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Fully Declarative Specification of Static Code Checkers
No full textStatic code checkers are tools that help software engineers by automatically finding defects without executing the programs. These tools contain a set of detectors that rely on static program analyses to find common programming defects or to enforce coding guidelines.While existing code checker frameworks package a rich collection of detectors, aimed at common bug defects, the effort to adapt these detectors to specific project needs is not trivial. In their definition, the detectors rely on checker-specific program representations and auxiliary data structures, which incurs a high up-front cost for customization attempts. Being encoded in a general-purpose programming language, the detectors inherit the evaluation model of the host programming language. This precludes the adoption of evaluation schemes that fit the dynamics of the project, such as incremental evaluation or caching of partial results.In this thesis we address the hindrances to adaptability in current checker frameworks by combining two declarative techniques: syntactic pattern matching and logic programming in Datalog. We use syntactic pattern matching to identify the program fragments that are of interest for a detector and Datalog logical rules to enable non-local reasoning between these fragments of interest. Syntactic patterns allow us to decouple the detector specification from the internal representations of programs, while the use of Datalog-style rules enables the adoption of alternative evaluation modes, such as incremental evaluation.We materialize our techniques in declarative specification languages and runtimes that facilitate the construction of declarative static code checking frameworks for the C and Java languages. We show that these declarative specification languages enable concise description of bug detectors, while achieving analysis quality and runtime performance that is comparable with established frameworks
Quantifying Coupling Errors in Atmosphere-Ocean-Sea Ice Models : A Study of Iterative and Non-Iterative Approaches in the EC-Earth AOSCM
No full textThe atmosphere, ocean, and sea ice components in Earth system models are coupled via boundary conditions at the sea surface. Standard coupling algorithms correspond to the first step of an iteration, so-called Schwarz waveform relaxation. Not iterating is computationally cheap but introduces a numerical coupling error, which we aim to quantify for the case of a coupled single column model: the EC-Earth AOSCM, which uses the same coupling setup and model physics as its host model, EC-Earth. To this end, we iterate until a reference solution is obtained and compare this with standard, non-iterative algorithms. Understanding the convergence behavior of the iteration, as well as the size of the coupling error, can inform model and algorithm development. Our implementation is based on the OASIS3-MCT coupler and allows to estimate the coupling error of multi-day simulations.In the absence of sea ice, SWR convergence is robust. Coupling errors for atmospheric variables can be substantial. When sea ice is present, results strongly depend on the model version. In the latest model version, coupling errors in sea ice surface and atmospheric boundary layer temperature are often large. Generally, we find that abrupt transitions between distinct physical regimes in certain parameterizations can lead to substantial coupling errors and even non-convergence of the iteration. We attribute discontinuities in the computation of atmospheric vertical turbulence and sea ice albedo as sources for these problems
Modeling of face mask flow and droplet filtration
No full textThis paper presents experimental and numerical investigations of liquid droplet/air two-phase flow through face masks. The study aims to provide a deeper understanding of the droplet filtration process, generate experimental data for modeling droplet/air two-phase flow across face masks, and develop and validate numerical models to simulate droplet motion through the mask and downstream. Droplet interception and collection in the mask are investigated by detailed lattice Boltzmann simulations. Experiments are conducted in a branching pipe rig to measure filtration efficiency and droplet distribution at the outlet. The numerical models are applied to predict droplet motion within the experimental setup, demonstrating good agreement in terms of droplet emissions. The model is further employed to simulate airflow and droplet behavior around a human face during coughing. The results reveal a significant reduction in flow velocity across the face mask and more than a 60% decrease in droplet penetration distance
Revisited inscriptions – roadmaps and anticipations of AI and education in the datafied welfare state
No full textThe rapid development of generative AI has prompted a surge in future-oriented documents on a wide range of anticipated educational concern within the Nordic welfare state. Among these, the roadmap has become an increasingly popular foresight technique, exemplified by the AI Commission’s Roadmap for Sweden, which is the focus of the paper. Mobilised within an anticipatory regime of future thinking, these documents shape what the future ought to be for AI and education. This paper explores what makes the future of AI and education seem reasonable by revisiting STS methodologies that trace document practices, such as those influenced by generative AI chatbots in the case of the Roadmap. Emphasising the document rather than the text (Strathern, 2006), the argument posits that the Roadmap’s good practice can be scrutinised through its temporalities (doing it now), effectiveness (doing it well) and uncontroversial assumptions (doing the right thing). This scrutiny demonstrates how certain futures of AI and education take precedence over others as a sociotechnical effect rather than as a powerful technology
Utvecklingsprojekt angående språkutbildningar i främmande språk : Rapport utifrån uppdrag
No full textAkademiska utbildningar i främmande språk är på många sätt ovanliga utbildningar i högre utbildning. Utbildningarna har krav på sig att vara vetenskapligt breda samtidigt som det finns stora behov av och förväntningar på grundläggande språkfärdighetsträning. Främmande språk studeras med flera olika syften, både för bredd och djup, och av studenter i olika skeden av livet och med heterogen bakgrund. I det nuvarande resurssystemet befinner sig därför utbildningarna i en utmanande situation präglad av resursbrist och svårigheter att uppfylla sina uppdrag. Det finns därför ett behov av en kollegial diskussion baserad på nuvarande kunskap och erfarenheter kring hur utbildningarna kan utvecklas för att bättre möta utmaningarna. Det saknas emellertid systematisk kunskap om främmande språk på många områden och inga förändringar i resurstilldelningssystemet verkar nära förestående. En nordisk jämförelse visar att Sverige har det mest flexibla utbildningssystemet vilket gör att en bredd i språkutbudet kunnat upprätthållas, men utbildningar i främmande språk står inför liknande utmaningar i hela Europa.Rapporten avslutas med korta presentationer av ett antal riktningar för att främja både bredd och djup i framtiden. Syftet med denna del är att främja vidare kollegial diskussion. Det finns möjligheter inom både utbildningsinformation, utbildningsorganisation, internationella kontakter och utbyten. AI-utvecklingen behöver särskilt uppmärksammas och kräver samarbeten med kompetens inom LU. För att säkerställa att det i framtiden finns utbildningar som syftar till djup och samtidigt är attraktiva och har hög vetenskaplig kvalitet är en möjlighet att inleda samarbeten med andra lärosäten
Comparative infectivity, virulence and molecular epidemiology of MDR and XDR Acinetobacter baumannii isolates emerging from war-related injuries in Ukraine
No full textBACKGROUND: Multidrug resistant Acinetobacter baumannii remains a global concern with its ability to adhere, disperse and sustain in areas involving suboptimal infection control measures, particularly in war areas. In this study we aimed to evaluate the susceptibility profiles, molecular epidemiology and pathogenesis of A. baumannii isolates from conflict zones in Ukraine.METHODS: A. baumannii wound isolates (n=46) were tested to comparatively assess antimicrobial resistance, molecular epidemiology, pathogenesis and infectivity. Briefly, antimicrobial susceptibility testing, whole genome sequencing, biofilm and capsule formation, as well as serum survival and bacterial viability in G. mellonella and a mouse infection model were performed.RESULTS: Dominating sequence types were ST2, ST19, ST78 and ST400 while 65.21% of isolates were from international clones. All isolates were multidrug resistant (MDR), and 7 isolates were extensively drug resistant (XDR). ST19 isolates had higher encapsulation, lower serum survival and missing T6SS, omp33-36 and biofilm production associated genes. However, bacteria expressed higher virulence and lethality during early infection compared to later stages in vivo.CONCLUSION: We report the first results characterizing the pathogenesis and infectivity of the emerging A. baumannii ST19. High MDR and XDR rates alongside clonally related isolates are concerning and highlight the importance of infection prevention and control measures in conflict zones