This paper presents a novel two-dimensional split-vector-radix fast-Fourier-transform (2D svr-FFT) algorithm. The modularizing feature of the 2D svr-FFT structure enables us to explore its characteristics by identifying the local structural property. Each local module is designated as a DFT (non-DFT) block if its output corresponds to DFT (non-DFT) values. The block attribute (DFT or non-DFT) d...

There are three different way to calculate DFT. First method is using formula of DFT or simultaneous equation. Second is Correlation technique and third one is using Fast Fourier Transform (FFT). First method is useful for understanding of basic idea of DFT, but it is not fit for practical and application purpose. In second method is based on detecting known waveform in another signal. It is us...

This paper presents a mixed-decimation multipath delay feedback (M 2 DF) approach for the radix-2 k fast Fourier transform. We employ the principle of folding transformation to derive the proposed architecture, which activates the idle period of arithmetic modules in multipath delay feedback (MDF) architectures by integrating the decimation-in-time operations into the decimation-in-frequency-op...

This paper proposes an RST−invariant multi−bit watermarking system based on LPM and DFT. This system embeds the watermark in a rotation and translation invariant domain obtained by first acquiring log−polar mapped DFT (LPM−DFT) magnitudes of an image, and then taking the magnitude of the 1−dimensional DFT along the angular axis of this LPM−DFT magnitudes. Neither the original cover image nor a ...

A review of the literature about calculating the adsorption properties of arsenic onto mineral models using density functional theory (DFT) is presented. Furthermore, this work presents DFT results that show the effect of model charge, hydration, oxidation state, and DFT method on the structures and adsorption energies for As and As onto Fe-(oxyhydr)oxide cluster models. Calculated interatomic ...

Turing machines and Gödel numbers are important pillars of the theory of computation. Thus, any computational architecture needs to show how it could relate to Turing machines and how stable implementations of Turing computation are possible. In this chapter, we implement universal Turing computation in a neural field environment. To this end, we employ the canonical symbologram representation ...

Here, we present a concise model that can predict the photoluminescent properties of given compound from first principles, both within and beyond Franck–Condon approximation. The formalism required to compute fluorescence, Internal Conversion (IC), Inter-System Crossing (ISC) is discussed. IC mechanism, in particular, difficult pathway due difficulties associated with computation bosonic config...

Photon-induced electronic excitations are ubiquitously observed in organic chromophore. In this context, we present a simple, alternative time-independent DFT procedure, for the computation of single-particle excitation energies, particular, lower bound excited singlet states, which primary interest photochemistry. This takes inspiration from recently developed Becke’s exciton model, where key ...

A comprehensive study of the effect of tensile strain (ε = 0% to 8%) on the electronic structures of two-dimensional (2D) transition-metal trichalcogenide (TMTC) monolayers MX3 (M = Ti, Zr, Hf, Nb; X = S, Se Te) is performed on the basis of density functional theory (DFT) computation. The unstrained TiS3, ZrS3, ZrSe3, HfS3, HfSe3 and NbS3 monolayers are predicted to be semiconductors with their...

The ability of unrestricted Hartree–Fock (UHF), Møller–Plesset (MP2), density functional theory (DFT), and hybrid density functional/Hartree–Fock methodologies to describe the structure and spin-state energetics of iron porphyrins was assessed. In the first place, these techniques have been applied to Fe, Fe+, Fe2+, and Fe3+ for which HF calculations overestimate energy gaps, favoring stabiliza...