Exploración con redes neuronales artificiales para estimar la resistencia a la compresión, en concretos fibroreforzados con acero

By designing and building concrete structures, the compressive strength achieved at 28-day curing typically represents the stability control specification of any work. Furthermore, reinforcing fibers into the cement based matrix has allowed a gain to their properties, as well as a high performance material. Technical literature states predictive formulations of compressive strength of concrete in function of a few composition parameters, such as water/cement ratio and the Portland cement. Also, there are formulations to find the proportion of the raw materials to get a defined compressive strength, specifically non-reinforced ordinary concrete. Besides artificial neural networks as a metaphor of biological neurons have been used as a tool to predict concrete compressive strength. The experience in this application shows an increasing interest to develop applications using fiber-reinforced concrete. In this paper, an artificial neural network has been developed to predict the compressive strength of steel-fiber-reinforced-concrete. The results prove that developed artificial neural networks may perform an adequate approximation to the actual value of the mechanical property.En diseño y construcción de estructuras de concreto, la resistencia a la compresión a 28 días de curado es la especificación de control de estabilidad de la obra. La inclusión de fibras como reforzamiento de la matriz cementicia permite una ganancia en sus propiedades, además de obtener un material de alto desempeño. En las normativas, se plantean formulaciones predictivas de la resistencia a la compresión basadas en unos pocos parámetros de composición del concreto, tales como la relación agua/cemento y el contenido de cemento Portland. Por otra parte, también se han planteado métodos de diseños de concreto para definir la ponderación de sus materiales componentes, teniendo como referencia la resistencia a la compresión del concreto simple. Además, las redes neuronales artificiales, como un símil de las neuronas biológicas, han sido utilizadas como herramientas de predicción de la resistencia a la compresión en el concreto, también con referencia al concreto simple, sin reforzamiento con fibras. Los antecedentes en este uso muestran que es interesante desarrollar aplicaciones en los concretos reforzados con fibras. En el presente trabajo se elaboraron redes neuronales artificiales para predecir la resistencia a la compresión en concretos reforzados con fibras de acero. Los resultados de los indicadores de desempeño mostraron que las redes neuronales artificiales elaboradas pueden realizar una aproximación adecuada al valor real de la propiedad mecánica

Redes neuronales artificiales para estimar propiedades en estado fresco y endurecido, para hormigones reforzados con fibras metálicas

Concrete is made from cement, water, aggregates, additives and mineral additions. In its fresh state, one of its properties is the settlement. Meanwhile, when hardened, its mechanical properties are reached at an age of 28 days after the mixing of the raw materials, as a brittle material it requires fiber to be incorporated to acquire ductility. Both in concrete, without fiber and with fiber, the use of artificial neural networks (ANNs) to predict mainly compressive strength has been expanded, which, as well as for its settlement properties, it also makes its other properties interesting . In this paper, the development of ANN is reported in combination withtraining from Levenberg-Maquardt and Scaled Conjugated Gradient Algorithms, using MATLAB software to predict the settlement and design strengths of compression, tension, shear, and flexural strength, flexural toughness, and for steel fiber reinforced concrete. The results of correlation between actual and predicted values show that the computational tool developed is reliable for predictive use.Keywords: Concrete´s settlement, Fiber reinforced concrete, Artificial Intelligence, Predictive tool, Concrete’s mechanical properties, Artificial Neural Network.El hormigón se elabora con cemento, agua, agregados, aditivos y adiciones minerales. Una de sus propiedades en estado fresco, es el asentamiento. Por su parte, en estado endurecido, sus propiedades mecánicas se alcanzan a una edad de 28 días, después del mezclado de las materias primas. Como material frágil, requiere de la incorporación de fibra para adquirir ductilidad. Tanto sin fibra como con fibras, se ha extendido el uso de redes neuronales artificiales (RNA) para predecir principalmente la resistencia a la compresión, lo cual hace interesante aplicarlo también para otras propiedades mecánicas, así como para el asentamiento. En el presente artículo se reporta la elaboración de RNA, entrenadas con los algoritmos de Levenberg-Maquardt y Gradiente Conjugado Escalonado, usando el software MATLAB, para predecir el asentamiento y las resistencias de diseño a la compresión, a la tensión, a la cortante, y a la flexión, así como la tenacidad flexural en hormigones reforzados con fibras de acero. Los resultados de correlación entre los valores obtenidos y reales, muestran que la herramienta computacional elaborada es confiable para su uso predictivo.Palabras Clave: Asentamiento del hormigón, Hormigón reforzado con fibra, Inteligencia Artificial, Propiedades mecánicas del hormigón, Redes Neuronales Artificiales

Arquitectura computacional para estimar propiedades mecánicas de concretos fibrorreforzados con acero, con empleo de redes neuronales artificiales

De acuerdo con Sánchez (1) el concreto o ‘piedra artificial’ es un conglomerado elaborado a partir de agregados, cemento, agua y otros componentes denominados adiciones minerales y aditivos químicos. Sus propiedades mecánicas de diseño son alcanzadas veintiocho días después de hecha la mezcla y se determina con ensayos estandarizados. El concreto es un material frágil y la incorporación de fibra le permite seguir soportando esfuerzos a pesar de haber alcanzado su máxima resistencia, por lo que experimenta un comportamiento cuasi-dúctil. La predicción de sus propiedades mecánicas se ha logrado con modelos matemáticos donde la complejidad y la alta relación de dependencia no-lineal entre las variables de entrada ha llevado a la estimación al campo de la inteligencia artificial (2). La literatura reporta diversos desarrollos con RNA para estimar propiedades en concretos planos, al ser de interés la temática en concretos reforzados con fibras de acero. En este trabajo se presenta la elaboración de una arquitectura prototipo conformada por códigos computacionales con RNA, cuyo objetivo es predecir la resistencia a compresión, tracción y flexión de mezclas de concreto reforzadas con fibras de acero

Penilaian Kinerja Keuangan Koperasi di Kabupaten Pelalawan

This paper describe development and financial performance of cooperative in District Pelalawan among 2007 - 2008. Studies on primary and secondary cooperative in 12 sub-districts. Method in this stady use performance measuring of productivity, efficiency, growth, liquidity, and solvability of cooperative. Productivity of cooperative in Pelalawan was highly but efficiency still low. Profit and income were highly, even liquidity of cooperative very high, and solvability was good

Juxtaposing BTE and ATE – on the role of the European insurance industry in funding civil litigation

One of the ways in which legal services are financed, and indeed shaped, is through private insurance arrangement. Two contrasting types of legal expenses insurance contracts (LEI) seem to dominate in Europe: before the event (BTE) and after the event (ATE) legal expenses insurance. Notwithstanding institutional differences between different legal systems, BTE and ATE insurance arrangements may be instrumental if government policy is geared towards strengthening a market-oriented system of financing access to justice for individuals and business. At the same time, emphasizing the role of a private industry as a keeper of the gates to justice raises issues of accountability and transparency, not readily reconcilable with demands of competition. Moreover, multiple actors (clients, lawyers, courts, insurers) are involved, causing behavioural dynamics which are not easily predicted or influenced. Against this background, this paper looks into BTE and ATE arrangements by analysing the particularities of BTE and ATE arrangements currently available in some European jurisdictions and by painting a picture of their respective markets and legal contexts. This allows for some reflection on the performance of BTE and ATE providers as both financiers and keepers. Two issues emerge from the analysis that are worthy of some further reflection. Firstly, there is the problematic long-term sustainability of some ATE products. Secondly, the challenges faced by policymakers that would like to nudge consumers into voluntarily taking out BTE LEI

Search for stop and higgsino production using diphoton Higgs boson decays

Results are presented of a search for a "natural" supersymmetry scenario with gauge mediated symmetry breaking. It is assumed that only the supersymmetric partners of the top-quark (stop) and the Higgs boson (higgsino) are accessible. Events are examined in which there are two photons forming a Higgs boson candidate, and at least two b-quark jets. In 19.7 inverse femtobarns of proton-proton collision data at sqrt(s) = 8 TeV, recorded in the CMS experiment, no evidence of a signal is found and lower limits at the 95% confidence level are set, excluding the stop mass below 360 to 410 GeV, depending on the higgsino mass

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at √s = 7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb[superscript −1]. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pT distributions of the leading jets at high pT values, the distributions of the HT at high-HT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.United States. Dept. of EnergyNational Science Foundation (U.S.)Alfred P. Sloan Foundatio

Severe early onset preeclampsia: short and long term clinical, psychosocial and biochemical aspects

Preeclampsia is a pregnancy specific disorder commonly defined as de novo hypertension and proteinuria after 20 weeks gestational age. It occurs in approximately 3-5% of pregnancies and it is still a major cause of both foetal and maternal morbidity and mortality worldwide1. As extensive research has not yet elucidated the aetiology of preeclampsia, there are no rational preventive or therapeutic interventions available. The only rational treatment is delivery, which benefits the mother but is not in the interest of the foetus, if remote from term. Early onset preeclampsia (<32 weeks’ gestational age) occurs in less than 1% of pregnancies. It is, however often associated with maternal morbidity as the risk of progression to severe maternal disease is inversely related with gestational age at onset2. Resulting prematurity is therefore the main cause of neonatal mortality and morbidity in patients with severe preeclampsia3. Although the discussion is ongoing, perinatal survival is suggested to be increased in patients with preterm preeclampsia by expectant, non-interventional management. This temporising treatment option to lengthen pregnancy includes the use of antihypertensive medication to control hypertension, magnesium sulphate to prevent eclampsia and corticosteroids to enhance foetal lung maturity4. With optimal maternal haemodynamic status and reassuring foetal condition this results on average in an extension of 2 weeks. Prolongation of these pregnancies is a great challenge for clinicians to balance between potential maternal risks on one the eve hand and possible foetal benefits on the other. Clinical controversies regarding prolongation of preterm preeclamptic pregnancies still exist – also taking into account that preeclampsia is the leading cause of maternal mortality in the Netherlands5 - a debate which is even more pronounced in very preterm pregnancies with questionable foetal viability6-9. Do maternal risks of prolongation of these very early pregnancies outweigh the chances of neonatal survival? Counselling of women with very early onset preeclampsia not only comprises of knowledge of the outcome of those particular pregnancies, but also knowledge of outcomes of future pregnancies of these women is of major clinical importance. This thesis opens with a review of the literature on identifiable risk factors of preeclampsia

Impacts of the Tropical Pacific/Indian Oceans on the Seasonal Cycle of the West African Monsoon

The current consensus is that drought has developed in the Sahel during the second half of the twentieth century as a result of remote effects of oceanic anomalies amplified by local land–atmosphere interactions. This paper focuses on the impacts of oceanic anomalies upon West African climate and specifically aims to identify those from SST anomalies in the Pacific/Indian Oceans during spring and summer seasons, when they were significant. Idealized sensitivity experiments are performed with four atmospheric general circulation models (AGCMs). The prescribed SST patterns used in the AGCMs are based on the leading mode of covariability between SST anomalies over the Pacific/Indian Oceans and summer rainfall over West Africa. The results show that such oceanic anomalies in the Pacific/Indian Ocean lead to a northward shift of an anomalous dry belt from the Gulf of Guinea to the Sahel as the season advances. In the Sahel, the magnitude of rainfall anomalies is comparable to that obtained by other authors using SST anomalies confined to the proximity of the Atlantic Ocean. The mechanism connecting the Pacific/Indian SST anomalies with West African rainfall has a strong seasonal cycle. In spring (May and June), anomalous subsidence develops over both the Maritime Continent and the equatorial Atlantic in response to the enhanced equatorial heating. Precipitation increases over continental West Africa in association with stronger zonal convergence of moisture. In addition, precipitation decreases over the Gulf of Guinea. During the monsoon peak (July and August), the SST anomalies move westward over the equatorial Pacific and the two regions where subsidence occurred earlier in the seasons merge over West Africa. The monsoon weakens and rainfall decreases over the Sahel, especially in August.Peer reviewe

Search for anomalous production of events with three or more leptons in pp collisions at √s = 8TeV

Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published articles title, journal citation, and DOI.A search for physics beyond the standard model in events with at least three leptons is presented. The data sample, corresponding to an integrated luminosity of 19.5fb-1 of proton-proton collisions with center-of-mass energy s=8TeV, was collected by the CMS experiment at the LHC during 2012. The data are divided into exclusive categories based on the number of leptons and their flavor, the presence or absence of an opposite-sign, same-flavor lepton pair (OSSF), the invariant mass of the OSSF pair, the presence or absence of a tagged bottom-quark jet, the number of identified hadronically decaying τ leptons, and the magnitude of the missing transverse energy and of the scalar sum of jet transverse momenta. The numbers of observed events are found to be consistent with the expected numbers from standard model processes, and limits are placed on new-physics scenarios that yield multilepton final states. In particular, scenarios that predict Higgs boson production in the context of supersymmetric decay chains are examined. We also place a 95% confidence level upper limit of 1.3% on the branching fraction for the decay of a top quark to a charm quark and a Higgs boson (t→cH), which translates to a bound on the left- and right-handed top-charm flavor-violating Higgs Yukawa couplings, λtcH and λctH, respectively, of |λtcH|2+|λctH|2<0.21