1676 results about "Linear arrays" patented technology

The invention provides a coherent signal arrival direction estimation method and device based on a deep convolutional network, and belongs to the field of array signal processing. The method comprises the following steps: receiving a to-be-detected signal containing a coherent signal by using a uniform linear array antenna to obtain an array receiving data matrix and extract a covariance matrix; forming an input feature vector by right upper triangular elements divided from a diagonal line in the covariance matrix, inputting the input feature vector into a covariance estimation model formed by a deep convolutional network, obtaining an estimation value of the right upper triangular elements under an ideal incoherent condition, and reconstructing the estimation value to obtain a covariance matrix estimation value; and performing characteristic decomposition on the covariance matrix estimation value, and generating a spatial spectrum by using a MUSIC algorithm to obtain an estimation result of the signal arrival direction. According to the method, the noise-containing mixed signal covariance matrix is mapped into the ideal incoherent noise-free signal covariance matrix through a physical constraint supervised learning framework, so that the estimation precision and robustness of the MUSIC algorithm in a coherent scene are improved.

The invention discloses a low-voltage cable branch box with protection structures at wire inlets, and belongs to the technical field of cable branch boxes, the low-voltage cable branch box comprises a box body, the interior of the box body is fixedly connected with a mounting rack for mounting electrical appliance elements through bolts, the bottom of the box body is provided with a plurality of wire inlets distributed in a linear array, and the wire inlets are arranged in the box body. The bottom of the inner wall of the box body is fixedly connected with a fixing frame corresponding to each wire inlet, and the front and back surfaces of the fixing frame are movably provided with plugging plates in a penetrating manner. The plugging plate is arranged to plug the wire inlet, and the gap sealing mechanism is arranged to fill and seal the gap between the cable and the plugging plate, so that external humid gas cannot enter the box body from the wire inlet, and when the sealing door of the box body is in a closed state, the whole branch box can be in a totally closed state; dust or humid gas in external air is prevented from entering the branch box, and electronic components in the branch box are well protected.

The invention discloses a deep-sea self-expanding horizontal array acoustic subsurface buoy, which relates to the field of deep-sea underwater acoustic detection and comprises an expanding platform arranged at the top of the acoustic subsurface buoy, a subsurface buoy main body positioned below the expanding platform and an anchoring structure connected below the subsurface buoy main body, the subsurface buoy body comprises a buoyancy platform arranged below the unfolding platform and an equipment platform arranged below the buoyancy platform. The problem that a hydrophone linear array composed of a plurality of large-scale acoustic linear arrays is folded and automatically unfolded into a cross horizontal array is solved, and integration of a deep-sea acoustic emission system, an acoustic receiving system, an underwater acoustic communication system and an equipment supply system is achieved. The whole subsurface buoy can be quickly and conveniently released and recycled, and high-reliability anchor mooring is achieved.

The invention discloses a server liquid cooling cabinet group heat dissipation system with phase change energy storage, which comprises two linear array type server liquid cooling cabinet groups, two cooling capacity distribution units, two heat pipe air conditioner all-in-one machines, a multi-channel cold liquid distributor, a multi-channel hot liquid backflow device and the like, the all-in-one machine comprises a heat pipe natural cold source refrigerating loop and a compressor mechanical refrigerating loop, the two refrigerating loops independently or jointly provide an outdoor cold source, heat of all the liquid cooling cabinets is transmitted to the all-in-one machine in the cold capacity distribution unit, and therefore the heat is transmitted out of the machine room. A phase change energy storage flow channel is preferably arranged on the primary side of the intermediate heat exchanger in parallel, cold storage and buffering are achieved by switching a channel, a cold storage and cold release intelligent control strategy based on a lag temperature difference threshold value is constructed, a main cold source linkage and cold source switching smooth transition mechanism is achieved, the thermal stability, operation continuity and response capacity of the system are improved, and the system reliability is improved. The liquid cooling heat dissipation device is suitable for data center liquid cooling heat dissipation scenes with high heat density, high energy efficiency and high reliability requirements.

The invention relates to the technical field of satellite internet, and discloses a low-orbit satellite phased array multi-beam interference modeling and suppression method and system, and the method comprises the steps: selecting a Kaiser window as a core filtering method, and achieving the optimization of beam characteristics through the dynamic adjustment of a shape parameter beta; generating an initial beam directional diagram based on a digital phase matching method, and multiplying the Kaiser window function coefficient by the excitation weight of the 64-array-element linear array element by element to realize spatial domain weighted filtering; the method comprises the following steps: constructing a training data set containing multi-scene interference characteristics, calculating a corresponding covariance matrix and an accurate inverse matrix thereof to form a sample pair, designing a deep neural network architecture, inputting a flattened covariance matrix vector, and learning a complex nonlinear mapping relation from the covariance matrix to the inverse matrix through a multi-layer full-connection structure; a mean square error is used as a loss function to constrain network output precision, and a multi-beam interference system model is constructed; according to the invention, stable and efficient communication of the low-orbit satellite system in a complex electromagnetic environment and under rapid channel change is ensured.

The invention relates to the field of sound velocity, opto-acoustic and ultrasonic imaging, in particular to a dynamic sound velocity self-adaptive ultrasonic opto-acoustic bimodal imaging method and a dynamic sound velocity self-adaptive ultrasonic opto-acoustic bimodal imaging system. The method comprises the following steps: acquiring an ultrasonic signal and a photoacoustic signal; reconstructing a sound velocity distribution diagram according to the ultrasonic signal; based on the sound velocity distribution diagram, reconstructing a related time delay diagram; and reconstructing an ultrasonic image and a photoacoustic image based on the related time delay graph. The problems that a traditional sound velocity correction method is limited in application range, inconvenient to operate, high in cost, low in resolution and the like are solved; the adopted sound velocity correction algorithm is high in resolution, is suitable for various transducers of linear arrays, convex arrays, ring arrays, spherical arrays and the like, and is widely applied to most parts of a human body; cancerous tissues, normal tissues, muscles, fat and the like can be accurately distinguished; the ultrasonic and photoacoustic dual-mode imaging system is simple in structure, is not influenced by illumination, is high in sound velocity resolution and signal-to-noise ratio, supports seamless correction and registration of ultrasonic and photoacoustic dual-mode imaging, and promotes clinical application and development of ultrasonic and photoacoustic dual-mode imaging.

The invention discloses a two-dimensional bionic multi-stage conical flow divider for laser processing and an application device thereof, and the two-dimensional bionic multi-stage conical flow divider is characterized in that the upper surface and the lower surface of the two-dimensional bionic multi-stage conical flow divider are provided with micro-groove structures, and the micro-groove structures are longitudinal parallel grooves distributed in a linear array; the two-dimensional bionic multistage cone flow divider is of a bilateral symmetry structure and specifically comprises a single primary main cone and a plurality of secondary small cones on the single side, the secondary small cones are distributed on the two sides of the primary main cone at equal intervals, and the included angle between each secondary small cone and the primary main cone ranges from 9 degrees to 21 degrees. The cone angle of the first-stage main cone structure is 9-21 degrees, the length of the first-stage main cone structure is 8-12 mm, the cone angle of the second-stage small cone structure is 9-21 degrees, the length of the second-stage small cone structure is 1-3 mm, the depth of the micro-groove structure is 35-45 micrometers, and the center-to-center distance of the micro-groove structure is 28-35 micrometers. According to the two-dimensional bionic multistage conical flow divider for laser processing and the application device thereof, the problem that the efficiency of spontaneous continuous separation of existing multiphase immiscible organic liquid drops is low is solved.

A station keeping waterfowl system includes at least one self propelled station keeping waterfowl decoy and a homing buoy each having water resistant housings, with at least a portion of the decoy housing having a form of a waterfowl. The decoy and buoy each include batteries, microprocessors, and power switches. The decoy includes a motor driven propeller, a motor driven rudder, and a receiving array of antennae for radio direction finding and radio ranging to the buoy. The receiving array is a T-array of antennae comprising a first transverse linear array and a second longitudinal linear array. The homing buoy emits a homing signal and the one or more waterfowl decoys autonomously navigate to remain within a predetermined radius around the buoy. The system includes a simple handheld controller which preferably comprises no more than two switches or buttons.

Base station antennas include a reflector, a first linear array of radiating elements extending forwardly from the reflector, the radiating elements in the first linear array configured to operate in a first frequency band, and a second linear array of radiating elements extending forwardly from the reflector, the radiating elements in the second linear array configured to operate in the first frequency band. These antennas further include an isolation wall that is positioned in between the first linear array of radiating elements and the second linear array of radiating elements. This isolation wall comprises at least one partially reflective surface that is configured to reflect, on average as a function of frequency, between 20% and 80% of incident radiation in the first frequency band.

An optical arrangement for a LIDAR system includes a laser, scanner, fold mirror, lens, and sensors. Adding a wedge-shaped optical element creates an auxiliary field of view, when positioned to overlie an edge portion of the lens. The wedge-shaped optical element may have a variable transparency preventing reception by the sensors of excessive signals from close targets. The sensors may be: a plurality of sensors with unique lengths / widths, arranged to form a linear array; or sensors with the same length / width, but positioned to form an arcuate shape, compensating for an arcuate scan line; or two columns of sensors, one with a field of view in focus at far field positions, and the other in focus at near field positions, correcting for parallax effect / error; or a column of highly sensitive sensors surrounded by a plurality of guard rail sensors having higher immunity to damage from stray laser light.

The invention discloses an array amplitude-phase error calibration method based on joint sparse estimation. The method comprises the following steps: setting a correction sound source to be positioned in an unknown far-field direction relative to a sensor linear array; the method comprises the following steps: dividing an observation area of a sensor linear array to obtain a plurality of grid points, correcting an array sampling signal based on the grid points and offset, constructing an array response signal model, and performing joint sparse direction-of-arrival estimation of the grid points and the offset to obtain a corrected sound source signal direction-of-arrival; the joint sparse estimation method for solving and correcting the direction of arrival of the sound source signal is popularized to a planar array and a multi-frequency cross array through iterative correction; and on the basis of the estimated corrected sound source direction of arrival, array amplitude-phase error calibration is completed by adopting a spatial filtering method. According to the method, the problem of beam pattern attenuation caused by existing array amplitude phase error calibration is solved, the error correction precision and correction efficiency are improved, and the application range of the error calibration method in multiple array types is widened.

The invention relates to a high-signal-to-noise-ratio ultrasonic imaging method and device for internal defects of a curved surface component, a medium and a product, and belongs to the technical field of ultrasonic imaging. According to the method, a linear array ultrasonic probe is adopted to carry out single-time ultrasonic excitation on a curved surface component, a full-matrix echo signal is obtained, first arrival time extraction is carried out on the collected signal, an ultrasonic incident angle is estimated, and discrete coordinates of the surface of the component are obtained; the method comprises the following steps of: fitting a curved surface model, constructing an equivalent virtual array model, calculating transmitting and receiving delay time of each pixel point, realizing initial full-focusing beam forming of signals, estimating an expected signal variance and a noise variance based on maximum likelihood estimation, constructing an initial coherent beam forming machine and performing iterative updating, and finally forming a beam. And taking the coherent beam synthesizer obtained by iteration as a weighting factor, acting on an initial beam synthesis signal for weighting, and completing image reconstruction. The method has the advantages of being high in calculation efficiency, low in system overhead, high in imaging signal-to-noise ratio and the like, and accurate imaging can be achieved in a curved surface structure scene.

A flexible weight that can be secured to a wearer during performance of an exercise. The weight is segmented, with each segment from a set of segments including an associated bolster-shaped unit having a plurality of pellets suspended in a cured gel, the pellets / gel being positioned within a casing. The set of segments is contained within an outer pouch that is substantially conformal with the set of segments, and the segments from the set of segments are arranged in a linear array. The weight also includes an endcap with a colored light indicator and electronics for communicating with a smart mirror.

The invention discloses a super-condensation composite brightness enhancement film and a liquid crystal display backlight module, and particularly relates to the technical field of brightness enhancement films.The super-condensation composite brightness enhancement film comprises a core layer, an upper-layer brightness enhancement structure and a lower-layer brightness enhancement structure, the core layer is a multi-layer film made of poly (ethylene naphthalate) and a copolymer thereof, the upper-layer brightness enhancement structure is fixed to the top of the core layer, and the lower-layer brightness enhancement structure is fixed to the bottom of the core layer; the upper-layer brightening structure comprises a plurality of light gathering blocks, the light gathering blocks are distributed on the top of the core layer in a linear array mode, the light gathering blocks are arranged to be in a trapezoid quadrangular prism shape or a hexagonal pyramid shape, and the lower-layer brightening structure is fixed to the bottom of the core layer. The large-angle light of the incident surface is subjected to primary convergence through the plurality of inverse prism structures at the bottom of the core layer, and the large-angle light of the emergent surface is subjected to secondary convergence through the plurality of concave trapezoidal quadrangular prism-shaped or hexagonal pyramid-shaped light condensation blocks at the top of the core layer, so that the light loss is reduced, and the brightness of the backlight center is improved; and the hexagonal pyramid-shaped light condensation block can also improve the uniformity of the visual angle.

Wake-word processing by a wearable electronic device could be carried out when the device is worn by a user and is in a device sleep state, the device including a linear microphone array having at least two microphones vertically spaced from each other, and the device also including a processor. And the example method could involve (i) the at least two microphones of the linear microphone array receiving an audio waveform representing a wake-word utterance, (ii) the processor making a determination, based at least on an angle of arrival of the audio waveform at the at least two microphones of the linear microphone array and / or an energy level of the audio waveform received at the at least two microphones of the linear array, of whether to accept the wake-word utterance or rather to reject the wake-word utterance, and (iii) the processor controlling operation of the device based on the determination.

Disclosed is a linear array scanning Brillouin scattering elastic imaging device. In the device, a signal generating system consists of a narrow linewidth continuous wave laser, a half-wave plate, a beam expander, a Y-direction scanning galvanometer, a microlens array, a pinhole array filter, a first plano-convex lens, a polarization beam splitter, a quarter-wave plate and a microscope objective. A signal receiving system consists of a microscope objective, a quarter-wave plate, a polarization beam splitter and an eight-channel optical collimator array. Each channel of an eight-channel spectrometer consists of an optical collimator, a convex lens, a scanning Fabry-Perot interferometer, a photomultiplier tube and an eight-channel photon collection card.

The utility model relates to the technical field of stair manufacturing, in particular to a mould for a concrete prefabricated stair. Comprising a first template body, a second template body is arranged on one side of the first template body, lock catches are symmetrically and fixedly connected to the two sides of the second template body, the second template body and the first template body are clamped and fixed through the lock catches, two partition plates are arranged in the first template body, and the two sides of each partition plate make contact with the inner wall of the first template body and the inner wall of the second template body respectively. Inserting rods are fixedly connected to the positions, close to the upper ends, of the two sides of the partition plate, and a plurality of inserting grooves are formed in the tops of the first template and the second template in a linear array mode. After the distance between the two partition plates is adjusted, the two partition plates are installed between the first formwork and the second formwork, a small pouring cavity is formed among the two partition plates, the inner wall of the first formwork and the inner wall of the second formwork, concrete is poured into the small pouring cavity, a stair with the specified length and width can be manufactured, and use is convenient.

The invention relates to the field of underwater sound signal processing, in particular to an underwater DOA (direction of arrival) estimation method based on graph nerves and a convolutional neural network, which comprises the following steps: 1, establishing a linear array, and enabling narrow-band signals to simultaneously reach an underwater sound array; 2, performing signal preprocessing to obtain a signal covariance matrix, and performing normalization processing; 3, extracting correlation between array elements and spatial features of array signals, and performing data supplementation on sparse linear array information; 4, forming a double-branch structure, enhancing the information aggregation capability, and extracting features from a space path and a time domain path; and 5, constructing an adjacent matrix, filling node features of damaged array elements, adopting a double-branch structure, extracting spatial features and time domain features, carrying out feature integration, and outputting a DOA estimation result. The spatial correlation between array elements is extracted and the array sparsity problem is processed by using the graph neural network, and the time domain features of the signals are extracted in combination with the convolutional neural network, so that more accurate and more robust DOA estimation can be realized under the conditions of low signal-to-noise ratio and array sparsity.

The invention provides an automatic container loading and unloading system and method, and mainly relates to the field of automatic loading and unloading. An automatic container loading and unloading system comprises an AGV body and a telescopic conveying belt, an adjusting unit is arranged on the front side of the AGV body, and an action unit with a visual recognition system is arranged at the top of the AGV body. The adjusting unit comprises a reversing mechanism, a conveying mechanism and a positioning mechanism, the action unit comprises a longitudinal displacement mechanism, a transverse displacement mechanism, a lifting mechanism and a grabbing mechanism, the grabbing mechanism is a suction cup set arranged in a linear array mode, and the coverage range of the suction cup set is half of the width of a container. The semi-row goods grabbing device has the beneficial effects that semi-row goods can be grabbed at a time, so that synchronous stacking or unstacking of the semi-row goods is conducted at a time through the action unit, the tedious steps of repeated action are reduced by multiple times, and the stacking efficiency is greatly improved.

The invention relates to the technical field of reaction kettles.The reaction kettle comprises a kettle body, a protective cover is fixedly connected to the top of the kettle body, a feeding opening is formed in the top of the kettle body in a penetrating mode, a supporting plate is fixedly connected to the bottom of the interior of the kettle body, and stirring shafts are rotationally connected to the interiors of the supporting plate, the kettle body and the protective cover; the stirring shaft is located at the center of the kettle body, the surface of the stirring shaft is fixedly connected with three stirring blades, the three stirring blades are distributed in a linear array from top to bottom, and the bottom of the stirring shaft is fixedly connected with a paddle. Through the heterogeneous sensing network constructed by the multi-parameter sensing subsystem, synchronous monitoring of multi-dimensional physical quantities such as discharge port pressure, stirring torque and kettle wall vibration is realized, the limitation of traditional single parameter monitoring is broken through, and the early recognition precision and reliability of the crystallization blockage risk are greatly improved.

The utility model provides a branching device for a distribution box, which relates to the technical field of distribution boxes and comprises a distribution box body, one side of the distribution box body is provided with a wire inlet hole, the rear inner wall of the distribution box body is provided with a bunch adjusting mechanism, and the bunch adjusting mechanism comprises a fixed support. The two fixing supports are symmetrically distributed and fixedly connected with the rear inner wall of the distribution box body, the front faces of the fixing supports are fixedly connected with limiting plates, the upper ends of the limiting plates are provided with limiting grooves distributed in a linear array mode, the front faces of the fixing supports are provided with movable sliding grooves, and the inner walls of the movable sliding grooves are slidably connected with movable sliding blocks distributed in a linear array mode. Through the bunch adjusting mechanism, the branching cable can be conveniently clamped, cables of different sizes can be stably clamped, the application range is wide, the branching cable is independently locked, the situation of batch movement and dislocation during adjustment is avoided, the operation is convenient, and the practicability is high. And the wiring efficiency is greatly improved.

The invention specifically discloses a satellite navigation interference source positioning method based on a distributed unmanned aerial vehicle, and relates to the technical field of satellite navigation interference resistance. According to the method, firstly, an unmanned aerial vehicle cluster carrying uniform linear array antennas is deployed in a target area, and after parameters of a system are initialized, all unmanned aerial vehicles synchronously collect interference signals and estimate the direction of arrival (DOA) of an interference source; then performing dual-domain interference suppression based on DOA information, calculating an interference source coordinate in combination with an unmanned aerial vehicle coordinate, and performing noise reduction; planning a path by using a path planning model of a multi-modal Markov decision process and a reinforcement learning algorithm to realize tracking of a dynamic interference source; and finally, judging and outputting a final coordinate through Euclidean distance convergence. The method solves the problems of limited coverage of a traditional fixed monitoring station and insufficient positioning precision of a single unmanned aerial vehicle, can efficiently position dynamic and multiple interference sources, improves the positioning precision and the anti-interference capability, reduces the deployment cost, and is suitable for satellite navigation interference source positioning in a complex environment.

The invention discloses detection equipment for power battery recycling, and belongs to the technical field of recycling detection, the detection equipment comprises a base plate, two symmetrically arranged support plates are connected to two sides of the top of the base plate, and a plurality of conveying rollers distributed in a linear array are rotatably connected between the two support plates. According to the invention, through the cooperation of the positioning and clamping assembly, the lifting push rod and the lifting groove seat, automatic supporting and accurate positioning of the power battery are realized, and stable support is formed when the lifting groove seat passes through the conveying roller, so that the stability of the battery in the detection process is ensured; a transmission gear, a connecting rack, a positive and negative lead screw and a second lead screw seat drive a clamping plate to relatively move, self-adaptive clamping of the side edge of the battery is achieved, an elastic buffering mechanism of a sliding rod and a supporting spring is matched, the battery clamping device is effectively compatible with batteries of different sizes and specifications, the universality of the device is improved, the clamping force is dynamically adjusted through counter-acting force in the clamping process, and the clamping efficiency is improved. The surface damage of the battery is avoided, and meanwhile, the clamping firmness is ensured.

The invention discloses a ceramic solar heat collector and a using method thereof, and belongs to the technical field of solar heat collectors, the ceramic solar heat collector comprises a mounting frame, a plurality of ceramic heat collecting pipes distributed in a linear array are arranged in the mounting frame, and a mirror surface adjusting assembly is arranged below the ceramic heat collecting pipes. According to the heat exchange device, by arranging the layered dust removal assembly and forming an upper cavity and a lower cavity through a layered box, cold and hot circulation in the ceramic heat collection pipe is guided, mutual interference of the cold and hot circulation is avoided, the area where cold water flows is always right opposite to the direct sunlight irradiation direction, and the heat exchange efficiency and the heat exchange performance are improved; the layering box drives the inclined cleaning brush to be matched with clear water to clean the inner wall of the ceramic heat collecting pipe through the fixed sleeve and the movable sleeve, the cleaning brush is in a deflection state in the cleaning process, shear stress and vortex are generated on the inner wall of the ceramic heat collecting pipe in the rotating process, and therefore the cleaning efficiency of impurities such as water scales is improved.

The utility model discloses a knob type mechanical self-locking mechanism which comprises a fixing rod, a sliding rod is connected to the inner wall of the fixing rod in a sliding mode, positioning holes are formed in the outer wall of the sliding rod in a linear array mode, the appearance of the positioning holes is round, and a self-locking mechanism is fixedly connected to the top of the fixing rod. The outer wall of the self-locking mechanism is fixedly connected with a limiting mechanism, and the self-locking mechanism comprises a fixing ring. According to the rotary knob type mechanical self-locking mechanism, the bottom of the rotary knob abuts against and makes contact with the top of the sliding buckle by rotating the rotary knob, due to the particularity of the appearance of the bottom of the rotary knob and the appearance of the top of the sliding buckle, when force generated when the bottom of the rotary knob makes contact with the top of the sliding buckle is enough, the sliding buckle can move towards the bottom, and the sliding buckle drives the positioning block to move synchronously; and the outer wall of the positioning block is inserted into the inner wall of the positioning hole, so that self-locking is completed, the sliding rod cannot continuously slide on the inner wall of the fixed rod, and the self-locking effect is achieved.

The invention discloses a multi-mode control method for voice interaction and gesture recognition of an atmosphere lamp, and belongs to the field of intelligent control. The method comprises the following steps: S1, constructing a multi-mode sensing module, and arranging a bidirectional linear array microphone, a dual-lens infrared depth camera and a space calibration laser transmitter; s2, extracting voice features by adopting an extended spectrogram domain attention network, and generating a first semantic vector; s3, dynamic attitude features are extracted through the time-airspace sparse convolutional network; s4, performing modal alignment and cooperative coding on the two semantic vectors based on a bidirectional gating fusion mechanism, generating a joint interaction instruction vector, and solving modal conflicts by a time sequence synchronization and confidence regulation strategy; s5, inputting the vector into a multi-task intention classifier, analyzing a user intention and outputting a unique atmosphere lamp control code; and S6, transmitting the control code to a driving unit to realize light control. The beneficial effects are that voice and gesture fusion control is realized, and atmosphere lamp interaction intelligence and response precision are improved.

The present invention discloses a direction of arrival estimation method, direction of arrival estimation device, and system. The method comprises: using antennas to form a uniform linear array, establishing a received signal model based on array signal input signals, and determining a received signal matrix; performing low-rank matrix approximation on the received signal matrix using a low-rank matrix estimation algorithm to obtain a low-noise, low-dimensional matrix; updating the variable step size of a least mean square algorithm (LMS) using statistical parameters of the low-noise, low-dimensional matrix to update and iteratively calculate weight vector coefficients; and calculating the antenna array pattern and spatial spectrum based on the obtained weight vector coefficients to estimate the direction of arrival of the signal. The present invention uses the low-rank matrix approximation method to obtain a low-noise, low-dimensional matrix from the received signal matrix. Utilizing the instantaneous prediction error of the low-noise, low-dimensional matrix and the variable step size of the noise reduction signal power update algorithm, the method can ensure accurate DOA estimation even under unfavorable conditions such as low signal-to-noise ratio, a small number of antenna array elements, and a small amount of signal sampling data, due to prior noise reduction preprocessing.

The utility model provides a device for automatically fixing books and preventing the books from toppling over, which comprises a positioning mechanism, a clamping mechanism and a clamping mechanism, the positioning mechanism comprises a mounting assembly, a guide assembly, a driving assembly and a contact assembly; one side of the cabinet body is in an opening shape, a plurality of horizontal partition plates are fixedly installed in the cabinet body in a linear array mode in the vertical direction, and the interior of the cabinet body is divided into a plurality of independent book placing layers through the partition plates. When books are placed in the book placing cavity of the cabinet body to be stored, the contact assembly is in contact with the books, so that the books placed in the book placing cavity can be positioned through the contact assembly under the action of the driving assembly, the attractiveness of the books during storage is improved, and meanwhile, the situation that the books are not fully placed in the book placing cavity, and the book storage efficiency is improved is effectively avoided. Therefore, the cover is crushed or folds appear when the book is inclined or toppled over, and the situation that the book is damaged when the book is stored is effectively avoided.

A hybrid scanning antenna including: a reflector having a focal line; a first mechanical movement to move the reflector about a first axis; a second mechanical movement to move the reflector about a second axis; a linear array fixedly disposed along the focal line to electronically scan at a scan angle about a third axis; and a controller to control the first mechanical movement, the second mechanical movement and the scan angle of the linear array to orient the hybrid scanning antenna to a look angle of a remote transceiver.

The invention discloses a machining die suitable for an LED screen frame, and relates to the technical field of LED screen frame machining, the machining die comprises a frame profile matched with the required length of an LED screen and a stamping mechanism arranged on a workbench, and the machining die comprises a stamping seat fixedly arranged on the workbench; the limiting units are arranged on the punching base in a linear array mode in the length direction; the clamping and fixing assemblies are arranged at the two ends of the stamping base and comprise first baffles assembled at the first ends in a sliding mode. According to the machining die suitable for the LED screen frame, the number of the limiting units is determined according to the length of the stamping base and the length of the frame sectional material, the limiting area can cover the length of the frame sectional material, different specification requirements are met, then the frame sectional material is subjected to stamping forming and then subjected to bending treatment, and the needed screen frame can be obtained; and the frame profile is limited through the limiting unit before stamping, so that the frame profile is prevented from deviating, and the quality of a finished product is higher.