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Dynamic Spectrum Access Protocol for the Digital Dividend

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Circuits and Systems 2016年第13期7卷 4124-4144页

作者： Raoul Zamblé Raymond Gbégbé Jean-Marie Kadjo Olivier Asseu pacôme brou Ecole Supérieure Africaine des Technologies de l’Information et de la Communication (ESATIC) Abidjan Cote d’Ivoire Institut National Polytechnique Houphouet Boigny (INPHB) Yamoussoukro Cote d’Ivoire

It is not more and more, easy to satisfy the important and growing spectrum demands in the context of the static conventional policy spectrum allocation. Therefore, to find a suitable solution to this problem, we are to days observing the apparition of flexible dynamic spectrum allocation methods. These methods that ought to improve more significantly the spectrum use have gained much interest. In fact, the digital dividend due to the change-over from the analog television to the digital terrestrial television must be efficiently used. So the Dynamic Spectrum Access (DSA) can potentially play a key role in shaping the future digital dividend use. In the DSA, two kinds of users or networks coexist on different channels. The first one, known as the primary user, accesses to a channel with high priority;and the second one, known as secondary user has a low priority. This paper presents a dynamic spectrum access protocol based on an auction framework. Our protocol is an interesting tool that allows the networks to bid and obtain on the available spectrum, the rights to be primary and secondary users according their valuations and traffic needs. Based on certain offers, our protocol selects primary and secondary users for each idle channel in order to realize the maximum economic for the regulator or social benefits. We deal with the case in which the offers of the networks are independent one another even if they will share the same channels. We design an algorithm in accordance with our dynamic spectrum access protocol. The algorithm is used here to find an optimal solution to the access allocation problem, specifically to digital dividend. Finally, the results in the numeric section, regarding the three suggested scenarios, show that the proposed dynamic spectrum access protocol is viable. The algorithm is able to eliminate all non-compliant bidders for the available spectrum sharing. We notice that the revenue or social benefits of the regulator is maximized when we

关键词： Dynamic Spectrum Access Protocol Centralized Spectrum Sharing Spectrum Auctions Digital Dividend

Distribution, Mobility, and Health Risks Assessment of Trace metals in River Sediments from Intense Agricultural Activity Areas in West Africa

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Journal of Materials Science and Chemical Engineering 2024年第8期12卷 12-42页

作者： Ahbeauriet Ahmed Ouattara Maley-pacôme Soro Albert brou Kouadio Horo Koné Albert Trokourey Dpartment des Sciences et Technique Universit Alassane Ouattara Bouak Cte dIvoire Laboratoire de Thermodynamique et de Physico-Chimie du Milieu Universit Nangui Abrogoua Abidjan Cte dIvoire Laboratoire de Chimie Physique Universit Flix Houphout Boigny Abidjan Cte dIvoire

The economy of West African countries is mainly based on agriculture. However, the trace metal(loid)s contamination status in rivers is relatively unknown in the region. In this work, 45 surface sediments collected from the Bandama, Comoé, and Bia Rivers in south and south eastern Côte d’Ivoire (West Africa), were analyzed for total metal concentrations and chemical speciation. The results showed that the river sediments were considerably contaminated by Cd and moderately contaminated by As, Cu, Pb, and Zn. Significant spatial variations were observed among the stations but not between the rivers. metals Cd and Cu were likely to cause more ecological risks. The speciation analysis unravelled that the metal(loid)s partitioned mainly in the residual fraction, with the potential mobile fraction varying from 14% to 28%. The study calls for establishment of strict policies relative to the application of fertilizers and agrochemicals and mining activities to protect the environment and human health risks.

关键词： River Sediment Trace metal (Loid)s Multivariate Analysis Potential Ecological Risk Assessments Sequential Extraction Geochemical Indices

A Secure Mutual Authentication Protocol Based on Visual Cryptography Technique for IoT-Cloud

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Chinese Journal of Electronics 2024年第1期33卷 43-57页

作者： brou Bernard Ehui Chen CHEN Shirui WANG Hua GUO Jianwei LIU School of Cyber Sciences and Technology Beihang University State Key Laboratory of Software Development Environment Beihang University Sino-French Engineering School Beihang University Beihang Hangzhou Innovation Institute Yuhang

Because of the increasing number of threats in the IoT cloud, an advanced security mechanism is needed to guard data against hacking or attacks. A user authentication mechanism is also required to authenticate the user accessing the cloud services. The conventional cryptographic algorithms used to provide security mechanisms in cloud networks are often vulnerable to various cyber-attacks and inefficient against new attacks. Therefore,developing new solutions based on different mechanisms from traditional cryptography methods is required to protect data and users’ privacy from attacks. Different from the conventional cryptography method, we suggest a secure mutual authentication protocol based on the visual cryptography technique in this paper. We use visual cryptography to encrypt and decrypt the secret images. The mutual authentication is based on two secret images and *** user requests the ticket from the authentication server(AS) to obtain the permission for accessing the cloud services. Three shared secret keys are used for encrypting and decrypting the authentication process. We analyze the protocol using the Barrows-Abadi-Needham(BAN)-logic method and the results show that the protocol is robust and can protect the user against various attacks. Also, it can provide a secure mutual authentication mechanism.

关键词： Visualization Cloud computing Data privacy Protocols Biometrics (access control) Authentication Resists

Intelligent Detection and Identification of Attacks in IoT Networks Based on the Combination of DNN and LSTM methods with a Set of Classifiers

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Open Journal of Applied Sciences 2024年第8期14卷 2296-2319页

作者： brou Médard Kouassi Vincent Monsan Kablan Jérôme Adou Department of Mathematics and Computer Science University Felix Houphouet-Boigny Abidjan Cte dIvoire

Internet of Things (IoT) networks present unique cybersecurity challenges due to their distributed and heterogeneous nature. Our study explores the effectiveness of two types of deep learning models, long-term memory neural networks (LSTMs) and deep neural networks (DNNs), for detecting attacks in IoT networks. We evaluated the performance of six hybrid models combining LSTM or DNN feature extractors with classifiers such as Random Forest, k-Nearest Neighbors and XGBoost. The LSTM-RF and LSTM-XGBoost models showed lower accuracy variability in the face of different types of attack, indicating greater robustness. The LSTM-RF and LSTM-XGBoost models show variability in results, with accuracies between 58% and 99% for attack types, while LSTM-KNN has higher but more variable accuracies, between 72% and 99%. The DNN-RF and DNN-XGBoost models show lower variability in their results, with accuracies between 59% and 99%, while DNN-KNN has higher but more variable accuracies, between 71% and 99%. LSTM-based models are proving to be more effective for detecting attacks in IoT networks, particularly for sophisticated attacks. However, the final choice of model depends on the constraints of the application, taking into account a trade-off between accuracy and complexity.

关键词： Internet of Things Machine Learning Attack Detection Jamming Deep Learning

Geochemistry of Micas from Issia Granite Complexe: A Marker of Geodynamic Evolution

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Open Journal of Geology 2024年第8期14卷 787-804页

作者： Koffi Joseph brou Alain Nicaise Kouamelan Koffi Raoul Teha Universit Flix Houphout-Boigny (UFHB) Abidjan Cte dIvoire

The granites and pegmatites located in the southern part of the Issia region, near the columbo-tantaliferous placers, are characterized by the presence of rare metals such as beryl, lithium and Nb-Ta oxides. They mainly consist of micas, quartz, plagioclase and potassium feldspar. The work carried out on the micas of these granites and pegmatites (EPMA analyses) has provided new geochemical data contributing to the understanding of the magmatic evolution of the Issia granite complex. Mineralogically, the most evolved G3 granites are characterized by their abundance of muscovite compared to biotite and the presence of pegmatite veins. Geochemically, the muscovites of the G1 and G2 granites are more ferriferous than those of the G3 granites, however, the latter display higher Na contents than the G2 and G3. The muscovites of the granites show an evolution from the pure muscovite series to the zinnwaldite series (micas of the pegmatites) which are lithium-bearing micas. The mineralogical and chemical data of the micas show that they are S-type peraluminous granites and demonstrate the formation of granites and pegmatites through fractional crystallization of the same parental magma.

关键词： G3 Granites Peraluminous Granites Rare metals Fractional Crystallization

A Comparison of Hydrothermal Aging, SO₂ and Propene Poisoning Effects on NH₃-SCR over Cu-ZSM-5 and Cu-SAPO-34 Catalysts

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Journal of Materials Science and Chemical Engineering 2024年第5期12卷 10-28页

作者： Kouadio brou Albert Koffi Konan Martin Zran Van Eric-Simon Horo Kone Unité de Formation et de Recherche des Sciences et de Technologies (UFR ST) Universit&#233 Alassane Ouattara Bouak&#233 C&#244te d&#8217Ivoire Unité de Formation et de Recherche Environnement (UFR E) Universit&#233 Jean Lorougnon Gu&#233d&#233 Daloa C&#244te d&#8217Ivoire Unité de Formation et de Recherche des Sciences des Structures de la Mati&#232re et de Technologie (UFR SSMT) Abidjan C&#244te d&#8217Ivoire

This study was aimed to investigate the effects of hydrothermal aging, propene and SO2 poisoning on the ammonia-selective catalytic reduction (NH3-SCR) performance of both Cu-SAPO-34 and Cu-ZSM-5. The catalytic activities of fresh, aged and poisoned samples were tested in ammonia-selective catalytic reduction (NH3-SCR) of NOx conditions. The XRD, TG and N2-desorption results showed that the structures of the Cu-SAPO-34 and Cu-ZSM-5 remained intact after 750˚C hydrothermally aged, SO2 and propene poisoned. After hydrothermal aging at 750˚C for 12 h, the NO reduction performance of Cu-ZSM-5 was significantly reduced at lower temperatures, while that of Cu-SAPO-34 was less affected. Moreover, Cu-SAPO-34 catalyst showed high NO conversion with SO2 or propene compared to Cu-ZSM-5. However, Cu-ZSM-5 showed a larger drop in catalytic activity with SO2 or propene compared to Cu-SAPO-34 catalyst. The H2-TPR results showed that Cu2 ions could be reduced to Cu and Cu0 for Cu-ZSM-5, while no significant transformation of copper species was observed for Cu-SAPO-34. meanwhile, the UV-vis DRS results showed that CuO species were formed in Cu-ZSM-5, while little changes were observed for the Cu-SAPO-34. Cu-SAPO-34 showed high sulfur and hydrocarbon poison resistance compared to Cu-ZSM-5. In summary, Cu-SAPO-34 with small-pore zeolite showed higher hydrothermal stability and better hydrocarbon and sulfur poison resistant than Cu-ZSM-5 with medium-pore.

关键词： Hydrothermal Aging Propene and SO2Poisoning Ammonia-Selective Catalytic Reduction(NH3-SCR) Cu-SAPO-34 Cu-ZSM-5

Bacteriological Profile of Infections Encountered in a Pneumology Service in a Moderate-Income Country [Pneumology Department of CHU Cocody (Côte d’Ivoire)]

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Open Journal of Respiratory Diseases 2024年第1期14卷 1-11页

作者： brou Jean Marcel Ahui Alitonde Eudoxie Djegbeton Alima Kone Marc-Olivier Koffi Kouame Clarisse Elogne Mobio Nancy Hermine Benjamin Kouraogo Erick Akouatia Constante Virginie brou-Gode Kigninlman Horo Boko Alexandre Kouassi Ngoran Koffi Pneumology Service Teaching Hospital of Cocody Abidjan C&#244te d’Ivoire medical School of Abidjan University Félix Houphou&#235t Boigny Abidjan C&#244te d’Ivoire Pasteur Institute of Cô te d’Ivoire Abidjan C&#244te d’Ivoire

Introduction: Infections represent a real public health problem aggravating the morbidity and mortality of hospitalized patients. methods: This was a retrospective study with descriptive purposes over a period of 05 years, in the Pneumology Department of the University Hospital of Cocody. Results: The average age in our population was 42 years. We observed a male predo- minance of 64.5%, with a sex ratio of 1.8. medical history was dominated by HIV infection (23.5%), followed by tuberculosis (15.6%). Concerning lifestyle, smoking was found in 38% of cases. Symptoms progressed chronically in 80% of cases. An infectious syndrome was found in 75% of cases. Microbial culture was positive in 42% of cases. Pseudomonas aeruginosa and Klebsiella pneumoniae were encountered in 26.4% of cases each, followed by Echerichia coli in 10.4% of cases. Klebsiella pneumoniae in the first three years topped the list, but gradually. Pseudomonas aeruginosa maintained its leadership over the last three years. Pseudomonas aeruginosa isolates expressed a resistance rate of 9.8% to ceftazidime and 8.1% to imipenem;to aztreonam (36%), ticarcillin (33.3%) and levofloxacin. These strains were susceptible to fosfomycin (100%), mero- penem (96.6%) and amikacin (96%). For isolated strains of Entero- bacteria- ceae, resistance was observed about ticarcillin (83.3%) and amoxicillin clavula- nic acid (71.2%). Streptococcaceae showed resistance to tetracycline (69.2%) and erythromycin (50%). Over the years there has been an increase in re- sistance to amoxicillin-clavulanic acid ceftriaxone. The death rate was 14%. Conclusion: The bacterial profile of infections is dominated by germs respon- sible for nosocomial infection with significant mortality.

关键词： Bacterial Pleural Pneumonia Nosocomial Infection Sub-Saharan Africa Antibiotic Therapy

Study of the Viscosity and Specific Gravity of the Ternary Used Frying Oil (UFO)-Bioethanol-Diesel System

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Journal of Materials Science and Chemical Engineering 2024年第4期12卷 53-66页

作者： Konan Edmond Kouassi Abollé Abolle N’guessan Luc brou David Boa N’guessan Raymond Kre Kouassi Benjamin Yao Laboratoire de Thermodynamique et Physico-Chimie du Milieu (LTPCM) UFR-SFA UNA Abidjan C&#244te d&#8217Ivoire Laboratoire de Physiques Fondamentales et Appliqué es (LPFA) UFR-SFA UNA Abidjan C&#244te d&#8217Ivoire Laboratoire des Procé d&#233s Industriels de Synth&#232se de l&#8217Environnement et des Energies Nouvelles (LAPISEN) de l&#8217Institut National Polytechnique F&#233lix Houphou&#235t Boigny de Yamoussoukro Yamoussoukro C&#244te d&#8217Ivoire

Fossil fuels cover around 80% of global energy consumption. However, the problems linked to their use justify the choice of using biofuel. In order to reduce as much as possible, diesel rate, an increase in the number of additives may be considered. Thus, in this work, the study of the used frying oil (UFO), bioethanol and diesel ternary system was undertaken. It emerges from this study that the addition of bioethanol reduces the viscosity and the density of the ternary system and permits a 90% substitution rate for diesel between the UFO and bioethanol. Finally, the percentage of oil becomes 40% after adding alcohol compared to the binary diesel crude vegetable oil mixture where this rate is 30%.

关键词： Biofuel UFO-Bioethanol-Diesel Ternary Density Viscosity

Magma Mixing Genesis of the Mafic Enclaves and Related Granitoids in the Kan Granite-Gneiss Complex of Central Côte d’Ivoire: Evidence from Geology, Petrology and Geochemistry

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Open Journal of Geology 2024年第8期14卷 760-786页

作者： Koffi Raoul Teha Koffi Kossonou Jean-Marie Pria Koffi Joseph brou Alain Nicaise Kouamelan Marc Ephrem Allialy Souad M’Rabet Mineral and Energy Resources Laboratory (LGRme) Flix Houphout-Boigny University Abidjan Ivory Coast Environmental Sciences and Technology Laboratory Department of Earth Sciences Jean Lorougnon-Guede Daloa University Daloa Ivory Coast Laboratory of Geosciences and Environment Department of Geology Ibn Tofal University of Knitra Knitra Morocco

The mafic enclaves from Paleoproterozoic domain are considered to be the results of large-scale crust-mantle interaction and magma mixing. In this paper, petrography, mineralogy and geochemistry were jointly used to determine the origin of the mafic enclaves and their relationship with the host granitoids of the Kan granite-gneiss complex. This study also provides new information on crust-mantle interactions. The mafic enclaves of the Kan vary in shape and size and have intermediate chemical compositions. The diagrams used show a number of similarities in the major elements (and often in the trace elements) between the mafic enclaves and the host granitoids. Geochemical show that the Kan rock are metaluminous, enriched in silica, medium to high-K calc-alkaline I-type granite. The similarities reflect a mixing of basic and acid magma. Mafic enclaves have a typical magmatic structure, which is characterized by magma mixing. The genesis of these rocks is associated with the context of subduction. They result from the mixing of a mafic magma originating from the mantle and linked to subduction, and a granitic magma (type I granite) that arises from the partial melting of the crust.

关键词： Magma Mixing Mafic Microgranular Enclaves Host Granitoids Kan Granite-Gneiss Complex West Africa