Comportement chaotique des filtres récursifs adaptatifs: application à la compression des signaux téléphoniques

Adaptive filtering gives simple iterative methods for extracting a useful signal by linearly filtering an observation correlated with this useful signal. When the observation contains past values of the filter output—as is the case for a recursive structure— the adaptive filter is a non linear operator which can generate complex behaviours even though adaptation is a standard derivative of the gradient algorithm. Such behaviours are observed in a particular case : theArma adaptive prediction with a sinusoidal input. A slow adaptation speed involves a quasi-periodic behaviour due to the locally unstable character of the predictor. This phenomenon called selfstabilization persists as the adaptation speed increases. Its study is more complicated : the behaviour becomes chaotic. As an illustration, the digitization of telephone signals throughArma adaptive prediction shows the necessity of controlling the qualitative behaviour of the adaptive filtering solutions.     

Adaptive type-2 fuzzy sliding mode controller for SISO nonlinear systems subject to actuator faults

In this paper, an adaptive type-2 fuzzy sliding mode control to tolerate actuator faults of unknown nonlinear systems with external disturbances is presented. Based on a redundant actuation structure, a novel type-2 adaptive fuzzy fault tolerant control scheme is proposed using sliding mode control. Two adaptive type-2 fuzzy logic systems are used to approximate the unknown functions, whose adaptation laws are deduced from the stability analysis. The proposed approach allows to ensure good tracking performance despite the presence of actuator failures and external disturbances, as illustrated through a simulation example.     

An Efficient Mobile Data Gathering Method with Tree Clustering Algorithm in Wireless Sensor Networks Balanced and Unbalanced Topologies

Wireless Personal Communications - Electroencephalography (EEG) is a technique of Electrophysiology used in a wide variety of scientific studies and applications. Inadequately, many commercial...     

Effect of some operating variables on the microstructure and physical properties of a novel Kefir formulation

In this work, the rheological and textural properties, water-holding capacity (WHC), syneresis, and microstructure of a novel formulation of Kefir were studied by varying the incubation time and temperature, as well as the ratio of peanut-milk and skimmed-milk. Generally, all the experimental responses resulted to be significantly affected (p < 0.05) by all dependent variables examined. Kefir WHC was not significantly influenced (p > 0.05) by the fermentation temperature.     

Extended Bayesian generalization model for understanding user’s intention in semantics based images retrieval

Multimedia Tools and Applications - Learning concepts from examples presented in user’s query and infer the other items that belong to this query is still a significant challenge for images...     

Molecular Characterization of α- and β-Thalassaemia among Malay Patients

Both α- and β-thalassaemia syndromes are public health problems in the multi-ethnic population of Malaysia. To molecularly characterise the α- and β-thalassaemia deletions and mutations among Malays from Penang, Gap-PCR and multiplexed amplification refractory mutation systems were used to study 13 α-thalassaemia determinants and 20 β-thalassaemia mutations in 28 and 40 unrelated Malays, respectively. Four α-thalassaemia deletions and mutations were demonstrated. −−^SEA deletion and α^CSα accounted for more than 70% of the α-thalassaemia alleles. Out of the 20 β-thalassaemia alleles studied, nine different β-thalassaemia mutations were identified of which β^E accounted for more than 40%. We concluded that the highest prevalence of (α- and β-thalassaemia alleles in the Malays from Penang are −−^SEA deletion and β^E mutation, respectively.     

Similarity solutions for unsteady shear-stress-driven flow of Newtonian and power-law fluids: slender rivulets and dry patches

Unsteady flow of a thin film of a Newtonian fluid or a non-Newtonian power-law fluid with power-law index N driven by a constant shear stress applied at the free surface, on a plane inclined at an angle α to the horizontal, is considered. Unsteady similarity solutions representing flow of slender rivulets and flow around slender dry patches are obtained. Specifically, solutions are obtained for converging sessile rivulets (0 < α < π/2) and converging dry patches in a pendent film (π/2 < α < π), as well as for diverging pendent rivulets and diverging dry patches in a sessile film. These solutions predict that at any time t, the rivulet and dry patch widen or narrow according to |x|^3/2{|x|^{3/2}} , and the film thickens or thins according to |x|{|x|} , where x denotes distance down the plane, and that at any station x, the rivulet and dry patch widen or narrow like |t|^-1{|t|^{-1}} , and the film thickens or thins like |t|^-1{|t|^{-1}} , independent of N.     

Fatty acids,sterols, and tocopherols composition in seed oil extracts from four moroccan ecotypes of Ceratonia siliqua L.

Morphological characterization was investigated by agro-morphological criteria related to carob seed size in four different moroccan regions collected in 2018 and 2019. There was no significant difference (p ≤ 0.05) on the seeds lengths and widths. However, a significant difference between seeds thickness and total seeds weight per pod (p ≤ 0.05) were observed between these four populations. The fatty acid, sterol, tocopherol, hydrocarbon, and the unoxygenated composition of carob seed extracts (Ceratonia siliqua L.) were studied. The mean fat yield of the seeds obtained is 1.53%–2.17%, 2.14%–2.15%, 1.61%–1.62%, 1.71%–1.75% for, respectively, the P1 (Meknes), P2 (Fez), P3 (Khemisset), and P4 (Marrakech) in 2018 and 2019. The seed oil was extracted with hexane and the analysis of the fatty fraction was performed by gas chromatography–mass spectrometry (GC–MS). Results show that the major fatty acids for 2018 and 2019 are linoleic acid (61.48%–61.52%, 52.12%–52.14%, 57.76%–58.15%, 61.33%–61.52%), palmitic acid (15.78%–15.81%, 16.44%–16.45%, 19.11%–18.37%, 20.24%–20.32%), oleic acid (11.03%–11.04%, 8.72%–8.82%, 8.51%–8.61%, 8.41%–8.53%), stearic acid (4.35%–3.14%, 5.40%–5.43%, 3.12%–3.13%, 0.96%–1.56%), and cerotic acid (0.62%–0.53%, 4.51%–4.52%, 4.03%–4.06%, 3.84%–3.87%). The unsaturated fatty acids (69.39% in 2018 and 69.68% in 2019) are the most dominant in the four seed extracts compared to the saturated fatty acids. In addition, the oil carob seeds analysis revealed the presence of γ-tocopherol, α-tocopherol and four sterols that included campesterol, stigmasterol, and β-sitosterol. Moreover, the determination of hydrocarbon and un-oxygenated compounds confirmed the existence of major compounds such as heptadecane, 2-methyltriacontane, 1-iodo hexadecane and 1-iodo octadecane. The hierarchical analysis based on the morphological and chromatographic characterization of the seeds allowed the identification of three groups. Consequently, the first group consisted of populations from Marrakesh (P4) and Khemisset (P3), the second group consisted of the P1 from Meknes, and the P2 from Fez constituted the third group.     

Effects of fermentation conditions and homogenization pressure on the rheological properties of Kefir

In this study, the effects of fermentation conditions (temperature and time) as well as homogenization pressure on the rheology and EPS production in Kefir made from bovine whole milk were investigated. Results showed that the rheological characteristics and EPS production are affected significantly (p < 0.05) by the fermentation temperature but not by the incubation time. Furthermore, the homogenization pressure was found to influence significantly (p < 0.05) the rheology but not the production of EPS in Kefir.