Robusna procedura za umetanje vodenog žiga u sliku zasnovana na Hermitovoj projekcijskoj metodi

A procedure for combined image watermarking and compression, based on the Hermite projection method is proposed. The Hermite coefficients obtained by using the Hermite expansion are used for watermark embedding. The image can be efficiently reconstructed by using a set of Hermite coefficients that is quite smaller than the number of original ones. Hence, the watermark embedding is actually done in the compressed domain, while maintaining still high image quality (measured by high PSNR). The efficiency of the proposed procedure is proven experimentally, showing high robustness even for very strong standard attacks. Moreover, the method is robust not only to the standard attacks, but to the geometrical attacks, as well. The proposed approach can be suitable for different copyright and ownership protection purposes, especially in real-applications that require image compression, such as multimedia and Internet applications, remote sensing and satellite imaging.U radu je predložena procedura za umetanje vodenog žiga u sliku i kompresiju slike zasnovana na Hermitovoj projekcijskoj metodi. Odgovarajući koeficijenti, dobiveni kao rezultat primjene razvoja slike u red Hermitovih funkcija, korišteni su za umetanje vodenog žiga watermark). S obzirom na to da se slika može efikasno rekonstruirati korištenjem znatno manjeg broja Hermitovih koeficijenata u odnosu na broj originalnih koeficijenata slike, umetanje vodenog žiga zapravo je provedeno u domeni kompresije, uz očuvanje visoke kvalitete slike (velika vrijednost PSNR). Učinkovitost predložene procedure ispitana je eksperimentalno i pokazuje značajnu otpornost na uobičajene napade. Osim uobičajenih, procedura pokazuje robusnost i na geometrijske napade. Predloženi pristup može biti korišten u različitim aplikacijama za zaštitu autorskih prava, naročito u aplikacijama koje ujedno zahtijevaju i kompresiju slike, kao što su multimedijske i internetske aplikacije, daljinsko očitavanje podataka i satelitska snimanja

L'effet de l'extrait végétal de Yucca Schidigera sur l'excrétion oocystale chez le poulet de chair

In Algeria, coccidiosis constitutes one of the main constraints which hinder the development of the poultry production and is responsible for major losses to the poultry industry, reducing performance and increasing production costs, especially an increase of mortality and misuse of antibiotics. These molecules have fatal effects on the animal and public health, thus, alternatives were introduced, in particular the extracts of plants. The present study, conducted in October 2013, was carried out in five hundred broiler chicks (Hubbard F15 strain). The chicks were monitored from birth to the 52nd day. These animals, with homogeneous weight of 93 g and mixed sexes, came from the same hatchery and underwent the same environmental conditions. Animals of the first lot, identified as “Control lot” received a food exempt from any additive but antibiotics added to water. The animals of the second lot, identified as “Experimental lot”, received a water exempt from any additive and the same food added with the Yucca Schidigera extract. The objective of this study was the evaluation of the oocystale excretion by Mac Master’s method to estimate the activity of the Yucca Schidigera extract. The results highlighted an increase of oocystale excretion until 82.250 oocysts.g-1 of feces in the control lot and 22.950 oocysts.g-1 of feces in the experimental lot. The average levels of oocysts were significantly lower during three weeks from J14 to J35 in the experimental lot, then remained comparable for the rest of the experiment period (J36 to J51). These results showed that this additive considerably reduced the coccidian eggs elimination and proved its efficiency in the coccidiosis control. Keywords: Yucca Schidigera, Coccidiosis, Broilers, Antibiotics.En Algérie, la coccidiose constitue l’une des principales contraintes qui entrave le développement de la production avicole et cause d’énormes pertes économiques, en l’occurrence l’augmentation du taux de mortalité et l’usage abusif des antibiotiques. Ces derniers ont des effets néfastes sur la santé humaine et animale. Ainsi, des alternatives ont vu le jour, en particulier l’utilisation des extraits de plantes. La présente étude, mise en place en octobre 2013, a été menée dans un élevage comportant cinq cent poussins d’un jour appartenant à la souche de type chair Hubbard F15. Les poussins ont été suivis de leur naissance jusqu’au 52ème jour. Ces animaux, d’un poids homogène de 93 g et de sexes mélangés, provenaient du même couvoir et ont subi les mêmes conditions d’ambiance. Les animaux du premier lot, identifié comme «Lot témoin», recevaient un aliment exempt de tout additif mais une eau additionnée d’antibiotiques. Les animaux du deuxième lot, identifié comme «Lot expérimental», recevaient une eau de boisson exempte de tout additif et un même aliment additionné de l’extrait de Yucca Schidigera. L’objectif de cette étude a été l’évaluation de l’excrétion oocystale, par la méthode de Mac Master, pour déterminer l’activité de l’extrait de Yucca Schidigera. Les résultats ont révélé une augmentation d’excrétion oocystale jusqu’à 82.250 oocystes.g-1 de matières fécales pour le lot témoin et 22.950 oocystes.g-1 de matières fécales pour le lot expérimental. Les nombres moyens d’oocystes ont été significativement plus bas durant 3 semaines allant de J14 à J35 dans le lot expérimental, puis devenaient comparables le reste du temps de J36 à J51. Ces résultats montrent que cet additif a considérablement réduit l’élimination des œufs de coccidies et prouvé son efficacité dans la maîtrise de la coccidiose. Mots clés: Yucca Schidigera, Coccidiose, Poulet de chair, Antibiotiques.   &nbsp

Enhanced magnetic properties in antiferromagnetic-core/ferrimagnetic-shell nanoparticles

Bi-magnetic core/shell nanoparticles are gaining increasing interest due to their foreseen applications. Inverse antiferromagnetic(AFM)/ferrimagnetic(FiM) core/shell nanoparticles are particularly appealing since they may overcome some of the limitations of conventional FiM/AFM systems. However, virtually no simulations exist on this type of morphology. Here we present systematic Metropolis Monte Carlo simulations of the exchange bias properties of such nanoparticles. The coercivity, H C, and loop shift, H ex, present a non-monotonic dependence with the core diameter and the shell thickness, in excellent agreement with the available experimental data. Additionally, we demonstrate novel unconventional behavior in FiM/AFM particles. Namely, while H C and H ex decrease upon increasing FiM thickness for small AFM cores (as expected), they show the opposite trend for large cores. This presents a counterintuitive FiM size dependence for large AFM cores that is attributed to the competition between core and shell contributions, which expands over a wider range of core diameters leading to non-vanishing H ex even for very large cores. Moreover, the results also hint different possible ways to enhance the experimental performance of inverse core/shell nanoparticles for diverse applications

Schémas d'estimation de mouvement multirésolution -multigrille en codage de séquences d'images

Dans le cadre des schémas de codage en sous-bandes de séquences d'images, plusieurs approches multigrille et multicontrainte pour l'estimation de champs de vecteurs mouvement sont présentées ici, sur différentes décompositions pyramidales. L'estimation multicontrainte par approche Wiener permet d'introduire simultanément et efficacement la contribution de plusieurs bandes fréquentielles . Ce champ estimé de mouvement, de taille moindre, effectue une reconstruction par compensation de mouvement de qualité comparable aux usuelles méthodes monorésolution plus coûteuses. Des résultats portant sur la rapidité de convergence et l'erreur de reconstruction sont illustrés sur séquences réelles

Impact of Scan Conversion Methods on the Performance of Scalable Video Coding

The ability to flexibly access coded video data at different resolutions or bit rates is referred to as scalability. We are concerned here with the class of methods referred to as pyramidal embedded coding in which specific subsets of the binary data can be used to decode lower-resolution versions of the video sequence. Two key techniques in such a pyramidal coder are the scan-conversion operations of down-conversion and up-conversion. Down-conversion is required to produce the smaller, lower-resolution versions of the image sequence. Up-conversion is used to perform conditional coding, whereby the coded lower-resolution image is interpolated to the same resolution as the next higher image and used to assist in the encoding of that level. The coding efficiency depends on the accuracy of this up-conversion process. In this paper techniques for down-conversion and up-conversion are addressed in the context of a two-level pyramidal representation. We first present the pyramidal technique ..

Competency Assessment of Final-Year Dental Students in Tunisia

Introduction. The educational program assessment has always been the main objective of quality improvement in all curricula. The aim of this study was to describe the levels of competency of final-year students of the Faculty of Dental Medicine of Monastir in Tunisia in the major skills needed for a new dentist. Methods. In this cross-sectional descriptive study, 154 students filled out a questionnaire including 53 competencies, rated on a four-point Likert scale, broadly based on the competencies described in the profile and competences for the graduating dentist in Europe. Results. The response rate was 67% (145/230). For twenty items in the questionnaire, over 75% of the students reported being competent. The five items with the highest percentages were “undertaking supragingival and subgingival scaling-Item 22” (97.2%), “evaluating the periodontium, establishing a diagnosis and formulating a treatment plan-Item 2” (96.6%), “identify the location and degree of activity of dental caries-Item 24 (95.9%), “taking and interpreting dental radiographs-Item 12” (94.4%), “restoring damaged teeth-Item 25” (93.8%), and “managing primary oral health care-Item 16” (93.8%). For eighteen skills, more than 75% of students self-rated being not competent, demonstrating a need of more thorough training, notably in periodontal surgery and implantology, among these, five skills were found that demand in-depth acquisition according to the students. Conclusion. The general state of competency of the last-year dental students was described as fairly satisfactory based on the students’ self-reported responses. However, theoretical and practical backgrounds related to some subjects in the school need to be improved

Electronic structure, phase stability, and vibrational properties of Ir-based intermetallic compound IrX (X=A1, Sc, and Ga)

WOS: 000346952600017The phase stability and mechanical properties of B2 type IrX (X=Al, Sc and Ga) compounds are investigated. Self-consistenttotal-energy calculations in the framework of density functional theory using the Generalized Gradient Approximation (GGA) to determine the equations of state and the elastic constants of IrX (X=Al, Sc, and Ga) in the B2 phase have been performed. The calculations predicted the equilibrium lattice constants, which are about 1% greater than experiments for IrAl, 1.81% for IrGa, and 0.71% for IrSc compound. IrAl is shown to be the least compressible, and it is followed by IrGa and the IrSc compound. The phase stability of the studied compounds is checked. The brittleness and ductility properties of IrX (X=Al, Sc, and Ga) are determined by Poisson's ratio sigma criterion and Pugh's criterion. IrGa compound is a ductile material; however, IrAl and IrSc show brittleness. The band structure and density of states (DOS), and phonon dispersion curves have been obtained and analyzed. The position of the Fermi level and the contribution of d electrons to the density of states near E-F is studied and discussed in detail. We also used the phonon density of states and quasiharmonic approximation to calculate and predict some thermodynamic properties such as constant-volume specific heat capacity of the B2 phase of IrX (X=Al, Sc and Ga) compounds. (C) 2014 Elsevier Ltd. All rights reserved.Ahi Evran University Research Project UnitAhi Evran University [PYO-EGF.4001.14.003]This work was supported by the Ahi Evran University Research Project Unit under Project no: PYO-EGF.4001.14.003

A first-principle study of Os-based compounds: Electronic structure and vibrational properties

WOS: 000378960700016The electronic structure, elastic, and phonon properties of OsM (M=Hf, Ti, Y and Zr) compounds are studied using first-principles calculations. Elastic constants of OsY and specific heat capacity of OsM (M=Hf, Ti, Y, and Zr) are reported for the first time. The predicted equilibrium lattice constants are in excellent agreement with experiment. The calculated values of bulk moduli are considerably high but are much smaller than that of Osmium, which is around 400 GPa. The phase stability of the OsM (M=Hf, Ti, Y and Zr) compounds were studied by DOS calculations and the results suggest that OsY is unstable in the B2 phase. The brittleness and ductility properties of OsM (M=Hf, Ti, Y and Zr) are determined. OsM (M=Hf, Ti, Y and Zr) compounds are predicted to be ductile materials. The electronic structure and phonon frequency curves of OsM (M=Hf, Ti, Y and Zr) compounds are obtained. The position of Fermi level of these systems was calculated and discussed in terms of the pseudo gaps. The finite and small DOS at the Fermi level 0.335, 0.375, 1.063, and 0.383 electrons/eV for OsHf, OsTi, OsY, and OsZr, respectively, suggest that OsM (M=Hf, Ti, Y and Zr) compounds are weak metals. (C) 2016 Elsevier Ltd. All rights reserved.Czech Science FoundationGrant Agency of the Czech Republic [13-03708S]This work was supported by the Czech Science Foundation, Project no. 13-03708S. The authors thank to Mariana Klementova for simulations in programme JEMS

Electronic structure, optical and thermodynamic properties of ternary hydrides MBeH3 (M = Li, Na, and K)

WOS: 000383768200010Electronic band structure, optical and thermodynamic properties of ternary hydrides MBeH3 (M = Li, Na, and K) were studied using ab initio density functional theory (DFT). The effect of the adopted approximation to the exchange-correlation functional of the DFT is explicitly investigated by considering four different expressions of two different classes (local-density approximation and generalized-gradient approximation). The calculated magnitude of B classifies MBeH3 (M = Li, Na, and K) as easily compressible materials. The bonding interaction in these compounds is quite complicated. The interaction between M and BeH6 is ionic and that between Be and H comprises both ionic and covalent characters. The electronic structure of the complex hydride was investigated by calculating the partial and total densities of states, and electron charge density distribution. Large gaps in the density of states appear at the Fermi energy of LiBeH3, NaBeH3, and KBeH3 indicating that these classes of hydrides are insulators. Optical properties, including the dielectric function, reflectivity, and absorption coefficient, each as a function of photon energy, are calculated and show an optical anisotropy for LiBeH3 and KBeH3. Through the quasi-harmonic Debye model, in which the phononic effects are considered, temperature dependence of volume V(T), bulk modulus B(T), and thermal expansion coefficient alpha(T), constant-volume and constant-pressure specific heat (C-v and C-p) and Debye temperature Theta(D), the entropy S, and the Gruneisen parameter gamma were calculated at wide pressure and temperature ranges. The principal aspect of the obtained results is the close similarity of MBeH3 (M = Li, Na, and K) compounds.Algerian University research project (CNEPRU) [D05620140014]This work is supported by the Algerian University research project (CNEPRU) under grant No. D05620140014