Iago Augusto Carvalho

Universidade Federal de Alfenas | UNIFAL · Computer Science Department

Network Design Problems (NDP) constitute a traditional class of combinatorial optimization problems. They usually rely on finding an optimal tree on a graph that respects the particular constraints of the problem at hand. When using evolutionary algorithms to solve NDP, one can use specific encodings to represent a tree. A newly proposed tree encod...

The Minimum-Cost Bounded-Error Calibration Tree problem (MBCT) is a wireless network optimization problem that arises from the sensors’ need of periodical calibration. The MBCT takes into account two objectives. The first is to minimize the communication distance between the network sensors, while the second is to reduce the maximum post-calibratio...

Recent studies show that Quantum-dot Cellular Automata devices (QCA) can reach ultra-low power consumption, notably when operating under reversible computing techniques. Partially Reversible Pipelined QCA circuits are one of such examples, which can balance energy efficiency and throughput degrading. This work proposes a method to divide those circ...

We study two problems where k autonomous mobile agents are initially located on distinct nodes of a weighted graph with n nodes and m edges. Each agent has a predefined velocity and can only move along the edges of the graph. The first problem is to deliver one package from a source node to a destination node. The second is to simultaneously delive...

The experimental evaluation of algorithms results in a large set of data which generally do not follow a normal distribution or are not heteroscedastic. Besides, some of its entries may be missing, due to the inability of an algorithm to find a feasible solution until a time limit is met. Those characteristics restrict the statistical evaluation of...

The empirical evaluation of algorithms usually produces a large set of data that needs to be assessed through an appropriate statistical methodology. Sometimes, the generated dataset has missing entries due to the inability of an algorithm to compute a solution for a given benchmark. These missing entries largely restrict the use of statistical tes...

The empirical evaluation of algorithms usually produces a large set of data that needs to be assessed through an appropriate statistical methodology. Sometimes, the generated dataset has missing entries due to the inability of an algorithm to compute a solution for a given benchmark. These missing entries largely restrict the use of statistical tes...

This paper investigates two approaches for solving bi-objective constrained minimum spanning tree problems. The first seeks to minimize the tree weight, keeping the problem's additional objective as a constraint, and the second aims at minimizing the other objective while constraining the tree weight. As case studies, we propose and solve bi-object...

Finding disjoint and widest paths are key problems in telecommunication networks. In this paper, we study the Widest k-set of Disjoint Paths Problem (WKDPP), an NP-Hard optimization problem that considers both aspects. Given a digraph G=(N,A), WKDPP consists of computing k arc-disjoint paths between two nodes such that the sum of its minimum capaci...

The Binary Integer Programming problem (BIP) is a mathematical optimization problem, with linear objective function and constraints, on which the domain of all variables is {0,1}. In BIP, every variable is associated with a determined cost coefficient. The Minmax regret Binary Integer Programming problem under interval uncertainty (M-BIP) is a gene...

Apresentação realizada no Simpósio Brasileiro de Pesquisa Operacional, em 10 de Novembro de 2022

Este trabalho propõe um modelo bi-objetivo para o problema da Árvore Geradora Mínima com Restrição de Saltos. Neste problema, o primeiro objetivo visa minimizar o peso daárvore geradora, enquanto o segundo objetivo minimiza o número de vértices no caminho entre um nó raiz dá arvore e os demais vértices desta mesma árvore. Nós propomos um modelo bi-...

Machine learning algorithms are widely used for predicting the consumer response to several food products. Recent studies in the literature demonstrated that it is possible to predict the consumer response to fruits using the physical, chemical, and physical–chemical data of fruits as input for the machine learning algorithms. However, a myriad of...

This paper tackles the 2-Dimensional Guillotine Cutting Stock Problem with Stack Constraints. The problem asks for the cutting of a set of items with the minimum amount of raw material. The cutting patterns are subject to a number of constraints, including a new realistic constraint, regarding item precedence, which has just been introduced in the...

The most popular and successful way to maintain a healthy body is to have a rich and balanced diet combined with physical exercise. Since the diet dilemma was proposed, several works in the literature suggested calculating a diet that respects the nutritional needs of each person. In the Caloric-Restricted Diet Problem (CRDP), the goal is to find a...

The most popular and successful way to maintain a healthy body is to have a rich and balanced diet, combined with physical exercise. Since it was proposed the diet dilemma, several works in the literature suggested calculating a diet that respects an individual's nutritional needs. In the Caloric-Restricted Diet Problem (CRDP), the goal is to find...

The Minmax regret Shortest Path Arborescence problem under interval uncertainty (M-SPA) is a robust counterpart of the Shortest Path Arborescence Problem, where arc costs are modeled as intervals of possible values. This problem finds applications in the design of topologies for low-power wireless personal area networks. Previous work presented a M...

BACKGROUND Strawberry quality is one of the most important factors that guarantees consistent commercialization of the fruit and ensures the consumer's satisfaction. This work makes innovative use of Random Forest (RF) to predict sensory measures of strawberries and to classify them in “satisfied” or “not satisfied” and “would pay more” or “wouldn...

Let G=(V,E) be a connected graph, where V and E represent, respectively, the node-set and the edge-set. Besides, let Q \subseteq V be a set of terminal nodes, and r \in Q be the root node of the graph. Given a weight c_{ij} \in \mathbb{N} associated to each edge (i,j) \in E, the Steiner Tree Problem in graphs (STP) consists in finding a minimum-wei...

Let G = (V, E) be a connected graph, where V and E represent, respectively, the node-set and the edge-set. Besides, let Q ⊆ V be a set of terminal nodes, and r ∈ Q be the root node of the graph. Given a weight c ij ∈ N associated to each edge (i, j) ∈ E, the Steiner Tree Problem in graphs (STP) consists in finding a minimum-weight subgraph of G tha...

Este trabalho propõe o Problema de Roteamento de Veículos Capacitado com Janelas de Tempo e Clientes Estocásticos (CVRPTWSC), uma variação do Problema de Roteamento de Veículos Capacitado com Janelas de Tempo (CVRPTW) onde um subconjunto dos clientes são incertos. O CVRPTWSC é formulado como um problema de programação linear inteira estocástico em...

Soccer is the most popular sport in the world and due its popularity, soccer moves billions of euros over the years, in most diverse forms, such as marketing, merchandising, TV quotas and players transfers. As example, in the 2016/2017 season, only England has moved about 1.3 billion of euros only in players transfers. In this work, it is performed...

The objective of this work was to evaluate the expectations of consumers and specialists of craft beers regarding the visual impact of different styles of craft beer served in different beer glasses. An online survey was designed to determine the effect of different shaped glasses on consumer expectations of craft beer. A total of 252 answers from...

Strawberries' quality greatly varies, and assessing their sensory quality is a costly task. Thus, this work employs physical and physical-chemical data (height, diameter, firmness, color, pH, acidity, and soluble solids) to predict the sensory quality of strawberries. Six sessions, with 30 strawberry samples in total, were performed. A total of 715...

We address the Interval Data Min-Max Regret 0-1 Integer Linear Programming problem (MMR-ILP), a variant of the 0-1 Integer Linear Programming problem where the objective function coefficients are uncertain. We solve MMR-ILP using a Benders-like Decomposition Algorithm and two metaheuristics for min-max regret problems with interval data. Computatio...

We address the Interval Data Min-Max Regret 0-1 Integer Linear Programming problem (MMR-ILP), a variant of the 0-1 Integer Linear Programming problem where the objective function coefficients are uncertain. We solve MMR-ILP using a Benders-like Decomposition Algorithm and two metaheuristics for min-max regret problems with interval data. Computatio...

Football is the most popular sport in the world. The growth in the number of transactions of purchase and sale, marketing, sponsorships, sale of tickets, TV contracts, among other forms of monetization of football makes the flow of values increasingly higher. The majority of works related to this sport is associated with sociological analysis. This...

We study a problem where k autonomous mobile agents are initially located on distinct nodes of a weighted graph (with n nodes and m edges). Each autonomous mobile agent has a predefined velocity and is only allowed to move along the edges of the graph. We are interested in delivering a package, initially positioned in a source node s, to a destinat...

We study a problem where k autonomous mobile agents are initially located on distinct nodes of a weighted graph (with n nodes and m edges). Each autonomous mobile agent has a predefined velocity and is only allowed to move along the edges of the graph. We are interested in delivering a package, initially positioned in a source node s, to a destinat...

Moore's law provoked decades of advances in com-puter's performance due to transistor's evolution. Despite all success in its improvement, current technology is reaching its physical limits and some replacements are the focus of investigations , such as the Field-Coupled Nanocomputing devices. These devices achieve information transfer and computat...

Recent studies show that Field-Coupled Nanocomputing devices, such as Quantum-dot Cellular Automata (QCA), can reach ultra-low power consumption, notably when operating with reversible computing techniques. Partially Reversible Pipelined QCA circuits are one of such examples where improving energy efficiency can be balanced with throughput degradin...

O futebol é hoje o esporte mais popular do mundo. O crescimento no número de transações de compra e venda, marketing, patrocínios, venda de ingressos, contratos de TV, entre outras formas de monetização do futebol faz com que o fluxo de valores seja cada vez maior. Grande parte dos trabalhos relacionados a esse esporte são associados a análises soc...

The min-max regret Shortest Path Tree problem (RSPT) is a NP-Hard Robust Optimization counterpart of the Shortest Path Tree problem, where arcs costs are modeled as intervals of possible values. This problem arises from the uncertainty in link quality the routing protocols for IPv6 Low Wireless Personal Area Networks have to handle. In this paper,...

In this paper we study the Algorithm Mean Upper (AMU), a simple 2-approximative algorithm that can be applied to any interval data min-max regret optimization problem. We perform computational experiments in more than one thousand instances of three min-max regret optimization problems: the Robust Shortest Path Problem; the Robust Minimum Spanning...

Uma alimentação rica e balanceada, junto a prática de exercícios físicos, são a forma mais comum e eficaz de obter uma boa forma física e um corpo saudável. Desde o clássico problema da dieta, proposto por Stigler, vários outros trabalhos tiveram como objetivo formular dietas seguindo certo número de restrições. Este trabalho aborda uma variação do...

A rich and balanced diet, combined with physical exercises, is the most common and efficient manner to achieve a healthy body. Since the classic Diet Problem proposed by Stigler, several works in the literature proposed to compute a diet that respects the nutritional needs of an individual. This work deals with a variation of the Diet Problem, call...

Heuristics and metaheuristics are known to be sensitive to input parameters. Bat algorithm (BA), a recent optimization metaheuristic, has a great number of input parameters that need to be adjusted in order to increase the quality of the results. Despites the crescent number of works with BA in literature, to the best of our knowledge, there is no...

Given a weight for each network link, which is set by the network operator, the OSPF routing protocol states that the data between each pair of nodes is routed through the shortest path between the sender and the receiver. In the case of multiple shortest paths, the traffic is split evenly, among all outgoing links that belong to the shortest paths...

O problema da Árvore de Caminhos Mais Curtos Robusta (ACMC-R) é um problema de otimização robusta derivado do problema clássico da Árvore de Caminhos Mais Curtos. O ACMC-R está relacionado a problemas de roteamento em redes 6LoWPAN (IPv6 Low Wireless Personal Area Networks), onde há uma grande incerteza na qualidade dos enlaces. Embora o ACMC-R já...

This is the food table used by the papers in this project. It contains the food products filtered from TACO and their nutrients. After download, please read the README file for more instructions.

The classical diet problem seeks a diet that respects the indicated nutritional restrictions at a person with the minimal cost. This work presents a variation of this problem, that aims to minimize the number of ingested calories, instead of the financial cost. It aims to generate tasty and hypocaloric diets that also respect the indicated nutritio...

IPv6 Low Wireless Personal Area Networks (6LoWPAN) is the most promising technology for implementing the Internet of Things (IoT). In order for IoT to become a reality, many challenges still need to be addressed, such as the design of energy-efficient routing protocols. The latter have to be specially resilient to high variations in transmission qu...

Given a weight for each network link, which is set by the network operator, the OSPF routing protocol states that the data between each pair of nodes is routed through the shortest path between the sender and the receiver. In the case of multiple shortest paths, the traffic is split evenly, among all outgoing links that belong to the shortest paths...

IPv6 Low Wireless Personal Area Networks (6LoWPAN) is the most promising technology for implementing the Internet of Things (IoT). In order for IoT to become a reality, many challenges still need to be addressed, such as the design of energy-efficient routing protocols. The latter have to be specially resilient to high variations in transmission qu...

Neste trabalho apresentamos um estudo dos parâmetros de entrada de um Algoritmo Genético e um algoritmo de Evolução Diferencial para o ajuste de histórico automático em reservatórios de petróleo. O problema de Ajuste de Histórico é um problema inverso que procura por um conjunto de parâmetros que minimiza a diferença entre o comportamento do modelo...

A classificação e o ranqueamento de vértices é um tema muito estudado em redes complexas. Existem na literatura diversas métricas utilizadas na classificação de vértices em uma rede. Este trabalho visa comparar as diferentes métricas calculando o coeficiente de correlação entre elas. Resultados demonstram que as métricas Grau e Hub apresentam a mai...

IPv6 Low Wireless Personal Area Networks (6LoWPAN) is the most promising technology for implementing the Internet of Things (IoT). In order to IoT become a reality, routing protocols have to be resilient to variations in transmission quality, due to constant changes in the network surrounding. The most promising of these protocols is the IPv6 Routi...

In order to Internet of Things (IoT) become a reality, many challenges still need to be outweighed. Efficient protocols have to be specially resilient to high variations in transmission quality, due to constant changes in the network surrounding, which is characteristic of IoT. The most promising of these protocols is the IPv6 Routing Protocol for...