Performance evaluation of a two stage adaptive genetic algorithm (TSAGA) in structural topology optimization

Genetic algorithm with island and adaptive features has been used for reaching the global optimal solution in the context of structural topology optimization. A two stage adaptive genetic algorithm (TSAGA) involving a self-adaptive island genetic algorithm (SAIGA) for the first stage and adaptive techniques in the second stage is proposed for the use in bit-array represented topology optimization. The first stage, consisting a number of island runs each starting with a different set of random population and searching for better designs in different peaks, helps the algorithm in performing an extensive global search. After the completion of island runs the initial population for the second stage is formed from the best members of each island that provides greater variety and potential for faster improvement and is run for a predefined number of generations. In this second stage the genetic parameters and operators are dynamically adapted with the progress of optimization process in such a way as to increase the convergence rate while maintaining the diversity in population. The results obtained on several single and multiple loading case problems have been compared with other GA and non-GA-based approaches, and the efficiency and effectiveness of the proposed methodology in reaching the global optimal solution is demonstrated.     

Impact of Silver Addition on Room Temperature Magneto-Resistance in La0.7Ba0.3MnO3 (LBMO): Ag x ?( x =0.0,?0.1, 0.2, 0.3, 0.4)

La_0.7Ba_0.3MnO₃ (LBMO): Ag _x (x=0.0, 0.1, 0.2, 0.3, and 0.4) composites are synthesized by a solid-state reaction route, the final sintering temperatures are varied from 1300 °C (LBMO1300Ag) to 1400 °C (LBMO1400Ag), and their physical properties are compared as a function of temperature and Ag content. All samples are crystallized in single phase accompanied by some distortion in main structural phase peaks at higher angles with an increase in silver content. Though the lattice parameters (a,c) decrease, the b increases slightly with an increase in Ag content. The scanning electron micrographs (SEM) showed better grains morphology in terms of size and diffusion of grain boundaries with an increase in Ag content. In both LBMO1300Ag and LBMO1400Ag series, the metal insulator transition (T ^MI) and accompanied paramagnetic-ferromagnetic transition (T _C) temperatures are decreased with an increase in Ag content. The sharpness of MI transition, defined by temperature coefficient of resistance (TCR), is improved for Ag added samples. At a particular content of Ag(0.3), the T ^MI and T _C are tuned to 300 K and maximum magneto-resistance at 7 Tesla applied field (MR^{7 T}) of up to 55% is achieved at this temperature, which is more than double to that as observed for pure samples of the both 1300 and 1400 °C series at same temperature. The MR^{7 T} is further increased to above 60% for LBMOAg(0.4) samples, but is at 270 K. The MR^{7 T} is measured at varying temperatures of 5, 100, 200, 300, and 400 K in varying fields from ±7 Tesla, which exhibits U and V type shapes. Summarily, the addition of Ag in LBMO improves significantly the morphology of the grains and results in better physical properties of the parent manganite system.     

Encrypted Biography of Biomedical Image - a Pentalayer Cryptosystem on FPGA

Secure transmission of medical information occupies a crucial role in the world of telemedicine applications. Reconfigurable hardware implementation offers several advantages over software implementation especially for real time security applications. This work aims to propose the novel implementation of a penta-layer medical image encryption using a reconfigurable Cyclone II Field Programmable Gate Array (FPGA) EP2C35F672C6. The first layer of encryption performs the row-wise and column-wise pixel permutations based on Linear Feedback Shift Register (LFSR). The second and third layers of encryption are based on maximal length sequence Pseudo Random Number Generator (PRNG) 16-bit Cellular automata (CA) circuit and Galois Field (GF) product. In the fourth layer, a synthetic image is subsequently created by chaotic clock with Phase Lock Loop (PLLs) and gates to diffuse the image pixels. This creation of synthetic image for diffusion makes the developed cryptosystem totally hardware dependent. Last layer performs the diffusion using one dimensional logistic map. The synthesized result reveals that the reconfigurable implementation of proposed encryption process consumes comparatively lesser logic elements (2480) and low power consumption (278.65 mW) with an encryption time of 215.92 ms for encrypting a 256?×?256 DICOM medical image. Finally, various analyses such as Number of Pixel Change Rate (NPCR), Unified Average Change in Intensity (UACI), Entropy, Correlation, Uniform distribution and NIST statistical test suite have been performed to prove the robustness of the algorithm against various attacks.

     

Effects on the development of blown pack spoilage of the initial numbers of Clostridium estertheticum spores and Leuconostoc mesenteroides on vacuum packed beef

Beef steaks were inoculated with Clostridium estertheticum spores and Leuconostoc mesenteroides cells at all combinations of numbers of 0, 10, 100 or 1000/cm(2) for each organism. After vacuum packaging the steaks were stored at 4, 1, or -1.5°C. Pack volumes were determined by water displacement at suitable intervals. Irrespective of L. mesenteroides numbers, for packs containing meat inoculated with 0, 10, 100 or 1000 spores/cm(2), 60, 16, 3 and 1 of 60 packs did not swell. The times of onset of swelling were twice as long at -1.5 as at 4°C, but they were not affected by the inoculated numbers of L. mesenteroides. Rates of pack swelling increased with increasing storage temperature and number of spores, but decreased with increasing numbers of inoculated L. mesenteroides. Lactic acid bacteria can apparently prevent development of blown pack spoilage of vacuum packs containing meat contaminated with low numbers of C. estertheticum.     

Modelling the centroid and charge density in double-gate MOSFETs including quantum effects

An analytical model for double-gate metal–oxide–semiconductor field-effect transistors considering quantum effects is presented in this article. The variational method is used to solve the Schrodinger–Poisson's equation. The simple and accurate mathematical expressions for centroid and inversion charge density are obtained. It is seen that the minimum energy of the sub-bands and the inversion charge density decreases as the silicon thickness of the device increases. The analytical results obtained from the proposed model are compared and agreed well with a device simulation tool named SCHRED.     

Rheology of Steel Fibre Containing Alumina-Magnesia-Extruded Graphite Pellets Self-Flowing Castables

The influences of adding steel fibres of different lengths up to 3 volume percentages, on the rheological behaviour of an alumina-magnesia-extruded graphite pellet containing castables have been studied using a rheometer. Free-flow measurements have shown that the flow is severely affected by increasing the length of steel fibres. The calculated values of rheological constants indicate that 19 mm and 25 mm fibre up to 2 volume percentage is permitted while one volume percentage of 50 mm fibres severely degrades the rheology of the castable.     

Variations in first principles calculated defect energies in GaAs and their effect on practical predictions

There is an abundant literature on calculations of formation and ionization energies of point defects in GaAs. Since most of these energies, especially the formation energies, are difficult to measure, the calculations are primary means of obtaining their values. However, based on the assumptions of the calculations, the reported values differ greatly among the various calculations. In this paper we discuss the sources of errors and their impact on practical predictions valuable in GaAs device fabrication. In particular, we have compared a large set of computed energies and selected the most appropriate values. Then, in the context of GaAs material quality, we investigated the impact of errors in calculation of formation energies on the performance of the GaAs substrate for device fabrication. We find that in spite of the errors inherent in ab initio calculations, it is possible to correctly predict the behaviour of GaAs substrate.     

Distribution of D1S80 alleles in the Jordanian population

This study demonstrates that the locus D1S80 is highly polymorphic, with 24 different alleles and 66 genotypes in 215 Jordanians. This data set conforms to Hardy-Weinberg expectations(HWE).     

Synthesis of antenna patterns of circular arc arrays

A new method is described for the synthesis of antenna patterns of circular are arrays. The method is based on the application of the simulated annealing technique to achieve the excitations of elements for a desired radiation pattern. Design specifications include sidelobe level, beamwidth, control of nulls, and other parameters such as the dynamic range of excitations     

Corrosion aspects of metallic implants — An overview

The ability to replace or augment diseased body parts totally or partially has improved both the quality and life span of human population. The decline in surgical risks during recent decades has encouraged the development of more complex procedures for prosthetic implantation. Additionally, a variety of extracorporeal devices, such as the heart, lung and blood dialysis machines are used routinely, but these prosthetic elements have several limitations. Hence, research projects are currently underway to overcome the limitations of synthetic materials by developing formulations with varying properties, such as asymptomatic, long‐term function in the human physiological environment, etc., to meet the needs of biomedical surgeons. This review focuses on the several biomaterials corrosion and its measures to prevent corrosion.