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Related papers: Fourier Codes and Hartley Codes

200 papers

The fast Fourier transform (FFT) is one of the most successful numerical algorithms of the 20th century and has found numerous applications in many branches of computational science and engineering. The FFT algorithm can be derived from a…

Numerical Analysis · Mathematics 2021-02-10 Daan Camps , Roel Van Beeumen , Chao Yang

HF-DFT, the practice of evaluating approximate density functionals on Hartree-Fock densities, has long been used in testing density functional approximations. Density-corrected DFT (DC-DFT) is a general theoretical framework for identifying…

Chemical Physics · Physics 2021-10-18 Suhwan Song , Stefan Vuckovic , Eunji Sim , Kieron Burke

Large scale Density Functional Theory (DFT) based electronic structure calculations are highly time consuming and scale poorly with system size. While semi-empirical approximations to DFT result in a reduction in computational time versus…

Materials Science · Physics 2016-12-21 Ganesh Hegde , R. Chris Bowen

Exploratory variational pseudopotential density functional calculations are performed for the electronic properties of many-electron systems in the 3D cartesian coordinate grid (CCG). The atom-centered localized gaussian basis set,…

Chemical Physics · Physics 2015-05-18 Amlan K Roy

We present a purely numerical approach in Cartesian grid, for efficient computation of Hartree-Fock (HF) exchange contribution in the HF and density functional theory models. This takes inspiration from a recently developed algorithm [Liu…

Chemical Physics · Physics 2019-04-05 Abhisek Ghosal , Tanmay Mandal , Amlan K. Roy

Continuous symmetries are fundamental to many scientific and learning problems, yet they are often unknown a priori. Existing symmetry discovery approaches typically search directly in the space of transformation generators or rely on…

Machine Learning · Computer Science 2026-03-10 Pavan Karjol , Kumar Shubham , Prathosh AP

For any finite group $G$, we give an arithmetic algorithm to compute generalized Discrete Fourier Transforms (DFTs) with respect to $G$, using $O(|G|^{\omega/2 + \epsilon})$ operations, for any $\epsilon > 0$. Here, $\omega$ is the exponent…

Data Structures and Algorithms · Computer Science 2019-01-10 Chris Umans

This paper describes a flexible architecture for implementing a new fast computation of the discrete Fourier and Hartley transforms, which is based on a matrix Laurent series. The device calculates the transforms based on a single bit…

Numerical Analysis · Computer Science 2018-01-26 R. C. de Oliveira , H. M. de Oliveira , R. M. Campello de Souza , E. J. P. Santos

In this paper a deterministic sparse Fourier transform algorithm is presented which breaks the quadratic-in-sparsity runtime bottleneck for a large class of periodic functions exhibiting structured frequency support. These functions…

Numerical Analysis · Mathematics 2017-11-21 Sina Bittens , Ruochuan Zhang , Mark A. Iwen

The marriage of density functional theory (DFT) and deep learning methods has the potential to revolutionize modern computational materials science. Here we develop a deep neural network approach to represent DFT Hamiltonian (DeepH) of…

Materials Science · Physics 2023-01-02 He Li , Zun Wang , Nianlong Zou , Meng Ye , Runzhang Xu , Xiaoxun Gong , Wenhui Duan , Yong Xu

A construction is presented that allows to produce subspace codes of long length using subspace codes of shorter length in combination with a rank metric code. The subspace distance of the resulting code, called linkage code, is as good as…

Information Theory · Computer Science 2015-05-12 Heide Gluesing-Luerssen , Carolyn Troha

First-principles density functional theory (DFT) codes which employ a localized basis offer advantages over those which use plane-wave bases, such as better scaling with system size and better suitability to low-dimensional systems. The…

Materials Science · Physics 2024-11-25 Daniel Bennett , Michele Pizzochero , Javier Junquera , Efthimios Kaxiras

Linear codes with complementary duals are linear codes whose intersection with their duals are trivial, shortly named LCD codes. In this paper we outline a construction for LCD codes over finite fields of order $q$ using weighing matrices…

Combinatorics · Mathematics 2019-12-02 Dean Crnkovic , Ronan Egan , B. G. Rodrigues , Andrea Svob

We introduce HP, an implementation of density-functional perturbation theory, designed to compute Hubbard parameters (on-site $U$ and inter-site $V$) in the framework of DFT+$U$ and DFT+$U$+$V$. The code does not require the use of…

Materials Science · Physics 2022-07-11 Iurii Timrov , Nicola Marzari , Matteo Cococcioni

Much progress has been made on decoding algorithms for error-correcting codes in the last decade. In this article, we give an introduction to some fundamental results on iterative, message-passing algorithms for low-density parity check…

Information Theory · Computer Science 2007-07-16 Venkatesan Guruswami

We introduce tile codes, a simple yet powerful way of constructing quantum codes that are local on a planar 2D-lattice. Tile codes generalize the usual surface code by allowing for a bit more flexibility in terms of locality and stabilizer…

This paper produces a rate-compatible protograph LDPC code at 1k information blocklength with superior performance in both waterfall and error floor regions. The design of such codes has proved difficult in the past because the constraints…

Information Theory · Computer Science 2013-02-22 Thuy Van Nguyen , Aria Nosratinia , Dariush Divsalar

For a real sequence of length of m = nl, we may deduce its congruence derivative sequence with length of l. The discrete Fourier transform of original sequence can be calculated by the discrete Fourier transform of the congruence derivative…

Signal Processing · Electrical Eng. & Systems 2019-04-19 Jiasong Wang , Changchuan Yin

We introduce a general framework for end-to-end optimization of the rate--distortion performance of nonlinear transform codes assuming scalar quantization. The framework can be used to optimize any differentiable pair of analysis and…

Information Theory · Computer Science 2020-07-28 Johannes Ballé , Valero Laparra , Eero P. Simoncelli

In this paper, fast-decodable lattice code constructions are designed for the nonorthogonal amplify-and-forward (NAF) multiple-input multiple-output (MIMO) channel. The constructions are based on different types of algebraic structures,…

Information Theory · Computer Science 2012-02-28 Camilla Hollanti , Nadya Markin