43results about How to "Reduce sampling points" patented technology

The invention relates to an indoor positioning method applied to a mobile sensing network. The precision of the positioning method is improved by fully utilizing the mobility of nodes so as to overcome the shortcomings in the prior. The mobile node positioning method comprises the following steps of: 1) setting the position of an anchoring node; 2) setting the positions of the mobile nodes, and estimating the initial positions of the nodes; 3) forecasting; 4) filtering, and repeating the step 3) and the step 4) to reselect forecast points and to refilter till finding enough points meeting requirements if the number of samples in a filtered position sampling set meeting the requirements is less than N; and 5) correcting the positions, namely correcting the estimated positions of the nodes, to obtain the corrected estimated positions of the nodes. The method has the beneficial effects that the node mobility and the correlations among the nodes in the mobile sensing network are fully utilized to put forward the novel method which is used for determining the positions of the mobile nodes in the mobile wireless sensor network and mainly used for realizing the self-positioning of the nodes in the mobile sensing network in an indoor environment; and due to the method, extra hardware is not added to the sensor nodes, and the positioning precision and the positioning instantaneity of the sensor nodes can be improved.

The invention discloses a method for reconstructing multi-spectral information calculation based on principal component analysis. The method comprises the following steps of: 1, acquiring two paths of multi-spectral images; 2, performing principal component analysis on the spectral information of sampling points of the multi-spectral images to obtain a principal component spectral vector basis; and 3, reconstructing the spectral information on the unknown spectral points according to the principal component spectral vector basis, red, green and blue (RGB) vectors which are acquired by a camera, an R channel integral curve of the camera, a G channel integral curve of the camera and a B channel integral curve of the camera. By the method, multi-spectral information can be more simply and more quickly reconstructed; the required scene spectral sampling points are few; and principal components of the multi-spectral information can provide instructive significance for related research.

The invention discloses a space calibrating body and method based on a virtual ball. According to the space calibrating body and method based on the virtual ball, calibration is conducted in the form that a standard bar piece is separated from a base, a laser tracker is adopted to serve as measurement equipment, and a hard aluminum alloy plate is adopted by the base to serve as an installation platform of the standard bar piece. The space calibrating method based on the virtual ball comprises the steps that the space calibrating body which has three degrees of freedom is manufactured firstly, threads are machined at the two ends of the standard bar piece, one end of the standard bar piece is fixed to the hard aluminum alloy plate, the other end of the standard bar piece is used for fixing the body of the virtual ball, a regular octahedron with the top end cut off serves as the body of the virtual ball, a cone nest is machined on each face of the virtual ball, and then the virtual ball is calibrated with the laser tracker serving as the measurement equipment. The space calibrating body and method based on the virtual ball have the advantages that the precision is high, machining requirements for the standard piece are low, the number of needed sampling points is small when the space calibrating body and method are used, the calibrating efficiency is improved, and the sampling workload is greatly reduced and the calibrating efficiency is improved when an articulated type coordinate measuring machine is calibrated.

The invention relates to a generation method of the switching trigger pulse of a cascaded H-bridge multilevel converter, belonging to the switch modulation technical field of the power electronic converter. The invention mainly aims at the conflict between the generation precision of trigger pulse, and the number of sampling points and the computing workload, in the existing converter switch sine pulse width modulation (SPWM) trigger pulse generation technology and provides the generation method of the switching trigger pulse of the cascaded H-bridge multilevel converter, wherein the generation method is based on the carrier phase shifted-SPWM (CPS-SPWM) technology. According to the specific sampling method, sampling time sequence and algorithm of duty cycle of the invention, the SPWM trigger pulse of the converter switch can be generated rapidly. Compared with the existing CPS-SPWM pulse generation technology based on the symmetrical rule sampling method, the SPWM trigger pulse generated by the method of the invention has high precision; and compared with the CPS-SPWM pulse generation technology based on the unsymmetric rule sampling method, the number of the sampling points and the computing workload are reduced to half. In addition, by adopting the method, the time delay between the fundamental component of the output voltage of the converter and the modulated wave is small, namely the generation speed of the trigger pulse is high.

The invention provides a method for positioning a pseudo base station. The method comprises the following steps that (I) a signaling collection system acquires and filters location updating signaling of a user; (II) a location area of the pseudo base station is determined and is divided into location blocks; (III) a high-risk location block is determined; (IV) the pseudo base station is positioned by applying rayleigh distribution based on signal attenuation and a cooperative positioning technology based on an electromagnetic wave free space propagation model. According to the method, the area where the pseudo base station appears can be obtained in real time, and accurate positioning can be performed in the area; the problems that a traditional positioning method is slow in response and low in accuracy are solved, resources of law enforcement are saved, the pseudo base station can be effectively fought against, and normal network communication is protected.

The invention provides a method and a system for performing rapid diffusion tensor imaging under a compression sensing framework. The rapid diffusion tensor imaging method comprises the following steps: A, initializing a sampling mask1 which corresponds to a first diffusion gradient, and adopting a ray type sampling locus; and B, rotating the sampling mask 1 which corresponds to the first diffusion gradient by a fixed angle to obtain a sampling mask2 which corresponds to a second diffusion gradient, rotating the sampling mask2 which corresponds to the second diffusion gradient by a fixed angle in the same direction to obtain a sampling mask3 which corresponds to a third diffusion gradient, and so on till L sampling masks are obtained in total. The method and the system have the beneficial effects that under the situation of same sampling points, diffusion images of higher quality can be obtained by remodeling. In other words, less sampling points are needed in a novel scheme while the same image quality is obtained, the sampling time is shortened, and the aim of accelerating imaging is fulfilled.

The invention provides a magnetic resonance imaging method and device based on a neural network. According to one instance, the method comprises the steps that according to a detection part of a detected body, the pre-trained neural network is selected, wherein a sampling track corresponding to the neural network is a matrix as large as a k-space and is used for identifying whether to sample points at corresponding positions in the k-space; a magnetic resonance imaging system is utilized to scan the detected body according to the sampling track corresponding to the neural network, and k-spacedata is obtained; and the k-space data is input into the neural network to obtain a magnetic resonance image of the detection part of the detected body. According to the method, the detected body is scanned through the sampling track corresponding to the pre-trained neural network, then image reconstruction is performed through the neural network, and therefore sampling points can be reduced as many as possible to shorten sampling time while image quality is guaranteed.

A topographical map high-fidelity reducing method utilizing rotating TIN (triangulated irregular network) overlay analysis overcomes the shortcoming that an existing square or rectangular network is severe in distortion when a topographical map is reduced. The topographical map high-fidelity reducing method comprises the following steps of determining the side length of a basic square; respectively arranging four sampling points at four vertexes of the basic square, and arranging 3-n sampling points on sides of the basic square and the inside of the basic square in a scattered manner to form a basic unit; counterclockwise rotating the basic unit to form a primary unit body, a secondary unit body and a tertiary unit body; splicing the basic unit, the primary unit body, the secondary unit body and the tertiary unit body to form a square assorted unit; utilizing the assorted unit as a replication unit, and performing translation replication repeatedly to form a rotating staggered assorted network covering a topographical map; respectively utilizing a unit in the assorted unit as a start unit of a rotating staggered scaling network to reduce the topographical map; and comprehensively analyzing after overlaying 4 reduced results, and selecting useful results to obtain a reduced synthesized topographical map.

The invention provides a cyclically symmetrical preamble signal sending system and method, and a cyclically symmetrical permeable signal receiving system and method. The cyclically symmetrical permeable signal sending method comprises the following steps: generating a first time-domain basis symbol with a length of N; cyclically shifting the first time-domain basis symbol leftwards or rightwards by m sampling points, so that a second time-domain basis symbol with a length of N is obtained; carrying out repeated and alternate cascading extensions on the first time-domain basis symbol and the second time-domain basis symbol to obtain a random length, so that a preamble symbol is formed; carrying out signaling or data frame cascading behind the preamble symbol, so that a preamble baseband frame is formed; and modulating the preamble baseband frame into a radio frequency signal, and sending the radio frequency signal. The cyclically symmetrical preamble signal sending system and method and the cyclically symmetrical permeable signal receiving system and method provided by the invention have the advantages that timing estimation is more accurate, so that the timing estimation performance is greatly improved; regarding decimal carrier frequency offset estimation, the frequency offset estimation accuracy is improved; and the number of sampling points that are needed for sliding for peak detection is smaller, so that the detection time is shorter.

The invention discloses a method and a device for estimating a channel. The method comprises the following steps of: presetting extracting multiple of at least two stages, and dynamically determining the current extracting multiple according to link quality; according to the current extracting multiple, extracting a received frequency domain demodulation reference mark and a local frequency domain demodulation reference mark; and figuring out the current frequency domain chain estimated value by using the extracted received frequency domain demodulation reference mark and the local frequency domain demodulation reference mark. The device comprises an extracting multiple judging module, a pilot frequency extraction module and a channel estimation module, wherein the extracting multiple judging module is used for presetting the extracting multiple of the at least two stages, and dynamically determining the current extracting multiple according to the link quality; the pilot frequency extraction module is used for extracting the received frequency domain demodulation reference mark and the local frequency domain demodulation reference mark according to the current extracting multiple; and the channel estimation module is used for figuring out the current frequency domain chain estimated value through the extracted received frequency domain demodulation reference mark and the local frequency domain demodulation reference mark. The method and the device have the advantages of reducing the complexity of a receiver and reducing the processing time delay.

The invention discloses a grounding parameter acquisition method based on an arbitrary layered soil Green function. Aiming at the two limitations of global equal-interval sampling and PRONY methods adopted by most layered soil green function calculation in current base parameter calculation, the method comprises the following steps: 1, the complex exponential term of the PRONY method is twice of the number of soil layers, and the calculated amount is linearly increased along with the number of soil layers; 2, key features of an integral kernel function cannot be effectively sampled through global equal-interval sampling; in order to solve the problem that a complex stratified soil model cannot be solved completely due to the fact that the complex stratified soil model cannot be solved completely, the invention provides an arbitrary stratified soil Green function calculation method for performing segmented sampling according to extreme points of an integral kernel function and fitting data points of segmented sampling in combination with a least square method by analyzing distribution characteristics of the integral kernel function. Compared with a PRONY method under global sampling, the method provided by the invention can better approach an integral kernel function, and has the advantages of high calculation efficiency, good precision and the like.

The invention discloses an active battery equalization circuit utilizing relevance of a flyback transformer clamped by a battery. The circuit comprises a control unit, a driving unit and a rechargeable battery pack. The method comprises steps of testing a total voltage before equalizing charging of the battery, and calculating an average voltage of all battery packs; testing a voltage of each battery pack in the circuit, calculating voltage difference between the voltage of all the battery packs and the average voltage, and selecting the battery to charge according to the relationship betweenthe voltage difference and a preset threshold. The circuit and the method are advantaged in that large-current equalization can be carried out on the batteries at any time, so all single batteries inthe battery pack both can be charged to the highest voltage and discharged to the lowest voltage, the capacity and the utilization rate of the battery pack are fully improved, and simplicity and highefficiency of the system are kept. By utilizing conciseness of the single-ended flyback transformer and relevance of the winding voltage of the same transformer, the number of transformers is reduced,sampling points are reduced, and equalization and speediness are achieved.

The invention discloses a broadband electromagnetic simulation method using efficient adaptive frequency scanning. According to the method, frequency response convergence judgment is carried out by utilizing an error formula, so that appropriate frequency sampling points can be obtained, and compared with other methods, the required sampling points are reduced, and the simulation speed is increased. According to the method, a nonlinear problem is converted into two linear problems, accurate values of poles and residues are calculated through iteration, a linear equation is solved, an accurate frequency response fitting value is obtained, the calculation speed is increased, and the accuracy is improved.

The invention discloses a structure identification method of vulcanized joints of a steel wire rope core conveyer belt of a coal mine. The method comprises steps of 1, acquiring vulcanized joint magnetic flux leakage signals; 2, de-noising the vulcanized joint magnetic flux leakage signals; 3, selecting de-noising magnetic flux leakage sampling effective sequences; 4, carrying out signal smoothing processing; 5, acquiring a local extreme point of a magnetic flux leakage smooth signal z(i); 6, determining positions of a maximum value point and a minimal value point of the magnetic flux leakage smooth signal z(i); 7, removing interference abnormal local extreme points; and 8, identifying orders of the vulcanized joints of the steel wire rope core conveyer belt. According to the invention, the orders of the vulcanized joints of the steel wire rope core conveyer belt are judged through the quantity of effective maximum value points or effective minimal value points of the magnetic flux leakage signals of the vulcanized joints; the firm foundation is laid for quantitative detection of twitching of vulcanized joints of the steel wire rope core conveyer belt; the method is simple to operate, and easy to achieve and produces favorable effects; and the method has important meaning for prevention of occurrence of fracture accidents of the vulcanized joints of the steel wire rope core conveyer belt.