93 results about "Peak location" patented technology

A method of determining locations of at least two pointers in a captured image frame comprises generating a vertical intensity profile (VIP) from the captured image frame, the VIP comprising peaks generally corresponding to the at least two pointers; determining if the peaks are closely spaced and, if the peaks are closely spaced, fitting a curve to the VIP; analyzing the fitted curve to determine peak locations of the fitted curve; and registering the peak locations as the pointer locations.

After one or both of a pair of images are obtained, an auto-correlation function for one of those images is generated to determine a smear amount and possibly a smear direction. The smear amount and direction are used to identify potential locations of a peak portion of the correlation function between the pair of images. The pair of images is then correlated only at offset positions corresponding to the one or more of the potential peak locations. In some embodiments, the pair of images is correlated according to a sparse set of image correlation function value points around the potential peak locations. In other embodiments, the pair of images is correlated at a dense set of correlation function value points around the potential peak locations. The correlation function values of these correlation function value points are then analyzed to determine the offset position of the true correlation function peak.

A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. In one embodiment, the invention includes a sensing unit configured to generate a signal indicative of the sensed magnetic field and an amplifier. The amplifier is in communication with the sensing unit, is configured to amplify signals having amplitudes less than a threshold by at least a first factor and configured to amplify signals having amplitudes greater than the threshold by at most a second factor. The first factor is greater than the second factor. The invention also includes an analog-to-digital converter (ADC) in communication with the amplifier and configured to digitize the analog signal, a filter in communication with the ADC configured to attenuate the portion of the digitized signal indicative of the stored data, a data extraction unit in communication with the ADC and the filter, which is configured to measure bit duration and peak location and an authentication extraction unit in communication with the filter and the data extraction unit, which is configured to extract a set of scaled samples representative of the remanent noise characteristic.

The repetitive structure of a preamble signal is exploited to enhance timing synchronization performance and frame start detection performance under adverse channel conditions. Received values are cross-correlated in time against a known noise-free version of the preamble. The presence of peaks in the cross-correlation output indicates presence of a frame. The peak locations provide symbol timing. Further cross-correlation processing and/or non-linear processing can be used to enhance the signal to noise ratio of the peaks.

A system for verifying the authenticity of data contained in a magnetic medium using the remanent noise characteristics of the magnetic medium. In one embodiment, the invention includes a sensing unit configured to generate a signal indicative of the magnetic field of the magnetic medium, an analog-to-digital converter (ADC) in communication with the sensing unit and configured to digitize the analog signal, a filter in communication with the ADC configured to enhance the component of the signal associated with the remanent noise characteristic, a data extraction unit, in communication with the ADC and the filter configured to measure at least bit duration and peak location and an authentication extraction unit, in communication with the filter and the data extraction unit configured to extract a set of scaled samples from the output of the filter representative of the remanent noise characteristic.

The invention provides an electrocardio signal QRS complex wave detection method based on morphology and wavelet transform. The method comprises a first step of inputting an electrocardiograph (ECG) signal which restrains base line drift and after high-frequency noise is removed and carrying out segmentation, a second step of using a db6 wavelet to carry out four-layer wavelet decomposition to the segmented ECG signal obtained in the first step, a third step of using a multiresolution morphology decomposition method to decompose the segmented ECG signal obtained in the first step and searching a common model maximum value point on a third layer detail component and a fourth layer detail component and regarding the common model maximum value point as an R peak location, a fourth step of carrying out the OR operation to the R peak locations obtained in the second step and the third step and preserving a result as a new R peak location if the result is 1, a fifth step of recalling an R peak, a sixth step of confirming a starting point and a terminal point of an QRS complex wave, and a seventh step of confirming whether total ECG signal detection is finished or not, finishing the operation if the detection is finished, and updating a threshold value and repeating the second step to the seventh step until an algorithm is finished, if the detection is not finished. The method can reach detection accuracy rate of more than 99%.

A robust multi-criteria minimum timing for the best torque (MBT) timing estimation method and apparatus utilizes different ionization signal waveforms that are generated under different engine operating conditions. The MBT timing criteria is calculated based upon both ionization and analog derivative ionization. Multiple MBT timing criteria are determined and combined to increase the reliability and robustness of MBT timing estimation based upon spark plug ionization signal waveforms. In a preferred embodiment, a combination of the MBT timing estimation criteria comprises a maximum flame acceleration location, a 50% burn location, and a second peak location.

The present invention relates to a method and a device for verifying identity of an individual by employing biometric data derived from a physical feature of the individual. A basic idea of the invention is that, rather than determining peak locations in cyclic signals such as ECG or PPG signals when using these signals as a representation of biometric data for verifying identity of an individual, shape or morphology of the signals is considered.

The present invention relates to a highly controlled method of preparation of a microporous biodegradable polymeric article. Firstly, at least one biodegradable polymer A, one polymer B, biodegradable or not, partially or totally immiscible with A, and a compatibilizer C for A and B are selected. Secondly, the selected polymers are melt-blended, thereby preparing a polymer blend; wherein said polymers A and B have an essentially continuous morphology. Thirdly, after cooling, polymer B and compatibilizer C are selectively extracted from the polymer blend by dissolution in a solvent that is a non-solvent of polymer A. The resulting polymeric article has an essentially continuous porosity with a void volume between 10 and 90% and a unimodal diameter distribution set to a predefined unimodal peak location. It can be used in tissue engineering, for controlled release applications or as an implantable medical device.

A correlation function peak finding method for an image correlation displacement sensing system is provided. The method may include capturing a reference image and a displaced image, and searching for an initial peak correlation function value point (CFVP) with pixel-level resolution based on correlating the reference image and displaced images at a plurality of offset positions. Then a complete set of CFVPs may be determined at each offset position in an analysis region surrounding the initial peak CFVP. Then a preliminary correlation function peak location is estimated with sub-pixel resolution, based on CFVPs included in the analysis region. Finally, curve-fitting operations are performed to estimate a final correlation function peak location with sub-pixel accuracy, wherein the curve-fitting operations apply a windowing function and/or a set of weighting factors that is/are located with sub-pixel resolution based on the preliminary sub-pixel correlation function peak location.

A system, method and memory medium for operating on an electrocardiogram (ECG) signal. A multiscale short-time Fourier transform (STFT) is perform on a set of ECG samples {s(n)} to obtain a transform array. For each sufficiently energetic peak in the transform array, a refined window width value and a refined window displacement value is generated by: computing an inner product between the set of samples and each of a plurality of functions, where the plurality of functions are sufficiently close to a coarse approximation function given by the peak location; and solving a linear system Av=c for the unknown vector v, where the vector c is determined by the inner products, where the matrix A is determined by the center times of the plurality of functions. After appropriate selection, the refined window width and refined window displacement may be used to represent ECG waveform features.

The peak detection method using blind source separation extracts true peaks from noisy peaks in a more robust way that does not require any a priori information. Information regarding true peak location is obtained by thresholding the output of a wavelet transform. The value of the threshold is dependent on noise variance. While noise variance is normally unknown, the present method implements a blind source separation technique to calculate the noise variance. The blind source separation technique does not require information of the incoming signal or the channel noise, and hence is suitable for CR (cognitive radio) peak detection.

The invention discloses a rhythmicity physiological signal optimization method and device. The method includes the following steps: local energy enhancement is carried out on alternating current partof rhythmicity physiological signal, and peak location is confirmed. The invention enhances characteristics of systole by local energy enhancement technology and inhibits noise, thus improving accuracy of measurement.

The invention relates to a signal processing method of propagation speed difference type ultrasonic flow meter used to measure the propagation time in measuring pipe of ultrasonic signal so as to measure the speed of the flow. The method comprises: (1) using coding modulating ultrasonic signal with self-relative character to generate the sending signal; (2) carrying the flow information by pipe flow field propagation by the sending signal; (3) receiving the sending signal with flow information and doing relative computing with the sending signal of the step one; (4) measuring the propagation time of the ultrasonic signal by the peak location of the relative function to compute the speed of the flow.

The time delay (and therefore the OPD) between object and reference beams in an interferometer is manipulated by changing the spectral properties of the source. The spectral distribution is tuned to produce a modulation peak at a value of OPD equal to the optical distance between the object and reference arms of a Fizeau interferometer, thereby enabling the use of its common-axis configuration to carry out white-light measurements free of coherence noise. Unwanted interferences from other reflections in the optical path are also removed by illuminating the object with appropriate spectral characteristics. OPD scanning is implemented without mechanical means by altering the source spectrum over time so as to shift the peak location by a predetermined scanning step between acquisition frames. Finally, the spectrum is controlled on a pixel-by-pixel basis to create a virtual surface that matches the profile of a particular sample surface.

Improved correlation techniques employ data from forward (template-to-reference) and reverse (reference-to-template) correlation to identify valid correlation peaks, enforce symmetry in correlation peaks, and/or combine forward and reverse correlation data. In embodiments, these techniques eliminate or reduce rms noise in a recovered signal peak location by enforcing correlation peak symmetry. The forward and reverse correlation methods described herein may be used for validation of correlation peaks, detection of outlier data points and improved interpolation, such as for higher accuracy localization of a peak center with sub-pixel resolution.

The invention provides a Bluetooth layout and location method for underground parking lots. Firstly, Bluetooth base stations are arranged at the height of about three meters right above the road at the key nodes of an underground parking lot, such as intersections and corners, and Bluetooth base stations are arranged at regular intervals with the key nodes as the center. After the Bluetooth of a handheld terminal of a user is opened, the handheld terminal is connected with the Bluetooth base stations and obtains the entrance of the indoor micro-map. After the user accesses the indoor micro-map, the handheld terminal of the user periodically receives and parses the information data of the Bluetooth base stations. After the distance between each base station and the handheld terminal of theuser and the unique identification mark minor numbers of the base stations obtained by parsing are matched with the indoor map description file, the location of the user can be determined by using a section peak location algorithm. A simpler and cost-saving underground parking lot location mode is provided, and efficient, energy-saving and intelligent operation of underground parking lots is realized.

The invention discloses an improved phase difference frequency estimation method. The method comprises: (2N-1) samples are inputted, windowless full-phase fast fourier transform is carried out on the samples to obtain a frequency spectrum Y(k), and N points are selected from the samples to carry out windowless full-phase fast fourier transform to obtain a frequency spectrum X(k); searching is carried out on the X(k) and the Y(k) to obtain a spectral peak location, spectral peak phases phiX(k<*>) and phiY(k<*>), a difference value delta phi~, phase adjustment is carried out to obtain delta phi, and dividing is carried out by tau=(N-1)/2 to obtain a frequency offset estimation value delta^1; |delta^1| is larger than or equal to xi, a sequence s(n)=exp(-j2pidelta^1n/N), time-domain modulation is carried out on the samples to obtain a frequency offset estimation value delta^<*>1, the delta^<*>1 is added to a delta^2 to obtain a frequency offset estimation value delta^; the |delta^1| is larger than or equal to 1 and is less than xi and the frequency offset estimation value delta^ is equal to delta^1; and the delta^ is substituted into a formula: f^0=(k<*>+delta^)/N to calculate a frequency offset estimation value. With introduction of frequency shift compensation measures, a solution measure to phase difference integer ambiguity is put forward, so that practicability is enhanced.