the Bayesian posterior transition probability density function, obtained in the step 5, of the actually measured flow of the different forecast periods.
Owner:WUHAN UNIV

Highly effective slurry phase bed reactor

The invention relates to a kind of efficient reactor with paddle bed, which belongs to the chemical machinery field. It is composed mainly with the solid and liquid separator, the inner tube that the track is changeable, the reactor cover, the heat exchanger with an internal component, the riser with the spray nozzle, the inner-tube tank that has the heating and gas distribution function, the spray nozzle for protecting from choking, the mounting plate of the spray nozzle, the heat exchanger, the outlet of the heating coil, the quadratic distribution plate, the heating coil and so on. The beneficial effictiveness of the invention can be described as follows: the reactor and the distributor can't block up easily; the gas and the liquid can be mixed evenly; the reactive efficiency is high; the carrying amount of the catalyst and the solvent is so bit that it can not occur the bias current, channeling and dead bed; the size running quickly, and the viscosity of the size in the reactor is identical generally; the reactor can be shifted out in time, and especially in the stage of the catalytic, reducing and intensifying, it can realize to operate the reactor steadily; otherwise, the distribution of the virgin gas in the reactor along the axle is in agreement on the concentration of the catalyst, so that can make the catalyst have the most activity, and then it can be make the full use of the reactor space.
Owner:TAIYUAN UNIV OF TECH

Small current earth fault line selection method for radial distribution network

The invention relates to a small current earth fault line selection method for a radial distribution network. The small current earth fault line selection method for the radial distribution network comprises the steps that firstly, the line reference values of fault lines and non-fault lines are calculated according to the number of branch lines of a current radial distribution network system; secondarily, taking a Gabor atom dictionary as the index, a matching tracing algorithm is utilized to carry out time frequency atomic decomposition on transient zero-sequence current of each fault branch line within the first one quarter cycle, and attenuation sinusoidal quantity atoms representing the fault feature information of branch lines are further obtained; thirdly, an improved gray correlation analytic method is adopted to carry out correlation degree analysis on the attenuation sinusoidal quantity atom of each branch line, so that the feature value of each branch line is obtained; and finally, Euclidean distance is obtained by using the feature value of each branch line and the reference values of the fault lines and the non-fault lines, the Euclidean distances are compared, so that the accurate line selection is realized through the comparison of the Euclidean distances. The small current earth fault line selection method for the radial distribution network realizes low calculated amount and high line selection accuracy and is particularly applicable to radial distribution network systems with multiple branch lines.
Owner:HENAN POLYTECHNIC UNIV

Time domain self-correlation Nakagami-m fading complex channel simulation method

The invention discloses a time domain self-correlation Nakagami-m fading complex channel simulation method, which comprises the steps of: firstly, carrying out independent simulation on envelope distribution, so that a probability density function and a cumulative distribution function of envelopes are consistent with theoretical values; secondly, carrying out independent simulation on phase distribution, so that statistical indexes of a probability density function and a cumulative distribution function of phases are consistent with theoretical values; then ranking an envelope sequence and a phase sequence, so that a self-correlation function and a power spectral density are consistent with theoretical values; and finally, superposing the ranked envelope sequence and phase sequence to obtain a time domain self-correlation Nakagami-m fading complex channel random sequence satisfying all simulation performance evaluation statistics. The time domain self-correlation Nakagami-m fading complex channel simulation method realizes good self-correlation characteristic fading simulation and fast fading simulation of a time domain self-correlation Nakagami-m fading complex channel, has good extensibility, and brings convenience for subsequent adoption of a more efficient module simulation algorithm.
Owner:XIDIAN UNIV

A normal interface rigidity prediction method considering three-dimensional fractal

The invention relates to a normal interface rigidity prediction method considering three-dimensional fractal, the method comprising the steps of: improving a curvilinear function describing two-dimensional fractal into a correction function simulating three-dimensional fractal topography and expressing amplitudes of peaks and troughs described by the function as contact deformation quantities; making contact between two rough micro-bulges equivalent to contact between a rigid plane and an equivalent micro-bulge, wherein the actual contact area between the equivalent micro-bulge and the rigid plane meets a=pi R delta; separately calculating the deformation quantities of an elastic deformation stage and an elastoplastic deformation stage; calculating an area distribution function and the actual contact area; calculating the rigidity of a single micro-bulge and total interface rigidity; calculating the rigidity kn1 of the elastic stage, the rigidity kn2 of the elastoplastic stage and the total interface rigidity. The prediction method for acquiring the between-interface rigidity of precision machinery is simple and easy to implement. The method takes into consideration elastoplastic deformation of micro-bulges, contact friction factors and three-dimensional fractal distribution and obtained results can provide technical reference for prediction and control of dynamic characteristics of interfaces.
Owner:NORTHEASTERN UNIV

Logistic distribution vehicle path optimizing method based on improved Cuckoo algorithm

ActiveCN105260785ASolving Shipping Optimization ProblemsEnrich the method of solving logistics distribution route optimization problemForecastingEffective solutionAlgorithm
The invention relates to a logistic distribution vehicle path optimizing method based on an improved Cuckoo algorithm, which is characterized by comprising the following steps of 1, setting the parameters of the improved Cuckoo algorithm; 2, initializing population and calculating a fitness value, wherein the population adopts a uniform distribution function to generate size parasitic nests with an nd-dimensional searching space range of [1, carnumber], calculation of the fitness value comprises firstly adopting a 2-opt algorithm to locally optimize the path in each route and solving the path value of each optimized route by a segmented penalty function; 3, executing the levy migration operation of the parasitic nests; 4, executing the operation that the parasitic nests are detected; 5, executing the mutation operation of the parasitic nests; and 6, dynamically adjusting detection probabilities. According to the logistic distribution vehicle path optimizing method based on the improved Cuckoo algorithm, combination of the improved Cuckoo algorithm and the 2-opt algorithm is applied to solving the problem about the logistic distribution vehicle path, a novel available and effective solution is provided for solving the problem about the optimization of logistic vehicle distribution, and methods for solving the problem about optimizing the logistic distribution path are enriched.
Owner:屈迟文

Measuring apparatus for continuous spectrum bidirectional scattering distribution function

InactiveCN102854149AReal physical propertiesReal structureColor/spectral properties measurementsFiberMeasurement device
The invention provides a measuring apparatus for a continuous spectrum bidirectional scattering distribution function (BSDF), which relates to optical measurement equipment. The invention aims to overcome the problems of incapable measurement of the continuous spectrum BSDF, a narrow measurement spectral band, a small measurement angle and a low measuring speed. The rotating shaft of a rotating table board is connected with the motor shaft of a stepping motor; a sample ring is fixedly arranged at a through hole in the center of the rotating table board; a lighting source probe is fixedly arranged above the sample ring; a collimation amplifier assembly is fixedly arranged at a ray emitting lens of the lighting source probe; a reflection ray reception probe is installed above the sample ring, and a ray reception lens of the reflection ray reception probe faces the sample ring; a transmitted ray reception probe is fixedly arranged below the sample ring; a ray reception lens of the transmitted ray reception probe faces the sample ring; a ray signal input end of a control and data processor is connected with a ray signal output end of a two-channel fiber spectrometer. The measuring apparatus provided by the invention can be extensively used for measuring optical scattering characteristics of a material.
Owner:HARBIN INST OF TECH

Fuzzy cluster SAR image segmentation method based on Gamma distribution

The invention provides a fuzzy cluster SAR image segmentation method based on Gamma distribution. The method comprises the following steps: taking ray values of pixels of an SAR image to be segmented as sampling points, and constructing an FCM object function with a Gamma distribution function; determining solution formulas of parameters in the FCM object function; carrying out fuzzy clustering on the SAR image to be segmented by use of the FCM object function with the Gamma distribution function to obtain fuzzy membership degree matrixes when the gray value of each pixel of the SAR image to be segmented belongs to each ground object type; and performing defuzzification on the fuzzy membership degree matrixes according to a maximum membership degree principle so as to realize SAR image segmentation. According to the invention, a dissimilarity measure from pixel points to clusters is described by use of negative logarithms of a Gamma distribution probability density function, through accurate fitting of SAR image distribution features, the influence exerted by noise in the SAR image on a segmentation result is further overcome, the segmentation precision is improved, and the fitting and segmentation precision of the SAR image is effectively improved.
Owner:LIAONING TECHNICAL UNIVERSITY

Stochastic robust optimization-based energy storage allocation method of wind field system

The invention discloses a stochastic robust optimization-based energy storage allocation method of a wind field system. A scenario method, stochastic programming, interval programming and an artificial intelligence method are widely used for energy storage planning of a renewable energy-containing system at present. These methods are based on accurate renewable energy output or accurate probability distribution and have certain limitations. The method comprises the steps of describing a wind power prediction error as a random variable meeting given second-order moment and fluctuation quantity; describing an energy storage allocation problem containing the wind field system by a probability distribution function set meeting the second-order moment characteristics of the random variable by adopting a probability distribution robust joint opportunity constraint optimization model; converting the probability distribution robust joint opportunity constraint optimization model into definitive linear matrix inequalities; and finally solving the definitive linear matrix inequalities by adopting a convex optimization algorithm. According to the stochastic robust optimization-based energy storage allocation method, an economical and optimal energy storage allocation scheme meeting the safe operation requirements of a power system under the worst distribution of wind power can be obtained.
Owner:STATE GRID ZHEJIANG ELECTRIC POWER +1

Probability load flow calculation method considering admitting ability of power grid

The invention discloses a probability load flow calculation method considering the admitting ability of a power grid. The method comprises the following steps that 1, a cumulative distribution function of a new energy power generation power variable is built according to the admitting ability of the power grid to new energy power generation power, wherein the cumulative distribution function is described in the form of a piecewise function; 2, the sampling frequency between all sections of the new energy power generation variable is calculated according to the cumulative distribution function F(pk) of the built new energy power generation power variable based on the proportional distribution principle, then a Latin hypercube sampling method is utilized for sampling all the sections of the new energy power generation power variable, and a sample matrix of the new energy power generation power variable is built; 3, the sample matrix of the new energy power generation power variable is adopted as an input variable for probability load flow calculation, a disperse result of an output variable is obtained, an empirical distribution function is utilized for fitting, and a probability distribution function of the output variable is obtained. The application range of the Latin hypercube sampling method is widened, and calculating precision is guaranteed.
Owner:NARI TECH CO LTD +2
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