Examinando por browse.metadata.type "info:eu-repo/semantics/article"
  • Publicación
    10-pi-Electron arenes a la carte: structure and bonding of the [E-(CnHn)-E](n-6) (E = Ca, Sr, Ba; n=6-8) complexes
    ( 2016)
    Mondal, S
    ;
    Cabellos, JL
    ;
    Pan, S
    ;
    Osorio, E
    ;
    Torres-Vega, JJ
    ;
    Tiznado, W
    ;
    Restrepo, A
    ;
    Merino, G
    En este artículo, brindamos evidencia sólida para demostrar que, entre una diversidad estructural abrumadora, los metales alcalinotérreos (Ca, Sr, Ba) tienen la capacidad de formar compuestos sándwich invertidos con C6H6, C7H7+ y C8H82+ de simetría Dnh y fórmula general [E –(CnHn)–E]n−6 (n = 6–8) con núcleos aromáticos planares de 10 π electrones en virtud de la transferencia de dos electrones por átomo de metal al anillo.
  • Publicación
    112 hormonal supplementation strategies for improvement of pregnancy rates in embryo transfer in alpacas
    (CSIRO Publishing, 2017)
    Vivanco-Mackie, H. W.
    ;
    Ponce-Salazar, M. D.
    ;
    Miguel-Gonzales, M.
    ;
    Youngs, C. R.
    ;
    Osorio, C.
    ;
    Asparrin, M.
    The aim was to improve the pregnancy rate in recipient alpacas following embryo transfer. Two experiments were carried out, Experiment 1 in the southern highlands (4,100 m elevation) and Experiment 2 (E2) in the central highlands (3,200 m elevation) of the Peruvian Andes. In both experiments, a group of alpaca donors was subjected to superovulation and embryo flushing as per procedures already described (Vivanco 2013 29th Annu. Mtg. European Embryo Transfer Association, 43–74). The synchronization of the recipient alpacas and ovulation induction in both experiments was made by ultrasonography selection of the alpacas with follicles greater than 8 mm and their exposure to vasectomized males followed by an injection of GnRH (0.0042 mg of acetate of buserelin, Buserelina Zoovet®, Laboratorio Zoovet, Santa Fe, Argentina). The embryo transfers in both locations were made by laparoscopically aided laparotomy 6.5 days after ovulation induction. In Experiment 1, 29 recipient alpacas were distributed in 2 treatments: treatment 1 (n = 14) was the control (no hormonal supplementation); alpacas in treatment 2 (n = 15) received an injection of 300 IU of eCG (Novormon®, Partnar Animal Health, Port Huron, MI, USA) and the insertion of an intravaginal sponge containing 60 mg of medroxyprogesterone acetate (Progespon®, Syntex SA, Buenos Aires, Argentina) 72 h after the injection of the GnRH applied at ovulation induction, the sponges remained in the vagina of the recipients up until Day 21 post-transfer. In Experiment 2, ten recipient alpacas were distributed into 2 treatments, treatment 1 as the control (n = 5, no hormonal supplementation) and treatment 2 (n = 5) in which the recipient alpacas received a dose of a nonsteroidal anti-inflammatory (2 mg/kg of tolfenamic acid, Tolfén L.A. 8%®, Agrovet Market Animal Health, Lima, Peru) 12 h before the embryo transfer with the aim of blocking PGF2α secretion and preventing corpus luteum (CL) regression. At time of transfer, control recipients in Experiment 1 showed in average 0.71 ± 0.71 follicles and 1.14 ± 0.53 CL and the treatment 2 recipients showed 2.73 ± 2.52 follicles and 1.20 ± 0.56 CL, respectively, and there was no significant differences (P > 0.05) between treatment groups in the pregnancy rates 60 days post-transfer, being 35.7% (5/14) and 26.7% (4/15) for treatment 1 (control) and 2 (hormonally supplemented), respectively. In Experiment 2, the number of follicles and CL were not recorded; the differences between treatments for pregnancy rates were also nonsignificant (P > 0.05), the pregnancy rates were 20% (1/5) and 40% (2/5) for treatment 1 (control) and treatment 2 (injected with anti-inflammatory) respectively. In the first experiment, the hormonal treatment increased the number of non-ovulatory follicles; this could have negatively influenced its effectivity on increasing pregnancy rates. In the second experiment, a tendency can be observed for better holding rates in alpacas receiving the anti-inflammatory treatment; it will be necessary to increase the number of observations in a new experiment in order to determine if this will have a significant effect on improving holding rates in alpacas.
  • Publicación
    1D TiO2 Nanostructures Prepared from Seeds Presenting Tailored TiO2 Crystalline Phases and Their Photocatalytic Activity for Escherichia coli in Water
    ( 2018)
    Cabrera, J
    ;
    Acosta, D
    ;
    Lopez, A
    ;
    Candal, RJ
    ;
    Marchi, C
    ;
    Garcia, P
    ;
    Rios, D
    ;
    Rodriguez, JM
    TiO2 nanotubes were synthesized by alkaline hydrothermal treatment of TiO2 nanoparticles with a controlled proportion of anatase and rutile. Tailoring of TiO2 phases was achieved by adjusting the pH and type of acid used in the hydrolysis of titanium isopropoxide (first step in the sol-gel synthesis). The anatase proportion in the precursor nanoparticles was in the 3–100% range. Tube-like nanostructures were obtained with an anatase percentage of 18 or higher while flake-like shapes were obtained when rutile was dominant in the seed. After annealing at 400°C for 2 h, a fraction of nanotubes was conserved in all the samples but, depending on the anatase/rutile ratio in the starting material, spherical and rod-shaped structures were also observed.
  • Publicación
    3D elasticity numerical solution for the static behavior of FGM shells
    (Elsevier Ltd, 2020)
    Monge J.C.
    ;
    Mantari J.L.
    Se presenta una solución numérica para el análisis estático tridimensional de láminas graduadas funcionalmente con curvatura constante. La solución se basa en tres ecuaciones de elasticidad escritas en coordenadas curvilíneas ortogonales que son válidas para paneles de cubierta esféricos, cilíndricos y placas rectangulares. Las ecuaciones en términos de las variables de la superficie media se resuelven mediante una suma de armónicos en términos del método de Navier, que es válido solo para estructuras simplemente apoyadas. Las ecuaciones en función de la dirección del espesor se resuelven numéricamente por el método de Cuadratura Diferencial (DQM) que permitió calcular fácilmente la derivada aproximada de una función utilizando una suma ponderada de las funciones evaluadas en una determinada grilla. Las capas de la estructura se discretizan por separado mediante la cuadrícula de Chebyshev-Gauss-Lobatto y los polinomios de interpolación de Lagrange se consideran como funciones base. La continuidad interlaminar del corte transversal se impone como parte de las condiciones de contorno del método presentado. Las condiciones de contorno de las tensiones fuera del plano en la parte superior e inferior debidas a las cargas aplicadas en la lámina también se consideran para el análisis, como resultado, este método puede predecir el comportamiento correcto de la distribución a través del espesor de las fuerzas transversales. hace hincapié Este método permitió discretizar fácilmente el material en términos de la dirección del espesor y se analizaron varios tipos de estructuras de sándwich y capas individuales graduadas funcionalmente con núcleo graduado funcionalmente. Se analizan varias láminas sometidas a carga distribuida bisinusoidal y uniforme. Los resultados se comparan con otras soluciones tridimensionales propuestas en la literatura y modelos bidimensionales precisos. © 2019
  • Publicación
    A categorization of simultaneous localization and mapping knowledge for mobile robots
    (Association for Computing Machinery, 2020)
    Cornejo Lupa M.A.
    ;
    Ticona-Herrera R.P.
    ;
    Cardinale Y.
    ;
    Barrios-Aranibar D.
    Los robots autónomos están desempeñando un papel importante en las actividades académicas, tecnológicas y científicas. Por lo tanto, su comportamiento es cada vez más complejo. Las principales tareas de los robots autónomos incluyen mapear un entorno y localizarse a sí mismos. Estas tareas comprenden el problema de localización y mapeo simultáneos (SLAM). La representación del conocimiento de SLAM (p. ej., características del robot, información del entorno, información de mapeo y ubicación), con un modelo estándar y bien definido, proporciona la base para desarrollar soluciones eficientes e interoperables. Sin embargo, hasta donde sabemos, no existe una clasificación común de tales conocimientos. Muchos trabajos existentes basados ​​en la Web Semántica han formulado ontologías para modelar información relacionada solo con algunos aspectos de SLAM, sin un arreglo estándar. En este artículo proponemos una categorización del conocimiento gestionado en SLAM, basada en ontologías existentes y principios de SLAM. También clasificamos ontologías recientes y populares según nuestras categorías propuestas y destacamos las lecciones a aprender de las soluciones existentes. © 2020 ACM.
  • Publicación
    A comparative study of linen (Flax) fibers as reinforcement of fly ash and clay brick powder based geopolymers
    (IOP Publishing, 2018-10-26)
    Silva, G.
    ;
    Kim de Aguilar, Suyeon
    ;
    Castañeda, A.
    ;
    Donayre, R.
    ;
    Nakamatsu Kuniyoshi, Javier
    ;
    Aguilar, R.
    ;
    Korniejenko, K.
    ;
    ?ach, M.
    ;
    Miku?a, J.
    Los geopolímeros tienen un gran potencial para el desarrollo de materiales de construcción sostenibles debido a la utilización de subproductos industriales y materiales de desecho para su producción. La introducción de fibras naturales en matrices de geopolímeros ha mostrado resultados interesantes para producir materiales de construcción alternativos con propiedades mecánicas mejoradas. Esta investigación explora el uso de fibras de lino (lino) como refuerzo de geopolímeros a base de polvo de ladrillo de arcilla y geopolímeros a base de cenizas volantes. Las fibras de lino se obtuvieron del Instituto de Fibras Naturales y Plantas Medicinales, mientras que el polvo de ladrillo de arcilla se obtuvo de los residuos de construcción en Lima (Perú) y las cenizas volantes se extrajeron de Skawina (Polonia). La influencia de la adición de fibras de lino en las propiedades mecánicas de la matriz de geopolímero se estudió mediante pruebas de compresión no confinada y pruebas de flexión de tres puntos. Los resultados muestran que la adición de fibras de lino mejoró significativamente tanto la resistencia a la compresión como a la flexión de los geopolímeros a base de cenizas volantes y polvo de ladrillos de arcilla.
  • Publicación
    A Comparative Study on Activated Carbons Derived from a Broad Range of Agro-industrial Wastes in Removal of Large-Molecular-Size Organic Pollutants in Aqueous Phase
    (Springer Nature, 2015)
    Cruz, GJF
    ;
    Matejova, L
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    Pirila, M
    ;
    Ainassaari, K
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    Canepa, CA
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    Solis, J
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    Cruz, JF
    ;
    Solcova, O
    ;
    Keiski, RL
    Microporous–mesoporous activated carbons from five different types of agro-industrial wastes were produced using chemical activation with ZnCl2 and carbonization at mild conditions of 600 °C, comprehensively characterized and investigated for removal of methylene blue (MB) in aqueous solution, a model large-molecular-size organic pollutant. The external part of the mango pit (mango seed husk) was used for the production of activated carbon (AC) for the first time. Despite that the raw agro-materials exhibited significantly different porosity, all activated carbons produced possessed well-developed microporous–mesoporous structures showing high surface areas and micropore volumes.
  • Publicación
    A comparative study on the phenolic bioaccessibility, antioxidant and inhibitory effects on carbohydrate-digesting enzymes of maca and mashua powders
    (Academic Press, 2020)
    Paucar-Menacho L.M.
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    Peñas E.
    ;
    Hernandez-Ledesma B.
    ;
    Frias J.
    ;
    Martínez-Villaluenga C.
    The polyphenolic content of dehydrated maca (MA) and mashua (M) powders, promising functional ingredients, and their antioxidant activity and inhibition of carbohydrate digestion was evaluated following in vitro gastrointestinal digestion (GID). Moreover, the impact of steaming on bioaccessibility and bioactivity of the M phenolic fraction was investigated. MA phenolic fraction composed mainly of caffeic-4-O-glucosides showed high bioaccessibility (117.8%), antioxidant activity (142.9 μmol Trolox equivalents, TE/g) and weak effectiveness to inhibit carbohydrate digestion after GID. Anthocyanins were the major compounds in the M phenolic fraction with low bioaccessibility (22.4%), although a superior antioxidant activity (446.7 μmol TE/g) and modest inhibitory effects on carbohydrate digestion after GID. Generally, bioaccessibility and bioactivity of M decreased after steaming process. MA and M powders contain appreciable concentrations of phenolics, although M polyphenols were more effective on modulating carbohydrate digestion. © 2020 Elsevier Ltd
  • Publicación
    A Complementary Mechanism of Bacterial mRNA Translation Inhibition by Tetracyclines
    (Frontiers Media S.A., 2021)
    Barrenechea V.
    ;
    Vargas-Reyes M.
    ;
    Quiliano M.
    ;
    Milón P.
    Tetracycline has positively impacted human health as well as the farming and animal industries. Its extensive usage and versatility led to the spread of resistance mechanisms followed by the development of new variants of the antibiotic. Tetracyclines inhibit bacterial growth by impeding the binding of elongator tRNAs to the ribosome. However, a small number of reports indicated that Tetracyclines could also inhibit translation initiation, yet the molecular mechanism remained unknown. Here, we use biochemical and computational methods to study how Oxytetracycline (Otc), Demeclocycline (Dem), and Tigecycline (Tig) affect the translation initiation phase of protein synthesis. Our results show that all three Tetracyclines induce Initiation Factor IF3 to adopt a compact conformation on the 30S ribosomal subunit, similar to that induced by Initiation Factor IF1. This compaction was faster for Tig than Dem or Otc. Furthermore, all three tested tetracyclines affected IF1-bound 30S complexes. The dissociation rate constant of IF1 in early 30S complexes was 14-fold slower for Tig than Dem or Otc. Late 30S initiation complexes (30S pre-IC or IC) exhibited greater IF1 stabilization by Tig than for Dem and Otc. Tig and Otc delayed 50S joining to 30S initiation complexes (30S ICs). Remarkably, the presence of Tig considerably slowed the progression to translation elongation and retained IF1 in the resulting 70S initiation complex (70S IC). Molecular modeling of Tetracyclines bound to the 30S pre-IC and 30S IC indicated that the antibiotics binding site topography fluctuates along the initiation pathway. Mainly, 30S complexes show potential contacts between Dem or Tig with IF1, providing a structural rationale for the enhanced affinity of the antibiotics in the presence of the factor. Altogether, our data indicate that Tetracyclines inhibit translation initiation by allosterically perturbing the IF3 layout on the 30S, retaining IF1 during 70S IC formation, and slowing the transition toward translation elongation. Thus, this study describes a new complementary mechanism by which Tetracyclines may inhibit bacterial protein synthesis. © Copyright © 2021 Barrenechea, Vargas-Reyes, Quiliano and Milón.
  • Publicación
    A differential DNA methylome signature of pulmonary immune cells from individuals converting to latent tuberculosis infection
    (Nature Research, 2021)
    Karlsson L.
    ;
    Das J.
    ;
    Nilsson M.
    ;
    Tyrén A.
    ;
    Pehrson I.
    ;
    Idh N.
    ;
    Sayyab S.
    ;
    Paues J.
    ;
    Ugarte-Gil C.
    ;
    Méndez-Aranda M.
    ;
    Lerm M.
    Tuberculosis (TB), caused by Mycobacterium tuberculosis, spreads via aerosols and the first encounter with the immune system is with the pulmonary-resident immune cells. The role of epigenetic regulations in the immune cells is emerging and we have previously shown that macrophages capacity to kill M. tuberculosis is reflected in the DNA methylome. The aim of this study was to investigate epigenetic modifications in alveolar macrophages and T cells in a cohort of medical students with an increased risk of TB exposure, longitudinally. DNA methylome analysis revealed that a unique DNA methylation profile was present in healthy subjects who later developed latent TB during the study. The profile was reflected in a different overall DNA methylation distribution as well as a distinct set of differentially methylated genes (DMGs). The DMGs were over-represented in pathways related to metabolic reprogramming of macrophages and T cell migration and IFN-? production, pathways previously reported important in TB control. In conclusion, we identified a unique DNA methylation signature in individuals, with no peripheral immune response to M. tuberculosis antigen who later developed latent TB. Together the study suggests that the DNA methylation status of pulmonary immune cells can reveal who will develop latent TB infection. © 2021, The Author(s).
  • Publicación
    A distance between bounded linear operators
    (Elsevier BV, 2020)
    Jung, W.
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    Metzger, R.
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    Morales, C. A.
    ;
    Villavicencio, H.
    We extend the classical Banach-Mazur distance [3] from Banach spaces to linear operators between these spaces. We prove in the finite dimensional case that the corresponding topology is metrizable, complete, separable and locally compact. Furthermore, we prove that the Banach-Mazur compactum embeds isometrically into the resulting topological space. (C) 2020 Elsevier B.V. All rights reserved.
  • Publicación
    A FAIR evaluation of public datasets for stress detection systems
    (IEEE Computer Society, 2020)
    Cuno A.
    ;
    Condori-Fernandez N.
    ;
    Mendoza A.
    ;
    Lovon W.R.
    Nowadays, datasets are an essential asset used to train, validate, and test stress detection systems based on machine learning. In this paper, we used two sets of FAIR metrics for evaluating five public datasets for stress detection. Results indicate that all these datasets comply to some extent with the (F)indable, (A)ccessible, and (R)eusable principles, but none with the (I)nteroperable principle these findings contribute to raising awareness on (i) the need for the FAIRness development and improvement of stress datasets, and (ii) the importance of promoting open science in the affective computing community. © 2020 IEEE.
  • Publicación
    A generative adversarial network approach for super-resolution of sentinel-2 satellite images
    (International Society for Photogrammetry and Remote Sensing, 2020)
    Pineda F.
    ;
    Ayma V.
    ;
    Beltran C.
    Las imágenes de satélite de alta resolución siempre han tenido una gran demanda debido al mayor detalle y precisión que ofrecen, así como al amplio alcance de los campos en los que se podrían aplicar; sin embargo, los satélites en operación que ofrecen imágenes de muy alta resolución (VHR) han experimentado un aumento importante, pero se mantienen en una proporción menor frente a los satélites de menor resolución (HR) existentes. Los modelos recientes de redes neuronales convolucionales (CNN) son muy adecuados para aplicaciones con procesamiento de imágenes, como la mejora de la resolución de imágenes; pero para obtener un resultado aceptable, es importante, no solo definir el tipo de arquitectura de la CNN, sino también el conjunto de imágenes de referencia para entrenar el modelo. Nuestro trabajo propone una alternativa para mejorar la resolución espacial de las imágenes HR obtenidas por el satélite Sentinel-2 utilizando las imágenes VHR de PeruSat1, un satélite peruano, que sirven como referencia para la implementación del enfoque de superresolución basado en una Red Generativa Adversarial ( modelo GAN), como alternativa para la obtención de imágenes VHR. El conjunto de datos de imágenes VHR PeruSat-1 se utiliza para el proceso de entrenamiento de la red. Los resultados obtenidos se analizaron teniendo en cuenta las relaciones pico de señal a ruido (PSNR) y la similitud estructural (SSIM). Finalmente, se presentan algunos resultados visuales, sobre un conjunto de datos de prueba dado, para que también se pueda analizar el rendimiento del modelo. © 2020 Archivos Internacionales de Fotogrametría, Teledetección y Ciencias de la Información Espacial - Archivos ISPRS.
  • Publicación
    A genomotaxonomy view of the bradyrhizobium genus
    (Frontiers Media S.A., 2019)
    Ormeño-Orrillo E.
    ;
    Martínez-Romero E.
    Whole genome analysis of the Bradyrhizobium genus using average nucleotide identity (ANI) and phylogenomics showed the genus to be essentially monophyletic with seven robust groups within this taxon that includes nitrogen-fixing nodule forming bacteria as well as free living strains. Despite the wide genetic diversity of these bacteria no indication was found to suggest that the Bradyrhizobium genus have to split in different taxa. Bradyrhizobia have larger genomes than other genera of the Bradyrhizobiaceae family, probably reflecting their metabolic diversity and different lifestyles. Few plasmids in the sequenced strains were revealed from rep gene analysis and a relatively low proportion of the genome is devoted to mobile genetic elements. Sequence diversity of recA and glnII gene metadata was used to theoretically estimate the number of existing species and to predict how many would exist. There may be many more species than those presently described with predictions of around 800 species in nature. Different arguments are presented suggesting that nodulation might have arose in the ancestral genus Bradyrhizobium. Copyright © 2019 Ormeño-Orrillo and Martínez-Romero.
  • Publicación
    A geostatistical method in GIS to estimate the amount of seabird guano accumulated on islands and headlands of Perú
    (Asociacion Argentina de Ecologia, 2020)
    Sifuentes-García Á.
    ;
    Zavalaga C.B.
    ;
    Lozano-Sanllehi S.
    The ‘guano of the islands’ in Perú is the excrement of cormorants, boobies and pelicans (guano birds), accumulated in large deposits on islands and headlands. This guano is harvested and marketed by the governmental agency AGRORURAL to meet the demands of local organic agriculture. As part of its management and commercialization plans, AGRORURAL estimates the total quantity of guano built-up on the seabird colonies using a volumetric method. The objective of this research was to propose an alternative geostatistical method that uses the volumetric data collection as baseline but incorporates the slope of the terrain and makes estimations of the total amount and distribution of guano using an interpolation grid model in a Geographic Information System (GIS). The data of the slope of the terrain, depth of guano layer, guano density and proportion guano/rock of georeferenced sampling points (taken with a hand-held GPS) on the island/headland surface were used to interpolate the quantity of guano over the entire surface using a raster kriging model, so that each cell contained an estimated quantity of guano. For this study, six guano bird colonies were visited between June 2014 and February 2018. Based on the geostatistical method, the total quantity of guano estimated varied between 10921 t on Isla Mazorca and 26142 t on Isla Guañape Sur. The GIS grid maps showed that the quantity of guano deposits was not uniformly distributed over the island/headland surface. When the guano total quantity estimates based on the geostatistical method were validated with the amount of guano harvested, the estimation error was less than 18%. This error may decrease with the use of a submetric GPS, ground-penetrating radars and augers. An accurate method of guano volume quantification is crucial for budget, logistic and marketing planning of the guano islands and headlands of Perú. © 2020, Asociacion Argentina de Ecologia. All rights reserved.
  • Publicación
    A GWAS in Latin Americans highlights the convergent evolution of lighter skin pigmentation in Eurasia
    (Nature Publishing Group, 2019)
    Adhikari K.
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    Mendoza-Revilla J.
    ;
    Sohail A.
    ;
    Fuentes-Guajardo M.
    ;
    Lampert J.
    ;
    Chacón-Duque J.C.
    ;
    Hurtado M.
    ;
    Villegas V.
    ;
    Granja V.
    ;
    Acuña-Alonzo V.
    ;
    Jaramillo C.
    ;
    Arias W.
    ;
    Lozano R.B.
    ;
    Everardo P.
    ;
    Gómez-Valdés J.
    ;
    Villamil-Ramírez H.
    ;
    Silva de Cerqueira C.C.
    ;
    Hunemeier T.
    ;
    Ramallo V.
    ;
    Schuler-Faccini L.
    ;
    Salzano F.M.
    ;
    Gonzalez-José R.
    ;
    Bortolini M.-C.
    ;
    Canizales-Quinteros S.
    ;
    Gallo C.
    ;
    Poletti G.
    ;
    Bedoya G.
    ;
    Rothhammer F.
    ;
    Tobin D.J.
    ;
    Fumagalli M.
    ;
    Balding D.
    ;
    Ruiz-Linares A.
    We report a genome-wide association scan in >6,000 Latin Americans for pigmentation of skin and eyes. We found eighteen signals of association at twelve genomic regions. These include one novel locus for skin pigmentation (in 10q26) and three novel loci for eye pigmentation (in 1q32, 20q13 and 22q12). We demonstrate the presence of multiple independent signals of association in the 11q14 and 15q13 regions (comprising the GRM5/TYR and HERC2/OCA2 genes, respectively) and several epistatic interactions among independently associated alleles. Strongest association with skin pigmentation at 19p13 was observed for an Y182H missense variant (common only in East Asians and Native Americans) in MFSD12, a gene recently associated with skin pigmentation in Africans. We show that the frequency of the derived allele at Y182H is significantly correlated with lower solar radiation intensity in East Asia and infer that MFSD12 was under selection in East Asians, probably after their split from Europeans.
  • Publicación
    A hybrid high-order formulation for a Neumann problem on polytopal meshes
    (Wiley, 2019)
    Bustinza, Rommel
    ;
    Munguia-La-Cotera, Jonathan
    In this work, we study a hybrid high-order (HHO) method for an elliptic diffusion problem with Neumann boundary condition. The proposed method has several features, such as: (a) the support of arbitrary approximation order polynomial at mesh elements and faces on polytopal meshes, (b) the design of a local (element-wise) potential reconstruction operator and a local stabilization term, that weakly enforces the matching between local element- and face-based on degrees of freedom, and (c) cheap computational cost, thanks to static condensation and compact stencil. We prove the well-posedness of our HHO formulation, and obtain the optimal error estimates, according to previous study. Implementation aspects are thoroughly discussed. Finally, some numerical examples are provided, which are in agreement with our theoretical results.
  • Publicación
    A low-cost measurement device for recording perceptions of thermal comfort
    (Institute of Physics Publishing, 2020)
    Molina J.R.
    ;
    Nakama V.L.
    ;
    Lefebvre G.
    In this article, we describe the implementation of a low-cost device that registers perceptions of thermal comfort. The parameters of relative humidity (RH), temperature, thermal sensation (cold, cool, neutral, warn, hot) and clothing worn by people are collected. The design and validation of the device in an indoor environment are explained, and the calibration curves of the temperature and relative humidity sensors are obtained. The measurement results for the device from 10 people are shown. The study was carried out in the village of Imata (high Andean zone), at 4700 masl in the south of Peru. © Published under licence by IOP Publishing Ltd.
  • Publicación
    A method to include life cycle assessment results in choosing by advantage (Cba) multicriteria decision analysis. a case study for seismic retrofit in peruvian primary schools
    (MDPI AG, 2021)
    Vázquez-Rowe I.
    ;
    Córdova-Arias C.
    ;
    Brioso X.
    ;
    Santa-Cruz S.
    Building information modeling (BIM) is an emerging technology that improves visualization, understanding, and transparency in construction projects. Its use in Latin America and the Caribbean (LA&C), while still scarce, is developing in combination with multi-criteria decision-making (MCDM) methods, such as the choosing by advantages (CBA) method. Despite the holistic nature of MCDM methods, the inclusion of life cycle environmental metrics is lagging in construction projects in LA&C. However, recent studies point toward the need to optimize the synergies between BIM and life cycle assessment (LCA), in which a method like CBA could allow improving the quality of the decisions. Therefore, the main objective of this study is to integrate LCA and CBA methods to identify the effect that the inclusion of environmental impacts can have on decision-making in public procurement, as well as comparing how this final decision differs from an exclusively LCA-oriented interpretation of the results. Once the LCA was performed, a set of additional criteria for the CBA method were fixed, including transparency, technical, and social indicators. Thereafter, a stakeholder participative workshop was held in order to gather experts to elucidate on the final decision. The methodology was applied to a relevant construction sector problem modelled with BIM in the city of Lima (Peru), which consisted of three different construction techniques needed to retrofit educational institutions. Results from the LCA-oriented assessment, which was supported by Monte Carlo simulation, revealed a situation in which the masonry-based technique showed significantly lower environmental impacts than the remaining two options. However, when a wider range of technical, social, and transparency criteria are added to the environmental indicators, this low-carbon technique only prevailed in those workshop tables in which environmental experts were present and under specific computational assumptions, whereas teams with a higher proportion of government members were inclined to foster alternatives that imply less bureaucratic barriers. Finally, the results constitute an important milestone when it comes to including environmental factors in public procurement in LA&C. © 2021 by the author. Licensee MDPI, Basel, Switzerland.
  • Publicación
    A Methodological Approach to Compare Ontologies: Proposal and Application for SLAM Ontologies
    (Association for Computing Machinery, 2020)
    Cardinale Y.
    ;
    Cornejo-Lupa M.A.
    ;
    Ticona-Herrera R.
    ;
    Barrios-Aranibar D.
    Representation of the knowledge related to any domain with flexible and well-defined models, such as ontologies, provides the base to develop efficient and interoperable solutions. Hence, a proliferation of ontologies in many domains is unleashed. It is necessary to define how to compare such ontologies to decide which one is the most suitable for specific needs of users/developers. Since the emerging developing of ontologies, several studies have proposed criteria to evaluate them. Nevertheless, there is still a lack of practical and reproducible guidelines to drive a comparative evaluation of ontologies as a systematic process. In this paper, we propose a methodological process to qualitatively and quantitatively compare ontologies at Lexical, Structural, and Domain Knowledge levels, considering Correctness and Quality perspectives. Since the evaluation methods of our proposal are based in a golden-standard, it can be customized to compare ontologies in any domain. To show the suitability of our proposal, we apply our methodological approach to conduct a comparative study of ontologies in the robotic domain, in particularly for the Simultaneous Localization and Mapping (SLAM) problem. With this study case, we demonstrate that with this methodological comparative process, we are able to identify the strengths and weaknesses of ontologies, as well as the gaps still needed to fill in the target domain (SLAM for our study case). © 2020 ACM.