36 results about "Noise reduction" patented technology

Noise reduction conduit for non rotary components of aircraft engines, subjected to a characteristic range of temperatures of a gas turbine engine, constituted by an annular structure composed of an aerodynamic wet wall (10a, 10b), perforated and resistant mechanically and thermally; of a dry wall (12a, 12b), not resistant and of light weight; and of some intermediate elements to which both walls are mechanically attached and that define a jump or difference of temperature between the wet and dry walls; between which wet (10a, 10b) and dry walls (12a, 12b) there are partitions that define cavities (16a, 16b) isolated with regard to each other.

The invention relates to an online fault detection method for a reduced set-based downsampling unbalance SVM (Support Vector Machine) transformer. At present, the research of improving the performance of an unbalance data downsampling SVM algorithm comprises upsampling and downsampling. The SVM model calculating cost of the upsampling algorithm is increased. The downsampling algorithm is selected improperly sometimes, and thus the poor classifying effect is caused. The online fault detection method comprises the following steps: (1), acquiring a vibration signal of a transformer; (2), obtaining a noise reduction vibration signal; (3), obtaining multiple groups of fault detection feature data; (4), clustering by using a K-mean algorithm; (5), figuring out a weight value of each sample; (6), establishing a majority sample reduction vector solution optimization model; (7), obtaining an SVM fault diagnosis model; and (8), inputting a sample to be tested to an unbalance SVM detector trained in the step 7, analyzing a result output from the detector to obtain a working state of the transformer, and realizing online fault detection of the transformer. The online fault detection method is used for detecting the fault of the transformer online.

The invention discloses an image retrieval method comprising the following steps of: firstly, carrying out grey level transformation and noise reduction treatment on a scene image acquired by an image module to obtain a scene grey image; then, detecting a target object outline in the scene grey image; and finally, updating the target grey image or the feature description of the target grey image in the target object outline to an image retrieval server end for image retrieval. Correspondingly, the invention also discloses an image retrieval device, a mobile terminal and an image retrieval system. Before image retrieval, a target object is extracted precisely through outline detection, so that the influence of an image background to an image retrieval result is effectively reduced, and the retrieval precision is improved.

The invention discloses a PET image reconstruction method based on non-local features and total variation joint constraint. The method comprises the following steps: establishing a mathematical modelof a reconstruction problem, adding the low-rank constraint based on non-local features and adding the total variation constraint to perform PET image reconstruction. The low-rank constraint filters noises in the structural information of an image according to the non-local similarity feature of the image. Meanwhile, the defect that a step effect exists in the total variation method is overcome. The total variation serves as a constraint for edge protection and noise reduction based on pixel points. At the same time, the defect that the edge of an image exists on the basis of an image block isovercome. The convergence speed is accelerated. Therefore, the constraint joint solving means is effectively utilized, and the defects of two methods are overcome. The problems that the result is lowin resolution and the noise interference is generated in the PET image reconstruction process can be further solved. Compared with an experiment of an existing reconstruction method, the reconstruction method disclosed by the invention has the advantage that a good reconstruction effect can be obtained.

The invention discloses a manufacturing method of a bamboo spring bracket. The manufacturing method of the bamboo spring bracket comprises the following steps of bamboo chip pretreatment, gluing and assembly, molding and demolding. The manufacturing method of the bamboo spring bracket has the advantages that traditional metal and rubber spring materials are replaced, and natural bamboo wood is selected, thereby being capable of improving the environmental protection performance and natural degradability of the product; the bamboo wood is treated by using a high temperature poaching, bleaching,drying and carbonization method to obtain the better water-proof bamboo wood; and a bamboo spring material with better mechanical and elastic properties and shock absorption and noise reduction functions is generated by adopting bamboo chips with different thicknesses and steel tubes with different diameters and using a mode of stacking and gluing of multi-layer bamboo chips. The manufacturing method of the bamboo spring bracket can be applied to automobile cushions or middle plate beds.

The invention discloses a test method of noise reduction equipment, and the method is applied to a noise reduction test device, and comprises the following steps: presetting a plurality of noise reduction gain values; in the preset noise environment, acquiring the noise data of the to-be-tested noise reduction equipment under each noise reduction gain value, wherein the noise data comprises first noise data of the to-be-tested noise reduction equipment when noise reduction is started and second noise data of the to-be-tested noise reduction equipment when noise reduction is stopped; obtaining a first frequency response curve according to the first noise data under each noise reduction gain value, obtaining a second frequency response curve according to the second noise data under the noise reduction gain value, and calculating the variable quantity between the first frequency response curve and the second frequency response curve; and determining the noise reduction gain value corresponding to the maximum variable quantity as the optimal noise reduction gain value of the noise reduction equipment to be tested. According to the invention, the optimal noise reduction gain value of the to-be-tested noise reduction equipment can be determined, the optimal noise reduction effect of the to-be-tested noise reduction equipment is ensured, and the accuracy of a test result is improved. The invention further discloses a noise reduction testing device.

The invention discloses a split-type magnetic resonance imaging system, which comprises a body, a supporting table and a sliding table, wherein the upper end surface of the sliding table is provided with a noise reduction device; the noise reduction device comprises a noise reduction box and an upper cover body; a headrest is arranged in the noise reduction device; two sides of the headrest are symmetrically provided with a noise reduction earphone; the inner wall of the upper cover body is provided with an audio and video screen; noise reduction composite plates are embedded into the noise reduction box; two sides of the sliding table are symmetrically provided with sliding chutes; and a sound-proof plate is clamped in the sliding chutes in a sliding way. By use of the split-type magneticresonance imaging system, the sliding table is provided with the noise reduction box, multiple layers of noise reduction composite plates are embedded into the noise reduction box so as to realize multilevel absorption of noise, the noise reduction earphones and the audio and video screen are configured in the box body, while noise is isolated, multimedia audio and video service is provided for apatient, the attention of the patient is distracted, and the irritable emotion of the patient is lowered. The split-type magnetic resonance imaging system is also provided with the push-and-pull sound-proof plate, the sound-proof plate is for plugging the empty cavity of the body so as to further prevent noise from spreading, and through multiple noise reduction processing, a harmful degree of noise borne by the patient is greatly lowered.

The invention discloses a GIS mechanical fault diagnosis method based on mechanical state signal analysis, and relates to the technical field of power equipment monitoring, and the method comprises the steps: collecting a vibration signal of GIS equipment in a running state; performing noise reduction processing on the acquired vibration signal by using a pole symmetry mode decomposition (ESMD) method and a relative entropy method; extracting a feature vector contained in the signal by using Hilbert transformation; performing attribute reduction on the feature vectors by using a rough set theory and establishing a diagnosis decision table; and establishing a three-layer forward neural network fault diagnosis model according to the diagnosis characteristic decision table. Compared with a traditional method, the method can be applied to intelligent diagnosis of different types of mechanical faults of the GIS device, and has the advantages of being good in real-time performance and high in diagnosis accuracy.

A sample-and-hold circuit comprises a sampling capacitor; an amplifier transistor; and a noise reduction circuit including an integration capacitor and a feedback capacitor, the noise reduction circuit being configured to reduce noise via a four-phase operation including: an auto-zero phase in which the feedback capacitor is discharged, a feedback phase in which a gate voltage of the amplifier transistor is partially compensated through the feedback capacitor, an integration phase in which the integration capacitor is charged, and a feedforward phase in which the gate voltage of the amplifier transistor is fully compensated by a voltage on the integration capacitor through the feedback capacitor.

The invention discloses a central air-conditioning outdoor unit mounting mechanism. The central air-conditioning outdoor unit mounting mechanism comprises a transmission mechanism used for moving an outdoor unit. The transmission mechanism comprises a carrying platform. The bottom of the carrying platform is provided with a linkage block. The linkage block is provided with a ball screw. One end ofthe ball screw is connected with a transmission motor, and the other end of the ball screw is connected with a first locating block. A supporting sliding bar parallel to the ball screw further penetrates through the carrying platform. One end of the supporting sliding bar is fixedly connected to the first locating block. A polyurethane sound absorption shell used for noise reduction protection isarranged on the carrying platform. The polyurethane sound absorption shell is further provided with a noise wave reduction long pipe. The carrying platform is internally provided with a water collection tank. The water collection tank is internally provided with a flow guide pipe. The flow guide pipe extends out of the carrying platform. Through the central air-conditioning outdoor unit mountingmechanism, the large and heavy outdoor unit can be more convenient and safer to install, and the influence of noise and water dropping of the outdoor unit is reduced.

The invention discloses an intelligent voice communication processing method and belongs to the voice communication technology field. The method comprises steps that a voice communication signal is acquired; after one of multiple voice processing modules preset in a terminal device is activated, noise reduction of the voice communication signal is carried out through utilizing the voice processingmodule; the multiple voice processing modules have different noise reduction capabilities for the voice communication signal. Before the voice communication signal is acquired, a step of setting themultiple voice processing modules on the terminal device is comprised. The method is advantaged in that the voice communication signal after noise reduction has diversity, and the method can adapt todifferent environments and different users' requirements for voice signals.

The invention discloses a high-performance wood-plastic composite packaging box, which comprises a rectangular box cover and a rectangular box body made of high-performance wood-plastic composite packaging boards; a wear-resistant layer from the outside to the inside of the high-performance wood-plastic composite packaging boards , wood-plastic layer, the wear-resistant layer is an ultra-thin film made of one or more materials from transparent PVC, ASA, PE, PET and PMMA, and the wood-plastic layer is a shock-absorbing and sound-absorbing layer; The upper end of the box body; the box cover is bent sideways and downwards to form a skirt; the inner wall of the skirt of the box cover is provided with a protrusion Ⅰ surrounding the box body; The protrusion I is fastened under the protrusion II on the outer wall of the box, so that the box cover and the box body are tightly combined in the upper and lower directions; the further improvement is: the middle part of the box cover is concave to form a groove; there are several reinforcing ribs in the groove of the box cover plate; the stiffener plate in the groove of the cover intersects vertically. The invention has the advantages of wear resistance, long service life and good shock absorption and noise reduction effect.

The invention discloses a production process for rubber of a spherical hinge and belongs to the technical field of rubber production. The production process comprises six steps of compounding, shaping, first-section mixing, second-section mixing, vulcanization and after-treatment, wherein in the step S1, the weighing error of fines is required to be +/-2 g and the weighing error of coarse materials is required to be +/-10 g; in the step S2, the temperature of a roller of an open mill is 30-50 DEG C, and the roller spacing is less than 1 mm; after finish of the step S4, a glue stock needs to beplaced for 8 h or more, the surface of an iron piece needs to be subject to sand blasting before gluing and placed in a ventilated place for drying after gluing; in the step S5, the vulcanizing temperature is controlled to be 150-160 DEG C, the vulcanizing time is controlled to be 50-10 min, and the pressure is controlled to be 10-15 Mpa; and a product vulcanized in the step S6 is ground for edging before electroplating, and subject to extruding and reducing treatment. The production process provided by the invention can greatly improve the attractiveness, the vibration and noise reduction performance, the aging resistance and the fatigue resistance of rubber.

The invention relates to a silencing structure. The silencing structure comprises a first panel, a second panel and a filling structure, wherein the second panel is connected with the first panel; a containing space is formed between the second panel and the first panel; the filling structure is arranged in the containing space and can be used for reducing noise; and the filling structure sequentially comprises a first foaming layer, a reinforcing layer and a second foaming layer from one side of the first panel to one side of the second panel, and the reinforcing layer is a noise reduction material layer. The invention further relates to an air conditioner with the silencing structure. The filling structure formed by compounding three layers of structures is beneficial to improve the silencing and heat preservation performance of the silencing structure, the thickness of the silencing structure is reduced, and the transportation cost and the installation cost are reduced; the silencing structure can be directly used as a wallboard of an air conditioner unit, so that the complete silencing structure is formed on the outer portion of the air conditioner unit, and the silencing effect of the air conditioner unit is enhanced advantageously.

The invention discloses a spectral noise reduction method based on digital filtering. The spectral noise reduction method comprises the following steps of: 1, selecting a spectral signal S to be denoised, 2, designing a frequency-amplitude response function PF of the spectral signal S to be denoised, 3, converting the frequency-amplitude response function PF to obtain a corresponding filtering convolution transfer function H, 4, calculating the convolution Y of the spectral signal S to be denoised and the convolution transfer function H, 5, intercepting data with the same length as the S fromthe beginning of the Y, i.e., a result after noise reduction of the S, and 6, selecting parameters Wr and Wp with optimal filtering effects to obtain a corresponding optimal filtering convolution transfer function H, and then obtaining an optimal noise reduction result. Data points obtained through the method are more compact and uniform, an end point is not cut off, and the length of a data sequence can be selected according to the precision requirement; and polynomial order limitation does not exist, the Runge phenomenon occurring under a high-order condition does not exist, and the result is more precise.

The invention discloses a low-noise magnetic-suspension centrifugal air compressor which comprises a pedestal, a noise reduction casing, a centrifugal air compressor body and damping legs. The centrifugal air compressor body is installed on the upper surface of the pedestal via bolts, the centrifugal air compressor body internally provided with a driving cavity and a compression cavity along the axial direction successively, the inner wall of the driving cavity is provided with a stator, a rotating shaft is arranged in the driving cavity, and the rotating shaft is provided with a rotor in a position in the driving cavity. A bearing in a traditional centrifugal air compressor is replaced by a magnetic suspension bearing, the noise generated by the centrifugal air compressor body during workis lower, the noise reduction casing is added to the outer side of the centrifugal air compressor body on the pedestal to further absorb noise generated by the centrifugal air compressor body duringwork, and noise reduction holes with the Z-shaped cross sections are arranged in the noise reduction casing to ensure a better noise reduction effect of the casing.

The invention discloses a manual mouth pressing assembly which comprises a supporting rod assembly and a pressing rod, one end of the pressing rod is hinged to the top of the supporting rod assembly around a horizontal shaft, the manual mouth pressing assembly is characterized by further comprising a tension spring, and the two ends of the tension spring are connected to the supporting rod assembly and the pressing rod respectively. An artificial mouth noise reduction device comprises a shell used for containing an artificial mouth, an opening used for allowing sound waves generated by the artificial mouth to pass through is formed in the top of the shell, the artificial mouth noise reduction device is characterized by further comprising the artificial mouth pressing assembly, the artificial mouth pressing assembly is fixed to the shell, and the pressing rod is located on the opening. The artificial nozzle device comprises an artificial nozzle, and is characterized by further comprising the artificial nozzle noise reduction device.

The invention discloses a pipeline with noise reduction and thermal insulation. The pipeline comprises a pipeline body (1) and is characterized in that a hollow protective layer (2), a reinforced polyethylene layer (3) and an outer sheath (4) are sequentially arranged outside the pipeline line body (1) from inside to outside, and the hollow protective layer (2) is formed to be in a hollow shape by processing polycarbonate or polyethylene. By the structure provided by the invention, the leakproofness and thermal insulation of a primary pipeline can be greatly improved by the cooperation of the hollow protective layer, the reinforced polyethylene layer and the outer sheath, especially, the good noise reduction and thermal insulation effects can be realized when the pipeline is transported; however, the more remarkable rigidity can be provided for the pipeline by reinforcing the polyethylene layer, and the service life of the pipeline can be prolonged.

The present invention provides a noise reduction transformer, which includes a box body, a sound-absorbing barrier is arranged on both sides of the box body, and the bottom end of the sound-absorbing barrier is fixedly connected with the box body; the top of the box body is arranged There is a ventilation opening, and a fan, an electronic switch and a temperature sensor are arranged inside the ventilation opening; a ventilation duct is arranged at the bottom of the box body, and the ventilation duct is fixedly connected with the box body. The advantages of the present invention are: simple structure, multiple functions, various noise reduction methods, noise transmission can be blocked through the sound-absorbing barrier, noise can be attenuated during the transmission process through the upper ventilation device and the lower ventilation pipe, the method Practical, can achieve the purpose of noise reduction, energy saving and environmental protection.

The invention discloses a pickup and noise reduction method for a built-in earphone of a transmitting pickup microphone, and belongs to the technical field of earphones. According to the a built-in earphone of a transmitting pickup microphone, the transmitting and pickup microphone is arranged in an independent sealed cavity in the inner wall of the earphone, and the pickup and noise reduction method specifically comprises the following steps: (1) preprocessing a voice signal, including anti-aliasing, A/D conversion, pre-emphasis and central wave elimination processes; (2) channel mapping processing, including four stages of LPC-based feature extraction, channel mapping, speech synthesis and de-emphasis; and (3) voice focusing enhancement processing, wherein the voice focusing enhancementprocessing comprises power spectrum estimation and amplitude attenuation processing, voice centering, high-pass filtering, high-frequency enhancement, dynamic compression and later-stage enhancement processing, and pickup and noise reduction are realized. According to the pickup and noise reduction method disclosed by the invention, the definition, intelligibility and the like of voice transmission on a full frequency band are obviously enhanced; AND the structure is simple and the cost is low.

The invention relates to a low-noise solenoid valve assembly used for a PES headlamp. The low-noise solenoid valve assembly comprises an installing base, a visor and a solenoid valve. Supports used for enabling lens modules to be connected are arranged on the two sides of the installing base. The solenoid valve is installed on the upper portion of the installing base through a solenoid base. Output shafts on the two sides of the solenoid valve are connected with two support pins on the visor. One or more flexible damping blocks is/are installed on the solenoid valve base or/and a solenoid valve shell. At least one flexible damping pad is installed on the visor, and the lower portions of the flexible damping pads stretch out of the lower surface of the visor. In addition, when the solenoid valve drives the visor to rotate upwards, the visor is connected with the flexile damping block, and when the solenoid valve drives the visor to rotate downwards, the visor is connected with a fixing piece on the installing base through the flexible damping pads. The low-noise solenoid valve assembly is simple in structure, and damping and noise reduction can be conducted on the visor during distance light/passing light adjustment of the visor.