926 research outputs found
Experimental research testbed for internet of things: A survey from security services perspectives
No Abstract
Emergence of turbulence in an oscillating Bose-Einstein condensate
We report on the experimental observation of vortices tangle in an atomic BEC
of Rb-87 atoms when an external oscillatory perturbation is introduced in the
trap. The vortices tangle configuration is a signature of the presence of a
turbulent regime in the cloud. We also show that this turbulent cloud has
suppression of the aspect ratio inversion typically observed in quantum
degenerate bosonic gases during free expansion. Instead, the cloud expands
keeping the ratio between their axis constant. Turbulence in atomic superfluids
may constitute an alternative system to investigate decay mechanisms as well as
to test fundamental theoretical aspects in this field.Comment: accepted for Phys. Rev. Let
Breakdown characteristics of polyethylene/silicon nitride nanocomposites
Silicon nitride (Si3N4) has been utilized as a nanofiller in polymeric insulation due to its good characteristics in both electrical insulation and thermal conduction properties. In this work, a comparative study was performed between unfilled polyethylene and polyethylene containing different amounts of Si3N4 nanofiller. The study showed that the low density polyethylene (LDPE) added with 15 wt% of Si3N4nanofiller could have higher breakdown strength compared to equivalent LDPE with 10 wt% of Si3N4nanofiller. Morphological characterizations of the nanocomposite samples were performed using field emission electron microscopy (FESEM) and the results showed that the breakdown performance of the investigated materials were affected by the agglomeration of Si3N4 nanoparticles
Current implementation of advance encryption standard (AES) S-Box
Although the attack on cryptosystem is still not severe, the development of the scheme is stillongoing especially for the design of S-Box. Two main approach has beenused, which areheuristic method and algebraic method. Algebraic method as in current AES implementationhas been proven to be the most secure S-Box design to date. This review paper willconcentrate on two kinds of method of constructing AES S-Box, which are algebraic approachand heuristic approach. The objective is to review a method of constructing S-Box, which arecomparable or close to the original construction of AES S-Box especially for the heuristicapproach. Finally, all the listed S-Boxes from these two methods will be compared in terms oftheir security performance which is nonlinearity and differential uniformity of the S-Box. Thefinding may offer the potential approach to develop a new S-Box that is better than theoriginal one.Keywords: block cipher; AES; S-Bo
Application Method of Antimicrobial Substances for the Control of Schizophyllum Commune Fr. Causing Brown Germ and Seed Rot of Oil Palm
Biological seed treatment promotes to save the environment from toxic chemicals in the agricultural practices. Schizophyllum commune is one of the important seedborne pathogenic fungi causing brown germ and seed rot of oil palm which required effective and efficient treatment based on environmental friendly approaches. Anti-microbial substances are extracted from antagonistic bacteria of B. multivorans and M. testaceum after mass production in the liquid media. Application method of anti-microbial substances for the control of Schizophylllum commune was done by seed dipping for 30 minutes and vacuum infiltration at 400 mm Hg. vac. for 2 min. in supernatant of anti-microbial substances diluted in sterilized distilled water with concentration ratio of 1:4. Application method using anti-microbial substances from antagonistic bacteria inhibited the growth of pathogenic fungus, enhanced seed germination, and without causing any abnormal growth of oil palm seedlings
Mountain-Shaped Coupler for Ultra Wideband Applications
This paper demonstrates a novel mountain-shaped design for a compact 3-dB coupler operating at ultra-wideband (UWB) frequencies from 3.1GHz to 10.6 GHz. The proposed design was accomplished using multilayer technology in which the structure is formed by three layers of conductors interleaved by a layer of substrate between each conductor layer. Simulation was carried out using CST Microwave Studio; the result was then compared with results from rectangular and star-shaped couplers that implemented the same technique. The results obtained show that the proposed new coupler has better performance compared to both rectangular and star-shaped coupler designs in terms of return loss, isolation, and phase difference. The coupler was fabricated and measured; the measurement results satisfactorily agree with the simulation results
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