Expressions approchées aux basses et aux hautes fréquences des tensions induites de mode commun aux extrémités d’une ligne blindée soumise à une injection ponctuelle de courant

With reference to a preceding paper, this paper allows, in a first step, to determine, at low and high frequencies, approached expressions of the induced common mode voltages at the extremities of a shielded line influenced by a punctual current injection along the shield. These expressions are established for the case of a helicoidal screen with four different schemes of earth connections at the extremities. In a second step, the correction function, i.e. the ratio between the exact and approached solution, and the limit of validity of this latter at high frequencies are addressed.     

Self-organizing multi-modeling: A different way to design intelligent predictors

Identification of nonlinear systems is an important task for a large number of areas dealing with real-world applications and requirements. Recently, multiple works proposed “multi-model” based approaches to model nonlinear systems. Contrary to the conventional point of view, we propose to deem the multi-modeling as building a modular architecture, inspired from Artificial Neural Networks operation mode, where each neuron (module), represented by one of the local models, realizes some higher level transfer function. This article, deals with generalization of this new multi-modeling concept in the frame of nonlinear system's behavior identification and prediction context. Several multi-model construction strategies and identifiers issued architectures are presented and discussed. Experimental results validating presented multi-model based identifiers have been reported and discussed.     

Analyses et mesures du rayonnement Électromagnétique engendré par des communications haut débit transmises sur des lignes d’énergie

Use of Power Lines Communication for purpose such as Internet access or in-home applications seems to be a very attractive way, however, the problem of conducted and radiated electromagnetic emissions due to these new systems is quite set. The risk of disturbing the Radio communications is, at all, critical in the so-called Short Waves band, from 1 MHz to 30 MHz, allowed to PLC. This paper is aimed in analysing the phenomena that rise to these radiated electromagnetic emissions. We focus especially the analysis to the characterisation of magnetic field by means of simple physical concepts. The experimental and theoretical investigations involve usual power lines owning different dimension and complexity. A large part of this paper is devoted to physical interpretations of the measurement results, underlining the correlation between the magnetic field emission and the common and differential modes currents driven through the line, as well as the connection with the geometrical parameters of the line and with the connected loads. Finally, we present an approach that allows the assessment of the power deliverable by PLC. devices in accordance with the requirements of the harmonised standard EN55022 dealing with conducted emission on the power network.     

Annual Rainfall Forecasting Using Hybrid Artificial Intelligence Model: Integration of Multilayer Perceptron with Whale Optimization Algorithm

Water Resources Management - Rainfall, as one of the key components of hydrological cycle, plays an undeniable role for accurate modelling of other hydrological components. Therefore, a precise...     

Modeling of Hydro-Viscoelastic State of Deformable and Saturated Product During Convective Drying

A mathematical model was developed to simulate in 2D the spatiotemporal evolution of the moisture content, the temperature and the mechanical stress within a deformable and saturated product during convective drying. A comprehensive hydro-thermal model had been merged with a Maxwell model with two branches, assuming a viscoelastic material, a plane deformation and an isotropic hydric-shrinkage of the sample. A long sample of clay mixture with a square section was chosen as an application case. The transport and equilibrium properties of the product required for the modeling were determined from previous experiments which were independent of the drying trials. In order to validate the hydro-thermal part of the model, several drying tests were carried out for different values of temperature, relative humidity and air velocity in a vertical drying tunnel (designed and constructed in the LETTM laboratory). The theoretical and experimental results appeared in good agreement. The simulations of the spatio-temporal distribution of mechanical stress were performed and interpreted in terms of product potential damage. The sample shape was also predicted all aver the drying process with reasonable accuracy.     

Q2ABR: QoE‐aware adaptive video bit rate solution

In this paper, we propose a new adaptive bit rate (ABR) streaming method. This method is based on estimating and monitoring users' video streaming experience, their quality of experience (QoE). This ensures a good user QoE and optimises bandwidth utilisation by monitoring video buffer fill rate to ensure minimal data traffic. First, we achieve a QoE evaluation model based on network bandwidth, video segment representation, and dropped video frame rate parameters. Second, following our QoE evaluation model, we formulate an ABR method using the reinforcement learning (RL) paradigm to select video representations and using a breakpoint detection mechanism to monitor end‐user QoE variation. The proposed ABR method is called “QoE‐aware adaptive bit rate (Q2ABR)” and is composed of three individual modules, one for QoE estimation using machine learning methods, one for QoE variation monitoring using the breakpoint detection mechanism, and one for video representation selection using reinforcement learning. The design objective of Q2ABR is to ensure the overall QoE of these users while maintaining a minimum variation in the standard deviation of the users' QoE values. Third, the performance of the Q2ABR method is evaluated and compared with several existing ABR approaches in the literature using real traces that we collect on different transport scenarios (such as bus and train, among others). Since this method considers the user's perception of video quality as a regulator for optimising the overall video distribution network, good results are ensured in terms of the user's experience and buffer fill rate.     

Identification and Quantification of the Main Active Anticancer Alkaloids from the Root of Glaucium flavum

Glaucium flavum is used in Algerian folk medicine to remove warts (benign tumors). Its local appellations are Cheqiq el-asfar and Qarn el-djedyane. We have recently reported the anti-tumoral activity of Glaucium flavum root alkaloid extract against human cancer cells, in vitro and in vivo. The principal identified alkaloid in the extract was protopine. This study aims to determine which component(s) of Glaucium flavum root extract might possess potent antitumor activity on human cancer cells. Quantitative estimation of Glaucium flavum alkaloids was realized by HPLC-DAD. Glaucium flavum effect on human normal and cancer cell viability was determined using WST-1 assay. Quantification of alkaloids in Glaucium flavum revealed that the dried root part contained 0.84% of protopine and 0.07% of bocconoline (w/w), while the dried aerial part contained only 0.08% of protopine, glaucine as the main alkaloid, and no bocconoline. In vitro evaluation of the growth inhibitory activity on breast cancer and normal cells demonstrated that purified protopine did not reproduce the full cytotoxic activity of the alkaloid root extract on cancer cell lines. On the other hand, bocconoline inhibited strongly the viability of cancer cells with an IC₅₀ of 7.8 μM and only a low cytotoxic effect was observed against normal human cells. Our results showed for the first time that protopine is the major root alkaloid of Glaucium flavum. Finally, we are the first to demonstrate a specific anticancer effect of Glaucium flavum root extract against breast cancer cells, which can be attributed, at least in part, to bocconoline.