36 results about "Correlogram" patented technology

Apparatus and methods for modulated plasticity in a spiking neuron network. A plasticity mechanism may be configured for example based on a similarity measure between post-synaptic activities of two or more neurons that may be receiving the same feed-forward input. The similarity measure may comprise a dynamically determined cross-correlogram between the output spike trains of two neurons. An a priori configured similarity measure may be used during network operation in order to update efficacy of inhibitory connections between neighboring neurons. Correlated output activity may cause one neuron to inhibit output generation by another neuron thereby hindering responses by multiple neurons to the same input stimuli. The inhibition may be based on an increased efficacy of inhibitory lateral connection. The inhibition may comprise modulation of the pre synaptic portion the plasticity rule based on efficacies of feed-forward connection and inhibitory connections and a statistical parameter associated with the post-synaptic rule.

Apparatus and methods for plasticity in spiking neuron network. The network may comprise feature-specific units capable of responding to different objects (red and green color). Plasticity mechanism may be configured based on difference between two similarity measures related to activity of different unit types obtained during network training. One similarity measure may be based on activity of units of the same type (red). Another similarity measure may be based on activity of units of one type (red) and another type (green). Similarity measures may comprise a cross-correlogram and/or mutual information determined over an activity window. Several similarity estimates, corresponding to different unit-to-unit pairs may be combined. The combination may comprise a weighted average. During network operation, the activity based plasticity mechanism may be used to potentiate connections between units of the same type (red-red). The plasticity mechanism may be used to depress connections between units of different types (red-green).

A nonlinear overlap method for time scaling to synthesize an S₁[n] and an S₂[n] into an S₃[n] is disclosed. The S₁[n] and the S₂[n] having N₁ and N₂ signals respectively. The nonlinear overlap method includes the following steps: (a) delaying the S₂[n] by a predetermined number and forming an S₅[n], (b) establishing a correlogram of a cross-correlation function of the S₁[n] and S₅[n], and (c) setting S₃[n] as a number of S₁[n] when 0<=n<; as a number formed by overlap-adding the S₁[n] and an S₄[n] in a weighting manner when (the predetermined number+the maximum index+the first threshold)<=n<(N₁−a second threshold); and as a number of S₄ wherein the first and second thresholds are not equal to zero at the same time, and the S₄[n] is formed by delaying the S₅[n] by the maximum index.

Interferometric measurements are carried out in conventional manner to produce a correlogram corresponding to successive scanner steps. An approximation of the actual scan-step size between frames is calculated from multiple-frame intensity data collected around the frame of interest using common irradiance algorithms. The scan-step size so measured is then used in standard PSI, VSI or PSIOTF algorithms, instead of the scanner's nominal phase step. According to one embodiment, the invention utilizes a five-frame PSI algorithm to produce an average scan-step size of four scan steps. According to another embodiment, the phase step between frames is calculated directly utilizing a novel five-frame algorithm that produces an approximation of actual phase step for a given frame, rather than an average value of four steps around the frame. The method requires reduced data processing and can advantageously be applied "on-the fly" as intensity data are acquired during scanning.

Bat wings are removed at step discontinuities within the coherence length of the light source of a vertical-scanning interferometer. A first height profile is obtained from a correlogram using a coherence-sensing technique. A second height profile is obtained from phase measurements at the best-focus frame position of the scanner. The two profiles are compared, and phase ambiguities are removed in conventional manner. In addition, during unwrapping the differences in height between two adjacent pixels obtained both by coherence sensing and by phase measurements are compared to flambd/4. Where the inter-pixel height difference calculated by coherence sensing is smaller and the inter-pixel height difference calculated by phase is larger than flambd/4, the phase measurement is corrected by 2pi increments until both coherence and phase inter-pixel height differences are within flambd/4. This additional step removes bat-wing effects from profiles obtained by phase measurement.

The rough bottom surface of a recessed feature partially obscured by an overlying structure is profiled interferometrically with acceptable precision using an objective with sufficiently large numerical aperture to illuminate the bottom under the obscuring structure. The light scattering produced by the roughness of the surface causes diffused light to return to the objective and yield reliable data fringes. Under such appropriate numerical-aperture and surface roughness conditions, the bottom surface of such recessed features can be profiled correctly simply by segmenting the correlograms produced by the scan and processing all fringes that correspond to the bottom surface elevation.

The invention relates to a method and an apparatus for measuring the thickness of a transparent film by broad band interferometry, comprising the steps of preparing a correlogram of the film by an interferometer, applying a Fourier transformation to said correlogram to obtain a Fourier phase function, removing a linear component thereof, applying a second integral transformation to the remaining non-linear component to obtain an integral amplitude function of said non-linear component, identifying the peak location of said integral amplitude function and determining the thickness of the film as the double value of the abscissa at said peak location considering a refractive index of a film which is dependent on wavelength. The last two steps may be replaced by identifying the peak locations of said integral amplitude function and determining the thickness of the films as the double values of the abscissas at the peak locations.

Heterodyne interferometry is combined with spectrally-controlled interferometry (SCI) to achieve the advantages of both. Phase shifts produced by SCI produce phase-shifted correlograms suitable for heterodyne interferometric analysis, thereby enabling interferometric measurements with conventional common-path apparatus free of coherence noise and scanning-related errors, and with the precision of conventional heterodyne interferometry. A spectrum-modulating light source suitable for the invention is obtained by combining a rotating spiral grating with a multi-slit grating placed in the front focal plane of a collimating lens that propagates the light toward a blazed diffraction grating. Another exemplary spectrum-modulating light source is obtained by combining a slit spectrometer with an acousto-optic modulator.

Method of determining a property of a sample from a correlogram obtainable by scanning of a surface of the sample through a focal plane of an objective using broad-band interferometry is provided. The correlogram may be displaying interference radiation intensity as a function of the scanning distance from the surface. The correlogram may be correlated with a secondary correlogram to obtain a cross correlogram or with the same correlogram to obtain an autocorrelogram. A property of the sample may be determined from the auto or cross correlogram.

Sinusoidal in-phase and in-quadrature signals at a given spatial frequency are combined with the irradiance signals generating a correlogram of interest and integrated over the length of the correlogram data-acquisition scan. The integration outputs are then used to calculate the amplitude and the phase of the correlogram signal at the selected spatial frequency, thereby producing targeted spectral information. The signal generator used to generate the in-phase and in-quadrature sinusoidal signals may be scanned advantageously through any desired range of spatial frequencies, thereby producing corresponding amplitude and phase spectral information for the correlogram. Because the procedure produces spectral information independently of the number of data frames acquired during the interferometric scan, it is materially more rapid than conventional FFT analysis.

The invention provides a watershed pollution traceability prediction method and device based on artificial intelligence, and relates to the technical field of water environment information processing. The method comprises the following steps: carrying out cross correlation calculation on water quality monitoring indexes, taking a correlation map between the water quality indexes as input basic data, and delaying the correlation between the indexes to the correlation between point source pollution through an association rule algorithm; finally, mining potential laws of the water quality related atlas in time by using an LSTM algorithm, and realizing accurate prediction of point source pollution. The method aims to predict a main control industry point source causing water quality change, point source pollution, water quality monitoring data and an industry pollution knowledge base are used as data sets, a core algorithm in an intelligent voice technology is innovatively introduced into the environment field, algorithms such as cross correlation, association rules and a long-short term memory network are adopted, the artificial intelligence technology is used for identifying main point source pollution influencing future water quality changes.

The invention relates to a method and an apparatus for measuring the thickness of a transparent film by broad band interferometry, comprising the steps of preparing a correlogram of the film by an interferometer, applying a Fourier transformation to said correlogram to obtain a Fourier phase function, removing a linear component thereof, applying a second integral transformation to the remaining non-linear component to obtain an integral amplitude function of said non-linear component, identifying the peak location of said integral amplitude function and determining the thickness of the film as the double value of the abscissa at said peak location considering a refractive index of a film which is dependent on wavelength. The last two steps may be replaced by identifying the peak locations of said integral amplitude function and determining the thickness of the films as the double values of the abscissas at the peak locations.