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Senast publicerade
- The Benefits and Limitations of Rust for Implementing Concurrent Data Structures - Comparing Concurrent Skip Lists in Rust to C(2026) Hultgren, Elliot; Vallin Ek, MaxThe Rust programming language has become increasingly relevant to the software industry for its memory safety and performance, especially since memory safety issues have been seen as a prevalent source of security vulnerabilities in recent years. Rust has also been praised for its "Fearless Concurrency", with concurrency being essential for achieving better performance in modern computers. The "Fearless Concurrency" of Rust has been shown to primarily help with regular parallelism as opposed to the parallelism needed by complex concurrent data structures with intricate access patterns. This leaves many open questions of how Rust handles these access patterns. This thesis will investigate the validity of the claims of "Fearless Concurrency" in Rust for implementing complex concurrent data structures, and see how this compares to languages like C. In particular, skip lists will be investigated since they are important for many concurrent systems and make use of many intricate concurrent programming techniques. We implemented several state-of-the-art skip lists in Rust, and created a comprehensive benchmarking framework used for comparing our implementations against existing Rust and C implementations. We also qualitatively analysed the experience of implementing performant concurrent data structures in Rust. Our findings show that skip lists in Rust performed comparably well to those in C and sometimes even outperforming them depending on workload. We also found that many of the existing implementations in Rust had problems or did not work. Lastly, while Rust provides many safety guarantees, Unsafe Rust may be needed for many complex concurrent data structures limiting these guarantees such as in our lock-free skip list implementations. In these cases, the safety guarantees of Rust are not applicable to the entire application, but rather for the parts of the application where safe Rust is used.
- MELLAN-RUM(2026) Thorén, Emil
- Vectorising Tabular Data for RAG and Vector Database Validation - A study of tabular data retrieval and anomaly detection methods against poisoning attacks in RAG(2026) Källman, Eric; Sjödahl, MaxCurrent Retrieval-Augmented Generation (RAG) systems are primarily optimised for unstructured text and lack mechanisms for ensuring data integrity in the knowledge base. This thesis investigates two challenges in the context of SVEA, AI Sweden’s digital assistant for the Swedish public sector. Firstly, how structured tabular data should be represented for vector retrieval. Secondly, how a validation layer can protect the vector database against data poisoning attacks. The two attacks tested are prompt injections and hate speech. Four table representation methods are evaluated on a corpus of 23,638 chunks from Swedish government and municipality documents. The methods are the following: Unmodified Tabular Extraction (UTE), Metadata-Enriched Representation (MER), Natural Language Summarization (NLS), and Summary-Augmented Hybrid Representation (SAHR). The results indicate that SAHR achieves the highest table Recall@1, Recall@3 and MRR (0.362, 0.496 and 0.445), while UTE achieves the highest Recall@10 (0.630). This shows a trade-off between ranking quality and retrieval coverage. In addition, the cost in terms of latency of generating summaries with an LLM must be considered. Unsupervised anomaly detection using HDBSCAN and Isolation Forest is combined with pre-trained classifiers for prompt injection and hate speech detection as a potential validation layer. Using only classifiers achieves the highest F1-score (0.592 for prompt injection on Regeringen), while hybrid two-stage approaches reduce latency at the cost of reduced detection performance.
- Mapping the Need for Inter-Municipal Climate Adaptation - Barriers and Enablers in the Gothenburg Metropolitan Area(2026) Carlsson, Alice; Hellström, LisaClimate change is increasingly affecting our societies. Sea level is rising, heatwaves are becoming more frequent and precipitation more intense. These are just some of the events our societies have to manage, making climate adaptation an essen tial area of work. Municipalities play an important role in this process, and since climate-related events do not follow administrative boundaries, climate adaptation efforts could benefit from inter-municipal collaboration. This study investigates mu nicipalities’ perceived need of inter-municipal collaboration in situations in order to achieve effective measures. It also identifies barriers and enablers related both to such collaboration and to the municipalities’ internal climate adaptation work. The findings of the study may contribute to the initiation and development of inter municipal collaboration aimed at addressing regional climate adaptation challenges. Empirical data has been collected through semi-structured interviews with officials from nine of the municipalities in the Gothenburg metropolitan area participating in the climate adaptation network run by the municipal association Göteborgsregionen (GR). Interviews with two officials from the County Administrative Board of Västra Götaland and the Delegation for Göta älv were also conducted. Drainage basins that extend across multiple municipalities were identified as the primary context in which there is a perceived need for inter-municipal collaboration. In these areas, a more holistic perspective is required to implement effective measures and to ensure that actions taken upstream do not negatively affect downstream areas. Identified barriers to such collaboration include the absence of established models for this type of cooperation, limited access to expertise such as geotechnical knowledge, and the high costs associated with climate adaptation measures. The complexity of climate change and its impacts also constitutes a challenge, highlighting the need for collab oration involving a broad range of expertise and stakeholders. The municipalities’ internal climate adaptation work also affects the perceived need of inter-municipal collaboration and the possibility of it. Several institutional and organizational bar riers, as well as political prioritization and the availability of resources, affect the municipalities’ internal climate adaptation work. This study proposes that resilience within collaborative structures and the involvement of diverse actors should be con sidered key factors when designing inter-municipal collaboration.