267 results about "Expansion factor" patented technology

A method of correcting wavefront aberrations of an eye includes determining a high precision conventional intrastromal corneal ablation profile based on a direct removal of the intrastromal corneal tissue. An expanded ablation volume profile is constructed based on the direct tissue removal profile and the expanded tissue volume is to be ablated instead to correct to the wavefront aberrations. The thickness of the ablated profile of a conventional ablation profile is expanded by an expansion factor (Nc-1) / (Nm-Nc), Nc is the index of refraction of the cornea and Nm the index of fill material. An expanded ablation volume filled with the fill material produces the effect of correcting wavefront aberrations as if a much smaller tissue volume were ablated without the fill material.

The invention provides a method and device for encoding a low-density parity check code. The method comprises the following steps of: comparing a mother code rate and a transmission code rate which are supported by a uniform basic matrix; determining the length K'of an input information grouping bit according to a comparison result; determining an encoding matrix of the low-density parity check (LDPC) code according to the uniform basic matrix and an expansion factor; determining an information bit to be encoded according to the received information grouping bit with the length of K'; and performing LDPC encoding on the information bit to be encoded by using the encoding matrix, and processing a mother code word bit obtained through encoding to acquire a code word bit to be transmitted. By the method and device for encoding the LDPC code, the basic matrix and the expansion factor are determined; the input information grouping length is determined or the encoding matrix is processed according to the received transmission code rate, so the code word which is in accordance with the transmission code rate can be acquired; on the basis of the optimal performance, the changeability of the code rate is realized; furthermore, the hardware design complexity is reduced and the cost is lower.

An encoding method, decoding method, encoding device and decoding device for a structured LDPC. The method comprises: determining a basic matrix used for encoding and containing K0 pairs which are adjacent up and down; and according to the basic matrix and an expansion factor corresponding thereto, completing an LDPC encoding operation of obtaining Nb × z bits of code words from (Nb - Mb) × z bits of source data, where z is the expansion factor, and z is a positive integer which is greater than or equal to 1. The provided technical solution is suitable for the encoding and decoding of structured LDPC, thereby realizing the encoding and decoding of LDPC at high production line speed.

The invention discloses lead-free glass powder, a preparation method thereof, silver paste containing the glass powder and a crystal silicon solar cell manufactured by using the silver paste. The lead-free glass powder comprises the following components in percentage by weight: 20-30 percent of SiO2, 2-15 percent of B2O3, 40-70 percent of Bi2O3, 1-10 percent of ZnO, 1-10 percent of Al2O3 and 1-5 percent of BaO. The preparation method comprises the following steps of: (1) weighing the components for preparing a mixture; (2) putting the mixture into a crucible for melting; (3) performing water quenching on molten glass; (4) drying; (5) smashing the mixture into powder by planetary ball milling; and (6) screening. The needed silver paste is prepared from the lead-free glass powder, silver powder, an additive and an organic carrier. A solar panel front face electrode and a grid line are manufactured by performing screen printing and sintering on conductive silver paste on a cell substrate, so that the needed solar cell is obtained. The lead-free glass powder has low melting temperature, low softening temperature and low linear expansion factor.

The invention discloses graphene oxide modified compound type heat conducting silicone rubber and a preparation method thereof. According to the preparation method, the compound type silicon resin with high heat conduction property and low expansion factor is prepared by using 0.5-1 part of graphene oxide as heat conducting stuffing and an inorganic crosslinking agent, 10-50 parts of nanometer SiO2 as the heat conducting stuffing, 5-30 parts of compound of two MQ silicone resin containing hydroxyl and vinyl and different in viscosity as a special bonding modifying agent, 1-10 parts of organic hydrogen polysiloxane as an organic crosslinking agent, 0.1-2 parts of platinum complex as a catalyst, 0.01-0.001 part of alkynol substance as an inhibitor and 60-100 parts of polysiloxane resin as base rubber and adopting a nanometer compounding method, wherein the graphene oxide is partially modified by a silane coupling agent, and the nanometer SiO2 is prepared by a sol-gel method. The compound type silicon resin can be widely applied to encapsulation of various electronic components and plays a role in shock absorption and heat dissipation.

The invention belongs to the communication technology field, relating to a channel coding transmission method based on an unequal mistake protection fountain code. The method comprises the following steps: classifying a signal source according to importance; carrying out virtual expansion on each r layer data according to expansion factor; putting obtained virtual extension layer data into each window; carrying out progressive analysis on the window data with and / or tree algorithm; carrying out LT coding and index replacement according to robustness solitary wave degree; obtaining coding word; carrying out transmission; carrying out decoding. According to the invention, protection of important data is reinforced, simultaneously protection of less important data is not decreased to guarantee to reliable transmission of data.

The invention discloses a quasi-cyclic low density parity check code (LDPC) construction method and a device based on protographs. The protographs are expanded for two times in the construction method. A first expansion time L1 is smaller. A correcting progressive edge growth (PEG) algorithm is adopted to remove multiple edges of protographs. The girths of codes which are expanded are increased. A second expansion time is L2 and a cyclic shift offset is selected for connection which is established in the first expansion. Each connection corresponds to a unit cyclic matrix, wherein the size of the unit cyclic matrix is L2 * L2. The method references a local optimization idea of the PEG algorithm to construct a basis matrix of the quasi-cyclic LDPC code. The connection is established between each row of variable nodes and checking nodes and is confirmed in corresponding cyclic shift offset process. According to the correcting PEG algorithm, new rings formed in the basis matrix caused by the newly established connection are gone through. The fact that expansion factors A of the rings are larger than one is guaranteed. Thus, the rings with length of four are avoided. The number of short rings is reduced. The short rings which are small in connectivity emerge in a checking matrix are avoided by utilizing an ACE multiplication principle.

The embodiment of the invention firstly provides a method for coding or decoding low-density parity-check (LDPC) codes with variable code length, which comprises the steps of: obtaining a base exponent matrix of the LDPC codes, and grouping code lengths during the construction of the base exponent matrix; modifying the base exponent matrix according to the grouped modifying factor to obtain a grouping exponent matrix corresponding to the grouped modifying factor; expanding the exponent matrix according to an expansion factor corresponding to the code length in the grouping to obtain an LDPC matrix corresponding to the code length; and coding or decoding according to the LDPC matrix. By adopting the method for coding or decoding the low-density parity-check (LDPC) codes with variable code length and adopting grouping and repeatedly constructing, the obtained LDPC codes do not have short links at each required code length, and the performance is greatly improved. Meanwhile, the embodiment of the invention also provides a device for coding or decoding, a coder and decoder.

A video image display device is provided. The device includes an expansion factor deriving unit deriving and outputting an expansion factor for each frame of the video image data, for use in a luminance range expansion process for expanding a luminance range of the video image data on the basis of an image characterizing quantity related to the luminance of the video image data corresponding to the frame; a luminance range expansion processing unit performing the luminance range expansion process to the video image data on the basis of the expansion factor output from the expansion factor deriving unit; and a scene-change detecting unit detecting a change in a screen state of a present frame into a black screen state on the basis of the video image data and detecting a scene-change indicating that the scene of the video image has changed.

The invention relates to a preparation method of a carbon-graphite composite material. The preparation method is characterized in that the carbon-graphite composite material is prepared from the following raw materials in percentage by weight: 1.5-2.5% of carbon black, 5%-8% of graphite with the particle size smaller than or equal to 1mm, 25%-30% of calcined petroleum coke powder with the particle size smaller than or equal to 0.075mm, 15%-20% of calcined petroleum coke with the particle size of 1mm-4mm, 10%-15% of electric calcined anthracite with the particle size of 4mm-10mm, 5%-10% of electric calcined anthracite with the particle size of 10mm-16mm, 5%-15% of calcined pitch coke with the particle size of 10mm-16mm, 18%-20% of coal pitch and short carbon fiber, wherein short carbon fiber is equal to 1%-3% of total weight of the raw materials. The carbon-graphite composite material is prepared by the steps of material preparation, mixed kneading, forming, roasting and graphitization and is excellent in performance, high in breaking strength, relatively good in thermal shock resistance and relatively low in expansion factor; the carbon-graphite composite material does not crack and break and has good stability.

The embodiments of the present invention provide a method of constructing parity-check matrix of LDPC code. The method comprises the following steps of: constructing a MB×NB base matrix B for an LDPC code with code rate R and code length N, wherein MB=M / K, NB=N / K, M=N (1−R), K is the expansion factor of the base matrix, Kεφ, and φ is the set of the common factors of M and N; and replacing the elements of the base matrix B with a K×K matrix, and expanding the base matrix B into a parity-check matrix H with size of M×N for the encoding or decoding of the LDPC code. An encoding method and apparatus of LDPC code are also provided by the embodiments of the present invention. The technical solutions provided by the embodiments of the present invention can construct LDPC codes with good performance, solve the storage problem of the parity-check matrix, and effectively reduce the implementation complexity of the encoding apparatus.

A system and method for expansion and reduction of images uses pyramidal retargeting to reduce complexity in image resizing. An image pyramid may be generated dependent on a function of pixel data or energy values for each pixel of an input image. An image resizing solution may be developed by applying seam carving techniques to a lower-resolution version of the input image represented by the image pyramid, and may identify bands in the higher-resolution input image to be resized. A resizing operation may then be applied the bands based on local content. The resizing operation may include seam carving techniques, scaling techniques, and / or hybrid resizing techniques, and may be selectable by a user. Identified bands may be expanded to obtain a smoother solution. Different bands may be expanded by different amounts, based on local content. The number of bands and the expansion factors may be configurable based on user input.

A signal processing method divides a first signal of two signals to be compared in similarity into smaller regions, selects one of the regions, and calculates the correlation of the selected one with the other second signal. The method finds a time difference, an expansion factor, and a similarity in one region in which the maximum similarity as the square of the correlation is obtained, and performs integration in the position represented by the time difference and the expansion factor of values based on similarities. The method performs similar processing on all the regions, and evaluates similarity by, in a peak where the integrated value of similarities is a maximum, compares its magnitude with a threshold value. The region corresponding to the peak can be extracted.

The invention discloses a production formula and a manufacturing method of a modified ultra-high molecular weight polyethylene resin. The modified ultra-high molecular weight polyethylene resin comprises an ultra-high molecular weight polyethylene resin, molybdenum disulfide, nano graphite, superfine talcum powder, ethylene bis stearamide, polytetrafluoroethylene and benzoyl peroxide. The modified ultra-high molecular weight polyethylene resin has ultra high wear resistance and favorable temperature tolerance and self-lubricating property. Compared with the resin before the modification, the modified resin has the advantages that the heat distortion temperature is increased by 38 DEG C, the Shore hardness is improved by 20 degrees, the friction factor is decreased by 40%, and the expansion factor is decreased by 30%. The modified resin is widely used for producing products such as gears, valves, artificial joints, skis, oil field transfer pipelines and the like.

Low density parity check code (LDPC) base parity check matrices and the method for use thereof in communication systems. The method of expanding the base check parity matrix is described. Examples of expanded LDPC codes with different code lengths and expansion factors are also shown.

The invention discloses a connecting method for sintering / welding titanium-steel dissimilar metal. The differences of physical properties of the titanium and the steel which are dissimilar metal are large, and the titanium and the steel are hard to connect through conventional methods. According to the connecting method, firstly, the titanium or titanium alloy, V-Cu gradient alloy powder C1, C2 and C3 and stainless steel are placed in a die one by one to be pressed in advance, and secondly, the die is placed in a sintering device to be sintered in a spark plasma mode, wherein the V-Cu gradient alloy powder C1, C2 and C3 are composed of mixed powder which is formed by mixing a plurality of kinds of metal powder according to different proportions, and the expansion factor gradient of the V-Cu gradient alloy powder C1, the expansion factor gradient of the V-Cu gradient alloy powder C2 and the expansion factor gradient of the V-Cu gradient alloy powder C3 are matched with one another. The titanium or the titanium alloy and the stainless steel are directly connected and formed at a time in a sintering mode, the method of spark plasma sintering is particularly suitable for sintering molding of V-Cu gradient connectors of the titanium and the stainless steel, and a titanium-steel dissimilar metal sintering / welding connector can have a high mechanical property.

The invention provides a rapid-annealing method for growing large-size sapphire single-crystal with the SAPMAC method. The SAPMAC method is adopted for growing sapphire single-crystal; after growing is finished, the vacuum degree of a crystal growing furnace is kept; electric power source is not cut off; heating power is lowered according to certain temperature reduction procedure until heating power is zero; and then inert gases are led in for rapid cooling. The invention has the beneficial effects that: 1. crystal dislocation density can be lowered, the lattice vacancy of crystal with big diameter and high expansion factor can be lowered, defect concentration such as distortion of lattice, dislocation and the like can be eliminated, crystal cleavage is avoided, and crystal quality and utilization factor can be improved; 2. in-situ annealing of crystal can be realized, crystal growing cycle can be shortened under the precondition of ensuring crystal quality; and 3. production cost can be lowered.

The invention relates to a virtual expansion method of laser television color gamut based on a 1931CIE (Coherent Infrared Energy)-XYZ system. The invention has the advantages that the features of laser large color gamut and high saturation are fully utilized so that the expression color of television images is enriched, the images presented are more graduated and more close to the true color of the nature, and the like. The method comprises the following steps: step 1. performing coordinate transformation under the 1931CIE-RGB system to obtain a coordinate under the CIE1931 color space; step 2. performing laser display matrix transformation; step 3, solving a virtual expansion factor; step 4, expanding equal tone; and step 5, establishing a three-dimensional lookup table to obtain virtual expansion numerical value to be output according to RGB value for inputting television signals by a cube interpolation algorithm method so as to realize virtual expansion finally.

The invention discloses a two-dimensional wake flow numerical simulation method. The method is characterized by comprising the steps that 1, wake flow expansion factors are calculated; 2, based on the step 1, the wake flow air speed under a Park model is calculated; 3, the initial wake flow radius under the Park model is corrected; 4, based on the step 2 and the step 3, the wake flow air speed under the corrected Park model is calculated; 5, based on the step 4, a new wake flow model is set up and named as a Park-Polynomial model; 6, the wake flow air speed under the Park-Polynomial model is calculated. By means of the two-dimensional wake flow numerical simulation method, the air speed of a wake flow zone can be well simulated, the precision is approximately consistent with testing results, the radial distribution better accords with a real flow field, and the advantages of a simple mode, easy encoding, efficient calculation and the like of an engineering model are achieved.

The invention discloses a method for preparing a high-strength water-absorbing expansive polymer plugging agent and belongs to the technical field of preparation of plugging agents. By virtue of a liquid polymer composed of acrylic acid, acrylamide and an acrylonitrile monomer, the acrylamide has high water absorbing capacity of the amide group, so that the water-absorbing expansion rate of the polymer plugging agent is improved; due to the addition of a bisphenol A epoxy resin and a phenolic resin, the bisphenol A epoxy resin and the phenolic resin are modified by using a modified glass fiberflexibilizer, so that the strength and viscosity of the polymer plugging agent are improved; by utilizing modification of sodium fluoride and sodium hydroxide on the bentonite and montmorillonoid inorganic matters, the modified bentonite and montmorillonoid have high expansion factor, and by utilizing sodium persulfate initiation, calcium chloride solidification, cross-linking of the N,N-methylenebis acrylamide and adhesion of polyvinylidene fluoride, the calcium chloride is induced to carry out a cross-linking reaction by the sodium persulfate. Moreover, the plugging agent can absorb water to expand in the reaction process, the strength and water-absorbing expansion rate of the polymer plugging agent are improved, and the polymer plugging agent has wide application prospects.

The invention discloses a GBAS integrity warning threshold estimation method based on a Gaussian expansion method. The method comprises the following steps: calculating integrity sample data accordingto integrity monitoring criteria; then, dividing parameter intervals according to the satellite elevation angle, and calculating mean value and standard deviation of the sample data in each interval;carrying out normalization on the sample data; then, drawing a distribution histogram of the normalized data; and finally, determining the optimal expansion factor through the Gaussian expansion method and generating a warning threshold value. The method meets requirements of a ground-based augmentation system for false alarm rate, and meanwhile, the integrity warning threshold determined throughthe Gaussian expansion method based on system actual data accords with the actual characteristics of the system more.

A zoom system for an illumination device of a microlithographic projection exposure system is configured in the form of a focal-length zoom lens. The lenses of the zoom system define an object plane (6) and an image plane (8) that is a Fourier transform of the object plane. The zoom system is characterized by a large expansion of the illuminated area in the image plane, where expansion factors (D) in excess of four are feasible and are obtained by employing lens groups (33, 36) that are movable over large moving ranges.

The invention provides a threshold value determining method for local enhanced system completeness monitoring. According to the method, the corresponding quantile is calculated according to the false alarm rate requirements of a local enhanced system; then, a satellite elevation angle interval is divided according to actual use requirements, and in addition, collected observation quantity data are grouped according to the intervals; the average value and the standard difference of each group of data are calculated, and normalization processing is carried out; then, the expansion Gaussian distribution is utilized for enveloping the probability density distribution of the normalization data for thus calculating an expansion factor; the quantile, the average value, the standard value and the expansion factor are used for calculating the threshold value of each interval; finally, the threshold value of each interval is utilized for fitting to obtain a threshold value curve. The threshold value determining method has the advantages that the requirements of the local enhanced system on the false alarm rate are met, and meanwhile, the threshold value is determined by using the data collected by the system per se, so the threshold value determining method better conforms to the actual characteristics of the system.

The invention relates to a cordierite-mullite kiln furniture material with high thermal shock resistance and belongs to the field of the kiln furniture material. According to the kiln furniture material, floating beads, cordierite clinker, cordierite-mullite waste blanks, chamotte clay and wood meal are taken as aggregate, talc, aluminum oxide and clay are taken as a substrate material, a solid substance of the kiln furniture material is prepared from the aggregate, the substrate material and an additive yellow dextrin, water is added to the solid substance and is stirred, and a mixture is formed. After optimization, the requirement that the final composition is consistent with the composition of the cordierite-mullite kiln furniture material in the market is met, and the firing temperatures also keep consistent; the material has the advantages that the expansion factor is low, the number of thermal shock times is large, the volume density is low and the strength is high, and the material is suitable for being used as the excellent cordierite-mullite kiln furniture material with high thermal shock resistance.

The invention discloses a graphite surface titanium metallization method and a product manufactured with the same to solve the problem that when graphite is connected with Cu or Cu alloy, it is difficult to wet graphite with liquid metal, the difference between graphite and Cu or Cu alloy is large in terms of expansion factor and elasticity modulus, and connection is hard. According to the method, a titanium film is deposited on the surface of a graphite substrate with the magnetron sputtering method, and then hot isostatic pressing is conducted on the deposited titanium film, so that a titanium thin film is formed on the surface of the graphite substrate. The problem that coating-substrate combination strength of a surface titanium metallization layer is low during diffusion bonding of the non-metal material graphite can be effectively solved, and the metal titanium thin film high in coating-substrate combination strength can be prepared on the graphite substrate. According to the titanium thin film, the concentration of titanium becomes larger gradually from the graphite substrate to the outside in a gradient mode, and the strength of combination between a titanium coating and the substrate is high. The method can meet the requirement for research of fusion reactor plasma facing materials and has great significance for development of fusion reactor elements.

To judge impacts with a three-dimensional model constituted by a plurality of polygons, rapidly and accurately. The vertex-coordinates of the partial models constituting the three-dimensional model are represented by central-coordinates being the average values of the maximum values and minimum values of respective coordinate components, an expansion factor for achieving prescribed values by multiplication by the differentials between the maximum values and minimum values of each coordinate component, and converted vertex-coordinates obtained by subtracting the central-coordinates from the respective vertex-coordinates and then multiplying by the expansion factor; the central-coordinates and the expansion factor being stored as floating-point values, and the converted vertex-coordinates being stored as integers (ST3). Moreover, a judgement subject partial model, being a partial model of the partial models constituting the three-dimensional model to which impact judgement is to be applied, is selected (ST1), and impact judgement is performed with respect to this judgement subject partial model (ST7-ST11).

The invention belongs to the technical field of electronic communication, and discloses a method and a system for suppressing ACE of a peak-to-average ratio of a high-order modulation OFDM signal. Themethod comprises steps of redefining expansion rules of constellation in frequency domain; dynamically adjusting a peak clipping threshold according to the peak-to-average ratio of the current signalto obtain an effective peak-to-average ratio suppression gain, and enabling the bit error rate of the system not to be seriously deteriorated; after the effective peak-to-average ratio suppression gain is obtained, obtaining a proper expansion factor by correcting a least square approximation formula, amplifying an original time domain signal, and enhancing the signal peak-to-average ratio suppression effect. Based on the optimization strategy, the peak-to-average ratio of OFDM transmission signals is remarkably reduced under the condition that only one iteration is needed, the implementationcomplexity of the system is greatly reduced, meanwhile, it is guaranteed that the bit error rate and the loss of the out-of-band power spectrum performance are within an acceptable range, and the overall performance of the OFDM system is effectively improved.

The invention discloses an RBF (Radial Basis Function) neural network-based coal and gas outburst prediction method. The method comprises the steps of 1, performing dimensionality reduction on feature data of coal and gas outburst, and performing normalization processing on the feature data subjected to the dimensionality reduction to obtain normalized feature data; 2, clustering the normalized feature data by using a K-mean algorithm and calculating the center of an RBF; 3, training an RBF neural network on the normalized feature data, and introducing an optimal expansion factor and an optimal weight when the number of neurons in a hidden layer is determined by an adaptive differential evolution algorithm; 4, increasing the number of the neurons in the hidden layer, and repeating the steps 2-3 to obtain global optimal parameters of the RBF neural network, thereby determining a prediction model of the RBF neural network; and 5, predicting test data by using the prediction model of the RBF neural network. According to the method, the optimal parameter adaptive problem of the RBF neural network can be solved, so that the coal and gas outburst can be quickly and accurately predicted.

This invention relates to receiver combined with equilibrium and integration technique, which comprises the following parts: equilibrium receiver to receive the expansion factors activated and to process the interference signals through equilibrium technique; integration test receiver to receive the data expansion factors activated and process the multiple-address interference between signals though integration technique; selector to selectively output; controller to activate the said receiver and test receiver according to senior expansion factors and to control the output of the receivers.

The invention provides a structured LDPC coding and decoding method and device. The coding method comprises the following steps: a basic matrix used for coding operation is determined, and the basic matrix comprises one or more sub-matrixes; the sub-matrixes comprise a top left corner matrix Hb1 and a top left corner matrix Hb2, a number of lines and a number of rows of each of the top left corner matrix Hb1 and the top left corner matrix Hb2 are lower than a number of lines and a number of rows of the basic matrix, and the top left corner matrix Hb1 is a top left corner matrix for the top left corner matrix Hb2; according to the basic matrix and an expansion factor Z corresponding to the basic matrix, LDPC coding operation is conducted on a source information bit sequence, a code word sequence is obtained, and Z is a positive integer which is larger than or equal to 1. Via adoption of the structured LDPC coding and decoding method and device disclosed a technical solution provided in the invention, a problem that an LDPC coding and decoding device of relevant technologies cannot support progressive increase redundancy HARQ and is in sufficient in flexibility can be solved.