Results 31 to 40 of about 2,401,712 (281)

Increasing the spatial resolution of signals in optical systems

Компьютерная оптика, 2022
Reconstruction of the signal in the intervals between discrete values is of great importance in solving the problem of spatial superresolution in optical microscopy and digital holography.
V.I. Guzhov, I.O. Marchenko, E.E. Trubilina   +2 more
doaj   +1 more source

On the computational complexity of the general discrete fourier transform

Theoretical Computer Science, 1987
The complexity of computing the General Discrete Fourier Transform over group algebras of finite groups is studied. Starting with a short introduction to known results, the complexity gains of a new algorithm derived from Clifford's theorem are discussed.
openaire   +3 more sources

Properties of continuous Fourier extension of the discrete cosine transform and its multidimensional generalization [PDF]

Journal of Mathematical Physics, 2004
A versatile method is described for the practical computation of the exact discrete Fourier transforms (DFT), both the direct and the inverse ones, of a continuous function g given by its values gj at the points of a uniform grid FN generated by conjugacy classes of elements of finite adjoint order N in the fundamental region F of compact semisimple ...
Atoyan, A., Patera, J.
openaire   +2 more sources

Parameterising Arbitrary Shapes via Fourier Descriptors for Evidence-Gathering Extraction

, 1998
According to the formulation of the Hough transform it is possible to extract any shape that can be represented by an analytic equation with a number of free parameters.
Nixon, M.S., Aguado, A.S., Montiel, M.E.
core   +1 more source

From Photoalignment to Structured Light: Liquid Crystal Platforms for Beam Shaping and Complex Wavefronts

Advanced Functional Materials, EarlyView.
Photoaligned and photopatterned liquid crystal platforms provide programmable control of optical phase, polarization, and spin‐orbit interactions, enabling compact generation of structured light and complex wavefronts. This review highlights how tailored molecular orientations transform simple beams into designed optical fields, opening versatile ...
Le Zhou, Tingjun Zhong, Sijie Liu, Pouya Nosratkhah, Ke Xu, Yuzhen Zhao, Kristiaan Neyts   +6 more
wiley   +1 more source

Frequency-domain subcarrier diversity receiver for discrete Hartley transform OFDM systems

EURASIP Journal on Wireless Communications and Networking, 2019
In recent years, there has been an increasing interest in the use of the discrete Hartley transform (DHT) for orthogonal frequency-division multiplexing (OFDM).
Mishal Al-Gharabally, Ali F. Almutairi
doaj   +1 more source

Ultrafast Thermal Shock Synthesis of CuNiSnLa Medium‐Entropy Metallic Glass for Sustainable Nitrogen Fixation via Plasma‐Coupled Electrocatalysis

Advanced Functional Materials, EarlyView.
This work introduces an ultrafast thermal shock strategy to synthesize a CuNiSnLa medium‐entropy metallic glass (MEMG). The rapid heating and cooling process generates a robust, highly active catalyst for electrocatalytic nitrate reduction to ammonia (NRA).
Hongbo Chen, Peng‐Jun Deng, Yang Liu, Shenglong Huang, Shuo Sun, Haoxuan Li, Jiajia Lu, Panagiotis Tsiakaras   +7 more
wiley   +1 more source

Real time QRS detection based on M-ary likelihood ratio test on the DFT coefficients.

PLoS ONE, 2014
This paper shows an adaptive statistical test for QRS detection of electrocardiography (ECG) signals. The method is based on a M-ary generalized likelihood ratio test (LRT) defined over a multiple observation window in the Fourier domain. The motivations
Juan Manuel Górriz, Javier Ramírez, Alberto Olivares, Pablo Padilla, Carlos G Puntonet, Manuel Cantón, Pablo Laguna   +6 more
doaj   +1 more source

Pressure‐Assisted Dimensional Transformation of 2D Hydrogenated Borophene into 0D Boron Quantum Dots

Advanced Functional Materials, EarlyView.
Hydrogenated borophene (HB) is transformed into distinct boron nanostructures through a solvent‐free thermal process. Under flowing nitrogen, hydrogen escape promotes reconstruction into B2O3 nanoplatelets, whereas hydrogen‐induced pressure under sealed conditions facilitates fragmentation into boron quantum dots.
Ozden Gunes Yildiz, Ramin Yazdaanpanah, Yongfeng Guo, Pouriya Naziri, Sachin Kulkarni, Martina Mercurio, Maria Cristina Larciprete, Ilaria Fratoddi, Paul Simon, Wan‐Lu Li, Koray Aydin, Umut Aydemir   +11 more
wiley   +1 more source

Designing Vanadium‐Based Oxide Electrocatalysts for Water Splitting: Experimental and Mechanistic Insights with Machine Learning

Advanced Functional Materials, EarlyView.
This review establishes structure‐property‐mechanism relationships across six modification strategies for V‐based oxide water‐splitting electrocatalysts: lattice engineering, heteroatom doping, interface engineering, carbon‐based hybridization, morphology engineering, and surface reconstruction and pre‐catalyst design, where dissolution is reframed as ...
Youness El Issmaeli, Amina Lahrichi, Hoje Chun, Rafael Gómez‐Bombarelli, Bruno G. Pollet   +4 more
wiley   +1 more source