Abstract: Methods and systems for tracking an electronic signal corresponding to an operating frequency of an electronic component are provided. A method may include sampling the signal to determine previous and current time samples of the signal. A frequency of interest in the signal may also be pre-warped to decrease adverse warping effects resulting from processing signals having relatively higher operating frequencies. The previous and current time samples of the signals, along with the pre-warped frequency of interest, may be input into a digital tracking filter. The digital tracking filter may be configured to execute one or more algorithms on the previous and current time samples and the pre-warped frequency of interest to estimate a current operating frequency.

Abstract: A self check-type flame detector includes a casing provided with a monitoring window formed therein. A wavelength generation unit is disposed inside the casing and generates a wavelength in a direction of the monitoring window. A wavelength detection element is disposed inside the casing and detects the wavelength. A comparison unit is provided with a wavelength DB for storing intensity of a reference wavelength and determines whether the monitoring window has been contaminated. A display unit is located outside the casing and displays a state of the monitoring window. A communication unit is disposed inside the casing and configured to receive operation information for the wavelength generation unit, to provide the operation information to the wavelength generation unit, and to transmit the intensity of the wavelength, or a normal signal or a contamination signal of the monitoring window.

Abstract: The present invention provides methods, apparatus, and systems of measuring frequency. The invention includes sampling a first number of full cycles of a signal at a rate based on a nominal frequency of the signal; converting the samples to digital samples; processing the digital samples to identify a first pair of digital samples with each one disposed on either side of a first zero-crossing and a second pair of digital samples with each one disposed on either side of a last full cycle zero-crossing; interpolating the first pair of digital samples and the second pair of digital samples to determine a position of the first and last zero-crossings relative to each other in time; and calculating a fundamental frequency of the signal based on the first number of full cycles sampled and the relative position of the first and last zero-crossings. Numerous additional aspects are disclosed.

Abstract: A correlation image detector is provided that co-registers sonar images by finding peaks in correlation images. To obtain the peaks, the mean of the absolute values of the correlation coefficients in the correlation image is found and the Rayleigh parameter is determined from the mean. Based on the Rayleigh parameter, an appropriate threshold can be determined using a desired probability of false detection. The threshold can be chosen such that the probability of a single false detection over the expected life of the mission for which correlation detection is being performed is extremely low, e.g., one in a million. The peak value in the image is determined and a correlation is considered detected when the peak value is greater than the product of the threshold and the Rayleigh parameter. If a detection occurs, the correlation image detector returns the transformation that co-registers the two images.

Abstract: A technique detects an abnormal signal in a compound sampled signal recorded in the time domain. The technique involves dividing the sampled signal recorded in the time domain into sample segments; transforming each of the sample segments from the time domain into the frequency domain to determine transformed segments, each transformed segment having frequency points, each frequency point having an amplitude associated with a certain frequency; for a frequency point in a given transformed segment, determining a ratio by dividing the amplitude of the frequency point by a value indicative of an average of the amplitudes of the frequency points at the same frequency across transformed segments; repeating the determination of a ratio for frequency points in each transformed segment to determine ratios for each transformed segment; repeating the determination of ratios for transformed segments; and using the ratios to detect the abnormal signal in the compound sampled signal.

Abstract: An oscillating frequency drift detecting method, which comprises: receiving an oscillating signal with an oscillating frequency, wherein the oscillating signal is generated by a crystal oscillator; generating a self-mixing signal according to the oscillating signal; obtaining a self-mixing frequency of a maximum power of the self-mixing signal in a specific frequency range; and computing a frequency drift of the oscillating frequency, according to the self-mixing frequency of the maximum power, and the oscillating frequency.

Abstract: A sampling rate adjustment system includes a detecting circuit and a processor. The detecting circuit detects a frequency of an alternating current (AC) power source and outputs a detecting signal. The processor receives the detecting signal of the detecting circuit and determines whether a difference between the frequency of the AC power source and a sampling rate of a camera is less than a predetermined value. The processor outputs a control signal to the camera and changes the sampling rate of the camera when the difference between the frequency of the AC power source and the sampling rate of the camera is less than the predetermined value.

Abstract: A method and apparatus for detecting and locating illegal grow operations. The method involves using a radio receiver coupled to more than one antenna to detect a radio frequency signature associated with incoherent radio noise associated with grow lights typical of illegal grow operations. At least one antenna is provided which capable of detecting the presence of high energy radio emissions. At least one antenna is provided with directional sensitivity to pinpoint a source of the high energy radio emissions.

Abstract: Computer system and method for determining frequencies of various components of a volume choke volume dampener to be attached to a compressor. The method includes determining a sound spectrum of a cavity of the compressor without attaching the dampener to the compressor; calculating an acoustic wavelength of the cavity; receiving a length of a proximal nozzle of the dampener; and calculating, based on the acoustic wavelength of the cavity and the length of the proximal nozzle of the dampener, multiple order frequencies associated with the proximal nozzle of the dampener and the cavity of the compressor, wherein the proximal nozzle of the dampener is proximal to the cavity of the compressor when the dampener is attached to the compressor.

Abstract: In one embodiment, a measuring device may comprise two oscillators. The first oscillator may generate a local reference signal in a frequency detector to detect a fundamental frequency of the AC. The second oscillator may generate two substantially mutually orthogonal sinusoid signals having the selected frequency. The measuring device further may comprise a first group of multipliers that mixes the two sinusoid signals with a current and a voltage data signal of the AC respectively, a group of low-pass filters for removing high frequency components from the multiplication products, a second group of multipliers for mixing the filtered multiplication products respectively, and a plurality of adders each to sum together a pair of multiplication products of the second group of multipliers.

Abstract: A method of wirelessly interrogating a sensing device comprising a plurality of passive sensors, to determine a measurement parameter, comprises the steps of repeatedly interrogating the sensing device using a predetermined transmission signal and detecting the response; estimating the measurement parameter for each sensor by means of an analysis of the data accumulated as a result of the interrogation step, and determining the average of the parameters derived from the estimating step for each sensor, using a weighted average, in which the weightings depend on the amplitude of the sensor response. The measurement parameter may be a resonant frequency where the passive sensors are resonant devices, and the sensors may be SAW devices.

Abstract: A method is provided that includes receiving and processing a sample signal scan. Processing the sample signal scan includes applying an inner-product operation on the sample signal scan and each of a plurality of eigenvectors to generate a plurality of corresponding coefficients, and subtracting the sample signal scan from a linear combination of the eigenvectors and corresponding coefficients to thereby produce a corrected sample signal scan. In this regard, the eigenvectors have been generated by decomposing a plurality of background reference signal scans according to a singular value decomposition technique. The signal scans include a plurality of electromagnetic signal measurements at a discrete set of frequencies, where each measurement has been taken by a spectrometer system passing an electromagnetic signal through a sample cell including just a base medium (for the background reference signal scans), or both a base medium and a sample medium (for the sample signal scan).

Abstract: Method for finding the probability density function type and the variance properties of the noise component N of a raw signal S of a machine or a system, said raw signal S being combined of a pure signal component P and said noise component N, the method comprising: (a) defining a window within said raw signal; (b) recording the raw signal S; (c) numerically differentiating the raw signal S within the range of said window at least a number of times m to obtain an m order differentiated signal; (d) finding a histogram that best fits the m order differentiated signal; (e) finding a probability density function type that fits the distribution of the histogram; (f) determining the variance of the histogram, said histogram variance being essentially the m order variance ?2(m) of the noise component N; and (g) knowing the histogram distribution type, and the m order variance ?2(m) of the histogram, transforming the m order variance ?2(m) to the zero order variance ?2(0), ?2(0) being the variance of the pdf of the n

Abstract: A method is provided to minimize common rail pressure irregularities due to aliasing effect on battery voltage monitoring in a digital electronic control unit that is capable of PWM regulations of a metering valve unit in a diesel common-rail power-train system. At least an engine rotary speed signal is detected and at least a battery voltage signal is monitored, the method includes, but is not limited to calculating the aliasing frequency on said battery voltage signal as a function of said engine rotary speed signal, filtering the battery voltage signal before it is input to said controller module with at least one digital non-linear notch filter, the at least one digital non-linear notch filter substantially centered on the first harmonic of the aliasing frequency, and input the filtered battery voltage signal, at least with the engine rotary speed signal, to the controller module for PWM regulating the metering valve unit.

Abstract: A method and apparatus for detecting objects. A first plurality of electromagnetic signals having a first frequency and a second plurality of electromagnetic signals having a second frequency are transmitted. At least one of the first frequency and the second frequency is changed through a range of frequencies. A delayed difference frequency signal substantially equal to a difference between the first frequency and the second frequency is monitored for. The delayed difference frequency signal is generated by an object having non-linear electrical characteristics in response to the object receiving the first plurality of electromagnetic signals and the second plurality of electromagnetic signals. A range measurement is generated for the object by comparing the delayed difference frequency signal and an undelayed difference frequency signal. The undelayed difference frequency signal is substantially equal to the difference between the first frequency and the second frequency.

Abstract: A small form-factor pluggable (SFP) unit having signal diagnostic capabilities comprises one or more diagnostic measurement points. At least one of the one or more diagnostic measurement points provides a signal diagnostic measurement for diagnostic of the SFP unit.

Abstract: A method, system, and computer program product for optimizing power consumption of an executing processor executing. The method includes determining a first sensitivity relationship (SR) based on a first and a second performance metric value (PMV) measured at a first and second operating frequency (OF), respectively. The first SR predicts workload performance over a range of OFs. A third OF is determined based on the first SR and a specified workload performance floor. A third PMV is measured by executing the processor operating at the third OF. A second SR based on the second and third PMVs is then determined. The first and second SRs are logically combined to generate a third SR. Based on the third SR, a fourth OF is outputted.

Abstract: Disclosed is a system and related methodology for providing fast low frequency jitter rejection in the measurement of signals under test. A signal under test may be sampled alternately with a reference signal under similar conditions. The resulting sampled signal blocks may then be processed to subtract the known calibrated value of the reference signal from the average signal under test.

Abstract: An apparatus for detecting an operational status of a semiconductor equipment includes an audio frequency signal receiving unit and an analysis and determination unit. The audio frequency signal receiving unit is used for receiving an audio frequency signal from the semiconductor equipment while the semiconductor equipment is working. The analysis and determination unit is used for analyzing the audio frequency signal to determine statuses of components of the semiconductor equipment.

Abstract: A method for measuring the mains frequency by a digital control system of an electrical appliance, in particular an electrical household appliance, in which the digital control system is prearranged for performing rigorous measurements of the value of the mains frequency and of its variations through an operation of calibration of the means for measurement of the mains frequency performed prior to marketing of the product.

Abstract: One embodiment provides a system that analyzes a target electromagnetic signal radiating from a monitored system. During operation, the system monitors the target electromagnetic signal using a set of antennas to obtain a set of received target electromagnetic signals from the monitored system. Next, the system calculates a weighted mean of the received target electromagnetic signals using a first pattern-recognition model. The system then subtracts the received target electromagnetic signals from the weighted mean of the received target electromagnetic signals to obtain a set of noise-reduced signals for the monitored system. Finally, the system assesses the integrity of the monitored system by analyzing the noise-reduced signals using a second pattern-recognition model.

Abstract: A realtime spectrum trigger system on a realtime oscilloscope considers both the magnitude and phase of an input signal having a periodic component so that successive acquisitions of the input signal are time aligned. A user inputs a frequency, threshold and phase for triggering on the periodic component. Input signal samples are filtered by quadrature filters according to the frequency input to produce quadrature signal components. The square of the magnitude of the input signal is computed from the quadrature signal components, as well as the phase ratio and sign, for comparison with calculated values. When enabled by the magnitude of the input signal, a phase crossing determinator compares the phase ratio and sign with calculated values to determine the phase crossing to generate a trigger, resulting in successive acquisitions of the input signal being in time alignment.

Abstract: A representative digital circuit of the invention has an on-chip, non-volatile memory, to which chip-specific speed-binning data that characterize performance of the digital circuit are written during production testing. During normal operation, the power controller that controls power-supply signals applied to the digital circuit reads the speed-binning data from the on-chip memory for use as input parameters for dynamic supply-voltage scaling, dynamic clock scaling, and/or adaptive power control that optimize (e.g., minimize) power consumption in the digital circuit. Advantageously over the prior art, the accuracy and efficiency of dynamic and/or adaptive power control arc improved because the chip-specific speed-binning data enable the power controller to better customize the power-management algorithm for the given digital circuit.

Abstract: A frequency offset estimating apparatus includes an nth power computing module and a spectrum analyzing module. By raising a received signal to nth power to generate an nth power signal and analyzing the spectrum of the nth power signal, the present invention is capable of quickly and accurately estimating a frequency offset of the received signal. As being unaffected by channel characteristics, the estimating frequency offset apparatus is suitable for all channel environments.

Abstract: A system and method for synchronizing otherwise independent oscillators private to I2C Bus slave devices. An I2C Bus master device can issue two new general call commands, CALIBRATE and ZERO COUNTERS. The I2C Bus slave devices respond to the CALIBRATE command by counting the number of cycles its local, private oscillator makes through during the communication transfer period of the CALIBRATE command on the I2C Bus. All such I2C Bus slave devices measure the same communication transfer period on the I2C Bus, so the differences in the digital measurements obtained by each of them are proportional to their respective oscillator frequencies. The digital measurements are privately used by each I2C Bus slave device to calculate appropriate oscillator prescale factors, and to automatically load the values that will harmonize the final product frequencies of all of the local oscillators on all of the I2C Bus slave devices in the system.

Abstract: A method and system for continuously predicting an input line power waveform frequency of alternating current having maximum and minimum values, and a reference value located therebetween by specifying an outer window defining a sense point of the waveform between lower and upper limits of the outer window, the sense point being located away from the reference value and having a corresponding predicted sense point time; providing an inner window having an inner time interval less than an outer time interval corresponding to time between the lower and upper limits; positioning the inner window at the predicted sense point time; identifying an actual sense point time of a measured inner sense point value and excluding one or more identified actual outer sense point values being both outside of the inner time interval and within the outer time interval; and calculating the frequency of a future cycle of the waveform.

Abstract: A load shedding system and method for controlling imbalances in a power system includes a signal generator adapted to generate a signal representative of a local system, and a modifying circuit adapted to adjust set frequencies. The system also includes a processing circuit adapted to process data received from the signal generator and modifying circuit and set load shedding priorities for the local system based on the processed data.

Abstract: System and method implementations for testing a cooling fan in an electronic device are disclosed. As one example, a method of testing a cooling fan of a sample electronic device is disclosed that includes generating an audio input at an audio speaker and receiving an audio output at an audio microphone to obtain an audio output signal. The method further includes processing the audio output signal to identify frequency modulation in the audio output signal, and identifying a state of motion of fan blades of the cooling fan based, at least in part, on the frequency modulation.

Abstract: A method and device characterize linear properties of an electrical component having n>1 ports. The linear properties of the component are described in a matrix relating a voltage applied to the ports to a current through the ports. A frequency dependence of the matrix is approximated to preserve eigenvalues of the matrix by a pole-residual model. The method includes: (a) obtaining a set of values of the matrix at discrete frequencies, and obtaining eigenvalues and eigenvectors for each value; (b) fitting a set of vector equations to the eigenvalues and eigenvectors with a first set of pole frequencies; and (c) calculating a second set of pole frequencies by a vector fitting process for all modes of an element of the matrix. Steps (b) and (c) are repeated using the second set of pole frequencies in step (c) in a subsequent step (b) until a stop condition is met.

Abstract: Frequencies of plural peak signals which appear in a band ½ of a sampling frequency are detected from a spectrum obtained from a measuring target signal sampled with the sampling frequency in order to detect the repetition frequency of the measuring target signal having plural harmonic components with a similar power. Each of the plural peak signals is successively assumed to be a fundamental wave beat component originating from the fundamental wave of the measuring target signal and theoretical frequencies of harmonic beat components originating from harmonic components of the measuring target signal are successively calculated. The theoretical frequencies are compared with the frequencies of the plural peak signals to determine one of the plural peak signals as a fundamental wave beat component originating from the fundamental wave of the measuring target signal.

Abstract: Data analysis systems and related methods. An implementation of a method of determining a relationship between a variable of interest and one or more process variables represented by a corresponding plurality of tags may include accessing a data historian including historical data including a variable of interest and a plurality of tags. The method may include defining a plurality of bins, retrieving historical data corresponding with the plurality of bins using the data historian, filtering the historical data for each of the plurality of bins using one or more filters to produce filtered historical data, generating an output display using the filtered historical data for the variable of interest and each of the plurality of tags, and determining which of the plurality of tags correlate with the variable of interest using the output display. The output display may include an overlay CUSUM chart and a correlation plot.

Abstract: First and second devices having clocks which may have different clock rates. Obtaining a measure of the distance of propagation of a signal passing between the devices involves transmitting a first signal 12 from the first device to the second device. After a turnaround time TAT, a second signal 14 is transmitted from the second device to the first device. Any error in the clocks may lead to an error in the measurement of the turnaround time TAT. One device contains circuitry to calculate the ratio of the clock rates of the first and second devices, either by adjusting frequency divider ratios until there is LO frequency match, or by determining the offset frequency of an envelope of a mixed signal. The ratio of the clock rates is used to compensate the turnaround time TAT, to mitigate error. The accurate distance measurement can be used to determine if a relay attack has taken place in a vehicle security system.

Abstract: The invention relates to a frequency measurement apparatus which is arranged in such a way as to obtain an amplitude, chord length and rotation phase angle of a voltage rotation vector by means of an integration method, and furthermore, obtain a change rate of the rotation phase angle, and a rotational acceleration change rate of the rotation vector, and measure a dynamic frequency by determining a frequency change rate for every step.

Abstract: A method and system for estimating a magnitude of extremely rare events upon receiving a complete data sample and a specific exceedance probability are described. A distribution is chosen for a complete data sample. An optimal subsample fitted to the distribution is obtained. The optimal subsample is a largest acceptable subsample. A subsample is considered as an acceptable subsample when a goodness-of-fit test on the subsample is satisfactory (i.e., higher than a predetermined threshold). In addition, if a tail measure of an acceptable subsample lies outside a confidence interval of any smaller acceptable subsample, the acceptable subsample is considered as an unacceptable. Based on the optimal subsample and an inputted exceedance probability, a quantile estimate is computed, e.g., by executing an inverse of a cumulative distribution function of generalized Pareto distribution.

Abstract: The condition of a structure using remote interrogation of a multi-state passive wireless antenna sensor that has a known resonant frequency when mounted on the structure. The passive wireless antenna sensor is connected to a remotely operated switching circuit that includes a photocell. An interrogation system transmits a series of radio frequency signals with sweeping frequencies around the known resonant frequency to the passive wireless antenna sensor, while simultaneously pulsing a laser to switch the passive wireless antenna sensor between a first state and a second state in which it is exposed to open-circuit or short-circuit conditions. A signal is reflected from the passive wireless antenna sensor in each of the first and second states, and a resonant frequency of the passive wireless antenna sensor is determined by normalizing the received signals to isolate the antenna mode.

Abstract: A variable speed drive for an electric motor has an inverter for receiving pulse width modulation controls. The inverter communicates power signals to a poly-phase electrical motor. A resolver communicates signals from the poly-phase motor back to a motor control. The motor control includes a speed control, a field-oriented control, and a pulse width modulation drive for driving the inverter. The resolver is connected to the speed control and to the field-oriented control, and further communicates with a synchronous compensator. The synchronous compensator is configured to drive the harmonic content at a target frequency or frequencies in a selected signal towards zero over time.

Abstract: Various aspects of the present invention are shown and described, each of which has stand alone utility in a navigated medical environment. A receiver position calibration system and method facilitates calibration of a reference frame prior to each navigated procedure. A concept and application of confidence weights is introduced. Confidence weights can be applied to distance calculations to mitigate the effects of interference and increase the tolerance of the navigated medical system. Multi-path interference is minimized through the transmission of a signal having a pattern of unique frequencies and filtering of the distance calculations for each frequency to identify the ‘best’ distance in the presence of multi-path interference. A position determination method and system that transmits a signal having multiple frequency components permits positions to be identified with high resolution over a large area.

Abstract: A system and methods for determining points for an algorithm to calculate the frequency of a waveform measured from a monitoring device. Data points are measured from the waveform. A last point of interest from the previous cycle of the waveform is referenced. Four points of interest at equally spaced phase angles from the current cycle of the waveform are determined by calculating the average of the data points around each of the respective equally spaced phase angles of the current cycle of the waveform. The average value of the points of interest in the current cycle is subtracted from the four points of interest and the last point of interest from the previous cycle to compensate for DC bias. A frequency of the waveform is determined based on the determined four points of interest of the current cycle and the last point of interest from the previous cycle. The correction factor for determining sample frequency may be reduced for subsequent cycles in order to increase stability.

Abstract: Systems and methods for estimating a physical characteristic of a seafood product are provided. In one system, the estimate is based on a slope defined by a ratio of changes in peak resonant amplitude and frequency of an electromagnetic resonant circuit in loaded and unloaded states. In another system, a first probe of a plurality of probes is driven with a test signal when the plurality of probes is loaded by a seafood product and the estimate is based on received test signals at one or more of the other probes. In another system, the estimate is based on the loading effect of a seafood product on an electromagnetic resonant circuit, which is also used to read an ID from an RFID associated with the seafood product. The systems and methods may be used for individual specimens, or to determine an average estimate for multiple specimens at one time.

Abstract: Real-time battery impedance spectrum is acquired using a one-time record. Fast Summation Transformation (FST) is a parallel method of acquiring a real-time battery impedance spectrum using a one-time record that enables battery diagnostics. An excitation current to a battery is a sum of equal amplitude sine waves of frequencies that are octave harmonics spread over a range of interest. A sample frequency is also octave and harmonically related to all frequencies in the sum. The time profile of this signal has a duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known and octave and harmonically related, a simple algorithm, FST, processes the time record by rectifying relative to the sine and cosine of each frequency. Another algorithm yields real and imaginary components for each frequency.

Abstract: A self check-type flame detector includes a casing provided with a monitoring window formed therein. A wavelength generation unit is disposed inside the casing and generates a wavelength in a direction of the monitoring window. A wavelength detection element is disposed inside the casing and detects the wavelength. A comparison unit is provided with a wavelength DB for storing intensity of a reference wavelength and determines whether the monitoring window has been contaminated. A display unit is located outside the casing and displays a state of the monitoring window. A communication unit is disposed inside the casing and configured to receive operation information for the wavelength generation unit, to provide the operation information to the wavelength generation unit, and to transmit the intensity of the wavelength, or a normal signal or a contamination signal of the monitoring window.

Abstract: Independent frequency measurement and tracking of a signal using a measurement interval where the frequency of the signal is measured and a sampling rate is calculated, and a settling interval where the frequency of the signal is not measured. The sampling rate is calculated to correspond with the frequency of the signal and updated only after the calculation of the sampling rate in the measuring interval. The signal may be a signal of an electric power system such as a voltage waveform or a current waveform. The frequency calculation may include determination of a rate of rotation of a positive-sequence phasor of the signal.

Abstract: A system and method for determining a received signal frequency by sampling the received signal at a rate less than twice a predefined nyquist rate. The system includes a distorting component configured to distort the received signal in a frequency dependent manner, at least one analog to digital converter configured to sample the received signal and the distorted signal at a rate less than twice a predefined nyquist rate, and a processing component configured to determine a frequency of the received signal based on the sampled received signal and the sampled distorted signal. The method includes distorting the received signal, sampling the received signal and the distorted signal at a rate less than twice a predefined nyquist rate, and determining a frequency of the received signal. In an embodiment, distorting includes at least one of distorting an amplitude or a group delay of the received signal.

Abstract: Apparatus for registering the spectral signature of a dynamic source event include an imaging-sensor array configured to register electromagnetic energy over a predetermined range of electromagnetic wavelengths and an optical system configured for imaging onto the imaging-sensor array a dispersion pattern of electromagnetic energy emitted from a source event external to the optical system. The optical system includes (i) a focusing element and (ii) a selected set of optical dispersion apparatus.

Abstract: The invention as disclosed is of a method to authenticate identify and trace sonar transmissions and echoes by embedding transparent, secure and robust digital watermarks in signal space, where the additional information incurs no cost in bandwidth. The complex short time Fourier transform is selected as the domain for embedding the digital watermark, secured by a secret key, in the time frequency representation of the signal. The watermark is designed through an iterative optimization step. This step insures that the watermarked sonar is also realizable. Selection of the time frequency region for watermarking is driven by avoidance of interference with the sonar itself, or in case of network operation, other watermarks. In addition, the selected time-frequency region remains robust to sound channel and other transmission effects. Sonar echoes are authenticated in the time-frequency plane by a correlation receiver tuned to the watermarked region using the secret key.

Abstract: Disclosed is a method of signal detection. A received input signal is divided into a frame unit and each input signal present in a first frame and a second frame is transformed into a frequency signal. Then, first power spectrum information and second power spectrum information are computed utilizing the transformed frequency signal and a delta spectrum entropy value corresponding to a difference of the two computed power spectrum information is obtained. A predetermined input signal is included in a predetermined frame among the input signal after judging through comparing the delta spectrum entropy value with a critical value. Desired signal can be detected in a noisy environment including a noise signal by using the delta spectrum entropy value.

Abstract: Various embodiments of the present invention provide systems and methods for servo data based harmonics calculation. For example, a circuit for determining harmonics is disclosed that includes an analog to digital conversion circuit that provides a series of digital samples corresponding to a pattern within a servo data region of a storage medium, and a harmonic calculation circuit. The harmonic calculation circuit is operable to calculate a first harmonic value for the series of digital samples, calculate a second harmonic value for the series of digital samples, and calculate a ratio of the first harmonic value to the second harmonic value.

Abstract: A remote engine start confirmation and vehicle monitoring and control system includes a transmitter and a controller capable of receiving and processing transmitter signals, the controller comprising a monitoring circuit for detecting a first pulsed voltage pattern and a second pulsed voltage pattern across the battery during an engine start procedure, a signaling circuit for signaling the disengagement of the starter from the engine after a detection of the termination of the first pulsed voltage pattern and the start of the second pulsed voltage pattern, and an initiation circuit for initiating the monitoring of a vehicle condition, such as overheating or low fuel, after the detection. A method for controlling the vehicle operation includes detecting an occurrence of a vehicle condition and performing an operation based on the detection, such as terminating ignition voltage or fuel supply or notifying the operator of the vehicle condition via the transmitter.

Abstract: A method includes ascertaining harmonic components of a periodic analog signal at a fundamental frequency which changes over time. The signal is digitized and fast Fourier transformed. A target signal is produced by modulating the signal using a first carrier frequency to form two frequency sidebands, the first carrier frequency being greater than the fundamental frequency of the signal. One of the two frequency sidebands of the modulated signal is filtered. The filtered frequency sideband is modulated using a second carrier frequency forming two frequency sidebands. The second carrier frequency is greater than the fundamental frequency of the signal. The difference between the second and first carrier frequencies is the same as the difference between the fundamental frequency and the target fundamental frequency. One of these two frequency sidebands is output as the target signal to calculate the fast Fourier transformation.

Abstract: A system and method for acquiring phasors outside of the frequency tracking range for power protective relays. As the frequency of a power system varies from the rated frequency, phasors calculated from such samples include errors. A frequency tracking range is used to sample the signal waveform at a rate corresponding to the frequency when the frequency is within the frequency tracking range. When the frequency is outside of the frequency tracking range, the signal waveform is sampled at a rate corresponding with the maximum or minimum of the frequency tracking range depending on whether the frequency exceeds or falls below the frequency tracking range. The difference between the frequency and the minimum or maximum of the frequency tracking range is used to correct the measured phasors to result in accurate phasors.