46 research outputs found

    Dry Clutch Modeling, Estimation, and Control

    Get PDF
    A Doctor’s degree comprises 240 ECTS credits (4 years of full-time postgraduate studies), of which at least 120 ECTS credits constitute a doctoral dissertation

    Curvature and Harmonic Forms on Complete Manifolds

    Get PDF
    MasteroppgÄve i matematikkMAT399MAMN-MA

    BĂŠrekraftig aluminiumsproduksjon: Resirkulering i aluminiumsbransjen: En lĂžnnsomhetsanalyse av aktĂžrer i det europeiske aluminiumsmarkedet.

    Get PDF
    Aluminiumsbransjen er i stadig endring og i takt med et Þkende miljÞ- og bÊrekraftsfokus i samfunnet, har flere aktÞrer i bransjen tatt strategiske grep for Ä styrke sine posisjoner innenfor resirkulering av aluminium. Norsk Hydro ASA er blant disse, og det er deres planer om Þkt eksponering mot resirkulering som er utredningens utgangspunkt. FormÄlet med utredningen blir Ä beskrive og utforske lÞnnsomheten blant aktÞrer i det europeiske markedet som allerede har inkludert resirkulering av aluminium i sin forretningsmodell. Utredningens studieobjekt bestÄr av 12 aluminiumsprodusenter, med produksjonslokaler i Europa, som Hydro selv anser som sentrale konkurrenter pÄ resirkuleringssiden av aluminiumens verdikjede. Analyseperioden strekker seg fra 2016 til 2020, og vi vil benytte bÄde kvantitativ og kvalitativ metode for Ä svare pÄ utredningens problemstilling. Gjennom utredningen har vi valgt Ä fokusere pÄ hvordan utvalgets makroomgivelser, konkurranseforhold og bedriftsspesifikke karakteristika ved aluminiumsprodusentene kan bidra med Ä forstÄ utvalgets lÞnnsomhetsnivÄ og- variasjoner. Vi har samlet inn regnskapsdata fra aluminiumprodusentenes offentlig tilgjengelige Ärs- og bÊrekraftsrapporter. Basert pÄ utvalgte nÞkkeltall som mÄler lÞnnsomhetsprestasjonene, ser utvalget ut til Ä ha et stigende lÞnnsomhetsnivÄ fra 2016 til 2018, fÞr det faller mot slutten av analyseperioden. For Ä kunne si noe om hvor godt utvalgets lÞnnsomhetsnivÄ er, har vi kalkulert et bransjegjennomsnitt, med utgangspunkt i selskaper som opererer innenfor samme nÊringsgruppe. Utvalgets aluminiumsprodusenter presterer godt over bransjegjennomsnittet, mÄlt ved EBITDA-margin. LÞnnsomhetsnivÄet er i stÞrre grad varierende, nÄr vi mÄler prestasjonene opp mot nÞkkeltallene ROCE og TKR. VÄre hovedfunn viser at varekostandel og omlÞpshastighet kan bidra med pÄ Ä forklare de relative lÞnnsomhetsvariasjonene i utvalget. Videre ser vi at aluminiumprodusentenes stÞrrelse, erfaring og grad av vertikal integrasjon, har en signifikant sammenheng med deres lÞnnsomhetsprestasjon, mÄlt ved EBITDA-margin. I analyseperioden observerer vi en tydelig Þkning i produsentenes bÊrekraftsfokus, men vi finner ingen signifikant sammenheng som sier at dette Þkte fokuset har fÞrt til verken bedre eller dÄrligere lÞnnsomhetsprestasjoner, mÄlt med nÞkkeltall for overordnet lÞnnsomhet. Vi ser imidlertid en sammenheng som tyder pÄ at det Þkte fokuset pÄ bÊrekraft har gitt lavere omlÞpshastighet pÄ produsentenes totalkapital.nhhma

    Norwegian society of rheumatology recommendations on diagnosis and treatment of patients with giant cell arteritis

    Get PDF
    ObjectiveTo provide clinical guidance to Norwegian Rheumatologists and other clinicians involved in diagnosing and treating patients with giant cell arteritis (GCA).MethodsThe available evidence in the field was reviewed, and the GCA working group wrote draft guidelines. These guidelines were discussed and revised according to standard procedures within the Norwegian Society of Rheumatology. The European Alliance of Associations for Rheumatology (EULAR) recommendations for imaging and treatment in large vessel vasculitis and the British Society for Rheumatology (BSR) guidelines for diagnostics and treatment in GCA informed the development of the current guidelines.ResultsA total of 13 recommendations were developed. Ultrasound is recommended as the primary diagnostic test. In patients with suspected GCA, treatment with high doses of Prednisolone (40–60 mg) should be initiated immediately. For patients with refractory disease or relapse, Methotrexate (MTX) should be used as the first-line adjunctive therapy, followed by tocilizumab (TCZ).ConclusionNorwegian recommendations for diagnostics and treatment to improve management and outcome in patients with GCA were developed

    Vasculitis distribution and clinical characteristics in giant cell arteritis: a retrospective study using the new 2022 ACR/EULAR classification criteria

    Get PDF
    IntroductionGiant cell arteritis (GCA) is the most common vasculitis of the elderly. In recent years, advanced imaging has to a certain extent replaced temporal artery biopsy (TAB) to aid diagnosis in many institutions and helped to identify three major phenotypes of GCA, namely, cranial GCA (c-GCA), large-vessel non-cranial GCA (LV-GCA), and a combination of these two patterns called mixed-GCA, which all show different clinical patterns. Recent 2022 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria respect the changing conception and clinical practice during the last two decades. In this cohort study, we present vasculitis distribution and baseline characteristics using the 2022 ACR/EULAR classification criteria as well as the EULAR core data set.MethodsIn this retrospective study from Southern Norway, we identified all patients diagnosed with GCA between 2006 and 2019 in our single-center fast-track clinic (FTC). We included all patients who were examined using ultrasound (US) of cranial as well as non-cranial large vessels at diagnosis to depict vascular distribution. EULAR core data set, ACR 1990, and 2022 ACR/EULAR classification criteria were used to characterize the cohort.ResultsSeventy-seven patients were diagnosed with GCA at our institution in the aforementioned period. Seventy-one patients (92.2%) were diagnosed with the help of US and included in the further analysis. The 2022 ACR/EULAR classification criteria allocated 69 patients (97.2%), while the ACR 1990 classification criteria allocated 49 patients (69.0%) in our cohort as having GCA. Mixed-GCA was the most common type in 33 patients (46.5%). Weight loss was significantly more common in patients with large-vessel non-cranial vasculitis in LV-GCA and mixed-GCA. Headache, on the other hand, was significantly more common in patients with involvement of cranial vessels.ConclusionMixed GCA was the most common form of GCA in our cohort. In our study, the 2022 ACR/EULAR classification criteria seem to be a more useful tool compared with the old ACR 1990 classification criteria to allocate GCA patients diagnosed and treated at our US-based FTC as having GCA

    Vann, juss og samfunn

    Get PDF
    Society’s use and management of water relies on professional expertise spanning diverse fields: from biology and technology to economics and law. This book examines current issues related to regulating water through chapters summarizing various sets of regulation as well as chapters that take a scientific deep dive into selected themes. The diversity of professional expertise is also reflected in the law aspect. We explore such subjects as surface runoff, natural disasters, drinking water, groundwater, salmon, hydropower, and human rights, as well as general impact assessment requirements and duty of knowledge in environmental law administration. A key objective of the book has been to provide an interdisciplinary understanding of the legal circumstances associated with water, and in addition, deliberate the pros and cons of some of the current regulations. This book will be particularly useful for those who in various ways support and facilitate procedures within the public sector at both the national and municipal levels. It will also be useful for private sector actors seeking familiarity with legal questions that can arise in relation to public administration and other private actors. From a broader perspective, we hope the book can help to throw light on conflicts between different interests and groups within society that occur, for example, when introducing fees, special injunctions against private actors, and requirements for knowledge basis. This book project is the result of legal research conducted at the Norwegian University of Life Sciences (NMBU) and is supplemented by national expertise in several areas. It has been edited by Steinar TaubĂžll, a professor at NMBU’s Department of Property and Law. TaubĂžll has a background in both law and the natural sciences, and extensive experience with interdisciplinary work.HĂ„ndtering og bruk av vann i samfunnet krever et faglig mangfold fra biologi og teknikk til Ăžkonomi og juss. Denne boken drĂžfter aktuelle temaer knyttet til rettslig regulering av vann, bĂ„de i form av oversiktskapitler om ulike regelsett og gjennom vitenskapelige dypdykk i utvalgte temaer. Den faglige spennvidden gjenspeiler seg ogsĂ„ innen det juridiske. I boken finner man stoff om overvannshĂ„ndtering, naturfare, drikkevann, grunnvann, villaks, kraftutbygging, menneskerettigheter, samt om generelle utredningskrav og kunnskapsplikter i miljĂžrettsforvaltning. Et sentralt siktemĂ„l er Ă„ bygge opp tverrfaglig forstĂ„else av gjeldende juridiske forhold knyttet til vann, og dessuten sette noen av dagens reguleringer under debatt. Boken retter seg sĂŠrlig til de ressurspersonene som pĂ„ ulike mĂ„ter stĂžtter saksbehandlingen i stat og kommune. Boken antas ogsĂ„ Ă„ vĂŠre nyttig for private aktĂžrer som vil gjĂžre seg mer kjent med rettsspĂžrsmĂ„l som kan oppstĂ„ i forhold til forvaltningen og til andre private aktĂžrer. I et bredere perspektiv er det dessuten Ăžnskelig at boken kan bidra til Ă„ belyse konflikter mellom ulike hensyn og grupper i samfunnet, for eksempel ved innfĂžring av gebyrer, pĂ„legg rettet mot private, innfĂžring av tyngende vilkĂ„r og krav til kunnskap og faktagrunnlag. Bokprosjektet springer ut av den juridiske forskningen ved Norges miljĂž- og biovitenskapelige universitet, og har i tillegg knyttet til seg nasjonal spisskompetanse pĂ„ mange temaer. Bokas redaktĂžr er dosent Steinar TaubĂžll ved Institutt for eiendom og juss ved NMBU, som har naturfaglig og juridisk utdannelse, samt lang erfaring med tverrfaglig arbeid

    Vann, juss og samfunn

    Get PDF
    Society’s use and management of water relies on professional expertise spanning diverse fields: from biology and technology to economics and law. This book examines current issues related to regulating water through chapters summarizing various sets of regulation as well as chapters that take a scientific deep dive into selected themes. The diversity of professional expertise is also reflected in the law aspect. We explore such subjects as surface runoff, natural disasters, drinking water, groundwater, salmon, hydropower, and human rights, as well as general impact assessment requirements and duty of knowledge in environmental law administration. A key objective of the book has been to provide an interdisciplinary understanding of the legal circumstances associated with water, and in addition, deliberate the pros and cons of some of the current regulations. This book will be particularly useful for those who in various ways support and facilitate procedures within the public sector at both the national and municipal levels. It will also be useful for private sector actors seeking familiarity with legal questions that can arise in relation to public administration and other private actors. From a broader perspective, we hope the book can help to throw light on conflicts between different interests and groups within society that occur, for example, when introducing fees, special injunctions against private actors, and requirements for knowledge basis. This book project is the result of legal research conducted at the Norwegian University of Life Sciences (NMBU) and is supplemented by national expertise in several areas. It has been edited by Steinar Taubþll, a professor at NMBU’s Department of Property and Law. Taubþll has a background in both law and the natural sciences, and extensive experience with interdisciplinary work

    Climate control of terrestrial carbon exchange across biomes and continents

    Get PDF
    Peer reviewe

    Modeling and Estimation for Dry Clutch Control

    No full text
    Increasing demands on comfort, performance, and fuel efficiency in vehicles lead to more complex transmission solutions. One such solution is the Automated Manual Transmission (AMT). It works just like an ordinary manual transmission but the clutch and gear selection are computer controlled. In this way high efficiency can be accomplished with increased comfort and performance. To be able to control and fully utilize an AMT it is of great importance to have knowledge about how torque is transmitted in the clutch. The transmitted torque in a slipping dry clutch is therefore studied in experiments with a heavy duty truck (HDT). It is shown that material expansion with temperature can explain torque variations up to 700 Nm for the same clutch actuator position. A dynamic clutch temperature model that can describe the torque variations is developed. The dynamic model is validated in experiments, and shown to reduce the error in transmitted torque from 7 % to 3 % of the maximum engine torque compared to a static model. The clutch model is extended with lock-up/break-a-part dynamics and an extra state describing wear. The former is done using a state machine and the latter using a slow random walk for a parameter corresponding to the clutch disc thickness. An observability analysis shows that the augmented model is fully or partially observable depending on the mode of operation. In particular, by measuring the actuator position the temperature states are observable, both during slipping of the clutch and when it is fully closed. An Extended Kalman Filter (EKF) was developed and evaluated on measurement data. The estimated states converged from poor initial values, enabling prediction of the translation of the torque transmissibility curve. The computational complexity of the EKF is low and it is thus suitable for real-time applications. The clutch model is also integrated into a driveline model capable of capturing vehicle shuffle (longitudinal speed oscillations). Parameters are estimated to fit an HDT and the complete model shows good agreement with data. It is used to show that the effect of thermal expansion, even for moderate temperatures, is significant in launch control applications. An alternative use of the driveline model is also investigated here. It is found that the amplitude discretization in production road-slope sensors can excite vehicle shuffle dynamics in the model, which is not present in the real vehicle. To overcome this problem road-slope information is analyzed and it is shown that a third-order butterworth low-pass filter can attenuate the vehicle shuffle, while the shape of the road profile is maintained.  All experiments in the thesis are performed using production HDTs only, i.e. production sensors only. Since all modeling, parameter estimation, observer design and validation are performed with production sensors it is straight forward to implement the results in a production HDT following the presented methodology.LINK-SI
    corecore