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https://hdl.handle.net/10784/28313

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Airline choice model for an international round-trip flight considering outbound and return flight schedules
(Warsaw University of Technology, 2020-01-01) Munoz C.; Laniado H.; Córdoba J.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
This paper quantified the impact of outbound and return flight schedule preferences on airline choice for international trips. Several studies have used airline choice data to identify preferences and trade-offs of different air carrier service attributes, such as travel time, fare and flight schedule. However, estimation of the effect return flight schedules have on airline choice for an international round-trip flight has not yet been studied in detail. Therefore, this study introduces attributes related to return flight characteristics and round-trip flight schedule interaction into the airline choice models, which have not previously been reported in the literature. We developed a stated preference survey that includes round-trip fares based on flight schedule combinations and the number of days prior to departure fares was purchased. We applied modelling techniques using a set of stated preference data. A mixed logit model was tested for the presence of heterogeneity in passengers' preferences. Our results indicated that models with attributes related to return flight and its interaction with outbound flight attributes have a superior fit compared with models only based on attributes reported in the literature review. The model found shows that airfare, travel time, arrival preference schedule in the outward journey, departure preference in the return journey and the schedule combination of round-trip flight are significantly affecting passenger choice behaviour in international round-trip flights. Sensitivity analysis of airline service characteristics and their marketing implications are conducted. The analysis reports seven policies with the greatest impact on each airline choice probabilities. It shows that by reducing travel time and airfare and by adopting an afternoon and night schedule preference for outbound and return flight, respectively, the highest probability on airline choice would be reached. This research contributes to the current literature by enhancing the understanding of how passengers choose airlines, considering both outbound and inbound journey characteristics. Thus, this study provides an analytical tool designed to provide a better understanding of international round-trip flight demand determinants and support carrier decisions. © 2020 Warsaw University of Technology. All rights reserved.
Analysis of driving safety criteria based on national regulations for the suspension systems of NGVS
(Mendel University of Agriculture and Forestry Brno, 2015-01-01) Martinod, R.M.; Betancur, G.R.; Castañeda, L.F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
The work analyses the technical evaluation process of the suspension system for vehicles that have been adapted to natural-gas-fuelled engines from power light-duty gasoline, and diesel vehicles; this evaluation is done through a mechanical review established by national regulations. The development of this analysis is focused on establishing the relationship between the natural-gas-fuelled equipment and the dynamic effect caused by the extra-weight, according to two measuring criteria that determine the safety and driving comfort, these are: (i) tire-road adhesion index; and (ii) tire excitation phase angle. The paper also proposes new elements that can be added to the current national regulations and that are currently applied to assess the suspension of natural gas vehicles, recorded using a test standard benchmark for the evaluation of the suspension.
Analysis of the procedure for suspension evaluation of civil armoured vehicles: Reliability and safety driving criteria
(Inderscience Enterprises, 2013-01-01) Martinod, R.M.; Betancur, G.R.; Mesa, J.F.; Benavides, O.M.; Castañeda, L.F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
The present study exposes an analysis of the suspension system technical state evaluation for civil vehicles that have been subject to armouring processes. Such evaluation is performed through a mechanised revision established by state regulation and is based on the method defined by EuSAMA. The development of this analysis focuses on establishing the existing relation between the ballistic resistance integrated to a vehicle and the dynamic effect exercised for the modification of its mass, according to two reliability/safety driving measurement criteria: (i) tyre-road adhesion index and (ii) tyre excitation phase angle. The study proposes new elements to the current procedure established to evaluate the suspension of civil armoured cars considering the two measurement criteria, which can be acquired by a standard commercial suspension tester machine. Copyright © 2013 Inderscience Enterprises Ltd.
Assessment properties of the coherence function on combustion engines technical state
(División de Ingenierías de la Universidad Santo Tomás, 2011-01-01) CASTAÑEDA, LEONEL FRANCISCO; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
¿Cómo lograr pronósticos más acertados? Modelos AR.I.MA Parte 2
(2008-01-01) MORA, LUIS ALBERTO; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
¿Cómo lograr pronósticos más acertados? Modelos AR.I.MA. Parte 1
(2008-01-01) MORA, LUIS ALBERTO; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Computer-Aided Support for the Rapid Creation of Parametric Models of Milling Units for Longwall Shearers
(Sciendo, 2018-12-01) Boloz L.; Castañeda L.F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
The cutting drums are the basic working components of many mining machines. The article focuses on differences in the design of cutting drums depending on the expected working conditions. Then, the unique calculation procedure is presented which allows to determine the load on the unit by reducing the forces acting on a single pick, taking into account the picks bent on the cut-off disc. Until now, this has been omitted in the literature. The results of the calculations for the selected cutting drum performed in MATLAB are also presented. The further section proposes to use Autodesk Inventor Professional's iLogic Tool for quick modelling of cutting drums. The principles of creating parameterized models and compositions using programming elements in the form of iLogic scripts are presented. The articles presented a ready-made units generator, taking into account the possibility to determine values of selected numerical parameters of the unit: diameter, web, number of patches and cutting pitch. The generator also allows you to select the type of pick holders, conical pick types, as well as the choice of pick system for repositioning or matching picks. © 2018 Lukasz Boloz, Leonel F. Castañeda, published by Sciendo 2018.
Computer-Aided Support for the Rapid Creation of Parametric Models of Milling Units for Longwall Shearers
(Sciendo, 2018-08-01) BO£OZ, £ukasz; Castaneda Heredia Leonel F.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
The cutting drums are the basic working components of many mining machines. The article focuses on differencesin the design of cutting drums depending on the expected working conditions.
Conclusiones en torno a la jornada de reflexión sobre la virtualización
(Fondo editorial Universidad EAFIT, 2003-11-13) Villegas, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
El confort en vehículos ferroviarios de pasajeros
(Universidad EAFIT, 2006-06-01) CASTAÑEDA, LEONEL FRANCISCO; Betancur, German René; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Design of load optimized replacement parts with a railway car undercarriage as example
(Springer-VDI-Verlag, 2010-01-01) Arnold, R.; Martinez, G.; Ronald, M.; Martinod, R.; Leonel, F.; Castañeda, H.; Mauricio, E.; Palacio, L.; Jensen, J.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Detección de infracciones y matrículas en motocicletas, mediante visión artificial, aplicado a sistemas inteligentes de transporte
(Associacao Iberica de Sistemas e Tecnologias de Informacao, 2020-06-01) VALENCIA, JESÚS FERNANDO; Ramirez-Guerrero, T.; Castañeda, L.; Toro, M.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Incomplete operation of transportation systems has led to an increase in illegal passenger transportation, by the means of motorcycles, at worldwide, causing high accident rates. In the intermediate cities of Colombia, the main control method applied to informal transportation is to impose fines to identified offenders by transit authorities. This work proposes the development of an application that, by means of computer vision, serves as a tool for transit officers in the detections of three infringements types committed by motorcyclists: not wearing a helmet; circulate in prohibited areas; transporting passenger in sites where it’s not allowed. Our case study was Valledupar city, where 105 motorcyclists’ images were taken while they are driving. Results show an accuracy of 87,5% in infringements detection, showing the relevance of this application as an assistance tool to disincentive informal transportation. © 2020, Associacao Iberica de Sistemas e Tecnologias de Informacao. All rights reserved.
Detection o structural damage and estimation of reliability using a multidimensional monitoring approach
(SAGE PUBLICATIONS LTD, 2017-05-11) Ortiz, Juan Orlando; Betancur G, G.R.; Gómez, Johnny; Castaneda Heredia Leonel F.; ZAJAC, GRZEGORZ; Gutiérrez-Carvajal, R.E.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Many structural elements are exposed to load conditions that are difficult to model during the design phase, such as environmental uncertainties, random impacts, and overloading, amongst others, thus increasing unprogrammed maintenance and reducing confid
Detection of structural damage and estimation of reliability using a multidimensional monitoring approach
(SAGE PUBLICATIONS LTD, 2018-04-01) Ortiz J.O.; Betancur G.R.; Gómez J.; Castañeda L.F.; Zajsc G.; Gutiérrez-Carvajal R.E.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Many structural elements are exposed to load conditions that are difficult to model during the design phase, such as environmental uncertainties, random impacts, and overloading, amongst others, thus increasing unprogrammed maintenance and reducing confidence in the reliability of the structure in question. One way to deal with this problem is to monitor the structural condition of the element. This approach requires supervising several signals coming from critical locations and then performing an accurate condition estimation of the element in question based on the data collected. This study implements a method to diagnose and evaluate the reliability of the bolster beam structure of the railway vehicle during a fatigue test. The results show that multidimensional monitoring not only diagnoses the element accurately but also results in correct estimation of reliability. © 2017, © IMechE 2017.
Determination of the technical state of suspension elements based on the OMA-LSCE method
(Collegio Ingegneri Ferroviari Italiani, 2012-01-01) Castañeda, L.; Martinod, R.; Betancur, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
A study is established regarding the behavior of the vehicle under the influence of the damping elements, proposing a methodology for the validation of the technical state of the dampers through the registration of dynamic variables under commercial operating conditions of the vehicle, by applying the Operational Modal Analysis COMA) technique via Least-Square Complex Exponential (LSCE) method to experimental tests and numeric simulations to a multi-body system (MBS) model. The OMA-LSCE method is applied to the signals acquired during a test performed on a passenger of a three- car unit in typical commercial travel operation. From the signals in time domain of each section of the segment, the respective discrete function PSD is calculated. Once the model is defined, a set of numeric simulation is executed according to the design of the experiment. The results of the numeric simulations show that the natural frequency generates a lineal regressive model with correlation coefficient values.
Determinazione dello stato tecnico degli elementi delle sospensioni sulla base del metodo OMA-LSCE
(Collegio Ingegneri Ferroviari Italiani, 2012-01-01) Castañeda, L.; Martinod, R.; Betancur, G.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
A study is established regarding the behavior of the vehicle under the influence of the damping elements, proposing a methodology for the validation of the technical state of the dampers through the registration of dynamic variables under commercial operating conditions of the vehicle, by applying the Operational Modal Analysis COMA) technique via Least-Square Complex Exponential (LSCE) method to experimental tests and numeric simulations to a multi-body system (MBS) model. The OMA-LSCE method is applied to the signals acquired during a test performed on a passenger of a three- car unit in typical commercial travel operation. From the signals in time domain of each section of the segment, the respective discrete function PSD is calculated. Once the model is defined, a set of numeric simulation is executed according to the design of the experiment. The results of the numeric simulations show that the natural frequency generates a lineal regressive model with correlation coefficient values.
Development of a robust customer satisfaction index for domestic air journeys
(Elsevier Ltd, 2020-01-01) Munoz, C.; Laniado, H.; Córdoba, J.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
This research proposes a Robust Customer Satisfaction Index for air domestic journeys (RCSI), which could be less sensitive to outlier data than index scores based on the American customer satisfaction index (ACSI) formulation. Since traveler experiences in air journeys are a chain of services related to departure airport service, airline service, and arrival airport service, a new index for measuring passenger satisfaction for air journeys is required. In a sense then, this study is the first step towards integrating satisfaction literature to propose a robust index for air journeys. The Structural Equation Model (SEM) was used to validate the theoretical model. The RCSI model was tested in the context of Colombian major domestic air-route where traveler's perceived quality and perceived value were found to predict significantly overall passenger satisfaction. In this study, we found that the RCSI score is similar to the average for the airline industry in ACSI. The findings show that the RCSI is less sensitive to outlier data than customer satisfaction indexes (CSIs) based on the ACSI model formulation. The RCSI model also allows the airline and airport managers to understand the specific factors, which significantly influence overall traveler satisfaction, by reading the causal relationship in the RCSI model. © 2020 Elsevier Ltd
The Effect of Student Work Group Emotional Intelligence on Individual Task Performance in Teams
(SAGE Publications Ltd, 2020-07-15) Roman, J.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
The Effect of Student Work Group Emotional Intelligence on Individual Task Performance in Teams
(SAGE Publications Ltd, 2020-01-01) Román-Calderón J.P.; Aguilar-Barrientos S.; Escalante J.E.; Barbosa J.; Arias Salazar A.; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)
Background: The development of employability skills is a concern of educational institutions, which must introduce experiential learning scenarios for undergraduate students. Purpose: This study is aimed at testing the relationship between emotional intelligence and individual task performance in teams, during a recruiting activity for an experiential learning program. Methodology/Approach: Self-reported and third rater’s measures were used to assess both variables as part of the selection process of participants on an experiential learning program focused on engineering competitions. Exploratory structural equation modeling was used for data analysis. Findings/Conclusions: Results show partial support of the hypothesis by revealing a significant but apparently counterintuitive relationship. Implications: The study reveals the measurement of employability skills as a challenge and a necessity. For employers, it reinforces that teamwork, socialization, and daily organizational endeavors require the appropriate soft skills to obtain good performance levels. © The Authors 2020.
Entwicklung eines rotordynamischen Schwingungsmodells zur technischen Diagnose einer Francis-Turbine
(Springer-VDI-Verlag, 2009-01-01) CASTAÑEDA, LEONEL FRANCISCO; Universidad EAFIT. Departamento de Ingeniería Mecánica; Estudios en Mantenimiento (GEMI)

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