Secuenciación dinámica de sistemas de fabricación flexible mediante aprendizaje automático: análisis de los principales sistemas de secuenciación existentes

Una forma habitual de secuenciar de modo dinámico los trabajos en los sistemas de fabricación es mediante el empleo de reglas de secuenciación. Sin embargo, el problema que presenta este método es que el comportamiento del sistema de fabricación dependerá de su estado, y no existe una regla que supere a las demás en todos los posibles estados que puede presentar el sistema de fabricación. Por lo tanto, sería interesante usar en cada momento la regla más adecuada. Para lograr este objetivo, se pueden utilizar sistemas de secuenciación que emplean aprendizaje automático que permiten, analizando el comportamiento previo del sistema de fabricación (ejemplos de entrenamiento), obtener el conocimiento necesario para determinar la regla de secuenciación más apropiada en cada instante. En el presente trabajo se realiza una revisión de los principales sistemas de secuenciación existentes en la literatura que utilizan aprendizaje automático para variar de forma dinámica la regla de secuenciación empleada en cada momento

Signals of CP Violation Beyond the MSSM in Higgs and Flavor Physics

We study an extension of the Higgs sector of the Minimal Supersymmetric Standard Model (MSSM), considering the effects of new degrees of freedom at the TeV scale, and allowing for sources of CP violation beyond the MSSM (BMSSM). We analyze the impact of the BMSSM sources of CP violation on the Higgs collider phenomenology and on low energy flavor and CP violating observables. We identify distinct Higgs collider signatures that cannot be realized, either in the case without CP violating phases or in the CP violating MSSM, and investigate the prospects to probe them at the Tevatron and the LHC. The most striking benchmark scenario has three neutral Higgs bosons that all decay dominantly into W boson pairs and that are well within the reach of the 7 TeV LHC run. On the other hand, we also present scenarios with three Higgs bosons that have masses M_Hi > 150 GeV and decay dominantly into b bbar. Such scenarios are much more challenging to probe and can even lie completely outside the reach of the 7 TeV LHC run. We explore complementary scenarios with standard MSSM Higgs signals that allow to accommodate a sizable B_s mixing phase as indicated by D0, as well as the excess in B_s --> mu+ mu- candidates recently reported by CDF. We find that, in contrast to the MSSM, a minimal flavor violating soft sector is sufficient to generate significant corrections to CP violating observables in meson mixing, compatible with EDM constraints. In particular, a sizable B_s mixing phase, S_psiphi < 0.4, can be achieved for specific regions of parameter space. Such a large B_s mixing phase would unambiguously imply a sizable suppression of S_psiKs with respect to the SM prediction and a BR(B_s --> mu+ mu-) close to the 95% C.L. upper bound reported by CDF.Comment: 58 pages, 15 figures, 2 tables, v2 matches published versio

Localization Method for Autonomous Vehicles by using Vertical Elements in the Environment

The goal of this work is to provide autonomous cars with an alternative method to estimate their position in the world. It focuses on those situations when the GPS signal gets imprecise, weak or even lost due to environment conditions (long tunnels, dense forests, high buildings around, etc.). By installing two Velodyne VLP-16 LiDAR devices on the top of the car, located on both front corners of the vehicle structure, it is possible to acquire a 3D representation of this environment as a point cloud. This point cloud will be analyzed in order to find thin, vertical elements, such as traffic signals, traffic lights and so on. If these elements have been previously georeferenced, this is, their coordinates have been acquired and saved, the method will try to compare and match the incoming information from the environment to the georeferenced objects, i.e., performing data association. If the detected elements match any of the georeferenced ones, the car will correct an estimate of its position in a global frame.RoboCity2030-DIH-CM, Madrid Robotics Digital Innovation Hub, S2018/NMT-4331, funded by R&D Activities Program in Comunidad de Madrid and cofunded by EU Structural Funds.Peer reviewe

Dynamic rupture modeling on unstructured meshes using a discontinuous Galerkin method

We introduce the application of an arbitrary high-order derivative (ADER) discontinuous Galerkin (DG) method to simulate earthquake rupture dynamics. The ADER-DG method uses triangles as computational cells which simplifies the process of discretization of very complex surfaces and volumes by using external automated tools. Discontinuous Galerkin methods are well suited for solving dynamic rupture problems in the velocity-stress formulation as the variables are naturally discontinuous at the interface between two elements. Therefore, the fault has to be honored by the computational mesh. The so-called Riemann problem can be solved to obtain well defined values of the variables at the discontinuity itself. Fault geometries of high complexity can be modeled thanks to the flexibility of unstructured meshes, which solves a major bottleneck of other high-order numerical methods. Additionally, element refinement and coarsening are easily controlled in the meshing process to better resolve the near-fault area of the model. The fundamental properties of the method are shown, as well as a series of validating exercises with reference solutions and a comparison with the well-established finite difference, boundary integral, and spectral element methods, in order to test the accuracy of our formulation. An example of dynamic rupture on a nonplanar fault based upon the Landers 1992 earthquake fault system is presented to illustrate the main potentials of the new method

VPS-SLAM: Visual Planar Semantic SLAM for Aerial Robotic Systems

Indoor environments have abundant presence of high-level semantic information which can provide a better understanding of the environment for robots to improve the uncertainty in their pose estimate. Although semantic information has proved to be useful, there are several challenges faced by the research community to accurately perceive, extract and utilize such semantic information from the environment. In order to address these challenges, in this paper we present a lightweight and real-time visual semantic SLAM framework running on board aerial robotic platforms. This novel method combines low-level visual/visual-inertial odometry (VO/VIO) along with geometrical information corresponding to planar surfaces extracted from detected semantic objects. Extracting the planar surfaces from selected semantic objects provides enhanced robustness and makes it possible to precisely improve the metric estimates rapidly, simultaneously generalizing to several object instances irrespective of their shape and size. Our graph-based approach can integrate several state of the art VO/VIO algorithms along with the state of the art object detectors in order to estimate the complete 6DoF pose of the robot while simultaneously creating a sparse semantic map of the environment. No prior knowledge of the objects is required, which is a significant advantage over other works. We test our approach on a standard RGB-D dataset comparing its performance with the state of the art SLAM algorithms. We also perform several challenging indoor experiments validating our approach in presence of distinct environmental conditions and furthermore test it on board an aerial robot. Video:https://vimeo.com/368217703Released Code:https://bitbucket.org/hridaybavle/semantic_slam.git

Coexistence of antiferro- and ferrimagnetism in the spinel ZnFe2O4 with an inversion degree d lower than 0.3

Samples with inversion parameter values (d) ranging from 0.27 to 0.14 while maintaining the crystallite size value have been successfully fabricated from commercially available powders by mechanical grinding and thermal annealing treatments at temperatures ranging between 400 and 600 °C. Detailed characterization studies of these samples using X-ray, neutron diffraction and magnetic measurements have confirmed for the first time the simultaneous coexistence at 2 K of short range antiferromagnetic and ferrimagnetic ordering for a wide range of the inversion parameter. The magnetic phase diagram obtained is different from the one previously reported, which shows at 2 K the coexistence of long range antiferromagnetic order and short range order for values of inversion parameters less than 0.1 and the presence of a ferrimagnetic order only for values of d > 0.2. At room temperature, the Rietveld analysis of NPD patterns and the magnetization curves showed a paramagnetic behavior in the samples with d = 0.1. For the samples with higher cationic inversion, typical hysteresis curves of ferrimagnetic materials were observed and the saturation magnetization values obtained agree quite well with the net magnetic moment obtained from the Rietveld refinement of the neutron diffraction patterns. © 202

Circulating vitamin D levels and colorectal cancer risk: a meta-analysis and systematic review of case-control and prospective cohort studies

The associations between circulating vitamin D concentrations and total and site-specific colorectal cancer (CRC) incidence have been examined in several epidemiological studies with overall inconclusive findings. The aim of this systematic review and meta-analysis of both case-control and prospective cohort studies was to evaluate the association between CRC and circulating levels of vitamin D. The main exposure and outcome were circulating total 25(OH)D and CRC, respectively, in the overall population (i.e., all subjects). Two reviewers, working independently, screened all the literature available to identify studies that met the inclusion criteria (e.g., case-control or prospective cohort studies, published in English, and excluding non-original papers). Data were pooled by the generic inverse variance method using a random or fixed effect model, as approriate. Heterogeneity was identified using the Cochran's Q-test and quantified by the I2 statistic. Results were stratified by study design, sex, and metabolite of vitamin D. Sensitivity and subgroup analyses were also performed. A total of 28 original studies were included for the quantitative meta-analysis. Meta-analyses comparing the highest vs lowest categories, showed a 39% lower risk between levels of total 25(OH)D and CRC risk (OR (95% CI): 0.61 (0.52; 0.71); 11 studies) in case-control studies; whereas a 20% reduced CRC risk in prospective cohort studies (HR (95% CI): 0.80 (0.66; 0.97); 6 studies). Results in women mirrored main results, whereas results in men were non-significant in both analyses. Our findings support an inverse association between circulating vitamin D levels and CRC risk

DNA Testing Reveals the Putative Identity of JB55, a 19th Century Vampire Buried in Griswold, Connecticut

In 1990 in Griswold, Connecticut, archaeologists excavated a burial found in a "skull and crossbones" orientation. The lid of the 19th century coffin had brass tacks that spelled "JB55", the initials of the person lying there and age at death. JB55 had evidence of chronic pulmonary infection, perhaps tuberculosis. It is possible that JB55 was deemed a vampire due to his disease, and therefore had to be "killed" by mutilating his corpse. In an attempt to reveal the identity of JB55, DNA testing was performed. Ancestry informative single nucleotide polymorphism (SNP) analysis using the Precision ID Ancestry Panel indicated European ancestry. A full Y-chromosomal short tandem repeat (Y-STR) profile was obtained, belonging to haplogroup R1b. When the Y-STR profile was searched in the publicly accessible FamilyTreeDNA R1b Project website, the two closest matches had the surname "Barber". A search of historical records led to a death notice mentioning John Barber, whose son Nathan Barber was buried in Griswold in 1826. The description of Nathan Barber closely fits the burial of "NB13," found near JB55. By applying modern forensic DNA tools to a historical mystery, the identity of JB55 as John Barber, the 19th century Connecticut vampire, has been revealed

Structural and Electronic Properties of Small Neutral (MgO)n Clusters

Ab initio Perturbed Ion (PI) calculations are reported for neutral stoichiometric (MgO)n clusters (n<14). An extensive number of isomer structures was identified and studied. For the isomers of (MgO)n (n<8) clusters, a full geometrical relaxation was considered. Correlation corrections were included for all cluster sizes using the Coulomb-Hartree-Fock (CHF) model proposed by Clementi. The results obtained compare favorably to the experimental data and other previous theoretical studies. Inclusion of correlaiotn is crucial in order to achieve a good description of these systems. We find an important number of new isomers which allows us to interpret the experimental magic numbers without the assumption of structures based on (MgO)3 subunits. Finally, as an electronic property, the variations in the cluster ionization potential with the cluster size were studied and related to the structural isomer properties.Comment: 24 pages, LaTeX, 7 figures in GIF format. Accepted for publication in Phys. Rev.