40results about How to "Guaranteed Compression Efficiency" patented technology

The invention relates to a H.264 video information hiding method tightly coupled to a compression coding process. The core concept of the H.264 video information hiding method is as follows: on the basis of complete coding, high-security or high-capacity information hiding without distortion drift phenomenon is realized in a manner of tightly coupling to compression coding. The method is designed based on complete compressing and coding, so that the distortion drift phenomenon can be completely avoided; simultaneously, the concept of an independent coding unit is introduced; therefore, users can perform different configuration of a design framework according to different requirements, so that demand preferences on the security or the embedding capacity can be satisfied; the method is different from the past any H.264 video steganography method; and thus, the method disclosed by the invention is particularly suitable for a hiding communication scene having low real-time requests and relatively high algorithm performance (the security or the embedding capacity) requests.

It is intended to provide a centrifugal compressor equipped with a resin housing which does not compression efficiency without offsetting merits such as weight saving and cost reduction. A centrifugal compressor 10 includes a resin housing 20 formed by a volute section 20a and a path forming section 20b. An impeller 14 fixed to a rotating shaft 12 in a center of the path forming section 20b. An annular shroud 22 is arranged in a depression 20b 2 carved in an inner wall 20b 1 of the path forming section 20b. The annular shroud 22 forms an outer wall of a flow path c for a gas to be compressed and an outer wall of a diffuser d (static-pressure increasing region). A downstream end of the annular shroud 22 is fixed via a spacer 24 to a wall 32 by a bolt 6. The wall 32 constitutes a part of a bearing housing 30. Even when the resin housing 20 thermally deforms, a clearance T between the annular shroud 22 and a curved profile 16a of the blade 16 can be kept at a set dimension.

The invention discloses a compression method for three-dimensional space measurement result data, and the method comprises the steps: obtaining point cloud data: obtaining initial data after scanningan object through employing laser radar equipment, and converting the initial data through employing a trigonometric function to obtain rectangular coordinate system data; carrying out uniform mesh generation of the point cloud data, and carryig out proportional generation on the point cloud data according to the transmitted parameters, wherein a uniform generation mode is adopted for point clouddata generation; removing discrete abnormal points of the point cloud data, wherein discrete points deviating from the whole and abnormal points exceeding a normal value are generated in the laser radar operation scanning process, and the discrete abnormal points are removed by applying a difference value; extracting feature points, performing judging according to the point location data values inthe grids, and if the maximum and minimum difference values in the grids are greater than the height values, indicating that the feature points exist in the grids; carrying out point cloud compression, carrying out compression in a certain proportion according to the divided grids, and adding the extracted feature points to the compressed point cloud data.

The invention discloses a HEVC inter-frame prediction mode selection method and device, which are used to reduce the complexity of inter-frame prediction mode selection and improve processing efficiency. The method is: when determining that the pixel size of the coding unit CU block of the current frame is within a set range, calculate and obtain the first rate-distortion cost of each inter-frame prediction mode of the CU block based on the absolute error and the SAD algorithm; according to the obtained The first rate-distortion cost of each inter-frame prediction mode, the optimal first rate-distortion cost SadCost0 and the corresponding first inter-frame prediction mode and the suboptimal first rate-distortion cost SadCost1 and the corresponding second inter-frame prediction mode ; When it is determined that (SadCost1-SadCost0) / SadCost0 is greater than a threshold, select the first inter-frame prediction mode as the optimal inter-frame prediction mode of the CU block.

The invention discloses a compressor and a control method thereof, and belongs to the technical field of compressors. The compressor comprises a stop mechanism arranged on an air cylinder end cover and provided with a stop piece capable of moving telescopically relative to an exhaust valve plate, and the stop piece is used for limiting the stop position where the exhaust valve plate moves backwards when the compressor exhausts air; a controller is also included and used for obtaining operation parameters when the compressor operates, the operation parameters are one of the operation power andthe operation frequency, and the stop position of the stop piece of the stop mechanism is adjusted according to a load parameter. According to the compressor provided by the invention, the stop mechanism and the controller are additionally arranged in an existing compressor, and the stop position of the stop piece of the stop mechanism on the exhaust valve plate can be adjusted by utilizing the controller, so that the maximum retreating distance of the exhaust valve plate can be limited again; and the time for re-adjusting the exhaust valve plate to the position for closing an exhaust valve port can be shortened, so that the exhaust valve port can be quickly re-closed after the exhaust valve plate finishes exhausting.

The invention discloses a multi-cylinder rotary type compressor. The multi-cylinder rotary type compressor comprises a seal shell, a motor and a compressing mechanism portion, wherein the seal shell is composed of a cylindrical shell and end plates sealing the opening ends of the cylindrical shell; the motor is composed of a stator and a rotor; the space between two adjacent air cylinders of the compressing mechanism portion is provided with an intermediate partition plate; the outer circumferential wall of the stator is composed of multiple round edges which are connected with the inner circumferential wall of the cylindrical shell and multiple notch edges which are not connected with the inner circumferential wall of the cylindrical shell; the outer circumferential wall of the intermediate partition plate is composed of multiple jointing edges which are connected with the inner circumferential wall of the cylindrical shell and multiple gap edges which are not connected with the inner circumferential wall of the cylindrical shell; the multiple round edges and the multiple jointing edges are arranged in a one-to-one-correspondence mode in the axial direction of the cylindrical shell. According to the multi-cylinder rotary type compressor, deformation of the compressing mechanism portion can be avoided, centering adjustment precision of the stator and the rotor can be guaranteed, and therefore compression efficiency and motor performance are guaranteed.

The invention discloses a rotating compressor and a refrigeration system provided with the same. An electro-dynamic motor, a rotating compression mechanism and lubricating oil are accommodated in a closed casing of the rotating compressor, a suction pipe communicated with the interior of the casing is arranged on the casing, and the motor comprises a stator and a rotor. The compression mechanism comprises an eccentric shaft for fixing the rotor, a main bearing, an auxiliary bearing, an air cylinder connected with the main bearing and the auxiliary bearing and a suction muffler arranged on the main bearing, wherein the main bearing and the auxiliary bearing are used for supporting the eccentric shaft in a sliding manner; a rotating barrel is fixed on the side, adjacent to the main bearing, of the rotor, and is communicated with the suction muffler; low-pressure refrigerant sucked from the suction pipe reaches the inner side of the rotating barrel from the outer side of the rotating barrel and flows into a compression cavity of the air cylinder through the suction muffler. According to the rotating compressor, the rotating barrel can have an air-liquid separation function, the compression efficiency is guaranteed, and liquid compression of the compression cavity is avoided.

The invention discloses a rotary air compressor head which comprises a cylinder body, a translation piston, a slide plate and a crankshaft, wherein a rotation center of the crankshaft is concentric with the cylinder body; the translation piston is arranged on the crankshaft; the side face of an external circumference of the translation piston is tangent with the inner side face of the circular cylinder body to form a crescent operation cavity; an air inlet channel and an air outlet channel communicated with the operation cavity are arranged on the cylinder body; the translation piston is rotationally connected with the crankshaft via a bearing; a mounting groove for mounting the slide plate is formed in the side face of an internal circumference of the cylinder body; the slide plate is mounted in the mounting groove; one end of the slide plate is contacted with the translation piston; an elastic return piece is arranged at one end, far away from the translation piston, of the slide plate; a slide groove is formed in a side wall of the mounting groove; a slide bar is arranged in the slide groove and pushes against the side face of the slide plate; and an elastic slide piece is arranged at one end, far away from the slide plate, of the slide bar. The air compressor head can keep stable compression efficiency and is long in service life, and the maintenance cost is lowered effectively.

The invention discloses a symmetrical balance-type free piston compressor, in particular to a clearance control method of a symmetrical balance-type free piston compressor, which comprises the following steps of: (1) setting a target clearance H and an initial steering position S on a control device; (2) confirming the steering position Sn of the same gas cylinder piston in the current compression period Tn according to delta Hn; (3) sending a steering instruction to a hydraulic device according to the Sn and the gas cylinder piston position signal measured by a displacement sensor; and (4) measuring the practical endpoint position of the current compression period Tn by the displacement sensor, calculating a practical clearance Hn. before the step (2) of the current compression period orafter the step (4) of the last compression period Tn-1, calculating the gas correction value delta Hn of the gas cylinder piston in the current compression period Tn according to H and the practical clearance Hn-1 of the last compression period, wherein the steering position of the first compression period T1 is S. By compensating H, the invention prevents the practical clearance from increasing with a pressure difference and improves the efficiency of the compressor.

The invention relates to an intra-frame fast coding method, which comprises the following steps of: when a coding unit is coded, firstly trying an intra-frame coding method by the current coding unit to obtain an optimal intra-frame prediction mode, rate distortion cost and an all-zero block mark; then, deciding a quadtree division mode according to the decided intra-frame coding information; then, according to the decided intra-frame coding information and the decided division result and information of the quadtree, deciding a binary tree division mode; and finally, according to the decided intra-frame coding information and the decided division results and information of the quadtree and the binary tree, deciding the division mode of the extended quadtree.

A dust collection barrel provided with a speed-changing compressed structure comprises a bottom cover connected at the bottom end of a barrel body, a baffle, a compressed plate and a connecting shaft driving the compressed plate to rotate, wherein the baffle and the compressed plate are arranged inside the barrel body, and a high-speed gear, a low-speed gear and a speed regulating knob which is connected with the high-speed gear and the low-speed gear are arranged on the lower side of the bottom cover. According to the dust collection barrel provided with the speed-changing compressed structure, the high-speed gear, the low-speed gear and the speed regulating knob which is connected with the high-speed gear and the low-speed gear are arranged at the bottom of the dust collection barrel. The speed regulating knob is rotated, the gears driving the compressed plate are switched, and the rotating speed of the compressed plate is changed. A user can regulate the rotating speed of the compressed plate of the dust collection barrel according to actual needs of a dust collector and types of inhaled dust. For example, if large and hard dust is needed to be inhaled, the speed is regulated to be slow, and when floccus soft dust is needed to be inhaled, the speed is regulated to be fast. Therefore, compressing efficiency of the dust collector is ensured, and service life of the compressed plate is prolonged.

The invention provides a refrigerating and freezing device. The refrigerating and freezing device comprises a tank, a nitrogen-making device and a sealed housing, wherein a storage chamber for storing goods is defined in the tank; the nitrogen-making device is used for providing nitrogen for the storage chamber, and the nitrogen-making device is provided with a nitrogen-oxygen separating assembly for separating nitrogen from oxygen in air, and an air compressor for providing compressed air for the nitrogen-oxygen separating assembly; and the sealed housing defines a containing space, and the air compressor is arranged in the containing space of the sealed housing. Due to the fact that the air compressor is arranged in the sealed housing, noise generated during operation of the air compressor can be lowered, and user experience is improved.

The invention discloses a rotary air compressor head which comprises a cylinder body, a translation piston, a slide plate and a crankshaft, wherein a rotation center of the crankshaft is concentric with the cylinder body; the translation piston is arranged on the crankshaft; the side face of an external circumference of the translation piston is tangent with the inner side face of the circular cylinder body to form a crescent operation cavity; an air inlet channel and an air outlet channel communicated with the operation cavity are arranged on the cylinder body; the translation piston is rotationally connected with the crankshaft via a bearing; a mounting groove for mounting the slide plate is formed in the side face of an internal circumference of the cylinder body; the slide plate is mounted in the mounting groove; one end of the slide plate is contacted with the translation piston; an elastic return piece is arranged at one end, far away from the translation piston, of the slide plate; a slide groove is formed in a side wall of the mounting groove; a slide bar is arranged in the slide groove and pushes against the side face of the slide plate; and an elastic slide piece is arranged at one end, far away from the slide plate, of the slide bar. The air compressor head can keep stable compression efficiency and is long in service life, and the maintenance cost is lowered effectively.