Hugo Repolho | PUC-RJ - Academia.edu (original) (raw)

Papers by Hugo Repolho

Journal of Transport Literature, 2015

This paper presents a new methodology to optimize the Airport Check-in Counter Allocation Problem... more This paper presents a new methodology to optimize the Airport Check-in Counter Allocation Problem. The methodology combines optimization, simulation and adjacent resource scheduling and aims to determine the optimal number, location and schedule of check-in desks to open for departing flights, such that operational costs are minimized and a given service level is ensured. The methodology is composed of three steps. Step 1 uses optimization models to determine the optimal number of desks. Step 2 uses simulation to assess if the first step results meet the overall service level. Step 3 uses an optimization model to enforce the adjacent constraint. The paper focus then on Step 1, to which we present two new optimization models for common and dedicated check-in systems which include a service level constraint. Finally, these models are applied to a case study with actual data. We conclude the best time interval length should be 30 minutes or less and, as expected, the dedicated system requires, in general, more desks than the common system. Additionally, the results demonstrate the accuracy of the models to reach the trade-off between the operational costs and a given service level.

Transportation Science, 2013

Rail transportation has experienced a rebirth in the last few decades, and a very large investmen... more Rail transportation has experienced a rebirth in the last few decades, and a very large investment will certainly be made in new railway lines in the years to come—especially in high-speed rail lines. The success of such investment is heavily dependent on rail ridership, which in turn is dependent on the location of railway stations. In this paper, we present a mixed-integer optimization model that determines the optimal location (and number) of stations along a railway line that will be introduced over an existing transportation network. The stations are chosen within a set of possible locations defined a priori according to the objective of maximizing travel cost savings. The model takes into account the sensitivity of rail ridership to time losses because of stops at intermediate stations, as well as (static) competition from other modes. The practical usefulness of the model is illustrated with a case study involving a high-speed rail line expected to be built in Portugal in the...

Journal of Transportation Engineering, 2011

ABSTRACT

Transportmetrica A: Transport Science, 2016

ABSTRACT This paper proposes two optimization models for locating motorway interchanges when deal... more ABSTRACT This paper proposes two optimization models for locating motorway interchanges when dealing with public–private partnerships. The models innovate by considering simultaneously the conflicting goals of the two main parties involved, government and concessionaires, in their pursuit to maximize social welfare benefits and profits, respectively. The models maximize social welfare benefits (using a consumers' surplus measure) such that a given level of profits is ensured, being one deterministic and the other stochastic. The application of the models to a real case study, involving the A25 motorway in Portugal, show that they can help determine win–win solutions for both government and concessionaires, that is, solutions with high levels of profits and social welfare benefits.

Transportation Research Part E: Logistics and Transportation Review, 2016

Tese de doutoramento em Engenharia Civil, na especialidade de Urbanismo, Ordenamento do Territori... more Tese de doutoramento em Engenharia Civil, na especialidade de Urbanismo, Ordenamento do Territorio e Transportes, apresentada a Faculdade de Ciencias e Tecnologia da Universidade de Coimbra

International Joint Conference on Industrial Engineering and Operations Management Proceedings

European Journal of Operational Research

Abstract Location modeling techniques have been applied to an extremely wide variety of public fa... more Abstract Location modeling techniques have been applied to an extremely wide variety of public facilities. However, their application to one of the most ubiquitous public facilities – courts of justice – has been very rare. In this paper, we describe a study promoted by the Ministry of Justice of Portugal to define a proposal for the country's new judiciary map – that is, the spatial organization of the judicial system. The new map aims to promote the efficiency and specialization of the justice system (leading to better and faster court decisions) and to provide a good level of accessibility to courts. We developed two optimization models addressing those goals – a districting model, to determine the borders of new, large judicial districts; and a court location model, to determine the location, type, size, and coverage area of the courts included in each new district. Both models are discrete facility location models and consider hierarchical facilities – generic courts and specialized courts of multiple types. Our study was publicly acknowledged by the Portuguese government as having contributed to the new judiciary map that has since been approved and implemented.

Soft Computing

We present a variant of the weighted vehicle routing problem to design distribution routes in hig... more We present a variant of the weighted vehicle routing problem to design distribution routes in high theft risk areas. The model aims to minimize transportation and cargo theft costs. It uses a set of flow decision variables to calculate cargo value in each edge. Theft probability is calculated for each customer according to the historical frequency of theft occurrences reported in each location. The inclusion of theft costs derives in not so obvious route solutions as it might be less costly to drive longer distances or use more vehicles in order to minimize the value of cargo arriving to risky areas and therefore cargo theft losses. We adopt a simulated annealing metaheuristic as solution method. The model is tested in a real Brazilian pharmaceutical distribution company, highlighting the benefits of preventive routing in relation to theft occurrences.

Journal of Air Transport Management

This paper expands the fields of application of combined Bootstrap aggregating (Bagging) and Holt... more This paper expands the fields of application of combined Bootstrap aggregating (Bagging) and Holt Winters methods to the air transportation industry, a novelty in literature, in order to obtain more accurate demand forecasts. The methodology involves decomposing the time series into three adding components: trend, seasonal and remainder. New series are generated by resampling the Remainder component and adding back the trend and seasonal ones. The Holt Winters method is used to modelling each time series and the final forecast is obtained by aggregating the forecasts set. The approach is tested using data series from 14 countries and the results are compared with five methodology benchmarks (SARIMA, Holt Winters, ETS, Bagged.BLD.MBB.ETS and Seasonal Naive) using Symmetric Mean Absolute Percentage Error (sMAPE). The empirical results obtained with Bagging Holt Winters methods consistently outperform the benchmarks by providing forecasts that are more accurate.

International Journal of Production Economics

This chapter aims at pointing some remarks on the relevance of being aware of accessibility issue... more This chapter aims at pointing some remarks on the relevance of being aware of accessibility issues at the regional level. Although often under-valued, the regional meso-scale sets the framework between local (land use) and national (transport) level planning. For this reason, our goal is to present the importance of a regional viewpoint when planning for more sustainable territories. In this case, we opt for the simplicity of data inputs and analysis as a way to introduce and guide stakeholders towards more sophisticated and accurate analysis, should they have the capacity to allocate resources to accomplish them. Simple isochrones and contour measures evidence the potentiality of further cross-border cooperation for resident population on both sides of the border, which is in accordance with the literature on freight transport and spillover effects.

Energies

This paper introduces the mobile battery network for electronic devices through powerbanks in a c... more This paper introduces the mobile battery network for electronic devices through powerbanks in a city, and proposes an optimization model to find the optimum site and set-up of the network considering costumers demand, logistics components, the batteries degradation, and terminal’s charger regime. To this end, a series of degradation tests were carried out on lithium-ion batteries, in four different charger regimes, in which the battery voltage amplitude and the charging electric current were varied. The results of these tests were incorporated into the optimization model as the depreciation rate and charge time over battery life. The mathematical modeling innovates by including new components designed specifically for this new problem: battery availability according to charging time; different types of customer service; objective function modeling that includes the logistical costs of battery relocation, terminal maintenance, and battery depreciation. The results indicate that the n...

RESUMO Existe uma relação recíproca entre desenvolvimento dos transportes e progresso econômico d... more RESUMO Existe uma relação recíproca entre desenvolvimento dos transportes e progresso econômico das nações, não podendo cada um deles preceder o outro por um período de tempo alongado (Fair e Williams, 1959). No Brasil, país de grandes dimensões, a ...