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71.
On Analyzing the Potential of a Layer-2 Multi-hop Authentication and Credential Delivery Scheme for Vehicular Communications 总被引:1,自引:1,他引:0
Christian Tchepnda Hassnaa Moustafa Houda Labiod Gilles Bourdon 《Wireless Personal Communications》2009,51(1):31-52
In this paper we introduce a new security architecture and security mechanisms for vehicular networks providing a layer-2
multi-hop authentication and credential delivery scheme between vehicles and the network operator authentication server. We
present a performance analysis of the proposed solution under various vehicles and Access Points (APs) densities, showing
the potential of our scheme in providing a more efficient, robust and scalable authentication and credential delivery to vehicles
when compared against the classical single-hop scheme. 相似文献
72.
Roland Steim Tayebeh Ameri Pavel SchilinskyChristoph Waldauf Gilles DennlerMarkus Scharber Christoph J. Brabec 《Solar Energy Materials & Solar Cells》2011,95(12):3256-3261
Here we report on organic photovoltaic's (OPV) suitable for low light applications. In this paper, we illustrate the impact of Rs and Rp for indoor and outdoor applications. In addition, we propose a simple physics approach to predict the behavior of organic solar cells under various illumination intensities through electrical modeling. The combination of simulation and modeling allows to define a set of design rules for OPVs under low light illumination. The performance of various organic solar cells under low light intensity is compared with our predictions and excellent correlation is found. OPV shows high performance under low light conditions. 相似文献
73.
Honorine Angue Mintsa Gilles Roy Cong Tam Nguyen Dominique Doucet 《International Journal of Thermal Sciences》2009,48(2):363-371
This paper presents effective thermal conductivity measurements of alumina/water and copper oxide/water nanofluids. The effects of particle volume fraction, temperature and particle size were investigated. Readings at ambient temperature as well as over a relatively large temperature range were made for various particle volume fractions up to 9%. Results clearly show the predicted overall effect of an increase in the effective thermal conductivity with an increase in particle volume fraction and with a decrease in particle size. Furthermore, the relative increase in thermal conductivity was found to be more important at higher temperatures. Obtained results compare favorably with certain data sets and theoretical models found in current literature. 相似文献
74.
Moez Smaoui Zoubeir Bouaziz Ali Zghal Gilles Dessein Maher Baili 《The International Journal of Advanced Manufacturing Technology》2011,56(5-8):463-474
Since industry is rapidly developing, either locally or globally, manufacturers witness harder challenges due to the growing competitivity. This urges them to better consider the four factors linked to production and output: quality, quantity, cost and price, quality being of course the most important factor which constitutes their main concern. Efforts will be concentrated??in this research??on improving the quality and securing more accuracy for a machined surface in ball-end milling. Quality and precision are two essential criteria in industrial milling. However, milling errors and imperfections, due mainly to the cutting tool deflection, hinder the full achieving of these targets. Our task, all along this paper, consists in studying and realizing the simulation of the deflected cutting tool trajectory, by using the methods which are available. In a future stage, and in the frame of a deeper research, the simulation process will help to carry out the correction and the compensation of the errors resulting from the tool deflection. The corrected trajectory which is obtained by the method mirror will be sent to the machine. To achieve this goal, the next process consists??as a first step??in selecting a model of cutting forces for a ball-end mill. This allows to define??later on??the behavior of this tool, and the emergence of three methods namely the analytical model, the finite elements method, and the experimental method. It is possible to tackle the cutting forces simulation, all along the tool trajectory, while this latter is carrying out the sweeping of the part to be machined in milling and taking into consideration the cutting conditions, as well as the geography of the workpiece. A simulation of the deflected cutting tool trajectory dependent on the cutting forces has been realized. 相似文献
75.
Malay Patra Gilles Gasser Dr. Antonio Pinto Klaus Merz Dr. Ingo Ott Prof. Dr. Julia E. Bandow Prof. Dr. Nils Metzler‐Nolte Prof. Dr. 《ChemMedChem》2009,4(11):1930-1938
The recent discovery of the natural product platensimycin as a new antibiotic lead structure has triggered the synthesis of numerous organic derivatives for structure–activity relationship studies. Herein, we describe the synthesis, characterization and biological evaluation of the first organometallic antibiotic inspired by platensimycin. Two bioorganometallic compounds containing (η6‐pentamethylbenzene)Cr(CO)3 ( 2 ) and (η6‐benzene)Cr(CO)3 ( 3 ), linked by an amide bond to the aromatic part of platensimycin, were synthesized. Their antibiotic activities were tested against B. subtilis 168 (Gram positive) and E. coli W3110 (Gram negative) bacterial strains. Both compounds were found to be inactive against E. coli but derivative 2 inhibits B. subtilis growth at a moderate MIC value of 0.15 mM . To test the intrinsic toxicity of chromium, several chromium salts along with {η6‐(3‐pentamethylphenyl propionic acid)}Cr(CO)3 ( 5 ) and {η6‐(3‐phenyl propionic acid)}Cr(CO)3 ( 6 ) were tested against both bacterial strains. No activity was observed against E. coli for any of the compounds; B. subtilis growth was not inhibited by Cr(NO3)3 and only very weakly by 5 , K2Cr2O7 and Na2CrO4 at MIC values of 0.5, 0.68 and 1.24 mM , respectively. Compounds 2 , 3 , 5 and 4 (the pure organic analogue of 2 ) show similar cytotoxicity against HeLa, HepG2 and HT‐29 mammalian cell lines. Furthermore, the cellular uptake and the intracellular distribution of compounds 2 , 3 and Cr(NO3)3 in B. subtilis were studied using atomic absorption spectroscopy to gain insight in to the possible cellular targets. Compound 2 was found to be readily taken up and distributed almost equally among cytosol, cell debris and cell membrane in B. subtilis. 相似文献
76.
Christophe Charrier Olivier Lézoray Gilles Lebrun 《Signal Processing: Image Communication》2012,27(3):209-219
A crucial step in image compression is the evaluation of its performance, and more precisely, available ways to measure the quality of compressed images. In this paper, a machine learning expert, providing a quality score is proposed. This quality measure is based on a learned classification process in order to respect human observers. The proposed method namely Machine Learning-based Image Quality Measure (MLIQM) first classifies the quality using multi-Support Vector Machine (SVM) classification according to the quality scale recommended by the ITU. This quality scale contains 5 ranks ordered from 1 (the worst quality) to 5 (the best quality). To evaluate the quality of images, a feature vector containing visual attributes describing images content is constructed. Then, a classification process is performed to provide the final quality class of the considered image. Finally, once a quality class is associated to the considered image, a specific SVM regression is performed to score its quality. Obtained results are compared to the one obtained applying classical Full-Reference Image Quality Assessment (FR-IQA) algorithms to judge the efficiency of the proposed method. 相似文献
77.
Véronique Demers-Mathieu Sylvie F. Gauthier Michel Britten Ismaïl Fliss Gilles Robitaille Julie Jean 《International Dairy Journal》2013,28(2):94-101
Ultrafiltration permeate of whey protein tryptic hydrolyzate was processed by nanofiltration (NF) to obtain retentate (NFR) and permeate (NFP) that were then tested as inhibitors of Listeria, Staphylococcus aureus and Escherichia coli. NFR at 20 mg mL?1 was most effective as an inhibitor (P < 0.001); whereas E. coli was relatively resistant, the effect on Listeria and S. aureus was greater at 20 mg mL?1 than at 10 mg mL?1 (P < 0.01). Peptide analysis revealed that NFR was rich in anionic peptides over eight amino acid residues in length. The antibacterial activity of two anionic peptides (84–91 and 125–135) and a cationic peptide (36–42) derived from β-lactoglobulin was tested. Peptide 125–135 was more inhibitory (P < 0.05) than peptide 84–91 against Listeria monocytogenes and S. aureus; peptide 36–42 was not inhibitory. NFR appears to have potential as a natural bio-preservative. 相似文献
78.
Eui-Jong Kim Jean-Jacques Roux Gilles Rusaouen Frédéric Kuznik 《Applied Thermal Engineering》2010,30(6-7):706-714
According to the introduction of a dynamic operating mode in ground-coupled heat pump systems, a short time analysis within and around borehole heat exchangers is required in the modern geothermal system simulation. A numerical modelling could be a proper answer for this challenge. However, the numerical model is time consuming and necessitates a large memory particularly in such large systems. Therefore, the state model size reduction technique has been applied in this paper with various numerical techniques particularly in the finite elements method. As a result, the reduced model developed is: (a) relevant with a validation using a traditional analytical model (using 100% modes) and (b) efficient in calculation time, only using 6% modes and consequently reducing time consumption up to 95%. 相似文献
79.
Ashish Bhaskar Edward Chung André‐Gilles Dumont 《Computer-Aided Civil and Infrastructure Engineering》2011,26(6):433-450
Abstract: This article presents a methodology that integrates cumulative plots with probe vehicle data for estimation of travel time statistics (average, quartile) on urban networks. The integration reduces relative deviation among the cumulative plots so that the classical analytical procedure of defining the area between the plots as the total travel time can be applied. For quartile estimation, a slicing technique is proposed. The methodology is validated with real data from Lucerne, Switzerland and it is concluded that the travel time estimates from the proposed methodology are statistically equivalent to the observed values. 相似文献
80.
Annie Guerriero Sylvain Kubicki Gilles Halin 《Computer-Aided Civil and Infrastructure Engineering》2010,25(4):253-268
Abstract: The growing complexity of AEC projects is increasing the importance of the building construction coordination role. Moreover, the uncertainty linked to the environment of the construction activity makes way for the notion of trust. The coordinator can make use of multiple tools/views for accomplishing his mission. This research work suggests analyzing data coming from these different views to consolidate trust indicators informing the coordinator about “trust in the correct progression of the construction activity.” The approach suggested in this article distinguishes between four aspects of the activity determining the global trust level: task progress, actor's performance, documents required to perform the task, and building elements resulting from the task. The proposal suggests introducing these trust indicators in a dashboard, included in a multiview interface, thus allowing the coordinator to identify the tasks with a low trust level and to understand the nature of dysfunctions. A prototype has been developed and integrated in a service‐based IT infrastructure. Results of an experiment stage are finally discussed to validate the approach. 相似文献