GPU-Accelerated Algorithm to Compute Bessel-Fourier Moments

Bessel-Fourier moments have been applied in image pattern reconstruction since their introduction in 2010. In this research, a scalable GPU-based algorithm is proposed to accelerate the computation of Bessel-Fourier moments of high orders while preserving accuracy. To analyze our new algorithm, image reconstructions from Bessel-Fourier moments of orders up to 1000 were tested on two systems. The experimental results prove the correctness and scalability of the algorithm. In addition, by investigating the precision-related performance, both 64-bit and 32-bit precisions were shown to provide the same level of computational accuracy for Bessel-Fourier moments of orders up to 1000. Nevertheless, reconstructions with 64-bit precision are computationally more costly. Furthermore, we applied filtering in Bessel-Fourier moments and Fourier Frequency domains and found that Bessel-Fourier moments share some similarities with the frequencies in Fourier Frequency domain, though more image power is distributed in the Bessel-Fourier moments of lower orders.Master of Science in Applied Computer Scienc

Chiral discrimination in optical trapping and manipulation

When circularly polarized light interacts with chiral molecules or nanoscale particles powerful symmetry principles determine the possibility of achieving chiral discrimination, and the detailed form of electrodynamic mechanisms dictate the types of interaction that can be involved. The optical trapping of molecules and nanoscale particles can be described in terms of a forward-Rayleigh scattering mechanism, with trapping forces being dependent on the positioning within the commonly non-uniform intensity beam profile. In such a scheme, nanoparticles are commonly attracted to local potential energy minima, ordinarily towards the centre of the beam. For achiral particles the pertinent material response property usually entails an electronic polarizability involving transition electric dipole moments. However, in the case of chiral molecules, additional effects arise through the engagement of magnetic counterpart transition dipoles. It emerges that, when circularly polarized light is used for the trapping, a discriminatory response can be identified between left- and right-handed polarizations. Developing a quantum framework to accurately describe this phenomenon, with a tensor formulation to correctly represent the relevant molecular properties, the theory leads to exact analytical expressions for the associated energy landscape contributions. Specific results are identified for liquids and solutions, both for isotropic media and also where partial alignment arises due to a static electric field. The paper concludes with a pragmatic analysis of the scope for achieving enantiomer separation by such methods