Artículos Ingeniería

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Necesidades arquitectónicas en viviendas de personas en situación de discapacidad
(2023) Valderrama-Ulloa, Claudia; Bucarey, Viviana; Marchetti Juan Pablo
Housing represents encounter, memories and security, but for people with disabilities some of its characteristics can become barriers to its full use. If disability is considered to be a poor relationship between environment and capacity. Housing may be inaccessible for this group of people. Based on the components of the International Classification of Functioning, Disability and Health, of the World Health Organization, and the application of 16 semi-structured interviews, this research analyzed the architectural barriers and identified the needs faced by people with Alzheimer, Parkison, blindness, children on the autism spectrum, the elderly, wheelchair users and people with deafness in relation to carrying out general tasks and demands, communication, mobility, self-care and domestic life inside the homes. Among the spaces with the greatest barriers are the bathroom and the kitchen for most of the cases analyzed. On the other hand, various strategies were observed that the interviewees use to cope with these barriers and increase their well-being or reduce the risks in the activities of daily living inside the dwellings.
Microbial community and enzyme activity of forest plantation, natural forests, and agricultural land in chilean coastal cordillera soils
(2023) Rivas, Yessica; Aponte, Humberto; Rivera-Salazar, Diego; Matus, Francisco; Martínez, Oscar; Encina, Carolina; Retamal-Salgado, Jorge
Despite the global expansion of forest plantations in Chile, their effect on biology properties of soil has still been only scarcely studied. Land use change in the Chilean Coastal Cordillera (36° to 40° S) is mainly attributed to the conversion of native forest to agriculture and forest plantations (Eucalyptus globulus and Pinus radiata de Don). The aim of this paper was to evaluate the changes in microbial composition (PCR-DGGE) and enzyme activity after the substitution of a native forest (e.g., Nothofagus spp.) by fast-growing exotic species and cropping. The most important factors that influence the abundance and diversity of bacteria and the fungi community were the soil organic matter (SOM) content, phosphorous (P-Olsen), calcium (Ca), boron (B), and water-holding capacity. These variables can better predict the microbial community composition and its enzymatic activity in the surface Ah horizon. Land use change also affected chemical soil properties of biogeochemical cycles. However, to deeply understand the connection between chemical and physical soil factors and microbial community composition, more research is needed. On the other hand, the expansion of forest plantations in Chile should be subject to legislation aimed to protect the biological legacy as a strategy for forest productivity as well as the soil microbial biodiversity.
Implementation of a course on disruptive technologies for nursing students in Chile
(2023) Contreras Romo, Jorge Sebastián; Cepeda Salas, Andrés Octavio
Several institutions and countries have recognized the need to integrate disruptive technologies in the training of health professionals. An elective course on disruptive technologies in health for nursing was developed, structured in 5 units: a) innovation in health and nursing, b) creation of apps and virtual environments, c) digital manufacturing for nursing, d) sensors and internet of things, and e) data science in health. For its implementation, the didactic model proposed by Jorba and Sanmartí was considered; and for the evaluation of the units and the impact of the course, Urquidi's extended model of technological adoption was used. Forty-four students participated (39 women and 5 men), with an average age of 23 years. According to the technology acceptance model, statistically significant differences were found between the pre- and post-intervention groups in all dimensions of the model (Wilcoxon test, p < 0.05). In addition, a positive correlation was found between ease of use, subjective norm and intention to use the technologies taught. The implementation of the disruptive technologies course proved to be effective in the development of technological skills among nursing students in Chile.
Generation of soil maps permeability. Case study in two cantons of Loja province, Ecuador
(2023) Espinosa Marín, Jorge Andrés; Rivera, Diego; Haro Prado, Renato
The generation of permeability maps is based on the analysis and interpretation of geology, environmental morphology, land use, and slope, which enables the selection of sampling areas with similar characteristics. The method represents the integration of the physical characteristics of the study area and then determines the infiltration capacity differences in the most representative geopedologic units. In determining the basic data, minidisc infiltrometers were used to perform seventy-two infiltration tests in different types of soils with varying organic matter content, texture, soil structure, and vegetation cover, which showed the spatial variability that exists in two cantons of Loja province, Ecuador. In addition, it was observed that the infiltration rate depended mainly on the content of the organic matter in the soil and is consistent with information collected on permeability worldwide. In this study, generated pedotransfer function (FTP) coefficient of determination R. 0.78, the determination of the coefficient indicates a satisfactory estimate of the permeability with the variables that were analyzed; in addition, the methodology for assessing the permeability was suitable for the conditions of this investigation. For this reason, the method described here should be tested in other areas of the country with a greater number of field trials and with more variable contents of organic matter and soil textural classes.
From co-location patterns to an informal social network of gig economy workers
(2023) Pilatti, Gustavo; Candia, Cristian; Montini, Alessandra; Pinheiro, Flávio L.
The labor market has transformed with the advent of the gig economy, characterized by short-term and flexible work arrangements facilitated by online platforms. As this trend becomes increasingly prevalent, it presents unique opportunities and challenges. In this manuscript, we comprehensively characterize the social networks of gig economy workers in each of the 15 cities studied. Our analysis reveals a scaling relationship between networks and the city population. In particular, we note the high level of modularity of the networks, and we argue that it results from the natural specialization of couriers along different areas of the cities. Furthermore, we show that degree and betweenness centrality is positively correlated with income but not with tenure. Our findings shed new light on the social organization of the gig economy workers and provide valuable insights for the management and design of gig economy platforms.
Evaluación de la accesibilidad para sistemas de transporte subterráneo: análisis del metro de Santiago - Chile
(2023) Navas, Liborio; Valderrama-Ulloa, Claudia; Ferrada, Ximena; Contreras, Jorge; Gimenez, Zulay
Considerando que una parte importante de la población mundial vive con algún tipo de discapacidad y que la esperanza de vida aumenta, el hecho de tener un transporte accesible permitiría que las personas mejoraran su calidad de vida, accediendo a más oportunidades socioeconómicas. A partir de un diseño descriptivo mixto (cualitativo etnográfico y cuantitativo), este artículo presenta una herramienta de evaluación del nivel de accesibilidad en el uso del tren subterráneo para personas con discapacidad visual, física, cognitiva y auditiva. Se analizaron los datos de 30 estaciones del Metro de Santiago de Chile, estudiando el desplazamiento desde el exterior a la estación, la permanencia en zona de pagos y el desplazamiento hacia andenes y combinaciones. De los indicadores evaluados, los que tienen relación con el desplazamiento hacia el andén son los que presentan menores niveles de accesibilidad, ya que no responden a todas las necesidades para los distintos tipos de discapacidad analizados.
Estimation of trip purposes in public transport during the COVID-19 pandemic: The case of Santiago, Chile
(2023) Pezoa, Raúl; Basso, Franco; Quilodrán, Paulina; Varas, Mauricio
The COVID-19 pandemic strongly affected the mobility of people. Several studies have quantified these changes, for example, measuring the effectiveness of quarantine measures and calculating the decrease in the use of public transport. Regarding the latter, however, a low level of understanding persists as to how the pandemic affected the distribution of trip purposes, hindering the design of policies aimed at increasing the demand for public transport in a post-pandemic era. To address this gap, in this article, we study how the purposes of trips made by public transport evolved during the COVID-19 pandemic in the city of Santiago, Chile. For this, we develop an XGBoost model using the latest available origin-destination survey as input. The calibrated model is applied to the information from smart payment cards during one week in 2018, 2020, and 2021. The results show that during the week of maximum restriction, that is, during 2020, the distribution of trips by purpose varied considerably, with the proportion of trips to work increasing, recreational trips decreasing, and trips for health purposes remaining unchanged. In sociodemographic terms, in the higher-income communes, the decrease in the proportion of trips for work purposes was much greater than that in the communes with lower income. Finally, with the gradual return to in-person activities in 2021, the distribution of trip purposes returned to values similar to those before the pandemic, although with a lower total amount, which suggests that unless relevant measures are taken, the low use of public transportation could be permanent.
Discovering the Spread Patterns of SARS-CoV-2 in Metropolitan Areas
(2023) Herrera Marín, Mauricio René; Vergara Perucich, Francisco; Aguirre-Núñez, Carlos; Godoy-Faúndez, Alex
The spread of COVID-19 has been extensively studied, but the intricate dynamics of its transmission in interdependent and segregated urban areas, constrained by mobility restrictions, have not been completely understood yet. The pandemic's dynamic-adaptive nature implies that virus spread is influenced by diverse factors operating disparately in urban areas with distinct roles. This study investigates the dynamic spread patterns of COVID-19 in the Santiago Metropolitan Area (SMA), Chile, leveraging explanatory variables related to urban mobility, socio-spatial characteristics, segregation, and sanitary measures. Using publicly available mobility data, we used two indices—the Internal Mobility Index (capturing individual trips within a city’s commune), and the External Mobility Index (indicating trips crossing commune borders). These indices were derived from geolocation data recorded by the cellular telephone antenna network of the Telefónica company by tracking successive antenna transitions during trips. The analysis encompasses a three-stage pandemic pattern, corresponding to periods before, during, and after an initial lockdown in the pandemic's first year. Elastic-Net-Penalty regression models, skillful in both feature selection and managing highly correlated predictors while maintaining the interpretability of the models, are used. These models employ a combination of L1 (ridge) and L2 (lasso) regularized log-likelihood optimization. The ridge penalty functions by contracting the coefficients of correlated predictors, pulling them closer to each other. In contrast, the lasso method tends to choose one predictor and exclude the others. The analysis with these models unveils influences of various explanatory variable subsets throughout the pandemic. Importantly, the study provides evidence justifying the suboptimal outcomes of the dynamic quarantine imposed by authorities. Mobility restrictions were implemented without considering the intricate contextual factors, thus impacting vulnerable areas of the city adversely.
Crowding on public transport using smart card data during the COVID-19 pandemic : New methodology and case study in Chile
(2023) Basso, Franco; Hernández, Hugo; Frez, Jonathan; Leiva, Víctor; Pezoa, Raúl; Varas, Mauricio
Most crowding measures in public transportation are usually aggregated at a service level. This type of aggregation does not help to analyze microscopic behavior such as exposure risk to viruses. To bridge such a gap, our paper proposes four novel crowding measures that might be well suited to proxy virus exposure risk at public transport. In addition, we conduct a case study in Santiago, Chile, using smart card data of the buses system to compute the proposed measures for three different and relevant periods of the COVID-19 pandemic: before, during, and after Santiago’s lockdown. We find that the governmental policies diminished public transport crowding considerably for the lockdown phase. The average exposure time when social distancing is not possible passes from 6.39 min before lockdown to 0.03 min during the lockdown, while the average number of encountered persons passes from 43.33 to 5.89. We shed light on how the pandemic impacts differ across various population groups in society. Our findings suggest that poorer municipalities returned faster to crowding levels similar to those before the pandemic.
Comparing Methods for the Regionalization of Intensity−Duration−Frequency (IDF) Curve Parameters in Sparsely-Gauged and Ungauged Areas of Central Chile
(2023) Sangüesa, Claudia; Pizarro, Roberto; Ingram, Ben; Ibáñez, Alfredo; Rivera, Diego; García-Chevesich, Pablo; Pino, Juan; Pérez, Felipe; Balocchi, Francisco; Peña, Francisco
Estimating intensity−duration−frequency (IDF) curves requires local historical information of precipitation intensity. When such information is unavailable, as in areas without rain gauges, it is necessary to consider other methods to estimate curve parameters. In this study, three methods were explored to estimate IDF curves in ungauged areas: Kriging (KG), Inverse Distance Weighting (IDW), and Storm Index (SI). To test the viability of these methods, historical data collected from 31 rain gauges distributed in central Chile, 35° S to 38° S, are used. As a result of the reduced number of rain gauges to evaluate the performance of each method, we used LOOCV (Leaving One Out Cross Validation). The results indicate that KG was limited due to the sparse distribution of rain gauges in central Chile. SI (a linear scaling method) showed the smallest prediction error in all of the ungauged locations, and outperformed both KG and IDW. However, the SI method does not provide estimates of uncertainty, as is possible with KG. The simplicity of SI renders it a viable method for extrapolating IDF curves to locations without data in the central zone of Chile
A New Highly Portable Simulator (SECMA) Based on Virtual Reality for Teaching Essential Skills in Minimally Invasive Surgeries
(2023) Gúzman Montoto, José Ignacio; Herrera Marín, Mauricio René; Rodríguez Beltrán, Camilo Ignacio
This study presents a new minimal access surgery training system, SECMA, and its constructive validation to determine its usefulness for training basic laparoscopic skills. SECMA is an affordable, highly portable, mobile virtual reality training tool for laparoscopic techniques that integrates the Oculus Quest with a mechanical interface for surgeon simulation of forceps using the hand controllers of these devices. It allows the execution of structured activities (supported by virtual scenarios simulating operating rooms developed in Unity), performance evaluation, and real-time data capture. Two experiments were carried out: 1) coordination; and 2) capture and transport, with a total of 21 individuals divided into two groups: a novice group (inexperienced) of 10 participants and an expert group (>100 endoscopic procedures) of 11 participants. Total task time score, right-hand speed, path length, and other metrics from several consecutive runs on the simulator were compared between experts and novices. Data automatically recorded by SECMA during the experiments were analyzed using hypothesis tests, linear regressions, analysis of variance, principal component analysis, and machine learning-supervised classifiers. In the experiments, the experts scored significantly better than the novices in all the parameters used. The tasks evaluated discriminated between the skills of experienced and novice surgeons, giving the first indication of construct validity for SECMA.
A dataset to assess mobility changes in Chile following local quarantines
(2023) Pappalardo, Luca; Cornacchia, Giuliano; Navarro, Victor; Bravo, Loreto; Ferres, Leo
Fighting the COVID-19 pandemic, most countries have implemented non-pharmaceutical interventions like wearing masks, physical distancing, lockdown, and travel restrictions. Because of their economic and logistical effects, tracking mobility changes during quarantines is crucial in assessing their efficacy and predicting the virus spread. Unlike many other heavily affected countries, Chile implemented quarantines at a more localized level, shutting down small administrative zones, rather than the whole country or large regions. Given the non-obvious effects of these localized quarantines, tracking mobility becomes even more critical in Chile. To assess the impact on human mobility of the localized quarantines, we analyze a mobile phone dataset made available by Telefónica Chile, which comprises 31 billion eXtended Detail Records and 5.4 million users covering the period February 26th to September 20th, 2020. From these records, we derive three epidemiologically relevant metrics describing the mobility within and between comunas. The datasets made available may be useful to understand the effect of localized quarantines in containing the COVID-19 pandemic.
A class of solutions for the graphene hamiltonian operator
(2022) Conca, C.; San Martín, J.; Solano, Viviana
The graphene is a substance with carbon atoms arranged in a honeycomb lattice. The dynamics of the electrons in the structure is governed by the Hamilton equations of the system in the form of its associated spectral problem: HΨ = λΨ, with the additional condition that the eigenfunction Ψ must satisfy the so-called Kirchhoff’s conditions. In this paper, we study a class of solutions (λ, Ψ) that, in addition to meeting these conditions, are periodic in one of the two main directions of the lattice, and satisfy a pseudo-periodicity type like condition in the other direction. Our main results lead to an adequate characterization of the dispersion relationships of the honeycomb lattice, providing a precise description of the regions of stability and instability of the eigenfunctions in terms of λ. As a consequence, a tool is thus obtained for a better understanding of the propagation properties and the behavior of the wave function of electrons in a hexagonal lattice, a key issue in graphene-based technologies.
Electromobility in forest transport. Is it feasible? Perceptions regarding implementation in the chilean industry
(2022) Valdés-González, Héctor; Larenas-Barra, Sebastián; Méndez-Dedes, Luis; Reyes-Bozo, Lorenzo; Sandoval-Yáñez, Claudia
Este trabajo examina las distintas impresiones y perspectivas relacionadas con la implementación de electromovilidad en el transporte de rollizos con ca-miones de capacidad de carga de hasta 45 tonela-das en el sector forestal de la octava y decimosexta región de Chile. El objetivo de este trabajo es esta-blecer los aspectos críticos que los actores claves de la industria forestal identifican y perciben para una correcta implementación de camiones eléctricos de alto tonelaje. Para esto se propone un estudio me-todológico de tipo cualitativo con un diseño no ex-perimental basado en entrevistas semiestructuradas dirigidas a actores del sector forestal de la zona es-tudio. Se utiliza una muestra por conveniencia apli-cada a 4 empresarios del rubro, 3 ejecutivos de empresas forestales principales y 2 representantes de distribuidores de camiones. Los datos muestran que actualmente hay poco conocimiento, derivado de la inexistencia de proyectos y plataformas de di-fusión específicos que consideren la tecnología en el rubro, pero, por el contrario, demuestran que existe una buena disposición por parte de los actores para implementar planes piloto con miras a la sustentabi-lidad económica que se le proyecta a la electromo-vilidad. Se evidencia una concentración de aspectos críticos que es necesario abordar para implementar la electromovilidad en el transporte forestal y que, atendi-dos por un trabajo público-privado, permitirían al rubro y al país obtener los beneficios económicos y ambien-tales de esta tecnología.
Metodologías ágiles: un análisis de los desafíos organizacionales para su implementación
(2022) Valdés-González, Héctor; Flores-Cerna, Fernando; Sanhueza-Salazar, Víctor-Manuel; Reyes-Bozo, Lorenzo
Este trabajo analiza las principales brechas que influyen en las PyMEs TI (pequeñas y medianas empresas de tecnología de la información) con metodología tradicional, al iniciar la implementación de metodologías ágiles para la gestión de proyectos. El objetivo de esta investigación es determinar las principales brechas existentes antes de implementar metodologías ágiles en una PyME TI con metodología tradicional para la gestión de proyectos. Para lograrlo se propone una aproximación cualitativa a las opiniones de tres gerentes, dos ingenieros de proyecto y seis analistas programadores de la empresa, basada en entrevistas semiestructuradas, considerando una muestra por conveniencia, para entender las dificultades existentes en la empresa de estudio, contrastando dicha realidad mediante encuestas dirigidas a 29 profesionales de áreas TI de otras organizaciones. Los resultados del análisis revelan que las principales brechas para la implementación de metodologías ágiles en la PyME son la cultura organizacional en desacuerdo con la agilidad, la falta de compromiso de la gerencia y la resistencia al cambio. Se concluye que la propuesta resulta ser efectiva para conocer las principales brechas a resolver antes de comenzar la implementación de una metodología ágil en una PyME TI, permitiendo alinear a la organización con la agilidad.
Análisis técnico sobre protecciones provisionales de borde para prevenir riesgos de caídas en trabajos en altura en la construcción: el caso de Chile
(2023) Valderrama-Ulloa, Claudia; Ferrada, Ximena; Serpell, Alfredo; Cabello, María José
El objetivo principal de este trabajo es presentar un análisis técnico de los distintos sistemas de protección de borde (barandas) y aportar al desarrollo de normativa sobre su uso en Chile. La metodología incluye una amplia revisión bibliográfica nacional e internacional para describir el contexto del uso de barandas. Se realiza un levantamiento de información en terreno para describir los principales problemas de uso de estos sistemas, tales como ritmo de avance del proyecto, singularidad de aspectos geométricos y arquitectónicos, requisitos estructurales y uso de soluciones artesanales. Se realizan 16 entrevistas semi-estructuradas a profesionales de la construcción y de empresas proveedoras nacionales para describir las distintas necesidades respecto a temas técnicos en el uso de barandas, destacándose aspectos como calidad de la información, trazabilidad, homologación y estandarización de productos. En conclusión, este estudio contribuye a especificar los criterios necesarios a aplicar en la industria de la construcción para promover el uso adecuado de protecciones de bordes para evitar caídas.
Review Breaking Down Barriers: Findings from a Literature Review on Housing for People with Disabilities in Latin America
(2023) Valderrama-Ulloa, Claudia; Ferrada, Ximena; Herrera, Felipe
Accessibility to housing is crucial for people with disabilities as it provides them with equal opportunities and allows them to live independently. A systematic literature review has been conducted to understand the current research on accessibility in housing for people with disabilities in Latin America. The study analysed 56 papers and used co-word analysis to identify common themes and topics within the documents. The results of the analysis showed that Brazil (61%) is the country with the most research on the subject, physical disability, at 36%, is the impairment most analysed, and interventions or analysis for the older people (45%) in their homes is the most researched type of population. The co-word analysis revealed that topics such as policy, regulations, the use of technologies, ergonomics interventions, and architectural criteria or barriers to the daily life of disabled people were frequently discussed in the papers. Although this work shows a substantial and growing increase in research on housing for people with disabilities in Latin America, it also demonstrates the importance of increasing research on other types of impairment, such as visual and cognitive-intellectual disabilities, and including children, caregivers, or even young adults.
A tool for universal accessibility assessment in the interior of dwellings
(2023) Valderrama-Ulloa, Claudia; Ferrada, Ximena; Rouault, Fabien
The present study proposes a tool for assessing universal accessibility in the interior of apartments, presenting a novel quantitative model for assessing the accessibility of buildings for buyers or tenants. For this, a multicriteria analysis for aggregating the assessment indicators with different units and scales is employed using a unique grade of accessibility according to four main pillars: Autonomy, Mobility, Comfort, and Safety. The assessment method has been applied in 35 show apartments in the urban area of Santiago in Chile. This work shows the application and results of 4 departments. The evaluation results are presented visually with a circular bar plot and a final grade in letter format from F to A. In general, it is observed that the four apartments proposed have a low degree of accessibility (letters F to D). And, the Autonomy pillar is clearly the lowest pillar in the selected apartments.
A Robust Statistical Methodology for Measuring Enterprise Agility
(2023) Moraga-Díaz, Roberto; Leiva-Araos, Andrés; García, José
In an era characterized by rapid technological advancements, economic fluctuations, andglobal competition, adaptability and resilience have become critical success factors for businessesnavigating uncertainty and complexity. This article explores the role of enterprise agility in today’sbusiness landscape at Latam branch of Tata Consultancy Services, where organizations face complexand diverse operations. We aim to examine how companies can become more agile in the faceof emerging challenges and seize opportunities swiftly to drive growth and deliver value. Since2014, the division has embarked on an agile transformation journey to drive growth, deliver value,foster innovation, and build resilience in an increasingly dynamic environment. We scrutinizean approach to measuring and enhancing enterprise agility, employing statistical analysis andcontinuous improvement methodologies to tackle real-world challenges while offering valuableinsights and recommendations for organizations aiming to implement similar systems. The resultsof an agile transformation in a certain company’s Latam branch serve as a compelling case study,demonstrating how the implementation of targeted measures and continuous improvement cansignificantly bolster enterprise agility. Methodologically, our work applies a novel sequence ofparametric statistical tests which, to the best of our knowledge, have not been used in the industryto validate the results of business agility metrics. In future work, we aim to create a new workflowconsidering non-parametric tests to address data with other statistical distributions. We conclude ourwork by proposing a sequence of steps for organizations to implement business agility metrics
A data fusion approach with mobile phone data for updating travel survey-based mode split estimates
(2023) Graells-Garrido, Eduardo; Opitz, Daniela; Rowe, Francisco; Arriagada, Jacqueline
Up-to-date information on different modes of travel to monitor transport traffic and evaluate rapid urban transport planning interventions is often lacking. Transport systems typically rely on traditional data sources providing outdated mode-of-travel data due to their data latency, infrequent data collection and high cost. To address this issue, we propose a method that leverages mobile phone data as a cost-effective and rich source of geospatial information to capture current human mobility patterns at unprecedented spatiotemporal resolution. Our approach employs mobile phone application usage traces to infer modes of transportation that are challenging to identify (bikes and ride-hailing/taxi services) based on mobile phone location data. Using data fusion and matrix factorisation techniques, we integrate official data sources (household surveys and census data) with mobile phone application usage data. This integration enables us to reconstruct the official data and create an updated dataset that incorporates insights from digital footprint data from application usage. We illustrate our method using a case study focused on Santiago, Chile successfully inferring four modes of transportation: mass-transit (all public transportation), motorised (cars and similar vehicles), active (pedestrian and cycle trips), and taxi (traditional taxi and ride-hailing services). Our analysis revealed significant changes in transportation patterns between 2012 and 2020. We quantify a reduction in mass-transit usage across municipalities in Santiago, except where metro/rail lines have been more recently introduced, highlighting added resilience to the public transport network of these infrastructure enhancements. Additionally, we evidence an overall increase in motorised transport throughout Santiago, revealing persistent challenges in promoting urban sustainable transportation. Findings also point to a rise in the share of taxi usage, and a drop in active mobility, suggesting a modal shift towards less sustainable modes of travel. We validate our findings comparing our updated estimates with official smart card transaction data. The consistency of findings with expert domain knowledge from the literature and historical transport usage trends further support the robustness of our approach.

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