DESARROLLO DE UN MODELO ESTADÍSTICO PARA LA ESTIMACIÓN DE LA VIDA ÚTIL Y PREDICCIÓN DE FALLOS EN TUBERÍAS DE AGUA POTABLE Y SU APLICACIÓN EN LA GESTIÓN DE ACTIVOS

[ES] En los sistemas de redes de distribución de agua potable es crucial llevar a cabo una gestión eficaz de la operación, el mantenimiento y los recursos con los que cuentan las empresas prestadoras de este servicio, de manera que se garantice el suministro de agua tanto en cantidad y calidad a los usuarios; así como también asegurar la operación y sostenibilidad del sistema a lo largo del tiempo. Una red de distribución de agua se conforma de diferentes tipos de equipos y elementos, dentro de los cuales las tuberías forman la parte medular de estas infraestructuras. Estas tuberías pueden verse afectadas por diversos factores de tipo externo o propios de la misma operación de la red, lo cual a su vez puede condicionar su tiempo de vida útil de servicio. Por lo tanto, es importante conocer los principales factores que las afectan, así como también poder estimar su frecuencia de fallos en el tiempo, a fin de tomar con anticipación las acciones más adecuadas para prevenir fallos repentinos que ocasionan interrupciones de servicio, y con ello perdidas económicas tanto a los usuarios como a las empresas operadoras. En este trabajo se recoge la aplicación de un modelo estocástico de variable simple, el cual se desarrolla en base a la aplicación de una metodología propuesta dentro del campo de la ingeniería de la mantenibilidad y confiabilidad, a partir del cual se estiman tiempos de vida útil y predicción de fallos para muestras de tubería de similares características. Además, se realiza una comparación del método propuesto con uno de vida acelerada de múltiples variables. De esta manera, se busca proponer un método sencillo y práctico con base técnica y científica del análisis de supervivencia de redes de agua potable, con el fin que pueda ser adoptado por las empresas de agua que busquen dentro de sus objetivos desarrollar su nivel en la gestión de activos. Como caso de estudio para la aplicación de la metodología se cuenta con los datos de un abastecimiento que cuenta con una estructura de datos básica y un sistema de gestión de información SIG, del cual se tiene además un registro de incidencias de fallos por un periodo menor a tres años. Por lo tanto, se aplicará la metodología a un caso de estudio sobre el cual se tiene un registro de datos a corto plazo, lo cual a nivel general se puede considerar una condición común entre las empresas de agua. En la metodología propuesta se estima la vida útil de servicio para muestras de tuberías de características homogéneas o similares, tomando en consideración dos escenarios. Uno en el que se considera solo el primer fallo presentado en cada tubería y otro en el que se analizan todos los fallos, esto es, incluyendo fallos repetitivos sobre un mismo elemento; en ambos casos sobre un periodo de observación determinado. Además, inicialmente se asume y posteriormente se verifica que los tiempos de incidencias de los fallos pueden ser representados mediante ciertas funciones de distribución de probabilidad paramétricas, como por ejemplo la distribución Weibull, a partir de la cual es posible representar la curva de Davies o también conocida como curva de bañera, la cual es comúnmente usada para representar los fallos durante la vida útil de diversos sistemas o equipos. Finalmente, el análisis e interpretación de las curvas y parámetros que describen la función de distribución contemplada, brindan una orientación en términos de confiabilidad para la toma de decisiones en cuanto al planteamiento de estrategias, tácticas y acciones de mantenimiento recomendadas dentro de un plan de gestión de activos.[EN] In potable water distribution systems it is crucial to carry out effective management of the operation, maintenance and the resources available to the companies providing this service, so that the water supply is guaranteed in both quantity and quality to users, as well ensuring the operation and sustainability of the system through the time. A water distribution network is composed of different types of equipment and elements, within which the pipes represent the core of these infrastructures. These pipes can be affected by various factors of external type or inherent to the operation of the network itself, which can also condition its service lifetime. Therefore, it is important to know the main factors affecting them, as well as to be able to estimate their frequency of failures over the time, in order to take in advance the most adequate actions to prevent sudden failures that cause service interruptions, and with it, economic losses both to the users and to the operating companies. In this work, the application of a stochastic model of simple variable is collected, which is developed based on the application of a proposed methodology within the maintainability and reliability engineering field, from which useful life times are estimated and it is also predicted failures of samples of pipes with similar characteristics. In addition, a comparison of the proposed method with one of accelerated life of multiple variables is carried out. In this way, the aim of this work is to propose a simple and practical method, with technical and scientific basis, of the survival analysis of potable water networks, in order to be adopted by water companies that seek within their objectives to develop their level in asset management. As a case of study for the application of this methodology, we have the data of a supply which has a basic data structure and an information management system GIS, vi which also has a record of failures incidents for a period of less than three years. Therefore, the methodology will be apply to a case of study on which there is a shortterm data record, which at a general level can be considered a common condition among water companies. In the proposed methodology, the service life for pipe samples of homogenous or similar characteristics is estimated taking into consideration two scenarios. In one scenario only the first failure occurred in each pipe is considered and in the other scenario all the failures are analyzed, that is, including repetitive failures on a same element; in both cases over a given observation period. In addition, it is initially assumed and subsequently verified that fault incidence times can be represented by certain parametric probability distribution functions, such as the Weibull distribution, from which it is possible to represent the Davies curve or also known as bathtub curve, which is commonly used to represent failures during useful life of some systems or equipment. Finally, the analysis and interpretation of the curves and parameters that describe this distribution function, provide an orientation in terms of reliability for decision making regarding the approach of recommended maintenance strategies, tactics and actions within an asset management planRamírez Aguilar, RX. (2019). DESARROLLO DE UN MODELO ESTADÍSTICO PARA LA ESTIMACIÓN DE LA VIDA ÚTIL Y PREDICCIÓN DE FALLOS EN TUBERÍAS DE AGUA POTABLE Y SU APLICACIÓN EN LA GESTIÓN DE ACTIVOS. http://hdl.handle.net/10251/128426TFG

A Front-Line and Cost-Effective Model for the Assessment of Service Life of Network Pipes

[EN] In any water utility, a reliable assessment of the service life of the network pipes is a key piece within the big puzzle of assets management. This paper presents a new statistical model (basic pipes life assessment, BPLA) to assess the service life of pipes, to locate the pipes on the failures bath curve and to forecast the expected failures in future years. Its main novelties are the processing of pipe information (is that information what is adapted to the classical maintenance engineering and not the other way back) and the definition of two different time variables that can be analyzed in parallel. The first novelty makes the model less demanding in terms of data and software tools than others currently available, and the second one allows to get all the results after one single stage of calculation. To show its usability, the BPLA has been applied to a pipe network that supplies water to 500,000 citizens for which two years of failure records are available. Procedures and results have been compared to the well-known Weibull proportional hazard model (WPHM), with final relative errors lower than 10% and 15% on each particular result.The authors would like to thank Global Omnium for the support provided, both directly and through the Catedra Aguas de Valencia of the UPV, for the development of the works presented in this paper.Ramírez-Aguilar, RX.; López Jiménez, PA.; Torres Toro, D.; Cobacho Jordán, R. (2020). A Front-Line and Cost-Effective Model for the Assessment of Service Life of Network Pipes. Water. 12(3):1-23. https://doi.org/10.3390/w12030667S123123Shamir, U., & Howard, C. D. D. (1979). An Analytic Approach to Scheduling Pipe Replacement. Journal - American Water Works Association, 71(5), 248-258. doi:10.1002/j.1551-8833.1979.tb04345.xKleiner, Y., Nafi, A., & Rajani, B. (2010). Planning renewal of water mains while considering deterioration, economies of scale and adjacent infrastructure. Water Supply, 10(6), 897-906. doi:10.2166/ws.2010.571Christodoulou, S., & Deligianni, A. (2009). A Neurofuzzy Decision Framework for the Management of Water Distribution Networks. Water Resources Management, 24(1), 139-156. doi:10.1007/s11269-009-9441-2Kutyłowska, M. (2015). Neural network approach for failure rate prediction. Engineering Failure Analysis, 47, 41-48. doi:10.1016/j.engfailanal.2014.10.007Motiee, H., & Ghasemnejad, S. (2018). Prediction of pipe failure rate in Tehran water distribution networks by applying regression models. Water Supply, 19(3), 695-702. doi:10.2166/ws.2018.137Di Nardo, A., Di Natale, M., Giudicianni, C., Greco, R., & Santonastaso, G. F. (2017). Complex network and fractal theory for the assessment of water distribution network resilience to pipe failures. Water Supply, 18(3), 767-777. doi:10.2166/ws.2017.124Kutyłowska, M. (2018). Forecasting failure rate of water pipes. Water Supply, 19(1), 264-273. doi:10.2166/ws.2018.078Le Gat, Y., & Eisenbeis, P. (2000). Using maintenance records to forecast failures in water networks. Urban Water, 2(3), 173-181. doi:10.1016/s1462-0758(00)00057-1Alvisi, S., & Franchini, M. (2010). Comparative analysis of two probabilistic pipe breakage models applied to a real water distribution system. Civil Engineering and Environmental Systems, 27(1), 1-22. doi:10.1080/10286600802224064Kimutai, E., Betrie, G., Brander, R., Sadiq, R., & Tesfamariam, S. (2015). Comparison of Statistical Models for Predicting Pipe Failures: Illustrative Example with the City of Calgary Water Main Failure. Journal of Pipeline Systems Engineering and Practice, 6(4), 04015005. doi:10.1061/(asce)ps.1949-1204.0000196Santos, P., Amado, C., Coelho, S. T., & Leitão, J. P. (2016). Stochastic data mining tools for pipe blockage failure prediction. Urban Water Journal, 14(4), 343-353. doi:10.1080/1573062x.2016.1148178Debón, A., Carrión, A., Cabrera, E., & Solano, H. (2010). Comparing risk of failure models in water supply networks using ROC curves. Reliability Engineering & System Safety, 95(1), 43-48. doi:10.1016/j.ress.2009.07.004Davis, P., Silva, D. D., Marlow, D., Moglia, M., Gould, S., & Burn, S. (2008). Failure prediction and optimal scheduling of replacements in asbestos cement water pipes. Journal of Water Supply: Research and Technology-Aqua, 57(4), 239-252. doi:10.2166/aqua.2008.035Punurai, W., & Davis, P. (2017). Prediction of Asbestos Cement Water Pipe Aging and Pipe Prioritization Using Monte Carlo Simulation. Engineering Journal, 21(2), 1-13. doi:10.4186/ej.2017.21.2.1Yoo, D., Kang, D., Jun, H., & Kim, J. (2014). Rehabilitation Priority Determination of Water Pipes Based on Hydraulic Importance. Water, 6(12), 3864-3887. doi:10.3390/w6123864D’Ercole, M., Righetti, M., Raspati, G., Bertola, P., & Maria Ugarelli, R. (2018). Rehabilitation Planning of Water Distribution Network through a Reliability—Based Risk Assessment. Water, 10(3), 277. doi:10.3390/w10030277Rajani, B., & Kleiner, Y. (2001). Comprehensive review of structural deterioration of water mains: physically based models. Urban Water, 3(3), 151-164. doi:10.1016/s1462-0758(01)00032-2Kropp, I., & Baur, R. (2005). Integrated failure forecasting model for the strategic rehabilitation planning process. Water Supply, 5(2), 1-8. doi:10.2166/ws.2005.0015García-Mora, B., Debón, A., Santamaría, C., & Carrión, A. (2015). Modelling the failure risk for water supply networks with interval-censored data. Reliability Engineering & System Safety, 144, 311-318. doi:10.1016/j.ress.2015.08.003Lei, Y. (2008). Evaluation of three methods for estimating the Weibull distribution parameters of Chinese pine (Pinus tabulaeformis ). Journal of Forest Science, 54(No. 12), 566-571. doi:10.17221/68/2008-jfsDatsiou, K. C., & Overend, M. (2018). Weibull parameter estimation and goodness-of-fit for glass strength data. Structural Safety, 73, 29-41. doi:10.1016/j.strusafe.2018.02.002Package survival https://cran.r-project.org/web/packages/survival/survival.pdfChristodoulou, S. E. (2010). Water Network Assessment and Reliability Analysis by Use of Survival Analysis. Water Resources Management, 25(4), 1229-1238. doi:10.1007/s11269-010-9679-

5to. Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad. Memoria académica

El V Congreso Internacional de Ciencia, Tecnología e Innovación para la Sociedad, CITIS 2019, realizado del 6 al 8 de febrero de 2019 y organizado por la Universidad Politécnica Salesiana, ofreció a la comunidad académica nacional e internacional una plataforma de comunicación unificada, dirigida a cubrir los problemas teóricos y prácticos de mayor impacto en la sociedad moderna desde la ingeniería. En esta edición, dedicada a los 25 años de vida de la UPS, los ejes temáticos estuvieron relacionados con la aplicación de la ciencia, el desarrollo tecnológico y la innovación en cinco pilares fundamentales de nuestra sociedad: la industria, la movilidad, la sostenibilidad ambiental, la información y las telecomunicaciones. El comité científico estuvo conformado formado por 48 investigadores procedentes de diez países: España, Reino Unido, Italia, Bélgica, México, Venezuela, Colombia, Brasil, Estados Unidos y Ecuador. Fueron recibidas un centenar de contribuciones, de las cuales 39 fueron aprobadas en forma de ponencias y 15 en formato poster. Estas contribuciones fueron presentadas de forma oral ante toda la comunidad académica que se dio cita en el Congreso, quienes desde el aula magna, el auditorio y la sala de usos múltiples de la Universidad Politécnica Salesiana, cumplieron respetuosamente la responsabilidad de representar a toda la sociedad en la revisión, aceptación y validación del conocimiento nuevo que fue presentado en cada exposición por los investigadores. Paralelo a las sesiones técnicas, el Congreso contó con espacios de presentación de posters científicos y cinco workshops en temáticas de vanguardia que cautivaron la atención de nuestros docentes y estudiantes. También en el marco del evento se impartieron un total de ocho conferencias magistrales en temas tan actuales como la gestión del conocimiento en la universidad-ecosistema, los retos y oportunidades de la industria 4.0, los avances de la investigación básica y aplicada en mecatrónica para el estudio de robots de nueva generación, la optimización en ingeniería con técnicas multi-objetivo, el desarrollo de las redes avanzadas en Latinoamérica y los mundos, la contaminación del aire debido al tránsito vehicular, el radón y los riesgos que representa este gas radiactivo para la salud humana, entre otros

The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well

Measurement of b jet shapes in proton-proton collisions at root s=5.02 TeV

We present the first study of charged-hadron production associated with jets originating from b quarks in proton-proton collisions at a center-of-mass energy of 5.02 TeV. The data sample used in this study was collected with the CMS detector at the CERN LHC and corresponds to an integrated luminosity of 27.4 pb(-1). To characterize the jet substructure, the differential jet shapes, defined as the normalized transverse momentum distribution of charged hadrons as a function of angular distance from the jet axis, are measured for b jets. In addition to the jet shapes, the per-jet yields of charged particles associated with b jets are also quantified, again as a function of the angular distance with respect to the jet axis. Extracted jet shape and particle yield distributions for b jets are compared with results for inclusive jets, as well as with the predictions from the pythia and herwig++ event generators.Peer reviewe

Measurement of the top quark forward-backward production asymmetry and the anomalous chromoelectric and chromomagnetic moments in pp collisions at √s = 13 TeV

Abstract The parton-level top quark (t) forward-backward asymmetry and the anomalous chromoelectric (d̂ t) and chromomagnetic (μ̂ t) moments have been measured using LHC pp collisions at a center-of-mass energy of 13 TeV, collected in the CMS detector in a data sample corresponding to an integrated luminosity of 35.9 fb−1. The linearized variable AFB(1) is used to approximate the asymmetry. Candidate t t ¯ events decaying to a muon or electron and jets in final states with low and high Lorentz boosts are selected and reconstructed using a fit of the kinematic distributions of the decay products to those expected for t t ¯ final states. The values found for the parameters are AFB(1)=0.048−0.087+0.095(stat)−0.029+0.020(syst),μ̂t=−0.024−0.009+0.013(stat)−0.011+0.016(syst), and a limit is placed on the magnitude of | d̂ t| < 0.03 at 95% confidence level. [Figure not available: see fulltext.

Search for Physics beyond the Standard Model in Events with Overlapping Photons and Jets

Results are reported from a search for new particles that decay into a photon and two gluons, in events with jets. Novel jet substructure techniques are developed that allow photons to be identified in an environment densely populated with hadrons. The analyzed proton-proton collision data were collected by the CMS experiment at the LHC, in 2016 at root s = 13 TeV, and correspond to an integrated luminosity of 35.9 fb(-1). The spectra of total transverse hadronic energy of candidate events are examined for deviations from the standard model predictions. No statistically significant excess is observed over the expected background. The first cross section limits on new physics processes resulting in such events are set. The results are interpreted as upper limits on the rate of gluino pair production, utilizing a simplified stealth supersymmetry model. The excluded gluino masses extend up to 1.7 TeV, for a neutralino mass of 200 GeV and exceed previous mass constraints set by analyses targeting events with isolated photons.Peer reviewe

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at root s(NN)=5.02 TeV

The second-order Fourier coefficients (v(2)) characterizing the azimuthal distributions of Y(1S) and Y(2S) mesons produced in PbPb collisions at root s(NN) = 5.02 TeV are studied. The Y mesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb(-1). The scalar product method is used to extract the v2 coefficients of the azimuthal distributions. Results are reported for the rapidity range vertical bar y vertical bar < 2.4, in the transverse momentum interval 0 < pT < 50 GeV/c, and in three centrality ranges of 10-30%, 30-50% and 50-90%. In contrast to the J/psi mesons, the measured v(2) values for the Y mesons are found to be consistent with zero. (C) 2021 The Author(s). Published by Elsevier B.V.Peer reviewe

Calibration of the CMS hadron calorimeters using proton-proton collision data at root s=13 TeV

Methods are presented for calibrating the hadron calorimeter system of theCMSetector at the LHC. The hadron calorimeters of the CMS experiment are sampling calorimeters of brass and scintillator, and are in the form of one central detector and two endcaps. These calorimeters cover pseudorapidities vertical bar eta vertical bar ee data. The energy scale of the outer calorimeters has been determined with test beam data and is confirmed through data with high transverse momentum jets. In this paper, we present the details of the calibration methods and accuracy.Peer reviewe

Measurement of the Jet Mass Distribution and Top Quark Mass in Hadronic Decays of Boosted Top Quarks in pp Collisions at root s=13 TeV

A measurement is reported of the jet mass distribution in hadronic decays of boosted top quarks produced in pp collisions at root s = 13 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 35.9 fb(-1). The measurement is performed in the lepton + jets channel of t (t) over bar events, where the lepton is an electron or muon. The products of the hadronic top quark decay t -> bW -> bq (q) over bar' are reconstructed as a single jet with transverse momentum larger than 400 GeV. The t (t) over bar cross section as a function of the jet mass is unfolded at the particle level and used to extract a value of the top quark mass of 172.6 +/- 2.5 GeV. A novel jet reconstruction technique is used for the first time at the LHC, which improves the precision by a factor of 3 relative to an earlier measurement. This highlights the potential of measurements using boosted top quarks, where the new technique will enable future precision measurements.Peer reviewe