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3709 results about "Wideband" patented technology

In communications, a system is wideband when the message bandwidth significantly exceeds the coherence bandwidth of the channel. Some communication links have such a high data rate that they are forced to use a wide bandwidth; other links may have relatively low data rates, but deliberately use a wider bandwidth than "necessary" for that data rate in order to gain other advantages; see spread spectrum.

Intelligent identification and grading early warning method, system and equipment based on mine production abnormity

The invention discloses an intelligent identification and grading early warning method based on mine production abnormity, and a system and equipment thereof. The method comprises the following steps: obtaining space-time evolution data, earth surface deformation data and environment monitoring data of rock mass stress in a target area; performing abnormal mode detection on the data by using a space-time convolutional network to obtain accident risk probability distribution data; using an ultra wide band positioning system to track the movement track of the person entering the target area in real time to obtain the movement track data of the person; and constructing a three-dimensional early warning index system in combination with the accident risk probability distribution data in the target area and a dynamic early warning mechanism, performing dynamic early warning grading on different positions in the target area by using the three-dimensional early warning index system, and generating a grading response strategy matched with the personnel activity trajectory data. According to the invention, the problems of incapability of tracking a personnel movement track in real time and low timeliness of mine production abnormity early warning are solved.
Owner:JIANGXI COPPER +1

Energy storage battery thermal runaway damage diffusion early warning method based on dynamic thermal model

The invention discloses an energy storage battery thermal runaway damage diffusion early warning method based on a dynamic thermal model, and relates to the technical field of battery safety monitoring, and the early warning method comprises the specific steps: multi-source parameter collection: arranging a plurality of sensors to collect data, and preprocessing and storing the data; thermal stress modeling is conducted, units are divided through a finite element method to calculate thermal stress, and structural damage is judged in combination with a damage threshold value; multi-physics field cooperative calibration is carried out, and characteristic quantity is acquired and substituted into a formula to correct thermal stress; dynamic thermal model construction: introducing thermal stress influence to construct a model containing a damage diffusion term; thermal runaway early warning judgment is carried out, a multi-dimensional index system is constructed, a risk value is calculated, and early warning is triggered; through a multi-source parameter acquisition technology, in combination with temperature, current, voltage, ultrasonic wave and broadband impedance multi-dimensional sensor data, and assisted by external condition monitoring of environment temperature and humidity, heat dissipation system flow and rotation speed, comprehensive perception of the working state of the battery is realized, and richness and accuracy of data acquisition are improved.
Owner:JIANGSU WEITENG ECOLOGICAL TECH DEV CO LTD

Broadband oscillation identification method and system based on multi-band Nyquist criterion

The invention discloses a broadband oscillation identification method and system based on a multi-band Nyquist criterion, and the method comprises the steps: dividing the frequency of broadband oscillation into a low frequency band, a middle frequency band and a high frequency band with overlapped frequency bands, and obtaining the oscillation signals of a monitoring node in a power grid in different frequency bands; respectively calculating the equivalent impedance of the non-overlapped frequency band of each frequency band and the equivalent impedance of the overlapped frequency band in the two adjacent frequency bands so as to construct the equivalent impedance of the low frequency band, the middle frequency band and the high frequency band with the overlapped frequency bands; establishing a Nyquist criterion of each frequency band based on a transfer function of dynamic characteristics of each frequency band in an open-loop state of the system; a generalized Nyquist criterion of the overlapped frequency bands is constructed by using the multi-frequency-band coupling matrix; constructing a comprehensive decision function according to the recognition result of the generalized Nyquist criterion on the system stability, the broadband oscillation comprehensive characteristic quantity and the change rate of the high-frequency-band impedance module value along with the frequency; and according to the value of the comprehensive decision function and a threshold value, a broadband oscillation identification result is determined, and the broadband oscillation identification capability is improved.
Owner:STATE GRID LIAONING ELECTRIC POWER CO LTD +1

Wideband / multiband add-on metasurface modules for enhanced noise suppression in server infrastructure

The technology described herein is directed towards modular metasurfaces arranged with unit cells for narrowband, wideband and / or multiband sound absorption, in which the unit cells are based on Helmholtz resonators that are deployed in a server rack, proximate to a server, without substantially obstructing airflow from the server fan(s). Each sound absorbing unit-cells is designed and constructed based on a specific resonance frequency, and includes a neck portion and air chamber dimensioned to resonate at the desired resonance frequency and thereby inverse phase cancel corresponding narrowband frequencies of incoming sound waves. Differently-dimensioned unit cells can be built into a single metasurface module, thereby facilitating wideband and / or multiband sound absorption with that metasurface. The modular metasurfaces can be attached to the sidewalls of a server rack, or positioned in otherwise empty slots above and below a server, optionally coupled to blanking panels for covering the openings of those slots.
Owner:DELL PROD LP

Combustion state monitoring method and system based on vibration and noise fusion analysis

The invention relates to the technical field of combustion equipment state monitoring, in particular to a combustion state monitoring method and system based on vibration and noise fusion analysis, and the method comprises the steps: collecting a combustion signal in real time through a vibration sensor and a broadband noise sensor, extracting a characteristic frequency band through noise reduction and filtering, and obtaining a combustion state; fPGA hardware-level clock synchronization is adopted to realize time alignment of bimodal signals, a vibration-noise joint feature matrix is constructed and multidimensional coupling is carried out, a combustion state feature vector is generated through a mixed deep learning model, a combustion state is determined based on a bimodal confidence weighting decision, and a linkage control instruction is generated during interruption. The system comprises a signal acquisition synchronization unit, a feature fusion and modeling unit, a state decision and instruction generation unit and a safety linkage execution unit, executes a method and activates a standby safety system, solves the problems of asynchronous bimodal data and insufficient monitoring precision, and improves the combustion state monitoring accuracy and safety response efficiency.
Owner:ZHONGXINRAN NEW ENERGY GROUP CO LTD

Unmanned aerial vehicle full-aviation electromagnetic emission system and control method

The invention belongs to the technical field of unmanned aerial vehicle full-aviation electromagnetic detection, and particularly relates to a full-aviation frequency domain electromagnetic emission system and a control method. A broadband frequency mixing and matching circuit is connected in series between an H-bridge power inverter and an emission coil of an unmanned aerial vehicle electromagnetic emission system; the broadband mixing and matching circuit comprises a first resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel and a second resonance unit formed by connecting a fixed capacitor and an adjustable inductor in parallel, and the first resonance unit and the second resonance unit are connected in series. The adjustable inductor is matched with the dynamic impedance of the inductive load by adjusting the inductance value, and the broadband frequency mixing and matching circuit can adjust the impedance in real time, so that the matching of different resonant frequencies is realized, and the frequency range of a matching signal can be obviously widened.
Owner:JILIN UNIVERSITY

Broadband wave-absorbing material based on MAX phase metasurface structure and impedance matching optimization method thereof

The invention discloses a broadband wave-absorbing material based on an MAX-phase metasurface structure and an impedance matching optimization method of the broadband wave-absorbing material. The wave-absorbing material comprises an MAX-phase ceramic substrate and periodic metasurface structures which are arranged on the surface of the MAX-phase ceramic substrate in an array mode and composed of conductive resonance units. The resonance units are isolated through gaps, an equivalent R1L1C1 series resonance circuit is formed in an electromagnetic field, and a base body is equivalent to a parallel resistor R2. By establishing an equivalent circuit model and optimizing parameters R1, L1, C1 and R2, impedance matching of the wave-absorbing material in a target frequency band can be regulated and controlled, so that the wave-absorbing material at least has an absorption peak of which the reflection loss is less than-10 dB. According to the optimization method, electromagnetic simulation and circuit simulation are combined, optimized circuit parameters are reversely mapped into structure geometric parameters, material preparation is guided, and accurate design and broadband absorption of the wave absorbing performance are achieved.
Owner:HEFEI INNOVATION RES INST BEIHANG UNIV +1

Multi-source fusion spectrum cross-domain high-precision prediction method and system based on transfer learning

The invention provides a multi-source fusion spectrum cross-domain high-precision prediction method and system based on transfer learning. The method comprises the following steps: S1, acquiring spectrograms collected by a spectral imaging device under multiple wavelengths; s2, extracting various types of features from the spectrogram; s3, training a fusion model to obtain a trained fusion model; and S4, inputting a to-be-predicted spectrum into the trained fusion model, and outputting a result. According to the invention, 10 <-4 > nm-level wavelength prediction can be achieved in a common industrial camera system, and the level of a scientific research-level grating spectrometer (0.001-0.002 nm) can be reached / exceeded; on a narrow-band, middle-band and wide-band multi-scene cross-domain data set, the mean absolute error (MAE) can be reduced from the nanoscale to the magnitude of 10 <-4 > nm, and excellent robustness is kept under the conditions of noise, feature deficiency and few samples.
Owner:HONG KONG UNIV OF SCI & TECH (GUANGZHOU)

Power adaptive digital pre-distortion method, system and device based on sparse GRU and medium

The invention discloses a power adaptive digital pre-distortion method, system and device based on sparse GRU and a medium. The method comprises the steps that input and output signals under different powers are collected, a composite feature vector is constructed through amplitude normalization and phase alignment, and a pre-distortion training target is generated in combination with indirect learning; constructing a sparse GRU neural network, introducing L1 regularization constraint, and obtaining a sparse pre-distortion model through joint optimization of mean square error and sparse constraint; partial weight updating is realized based on power grading, and weight fusion output is carried out during power interval switching so as to complete power adaptive optimization; pruning and compressing the sparse GRU model and then deploying the sparse GRU model in a pre-distortion module to compensate the nonlinearity of the power amplifier; according to the method, the model complexity is reduced through rarefaction, the dynamic working condition stability is improved through a power adaptive mechanism, pruning compression adapts to low-power-consumption hardware, high precision, low complexity and adaptive capacity are considered, and the method is suitable for the low-power-consumption and high-performance requirements of a broadband wireless communication system.
Owner:XIDIAN UNIV

Metasurface array antenna housing

The invention discloses a metasurface array antenna housing, belongs to the technical field of electromagnetic wave regulation and control, and solves the problem of how to improve the transmittance and absorptivity of a metasurface to electromagnetic waves. Electromagnetic waves with different frequencies resonate on the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer respectively, so that the electromagnetic waves are absorbed by the lumped resistor. And the metasurface wave-transmitting layer re-radiates electromagnetic waves of a communication frequency band to enable the electromagnetic waves to penetrate through the metasurface unit, and meanwhile, the surface of the metasurface wave-transmitting layer can serve as a metal floor of the first metasurface wave-absorbing layer and the second metasurface wave-absorbing layer due to copper coating. The antenna can be widely used in the scenes of radar stealth, communication antenna integration, electromagnetic compatibility, wireless energy transmission and the like, and has a good application prospect.
Owner:ANHUI UNIV

Method and system for capturing ultra wide band navigation signal of low earth orbit satellite

The invention discloses a method and a system for capturing an ultra-wideband navigation signal of a low-orbit satellite, which are used for solving the technical problem that the existing method for capturing the ultra-wideband navigation signal of the low-orbit satellite is easy to cause that the signal cannot be locked, and finally the capturing success rate is low. The method comprises the following steps: acquiring ka-band low-orbit satellite signals and low-orbit satellite pseudo-random noise codes corresponding to a plurality of low-orbit satellite ultra-wideband navigation signals; generating a complex signal and an original intermediate-frequency signal according to a preset sampling rate, preset skipping time and the ka-band low-orbit satellite signal; constructing a pseudo-code spectrum library based on the pseudo-random noise codes of the low-orbit satellites, and outputting the pseudo-code spectrum library; determining a discrete frequency search sequence based on known intermediate frequency parameters of the original intermediate frequency signal, performing matrix construction in combination with the complex signal and the pseudo code spectrum library, and outputting a three-dimensional result matrix; and capturing and judging the ultra-wideband navigation signals of the low-orbit satellites by adopting the three-dimensional result matrix, and determining a plurality of successfully captured ultra-wideband navigation signals of the low-orbit satellites.
Owner:SUN YAT SEN UNIV

Permitting wideband simultaneous transmit and receive communications on overlapping frequency bands

Wideband simultaneous transmit and receive communications on overlapping frequency bands may be achieved by communicating via a communication device having a transmit signal path and a receive signal path. The transmit signal path and receive signal path are operable to transmit and receive simultaneously at the same frequency. A first remote communication device communicates over a first interference suppressed band using a first channel in the transmit signal path and receive signal path. A second remote communication device communicates over a second interference suppressed band using a second channel in the transmit signal path and receive signal path.
Owner:RESONANT SCIENCES LLC

Multi-mode oscillation suppression method and system for network-forming type power supply grid-connected system

The invention relates to a multi-modal oscillation suppression method and system for a network construction type power supply grid-connected system, belongs to the technical field of power system control, and solves the problem that multi-modal oscillation of a large-scale inversion type power supply grid-connected system cannot be cooperatively and rapidly suppressed. The method comprises the following steps: when a system generates broadband oscillation, collecting grid-connected point voltage and current signals of each power station to extract a dominant oscillation mode of each power station; constructing a modal coupling matrix based on the dominant oscillation mode to extract modal coupling strength; identifying a key path of oscillation propagation in the dominant oscillation mode, and extracting a path weight and a power station participation degree; calculating the comprehensive power regulation and control weight of each power generation station in multiple modes so as to determine the power regulation quantity; and distributing the power regulation quantity to an energy storage device, a static var generator (SVG) and each power generation station according to oscillation characteristics of different frequency bands so as to cooperatively suppress multi-modal oscillation. The active / reactive oscillation energy is cooperatively adjusted, so that the oscillation energy of each frequency band is effectively suppressed.
Owner:NORTH CHINA ELECTRIC POWER UNIV +1

Electrical automation quality detection method and system

The invention belongs to the technical field of quality detection, and discloses an electrical automation quality detection method and system. The method comprises the steps of collecting original voltage and current signals of a PCC point of a power grid and performing FFT to obtain a background harmonic frequency set and a background harmonic amplitude set; generating an initial frequency grid based on a preset target frequency band, and generating a sparse frequency grid in combination with the background harmonic waves; calculating the estimated signal-to-noise ratio of each candidate frequency, performing ascending sorting to obtain an injection sequence, injecting sinusoidal signals, collecting PCC point voltage response and total current, and calculating a frequency impedance data pair; performing rational function fitting based on the frequency impedance data to obtain a broadband impedance curve; analyzing the curve, extracting quality characteristic parameters, and performing quality judgment according to the parameters; according to the method, the technical problem that the grid-connected stability quality of a single new energy converter cannot be quickly and automatically qualified in a production line offline detection scene in the prior art is effectively solved.
Owner:NANTONG SONGLIN TECH CO LTD

Perovskite laminated cell and manufacturing method thereof

The invention belongs to the technical field of solar cells, and relates to a perovskite laminated cell and a preparation method thereof, the perovskite laminated cell can reduce light parasitic absorption, the perovskite laminated cell comprises a bottom crystalline silicon cell, the bottom crystalline silicon cell comprises a substrate, the substrate comprises a first surface and a second surface which are opposite to each other, a first tunneling oxide layer and a first composite passivation layer are sequentially arranged on the first surface in the direction perpendicular to and away from the first surface, and the first composite passivation layer comprises first doped crystalline silicon conductive regions and first wide-band gap conductive regions which are alternately arranged in the direction parallel to the first surface; the top perovskite cell is arranged on the first composite passivation layer and is electrically connected with the bottom crystalline silicon cell, and the top perovskite cell comprises a hole transport layer, a perovskite active absorption layer, an electron transport layer, an interface buffer layer, a transparent conductive layer and an anti-reflection layer which are sequentially far away from the first composite passivation layer; and a first electrode in electrical contact with the transparent conductive layer.
Owner:JINKO SOLAR CO LTD +1

Voltage stability control method for multi-output switching power supply

PendingCN121124516APower conversion systemsFrequency spectrumCircuit extraction
The invention provides a voltage stability control method for a multi-output switching power supply, which comprises the following steps of: sampling a main output channel in real time to obtain a voltage signal; the voltage signal is processed through a wide bandwidth error amplifier, a main channel adjusting signal is generated, and the main channel adjusting signal is used for driving a main power switch device; receiving an input voltage fluctuation frequency band of an auxiliary channel, a load current transient change gradient and a frequency spectrum coupling characteristic of a main channel adjusting signal through a dynamic prediction model, and generating an auxiliary channel adjusting signal with a phase lead compensation characteristic; a cross coupling active offset mechanism is constructed, time domain-frequency domain characteristics of coupling interference are extracted through a high-precision differential detection circuit, amplitude-frequency adjustable reverse correction signals are generated in real time through an adaptive compensation algorithm and injected into control nodes of an auxiliary output channel, and dynamic decoupling and ripple suppression are carried out. According to the method, high-stability control of multi-channel voltage under all working conditions is realized, and the dynamic response speed and the anti-interference capability are improved.
Owner:CHANGZHOU UNIV

Broadband / narrowband adaptive switching power internet of things communication system and control method

The invention relates to the technical field of power internet of things, in particular to a broadband / narrowband self-adaptive switching power internet of things communication system and a control method, which intelligently identify the priority and quality of service (QoS) requirements of different services by collecting network states, terminal states and service flow data in real time. And an optimal communication mode switching strategy is dynamically generated based on a pre-trained machine learning model, seamless switching of broadband and narrowband communication links is realized, and the decision accuracy is continuously improved through a feedback optimization mechanism. According to the method, the problems that a traditional electric power Internet of Things communication mode is fixed and single and cannot intelligently adapt to services and network states are effectively solved, the system communication reliability is remarkably improved, the transmission time delay and energy consumption are reduced, and high-adaptability and high-reliability intelligent communication guarantee in a complex electric power scene is achieved.
Owner:NANJING CHUYU ELECTRONIC TECHNOLOGY CO LTD

Synthetic broadband waveform optimization method based on reinforcement learning

The invention relates to the technical field of radar waveform optimization, in particular to a synthetic broadband waveform optimization method based on reinforcement learning. According to the method, a deep reinforcement learning framework is adopted, and end-to-end optimization is carried out on the center frequency and amplitude parameters of multiple sub-pulses. The method comprises the following steps: constructing a synthetic broadband waveform signal model, and parameterizing sub-waveforms to determine a search space of an optimization problem; converting a waveform optimization problem into a reinforcement learning form, and defining a state space, an action space, a reward function and a state transition mechanism; based on a deterministic soft action value iteration strategy algorithm, point spread function features are extracted in combination with a Transform encoder, and sub-pulse parameters are dynamically adjusted. Through the method, the main lobe resolution can be effectively suppressed and improved, the target detection performance of a radar system is improved, and the method has good global optimization capability and environmental adaptability and is suitable for cognitive radar and adaptive waveform design scenes.
Owner:WUHAN BINHU ELECTRONICS

Vibration test bench

The invention provides a vibration test bench, and relates to a vibration test device, and the vibration test bench comprises a pedestal, and a plurality of vibration frames which are arranged on the pedestal in parallel at intervals and are sequentially arranged on the pedestal from top to bottom; each sliding guide rail is arranged between every two adjacent vibration frames and between the vibration frame on the lowermost layer and the base, and the guide directions of the sliding guide rails are different from one another; each driving mechanism is fixedly connected to the vibration frame located on the lower layer or the base and drives the vibration frame located on the upper layer to do reciprocating rectilinear motion along the corresponding sliding guide rail. Each locking mechanism is arranged between every two adjacent vibrating frames and between the vibrating frames and the base, and each locking mechanism can selectively lock the reciprocating motion of the vibrating frame located on the upper layer; the control unit is in communication connection with all the driving mechanisms and independently controls operation of all the driving mechanisms. The vibration test bench can realize multi-degree-of-freedom movement, and has a broadband vibration frequency / amplitude adjusting function.
Owner:CHINA STATE RAILWAY GRP CO LTD +4

Multi-degree-of-freedom resonant excitation motor dynamic vibration test system and test method

The invention relates to the technical field of motor fault diagnosis, and discloses a multi-degree-of-freedom resonant excitation motor dynamic vibration test system and a test method, the system injects a specific harmonic current into a motor through closed-loop control and calculation and a high-bandwidth harmonic injection driver, so that the actual vibration of the tested motor tracks a preset target vibration profile in real time. In the testing process, the cross-spectral density of multi-point vibration signals is analyzed, and a transmission path and a collection area of vibration energy in a motor structure are calculated; and meanwhile, the electromagnetic impedance and the mechanical impedance of the motor are identified and decoupled on line by superposing a broadband disturbance signal in the driving current. In combination with energy flow analysis and an impedance decoupling result, the method can accurately position a vibration abnormal position, clearly causes whether a fault source is from mechanical structure characteristic change or electromagnetic part performance change from a physical level, and realizes deep and accurate diagnosis of the dynamic characteristics of the motor.
Owner:NANJING TESTECH TECH

Vibration control method for offshore wind turbine structure

The invention discloses a vibration control method for an offshore wind turbine structure, which comprises the following steps of: a, implementing real-time multi-source data acquisition which is realized by deploying a series of sensors on the offshore wind turbine structure and in the surrounding environment so as to obtain environmental load parameters, structural response parameters and running state parameters of the offshore wind turbine; and b, inputting the acquired data into a composite environment and structure state decoupling and feature extraction module, preprocessing the acquired data by the module, and identifying an environment load spectrum in real time. According to the vibration control method for the offshore wind turbine structure, through multi-source information fusion, online system identification and self-adaptive multi-target control, broadband, multi-mode and self-adaptive suppression of vibration of the offshore wind turbine structure is achieved, and the limitation of a traditional fixed parameter damper in a complex dynamic marine environment is overcome; complex excitation sources such as wind, waves and ocean currents and the coupling effect of the excitation sources are effectively handled.
Owner:CHONGQING UNIVERSITY OF SCIENCE AND TECHNOLOGY

A deep learning method for low-frequency SKA broadband effect and synthetic beam effect elimination

ActiveCN119295329BImage enhancementImage analysisAstronomical image processingImaging processing
The application discloses a kind of deep learning methods for low-frequency SKA broadband effect and synthetic beam effect elimination, belong to radio astronomy image processing field, including steps: S1, establish FSAS, FERM and FGFN;S2, based on the FSAS, FERM and FGFN of S1 establishment establishes IFS-Transformer network model;S3, two FERM modules are applied to obtain dirty image I ∈ R H×W×C Low-level features F0 ∈ R H×W×C ;S4, F0 is input FGFN module, and coding part is completed after twice downsampling operation;S5, the feature obtained by coding part is passed through 3 FSAS and twice upsampling, realizes feature learning and decoding operation;S6, after being processed by two FERM, final recovered image is obtained.The effect elimination method based on deep learning can more effectively eliminate the joint of broadband effect and synthetic beam effect, and can greatly reduce the time of effect elimination to a greater extent to restore and reconstruct original sky brightness;The manual operation process of the method of the patent can be greatly simplified by using deep learning technology.
Owner:GUIZHOU UNIV

Millimeter radar for interrogation, classification and localization of target objects having a non-linear frequency dependent frequency response, enhanced by wideband chaos generating material (WCGM)

A system for millimeter RADAR object recognition and classification using sub-band frequency interference and resonance effects from primary targets signals and reflected signals from secondary target preferably in the form of Wideband Chaos Generating Material (WCGM) objects, preferably detecting frequency dependent absorbing material, frequency dependent resonance effects from the second and primary target objects, frequency signal resonance effects caused by water molecule dipole effects in different sugar solutions, impedance of material, shape of metamaterial, and interference effects due to combination of signal sources resulting in a wider range of transmitter and scanning frequency band for RADAR based interrogation of target objects. The RADAR system makes opportunistic use of traditionally seen problematic interference signals, as extra signal sources providing extended range and frequency bandwidth for frequency-based interrogation of target object signatures in a frequency-intensity plane, a frequency-polarization plane, and a frequency-phase shift plane for doppler effects.
Owner:XFINDER SWEDEN AB

Micro-perforated plate composite gradient spiral pipe sound absorption device and method

The invention belongs to the technical field of low-frequency sound absorption, and discloses a micro-perforated plate composite gradient spiral pipe sound absorption device and method.The micro-perforated plate composite gradient spiral pipe sound absorption device comprises a variable cross-section spiral pipe, and the diameter of the inlet end of the variable cross-section spiral pipe is larger than that of the outlet end of the variable cross-section spiral pipe; a plurality of MPP plates are mounted in the variable-cross-section spiral pipe, one MPP plate is embedded into the inlet end of the variable-cross-section spiral pipe, and the other MPP plates are sequentially embedded into the variable-cross-section spiral pipe at equal intervals, so that a multi-stage MPP plate composite sound absorption structure is formed; and the cross-section pipe diameter of the variable cross-section spiral pipe is linearly reduced from the inlet end of the variable cross-section spiral pipe to the outlet end of the variable cross-section spiral pipe. Through the gradient design of the variable cross-section spiral tube integrated micro-perforated plate, low-frequency broadband efficient sound absorption is realized in a compact space, the problem of heavy structure caused by dependence on a deep and large back cavity in the traditional technology is avoided, the limitation of narrow sound absorption frequency band is overcome, and the sound absorption device is particularly suitable for being applied to occasions with limited spaces and has wide application prospects. And low-frequency performance and broadband characteristics are considered in a limited space.
Owner:QINGDAO UNIV OF TECH

Ultra-wideband array antenna based on common-caliber layout

The invention relates to the technical field of array antennas, and discloses a common-caliber layout-based ultra-wideband array antenna, which comprises a low-frequency unit and a high-frequency unit which are arranged based on a common caliber, and is characterized in that the working frequency of the low-frequency unit covers an fmin-f0 frequency band, and the working frequency of the high-frequency unit covers an f0-fmax frequency band. The low-frequency unit is a broadband dual-polarized antenna, a uniform tight coupling array distributed at equal intervals is formed by adopting a tight coupling principle, and the unit interval is calculated based on a grating lobe suppression condition at the frequency f0. The high-frequency unit is a miniaturized broadband dual-polarized antenna and adopts a sparse array form; the initial unit spacing and the unit number of the sparse array are calculated based on the grating lobe suppression condition at the highest frequency f2 of the f1-f2 frequency band with the side lobe requirement between the f0-fmax frequency bands. The ultra-wideband array antenna gives consideration to full-band array performance, can provide sufficient space for active circuit arrangement, and effectively reduces power consumption and cost.
Owner:10TH RES INST OF CETC

Method and system for improving resolution of spectral interference system

The invention discloses a spectral interference system resolution improving method and system, and the method comprises the steps: building an ISE-Net end-to-end deep neural network model, enabling the convolution kernel size of an efficient channel attention module of the ISE-Net end-to-end deep neural network model to be adaptively determined according to the number of input channels, and constructing a mapping relation between narrowband and broadband interference signals; and generating an ideal narrowband signal and a double-bandwidth target signal according to a spectral interference physical formula, defining a loss function by minimizing deviation between model output and the target signal, updating parameters and dynamically adjusting a learning rate by using an AdamW optimizer until model loss is converged, and completing data generation and training. An input narrowband signal horizontal axis is converted to a corresponding frequency domain axis, and is subjected to time shifting and intensity scaling preprocessing to adapt to the model. A signal processing flow suitable for a single / multi-layer structure is constructed, a bandwidth expansion signal is obtained through decomposition, expansion and reconstruction, and the resolution of a spectrum interference system is improved. The method has the advantages of high calculation efficiency, high generalization and flexible deployment.
Owner:HUAZHONG UNIV OF SCI & TECH +1

Otological disease prediction method based on multi-modal data fusion and confidence evaluation

The invention relates to the field of otological disease prediction, in particular to an otological disease prediction method based on multi-modal data fusion and confidence evaluation. According to the technical scheme, the method comprises the following steps: acquiring an otoendoscope digital image, broadband tympanic image measurement data and structured or unstructured clinical information; carrying out integrity verification and quality verification on the collected data, and checking whether the resolution of the digital image of the otoendoscope meets the minimum pixel requirement or not and whether the information is complete or not; preprocessing the otology data and extracting multi-modal features, and extracting an ear endoscope digital image feature vector, a feature vector representing broadband tympanic chamber image data and a clinical information feature vector; fusion is carried out after feature extraction, and confidence evaluation and recurrence risk prediction are carried out after fusion. According to the method, the three-mode data of the image, the physiological signal and the clinical text are deeply fused through the attention mechanism, so that the prediction accuracy of the otological diseases is remarkably improved. The method is suitable for otological disease prediction.
Owner:SICHUAN AGRI UNIV

Reflective array antenna control method and system based on broadband dual-polarization unit

The invention discloses a reflective array antenna control method and system based on a broadband dual-polarization unit, and the method comprises the steps: obtaining a target wave beam pointing instruction, and carrying out the orthogonal decomposition of the target wave beam pointing instruction into a first polarization control vector and a second polarization control vector; calculating a theoretical phase frequency spectrum of each unit according to the polarization control vector; calling a preset database to extract a basic phase spectrum; quantitative mapping is carried out by calculating a matching error between a theory and a basic phase frequency spectrum, a phase control code containing the first polarization and the second polarization is obtained and loaded to a corresponding broadband dual-polarization unit to drive the switching of a physical state of the broadband dual-polarization unit, and real-time reconstruction of a wave beam is realized. Compared with the prior art, the antenna can overcome the defects that a traditional reflective array antenna is serious in polarization component coupling, low in phase matching degree in a broadband range and inaccurate in phase control code acquisition, and remarkably enhances the independent pointing precision and the full-band gain stability of dual-polarization beams. Therefore, flexible reconstruction of the wave beam in polarization and frequency dimensions is realized.
Owner:SUZHOU ZHONGXING ZHIHANG AEROSPACE TECH CO LTD

UWB robust Kalman positioning algorithm based on dynamic reliability evaluation

The invention discloses an ultra wide band (UWB) robust positioning method for a non-line-of-sight (NLOS) interference environment, and belongs to the technical field of wireless positioning. According to the method, firstly, all three-base-station combinations are generated through a permutation and combination method, the initial position of each group of base stations is solved through a trilateral positioning method, and a multi-dimensional coarse positioning point cloud is formed; then grouping the coarse positioning points according to the resolving participation condition of the base stations, acquiring representative position points of the base stations by adopting a central position estimation algorithm, and constructing a base station space distribution model; a mean vector and a covariance matrix of the point cloud are calculated, after a pseudo-inverse matrix is solved through SVD decomposition, the mahalanobis distance from each representative point to the distribution center is calculated, a dynamic threshold value is set according to the 95% confidence coefficient of chi-square distribution, a base station with the distance exceeding the threshold value is judged as an NLOS abnormal node, and data of the base station is abandoned; and finally, constructing a dual-stage anomaly suppression mechanism: screening reliable base stations based on geometric consistency at a measurement stage, dynamically adjusting the Kalman gain through an exponential gain constraint factor at a residual stage, constructing a dynamic noise model by fusing a geometric precision factor, and realizing position calculation by adopting improved extended Kalman filtering. According to the method, the positioning error can be effectively reduced in the NLOS interference environment, and a centimeter-level reliable positioning solution is provided for the fields of industrial Internet of Things or indoor positioning and the like.
Owner:NORTHEAST DIANLI UNIVERSITY

Mobile device supporting wideband operation

A mobile device includes a feeding radiation element, a first radiation element, a second radiation element, a grounding radiation element, a shorting radiation element, and a third radiation element. The first radiation element is coupled to the feeding radiation element. The second radiation element is coupled to the feeding radiation element. The first radiation element and the second radiation element substantially extend in opposite directions. The first radiation element is further coupled through the grounding radiation element to a ground voltage. The shorting radiation element is coupled between the feeding radiation element and the grounding radiation element. A closed loop structure is formed by the feeding radiation element, the first radiation element, the grounding radiation element, and the shorting radiation element. The third radiation element is coupled to the ground voltage. The third radiation element is adjacent to the feeding radiation element and the second radiation element.
Owner:ACER INC