72 results about "Variable window" patented technology

A method and system for processing radar data obtained from a platform which is subjected to non-uniform movement, the distance the platform travels during the formation of an image comprising an aperture; the system comprising software programming for performing a subroutine for building up an average pulse representing a single point on the aperture; the subroutine comprising the steps of inputting radar data from a radar antenna; passing the radar signal through low noise amplifier to reduce impact of electronic noise from the radar system; down converting the signal with a mixer to obtain a lower frequency; filtering out harmonics from the higher frequency range; sampling the radar data using an analog to digital converter at least at Nyquist down range frequency; based upon the IF of the radar; determining a scene center (center of SAR imagery) for the purpose of motion compensation; performing a two stage averaging scheme of the received signals with a variable window function; determining a window function based upon the velocity and acceleration of the platform and scene center; the window function comprising a first stage window; coherently averaging N pulses together to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon both the GPS and inertial navigational system; summing the average pulses using low pass filter; the software programming operating to repeat the step of building up an average pulse a first predetermined number of times for a time period that is less than the Nyquist sample time interval; the software programming operating to repeat the step of building an average pulse for a predetermined number of times to generate a second predetermined number of average pulses; the software programming operating to perform a two dimensional inverse Fourier transform to obtain SAR image; outputting the SAR image on a display screen; and a display for displaying the outputted SAR image.

The invention provides transducer arrays which are capable of outputting sound beams having a relatively constant width, and with minimal sidelobes, across a range of frequencies. This is achieved by utilising one or more digital signal modifiers within the signal path between the input sound signal and the array of transducers. Variable window functions are also disclosed.

The invention belongs to the technical field of vision measurement, in particular to an automatic focusing method. In the method, an idea, which comprises that an image definition evaluation function is designed on the basis of improved discrete cosine transformation (DCT) to represent detail information of the image and highlight high frequency energy, and the relative definition is brought in by consideration of a close relation between the definition of the image and the brightness and the gray scale of the image, is provided. Meanwhile, in the method, a scale-variable window selecting scheme is provided on the basis of analyzing the influence from the selection of a focusing window on a focusing result. Experimental results show that the effect of the improved image definition judgment is improved greatly; in the actual application of the method, a partial extreme value of the image definition judgment is hard to avoid, so, by combining return information of a lens, an improved climbing method search strategy of total-range rough adjustment large step length focusing and partial refine adjustment small step length focusing is provided; and in the method, a scheme of starting automatic focusing when a shooting scene is changed or the lens is zoomed is provided.

A method and system for processing radar data obtained from a platform which is subjected to non-uniform movement, the distance the platform travels during the formation of an image comprising an aperture; the system comprising software programming for performing a subroutine for building up an average pulse representing a single point on the aperture; the subroutine comprising the steps of inputting radar data from a radar antenna; passing the radar signal through low noise amplifier to reduce impact of electronic noise from the radar system; down converting the signal with a mixer to obtain a lower frequency; filtering out harmonics from the higher frequency range; sampling the radar data using an analog to digital converter at least at Nyquist down range frequency; based upon the IF of the radar; determining a scene center (center of SAR imagery) for the purpose of motion compensation; performing a two stage averaging scheme of the received signals with a variable window function; determining a window function based upon the velocity and acceleration of the platform and scene center; the window function comprising a first stage window; coherently averaging N pulses together to create an average pulse; performing an inverse Fourier transform; compensating to the scene center by multiplying by a complex exponential based upon both the GPS and inertial navigational system; summing the average pulses using low pass filter; the software programming operating to repeat the step of building up an average pulse a first predetermined number of times for a time period that is less than the Nyquist sample time interval; the software programming operating to repeat the step of building an average pulse for a predetermined number of times to generate a second predetermined number of average pulses; the software programming operating to perform a two dimensional inverse Fourier transform to obtain SAR image; outputting the SAR image on a display screen; and a display for displaying the outputted SAR image.

A method for measuring physician efficiency and patient health risk stratification is disclosed. Episodes of care are formed from medical claims data and an output process is performed. Physicians are assigned to report groups, and eligible physicians and episode assignments are determined. Condition-specific episode statistics and weighted episode statistics are calculated, from which physician efficiency scores are determined.

The invention discloses an innovating experiment platform for the machine vision teaching, which comprises a machine case, a power button, a speed adjustment knob, a photoelectric sensor, a motor, a transmission mechanism, an inspection table base, an annular light source, a camera, a camera bracket and an image processing unit, wherein, the power button controls the power supply of the whole system, a variety of arithmetics used for realizing the machine vision teaching innovating experiment are arranged in the image processing unit, an mage processing software platform comprises a code window, a parameter window, an image window and a variable window; twenty innovating experiments with different difficulty degree are provided, which comprises ten image measuring and treating foundation experiments, five pattern recognition experiments and five machine vision field study hot point problems. Through the experiments, students can thoroughly understand and firmly grasp the basic theoretical knowledge relative to the machine vision, image measuring and pattern recognition aspects, and has direct experience to the product vision detection and determination simulation process of an industrial automatic production line and improves the ability of independently solve the technical difficult problem.

The invention provides a synchronous phasor measurement method based on a self-adoption variable window, which is used for the field of a synchronous phase measurement of a power system. When being variable, a signal frequency is measured in real time, and the signal frequency in the next sampling time is estimated. The method used by the invention is used for keeping a sampling frequency unchanged rather than adjusting the sampling frequency fs. A data length N belonging to current calculation can be automatically adjusted according to an estimation frequency, so as to keep N*Ts=T (Ts=1/fs is a fixed sampling period, fs is the sampling frequency, T=1/f is an actual signal period value, and f is a signal frequency). Thus, the error compensation precision is improved; the frequency estimation precision is greatly improved. The synchronous phasor measurement method provided by the invention is applicable to synchronous phasor measurement calculation and frequency calculation correction in a ship power system.

Method, system and article of manufacture for monitoring variables. In one embodiment, information generated by a compiler is used to determine which variables need to be updated when performing a step, a “run to cursor” operation, and when a breakpoint is hit. This may be accomplished by providing as debugger data which variables may be affected at each statement of a program and a control flow graph for the program or procedure. The information about which variables may be affected can be stored as individual variables or sets of variables. When execution of the program being debugged is halted, only those variables whose values may have changed are refreshed in a variables window of a user interface.

Systems and methods are used to rapidly screening samples. A fast sample introduction device that is non-chromatographic is instructed to supply each sample of a plurality samples to a tandem mass spectrometer using a processor. The fast sample introduction device can include a flow injection analysis device, an ion mobility analysis device, or a rapid sample cleanup device. The tandem mass spectrometer is instructed to perform fragmentation scans at two or more mass selection windows across a mass range of each sample of the plurality of samples using the processor. The two or more mass selection windows across the mass range can have fixed or variable window widths. The tandem mass spectrometer can be instructed to obtain a mass spectrum of the mass range before instructing the tandem mass spectrometer to perform the fragmentation scans.

The invention discloses a method and a device for estimating self-interference channel of CCFD (Co-frequency Co-time Full Duplex) system based on variable window length. The method comprises the following steps: S1, designing pilot symbols orthotropic at near end and far end; S2, receiving a pilot vector of base band interference signal and performing FFT (Fast Fourier Transform Algorithm) conversion on the pilot vector so as to obtain a frequency-domain received interference signal pilot vector Y; S3, performing LS (Least Squares) estimation on Y so as to obtain an LS estimation output vector; S4, performing IDFT (Inverse Discrete Fourier Transform) conversion on the LS estimation output vector so as to obtain a time-domain signal vector; S5, performing time-domain windowing on the time-domain signal vector; S6, performing DFT (Discrete Fourier Transform) conversion on the time-domain signal vector after being windowed. The method and the device solve the problem that the channel estimation precision is worsened since the traditional LS channel estimation is free of nose filtering capacity, the noise effect is fully filtered under the precondition that the channel energy is conserved as much as possible, and the estimation precision of interference channel is improved.

The invention discloses a multiple-inverter parallel control method for quickly restraining harmonic circulating current. The method comprises the following steps: obtaining harmonic circulating current of output current of inverters by adopting an ip-iq algorithm, reversing the phase of the harmonic circulating current to be superposed to a voltage loop to be output to obtain an instruction of a current regulating loop, so that the harmonic circulating current of the output current of the inverters can be efficiently and quickly restrained, and the fact that the harmonic circulating current is restrained through parallel connection of multiple inverters is realized. The invention further provides a variable-window computing method for the moving average power to improve the average power calculation, reduce deviation caused by conventional fixed period calculation and improve the calculating accuracy for average power; with the moving average calculation, the average power can be calculated once in each sampling period, so that the real-time property for power calculation is greatly improved, the power sharing can be well realized through performing droop control on power, the harmonic circulating current can be further reduced. The multiple-inverter parallel control method for quickly restraining the harmonic circulating current can be widely applied to a multiple-inverter parallel control system of a microgrid, and especially suitable for a microgrid with nonlinear load operation.

The invention discloses a data similarity detection method based on a sliding window, which comprises the steps that S1, an empirical vector G of an attribute is computed by a ranking method; S2,a statistic vector C of the attribute is computed by a mathematical statistic method; S3, the empirical vector G and the statistic vector C are integrated, and a final weight vector W is computed; S4, a window upper bound of a queue of sizes of variable windows is computed; S5, a plurality of threads are created according to the number of the attributes; S6, a record set is scanned sequentially in each thread, and a similarity degree of a current record and a record in the variable queue is computed; and S7, duplicated record sets detected from the threads are merged. Multi-round detection is replaced by the detection algorithm based on multithread concurrence, so that the detection efficiency is improved, and the detection time is saved.

An apparatus and method for turbo decoding using a variable window size. A control logic block receives information about a code rate of received data bits and a data block size, adjusts a window size according to the code rate information, and computes an initial delay. Delta metric blocks compute delta metrics from input data bits of the block size, wherein the delta metrics represent a transition probability for a path from a state to another state, respectively. An alpha metric block receives a delta metric in synchronization with the initial delay, and computes an alpha metric representing a forward state transition probability in each state. One or more beta metric blocks receive delta metrics according to the adjusted window size, and compute beta metrics representing a backward state transition probability in each state, respectively. A log likelihood ratio (LLR) block receives the alpha metric and the beta metrics in synchronization with the initial delay, and computes LLR values for symbols in an ending state. Code reliability is maintained by using a sliding window structure based on a window size varying with a code rate, while simultaneously reducing a decoding time due to an unnecessary initial delay.

A multi-target tracking method based on variable processing windows and variable coordinate systems includes: step one, performing an initialization process; step two, constructing a space-time processing block for the k frame image; step three, solving a position energy density of the space-time processing block constructed in the step two; step four, extracting position parameters of all targets in the k frame image; step five, matching the target with the position parameter in each processing block to obtain a position observed value Z (k+1) of each target; step six, calculating target speed parameters with the Kalman filter algorithm with weighted gain to reduce calculated amount, amending the position observed value of each object, and strengthening accuracy and robustness of the tracking; and step seven, calculating the motion scale of each target in the k frame image. According to the multi-target tracking method, the variable window, variable projection method and Kalman motion estimation are introduced on the basis of continuous wavelet transform and expectation maximization (EM) fitting algorithm, motion parameters are accurately extracted; and calculated amount is reduced; and accurate tracking of a plurality of motion targets is achieved.

The invention discloses a method for identifying the image authenticity. The method comprises the following steps: step 1, performing computer generated feature detection on an image to be detected; step 2, performing color interpolation filter detection on the image passing the computer generated feature detection, if a detection value is greater than a threshold, judging the image as an unreal image, and if the detection value is smaller than a passing threshold, executing the step 3; step, performing the detection based on a variable window on the image passing the color interpolation filter detection, if a detection value is greater than the threshold, judging the image as the unreal image, and if the detection value is smaller than the passing threshold, executing the step 4; step 4, performing the detection based on a sliding window on the image passing the color variable window detection, if a detection value is greater than the threshold, judging the image as the unreal image, and if the detection value is smaller than the passing threshold, executing the step 5; step 5, performing consistency detection on the image, if a detection value is greater than the threshold, judging the image as the unreal image, and if the detection value is smaller than the passing threshold, judging the image as a real image.

The invention discloses a self-adaptive window switching method based on the TDA domain, belongs to the field of audio encoding, and particularly relates to a processing method used after performing time domain aliasing (TDA) on audio transient signals. The method is characterized in that detected time domain transient signals are mapped to the TDA domain after time domain aliasing, time-frequency analysis of variable window length can be executed on TDA domain signals by aid of a self-adaptive window switching method, different window switching modes can be selected according to TDA domain transient position and time-frequency analysis effect so as to realize switching and transiting of sub-frames with different lengths, and then a window switching mode of the TDA domain is selected by adopting a strategy of combining an open loop and a closed loop. By aid of the method, self-adaptive window switching aiming at TDA domain signals can be achieved to select the optimum time resolution, the pre-echoes distortion of the transient signals is avoided, and simultaneously fine time-frequency analysis results can be kept, thereby being favorable for increasing audio encoding quality on complex conditions such as mixing of transient and steady and the like.

The invention discloses an infrared focal plane detector blind pixel correction method. The method comprises the following steps: calculating an image pixel I, which serves as a center, and an initial window n*n(n=3) formed by surrounding pixels; calculating a window median M, and judging whether the I-M is larger than a preset threshold value v_thd; if I-M>v_thd fails, judging whether n is larger than a preset threshold value n_thd, and if n >n_thd, judging the point is a non-blind pixel, and turning to a next pixel point; if n >n_thd fails, enlarging the window n*n(n=n+2), and calculating the window median M; if I-M> v_thd, skipping to the next step; enlarging the window n*n(n=n+2), and calculating the window median M1; and judging whether the I-M1 is larger than the v_thd, if not, judging the point is a non-blind pixel, and if so, judging the point is a blind pixel, using M to replace the pixel and turning to the next pixel point. The basic idea is a variable window blind pixel elimination method; and the method, based on characteristics of blind pixels in the practical application, does not need to store the blind pixel information, and can finish correction of all blind pixels without iteration for any qualified detector at any time.

The invention discloses a VoIP service security assurance method and system based on a scale variable window mechanism. The method comprises the following steps: a voice sending end (sender) launches conversation request to a voice receiving end (receiver), and builds safety conversation after bothway verification through an agent end, the sender sends the voice, which is encrypted through the encryption module, to the receiver, the receiver decrypts the encrypted voice and sends the voice to a voice quality assurance module, and the voice display time is adjusted through the caching technology based on the scale variable window, so as to guarantee the display quality of the voice; the system comprises the voice sending end (sender), a voice sending end proxy server (proxy 1), a voice receiving end proxy server (proxy 2), the voice receiving end (receiver) and a private key generator; the voice sending end (sender) comprises a safety SIP conversation module (SSM) and a voice encryption/decryption module (VEM), the voice receiving end (receiver) comprises an SIP conversation module (SSM), a voice encryption/decryption module (VEM) and a voice quality guarantee module (QEM); the method and system can effectively improve VoIP communication safety and communication quality.

An automatically controlled X-ray irradiation field limiting device includes a main body disposed in front of an X-ray generator for generating X-rays, an X-ray irradiation field limiting unit mounted to the main body and configured to adjust an X-ray irradiation field formed by the X-rays generated from the X-ray generator in accordance with an opening area of a variable window, a drive unit configured to operate the X-ray irradiation field limiting unit to adjust the X-ray irradiation field, a light irradiation field device mounted inside the main body and configured to form a light irradiation field, a distance information acquiring device mounted on the main body and configured to measure and acquire a distance between a focus of the X-ray generator and the subject, and a controller configured to control an operation of the drive unit based on the distance received from the distance information acquiring device.

The invention discloses a method and a device for estimating a blind signal bandwidth. The method comprises the following steps of: transforming a received signal according to a preset discrete Fourier transformation (DFT) point number; acquiring a mid-value bandwidth DFT point number corresponding to a bandwidth mid-value in a signal bandwidth range required by a system and calculating to obtainan initial sliding window length according to the mid-value bandwidth DFT point number; smoothing a DFT transformation result by using the initial sliding window length to obtain an estimated value of an initial bandwidth DFT point number; comparing the estimated value of the initial bandwidth DFT point number with the mid-value bandwidth DFT point number and selecting a window length factor according to a comparison result; acquiring a variable sliding window length processed by the window length factor; processing the DFT transformation result according to the variable sliding window length; and acquiring an estimated value of a signal bandwidth. In the method for estimating the blind signal bandwidth disclosed by the embodiment of the invention, the variable window length is adjusted by increasing the size of an initial estimated bandwidth of an input signal and the input signal is further smoothed, so that an estimated result is more accurate and accuracy is improved.