34 citations · 77 across the 12 of their papers we have counts for
16 papers
Bisimulations Respecting Duration and Causality for the Non-interleaving Applied -Calculus
Clément Aubert, Ross Horne, Christian Johansen
This paper shows how we can make use of an asynchronous transition system, whose transitions are labelled with events and which is equipped with a notion of independence of events,…
Generating Posets with Interfaces
Olavi Äikäs, Uli Fahrenberg, Christian Johansen +1
We generate and count isomorphism classes of gluing-parallel posets with interfaces (iposets) on up to eight points, and on up to ten points with interfaces removed. In order to do…
Kleene Theorem for Higher-Dimensional Automata
Uli Fahrenberg, Christian Johansen, Georg Struth +1
We prove a Kleene theorem for higher-dimensional automata. It states that the languages they recognise are precisely the rational subsumption-closed sets of finite interval pomsets…
Posets with Interfaces as a Model for Concurrency
Uli Fahrenberg, Christian Johansen, Georg Struth +1
We introduce posets with interfaces (iposets) and generalise their standard serial composition to a new gluing composition. In the partial order semantics of concurrency, interface…
lr-Multisemigroups and Modal Convolution Algebras
Uli Fahrenberg, Christian Johnsen, Georg Struth +1
We show how modal quantales arise as convolution algebras of functions from lr-multisemigroups that is, multisemigroups with a source map l and a target map r, into modal quantales…
Languages of Higher-Dimensional Automata
Uli Fahrenberg, Christian Johansen, Georg Struth +1
We introduce languages of higher-dimensional automata (HDAs) and develop some of their properties. To this end, we define a new category of precubical sets, uniquely naturally isom…
A Multidisciplinary Definition of Privacy Labels: The Story of Princess Privacy and the Seven Helpers
Johanna Johansen, Tore Pedersen, Simone Fischer-Hübner +6
Privacy is currently in distress and in need of rescue, much like princesses in the all-familiar fairytales. We employ storytelling and metaphors from fairytales to make reader-fri…
Multimode-polariton superradiance via Floquet engineering
Christian Høj Johansen, Johannes Lang, Andrea Morales +3
We consider an ensemble of ultracold bosonic atoms within a near-planar cavity, driven by a far detuned laser whose phase is modulated at a frequency comparable to the transverse c…
Domain Semirings United
Uli Fahrenberg, Christian Johansen, Georg Struth +1
Domain operations on semirings have been axiomatised in two different ways: by a map from an additively idempotent semiring into a boolean subalgebra of the semiring bounded by the…
Studying the Transfer of Biases from Programmers to Programs
Johanna Johansen, Tore Pedersen, Christian Johansen
It is generally agreed that one origin of machine bias is resulting from characteristics within the dataset on which the algorithms are trained, i.e., the data does not warrant a g…
Generating Posets Beyond N
Uli Fahrenberg, Christian Johansen, Georg Struth +1
We introduce iposets---posets with interfaces---equipped with a novel gluing composition along interfaces and the standard parallel composition. We study their basic algebraic prop…
Sculptures in Concurrency
Uli Fahrenberg, Christian Johansen, Christopher A. Trotter +1
We give a formalization of Pratt's intuitive sculpting process for higher-dimensional automata (HDA). Intuitively, an HDA is a sculpture if it can be embedded in (i.e., sculpted fr…
InfoInternet for Education in the Global South: A Study of Applications Enabled by Free Information-only Internet Access in Technologically Disadvantaged Areas (authors' version)
Johanna Johansen, Christian Johansen, Josef Noll
This paper summarises our work on studying educational applications enabled by the introduction of a new information layer called InfoInternet. This is an initiative to facilitate…
The Snowden Phone: A Comparative Survey of Secure Instant Messaging Mobile Applications
Christian Johansen, Aulon Mujaj, Hamed Arshad +1
In recent years, it has come to attention that governments have been doing mass surveillance of personal communications without the consent of the citizens. As a consequence of the…
Automated verification of dynamic root of trust protocols (long version)
Sergiu Bursuc, Christian Johansen, Shiwei Xu
Automated verification of security protocols based on dynamic root of trust, typically relying on protected hardware such as TPM, involves several challenges that we address in thi…
Dynamic Structural Operational Semantics
Christian Johansen, Olaf Owe
We introduce Dynamic SOS as a framework for describing semantics of programming languages that include dynamic software upgrades, for upgrading software code during run-time. Dynam…