Ramūnas Forsberg Gutkovas, Ph.D.

ramunasg@gmail.com

About

I am a consultant at Ictech. On this site you can find my previous work that I've done as an academic and personal projects.

I am a computer scientist interested in programming language theory and formal verification of concurrent systems.

Previously, I was a research fellow at NOVA LINCS, working with Luís Caires and the Software Systems group.

I earned a computer science doctorate degree from Uppsala University for my work on concurrent system verification. There, I was advised by Johannes Borgström and Björn Victor.

Publications

My publication list can also be found on the dblp page.

Licentiate Thesis

PhD Thesis

Languages, Logics, Types and Tools for Concurrent System Modelling

The cover page of the PhD Thesis 'Languages, Logics, Types and Tools for Concurrent System Modelling'

I defended my Ph.D. thesis on Sep 9, 2016. The opponent was associate professor Thomas T. Hildebrandt of IT University of Copenhagen. The grading comitee was comprised of Prof. Nobuko Yoshida, Prof. Jan Frisco Groote, and Assoc. Prof. Tobias Wrigstad.

Abstract

A concurrent system is a computer system with components that run in parallel and interact with each other. Such systems are ubiquitous and are notably responsible for supporting the infrastructure for transport, commerce and entertainment. They are very difficult to design and implement correctly: many different modeling languages and verification techniques have been devised to reason about them and verifying their correctness. However, existing languages and techniques can only express a limited range of systems and properties.

In this dissertation, we address some of the shortcomings of established models and theories in four ways: by introducing a general modal logic, extending a modelling language with types and a more general operation, providing an automated tool support, and adapting an established behavioural type theory to specify and verify systems with unreliable communication.

A modal logic for transition systems is a way of specifying properties of concurrent system abstractly. We have developed a modal logic for nominal transition systems. Such systems are common and include the pi-calculus and psi-calculi. The logic is adequate for many process calculi with regard to their behavioural equivalence even for those that no logic has been considered, for example, CCS, the pi-calculus, psi-calculi, the spi-calculus, and the fusion calculus.

The psi-calculi framework is a parametric process calculi framework that subsumes many existing process calculi. We extend psi-calculi with a type system, called sorts, and a more general notion of pattern matching in an input process. This gives additional expressive power allowing us to capture directly even more process calculi than was previously possible. We have reestablished the main results of psi-calculi to show that the extensions are consistent.

We have developed a tool that is based on the psi-calculi, called the psi-calculi workbench. It provides automation for executing the psi-calculi processes and generating a witness for a behavioural equivalence between processes. The tool can be used both as a library and as an interactive application.

Lastly, we developed a process calculus for unreliable broadcast systems and equipped it with a binary session type system. The process calculus captures the operations of scatter and gather in wireless sensor and ad-hoc networks. The type system enjoys the usual property of subject reduction, meaning that well-typed processes reduce to well-typed processes. To cope with unreliability, we also introduce a notion of process recovery that does not involve communication. This is the first session type system for a model with unreliable communication.

Talks/Slides

The title slide of the presentation Languages, Logics, Types and Tools for Concurrent System Modelling

Languages, Logics, Types and Tools for Concurrent System Modelling

NOVA LINCS Seminar
2016-12-14
The title slide of the presentation Advancing Concurrent System Verification

Advancing Concurrent System Verification

Licentiate Seminar, Uppsala University
2014-10-20
The title slide of the presentation A Parametric Tool for Applied Process Calculi

A Parametric Tool for Applied Process Calculi

Psi-Calculi Workbench
ProFuN Project Seminar, Uppsala, Uppsala University
2014
The title slide of the presentation Process Calculi for WSNs and more

Process Calculi for WSNs and more

ProFuN Project Workshop, Uppsala
2014
The title slide of the presentation A Parametric Tool for Applied Process Calculi

A Parametric Tool for Applied Process Calculi

Psi-Calculi Workbench
ACSD13, Barcelona, Spain
2013
The title slide of the presentation Presentation of DPLL(T)

Presentation of DPLL(T)

The SMT Reading Group, Uppsala, Uppsala University
2012-10-31
The title slide of the presentation Psi-Calculi Workbench

Psi-Calculi Workbench

YR-CONCUR, New Castle, UK
2012

Software

I keep my software projects on GitHub Icon GitHub.

Psi-Calculi Workbench (GitHub Icon source code) is a tool for concurrent system verification (e.g., internet protocols, security protocols, cache coherence algorithms, etc.) based on the Psi-calculi framework. Produces symbolic execution traces, can be interfaced with external constraint solvers (e.g., SMTs).

This page is generated form a Plain TeX file using my plain GitHub Icon TeX engine.