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71.
Bargach Walid Zidane Mustapha Benyoussef Abdelilah Ez-Zahraouy Hamid Laamara Rachid Ahl 《Journal of Superconductivity and Novel Magnetism》2022,35(2):331-338
Journal of Superconductivity and Novel Magnetism - Electronic and magnetic properties of CdS-based, doped by various transition metal elements (Ti, V, Cr, Mn, Fe, Co or Ni), dilute magnetic... 相似文献
72.
In this article, an extension of the spatial filter method to study Fabry‐Perot antennas with homogeneous or inhomogeneous partially reflecting surface (PRS) of finite size is proposed. This tool was subsequently validated through the study of different Fabry‐Perot antennas, with homogeneous PRS and inhomogeneous GRadient‐INdex (GRIN) PRS that present very high side lobe level (SLL). Since they are due to structure truncation, a new inhomogeneous PRS to reduce the SLL is designed with the new analytical tool. The new inhomogeneous PRS for Fabry‐Perot antenna is characterized by simulations and measurements. Compared to the homogeneous PRS antenna, the proposed PRS allows a SLL reduction of 5 dB without decreasing the 14 dBi directivity. 相似文献
73.
Hafri Mohamed Toumi Hechmi Lespessailles Eric Jennane Rachid 《Pattern Analysis & Applications》2020,23(2):581-591
Pattern Analysis and Applications - This paper investigates a 3D novel dual active contours approach to segment multiple regions in medical images. The locally based segmentation approaches can... 相似文献
74.
Samir Chabbi Rachid Boudour Djalel Chefrour 《Information Security Journal: A Global Perspective》2020,29(6):327-340
ABSTRACT Near Field Communication (NFC) technology has been used recently for electronic payment between an Automated Teller Machine (ATM) and a Smartphone. It is threatened by several attacks that can steal the user personal data like the password or the Personal Identification Number (PIN). In this paper, we present Dynamic Array PIN (DAP), a novel approach for user authentication on a Smartphone that uses NFC electronic payment with an ATM. Our analysis and experimentation prove that this technique protects against thirteen different attacks and is cost-effective in terms of required hardware, authentication time, computing power and storage space. 相似文献
75.
Wireless Personal Communications - This paper presents a radial cluster heads selection mechanism for homogenous wireless sensor networks. It aims to ensure a good load balancing and enhance the... 相似文献
76.
Mustapha El HANINE ;Elhassane ABDELMOUNIM ;Rachid HADDADI ;Abdelaziz BELAGUID 《计算机技术与应用:英文》2014,(2):98-104
The most common noises in ECG (electrocardiogram) signal processing are BW (baseline wandering) and the 50 or 60 Hz PLI (power line interferences). In order to remove these two major source of noises, we have used the recent powerful DWT (discrete wavelet transform) signal processing in ECG signals which are obtained from MIT-BIH Arrhythmia Database. The results indicate that DWT is a good method for filtering noises without changing the morphology of ECG, and can be applied to all types of ECG signals, whether normal or presenting arrhythmias. 相似文献
77.
Nicolas A. Blanc Quentin Williams Brahim El Bali Rachid Essehli 《Journal of the American Ceramic Society》2018,101(11):5257-5268
The vibrational properties of synthetic iron diphosphate (Fe2P2O7) and chromium diphosphate (Cr2P2O7) are studied under high‐pressure conditions between ~22 and ~30 GPa, respectively. Each compound's structural response to pressure and pressure‐induced phase transitions are characterized. The chromium‐bearing sample shows coalescence of infrared bands occurring near 6 and 17 GPa: these may be associated with increases in the local symmetry of the P2O7 group. The iron sample undergoes a first‐order phase transition near ~9 GPa, and a possible phase transition near 5.5 GPa. At 9 GPa, the initially single, strong symmetric PO4 stretching mode splits into four modes, and the sole asymmetric PO4 stretching mode splits into two bands. These changes indicate the presence of multiple tetrahedral environments within a larger volume unit cell, and the relative frequencies of the split vibrations indicate a P2O7 environment with a markedly narrowed P–O–P angle. The difference between the behavior of the iron and chromium compounds is probably generated by the smaller iron ion producing a discontinuous decrease in the P–O–P angle at lower pressures than in the analogous chromium compound. Our results demonstrate that the dimerized P2O7 group remains stable under compression to over 20‐30 GPa at 300 K. 相似文献
78.
This study extends the boundary conditions of mediated contact theory by (a) differentiating between mediated contact quantity and quality, (b) examining whether mediated contact exerts effects above and beyond direct contact, and (c) offering causal and generalizable evidence on the effects of exposure to numerous individual outgroup members in news media. We match individual‐level data from a representative panel survey with data on the amount of coverage about members from two outgroups and with the results from validated sentiment analysis. Mediated contact, and especially its quantity, improved outgroup attitudes independently of direct contact. These findings emerged for both outgroups and across two outcome measures. 相似文献
79.
This paper presents the abstraction of open consensus and argues for its use as an effective component for building reliable agreement protocols in practical asynchronous systems where processes and links can crash and recover. The specification of open consensus has a decoupled, on‐demand and re‐entrant flavour that make its use very efficient, especially in terms of forced logs, which are known to be major sources of overhead in distributed systems. We illustrate the use of open consensus as a basic building block to develop a modular, yet efficient, total‐order broadcast protocol. Finally, we describe our Java implementation of our open‐consensus abstraction and we convey our efficiency claims through some practical performance measures. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
80.
J.A. Peças Lopes Silvan A. Polenz C.L. Moreira Rachid Cherkaoui 《Electric Power Systems Research》2010
This paper addresses issues concerning the integration of single-phase charging devices for electric vehicles (EV) in low-voltage microgrids. Fast release energy storage is a key issue for microgrid islanding operation. EV batteries provide an additional storage capacity, which can now be exploited in order to improve MG islanding. Aiming to do so, different control strategies were developed and tested: (1) a local control approach where no communication link is required and (2) a centralized charging control solution. The local control approach is based on the measuring of EV terminal voltage and frequency in order to define the charging or discharging rates of the batteries. The centralized control strategy allows balancing single-phase loads connected to the microgrid by adapting the charging rates of the EV storage devices. Simulation results show that EV batteries can actively contribute for voltage balancing and frequency control during islanding operating conditions. 相似文献