IMPLEMENTATION OF RSA KEY GENERATION BASED ON RNS USING VERILOG

RSA key generation is of great concern for implementation of RSA cryptosystem on embedded system due to its long processing latency. In this paper, a novel architecture is presented to provide high processing speed to RSA key generation for embedded platform with limited processing capacity. In order to exploit more data level parallelism, Residue Number System (RNS) is introduced to accelerate RSA key pair generation, in which these independent elements can be processed simultaneously. A cipher processor based on Transport Triggered Architecture (TTA) is proposed to realize the parallelism at the architecture level. In the meantime, division is avoided in the proposed architecture, which reduces the expense of hardware implementation remarkably. The proposed design is implemented by Verilog HDL and verified in matlab. A rate of 3 pairs per second can be achieved for 1024-bit RSA key generation at the frequency of 100 MHz

Re-equilibration after quenches in athermal martensites:Conversion-delays for vapour to liquid domain-wall phases

Entropy barriers and ageing states appear in martensitic structural-transition models, slowly re-equilibrating after temperature quenches, under Monte Carlo dynamics. Concepts from protein folding and ageing harmonic oscillators turn out to be useful in understanding these nonequilibrium evolutions. We show how the athermal, non-activated delay time for seeded parent-phase austenite to convert to product-phase martensite, arises from an identified entropy barrier in Fourier space. In an ageing state of low Monte Carlo acceptances, the strain structure factor makes constant-energy searches for rare pathways, to enter a Brillouin zone `golf hole' enclosing negative energy states, and to suddenly release entropically trapped stresses. In this context, a stress-dependent effective temperature can be defined, that re-equilibrates to the quenched bath temperature.Comment: 11 pages, 12 figures. Under process with Phys. Rev. B (2015

2-D IMPLEMENTATION OF DIGITAL GABOR FILTER DESIGN USING VERILOG

Fingerprint or Face Image enhancement using Gabor filter is one of highly computational complexity in fingerprint verification process. Gabor filter has a complex valued convolution kernel and a data format with complex values is used. So implementing Gabor filter is very significant in fingerprint verification process. Designing Gabor filter will help enhancing the quality of fingerprint image. In fingerprint recognition, Gabor filter optimally capture both local orientation and frequency information from a fingerprint image. By tuning a Gabor filter to specific frequency and direction, the local frequency and orientation information can be obtained. Thus, it is suited for extracting texture information from images. This paper presents the implementation of 2-D Gabor Filter design using Verilog HDL. This paper details important enhancement made to the 2D -Digital Gabor filter to minimize the sizing problem and the coding style that synthesizable. The intention is to study, analyze, simplify and improvise the design synthesis efficiency and accuracy while maintaining the same functionality. The result provides area efficiency architecture for the effective design

2-(Piperidin-1-yl)-6-(1H-pyrrol-1-yl)pyridine-3,5-dicarbonitrile

The piperidine ring of the title compound, C16H15N5, adopts a chair conformation. The pyridine ring is essentially planar, with a maximum deviation of 0.035 (3) Å. The pyrrole and pyridine rings are almost coplanar, forming a dihedral angle of 3.48 (14)°. In the crystal, no classical hydrogen bonds were found. In the crystal, the molecules are linked by aromatic π–π stacking [centroid–centroid separations = 3.4984 (16) and 3.9641 (15) Å between pyrrole and pyridine rings and between pyridine rings, respectively]

Enantioselective total syntheses of ropivacaine and its analogues

An alternative asymmetric synthesis of ropivacaine and analogues employing the 'cation pool' strategy and host/guest supramolecular co-catalysis approach is presented. In this study, chiral auxiliaries, several soft nucleophiles as well as one-pot conditions for anodic oxidation, followed by nucleophilic addition, have been applied. (c) 2008 Elsevier Ltd. All rights reserved.49345098510

Erratum: Understanding Vogel-Fulcher–like equilibration times through the partial equilibration scenario

Original article: EPL, 142 (2023) 3600

Understanding Vogel-Fulcher–like equilibration times through the partial equilibration scenario

We test a post-quench Partial Equilibration Scenario (PES) of Ritort and colleagues, through Monte Carlo quench simulations, of a vector-spin model for a cubic-to-tetragonal, martensitic structural transition. We confirm the PES signature distribution of an exponential tail in heat releases, scaled in an effective search temperature that regulates energy-lowering passages between fixed-energy shells. Our simulations find that this effective temperature vanishes linearly in the deviation of the quench temperature from a divergence temperature, where passage bottlenecks in phase space segment their topology, and entropy barriers diverge. Equilibration delay times, exponential in the inverse effective temperature, are thus predicted to show singular Vogel-Fulcher behaviour, understood here as an arrest of PES heat releases to the bath, and confirmed by experimental data on martensitic alloys