Efficient heuristic algorithms for location of charging stations in electric vehicle routing problems

Indexación: Scopus.This work has been partially supported by CONICYT FONDECYT by grant 11150370, FONDEF IT17M10012 and the “Grupo de Logística y Transporte” at the Universidad del Bío-Bío.. This support is gratefully acknowledged.Eco-responsible transportation contributes at making a difference for companies devoted to product delivery operations. Two specific problems related to operations are the location of charging stations and the routing of electric vehicles. The first one involves locating new facilities on potential sites to minimise an objective function related to fixed and operational opening costs. The other one, electric vehicle routing problem, involves the consolidation of an electric-type fleet in order to meet a particular demand and some guidelines to optimise costs. It is determined by the distance travelled, considering the limited autonomy of the fleet, and can be restored by recharging its battery. The literature provides several solutions for locating and routing problems and contemplates restrictions that are closer to reality. However, there is an evident lack of techniques that addresses both issues simultaneously. The present article offers four solution strategies for the location of charging stations and a heuristic solution for fleet routing. The best results were obtained by applying the location strategy at the site of the client (relaxation of the VRP) to address the routing problem, but it must be considered that there are no displacements towards the recharges. Of all the other three proposals, K-means showed the best performance when locating the charging stations at the centroid of the cluster. © 2012-2018. National Institute for R and D in Informatics.https://sic.ici.ro/wp-content/uploads/2018/03/Art.-8-Issue-1-2018-SIC.pd

Del 'optimismo' historiográfico a la 'crisis' de la historia. Actualidad y relevancia de la epistemología de la historia

En el curso del siglo XX, el saber histórico ha conocido una profunda renovación tanto en el plano metodológico como epistemológico. "Nuevos objetos"; "Nuevos problemas"; "Nuevas aproximaciones" han modificado sustancialmente el te-rritorio del historiador. Una de las notas distintivas de la historiografía contemporánea, sobre todo como corolario del aporte significativo de la historiografía francesa, especialmente la escuela de los "Annales", fundada por Marc Bloch y Lucien Febvre y que alcanza su cumbre en la obra monumental de Fernand Braudel, ha sido promover la in-tegración de la historia y las ciencias sociales, colocando como factores esenciales del devenir histórico, los factores económicos y sociales. Sin embargo, con la "Nouvelle Histoire", heredera directa de los "Annales", sobre todo a la cabeza de Jacques Le Goff, la historia se ha ido progresivamente desperfilando frente a la expansión arrolladora de las ciencias sociales. Esto ha ido generando a partir de mediados de los años setenta, un clima de incertidumbre y de dudas con respecto a aquello que pertenece es-pecíficamente al oficio del historiador. Uno de los hechos que más ha contribuido a este clima intelectual caracterizado por la sensación de crisis es lo que se ha llamado "el desmigajamiento de la historia" (François Dosse). Es en este contexto actual, donde la cuestión sobre el estatuto epistemológico del saber histórico cobra plena actualidad, manifestando la importancia de la filosofía crítica de la historia para aportar luces que permitan clarificar con rigor y profundidad el sentido y significado de la historia entre las diversas disciplinas que le disputan, hoy más que ayer, el conocimiento de la condición existencial del sujeto humano

Evaluation of Risk Factors in Agriculture: An Application of the Analytical Hierarchical Process (AHP) Methodolog

Engler, A (reprint author), Univ Talca, Fac Ciencias Agr, Av Lircay S-N, Talca, Chile.Risk in the agricultural sector has multiple dimensions or factors and prioritization of these can support decision making. On the other hand, knowing the importance of these risk factors for distinct agricultural activities and how they vary according to geographic zone constitutes relevant information for agricultural development. The objective of this study was to prioritize risk factors that are highly relevant for farmers in Central South Chile. The multicriteria Analytical Hierarchical Process (AHP) methodology was used to define a decision structure with four risk factors or criteria: climate, price and direct cost variability, human factor, and commercialization. In general, results obtained showed that there are no important imbalances in the weightings of different risk factors. Price and cost variability was the most important factor (0.30) whereas climate was the least important (0.20). It also confirmed that there are spatial differences in the weightings obtained for the distinct risk factors which determine distinct risk levels for the respective agricultural activities according to geographic region

Seven years of marine environmental changes monitoring at coastal OOCS stations (Catalan Sea, NW Mediterranean)

Since March 2009 up to the present (more than 7 years now), the Operational Observatory of the Catalan Sea (OOCS; http://www2.ceab.csic.es/ oceans/) remains a witness of persistent marine environmental changes. The OOCS has two fixed observation stations at the head of the Blanes Canyon (200 m depth, 41.66°N; 2.91°E) and at the Blanes bay (20 m depth, 41.67°N; 2.80°E) in the Catalan Sea, NW Mediterranean. At the canyon station, a multi-parametric buoy presently installed delivers high frequency (by 30 min) and multi-parametric oceanographic (i.e. salinity, temperature, chlorophyll, turbidity, as well as light intensity in the PAR range for the upper 50 m depth) and atmospheric (air temperature, relative humidity, wind speed and direction and PAR) data. Subsurface photos and videos by an IP high resolution fisheye camera attached to the buoy are also delivered at 4-hour basis. Data and multimedia are transmitted in near real time for public access, via combined GSM/GPRS and 3G connections. At both stations, CTD profiles and water samples (collected for nutrients and picoplankton analyses) are carried out on board a research vessel at fortnightly basis. Numerical simulations along with the time series of in-situ observations show inter-annual seasonality anomalies possibly linked to global environmental changes. The lower-atmosphere and upper-sea environmental time series data collected prove the occurrence of shifting patterns of heat and matter fluxes impacting pelagic and benthic organisms.Peer Reviewe

The ceab's marine observatory in the catalan sea : consolidating long time series observations?

Peer Reviewe

Research of writing in primary education in Chile: A review of decade (2007-2016)

Indexación: Scopus; Scielo.Por otra parte, se observa que los investigadores han adoptado enfoques teó-ricos provenientes de la lingüística, la didáctica de la lengua y de los modelos cognitivos y socioculturales para indagar e interpretar la enseñanza de la escri-tura en las aulas. En el aspecto teórico, nos parece relevante establecer mayores puentes entre los investigadores nacionales del área para establecer debates in-terdisciplinarios acerca de las actuales teorías del aprendizaje de la escritura en la infancia y la niñez (Bazerman et al., 2017, 2018; Beard et al., 2009; Berninger, 2012; Grigorenko et al., 2012) y de modelos de enseñanza de la escritura en la educación básica (Fidalgo et al., 2017; Graham, MacArthur y Fitzgerald, 2013), que permitan establecer marcos teóricos más integrales que orienten las bases curriculares y la formación inicial y en servicio del profesorado, a la luz de las evidencias científicas en el área.La revisión aporta una síntesis de las investigaciones de la escritura en la educación básica realizadas durante el periodo 2007-2016 en Chile. Mediante el método de revisión integradora se identificaron 27 fuentes académicas que fueron clasificadas y analizadas en dos grandes áreas de estudio: aprendizaje de la escritura y enseñanza de la escritura. En el área del aprendizaje de la escritura de los estudiantes, las investigaciones se han enfocado principalmente en el análisis de conocimientos lingüísticos (ortografía y producción de oraciones) y en la valoración de la calidad de los textos, en su mayoría en textos narrativos, y en menor medida expositivos y de opinión. Por su parte, en el área de la enseñanza de la escritura, la atención se ha puesto principalmente en entender las prácticas de enseñanza de la composición de cuentos o textos de opinión. Menor atención han dedicado al estudio de las prácticas de evaluación de la escritura y de las necesidades de formación inicial y continua del profesorado relacionadas con la didáctica de la escritura. Destaca también la ausencia de encuestas nacionales y de estudios observacionales con docentes de otras regiones distintas a la Región Metropolitana, que permitan disponer de un panorama más completo de las prácticas de enseñanza de la escritura que ocurren en los diversos contextos educacionales, en términos de las estrategias de enseñanza y evaluación, así como de los géneros textuales que utilizan los docentes para enseñar a escribir, además de la frecuencia con la que enseñan la escritura, en comparación con los ejes de lectura y oralidad. A partir de una síntesis de resultados en cada área, la revisión propone recomendaciones para futuros estudios de la escritura en el contexto chileno de educación básica.The review provides a synthesis of the basic education writing research carried out during the 2007-2016 period in Chile. Through the integrative review method, 27 academic sources were identified and classified into two main areas of study: writing learning and writing instruction. In the area of student writing learning, research has focused mainly on the analysis of linguistic knowledge (spelling and sentence production) and the evaluation of the quality of texts, mostly in narrative texts, and to a lesser extent expository and opinion. In the area of teaching writing, attention has been focused mainly on understanding the teaching practices of story writing or opinion texts. Less attention, they have dedicated to the study of the practices of evaluation of the writing and of the needs of initial and continuous formation of the professors related to the didactics of the writing. It also highlights the absence of national surveys and observational studies with teachers from other regions than the Metropolitan Region, which provide a more complete picture of the teaching practices of writing that occur in different educational contexts, in terms of teaching and evaluation strategies, as well as the text genres that teachers use to teach writing, in addition to the frequency with which they teach writing, compared to the teaching of reading and orality. Based on a synthesis of results in each area, the review proposes recommendations for future studies of writing in the Chilean context of basic education.https://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0718-48832018000100059&lng=en&nrm=iso&tlng=e

Estudio farmacocinético de propofol en equinos

Se estudian las características farmacocinéticas de propofol en 6 caballos. Se determinaron parámetros farmacocinéticos de propofol cuantificando sus concentraciones sanguíneas en función del tiempo por HPLC, tras su administración de 2.4 mg/kg por vía endovenosa al grupo de animales. Los datos de concentración se interpretaron por un modelo abierto de 2 compartimentos, obteniéndose, entre otros, los valores de t1/2a, t1/2b,Vdc, Vdss, Vdb, Cltotaly MRT. Las variables farmacodinámicas se encuentran acordes a la disposición cinética de este fármaco. El análisisde los parámetros farmacocinéticos del propofol indica que éste posee una rápida y pronta distribución a los tejidos y una rápida eliminación del organismo. El propofol se presenta como una alternativa anestésica factible de ser incorporada dentro de un protocolo anestésico en caballos. Los parámetros farmacocinéticos obtenidos contribuyen para una correcta dosificación ya sea para mantener un estado de anestesia por infusión continua o por inyecciones repetidasPharmacokinetic variables of propofol were studied in 6 horses. Blood concentration of propofol at different times, after a single dose of 2.4mg/kg bw, was determined by HPLC. An open two compartment model was used to evaluate blood concentrations of propofol. Values of t1/2a,t1/2b, Vdc, Vdss,Vdb, Cltotal y MRT were obtained.The pharmacodynamic values show a narrow relationship with the pharmacokinetic disposition of this drug. Propofol s pharmacokinetic disposition presented a rapid distribution and removal from organic tissues. It is concluded that propofol is an alternative to be considered in anaesthetic protocolsin horses, and the pharmacokinetic variables presented contribute to determinethe appropriate dose to be give

Farmacocinética de propofol en potrillos de 10 a 15 días de edad

Se estudian las características farmacocinéticas de propofol en 6 potrillos de 10 a 15 días de edad. Se determinaron parámetros farmacocinéticos de propofol, cuantificando sus concentraciones sanguíneas en función del tiempo por HPLC, tras su administración de 2,4 mg/kg por vía endovenosa al grupo de animales. Los datos de concentración se interpretaron por un modelo abierto de 2 compartimentos, obteniéndose, entre otros, los valores de t1/2a, t1/2b, Vdc, Vdss, Vdb, Cltotal y MRT. El análisis de los parámetros farmacocinéticos del propofol, indican que éste posee una rápida y pronta distribución a los tejidos y una rápida eliminación del organismo. Los parámetros farmacocinéticos obtenidos contribuyen a efectuar cálculos para una correcta dosificaciónPharmacokinetic variables of propofol were studied in 8 foals. Plasma levels of propofol at different time after a single intravenous dose of 2.4 mg/kg bw, were determined by HPLC. An open two compartments model was used to evaluate plasma levels of propofol and values of t1/2a, t1/2b, Vdc, Vdss, Vdb, Cltotal y MRT were obtained. Propofol pharmacokinetic disposition showed a rapid distribution and removal from organic tissues, and the reported pharmacokinetic variables contribute to determine the appropriate dose to be give

Simple Stellar Population Models as probed by the Large Magellanic Cloud Star Cluster ESO 121-SC03

The presence of blue straggler stars (BSs) in star clusters has proven a challenge to conventional simple stellar population (SSP) models. Conventional SSP models are based on the evolution theory of single stars. Meanwhile, the typical locations of BSs in the colour-magnitude diagram of a cluster are brighter and bluer than the main sequence turn-off point. Such loci cannot be predicted by single-star evolution theory. However, stars with such properties contribute significantly to the integrated light of the cluster. In this paper, we reconstruct the integrated properties of the Large Magellanic Cloud cluster ESO 121-SC03, based on a detailed exploration of the individual cluster stars, and with particular emphasis on the cluster's BSs. We find that the integrated light properties of ESO 121-SC03 are dramatically modified by its BS component. The integrated spectral energy distribution (ISED) flux level is significantly enhanced toward shorter wavelengths, and all broad-band colours become bluer. When fitting the fully integrated ISED of this cluster based on conventional SSP models, the best-fitting values of age and metallicity are significantly underestimated compared to the true cluster parameters. The age underestimate is $\sim40$ per cent if we only include the BSs within the cluster's half-light radius and $\sim60$ per cent if all BSs are included. The corresponding underestimates of the cluster's metallicity are $\sim30$ and $\sim60$ per cent, respectively. The populous star clusters in the Magellanic Clouds are ideal objects to explore the potential importance of BSs for the integrated light properties of more distant unresolved star clusters in a statistically robust manner, since they cover a large range in age and metallicity.Comment: 11 pages, 7 figures, 2 tables, accepted for publication in MNRA

Operational Observatory of the catalan sea (OOCS)

The Operational Observatory of the Catalan Sea (OOCS) recently created by the Operational Oceanography Group at CEAB-CSIC is presented. The OOCS aims at performing observations of the marine environment in the Catalan Sea and beyond, assessing, modelling and forecasting the hydrodynamic and biogeochemical processes of the region. Some of the biogeochemical variables available in the models and forecast are phytoplankton, zooplankton and nutrients. Although OOCS is expected to be fully operational in 2011, some of its services are already available to the public through a dedicated webpage http://www.ceab.csic.es/~simob/.Peer Reviewe