Rodrigo de Alvarenga Rosa

A mathematical model and a Clustering Search metaheuristic for planning the helicopter transportation of employees to the production platforms of oil and gas

A mathematical model with new constraints for the Capacitated Helicopter Routing Problem.A Clustering Search (CS) metaheuristic for the Capacitated Helicopter Routing Problem.The model considers the transport between airport to platforms and between platforms.CS was able to solve instances with up to 1000 requests and 100 helicopters.This paper is motivated by a real logistic problem of a Brazilian Oil & Gas company. In several countries, the petroleum is explored offshore and the oil and gas companies use oil drilling facilities and platforms far away from the coast. Thus, the oil companies transport its employees by helicopters between onshore basins, airports and platforms. This problem is known as the Capacitated Helicopter Routing Problem (CHRP). In this paper, it is proposed a formal mathematical model to the CHRP with several specific constraints and a more realistic objective function. Besides a Clustering Search (CS) metaheuristic is proposed to solve it. The mathematical model and the CS metaheuristic were tested with real data from a Brazilian oil and gas company. A set of instances with up to 1000 transportation requests and 100 helicopters was generated. Computational experiments indicate that CPLEX is not able to solve optimally even small instances of the problem, but the CS metaheuristic is capable of solving the proposed model generating good, stable and fast solutions.

A method to assess the eco-efficiency of a public bus transportation service

Abstract Brazilian Public Bus Transportation Service transports over 34.4 million passengers daily using approximately 107,000 urban buses. This service costs millions of dollars annually to the municipality and emits several pollutants to the atmosphere. Therefore, this paper proposes a method to assess the eco-efficiency of a Public Bus Transportation Service. The proposed method was tested in a medium-sized urban region in Brazil. Different scenarios representing changes in the vehicles engines and fuels were tested and analyzed. Six eco-efficiency indicators regarding emissions and fuel consumption were proposed to assess which mix of engines and fuels would bring the greatest eco-efficiency. The results were compared to targets based on Brazilian regulation and showed that the renewal of the fleet is necessary to meet the environmental targets, while also achieving fuel costs reduction.

Planning the transport of loads to oil platforms considering the arrangement of the loads on the ship's deck

Abstract Oil exploration in Brazil is done mainly by offshore oil platforms located far from the coast and ships transport all supplies for them. This paper proposes a method based on a Hybrid Simulated Annealing with Ship’s Balance (HSA-SB) metaheuristic to plan the transport of loads to offshore platforms considering the arrangement of the loads on the ship’s deck and the ships balance about its keel. The main objective of HSA-SB is to minimize the ships affreightment costs by reducing the number of ships used and the distance sailed. It also arranges the loads on the deck, aiming to reduce ship’s imbalance. HSA-SB was tested on real instances from a major Brazilian oil company and the results showed possible financial benefits.

Mathematical model for planning the layout and stacking of granite blocks in a maritime terminal

The break-bulk trade has a significant role in international maritime trade. Brazil exports several break-bulk cargoes, especially granite blocks. The port administration should plan the yard operations, putting more granite blocks in the same area and also reducing the distance travelled by the trucks from the storage yard to the seaside. This paper proposes a mathematical model to plan the layout of the storage yard, named 3D-yard allocation problem (3D-YAP) that considers that a small block goes on top of a big block, only blocks from the same vessel can be stacked in one stack and blocks can be rotated on the X-Y plane. The model was tested on instances based on real data from Praia mole terminal (PMT), Brazil, that were solved by CPLEX 12.6. It is also important to say that the model can be applied to any kind of break-bulk cargo in any port yard or terminal.

Planning the berth allocation problem in developing countries with multiple cargos and cargo priority by a mathematical model and a clustering search metaheuristic

Some Brazilian ports operate several different cargos. These ports were privatised, and to avoid the private companies to restrict their operations to some few profitable cargos, the Brazilian Government established rules, called cargo priorities, to ensure that all cargos are handled at the ports. These rules have a direct impact on port operations, especially when it comes to defining the allocation of berth space for vessels. Thus, this paper presents a mathematical model and a clustering search (CS) metaheuristic for the berth allocation problem with multiple cargos and cargo priorities, considering time and space constraints. The paper is motivated by a port terminal located in Brazil, which handles containers, granites and cars. CS solved both instances based on real data and instances created to test large problems. An extensive analysis of all the results is also presented.

DIESEL SUPPLY PLANNING FOR OFFSHORE PLATFORMS BY A MATHEMATICAL MODEL BASED ON THE VEHICLE ROUTING PROBLEM WITH REPLENISHMENT

Oil exploration in Brazil is mainly held by offshore platforms which require the supply of several products, including diesel to maintain its engines. One strategy to supply diesel to the platforms is to keep a vessel filled with diesel nearby the exploration basin. An empty boat leaves the port and goes directly to this vessel, then it is loaded with diesel. After that, it makes a trip to supply the platforms and when the boat is empty, it returns to the vessel to be reloaded with more diesel going to another trip. Based on this description, this paper proposes a mathematical model based on the Vehicle Routing Problem with Intermediate Replenishment Facilities (VRPIRF) to solve the problem. The purpose of the model is to plan the routes for the boats to meet the diesel requests of the platform. Given the fact that in the literature, papers about the VRPIRF are scarce and papers about the VRPIRF applied to offshore platforms were not found in the published papers, this paper is important to contribute with the evolution of this class of problem, bringing also a solution for a real application that is very important for the oil and gas business. The mathematical model was tested using the CPLEX 12.6. In order to assess the mathematical model, tests were done with data from the major Brazilian oil and gas company and several strategies were tested. DOI: http://dx.doi.org/10.4995/CIT2016.2016.2217

Resolução de um caso real do problema dial-a-ride multicritério via clustering search

Abstract This paper presents a clustering search (CS) algorithm for the multicriteria dial-a-ride problem (DARP) from Vitoria, Espirito Santo State, Brazil. In Vitoria, users submit pickup and delivery requests for transportation between various origins and destinations with time windows for the pickup and delivery; these requests are serviced by a homogeneous fleet of vehicles based at the same depot. The aim is to plan a set of vehicle routes to service all requests while minimizing the transportation cost (commonly length or travel times), the number of vehicles used and the total waiting time inside the vehicles, under constraints such as vehicle capacities and precedence (the origin of a user must precede his/her destination on the route). Our CS was able to handle the particularities present in Vitoria. Good computational results are reported for practical instances provided by the Department of Transportation, Traffic and Urban Infrastructure of Vitoria. Keywords Dial-a-ride. Clustering search. Multicriteria.