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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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Journal ArticleDOI
TL;DR: In this paper, the authors show that Hadamard was not the first to discover the inequalities, but C. Hermite who obtained them in 1883, ten years before J.Hadamard.

246 citations

Journal ArticleDOI
TL;DR: In this article, a general method for constructing supersaturated 2 N-1 designs with a large number of interaction columns was proposed, and the efficiency of the constructed designs was studied by using three criteria.
Abstract: SUMMARY An N x N Hadamard matrix can be used to construct a saturated 2 N-1 design with N runs. Furthermore, if an interaction column for two of the columns of the matrix is not fully aliased with any column of the matrix, this interaction column can be used as a supplementary column for studying an additional factor. For some small Hadamard matrices studied by Plackett & Burman (1946), the number of such interaction columns is very large, thus allowing the construction of supersaturated designs whose number of factors far exceeds the number of runs. A general method of construction along these lines is proposed. The efficiency of the constructed designs is studied by using three criteria.

245 citations

Journal ArticleDOI
TL;DR: A Hadamard product induced bias matrix model is proposed, which only requires the use of the data in the original matrix to identify and adjust the cardinally inconsistent element(s) in a PCM and significantly enhances matrix consistency and improves the reliability of PCM decision making.

240 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that if a scalar field has the Hadamard singularity structure in an open neighborhood of a Cauchy surface, then it does so everywhere.
Abstract: In the point-splitting prescription for renormalizing the stress-energy tensor of a scalar field in curved spacetime, it is assumed that the anticommutator expectation valueG(x, x′)=〈o(x)o(x′)+o(x′)o(x)〉 has a singularity of the Hadamard form asx→x′. We prove here that ifG(x,x′) has the Hadamard singularity structure in an open neighborhood of a Cauchy surface, then it does so everywhere, i.e., Cauchy evolution preserves the Hadamard singularity structure. In particular, in a spacetime which is flat below a Cauchy surface, for the “in” vacuum stateG(x,x′) is of the Hadamard form everywhere, and thus the point-splitting prescription in this case has been rigorously shown to give meaningful, finite answers.

239 citations

Journal ArticleDOI
TL;DR: Several Hadamard-type inequalities for products of two convex and s-convex functions are proved and some new inequalities for differentiable functions based on concavity and s -conveXity are established.

239 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023339
2022850
2021391
2020444
2019427
2018372