A secure network coding based image communications in two-hop wireless relay networks

This paper investigates the image communications in two-hop wireless relay networks (TH-WRNs) where a source node sends images to a destination node with the assistance of a relay node via two hops, i.e. source-to-relay and relay-to-destination links. Due to the broadcast nature of wireless media, there exists an eavesdropper who tries to overhear and recover the images. Aiming to enhance the security and also to save transmission bandwidth of the image communications, we propose a secure relaying transmission (SRT) protocol by exploiting both random linear network coding (RLNC) and image super-resolution (ISR) techniques. In the proposed protocol, the original high-resolution (HR) images are downscaled at the source node and the RLNC is employed at both the source and relay nodes to conceal the original images from the eavesdropper. The RLNC decoding and ISR are adopted at the destination node to decode and recover the HR images, while the eavesdropper cannot decode the images due to the unawareness of the coefficient matrices and the reference images in the RLNC. It is shown that the proposed SRT protocol achieves a significantly higher performance at the destination than at the eavesdropper. Furthermore, with high-quality relaying hops, the SRT protocol outperforms the secure direct transmission (SDT) protocol with only a direct link between the source and the destination nodes. Finally, simulation results are provided to verify the findings

Better-practice Approaches for Culture-based Fisheries Development in Asia

Resource /Energy Economics and Policy,

Inversion of DNA charge by a positive polymer via fractionalization of the polymer charge

Charge inversion of a DNA double helix by an oppositely charged flexible polyelectrolyte (PE) is widely used for gene delivery. It is considered here in terms of discrete charges of DNA. We concentrate on the worst scenario case when in the neutral state of the DNA-PE complex, each of the DNA charges is locally compensated by a PE charge and show that charge inversion exists even in this case. When an additional PE molecule is adsorbed by DNA, its charge gets fractionalized into monomer charges of defects (tails and arches) on the background of the perfectly neutralized DNA. These charges spread all over the DNA eliminating the self-energy of PE. Fractionalization leads to a substantial charge inversion of DNA. We show that fractionalization mechanism charge inversion works also for nonlinear polymers such as dendrimers. Remarkably, such fractionalization happens for adsorption of both PE or dendrimers on a two-dimensional charged lattice, as well. Relation of fractionalization to other mechanisms of charge inversion is discussed.Comment: Accepted for publication in Physica

Overcharging of a macroion by an oppositely charged polyelectrolyte

The complexation of a polyelectrolyte with an oppositely charged spherical macroion is studied for both salt free and salty solutions. When a polyelectrolyte winds around the macroion, its turns repel each other and form an almost equidistant coil. It is shown that this repulsive correlations of turns lead to the charge inversion: more polyelectrolyte winds around the macroion than it is necessary to neutralize it. The charge inversion becomes stronger with increasing concentration of salt and can exceed 100%. This paper confirms that correlations are the universal mechanism of charge inversion.Comment: Monte-Carlo simulation details added. Many corrections and references added. Accepted to Physica

Determinants of E-Cmmerce Adoption in SMEs

A deep insight of determinants of e-commerce adoption process is in needed to help small- and medium-sized enterprises (SMEs) to fasten up their e-commerce rush and overcome a great number of existed obstacles. This paper analyzed and classified factors taking effects on SMEs’ e-commerce adoption into four groups, specifically: (1) perceived benefits, (2) organizational readiness, (3) external environment, and (4) leadership attitudes and competences. Especially, the paper also gets an overview on the role of leadership in motivating the uptake of e-commerce within SMEs. Thorough analysis within the research contributes not only a general view about core determinants of e-commerce adoption, but also the engine toward the success of e-commerce distribution channel in SMEs

The importance of Cu supplied at or before pegging for seed and pod yield of peanut on low Cu sand

See Attache

Soil health impacts of rubber farming: The implication of conversion of degraded natural forests into monoculture plantations

High revenues from rubber latex exports have led to a rapid expansion of commercial rubber cultivation and, as a consequence, the conversion of different land use types (e.g., natural forests) into rubber plantations, which may lead to a decrease in soil health. In this study in Quang Tri Province, Vietnam, we determined: (1) the variation of soil health parameters along a chronosequence of rubber tree stands and natural forests and (2) the relationships and potential feedback between vegetation types, vegetation structures and soil health. Our results revealed that: (1) soil health was higher in natural forests than in rubber plantations with a higher values in higher biomass forests; (2) soil health was lower in younger rubber plantations; (3) soil health depends on vegetation structure (with significantly positive relationships found between soil health and canopy cover, litter biomass, dry litter cover and ground vegetation cover). This study highlights the need for more rigorous land management practices and land use conversion policies in order to ensure the long-term conservation of soil health in rubber plantations