A color image watermarking framework for copyright protection of stereo images based on binocular just noticeable difference and LU decomposition

Multimedia Tools and Applications - The copyright protection of three-dimensional (3D) content is a matter of interest in artistic and creative works due to the rights of the holder for the...     

Active time scheduling for rechargeable sensor networks

Recent progress in energy harvesting technologies made it possible to build sensor networks with rechargeable nodes which target an indefinitely long operation. In these networks, the goal of energy management is to allocate the available energy such that the important performance metrics, such as the number of detected threats, are maximized. As the harvested energy is not sufficient for continuous operation, the scheduling of the active and inactive time is one of the main components of energy management. The active time scheduling protocols need to maintain the energy equilibrium of the nodes, while considering the uncertainties of the energy income, which is strongly influenced by the weather, and the energy expenditures, which are dependent on the behavior of the targets. In this paper, we describe and experimentally compare three active time scheduling protocols: (a) static active time, (b) dynamic active time based on a multi-parameter heuristic and (c) utility-based uniform sensing. We show that protocols which take into consideration the probabilistic models of the energy income and expenditure and can dynamically adapt to changes in the environment, can provide a significant performance advantage.     

Real-time 2D–3D filtering using order statistics based algorithms

The paper presents a review of the author’s own results obtained in the last several years. Some examples of real-time processing of 2D and 3D images are described. In particular, we discuss the noise model and objective criteria that can be applied to characterize the performance of the processing algorithms. Several proposed algorithms based on RM approach are compared with other known ones, demonstrating the advantages in noise suppressing and preservation of fine image details and edges. A number of 2D and 3D image denoising filters are implemented on DSP, realizing real-time mode in the image processing. The performances of the proposed processing algorithms and the known ones are discussed and evaluated here.

Rheological studies with spherically shaped thin liquid films

The present work shows the first experimental and theoretical results for investigations on the rheology of liquid films. The experiments are planned to be performed under microgravity conditions. This environment will allow forming films of different thickness, which is impossible under ground conditions due to drainage. Then the films are forced to harmonic oscillations of the film area so that the film elasticity can be measured as a function of frequency. The presented theoretical model demonstrates the main relationships to be solved under corresponding boundary conditions     

Morphology, optical, and photoelectrochemical properties of electrodeposited nanocrystalline ZnO films sensitized with Cd x Zn1−x S nanoparticles

Nanocrystalline ITO/ZnO films formed by porous zinc oxide microplatelets 1–3 μm in size and 100–200 nm in thickness, which consist of 30–50 nm ZnO crystallites, were sensitized to visible light by Cd _x Zn_1?x S nanocrystals deposited using the method of successive ionic layer adsorption and reaction (SILAR). The composition of Cd _x Zn_1?x S nanocrystals as well as the dependence between molar Cd(II) fraction in the films and the ratio of cadmium and zinc nitrate concentrations in solutions used for the SILAR procedure were determined by a combination of electron, Raman, and energy-dispersive X-ray spectroscopies. The photovoltage observed at illumination of the ITO/ZnO/Cd _x Zn_1?x S heterostructures by white light (λ >400 nm) in aqueous Na₂S solution increases with a decrease of Cd(II) content proportionally to an increment in the conduction band potential of the Cd _x Zn_1?x S nanocrystals. The photocurrent density normalized to the light absorbance of the ITO/ZnO/Cd _x Zn_1?x S films increases by a factor of around four when the conduction band potential of Cd _x Zn_1?x S nanocrystals grows by 220 mV as a result of Cd(II) fraction changing from 1.0 to 0.62–0.67. The results show that Cd _x Zn_1?x S solid solutions are more advantageous sensitizers for the short-wavelength part of the sensitivity window of the liquid-junction solar cells (400–450 nm) than conventionally used cadmium sulfide.     

Chloride and Indium‐Chloride‐Complex Inorganic Ligands for Efficient Stabilization of Nanocrystals in Solution and Doping of Nanocrystal Solids

Here, the surface functionalization of CdSe and CdSe/CdS core/shell nanocrystals (NCs) with compact chloride and indium‐chloride‐complex ligands is reported. The ligands provide not only short interparticle distances but additionally control doping and passivation of surface trap states, leading to enhanced electronic coupling in NC‐based arrays. The solids based on these NCs show an excellent electronic transport behavior after heat treatment at the relatively low temperature of 190 °C. Indeed, the indium‐chlorido‐capped 4.5 nm CdSe NC based thin‐film field‐effect transistor reaches a saturation mobility of μ = 4.1 cm² (V s)^?1 accompanied by a low hysteresis, while retaining the typical features of strongly quantum confined semiconductor NCs. The capping with chloride ions preserves the high photoluminescence quantum yield ( ≈ 66%) of CdSe/CdS core/shell NCs even when the CdS shell is relatively thin (six monolayers). The simplicity of the chemical incorporation of chlorine and indium species via solution ligand exchange, the efficient electronic passivation of the NC surface, as well as their high stability as dispersions make these materials especially attractive for wide‐area solution‐processable fabrication of NC‐based devices.     

Lignite oxidative desulphurization: notice 3—process technological aspects and application of products

International Journal of Coal Science & Technology - The study reviews the process of oxidative desulphurization of high-sulphur Ukrainian lignite, which was performed by coal treatment using...     

A novel copolymer of N-[(tert-butylperoxy)methyl]acrylamide and maleic anhydride for use as a reactive surfactant in emulsion polymerization

A new copolymer of N-[(tert-butylperoxy)methyl]acrylamide (tBPMAAm), containing a primary–tertiary peroxide group and maleic anhydride (MA), was synthesized and employed as a reactive surfactant (inisurf) for the emulsion polymerization of styrene to yield surface-functionalized (peroxidized) reactive latex particles. The copolymerization characteristics were analyzed to determine the monomer reactivity ratios and to provide a way to control the copolymer composition. The ability of tBPMAAm–MA to act as a reactive surfactant during emulsion polymerization was confirmed by the synthesis of monodisperse polystyrene latexes of varying particle size. In addition, peroxide groups were localized on the surface of the particles in a controllable amount (depending on the copolymer concentration), thus, providing the opportunity for further modification of the surface of the particles. This novel copolymer is expected to be a promising and efficient material in the synthesis of functional polymer nanoparticles with well-defined core–shell morphologies.