A secure image steganography based on modified matrix encoding using the adaptive region selection technique

This paper introduced an image steganography technique based on modified matrix encoding to enhance the perceptual quality of the stego images. Additionally, more pixel bit-planes are exploited in the data hiding process to improve the embedding capacity. The number of used image layers depends on the size of the given secret message and the texture characteristic of the cover image. The complexity of the pixel block is identified by the difference between the middle pixel and its neighbors. By performing the suitable embedding solutions of modified matrix encoding, the complexity is unchanged by the data hiding stage. Therefore, the used image regions could be determined precisely in the extraction process without using any additional information. The experimental results proved that the stego images created by the proposed approach achieved higher security against statistical and visual steganalysis techniques than the previous methods. The improvement of the security against detection by Ensemble Classifier is four times as secure as the best security performance of the existing methods.

     

On data dependence of stability domains,exponential stability and stability radii for implicit linear dynamic equations

We shall deal with some problems concerning the stability domains, the spectrum of matrix pairs, the exponential stability and its robustness measure for linear implicit dynamic equations of arbitrary index. First, some characterizations of the stability domains corresponding to a convergent sequence of time scales are derived. Then, we investigate how the spectrum of matrix pairs, the exponential stability and the stability radii for implicit dynamic equations depend on the equation data when the structured perturbations act on both the coefficient of derivative and the right-hand side.     

Impact of hydropower dam development on agriculturally based livelihoods of resettled communities: a case study of Duong Hoa Commune in central Vietnam

Dam development is widespread in central Vietnam. Interviews were conducted with households that had been resettled and those that had not to determine the type of agricultural livelihoods that were re-established nine years after resettlement due to the Ta Trach reservoir project. Results showed that resettled households, despite having more forest land, were economically worse off compared with households that were not moved. This discrepancy between households was attributed to less arable land allocated to resettled households. The provision of good-quality land, able to grow crops and food trees, was essential if households were to re-establish a comparable agriculturally based livelihood.     

Investigation of the effects of recycled engine oil bottoms on asphalt field performance following an oxidation modeling approach

This work investigates the effects of recycled engine oil bottoms (REOBs) on asphalt field performance by comparing asphalts with and without REOBs in terms of the asphalt properties required for pavement oxidation modeling. Specifically, oxidation reaction kinetics parameters, dynamic shear rheometer (DSR) function (DSRFn) hardening susceptibility (HS), and low sheer viscosity (LSV) HS are determined and compared for base binder, 5 wt.% REOBs, and 15 wt.% REOBs blends. At the higher percentage, addition of REOBs appears to increase the initial oxidation rate at field temperatures and significantly increases LSV HS, but does not significantly increase the DSRFn HS. A field modeling example elucidates the effects.     

Test bed for power amplifier behavioral characterization and modeling

Traditional test bed of power amplifier (PA) behavioral characterization and modeling based on vector signal analyzer (VSA) and often equipped with specialized software is both expensive and inflexible to modify to suit different scenarios. In this paper, a new test bed based on an oscilloscope or other general purpose data acquisition systems, which works as analog to digital converter (ADC) with a proper (radio frequency) RF bandwidth and maximum sampling rate, is proposed. The common impairments, e.g. transmitter IQ imbalances, channel delay, frequency offset, and carrier phase offset, are all well compensated. The accurately recovered envelopes of the PA’s input and output signals are used for a PA behavioral characterization and modeling. Furthermore, Relative envelope error (REE) parameter is proposed to evaluate the accuracy of envelope recovery. The experiment shows a very accurate RF signal envelope recovery, and a good performance of PA behavioral modeling.     

Lumped parameter modeling and analysis of hybrid magnet engine valve actuator

The hybrid magnet engine valve actuator (HMEVA) composed of two types of magnets (permanent magnet and electromagnet) and two balanced springs is a promising tool for implementing innovative engine management strategies for variable valve timing. Finite Element Method (FEM), a favored actuator design tool due to its high accuracy, was utilized to analyze the electromagnetic actuator, but it consumes a lot of time especially in computation iterations for optimization. Accordingly, the magnetic equivalent circuit analysis can be an alternative tool to FEM because of its computation iteration capability with fair accuracy. In this paper, an equivalent magnetic circuit model of an HMEVA is developed considering the reluctances, external magnetic forces and so on, and the simulation results are presented. In addition, the result of lumped parameter analysis (LA) is compared with those obtained from finite element analysis for verification.     

High throughput optical readout of dense arrays of nanomechanical systems for sensing applications

We present an instrument based on the scanning of a laser beam and the measurement of the reflected beam deflection that enables the readout of arrays of nanomechanical systems without limitation in the geometry of the sample, with high sensitivity and a spatial resolution of few micrometers. The measurement of nanoscale deformations on surfaces of cm(2) is performed automatically, with minimal need of user intervention for optical alignment. To exploit the capability of the instrument for high throughput biological and chemical sensing, we have designed and fabricated a two-dimensional array of 128 cantilevers. As a proof of concept, we measure the nanometer-scale bending of the 128 cantilevers, previously coated with a thin gold layer, induced by the adsorption and self-assembly on the gold surface of several self-assembled monolayers. The instrument is able to provide the static and dynamic responses of cantilevers with subnanometer resolution and at a rate of up to ten cantilevers per second. The instrumentation and the fabricated chip enable applications for the analysis of complex biological systems and for artificial olfaction.