1,030 research outputs found
InVAErt networks: a data-driven framework for emulation, inference and identifiability analysis
Use of generative models and deep learning for physics-based systems is
currently dominated by the task of emulation. However, the remarkable
flexibility offered by data-driven architectures would suggest to extend this
representation to other aspects of system synthesis including model inversion
and identifiability. We introduce inVAErt (pronounced \emph{invert}) networks,
a comprehensive framework for data-driven analysis and synthesis of parametric
physical systems which uses a deterministic encoder and decoder to represent
the forward and inverse solution maps, normalizing flow to capture the
probabilistic distribution of system outputs, and a variational encoder
designed to learn a compact latent representation for the lack of bijectivity
between inputs and outputs. We formally investigate the selection of penalty
coefficients in the loss function and strategies for latent space sampling,
since we find that these significantly affect both training and testing
performance. We validate our framework through extensive numerical examples,
including simple linear, nonlinear, and periodic maps, dynamical systems, and
spatio-temporal PDEs
Ureteral tunnel length versus ureteral orifice configuration in the determination of ureterovesical junction competence: A computer simulation model
Introduction The long-held belief that a ureteral re-implant tunnel should be five times the diameter of the ureter, as proposed by Paquin in 1959, ignores the effect of the orifice on the occurrence of reflux. In 1969, Lyon proposed that the shape of the ureteral orifice (UO) is more important than the intravesical tunnel. However, both theories missed quantitative evidence from principles of physics. The goal of the current study was to test Lyon’s theory through numerical models (i.e. to quantify the sensitivity of ureterovesical junction (UVJ) competence to intravesical tunnel length and to the UO).
Materials and methods The closure of a three-dimensional spatial configuration of ureter, constrained within a bladder, was simulated. Two common UO shapes (i.e. golf type vs 2-mm volcano type (Summary Fig.)), and two different intravesical ureteral tunnel length/diameter ratios (3:1 and 5:1) were examined. The required closure pressures were then compared.
Results The UO was a significant factor in determining closure pressure. Given the same intravesical ureteral tunnel length/ diameter ratio, the required closure pressure for the volcanic orifice was 78% less than that for the golf orifice. On the other hand, the intravesical ureteral tunnel length/diameter ratio had minimal effect on the required closure pressure. As the intravesical ureteral tunnel length/diameter ratio changed from3:1 to 5:1, the required closure pressure was reduced by less than 7%, regardless of the orifice shape.
Conclusions The simulation results showed that UVJ competence was more sensitive to a 2-mm protrusion of the UO compared to an increase in the intravesical tunnel length from 3:1 to 5:1. This agrees with Lyon’s theory, and at the same time challenges Paquin’s 5:1 rule. Researchers could use this information to consider the UO configuration in further animal, human, computer or material models
Measurement and Calculation for CO2 Solubility and Kinetic Rate in Aqueous Solutions of Two Tertiary Amines
AbstractAbsorbing CO2 with amine solutions is one of the most promising methods of CCS and has been widely applied. In order to improve efficiency and reduce costs, new solvents need to be selected. In this work, two amine solvents, N,N-dimethylethanolamine(DMEA) and Triethylene diamine (TEDA), have been characterized, with the use of gas- liquid reactor for CO2 solubility and kinetic rate measurements. Solubility of CO2 has been measured for amine concentrations of 1.0, 2.5 and 4.0mol/L at temperatures of 313.2K, 343.2K, 373.2K, and 393.2K while partial pressure of CO2 varies from 1 to 300kPa. The e-NRTL model has been used for these amine-water-CO2 systems in order to calculate CO2 solubility. Meanwhile the thermo-regulated constant interfacial area Lewis-type cell was also operated to obtain absorption kinetic data for CO2 absorption in 0.5M and 1.0M amine solutions
Utilizando el Facebook para desarrollar capacidades comunicacionales gráficas en alumnos de tercer año de la carrera de publicidad de una universidad privada de Lima
El presente documento consiste en una propuesta de innovación educativa donde se
identifica como problema principal el limitado desarrollo de capacidades en comunicación gráfica de los estudiantes del curso de Diseño Publicitario de una universidad privada. Esto puede perjudicar su futuro profesional.
Frente a ello se propone como objetivo principal mejorar el desarrollo de las capacidades comunicacionales gráficas de estos estudiantes. Adicionalmente, se
consideran tres objetivos específicos: la implementación de estrategias para el desarrollo de capacidades comunicacionales en investigación visual y creación de
imágenes gráficas, el uso de Facebook y otros recursos tecnológicos para la retroalimentación oportuna y el seguimiento del proceso de aprendizaje y por último
la generación de un portafolio de trabajos para la inserción en el mundo laboral.
El proceso metodológico consta de cinco fases: Planificación, capacitación, implementación, ejecución y evaluación. La primera consiste en la planificación del
curso incorporando Facebook, la segunda consisten en la capacitación del docente
sobre el uso pedagógico de Facebook y estrategias para el trabajo colaborativo, la
tercera etapa es la implementación del curso con la elaboración de los recursos y
materiales a utilizar. La cuarta etapa es la ejecución de los tres momentos de la
propuesta: En clase, fuera del salón de clases y en Facebook. Finalmente la fase
evaluativa donde se registra la información de resultados. Para ello se diseñó y
ejecutó una experiencia piloto de cuatro sesiones donde participaron docente, jefe
de práctica y estudiantes.
Como resultado se obtiene que incorporando Facebook, se mejoran las capacidades
en comunicación gráfica, interacción y diálogo entre docente y alumno, entre los
mismos alumnos, y con ello, además de la satisfacción de los estudiantes, el
desempeño resulta muy positivo.Tesi
Infection of laboratory-colonized Anopheles darlingi mosquitoes by Plasmodium vivax.
Anopheles darlingi Root is the most important malaria vector in the Amazonia region of South America. However, continuous propagation of An. darlingi in the laboratory has been elusive, limiting entomological, genetic/genomic, and vector-pathogen interaction studies of this mosquito species. Here, we report the establishment of an An. darlingi colony derived from wild-caught mosquitoes obtained in the northeastern Peruvian Amazon region of Iquitos in the Loreto Department. We show that the numbers of eggs, larvae, pupae, and adults continue to rise at least to the F6 generation. Comparison of feeding Plasmodium vivax ex vivo of F4 and F5 to F1 generation mosquitoes showed the comparable presence of oocysts and sporozoites, with numbers that corresponded to blood-stage asexual parasitemia and gametocytemia, confirming P. vivax vectorial capacity in the colonized mosquitoes. These results provide new avenues for research on An. darlingi biology and study of An. darlingi-Plasmodium interactions
Tratamiento de aguas residuales mediante métodos convencionales en el Anexo de Ñahuimpuquio, Distrito de Ahuac, Región Junín en el 2018
El anexo de Ñahuimpuquio, es un centro poblado ubicado a las orillas de la laguna
de Ñahuimpuquio el cual es un punto de turismo, por sus paisajes y el centro
arqueológico de Arwaturo. Motivo por el cual, es importante generar conciencia en
la población sobre la conservación de las fuentes de agua y la importancia de
realizar un adecuado tratamiento de las aguas residuales para la conservación del
medio ambiente. Para ello, en este presente trabajo de investigación, se tuvo como
objetivo analizar la eficiencia de los métodos convencionales empleados para el
tratamiento de los compuestos físicos, químicos y Microbiológicos de las aguas
residuales del anexo de Ñahuimpuquio. Se tuvo que aplicar conocimientos de
ingeniería sanitaria y la elaboración de ensayos físico-químicos y bacteriológicos
de las aguas residuales, de los cuales se determinó que el biodigestor y el humedal
artificial funcionando independientemente, no logran satisfacer los Estándares de
Calidad del Ambiente para Agua, indicados en el D.S. N°004-2017-MINSA. Así
mismo, se determinó que el humedal artificial tiene mejor eficiencia para la DBO5,
en comparación con el biodigestor. Sin embargo, en cuanto al periodo de retención,
el biodigestor es mucho menor que el del humedal artificial
Small volume expansion of almost supersymmetric large N theories
We consider the small-volume dynamics of nonsupersymmetric orbifold and
orientifold field theories defined on a three-torus, in a test of the claimed
planar equivalence between these models and appropriate supersymmetric ``parent
models". We study one-loop effective potentials over the moduli space of flat
connections and find that planar equivalence is preserved for suitable averages
over the moduli space. On the other hand, strong nonlinear effects produce
local violations of planar equivalence at special points of moduli space. In
the case of orbifold models, these effects show that the "twisted" sector
dominates the low-energy dynamics.Comment: 20 pages, 3 figures; added references, minor change
Lighting up the LHC with Dark Matter
We show that simultaneously explaining dark matter and the observed value of
the muon's magnetic dipole moment may lead to yet unexplored photon signals at
the LHC. We consider the Minimal Supersymmetric Standard Model with
electroweakino masses in the few-to-several hundred GeV range, and opposite
sign of the Bino mass parameter with respect to both the Higgsino and Wino mass
parameters. In such region of parameter space, the spin-independent elastic
scattering cross section of a Bino-like dark matter candidate in direct
detection experiment is suppressed by cancellations between different
amplitudes, and the observed dark matter relic density can be realized via
Bino-Wino co-annihilation. Moreover, the observed value of the muon's magnetic
dipole moment can be explained by Bino and Wino loop contributions.
Interestingly, "radiative" decays of Wino-like neutralinos into the lightest
neutralino and a photon are enhanced, whereas decays into leptons are
suppressed. While these decay patterns weaken the reach of multi-lepton
searches at the LHC, the radiative decay opens a new window for probing dark
matter at the LHC through the exploration of parameter space regions beyond
those currently accessible. To complement the current electroweakino searches,
we propose searching for a single (soft) photon plus missing transverse energy,
accompanied by a hard initial state radiation jet
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