Optimizing the investments in mobile networks and subscriber migrations for a telecommunication operator

We consider the context of a telecommunications company that is at the same time an infrastructure operator and a service provider. When planning its network expansion, the company can leverage over its knowledge of subscribers dynamic to better optimize the network dimensioning, therefore avoiding unnecessary costs. In this work, the network expansion represents the deployment and/or reinforcement of several technologies (e.g. 2G,3G,4G), assuming that subscribers to a given technology can be served by this technology or older ones. The operator can influence subscribers dynamic by subsidies. The planning is made over a discretized time horizon while some strategic guidelines requirements are demanded at the end of the time horizon. Following classical models, we consider that the behavior of customers follows an S-shape piecewise constant function. We propose a Mixed-Integer Linear Programming formulation and a heuristic algorithm for the multi-year planning problem. The scalability of the formulation and the quality of the heuristic are assessed numerically on real instances for a use-case with two generations

Modélisation Territoriale des Types de Labour dans le Bassin Versant d’Affon-Donga au Bénin

L’élaboration d’une politique de gestion durable des terres agricoles par les décideurs s’avère d’une importance capitale pour les agriculteurs. La territorialisation de l’agriculture doit être vulgarisée suite à l’identification des terres aptes à l’agriculture durable. La présente étude vise à élaborer un modèle territorial des types de labour dans le bassin versant d’Affon-Donga (au Bénin) pour une pérennisation des terres en vue d’asseoir une agriculture durable. L’usage du modèle RUSLE a permis de localiser les secteurs exposés à l’érosion hydrique dans ledit bassin versant. La carte issue du modèle RUSLE, la carte d’épaisseur du sol et la carte d’occupation du sol ont été utilisées comme facteurs dans le modèle de superposition pondéré pour déterminer les zones aptes aux différents types de labour. Les résultats obtenus révèlent que 13,45 % de la superficie du bassin versant représente les sols relativement profonds où tout type de labour est possible ; 17,92 % du bassin versant correspond aux sols aptes au labour en billons perpendiculaires à la pente pour éviter considérablement l’érosion hydrique ; 56,17 % du bassin versant représente les sols aptes au labour en planches perpendiculaires à la pente pour pratiquer les cultures maraîchères uniquement dans les bas-fonds et 12,45 % du bassin versant représente les sols qui ne sont pas destinés aux labours. Pourtant, la production des fourrages y est possible. Pour la pérennité des terres agricoles, le modèle de la territorialisation des types de labour permet aux décideurs d’orienter les agriculteurs sur les terres agricoles aptes.   The development of a policy for the sustainable management of agricultural land by decision-makers is of paramount importance to farmers. The territorialization of agriculture must be popularized following the identification of land suitable for sustainable agriculture. This study aims to develop a territorial model of the types of plowing in the Affon-Donga watershed (in Benin) for the sustainability of the land with a view to establishing sustainable agriculture. The use of the RUSLE model made it possible to locate areas exposed to water erosion. The map from the RUSLE model, the soil thickness map and the land cover map were used as factors in the weighted overlay model to determine the areas suitable for different types of tillage. The results obtained show that 13.45% of the area of the watershed represents relatively deep soils where any type of plowing is possible; 17.92% of the watershed corresponds to soils suitable for plowing in ridges perpendicular to the slope to considerably avoid water erosion; 56.17% of the watershed represents soils suitable for plowing in planks perpendicular to the slope for cultivating market gardening only in lowlands and 12.45% of the watershed represents soils which are not intended for plowing. Nevertheless, the production of fodder is possible there. For the sustainability of agricultural land, the model of the territorialisation of types of plowing allows decision-makers to direct farmers to suitable agricultural land

Impact De L’urbanisation Sur La Qualité Physico-Chimique Des Eaux Souterraines : Cas De La Commune De Djougou Au Nord-Ouest Du Bénin

Les populations de la commune de Djougou utilisent les puits et les forages pour avoir accès aux eaux souterraines. Cependant, aucun contrôle n’est apporté à ces eaux, ce qui fait qu’elles sont souvent de qualité douteuse. L’objectif de ce travail est d’apprécier l’impact de l’urbanisation sur la qualité physico-chimique des eaux souterraines de la commune de Djougou. Pour cela, les données démographiques, les données physico-chimiques des eaux de puits et forages de Djougou et les images satellitaires de 2005 et de 2015 ont été utilisées. Grâce aux images satellitaires, les cartes d’occupation du sol de la commune de Djougou ont été réalisées. Ces cartes ont prouvé que de 2005 à 2015 Djougou a connu une extension de 2,78 % de la superficie occupée par les habitats. De plus, les graphes d’évolution temporelle des paramètres physico-chimiques ont révélé que les eaux souterraines des trois arrondissements de Djougou ont connu en 2017 une augmentation de leur conductivité électrique, de leurs concentrations en chlorures et surtout en nitrates

A bundle-type algorithm for routing in telecommunication data networks

To optimize the quality of service through a telecommunication network, we propose an algorithm based on Lagrangian relaxation. The bundle-type dual algorithm is adapted to the present situation, where the dual function is the sum of a polyhedral function (coming from shortest paths problems) and of a smooth function (coming from the congestion)

Use of GIS as a Tool for Integrated Water Resources Management in the City of Parakou, Benin

Water, a source of life, is the habitat, food, means of production and transportation and is threatened by irregular rainfall and evaporation. The objective of this study is to contribute with the help of GIS to a better management of water resources in the city of Parakou. To achieve this objective, the methodological approach was based on the collection, processing and analysis of data through the SWOT model. The sample consisted of 109 individuals distributed in the three districts of the city of Parakou. The study revealed that the water resources available in the city of Parakou are of three types (rainwater, surface water and groundwater). These resources are constantly decreasing due to the downward trend in rainfall with a slope of -3.99mm. In addition, the growing population with a growth rate (4.9%) from 2002 to 2013 and the poor use of these resources influence its availability. The unequal distribution of waterworks (58.94%) for the first arrondissement and 41.06% for the other two coupled arrondissements, as well as the unequal distribution of water from the Société Nationale des Eaux du Bénin (SONEB) lead to difficulty in accessing water. Under these conditions, the populations are developing various measures to adapt to the situation. These measures are related to the subscription of households to public water services, the purchase of drinking water, water treatment and water conservation. Given the effectiveness of the measures identified and their limitations, it is important that decision-makers develop a sectoral policy encompassing the construction of water supply infrastructure, better management of structures and support for the reorganization of the drinking water sector

Fondements Géographiques De La Valorisation Agricole Des Bas-Fonds Au Sud Du Bassin Versant De l’Oti (Bénin)

In the south of Oti catchment in Benin, the agricultural development of the lowlands for rice and vegetable cultivation, guarantees a large part of food resources. It also serves as an important source of financial income to agricultural households. This paper focuses on understanding the geographical foundations of this kind of agricultural production in the study area. Surveys of 207 farm households and the statistical processing of climatic, demographic, agricultural and socio-economic data have made it possible to highlight the natural and human factors of farm occupation and the use of these lowland agro-ecosystems. The results obtained revealed that the population of the south of Oti catchment has almost doubly increased between 1992 and 2013. It will increase four times in 2050 by creating the need to have excess food. In addition to this situation, climatic parameters fluctuation, plateau land qualitative tiredness, and major constraints of traditional agriculture were added. Henceforth, these are factors, in addition to the richness of the lowlands and water availability for a long period, which have helped in motivating the population of farmers. About 2000 ha of lowlands were reclaimed by irrigation schemes between 1982 and 2015 in this area. This was possible with the help of technical structures and agricultural development organizations