Coordination of Arctic Research in the U.S.A.

An Interagency Arctic Research Coordinating Committee was established in 1968, with members from the departments of Agriculture, Air Force, Army, Commerce, Health, Education and Welfare, Interior, Transportation and Navy, also the Atomic Energy Commission, National Aeronautics and Space Administration and National Science Foundation. The Committee's function is to coordinate basic, unclassified research, promote cooperative use of available logistics among research groups, maintain a current survey of foreign arctic research, and to encourage international meetings and cooperative fieldwork, data exchange and research analysis

Remote Control and Automatic Path-following for C/S Enterprise I and ROV Neptunus.

Remote control and monitoring of marine operations is in many cases desirable, due to distance, harsh environment, and dangers related to human life, and safety. Marine control systems in interaction with remote control give an accurate and reliable operation, where the aim is e.g. motion control, signal processing, maintenance, and installation. The system can perform its mission with a certain level of involvement from the operator, located remotely. The topic of this thesis is remote control and monitoring of two marine vehicles performing path following operations. The marine vehicles are the remotely operated vehicle Neptunus, a low-cost underwater vehicle, and Cybership Enterprise I (CSEI), a model-scale vessel in Marine Cybernetics laboratory (MC lab) at NTNU. Mathematical models for both vessels are established, based on Fossen s robot-like vectorial model. For Neptunus, system identification is performed, and the parameters are found using full scale towing tests, software simulations and expressions from the literature. For CSEI, these parameters have been calculated in previous works, and are only briefly presented. Simulation models for Neptunus and CSEI are set up, and a set of benchmark tests are conducted for validation. A comparing study against an estimated model of Neptunus is performed. Simulations revealed that the estimation model are in compliance with the identified model obtained in this thesis. Path following algorithms working in the horizontal plane (surge, sway, and yaw) for Neptunus and CSEI are developed and tested. The control systems vary in complexity and performance related to their control objectives. In all the control systems, integral action to account for current is implemented. Neptunus is underactuated, and CSEI is made underactuated by disabling the bow thruster, and mapping the Voith Schnei- der propellers to a rudder-propeller system. This is done using the first order Nomoto model of the yaw dynamics. Simulations rendered satisfying and stable behavior for the two vehicles. However, for more advanced motion control systems, full and accurate state feedback is needed for optimal performance, together with a robust mathematical model of the system. Neptunus is not lab-functional. Thus, CSEI is working as test platform. For testing of the performance, hardware in the loop (HIL) is conducted. Successful HIL opened for model-scale testing in the MC lab. The establishment of a interface that allowed communication between CSEI and a tablet opened for remote control and monitoring. The tablet is used to tune controller gains online and to investigate the control objective real time

Methodology for Assesment of Drilling Fluid Additives for Drilling of Depleted Reservoirs Using Barite-Weighted Oil-Based Drilling Fluid and Testing with Backflow Through Production Screens

Drilling through depleted reservoirs presents significant operational challenges due to potentially reduced formation pressure, increased risk of lost circulation, and potential wellbore instability. These issues create further complexities when drilling across reservoir sections where formation damage and production impairments must be minimized. The research investigates a methodology for evaluating and optimizing drilling fluid additives for depleted sandstone reservoirs, using barite-weighted oil-based mud by performing high-pressure fluid loss tests with backflow analysis through production screens. A primary focus is placed on the selection and evaluation of wellbore strengthening materials and lost circulation materials, targeting sealing of matrix permeability up to 40 µm and fractures in the 500 – 600 µm range, under high differential pressures. Key considerations include the particle size distribution, particle mechanical strength, filter cake formation and removability, and the ability to maintain backflow through 230 µm production screens, which is critical for a successful completion and production phase. In anticipation of increased reservoir depletion, which may lead to the development of higher differential pressures and larger induced fractures, additional formulations were prepared by incorporating coarser wellbore strengthening materials with particle sizes approaching the target fracture widths of 1500 – 2500 µm. Results show that: •An improved fluid formulation, with bimodal particle size distribution, successfully achieved the design criteria of low fluid loss and reduced formation damage, unimpeded backflow through production screens and effective sealing of 500 µm sotted discs. •Enhanced sealing performance on wider fractures was most effectively achieved by introducing coarser bridging materials with a D90 approaching fracture width, rather than merely increasing the concentration of existing materials. This strategy enabled more stable seals and reduced fluid loss at high differential pressures. •Fluids with an insufficient content of fine bridging materials failed to establish stable seals, even when coarse particles closely matched fracture widths and created a particle bridge.Drilling through depleted reservoirs presents significant operational challenges due to potentially reduced formation pressure, increased risk of lost circulation, and potential wellbore instability. These issues create further complexities when drilling across reservoir sections where formation damage and production impairments must be minimized. The research investigates a methodology for evaluating and optimizing drilling fluid additives for depleted sandstone reservoirs, using barite-weighted oil-based mud by performing high-pressure fluid loss tests with backflow analysis through production screens. A primary focus is placed on the selection and evaluation of wellbore strengthening materials and lost circulation materials, targeting sealing of matrix permeability up to 40 µm and fractures in the 500 – 600 µm range, under high differential pressures. Key considerations include the particle size distribution, particle mechanical strength, filter cake formation and removability, and the ability to maintain backflow through 230 µm production screens, which is critical for a successful completion and production phase. In anticipation of increased reservoir depletion, which may lead to the development of higher differential pressures and larger induced fractures, additional formulations were prepared by incorporating coarser wellbore strengthening materials with particle sizes approaching the target fracture widths of 1500 – 2500 µm. Results show that: •An improved fluid formulation, with bimodal particle size distribution, successfully achieved the design criteria of low fluid loss and reduced formation damage, unimpeded backflow through production screens and effective sealing of 500 µm sotted discs. •Enhanced sealing performance on wider fractures was most effectively achieved by introducing coarser bridging materials with a D90 approaching fracture width, rather than merely increasing the concentration of existing materials. This strategy enabled more stable seals and reduced fluid loss at high differential pressures. •Fluids with an insufficient content of fine bridging materials failed to establish stable seals, even when coarse particles closely matched fracture widths and created a particle bridge

Metacognitive particles, mental action and the sense of agency

This paper articulates metacognition using the language of statistical physics and Bayesian mechanics. Metacognitive beliefs, defined as beliefs about beliefs, find a natural description within this formalism, which allows us to define the dynamics of 'metacognitive particles', i.e., systems possessing metacognitive beliefs. We further unpack this typology of metacognitive systems by distinguishing passive and active metacognitive particles, where active particles are endowed with the capacity for mental actions that update the parameters of other beliefs. We provide arguments for the necessity of this architecture in the emergence of a subjective sense of agency and the experience of being separate from the environment. The motivation is to pave the way towards a mathematical and physical understanding of cognition -- and higher forms thereof -- furthering the study and formalization of cognitive science in the language of mathematical physics.Comment: 13 pages, 4 figure

Towards a Bayesian mechanics of metacognitive particles: A commentary on "Path integrals, particular kinds, and strange things" by Friston, Da Costa, Sakthivadivel, Heins, Pavliotis, Ramstead, and Parr

What could metacognition look like in simple physical terms? We define metacognition as having beliefs about beliefs, which can be articulated very simply using the language of statistical physics and Bayesian mechanics. We introduce a typology between cognitive and metacognitive particles and develop an example of a metacognitive particle. This can be generalized to provide examples of higher forms of metacognition: i.e. particles having beliefs about beliefs about beliefs and so forth. We conclude by saying that the typology of particles laid down in the target article seems promising, for seemingly enabling a physics of cognition that builds upon and refines the free energy principle, toward a physical description of entities that specifically possess higher forms of cognition.Comment: Comment on arXiv:2210.12761 . 2 pages, 1 figur

Forsiktige forskere, engasjerte journalister

Enkeltforskere har snakket om sammenhengen mellom CO₂-utslipp og klimaoppvarming i 150 år. Fra 1950-tallet økte interessen for fenomenet. I hvilken grad var denne innsikten en del av offentlig norsk debatt, og hvordan ble innsikten formidlet til allmennheten i nyhetene? En gjennomgang av nyhetsartikler og innsendt meningsstoff i Aftenposten, Dagbladet og VG i perioden 1959-1988, med ordet «drivhuseffekt» som arkivmarkør, ga til sammen 2859 treff i de tre avisene, med den største andelen i Aftenposten – 1735 treff. 44 prosent var nyhetsstoff og 17 prosent kronikker og debattinnlegg. Av meningsstoffet utgjorde debattinnleggene ti og kronikkene sju prosent. Tre til fire prosent av meningsstoffet stammer fra en kronikk skrevet av en forsker. Resultatene viser at kunnskapen om en mulig menneskeskapt klimaendring ble formidlet til et norsk avislesende publikum allerede på 1960-tallet. Men til tross for mange tegn som pekte i samme retning, var forskerne ofte forsiktige. Journalistene var djervere når de formidlet farene ved økt forbrenning av fossilt brennstoff.publishedVersio

Booktok, hashtag-chains og word trees: En visuell nettverksanalyse av BookTok-fellesskapet og deres kulturelle normer

Denne oppgaven undersøker bruken av emneknagger i BookTok-fellesskapet på TikTok, for å avdekke innsikt i fellesskapets interesser, kultur og normer. Ved å bruke forskningsverktøyet 4CAT, utforsker studien hvordan emneknagger brukes som kommunikasjon i fellesskapet, og hvordan emneknaggene avslører fellesskapets kultur og interesser. Gjennom å bruke en kombinasjon av ordtreanalyse og hashtag-chains undersøker den ytterligere forbindelsene mellom populære og mindre vanlige emneknagger, og demonstrerer hvordan undergrupper i BookTok skiller seg ut gjennom unike emneknagger. I tillegg undersøker den hvordan brukere strategisk kobler emneknagger sammen, for å sikre at innholdet når den rette målgruppen, og er med på å skape en følelse av samhold og tilhørighet. Oppgaven bygger på tidligere forskning, som ser på plattformfellesskapets bruk av emneknagger for å kommunisere, danne forbindelser og uttrykke deres leseridentitet. Dette gjør de ved å se på emneknagger som «BookTok», «bookish» og «bookrecs», som gjenspeiler fellesskapets delte vernacular (Soelseth, 2023, s. 3; Kaye et al. 2022, s. 108; Maddox & Gill, 2023, s. 6). Denne forskningen bidrar til forståelsen av BookTok, som mer enn ren underholdning, ved å undersøke den som en digital plattform for lesing, identitets og fellesskapsbygging

Making the Thermodynamic Cost of Active Inference Explicit

When describing Active Inference Agents (AIAs), the term “energy” can have two distinct meanings. One is the energy that is utilized by the AIA (e.g., electrical energy or chemical energy). The second meaning is so-called Variational Free Energy (VFE), a statistical quantity which provides an upper bound on surprisal. In this paper, we develop an account of the former quantity—the Thermodynamic Free Energy (TFE)—and its relationship with the latter. We highlight the necessary tradeoffs between these two in a generic, quantum information-theoretic formulation, and the macroscopic consequences of those tradeoffs for the ways that organisms approach their environments. By making this tradeoff explicit, we provide a theoretical basis for the different metabolic strategies that organisms from plants to predators use to survive

Parallel languages in the history of language ideology in Norway and the lesson for Nordic higher education

This chapter compares recent policy on the use of English and Norwegian in Higher Education with earlier policies on the relationship between the two standard varieties of Norwegian, and it charts how and why English became a policy issue in Norway. Based on the experience of over a century of language planning, a highly interventionist approach is today being avoided and language policies in the universities of Norway seek to nurture a situation where English and Norwegian may be used productively side-by-side. However, there remain serious practical challenges to be overcome. This paper also builds on a previous analysis (Linn 2010b) of the metalanguage of Nordic language policy and seeks to clarify the use of the term ‘parallelingualism’