Eduard Kamburjan

• Kamburjan, Eduard; Klungre, Vidar Norstein; Qu, Yuanwei; Schlatte, Rudolf; Kostylev, Egor V. & Giese, Martin [Vis alle 7 forfattere av denne artikkelen] (2026). Semantically Reflected Programs. Transactions on Graph Data and Knowledge (TGDK). 4(1), s. 3:1–3:52. doi: 10.4230/TGDK.4.1.3. Fulltekst i vitenarkiv Vis sammendrag

  This paper addresses the dichotomy between the formalization of structural and the formalization of executable behavioral knowledge by means of semantically lifted programs, which explore an intuitive connection between imperative programs and knowledge graphs. While knowledge graphs and ontologies are eminently useful to represent formal knowledge about a system’s individuals and universals, programming languages are designed to describe the system’s evolution. To address this dichotomy, we introduce a semantic lifting of the program states of an executing progam into a knowledge graph, for an object-oriented programming language. The resulting graph is exposed as a semantic reflection layer within the programming language, allowing programmers to leverage knowledge of the application domain in their programs during execution. In this paper, we formalize semantic lifting and semantic reflection for a small imperative programming language, SMOL, explain the operational aspects of the language, and consider type correctness and virtualization for runtime program queries through the semantic reflection layer. We illustrate semantic lifting and semantic reflection through a case study of geological modeling and discuss different applications of the technique. The language implementation is open source and available online.

• Lyu, Qianhang; Zhou, Baifan; Skjæveland, Martin Georg; Kamburjan, Eduard; Schüller, Andreas & Cameron, David B. [Vis alle 9 forfattere av denne artikkelen] (2026). A system information modelling method in the cross-disciplinary project collaboration context for industrial digitalisation. Scientific Reports. 16. doi: 10.1038/s41598-026-51522-x. Fulltekst i vitenarkiv Vis sammendrag

  Industrial digitalisation for project management (PM) is a promising strategy for organising knowledge, skills, tools, and techniques to successfully complete projects. However, system information modelling (SIM), as a key approach that enables the digitalisation of industrial systems, is often applied separately without a PM context. This situation results in fragmentation of project information and hinders collaboration among stakeholders. Limited research has explored on integrating SIM technologies and PM principles. To bridge this gap, this paper proposes IMF-PM, a SIM methodology that integrates the Information Modelling Framework (IMF) with Project Management Body of Knowledge (PMBOK) standards for digitalisation in the context of cross-disciplinary project collaboration. IMF-PM provides an engineer-friendly, multi-aspect language that enables cross-disciplinary modelling within a unified framework, while also supporting Resource Description Framework (RDF) serialisation for digitalisation. We present an industrial case study of a gas cooling system, providing exploratory practical evidence of function-implementation consistency and non-destructive integration. The case study and comparative analysis provide exploratory evidence of the practical utility of IMF-PM for interdisciplinary coordination, traceability, and project information integration in cross-disciplinary industrial projects. This research provides a new paradigm for project information digitalisation in the industry.

• John, Tobias; Johnsen, Einar Broch & Kamburjan, Eduard (2026). Mutation-Based Integration Testing of Knowledge Graph Applications (Summary). GI-Edition Lecture Notes in Informatics (LNI). ISSN 1617-5468. P-377, s. 143–144. doi: 10.18420/se2026_44. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Bencomo, Nelly; Johnsen, Einar Broch & Tarifa, Silvia Lizeth Tapia (2026). Declarative Lifecycle Management for Self-Adaptive Systems. Software and Systems Modeling (SoSyM). ISSN 1619-1366. doi: 10.1007/s10270-026-01358-w. Fulltekst i vitenarkiv Vis sammendrag

  Self-adaptive systems can be realised as layered systems with a feedback loop: a managing system monitors a managed system, updates an internal model, and adjusts the managed system by means of controllers to maintain given requirements. For example, a digital twin coupled with its physical twin constitute such a self-adaptive system. As the managed system shifts between different stages in its lifecycle, these requirements, as well as the associated analysers and controllers, may need to change. The exact triggers for such shifts in a managed system are often hard to predict: they may be difficult to describe or even unknown. However, the shifts can generally be observed once they have occurred, in terms of changes in the system behaviour. This paper proposes an automated method for self-adaptation in self-adaptive systems to address shifts between lifecycle stages in a managed system. Our method is based on declarative descriptions of lifecycle stages for assets in a managed system and their associated counterparts in the managing system. Declarative lifecycle management provides a high-level, flexible method of self-adaptation for self-adaptive systems to reflect disruptive shifts between stages in a managed system.

• John, Tobias; Johnsen, Einar Broch & Kamburjan, Eduard (2026). Mutation-based testing of knowledge graphs. Empirical Software Engineering. ISSN 1382-3256. 31. doi: 10.1007/s10664-026-10810-w. Fulltekst i vitenarkiv Vis sammendrag

  With the advent of AI-driven applications, testing faces new challenges when it comes to the integration of software with AI components. We present a novel testing approach to tackle the integration of software with symbolic AI in the form of knowledge graphs (KG). As the KG is expected to change during the run- and lifetime of the software, we must ensure the robustness of the system w.r.t. changes in the KG. Starting with a single KG, we mutate its content and test the unchanged software with the original test oracle. To address the specific challenges of KGs, we introduce two additional concepts. First, as generic mutations on single triples are too fine-grained to reliably generate a KG describing a different, consistent KG, we introduce domain-specific mutation operators that manipulate subgraphs in a domain-adherent way. Second, we need to specify those parts of the knowledge graph that the software relies on for correctness. We introduce the notion of a robustness mask to describe shapes in the graph to which the mutant must conform. We evaluate our approach on two software applications from the robotic and simulation domain that tightly integrate with their respective KG, as well as three OWL reasoners, where we found several previously unknown bugs.

• Kamburjan, Eduard; Pernisch, Romana; Corcho, Oscar & Chaves-Fraga, David (2025). On Dependencies in Knowledge Graph Construction. CEUR Workshop Proceedings. 3999. doi: https:/ceur-ws.org/Vol-3999/. Fulltekst i vitenarkiv Vis sammendrag

  Knowledge graph construction (KGC) requires numerous assets, such as shapes or mappings, to interact correctly. However, maintenance and assessment of the quality of the pipeline implementing the construction is difficult, as software engineering analyses and quality measures do not address the technologies used in KGC. In this paper, we propose a syntactic, easy to compute notion of dependencies between assets, and show its capability to assess change propagation. Furthermore, we discuss potential to use it for coupling and impact estimation. We evaluate our approach using a prototypical implementation and a case study from the literature, where we find two bugs where missing dependencies indicated an error due to miscommunication during change propagation between the developers of two different assets.

• Kamburjan, Eduard; Slaughter, Laura Ann; Johnsen, Einar Broch; Pferscher, Andrea & Weihl, Laura (2025). Towards Self-Adaptive Data Management in Digital Twins for Biodiversity Monitoring. I Kessentini, Marouane; Sahraoui, Houari & Ali, Shaukat (Red.), 2025 ACM/IEEE 28th International Conference on Model Driven Engineering Languages and Systems Companion (MODELS-C). IEEE (Institute of Electrical and Electronics Engineers). ISSN 9798331579906. s. 257–263. doi: 10.1109/models-c68889.2025.00044. Fulltekst i vitenarkiv Vis sammendrag

  Biodiversity monitoring is concerned with keeping track of different species in an ecosystem over time, with respect to their abundance, distribution and diversity. Environmental digital twins used for biodiversity monitoring share characteristics with industrial digital twins, but face additional challenges in connecting data and models: Biodiversity data is often not livestreamed, interventions are slow and require human interaction, and the scientific knowledge about species and their habitats constantly evolves. Today, environmental digital twins offer little automation support, or any support to help scientists link species observations to assumptions about biodiversity. This paper presents an application of structural self-adaptation, originally developed in the industrial domain, to environmental digital twins. We show how structural self-adaptation enables to autonomously adapt monitored assumptions to changes in the available data sources, and further discuss how digital twins can adapt to changes in the domain knowledge. A first evaluation is given based on underwater cameras in the Oslo Fjord.

• Muctadir, Hossain Muhammad; Kamburjan, Eduard; Cleophas, Loek & Brand, Mark van den (2025). A consistency management framework for digital twin models. Journal of Systems and Software. ISSN 0164-1212. 234. doi: 10.1016/j.jss.2025.112750. Fulltekst i vitenarkiv Vis sammendrag

  Digital twins (DTs) encapsulate the concept of a real-world entity (RE) and corresponding bidirectionally connected virtual one (VE) mimicking certain aspects of the former in order to facilitate various use-cases such as predictive maintenance. DTs typically encompass various models that are often developed by experts from different domains using diverse tools. To maintain consistency among these models and ensure the continued functioning of the system, effective identification of any consistency issues and addressing them whenever necessary is imperative. In this paper, we investigate the concept of consistency management and propose a consistency management framework that addresses various characteristics of DT models. Subsequently, we present three working examples that implement the proposed framework with graph-based techniques. Taking the working examples into account, we demonstrate and argue that our consistency management framework can provide crucial assistance in the consistency management of DT models.

• John, Tobias; Johnsen, Einar Broch & Kamburjan, Eduard (2025). RDFMutate : Mutation-Based Generation of Knowledge Graphs. I Garijo, Daniel; Kirrane, Sabrina; Salatino, Angelo; Shimizu, Cogan; Acosta, Maribel; Nuzzolese, Andrea Giovanni; Ferrada, Sebastián; Soulard, Thibaut; Kozaki, Kouji; Takeda, Hideaki & Gentile, Anna Lisa (Red.), The Semantic Web – ISWC 2025. 24th International Semantic Web Conference, Nara, Japan, November 2–6, 2025, Proceedings, Part II. Springer. ISSN 9783032095305. s. 295–312. doi: 10.1007/978-3-032-09530-5_17. Fulltekst i vitenarkiv Vis sammendrag

  This paper introduces RDFMutate, the first mutation-based tool to generate RDF knowledge graphs. RDFMutate enables developers to analyze the robustness of applications that operate on RDF, by generating variants of seed knowledge graphs, which are mutated according to a set of mutation operations and SHACL constraints. In contrast to existing tools to generate synthetic RDF graphs, RDFMutate provides a mutation-based approach that is accessible for both researchers and application developers, by providing a framework to define mutation rules and flexible selection of generated graphs.

• John, Tobias; Johnsen, Einar Broch; Kamburjan, Eduard & Steinhöfel, Dominic (2025). Language-Based Testing for Knowledge Graphs. I Curry, Edward; Acosta, Maribel; Poveda-Villalón, Maria; Erp, Marieke van; Ojo, Adegboyega; Hose, Katja; Shimizu, Cogan & Lisena, Pasquale (Red.), The Semantic Web: 22nd European Semantic Web Conference, ESWC 2025, Portoroz, Slovenia, June 1–5, 2025, Proceedings, Part II. Springer Nature. ISSN 9783031945779. s. 24–46. doi: 10.1007/978-3-031-94578-6_2. Fulltekst i vitenarkiv Vis sammendrag

  Knowledge graphs rely on a vast ecosystem of software tools, such as parsers, APIs and reasoners. Yet, tool developers have little support to ensure tool reliability. Here, we demonstrate how recent advantages in test case generation for highly structured and constrained inputs can support software developers in the semantic web field. We develop input generators for RDF Turtle and the OWL EL profile, and report on numerous bugs we found in parsers, reasoners and APIs of widely used tools and libraries, as well as imprecisions in standards and documentation. We provide actionable insights on using automated testing to increase the reliability of software tools for knowledge graphs.

• Rollshausen, Nils; Kamburjan, Eduard & Giese, Martin (2024). Generating Transparent and Query-Based RDF Layers. I Kamburjan, Eduard; Fraga, David Chaves; Nathan, Paco; Roover, Coen De; Corcho, Oscar; Jimenez-Ruiz, Ernesto; Waaler, Arild Torolv Søetorp & Zhou, Baifan (Red.), SOFLIM2KG-SEMIIM 2024 Joint Proceedings SOFLIM2KG and SEMIIM 2024. CEUR Workshop Proceedings. doi: https:/ceur-ws.org/Vol-3830/paper2.pdf. Fulltekst i vitenarkiv Vis sammendrag

  We present inkblot, a software tool that generates object-oriented API code to represent the data found in a semantic model in a way suitable for programmers not familiar with semantic technologies. The API interacts with an RDF triple store via a SPARQL endpoint, but hides this connection from the programmer. The approach generates adequately typed fields and methods, based on the types and cardinalities in the data. Unlike previous work, the generation is not driven by an OWL ontology or similar declarative description of the application domain, but by a SPARQL query that accesses the pertinent data.

• Kamburjan, Eduard; Sieve, Riccardo; Baramashetru, Chinmayi; Amato, Marco; Barmina, Gianluca & Occhipinti, Eduard [Vis alle 7 forfattere av denne artikkelen] (2024). GreenhouseDT: An Exemplar for Digital Twins. I Baresi, Luciano (Red.), SEAMS '24: Proceedings of the 19th International Symposium on Software Engineering for Adaptive and Self-Managing Systems. Association for Computing Machinery (ACM). ISSN 9798400705854. doi: 10.1145/3643915.3644108. Fulltekst i vitenarkiv Vis sammendrag

  Digital twins, which are increasingly adopted in industry, are model-centric systems used to improve the behavior of a twinned physical system. Seen as a whole, this system has several layers of self-adaptation: first, the digital twin manages its physical counterpart and maintains its models through a feedback loop to, e.g., fine-tune model parameters. Second, the digital twin needs to deal with unforeseen changes in the composition of the physical system, which require models to be partly replaced or recomposed. To facilitate research on self-adaptive digital twins, without requiring access to industrial production systems, this paper presents GreenhouseDT, an exemplar that explicitly separates these layers of self-adaptation. GreenhouseDT provides an extensible software architecture for a digital twin of a simple, low-cost greenhouse, in which plants, sensors and water pumps constitute the physical system. GreenhouseDT includes an asset model in the digital twin's knowledge base and uses reflection to lift twinned configurations into the knowledge base. We discuss how GreenhouseDT can be extended with different digital twin capabilities, demonstrated by the addition of plant health monitoring and model-based control.

• Talasila, Prasad; Gomes, Cláudio; Vosteen, Lars B; Iven, Hannes; Leucker, Martin & Gil, Santiago [Vis alle 9 forfattere av denne artikkelen] (2024). Composable digital twins on Digital Twin as a Service platform. Simulation. ISSN 0037-5497. doi: 10.1177/00375497241298653. Fulltekst i vitenarkiv
• Gil, Santiago; Kamburjan, Eduard; Talasila, Prasad & Larsen, Peter Gorm (2024). An architecture for coupled digital twins with semantic lifting. Software and Systems Modeling (SoSyM). ISSN 1619-1366. doi: 10.1007/s10270-024-01221-w. Fulltekst i vitenarkiv Vis sammendrag

  To enable the reuse of Digital Twins, in the form of simulation units or other forms of behavioral models, of single physical components, one must be able to connect and couple them. Current platform and architectures consider mostly monolithic digital twins and offer little support for coupling and checking the consistency of the coupling. The coupling must be internally consistent—satisfy constraints related to their co-simulation—and externally consistent—mirror the structure of the composed physical system. In this paper, we propose an extension to a behavior-extended Digital Twin architecture for individual Digital Twins to include co-simulation scenarios for coupled systems lifted from configuration files, which can be implemented along with a Digital-Twin-as-a-Service platform to make assets reusable in time. To monitor and query these connections, we introduce a semantic lifting service, which interprets the coupled Digital Twins as Knowledge Graphs and enables the use of queries to express internal and external consistency constraints. Two representative case studies for systems with coupled behavior are used for the demonstration of this approach and show that it indeed enables reusability of components and services between different Digital Twins.

• Qu, Yuanwei; Kamburjan, Eduard; Torabi, Anita & Giese, Martin (2024). Semantically triggered qualitative simulation of a geological process. Applied Computing and Geosciences. 21. doi: 10.1016/j.acags.2023.100152. Fulltekst i vitenarkiv
• Fitzgerald, John; Gomes, Cláudio; Johnsen, Einar Broch; Kamburjan, Eduard; Leucker, Martin & Woodcock, Jim (2024). Digital Twin Engineering. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 15223, s. 3–8. doi: 10.1007/978-3-031-75390-9_1. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Pferscher, Andrea; Schlatte, Rudolf; Sieve, Riccardo; Tarifa, Silvia Lizeth Tapia & Johnsen, Einar Broch (2024). Semantic Reflection and Digital Twins: A Comprehensive Overview. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 15240, s. 129–145. doi: 10.1007/978-3-031-73887-6_11. Fulltekst i vitenarkiv
• Johnsen, Einar Broch; Kamburjan, Eduard; Pardo, Raul; Voogd, Eisse Hendrik & Wasowski, Andrzej (2024). Towards a Proof System for Probabilistic Dynamic Logic. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 15260, s. 322–338. doi: 10.1007/978-3-031-75783-9_13. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Bencomo, Nelly; Tarifa, Silvia Lizeth Tapia & Johnsen, Einar Broch (2024). Declarative Lifecycle Management in Digital Twins. I Muñoz, Paula & Garmendia, Antonio (Red.), MODELS Companion '24: Proceedings of the ACM/IEEE 27th International Conference on Model Driven Engineering Languages and Systems. Association for Computing Machinery (ACM). ISSN 9798400706226. s. 353–363. doi: 10.1145/3652620.3688248. Fulltekst i vitenarkiv
• John, Tobias; Johnsen, Einar Broch & Kamburjan, Eduard (2024). Mutation-Based Integration Testing of Knowledge Graph Applications. Proceedings - International Symposium on Software Reliability Engineering (ISSRE). ISSN 1071-9458. doi: 10.1109/ISSRE62328.2024.00052. Fulltekst i vitenarkiv
• Kamburjan, Eduard & Din, Crystal Chang (2023). Runtime Enforcement Using Knowledge Bases. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 13991, s. 220–240. doi: 10.1007/978-3-031-30826-0_12. Fulltekst i vitenarkiv Vis sammendrag

  Knowledge bases have been extensively used to represent and reason about static domain knowledge. In this work, we show how to enforce domain knowledge about dynamic processes to guide executions at runtime. To do so, we map the execution trace to a knowledge base and require that this mapped knowledge base is always consistent with the domain knowledge. This means that we treat the consistency with domain knowledge as an invariant of the execution trace. This way, the domain knowledge guides the execution by determining the next possible steps, i.e., by exploring which steps are possible and rejecting those resulting in an inconsistent knowledge base. Using this invariant directly at runtime can be computationally heavy, as it requires to check the consistency of a large logical theory. Thus, we provide a transformation that generates a system which is able to perform the check only on the past events up to now, by evaluating a smaller formula. This transformation is transparent to domain users, who can interact with the transformed system in terms of the domain knowledge, e.g., to query computation results. Furthermore, we discuss different mapping strategies.

• Kamburjan, Eduard; Scaletta, Marco & Rollshausen, Nils (2023). Deductive verification of active objects with Crowbar. Science of Computer Programming. ISSN 0167-6423. 226. doi: 10.1016/j.scico.2023.102928. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Klungre, Vidar Norstein; Tarifa, Silvia Lizeth Tapia; Schlatte, Rudolf; Giese, Martin & Cameron, David B. [Vis alle 7 forfattere av denne artikkelen] (2023). Emerging Challenges in Compositionality and Correctness for Digital Twins. CEUR Workshop Proceedings. 3507. Fulltekst i vitenarkiv Vis sammendrag

  A digital twin is an information system that analyzes the behavior of a physical or digital system by connecting streams of observations to dynamic (e.g., simulation) and static (e.g., asset management) models of this twinned system. In large-scale industrial settings, the digital twin will often need to manage a multitude of models for subsystems reflecting different engineering disciplines, vendors, etc. To analyze such complex systems, digital twins must ensure the correct composition of these models and their correct exposure to the user. For the integration and transfer of information between models, digital twins may profit from a formalization of domain knowledge using ontologies, which have proven effective to unify data models. However, it is an open challenge to formalize and verify the correctness of digital twins. This paper discusses this problem for digital twins and illustrates challenges for formal methods with a focus on the composition of heterogeneous dynamic models.

• Kløvstad, Åsmund Aqissiaq Arild; Kamburjan, Eduard & Johnsen, Einar Broch (2023). Compositional Correctness and Completeness for Symbolic Partial Order Reduction. Leibniz International Proceedings in Informatics. 279, s. 9:1–9:16. doi: 10.4230/LIPIcs.CONCUR.2023.9. Fulltekst i vitenarkiv Vis sammendrag

  Partial Order Reduction (POR) and Symbolic Execution (SE) are two fundamental abstraction techniques in program analysis. SE is particularly useful as a state abstraction technique for sequential programs, while POR addresses equivalent interleavings in the execution of concurrent programs. Recently, several promising connections between these two approaches have been investigated, which result in symbolic partial order reduction: partial order reduction of symbolically executed programs. In this work, we provide compositional notions of completeness and correctness for symbolic partial order reduction. We formalize completeness and correctness for (1) abstraction over program states and (2) trace equivalence, such that the abstraction gives rise to a complete and correct SE, the trace equivalence gives rise to a complete and correct POR, and their combination results in complete and correct symbolic partial order reduction. We develop our results for a core parallel imperative programming language and mechanize the proofs in Coq.

• Qu, Yuanwei; Kamburjan, Eduard & Giese, Martin (2023). A Geological Case Study on Semantically Triggered Processes. I Pesquita, Catia; Jimenez-Ruiz, Ernesto; McCusker, Jamie; Faria, Daniel; Dragoni, Mauro; Dimou, Anastasia; Troncy, Raphaël & Hertling, Sven (Red.), The Semantic Web: 20th International Conference, ESWC 2023, Hersonissos, Crete, Greece, May 28–June 1, 2023, Proceedings. Springer. ISSN 9783031334559. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Din, Crystal Chang; Schlatte, Rudolf; Tarifa, Silvia Lizeth Tapia & Johnsen, Einar Broch (2022). Twinning-by-Construction: Ensuring Correctness for Self-adaptive Digital Twins. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 13701, s. 188–204. doi: 10.1007/978-3-031-19849-6_12. Fulltekst i vitenarkiv Vis sammendrag

  Digital twin applications use digital artefacts to twin physical systems. The purpose is to continuously mirror the structure and behavior of the physical system, such that users can analyse the physical system by means of the digital twin. However, the physical system might change over time. In this case, the digital twin’s ensemble of digital artefacts needs to be reconfigured to correctly twin the physical system again. This paper considers a digital twin infrastructure combining MAPE-K feedback loops and semantic reflection to automatically ensure that the digital artefacts correctly twin the physical system; i.e., the resulting system is twinned-by-construction. We consider the monitoring of both structural and temporal correctness properties for digital twin, including the time delay required by reconfiguration, and the capture of execution traces to reflect digital threads in the digital twin framework.

• Kamburjan, Eduard; Klungre, Vidar Norstein; Schlatte, Rudolf; Tarifa, Silvia Lizeth Tapia; Cameron, David & Johnsen, Einar Broch (2022). Digital Twin Reconfiguration Using Asset Models. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 13704, s. 71–88. doi: 10.1007/978-3-031-19762-8_6. Fulltekst i vitenarkiv
• Schlatte, Rudolf; Johnsen, Einar Broch; Kamburjan, Eduard & Tarifa, Silvia Lizeth Tapia (2022). The ABS simulator toolchain. Science of Computer Programming. ISSN 0167-6423. 223. doi: 10.1016/j.scico.2022.102861. Fulltekst i vitenarkiv
• Kamburjan, Eduard & Fiorini, Sandro Rama (2022). On the Notion of Naturalness in Formal Modeling. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. doi: 10.1007/978-3-031-08166-8_13. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Klungre, Vidar Norstein & Giese, Martin (2022). Never Mind the Semantic Gap: Modular, Lazy and Safe Loading of RDF Data. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 13261. doi: 10.1007/978-3-031-06981-9_12. Fulltekst i vitenarkiv
• Kamburjan, Eduard & Wasser, Nathan (2022). The Right Kind of Non-Determinism: Using Concurrency to Verify C Programs with Underspecified Semantics. Electronic Proceedings in Theoretical Computer Science (EPTCS). doi: 10.4204/EPTCS.365.1. Fulltekst i vitenarkiv
• Abusdal, Ole Jørgen; Kamburjan, Eduard; Pun, Violet Ka I & Stolz, Volker (2022). A Notion of Equivalence for Refactorings with Abstract Execution. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 13702, s. 259–280. doi: 10.1007/978-3-031-19756-7_15. Fulltekst i vitenarkiv Vis sammendrag

  Relational verification through dynamic logic is a promising approach for verifying object oriented programs. Recent advances from symbolic to abstract executions have enabled reasoning about incomplete/abstract versions of such programs. This has proven fruitful in the exploration of correctness of refactorings primarily related to code blocks in Java. In this paper we explore further types of equivalent transformations and refactorings and discuss the challenges that still need to be overcome for full round-trip correctness of refactorings in object-oriented languages.

• Damiani, Ferruccio; Hähnle, Reiner; Kamburjan, Eduard; Lienhardt, Michael & Paolini, Luca (2022). Variability Modules. Journal of Systems and Software. ISSN 0164-1212. 195. doi: 10.1016/j.jss.2022.111510. Fulltekst i vitenarkiv Vis sammendrag

  A Software Product Line (SPL) is a family of similar programs, called variants, generated from a common artifact base. A Multi SPL (MPL) is a set of interdependent SPLs: each variant can depend on variants from other SPLs. MPLs are challenging to model and to implement efficiently, especially when different variants of the same SPL must coexist and interoperate. We address this challenge by introducing the concept of a variability module (VM), a new language construct. A VM constitutes at the same time a module and an SPL of standard (variability-free), possibly interdependent, modules. Generating a variant of a VM triggers the generation of all variants required to satisfy its dependencies. Consequentially, a set of interdependent VMs represents an MPL that can be compiled into a set of standard modules. We illustrate the VM concept with an example from an industrial modeling scenario and formalize it in a core calculus. We define family-based analyses to check that a VM satisfies certain well-formedness conditions and whether all variants can be generated. Finally, we provide an implementation of VM for the Java-like modeling language ABS, and evaluate it with case studies.

• Kamburjan, Eduard & Johnsen, Einar Broch (2022). Knowledge Structures Over Simulation Units. I Martin, Martin Ruiz; Emami, Niloufar; Blas, María Julia & Rezaee, Roya (Red.), Annual Modeling and Simulation Conference, ANNSIM 2022. IEEE Press. ISSN 9781713852889. s. 78–89. doi: 10.23919/ANNSIM55834.2022.9859490. Fulltekst i vitenarkiv
• Schlatte, Rudolf; Johnsen, Einar Broch; Kamburjan, Eduard & Tarifa, Silvia Lizeth Tapia (2021). Modeling and Analyzing Resource-Sensitive Actors: A Tutorial Introduction. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. doi: 10.1007/978-3-030-78142-2_1. Fulltekst i vitenarkiv
• Kamburjan, Eduard & Kostylev, Egor (2021). Type Checking Semantically Lifted Programs via Query Containment under Entailment Regimes. CEUR Workshop Proceedings. 2954. Fulltekst i vitenarkiv Vis sammendrag

  Semantically lifted programs integrate declarative ontologybased knowledge modelling into imperative programming. In this approach, each state of a program is mapped into an OWL knowledge base (KB) and enriched with user-dfined knowledge; the resulting KB can be accessed from the program using standard SemanticWeb queries. The result of a query, however, should conform the type system of the program. We present a technique for checking type conformance statically, which is based on query containment over OWL KBs. We then discuss an approximation method for type checking, which exploits concept subsumption rather than containment and hence allows for an effcient implementation using existing tools. Finally, we describe our implementation of semantically lifted programs with static type checking in language SMOL.

• Damiani, Ferruccio; Hähnle, Reiner; Kamburjan, Eduard; Lienhardt, Michael & Paolini, Luca (2021). Variability Modules for Java-like Languages. I Mouosavi, Mohammed Reza & Schobbens, Pierre-Yves (Red.), SPLC '21: Proceedings of the 25th ACM International Systems and Software Product Line Conference - Volume A. Association for Computing Machinery (ACM). ISSN 9781450384698. doi: 10.1145/3461001.3471143. Fulltekst i vitenarkiv
• Kamburjan, Eduard (2021). From Post-Conditions to Post-Region Invariants: Deductive Verification of Hybrid Objects. I Bogomolov, Sergiy & Jungers, Raphaël (Red.), HSCC '21: Proceedings of the 24th International Conference on Hybrid Systems: Computation and Control. Association for Computing Machinery (ACM). ISSN 9781450383394. doi: 10.1145/3447928.3456633. Fulltekst i vitenarkiv
• Kamburjan, Eduard & Grätz, Lukas (2021). Increasing Engagement with Interactive Visualization: Formal Methods as Serious Games. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. s. 43–59. doi: 10.1007/978-3-030-91550-6_4. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Schlatte, Rudolf; Johnsen, Einar Broch & Tarifa, Silvia Lizeth Tapia (2021). Designing Distributed Control with Hybrid Active Objects. I Margaria, Tiziana & Steffen, Bernhard (Red.), Leveraging Applications of Formal Methods, Verification and Validation: Tools and Trends - 9th International Symposium on Leveraging Applications of Formal Methods, ISoLA 2020, Rhodes, Greece, October 20-30, 2020, Proceedings, Part IV. Springer. ISSN 9783030837228. s. 88–108. doi: 10.1007/978-3-030-83723-5_7. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Din, Crystal Chang; Hähnle, Reiner & Johnsen, Einar Broch (2020). Behavioral Contracts for Cooperative Scheduling. Lecture Notes in Computer Science (LNCS). ISSN 0302-9743. 12345, s. 85–121. doi: 10.1007/978-3-030-64354-6_4. Fulltekst i vitenarkiv
• Damiani, Ferruccio; Kamburjan, Eduard; Lienhardt, Michael & Paolinin, Luca (2008). Deltas for Functional Programs with Algebraic Data Types, ACM Portal. ACM Publications. doi: 10.1145/3579027.3608977. Fulltekst i vitenarkiv Vis sammendrag

  In this paper we discuss how the cooperation between developers and operations staff is practiced. We have analyzed data collected from a focus group of experienced software engineers and project managers, as well as interviews from two case studies. Our position is that well performed cooperation between the development team and the operations team is crucial for successful deployment and operations of a new or extensively revised software system. The data shows that cooperation can be improved in several development activities like requirements engineering, system design, documentation, testing, training, and deployment planning. Likely consequences of poor cooperation in these activities are lower productivity in development and operations, as well as unsatisfied users.

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• Kamburjan, Eduard; Fraga, David Chaves; Nathan, Paco; Roover, Coen De; Corcho, Oscar & Jimenez-Ruiz, Ernesto [Vis alle 8 forfattere av denne artikkelen] (2024). SOFLIM2KG-SEMIIM 2024 Joint Proceedings SOFLIM2KG and SEMIIM 2024. CEUR Workshop Proceedings. doi: https:/ceur-ws.org/Vol-3830/. Fulltekst i vitenarkiv
• Boer, Frank de; Damiani, Ferruccio; Hähnle, Reiner; Johnsen, Einar Broch & Kamburjan, Eduard (2024). Active Object Languages: Current Research Trends. Springer Nature. ISBN 9783031510595. 375 s. Fulltekst i vitenarkiv

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• Kamburjan, Eduard; Sieve, Riccardo; Baramashetru, Chinmayi; Amato, Marco; Barmina, Gianluca & Occhipinti, Eduard [Vis alle 7 forfattere av denne artikkelen] (2024). GreenhouseDT: An Exemplar for Digital Twins. Fulltekst i vitenarkiv
• Kamburjan, Eduard; Jimenez-Ruiz, Ernesto; Zhou, Baifan & Waaler, Arild Torolv Søetorp (2024). Preface: Semantic Industrial Information Modelling. CEUR Workshop Proceedings. 3830. Fulltekst i vitenarkiv
• Aiello, Marco; Beest, Nick van; Georgievski, Ilche; Kamburjan, Eduard; Koldehofe, Boris & Lazovik, Alexander (2024). Proceedings of the First International Workshop on Distributed Digital Twins (DiDiT 2024) June 17, 2024 - Groningen, the Netherlands. CEUR Workshop Proceedings. 3755. Fulltekst i vitenarkiv
• Fraga, David Chaves; Corcho, Oscar; Kamburjan, Eduard; Roover, Coen De & Nathan, Paco (2024). Preface: Software Lifecycle Management for Knowledge Graphs. CEUR Workshop Proceedings. 3830. Fulltekst i vitenarkiv
• Jakobs, Marie-Christine; Johnsen, Einar Broch; Kamburjan, Eduard & Wimmer, Manuel (2024). Preface for the special issue on “Fundamental Approaches to Software Engineering” (FASE 2022). Science of Computer Programming. ISSN 0167-6423. 232. doi: 10.1016/j.scico.2023.103055. Fulltekst i vitenarkiv
• John, Tobias; Johnsen, Einar Broch; Beetz, Michael & Kamburjan, Eduard (2025). Test Case Generation for Knowledge Graph Applications. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Knowledge graphs are a popular concept for building domain-specific databases. It is widely acknowledged that the data quality of knowledge graphs is central to built trust in systems that use them as components. However, little effort is spend on providing processes ensuring that the applications interacting with the knowledge graphs work correctly. In this thesis, we investigate to which extent automated testing can be used as such a process. In particular, we focus on techniques to generate synthetic knowledge graphs as test inputs for applications. Generating inputs that target the core logic of the tested Application and that do not only test the input logic is challenging. The structure of the test inputs needs to resemble valid knowledge graphs, i.e., the test inputs need to be valid data using one of the serialization formats. Furthermore, specialized applications only work on knowledge graphs that are within the domain of the application. This poses strict restrictions on the shape of the graphs that they expect as inputs. Additionally, some applications only work with knowledge graphs that are consistent, i.e., where the contained ontology is consistent. We investigate several techniques to generate test cases that address these challenges in this thesis. We use language-based generation techniques as well as mutation-based generation techniques. Additionally, we investigate if task planners can be used to generate test cases. To perform the testing campaigns, we define oracles based on common techniques. In particular, we use crash oracles, differential testing, and oracles created by the application developers. We evaluate our generation techniques by testing seven different applications. Some of the applications work on general Resource Description Framework (RDF) data or Web Ontology Language (OWL) ontologies, others only work with domain-specific data. We show that our techniques are able to reveal new insights about the tested applications. In particular, we found several issues in state-of-the art tools like parsers for the knowledge graph framework RDF and reasoners for the ontology language OWL. We implement tools for the techniques where existing tools cannot be used to make our generation techniques accessible to others.

• Kamburjan, Eduard; Hallerstede, Stefan & Kamburjan, Eduard (2023). Preproceedings of the Workshop on Applications of Formal Methods and Digital Twins. Universitetet i Oslo. ISSN 9788273686053. Fulltekst i vitenarkiv Vis sammendrag

  This technical reports contains the papers of the Workshop on Ap- plications of Formal Methods and Digital Twins, which is held 06.03.23 in Lübeck, Germany, co-located with the 25th International Symposium on Formal Methods. All papers were peer-reviewed prior to inclusion in this volume by the program committee of the workshop, and we thank the member of the PC for their constructive reviews. Additionally to the papers, the workshop will feature an invited talk by Ana Cavalcanti title "RoboStar Twins?". - Leveraging Runtime Verification for the Monitoring of Digital Twins by Sylvain Hallé, Chukri Soueidi and Yliès Falcone - Emerging Challenges in Compositionality and Correctness for Digital Twins by Eduard Kamburjan, Vidar Klungre, Silvia Lizeth Tapia Tarifa, Rudolf Schlatte, Martin Giese, David Cameron and Einar Broch Johnsen - Are Formal Contracts a useful Digital Twin of Software Systems? by Jonas Schiff and Alexander Weigl - Digital Twin for Rescue Missions - a Case Study by Martin Leucker, Martin Sachenbacher and Lars Bernd Vosteen - A Digital Twin for Coupling Mobility and Energy Optimization: The ReNuBiL Living Lab by Daniel Thoma, Martin Sachenbacher, Martin Leucker and Aliyu Tanko Ali - Mining Digital Twins of a VPN Server by Andrea Pferscher, BenjaminWunderling, Bernhard K. Aichernig and Edi Muskardin

• Kamburjan, Eduard; Klungre, Vidar Norstein & Giese, Martin (2022). Never Mind the Semantic Gap: Modular, Lazy and Safe Loading of RDF Data (Full Paper). Universitetet i Oslo. ISSN 9788273686022. Fulltekst i vitenarkiv Vis sammendrag

  Any attempt at a tight integration between semantic technologies and object oriented programming will invariably stumble over the gap between the two underlying object models. We illustrate how this semantic gap manifests from the point of view of data retrieval with SPARQL. We present a novel mechanism to load data from RDF knowledge graphs into object-oriented languages that gives static guarantees about the data access and modularly integrates the mapping between the program and the RDF view with the class definition in the program. This allows us to preserve the separation of concerns between the class system of RDF (geared towards domain modeling and data), and that of the program (geared towards typing and code reuse). Loading of RDF can be performed lazily, when required by the program, based on query-futures - subqueries that are only evaluated if and when the data is accessed. We formulate a Liskov principle for the mapping queries to characterize when they respect the subclass relation. Moreover, we provide tool support to detect when the user-provided mapping would cause the loading mechanisms to result in data structures that manifest the semantic gap.

• Kamburjan, Eduard; Klungre, Vidar; Schlatte, Rudolf; Johnsen, Einar Broch & Giese, Martin (2021). Programming and Debugging with Semantically Lifted States (Full Paper). Universitetet i Oslo. Institutt for informatikk. ISSN 9788273684646. Fulltekst i vitenarkiv Vis sammendrag

  We propose a novel integration of programming languages with semantic technologies. We create a semantic reflection mechanism by a direct mapping from program states to RDF knowledge graphs. This mechanism enables several promising novel applications including the use of semantic technology, including reasoning, for debugging and validating the sanity of program states, and integration with external knowledge graphs. Additionally, by making the knowledge graph accessible from the program, method implementations can refer to state semantics rather than objects, establishing a deep integration between programs and semantics. This allows the programmer to use domain knowledge formalized as, e.g., an ontology directly in the program’s control flow. We formalize this integration by defining a core object based programming language that incorporates these features. A prototypical interpreter is available for download.

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