26 papers · ranked by Valyu relevance
Andrew Teale, Trygve Helgaker, Andreas Savin, Carlo Adamo + 66 more
In this paper, the history, present status, and future of density-functional theory (DFT) is informally reviewed and discussed by 70 workers in the field, including molecular scientists, materials scientists, method developers and practitioners. The format of the paper is that of a roundtable discussion, in which the…
Omkar Deshpande, Kharanshu Solanki, Sree Pujitha Suribhatla, Sanya Zaveri + 1 more
'Sanya Zaveri' 'Luv Ghodasara'] Since the evolution of digital computers, the storage of data has always been in terms of discrete bits that can store values of either 1 or 0. Hence, all computer programs (such as MATLAB), convert any input continuous signal into a discrete dataset. Applying this to oscillating…
E. Zayas
I discuss the nature of a Fractional Discrete Fourier Transform (FrDFT) described algorithmically by a combination of chirp transforms and ordinary DFTs. The transform is shown to be consistent with a continuous two-dimensional rotation between the time and frequency domains. I further present a new closed-form…
Raimundo Corrêa de Oliveira, H. M. de Oliveira, R. Campello de Souza, Edval J. P. Santos
'Edval J. P. Santos'] 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 selection operator. The hardware structure and synthesis are…
Joshua Van Dijk, Marcos Casanova-Paez, Lars Goerigk
This work is the first thorough investigation of time-dependent double-hybrid density functionals (DHDFs) for the calculation of doublet- doublet excitation energies. It sheds light on the current state-of-the-art techniques in the field and clarifies if there is still room for future improvements. Overall, 29 hybrid…
Xueyang Yao, Natalie Baddour, Yilun Shang
The theory of the continuous two-dimensional (2D) Fourier Transform in polar coordinates has been recently developed but no discrete counterpart exists to date. In the first part of this two-paper series, we proposed and evaluated the theory of the 2D Discrete Fourier Transform (DFT) in polar coordinates. The theory of…
Richard Yang, Heather D. Orser, Kip A. Ludwig, Brandon S. Coventry
Digital implementations of discrete Fourier transforms (DFT) are a mainstay in feature assessment of recorded biopotentials, particularly in the quantification of biomarkers of neurological disease state for adaptive deep brain stimulation. Fast Fourier transform (FFT) algorithms and architectures present a substantial…
Tanaji Umaji Kamble, B. G. Patil, Rakhee S. Bhojakar
In this paper, an optimized efficient VLSI architecture of a pipeline Fast Fourier transform (FFT) processor capable of producing the reverse output order sequence is presented. Paper presents Radix-2 multipath delay architecture for FFT calculation. The implementation of FFT in hardware is very critical because for…
В. Р. Чечеткин, V. V. Lobzin
In many processes, the variations in underlying characteristics can be approximated by noisy multi-periodic patterns. If large-scale patterns are superimposed by a noise with long-range correlations, the detection of multi-periodic patterns becomes especially challenging. To solve this problem, we developed a discrete…
Bowen Ou, Bin Wang, Slava Maslennikov, Hanchao Liu + 1 more
—Phasor Measurement Units (PMUs) convert highspeed waveform data into low-speed phasor data, which are fundamental to wide-area monitoring and control in power systems, with oscillation detection and localization among their most prominent applications. However, representing electrical waveform signals with…
Kathryn G. Maskell, Anna Schönbichler, Andrew S. Flies, Amanda L. Patchett
The Tasmanian devil is threatened by two deadly transmissible Schwann cell cancers. A vaccine to protect Tasmanian devils from both devil facial tumour 1 (DFT1) and devil facial tumour 2 (DFT2), and improved understanding of the cancer cell biology, could support improved conservation actions. Previous transcriptomic…
Pushpendra Singh
The Hilbert transform (HT) and associated Gabor analytic signal (GAS) representation are well known and widely used mathematical formulations for modelling and analysis of signals in various applications. In this study, like the HT, to obtain quadrature component of a signal, we propose novel discrete Fourier cosine…
Mingai Li, Na Zhang
Directed transfer function (DTF) is good at characterizing the pairwise interactions from whole brain network and has been applied in discrimination of motor imagery (MI) tasks. Considering the fact that MI electroencephalogram signals are more non-stationary in frequency domain than in time domain, and the activated…
Francesco Sessa, Martin Rahm
Controlling the distribution of electrons in materials is the holy grail of chemistry and material science. Practical attempts at this feat are common but are often reliant on simplistic arguments based on electronegativity. One challenge is knowing when such arguments work, and which other factors may play a role.…
Ben Hitchcock, Nhien‐An Le‐Khac, Mark Scanlon
Due to budgetary constraints and the high level of training required, digital forensic analysts are in short supply in police forces the world over. This inevitably leads to a prolonged time taken between an investigator sending the digital evidence for analysis and receiving the analytical report back. In an attempt…
Chrissie E. B. Ong, Amanda L. Patchett, Jocelyn M. Darby, Jinying Chen + 4 more
Downregulation of major histocompatibility complex I (MHC-I) on tumor cells is a primary means of immune evasion by many types of cancer. Additionally, MHC-I proteins are a primary target of humoral and cellular mechanisms associated with transplant rejection. Transmissible tumors that overcome allograft rejection…
Andrew JE Seely, Peter T Macklem
Characteristic patterns of variation over time, namely rhythms, represent a defining feature of complex systems, one that is synonymous with life. Despite the intrinsic dynamic, interdependent and nonlinear relationships of their parts, complex biological systems exhibit robust systemic stability. Applied to critical…
Authors not listed
Electrochemical impedance spectroscopy (EIS) is a powerful analytical technique for studying electrochemical systems, offering broad frequency range coverage and straightforward implementation. However, EIS measurements at low frequencies are limited by both lengthy acquisition times and the risk of disrupting…
Eric Rawls
Time-frequency (TF) analysis of M/EEG data enables rich understanding of cortical dynamics underlying cognition, health, and disease. There are many algorithms for time-frequency decomposition of M/EEG neural data, but they are implemented in an inconsistent manner and most existing toolboxes either 1) contain only one…
Edward J Ciaccio, Angelo B Biviano, Hasan Garan
Background Complex fractionated atrial electrograms (CFAE) acquired during atrial fibrillation (AF) are commonly assessed using the discrete Fourier transform (DFT), but this can lead to inaccuracy. In this study, spectral estimators derived by averaging the autocorrelation function at lags were compared to the DFT.…
Demian Battaglia, Thomas Boudou, Enrique C. A. Hansen, Diego Lombardo + 6 more
Functional Connectivity (FC) during resting-state or task conditions is not fixed but inherently dynamic. Yet, there is no consensus on whether fluctuations in FC may resemble isolated transitions between discrete FC states rather than continuous changes. This quarrel hampers advancing the study of dynamic FC. This is…
Binke Yuan, Junjie Yang, Xiaolin Guo, Xiaowei Gao + 14 more
Numerous dynamic functional connectivity (dFC) methods have been proposed to study time-resolved network reorganization in rest and task fMRI. However, a comprehensive comparison of their performance is lacking. In this study, we compared the efficacy of seven dFC methods (and their enhanced versions) to track…
Rong-Guan Yeh, Chung-Wu Lin, Maysam F. Abbod, Jiann-Shing Shieh
A detrended fluctuation analysis (DFA) method is applied to image analysis. The 2-dimensional (2D) DFA algorithms is proposed for recharacterizing images of lymph sections. Due to Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), there is a significant different 5-year survival rates after multiagent…
Baptiste Py, Adeleke Maradesa, Francesco Ciucci
The distribution of relaxation times (DRT) method is a non-parametric approach for analyzing electrochemical impedance spectroscopy (EIS) data. However, we must be careful when using the DRT method on electrochemical systems with blocking electrodes, such as those encountered in batteries and supercapacitors. This is…
Authors not listed
Electrochemical impedance spectroscopy (EIS) is one of the most widely deployed methods to characterise electrochemical systems such as batteries, fuel cells or electrolyzers. The distribution of relaxation times (DRT) represents a technique to simplify EIS data by deconvolution with a suitable kernel, while with…
Emanuele Quattrocchi, Baptiste Py, Adeleke Maradesa, Quentin Meyer + 2 more
Electrochemical impedance spectroscopy (EIS) is a characterization technique widely used to evaluate the properties of electrochemical systems. The distribution of relaxation times (DRT) has emerged as a model-free alternative to equivalent circuits and physical models to circumvent the inherent challenges of EIS…