109 results about "Linear coding" patented technology

Improved method of encoding and repairing data for reliable storage and transmission using erasure codes, which is efficient enough for implementation in software as well as hardware. A systematic linear coding matrix over GF(2^q) is used which combines parity for fast correction of single erasures with the capability of correcting k erasures. Finite field operations involving the coding and repair matrices are redefined to consist of bitwise XOR operations on words of arbitrary length. The elements of the matrix are selected to reduce the number of XOR operations needed and buffers are aligned for optimal processor cache efficiency. Decode latency is reduced by pre-calculating repair matrices, storing them in a hashed table and looking them up using a bit mask identifying the erasures to be repaired.

This invention provides a distribution storage download system, a device and a method for network data, in which, said system includes: a source data terminal used in carrying out linear coding to source data to generate multiple data slices and carrying out linear de-coding to the data slices of the source data to resume the source data, a storage node connected with said source data terminal to download and store said data slices and an index server connected with the source data terminal and storage node for managing the information of the data slice and network information of the nodes to control the terminal or nodes to download data slices of the source data.

A method, device and system disclosed used in storage technique, comprising: splitting a file of size M into k blocks, that is to say, each block is of size M/k; issuing the above k blocks across k different storage nodes in the distributed network storage system in a distributed manner; using the k blocks, constructing n−k independent blocks via linear coding method, and satisfying the property that any k of the n encoded blocks can be used to reconstruct the original data in the file, which means the linear coding method is a kind of Maximum-Distance Separable (MDS) code; distribute the n−k encoded blocks to the rest n−k different storage codes in the distributed network storage systems.

The invention discloses a quantum key distribution after-treatment system and a quantum key distribution after-treatment method based on polar code correction. The system comprises a key screening module, a parameter estimation module, a polar code correction module, a consistency verification module and a privacy amplification module which are connected in sequence. The method comprises the following steps: only keeping original keys with the same base selection to form screening keys after quantum bite information is transmitted on a quantum channel; commonly selecting partial key bits from the screening keys to perform disclosed comparison; coding and decoding undisclosed key bits by adopting a system polar code algorithm under the condition that the quantum bit error rate is not higher than a safety threshold value; verifying the consistence of the corrected quantum keys by adopting cryptographic algorithm; and calculating safety information entropy and performing information compression to obtain absolutely safe key bits. The quantum key distribution after-treatment system has linear coding/decoding complexity characteristics, so that the after-treatment time delay and key length increase have linear relationship, and the after-treatment speed is improved.

A method of indicating the length of a mini cells in a mobile telephony network. Non linear coding of a short fixed length field in the header of the mini cell is described. Either an extension bit method or an extension code method is used to extend the length field so as to increase the number of length values available for coding of the mini cell sizes. The length of a mini cell is indicated in the individual mini cell or is indicated indirectly using a CID/length mapping table. Mini cell sizes are changed during a connection and methods are described for doing this. Cell header reading devices for extracting user information of individual mini cells are described. A mobile telephone network using the cell header reading devices is described.

The invention provides a safety cloud storage method and system. The safety cloud storage system comprises a cloud storage server, a key generation and distribution server and a client-side, wherein the cloud storage server is used for managing data and controlling data access; the key generation and distribution server is used for generating property public keys of shared data and a property secrete key of a user; the client-side is used for encrypting and decrypting data and setting the data access strategy. File data are encrypted in a file linear coding mode and are transmitted and stored as a ciphertext, and data safety is guaranteed; a file secrete key is encrypted according to a property encryption algorithm, and the obtained secret key can be used for realizing access control.

This invention discloses a method for false color process to medical grey image signals, which first of all utilizes a Gauss low-pass filter to eliminate noises of a polluted medical image, then utilizes a cross gradient operator to acquire the gradient value of each pixel of the image then to determine a threshold value based on the gradient value, then carries out false color coding in two modes based on the comparison of gradient value and threshold value, if the gradient value is greater than the threshold value, it applies red to false-code, otherwise, it applies a non-linear coding method based on the grey value, and medical images process by this method meets vision character of man-eye.

The invention discloses an algebraic construction method of LDPC (Low Density Parity Check) code based on cyclic matrixes; design parameters of cyclic matrixes are adjusted by short-loop check and minimum code weight check, which are nonnegative prime numbers a and b meeting two constraint conditions, and dimension q of an identity matrix, wherein the magnitude of dimension q of a shift identity matrix and whether the error rate characteristics of the designed LDPC code are influenced by prime numbers. The invention solves the problems of short-loop and low code coincident code word appearing in the existing QC LDPC code design. The method can check the existence of low code coincident code word in the designed code, thereby checking the existence of 4-loop. An irregular quasi-cyclic LDPC code structure disclosed by the invention divides the check matrix H into two submatrixes A and B, the nonsingular structure of the submatrix A is disclosed, and a matrix is generated by the two submatrixes A and B. Direct linear coding is carried out by generating the matrix. The embodiment validates the efficiency and good bit rate performance of the method disclosed by the invention.

Aspects of the present invention include systems and methods for generating an optical flow-based feature. In embodiments, to extract an optical flow feature, the optical flow at sparse interest points is obtained, and Locality-constrained Linear Coding (LLC) is applied to the sparse interest points to embed each flow into a higher-dimensional code. In embodiments, for an image frame, the multiple codes are combined together using a weighted pooling that is related to the distribution of the optical flows in the image frame. In embodiments, the feature may be used in training models to detect actions, in trained models for action detection, or both.

The invention relates to a quasi-cyclic low-density parity-check (QC-LDPC) code and a correcting and linear coding method thereof. The variable nodes of the LDPC code, the dimensionality of which is greater than 2, are informational nodes; and the variable nodes the dimensionality of which is 2 form a big end-to-end ring on a bipartite graph. The correcting method comprises the following implementation steps: randomly selecting one edge on the big ring the dimensionality of which is 2, cutting off the edge, and filling 0 in the corresponding position of a low-density check matrix, thereby acquiring a corrected structure of the code. The linear coding method of the corrected code comprises the following implementation steps: firstly, multiplying an input information vector s and a part of the check matrix the load of which is greater than 2 as a vector by a matrix to acquire an intermediate vector u; directly intercepting the corresponding position of the intermediate vector u to acquire a coding vector the variable node dimensionality of which is 1; computing bit by bit from a start bit according to the characteristics of the big ring on the bipartite graph to acquire a coding vector the variable node dimensionality of which is 2; and combining the two coding vectors to finally form a coding vector.

A communication method using random linear coding is disclosed. The communication method using a random linear code comprises receiving first code blocks randomly linear-coded from a transmitter; demodulating the first code blocks using a decision distance determined in accordance with a channel status; determining whether an error has occurred in the first code blocks, using the decision distance, and transmitting a NACK signal to the transmitter, the NACK signal including information of the number of the code blocks where an error has occurred. Since a block error rate can be controlled in accordance with channel status, throughput can be improved.

The invention relates to a high-resolution remote sensing image airplane detecting method based on high-level feature extraction of a depth boltzmann machine. The method comprises the steps that at first, a picture is divided into a plurality of segments, then scale-invariant feature transformation (SIFT) is utilized for extracting key points in the segments, the key points serve as low-level features of the segments, then a local restriction linear coding algorithm is utilized for coding the low-level features to obtain medium-level features, then the three-layer depth boltzmann machine is utilized for obtaining high-level features of the segments from the medium-level features, then the high-level features are utilized for training a support vector machine classifier, finally the classifier is used for detecting an airplane of the detected picture, and the airplane detection result high in accuracy and robustness can be obtained.

The invention provides an image classification method. An SPM framework is reserved, a covariance matrix feature extraction technology and an LLC (locality-constrained linear coding) technology are combined on the basis of an SIFT (scale invariant feature transform) feature extraction technology, and multiple covariance matrix features are fused and are not sensitive to the scale, rotation and illumination change. LLC is high in coding speed and high in efficiency and lays a foundation for linear classification. The training time is shortened due to usage of a linear classifier, and the system robustness is enhanced while the classification accuracy is increased.

Various high speed modem embodiments are provided, for example, having a receiver configured to receive an analog data signal over a telephone line from a first modem, from which digitized analog data signal samples are generated by a processor employing a linear coding process using, for example, a sampling rate of at least 16 kHz with an 8 bits/sample. Following, the digitized analog data signal samples are transmitted over one or more digital lines of a first time division multiplexed bus to a second modem, which may be a digital loop carrier modem, for example. Thereafter, the second modem may demodulate the digitized analog data signal samples to generate digitized data, which may then be transmitted over one or more digital signal lines of a second time division multiplexed bus.

The invention relates to the field of channel coding technologies in communication technologies, and specifically relates to a method for constructing a quasi-cyclic LDPC code based on finite field primitive elements. The method basically comprises five steps as follows: determining the parameters of the code, selecting two primitive elements in a finite field, constructing a basis matrix based on the primitive elements, extending the basis matrix, and selecting a sub matrix of a partitioned matrix as a check matrix, wherein the construction of a two-element field and the construction of a multi-element field share the basis matrix generated in the third step, and the difference lies in whether the matrix elements after extension operation in the fourth step belongs to the two-element field or the multi-element field. As the constructed code is a quasi-cyclic code, the generated matrix has a form of systemic cycle, and linear coding can be achieved.

The invention discloses a method for transmitting sensitive information in a wireless sensor network, and aims to solve the problem that in the prior art, the energy of the node is quickly consumed when the sensitive information is transmitted. The method comprises the following steps that: a sensor node linearly codes the sensitive information through a Gaussian random matrix to obtain a sensitive vector, performs zeroizing sparseness processing on normal information to obtain a sparse vector, fuses the sensitive vector and the sparse vector to obtain fused data, and transmits the fused data to a base station; and the base station observes the fused data to obtain an observed value, re-constructs the sparse vector according to a decoding matrix and the observed value, analyzes the sensitive vector from the fused data according to the re-constructed sparse vector, and decodes the analyzed sensitive vector through the Gaussian random matrix so as to obtain the sensitive information. By the method, coding and hidden communication of the sensitive information by the wireless sensor network can be realized in a mode of low energy consumption; the service life of the sensor node is prolonged; and the whole life time of the whole wireless sensor network is improved.

The invention discloses an image classification method based on an RGB-D fusion feature and sparse coding. The method comprises following steps of (1) extracting dense SIFT features and PHOG features of a color image and a depth image; (2) carrying out feature fusion on the extracted features of the images by use of a linear serial connection form so as to obtain four kinds of different fusion features finally; (3) using the K-means++ clustering method to carry out clustering processing on the different fusion features so as to obtain four kinds of different vision dictionaries; (4) carrying out local restriction linear coding on each vision dictionary to obtain different image expressing sets; and (5) using the linear SVM to classify the different image expressing sets and using a vote decision method to decide final classification conditions of the obtained classification results. According to the invention, the method is high in classification precision.

The invention discloses a rapid and high-efficiency near-duplicate image matching method. The method comprises the steps that 1) the ORB characteristic of each image in a training image library is extracted and nonlinear mapping is performed on the ORB characteristic of each image so that a visual word table of the training image library is constructed; 2) sparse coding is performed on the nonlinear mapping ORB characteristic of each image in the training image library by utilizing locally-constrained linear coding according to the constructed visual word table; 3) the ORB characteristic of the image to be matched is extracted and nonlinear mapping is performed on the ORB characteristic of the image to be matched, and then sparse coding is performed on the nonlinear mapping ORB characteristic of the image to be matched according to the constructed visual word table; and 4) similarity of sparse coding of the image to be matched and sparse coding of the images in the training image library is calculated, and if similarity exceeds the preset threshold value, matching succeeds, or matching fails. Reconstruction error of a hard quantification method is reduced so that matching speed is greatly enhanced and the method can be used for real-time matching.

The present invention belongs to the technical field of channel coding and relates to a method for generating an RC-LDPC code check matrix. The method is based on the complexity of the coding, and is modified based on the PEG algorithm to construct a check matrix with a lower triangular form. The obtained coding complexity is linear. On this basis, the method of expanding the check bit step by step is adopted to support the flexible and variable code rate, which provides a feasible channel coding method for the adaptation of a wireless link. At the same time, the obtained series of sub-codes also have a lower triangular form, which almost does not increase the complexity but can achieve linear coding with regard to the mother code. According to the invention, the method utilizes the PEG algorithm to optimize the position of the nonzero element in the expanded part and optimizes the code structure so as to eliminate the short loop, to reduce the computational complexity of the codec and to further improve the transmission performance.

The invention discloses a real-time video transmission method, which belongs to the technical field of Ad Hoc networks. The method comprises that: 1) a source node codes a video stream by adopting a priority linear coding method; 2) the source node packs each coded data block to form a data packet, and transmits the data packet in a broadcasting way by a radio link; 3) a forwarding node recodes the received data packet into a new data packet according to calculated forwarding probability by using a priority coding algorithm, and transmits the new data packet to a destination node; and 4) the destination node receives the data packet of which a destination is the destination node, decodes the data packet by adopting the priority linear coding method, and generates the original video stream. Compared with the prior art, the invention increases the utilization rate of a network bandwidth and improves video transmission quality.

The invention relates to a method of locating an image foreground using LLC (Locality-constrained Linear Coding) criterion. A large number of random images are selected from a standard test set, in combination of the salient region truth value annotation graph, the priori knowledge of the image foreground is extracted, an LLC codebook is formed, the LLC criterion is used for carrying out rough classification on whether each area of a to-be-detected image belongs to the foreground, and a corresponding salience probability value is given; contrast-based features such as a centroid distance away from an image center, a local Lab color contrast value and a global Lab color contrast value are used for describing image super pixel regions, typical features for learning the foreground/background serve as the priori knowledge for guiding classification of the image super pixel regions, high-level knowledge is acquired from an empirical perspective, region classification can be guided for multiple times as long as one-time learning is needed, the foreground locating speed is greatly quickened compared with a method of extracting high-level knowledge only from the current image, and due to advantage query for extraction, the foreground boundary in the acquired salience map based on manifold ranking can be more clear and has less noise.

The invention relates to a data downloading method and a data downloading system. The data downloading method is used for downloading data from a cellular network and comprises the following steps that to-be-downloaded original data are divided into multiple original data fragments, and random linear coding is performed on each original data fragment, so as to obtain multiple coded fragments; a first smart mobile device downloads partial coded fragments of the original data from a content server of the cellular network; the first smart mobile device acquires the residual coded fragments of the original data from at least one second smart mobile device with the coded fragments of the original data by virtue of near field communication, and the residual coded fragments and the partial coded fragments constitute the whole coded fragments of the original data; the first smart mobile device performs random linear decoding on the obtained whole coded fragments of the original data so as to recover the original data. The data downloading method and the data downloading system can be used for reducing the cellular network flow use amount of the smart mobile devices.

The invention provides a three-dimensional information acquisition method for sampling points of three gray level symmetrical linear coding periods. The three-dimensional information acquisition method includes steps of selecting the coding periods to prepare nine different gray level linear symmetrical phase-shift gratings of the three coding periods; projecting the gratings onto the surface of a detected object and obtaining nine stripe images by a stripe image acquiring device; calculating and obtaining relevant coding points corresponding to coding patterns in the coding periods, obtaining remainder equations of the sampling points in a frequency, leading the remainder equations to be simultaneous to obtain a congruence equation system of the sampling points in the three different coding periods, and adopting Chinese remainder theorem to confirm multiplying rate of the congruence equation system so as to obtain the solution of the equation system; and confirming projection angels of the sampling points and three-dimensional information of the sampling points according to a triangle principle. The three-dimensional information acquisition method overcomes shortcomings that in traditional double-frequency phase-shift three-dimensional measurement, errors are high, a measurement range is limited and the errors are accumulated and transmitted, and utilizes the non-contact three-dimensional measurement technology with high sampling density and precision.