# James Ortiz

> Associate Professor at the Laboratory of Algorithms, Complexity and Logic (LACL), Université Paris-Est Créteil (UPEC). Researcher in formal methods, timed automata, temporal logics, cybersecurity, and model-based testing.

Last updated: 2026-08-15
Site: https://jamesortiz.site/
Email: james.ortiz-vega@u-pec.fr

## Who is James Ortiz?

James Ortiz is an Associate Professor at the Laboratory of Algorithms, Complexity and Logic (LACL) at Université Paris-Est Créteil. He holds a PhD in Computer Science from the University of Namur and works on formal methods, timed automata, and cybersecurity.

He teaches at EPISEN and belongs to the Specification and Verification of Systems team. He previously was a postdoctoral researcher in the Autonomous and Critical Embedded Systems (ACES) group at Télécom Paris (LTCI), from February 2024 to August 2025. His PhD, defended in Namur in April 2023 under Prof. Pierre-Yves Schobbens, developed timed automata with partially independent clocks. He holds an M.Sc. in Computer Science from Universidad del Valle, Colombia (2006–2008). He is Belgian and Colombian.

## Biography

I am an associate professor at the Laboratory of Algorithms, Complexity and Logic (LACL) at Université Paris-Est Créteil (UPEC). I teach at EPISEN and am a member of the Specification and Verification of Systems team.

Previously, I was a postdoctoral researcher in the Autonomous and Critical Embedded Systems (ACES) group at the LTCI laboratory of Télécom Paris, within the Networks and Computer Science department, where I worked from February 2024 to September 2025. I obtained a PhD in Computer Science from the University of Namur, where my research focused on the development of timed automata using asynchronous clocks.

My research addresses both theoretical and practical aspects of formal methods, timed automata, model-based testing, temporal and timed logics, model checking, as well as cyber-physical systems and cybersecurity.

I have developed mutation testing techniques for timed models, logical frameworks for cybersecurity-oriented dynamic games, and verification tools (MUPPAAL, MIMETIC, MUTES). My work has particularly focused on clock synchronization and desynchronization in timed automata theory, as well as temporal logics for adversarial systems. These works are applied to cybersecurity, with a focus on real-time systems, security, and resilience against attacks.

## Spoken languages

- Spanish — native
- English — C1 (PhD and publications in English)
- French — C1 (teaching in French)
- Portuguese — B2

## Research

His research covers theoretical and applied formal methods: timed automata with asynchronous clocks, temporal and timed logics, model checking, model-based and mutation testing, and verification of cyber-physical and security-critical systems.

Topics: Cyber-Security Systems; Cyber-Physical Systems; Distributed Systems; Real-Time Systems; Critical Embedded Systems; Timed Automata (partially independent clocks); Temporal Logics (including TCTL); Simulation and Bisimulation; Model Checking (UPPAAL, SCADE); Formal Methods; Theorem Proving; Model-Based Testing; Mutation Testing; Software Product Lines; Analysis and Symbolic Representation.

## Tools

He has contributed to verification and testing tools including MUPPAAL, MIMETIC, and MUTES. These tools support mutation testing of timed models and formal analysis of real-time systems, with applications in cybersecurity and resilience against attacks.

MUPPAAL reduces and removes equivalent and duplicate mutants in UPPAAL models (STVR 2024). Related model checkers used in this work include UPPAAL, SCADE, Spin, PRISM, and νSMV.

## Publications

Profiles: ORCID https://orcid.org/0000-0001-5407-963X · Google Scholar https://scholar.google.com/citations?user=x5XHr_AAAAAJ&hl=en · DBLP https://dblp.org/pid/24/8836.html · ResearchGate https://www.researchgate.net/profile/James-Ortiz

### Journals

- MUPPAAL: Efficient Elimination and Reduction of Useless Mutants in Real-Time Model-based Systems (2024). Jaime Cuartas, David Cortés, Joan S. Betancourt, Jesús Aranda, Maxime Cordy, James Ortiz, Gilles Perrouin, Pierre-Yves Schobbens. Software Testing, Verification and Reliability (STVR).
- Applying parallelism to a bisimulation algorithm to improve efficiency in software testing of time-critical systems (2023). Joan S. Betancourt, Jesús Aranda, James Ortiz. Ingeniería y Competitividad. https://doi.org/10.25100/iyc.v25iSuplemento.1314
- Providing Command and Control Agility: a Software Product Line Approach (2023). Junier Caminha Amorim, Eduardo Lemos, Luigi Minardi, Vander Alves, Edison Pignaton de Freitas, Moussa Amrani, James Ortiz, Pierre-Yves Schobbens, Gilles Perrouin. Expert Systems with Applications, 216, 119473.
- Modeling and Specification of Distributed Timed Systems (2013). James Ortiz. Ingeniería y Competitividad.
- Crear: Consejero para la Repetición de Artículos y Evaluadores en Eventos Académicos (2004). James Jerson Ortiz, Jesus Aranda, Juan Francisco Díaz. Ingeniería y Competitividad.

### Conferences

- A Verification Framework for Obstruction, Probability, and Time (2026). Axel Oscar, James Ortiz, Jean Leneutre, Vadim Malvone. AAMAS 2026.
- Extending Timed Automata with Clock Derivatives (2025). James Ortiz, Jean Leneutre, Vadim Malvone, Pierre-Yves Schobbens. iFM 2025.
- Coalition Obstruction Temporal Logic (2025). Davide Catta, Jean Leneutre, Vadim Malvone, James Ortiz. IJCAI 2025.
- A Timed Obstruction Temporal Logic to Reason about Dynamic Game Models (2025). James Ortiz, Jean Leneutre, Vadim Malvone. AAMAS 2025.
- Time for Networks: Mutation Testing for Timed Automata Networks (2024). David Cortés, James Ortiz, Davide Basile, Jesus Aranda, Gilles Perrouin, Pierre-Yves Schobbens. FormaliSE 2024.
- MLv: A Distributed Real-Time Modal Logic (2019). James Ortiz, Moussa Amrani, Pierre-Yves Schobbens. NASA Formal Methods 2019.
- Model-based Mutation Operators for Timed Systems: A Taxonomy and Research Agenda (2018). James Ortiz, Gilles Perrouin, Moussa Amrani, Pierre-Yves Schobbens. IEEE QRS 2018.
- Multi-timed Bisimulation for Distributed Timed Automata (2017). James Ortiz, Moussa Amrani, Pierre-Yves Schobbens. NASA Formal Methods 2017.
- Memory Event Clocks (2010). James Ortiz, Axel Legay, Pierre-Yves Schobbens. FORMATS 2010.
- The Problem of Assigning Evaluators to the Articles Submitted in an Academic Event (2005). James Ortiz, Jesús Aranda, Juan Francisco Díaz. Mozart/OZ Conference, LNCS 3389.
- El Problema de la Asignación de Evaluadores para los Artículos Presentados a un Evento Académico (2005). James Ortiz, Jesús Aranda, Juan Francisco Díaz. CLEI.

### Workshops

- Reasoning about Real-Time and Probability on Obstruction Logic (2024). James Ortiz, Jean Leneutre, Vadim Malvone. SPIRIT 2024.
- An Alternative Semantics for Timed Automata with Independent Clocks (2023). James Ortiz, Pierre-Yves Schobbens. Recent Advances in Concurrency and Logic.
- Formal Verification of a Mechanical Ventilator using UPPAAL (2023). Jaime Cuartas, David Cortés, Joan S. Betancourt, Jesús Aranda, José I. García, Andrés M. Valencia, James Ortiz. FTSCS 2023.
- MUPPAAL: Reducing and Removing Equivalent and Duplicate Mutants in UPPAAL (2023). Jaime Cuartas, Jesus Aranda, Maxime Cordy, James Ortiz, Gilles Perrouin, Pierre-Yves Schobbens. A-MOST 2023.
- Extended Abstract: Multi-timed Bisimulation for Distributed Timed Automata (2016). James Ortiz, Pierre-Yves Schobbens. Open Problems in real-time computing.
- ArThUR: A Tool for Markov Logic Network (2014). Keyvin Evrand, Axel Bodart, James Ortiz, Pierre-Yves Schobbens. OTM 2014.

## Teaching

He teaches at EPISEN, the engineering school of Université Paris-Est Créteil. Current courses (2025–2026, Bachelor, 24 hours, Associate Professor):

- Software Security (ING3-1)
- Cloud Security (ING3-2)
- Algorithm Analysis (ECUE-143)
- Python Programming (ECUE-142)

Earlier: Model Checking (INFOM471) at the University of Namur; Fundamentals of Distributed System Verification at Télécom Paris (2024–2025); Programming 2, Algorithms 2, Language Theory, and Operations Research at Namur (2015–2024); Algorithms and Programming Languages at Universidad del Valle (2008–2010).

## Experience

- Associate Professor, LACL, Université Paris-Est Créteil, France (September 2025 – present)
- Post-Doctoral Researcher, Télécom Paris / Institut Polytechnique de Paris, France (February 2024 – August 2025). Supervised by Profs. Jean Leneutre and Vadim Malvone, ACES / LTCI.
- Post-Doctoral Researcher, University of Namur, Belgium (July 2023 – January 2024). Supervised by Prof. Pierre-Yves Schobbens.
- Research Engineer, University of Namur (2015–2017, D-DAMS; 2011–2015, TPA). Funded by the Walloon Region.
- Ph.D. in Computer Science, University of Namur (2017–2023). Thesis: Modeling and Verifying Distributed and Real-Time Systems using Timed Automata with Partially Independent Clocks.
- M.Sc. in Computer Science, Universidad del Valle, Colombia (2006–2008).

## Projects

- TAPAS (ANR, 2024–2027), Principal Investigator. Trustworthy Automated Protocol Analysis for Security. https://anr.fr/project/tapas
- Scaling Up Variability (EU Horizon Europe, 2023–2026), Co-Investigator.
- SecureIoT (Belgian Science Foundation, 2020–2023), Researcher.

## Contact

- Email: james.ortiz-vega@u-pec.fr
- Phone: (+33) 1.60.74.68.40
- Office: P2-212, Building P2, Campus Centre
- Address: Université Paris-Est Créteil, 61 avenue du Général de Gaulle, 94000 Créteil, France
- ORCID: https://orcid.org/0000-0001-5407-963X
- Google Scholar: https://scholar.google.com/citations?user=x5XHr_AAAAAJ&hl=en
- DBLP: https://dblp.org/pid/24/8836.html
- ResearchGate: https://www.researchgate.net/profile/James-Ortiz
- GitHub: https://github.com/jortizve
- LinkedIn: https://www.linkedin.com/in/james-ortiz-44bb9b53
- X / Twitter: https://twitter.com/jortizve

## Pages

HTML pages use a language prefix (`/en`, `/es`, `/fr`, `/pt`). Unprefixed URLs redirect to English.

- Home: https://jamesortiz.site/en · https://jamesortiz.site/index.md
- Research: https://jamesortiz.site/en/research · https://jamesortiz.site/research.md
- Publications: https://jamesortiz.site/en/publications · https://jamesortiz.site/publications.md
- Teaching: https://jamesortiz.site/en/teaching · https://jamesortiz.site/teaching.md
- Experience: https://jamesortiz.site/en/experience · https://jamesortiz.site/experience.md
- Projects: https://jamesortiz.site/en/projects · https://jamesortiz.site/projects.md
- Contact: https://jamesortiz.site/en/contact · https://jamesortiz.site/contact.md
- OKF bundle: https://jamesortiz.site/okf/index.md