Robust and secure fractional wavelet image watermarking

This paper presents an efficient fractional wavelet transform (FWT) image watermarking technique based on combining the discrete wavelet transform (DWT) and the fractional Fourier transform (FRFT). In the proposed technique, the host image is wavelet transformed with two resolution levels, and then, the middle frequency sub-bands are FRFT transformed. The watermark is hidden by altering the selected FRFT coefficients of the middle frequency sub-bands of the 2-level DWT-transformed host image. Two pseudo-random noise (PN) sequences are used to modulate the selected FRFT coefficients with the watermark pixels, and inverse transforms are finally applied to get the watermarked image. In watermark extraction, we just need the same two PN sequences used in the embedding process and the watermark size. The correlation factor is used to determine whether the extracted pixel is one or zero. The proposed fractional wavelet transform (FWT) image watermarking method is tested with different image processing attacks and under composite attacks to verify its robustness. Experimental results demonstrated improved robustness and security.     

Design of a Proportional-Integral-Derivative Controller for an Automatic Generation Control of Multi-area Power Thermal Systems Using Firefly Algorithm

Essentially, it is significant to supply the consumer with reliable and sufficient power. Since, power quality is mea sured by the consistency in frequency and power flow between control areas. Thus, in a power system operation and control, automatic generation control (AGC) plays a crucial role. In this paper, multi-area (Five areas: area 1, area 2, area 3, area 4 and area 5) reheat thermal power systems are considered with proportional-integral-derivative (PID) controller as a supplemen tary controller. Each area in the investigated power system is equipped with appropriate governor unit, turbine with reheater unit, generator and speed regulator unit. The PID controller parameters are optimized by considering nature bio-inspired firefly algorithm (FFA). The experimental results demonstrated the comparison of the proposed system performance (FFA-PID) with optimized PID controller based genetic algorithm (GA PID) and particle swarm optimization (PSO) technique (PSO PID) for the same investigated power system. The results proved the efficiency of employing the integral time absolute error (ITAE) cost function with one percent step load perturbation (1% SLP) in area 1. The proposed system based FFA achieved the least settling time compared to using the GA or the PSO algorithms, while, it attained good results with respect to the peak overshoot/undershoot. In addition, the FFA performance is improved with the increased number of iterations which outperformed the other optimization algorithms based controller.      

Light microscopy image de-noising using optimized LPA-ICI filter

Microscopic images are often corrupted by noise, where Poisson noise is one of the major types that can damage them. The local polynomial approximation (LPA) filter supported by the intersection confidence interval (ICI) rule was considered as an efficient filter for image de-noising. However, this filter depends on several parameters that affect its performance. In order to determine the optimal parameters, the present study employed the classic LPA-ICI (C-LPA-ICI) filter supported by optimization algorithms, namely the genetic algorithm (GA) and the particle swarm optimization (PSO) in the context of light microscopy imaging systems. Nevertheless, inclusion of the optimization algorithms increased the computational time. A novel automatic technique entitled “Standard Optimized LPA-ICI” (SO-LPA-ICI) is proposed. In this context, the average of the optimized ICI parameters was calculated, which obtained from both LPA-ICI-based GA (G-LPA-ICI) and LPA-ICI-based PSO (P-LPA-ICI). Thus, the proposed SO-LPA-ICI is included the optimal ICI parameters without optimization iterations. This procedure is proposed to speed up the optimized filter. A pool of 50 rats’ renal microscopic images is involved to test the proposed approach. A comparative study was conducted to compare the effectiveness of the four methods, namely C-LPA-ICI, G-LPA-ICI, P-LPA-ICI, and the SO-LPA-ICI for de-noising in the presence of Poisson noise. The experimental results established the outstanding performance of the SO-LPA-ICI in terms of the PSNR, MAE, and MSSIM with 28.27, 7.65, and 0.93 values, respectively. In addition, the proposed approach achieved fast de-noising compared to the G-LPA-ICI and the P-LPA-ICI.

     

Calculating air content in cement mortars

The new buying power of Saudi Arabia has quickened both building development and research and testing work in that country. Here, scientists at the Public Works Materials Testing Laboratories in Riyadh describe their methods of calculating air content of mortars made from home produced and imported cements.     

Prévision de la résistance mécanique du ciment en 30 heures

Le développement considérable de I'Arabie saoudite a obligé les laboratoires d'essai des matériaux à faire de grands progrès en peu de temps. Dans cet article, les chercheurs du Laboratoire d'essai des matériaux de Riyad expliquent comment ils ont utilisé un procédé accéléré pour prévoir la résistance à la compression de différents ciments Portland après 30 heures. Les résultats obtenus concordent, en moyenne, à ± 5% près avec les résistances que donnent les méthodes traditionnelles de conservation dans I'eau.     

Effect of Superimposed Sinusoidal a.c. on the Characteristics of Electrodeposited Ni,Cu and Cu-Ni Alloy Composites with α-Al2O3 and TiO2

Nickel, copper and copper-nickel alloy composites were electrodeposited without and with inclusions of inert α-Al₂O₃ and TiO₂ particles from closely similar selected baths. It was found that during electrodeposition a superimposed sinusoidal a.c. exerted a decrease in the cathodic polarization for the individual metals and the alloy composites. The higher the superimposed a.c. density and the lower its frequency the greater was the depolarizing effect. The combined effect of superimposed a.c. and inclusion of the inert particles in the bath on the cathodic polarization proved to be additive. Superimposed a.c. induced negligible changes in the cathodic current efficiency of nickel and copper metal composites deposition, whereas it caused a marked decrease (about 20%) in that of the copper-nickel alloy composites. The inert (α-Al₂O₃ and TiO₂) particles content in the individual metal and alloy composites as well as the alloy composition were influenced by the superimposed a.c. and correlated with its depolarizing effect. The above-mentioned changes exerted by superimposed a.c. controlled the growth morphology, as revealed by SEM, and the microhardness of the as-deposited metal and alloy composites. A correlation could be detected between superimposed a.c. and dispersion of α-Al₂O₃ or TiO₂ particles in an individual metal or alloy matrix, the grain refinement, and an improvement of its microhardness could be detected.     

Sonographic diagnosis of gallbladder perforation

An outbreak of 16 cases of ciprofloxacin-resistant Acinetobacter baumannii (calcoaceticus subspecies anitratus) infections occurred during a 7-month period in a medical intensive care unit. Fifteen of the patients developed pneumonia associated with ventilator support. Possible sources considered in the outbreak investigation were sinks, ice, personnel, patients on multiple antibiotic therapy, reusable ventilator circuits, and hemodialysis. The equipment and environment associated with the outbreak were cultured. Patients on ventilators were significantly more susceptible to Acinetobacter nosocomial infection compared with the rest of the patients in the medical intensive care unit (p < 0.05). Sputum cultures were only 5% sensitive to ciprofloxacin and gentamicin, but they were 100% sensitive to imipenem (p < 0.0001). Uncloaking imipenem was a significant contributing factor in controlling this outbreak. Once outbreak control measures were instituted, Acinetobacter isolates dropped from 77 (during the outbreak year) to 9 (during the subsequent year) and no new pneumonia cases occurred.     

Lateral Loaded Pile Response in Liquefiable Soil

This paper provides a new analysis procedure for assessing the lateral response of an isolated pile in saturated sands as liquefaction develops in response to dynamic loading such as that generated during earthquake shaking. This new procedure predicts the degradation in pile response and soil resistance due to the free-field excess porewater pressure generated by the earthquake, along with the near-field excess porewater pressure generated by lateral loading from the superstructure. The new procedure involves the integration of the developing (free- and near-field) porewater pressure in the strain wedge (SW) model analysis. The current SW model, developed to evaluate drained response (a nonlinear three-dimensional model) of a flexible pile in soil, has been extended in this paper to incorporate the undrained response of a laterally loaded pile in liquefied sand. This new procedure has the capability of predicting the response of a laterally loaded isolated pile and the associated modulus of subgrade reaction (i.e., the p–y curve) in a mobilized fashion as a result of developing liquefaction in the sand. Current design procedures assume slight or no resistance for the lateral movement of the pile in the liquefied soil which is a conservative practice. Alternatively, if liquefaction is assessed not to occur, some practitioners take no account of the increased free-field porewater pressure, and none consider the additional near-field porewater pressure due to inertial interaction loading from the superstructure; a practice that is unsafe in loose sands.     

Fabrication of conductive human bio‐nanoelectrode from graphene oxide modified with polyvinyl alcohol

It is time for electrodes prepared from graphene oxide (GO) to replace the traditional electrodes. However, GO is an electrically insulating material. However, in this study, a conductive electrode was prepared from GO modification with glycerol (GL) under the esterification reaction at 90°C for 3 h with sulphuric acid as a catalyst under vacuum conditions. Polyvinyl alcohol (PVA) acts as a polymer host. It was mixed with GO and modification was carried out under heating conditions. The mixture of the GO/GL/PVA nanocomposite was rapidly cooled and poured into the electrode mould. Finally, it is placed in a desiccator at room temperature for two days. The characterisation (Fourier transform infrared spectroscopy, X‐ray diffraction, and scanning electron microscopy) proved that the ester bond was formed and a complete distribution of GO/GL into the matrix of PVA was verified. The GO/GL/PVA nanocomposite was tested for electrocardiogram (ECG) electrodes. The biopic instrument was used to compare the behaviour of the GO/GL/PVA plastic electrode and the commercial one. The results indicated that the GO/GL/PVA plastic electrode efficiently detected ECG signals after two months with high conductivity and lower noise than the commercial electrode. The GO/GL/PVA plastic electrode has been reported for the first time in the literature.Inspec keywords: catalysts, scanning electron microscopy, filled polymers, nanofabrication, X‐ray diffraction, moulding, nanocomposites, graphene compounds, Fourier transform infrared spectra, nanomedicine, biomedical electrodes, electrocardiography, electrical conductivity, medical signal detection, bonds (chemical)Other keywords: graphene oxide, polyvinyl alcohol, electrode mould, electrocardiogram electrodes, conductive human bionanoelectrode, electrically insulating material, GO‐GL‐PVA nanocomposite, GO‐GL‐PVA plastic electrode, esterification reaction, sulphuric acid, catalyst, vacuum conditions, polymer host, heating conditions, desiccator, glycerol, Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, ester bond, biopic instrument, ECG signal detection, electrical conductivity, temperature 90.0 degC, time 3.0 hour, temperature 293 K to 298 K, time 2 day, CO     

Multi-scale analysis of generalised processor sharing queues with long-range-dependent traffic inputs and variable service rates

An analytical technique is provided to estimate queue-length and delay distributions for multi-queue systems using generalised processor sharing discipline with time-correlated variable service rates, based on two-dimensional multi-level decoupling. First, temporal decomposition is used to convert the time-correlated queuing problem into a set of sub-problems over several timescales. Subsequently, queue decomposition exploits the queue weight dependencies to convert a multi-queue problem into a set of single-queue problems. The core of the analysis lies in estimating the multi-scale service rate models for each of these queues. The authors show the hierarchy of this estimation and the dependency of the queue service rate on the unused capacity of the other queues and their weights. Simulation and analytical results on queue and delay survivor functions are in good agreement.