Damage identification in structural health monitoring: a brief review from its implementation to the Use of data-driven applications

The damage identification process provides relevant information about the current state of a structure under inspection, and it can be approached from two different points of view. The first approach uses data-driven algorithms, which are usually associated with the collection of data using sensors. Data are subsequently processed and analyzed. The second approach uses models to analyze information about the structure. In the latter case, the overall performance of the approach is associated with the accuracy of the model and the information that is used to define it. Although both approaches are widely used, data-driven algorithms are preferred in most cases because they afford the ability to analyze data acquired from sensors and to provide a real-time solution for decision making; however, these approaches involve high-performance processors due to the high computational cost. As a contribution to the researchers working with data-driven algorithms and applications, this work presents a brief review of data-driven algorithms for damage identification in structural health-monitoring applications. This review covers damage detection, localization, classification, extension, and prognosis, as well as the development of smart structures. The literature is systematically reviewed according to the natural steps of a structural health-monitoring system. This review also includes information on the types of sensors used as well as on the development of data-driven algorithms for damage identification.Peer ReviewedPostprint (published version

Transverse momentum dependence of the angular distribution of the Drell-Yan process

We calculate the transverse momentum Q_{\perp} dependence of the helicity structure functions for the hadroproduction of a massive pair of leptons with pair invariant mass Q. These structure functions determine the angular distribution of the leptons in the pair rest frame. Unphysical behavior in the region Q_{\perp} --> 0 is seen in the results of calculations done at fixed-order in QCD perturbation theory. We use current conservation to demonstrate that the unphysical inverse-power and \ln(Q/Q_{\perp}) logarithmic divergences in three of the four independent helicity structure functions share the same origin as the divergent terms in fixed-order calculations of the angular-integrated cross section. We show that the resummation of these divergences to all orders in the strong coupling strength \alpha_s can be reduced to the solved problem of the resummation of the divergences in the angular-integrated cross section, resulting in well-behaved predictions in the small Q_{\perp} region. Among other results, we show the resummed part of the helicity structure functions preserves the Lam-Tung relation between the longitudinal and double spin-flip structure functions as a function of Q_{\perp} to all orders in \alpha_s.Comment: 18 pages, 4 figures; typos corrected, references updated, a few clarifications recommended by the referee. Paper accepted for publication in Physical Review

On a theorem of Kang and Liu on factorised groups

[EN] Kang and Liu ['On supersolvability of factorized finite groups', Bull. Math. Sci. 3 (2013), 205-210] investigate the structure of finite groups that are products of two supersoluble groups. The goal of this note is to give a correct proof of their main theorem.The first author was supported by the grant MTM2014-54707-C3-1-P from the Ministerio de Economia y Competitividad, Spain, and FEDER, European Union, and a project of Natural Science Foundation of Guangdong Province (No. 2015A030313791).Ballester-Bolinches, A.; Pedraza Aguilera, MC. (2018). On a theorem of Kang and Liu on factorised groups. Bulletin of the Australian Mathematical Society. 97(1):54-56. https://doi.org/10.1017/S0004972717000363S5456971Ezquerro, L. M., & Soler-Escrivà, X. (2003). On MutuallyM-Permutable Products of Finite Groups. Communications in Algebra, 31(4), 1949-1960. doi:10.1081/agb-120018515Kang, P., & Liu, Q. (2013). On supersolvability of fatorized finite groups. Bulletin of Mathematical Sciences, 3(2), 205-210. doi:10.1007/s13373-013-0032-4Ballester-Bolinches, A., Esteban-Romero, R., & Asaad, M. (2010). Products of Finite Groups. de Gruyter Expositions in Mathematics. doi:10.1515/9783110220612Ballester-Bolinches, A., Cossey, J., & Pedraza-Aguilera, M. C. (2001). ON PRODUCTS OF FINITE SUPERSOLUBLE GROUPS. Communications in Algebra, 29(7), 3145-3152. doi:10.1081/agb-501

Kinetic Theory of Collisionless Self-Gravitating Gases: II. Relativistic Corrections in Galactic Dynamics

In this paper we study the kinetic theory of many-particle astrophysical systems imposing axial symmetry and extending our previous analysis in Phys. Rev. D 83, 123007 (2011). Starting from a Newtonian model describing a collisionless self-gravitating gas, we develop a framework to include systematically the first general relativistic corrections to the matter distribution and gravitational potentials for general stationary systems. Then, we use our method to obtain particular solutions for the case of the Morgan & Morgan disks. The models obtained are fully analytical and correspond to the post-Newtonian generalizations of classical ones. We explore some properties of the models in order to estimate the importance of post-Newtonian corrections and we find that, contrary to the expectations, the main modifications appear far from the galaxy cores. As a by-product of this investigation we derive the corrected version of the tensor virial theorem. For stationary systems we recover the same result as in the Newtonian theory. However, for time dependent backgrounds we find that there is an extra piece that contributes to the variation of the inertia tensor.Comment: 30 pages, 8 figures. v2: Minor corrections and references added. Conclusions unchanged. v3: Version published in PR

Anticoncepción poscoital. Características de la demanda

ObjetivoConocer el perfil de las mujeres que demandan anticoncepción poscoital (APC).DiseñoDescriptivo transversal. Emplazamiento. Centro de Orientación Familiar (COF), Área 4 del Instituto Madrileño de Salud. Madrid.ParticipantesTodas las mujeres que acudieron en el año 2000 para requerir APC (n = 404).MedicionesSe realizó una encuesta con variables sociodemográficas relacionadas con la APC y con la vida sexual.ResultadosLa edad media fue de 23,9 años (límites, 14–49); el 9,9% era menor de edad. La media de coitos al mes era de 6,7, el número de años de relaciones sexuales era de 4,9 y el primer coito se produjo, de media, a los 18 años. El 90,9% afirmaba tener pareja estable. Tenía estudios secundarios o universitarios un 75%. El 55,7% manifestaba no haber recibido información sobre anticonceptivos. El 19,5% utilizó APC en otra ocasión. El 6,5% había tenido alguna interrupción voluntaria de embarazo y de éstas, el 36% había utilizado APC anteriormente. Los motivos de consulta fueron: rotura de preservativo (69,3%), preservativo retenido (16,9%) y coito sin protección (12%). El 7% tuvo otros coitos de riesgo en el mismo ciclo. Un 33,2% las remitía su equipo de atención primaria, acudió por conocidos el 19% y desde servicios de urgencias el 16%. Conocía el COF un 26,1%. En el 12,2% no se prescribió APC por mínimo riesgo de embarazo. Realizaron la valoración una enfermera (52,6%), médicos residentes (34,4%) y una ginecóloga (13%).ConclusionesFalta información sobre métodos anticonceptivos. La mayoría de las pacientes son derivadas por otros servicios sanitarios.ObjectiveDefine the profile of the women that ask for emergency contraception (EC).DesignTransversal descriptive investigation.SettingFamiliar Planning Center of 4th Area of Instituto Madrileño de Salud. in Madrid. Participants. All the women that went in the year 2000 requiring EC (n=404).MeasurementsWas carried out a survey with sociodemographic variables, related with the EC and with the sexual life.ResultsThe average age was of 23.9 years (age range 14 to 49) were inquired, 9.9 were under 18. They had an average of 6.7 intercourses per month, the first intercourse when they were 18 years old on average, and 4.9 years of sexual relationships. 90.9% stated to have a couple. 75% were graduated from high school or university, and 55.7% said they had never received information about contraceptives. For 19.5% this was not the first time they asked for EC. 6.5% had interrupted on purpose pregnancy and 36% of them had used EC before. The reasons to demand EC were: condom break (69.3%), held condom (16.9%) and intercourse without any protection (12%). 7% acknowledged other risky intercourses during the same period. 33.2% had been sent by a General Practitioner, 26.1% knew the center, 19% were sent by acquaintances and 16% from Emergency Services. EC was not prescribed in 12.2% of the cases because of minimum risk to pregnancy. The evaluation was made by a nurse (52.6%), by a doctor (34.4%) and by a gynecologist (13%).ConclusionsThere is a lack of information about contraceptive methods. Most of the patients are sent from other sanitary services

Screening of herbicides in grain legumes: pre-emergence herbicides in faba beans

Ante la escasez de herbicidas autorizados en leguminosas, se realizaron dos ensayos en habas con 10 herbicidas elegidos por estar autorizados en otras leguminosas o en otros países. Ninguno de los productos resultó totalmente eficaz y selectivo. Algunos de los herbicidas de preemergencia autorizados en España en habas para grano resultaron menos eficaces contra las malas hierbas y produjeron mayor fitotoxicidad que otros no autorizados. Así mismo, productos autorizados en Francia resultaron fitotóxicos en nuestras condiciones. Los mejores resultados seguido de ixosaben y aclonifen. Sin embargo será necesario ajustar dosis y buscar otras alternativas, como combinaciones de productos o estrategias de control para mejorar las eficacias y la selectividad, y sobre todo elegir los productos en función de las especies de malas hierbas dominantes en cada finca.Faced with a shortage of herbicides in legumes, two trials were conducted in faba beans to evaluate 10 herbicides elected by being authorized in other legumes or in other countries. None of the product was completely effective and selective. Some of the pre-emergence herbicides authorized in Spain for grain faba beans were less effective against weeds and produced more phytotoxicity than others not authorized. Likewise, products authorized in France turned out quite phytotoxic in our conditions. The best results were obtained with metribuzin by its effective weed control and low phytotoxicity, followed by ixosaben and aclonifen. However it will be necessary to adjust dose, to look for other alternatives, such as combinations of products or control strategies to improve effectiveness and selectivity, and above all choose the products depending on the species of dominant weeds in each farm

Kinetic Theory of Collisionless Self-Gravitating Gases: Post-Newtonian Polytropes

In this paper we study the kinetic theory of many-particle astrophysical systems and we present a consistent version of the collisionless Boltzmann equation in the 1PN approximation. We argue that the equation presented by Rezania and Sobouti in A&A 354 1110 (2000) is not the correct expression to describe the evolution of a collisionless self-gravitating gas. One of the reasons that account for the previous statement is that the energy of a free-falling test particle, obeying the 1PN equations of motion for static gravitational fields, is not a static solution of the mentioned equation. The same statement holds for the angular momentum, in the case of spherical systems. We provide the necessary corrections and obtain an equation that is consistent with the corresponding equations of motion and the 1PN conserved quantities. We suggest some potential relevance for the study of high density astrophysical systems and as an application we construct the corrected version of the post-Newtonian polytropes.Comment: 23 pages, 24 figures. Accepted for publication in PR

A stochastic spectral analysis of transcriptional regulatory cascades

The past decade has seen great advances in our understanding of the role of noise in gene regulation and the physical limits to signaling in biological networks. Here we introduce the spectral method for computation of the joint probability distribution over all species in a biological network. The spectral method exploits the natural eigenfunctions of the master equation of birth-death processes to solve for the joint distribution of modules within the network, which then inform each other and facilitate calculation of the entire joint distribution. We illustrate the method on a ubiquitous case in nature: linear regulatory cascades. The efficiency of the method makes possible numerical optimization of the input and regulatory parameters, revealing design properties of, e.g., the most informative cascades. We find, for threshold regulation, that a cascade of strong regulations converts a unimodal input to a bimodal output, that multimodal inputs are no more informative than bimodal inputs, and that a chain of up-regulations outperforms a chain of down-regulations. We anticipate that this numerical approach may be useful for modeling noise in a variety of small network topologies in biology