Giordano Da Lozzo

Assistant Professor (RTDb)

Roma Tre University

Giordano Da Lozzo is a tenure-track assistant professor (RTDb) at Roma Tre University, working in the research group on Graph Algorithms and Network Visualization. Prior to this position, he was a research associate (RTDa) for three years and a postdoctoral researcher (assegnista di ricerca) for four years at the same institution, mentored by Giuseppe Di Battista, and an assistant project scientist for one year, between 2016 and 2017, in the Theory Group of the Center for Algorithms and Theory of Computation at University of California, Irvine, jointly mentored by Michael T. Goodrich and David A. Eppstein.

He obtained his PhD degree in Computer Science and Automation Engineering in 2015 from Roma Tre University, jointly advised by Giuseppe Di Battista and Maurizio Patrignani, where he also graduated cum laude in Computer Engineering presenting a thesis that received the AICA-Confindustria award as best thesis in Information Communication Technology. He was a Leonardo da Vinci fellow at the RIPE Network Coordination Center in Amsterdam and a visiting scholar at the Charles University in Prague. He was also a research visitor at the Universität Tübingen, the Technische Universiteit Eindhoven, and the Karlsruhe Institute of Technology. His Erdös Number is 2. He is a scientific advisor for the Scientific and Technological Area Library Council and has been serving as a member for several cycles of the Doctoral Program in Computer Science and Automation at Roma Tre University.

His research interests are in algorithm engineering and complexity, focused in particular on the practical and theoretical challenges arising from the design of efficient algorithms for the analysis and visualization of networks. His primary area of research lies in graph drawing, a research field at the intersection of the areas of computational geometry, combinatorial optimization, discrete mathematics, and graph theory. He is involved in several research projects exploring fundamental questions about the visualization of large and evolving networks, visualizations for cybersecurity, layouts of simultaneous and clustered networks, as well as contact and hybrid representations of real-world graphs.

He has published 41 articles in prestigious journals in the field of algorithms, such as ACM Transactions on Algorithms, Algorithmica, Discrete and Computational Geometry, SIAM Journal on Computing, and Theoretical Computer Science. He has published 57 conference papers in selective international venues, such as the Symposium on Data Structures and Algorithms (SODA), the Symposium on Computational Geometry (SoCG), the International Colloquium on Automata, Languages and Programming (ICALP), and the European Symposium on Algorithms (ESA). Moreover, he is the coauthor of a book chapter entitled Beyond Clustered Graphs. Finally, he has served as a program committee member in internal conferences and as a reviewer for several journals and research funding projects.

Interests

Graph Drawing
Graph Theory
Discrete & Computational Geometry
Algorithms and Data Structures
Quantum Computing

PhD Students

Giordano Andreola

current
Susanna Caroppo

current

Education

Associate Professor Habilitation (09/H1 - Information Processing Systems), from 2022 to 2031

The Italian Ministry of Education, Universities and Research (MIUR)
PhD in Computer Science and Automation Engineering, 2015

Roma Tre University
MEng in Computer Science (110/110 cum laude), 2010

Roma Tre University

Research Projects

AHeAD

Efficient Algorithms for HArnessing networked Data (funded by the Italian Ministry of University and Scientific Research)

CONNECT

Combinatorics of Networks and Computation (funded by EU Horizon 2020 Programme)

MODE

MOrphing graph Drawings Efficiently (funded by the Italian Ministry of University and Scientific Research)

STACS

The Space/Time Analysis for Cybersecurity program (funded by the U.S. Defense Advanced Research Projects Agency)

AMANDA

Algorithmics for MAssive and Networked DAta (funded by the Italian Ministry of University and Scientific Research)

GraDR

Graph Drawings and Representations (funded by the ESF EUROCORES EuroGIGA Programme)

AlgoDEEP

Algorithmic challenges for Data-intensivE processing on Emerging computing Platforms (funded by the Italian Ministry of University and …

University Service

Department level

Advisor for the BAT (Scientific and Technological Area Library) Scientific Council [web]
Expert member for the State Exam Committee for Computer Engineers [web]

Faculty level [Official page]

Member of the Doctoral Committee in Computer Science and Automation [web]
Member of the Study Plan and Student Practices Committee
Member of the Admission Evaluation Committee for the Master’s Degree in Computer Engineering
Member of the Entrance Exams Committee for the Degree Course in Computer Engineering

Teaching

PhD Courses

Algorithmic Tools for Massive Network Analytics; May 20 – June 25, 2021
Algorithms for Big Data; Sept 21 – Sept 28, 2020

First Level Masters

Python Programming (in Italian, Programmazione in Python); 1st semester; First Level Master a Specialist Operator in Information and Communication Technologies - “Operatore Specializzato in Information and Communication Technologies” (ICT); 6 CFU (2023/2024)

Master Courses

Algorithms for Big Data (in Italian, Algoritmi per Big Data); 1st semester; Master; 6 CFU (2022/2023, 2023/2024, 2024/2025)

Bachelor Courses

Foundations of Computer Science - Module II for Computer Engineering (in Italian, Fondamenti di Informatica): 1st semester; Bachelor; 6 CFU (2024/2025)
Foundations of Computer Science for Electronic Engineering (in Italian, Fondamenti di Informatica): 1st semester; Bachelor; 9 CFU (2022/2023, 2023/2024, 2024/2025)
Elements of Computer Science for Mechanical Engineering (in Italian, Elementi di Informatica): 1st semester; Bachelor; 6 CFU (2022/2023, 2023/2024)

Here are some of the courses for which I was formally appointed as a teaching assistant:

Master Courses

Theoretical Computer Science taught by Prof. Maurizio Patrignani (2015/2016, 2017/2018, 2018/2019)
Information Visualization taught by Prof. Maurizio Patrignani (2013/2014, 2014/2015, 2015/2016)

Bachelor Courses

Foundations of Computer Science taught by Prof. Fabrizio Frati (2017/2018, 2019/2018)

Editorships, Program Commitees, and Workshops

Editorships

JGAA: Special Issue on “Parameterized and Approximation Algorithms in Graph Drawing”, guest editors: G. Da Lozzo and P. Kindermann.

Program committees

WG 2025: 51st International Workshop on Graph-Theoretic Concepts in Computer Science
GD 2025: 33rd International Symposium on Graph Drawing and Network Visualization
EuroCG 2024: 40th European Workshop on Computational Geometry
GD 2022: 30th International Symposium on Graph Drawing and Network Visualization
CCCG 2022: 34th Canadian Conference on Computational Geometry
EuroCG 2022: 38th European Workshop on Computational Geometry
WADS 2021: 16th International Symposium on Algorithms and Data Structures
GD 2019: 27th International Symposium on Graph Drawing and Network Visualization
GD 2017: 25th International Symposium on Graph Drawing and Network Visualization

Chairing of Scientific Workshops

Summer Workshop on Graph Drawing 2025; Sept 7 – Sept 12, 2025 (Chair)
Summer Workshop on Graph Drawing 2024; Sept 1 – Sept 6, 2024 (Chair)
Summer Workshop on Graph Drawing 2023; Sept 10 – Sept 15, 2023 (Chair)
Workshop on Constrained Graph Layouts at Theory Fest 2022; June 20 – June 22, 2022 (Co-chair)
Summer Workshop on Graph Drawing 2022; Sept 1 – Sept 6, 2022 (Chair)
Summer Workshop on Graph Drawing 2021; Aug 31 – Sept 5, 2021 (Co-chair)

Keynote talks

Upward Book Embeddings Complexity and Parameterized Algorithms: Dagstuhl Seminar 23162: New Frontiers of Parameterized Complexity in Graph Drawing – Apr 17, 2023; Schloss Dagstuhl – Leibniz Center for Informatics, Dagstuhl, Germany.
How to Draw a Graph: Luiss Research Seminars – Feb 05, 2021; Luiss University, Rome, Italy.

Awards

Best Student Paper Award at the 18th International Conference and Workshops on Algorithms and Computation (WALCOM 2024):

Susanna Caroppo (Student), Giordano Da Lozzo, and Giuseppe Di Battista: Quantum Graph Drawing. WALCOM 2024: 32–46 PDF

Best Paper Award at the 14th International Symposium on Parameterized and Exact Computation (IPEC 2019):

Giordano Da Lozzo, David Eppstein, Michael T. Goodrich, Siddharth Gupta: C-Planarity Testing of Embedded Clustered Graphs with Bounded Dual Carving-Width. IPEC 2019: 9:1-9:17 PDF

Best Paper Award at the 42nd International Conference on Current Trends in Theory and Practice of Computer (SOFSEM 2016):

Patrizio Angelini, Giordano Da Lozzo, Marco Di Bartolomeo, Valentino Di Donato, Maurizio Patrignani, Vincenzo Roselli, Ioannis G. Tollis: L-Drawings of Directed Graphs. SOFSEM 2016: 134-147 PDF

Best Poster Award at the 23rd International Symposium on Graph Drawing & Network Visualization (GD 2015)

Patrizio Angelini, Giordano Da Lozzo, Giuseppe Di Battista, Fabrizio Frati, Maurizio Patrignani, Ignaz Rutter: On the Relationship Between Map Graphs and Clique Planar Graphs. Graph Drawing 2015: 548-550 PDF

Best MCS Thesis Award by Confindustria Servizi Innovativi e Tecnologici–AICA (CSIT 2011)

Giordano Da Lozzo: Design and analysis of a paradigm for visualizing and exploring relational data in a mobile environment and its implementation on the Google Android platform. Roma Tre University. 2011.

Featured Publications

Michael Bekos, Giordano Da Lozzo, Svenja Griesbach, Martin Gronemann, Fabrizio Montecchiani, Chrysanthi Raftopoulou

2020-01-01 In SoCG 2020

Book Embeddings of Nonplanar Graphs with Small Faces in Few Pages

An embedding of a graph in a book, called book embedding, consists of a linear ordering of its vertices along the spine of the book and an assignment of its edges to the pages of the book, so that no two edges on the same page cross. The book thickness of a graph is the minimum number of pages over all its book embeddings. For planar graphs, a fundamental result is due to Yannakakis, who proposed an algorithm to compute embeddings of planar graphs in books with four pages. Our main contribution is a technique that generalizes this result to a much wider family of nonplanar graphs, which is characterized by a biconnected skeleton of crossing-free edges whose faces have bounded degree. Notably, this family includes all 1-planar and all optimal 2-planar graphs as subgraphs. We prove that this family of graphs has bounded book thickness, and as a corollary, we obtain the first constant upper bound for the book thickness of optimal 2-planar graphs.

Project SoCG 2020 ArXiv

Juan Jose Besa, Giordano Da Lozzo, Michael Goodrich

2019-06-01 In ESA 2019

Computing k-Modal Embeddings of Planar Digraphs

Given a planar digraph $G$ and a positive even integer $k$ , an embedding of $G$ in the plane is $k$ -modal, if every vertex of $G$ is incident to at most $k$ pairs of consecutive edges with opposite orientations, i.e., the incoming and the outgoing edges at each vertex are grouped by the embedding into at most $k$ sets of consecutive edges with the same orientation. In this paper, we study the $k$ -Modality problem, which asks for the existence of a $k$ -modal embedding of a planar digraph. This combinatorial problem is at the very core of a variety of constrained embedding questions for planar digraphs and flat clustered networks.
First, since the $2$ -Modality problem can be easily solved in linear time, we consider the general $k$ -Modality problem for any value of $k > 2$ and show that the problem is NP-complete for planar digraphs of maximum degree $Δ \geq k + 3$ . We relate its computational complexity to that of two notions of planarity for flat clustered networks $:$ Planar Intersection-Link and Planar NodeTrix representations. This allows us to answer in the strongest possible way an open question by Di Giacomo et al. GD17, concerning the complexity of constructing planar NodeTrix representations of flat clustered networks with small clusters, and to address a research question by Angelini et al. JGAA17, concerning intersection-link representations based on geometric objects that determine complex arrangements. On the positive side, we provide a simple FPT algorithm for partial $2$ -trees of arbitrary degree, whose running time is exponential in $k$ and linear in the input size.
Second, motivated by the recently-introduced planar L-drawings of planar digraphs GD17, which require the computation of a $4$ -modal embedding, we focus our attention on $k = 4$ . On the algorithmic side, we show a complexity dichotomy for the $4$ -Modality problem with respect to $Δ$ , by providing a linear-time algorithm for planar digraphs with $Δ \leq 6$ . This algorithmic result is based on decomposing the input digraph into its blocks via BC-trees and each of these blocks into its triconnected components via SPQR-trees. In particular, we are able to show that the constraints imposed on the embedding by the rigid triconnected components can be tackled by means of a small set of reduction rules and discover that the algorithmic core of the problem lies in special instances of NaeSat, which we prove to be always NAE-satisfiable–a result of independent interest that improves on Porschen et al. SAT03.
Finally, on the combinatorial side, we consider outerplanar digraphs and show that any such a digraph always admits a $k$ -modal embedding with $k = 4$ and that this value of $k$ is best possible for the digraphs in this family.