Hesham Alhumyani^*

Intelligent Automation & Soft Computing, Vol.36, No.3, pp. 2933-2945, 2023, DOI:10.32604/iasc.2023.034689

Abstract This paper introduces an efficient image cryptography system. The proposed image cryptography system is based on employing the two-dimensional (2D) chaotic henon map (CHM) in the Discrete Fourier Transform (DFT). The proposed DFT-based CHM image cryptography has two procedures which are the encryption and decryption procedures. In the proposed DFT-based CHM image cryptography, the confusion is employed using the CHM while the diffusion is realized using the DFT. So, the proposed DFT-based CHM image cryptography achieves both confusion and diffusion characteristics. The encryption procedure starts by applying the DFT on the image then the DFT transformed image is scrambled using… More >

Adel Daoud^1,2,3,4,*, Ali Cheknane², Jean Michel Nunzi^3,4, Afak Meftah¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1569-1579, 2022, DOI:10.32604/fdmp.2022.022091

Abstract A solubility model for Merocyanine-540 dye together with the interface's electron transfer kinetics of MC-540/TiO₂ has been investigated (Merocyanine 540-based dye has been used effectively in dye-sensitized solar cells). The highest absorption peaks were recorded at 489 nm and 493 nm in Water and Ethanol solvent, versus the vacuum phase which yielded 495 nm (associated with a modest electron injection-free energy value (ΔGinj) of -2.34 eV for both Water and Ethanol solvents). The time-dependent density functional theory (TD-DFT) method approach has been applied in this simulation. Additionally, the electronic structure and simulated UV-Vis spectra of the dye in different solvents… More > Graphic Abstract

Daniel Dodzi Yao Setsoafia¹, Kiran Sreedhar Ram¹, Hooman Mehdizadeh-Rad^1,2, David Ompong^1,2, Vinuthaa Murthy^1,2, Jai Singh^1,2,*

Journal of Renewable Materials, Vol.10, No.10, pp. 2553-2567, 2022, DOI:10.32604/jrm.2022.020967

Abstract DFT and TD-DFT calculations of HOMO and LUMO energies and photovoltaic properties are carried out on four selected pentathiophene donor and one IDIC-4F acceptor molecules using B3LYP and PBE0 functionals for the ground state energy calculations and CAM-B3LYP functional for the excited state calculations. The discrepancy between the calculated and experimental energies is reduced by correlating them with a linear fit. The fitted energies of HOMO and LUMO are used to calculate the V_oc of an OSC based on these donors and acceptor blend and compared with experimental values. Using the Scharber model the calculated PCE of the donor-acceptor molecules… More >

S. Markkandan^1,*, S. Sivasubramanian², Jaison Mulerikkal³, Nazeer Shaik⁴, Beulah Jackson⁵, Lakshmi Naryanan⁶

Intelligent Automation & Soft Computing, Vol.32, No.1, pp. 361-375, 2022, DOI:10.32604/iasc.2022.021779

Abstract The codebook design is the most essential core technique in constrained feedback massive multi-input multi-output (MIMO) system communications. MIMO vectors have been generally isotropic or evenly distributed in traditional codebook designs. In this paper, Gaussian mixture model (GMM) based clustering codebook design is proposed, which is inspired by the strong classification and analytical abilities of clustering techniques. Huge quantities of channel state information (CSI) are initially saved as entry data of the clustering process. Further, split into N number of clusters based on the shortest distance. The centroids part of clustering has been utilized for constructing a codebook with statistic… More >

SHYAM BADU¹, SANJAY PRABHAKAR^1,2, RODERICK MELNIK^1,3,*

BIOCELL, Vol.44, No.3, pp. 279-291, 2020, DOI:10.32604/biocell.2020.010916

Abstract Photosynthesis is a fundamental process in biosciences and biotechnology that influences profoundly the research in other disciplines. In this paper, we focus on the characterization of fundamental components, present in pigment-protein complexes, in terms of their spectroscopic properties such as infrared spectra, nuclear magnetic resonance, as well as nuclear quadrupole resonance, which are of critical importance for many applications. Such components include chlorophylls and bacteriochlorophylls. Based on the density functional theory method, we calculate the main spectroscopic characteristics of these components for the Fenna-Matthews-Olson light-harvesting complex, analyze them and compare them with available experimental results. Future outlook is discussed in… More >

MINGHAO LI¹, YOULI QIU², WENHUI ZHANG¹, RUIHAO SUN¹, MEIJIN DU¹, LUZE YANG³, YU LI^1,*

BIOCELL, Vol.44, No.2, pp. 247-255, 2020, DOI:10.32604/biocell.2020.08835

Abstract While phthalate acid esters (PAEs) cannot fluoresce alone, they can be detected by fluorescence spectroscopy after chelation with bovine serum albumin (BSA). In this study, the types of amino acid residues at the active site of PAEs chelated with BSA were determined using molecular docking technology. A modification scheme of BSA with higher detection sensitivity fluorescence spectroscopy for PAEs was proposed based on the docking results and constructed for a novel BSA structure with a higher detection sensitivity of fluorescence spectroscopy using a homologous modeling method. Density functional theory (DFT) was employed to explore the influence before and after BSA… More >

Yuan Chen¹, Liangtao Duan¹, Weize Sun^{2, *}, Jingxin Xu³

CMC-Computers, Materials & Continua, Vol.62, No.2, pp. 849-859, 2020, DOI:10.32604/cmc.2020.07115

Abstract In this paper, we address the frequency estimator for 2-dimensional (2-D) complex sinusoids in the presence of white Gaussian noise. With the use of the sinc function model of the discrete Fourier transform (DFT) coefficients on the input data, a fast and accurate frequency estimator is devised, where only the DFT coefficient with the highest magnitude and its four neighbors are required. Variance analysis is also included to investigate the accuracy of the proposed algorithm. Simulation results are conducted to demonstrate the superiority of the developed scheme, in terms of the estimation performance and computational complexity. More >

Brian Schwarz, Patrick McHargue, Mark Richardson

Sound & Vibration, Vol.52, No.2, pp. 1-6, 2018, DOI:10.32604/sv.2018.03637

Abstract In this paper, we show how Operating Deflection Shapes (ODS’s) and mode shapes can be obtained experimentally from measurements that are made using only two sensors and two short wires to connect them to a multi-channel acquisition system. This new test procedure is depicted in Figure 1. Not only is the equipment required to do a test much more cost effective, but this method can be used to test any sized test article, especially large ones.
The testing method introduced here involves moving a pair of sensors along together in a prescribed manor, and calculating the Transmissibility between them. The… More >

Nobuko Ohba, Shuji Ogata

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 77-78, 2011, DOI:10.3970/icces.2011.019.077

Abstract We have been developing the concurrent-type, hybrid quantum-classical simulation scheme for various atomic processes at liquid-solid interfaces [1]. In this scheme, the density-functional theory (DFT) method is applied to the "quantum" region to calculate the electronic structure; while the semi-empirical inter-atomic potential, to the "classical" region. In this talk we review its recent developments both from methodology and application viewpoints.
In the hybrid simulation, the DFT method that is applied at each time-step to a cluster of typically a hundred atoms (i.e., the QM region) consumes most of the computation power. It is highly desirable to develop a less… More >

K. Williams¹, T. Cagin^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.4, pp. 153-160, 2010, DOI:10.3970/icces.2010.015.153

Abstract Designing magnetic shape memory materials with practicable engineering applications requires a thorough understanding of their electronic, magnetic, and mechanical properties. Experimental and computational studies on such materials provide differing perspectives on the same problems, with theoretical approaches offering fundamental insight into complex experimental phenomena. Many recent computational approaches have focused on first-principles calculations, all of which have been successful in reproducing ground-state structures and properties such as lattice parameters, magnetic moments, electronic density of states, and phonon dispersion curves. With all of these successes, however, such methods fail to include the effects of finite temperatures, effects which are critical in… More >