Ulisses Dias
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Research Subjects
Ulisses Dias has a total of 29 co-authors. Here are the top co-authors by number of shared publications:
- Zanoni Dias
University of Campinas
34 shared publications - Andre Rodrigues Oliveira
Faculdade de Computação e Informática, Universidade Presbiteriana Mackenzie, São Paulo, Brazil
32 shared publications - Klairton Lima Brito
Instituto de Computação, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
25 shared publications - Alexsandro Oliveira Alexandrino
Instituto de Computação, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
19 shared publications Zanoni Dias
Institute of Computing, University of Campinas, Campinas, Brazil
16 shared publications- Guillaume Fertin
Nantes Univ, Ecole Cent Nantes, CNRS, LS2N,UMR 6004, F-44000 Nantes, France
9 shared publications
Latest Publications
- Open Access
- 7 March 2026
- Published by Springer Nature in Journal of Combinatorial Optimization
- Vol. 51 (2) , 26
Maximum alternating clean balanced cycle decomposition and applications in rearrangement distance problems
In genome rearrangement, graph-based representations are widely used to analyze and solve rearrangement problems. In particular, when each gene occurs at most once, the breakpoint graph is a useful tool. A maximum cycle decomposition of this graph yields immediate lower bounds for several genome rearrangement distances. This paper introduces a generalization of the Maximum Alternating Cycle Decomposition problem ( MAX-ACD ), called the Maximum Alternating Clean Balanced Cycle Decomposition problem ( MAX-ACBCD ). The MAX-ACD problem is closely related to some rearrangement problems, where the orientation of the genes is unknown, and all genes are common to both genomes. The MAX-ACBCD problem has applications to related rearrangement problems, which allow genes present in only one of the genomes and consider both gene order and intergenic-region information. We present a constant-factor approximation and a heuristic for the MAX-ACBCD problem, and we performed tests with the heuristic applied to artificially generated genomes. Considering intergenic regions and a scenario where the orientation of the genes is known, we design an improved algorithm for the Sorting by Reversals and Intergenic Indels problem that guarantees an approximation factor of $$\frac{3}{2}$$ . For the scenario where the orientation of the genes is unknown, and using the MAX-ACBCD problem, we develop approximation algorithms for the Sorting by Reversals, the Sorting by Reversals and Intergenic Indels, the Reversal, Transposition and Indel Distance, the Sorting by DCJ, and the Sorting by DCJ and Intergenic Indels problems with approximation factors of 2 k , $$\frac{3k}{2}$$ , 4 k , 2 k , and k , respectively, where $$k=\frac{31}{21}+\epsilon $$ .- 7 March 2026
- Published by Springer Nature in Journal of Combinatorial Optimization
- Vol. 51 (2) , 26
Open AccessMaximum alternating clean balanced cycle decomposition and applications in rearrangement distance problems
In genome rearrangement, graph-based representations are widely used to analyze and solve rearrangement problems. In particular, when each gene occurs at most once, the breakpoint graph is a useful tool. A maximum cycle decomposition of this graph yields immediate lower bounds for several genome rearrangement distances. This paper introduces a generalization of the Maximum Alternating Cycle Decomposition problem ( MAX-ACD ), called the Maximum Alternating Clean Balanced Cycle Decomposition problem ( MAX-ACBCD ). The MAX-ACD problem is closely related to some rearrangement problems, where the orientation of the genes is unknown, and all genes are common to both genomes. The MAX-ACBCD problem has applications to related rearrangement problems, which allow genes present in only one of the genomes and consider both gene order and intergenic-region information. We present a constant-factor approximation and a heuristic for the MAX-ACBCD problem, and we performed tests with the heuristic applied to artificially generated genomes. Considering intergenic regions and a scenario where the orientation of the genes is known, we design an improved algorithm for the Sorting by Reversals and Intergenic Indels problem that guarantees an approximation factor of $$\frac{3}{2}$$ . For the scenario where the orientation of the genes is unknown, and using the MAX-ACBCD problem, we develop approximation algorithms for the Sorting by Reversals, the Sorting by Reversals and Intergenic Indels, the Reversal, Transposition and Indel Distance, the Sorting by DCJ, and the Sorting by DCJ and Intergenic Indels problems with approximation factors of 2 k , $$\frac{3k}{2}$$ , 4 k , 2 k , and k , respectively, where $$k=\frac{31}{21}+\epsilon $$ . - Open Access
- 5 September 2025
- Published by Associacao Nacional de Tecnologia do Ambiente Construido (ANTAC) in SIMPÓSIO BRASILEIRO DE TECNOLOGIA DE INFORMAÇÃO E COMUNICAÇÃO NA CONSTRUÇÃO
- Vol. 5
A Realidade aumentada como ferramenta de preservação e divulgação do patrimônio histórico e cultural
A preservação do patrimônio histórico-cultural enfrenta o desafio da disseminação do conhecimento e da ampliação do acesso à informação. Este estudo tem como objetivo desenvolver um aplicativo móvel em Realidade Aumentada (RA) para promover a valorização e conservação da Ilha Anchieta, unidade de conservação no litoral de Ubatuba (SP), por meio da visualização de modelos 3D, imagens 360° e recursos interativos. A metodologia adotada foi um estudo de caso com abordagem qualitativa, combinando pesquisa histórica, levantamento geográfico, modelagem tridimensional e desenvolvimento em Flutter com integração ao Unity. Os resultados incluem um aplicativo funcional que oferece navegação por mapa interativo, visualização em RA do antigo presídio da ilha e outros pontos turísticos, linha do tempo histórica e quiz educativo. Os testes indicaram elevado engajamento e imersão dos usuários. Como contribuição, o projeto propõe uma nova forma de sensibilização para o patrimônio, utilizando tecnologias digitais acessíveis para apoiar práticas de educação, turismo e preservação cultural.
- 5 September 2025
- Published by Associacao Nacional de Tecnologia do Ambiente Construido (ANTAC) in SIMPÓSIO BRASILEIRO DE TECNOLOGIA DE INFORMAÇÃO E COMUNICAÇÃO NA CONSTRUÇÃO
- Vol. 5
Open AccessA Realidade aumentada como ferramenta de preservação e divulgação do patrimônio histórico e cultural
A preservação do patrimônio histórico-cultural enfrenta o desafio da disseminação do conhecimento e da ampliação do acesso à informação. Este estudo tem como objetivo desenvolver um aplicativo móvel em Realidade Aumentada (RA) para promover a valorização e conservação da Ilha Anchieta, unidade de conservação no litoral de Ubatuba (SP), por meio da visualização de modelos 3D, imagens 360° e recursos interativos. A metodologia adotada foi um estudo de caso com abordagem qualitativa, combinando pesquisa histórica, levantamento geográfico, modelagem tridimensional e desenvolvimento em Flutter com integração ao Unity. Os resultados incluem um aplicativo funcional que oferece navegação por mapa interativo, visualização em RA do antigo presídio da ilha e outros pontos turísticos, linha do tempo histórica e quiz educativo. Os testes indicaram elevado engajamento e imersão dos usuários. Como contribuição, o projeto propõe uma nova forma de sensibilização para o patrimônio, utilizando tecnologias digitais acessíveis para apoiar práticas de educação, turismo e preservação cultural.
- Open Access
- 20 July 2025
- Published by Sociedade Brasileira de Computação
- p. 5-14
On Variants of the Genome Rearrangement Distance Problem
In comparative genomics, evolutionary distance can be estimated by determining a minimum sequence of genome rearrangements required to transform one genome into another. The length of this sequence is called the rearrangement distance. Traditionally, most studies assumed that compared genomes shared the same set of genes, with only their relative gene order being used for comparison. Recent studies indicate that incorporating intergenic region sizes leads to more accurate distance estimates when analyzing real genomes. Furthermore, they started to consider genomes having a distinct set of genes. In this work, we investigate genome rearrangement problems by incorporating additional information and complexity into the models, in order to achieve more realistic practical results that can benefit several scientific fields.
- 20 July 2025
- Published by Sociedade Brasileira de Computação
- p. 5-14
Open AccessOn Variants of the Genome Rearrangement Distance Problem
In comparative genomics, evolutionary distance can be estimated by determining a minimum sequence of genome rearrangements required to transform one genome into another. The length of this sequence is called the rearrangement distance. Traditionally, most studies assumed that compared genomes shared the same set of genes, with only their relative gene order being used for comparison. Recent studies indicate that incorporating intergenic region sizes leads to more accurate distance estimates when analyzing real genomes. Furthermore, they started to consider genomes having a distinct set of genes. In this work, we investigate genome rearrangement problems by incorporating additional information and complexity into the models, in order to achieve more realistic practical results that can benefit several scientific fields.
- Open Access
- 26 April 2024
- Published by Association for Computing Machinery (ACM) in ACM Computing Surveys
- Vol. 56 (8) , 1-27
Rearrangement Distance Problems: An updated survey
One of the challenges in the Comparative Genomics field is to infer how close two organisms are based on the similarities and differences between their genetic materials. Recent advances in DNA sequencing have made complete genomes increasingly available. That said, several new algorithms trying to infer the distance between two organisms based on genome rearrangements have been proposed in the literature. However, given the diversity of approaches, the diversity of genome rearrangement events, or even how each work models the genomes and what assumptions are made by each of them, finding the ideal algorithm for each situation or simply knowing the range of applicable approaches can be challenging. In this work, we review these approaches having the algorithmic and combinatorial advances since 2010 as our main focus. This survey aims to organize the recently published papers using a concise notation and to indicate the gaps filled by each of them in the literature. This makes it easier to understand what still needs to be done and what has room for enhancement.
- 26 April 2024
- Published by Association for Computing Machinery (ACM) in ACM Computing Surveys
- Vol. 56 (8) , 1-27
Open AccessRearrangement Distance Problems: An updated survey
One of the challenges in the Comparative Genomics field is to infer how close two organisms are based on the similarities and differences between their genetic materials. Recent advances in DNA sequencing have made complete genomes increasingly available. That said, several new algorithms trying to infer the distance between two organisms based on genome rearrangements have been proposed in the literature. However, given the diversity of approaches, the diversity of genome rearrangement events, or even how each work models the genomes and what assumptions are made by each of them, finding the ideal algorithm for each situation or simply knowing the range of applicable approaches can be challenging. In this work, we review these approaches having the algorithmic and combinatorial advances since 2010 as our main focus. This survey aims to organize the recently published papers using a concise notation and to indicate the gaps filled by each of them in the literature. This makes it easier to understand what still needs to be done and what has room for enhancement.
- 15 April 2024
- Published by Springer Nature
- p. 153-172
Maximum Alternating Balanced Cycle Decomposition and Applications in Sorting by Intergenic Operations Problems
- 15 April 2024
- Published by Springer Nature
- p. 153-172
Maximum Alternating Balanced Cycle Decomposition and Applications in Sorting by Intergenic Operations Problems
- 2 September 2023
- Published by Springer Nature
- p. 1-13
Block Interchange and Reversal Distance on Unbalanced Genomes
- 2 September 2023
- Published by Springer Nature
- p. 1-13
Block Interchange and Reversal Distance on Unbalanced Genomes
- 1 August 2023
- Published by SAGE Publications in Journal of Computational Biology
- Vol. 30 (8) , 861-876
Reversal and Transposition Distance on Unbalanced Genomes Using Intergenic Information
The most common way to calculate the rearrangement distance between two genomes is to use the size of a minimum length sequence of rearrangements that transforms one of the two given genomes into the other, where the genomes are represented as permutations using only their gene order, based on the assumption that genomes have the same gene content. With the advance of research in genome rearrangements, new works extended the classical models by either considering genomes with different gene content (unbalanced genomes) or including more genomic characteristics to the mathematical representation of the genomes, such as the distribution of intergenic regions sizes. In this study, we study the Reversal, Transposition, and Indel (Insertion and Deletion) Distance using intergenic information, which allows comparing unbalanced genomes, because indels are included in the rearrangement model (i.e., the set of possible rearrangements allowed when we compute the distance). For the particular case of transpositions and indels on unbalanced genomes, we present a 4-approximation algorithm, improving a previous 4.5 approximation. This algorithm is extended so as to deal with gene orientation and to maintain the 4-approximation factor for the Reversal, Transposition, and Indel Distance on unbalanced genomes. Furthermore, we evaluate the proposed algorithms using experiments on simulated data.
- 1 August 2023
- Published by SAGE Publications in Journal of Computational Biology
- Vol. 30 (8) , 861-876
Reversal and Transposition Distance on Unbalanced Genomes Using Intergenic Information
The most common way to calculate the rearrangement distance between two genomes is to use the size of a minimum length sequence of rearrangements that transforms one of the two given genomes into the other, where the genomes are represented as permutations using only their gene order, based on the assumption that genomes have the same gene content. With the advance of research in genome rearrangements, new works extended the classical models by either considering genomes with different gene content (unbalanced genomes) or including more genomic characteristics to the mathematical representation of the genomes, such as the distribution of intergenic regions sizes. In this study, we study the Reversal, Transposition, and Indel (Insertion and Deletion) Distance using intergenic information, which allows comparing unbalanced genomes, because indels are included in the rearrangement model (i.e., the set of possible rearrangements allowed when we compute the distance). For the particular case of transpositions and indels on unbalanced genomes, we present a 4-approximation algorithm, improving a previous 4.5 approximation. This algorithm is extended so as to deal with gene orientation and to maintain the 4-approximation factor for the Reversal, Transposition, and Indel Distance on unbalanced genomes. Furthermore, we evaluate the proposed algorithms using experiments on simulated data.
- 27 April 2023
- Published by World Scientific Pub Co Pte Ltd in Journal of Bioinformatics and Computational Biology
- Vol. 21 (02) , 2350009
Rearrangement distance with reversals, indels, and moves in intergenic regions on signed and unsigned permutations
Genome rearrangement events are widely used to estimate a minimum-size sequence of mutations capable of transforming a genome into another. The length of this sequence is called distance, and determining it is the main goal in genome rearrangement distance problems. Problems in the genome rearrangement field differ regarding the set of rearrangement events allowed and the genome representation. In this work, we consider the scenario where the genomes share the same set of genes, gene orientation is known or unknown, and intergenic regions (structures between a pair of genes and at the extremities of the genome) are taken into account. We use two models, the first model allows only conservative events (reversals and moves), and the second model includes non-conservative events (insertions and deletions) in the intergenic regions. We show that both models result in NP-hard problems no matter if gene orientation is known or unknown. When the information regarding the orientation of genes is available, we present for both models an approximation algorithm with a factor of 2. For the scenario where this information is unavailable, we propose a 4-approximation algorithm for both models.
- 27 April 2023
- Published by World Scientific Pub Co Pte Ltd in Journal of Bioinformatics and Computational Biology
- Vol. 21 (02) , 2350009
Rearrangement distance with reversals, indels, and moves in intergenic regions on signed and unsigned permutations
Genome rearrangement events are widely used to estimate a minimum-size sequence of mutations capable of transforming a genome into another. The length of this sequence is called distance, and determining it is the main goal in genome rearrangement distance problems. Problems in the genome rearrangement field differ regarding the set of rearrangement events allowed and the genome representation. In this work, we consider the scenario where the genomes share the same set of genes, gene orientation is known or unknown, and intergenic regions (structures between a pair of genes and at the extremities of the genome) are taken into account. We use two models, the first model allows only conservative events (reversals and moves), and the second model includes non-conservative events (insertions and deletions) in the intergenic regions. We show that both models result in NP-hard problems no matter if gene orientation is known or unknown. When the information regarding the orientation of genes is available, we present for both models an approximation algorithm with a factor of 2. For the scenario where this information is unavailable, we propose a 4-approximation algorithm for both models.
- 16 December 2022
- Published by Springer Nature
- p. 147-157
A 1.375-Approximation Algorithm for Sorting by Transpositions with Faster Running Time
- 16 December 2022
- Published by Springer Nature
- p. 147-157
A 1.375-Approximation Algorithm for Sorting by Transpositions with Faster Running Time
- 17 November 2022
- Published by Springer Nature in Journal of Combinatorial Optimization
- Vol. 45 (1) , 1-30
Approximation algorithms for sorting by k-cuts on signed permutations
- 17 November 2022
- Published by Springer Nature in Journal of Combinatorial Optimization
- Vol. 45 (1) , 1-30
Approximation algorithms for sorting by k-cuts on signed permutations