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Linde–Buzo–Gray Algorithm
The Linde–Buzo–Gray algorithm (introduced by Yoseph Linde, Andrés Buzo and Robert M. Gray in 1980) is a vector quantization algorithm to derive a good codebook. It is similar to the k-means method in data clustering. The algorithm At each iteration, each vector is split into two new vectors. *A initial state: centroid of the training sequence; *B initial estimation #1: code book of size 2; *C final estimation after LGA: Optimal code book with 2 vectors; *D initial estimation #2: code book of size 4; *E final estimation after LGA: Optimal code book with 4 vectors; References * The original paper describing the algorithm, as an extension to Lloyd's algorithm In electrical engineering and computer science, Lloyd's algorithm, also known as Voronoi iteration or relaxation, is an algorithm named after Stuart P. Lloyd for finding evenly spaced sets of points in subsets of Euclidean spaces and partitions of ...: ** {{DEFAULTSORT:Linde-Buzo-Gray algorithm Cluster analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Robert M
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of '' Hruod'' ( non, Hróðr) "fame, glory, honour, praise, renown" and '' berht'' "bright, light, shining"). It is the second most frequently used given name of ancient Germanic origin. It is also in use as a surname. Another commonly used form of the name is Rupert. After becoming widely used in Continental Europe it entered England in its Old French form ''Robert'', where an Old English cognate form (''Hrēodbēorht'', ''Hrodberht'', ''Hrēodbēorð'', ''Hrœdbœrð'', ''Hrœdberð'', ''Hrōðberχtŕ'') had existed before the Norman Conquest. The feminine version is Roberta. The Italian, Portuguese, and Spanish form is Roberto. Robert is also a common name in many Germanic languages, including English, German, Dutch, Norwegian, Swedish, Scots, Danish, and Icelandic. It can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Vector Quantization
Vector quantization (VQ) is a classical quantization technique from signal processing that allows the modeling of probability density functions by the distribution of prototype vectors. It was originally used for data compression. It works by dividing a large set of points ( vectors) into groups having approximately the same number of points closest to them. Each group is represented by its centroid point, as in k-means and some other clustering algorithms. The density matching property of vector quantization is powerful, especially for identifying the density of large and high-dimensional data. Since data points are represented by the index of their closest centroid, commonly occurring data have low error, and rare data high error. This is why VQ is suitable for lossy data compression. It can also be used for lossy data correction and density estimation. Vector quantization is based on the competitive learning paradigm, so it is closely related to the self-organizing map ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Codebook
A codebook is a type of document used for gathering and storing cryptography codes. Originally codebooks were often literally , but today codebook is a byword for the complete record of a series of codes, regardless of physical format. Cryptography In cryptography, a codebook is a document used for implementing a code. A codebook contains a lookup table for coding and decoding; each word or phrase has one or more strings which replace it. To decipher messages written in code, corresponding copies of the codebook must be available at either end. The distribution and physical security of codebooks presents a special difficulty in the use of codes, compared to the secret information used in ciphers, the key, which is typically much shorter. The United States National Security Agency documents sometimes use ''codebook'' to refer to block ciphers; compare their use of ''combiner-type algorithm'' to refer to stream ciphers. Codebook come in two forms, one-part or two-part: * In o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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K-means
''k''-means clustering is a method of vector quantization, originally from signal processing, that aims to Partition of a set, partition ''n'' observations into ''k'' clusters in which each observation belongs to the Cluster (statistics), cluster with the nearest mean (cluster centers or cluster centroid), serving as a prototype of the cluster. This results in a partitioning of the data space into Voronoi cells. ''k''-means clustering minimizes within-cluster variances (squared Euclidean distances), but not regular Euclidean distances, which would be the more difficult Weber problem: the mean optimizes squared errors, whereas only the geometric median minimizes Euclidean distances. For instance, better Euclidean solutions can be found using K-medians clustering, k-medians and k-medoids. The problem is computationally difficult (NP-hardness, NP-hard); however, efficient heuristic algorithms converge quickly to a local optimum. These are usually similar to the expectation-maximizati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Data Clustering
Cluster analysis or clustering is the task of grouping a set of objects in such a way that objects in the same group (called a cluster) are more similar (in some sense) to each other than to those in other groups (clusters). It is a main task of exploratory data analysis, and a common technique for statistical data analysis, used in many fields, including pattern recognition, image analysis, information retrieval, bioinformatics, data compression, computer graphics and machine learning. Cluster analysis itself is not one specific algorithm, but the general task to be solved. It can be achieved by various algorithms that differ significantly in their understanding of what constitutes a cluster and how to efficiently find them. Popular notions of clusters include groups with small distances between cluster members, dense areas of the data space, intervals or particular statistical distributions. Clustering can therefore be formulated as a multi-objective optimization problem. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Lloyd's Algorithm
In electrical engineering and computer science, Lloyd's algorithm, also known as Voronoi iteration or relaxation, is an algorithm named after Stuart P. Lloyd for finding evenly spaced sets of points in subsets of Euclidean spaces and partitions of these subsets into well-shaped and uniformly sized convex cells. Like the closely related ''k''-means clustering algorithm, it repeatedly finds the centroid of each set in the partition and then re-partitions the input according to which of these centroids is closest. In this setting, the mean operation is an integral over a region of space, and the nearest centroid operation results in Voronoi diagrams. Although the algorithm may be applied most directly to the Euclidean plane, similar algorithms may also be applied to higher-dimensional spaces or to spaces with other non-Euclidean metrics. Lloyd's algorithm can be used to construct close approximations to centroidal Voronoi tessellations of the input, which can be used for quantizat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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IEEE Transactions On Communications
''IEEE Transactions on Communications'' is a monthly peer-reviewed scientific journal published by the IEEE Communications Society that focuses on all aspects of telecommunication technology, including telephone, telegraphy, facsimile, and point-to-point television by electromagnetic propagation. The editor-in-chief is Tolga M. Duman (Bilkent University). According to the ''Journal Citation Reports'', the journal has a 2018 impact factor of 5.69. History The journal traces back to the establishment of the ''Transactions of the American Institute of Electrical Engineers Transaction or transactional may refer to: Commerce *Financial transaction, an agreement, communication, or movement carried out between a buyer and a seller to exchange an asset for payment *Debits and credits in a Double-entry bookkeeping syst ...'' in 1884. The journal has gone through several name changes and splits over the years. *1884–1951: ''Transactions of the American Institute of Electrical Engineers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Cluster Analysis Algorithms
may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Asteroid cluster, a small asteroid family * Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere * Galaxy cluster, large gravitationally bound groups of galaxies, or groups of groups of galaxies * Supercluster, the largest gravitationally bound objects in the universe, composed of many galaxy clusters * Star cluster ** Globular cluster, a spherical collection of stars whose orbit is either partially or completely in the halo of the parent galaxy ** Open cluster, a spherical collection of stars that orbits a galaxy in the galactic plane Biology and medicine * Cancer cluster, in biomedicine, an occurrence of a greater-than-expected number of cancer cases * Cluster headache, a neurological disease that involves an immense degree of pain * Cluster of differentiation, protocol used for the identification and investigation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Machine Learning Algorithms
The following outline is provided as an overview of and topical guide to machine learning. Machine learning is a subfield of soft computing within computer science that evolved from the study of pattern recognition and computational learning theory in artificial intelligence.http://www.britannica.com/EBchecked/topic/1116194/machine-learning In 1959, Arthur Samuel defined machine learning as a "field of study that gives computers the ability to learn without being explicitly programmed". Machine learning explores the study and construction of algorithms that can learn from and make predictions on data. Such algorithms operate by building a model from an example training set of input observations in order to make data-driven predictions or decisions expressed as outputs, rather than following strictly static program instructions. What ''type'' of thing is machine learning? * An academic discipline * A branch of science ** An applied science *** A subfield of computer science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |