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221 results about "Boundary effects" patented technology

Boundary effect : A sound reflection effect due to room modes ( standing waves) which accumulates at walls. sound wave reflections appear to make the localized sound level increase as all of the room modes terminate at the boundary (wall).

Horizontal well transient pressure rapid calculation model establishing method capable of improving near-wellbore pressure drop

The method discloses a horizontal well transient pressure rapid calculation model establishing method capable of improving the near-wellbore pressure drop. The method comprises steps as follows: S1, calculating the Laplace space solution of a horizontal well under the infinite oil reservoir and uniform flow rate distribution condition; S2 decomposing the Laplace space solution of the horizontal well under the infinite oil reservoir and uniform flow rate distribution condition into a planar flow part of a stratum and a mirror superposition part of a top and bottom closed boundary effect; S3, calculating the near-wellbore flow pressure drop of the horizontal well; S4, replacing the mirror superposition part of the top and bottom closed boundary effect in the Laplace space solution of the horizontal well under the infinite oil reservoir and uniform flow rate distribution condition with the near-wellbore flow pressure drop of the horizontal well to obtain a shaft pressure calculation model of the horizontal well. The pressure drop response composition of the horizontal well is decomposed, the near-wellbore flow pressure drop of the horizontal well is reasonably described by using a near-wellbore radial flow mechanism, and effects of vertical permeability, shaft position, positive and negative skins and shaft radius are reflected truly.
Owner:SOUTHWEST PETROLEUM UNIV +1

Test device for testing flow characteristics of liquefied sand and test method

The invention discloses a test device for testing flow characteristics of liquefied sand and a test method. The device comprises a vibration platform and a model box. Plastic face plates are adopted on two lateral faces of the model box, a horizontal rail is respectively arranged at the symmetrical positions of the plastic face plates, and a rigid circular pipe is placed between the rails. A steel wire rope is led out from the rigid circular pipe and connected with and pulls a force sensor, leads out the model box, then is connected with a dynamic displacement sensor, and finally is connected to a positive and reverse speed regulation motor. The test method comprises enabling saturated sand in the model box to achieve a liquefied state through the vibration platform, the motor drives the steel wire rope and then guides the rigid circular pipe to perform horizontal movement on the rails to measure the speed of the movement of the rigid circular pipe and horizontal tension force exerted on the rigid circular pipe, so that apparent viscosity of the liquefied sand is calculated, and the flow characteristics of the liquefied sand are analyzed. The test device for testing flow characteristics of the liquefied sand and the test method has the advantages of being high in efficiency, small in boundary effect and the like.
Owner:HOHAI UNIV

Method for boundary compensation based on morphological characteristics of geomagnetic anomaly data

The invention belongs to the field of geomagnetic navigation, and particularly relates to a method for boundary compensation based on morphological characteristics of geomagnetic anomaly data. The method for boundary compensation based on the morphological characteristics of the geomagnetic anomaly data comprises the steps that regular meshing processing is conducted on the actually-measured geomagnetic anomaly data; a geomagnetic anomaly mesh data set is translated, so that a mean value is zero; two-dimensional empirical mode decomposition is conducted on the translated mesh data set with the zero mean value; the morphological characteristics of a two-dimensional empirical mode decomposition result are extracted; a data block unit is segmented and characteristic similarity redundancy of adjacent units is eliminated in real time; characteristic similarity redundancy of all the data block units is eliminated; a multilayer geomagnetic anomaly data boundary compensation database is established; boundary compensation is conducted on the geomagnetic anomaly data to be analyzed. According to the method for boundary compensation based on the morphological characteristics of the geomagnetic anomaly data, the problem of the boundary effect in local geomagnetic anomaly data analysis can be effectively solved, and compared with other methods, the method is better in applicability and better in use convenience.
Owner:HARBIN ENG UNIV

Deep-sea pipeline segmented model bidirectional forced vibration experimental device under action of uniform flow

The invention provides a deep-sea pipeline segmented model bidirectional forced vibration experimental device under the action of uniform flow. The deep-sea pipeline segmented model bidirectional forced vibration experimental device comprises a deep-sea pipeline module, false body modules, a horizontal sliding module, a vertical sliding module, a measurement analysis and control module and a false bottom module, wherein the two ends of the deep-sea pipeline module are connected with the end part false body modules respectively; the vertical sliding module is connected with the end part false body modules and the horizontal sliding module respectively; the horizontal sliding module is fixedly connected with the bottom of a trailer truck; the measurement analysis and control module is arranged on the trailer truck, and is connected with two end part false body modules and two sliding modules respectively; and the false bottom module is fixedly connected with the trailer truck. In the experimental device, a false bottom plate is arranged, so that the surface effect of the sea bottom can be simulated; the coupling of a pipe fitting with a flow field is realized; the vibration of two freedom degrees of forward flow and vertical flow are considered; special end part false body modules are adopted, so that the problem of boundary effects on both sides of a deep-sea pipeline model is solved; and the practical Reynolds number range can be reached under the experimental condition.
Owner:SHANGHAI JIAO TONG UNIV

Bidirectional forced vibration experimental apparatus for deep sea riser segment model under action of uniform flow

The invention is suitable for the field of the oceanographic engineering and provides a bidirectional forced vibration experimental apparatus for a deep sea riser segment model under the action of uniform flow. The bidirectional forced vibration experimental apparatus comprises a deep sea riser module, end part prosthesis modules, horizontal sliding modules, vertical sliding modules and a measurement analysis control module, wherein both ends of the deep sea riser module are respectively connected with the end part prosthesis modules; the vertical sliding modules are respectively connected with the corresponding end part prosthesis modules and the corresponding horizontal sliding modules; the horizontal sliding modules are fixedly connected with the bottom of a trailer; and the measurement analysis control module is arranged on the trailer and is connected with the end part prosthesis modules, the horizontal sliding modules and the vertical sliding modules. In the invention, large-scale riser segments are adopted, so that a test Reynolds number is in the range of 106 for avoiding the scale effect; the double freedom degree forced movement is adopted to truly simulate the vortex-induced vibration form of a riser; and meanwhile, due to the adoption of end part prosthesis, the problem of the boundary effect at both sides of the model in an experiment is solved.
Owner:SHANGHAI JIAO TONG UNIV

Shield tunnel construction environment simulation unit

Disclosed is a shield tunnel construction environment simulation unit. A foundation trench of the shield tunnel construction environment simulation unit is a rectangular reinforce concrete foundation trench. The tops of the left and right walls of the foundation trench are provided with channels. Columns on two sides of a moving reaction frame are disposed in the channels. A plurality of jacks are disposed below the moving reaction frame. The foundation trench is longitudinally divided into an environment simulation site and a starting well by a partition wall. The partition wall is provided with a shield entry. Fixed reaction grids are disposed on the left wall, right wall and front wall of the environment simulation site respectively. A plurality of horizontal jacks are disposed on the fixed reaction grids. A sliding retainer wall unit is arranged in front of the jacks and is disposed at the bottom of the environment simulation site through slides. The jacks on the fixed reaction grids and the jacks on the moving reaction frame are both connected with a hydraulic loading device. The shield tunnel construction environment simulation unit is in an open large-space structure, capable of simulating rich stratum environments, available for large-scale similar model experiments, capable of effectively eliminating boundary effect, capable of more truly reflecting the complex shield tunnel construction environment, and is highly reliable.
Owner:SOUTHWEST JIAOTONG UNIV

Ground fracture expansion simulation device and use method thereof

The invention belongs to the field of geotechnical engineering, and relates to a ground fracture expansion simulation device and a use method thereof. The ground fracture expansion simulation device comprises a framework, an observation window, a baffle plate, a lower disc support plate, an upper disc support plate, a preserved fracture, a variable-inclination-angle device, a bottom loading deviceand a side wall loading device, wherein an artificial portable rainfall device can also be arranged on the top of the framework; the artificial portable rainfall device controls the rainfall quantitythrough a flow rate measuring instrument. The loading device comprises a bottom loading device and a side wall loading device. The bottom layer base rock in a model box can simulate the influence ofthe positive and reverse fault movement, strike-slip fault movement, strike-slip positive fault movement and strike-slip negative fault movement on the upside covering soil body. In addition, the method has the advantages that the operation process is simple and convenient; economic performance is realized; considered factors are various; the problems of single substrate movement type, movement inclination angle change incapability, obvious boundary effects, rainfall influence ignoring and the like in an ordinary simulation experiment can be overcome.
Owner:CHANGAN UNIV

Grey scale characteristic graph-based automatic separation method for conglutinated chromosomes

InactiveCN101520890AHigh degree of automationGood Continuity Boundary EffectImage analysisState of artBoundary effects
The invention provides an automatic separation method for conglutinated chromosomes. The method firstly carries out immersion and corrosion processing operation based on a grey scale characteristic graph of chromosomes, and then carries out conditioned expansion recovery processing operation. The invention designs a grey scale characteristic graph-based morphological processing method to separate the chromosomes which are seriously conglutinated but are neither sheltered nor overlapped. The method solves the technical problems and fills up the technical vacancy of separating the chromosomes which are seriously conglutinated but are neither sheltered nor overlapped in the prior art, meets the requirements of accurately separating the conglutinated chromosomes and detecting the number of the chromosomes in medical fields of chromosome analysis, cell research, pathological analysis, and the like, and further improves the automaticity in a chromosome analysis system. The method provides individual chromosomes with good continuous boundary effect and independence for the automatic separation processing in the chromosome analysis system, and particularly keeps concave and convex details of original chromosome image boundary completely and clearly so as to improve the separation automaticity of the conglutinated chromosomes and the accuracy of the chromosome number counting.
Owner:GUANGDONG VTRON TECH CO LTD

Porous medium penetration slip-casting multi-parameter monitoring device and test method thereof

The invention discloses a porous medium penetration slip-casting multi-parameter monitoring device and a test method thereof. The monitoring device comprises a slip-casting apparatus, which his connected to an inlet cabin. The inlet cabin is connected to one end of a connection steel pipe through connecting pieces, and the other end of the steel pipe is connected to an outlet cabin through connecting pieces. A joint position of the inlet cabin and the steel pipe and a joint position of the outlet cabin and the steel pipe are both provided with filter plates. The steel pipe is provided with a press measuring device. Slurry discharge pipes are connected at the bottom of the steel pipe, and a volume measuring apparatus is disposed below each slurry discharge pipe and positioned above a weighing apparatus. The filter plate of the outlet cabin is connected with a screw, and the screw is provided with a lower packing box. The outlet cabin is equipped with a flow measuring apparatus. The monitoring device helps to solve the problem of monitoring key parameters during porous medium penetration slip-casting. Compared with conventional research, the monitoring device has the advantages that various parameters can be monitored, the monitoring precision is high, the boundary effect of the device can be eliminated, and the device is adjustable in dimension and simple to operate.
Owner:SHANDONG UNIV

Compositing method of dovetail groove metal plate clearance fit interface

The invention discloses a composting method of a dovetail groove metal plate clearance fit interface. The compositing method is realized through the explosive cladding method, the rolling method and the like. According to the method, after a base plate with dovetail grooves and a surface plate with dovetail grooves are in interference fit, the base plate and the surface plate are composited together through combination of a metallurgical bonding mode and a squeezing meshing mode of the dovetail grooves under the actions of energy of explosives or a rolling mechanism. Physical and chemical properties of metal sheets on the two sides of a dovetail groove combination interface are not changed, and large-area metal sheet composition can be conducted; the explosive charge for a unit of compositing area is small, and atmospheric pollution, noise pollution, explosion vibration and overpressure are reduced; during explosive welding of the metal sheets with the dovetail grooves, no boundary effect exists, the compositing effect on the periphery is good, and the lower limit and the upper limit of an explosive welding window are both increased. The compositing technology of the dovetail groove metal plate clearance fit interface can be applied to the fields such as chemical reaction containers and ships so as to meet the requirement for large-area metal composite plates.
Owner:UNIV OF SCI & TECH OF CHINA

Modulation signal classification method for cuckoo search-improved gray wolf optimizer-least square support vector machine

The invention discloses a modulation signal classification method for cuckoo search-improved gray wolf optimizer-least square support vector machine. The method selects a high-order cumulant and a local mean decomposition amount approximate entropy for the characteristic parameter of a modulation signal, and utilizes cuckoo search for the second update of the wolf position to optimize the two keyparameters of a least squares support vector machine model, namely, the penalty coefficient Gamma and the kernel parameter Sigma, so as to obtain the optimal kernel limit learning machine parameter value. The method reduces the influence of noise factor on the signal recognition result, makes up for the defects of under-envelope, over-envelope and boundary effects in the traditional modal empirical decomposition, and effectively improves the defect that the gray wolf optimization global searching ability is poor and is easy to fall into the local optimal solution in processing of high-dimensional data, compared with the original gray wolf optimization result by MATLAB simulation, is it proved that the method can intelligently classify the modulated signal more efficiently and accurately, and has a good application prospect.
Owner:NANJING UNIV OF POSTS & TELECOMM

Forced vibration experiment facility for uniform down-flowing incoming flow of deep sea pipeline sectional model

The invention provides a forced vibration experiment facility for uniform down-flowing incoming flow of a deep sea pipeline sectional model; the forced vibration experiment facility comprises a deep sea pipeline module, a prosthesis module, a fixing module, a sliding module, a measuring and analyzing control module and a false bottom module, wherein both ends of the deep sea pipeline module are respectively connected with the end prosthesis module; the sliding module is respectively with an end prosthesis and the fixing module; the fixing module is fixedly connected with the bottom of a trailer; the measuring and analyzing control module is arranged on the trailer and is respectively connected with the end prosthesis module and the sliding module; and the false bottom module is fixedly connected with the bottom of the trailer. According to the forced vibration experiment facility, the surface effect of a seat floor can be simulated by arranging a false bottom plate under the deep sea pipeline model; the mutual coupling of a pipe fitting and a flow field is realized; by adopting the special end prosthesis module, the boundary effect of two sides of the deep sea pipeline model is solved; and the segmented size of the pipe fitting adopted in the forced vibration experiment facility is similar to the actual pipe fitting; and the working conditions of tests can reach the range of real Reynolds numbers.
Owner:SHANGHAI JIAO TONG UNIV

Deep-sea riser segmented model vertical flow forced vibration experimental device under action of uniform flow

The invention is suitable for the field of ocean engineering and provides a deep-sea riser segmented model vertical flow forced vibration experimental device under the action of uniform flow. The deep-sea riser segmented model vertical flow forced vibration experimental device comprises a deep-sea riser module, false body modules, a fixing module, a sliding module and a measurement analysis and control module, wherein the two ends of the deep-sea riser module are connected with the end part false body modules respectively; the sliding module is connected with the end part false body modules and the fixing module respectively; the fixing module is fixedly connected with the bottom of one end of a trailer truck; and the measurement analysis and control module is arranged on the trailer truck, and is connected with the end part false body modules and the sliding module respectively. In the experimental device disclosed by the invention, a riser model with an appropriate slenderness ratiois selected, so that the practical Reynolds number of 106 can be reached under the experimental condition, and the scale effect is avoided effectively; and meanwhile, end part false bodies are adopted, so that the problem of boundary effects on both sides of the model during an experiment is solved.
Owner:SHANGHAI JIAO TONG UNIV

Method for extracting geoscience spatial information based on generalized self-similarity principle

The invention relates to a method for extracting topographical spatial information based on a generalized self-similarity principle, which comprises: transforming the topographical spatial information into an energy spectral density space by Fourier transformation; eliminating the influence of boundary effect generated by the topographical data boundary part; drawing a double logarithmic scatter graph formed by the energy spectral density value (S) and the area (A) included by the isometric line of the energy spectral density value (S), and detecting the fractal rules of the energy spectral density and the area; determining the number and the interval of generalized self-similarity relations; determining the threshold and a corresponding fractal filter; and transforming filtered energy spectrum information back to a spatial domain by inverse Fourier transformation, and achieving the aims of decomposing anomaly and ambient fields and extracting interested topographical spatial information. The method has the advantages of wide practicality, high extraction precision and the like, and is suitable for topographical data such as geological data, mineral data, geochemical data, geophysical data, remote sensing data and the like, and the operations of topographical information extraction and topographical data mining such as mineral exploration, resource assessment, environmental pollution assessment, natural disaster analysis, marine vortex extraction and the like.
Owner:成秋明 +3

Maneuvering target tracking method with organic combination of Kalman filtering and empirical mode decomposition

ActiveCN101894097AOvercoming the divergence problemOvercome the "boundary effect"Complex mathematical operationsPattern recognitionDecomposition
The invention discloses a maneuvering target tracking method with organic combination of Kalman filtering and empirical mode decomposition, which relates to the field of maneuvering target filtering tracking and solves the divergence problem that boundary effect and Kalman filtering of high maneuvering target in the EMD method cannot be overcome. The method comprises the steps of: 1. acquiring measure data sequence of current sampling moment, acquiring system state predicating data of the next moment by means of a Kalman predication equation, and combining the data with the current sequence; 2, generating a filtering sequence by means of interpolation in the combined sequence; 3, decomposing the filtering sequence according to the EMD method, and removing noise-containing IMF to acquire a current filtering value; 4, displaying the filtering value as current filtering result; and 5, taking the filtering value as posterior estimate of the current state of the system, and acquiring calculative parameters at the next moment in combination with the measure data and Kalman equations, then returning to step 1 and taking the next moment as the current moment so as to realize maneuvering target tracking. The method according to the invention can be used in the field of maneuvering target filtering and tracking.
Owner:HARBIN INST OF TECH

R wave detection algorithm based on extremum field mean mode decomposition and improved Hilbert enveloping

The invention discloses an R wave detection algorithm based on extremum field mean mode decomposition and improved Hilbert enveloping and belongs to the technical field of weak biological signal processing. An electrocardio signal pre-processing algorithm based on the extremum field mean mode decomposition and the improved Hilbert enveloping and an R wave detection algorithm based on slope threshold are provided. Detection criteria are set according to wave form characteristics and time domain distribution characters of electrocardio signals, and positions of R waves with most obvious characters and highest information amount in the electrocardio signals are detected. An extremum field mean mode decomposition algorithm improves empirical mode decomposition speed and can effectively restrain mode superimposition and boundary effect. The improved Hilbert enveloping can effectively restrain interference of noise and other characteristic waves an can also enhance energy of the R waves. The R wave detection algorithm based on the extremum field mean mode decomposition and the improved Hilbert enveloping can also detect positions of R points accurately even if interference of strong noise and large P/T waves exists. A Massachusetts institute of technology-Beth Israel hospital (MIT-BIH) data base is used for detecting the R wave detection algorithm. Sensitivity of the R wave detection algorithm is 99.94%, and positive predictive rate is 99.87%.
Owner:TIANJIN POLYTECHNIC UNIV

Driving dynamic-static loading experimental device for confining pressure and explosion

The invention discloses a driving dynamic-static loading experimental device for confining pressure and explosion. The driving dynamic-static loading experimental device comprises an experimental device, a hydraulic system device, a surface-strain measuring system and an internal-strain measuring system, wherein the hydraulic system device, the surface-strain measuring system and the internal-strain measuring system are connected together by the experimental device. The driving dynamic-static loading experimental device disclosed by the invention has the advantages that the two-way stable pressure loading process is realized by the hydraulic system device, and by transition devices such as wedge-shaped blocks, the pressure on a test piece is more uniform and stable; by an internal sensor,accurate control for the internal response process of the test piece can be realized and simultaneously the interference effect of the boundary effect on the experiment is eliminated; by use of the internal sensor and an external high-speed shooting system, not only can the deformation process of the test piece under combined loading be captured, but also the growth and extension rules of microcracks of rock can be analyzed simultaneously; the driving dynamic-static loading experimental device is more beneficial to analyzing the process of large deformation or macroscopic fracture in engineering practices.
Owner:BEIJING INSTITUTE OF TECHNOLOGYGY
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