76 results about "Knickpoint" patented technology

The invention provides a method of determining long-term strength in rock creep tests, and relates to the technical field of rock mechanics. The method includes coring field rock samples; processing rock cores to form test pieces; mounting and adjusting axial and radial displacement sensors for the test pieces; applying axial and radial load to the test pieces until the text pieces are destroyed;acquiring test data, and converting and outputting the test dada; plotting axial and radial creep curves of the test pieces; computing creep Poisson ratios at various moments; determining the long-term strength of rock. The method for determining the long-term strength in the rock creep tests has the advantages that influence of axial and radial deformation in the rock creep procedures on the performance of the rock is comprehensively considered according to actual ductile dilation deformation of the rock, the creep time is segmented, creep Poisson ratio -time curves are plotted, the long-termstrength of the rock is determined according to stress corresponding to data of inflection points of the curves, accordingly, the timeliness of the rock can be effectively reflected by the solved long-term strength, subjective judgment can be eliminated, and the method is simple and reliable, is high in accuracy and is easy to popularize and apply to actual rock engineering.

The invention provides an existing engineering pile bottom depth determination method based on a parallel seismic inflexion-point method in the field of civil engineering pile foundation construction quality inspection. Detection is carried out in an exploratory hole after the exploratory hole is drilled beside a pile, a time-depth signal diagram is generated according to different depth signals in the depth direction, an inflection point is determined in the time-depth signal diagram, and the pile bottom depth is obtained after the depth of the inflection point is modified through a inflection-point depth modifier formula. Through the method, the influence on wave form from an upper structure is avoided, the inspection is convenient, and the determination of position of the inflection point is simple and visual. Compared with the conventional parallel seismic method, by which the pile bottom depth is determined based on intersection of two lines, the parallel seismic inflexion-point method has a lower requirement on the depth of the drill hole, just 2-3 m deeper than a pile to be inspected, thereby reducing the requirement on the depth of the exploratory hole, saving cost, having better maneuverability for technical personnel without engineering experience, and better solving the current problem that the pile depth of an engineering pile is hard to determine.

The invention relates to a method for optimizing contaminated soil restoration scope and boundary. According to the method, a relative coordinate system is established, a unit grid is located and subjected to grid processing, a dichotomy method is used to abandon or improve the optimization of the unit grid, a contaminated land area drawn according to a geostatistical analysis interpolation method is located in the unit grid, the optimized restoration boundary comprises multiple linear polylines, the measurement inflection point is greatly reduced, and meanwhile, the relative error of the restoration areas before and after optimization is controlled to be within a range from plus or minus 1% to plus or minus 5%. The method aims at the problems of artificial increase of the implementation difficulty of the restoration work and the relatively large measurement work amount caused by the universal low regularity, the curve boundary and the existence of a large quantity of inflection points in the restoration scope and boundary determined in a current ground investigation stage, the provided optimization method is relatively high in operability, and the optimum-determined restoration boundary can be conveniently restored after rapid measurement. The method is suitable for optimum determination of the soil restoration scope and boundary in the optimization design stage of contaminated site investigation and soil restoration work.

The invention discloses a detection algorithm of a cement concrete pavement slab staggering quantity. The detection algorithm specifically comprises the following steps of: inputting a three-dimensional image data matrix, and filtering the data; orderly taking each line of the three-dimensional image data matrix O'' after filtering, and solving the slab staggering quantity corresponding to each line in a line-by-line manner, namely solving the slab staggering quantity of the line after finding out all inflection points of the line; taking the inflection points, of which the difference of the horizontal ordinates is M, from an inflection point matrix G, and solving the difference between each two inflection points so as to obtain a height difference matrix after all the lines are processed, wherein the maximum of the height difference matrix is the slab staggering quantity corresponding to the line; solving the slab staggering quantities h1, h2,... and hm in a line-by-line manner, averaging the m slab staggering quantities, and thereby obtaining the pavement faulting quantity of the image acquisition area. The detection algorithm of the cement concrete pavement slab staggering quantity is simple in computation and short in run time, and does not need manual work. By using the surface measurement, the pavement faulting quantity can be detected by only inputting the acquired three-dimensional image data of the cement concrete pavement; and therefore, the detection algorithm is high in efficiency and accurate in detection.

The invention discloses a visibility detection method based on an optical model and a dark primary color priori theory. The method comprises the following steps of: (1) acquiring a correlative parameter required by visibility computation according to an imaging model of a video sensor; (2) acquiring a traffic video image 1 by using the arranged video sensor; (3) acquiring the transmissivity t(x) of the acquired image on the basis of the dark primary color priori theory; (4) refining the transmissivity acquired in the step (3) by using a multipoint anisotropic Gaussian filter and bilateral filtering; (5) substituting the transmissivity acquired in the step (4) into the inflection points, varying along the vertical direction, of a video image gray value and a function expression of the transmissivity in order to obtain the coordinates of the inflection points; and (6) substituting the vertical coordinate values of all the inflection points into a visibility detection model in order to determine a visibility value. The visibility detection method may satisfy visibility computation in complex scenes containing inhomogeneous pavements, shielded pavement signs, or multiple targets.

The invention discloses a regional winter wheat yield assessment method based on remote sensing phenology assimilation and a particle swarm optimization algorithm. The regional winter wheat yield assessment method comprises the following steps: acquiring data required for operating a crop growth model; acquiring remote sensing LAI data in the whole growth period of the research area, synthesizingaccording to a time sequence, and performing spline interpolation on the LAI node data of each lattice point unit for three times to obtain a continuous LAI curve; identifying a first inflection pointand a second inflection point of the LAI curve, and taking the first inflection point and the second inflection point as marks of a winter wheat reviving period and a heading period respectively; taking lattice points capable of simultaneously identifying a reviving period and a heading period as winter wheat planting areas; optimizing crop growth and development parameters year by year by usingdichotomy lattice points; optimizing the biophysical process parameters by using a particle swarm algorithm to complete parameter localization; substituting the localized crop growth and development parameters and the biophysical process parameters into a crop growth model to operate, obtaining the yield of each lattice point, and summarizing to obtain the total yield of the winter wheat plantingarea.

The invention discloses a reservoir flood-control dispatching optimization method based on flood-control dispatching data adaptive control and relates to the technical field of reservoir flood-control dispatching. The method comprises the following steps: establishing a target reservoir general flood-control dispatching chart; establishing a flood-control dispatching model; determining an objective function; according to the number of dispatching lines of the general flood-control dispatching chart and the number of inflection points of each dispatching line, obtaining the total number of optimization variables required by the general flood-control dispatching chart; according to the determined objective function and the optimization variables, carrying out optimization calculation through an NSGA-II algorithm, and carrying out Pareto non-dominated solution analysis on the objective function to obtain an optimized general flood-control dispatching chart; and carrying out flood control service calculation through the optimized general flood-control dispatching chart. Reservoir flood-season dispatching with the general flood-control dispatching chart being introduced can make full use of incoming water of a reservoir while ensuring safety of downstream flood control, thereby improving flood utilization efficiency, and meanwhile, improving solution efficiency of an optimization model.

The invention discloses a method for determining a horizontal seepage channel of a runoff area by adopting a tracing technology. According to the method, on the basis of karst region hydrogeology condition understanding, existing hydrogeology observation holes in a region are firstly selected, water level unified measurement is carried out, an underground water flow field is drawn, hydraulic connection among the holes is determined, then a tracing test is arranged, and the horizontal apparent flow velocity in the region is calculated; secondly, a representative drill hole is selected in a targeted manner to carry out long-term monitoring on underground water temperature and conductivity indexes, inflection points of underground water movement in the drill hole are judged, the occurrence depth of a horizontal seepage channel is determined, and the flow velocity of underground water in the drill hole in the vertical direction is calculated; and finally, the difference between flow velocities in the vertical direction and the horizontal direction is comprehensively analyzed to determine a seepage channel. The invention provides scientific basis and decision support for karst water system protection and karst water resource management.

The invention discloses a novel burning-through point forecasting technology, and belongs to the technical field of burning production process control. The novel burning-through point forecasting technology includes steps of 1), calculating basic exhaust gas temperature curves; 2), correcting the basic exhaust gas temperature curves through bellow pressure and breathability information; 3), summarizing data for a period of time and forecasting burning inflection points and the burning-through points according to newly-generated curves; wherein a method for calculating the basic exhaust gas temperature curves includes that one thermoelectric couple is mounted in each burning bellow and used for measuring exhaust gas temperature inside the bellow, the exhaust gas temperature inside the bellows is taken as a y-coordinate and a trolley bellow position as an x-coordinate to match basic temperature curves according to the multiple interpolation algorithm. Since various factors such as the exhaust gas temperature, the bellow pressure and breathability of mixed materials are taken into consideration and measured exhaust gas temperature is corrected, the temperature curves can more truly reflect a burning process so as to further accurately determine the burning inflection points and the burning-through points and provide reliable burning control information for operators.

The invention provides a method and a system for calculating soil remediation amount of a contaminated site, and the method comprises the steps: obtaining pollution risk distribution maps of differentsoil layers according to the soil sample data of the contaminated site; selecting an area of which the pollution risk level reaches a preset level as a to-be-repaired area, and simplifying the boundary contour of the to-be-repaired area according to a preset simplified tolerance; partitioning the pollutant migration depths of different soil layers by adopting a Thiessen polygon according to the soil sample data to obtain a pollutant migration depth block map; and superposing the pollution risk distribution map and the pollutant migration depth block map of the same soil layer, calculating thesoil remediation amount of the polluted site according to the to-be-remediated area on the superposition map, and obtaining the inflection point coordinates of the to-be-remediated area for soil remediation construction. The method is simple to operate and convenient for practical application, the contaminated site soil remediation amount can be scientifically and reasonably calculated, the sitesoil remediation treatment difficulty is reduced, and the construction efficiency is improved.

The invention discloses a sub-surface damage detection method based on temperature field finite element analysis and simulation. The method is characterized in that when a constant-temperature heat source is respectively added to the upper surface and the lower surface of a part, the temperature field distribution curve of the basal body of the part has two turning points which respectively correspond to the upper end and the lower end of a crack. The method comprises the following steps of: respectively adding a constant-temperature heat source to the upper surface and the lower surface of the part, detecting the stabilized temperature field distribution of the upper surface of the part by using a high-resolution scanning thermal probe to obtain an actually-measured temperature field change curve; establishing a three-dimensional model of a part with sub-surface damage cracks with different depths, and carrying out the finite element analysis and simulation of the temperature field distribution of the model of the part to obtain a simulated temperature field change curve; and finally determining the depth of the damage cracks according to the turning points of the simulated temperature field change curve by calculating and analyzing the relative error of the actually-measured temperature field distribution curve and the simulated temperature field distribution curve. The method can be used to detect the depth of the sub-surface damage cracks of the part in a short period with low cost under the condition of not damaging the part.

The invention discloses a method for realizing automatic precise feeding during breeding of river crabs. The method is used for realizing the functions that the speed and flow rate of an automatic-navigation feeding ship can be measured and controlled, the throwing width can be controlled, and residual baits can be measured. The method comprises the steps of measuring the position change of the ship within a period of time through a GPS system to obtain the average ship speed, and adjusting a given value of the ship speed to perform closed-loop control over the ship speed; determining a relation curve between a throwing width-throwing disc rotation speed (voltage) and a flow-vibration motor (voltage) through a bait throwing test; mounting a weighing sensor at the bottom of a feeding machine, determining a relation curve between the gross weight of the feeding machine and the output voltage of the weighing sensor through a feed addition test, and measuring the resistance value of the weighing sensor to obtain the quantity of residual baits; by taking the characteristic that feeding is not carried out in deep ditches of a river crab breeding pond or water plant planting areas into consideration, adopting a series of inflection points for defining the design of a track, wherein each inflection point is described by five parameters including the position (longitude and latitude) of the point, the ship speed of the corresponding straight path between the point and the next inflection point, the bait throwing width and the flow rate.

The invention discloses an estimation method of capacity exchange ability between large regional grids of an electric system. The method comprises the steps: based on sensitivity analysis of a section exchange capacity-voltage change ratio, carrying out analysis on the section exchange capacity-voltage stability of a tidal current section between the large regional grids, and obtaining the most sensitive node of voltage of a system; and carrying out spline interpolation on a trend of voltage change to sensitivity change, wherein the voltage change is based on the most sensitive node of the voltage of the exchange capacity, carrying out derivation after nonhomogeneous exponential function fitting is conducted on a discrete value obtained by the spline interpolation, obtaining a change rate function of the voltage change to sensitivity, calculating a limit of the exchange capacity according to discrimination conditions of a critical point of voltage stability, analyzing the voltage stability conditions of the system through a voltage stability margin, and carrying out checking and calibration on correctness of an inflection point and an estimation result of the exchange capacity.

The invention discloses a method for simulating riverway water quantity circulation by using SWMM software. The method adopts the steps that 1, a riverway is simplified into lines, and a riverway plane graph is drawn in CAD and saved as a file in the format of 'AutoCAD R12/LT2DXF(*.dxf)'; 'Dxf2EPANET' software is used for converting the file in the dxf format into a file in the inp format, and the file in the inp format is imported into the SWMM software; 2, in the SWMM software, a starting point, inflection points and an ending point of the riverway are sequentially connected through pipe duct straight lines from upstream to downstream; 3, in the SWMM software, the riverway attribute is input into a riverway model, and then river depths on the starting point, the inflection points and the ending point of the riverway are input into the riverway model; a dynamic wave is selected in a menu, and the duration in a time step menu is set below 60 s; water pumps are arranged in riverway segments needing circulation. The method is simple, fast and low in cost.

The invention discloses a method of determining a datum elevation of a river bottom based on large-section measurement data and a system thereof. The method comprises the following steps that a uniform large-section data model is established by combining a database; a large-section data measurement result standard format and a data structure specification are formulated; whether a large-section data measurement result meets a requirement and a specification is verified; and the river bottom datum elevation is calculated according to the large-section data meeting the requirement; and the riverbottom average elevation, a river bottom width, a river bottom area, a river bottom average elevation change rate and a river bottom area change rate are calculated on the basis of the river bottom datum elevation datum elevation. According to the method, the river bottom datum elevation is automatically calculated and identified based on the inflection point recognition algorithm by utilizing the large-section measurement data of a river channel, so that the inconsistency and randomness brought by manual operation are reduced; the average elevation of the river bottom is, and the accuracy ofcalculating the characteristic values such as the river bottom average elevation, the average river bottom width and the like are guaranteed, and the influence of a river bottom flushing change is faded caused by a non-river bottom characteristic value obtained by participating in calculating a non-river bottom part riverbed elevation section is eliminated.

The invention discloses a power utilization demand analysis prediction method taking business-expansion installation data into consideration. The method comprises that the amount of newly added users and capacities of newly added power utilization equipment are determined; the growth rate and the comparative growth rate of capacity are calculated; an S-type growth curve is used to construct power utilization trend after business-expansion installation, a principle component analysis method is used to a business-expansion power utilization growth curve, and the curve is interpreted stage by stage by taking the instant growth rate as a basic value and an inflection point as an identification basis; the power utilization amount and business-expansion installation are converted, a Census X12 algorithm is used to decompose an interpretation variable and a dependent variable seasonally, and an original variable is decomposed into a trend circulation item (TC), a seasonal factor (SF) and a random item (IR); and the correlation between variable trend items is analyzed, linear regression is carried out, and a prediction value of power utilization amount is confirmed after the seasonal factors are considered. The relation between the quantified capacity release rule and the installation capacity/power utilization amount can be obtained, and the power utilization amount can be predetermined accurately.

The invention discloses a stratum radial resistivity continuous inversion method, which comprises the following steps of 1) constructing a radial gradient stratum model on the basis of a quadratic fractal function according to the characteristics that invading stratum features show that two stable regions exist at two ends and asymptotic change exists between the two ends; 2) based on natural gamma and resistivity logging curves, performing automatic stratification on the stratum by combining wavelet transform multi-stage decomposition and Fourier transform; 3) for each layer, setting RAL1 = Rxo and RAL5 = Rt in combination with five logging curves in the lateral direction of the array, calculating initial values of parameters a and c by utilizing a formula (3), and determining an initialposition ri of an inflection point of a quadratic fractal function curve by calculating the difference of the five resistivity curves, thereby giving an initial value of a parameter b; and 4) throughapproximation iteration of a forward modeling calculation value and a measurement value of the radial gradient stratum model, solving the parameters a, b and c. The method provided by the invention utilizes the gradient stratum model to realize the stratum radial resistivity continuous inversion, and can obtain the resistivity of any position in the radial direction of the stratum.

The invention discloses a calculation method for determining contribution of chemical flooding in enhancing a recovery ratio. The calculation method comprises the steps of: (1) taking an inflection point on a chemical flooding water content curve when a water content decreases after a water flooding phase as a starting point, and making an arc surface wherein the starting point locates tangent with the water content curve which smoothly extends upwards to a post-water-flooding phase, so as to obtain a straight line and a tangent point; (2) projecting the starting point and the tangent point to the horizontal axis to obtain two perpendicular lines; calculating an area of a closed region enclosed by the perpendicular lines, the straight line and the horizontal axis, wherein the area is denoted as A1; (3) dividing the closed region into an upper region and a lower region by the water content curve, and calculating an area of the lower region, wherein the area is denoted as A2; (4) and subtracting A2 from A1 to obtain delta A, wherein the delta A indicates the recovery ratio enhanced by chemical flooding. The calculation method is conductive to studying the relation between the reduced area size of the chemical flooding water content curve and oil displacement efficiency through the reduced area obtained by calculation.

The invention discloses an optimal path planning and obstacle avoiding design method for an underwater vehicle, which is used for carrying out underwater vehicle optimal path planning and obstacle avoiding on the basis of fusion of a binary heap acceleration algorithm, a 26 neighbourhood NA* algorithm and an arc-straight line-arc turning strategy. According to the invention, firstly, an underwaterenvironment model is established in a mode of a discrete three-dimensional gird chart, and the gird chart partitions an underwater environment into a plurality of cells with the same size; then a path is planned by adopting the 26 neighbourhood NA* algorithm so as to eliminate a path zigzagging effect and avoid partial collision; and then the arc-straight line-arc turning strategy is used for avoiding the influence of a width of a vehicle body and a turning radius. The optimal path planning and obstacle avoiding design method has the advantages that the 26 neighbourhood NA* algorithm facing athree-dimensional scene is proposed and applied to autonomous navigation of the underwater vehicle; the characteristic of large turning radius of the underwater vehicle is considered and utilized soas to effectively avoid collision caused by the width of the vehicle; and the planned path is relatively smooth and has few inflection points.

The invention relates to a method for applying nitrogen to summer corn in different areas of the Beijing area in consideration of area yields and environmental risks. The method comprises steps as follows: 1) dividing medium-and-high-yield areas and medium-and-low-yield areas according to different yield levels of the summer corn in the different areas of the Beijing area, areas with the yield of the summer corn higher than or equal to 6800 kg/hm<2> are defined as medium-and-high-yield areas, and areas with the yield of the summer corn lower than 6800 kg/hm<2> are defined as medium-and-low-yield areas; 2) nitrogen fertilizer is applied at the nitrogen application rate of 100+/-10 Kg N/hm<2> for the summer corn in the medium-and-high-yield areas, and nitrogen fertilizer is applied at the nitrogen application rate of 135+/-13.5 Kg N/hm<2> for the summer corn in the medium-and-low-yield areas. A linear platform regression method for researching yield inflection points, a dynamic soil nitrate nitrogen leaching loss monitoring method and a dynamic nitrogen ammonia volatilization monitoring method are organically combined to determine optimal thresholds, harmonious development of agricultural production and environmental protection is prompted, and meanwhile, the optimal effect of the high yield and minimization of environmental pollution is realized.

The invention discloses an ancient oil-water interface recognition method and application thereof in the reestablishment of a crude oil charging history. According to the ancient oil-water interface recognition method, an ancient oil-water interface of oil and gas reservoirs can be rapidly and accurately recognized, and therefore, the crude oil charging history is reestablished. The ancient oil-water interface recognition method comprises the following steps: sampling different depth positions of a reservoir targeted formation of a single well in a research area so as to obtain reservoir samples, and recording corresponding depths of sampling points; acquiring adsorbed hydrocarbon extracts on the surfaces of reservoir sample particles, and determining the contents of trace elements in the adsorbed hydrocarbon extracts; drawing a distribution profile map of the content of the trace elements along the depthaccording to the depths of the sampling points and the data of the trace element content of adsorbed hydrocarbon on the surfaces of the corresponding reservoir sample particles; and recognizing an inflection point where the trace element content starts to continuously deviate from a base line in the map along the depths of the sampling points from large to small according to the distribution profile map, wherein the depth corresponding to the inflection point is the depth of the ancient oil-water interface of the oil and gas reservoirs.

The invention provides a drawing method of an LWD (logging while drilling) curve, and belongs to the field of oil and gas development and exploration. The method comprises the following steps: 1) establishing a longitudinal stratigraphic section; 2) projecting wellbore trajectory data to the longitudinal stratigraphic section; 3) constructing a two-dimensional vertical depth-logging response datapair sequence along a wellbore trajectory; 4) constructing a two-dimensional vertical depth-horizontal displacement pair sequence along the wellbore trajectory; 5) establishing a curve drawing coordinate drawing path, and drawing a first point N0 in the two-dimensional vertical depth-logging response data pair sequence; 6) along the wellbore trajectory, based on M successive points in the two-dimensional vertical depth-horizontal displacement pair sequence after the current drawing point, forming a regression equation through a cubic spline algorithm; 7)carrying out second-order derivation onthe regression equation, then, searching a turning point, and drawing a logging curve in a separate-path manner at the turning point; and 8) end. The method can realize clearer vertical stratigraphiccharacteristic display.

The invention discloses a building energy consumption prediction method based on a fractal theory, and the method comprises the steps: collecting energy consumption data, carrying out the selection ofa similar day, and ranking the similarity in the first three days as a prediction reference day; drawing an energy consumption curve of a reference date, selecting an extreme point and an inflectionpoint on the energy consumption curve as interpolation points, constructing an iterative function IFS in a complete interval according to the given interpolation points, and enabling the IFS to meet afractal collage theorem; solving the value of a vertical scale factor di of each similar day by adopting a random factor method; obtaining an attractor of the IFS according to the determined ith affine transformation of the IFS and each parameter of the IFS, and then obtaining a stable interpolation curve through multiple iterations; solving an attractor by adopting a deterministic iterative algorithm; and evaluating a prediction result by adopting the average relative error MRE and the root mean square error RMSE to realize building energy consumption prediction. The method has good prediction precision, universality and applicability, and is especially suitable for large fractal characteristic public buildings with periodically changing energy consumption.

The invention discloses a method for calculating coal oxidation temperature rise based on underground measured gas concentration values. According to the method, a relation curve of coal spontaneous combustion temperatures and gas concentration ratios in a laboratory environment is drawn; the average slope of the curve between any two adjacent points is calculated; the difference between the absolute values of the average slopes of every two consecutive groups of adjacent points is calculated; a point where the difference value is maximum is the feature point of the curve; a temperature valuecorresponding to the feature point is a coal spontaneous combustion inflection point temperature; with the ratio of a measured gas concentration value obtained under the normal temperature of coal inan underground environment to a measured gas concentration value obtained under the ignited state of the coal adopted as an end point, the feature points of the relation curve of coal spontaneous combustion temperatures and gas concentration ratios in the underground environment are determined on the basis of a similar triangle principle, so that the relation curve of the coal spontaneous combustion temperatures and the gas concentration ratios in the underground environment is fitted; and finally, underground coal oxidation temperature rise can be calculated. The method for calculating the coal oxidation temperature rise of the invention is logical, scientific and reliable, and improves the accuracy of coal spontaneous combustion prediction in an underground environment.