Institutional Repository Universidad San Sebastián
Not a member yet
9206 research outputs found
Sort by
Propuesta de mejora de procesos en el área de aprovisionamiento de empresa Ingeniería y Montajes Electrovolt SPA
Get PDFIngeniería y Montajes Electrovolt SPA es una empresa chilena especializada en
ingeniería, mantenimiento y montaje de instalaciones eléctricas. Ofrece servicios
de electricidad de baja tensión, mantenimiento predictivo, preventivo y correctivo,
proyectos eléctricos y más. Su equipo de trabajo está compuesto por 12
trabajadores: 60% egresados de carreras técnicas o certificados por la
Superintendencia de Electricidad y Combustibles (SEC) y 40% trabajadores de
oficio.
A través de un análisis de la empresa, se ha identificado un problema significativo
en su logística de aprovisionamiento, particularmente en los montajes eléctricos.
Esto ha causado incumplimiento de plazos de entrega, lo que ha generado
retenciones de pagos y pérdida de materiales. Durante los últimos tres años, la
empresa ha sufrido una creciente cantidad de proyectos con demoras y ha tenido
que enfrentar un incremento de las penalizaciones por retrasos.
Las principales causas identificadas de este problema incluyen la asignación
grupal de tareas, costumbres adquiridas de trabajos previos, falta de supervisión
adecuada, el uso erróneo de materiales y demoras en la reposición de estos.
Esto ha afectado negativamente la eficiencia de los proyectos, generando
demoras en entregas y afectando la relación con los clientes.
El objetivo de la tesis es proponer una mejora en los procesos del área de
aprovisionamiento, específicamente en el sector de montajes eléctricos. La
propuesta se enfoca en la implementación del ciclo de Deming, que fomenta la
mejora continua a través de la estandarización de procesos, la asignación de
tareas, supervisión constante de los proyectos y el uso de indicadores clave de
rendimiento (KPI´s) para medir los resultados. La propuesta incluye despedir al
personal que no cumpla con los estándares de calidad, optimizar los procesos
mediante la estandarización y mejorar la eficiencia general en la ejecución de los
proyectos, buscando reducir las penalizaciones y mejorar la satisfacción del
cliente.Ingeniería y Montajes Electrovolt SPA is a Chilean company specialized in
engineering, maintenance and assembly of electrical installations. It offers low
voltage electricity services, predictive, preventive and corrective maintenance,
electrical projects and more. Its work team is made up of 12 workers: 60%
graduates with technical degrees or certified by the Superintendency of Electricity
and Fuels (SEC) and 40% trade workers.
Through an analysis of the company, a significant problem has been identified in
its supply logistics, particularly in electrical assemblies. This has caused noncompliance with delivery deadlines, which has generated payment withholdings
and loss of materials. Over the past three years, the company has experienced
an increasing number of project delays and has faced increasing penalties for
delays.
The main causes of this problem include the group assignment of tasks, habits
formed from previous jobs, lack of proper supervision, incorrect use of materials,
and delays in material replenishment. These factors have negatively impacted the
efficiency of projects, causing delays in deliveries and affecting8 customer
relationships.
The objective of the thesis is to propose an improvement in the supply processes,
specifically in the electrical assembly sector. The proposal focuses on
implementing the Deming cycle, which promotes continuous improvement
through process standardization, task assignment, ongoing project supervision,
and the use of key performance indicators (KPIs) to measure results.
The proposal includes dismissing personnel who do not meet quality standards,
optimizing processes through standardization, and improving overall efficiency in
project execution, aiming to reduce penalties and improve customer satisfaction
Emociones y entropía en la toma de decisiones de equipos en dinámicas de aprendizaje caóticas
No full textPublisher Copyright: © (2024), (Centro de Informacion Tecnologica). All Rights Reserved.The main objective of this research study is to determine the relationship between entropy and behaviors that optimize learning decision-making among student teams during an experimental physics science class. An initial condition (IC) is applied by using a very short video with apparently unrelated content, emerging as a discovery the question that must be answered by each team and its experiment. The behaviors displayed are transformed into time series that are analyzed with a chaos theory software. The results show that the emotions time series, in chaotic dynamics, show that entropy has the highest thermal correspondence, positively influencing team collaborative learning while favoring each student’s training. It is concluded that using ICs within a context, at the beginning of a class, is suitable for inducing a positive emotional disposition among student teams that are committed to an experimental physics course
Sistema de imágenes plenópticas infrarrojas de onda corta multiespectrales sin ruido de patrón fijo
No full textPublisher Copyright: © 2013 IEEE.We propose a single-camera multispectral Short Wave Infrared (SWIR) plenoptic imaging system free of fixed pattern noise (FPN). The developed system can form, for each scene's object of interest, an in-focus noiseless 24 channels SWIR multispectral data cube. The Fourier Slice Photography Theorem is employed in the integrated multispectral light field to achieve images at a specific scene depth of focus. And, a reference-free image quality index is used for selecting the in-focus image for each scene object focal plane. Results are then compared to SWIR multispectral data cubes obtained from light fields achieved after applying to the SWIR camera a blackbody two-point calibration method. The scientific potential of the imaging system is proved by imaging thermal stressed plants at different scene depths of focus. The FPN SWIR spectral dependence is evaluated on the images digitally refocused at the farthest scene focal plane, resulting in concordance with the InGaAs FPA quantum efficiency. The lightfield (LF) system performance to naturally filter out the FPN was evaluated with a Black body (BB) reference base index, resulting in an SSIM index close to 98 % at the object image focus plane
Extreme High-Elevation Mammal Surveys Reveal Unexpectedly High Upper Range Limits of Andean Mice
No full textPublisher Copyright: © 2024 The University of Chicago. All rights reserved.In the world’s highest mountain ranges, uncertainty about the upper elevational range limits of alpine animals represents a critical knowledge gap regarding the environmental limits of life and presents a problem for detecting range shifts in response to climate change. Here we report results of mountaineering mammal surveys in the Central Andes, which led to the discovery of multiple species of mice living at extreme elevations that far surpass previously assumed range limits for mammals. We livetrapped small mammals from ecologically diverse sites spanning 16,700 m of vertical relief, from the desert coast of northern Chile to the summits of the highest volcanoes in the Andes. We used molecular sequence data and whole-genome sequence data to confirm the identities of species that represent new elevational records and to test hypotheses regarding species limits. These discoveries contribute to a new appreciation of the environmental limits of vertebrate life
Propuesta de mejora para el área de operaciones con la finalidad de reducir los costos de combustible y mantenimiento debido al bajo rendimiento de los equipos utilizados en la línea de trabajo de la empresa Macenor Chile Logistica SPA
No full textEmpresa del rubro del transporte internacional con más de 20 años en el mercado
entregando soluciones de transporte rodoviario a sus clientes aplicando un
servicio de calidad y atención al cliente para que tenga una experiencia
satisfactoria poniendo énfasis en la entrega de su Mercaderia en óptimas
condiciones respetando los tiempos y condiciones establecidas en el acuerdo de
cada embarque coordinado en el Mercosur.
La problemática que se está presentando actualmente en la empresa de
transporte rodoviario internacional es un bajo rendimiento en consumo de
combustible versus el kilómetro recorrido siendo esto un agente importante de
gasto de combustible y aumento en los costos de mantención correctivas,
trayendo como consecuencias unidades detenidas mermando nuestra calidad del
servicios de entregas, aumento del gasto en combustible, perjudicando la
reputación con sus clientes antiguos y no teniendo recomendaciones para
nuevos proyectos, esto enfocado en la demora en los viajes por tener que
ingresar a taller sumando días de improductividad operacional, perdiendo a su
vez nivel de atención y disponibilidad de la flota de camiones.
En razón a lo antes expuesto se busca realizar una mejora dentro de la empresa
Macenor Chile Logistica SpA, específicamente en el área operativa que tiene
como responsabilidad la flota de camiones, mantenimiento, conductores de la
compañía, este problema se detectó con la compañía, de las unidades antiguas
a nuevas lo cual no genero el impacto que se esperaba por la gerencia de la
empresa teniendo los mismos rendimiento de años anteriores con flota de
camiones con más de 10 años de circulación y más de un millón de kilómetros
recorridos, para ello se efectuará un análisis de la situación actual de la empresa y se aplicaran herramientas ingenieriles para detectar la causa raíz y aplicar la
mejora más adecuada para esta compañía , Ishikawa , 5 Why, Ciclo de Deming
como también el análisis económico para detectar los beneficios de la propuesta
a implementar.Company in the international transportation sector with over 20 years in the
market, providing road transport solutions to its clients by applying quality service
and customer care to ensure a satisfactory experience. The focus is on delivering
goods in optimal conditions while respecting the timelines and conditions
established in each shipment agreement coordinated within Mercosur. The
current issue facing the international road transport company is low fuel efficiency
relative to the kilometers traveled, which is a significant factor contributing to fuel
expenses and increased maintenance costs. This results in units being out of
service, diminishing our delivery service quality, increasing fuel expenditure,
harming our reputation with existing clients, and lacking recommendations for new
projects. This situation is exacerbated by delays in trips due to the need for
repairs, adding days of operational unproductivity and reducing the attention level
and availability of the truck fleet. In light of the above, we seek to implement
improvements within Macenor Chile Logística SpA, specifically in the operational
area responsible for the truck fleet, maintenance, and company drivers. This
problem was identified regarding both old and new units, which did not generate
the expected impact from management, as they maintained the same
performance as previous years with a fleet of trucks over 10 years old and more
than one million kilometers traveled. To address this, an analysis of the current
situation of the company will be conducted, and engineering tools will be applied
to identify the root cause and implement the most appropriate improvement for
this company, including Ishikawa diagrams, 5 Whys, Deming Cycle, as well as economic analysis to identify the benefits of the proposed implementation
Moderate-Intensity Constant and High-Intensity Interval Training Confer Differential Metabolic Benefits in Skeletal Muscle, White Adipose Tissue, and Liver of Candidates to Undergo Bariatric Surgery
No full textPublisher Copyright: © 2024 by the authors.Background/Objectives: Bariatric surgery candidates require presurgical physical training, therefore, we compared the metabolic effects of a constant moderate-intensity training program (MICT) vs. a high-intensity interval training (HIIT) in this population. Methods: Seventeen participants performed MICT (n = 9, intensity of 50% of heart rate reserve (HRR) and/or 4–5/10 subjective sensation of effort (SSE)) or HIIT (n = 8, 6 cycles of 2.5 min at 80% of the HRR and/or 7–8/10 of SSE, interspersed by 6 cycles of active rest at 20% of the FCR) for 10 sessions for 4 weeks. After training, tissue samples (skeletal muscle, adipose tissue, and liver) were extracted, and protein levels of adiponectin, GLUT4, PGC1α, phospho-AMPK/AMPK, collagen 1 and TGFβ1 were measured. Results: Participants who performed MICT showed higher protein levels of PGC-1α in skeletal muscle samples (1.1 ± 0.27 vs. 0.7 ± 0.4-fold change, p < 0.05). In the liver samples of the people who performed HIIT, lower protein levels of phospho-AMPK/AMPK (1.0 ± 0.37 vs. 0.52 ± 0.22-fold change), PGC-1α (1.0 ± 0.18 vs. 0.69 ± 0.15-fold change), and collagen 1 (1.0 ± 0.26 vs. 0.59 ± 0.28-fold change) were observed (all p < 0.05). In subcutaneous adipose tissue, higher adiponectin levels were found only after HIIT training (1.1 ± 0.48 vs. 1.9 ± 0.69-fold change, p < 0.05). Conclusions: Our results show that both MICT and HIIT confer metabolic benefits in candidates undergoing bariatric surgery; however, most of these benefits have a program-specific fashion. Future studies should aim to elucidate the mechanisms behind these differences
Detraining’s Effects on Cardiorespiratory Fitness and Maximal and Explosive Strength in Army Soldiers: Does Age Matter?
No full textPurpose: This study investigated the impact of four weeks of age-dependent detraining on army soldiers’ cardiorespiratory fitness and maximal and explosive strength. Methods: Fourteen volunteer tactical athletes participated, divided into two age groups (20 to 29 and 30 to 40 years). Before and after the detraining period, we assessed their anthropometric measurements (weight, height, body mass index, fat mass, and fat-free mass), cardiorespiratory fitness (maximal oxygen uptake [VO2max] and ventilatory thresholds [VT1 and VT2]), and kinematic properties during a single-leg counter-moving jump (CMJ) test for both the dominant and non-dominant legs. Two-way ANOVA followed by the Holm–Sidak post hoc test was used. Results: The anthropometric and cardiovascular variables did not show significant differences between the groups. However, both groups exhibited a significantly reduced maximum time and speed at the VO2max. Furthermore, the flight time and maximum height during the CMJ significantly decreased in the non-dominant leg for both age groups. Notably, the dominant leg’s concentric impulse (CI) significantly reduced during the CMJ, but this effect was observed only in the 30–40 age group. There were significant differences between the two age groups. Conclusions: Our findings suggest that four weeks of detraining negatively impacts aerobic fitness and muscular strength, independently of age. However, the dominant leg may be more susceptible to detraining effects in army soldiers aged 30–40. Furthermore, as a perspective, our results strongly suggest that a detraining period could affect successful missions (aerobic performance deterioration), as well as promote a muscle imbalance between the legs, which could encourage muscle injuries and endanger combat missions
Supra-Threshold LS CE-Chirp Auditory Brainstem Response in the Elderly
No full textPublisher Copyright: © 2024 S. Karger AG, Basel.Introduction: Aging deteriorates peripheral and central auditory structures and functions. In elders, for an accurate audiological evaluation, it is important to explore beyond the cochlear receptor. Audiograms provide an estimation of hearing thresholds, while the amplitudes and latencies of supra-threshold auditory brainstem response (ABR) can offer noninvasive measures of the auditory pathways functioning. Regarding ABR, in young populations, level-specific chirp (LS CE-chirp) stimulus has been proposed as an alternative synchronizing method to obtain larger ABR responses than those evoked by clicks. However, the supra-threshold characteristics of chirp evoked ABR, and their association to hearing thresholds is relatively unknown in the elderly. The aim of this study was to evaluate supra-threshold LS CEchirp ABRs in an aged population by comparing their features with click ABRs, and evaluating their relationship with audiometric hearing thresholds. Methods: We carried out a cross-sectional study to characterize the hearing of 125 adults aged over 65 years. We determined the audiometric hearing thresholds and supra-threshold ABRs elicited by LS CE-chirp and click stimuli at 80 dB nHL. We evaluated associations by means of partial correlations and covariate adjustment. We performed specific frequencies' analysis and subgroup analysis per hearing level. Results: Wave V responses had significantly shorter latencies and larger amplitudes when elicited by LS CE-chirp as compared to click-evoked responses. Audiometric hearing thresholds correlated with age, but ABR characteristics did not. We found mild correlations between hearing thresholds and ABR characteristics, predominantly at higher frequencies and with chirp. We found scarce evidence of correlation between ABR characteristics and the average of behavioral hearing thresholds between 0.5 to 4 kHz (0.5-4 kHz PTA). After subgroup analysis according to the hearing level, no stronger or more significant correlations were found between ABR characteristics and 0.5-4 kHz PTA. Discussion: In this study, we found that supra-threshold LS CE-chirp ABR presented some of the previously described similitudes and differences with supra-threshold click ABR in younger populations. Although, the average amplitude and latency of wave V evoked by LS CE-chirp were larger and faster than those evoked by clicks, these results should be taken with caution at the individual level, and further studies are required to state that LS CE-chirp ABRs are better than click ABRs in elders for clinical evaluations. We did not find consistent associations between hearing thresholds and supra-threshold wave V features, suggesting that these measures should be considered independently in the elderly
Lifestyle behavior of physiotherapy students from Ecuador upon admission to higher education : a cross-sectional study
No full textPublisher Copyright: 2024 Gutiérrez-Espinoza, Cassola-Cajiao, Garzón-Ulloa, Celi-Lalama, Bastidas-Caldes, Araya-Quintanilla, Cristi-Montero and López-Gil.Introduction: Admission to university has been identified as a period involving the adoption of unhealthy lifestyle behaviors. However, few studies have addressed the extent of this experience among Latin American university students. The aim of this study was twofold: first, to describe anthropometric variables, body composition, physical activity, sedentary behavior, sleep duration and quality, diet, and alcohol consumption in first-year students entering physiotherapy school at the Universidad de las Americas in Quito, Ecuador; second, to test differences in these variables between sexes. Methods: A total of 116 students were recruited. Sociodemographic variables, anthropometric indices, body composition, physical activity, sedentary behavior, sleep quality and duration, adherence to 24-hour movement guidelines, physical fitness (i.e., handgrip strength), diet, alcohol consumption, and smoking habits were evaluated. Results: A total of 50 male (43.1%) and 66 female (56.9%) students were assessed. Overall, the adherence to the 24-hour movement guidelines of the students upon admission to university was 8.6%. Conversely, 86 students (74.1%) did not meet any of the recommendations. Upon admission to university, only 8.6% of the students (female 2.6%; male 6%) met the overall 24-hour movement guidelines. Additionally, 82 students (70.7%) needed changes in diet quality, 81 students (69.8%) had significant sleep disturbances, and 22 students (18.9%) had harmful alcohol consumption. A greater proportion of males met all three 24-h movement recommendations (p = 0.025) than females did. In addition, females reported a greater percentage of occasional smokers (p = 0.025) and a greater prevalence of obesity (p < 0.001), a lower level of physical activity (p < 0.001), and a greater percentage of sleep disturbance (p < 0.001). Conversely, males reported greater waist circumference (p = 0.005), weight (p < 0.001), handgrip strength (p < 0.001), and a greater percentage of harmful alcohol consumption (p < 0.001). Discussion: Our study showed that upon admission to university, overall adherence to the 24-hour movement guidelines is low among university students. Additionally, a high percentage of students reported unhealthy lifestyle behaviors, with differences according to sex. Our findings could lead to the use of specific sex-specific strategies for the prevention and promotion of movement and lifestyle behaviors during this critical period
The parietal cortex has a causal role in ambiguity computations in humans
No full textPublisher Copyright: © 2024 Public Library of Science. All rights reserved.AU Humans: Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly often face the challenge of making decisions between : ambiguous options. The level of ambiguity in decision-making has been linked to activity in the parietal cortex, but its exact computational role remains elusive. To test the hypothesis that the parietal cortex plays a causal role in computing ambiguous probabilities, we conducted consecutive fMRI and TMS-EEG studies. We found that participants assigned unknown probabilities to objective probabilities, elevating the uncertainty of their decisions. Parietal cortex activity correlated with the objective degree of ambiguity and with a process that underestimates the uncertainty during decision-making. Conversely, the midcingulate cortex (MCC) encodes prediction errors and increases its connectivity with the parietal cortex during outcome processing. Disruption of the parietal activity increased the uncertainty evaluation of the options, decreasing cingulate cortex oscillations during outcome evaluation and lateral frontal oscillations related to value ambiguous probability. These results provide evidence for a causal role of the parietal cortex in computing uncertainty during ambiguous decisions made by humans