Search results for: André Melo Franco Lorena De Barros

Authors: Djamel Fawzi Hadj Sadok, Marrone Silvério Melo Dantas Pedro Henrique Dreyer, Gabriel Fonseca Reis de Souza, Daniel Bezerra, Ricardo Souza, Silvia Lins, Judith Kelner

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A radio base station (RBS), part of the radio access network, is a particular type of equipment that supports the connection between a wide range of cellular user devices and an operator network access infrastructure. Nowadays, most of the RBS maintenance is carried out manually, resulting in a time consuming and costly task. A suitable candidate for RBS maintenance automation is repairing faulty links between devices caused by missing or unplugged connectors. A suitable candidate for RBS maintenance automation is repairing faulty links between devices caused by missing or unplugged connectors. This paper proposes and compares two deep learning solutions to identify attached RJ45 connectors on network ports. We named connector detection, the solution based on object detection, and connector classification, the one based on object classification. With the connector detection, we get an accuracy of 0:934, mean average precision 0:903. Connector classification, get a maximum accuracy of 0:981 and an AUC of 0:989. Although connector detection was outperformed in this study, this should not be viewed as an overall result as connector detection is more flexible for scenarios where there is no precise information about the environment and the possible devices. At the same time, the connector classification requires that information to be well-defined.

Keywords: radio base station, maintenance, classification, detection, deep learning, automation

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Authors: Samara A. Testoni, Vander F. Melo, Lorna A. Dawson, Fabio A. S. Salvador

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Soil traces are useful as forensic evidence due to their potential to transfer and adhere to different types of surfaces on a range of objects or persons. The great variability expressed by soil physical, chemical, biological and mineralogical properties show soil traces as complex mixtures. Soils are continuous and variable, no two soil samples being indistinguishable, nevertheless, the complexity of soil characteristics can provide powerful evidence for comparative forensic purposes. This work aimed to establish a Standard Operating Procedure (SOP) for forensic soil analysis in Brazil. We carried out a simulated crime scene with double blind sampling to calibrate the sampling procedures. Samples were collected at a range of locations covering a range of soil types found in South of Brazil: Santa Candida and Boa Vista, neighbourhoods from Curitiba (State of Parana) and in Guarani and Guaraituba, neighbourhoods from Colombo (Curitiba Metropolitan Region). A previously validated sequential analyses of chemical, physical and mineralogical analyses was developed in around 2 g of soil. The suggested SOP and the sequential range of analyses were effective in grouping the samples from the same place and from the same parent material together, as well as successfully discriminated samples from different locations and originated from different rocks. In addition, modifications to the sample treatment and analytical protocol can be made depending on the context of the forensic work.

Keywords: clay mineralogy, forensic soils analysis, sequential analyses, kaolinite, gibbsite

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Authors: Jarek Krajewski, Andre Wittenborn, Martin Sauerland

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This abstract describes a promising approach for estimating post-traumatic stress disorder (PTSD) based on prosodic speech characteristics. It illustrates the validity of this method by briefly discussing results from an Arabic refugee sample (N= 47, 32 m, 15 f). A well-established standardized self-report scale “Reaction of Adolescents to Traumatic Stress” (RATS) was used to determine the ground truth level of PTSD. The speech material was prompted by telling about autobiographical related sadness inducing experiences (sampling rate 16 kHz, 8 bit resolution). In order to investigate PTSD-induced speech changes, a self-developed set of 136 prosodic speech features was extracted from the .wav files. This set was adapted to capture traumatization related speech phenomena. An artificial neural network (ANN) machine learning model was applied to determine the PTSD level and reached a correlation of r = .37. These results indicate that our classifiers can achieve similar results to those seen in speech-based stress research.

Keywords: speech prosody, PTSD, machine learning, feature extraction

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Authors: T. Costa, D. Narvaez, K. Melo, M. Villalva

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Installation of micro-generators based on renewable energy in power distribution system has increased in recent years, with the main renewable sources being solar and wind. Due to the intermittent nature of renewable energy sources, such micro-generators produce time-varying energy which does not correspond at certain times of the day to the peak energy consumption of end users. For this reason, the use of energy storage units next to the grid contributes to the proper leveling of the buses’ voltage level according to Brazilian energy quality standards. In this work, the effect of the addition of a photovoltaic solar generator and a store of energy in the busbar voltages of an electric system is analyzed. The consumption profile is defined as the average hourly use of appliances in a common residence, and the generation profile is defined as a function of the solar irradiation available in a locality. The power summation method is validated with analytical calculation and is used to calculate the modules and angles of the voltages in the buses of an electrical system based on the IEEE standard, at each hour of the day and with defined load and generation profiles. The results show that bus 5 presents the worst voltage level at the power consumption peaks and stabilizes at the appropriate range with the inclusion of the energy storage during the night time period. Solar generator maintains improvement of the voltage level during the period when it receives solar irradiation, having peaks of production during the 12 pm (without exceeding the appropriate maximum levels of tension).

Keywords: energy storage, power distribution system, solar generator, voltage level

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Authors: André M. Senna, Mary L. G. S. Senna, Rosa M. Machado-de-Sena

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One of the great challenges presented in educational practice is how to ensure the students not only acquire knowledge of training courses throughout their academic life, but also how to apply it in their current professional activities. Consequently, aiming to incite changes in the education system of healthcare professionals noticed the inadequacy of the training providers to solve the social problems related to health, the education related to these procedures should initiate in the earliest years of process. Following that idea, there is another question that needs an answer: If the change in the education should start sooner, in the period of basic training of healthcare professionals, what guidelines should a permanent education program incorporate to promote changes in an already established system? For this reason, the objective of this paper is to present different views of the teaching-learning process, with the purpose of better understanding the behavior adopted by healthcare professionals, through bibliographic study. The conclusion was that more than imparting knowledge to the individual, a larger approach is necessary on permanent education programs concerning the performance of professional health services in order to foment significant changes in education.

Keywords: Health Education, continuing education, training, behavior

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Authors: Andre M. Carvalho, Pedro Sebastiao

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This article is based on a dissertation that intends to analyze and make a model, intelligently, algorithms based on stochastic processes of a gamification application applied to marketing. Gamification is used in our daily lives to engage us to perform certain actions in order to achieve goals and gain rewards. This strategy is an increasingly adopted way to encourage and retain customers through game elements. The application of gamification aims to encourage children between 6 and 10 years of age to have healthy habits and the purpose of serving as a model for use in marketing. This application was developed in unity; we implemented intelligent algorithms based on stochastic processes, web services to respond to all requests of the application, a back-office website to manage the application and the database. The behavioral analysis of the use of game elements and stochastic processes in children’s motivation was done. The application of algorithms based on stochastic processes in-game elements is very important to promote cooperation and to ensure fair and friendly competition between users which consequently stimulates the user’s interest and their involvement in the application and organization.

Keywords: engage, games, gamification, randomness, stochastic processes

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Authors: S. M. Rifat, André L. Marchildon, Mark F. Tachie

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The effect of upstream surface roughness over a smooth forward facing step in an open channel was investigated using a particle image velocimetry technique. Three different upstream surface topographies consisting of hydraulically smooth wall, sandpaper 36 grit and sand grains were examined. Besides the wall roughness conditions, all other upstream flow characteristics were kept constant. It was also observed that upstream roughness decreased the approach velocity by 2% and 10% but increased the turbulence intensity by 14% and 35% at the wall-normal distance corresponding to the top plane of the step compared to smooth upstream. The results showed that roughness decreased the reattachment lengths by 14% and 30% compared to smooth upstream. Although the magnitudes of maximum positive and negative Reynolds shear stress in separated and reattached region were 0.02Ue for all the cases, the physical size of both the maximum and minimum contour levels were decreased by increasing upstream roughness.

Keywords: forward facing step, open channel, separated and reattached turbulent flows, wall roughness

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Authors: Lorena Polovina, Maddy Kennedy-Parrott, Mohammad Fakoor

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The construction industry accounts for approximately 40% of total GHG emissions worldwide. In order to limit global warming to 1.5 degrees Celsius, ambitious reductions in the carbon intensity of our buildings are crucial. Passive House presents an opportunity to reduce operational carbon by as much as 90% compared to a traditional building through improving thermal insulation, limiting thermal bridging, increasing airtightness and heat recovery. Up until recently, Passive House design was mainly concerned with meeting the energy demands without considering embodied carbon. As buildings become more energy-efficient, embodied carbon becomes more significant. The main objective of this research is to calculate the embodied carbon impact of a Passive House and compare it with the BC Energy Step Code (ESC). British Columbia is committed to increasing the energy efficiency of buildings through the ESC, which is targeting net-zero energy-ready buildings by 2032. However, there is a knowledge gap in the embodied carbon impacts of more energy-efficient buildings, in particular Part 3 construction. In this case study, life cycle assessments (LCA) are performed on Part 3, a multi-unit residential building in Victoria, BC. The actual building is not constructed to the Passive House standard; however, the building envelope and mechanical systems are designed to comply with the Passive house criteria, as well as Steps 1 and 4 of the BC Energy Step Code (ESC) for comparison. OneClick LCA is used to perform the LCA of the case studies. Several strategies are also proposed to minimize the total carbon emissions of the building. The assumption is that there will not be significant differences in embodied carbon between a Passive House and a Step 4 building due to the building envelope.

Keywords: embodied carbon, energy modeling, energy step code, life cycle assessment

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Authors: Seyed M. Khatami, H. Naderpour, R. Vahdani, R. C. Barros

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Many previous studies have been carried out to calculate the impact force and the dissipated energy between two neighboring buildings during seismic excitation, when they collide with each other. Numerical studies are an important part of impact, which several researchers have tried to simulate the impact by using different formulas. Estimation of the impact force and the dissipated energy depends significantly on some parameters of impact. Mass of bodies, stiffness of spring, coefficient of restitution, damping ratio of dashpot and impact velocity are some known and unknown parameters to simulate the impact and measure dissipated energy during collision. Collision is usually shown by force-displacement hysteresis curve. The enclosed area of the hysteresis loop explains the dissipated energy during impact. In this paper, the effect of using different types of impact models is investigated in order to calculate the impact force. To increase the accuracy of impact model and to optimize the results of simulations, a new damping equation is assumed and is validated to get the best results of impact force and dissipated energy, which can show the accuracy of suggested equation of motion in comparison with other formulas. This relation is called "n-m". Based on mathematical relation, an initial value is selected for the mentioned coefficients and kinetic energy loss is calculated. After each simulation, kinetic energy loss and energy dissipation are compared with each other. If they are equal, selected parameters are true and, if not, the constant of parameters are modified and a new analysis is performed. Finally, two unknown parameters are suggested to estimate the impact force and calculate the dissipated energy.

Keywords: impact force, dissipated energy, kinetic energy loss, damping relation

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Authors: Camilo Souza, Lidia Melo, Fernanda Terra, Francisco Caio, Marcelo Reis

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SIDIA is a research and development (R&D) institute that belongs to Samsung’s global software development process. The SIDIA’s Model Team (MT) is a part of Samsung’s Mobile Division Area, which is responsible for the development of Android releases embedded in Samsung mobile devices. Basically, in this software development process, the kickoff occurs in some strategic countries (e.g., South Korea) where some software requirements are applied and the initial software tests are performed. When the software achieves a more mature level, a new branch is derived, and the development continues in subsidiaries from other strategic countries (e.g., SIDIA-Brazil). However, even in the newly created branches, there are several interactions between developers from different nationalities in order to fix bugs reported during test activities, apply some specific requirements from partners and develop new features as well. Despite the GSD strategy contributes to improving software development, some challenges are also introduced as well. In this paper, we share the initial results about the application of the failure modes and effect analysis (FMEA) concept in the software development process followed by the SIDIA’s model team. The main goal was to identify and mitigate the process potential failures through the application of recommended actions. The initial results show that the application of the FMEA concept allows us to identify the potential failures in our GSD process as well as to propose corrective actions to mitigate them. Finally, FMEA encouraged members of different teams to take actions that contribute to improving our GSD process.

Keywords: global software development, potential failures, FMEA, recommended actions

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Authors: Sepideh Yeganegi, Andre Laplume, Parshotam Dass, Cam-Loi Huynh

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This paper empirically examines organizational and institutional antecedents of entrepreneurial entry. We employ multi-level logistic regression modelling methods on a sub-sample of the Global Entrepreneurship Monitor’s 2011 survey covering 30 countries. The results reveal that employees who have experience with activities unrelated to the core technology of their organizations are more likely to spin out entrepreneurial ventures, whereas those with experiences related to the core technology are less likely to do so. In support of the recent theory, we find that the strength of intellectual property rights and the availability of venture capital have negative and positive effects, respectively, on the likelihood that employees turn into entrepreneurs. These institutional factors also moderate the effect of relatedness to core technology such that entrepreneurial entries by employees with experiences related to core technology are curbed more severely by stronger intellectual property rights protection regimes and lack of venture capital.

Keywords: spinouts, intellectual property rights, venture capital, entrepreneurship, organizational experiences, core technology

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Authors: Samuel McLennan, Tane Moleta, Andre Brown, Marc Aurel Schnabel

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The development of Ecclesiastical buildings within New Zealand has produced some unique design characteristics that take influence from both international styles and local building methods. What this research looks at is how procedural modelling can be used to define such common characteristics and understand how they are shared and developed within different examples of a similar architectural style. This will be achieved through the creation of procedural digital reconstructions of the various timber Gothic Churches built during the 19th century in the city of Wellington, New Zealand. ‘Procedural modelling’ is a digital modelling technique that has been growing in popularity, particularly within the game and film industry, as well as other fields such as industrial design and architecture. Such a design method entails the creation of a parametric ‘ruleset’ that can be easily adjusted to produce many variations of geometry, rather than a single geometry as is typically found in traditional CAD software. Key precedents within this area of digital heritage includes work by Haegler, Müller, and Gool, Nicholas Webb and Andre Brown, and most notably Mark Burry. What these precedents all share is how the forms of the reconstructed architecture have been generated using computational rules and an understanding of the architects’ geometric reasoning. This is also true within this research as Gothic architecture makes use of only a select range of forms (such as the pointed arch) that can be accurately replicated using the same standard geometric techniques originally used by the architect. The methodology of this research involves firstly establishing a sample group of similar buildings, documenting the existing samples, researching any lost samples to find evidence such as architectural plans, photos, and written descriptions, and then culminating all the findings into a single 3D procedural asset within the software ‘Houdini’. The end result will be an adjustable digital model that contains all the architectural components of the sample group, such as the various naves, buttresses, and windows. These components can then be selected and arranged to create visualisations of the sample group. Because timber gothic churches in New Zealand share many details between designs, the created collection of architectural components can also be used to approximate similar designs not included in the sample group, such as designs found beyond the Wellington Region. This creates an initial library of architectural components that can be further expanded on to encapsulate as wide of a sample size as desired. Such a methodology greatly improves upon the efficiency and adjustability of digital modelling compared to current practices found in digital heritage reconstruction. It also gives greater accuracy to speculative design, as a lack of evidence for lost structures can be approximated using components from still existing or better-documented examples. This research will also bring attention to the cultural significance these types of buildings have within the local area, addressing the public’s general unawareness of architectural history that is identified in the Wellington based research ‘Moving Images in Digital Heritage’ by Serdar Aydin et al.

Keywords: digital forensics, digital heritage, gothic architecture, Houdini, procedural modelling

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Authors: Mandob Enyegue Damaris, Oko Ndjollo Viviane

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The prevalence of Metabolic Syndrome is increasing throughout the world. The etiology of the metabolic syndrome is dependent on different factors such as ethnic group. This study aimed to evaluate the metabolic syndrome among Mbo ethnic group people leaving in Yaounde, Cameroon. The study conducted on the hundred and thirty two people 40 men and 92 women aged between 18-60 years who were referred to the Andre Fouda Medical Fundation in Yaounde. Metabolic syndrome was diagnosed using Adult Treatment Panel-III (A.T.P-III) 2001 guidelines. The mean of age, high fasting blood glucose, triglycerides levels and total cholesterol levels were significantly (P<0.05) higher in women with metabolic syndrome. High blood pressure level (56.80%), high fasting glucose (20.45%) and high waist circumference (10.60%) were respectively the most frequent characteristics in comparison to others metabolic components. The overall prevalence of MetS was (4.55%) and higher in women (3.03%) than in men (1.52%). The prevalence of MetS is low in originates of Mbo ethnic group of Yaounde. High blood pressure is the most common abnormality.

Keywords: individual components, metabolic syndrome, Mbo ethnic group, Yaounde-Cameroon

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Authors: Ezequiel Garcia-Rodriguez, Lenin Hernandez-Ferreyra, Luis Ochoa-Franco

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The Sustainable Sewer Urban Systems (SSUS) are mechanisms integrated into the cities for manage rain water, reducing its runoff volume and velocity, enhancing the rain water quality and preventing flooding and other catastrophes associated to the rain, as well as improving the energy efficiency. The objective of SSUS is to mimic or to equal the runoff and infiltration natural conditions of the land before its urbanization, reducing runoff that may cause troubles within the houses, as well as flooding. At the same time, energy for warming homes and for pumping and treating water is reduced, contributing to the reduction of CO₂ emissions and therefore contributing to reduce the climate change. This paper contains an evaluation of the advantages that SSUS may offer within a zone of Morelia City, Mexico, applying support tools for decision making. The hydrological conditions prior to and after the urbanization of the study area were analyzed to propose the recommended SSUS. Different types of SSUS were proposed in this case study, assessing their effect on the rainwater flow behavior within the study area. SSUS usage in this case resulted, positively, in an important reduction of the magnitude and velocity of runoff, reducing therefore the risk of flooding. So that, it is recommended the implementation of SSUS in this case.

Keywords: energy efficiency, morelia, sustainablesewer, urban systems

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Authors: Khin Thanda Win, Chunying Zhang, Sanghyeob Lee

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Mildew resistance locus o (Mlo), a plant-specific gene family with seven-transmembrane (TM), plays an important role in plant resistance to powdery mildew (PM). PM caused by Podosphaera xanthii is a widespread plant disease and probably represents the major fungal threat for many Cucurbits. The recent Cucurbita maxima genome sequence data provides an opportunity to identify and characterize the MLO gene family in this species. Total twenty genes (designated CmaMLO1 through CmaMLO20) have been identified by using an in silico cloning method with the MLO gene sequences of Cucumis sativus, Cucumis melo, Citrullus lanatus and Cucurbita pepo as probes. These CmaMLOs were evenly distributed on 15 chromosomes of 20 C. maxima chromosomes without any obvious clustering. Multiple sequence alignment showed that the common structural features of MLO gene family, such as TM domains, a calmodulin-binding domain and 30 important amino acid residues for MLO function, were well conserved. Phylogenetic analysis of the CmaMLO genes and other plant species reveals seven different clades (I through VII) and only clade IV is specific to monocots (rice, barley, and wheat). Phylogenetic and structural analyses provided preliminary evidence that five genes belonged to clade V could be the susceptibility genes which may play the importance role in PM resistance. This study is the first comprehensive report on MLO genes in C. maxima to our knowledge. These findings will facilitate the functional analysis of the MLOs related to PM susceptibility and are valuable resources for the development of disease resistance in pumpkin.

Keywords: Mildew resistance locus o (Mlo), powdery mildew, phylogenetic relationship, susceptibility genes

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Authors: André Furtado, Hugo Rodrigues, António Arêde, Humberto Varum

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Besides characterized as non-structural elements, infill masonry (IM) walls have an important contribute in the structural response of reinforced concrete structures as proved by the damages observed recent earthquakes. In particular, the out-of-plane (OOP) collapse has been one of the most observed failure mechanism. The aim of this research is to contribute to the increase of understanding regarding the OOP behaviour of full-scale infill panels considering different variables such as panel support width and axial load on the top of columns. For this, it was carried out in the Laboratory of Earthquake and Structural Engineering (LESE) an experimental campaign of five full-scale IM walls subjected to OOP distributed cyclic loadings. Specimens with different variables such as previous in-plane damage, support conditions, axial load on the top of the columns were studied. The results will be presented and discussed along the manuscript in terms of force-displacement hysteretic curves, cracking pattern, initial stiffness, stiffness degradation and accumulative energy dissipation.

Keywords: infill masonry walls, experimental testing, out-of-plane, full-scale

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Authors: Omar Concepcion, Osvaldo De Melo, Arturo Escobosa

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Topological insulator (TI) materials are insulating in the bulk and conducting in the surface. The unique electronic properties associated with these surface states make them strong candidates for exploring innovative quantum phenomena and as practical applications for quantum computing, spintronic and nanodevices. Many materials, including Bi₂Te₃, have been proposed as TIs and, in some cases, it has been demonstrated experimentally by angle-resolved photoemission spectroscopy (ARPES), scanning tunneling spectroscopy (STM) and/or magnetotransport measurements. A clean surface is necessary in order to make any of this measurements. Several techniques have been used to produce films and different kinds of nanostructures. Growth and characterization in situ is usually the best option although cleaving the films can be an alternative to have a suitable surface. In the present work, we report a comparison of Bi₂Te₃ grown by physical vapor transport (PVT) and molecular beam epitaxy (MBE). The samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and ARPES. The Bi₂Te₃ samples grown by PVT, were cleaved in the ultra-high vacuum in order to obtain a surface free of contaminants. In both cases, the XRD shows a c-axis orientation and the pole diagrams proved the epitaxial relationship between film and substrate. The ARPES image shows the linear dispersion characteristic of the surface states of the TI materials. The samples grown by PVT, a relatively simple and cost-effective technique shows the same high quality and TI properties than the grown by MBE.

Keywords: Bismuth telluride, molecular beam epitaxy, physical vapor transport, topological insulator

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Authors: Sara D. Garduno-Diaz, Lorena Loriato

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Food selection is one of the main modifiable risk factors for the avoidance of several detrimental health conditions. Excessive and regular sugar intake has been identified as highly unfavorable, yet a highly occurring practice. A proposed approach to modify this eating practice is the online program developed here. The program targets a modification of mindset and lifestyle habits around food, through a four week raw-vegan guided eating program. While the focus of the program is to set up sustainable changes in sugar intake reduction, it also aims to promote a plant-based eating style. Three pilot sessions have been run with participants from seven different countries. Participants are guided through the program via a combination of daily e-mails, a 24-hour support platform, and by-weekly remote live sessions. Meal preparation techniques, as well as cooking instructions, are provided, following set menus developed by a team of professional chefs and nutritionists. Goal setting, as well as alternatives to specific food-related challenges, is addressed. While the program is intended for both women and men, the majority of participants to date have been female. Feedback has been positive, with changes in eating habits have included an elimination of added sugars, an increase in home cooking and vegetable intake, and a reduction in foods of animal origin. Difficulties in following the program have been reported as unavailability of certain ingredients depending on the country of residence of the participants, social and cultural hurdles, and time restrictions. Nevertheless, the results obtained to date indicate this to be a highly interactive program with the potential to be scaled up and applied to various populations as a public health measure on the way to better health.

Keywords: eating habits, food addiction, nutrition education, plant-based, remote practice

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Authors: Andre Peres Ramos, Franklin Cesar Flores

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Colorization is the process of add colors to a monochromatic image or video. Usually, the process involves to segment the image in regions of interest and then apply colors to each one, for videos, this process is repeated for each frame, which makes it a tedious and time-consuming job. We propose a new assisted method for video colorization; the user only has to colorize one frame, and then the colors are propagated to following frames. The user can intervene at any time to correct eventual errors in color assignment. The method consists of to extract intensity and texture descriptors from the frames and then perform a feature matching to determine the best color for each segment. To reduce computation time and give a better spatial coherence we narrow the area of search and give weights for each feature to emphasize texture descriptors. To give a more natural result, we use an optimization algorithm to make the color propagation. Experimental results in several image sequences, compared to others existing methods, demonstrates that the proposed method perform a better colorization with less time and user interference.

Keywords: colorization, feature matching, texture descriptors, video segmentation

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Authors: Charles Mota Possatti Júnior, André Schwanz de Lima, Maurício Vicente Donadon, Alfredo Rocha de Faria

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An interlaminar damage model is combined with a beam element formulation based on global-local superposition to assess delamination in composite laminates. The variations in the mechanical properties in the laminate, generated by the presence of delamination, are calculated as a function of the displacements in the interface layers. The global-local superposition of displacement fields ensures the zig-zag behaviour of stresses and displacement, and the number of degrees of freedom (DOFs) is independent of the number of layers. The displacements and stresses are calculated as a function of DOFs commonly used in traditional beam elements. Finally, the finite element(FE) formulation is extended to handle cases of different thicknesses, and then the FE model predictions are compared with results obtained from analytical solutions and commercial finite element codes.

Keywords: delamination, global-local superposition theory, single beam element, zig-zag, interlaminar damage model

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Authors: Emanuele Bonamente, Andrea Aquino, Franco Cotana

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The exploitation of the low-temperature geothermal resource via ground-source heat pumps is often limited by the high investment cost mainly due to borehole drilling. From the monitoring of a prototypal system currently used by a commercial building, it was found that a simple upgrade of the conventional layout, obtained including a thermal storage between the ground-source heat exchangers and the heat pump, can optimize the ground energy exploitation requiring for shorter/fewer boreholes. For typical applications, a reduction of up to 66% with respect to the conventional layout can be easily achieved. Results from the monitoring campaign of the prototype are presented in this paper, and upgrades of the thermal storage using phase change materials (PCMs) are proposed using computational fluid dynamics simulations. The PCM thermal storage guarantees an improvement of the system coefficient of performance both for summer cooling and winter heating (up to 25%). A drastic reduction of the storage volume (approx. 1/10 of the original size) is also achieved, making it possible to easily place it within the technical room, avoiding extra costs for underground displacement. A preliminary optimization of the PCM geometry is finally proposed.

Keywords: computational fluid dynamics (CFD), geothermal energy, ground-source heat pumps, phase change materials (PCM)

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Authors: Clarisse Lawson-Guidigbe, Nicolas Louveton, Kahina Amokrane-Ferka, Jean-Marc Andre

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Trust in automated driving systems is receiving growing attention in the research community. Anthropomorphism has been identified by past research as a trust-building factor. In this paper, we consider three anthropomorphic interfaces integrating three versions of a virtual assistant. We attempt to measure the impact of each of these interfaces on trust in the automated driving system. An experiment following a between-subject design was conducted in a driving simulator (N = 36) to evaluate participants’ performance and experience in two handover situations (a simple one and a critical one). Perception of anthropomorphism and trust was measured using scales, while participants’ experience was measured during elicitation interviews. We found no significant difference between the three interfaces regarding the perception of anthropomorphism, trust levels, or experience. However, regarding participants’ performance, we found a significant difference between the three interfaces in the simple handover situations but not the critical one. Learnings from anthropomorphism and trust measurement scales are discussed and suggestions for further research are proposed.

Keywords: highly automated driving, trust, anthropomorphic design, mindful anthropomorphism, mindless anthropomorphism

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Authors: Redrisse Djoumessi Fobasso, Baidyanath Sahu, Andre M. Strydom

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The R₂TX₃ (R = rare-earth, T = transition, and X = s and p block element) series of compounds are interesting owing to their fascinating structural and magnetic properties. In this present work, we have studied the magnetic and physical properties of the new Gd₂AgSi₃ polycrystalline compound. The sample was synthesized by the arc-melting method and confirmed to crystallize in the tetragonal α-ThSi₂-type crystal structure with space group I4/amd. Dc– and ac–magnetic susceptibility, specific heat, electrical resistivity, and magnetoresistance measurements were performed on the new compound. The structure provides a unique position in the unit cell for the magnetic trivalent Gd ion. Two magnetic phase transitions were consistently found in dc- and ac-magnetic susceptibility, heat capacity, and electrical resistivity at temperatures Tₙ₁ = 11 K and Tₙ₂ = 20 K, which is an indication of the complex magnetic behavior in this compound. The compound is found to be metamagnetic over a range of temperatures below and above Tₙ₁. From field-dependent electrical resistivity, it is confirmed that the compound shows unusual negative magnetoresistance in the antiferromagnetically ordered region. These results contribute to a better understanding of this class of materials.

Keywords: complex magnetic behavior, metamagnetic, negative magnetoresistance, two magnetic phase transitions

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Authors: Rui de Abrantes, André Luiz Silva Forcetto

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Air pollution is a big problem in many cities around the world. Brazilian big cities also have this problem, where millions of people are exposed daily to pollutants levels above the recommended by WHO. Brazil has taken several actions to reduce air pollution, among others, controlling the atmospheric emissions from vehicles, non-road mobile machinery, and motorcycles, but on the other side, there are no emissions controls for locomotives, which are exposing the population to tons of pollutants annually. The rail network is not homogeneously distributed in the national territory; it is denser near the big cities, and this way, the population is more exposed to pollutants; apart from that, the government intends to increase the rail network as one of the strategies for greenhouse gas mitigation, complying with the international agreements against the climate changes. This paper initially presents the estimated emissions from locomotive fleets with no emission control and with emission control equivalent to US Tier 3 from 2028 and for the next 20 years. However, we realized that a program equivalent to phase Tier 3 would not be effective, so we proposed a program in two steps that will avoid the release of more than 2.4 million tons of CO and 531,000 tons of hydrocarbons, 3.7 million tons of nitrogen oxides, and 102,000 tons of particulate matter in 20 years.

Keywords: locomotives, emission control, air pollution, pollutants emission

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Authors: Bruno S. Soria, Mauricio R. Policena, Andre J. Souza

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The state of the cutting tool is an important factor to consider during machining to achieve a good surface quality. The vibration generated during material cutting can also directly affect the surface quality and life of the cutting tool. In this work, the effect of mechanical broken failure (MBF) on carbide insert tools during face milling of AISI 304 stainless steel was evaluated using three levels of feed rate and two spindle speeds for each tool condition: three carbide inserts have perfect geometry, and three other carbide inserts have MBF. The axial and radial depths remained constant. The cutting forces were determined through a sensory system that consists of a piezoelectric dynamometer and data acquisition system. Discrete Wavelet Transform was used to separate the static part of the signals of force and vibration. The roughness of the machined surface was analyzed for each machining condition. The MBF of the tool increased the intensity and force of vibration and worsened the roughness factors.

Keywords: face milling, stainless steel, tool condition monitoring, wavelet discrete transform

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Authors: André Rafael Ferreira, Laurentina Vareiro, Raquel Mendes

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This study’s main objective is to explore residents’ perceptions of film-induced tourism and the impacts of filmmaking on the development of a destination. Specifically, the research examines resident´s perceptions of the social, economic, and environmental impacts on a Portuguese municipality (Arcos de Valdevez) given its feature in a popular Portuguese television series. Data is collected by means of an Internet survey, in which resident´s perceptions of the impacts of filmmaking are solicited. Residents generally agree that the recording and exhibition of the television series is important to the municipality, and contributes to the increased number of tourists. Given that residents consider that the positive impacts are more significant than the negative impacts, they supported the recording of another television series in the same municipality. Considering that destination managers and tourism development authorities aim to plan for optimal tourism development, and at the same time wish to minimize the negative impacts of this development on the local communities, monitoring residents’ opinions of perceived impacts is a good way of incorporating their reaction into tourism planning and development. The results of this research may provide useful information in this sense.

Keywords: film-induced tourism, residents’ perceptions, tourism development, tourism impacts

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Authors: Guilherme F. Guimaraes, Alfredo R. De Faria, Ronnie R. Rego, Andre L. R. D'Oliveira

Abstract:

The development of methods for predicting manufacturing phenomena steadily grows due to their high potential to contribute to the component’s performance and durability. One of the most relevant phenomena in manufacturing is the residual stress state development through the manufacturing chain. In most cases, the residual stresses have their origin due to heterogenous plastifications produced by the processes. Although a few manufacturing processes have been successfully approached by numerical modeling, there is still a lack of understanding on how these processes' interactions will affect the final stress state. The objective of this work is to analyze the influence of previous stresses on the residual stress state induced by plastic deformation of a quasi-static indentation. The model consists of a simplified approach of shot peening, modeling four cases with variations in indenter size and force. This model was validated through topography, measured by optical 3D focus-variation, and residual stress, measured with the X-ray diffraction technique. The validated model was then exposed to several initial stress states, and the effect on the final residual stress was analyzed.

Keywords: plasticity, residual stress, finite element method, manufacturing

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Authors: Andre Slonopas, Zona Kostic, Warren Thompson

Abstract:

Obfuscation is one of the most useful tools to prevent network compromise. Previous research focused on the obfuscation of the network communications between external-facing edge devices. This work proposes the use of two edge devices, external and internal facing, which communicate via private IPv4 addresses in a software-defined pseudo-random IP hopping. This methodology does not require additional IP addresses and/or resources to implement. Statistical analyses demonstrate that the hopping surface must be at least 1e3 IP addresses in size with a broad standard deviation to minimize the possibility of coincidence of monitored and communication IPs. The probability of breaking the hopping algorithm requires a collection of at least 1e6 samples, which for large hopping surfaces will take years to collect. The probability of dropped packets is controlled via memory buffers and the frequency of hops and can be reduced to levels acceptable for video streaming. This methodology provides an impenetrable layer of security ideal for information and supervisory control and data acquisition systems.

Keywords: moving target defense, cybersecurity, network security, hopping randomization, software defined network, network security theory

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Authors: Vanessa Caroline De Barros Bonato, Bruna Lima Gomes, Luciano Freschi, Eduardo Purgatto

Abstract:

The plant hormone ethylene is closely related to the metabolic changes that occur during fruit ripening, including volatile biosynthesis. Although knowledge about the biochemistry pathways that produce flavor compounds and the importance of ethylene to these processes are extensively covered, little is known about the regulation mechanisms. In addition, growing body of evidences indicates that auxin is also involved in controlling ripening. However, there is scarce information about the involvement of auxin in fruit volatile production. This study aimed to assess auxin-ethylene interactions and its influence on tomato fruit volatile profile. Fruits from tomato cultivar Micro-Tom were treated with IAA and ethylene, separately and in combination. The hormonal treatment was performed by injection (IAA) or gas exposure (ethylene) and the volatiles were extracted by Solid Phase Microextraction (SPME) and analyzed by GC-MS. Ethylene levels and color were measured by gas chromatography and colorimetry, respectively. The results indicate that the treatment with IAA (even in the presence of high concentrations of exogenous ethylene), impacted the profile of volatile compounds derived from fatty acids, amino acids, carbohydrates and isoprenoids. Ethylene is a well-known regulator of the transition from green to red color and also is implicated in the biosynthesis of characteristic volatile compounds of tomato fruit. The effects observed suggest the existence of a crosstalk between IAA and ethylene in the aroma volatile formation in the fruit. A possible interference of IAA in the ethylene sensitivity in the fruit flesh is discussed. The data suggest that auxin plays an important role in the volatile synthesis in the tomato fruit and introduce a new level of complexity in the regulation of the fruit aroma formation during ripening.

Keywords: aroma compounds, fruit ripening, fruit quality, phytohormones

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Authors: Hernan D. Mejia, Gilberto B. Gaitan, Mauricio A. Franco

Abstract:

420 steel is normally used in the manufacture of dental and surgical instrumentation, as well as parts in the chemical, pharmaceutical, and food industries, among others, where they must withstand heavy loads and often be in contact with corrosive environments, which leads to wear and deterioration of these steels in relatively short times. In the case of medical applications, the instruments made of this steel also suffer wear and corrosion during the repetitive sterilization processes due to the relatively low achievable hardness of just 50 HRC and its hardly acceptable resistance to corrosion. In order to improve the wear resistance of 420 steel, TiAlN coatings were deposited, increasing the aluminum content in the alloy by varying the power applied to the aluminum target of 900, 1100, and 1300 W. Evaluations using XRD, Micro Raman, XPS, AFM, SEM, and TEM showed a columnar growth crystal structure with an average thickness of 2 microns and consisting of the TiN and TiAlN phases, whose roughness and grain size decrease with a higher Al content. The AlN phase also appears in the sample deposited at 1300W. The hardness, determined by nanoindentation, initially increases with the aluminum content from 9.7 GPa to 17.1 GPa, but then decreases to 15.4 GPa for the sample with the highest aluminum content due to the appearance of hexagonal AlN and a decrease of harder TiN and TiAlN phases. It was observed that the wear coefficient had a contrary behavior, which took values of 2.7; 1.7 and 6.6x10⁻⁶ mm³/N.m, respectively. All the coated samples significantly improved the wear resistance of the uncoated 420 steel.

Keywords: hard coatings, magnetron sputtering, TiAlN coatings, surgical instruments, wear resistance

Procedia PDF Downloads 96