33 results about "Time domain" patented technology

A drive circuit is provided for an OLED pixel display. The drive circuit is adapted for use with a reference voltage source. It includes a first transistor and an OLED. The output circuit of the first transistor is operably connected between the reference voltage source and the OLED. Transmission gate means responsive to a control signal are provided to transmit a data signal to the first transistor. Means are provided for controlling the first transistor in accordance with a time domain modulation signal to provide an average current to the OLED which is a function of the data signal.

A towrope type ocean controllable source electromagnetism and earthquake data collection system is composed of electric field sensors (non-polarized electrodes) distributed in three or more towropes uniformly or not, three-component induction coil type or three-component fluxgate type magnetic field sensors and sonic sensors composed of hydrophones or accelerometers and is used for measuring ocean three-component magnetic-field components, electric field components EX distributed in the cable direction, electric field components EY distributed in the vertical cable direction and ocean earthquake data. The towrope type ocean controllable source electromagnetism and earthquake data collection system can collect ocean electromagnetism data and ocean earthquake data in the time domain and the frequency domain at the same time, increase the collection quantity of ocean geophysics data of advancing construction at a time in a multiplying mode, effectively improve the target detection precision and explore and evaluate ocean mineral products, oil and gas resources and methane hydrates through combination and comprehensive application of ocean controllable source time-frequency electromagnetism and the earthquake exploration technology.

The normalized iterative soft interference cancellation signal detection method relates to a signal detection method of multiaerial wireless communication system iterative receiver. Said detection method is characterized by that it makes the received multiaerial signal undergo the processes of interative detection, decoding and receiving treatment based on iterative soft interference cancellation detection. Said invention also provides the equipment for implementing said detection method.

The invention provides a behavior recognition method and system based on an attention mechanism double-flow network, and belongs to the technical field of behavior recognition, and the method comprises the steps: dividing an obtained whole video segment into a plurality of video segments with the same length, extracting an RGB image and an optical flow gray-scale image of each frame of each videosegment, and carrying out the preprocessing of the RGB images and the optical flow gray-scale images; carrying out random sampling on the preprocessed image to obtain an RGB image and an optical flowgrayscale image of each video clip; extracting appearance features and time dynamic features of the sampled images by using a double-flow network model introducing an attention mechanism, fusing the appearance features and the time dynamic features according to the types of a time domain network and a space domain network respectively, and performing weighted fusion on a fusion result of the timedomain network and a fusion result of the space domain network to obtain an identification result of the whole video. According to the invention, the video data can be fully utilized, the local key features of the video frame image can be better extracted, the foreground area where the action occurs is highlighted, the influence of irrelevant information in the background environment is inhibited,and the behavior recognition accuracy is improved.

The invention relates to a spatial resolution calibration device and a spatial resolution calibration method for distributed fiber-optic sensing. The spatial resolution calibration device and the spatial resolution calibration method for the distributed fiber-optic sensing are easy to understand and operate; and the spatial resolution of various distributed fiber-optic sensors is objectively and accurately calibrated, and a reference is provided for the work such as apparatus selection and purchasing, performance evaluation, monitoring design, measurement and data analysis of a technician. The technical scheme is that: the spatial resolution calibration device for a distributed fiber-optic sensing demodulator is characterized by comprising a water bath which is divided into two parts, wherein one side of the water bath is a low-temperature tank, and the other side of the water bath is a high-temperature tank with a heater; a cover plate is arranged on the water bath; and a reel holder is vertically arranged on each of the two sides of a middle partition plate in the water bath. The device and the method are applied to the spatial resolution calibration of modulation apparatuses such as a Raman optical time-domain reflectometer (ROTDR) and a Brillouin optical time-domain analyzer (BOTDA)/Brillouin optical time-domain reflectometer (BOTDR).

The invention discloses a microphone array-oriented channel attention weighted speech enhancement method. The method comprises the following steps: respectively acquiring a path of noisy speech time domain signal from each microphone in a microphone array; constructing a multi-channel speech enhancement model; taking a short-time Fourier transform spectrum of each path of noisy speech of the microphone array as an input feature of a multi-channel speech enhancement model, and pre-training the multi-channel speech enhancement model; and inputting multiple paths of noisy speech acquired by the microphone array into the multi-channel speech enhancement model, and realizing microphone array speech enhancement by using the multi-channel speech enhancement model. According to the method, a UNETnetwork is adopted to process the voice frequency spectrum features, the parameter quantity is small, the calculation complexity is low, attention mechanism weighting operation is adopted for the channel dimension on the basis, attention weighting is carried out on each layer of encoder and decoder in the channel dimension, the features are weighted in deep structure simulation beam forming, and the performance of speech enhancement is improved.

A transmitter including a signal generator to generate an analytic signal in frequency domain, having frequency components that when converted to time domain result in a time domain signal with a preamble that includes a first half of containing non zero information and a second half containing only zero data. A shaper configured to generate a cyclic prefix including only zero data based on the second half of the preamble included in the time domain signal, and to attach the cyclic prefix including only zero data to the time domain signal to output a pilot signal that is to be transmitted via an antenna.

The invention discloses a stainless steel weld defect efficient detection method based on multi-domain expression data enhancement and model self-optimization. The method comprises the following steps: deriving a one-dimensional echo time domain signal to spatial domains such as a time-frequency domain, a Gramb angle field domain and a Markov transfer field domain; sequentially inputting the data set constructed by each spatial domain into the MobileNetV3 neural network, and selecting the spatial domain with the most abundant feature expression as a final training data set; constructing a multi-scale depth separable convolution to improve the MobileNetV3 so as to enhance the recognition performance of the network; providing a particle swarm-chaos sparrow search algorithm for automatic optimization of a network structure and parameters; and adopting the CPU + FPGA heterogeneous cooperative calculation to accelerate the reasoning and recognition application speed of the defects. Five types of weld defects such as incomplete fusion, air holes, slag inclusion, incomplete penetration and cracks are taken as objects, the recognition accuracy of the five types of weld defects can reach 98.75%, and the method has practical engineering application value.

The invention discloses a system information sending and receiving method and device in a digital audio broadcasting system. The method comprises the following steps of: when in sending, performing CRC (cyclic redundancy check) coding and channel coding on the system information to generate a coding bit stream; performing bit interleaving and constellation mapping on the coding bit stream to obtain a continuous pilot frequency including the system information; multiplexing a continuous pilot frequency signal with other signal elements of the system to obtain a frequency-domain signal of an orthogonal multiplexing structure according to a carrier allocation method stipulated by a frequency spectrum mode; converting the frequency-domain signal into a time-domain signal for sending; when in receiving, converting the time-domain signal into a frequency-domain signal; extracting the continuous pilot frequency including the system information from an effective carrier of the frequency-domain signal according to the position stipulated by the frequency spectrum mode; obtaining an estimated value of the system information through de-mapping, de-interleaving and channel decoding; and judging the correctness of the system information by use of CRC decoding, and outputting the system information. The method and device disclosed by the invention can improve the transmission robustness on the basis of guaranteeing the transmission efficiency of the system information.

The invention relates to a distribution equipment operation efficiency evaluation method involving reliability and economy, comprising the steps of: (1) determining upper and lower limits P2 and P1 of an economical operation interval; (2) rearranging distribution equipment time sequence load curves in order of size to obtain a load duration curve; (3) determining the supplied electric quantity S1 exceeding the upper limit P2 of the economical operation interval, the supplied electric quantity S2 in the economical operation interval, and the electric quantity S3 below the lower limit P1 of the economical operation interval; (4) determining the equipment lacked electric quantity S4 and equipment loss electric quantity S5; (5) determining the correction factor alpha of the GDP generated by each kilowatt-hour according to the GDP of the area where equipment is located, social electricity consumption per year and average retail price; and (6) determining equipment operation efficiency according to an equipment operation efficiency evaluation model. The method involves the factors of safety, reliability, economic operation, utilization rate and duration, and can more comprehensively evaluate the operation efficiency of distribution equipment in a full time domain.

The invention provides a pulse interference signal detection and suppression method. The method comprises the steps of: firstly judging whether there is pulse interference, calculating an interferencesuppression threshold if there is interference, and performing suppression processing on interference with the amplitudes of time domain sampling signals exceeding the threshold. Thus, the method cansuppress interference, reduce the influence of artificial or unintentional pulse interference signals on received signals and provide early warning for relevant apparatuses and products being used inan environment.

When a signal transmitted by orthogonal frequency division multiplexing is received, the received signal having been converted to a desired frequency is transformed by Fourier transformation (1); a sub-carrier frequency is divided into an even-number multiple sub-carrier component (D2) and an odd-number multiple sub-carrier component (D4) of a sub-carrier interval; the position of an impulse noise component is determined based on the size of electric power of front halves (D3p, D5p) and rear halves (D3q, D5q) of signals that have undergone reverse Fourier transformation (3, 5); and signals little affected by impulse noise are used to reconfigure a time domain signal (D) of even-numbered sub-carrier components and a time domain signal (D) of odd-numbered sub-carrier components, after which the signals are added (10), transformed again by Fourier transformation (11) and demodulated (12). The effects of impulse noise can be reduced to improve reception performance.

The invention discloses a similar k-line retrieval method and retrieval system for stock trend prediction. The method comprises the following steps: determining a first dimension of a search sequenceof candidate stocks; adjusting a second dimension of a target sequence corresponding to the target stock according to the determined first dimension; in a specified time domain, traversing k-line dataof all stocks in a first dimension of search sequence retrieval to obtain candidate sequences corresponding to a plurality of candidate stocks, and storing the candidate sequences; calculating the similarity between each candidate sequence and the target sequence, sorting the candidate sequences according to the similarity, updating a sorting result, and finally outputting a similarity calculation result. According to the method, the candidate stocks with the k-line similarity under different dimensions can be matched, and the intermediate result is calculated by utilizing the similarity, sothe complexity of k-line similarity calculation is reduced, the operation speed is increased, and the stock retrieval range is expanded.

The invention discloses a filter and a self-adaptive filtering method thereof and a computer readable storage medium. The self-adaptive filtering method comprises the steps: acquiring an expected signal and an input signal of the filter, and filtering the expected signal and the input signal to obtain an error signal; judging whether the filter converges or not; if the filter does not converge, obtaining at least one first filtering unit of the filter; and performing time domain constraint updating on the filtering parameters of the first filtering unit by utilizing the input signal and the error signal, and performing non-time domain constraint updating on the filtering coefficients of other filtering units of the filter by utilizing the input signal and the error signal. In this way, theoperation complexity of the filter can be reduced on the premise that the convergence rate and the steady-state error of the filter are guaranteed.

Disclosed are a receiving apparatus and a receiving method. More particularly, disclosed are a receiving apparatus and a receiving method in an OFDM system. The receiving apparatus in the OFDM system includes a receiver for receiving wireless signals transmitted through wireless channels, a transformer for transforming the wireless signals into signals of a frequency domain, an inverse transformer for inversely transforming reference signals into signals of a time domain based on a number of reference signals included in the signals of the frequency domain and an arrangement interval of the reference signals included in the signals of the frequency domain, and a determiner for determining a delay spread based on the inversely transformed signals of the time domain.

The invention discloses a non-contact heart rate variability feature extraction method based on a real application scene. The method comprises the following steps: 1) collecting an image containing a human face; 2) acquiring an image face area by using a face detection and tracking combined strategy; 3) enhancing skin color change through Euler amplification; 4) color space conversion and channel separation; 5) self-adaptive threshold skin detection; 6) extracting a source signal; (7) EEMD denoising; 8) carrying out five-point sliding smoothing filtering; 9) peak point detection and abnormal peak point correction; and 10) RR interval calculation and time domain, frequency domain and nonlinear HRV feature extraction. According to the method, the strategy for improving the feature extraction speed and the strategy for overcoming the influence of shaking and illumination and improving the feature extraction accuracy are integrated in the feature extraction method, the HRV features can be rapidly extracted in a non-contact mode in a real application environment, and it is guaranteed that the HRV features are consistent with contact type extraction results.

The invention discloses an electron spin emission based terahertz spectrometer and spectral analysis system. The terahertz spectrometer comprises a fiber femtosecond laser which enables femtosecond light at a spatial light output port to enter a transmitting end; coherent detection light of the fiber output port is input to a receiving end through an optical delay line; a sample holder is positioned between the transmitting end and the receiving end; the transmitting end is used for generating terahertz pulses based on the electron spin effect of a hetero-structure under the combined effect offemtosecond laser excitation and an internal magnetic field; and the receiving end is used for forming a current under the effect of the sample terahertz pulse electric field, measuring the intensityof a specific terahertz pulse waveform point location based on the magnitude of the current, and outputting the intensity to a data acquisition and processing module so as to perform spectral analysis. Thus, the key performance indexes of the bandwidth and dynamic range of the terahertz time domain spectrometer can be effectively improved, the reliability of the whole spectrometer is improved, and the research difficulty and cost are effectively reduced.

The invention discloses an acquisition method for a movable arm angle parameter of a vehicle-mounted hydraulic weighing device. In the method, an incremental photoelectric encoder is used for sensing change of a movable arm angle; a time domain for the change of the movable arm angle is determined through signal sampling point number and sampling frequency of a sensor of the weighing device, thereby determining the change rate of the movable arm angle; and a starting point and an ending point of the angle change are detected by taking a proximity switch as the photoelectric encoder. The method respectively comprises the following execution steps of: A, acquiring a movable arm angle change value; B, acquiring the sampling point number and the sampling frequency of the sensor; C, calculating the change time of the movable arm angle; and D, calculating the movable arm change angular rate. In the method, by acquiring the movable arm angle change rate, the weighing operation behavior of a driver is effectively regularized, so that the detection accuracy of the hydraulic weighing device is improved.

The invention discloses a channel estimation algorithm of an IQ imbalance OFDM system under a sparse environment. A pilot symbol passes through a channel under the IQ imbalance condition, and a receiving end signal is obtained. IQ imbalance is taken as a channel parameter to be brought in estimation, sparse characteristics are utilized, and a time domain channel impact response is estimated through a least square method. A proper threshold is determined by estimating noise variance, and noise within cyclic prefix length is filtered out. According to the threshold time domain least-square estimation method based on noise variance estimation, good compromise of performance and complexity is achieved, meanwhile, only one OFDM symbol is needed, the high spectrum utilization rate is achieved, and system error code performance can be effectively improved.

The invention discloses a video watermarking method based on the key frame selection and safe spread spectrum technology. The method comprises the following steps: for a target video, randomly and uniformly selecting a plurality of key frames in a time domain; and extracting a host signal from the selected key frames through transformation operation, and for each selected key frame, embedding watermark information into a set distribution area by using a spread spectrum watermark algorithm. The invention provides the safe and robust novel video watermarking technology, so that the embedded watermarking information is more robust to some common video processing technologies, noise and exchange, insertion and discard of video frames, and other people can be prevented from erasing the watermarking.

The invention provides an artificial neural network design method based on multi-domain learning, and belongs to the artificial intelligence technology. The method comprises the following steps: constructing a neural network suitable for a current task as a backbone network according to a target task; according to task characteristics or experimental results, selecting one or more orthogonal transformation domains except a time domain/space domain as target domains of multi-domain learning; constructing a multi-domain learning structure in a feature extraction part in the network; training the network on a selected data set to obtain a trained network model; and verifying the network model according to the verification set. According to the network design method, the image features are converted into the domain outside the time domain/space domain for learning, the cost problem of learning of a network model in a single domain is solved, the effect of the network model can be effectively improved, and the generalization ability of the network is improved.

The invention discloses a self-adaptive voice endpoint detection method. The method comprises the following steps: segmenting an input voice signal into a single-frame time domain signal; calculating time domain basic background energy, time domain maximum background energy, time domain final background energy and time domain voice existence probability; performing windowing processing and discrete Fourier transform on the single-frame time domain signal, and calculating the frequency domain voice existence probability; calculating an effective judgment probability according to the time domain voice existence probability, the frequency domain voice existence probability and the signal-to-noise ratio; and judging whether effective voice exists or not according to the effective judgment probability Pfinal. According to the method, the signal-to-noise ratio is used as a judgment condition for selecting time domain processing or frequency domain processing to judge whether voice exists or not, the problem that the requirement for high adaptability to a complex environment is difficult to meet in the prior art is solved, and the adaptability and robustness of an algorithm to the environment are improved.