Time-aware selection approach for service composition based on pruning and improvement techniques

Software Quality Journal - In service-oriented environments, abstract business processes can be implemented by concrete services to build complex applications. Given global user constraints,...     

Blind watermarking algorithm based on spiral scanning method and error-correcting codes

This work is a connecting link between the field of digital transmission and (3 Dimension) 3D watermarking. In fact, we propose in this paper a blind and robust watermarking algorithm for 3D multiresolution meshes. This data type, before being watermarked, is divided into GOTs (Group Of Triangles) using a spiral scanning method. At every instant, only one GOT is loaded into memory. It undergoes a wavelet transform. Embedding modifies the wavelet coefficients vector thus generated after being presented in a cylindrical coordinate system. After being watermarked, the current GOT will be released from memory to upload the next GOT. Information is coded using a turbo encoder to generate the codeword to be inserted. Once the entire mesh is scanned, the watermarked mesh is reconstructed. During extraction, the same steps are applied only on the watermarked mesh: our algorithm is then blind. Extracted data are decoded using Error-Correcting Code (turbocode) to correct errors that occurred. The results show that our algorithm preserves mesh quality even with a very large insertion rate while significantly minimizing used memory. Data extraction was done correctly despite the application of various attacks. Our algorithm is robust against most popular attacks such as similarity transformation, noise addition, smoothing, coordinate quantization, simplification and compression.     

Facile synthesis of pure BiFeO3 and Bi2Fe4O9 nanostructures with enhanced photocatalytic activity

Journal of Materials Science: Materials in Electronics - In the present work, pure BiFeO3 and pure Bi2Fe4O9 single phases were successfully synthesized by tailoring hydrothermal synthesis route....     

Multivariate Data Analysis of Fatty Acid Content in the Classification of Olive Oils Developed Through Controlled Crossbreeding

The fatty acid (FA) composition of 540 Tunisian virgin olive oil hybrids (VOO) were classified by principal component analysis (PCA). Pearson correlation between FA variables revealed an inverse association between C18:1 and C18:2; C18:1 and C16:0, while C16:0 and C16:1 were positively correlated. PCA yielded five significant PCs, which together account for 79.95% of the total variance; with PC1 contributing 36.84% of the total. Eigenvalue analysis revealed that PC1 was mainly attributed to C18:1, monounsaturated fatty acids (MUFA) and the ratios oleic/linoleic (O/L) and monounsaturated fatty acids/polyunsaturated fatty acids (MUFA/PUFA); PC2, by C16:0, saturated fatty acids (SFA) and the palmitic/linoleic ratio (P/L); PC3 by C18:2 and C22:0, PC4 by C18:0 and PC5, by C17:1. Then, PCA analysis indicated that in addition to C16:0, C18:0, C18:1, C17:1, and C22:0, MUFA, SFA and the ratios O/L, P/L and MUFA/PUFA were determined to be the main factors responsible for the olive oil hybrids discrimination.     

Silicon lifetime enhancement by SiNx:H anti-reflective coating deposed by PECVD using SiH4 and N2 reactive gas

Hydrogenated films of silicon nitride SiN_x:H are largely used as antireflective coating as well as passivation layer for industrial crystalline and multicrystalline silicon solar cells. In this work, we present a low cost plasma enhanced chemical vapor deposition (PECVD) of this thin layer by using SiH₄ and N₂ as a reactive gases. A study was carried out on the variation effect of the ratio silane (SiH₄) to nitrogen (N₂) and time deposition on chemical composition, morphologies, reflectivity and carrier lifetime. The thickness was varied, in order to obtain a homogeneous antireflective layer. The Fourier transmission infrared spectroscopy (FTIR) shows the existence of Si–N and Si–H bonds. The morphologies of the sample were studied by Atomic Force Microscopy (AFM). The resulting surface of the SiN_x:H shows low-reflectivity less than 5% in wavelength range 400–1200 nm. As a result, an improvement in minority carrier lifetime has been achieved to about 15 μs.     

Robust crypto-watermarking approach based on spherical harmonics and AES algorithm for 3D mesh safe transmission

Multimedia Tools and Applications - The wide range of applications of 3D meshes and the birth of very high-speed networks for storing 3D models in remote multimedia databases have made the...