Topic
Hadamard transform
About: Hadamard transform is a research topic. Over the lifetime, 7262 publications have been published within this topic receiving 94328 citations.
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01 Jan 2000
TL;DR: It is shown how a simple feed-forward neural network can be trained to filter documents when only positive information is available, and that this method seems to be superior to more standard methods, such as tf-idf retrieval based on an “average vector”.
Abstract: In this paper, we show how a simple feedforward neural network can be trained to filter documents when only positive information is available, and that this method seems to be superior to more standard methods, such as tf-idf retrieval based on an "average vector". A novel experimental finding that retrieval is enhanced substantially in this context by carrying out a certain kind of uniform transformation ("Hadamard") of the information prior to the training of the network.
28 citations
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28 citations
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29 Jun 1972
TL;DR: In this paper, a method and system for a computer implementation of a digital Walsh-Hadamard transformation of a two-dimensional discrete NxN figure is described, where the elements of an nxN Hadamard matrix and the elements representing optical densities of the figure are factors in a first multiplication operation producing a matrix consisting of a series of column vectors.
Abstract: A method and system for a computer implementation of a digital Walsh-Hadamard transformation of a two-dimensional discrete NxN figure. The elements of an NxN Hadamard matrix and the elements of an NxN matrix representing optical densities of the figure are factors in a first multiplication operation producing a matrix consisting of a series of column vectors. This matrix is again multiplied by the NxN Hadamard stored matrix in a second multiplication operation and selected products are summed to complete the matrix multiplication, the output thereof being entries in the Walsh-Hadamard transform.
28 citations
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TL;DR: Using the properties of the element by element (or Hadamard) product of matrices, this paper obtained the robot dynamics in parameter-isolated form, from which a new control scheme was developed.
Abstract: Using the properties of the element by element (or Hadamard) product of matrices, the authors obtain the robot dynamics in parameter-isolated form, from which a new control scheme is developed. The controller proposed yields zero asymptotic tracking errors when applied to robotic systems with time-varying parameters by using a switching type control law. The results obtained are global in the initial state of the robot, and can be applied to rapidly varying systems. >
28 citations
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TL;DR: A symmetric 2-(324, 153, 72) design is constructed that admits a tactical decomposition into 18 point and block classes of size 18 such that every point is in either 0 or 9 blocks from a given block class.
Abstract: A symmetric 2-(324, 153, 72) design is constructed that admits a tactical decomposition into 18 point and block classes of size 18 such that every point is in either 0 or 9 blocks from a given block class, and every block contains either 0 or 9 points from a given point class. This design is self-dual and yields a symmetric Hadamard matrix of order 324 of Bush type, being the first known example of a symmetric Bush-type Hadamard matrix of order 4n^2 for n > 1 odd. Equivalently, the design yields a strongly regular graph with parameters v=324, k=153, \lambda=\mu=72 that admits a spread of cocliques of size 18. The Bush-type Hadamard matrix of order 324 leads to two new infinite classes of symmetric designs with parameters
v=324(289^m+289^{m-1}+\cdots+289+1), \quad k=153(289)^m, \quad \lambda=72(289)^m,
and
v=324(361^m+361^{m-1}+\cdots+361+1), \quad k=171(361)^m, \quad \lambda=90(361)^m,
where m is an arbitrary positive integer.
28 citations