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Logistics companies are largely encouraged to make greener their operations through an efficient solution with electric vehicles (EVs). However, the driving range is one of the limiting aspects for the introduction of EVs in logistics fleet, due to the low capacity provided by the batteries to perform the routes. In this regards, it is necessary to set up a framework to virtually increase this battery capacity by locating EV charging stations (EVCSs) along the transportation network for the completion of their routes. By the other side, the Distribution Network Operators (DNOs) express the concern associated with the inclusion of new power demands to be attended (installation of EVCSs) in the Distribution Network (DN), without reducing the optimal power supply management for the end-users. Under these circumstances, in this paper the Electric Vehicle Routing Problem with Backhauls and optimal operation of the Distribution Network (EVRPB-DN) is introduced and formulated as a mixed-integer linear programming model, considering the operation of the DN in conditions of maximum power demand. Different candidate points for the EVs charging are considered to recharge the battery at the end of the linehaul route or during the backhaul route. The problem is formulated as a multi-objective approach where the transportation and power distribution networks operation are modeled. The performance and effectiveness of the proposed formulation is tested in VRPB instance datasets and DN test systems from the literature. Pareto fronts for each instance are presented, using the ε-constraint methodology.

El brote actual de la enfermedad por coronavirus (COVID-19), que se informó por primera vez en Wuhan, China, el 31 de diciembre de 2019, ha dejado un saldo al 19 de abril de 2020 de más de 3500000 infectados y 160000 muertes en 185 países. En este trabajo utilizamos un modelo basado en el Método de Cadena Microscópica de Markov (MCMM, Markov Microscopic Chain Approach) para estimar la propagación del COVID-19 en la ciudad de Pereira (Risaralda-Colombia). Este modelo incorpora importantes aspectos de la población, relacionados con: ubicación espacial dentro de la ciudad discretizada por comunas, movilidad entre comunas, estratificación por grupos de edad y separación de individuos en siete compartimientos epidemiológicos. Este modelo se utiliza para predecir, en una línea de tiempo, la incidencia de epidemias en poblaciones geolocalizadas, lo que se traduce en una herramienta indicadora para tomar medidas de control. Así, el resultado de la metodología caracteriza la evolución en el tiempo y el espacio de la proporción de los individuos en cada uno de los compartimientos epidemiológicos y en cada grupo etario. Los datos que se refieren a COVID-19, desde la municipalidad de Pereira, hasta el 20 de abril de 2020, se utilizan para alimentar el modelo y obtener las proyecciones espacio-temporales. Los resultados presentados consideran múltiples escenarios de movilidad, de forma que el aplanamiento de las curvas de los diferentes compartimientos epidemiológicos pueda ser visualizados de acuerdo a diferentes estrategias de confinamiento. Por tratarse de un modelo espacio-temporal, los resultados del modelo pueden ser presentados fácilmente como mapas de calor sobre cada uno de los compartimientos epidemiológicos, a fin de facilitar los procesos de toma de decisiones.

Network operators work constantly to maintain an appropriate level of reliability in their power supply and to preserve the integrity of the vegetation growing underneath overhead power distribution systems. Accordingly, this article proposes and adopts different approaches to optimally manage vegetation maintenance in such field. Mathematical modeling is used to represent the problem in terms of several aspects involved in vegetation management, based on the technical capacity of the utility company and the reliability goals established by governmental regulatory entities. The solution is a vegetation maintenance schedule in terms of when, where, and which crews must perform the pruning activities along the distribution network. As a result, the Non-Served Energy Level NSEL is minimized and the financial resources earmarked for this type of maintenance tasks are optimized.