Alexander Salveson Nossum

• Brådland, Henrik; Goodwin, Morten; Andersen, Per-Arne; Nossum, Alexander & Gupta, Aditya (2025). A New HOPE: Domain-agnostic Automatic Evaluation of Text Chunking. SIGIR '25: Proceedings of the 48th International ACM SIGIR Conference on Research and Development in Information Retrieval. doi: 10.1145/3726302.3729882. Fulltekst i vitenarkiv Vis sammendrag

  Document chunking fundamentally impacts Retrieval-Augmented Generation (RAG) by determining how source materials are segmented before indexing. Despite evidence that Large Language Models (LLMs) are sensitive to the layout and structure of retrieved data, there is currently no framework to analyze the impact of different chunking methods. In this paper, we introduce a novel methodology that defines essential characteristics of the chunking process at three levels: intrinsic passage properties, extrinsic passage properties, and passages-document coherence. We propose HOPE (Holistic Passage Evaluation), a domain-agnostic, automatic evaluation metric that quantifies and aggregates these characteristics. Our empirical evaluations across seven domains demonstrate that the HOPE metric correlates significantly (𝜌 > 0.13) with various RAG performance indicators, revealing contrasts between the importance of extrinsic and intrinsic properties of passages. Semantic independence between passages proves essential for system performance with a performance gain of up to 56.2% in factual correctness and 21.1% in answer correctness. On the contrary, traditional assumptions about maintaining concept unity within passages show minimal impact. These findings provide actionable insights for optimizing chunking strategies, thus improving RAG system design to produce more factually correct responses.

• Brådland, Henrik; Goodwin, Morten; Andersen, Per-Arne & Nossum, Alexander (2024). PlanBERT: From Messy Zonal Plans to Informative Vector Embeddings. I Bramer, Max & Stahl, Frederic (Red.), Artificial Intelligence XLI: 44th SGAI International Conference on Artificial Intelligence, AI 2024. Springer. ISSN 9783031779145. s. 175–188. doi: 10.1007/978-3-031-77915-2_13. Fulltekst i vitenarkiv Vis sammendrag

  Text embedding models trained on vast web-scraped corpus generalize well to daily language. However, they often fall short when applied in specialized domains that require precise language and foreign terms, like law and medicine. This gap highlights the necessity for data-efficient methodologies to fine-tune these models for narrow-domain applications. This paper introduces PlanBERT, a new approach for enabling data-efficient domain adaptation and fine-tuning of embedding models. The approach builds on self-supervised contrastive pre-training, synthetic training data generated by large language models (LLMs), and decorrelation of embedding features. The paper also introduces the term “informative vector embeddings” to adjust the training objectives to incentivise more analytics-friendly embeddings and demonstrate that PlanBERT can learn the domain language of zonal plans and outperform larger and more complex state-of-the-art models in challenging real-world zonal plan tasks.

• Krogstie, John & Nossum, Alexander (2014). A Semiotic Approach for Guiding the Visualizing of Time and Space in Enterprise Models, Service Science and Knowledge Innovation. Springer. ISSN 9783642553547. s. 74–86. doi: 10.1007/978-3-642-55355-4_8. Fulltekst i vitenarkiv
• Nossum, Alexander (2014). Exploring Eye Movement Patterns on Cartographic Animations Using Projections of a Space-Time-Cube. The Cartographic Journal. ISSN 0008-7041. 51(3), s. 249–256. doi: 10.1179/1743277412Y.0000000031. Fulltekst i vitenarkiv
• Nossum, Alexander (2013). Developing a Framework for Describing and Comparing Indoor Maps. The Cartographic Journal. ISSN 0008-7041. 50(3), s. 218–224. doi: 10.1179/1743277413Y.0000000055. Fulltekst i vitenarkiv
• Nossum, Alexander Salveson (2012). Semistatic Animation ‐ Integrating Past, Present and Future in Map Animations. The Cartographic Journal. ISSN 0008-7041. 49(1), s. 43–54. doi: 10.1179/1743277411Y.0000000014. Fulltekst i vitenarkiv
• Chorianopoulos, Konstantinos; Jaccheri, Maria Letizia & Nossum, Alexander (2012). Creative and Open Software Engineering Practices and Tools in Community Projects, Proceedings of the 4th ACM SIGCHI symposium on Engineering interactive computing systems. ACM Publications. ISSN 9781450311687. s. 333–334. doi: 10.1145/2305484.2305545. Fulltekst i vitenarkiv
• Opach, Tomasz & Nossum, Alexander (2011). EVALUATING THE USABILITY OF CARTOGRAPHIC ANIMATIONS WITH EYE-MOVEMENT ANALYSIS. I Ruas, Anne (Red.), Proceedings of the 25th International Cartographic Conference. International Cartographic Association. ISSN 9781907075056. Fulltekst i vitenarkiv
• Opach, Tomasz; Midtbø, Terje & Nossum, Alexander (2011). A New Concept of Multi-Scenario, Multi-Component Animated Maps for the Visualization of Spatio-Temporal Landscape Evolution. Miscellanea Geographica - Regional Studies on Development. ISSN 0867-6046. 15, s. 215–229. doi: 10.2478/v10288-012-0013-6. Fulltekst i vitenarkiv
• Opach, Tomasz; Midtbø, Terje & Nossum, Alexander Salveson (2011). A New Concept of Multi-Scenario, Multi-Component Animated Maps for the Visualization of Spatio-Temporal Landscape Evolution. Miscellanea Geographica - Regional Studies on Development. ISSN 0867-6046. 15, s. 215–229. doi: 10.2478/v10288-012-0013-6. Fulltekst i vitenarkiv Vis sammendrag

  In this paper, we propose a new approach to the presentation of the spatio-temporal evolution of landscape using a multi-component multi-scenario animated map system. The concept of multi-scenario map was introduced with a few conceptual level objectives. Firstly, to facilitate understanding of geographic spatio-temporal changeability (especially landscape changeability) by the use of complex cartographic animations. Secondly, to investigate factors which influence an intuitive and effective use of multi-component cartographic applications. In relation to understanding processes, the overriding purpose was to build up a generic approach that allows users to recognize features of complex geographic phenomena. Finally, since the implementation of the concept was of importance, a prototype has been prepared.

• Nossum, Alexander Salveson (2011). IndoorTubes A Novel Design for Indoor Maps. Cartography and Geographic Information Science. ISSN 1523-0406. 38(2), s. 192–200. doi: 10.1559/15230406382192. Fulltekst i vitenarkiv
• Nossum, Alexander & Krogstie, John (2009). Integrated Quality of Models and Quality of Maps. I Halpin, Terry; Krogstie, John; Nurcan, Selmin; Proper, Erik; Schmidt, Rainer; Soffer, Pnina & Ukor, Roland (Red.), Enterprise, Business-Process and Information Systems Modeling. Springer. ISSN 9783642018619. s. 264–276. Fulltekst i vitenarkiv

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• Nossum, Alexander; Simensen, Trond; Strand, Geir-Harald; Kittelsrud, Reidun & Tomren, Liv Heidi (2024). KI - En forutsetning for godt arealregnskap? Paneldebatt om Arealregnskap, kunstig intelligens (AI) og Geografisk teknologi. Fulltekst i vitenarkiv
• Krogstie, John & Nossum, Alexander (2014). A Semiotic Approach for Guiding the Visualizing of Time and Space in Enterprise Models - Presentation. Fulltekst i vitenarkiv
• Midtbø, Terje & Nossum, Alexander (2013). Geomatikk. Kart og Plan. ISSN 0047-3278. 73(3). Fulltekst i vitenarkiv
• Nossum, Alexander; Midtbø, Terje; Haakonsen, Trond Arve & Nordan, Robert Patrick Victor (2012). Are indoor positioning systems mature for cartographic tasks? Fulltekst i vitenarkiv Vis sammendrag

  ABSTRACT: Better indoor mapping are linked together with better indoor positioning. This paper gives a brief overview over existing methods for indoor positioning. To get an impression of how well a WiFi based commercial indoor positioning system works as an input to indoor real time visualization, a network of control points were established. Accurate coordinates for existing access points were also measured to see if these could improve the WiFi measured coordinates. Our experiment indicates that the geometry of the access points/mobile platform, the nearness to the access points and obstacles, as for example walls, are the dominating limitations when it comes to measure more accurate positions.

• Nossum, Alexander (2012). Comparing Two Different Map Types for Patient Navigation Inside a Hospital. Fulltekst i vitenarkiv
• Nossum, Alexander & Haakonsen, Trond Arve (2012). FaceScan - få et 3D-bilde av ansiktet ditt. Fulltekst i vitenarkiv
• Midtbø, Terje; Taraldsvik, Mats & Nossum, Alexander Salveson (2012). Kva vil HTML5 ha å seie for GIS og kartografi på Web. Fulltekst i vitenarkiv
• Midtbø, Terje; Taraldsvik, Mats & Nossum, Alexander Salveson (2012). The future of maps and the Internet - possibilities of GIS and Cartography made available by HTML 5. Fulltekst i vitenarkiv
• Nossum, Alexander Salveson (2012). Cartographic design for indoor maps for real-time use. Fulltekst i vitenarkiv
• Midtbø, Terje; Nossum, Alexander; Haakonsen, Trond Arve & Nordan, Robert Patrick Victor (2012). Innandørsnavigering. Fulltekst i vitenarkiv
• Nossum, Alexander & Nguyen, An Mai (2012). Selvinnsjekk på sykehuset - hvordan skal pasienten finne frem. Fulltekst i vitenarkiv
• Opach, Tomasz & Nossum, Alexander (2011). EVALUATING THE USABILITY OF CARTOGRAPHIC ANIMATIONS WITH EYE-MOVEMENT ANALYSIS. Fulltekst i vitenarkiv
• Nossum, Alexander Salveson; Skogseth, Terje & Haakonsen, Trond Arve (2011). FaceScan og Totalstasjonskyting. Fulltekst i vitenarkiv
• Nossum, Alexander Salveson (2011). Geomatikk i skolen. Et kart er ikke lenger bare et kart ... Bedre Skole. ISSN 0802-183X. s. 50–52. Fulltekst i vitenarkiv
• Nossum, Alexander (2010). Semistatic Animations - Integrating past, present and future in map animations. Fulltekst i vitenarkiv
• Nossum, Alexander Salveson (2010). Indoortubes - A novel design for indoor maps. Fulltekst i vitenarkiv
• Nossum, Alexander (2013). EXPLORING NEW VISUALIZATION METHODS FOR MULTI-STOREY INDOOR ENVIRONMENTS AND DYNAMIC SPATIAL PHENOMENA. Norges teknisk-naturvitenskapelige universitet. ISSN 9788247144411. Fulltekst i vitenarkiv

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