Papers by Victor Cantillo
The role and potential of trusted change agents and freight demand management in mitigating “Panic Buying” shortages
Transportation research interdisciplinary perspectives, May 1, 2023
Uncovering the wage differential between formal and informal jobs: Analysis from the Colombian Caribbean region
Latin American Economic Review, Jan 18, 2022
The paper aims to assess the wage differential that would induce workers to switch between inform... more The paper aims to assess the wage differential that would induce workers to switch between informal and formal sectors, analysing the informal labour market in the Colombian Caribbean region. Relying on the theory of equalising differences, we uncover which workers perceive the highest utility from holding a formal job. Our research sheds light on how workers derive utility from formal and informal job sectors' benefits and to which extent informal workers are willing to accept a lower (or higher) wage to get a job in the formal sector. We also analyse the factors increasing the likelihood to seek employment in the formal sector. Results suggest that, on average, informal workers in the study region are willing to switch to a formal job only if they are offered a salary higher than their current income but are also willing to accept a salary slightly lower than the legal minimum wage in the formal sector. Finally, perceptions of benefits from formal and informal jobs vary with the socio-economic characteristics of individuals, especially by education level and previous work experience.
Special issue on “Urban transportation sustainability: Experiences and innovative approaches”
Transportation Research Part A-policy and Practice, Jul 1, 2020
Transportation Research Part E: Logistics and Transportation Review
The research in this paper seeks to advance the effective management of one of the most intractab... more The research in this paper seeks to advance the effective management of one of the most intractable aspects of disaster response phenomena: material convergence-the sudden and mostly uncoordinated arrival of physical donations in the aftermath of large disasters and catastrophic events-referred to by disaster respondents as a "second-tier disaster." To do so, the paper analyzes the strategic interactions among, and the incentives presented to, the various agents that influence the generation and management of material convergence, establishing that material convergence management is a Collective Action Problem. Then, the paper defines the agents' roles in material convergence management and assesses the potential of demand management, a promising tool that has not been systematically used to reduce material convergence. A key tenet of the paper is that mitigating the root of the problem, as much as possible, is more effective than solely dealing with its symptoms. To achieve the desired switch of donation choice the paper investigates the use of appeals made by trusted change agents, i.e., representatives of the disaster agents considered by survey respondents as the most trustworthy and knowledgeable of the conditions at the disaster area. The research is based on unique data, the first of its kind available to researchers, assembled by a survey of registered donors in a donation campaign after the Tohoku disasters in 2011. As part of the research, the data is used to: gain insight into the factors that influence donors to donate physical goods or cash; identify the agent(s) that ought to lead the demand management effort; quantify the potential impact of appeals from trusted change agents; and identify a preliminary list of the key messages that trusted change agents should employ in their appeals to induce donors to switch donations from physical supplies to cash. The data show that about 21% to 32% of donors in the sample would very likely switch to cash donations if trusted change agents (TCAs) requested them to do so. Finally, the paper identifies a set of Operations Management actions to complement efforts of donor behavior change.
Influencing factors of trucking companies willingness to shift to alternative fuel vehicles
Transportation Research Part E: Logistics and Transportation Review
Freight transportation is a manifestation of a vibrant economy, but it is also associated with ne... more Freight transportation is a manifestation of a vibrant economy, but it is also associated with negative externalities such as greenhouse gas emissions. To mitigate these impacts, freight vehicles using alternative fuels have been developed, but they are not widely adopted. Moreover, there is not much information on the factors that could incentivize trucking companies to adopt such vehicles, especially in emerging economies where diesel engines dominate the market. Using Colombia as a case study, this paper aims to evaluate the factors that influence businesses to shift towards acquiring trucks powered by alternative fuels, applying an econometric approach based on discrete choice models. Results suggest that demand for alternative fuel vehicles (AFVs) is highly sensitive to purchase costs, operational range, and environmental awareness. Hybrid fuel alternatives seem to be preferred over electric and compressed natural gas vehicles. The analysis is supplemented with the estimation of marginal substitution rates, elasticities, and the simulation of scenarios considering subsidies and tax exemptions, from which we identify implications and draw policy recommendations to promote the use of AFVs.
A Stochastic Facility Location Model for Intermodal Freight Hubs
International Journal of Shipping and Transport Logistics
Understanding how individuals perceive changes in the built environment and the transport system after implementing a BRT system. The case of Barranquilla, Colombia
Journal of Transport Geography
Optimización De La Cadena De Valor Del Bio-Etanol a Partir De La Caña De Azúcar y De La Yuca en Colombia
Un sistema de colonias de hormigas de dos feromonas: enfoque de búsqueda tabú para el problema heterogéneo de enrutamiento de vehículos con ventanas de tiempo y múltiples productos
20 páginasEste documento considera una variante práctica del problema de enrutamiento del vehícul... more 20 páginasEste documento considera una variante práctica del problema de enrutamiento del vehículo (VRP) conocido como el problema de enrutamiento heterogéneo del vehículo con ventanas de tiempo y múltiples productos (HVRPTWMP). Como el problema es NP-hard, el enfoque de resolución propuesto aquí es un algoritmo de búsqueda secuencial de sistema de colonias de hormigas (ACS). El enfoque introduce una estrategia de rastro de dos feromonas para acelerar el proceso de aprendizaje de los agentes (hormigas). Su convergencia con buenas soluciones se da en términos del tamaño de la flota y el tiempo de viaje al completar los recorridos y el servicio a todos los clientes. El procedimiento propuesto utiliza memorias de frecuencia y regencia de Tabu Search para mejorar aún más la calidad de las soluciones. Los experimentos se llevan a cabo utilizando ejemplos de la literatura y muestran la efectividad de este procedimiento.This paper considers a practical variant of the Vehicle Routing Proble...
Applied Mathematical Modelling, 2022
This research develops a non-linear continuous optimisation model to estimate tolls for multi-cla... more This research develops a non-linear continuous optimisation model to estimate tolls for multi-class and multi-period traffic considering integral social costs such as congestion externalities, pavement damage, environmental emissions, operational travel costs, and user travel time cost, in addition to maintenance and construction of road infrastructure costs. The approach uses social welfare principles, formulating a function to calculate the social welfare of a multi-class flow that moves in multiple periods based on a stochastic discrete choice model and considering infrastructure financing constraints. A case study was conducted applying the model to a road in the Colombian Caribbean region and estimated the value of tolls using the particle swarm optimisation heuristic. Results showed that infrastructure policies considering partial financing resulted in higher social welfare values. Scenarios requiring toll revenue to be higher than infrastructure cost can shrink demand and cause distributive issues.
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attribute thresholds of perception
Optimisation approach to solve the truck loading and delivery problem at long haul distances with heterogeneous products and fleet
International Journal of Operational Research, 2021
This paper proposes a sequential optimisation approach for addressing a complex real world proble... more This paper proposes a sequential optimisation approach for addressing a complex real world problem of dispatch planning and freight loading for a set of highly irregular products with a heterogeneous fleet of trucks. The approach focuses on the case of goods with 'low-density values', highly varied with large travel distances. The proposed approach is based on a two-phase strategy: the first optimises the space assignment process inside trucks to each type of product. It is achieved by minimising long-haul transportation costs as a function of the fleet size and capacity, considering a set of predefined feasible and efficient loading solutions or patterns. The second phase minimises the number of visits per truck, assuming a fleet with fixed size and capacities for each type of product, which is determined in the first stage. The approach was successfully applied to a rolled steel company in Colombia, whose results show that the proposed model efficiently addresses the analysed problem, which is reflected in reasonable solution times and costs from a practical implementation perspective.
Accessibility Variables in Freight Generation Models for Agricultural Products: An Elastic Nationwide Model for Evaluating the Impact of Infrastructure Projects
La importancia de las publicaciones La frase Publish or perish refleja la creciente necesidad de ... more La importancia de las publicaciones La frase Publish or perish refleja la creciente necesidad de la comunidad académica de acrecentar el acervo de conocimientos de cada área no solo mediante la realización de investigaciones sino también a través de la publicación de los respectivos resultados.
Design of Optimal Model for Traffic Signal Plan Transition Based on Social Cost Function
The transition phase is generally defined as the process of switching from one timing plan to ano... more The transition phase is generally defined as the process of switching from one timing plan to another; this process may include changes in offset, phase split or cycle length until coordination for a new timing plan is reached once again. This paper proposes a non-linear mathematical model to improve the performance of the transition between signal timing plans at coordinated intersections. The model comprises the minimization of a social costs function, which includes a reduction in delay, gas emissions and fuel consumption by considering multiple objectives that embrace more measures of effectiveness. An ant colony algorithm is used to find the optimal parameters of coordination and to determine the time required during transition. Finally, an evaluation of the effectiveness of the new model is realized based on its ability to minimize, delays, and air pollution emissions and fuel consumption. Numerical results show that model proposed is effective method for to reduce social cost...
A Stochastic, Multi-Commodity Multi-Period Inventory-Location Problem: Modeling and Solving an Industrial Application
Lecture Notes in Computer Science, 2019
This paper addresses the real-world supply chain network design problem with a strategic multi-co... more This paper addresses the real-world supply chain network design problem with a strategic multi-commodity and multi-period inventory-location problem with stochastic demands. The proposed methodology involves a complex non-linear, non-convex, mixed integer programming model, which allows for the optimization of warehouse location, demand zone’s assignment, and manufacturing settings while minimizing the fixed costs of a distribution center (DC), along with the transportation and inventory costs in a multi-commodity, multi-period scenario. In addition, a genetic algorithm is implemented to obtain near-optimal solutions at competitive times. We applied the model to a real-world industrial case of a Colombian rolled steel manufacturing company, where a new, optimized supply chain distribution network is required to serve customers at a national level. The proposed approach provides a practical solution to optimize their distribution network, achieving significant cost reductions for the company.
Research in Transportation Business & Management, 2020
The article studies the demand for public transport in Colombian cities, identifying the main det... more The article studies the demand for public transport in Colombian cities, identifying the main determinants explaining market shares for transit services. We used aggregated choice models to estimate overall price, income, speed and frequency elasticities for urban public transport demand in the country. The model successfully accounts for unobservable information about attributes of alternative public transport modes. The results suggest high demand elasticities to price and frequency, while demand responds moderately to speed. We also find a negative income elasticity, which classifies public transport as an inferior good. Results provide relevant information for the current discussion about new transport systems in cities of developing countries, with a deeper understanding of the elements to consider in the design of public transport policies.
Transportation Research Part F: Traffic Psychology and Behaviour, 2020
The Subset Feedback Vertex Set problem takes as input a pair (G, S), where G = (V, E) is a graph ... more The Subset Feedback Vertex Set problem takes as input a pair (G, S), where G = (V, E) is a graph with weights on its vertices, and S ⊆ V. The task is to find a set of vertices of total minimum weight to be removed from G, such that in the remaining graph no cycle contains a vertex of S. We show that this problem can be solved in time O(1.8638 n), where n = |V |. This is a consequence of the main result of this paper, namely that all minimal subset feedback vertex sets of a graph can be enumerated in time O(1.8638 n).
A collaborative supply chain model for non-for-profit networks based on cooperative game theory
International Journal of Logistics Systems and Management, 2017
For both the commercial logistics networks as the non-for-profit ones, collaboration among suppli... more For both the commercial logistics networks as the non-for-profit ones, collaboration among suppliers is an important strategic resource. This paper considers a tactical model for the optimisation of a commercial supply chain for a non-for-profit relief network, inspired on a previously developed post-disaster logistics model. In order to evaluate the effect of cooperation among the different competitors, a logistic network was simulated and several cooperation scenarios were considered, based on the strengths of each one of the actors involved. The model aims the minimum cost of supplying a specific item for the network and, at the same time, it allows for the different suppliers assess the benefits derived from cooperation. Following a cooperative game theory approach, the Shapley value was calculated in order to determine the distribution of costs as well as the utilities of the players involved and to determine the feasibility of the cooperation scheme designed.
Analisis Economico de Politicas de Transporte Erroneas. Caso de Restriccion a Vehiclos Segun Numeros de Patente y de Subsidios a Motocicletas
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Papers by Victor Cantillo