检索结果-南通市图书馆

Analysis, Variability and rainfall Prediction in Sub-Saharan Africa: the Case of the Lake Guiers in senegal

Open Journal of Ecology 2023年第11期13卷 806-819页

作者： Abdou Arame Fall Saidou Ndao Aba diop UFr Sciences et Technologies (seT) University Iba Der Thiam of Thies (UIDT) Thies Senegal Laboratory of Water and Environment Sciences and Technologies (LaSTEE) Polytechnic School of Thies (EPT) Thies Senegal Statistics and random Models research Team (ErESMA) University Alione Diop (UAD) Bambey Senegal

the aim of this article is to predict the rainfall evolution of a sub-Saharan area in which one of the most important freshwater resources is located: Lake Guiers. Characterized by short seasonal rains of three months, it experienced a long period of drought in the 1970s. We begin by analyzing the temporal distribution of the rainfall including the variability of the data, with a view to predicting a possible return. For this reason, we present here univariate modeling results of rainfall series collected on three stations in the area. the challenge lies in the adequacy of the parameters for the monthly rainfall series, which generates more or less significant forecast errors on the learning bases because of the missing data. this later motivated their conversion to moving average series. On the other hand, the normality of the latter seems to be rejected by the D’Agostino test. Student’s and Mann-Whitney’s tests confirmed the homogeneity. the autocorlograms show the presence of autoregressive terms in the data. Dickey-Fuller and Mann-Kendall tests reveal both trend and seasonality. the stationarity tests of Dickey-Fuller, Phillips-Perron and KPSS have shown that they are non-stationary. As a result, we did an ArIMA modeling method using the Box-Jenkins [1] method with the r software, which involves estimating model parameters, tests of significance, analysis of residualss, selection according to information criteria and forecasts. the results obtained during the learning-test phase showed a quasi-similarity of the base-tests in all the series except for that of Louga.

关键词： Time series rain Trend Stationarity residuals Model Forecast

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of an Intelligent Queue Manager that Takes Account of the Social and Health Context

引用

Engineering（科研） 2023年第9期15卷 561-579页

作者： Jupiter Ndiaye Ousmane Sow Oumar Diallo Ababacar Sadikh Faye Youssou Traore Mame Andallah diop Abdoulaye diop ED2DS Iba Der Thiam University Thies Senegal University Institute of Technology Iba Der Thiam University Thies Senegal

Virus prevention has been considered central to the fight against the COVID- 19 coronavirus pandemic. To limit the spread of the virus in public places, several measures have been taken, in particular respect for barrier gestures. this work is part of this dynamic and sets up a new wireless version of an electronic and nominative queue manager using artificial intelligence for more equity, inclusion and solidarity. this system, named Gifa is developed in our laboratory. the first prototype, whose connections are largely provided by a wired system with an artisanal acquisition module, is difficult to deploy for general public use, especially in buildings already built. this article deals with an artificial intelligence queue management system, presenting more functionalities, whose access to the service is ensured in very large part by wireless exchanges with a modern acquisition module realized by 3D printing. the flexible and autonomous design of this device makes it particularly easy to deploy on premises open to the public without having to modify the existing installation for commissioning. the manager is equipped with a configuration terminal, and at the counters the call is made by a cashier also equipped with a tablet connected to the wifi network. Its display screen shows certain information relating to the identity of the customer such as his face, his order number, his first name and last name. this reduces the authentication time of the person at the checkout, queue bypasses for more fairness and less stress. this work has resulted in the improvement of queue management systems by giving them more flexibility to make them more adaptable in several types of environments and other contexts.

关键词： GiFa Public Health Wireless Node red Arduino Cloud and AI 3D Printing

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

resilience, Adaptability, and regime Shifts thinking: A Perspective of Dryland Socio-ecology System

引用

Journal of resources and Ecology 2021年第3期12卷 376-383页

作者： PENG Yu ZHANG Qiuying CHEN Yuanzhan XU Ning QIAO Yunfeng TIAN Chao Hubert HIrWA Salif diop Aliou GUISse LI Fadong Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China Chinese research Academy of Environmental Sciences Beijing 100012China School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China National Academy of Sciences of senegal Dakar 4344Senegal Faculty of Science and Technology University Cheikh Anta Diop of DakarDakar 5005Senegal International Ecosystem Management Partnership-United Nations Environment Programme(UNEP-IEMP) Beijing 100101China

Arid areas are widespread globally and support a third of the world’s population’s livelihoods. the increasing population, urbanization, land-use changes, and the climate significantly affect coupled natural and human systems and threaten environments and socio-ecological land systems. the degradation of drylands poses a severe and widespread threat to the lives of millions of people, especially in developing countries and in the global environment. this review assesses published literature on dryland socio-ecological systems to reveal current research trends and changes in research themes over time and introduces basic theories and advances in dryland socio-ecological system frameworks, resilience measurement, and regime shifts. Developing a more general but adaptable framework and a more practical strategy for long-term coordination and partnership and attaining specific insights into ecological services should receive more attention and be strengthened in future studies on drylands sustainability.

关键词： dryland socio-ecological system coupled human-natural system adaptability resilience sustainability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interannual Variability of rainfall over the West Africa Sahel

引用

Journal of Geoscience and Environment Protection 2020年第3期8卷 85-101页

作者： Aichetou Dia-diop Sinclaire Zebaze Malick Wade rinelle Ngongang Djiondo Bouya diop Eric Efon Andre Lenouo Laboratoire des Sciences de l’Atmosphère et des Océans-Matériaux-énergie-Dispositifs (LSAO-MED) Université Gaston Berger Saint-Louis Sénégal Department of Physics Faculty of Science University of Douala Douala Cameroon Department of Physics Faculty of Science University of Bamenda Bamenda Cameroon

Interannual variability of the precipitation over West Africa Sahel is analyzed based on 32 years (1979-2010) from monthly and daily database of the Global Precipitation Climatology Project (GPCP). In this region, we found that there is a link between the West Africa Monsoon (WAM) and the daily means of the precipitation in the summer, unseasonal rains can occur in the transition seasons and even in the heart of the dry season. rainfall is the most important element for agro-pastoral activities in this region. the 850-hPa wind and wind divergence structure show a maximum convection over Mountain region (Fouta-Djalon and Mont-Cameroon) which corresponds to the high precipitation and OLr observed in these regions. the trend and empirical orthogonal function (EOF) of the precipitation are presented, including the mid-July variability of the precipitation. the dominant EOF of GPCP precipitation accounts for around 25.3% of the variance with slightly large amplitude in the north while relatively small in the equatorial band respectively. the second and third EOF which accounts for 20.5% and 14%, describes a longitudinal contrast with a zonal gradient.

关键词： GPCP Precipitation West Africa Monsoon Inter Tropical Convergence Zone Trend

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental and Numerical Investigation of the Diffusion of a Confined Wall Jet through a Perforated Plate

引用

Open Journal of Fluid Dynamics 2022年第2期12卷 168-212页

作者： Moussa diop Denis Flick Graciela Alvarez Jean Moureh refrigerating Process Engineering Unit INRAE Antony Antony France Université Paris Saclay INRAE AgroParisTech UMR SayFood Massy France

When performing numerical modeling of fluid flows where a clear medium is adjacent to a porous medium, a degree of difficulty related to the condition at the interface between the two media, where slip velocity exists, is encountered. A similar situation can be found when a jet flow interacts with a perforated plate. the numerical modeling of a perforated plate by meshing in detail each hole is most often impossible in a practical case (many holes with different shapes). therefore, perforated plates are often modeled as porous zones with a simplified hypothesis based on pressure losses related to the normal flow through the plate. Nevertheless, previous investigations of flow over permeable walls highlight the impossibility of deducing a universal analytical law governing the slip velocity coefficient since the latter depends on many parameters such as the reynolds number, porosity, interface structure, design of perforations, and flow direction. this makes the modeling of such a configuration difficult. the present study proposes an original numerical interface law for a perforated plate. It is used to model the turbulent jet flow interacting with a perforated plate considered as a fictitious porous medium without a detailed description of the perforations. It considers the normal and tangential effects of the flow over the plate. Validation of the model is realized through comparison with experimental data.

关键词： Perforated Plate Porous Medium Wall Jet Air Ventilation Aeraulic Turbulence Diffusion

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Prevalence of Intestinal Parasitic Infection among Pre-School and School-Aged Children Attending to Fann University Hospital, Dakar: results from retrospective Analysis

引用

Advances in Infectious Diseases 2022年第4期12卷 847-860页

作者： Khadime Sylla Doudou Sow Souleye Lelo Cheikh B. Fall Isaac Akhenaton Manga Magatte Ndiaye Babacar Faye thérèse Dieng roger Clement Tine Département de Parasitologie-Mycologie Faculté de Médecine Pharmacie et Odontologie Université Cheikh Anta Diop Dakar Sénégal Laboratoire de Parasitologie-Mycologie Centre National Hospitalier Universitaire Fann Dakar Sénégal service de Parasitologie-Mycologie UFR Sciences de la Santé Université Gaston Berger Saint-Louis Sénégal Laboratoire de Parasitologie-Mycologie Centre National Hospitalier d’enfant Albert Royer Dakar Sénégal

Background: Intestinal parasitic infections represent a major public health problem worldwide. Pre-school and school children have a high risk of infection. the study aimed to determine the epidemiological aspects of intestinal parasitic infections in preschool and school-aged children in Dakar, senegal. Methods: A retrospective analysis of laboratory records from preschool and school-aged children referred to the Laboratory of Parasitology at the Fann University Hospital in Dakar, senegal, was carried out. the analysis of the period from 2016 to 2020. Stool samples were examined for the presence of parasites using direct, formal-ether concentration method and the Modified Ziehl Neelsen staining technique. Descriptive and analytic analysis was performed with Stata MP 16.1 software. results: the overall prevalence of intestinal parasitic infection was 26.8% (429/1603). Blastocystis sp. (34%), Entamaeba coli (28%), Giardia intestinalis (9.6%), Endolimax nana (4.9%) and Ascaris lumbricoides (3.5%) were the common parasites found. Out of the 429 children positive for intestinal parasites, protozoa parasites represent 93.9%. Single infection and mixed infection represent 83.7% and 16.3%. the most prevalent associations were E. coli + Blastocystis sp. (6.3%), E. coli + E. nana (3.3%), and G. intestinalis + Blastocystis sp. (1.9%). Children between the ages of 5 - 10 years and those over 10 years had the most parasitic infections with 28.1% [aOr = 1.91;95% CI (1.25 - 2.89)] and 27.4% [aOr = 11.92 (1.07 - 3.07)]. According to the year of sample collection, the prevalence was higher in 2017, 32.6% [aOr = 1.49 (1.11 - 2.01]. the prevalence of intestinal parasitic infection was not significantly related to gender (p = 0.87), season (p = 0.85) and symptomatology (p = 0.19). the main clinical symptoms were dysenteric syndrome, dyspeptic disorders, constipation and abdominal pain. Intestinal parasite carriage in patients with acute diarrhea was 20.4%. In HIV positive with chronic

关键词： Intestinal Parasites Children Epidemiology senegal

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study of radio over Fiber Transmission with a Single Line in ring Topology for Deployment of MIMO Antenna Access Points in a Cell-less Network

引用

Journal of sensor Technology 2023年第2期13卷 13-23页

作者： Mamadou Sarr Dialo diop Ndolane Diouf Kharouna Talla Solids Physics and Materials Sciences Loboratory Group Faculty of Science and Technology Cheikh Anta Diop University Dakar Senegal

the massive growth of wireless traffic goes hand in hand with the deployment of advanced radio interfaces as well as network densification. this growth has a direct impact on the radio access architecture, which today is moving from centralized to distributed deployments through the use of a large number of access points (APs). this paper verifies the feasibility of deploying multiple APs in series on a single line in a ring topology in a cell-less network. On the one hand, this technique will further improve the communication capacity and flexibility of a radio-over-Fiber (roF) based mobile communication system and will reduce its construction cost. And on the other hand, this deployment topology is a solution to achieve a massive cell-free Multiple-Input Multiple-Output (MIMO) architecture and a cost-effective fronthaul solution. First, a passive optical add/drop multiplexer (OADM) is used to extract and add downlink and uplink signals from the remote access points of one kilometer. then, a deployment model is developed with version 17 Optisystem software. the results obtained showed that the quadrature amplitude modulation (QAM) does not adapt to this multi-carrier transmission to deploy several AP in series on a single line. thus, the performance degradation increases when the number of APs integrated on the line increases.

关键词： roF ring Topology MIMO Antennas Cell-less Network

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Comparative Study between the PID regulator and the Fuzzy regulator Applied to the Operation of a Brushless DC Motor

引用

Energy and Power Engineering 2021年第11期13卷 365-376页

作者： Mamadou Sall Abdoulaye Kebe Ibrahima Gueye Moustapha diop Laboratoire L3EPI Ecole Supérieure Polytechnique Ecole Normale Supérieure d’Enseignement Technique et Professionnel Université Cheikh Anta Diop Dakar Senegal

this paper presents the results of research on speed regulation of a brushless DC motor. this is mainly a comparative study between a PID regulator and a fuzzy regulator applied to the operation of this type of engine... 详细信息

this paper presents the results of research on speed regulation of a brushless DC motor. This is mainly a comparative study between a PID regulator and a fuzzy regulator applied to the operation of this type of engine in order to find the best control. The BLDC engine must operate under various speed and load conditions with improved performance and robust and complex speed control. Because of this complexity, the traditional PID command encounters difficulties in controlling the speed of a BLDC. Another control technique is currently developing and is producing good results. This is the fuzzy controller that handles process control problems, that is, managing a process based on a given set point per action on the variables that describe the process. To achieve the desired results, the brushless DC machine model will be studied. With the model obtained, both types of regulator will be tested. A synthesis of the observed comparison results will enable a conclusion to be drawn on the performance of the two types of regulators driving a BLDC (Brushless DC)rdana;">rdana;">rdana;">.

关键词： Fuzzy Logic Controller PID Controller Brushless DC Motor DC Motor

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Study of the Spatio-Temporal Variability of rainfall in the Northern region of senegal

引用

Journal of Geoscience and Environment Protection 2023年第4期11卷 1-14页

作者： Aichétou Dia diop Abdoul Karim Mbodji El Hadji Deme Malick Wade Mahamat Adoum Moussa Abdoulaye Bouya diop Younousse Biaye Djiby Sarr Abdou Karim Farota Aboubakary Diakhaby Bouya diop Laboratoire des Sciences de l’Atmosphère et des Océans Matériaux Energies Dispositifs UGB Saint Louis Senegal Laboratoire D’études et de recherches en Statistiques et Développement University Gaston Berger (UGB) Saint Louis Senegal Ecole Nationale Supérieure des TIC N’Djamena Tchad

senegal is a country of the Sahel. In this region, most of the populations live from agro-pastoral activities. the northern zone of senegal is strongly influenced by river cultures. And the dynamics of the senegal river are dependent on rainfall. the rainfall in the area is very closely linked to the dynamics of the atmosphere. the study of the spatio-temporal variability of rainfall in the northern region of senegal requires quality rainfall observation data. It includes the Ferlo and the senegal river valley, in particular the regions of Louga (department of Linguère included), Saint-Louis (departments of Dagana and Podor included) and Matam. these stations have been defined since Le Borgne (1988). the difficulty of having quality rain observation data can be resolved by using more accessible and good quality satellite data. Using satellite data, namely MSWEP, CrU, TAMSAT, ArC and PErSIANN, we showed the return of precipitation that appeared in 2000 and the unimodal cycle of precipitation in our study area. these data were validated using the correlation coefficient, the bias, the rMse and the Nash index with observation data from the regional Study Center for the Improvement of Adaptation to Drought (CErASS). the CrU data is then retained. thus, this study made it possible to show the zonal distribution of rainfall in the northern zone of senegal.

关键词： rainfall in the Northern region of senegal Variability of rainfall Satellite Data the Zonal Distribution of rainfall

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Characterization of Spatio-Temporal Variability of Irradiation, Nebulosity and Aerosols Optical Depth in 10˚North-20˚North African Band

引用

American Journal of Climate Change 2022年第2期11卷 155-171页

作者： Abdoulaye Bouya diop Abdoulaye Sy Malick Wade Abdoul Karim Mbodj Abdou Karim Farota Adoum Mahamat Moussa Babacar Niang Aicha Dia diop Bara Ndiaye Bouya diop Amadou thierno Gaye Aboubakary Diakhaby LSAO-MED Gaston Berger University Saint Louis Senegal CErDI Clermont Auvergne University Clermont Auvergne France University of Tchad Djamena Tchad LPAOSF ESP Cheikh Anta diop Univesity Dakar Senegal

this work concerns the 10? North, 20? North African band. Area renowned for having some of the poorest countries in the world. It is also home to the Sahelian strip and part of the Sahara. the countries in this zone have a relatively low electrification rate compared to the enlightened country. To solve this problem, these countries want to turn to renewable energies such as photovoltaics (renewable energy obtained through solar radiation). therefore, understanding the behavior of irradiation and cloudiness in the 10 - 20 band becomes necessary. the application of the empirical orthogonal functions to the different cloud layers and to the irradiation reveals a seasonality of the latter, in particular compared to the first modes of the empirical orthogonal functions (EOF1). Indeed, by filtering in time and space to isolate solar radiation and cloudiness, the EOF1 expresses respectively 94.3% of the variation of descending solar radiation in clear sky in the 10 - 20 band. Note 65.7% for global radiation, 54.4% for cloudiness at 450 hPa, 69.6% for cloudiness between 800 hPa and 450 hPa, 76.6% for low cloudiness, 61.4% for total cloudiness. these results allow us to say that we have generally good sunshine over several months, with little cloud cover in this band. However, since this zone is considered to be part of the main aerosol emission source zones, it is important in their temporal consideration of the optical depth. By doing the wavelet analysis on the optical depth data from Dakar and Banizoumbou, we note that the average dust presence spectrum over the entire period from 1997 to 2019 in the two stations with a slight shift compared to the peaks and the maximum observed value. A sign that there is a strong presence of dust in this area and that it should be taken into account for any photovoltaic installation in this area.

关键词： Sahel Irradiation Cloudiness Aerosol EOF Wavelet

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：