Maria Elena Bruni | University of Calabria (original) (raw)

Papers by Maria Elena Bruni

Journal of Cleaner Production, Jun 1, 2023

This paper introduces a new bi-objective minimum latency problem with profit collection, where ro... more This paper introduces a new bi-objective minimum latency problem with profit collection, where routes must be constructed in order to maximize the collected profit and to minimize the total latency. These objectives are usually conflicting. Thus, considering some important features, as the segmentation of the customers into two classes, mandatory and optional, and the presence of uncertain travel times, we follow a bi-objective approach, aiming to compute a set of Pareto-optimal alternatives with different trade-offs for a decision-maker to choose from. In order to address this computationally challenging problem, we propose a Multi-Objective Iterated Local Search. Computational results confirm the practicality of the algorithm, in terms of the quality of the solutions, and its computational efficiency in terms of time spent. We conclude that the algorithm finds good-quality solutions for small and medium-size instances.

Computers & Operations Research, Sep 1, 2022

Computers & Operations Research, Jul 1, 2022

Optimization Letters, Feb 4, 2022

In this paper, we study the multi-depot k-traveling repairman problem. This problem extends the t... more In this paper, we study the multi-depot k-traveling repairman problem. This problem extends the traditional traveling repairman problem to the multi-depot case. Its objective, similar to the single depot variant, is the minimization of the sum of the arrival times to customers. We propose two distinct formulations to model the problem, obtained on layered graphs. In order to find feasible solutions for the largest instances, we propose a hybrid genetic algorithm where initial solutions are built using a splitting heuristic and a local search is embedded into the genetic algorithm. The efficiency of the mathematical formulations and of the solution approach are investigated through computational experiments. The proposed models are scalable enough to solve instances up to 240 customers.

Social Science Research Network, 2022

With the easing of restrictions worldwide, drones will become a preferred transportation mode for... more With the easing of restrictions worldwide, drones will become a preferred transportation mode for last-mile deliveries in the coming years. Drones offer, in fact, an optimal solution for many challenges faced with last-mile delivery as congestion and emissions and can streamline the last leg of the supply chain. Despite the common conviction that drones will reshape the future of deliveries, numerous hurdles prevent practical implementation of this futuristic vision, among which the limited drone range and payload. To overcome this issue, big companies such as Amazon, are already filing up patents for the development of fulfilment centers where drones can be restocked before flying out again for another delivery, effectively extending their range. Only a few authors have addressed the joint problem of operating these facilities and providing services to retail companies. This paper addresses this problem and proposes a mathematical formulation to show the viability of the proposed approach.

Journal of Renewable and Sustainable Energy, 2013

By increasing concern over climate change and the security of energy supplies, wind power and pho... more By increasing concern over climate change and the security of energy supplies, wind power and photovoltaic are emerging as important sources of electrical energy throughout the world. The wind speed at a given location is continuously varying. There are changes in the annual mean wind speed from year to year (annual), changes with season (seasonal), with passing weather systems (synoptic), on a daily basis (diurnal), and from second to second (turbulence). Common sense tells us that irradiation varies regionally, with the changing seasons, and hourly with the daily variation of the sun's evaluation. This paper proposes a new method for optimal management of MicroGrids under uncertain environments. In this study, the 2m + 1 point estimate method is used to model the uncertainty in the load demands, the market prices, and the electric power generation of the wind farms and the photovoltaic systems. The Weibull, Beta, and normal distributions are used to handle the uncertain input ...

AIRO 2004 - 35th Conference of the Italian Association of Operations Research, 2004

IEEE Access, 2023

This paper studies the drone-aided last-mile delivery problem with shared depot resources. Our re... more This paper studies the drone-aided last-mile delivery problem with shared depot resources. Our research motivation comes from E-commerce logistics, where big companies such as Amazon, are already filing up patents for the development of drone-friendly fulfillment centers towers that could serve as both charging hubs and convenient pit stops for delivery drones to pick up and drop off packages efficiently. We mainly focus on the tactical decisions about the selection of shared fulfillment centers used as the drone launch and retrieve stations and the fleet size plans. The operational drone route decisions are also incorporated into a unified framework to account for the mutual impact between tactical and operational plans. Moreover, we consider explicitly the non-linear and load-dependent nature of the energy consumption function for drone batteries. The problem is formulated as a mixed integer program with linear constraints, developed in the realm of layered networks, where the non-linear nature of energy consumption and its load dependency are incorporated and efficiently handled without the need of approximating non-linear terms. The proposed model is tested on an extensive set of instances with up to 75 customers, showing its computational efficiency. Insights about the route costs and spatial configuration of depots are also discussed. INDEX TERMS Last-mile delivery, E-commerce, drone delivery, UAV, non-linear energy consumption, multi-depot routing problem. I. INTRODUCTION The two digits growth of e-commerce is reshaping the distribution of goods in our cities and the associated logistic business processes and models. Its disruptive impact on the delivery process has dramatically challenged transportation companies [1], [2], not only for the increased volume of last-mile deliveries, but also for the consequent change in customers, more connected and informed, and whose orders are smaller, more frequent and normally characterized by very tight time-windows (up to one hour). This prompted companies to explore new delivery methods, such as cargo bikes, lockers, and delivery robots [3], [4]. One of the more interesting options, both from an industrial and an academic The associate editor coordinating the review of this manuscript and approving it for publication was Shaohua Wan.

Springer eBooks, Oct 8, 2014

Resource Constrained Project Scheduling Problem (RCPSP) is a well-known scheduling problem where ... more Resource Constrained Project Scheduling Problem (RCPSP) is a well-known scheduling problem where aim is to optimize an objective under limited resources and activity constraints. From the real-life perspective, it has many applications such as construction, manufacturing, and R&D projects. It is shown by Blazewicz et al. [1] that RCPSP is NP-hard in the strong sense. Due to the nature of the problem itself, nature inspired algorithms are used extensively for the solution of the problem. Intelligent systems based on such algorithms can be used effectively if the proposed models can cover real life problems' complexities. Therefore, intelligent systems should be designed based on best fit models. Mainly RCPSP is modeled and solved in a deterministic environment where parameters are all assumed to be known [2]. Real life projects are consistent; production attributes are stochastic [3], and parameters are subject to change during execution of a project. Scheduling real life problems are subject to considerable uncertainties due to the dynamic nature of project environment [4]. These uncertainties and fluctuations may stem from project itself such as activity completion times, resource estimates, material delivery dates project externalities like severe weather conditions, owner's scope changes or imposed deadline changes. Thus, the limits of deterministic models are criticized by several researchers [5]. Contrary to the deterministic models, stochastic models portray the dynamic project environment with the assumption of varying project parameters. For the stochastic RCPSP, few researchers tried to model activity disruptions [6-7] and resource fluctuations separately [5]. Basic idea is to construct a

Dottorato di Ricerca in Matematica e Informatica (Ricerca Operativa). Ciclo XXXI

Top, Jun 9, 2016

Water distribution networks are important systems that provide citizens with an essential public ... more Water distribution networks are important systems that provide citizens with an essential public service which is crucial for the normal development of most basic activities of life. Despite many water distribution network problems have been extensively investigated in the literature, the presence of uncertainty in the data has often been neglected. This paper studies the challenging problem of designing an isolation system for water distribution networks under different failure scenarios. To solve the problem, three heuristic methods are presented and analyzed on a real case study taken from the literature. Numerical results show the merits of the suggested techniques for solving the problem.

Health Care Management Science, Apr 26, 2016

Community Based Organizations (CBOs) are important health system stakeholders with the mission of... more Community Based Organizations (CBOs) are important health system stakeholders with the mission of addressing the social and economic needs of individuals and groups in a defined geographic area, usually no larger than a county. The access and success efforts of CBOs vary, depending on the integration between health care providers and CBOs but also in relation to the community participation level. To achieve widespread results, it is important to carefully design an efficient network which can serve as a bridge between the community and the health care system. This study addresses this challenge through a locationallocation model that deals with the hierarchical nature of the system explicitly. To reflect social welfare concerns of S.

In this paper, we tackle the risk-averse profitable tour problem with stochastic costs and risk m... more In this paper, we tackle the risk-averse profitable tour problem with stochastic costs and risk measure objectives. This problem aims at determining a tour that maximizes the collected profit minus the total travel cost under a risk-averse perspective. We explore efficient implementations of a genetic algorithm and a tabu search method to solve the problem when the conditional value at risk and entropic risk measures are used. The computational study shows the superiority of the genetic algorithm over the tabu search on a set of instances adapted from the TSP library.