METODOLOGÍA PARA LA EXTRACCIÓN DE PATRONES DE MOVILIDAD URBANA MEDIANTE EL ANÁLISIS DE REGISTROS DE ACTIVIDAD TELEFÓNICA (CALL DETAIL RECORD)

In the last century, Europe has seen a strong migration from rural to urban areas. Urban mobility is key to the economic and social development of cities, but at the same time it generates a significant number of negative effects such as congestion or air pollution. Understanding urban mobility patterns is essential to evaluate which are the most appropriate policies and measures to achieve sustainable urban development. Most of the empirical studies on urban mobility are based on surveys, since they provide detailed information about population mobility patterns and a large amount of socio-demographic information. However, surveys have several practical limitations (Ortúzar & Willumsen, 2011) such as their high costs and long lead times. The pervasive used of mobile devices opens the opportunity of gather large amounts of anonymised, passively-collected geolocation data overcoming some of the limitations of traditional surveys. Mobile phone data are probably one of the best data sources from which extract population mobility patterns at city scale because of their advantages (large samples, wide spatial coverage, low data collection costs, etc.). The main objective of this research is to contribute to the recent advances in the analysis of mobile phone data by developing and validating a new methodology to extract population activity and mobility patterns in urban areas. The methodology developed present several improvements with respect to previous studies, such as the identification of frequent locations different from home and work, better trip time estimations, sample selection and expansion procedures and improvements on population density estimations. The methodology developed has been tested in three different case studies: (1) estimation of mobility statistics and origin-destination matrices, (2) analysis of the relationship between social network and travel behaviour and (3) evaluation of population exposure to air pollution taking into account population activity and mobility patterns. The results show the potential of mobile phone data to extract information about mobility patterns in urban areas, to better understand the relationship between social network and travel behaviour and to improve population exposure assessment to air pollutants. Despite the potential of mobile phone data to provide rich information about activity and mobility patterns, a number of drawbacks and limitations shall be taken into account. Limitations are mainly related to the spatio-temporal resolution of the data and the limited socio-demographic information available. The results of this research are of great interest for transport planning studies, social network and transport modelling, and population exposure assessments.En el último siglo, Europa ha vivido una fuerte migración del ámbito rural al urbano. La movilidad urbana es fundamental para el desarrollo económico y social de las ciudades pero al mismo tiempo conlleva a una serie de importantes efectos negativos, tales como la congestión o la contaminación del aire. El entendimiento de los patrones de movilidad urbana de los ciudadanos es esencial para que los gestores puedan evaluar cuáles son las políticas y medidas más adecuadas para conseguir un desarrollo urbano sostenible. La mayoría de los estudios empíricos sobre movilidad urbana se apoyan en encuestas. Sin embargo, las encuestas presentan una serie de limitaciones prácticas importantes (Ortúzar & Willumsen, 2011) tales como sus elevados costes económicos o sus largos plazos de ejecución. El uso generalizado de dispositivos móviles por parte de la población proporciona la posibilidad de recoger de manera anónima y pasiva una gran cantidad de información espacio-temporal de una gran muestra de usuarios, superando algunas de las limitaciones de los actuales métodos de recogida de información. En concreto, los datos de la red de telefonía móvil presentan una serie de ventajas que los posicionan como una de las mejores fuentes de datos para el estudio de la movilidad general de grandes núcleos de población (bajos costes de extracción de los datos, gran tamaño de muestra, amplía cobertura espacial, etc.). El objetivo principal de esta investigación es contribuir a los recientes avances en el campo del análisis de los datos de telefonía móvil mediante el desarrollo y validación de una metodología que permita extraer información de patrones de actividad y movilidad de la población en ámbitos urbanos. La metodología desarrollada presenta una serie de mejoras relevantes con respecto a estudios previos, como la estimación de localizaciones frecuentes distintas de casa y trabajo, la mejora en la estimación de la hora del viaje, procedimientos para la selección y expansión de la muestra o la mejora en la estimación del número de personas en un área específica a partir de los patrones de actividad y movilidad de las mismas. Esta metodología ha sido aplicada en tres casos de uso para: (1) la obtención de estadísticas básicas de movilidad y matrices origen-destino en ámbitos urbanos, (2) el análisis de la influencia de la red social en la movilidad y (3) el estudio de la exposición de la población a la contaminación. Los resultados obtenidos demuestran el potencial de los datos de telefonía móvil para extraer información sobre patrones de movilidad en ámbitos urbanos, entender mejor la influencia de la red social en la movilidad y mejorar las estimaciones de exposición de la población a la contaminación. A pesar de las ventajas que proporcionan los datos de telefonía móvil, también se han observado limitaciones relevantes en los distintos estudios realizados, derivadas principalmente de la resolución espacio-temporal de los datos y de la limitada información socio-demográfica disponible. Los resultados de esta investigación son de gran relevancia para estudios de planificación y gestión del transporte, para el desarrollo de nuevos modelos de transporte que tengan en consideración la influencia de la red social en la movilidad y en estudios de evaluación de la exposición de la población a la contaminación.En l'últim segle, Europa ha viscut una forta migració de l'àmbit rural a l'urbà. La mobilitat urbana és fonamental per al desenvolupament econòmic i social de les ciutats però al mateix temps comporta a una sèrie d'importants efectes negatius, com ara la congestió o la contaminació de l'aire. L'entesa dels patrons de mobilitat urbana dels ciutadans és essencial perquè els gestors puguin avaluar quines són les polítiques i mesures més adequades per aconseguir un desenvolupament urbà sostenible. La majoria dels estudis empírics sobre mobilitat urbana es recolzen en enquestes. No obstant això, les enquestes presenten una sèrie de limitacions pràctiques importants (Ortúzar & Willumsen, 2011) com ara els seus elevats costos econòmics o els seus llargs terminis d'execució. L'ús generalitzat de dispositius mòbils per part de la població proporciona la possibilitat de recollir de manera anònima i passiva una gran quantitat d'informació espai-temporal d'una gran mostra d'usuaris, superant algunes de les limitacions dels actuals mètodes de recollida d'informació. En concret, les dades de la xarxa de telefonia mòbil presenten una sèrie d'avantatges que els posicionen com una de les millors fonts de dades per a l'estudi de la mobilitat general de grans nuclis de població (baixos costos d'extracció de les dades, grans dimensions de mostra, amplia cobertura espacial, etc.). L'objectiu principal d'aquesta investigació és contribuir als recents avenços en el camp de l'anàlisi de les dades de telefonia mòbil mitjançant el desenvolupament i validació d'una metodologia que permeti extreure informació de patrons d'activitat i mobilitat de la població en àmbits urbans. La metodologia desenvolupada presenta una sèrie de millores rellevants pel que fa a estudis previs, com l'estimació de localitzacions freqüents diferents de casa i treball, la millora en l'estimació de l'hora del viatge, procediments per a la selecció i expansió de la mostra o la millora en l'estimació del nombre de persones en una àrea específica a partir dels patrons d'activitat i mobilitat de les mateixes. Aquesta metodologia ha estat aplicada en tres casos d'ús per a: (1) l'obtenció d'estadístiques bàsiques de mobilitat i matrius origen-destinació en àmbits urbans, (2) l'anàlisi de la influència de la xarxa social en la mobilitat i (3) l'estudi de l'exposició de la població a la contaminació. Els resultats obtinguts demostren el potencial de les dades de telefonia mòbil per extreure informació sobre patrons de mobilitat en àmbits urbans, entendre millor la influència de la xarxa social en la mobilitat i millorar les estimacions d'exposició de la població a la contaminació. Tot i els avantatges que proporcionen les dades de telefonia mòbil, també s'han observat limitacions rellevants en els diferents estudis realitzats, derivades principalment de la resolució espai-temporal de les dades i de la limitada informació sociodemogràfica disponible. Els resultats d'aquesta investigació són de gran rellevància per a estudis de planificació i gestió del transport, per al desenvolupament de nous models de transport que tinguin en consideració la influència de la xarxa social en la mobilitat i en estudis d'avaluació de l'exposició de la població a la contaminació.Picornell Tronch, M. (2017). METODOLOGÍA PARA LA EXTRACCIÓN DE PATRONES DE MOVILIDAD URBANA MEDIANTE EL ANÁLISIS DE REGISTROS DE ACTIVIDAD TELEFÓNICA (CALL DETAIL RECORD) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/88397TESI

Implementation of Earned Value Management in Unit-Price Payment Contracts

[EN] The earned value management (EVM) method is internationally considered a standard tool in the project management field, enabling professionals to plan and control cost and schedule in an integrated manner. However, evidence indicates that EVM is not typically implemented by contractors when the payment agreement is based on unit-prices. In this payment approach, the owner pays the quantities actually executed according to the preagreed rate established in the contract for each unit or task; the income received by the contractor from the owner (generally named production) is neither proportional to costs nor fixed a priori, as in cost-reimbursable and lump sum contracts, respectively. Therefore, contractors have to control not only cost but also production. The current formulation of EVM does not allow controlling production; an additional baseline is needed. In response, this paper presents a proposal for adapting EVM to contractors when using the unit-prices payment agreement. Using a case study to illustrate, an additional baseline to account for production and profitability, as well as new indicators, is applied to allow contractors using EVM with this payment approach; this is the contribution of this paper to the body of knowledge. The proposed EVM formulation provides information not only in terms of cost (as in the traditional EVM approach) but also in terms of production.This research was supported by the Universitat Politècnica de València, which funded a visiting scholarship for Dr. Monty Sutrisna (Action 19701344)Picornell, M.; Pellicer, E.; Torres-Machí, C.; Sutrisna, M. (2017). Implementation of Earned Value Management in Unit-Price Payment Contracts. Journal of Management in Engineering. 33(3):06016001-1-06016001-7. https://doi.org/10.1061/(ASCE)ME.1943-5479.0000500S06016001-106016001-733

Comparing and modeling land use organization in cities

The advent of geolocated ICT technologies opens the possibility of exploring how people use space in cities, bringing an important new tool for urban scientists and planners, especially for regions where data is scarce or not available. Here we apply a functional network approach to determine land use patterns from mobile phone records. The versatility of the method allows us to run a systematic comparison between Spanish cities of various sizes. The method detects four major land use types that correspond to different temporal patterns. The proportion of these types, their spatial organization and scaling show a strong similarity between all cities that breaks down at a very local scale, where land use mixing is specific to each urban area. Finally, we introduce a model inspired by Schelling's segregation, able to explain and reproduce these results with simple interaction rules between different land uses.Comment: 9 pages, 6 figures + Supplementary informatio

Uncovering the spatial structure of mobility networks

The extraction of a clear and simple footprint of the structure of large, weighted and directed networks is a general problem that has many applications. An important example is given by origin-destination matrices which contain the complete information on commuting flows, but are difficult to analyze and compare. We propose here a versatile method which extracts a coarse-grained signature of mobility networks, under the form of a $2\times 2$ matrix that separates the flows into four categories. We apply this method to origin-destination matrices extracted from mobile phone data recorded in thirty-one Spanish cities. We show that these cities essentially differ by their proportion of two types of flows: integrated (between residential and employment hotspots) and random flows, whose importance increases with city size. Finally the method allows to determine categories of networks, and in the mobility case to classify cities according to their commuting structure.Comment: 10 pages, 5 figures +Supplementary informatio

From mobile phone data to the spatial structure of cities

Pervasive infrastructures, such as cell phone networks, enable to capture large amounts of human behavioral data but also provide information about the structure of cities and their dynamical properties. In this article, we focus on these last aspects by studying phone data recorded during 55 days in 31 Spanish metropolitan areas. We first define an urban dilatation index which measures how the average distance between individuals evolves during the day, allowing us to highlight different types of city structure. We then focus on hotspots, the most crowded places in the city. We propose a parameter free method to detect them and to test the robustness of our results. The number of these hotspots scales sublinearly with the population size, a result in agreement with previous theoretical arguments and measures on employment datasets. We study the lifetime of these hotspots and show in particular that the hierarchy of permanent ones, which constitute the "heart" of the city, is very stable whatever the size of the city. The spatial structure of these hotspots is also of interest and allows us to distinguish different categories of cities, from monocentric and "segregated" where the spatial distribution is very dependent on land use, to polycentric where the spatial mixing between land uses is much more important. These results point towards the possibility of a new, quantitative classification of cities using high resolution spatio-temporal data.Comment: 14 pages, 15 figure

Convection-induced severe winds over Menorca Island 28th October 2018. Under the watch of a forecaster

Póster presentado en: 3rd European Nowcasting Conference, celebrada en la sede central de AEMET en Madrid del 24 al 26 de abril de 2019

Genetic Variation in the Population of Ibiza (Spain): Genetic Structure, Geography, and Language

This is the published version, also available here: http://www.jstor.org/stable/41465529

The germplasm bank of the Botanical Garden of the University of Malaga.

The collection of the Germplasm Bank of the University of Malaga began recently associated with its Botanical Garden, in October 2021. The collection is made up of diaspores (fruits/seeds) of plant species belonging to the botanical garden itself and other native species of the vegetation of different areas of the province of Malaga. After the identification of the plants and the collection of the samples, standardized procedures are applied for their adequate conservation in the short and medium term in refrigerators at 4ºC, since the objective is to maintain a dynamic collection. Additionally, the database allows international exchanges and research activities such as viability studies or the elaboration of a photo atlas supported by morphometric studies of the preserved structures. The biodiversity conserved in this germplasm bank will be also very useful in a scenario of global change in which many species are being threatened, or even disappearing, since it constitutes a reservoir that guarantees the possible recovery of the different species whose diasporas have been preserved. Currently, the germplasm bank contains a total of 155 samples belonging to 115 taxa subject to strict protocols that guarantees the maintenance of their viability and genetic integrity, the sanitary conditions of the germplasm, its availability and the physical security of the collections.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Influence of sociodemographic characteristics on human mobility

Human mobility has been traditionally studied using surveys that deliver snapshots of population displacement patterns. The growing accessibility to ICT information from portable digital media has recently opened the possibility of exploring human behavior at high spatio-temporal resolutions. Mobile phone records, geolocated tweets, check-ins from Foursquare or geotagged photos, have contributed to this purpose at different scales, from cities to countries, in different world areas. Many previous works lacked, however, details on the individuals' attributes such as age or gender. In this work, we analyze credit-card records from Barcelona and Madrid and by examining the geolocated credit-card transactions of individuals living in the two provinces, we find that the mobility patterns vary according to gender, age and occupation. Differences in distance traveled and travel purpose are observed between younger and older people, but, curiously, either between males and females of similar age. While mobility displays some generic features, here we show that sociodemographic characteristics play a relevant role and must be taken into account for mobility and epidemiological modelization.Comment: 13 pages, 11 figures + Supplementary informatio

Ses Fontanelles Shipwreck (Mallorca, Balearic Islands): An Exceptional Late Roman Vessel and Its Cargo

This article summarises the results of the underwater rescue excavation of the shipwreck of Ses Fontanelles (Mallorca, Balearic Islands). The excavation documented the remains of a vessel, 12 m long and 5 m beam, loaded with two tiers of amphorae, which had set sail from the south-eastern Iberian Peninsula. The cargo includes numerous amphorae which were still sealed and bearing tituli picti, allowing for the analysis of their content. There is little doubt that the shipwreck of Ses Fontanelles is a key site for our understanding of third–fourth-century trade in the Western Mediterranean