Professor Nelson Maculan, Fellow of CORE Academy, took part in the Third Brazil–China Joint Mathematical Meeting, held from August 9 to 14, 2026, in Luís Correia, Piauí, Brazil. In addition to helping organize the Brazilian participation, he delivered a presentation on the development of mathematical optimization models for the Euclidean Steiner Tree Problem.
Photo: Ana Santiago. Source: Brazilian Mathematical Society (SBM)
Convened by the Brazilian Mathematical Society (SBM), the Brazilian Society for Computational and Applied Mathematics (SBMAC), and the Chinese Mathematical Society, the meeting brought together approximately 130 researchers and students, including around 35 participants from China. It followed earlier editions held in Foz do Iguaçu in 2024 and China in 2025, continuing a steadily growing exchange between the mathematical communities of the two countries.
This year’s meeting was the first in the series to be held outside one of Brazil’s major academic centers. Its location on the coast of Piauí brought internationally recognized mathematicians into closer contact with students, faculty members, and institutions in the region.
The five-day scientific program encompassed pure, applied, and computational mathematics. It included eight plenary lectures, thematic sessions, poster presentations, and a concluding roundtable, with discussions ranging from geometry, algebra, and dynamical systems to differential equations, optimization, quantum mathematics, and industrial applications.
Photo: Ana Santiago. Source: Brazilian Mathematical Society (SBM)
Collaboration was built into the program itself. Thematic sessions were jointly proposed by researchers based in Brazil and China, encouraging colleagues from the two countries to identify shared interests and develop sessions together. This format reflected the wider purpose of the meeting: to turn academic exchange into sustained relationships, collaborative research, and opportunities for younger scholars.
Professor Maculan helped coordinate the Brazilian contribution together with three Brazilian professors who had completed their doctoral studies under his supervision. This intergenerational dimension was especially fitting for a meeting concerned not only with current research, but also with the future of mathematical cooperation between Brazil and China.
His presentation, “Mathematical Optimization Models for the Euclidean Steiner Tree Problem in Rⁿ,” examined a classical problem that remains computationally demanding. The Euclidean Steiner Tree Problem asks how a given collection of points in Euclidean space can be connected by a tree of minimum total length. Additional points, known as Steiner points, may be introduced when they shorten the resulting network.
The problem is simple to state but difficult to solve. Although many geometric properties of optimal Steiner trees are well understood, translating them into mathematical formulations that can be handled efficiently by optimization algorithms remains a considerable challenge, particularly in higher dimensions.
Photo: Ana Santiago. Source: Brazilian Mathematical Society (SBM)
Professor Maculan reviewed the development of optimization models for the problem since the late 1990s, identifying key modeling difficulties and the methods introduced to address them. His presentation considered mixed-integer nonlinear formulations, relaxations, conic models, exact algorithms, and heuristic approaches, as well as their application through numerical methods such as branch-and-bound.
The lecture drew upon a field of research to which Professor Maculan and his collaborators have contributed for more than two decades. In 2000, he co-authored one of the early mathematical programming formulations of the Euclidean Steiner Tree Problem in n-dimensional space. Subsequent collaborations explored conic formulations, exact and heuristic algorithms, and new mixed-integer nonlinear models. Most recently, he and his co-authors brought these developments together in an invited survey published in 4OR: A Quarterly Journal of Operations Research in 2025.
Professor Maculan’s participation also continued his longstanding engagement with Chinese mathematics. For more than ten years, he has maintained research ties with colleagues in applied mathematics at the Chinese Academy of Sciences, where he has also taught combinatorial optimization. Reflecting on the development of these relationships, he observed that there had been “significant growth in collaboration between the two countries.”
Photo: Ana Santiago. Source: Brazilian Mathematical Society (SBM)
He also emphasized that scientific knowledge cannot be confined within national borders. International meetings allow researchers to encounter different approaches, develop new questions, and form relationships that may grow into future projects and exchanges. Now 83, Professor Maculan described the meeting as another opportunity to learn from both Brazilian and international colleagues—an intellectual openness that has marked his long academic career.
Professor Maculan is Professor Emeritus at the Federal University of Rio de Janeiro, where he has been associated with COPPE’s Department of Systems Engineering and Computer Science and the Institute of Mathematics. His career has brought together research, education, and academic leadership. He has served as President of UFRJ, Brazil’s National Secretary of Higher Education, and President of the International Federation of Operational Research Societies. He is a Full Member of the Brazilian Academy of Sciences and the National Academy of Engineering of Brazil, as well as a Fellow of The World Academy of Sciences.
Professor Nelson Maculan’s CORE Academy Profile
Alongside his contributions to optimization, operations research, applied mathematics, and computer science, Professor Maculan has helped educate successive generations of scholars, supervising 82 doctoral theses and 177 master’s dissertations.
CORE Academy is pleased to recognize Professor Maculan’s continuing contributions to mathematical research and international scientific cooperation. The relationships connecting Brazil and China have been built over many years; through meetings such as this one, they continue to deepen and to open new paths for the generations that follow.
References and Related Links
1. Brazil–China Joint Mathematical Meeting (https://jointmeetingbrazilchina.org/)
2. Brazilian Mathematical Society: Third Brazil–China Meeting Strengthens Mathematical Cooperation (https://sbm.org.br/noticias/3o-encontro-brasil-china-fortalece-cooperacao-matematica-e-amplia-conexoes-cientificas-no-piaui/)
3. Professor Nelson Maculan’s CORE Academy Profile (https://coreacad.org/Member.aspx?ProId=40)
4. Mathematical Optimization Models for the Euclidean Steiner Tree Problem in R^d (https://doi.org/10.1007/s10288-025-00604-z)