78results about How to "Reduce the number of sampling points" patented technology

The invention provides methods and systems for ultrasonic imaging and microbubble imaging of plane waves based on compressive adaptive beam forming. The compressive adaptive beam forming algorithm is adopted, each array element receives useful frequency point information of data, and the useful frequency point information is all centralized in effective bandwidth of an ultrasonic echo signal, so that the data in the effective bandwidth is subjected to compressive sensing treatment instead of the whole frequency domain, and on the basis of frequency-domain adaptive beam forming, the number of frequency-domain sampling points is reduced and calculated amount required during beam forming is reduced; plane wave imaging is adopted, so that a problem of transient change of microbubbles in conventional ultrasonic imaging is solved; the whole microbubble distribution region is covered by emitting planar ultrasonic waves once, so that a microbubble distribution image in the whole imaging plane is obtained; microbubble imaging of ultrasonic plane wave emission is adopted, so that the time resolution on microbubble imaging is very high.

The invention discloses a vehicle-mounted manhole cover detection method based on arc-point combination. The method comprises the following steps that images shot by an automobile data recorder are converted into grey-scale images, and an edge extraction algorithm and a thinning algorithm are used for contour extracting and thinning; according to connectivity and regional relationships among points, the contour is broken off from cross points, segmental arcs are classified according to concavity and convexity of each segmental arc, and linear segments and small segmental arcs are removed; candidate segmental arcs are divided into groups, arcs which meet quadrant constraint and central constraint are classified, and a central point position is determined by central point constraint; points are selected from segmental arcs in different quadrants and least square fit of an ellipse is carried out; false removal and screening are conducted on a fitted ellipse, and the position of a manhole cover is judged. According to the vehicle-mounted manhole cover detection method based on the arc-point combination, segmental arc processing is used as preprocessing of the point fitting, most of the irrelevant interference is removed at the complicated road background, the probability of invalid random sampling is excluded, and the detection speed of road surface manhole covers is improved.

The invention discloses a panoramic video polygon sampling method and a panoramic video polygon sampling method. The method comprises steps: according to space resolution requirements, uniformly-spaced latitudes are used for dividing a spherical surface into N ring curved surfaces; according to space resolution requirements, L ring curved surfaces located near the equator are uniformly divided into M areas along the equator direction, and each area is corresponding to one sampling point; the other ring curved surfaces are uniformly divided into Mi parts along the equator direction according to an arithmetic sequence, the closer the ring curved surface is to the equator, the larger Mi is, and each part is corresponding to one sampling point; and the calculated average value of light in each area on the spherical surface serves as a sampling value of sampling points corresponding to the area. Sampling points on the spherical surface meet the characteristic that many sampling points are near the equator and few sampling points are at two poles, redundancy of the sampling structure is avoided, and in the same space resolution condition, the number of sampling points is reduced and the data amount after sampling is reduced.

The invention belongs to the radio signal positioning method technical field and relates to a multi-target direct positioning method for non-circular signals. According to the method, the extended covariance matrix of time-domain signals is obtained according to the non-circular characteristics of the signals and on the basis of a time-domain array signal model; noise subspaces in each time slot are calculated through using the extended covariance matrix; the data of the plurality of subspaces are fused on the basis of the orthogonality of the extended subspaces in each time slot, and therefore, an optimization model for each target position is built; and a Gauss-Newton iterative algorithm is designed to realize the precise positioning of each target sequentially. With the multi-target direct positioning method for the non-circular signals provided by the invention adopted, multi-target position estimation accuracy can be improved. The advantages of the method in positioning accuracy become more obvious with the decrease of a signal-to-noise ratio or the decrease of sample points; and the method can process a larger number of targets.

The invention provides an ultra-high harmonic detection device and detection method based on compressed sensing. A sensing circuit is installed on a measurement end of a power distribution network, asignal outputted by the sensing circuit passes through a high-pass filter at first, then is mixed with a pseudo-random sequence outputted by a D/A module of a multifunctional data collection card andis sent to a low-pass filter, low-speed sampling of the signal is realized by an A/D module of the multifunctional data collection card, and finally, the signal is uploaded by a USB bus to an upper computer to complete the reconstruction and display of the signal. The high-pass filter is designed to be adjustable in gain and can also condition the signal in addition to filtering the power frequency and other low-frequency signal interference. The low-pass filter is designed to be achieve adjustable in cut-off frequency, and then variable compression ratio detection can be realized. A synchronous trigger module of the multifunctional data collection card can achieve D/A and A/D synchronization, and construct an observation matrix with a phase deviation of 0 to improve the reconstruction precision. The ultra-high harmonic detection device and detection method provided by the invention have the distinct advantages of greatly reducing the sampling frequency and the number of sampling points of a measurement device while ensuring that ultra-high harmonics and the spectral reconstruction thereof are correct.

The invention discloses a magnetic resonance non-Descartes sampling quick rebuilding method. The magnetic resonance non-Descartes sampling quick rebuilding method is provided through utilizing the characteristics of the symmetry of sampling tracks and a back compensation grid algorithm, and belongs to the technical field of magnetic resonance imaging. According to the magnetic resonance non-Descartes sampling quick rebuilding method, a back compensation gridding rebuilding algorithm is effective on samples without severe sampling track variation, and additionally, a density compensating function in the back compensating algorithm is only related to the sampling point distribution (i.e. sampling tracks) and is not related to sampling values. The characteristics are combined together, so that the computing speed of the provided new non-Descartes sampling quick rebuilding method is greatly increased than that of a conventional grid rebuilding algorithm, and the rebuilding image quality is not obviously changed.

The invention discloses a local maximum efficacy invariance test spectrum sensing method based on a non-circular signal in a multi-antenna scenario. The method comprises the steps as follows: A, calculating a sampling covariance matrix according to a received signal of the receiving end of a cognitive user, and constructing a corresponding augmented sampling covariance matrix; B, calculating the F norm of the augmented sampling covariance matrix, and constructing the test statistical magnitude; C comparing the test statistical magnitude with a preset threshold, judging that the spectrum is occupied if the statistical magnitude is greater than the threshold, or judging that the spectrum is idle, thus completing detection. By means of the characteristics of the non-circular signal, the correlation structure of the signal is utilized fully. In a multi-antenna scenario, high detection accuracy can be guaranteed, the number of required sampling points is small, and the detection efficiency is high.

The invention discloses a far-field pattern rapid measurement method based on Fourier interpolation, and solves the problem that the far-field measurement requires a small sampling interval to accurately reconstruct an antenna far-field pattern. The method comprises steps of determining the far-field distance of an antenna to be measured according to the far-field measurement condition of an antenna; determining a sampling interval by using a far-field measurement interval criterion of the antenna to be measured; sampling and measuring the amplitude and the phase of a radiation far field on a certain surface of the antenna, and calculating and obtaining the Fourier expansion coefficient and the far field pattern function of the far field of the antenna to be measured and the amplitude pattern and the phase pattern of the antenna to be measured in sequence, so that the rapid measurement of the far field pattern is realized. According to the method, the directional diagram with any small angle interval is quickly and accurately reconstructed based on the Fourier interpolation method of the band-limited periodic function, and the test efficiency is improved.he method comprises steps of The method is suitable for multi-channel, multi-beam and frequency sweeping tests, the number of sampling points can be greatly reduced, and the test efficiency is remarkably improved.

The invention relates to the field of computational intelligence, and relates to a multi-scale quantum harmonic oscillator concurrent optimization system and method. The method in the invention is composed of three embedded iteration processes: scale iteration, quantum harmonic oscillator iteration and energy level iteration. By adopting the method provided by the invention, sampling points to be compared at each time are fewer and are easier to fully iterate, so the result is accurate. According to the concurrency of the multi-scale quantum harmonic oscillator multimode optimization method, the Multi-scale quantum harmonic oscillator concurrent optimization method is proposed, and the method can be concurrently operated on a cluster. By adopting the concurrent method, the operational speed is effectively accelerated.

The invention discloses a panorama video octagon sampling method and apparatus. The panorama video octagon sampling method includes the steps: according to a spatial definition requirement, utilizing latitude lines to divide a spherical surface into N annular curved surfaces Oi, wherein i=0, 1, ..., N-1 and N=8K, and K is an integer; utilizing longitudes to divide the annular curved surface Oi into Ti areas, wherein one of the longitudes is a 0DEG longitude; successively marking the obtained areas as Ai, j, and j=0, 1, ..., Ti-1; calculating the average value of the obtained light in every area Ai, j on the spherical surface, and taking the average value as the sampling value Si, j of a sampling point corresponding to the area; and according to the corresponding rules, arranging the sampling values into a 14K*6K matrix. The panorama video octagon sampling method and apparatus enable distribution of the sampling points to satisfy the situation that the sampling points around the equator are more and the sampling points at two poles are very few, thus avoiding redundancy of the sampling structure so as to reduce the number of the sampling points when achieving the same spatial definition.

The embodiment of the invention discloses a method, device and system for measuring the total radiation power of an array antenna, and the method comprises the steps: determining the Rayleigh resolution of the array antenna in an angle space, and setting the stepping grid spacing of sampling points according to the Rayleigh resolution; and determining sampling points according to the stepping gridspacing, measuring equivalent omnidirectional radiation power (EIRP) at the positions of the sampling points, and determining TRP according to the EIRP. Compared with the traditional test mode of anangle stepping grid theta grid and phi grid being 15 degrees, the embodiment of the invention has the advantages that the measurement error is reduced; in addition, through normalized wave vector space conversion, the number of sampling points is further reduced, and the measurement efficiency is improved.

The invention provides a correcting calculation method for suspended sediment runoff of a river. The correcting calculation method is characterized by comprising the following steps: firstly, calculating average sediment concentration of sections to obtain average value D_CSI and D_CSII of sediment concentrations of two sections; secondly, determining marginal distribution, and calculating joint distribution function parameters: determining marginal distribution functions F1(CSI) and F2(CSII) as well as a parameter theta of a Copula function Ctheta(u, v); thirdly, carrying out interval discrete: equally dividing a value taking interval into n parts, wherein each part h=( D_CSIImax-D_CSIImin)/n, and marking a midpoint of a subinterval [D_CSII(k), D_CSII(k+1)] as xk+1/2= xk+h/2; fourthly, establishing a joint distribution model based on the Copula function; calculating to obtain u= FCSI(xCSI) and v= FCSII(xCSII) as well as an inverse function F<-1>y(v) of y and the Copula function c(u, v) according to given sediment concentrations x_CSI and x_CSII of the sections and the marginal distribution F1(CSI) and F2(CSII); fifthly, correcting the calculated sediment concentration on the basis of conditional expectation. The method has higher applicability; according to the method, the correcting calculation precision of the sediment concentration can be effectively improved, and working intensity of a hydrologic survey is reduced.

The invention discloses a turbomachinery aerodynamic performance-blade load optimization method based on machine learning, and the method comprises the steps: determining a turbomachinery working fluid, carrying out the parameterization of a turbomachinery, obtaining an optimization process input variable and an optimization target, and determining the empirical design space of the input variable; performing Bayesian optimization sampling on the turbomachinery in the empirical design space of the input variable according to the optimization target, selecting a working fluid in the optimization sampling process, calculating to obtain an optimization target value, and storing all Bayesian optimization sampling data; constructing a Unet-CNN neural network, and carrying out network training; performing random sampling on optimization process input variables in an empirical design space, constructing a geometric model to perform unsteady CFD calculation, performing post-processing to obtain a high-performance test set and a low-performance test set of the Unet-CNN neural network, and testing the Unet-CNN neural network; and enabling the Unet-CNN neural network passing the test to be used for turbomachinery optimization, and obtaining the optimal turbomachinery structure. According to the method, the cost and time consumption for constructing the proxy model can be greatly reduced.

The invention discloses an ellipsoid drawing collaborative optimization method based on the digital earth. By using the method, efficient global or large-range volume rendering covering the digital earth can be realized, the average frame rate is 30FPS or above, and the method has a film fluency level. According to the method, the actual calculation number of light sampling points is greatly reduced by constructing the proxy ellipsoid geometry, the data ellipsoid shell three-dimensional grid bounding box and the digital earth ellipsoid and skipping the light sampling points or terminating light sampling in advance (mainly eliminating the sampling points in the earth and on the back of the earth); meanwhile, data of the ellipsoid shell three-dimensional grid are organized into three-dimensional textures, calculation of ellipsoid trilinear interpolation and a transfer function is optimized through efficient texture query based on a GPU, and finally the volume rendering performance facing the digital earth is integrally improved.

The invention discloses a wireless signal fingerprint establishment method. The method comprises the steps of obtaining at least one wireless signal measurement sample point sampled at preset reference points, wherein the measurement sample points at least comprise measurement location information, serving cell signal strength information and neighbour signal strength information of a serving cell; clustering the measurement sample points according to the measurement location information of the measurement sample points, the serving cell signal strength information and the neighbour signal strength information of the serving cell, thereby forming at least one wireless signal cluster; and generating wireless signal fingerprints corresponding to wireless signal clusters by taking the wireless signal clusters as units. The invention also discloses a wireless signal fingerprint establishment device.

The invention discloses a panoramic video hexagonal sampling method and apparatus. The method comprises the following steps: dividing a spherical surface into N=6 annular curved surfaces by using latitude lines with equal intervals, making the annular curved surfaces as Oi in sequence, i = 0, and 1 ,... N-1, observing from the angle of the centre of sphere, and arranging the Oi from top to bottom; uniformly dividing the annular curved surface Oi into Ti areas by using meridians with equal intervals; calculating an average value of light within each area on the spherical surface to serve as a sampling value of a sampling point corresponding to the area; and arranging the sampling values in a matrix. By adoption of the sampling method, the redundancy of the sampling structure is avoided, and under the condition of realizing the same spatial resolution, the number of the sampling points is reduced, and the data size after sampling is reduced.

The invention relates to an AC stabilized power supply technology, in particular to a voltage effective value sampling method applied to an AC stabilized voltage power supply. It includes sampling reference voltage value setting, input voltage acquisition and comparison, real-time voltage sample acquisition time start, real-time voltage sample acquisition of power supply according to the set sampling frequency, voltage sample value comparison, judgment of instantaneous voltage valley or peak occurrence timing, and determination AC regulated power supply voltage effective value and other steps, the purpose of which is to propose a voltage rms sampling method applied to AC regulated power supply, so that it can work normally when the frequency of the grid changes, and at the same time improve efficiency and Anti-interference performance. Compared with the prior art, it has the advantages of less sampling points, low CPU calculation load, high execution speed, and small voltage deviation when the voltage frequency changes.