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Systematic guidelines for software modelling: an empirical study on enhancing modelling education and training
Get PDFBackground: Software modelling holds significant promise for enhancing various aspects of software and systems engineering, including productivity and cost efficiency. Despite these advantages, its widespread adoption across the entire field remains limited. Extensive research has explored the reasons behind this limited adoption, uncovering issues such as subpar code generation, inadequate tool support, and a lack of guidance or training. Specifically, it has been suggested that engineers are reluctant to embrace modelling because it requires excessive effort and offers little usefulness, a view shaped by their educational background.
Aim: Overall, our goal is to conduct an empirical investigation with university students, understanding their perception of software modelling during their university studies. We aim to explore students' challenges with modelling assignments, tools, and the modelling content taught in courses. Additionally, we want to understand which aspects of modelling students find beneficial for learning and carry with them into their future academic or industry careers. Finally, we aim to create systematic guidelines for software modelling to be used by both students and instructors.
Method: To achieve our goal, we conducted several empirical studies with university students, teaching assistants, and instructors. We collected data through interviews, surveys, and observation studies. To evaluate the effectiveness of the systematic guidelines, we applied them to university courses where modelling was taught.
Results: The results described in the thesis are twofold: first, we present university students' perceptions of modelling, and then we describe the guidelines we created based on that perception. Our results show that students recognise the benefits of modelling, such as using models for planning and group communication, but their understanding is hindered by unclear assignment expectations, irregular and insufficient feedback, and lack of experience with problem domains. Finally, we conclude our thesis with systematic guidelines that will help students enhance their modelling skills and knowledge, guiding them to apply this knowledge in real-world industry settings.
Conclusion: Our results can potentially enhance education and training in software modelling, benefiting both academic settings and industrial environments. The modelling guidelines encourage students and instructors to follow a structured approach, starting from understanding a modelling problem to selecting a suitable modelling strategy based on the problem domain and tools and ultimately interpreting the resulting model. The guidelines also assist instructors in providing regular and systematic feedback on students' modelling efforts. The guidelines improve communication between students and the course by clearly outlining expectations and values for modelling assignments, which reflects the value of modelling in different future endeavours
Energy-efficient control of magnetic states
No full textEncoding data with magnetic states is currently used in various devices for data transmission, storage, and processing. The operating principle in these devices is often based on controlled switching, e.g., using a pulse of an external magnetic field, between stable magnetic states characterized by a certain direction of magnetization. However, for each act of magnetization change, a certain amount of energy is used. The challenge is to ensure that this operation is energy-efficient. In this thesis, we present the development and implementation of a theoretical framework for energy-efficient control of magnetization using an external magnetic field. The theory makes it possible to identify optimal control paths (OCPs) -- dynamical transition trajectories in the configuration space connecting the target states in the magnetic system and minimizing the energy cost -- from which all properties of optimal control pulses, including spatial and temporal distribution are systematically obtained without the need for an exhaustive scan over a range of amplitudes, frequencies or shapes. Therefore, the theory provides fundamental knowledge about the optimal manipulation of magnetization and solutions for low-power digital technologies based on magnetic materials. The theory is applied to the problem of energy-efficient control of magnetization switching in uniaxial and biaxial nanoparticles, as well as nanowires. For these systems, we show that following an OCP involves the rotation of magnetic moments in a manner that minimizes the impact of external stimuli while effectively harnessing the system's internal dynamics to facilitate the desired change in magnetization. Additionally, we show that the derived optimal switching protocols are robust with respect to thermal fluctuations in the technologically relevant regime and when the perturbation in the material parameters is not too large. Finally, we develop a method for enhancing the thermal stability of energy-efficient magnetization switching by applying an additional longitudinal magnetic field. The time-dependence of the stabilizing field can be obtained in a definite way by demanding bound dynamics of local perturbations induced by the thermal bath. The work presented in this thesis facilitates the development of energy-efficient information technology based on magnetic materials.Skráning gagna með segulástöndum er nú notuð í ýmiskonar tækni fyrir gagna utning, geymslu og úrvinnslu. Þessi tækni byggist á því að geta stjórnað breytingum á
seguástöndum, t.d. með púls af ytra segulsviði sem breytir stefnu seglunar. Hver segulbreyting krefst orku og það er mikilvægt að minnka þessa orkunotkun eins mikið og
mögulegt er. Þessi ritgerð lýsir þróun og innleiðingu á kennilegri umgjörð fyrir stjórn
segulástanda með segulsviði þar sem orkunotkunin er lágmörkuð. Með þessari aðferð
er hægt að nna bestu stjórn ferla (BSF), þ.e. ferla fyrir breytingu í segulstefnu milli
ge nna segulástanda þannig að lágmarksorku er kra st, og leiða út bestu stjórnpúlsa,
bæði í tíma og rúmi, á ker sbundinn hátt, án þess að skanna útslag, tíðni og lögun púlsanna. Þessi aðferðafræði veitir því grundvallarþekkingu fyrir bestu stjórn á seglun og
lausnum fyrir lág-orku stafræna tækni sem byggist á seglandi efnum. Aðferðafræðinni
er beitt á stjórn segulbreytinga í nanóögnum með einum og tveimur segulásum, sem
og nanóvírum. Fyrir þessi ker er sýnt fram á að BSF fela í sér snúnig segulvigra á
þann hátt sem krefst lágmarksáhrifa af ytra sviðinu á meðan eiginleg tímaframvinda
kerfanna nýtist sem best til að fá fram breytingarnar úr einu segulástandi í annað. Þar
að auki er sýnt fram á að lausnirnar sem fást fyrir bestu aðferðirnar fyrir seglunarbreytingar eru ekki næmar fyrir áhrifum hitastigs innan þeirra marka sem eru eðlileg
fyrir notkun í tækni eða fyrir frávikum í efnaeiginleikum svo lengi sem þau eru ekki
of stór. Að lokum, er þróuð aðferð til að auka enn frekar stöðulgeika bestu ferlanna
með því að bæta við segulsviði langsum. Tímaframvindu stöðgunarsviðsins er hægt að
ákvarða með því að stja mörk á staðbundnar tru anir frá varmabaðinu. Aðferðafræðin
sem lýst er í ritgerðinni auðveldar þróun á upplýsingatækni byggða á segulástöndum
þar sem orkunotkunin er lágmörkuð
Þróun ónæmismeðferðar gegn sumarexemi í hestum
No full textSumarexem er húðofnæmi af gerð I í hestum sem orsakast af framleiðslu á IgE mótefnum gegn ofnæmisvökum upprunnum úr biti smámýs (Culicoides spp.). Sjúkdómsvaldurinn lifir ekki á Íslandi. Tíðni sjúkdómsins er mun hærri í útfluttum hestum samanborið við íslenska hesta sem eru fæddir á flugusvæðum. Sumarexem hefur mikil áhrif á velferð hrossa. Aðalofnæmisvakarnir sem valda exeminu hafa verið skilgreindir og rannsóknir á ónæmissvari sjúkdómsins hafa leitt í ljós að meingerð sjúkdómsins einkennist af ójafnvægi milli Th2 hjálparfrumna og T stýrifrumna. Sökum þessa opnast sá möguleiki að þróa ofnæmisvakasértæka ónæmismeðferð við sumarexemi. Við þróun á fyrirbyggjandi ónæmismeðferð höfum við áður sýnt fram á að bólusetning í kjálkabarðseitla með hreinsuðum ofnæmisvökum í ónæmisglæði framkallar týpu 1 (Th1)/T-stýrifrumu miðað ónæmissvar. Markmið verkefnisins var frekari þróun á fyrirbyggjandi ónæmismeðferð gegn sumarexemi. Einnig framleiðsla á endurröðuðum ofnæmisvökum í skordýrafrumum og byggi auk hreinsunar þeirra til notkunar í ónæmisprófum.
Nýskilgreindir aðalofnæmisvakar sem valda sumarexemi (Cul o 8, Cul o 9, Cul o 10 og Cul o 11) voru tjáðir í skordýrafrumum með Baculoveirukerfi (Bac). Endurröðuðu ofnæmisvakarnir voru hreinsaðir og notaðir í ónæmisprófum til að meta ónæmissvörun í kjölfar bólusetningar. Einnig var sýnt fram á notagildi þeirra í greiningaprófi fyrir sumarexem. Fjórir ofnæmisvakar (Cul o 2, Cul o 2P, Cul o 3 og Cul n 8) voru tjáðir í byggi í samstarfi við ORF Líftækni. Tveir þeirra (Cul o 2P og Cul o 3) voru hreinsaðir úr byggi.
Í ritgerðinni er gerð samanburðarrannsókn á sprautun í eitla og sprautun undir húð. Tólf heilbrigðum hestum á Íslandi var skipt í tvo hópa sem sprautaðir voru í kjálkabarðseitla eða undir húð, þrisvar sinnum með fjögurra vikna millibili með hreinsuðum Culicoides ofnæmisvökum (rCul o 2P, rCul o 3 og rCul n 4) í ónæmisglæði (aluminum hydroxide (alum) og monophosphoryl lipid A (MPLA)). Sex hross til viðbótar voru bólusett undir húð með hreinsuðum ofnæmisvökum og veiru-líkum ögnum (VLP) til samanburðar við MPLA á stýringu ónæmissvars á Th1 braut. Allar þrjár bólusetningaraðferðirnar örvuðu myndun á ofnæmisvaka sértækum IgG1, IgG4/7 og IgG5 mótefnum án framleiðslu á IgE. Mótefnin hindruðu að hluta bindingu IgE úr sumarexemshestum við ofnæmisvakana.
Engin marktækur munur var á mótefnasvörun í kjölfar sprautunar í eitla samanborið við sprautun undir húð. Boðefnasvörun í kjölfar örvunar á hvítfrumum sýndi fram á marktæka aukningu á IFN- og IL-4 framleiðslu hjá eitla og undir húð bólusetningahópum og IL-10 í hestum bólusettum í eitla. Engin marktækur munur var á boðefnasvörun milli hópanna, en framleiðsla á IFN- var aðeins hærri í hestum bólusettnum í eitla samanborið við hesta bólusetta undir húð og IL-4 framleiðsla var minni. Hægt er að álykta að sprautun undir húð geti verið nothæf við ónæmismeðferð gegn sumarexemi í hestum.
Bólusetning með alum/VLP örvaði lægri IgG4/7 og IgG5 mótefnasvörun samanborið við alum/MPLA, en IgG1 svörun var sambærileg. IgG4/7 svörun var marktækt lægri gegn Bac-rCul o 2P og Bac-rCul n 4 í hestum bólusettum með alum/VLP, einnig IgG5 svörun gegn Bac-rCul o 2P. Enn fremur var hindrunargeta á IgE bindingu við ofnæmisvakana minni í hestum bólusettum með alum/VLP. Heilt yfir var mótefnasvar minna með VLP sem ónæmisglæði samanborið við MPLA og hlutfall IgG5:IgG4/7 lægra. IgG5 hefur verið tengt við ofnæmi. Í ljósi þess að IgG5 svörun var lægri með VLP gæti það verið mögulegur kostur við ofnæmisvakasértæka ónæmismeðferð gegn sumarexemi í hestum, en frekari rannsókna er þörf.
Sermi úr fyrri rannsókn var notað til að bera saman mótefnasvörun í kjölfar bólusetningar með 10 µg og 20 µg af ofnæmisvaka. Marktæk aukning á ofnæmisvakasértækum IgG mótefnum varð bæði með 10 µg og 20 µg af ofnæmisvökum. Framleiðsla á IgG1 mótefnum var marktækt minni, IgG4/7 nokkuð minni og IgG5 sambærileg með 10 µg af ofnæmisvökum samanborið við 20 µg. Draga má þá ályktun að 20 µg af hverjum ofnæmisvaka í bólusetningu sé ákjósanlegur kostur við frekari þróun á ónæmismeðferð gegn sumarexemi í hestum.
Til að meta hvort bólusetning með hreinsuðum ofnæmisvökum í ónæmisglæði veiti vörn gegn sumarexemi var framkvæmd áskorunartilraun. Tuttugu og sjö heilbrigðir íslenskir hestar voru bólusettir í kjálkabarðseitla með níu hreinsuðum ofnæmisvökum (Cul o 1P, Cul o 2P, Cul o 3, Cul o 5, Cul o 7, Cul o 8, Cul o 9, Cul o 11 and Cul n 4) í alum/MPLA ónæmisglæðum. Bólusetningin var framkvæmd á Íslandi og í kjölfarið voru hrossin flutt út til Sviss. Hestarnir voru óvarðir gegn biti smámýs og þeim fylgt eftir í þrjú ár með reglulegri klínískri skoðun, blóðtöku og örvunarbólusetningu í upphafi annars og þriðja sumars. Á fyrsta ári höfðu 6 hestar (23,1%) fengið sumarexem, 13 hestar (50,0%) á öðru ári og 16 (61,5%) á því þriðja. Mótefnasvörun á fyrstu tveimur árunum var mæld gegn þremur ofnæmisvökum (Cul o 2P, Cul o 8 og Cul o 9). Sambærilegt mótefnasnið (miðgildi) var á IgG1, IgG4/7 og IgG5 gegn öllum þremur ofnæmisvökunum eftir bólusetningu og örvunarbólusetningu en mikill breytileiki var milli einstaklinga. Engin marktækur munur var á IgG mótefnasvari á neinum tímapunkti fyrstu tvö árin milli bólusettra hesta sem fengu sumarexem og þeirra sem voru heilbrigðir út tímabilið. Við lok annars árs var IgE mótefna framleiðsla gegn Bac-rCul o 8 og Bac-rCul o 9 ofnæmisvökum marktækt hærri í bólusettum hestum sem fengu sumarexem samanborið við þau sem voru heilbrigð út tímabilið. Bólusetningin veitti því ekki vörn gegn sumarexemi en frekari prófun á þeim sýnum sem safnað var gæti gefið innsýn í orsök þess að bóluefnið varði ekki hestana.Insect bite hypersensitivity (IBH) is an allergic dermatitis of horses caused by IgE-mediated reactions to allergens of biting midges (Culicoides spp). Iceland is free of the causative agents but the prevalence of IBH in exported Icelandic horses is much higher than in Icelandic horses born in Culicoides rich environment. IBH can severely impact the well-being of affected horses. Numerous Culicoides allergens have been identified and studies on the pathogenesis demonstrate an imbalance between T-helper 2 (Th2) and regulatory T (Treg) cell subsets. This knowledge opens the possibility to develop an allergen-specific immunotherapy (AIT) against IBH. First studies showed that intralymphatic (i.l) injection of purified E. coli produced recombinant (r-) allergens with adjuvants induce a T-helper 1(Th1)/Treg focused immune response and is thus a promising approach for preventive AIT. The aim of the project is further development of preventive immunotherapy and production of r-Culicoides allergens in insect cells and transgenic barley for application in immunoassays.
Newly identified major Culicoides allergens (Cul o 8, Cul o 9, Cul o 10 and Cul o 11) were expressed and produced in insect cells (Bac). The r-allergens were purified and used in immune assays to evaluate responses following vaccination. The purified r-allergens were also found promising for use in diagnostic tests, distinguishing between IBH-affected and healthy horses. Four Culicoides allergens (Cul o 2, Cul o 2P, Cul o 3 and Cul n 8) were expressed in transgenic barley in collaboration with ORF Genetics and two of them (Cul o 2P and Cul o 3) purified.
For the development of preventive immunization, i.l. injection of purified E. coli produced r-allergens mixed with adjuvants was compared to the more practical subcutaneous (s.c.) route. Twelve healthy horses living in Iceland were injected, i.l. or s.c., three times with four-week interval, using the purified r-Culicoides allergens (rCul o 2P, rCul o 3 and rCul n 4) in a mixture with aluminium hydroxide (alum) and monophosphoryl lipid A (MPLA) as adjuvants. Six additional healthy horses were vaccinated s.c. with the same r-Culicoides allergens in alum and virus-like particles (VLP) for comparison with MPLA adjuvant for induction of Th1 type immune responses. The three vaccination methods significantly induced allergen-specific IgG1, IgG4/7 and IgG5 subclass antibody responses without allergen-specific IgE production. Furthermore, the antibodies generated were able to block the binding of IgE from IBH-affected horses to the corresponding r-allergens. Interestingly, there was no significant difference in the antibody response between the i.l. and s.c. injection routes at any time point following immunisation. Upon re-stimulation of peripheral blood mononuclear cells (PBMC), there was a significant increase in IFN- and IL-4 production in both vaccination groups compared to pre-vaccination, while a significant increase in IL-10 was only observed in the i.l. group. Horses vaccinated i.l. produced slightly more IFN- and less IL-4 as compared to the horses injected s.c., but the difference did not reach significance. It can be concluded that the simpler s.c. injection could be an option in immunotherapy against IBH. Use of VLP instead of MPLA as immunomodulator induced weaker IgG4/7 and IgG5 while IgG1 was similar in both groups. The IgG4/7 response was significantly lower against Bac-rCul o 2P and Bac-rCul n 4 in the s.c./VLP vaccination group compared to s.c./MPLA, as well for IgG5 responses against Bac-rCul o 2P. Furthermore, the IgE blocking capacity of the allergen-specific IgG antibodies induced following vaccination with alum/VLP was weaker compared to alum/MPLA. In conclusion, addition of VLPs as immunomodulator instead of MPLA resulted in a weaker antibody response and lower IgG5:IgG4/7 ratio. IgG5 has been associated with allergy. In the light of the low IgG5 response, VLP might present a promising adjuvant system for AIT against IBH but further investigation is needed. Sera from a previous vaccination experiment was used for comparison of the antibody response following i.l. immunization with 10 or 20 µg r-allergen in alum/MPLA. Both induced a significant IgG antibody response following vaccination. The 10 µg induced significantly lower IgG1 antibody levels as compared to 20 µg, the IgG4/7 response was slightly lower and the IgG5 was similar. Based on these results, 20 µg of each r-allergen in vaccination seems preferable for AIT against IBH.
To test the efficacy of a preventive allergen immunotherapy, a challenge experiment was conducted. Twenty - seven healthy Icelandic horses were vaccinated i.l. with 20 µL each of nine E. coli produced r-Culicoides allergens (Cul o 1P, Cul o 2P, Cul o 3, Cul o 5, Cul o 7, Cul o 8, Cul o 9, Cul o 11 and Cul n 4) in alum/MPLA. The vaccination was done in Iceland and the horses subsequently exported to Switzerland. They were kept unprotected from insect bites to ensure exposure to Culicoides and followed for three years with regular clinical examination and blood sampling. One horse was withdrawn from the study and excluded from sample analysis. Six horses developed IBH (23.1%) in the first year. In the second year a total of 13 horses (50.0%) and in the third year 16 (61.5%) horses were affected with IBH. The antibody response during the first two years was analysed against three Culicoides allergens (Cul o 2P, Cul o 8 and Cul o 9). A comparable time course pattern between horses that remained healthy and those that developed IBH was observed for IgG1, IgG4/7 and IgG5 antibody levels against all three r-allergens following vaccination and booster vaccination. However, there was considerable individual variability among horses. The IgG subclass response showed no difference at any time-point between horses which developed IBH and horses that remained healthy. However, at the end of the second Culicoides season IBH-affected horses had significantly higher IgE levels against Bac-rCul o 8 and Bac-rCul o 9. In conclusion, the vaccine did not reduce the incident of IBH in exported horses based on reported prevalence. Further analysis of collected samples could provide insights on why the vaccine does not protect the horses against IBH.This work was funded by The Icelandic Research Fund (grant no. 184998-051 and 206528-051), The University of Iceland Research Fund, The Horse Breeders Association of Iceland, Stofnverndarsjóður íslenska hestakynsins, Náttúruverndasjóður Pálma Jónssonar, Morris Animal Foundation (grant no. D20EQ-032), Stiftung pro Pferd and Swiss National Science Foundation (grant no. 310030_208152)
Bætt umönnun fólks með heilabilun í heimahúsi og stuðningur við aðstandendur
No full textAs the global population ages, the prevalence of dementia is on the rise, making it a reality for many families worldwide to care for a relative living with dementia at home. It is generally acknowledged globally that providing care for a person living with dementia at home comes with various challenges. While trying to address these challenges, families are often confronted with difficulties and helplessness related to their caregiving. People diagnosed with dementia and their family caregivers may experience isolation and a feeling of no longer belonging to their social circles. Studies have shown that families often feel forgotten and abandoned by the healthcare authorities in their caregiving responsibilities. This has increased researchers' and policymakers' interest in how formal services can better support these families.
By exploring how families manage their daily lives with dementia, this PhD thesis aims to enhance our knowledge of how they can be assisted in making life as good as possible. This study is conducted within a relational understanding of life and the shared context surrounding a person identified as the care collective of people and their connections. This research is based on three scientific papers (Articles I-III) that provide knowledge about the challenges faced by families where a member has been diagnosed with dementia and the arrangements they make. The idea for the future is to use these findings to develop community-based services for individuals living with dementia at home and their family caregivers.
This doctoral project comprised two studies using qualitative designs: an interview study with key informants (Article I) and a longitudinal ethnographic case study (Articles II and III). Study I involved interviews with 20 professionals who were key informants, field observations of their work settings and reviews of public documents on dementia caregiving. In Study I, data collection was made in the years 2016 and 2017 and analysed using the framework method. Study II, an ethnographic case study, was conducted with eight families, each with a member who had been diagnosed with dementia over a two-year period. All participants were on a waiting list for a placement in a specialised day programme for dementia care. Each family was followed through the waiting period, while receiving an offer of a placement in such a programme and for up to six months afterwards. The ethnographic data were collected from 2017 to 2019.
The findings of the interview study with the key informants reflect the reality faced by family caregivers of persons living with dementia in their local community in Iceland, in many ways comparable to the situation in neighbouring countries. As the key informants described, if signs of cognitive difficulties emerged, the person would be referred to the Memory Clinic for assessment, which focused on making an accurate diagnosis of an underlying illness, while exploring the condition's impact on family members was not emphasised. Participants recognised that families were often stressed and required more support but did not consider such support their primary responsibility. The connection between the Memory Clinic and primary and home care services was limited, and community services, in general, had not emphasised the development of expertise and work methods in relation to dementia care. The specialised day programmes were exceptions, with strong ties to the Memory Clinic. The drawback was the late delivery of such services, so families had limited access to support until their situations reached a severe level. Alzheimer Iceland, a nongovernmental organisation, provided individual consultations and organised support groups for relatives and specialised day programmes.
The case studies presented in Article II reflected some of the shortcomings of this situation. They depicted families' diverse experiences in finding ways to live with dementia at home while on a waiting list for formal support. They made multifaceted arrangements to make their daily lives work, but all longed for more guidance and for professionals to be interested in their situations.
According to professionals at the Memory Clinic, the current formal care system in Iceland seeks to provide families with space to be in control of their own process of living with dementia and protect their independence. However, this space also means that families must be on the lookout for the available services and be aware of what kind of support they should reach out for, but not all families have the capability to take on such a role. In Article III, we learned from the cases regarding how or whether an offer to attend a day programme supported families in living better at home. Again, the variety of situations and experiences brings to our attention the fact that families do not all fit into the formal service model provided. While some individuals living with dementia could be more engaged in daily life with the new energy they gained from the support at the specialised day programme, others were painfully reminded of their lost identity, which caused disappointment, distress and eventual withdrawal from the programme. Fear and anger rooted in the family members' pride could also prevent them from accepting a placement.
Health authorities have stressed the importance of creating a service trajectory for dementia that prioritises access to specialised day programmes. However, to meet the complex needs of individuals living with dementia and their family caregivers, the formal service providers must enhance their approach to primary care and home care. Time and space should be provided for professionals to understand families' different practices so that the former can offer family-centred support to the latter. Services for families of persons living with dementia must be designed to have the capacity to improvise and be adaptable. Learning from families about how they find their way in their daily lives with the challenges of cognitive changes enables formal service providers to better meet each family's varied and specific needs.Samfara breyttri aldurssamsetningu þjóða, þar sem fjölgun er mest meðal eldri
aldurshópa, eykst fjöldi þeirra einstaklinga sem greinast með heilabilun. Fjölskyldur um
allan heim þurfa því að takast á við áskoranir sem tengjast umönnun einstaklinga með
heilabilun heima fyrir. Í þessu umönnunarhlutverki upplifa fjölskyldur jafnan flækjur og
hjálparleysi, en bæði einstaklingarnir sem greindir hafa verið með heilabilun og þeirra
nánustu fjölskyldumeðlimir geta fundið fyrir einangrun og upplifað sig ekki lengur sem
hluta af því samfélagi sem þeir búa í. Rannsóknir sýna að fjölskyldur telja
heilbrigðisyfirvöld bregðast skyldum sínum hvað varðar umönnun fólks með heilabilun
og stuðning við fjölskyldur, en aðstandendur upplifa sig oft gleymda eða yfirgefna í
því samhengi. Þessar niðurstöður hafa aukið áhuga vísindamanna og stjórnvalda á að
skilja hvernig bæta megi stuðning við þessar fjölskyldur.
Í þessari doktorsritgerð er leitast við að varpa nýju ljósi á það hvernig styðja megi við
fjölskyldur einstaklinga með heilabilun í þeirra daglega amstri og stuðla að því að gera
líf þeirra og aðstæður eins góðar og völ er á. Fjölskyldum var fylgt eftir í þeirra
umhverfi þar sem daglegt líf var kannað og hvernig tekist var á við atburði.
Doktorsverkefnið var mótað innan hugmyndafræði um tengsl og samhengi einstaklinga
og aðstæðna þeirra. Sú hugmyndafræði snýr að skilningi á því að umönnun á sér stað
og kristallast í samhengi við þá einstaklinga sem um ræðir hverju sinni og tengsl þeirra
á milli (e. care collective). Rannsóknin byggir á þremur vísindagreinum (greinar I-III)
sem leggja upp með að auka þekkingu á þeim áskorunum sem fjölskyldur mæta í
heimilislífi sínu þegar fjölskyldumeðlimur hefur greinst með heilabilunarsjúkdóm. Þá
fjalla greinarnar einnig um það hvernig fjölskyldur takast á við mismunandi áskoranir
því tengdu og finna sér farveg í sínu daglega lífi. Vonast er til þess að niðurstöðurnar
geti nýst við þróun og betrumbætur á þeim formlega stuðningi sem hið opinbera
stuðningskerfi veitir einstaklingum með heilabilun og þeim aðstandendum sem sinna
umönnun heima fyrir.
Doktorsverkefni þetta byggir á tveimur rannsóknum þar sem notast var við eigindlegar
aðferðir; viðtalsrannsókn við lykilstarfsmenn (grein I) og langtímavettvangsrannsókn
með tilfellasniði (grein II og III). Í rannsókn I var rætt við 20 lykilstarfsmenn í
margvíslegri formlegri þjónustu vegna heilabilunar. Auk viðtala var unnið með
vettvangsathuganir á vinnustöðum þeirra og rýni á opinberum gögnum um þjónustu og
umönnun vegna heilabilunar. Gagnasöfnun í rannsókn I fór fram á árunum 2016 og
2017. Við gagnagreiningu var stuðst við þematengda rammaaðferð (e. framework
method). Rannsókn II, vettvangsrannsókn með tilfellasniði, var gerð á átta fjölskyldum
þar sem einstaklingur hafði greinst með heilabilun. Gagnasöfnun
vettvangsrannsóknarinnar stóð yfir tveggja ára tímabil, frá 2017 til 2019. Allir
þátttakendur voru tengdir minnismóttöku Landspítala og voru á biðlista fyrir sérhæfða
dagþjálfun vegna heilabilunar. Hverri fjölskyldu var fylgt eftir í gegnum tímabil þeirra á
biðlista, þar til boð um pláss í sérhæfðri dagþjálfun bauðst og í allt að sex mánuði eftir
það.
Niðurstöður viðtalsrannsóknar við lykilstarfsmenn í formlegri þjónustu sýndu að
aðstæður fjölskyldna sem sinna umönnun vegna heilabilunar á Íslandi eru að mörgu
leyti sambærilegar við aðstæður fjölskyldna í nágrannalöndum. Áherslur í formlegri
þjónustu eru á mat og nákvæma greiningu á undirliggjandi orsökum heilabilunar en
minni áhersla er lögð á áhrif aðstæðnanna á fjölskyldumeðlimi þess sem er með
heilabilun. Þeir lykilstarfsmenn sem rætt var við sögðust meðvitaðir um álagið sem oft
lægi á fjölskyldum og að þær þyrftu meiri stuðning. En þeir töldu jafnframt að slíkur
stuðningur væri ekki hluti af þeirra megináherslu í starfi. Lítil tengsl voru á
rannsóknartímanum á milli minnismóttöku, heilsugæslu og heimaþjónustu. Almennt
höfðu heilsugæsla og heimaþjónusta ekki lagt áherslu á þróun vinnulags eða
sérfræðinálgunar í sinni þjónustu við fólk með heilabilun og aðstandendur þeirra. Þó
höfðu sérhæfðar dagþjálfanir verið sérstaklega þróaðar með tilliti til þjónustu vegna
heilabilunar og voru nátengdar minnismóttöku Landspítala. Vankantar þeirrar þjónustu
voru langir biðlistar eftir því að komast að. Fjölskyldur höfðu því yfirleitt ekki aðgang að
þeim stuðningi fyrr en aðstæður heima fyrir voru orðnar mjög erfiðar vegna þróunar
heilabilunarsjúkdómsins. Til að bregðast við því ástandi hafa Alzheimersamtökin á
Íslandi, sjálfstæð stofnun utan opinberrar þjónustu, boðið upp á stuðning sem skortir
hjá hinu opinbera stuðningskerfi. Sá stuðningur felst m.a. í einstaklingsráðgjöf og
stuðningshópum fyrir aðstandendur, auk þess sem samtökin reka sérhæfðar
dagþjálfanir.
Tilfellin sem fjallað var um í grein II vörpuðu ljósi á ýmsa þá vankanta sem fjölskyldur
fundu fyrir í þjónustu. Þau gáfu til kynna þær fjölbreyttu aðferðir fjölskyldna í að finna
sér sinn eigin farveg til að komast í gegnum dagana heima með heilabiluninni, á
meðan beðið var eftir því að komast að hjá formlegum stuðningi sérhæfðrar
dagþjálfunar. Allar fjölskyldurnar í rannsókninni áttu það sameiginlegt að finna þörf fyrir
aukinn stuðning formlega kerfisins og að fagfólk sýndi aðstæðum þeirra áhuga.
Samkvæmt viðmælendum rannsóknar á minnismóttöku Landspítala liggur áhersla
formlegs stuðningskerfis á Íslandi í að veita fjölskyldum sem annast einstaklinga með
heilabilun svigrúm til að vera sjálfar við stjórnvölinn í aðstæðum sínum og auka þannig
sjálfstæði þeirra og sjálfræði. Slíkt aukið andrými felur þó í sér að fjölskyldur verða
sjálfar að vera meðvitaðar um hvers konar stuðningi er þörf á, vera sjálfar vakandi fyrir
því hvað er í boði og sækja sér þá þjónustu sem möguleg er. Það er ekki öllum
fjölskyldum gefið að hafa slíka yfirsýn. Í grein III var fjallað um þann tíma þegar boð um
dagþjálfun barst og þá hvort eða hvernig slíkt boð studdi við fjölskyldulíf. Niðurstöður
bentu áfram til mikils fjölbreytileika í aðstæðum og reynslu fjölskyldna. Sú vitneskja
v
rennir stoðum undir þá ályktun að ólíkar þarfir kalli á fjölbreytileika í veittri þjónustu.
Ekki falla allar fjölskyldur inn í þann ramma sem opinber þjónusta hefur byggt
þjónustuframboð sitt á. Sumir einstaklingar öðluðust aukinn lífsþrótt og lífsfyllingu með
þeim stuðningi sem veittur var í sérhæfðri dagþjálfun á meðan aðrir voru minntir á
sársaukafullan hátt á breyttar aðstæður sem höfðu áhrif á sjálfsmyndina. Sú reynsla gat
valdið vonbrigðatilfinningu og jafnvel það mikilli þjáningu að fjölskyldan sagði upp
plássi sínu í dagþjálfuninni, þó að það væri eini formlegi stuðningurinn sem í boði
væri. Tilfinningar eins og ótti og reiði kraumuðu innra með fólki, þær blönduðust stolti
og snertu við grunngildum í hugum fjölskyldumeðlima. Slíkt gat líka hindrað þau í að
þiggja boð um sérhæfða dagþjálfun.
Heilbrigðisyfirvöld hafa lagt áherslu á sérhæfða dagþjálfun sem lykilinn í
þjónustufarvegi vegna heilabilunar. En til þess að mæta megi flóknum og ólíkum
þörfum einstaklinga sem greindir hafa verið með heilabilun og fjölskyldna þeirra,
verður hið opinbera stuðningskerfi að efla slíka nálgun innan heilsugæslu og
heimaþjónustu. Það er mikilvægt að skapa tíma og rými fyrir fagfólk að öðlast skilning
á, lesa í og læra af mismunandi aðferðum fjölskyldna í daglegum áskorunum sínum
með heilabilun. Þjónusta við fjölskyldur og einstaklinga sem lifa með heilabilun verður
að vera hönnuð með það fyrir augum að svigrúm sé til að þróa og laga þjónustuna að
þörfum hverrar fjölskyldu. Það að hlusta og læra af fjölskyldum, hvernig þær takast á
við sitt daglega líf og þær áskoranir sem heilabilun felur í sér, gefur fagfólki einmitt
tækifæri til að þróa þjónustu sína svo að hún geti betur mætt ólíkum og breytilegum
þörfum hverrar fjölskyldu.The Icelandic Gerontological Research Center (RHLÖ),
The Icelandic Nurses' Association,
The Research Fund of Ingibjörg R. Magnúsdóttir,
The Memorial Fund of Helga Jónsdóttir and Sigurliði Kristjánsson,
The Memorial Fund of Kristín Thoroddsen, Landsbankinn,
The Icelandic Gerontological Society
Icelandic and Faroese: A usage-based cognitive analysis of morphological change
Get PDFThe current thesis presents three published articles on inflectional change in Insular Nordic (Icelandic and Faroese). Papers I and II deal with change in Icelandic, while Paper III focuses on Faroese. The three articles are related through employment of the usage-based cognitive approach, which views the structure of grammar as emergent from prior linguistic experience, assuming a central role for language use as the mechanism of linguistic innovation and change. Usage-based cognitive studies typically invoke factors such as frequency and schematicity to account for the varying degrees of productivity that inflectional classes exhibit cross-linguistically. Such studies also make recourse to domain-general cognitive processes like analogy, categorisation, entrenchment, and statistical learning as determinants in the direction of change. Crucially, the usage-based cognitive approach posits rich memory for language. Thus, the cognitive prerequisites for storage and utility of linguistic experience as informative of usage choices are no different from those which inform our interactions with the wider world generally.
Papers I and II account for the limited productivity of the low frequency Xó/æT-microclass which, before the addition of borrowed blók ‘wretch, non-entity’, contained five Icelandic feminine nouns in nominative/accusative plural -ur: bók ‘book’, bót ‘patch’, brók ‘trousers’, nót ‘fishing net’, and rót ‘root’ only, cf. plural bækur, bætur, brækur, nætur, rætur. Productivity is equated with the rate at which feminine grammatical gender is assigned to masculine nouns, while the motivation for such treatment is considered to be phonetic coherence with varyingly schematic feminine classes in plural -ur. Specifically, Paper I accounts for the different rates at which Icelandic masculine plural forms in with final -ur –– be that sequence an ending or part of the stem etymologically –– undergo reanalysis as feminine. Crucially, around 15% of nouns in Icelandic end in plural -ur: almost 92% of these are feminine, while all others are masculine. Further, syncretism in nominative/accusative plural is relatively rare among masculine nouns, but exceptionless among feminines. Also without exception, the relevant forms in plural -ur are always syncretic, irrespective of a noun’s gender.
Interestingly, in the minority of cases, plurals such as masculine eigendur ‘owners’, fætur ‘feet’, and vetur ‘winters’ alternate with overtly feminine definite forms such as pl.def. eigendurnar, fæturnar, veturnar, cf. original and more frequent masc.nom.pl.def. eigendurnir, fæturnir, veturnir, masc.acc.pl.def. eigendurna, fæturna, veturna. Additionally, masculine forms in plural -ur sometimes occur with feminine modifiers and determiners. Paper I argues that, given the highly schematic nature of the full set of nouns in plural -ur, reanalysis as feminine might be expected at a rate proportionate to the frequency of corresponding masculine forms –– all other things being equal. However, based on corpus data for Icelandic, Paper I reports a mismatch in frequency between sets of doublets defined in terms of gender. Through employment of Bybee’s network model, with some innovative notational features, Paper I demonstrates that graded phonetic structure of a broader feminine subtype in plural -ur –– as it centres around the Xó/æT-microclass –– impacts the rate of reanalysis by means of a gang effect, which is viewed as a function of analogy, i.e. the process by which existing knowledge is extended to new contexts.
In a similar vein, Paper II examines the limited productivity of the Icelandic Xó/æT-microclass. In the article, productivity is equated with the occasional inflection of feminine blók ‘nonentity’ and forms of neuter kók ‘CokeTM’ according to the morphophonological alternation exhibited by e.g. sg. bók ~ pl. bækur, rót ~ rætur, cf. blók ~ blækur, kók ~ kækur. These new plural forms are taken as evidence for the –– albeit highly limited –– productivity of the microclass. Indeed, doublet forms in both paradigms also pattern with inflection classes of higher type frequency, cf. pl. blókir, kókir, like fem. pl. myndir ‘pictures’, both of which prove more frequent than plural blækur and kækur. According to the usage-based cognitive approach to language, the impact of varyingly large and varyingly schematic classes is indeed expected to correlate with graded degrees of productivity.
Some have implied contrastive motivation and, therefore also, distinct cognitive mechanisms for the deduction of plural blækur from sg. blók and of plural kækur from sg. kók. Specifically, the opinion has been expressed that plural kækur belies “real” language use because the form only occurs in humorous contexts. Plural blækur, on the other hand, is considered “real” language use. However, it is clear that both forms are based on the pattern of alternation exemplified by e.g. sg. bók ~ pl. bækur. Therefore, Paper II seeks to dispel the idea that different motivations for deduction are at play as a misunderstanding of analogy. This objective is achieved through reference to schematicity, semantics, and pragmatics, as well as to Icelandic corpus data. By this means, Paper II demonstrates that new membership in the microclass is graded as a function of limited productivity. Finally, Paper II shows that innovative kækur and blækur are deduced by identical means, i.e. via analogy.
Paper III deals with analogical change in Faroese, with specific focus on levelling of the intricate vowel alternations which characterised the inflection of Old West Nordic u-stems. Crucially, levelling is defined as the extension of a stem variant to a cell in which it did not occur previously, as opposed to one form “changing into” another. The Faroese descendants of Old West Nordic u-stems have undergone significant levelling, as is evident from the paradigm of Far. vøllur ‘field, grassy ledge on a rock face, (sports) pitch, airport’: all cells of the paradigm contain the variant vøll- (< OWN nom.sg., acc.sg., acc.pl., dat.pl. vǫll-), while some also contain vall- (OWN gen.sg., gen.pl. vall-). The variant OWN (dat.sg., nom.pl.) vell- has been completely eradicated (see Markússon 2022b).
Conversely, the paradigm of Far. fjørður ‘fjord, inlet/bay, sound/strait’ has retained all stem variants, cf. Far. fjørð- (< OWN nom.sg., acc.sg., acc.pl., dat.pl. fjǫrð-), firð- (< OWN dat.sg., nom.pl. firð-), fjarð- (< OWN gen.sg., gen.pl. fjarð-). Further, it has extended those variants to other cells of the paradigm, cf. innovative dat.sg. fjørði, which exists beside older firði, innovative nom./acc.pl. fjørðir and fjarðir beside older firðir, and innovative dat.pl. fjarðum and firðum, which live alongside older fjørðum.
The basic forms of paradigms, i.e. those from which new inflectional forms take their stem, and the factors that establish them have typically been defined according to either of two opposing theoretical approaches. The first attributes basic status on account of so-called ‘markedness’, i.e. the perspective that new forms in a paradigm are likely to be based on existing ones that express semantically “natural” and/or “neutral” values, such as singular and nominative. In other words, such “unmarked” forms serve as basic. The opposing approach posits frequency as the determining factor. Thus, levelling proceeds from the most frequent member(s) of the paradigm, due to a correlation between frequency of use and its impact on the strength of representation in memory. In other words: frequent forms are better represented than less frequent forms and more readily accessible in moments of memory lapse. Therefore, frequent forms are most likely to be used as a base when the “correct” form evades the language user.
Paper III utilises Faroese corpus data in order to demonstrate that the basic forms of Far. vøllur and fjørður –– both of which refer to topographical entities and occur as complex place names –– are established on the basis of frequency, rather than semantics. Paper III argues that due to the overall low frequency of forms of Far. vøllur, the most frequent stem variant, i.e. vøll-, was extended to the whole paradigm, while vell- was easily forgotten. Conversely, the high token frequency of dat.sg. firði meant that it was well represented in memory and, therefore, easily accessible in moments of temporary memory lapse. Paper III argues that this property of dat.sg. firði triggered spread of the stem variant firð- to the dative plural through the context [í/á/úr + dat.], where younger dat.pl. firðum takes older fjørðum over in frequency. Further, presence of the stem variant firð- in all plural cells of the paradigm, cf. also nom./acc.pl. firðir, facilitated association of the form firð- with the meaning plural. Subsequently, an attempt was made to level the singular portion of the paradigm in favour of the variant fjørð- to contrive the formal opposition sg. fjørð- : pl. firð-. However, the new form never took over the role of older dat.sg. firði on account of the high token frequency of the latter.
The current thesis demonstrates that factors such as frequency and schematicity impact choices made in on-line language use as a function of stored experience with language. Further, if the course of language change correlates with the distributional properties of these factors in the acquired grammar, it follows logically that the usage events which incrementally facilitate change reflect the linguistic experience whence the grammar emerges. Moreover, the fact that language change is a function of language use demonstrates that the structure of grammar is an emergent and dynamic system, rather than one whose adaptive properties are constrained by genetic endowment and ontogeny. Therefore, in light of the conclusions drawn in Papers I–III, the current thesis also showcases the applicability of usage-based cognitive theory as a means to account for the direction of morphological change.The Icelandic Research Fund (RANNIS), grant no. 174253-015
Design and Evaluation of Parallel Machine Learning Approaches in Computational Fluid Dynamics Applications
No full textThe objective of this research is to investigate the potential of machine learning (ML) and deep learning (DL) within computational fluid dynamics (CFD) utilizing high-performance computing (HPC). Turbulent flow, a complex phenomenon prevalent in both natural sciences and industrial settings, poses a significant challenge in classical physics. Given its nonlinear and stochastic nature, DL emerges as a promising approach for comprehending turbulent flow dynamics.
This PhD Thesis introduces a novel data-driven methodology, leveraging experimental datasets to assess the efficacy and robustness of sequential DL models in turbulent flow analysis. The manuscript elaborates on the innovative aspects and advantages of employing DL within this context. Moreover, it outlines the necessity of HPC resources for executing cutting-edge DL models alongside the computationally demanding approaches for model tuning and hyperparameter optimization.
This study thoroughly followed a documented procedure to assess the efficacy of innovative DL modeling techniques. Initially, measured data obtained from experimental tests was analyzed in depth, establishing their relevance to DL models from a physical perspective. Subsequently, three DL model architectures— long short-term memory (LSTM), gated recurrent unit (GRU), and Transformer models—were systematically evaluated, and their outcomes were compared. Furthermore, a case study was undertaken in the wind energy sector within the realm of energy engineering, yielding promising results to validate the DL prediction model’s applicability.
In addition, optimization techniques for hyperparameter tuning were explored utilizing new HPC methodologies (e.g., modular supercomputing architectures and cutting-edge graphical processing units (GPUs)) to enhance the performance of the DL models. This optimization process was rigorously executed and assessed within the setup of a data-driven model capable of training with statistics data of CFD or EFD approaches, resulting in improved and cutting-edge approaches within the CFD domains, augmenting findings of physics-driven models with DL models.
The findings of this research demonstrate a noteworthy breakthrough in predicting turbulent flow behavior, showcasing the effectiveness of the proposed DL models while not losing sight of leveraging cutting edge HPC methodologies.Markmið rannsóknarinnar er að kanna mátt vélnáms (ML) og djúpnáms (DL) í tölulegri
straumfræði (CFD) með aðstoð háafkasta tölva (HPC). Iðustreymi, margslungið
fyrirbæri sem fyrirfinnst í bæði náttúrulegum aðstæðum og manngerðum iðnaði,
er vel þekkt óleyst eðlisfræðilegt viðfangsefni. Þrátt fyrir að iðustreymi sé bæði
ólínulegt og slembið fyrirbæri hefur djúpnám gefið góða raun um að vera fært um
að segja til um hegðun iðustreymis.
Í þessari doktorsritgerð er kynnt ný gagnadrifin aðferðafræði, sem notar gögn
frá tilraunum til að ná fram styrkleikum og áreiðanleika runubundins djúpnáms í
iðustreymisgreiningu. Ritgerðin sýnir fram á helstu nýjungar þróaðar hér og kosti
þess að nota djúpnám á þetta viðfangsefni. Einnig er farið í nauðsyn þess að nota
háafkastatölvur til að beita djúpnámsaðferðum auk tölulega krefjandi aðferða til að
stilla líkanið af og bestunar á yfirfæribreytu.
Í þessari rannsókn er lýst nákvæmlega stöðluðum aðferðum um hvernig má ná
fram hámarksvirkni djúpnámsaðferða. Í fyrstu var farið vandlega yfir tilraunagögn
og nýting þeirra til djúpnáms í raunverulegum aðstæðum skoðuð ítarlega. Næst eru
þrjár mismunandi djúpnáms aðferðir – minnugt endurkvæmnis tauganet (LSTM),
hlið endurtekin eining (GRU) og breytir (Transformer) – skoðaðar kerfisbundið í
þremur fösum og niðurstöður þeirra bornar saman. Auk þess var gerð tilviksrannsókn
úr vindorkugeiranum, þ.e. orkuverkfræði, sem sýndi niðurstöður sem lofa góðu til
að sannreyna færni djúpnáms til að spá fyrir um framtíðarhegðun.
Í lokafasa rannsóknarinnar var bestunaraðferðum fyrir yfirfæribreytu beitt með
því að nota skjákort (GPU) úr fremstu röð til að bæta virkni djúpnámslíkansins.
Bestunin var framkvæmd af mikilli nákvæmni og metin út frá gagnadrifnum líkönum
sem unnt var að þjálfa með tölfræðigögnum úr tölulegri straumfræði (CFD) og
gögnum úr tilraunum. Það leiddi til bættra og nýrra framúrskarandi aðferða í
tölulegri straumfræði þar sem niðurstöður módela byggðum á eðlifræði eru bætt
með djúpnámi.
Niðurstöður rannsóknarverkefnisins eru bylting í að spá fyrir um hegðun iðustreymis og sýna klárlega virkni djúpnáms þegar fremstu háafkastatölvuaðferðum er
beitt
Áhættugreiningu beitt til að samþætta öryggi við hönnun kerfa
No full textThe overall aim of this Ph.D. thesis is to contribute to the further development of the research area of risk analysis and risk management. It aims to bridge the gap between scientific research in this area and its practical application in industry and business, e.g., through the development of ISO standards. Industrial standards, notably ISO standards, are the tools organizations use to manage their risk, by following their guidance and complying with their requirements. Organizations confirm their compliance with these standards through certification, which means that they heavily depend on the quality of the ISO standards to enable them to effectively manage risk.
In this thesis, the scientific foundation of ISO standards is analyzed, focusing on the guidance provided for key elements of risk management. The research also explores how well ISO standards are aligned with state-of-the-art risk management literature. The research reveals that the ISO standards lack uniformity in risk terminology and guidance on risk management, particularly for risk analysis. As a result, it is expected that risk management, and specifically the analysis of risk, is not executed satisfactorily. Therefore, it is hypothesized that certain flaws in risk management will be evident in practice. This is verified through six real-life case study examples.
Part of this thesis work involved developing a two-step benchmarking model to assess the efficacy of ISO risk management systems with the aim of finding hidden risk issues and improvement opportunities. Furthermore, it is investigated whether risk analysis can be improved by using new and improved analysis techniques to identify hazards and threats. The thesis explores the application of recent analysis techniques that are based on systems theory to reinforce risk management systems based on ISO standards. Systems-Theoretic Accident Model and Processes (STAMP), and the derived Systems-Theoretic Process Analysis (STPA) and Systems-Theoretic Early Concept Analysis (STECA) are applied in real case studies and in an early phase of a major national infrastructure project to meet the safe-by-design engineering concept. The main contribution of this Ph.D. thesis is the identification of what is missing in ISO standards regarding risk management and the development of a two-step benchmarking model to assess the efficacy of ISO risk management systems. The research demonstrates how it is possible to improve risk identification and risk analysis with STAMP, STPA, and STECA techniques. To facilitate such analysis, a special STAMP/STPA software was developed as a part of this thesis work.Meginmarkmið þessarar doktorsritgerðar er að stuðla að frekari þróun innan rannsóknarsviðs áhættugreiningar og áhættustjórnunar. Hún miðar að því að brúa bilið sem er á milli vísindarannsókna á þessu sviði og hagnýtingar þeirra í iðnaði og viðskiptum, t.d. í gegnum þróun ISO-staðla. Iðnaðarstaðlar, sérstaklega ISO-staðlar, eru þau tæki sem fyrirtæki og stofnanir beita til að stjórna áhættu í rekstri, með því að fylgja leiðbeiningum og fara eftir kröfum þeirra. Fyrirtæki og stofnanir staðfesta að þau uppfylli þessa staðla með vottun, sem þýðir að þau eru mjög háð gæðum ISO-staðlanna til að gera þeim kleift að stjórna áhættu á áhrifaríkan hátt.
Í þessari ritgerð er vísindalegur grunnur ISO-staðla rannsakaður og sjónum sérstaklega beint að leiðbeiningum sem veittar eru í stöðlunum um lykilþætti áhættustjórnunar. Í ritgerðinni er ennfremur kannað hversu vel ISO-staðlar samræmast nýjustu vísindarannsóknum á sviði áhættustjórnunar. Rannsóknin leiðir í ljós að ISO-staðlana skortir samræmda hugtakanotkun í leiðbeiningum um áhættustjórnun, sérstaklega er varðar áhættugreiningu. Þess vegna er sett fram sú tilgáta að áhættustjórnun og þá sérstaklega greining áhættu sé ekki framkvæmd á fullnægjandi hátt og að ákveðnar veilur komi fram við framkvæmd áhættustjórnunar í reynd. Þetta er sannreynt með sex dæmum úr raunverulegum rekstri.
Hluti af þessari rannsókn fólst í því að þróa tveggja þrepa viðmiðunarlíkan til að meta virkni ISO-áhættustjórnunarkerfa með það að markmiði að finna dulda áhættuþætti og umbótatækifæri. Í tengslum við það er rannsakað hvort bæta megi áhættugreiningu með því að nota nýja og endurbætta greiningartækni til að greina hættur og ógnir. Ritgerðin fjallar um beitingu nýlegrar greiningartækni sem byggir á kerfisfræði til að styrkja áhættustjórnunarkerfi byggð á ISO-stöðlum. Beitt er kerfisfræðilegri aðferð sem byggist á gerð slysalíkans og greiningu verkferla, á ensku nefnd „Systems-Theoretic Accident Model and Processes“ (STAMP) og afleiddri kerfisfræðilegri aðferðagreiningu sem á ensku er nefnd „Systems-Theoretic Process Analysis“ (STPA) ásamt kerfisfræðilegri snemmgreiningu sem á ensku er nefnd „Systems-Theoretic Early Concept Analysis“ (STECA). Þessum aðferðum er beitt í raunverulegum tilviksrannsóknum og ennfremur á frumstigi stórs innviðaverkefnis á landsvísu í þeim tilgangi að uppfylla verkfræðihugmynd um örugga hönnun. Meginframlag þessarar doktorsritgerðar er að bera kennsl á það sem vantar í ISO-staðla varðandi áhættustjórnun og sýna fram á leiðir til að bæta og styrkja áhættustjórnkerfi sem byggja á slíkum stöðlum. Rannsóknin sýnir hvernig hægt er að bæta árangur við það að bera kennsl á áhættu og greina hana með STAMP, STPA og STECA tækni. Til að auðvelda slíka greiningu var sérstakur STAMP/STPA hugbúnaður þróaður sem hluti af þessari rannsókn
Simulation of short pulse photoemission in a microdiode with implications for optimal beam brightness
Get PDFMolecular dynamics simulations, with full Coulomb interaction, are used to model short-pulse photoemission from a finite area in a microdiode. We demonstrate three emission regimes, source-limited emission, space-charge-limited emission for short pulses, and space-charge-limited emission for the steady state. We show that beam brightness is at a maximum during the transition from the source-limited emission regime to the space-charge-limited emission regime for short pulses. From our simulations, it is apparent that the emitter spot size is an important factor when estimating the critical charge density for short-pulse electron emission and that simple capacitive models may considerably underestimate the total charge emitted.Icelandic Research Fund grant number 174512-051
Landsvirkjun energy research fund
Reykjavik University doctoral fundAccepted Manuscrip
The Role of Government in Economic Growth and Development: A Comparative Study of Malta and Iceland 1960-1980
Get PDFThis is a comparative study of the two small island states of Iceland and Malta in 1960-2000. It
focuses on the role of the two governments as they enacted public policies, intervened in the
functioning of their economies and foreign trade, invested in infrastructure, enhanced human
capital and developed welfare states. The governments aspired to boost economic growth,
improve quality of life, raise living standards, increase exports, combat recessions, create jobs,
reduce trade and economic volatility, reap political gains and advance foreign relations.
The thesis compares economic and political developments and their interplay, advancing
international relations and different routes to European cooperation. With their emerging public
sectors, political systems, and political customs and conflicts, both island states tried to secure
their rights, livelihoods and positions amongst other European nations.
Around 1960, Iceland´s economy was relatively advanced compared to Malta. Iceland
was a financially self-standing republic, financing growth through exports, foreign loans,
Marshall Aid and locally accumulated capital; and gifted with prolific fishing grounds and rich
renewable energy resources. The national economy was vulnerable due to dependency on the
volatile fishery and its export markets. However, Iceland could not yet control and manage the
fishing grounds, as they were open for foreign deep-sea trawlers until the mid-1970s. Iceland
maintained its focus on developing the fishery further during the last quarter of the twentieth
century but with parallel government-driven developments in the power sector, while foreign
investors built the associated power-intensive industries. A transferable quota system was
introduced and shaped in the fisheries from 1984 to the 1990s. The new system increased
efficiencies and labour productivity and reduced the over-capacity of fleet and plants. The 1970s
and 1980s were marked by slack macroeconomic policies - hyperinflation, frequent devaluations
of the ISK, rampant over-investments, subsidies in farming and uneconomical redistributive
systems in fisheries. The economy became more liberal, diversified, and productive in the
1990s, helped by the European Economic Area Agreement, which became effective in 1994.
In contrast to Iceland, Malta pursued rather stable macroeconomic policies throughout
the period considered. In the 1960s, Malta was at first preoccupied with the politics and
administrative issues of independence, which was achieved in 1964, and then during the
remainder of the decade with preparations for diversifying and strengthening the economy in
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reaction to a massive down-scaling of the workforce in the dockyards and the British services.
The 1960s saw a large-scale emigration. Based on local development plans and in line with
advice from foreign consultants, manufacturing for exports was targeted, and foreign technology
and investments were attracted to Malta. Industrial estates were built, and incentives offered to
foreign investors. Manufacturing firms, e.g. in textiles, electronics and pharmaceuticals, set up
plants in Malta. New hotels were built in the 1960s, initiating a growing tourism industry. Air
Malta was founded, and Malta became a popular tourist destination. In the 1990s and the 2000s,
financial services emerged as another successful economic initiative.
While Iceland restricted foreign investments and the shareholding of foreign firms in its
strategic sectors, i.e., the fishery and renewable power production, Malta used foreign
investments to its advantage. Iceland and Malta took steps in easing foreign trade restrictions.
Iceland made its first move in liberalising domestic trade in 1960 and took a further step when it
joined EFTA in 1970, involving a customs union with the EFTA countries. That same year,
Malta signed an Association Agreement with the European Economic Community (EEC),
creating a customs union based on free trade between Malta and the EEC.
Malta developed a rather centralised political system, while Iceland evolved a more
decentralised system. Malta inherited its political system from Britain, and Iceland its system
from Denmark. Both had self-government, preceding the republic in Iceland (1944) and
independence in Malta (1964). The political system in Malta paved the way for two-party
politics, with one party in power and the other in opposition. Meanwhile, the Icelandic system
favoured multi-party politics, which needed coalitions of 2-4 parties at any time for a majority in
the parliament. Two government levels made the political processes in Iceland more
complicated than in Malta, as many policies and programs had to be negotiated between the
state, the local authorities, the trade unions and business federations. One of the foremost
differences between the two island states was the size of the landmass, topography, climate and
location. It resulted in dissimilar political systems with a strong geographical dimension in
Iceland. Their dissimilar location in the North Atlantic and the Mediterranean swayed their
choices of foreign trading partners and political allies towards adjacent neighbourly countries
Landmótun og virkni fornra ísstrauma á Norðausturlandi
No full textThis thesis describes the evidence of palaeo-ice streams in northeast Iceland. Ice streams within the Iceland Ice Sheet (IIS) had been previously proposed, but limited studies existed on their geomorphology. The aim of this study was to advance the understanding of the geomorphological imprint, configuration, and dynamics of palaeo-ice streams and their development during and following the Last Glacial Maximum by mapping glacial landforms and analyze their internal architecture.
The research focuses on streamlined subglacial bedforms (SSBs; drumlins and mega-scale glacial lineations), crevasse-squeeze ridges (CSRs), and ribbed moraines; however, glaciofluvial and ice-marginal landforms, as well as hummocky terrain were also mapped. The distribution and orientation of SSBs reveal four flow-sets of cross-cutting palaeo-ice streams that shifted in time and space, along with ice divides. During the maximum glaciation, ice flow was towards the north, unconstrained by the topography, but became confined to the fjords and valleys as the ice sheet thinned. The CSRs and ribbed moraines indicate ice-stream shutdown following glacier readvances during the Late Glacial. The variance in landform morphology and distribution is used to reconstruct the configuration and dynamics of the ice streams.
The results provide new insight into the dynamics of the IIS and palaeo-ice streams within it and are essential for constraining numerical modelling experiments of the ice sheet’s evolution. This research has implications for our understanding of modern and palaeo-ice sheet behaviour during deglaciation and under warming climate, and paves the way for further studies and reconstructions of palaeo-ice streams in Iceland.Þessi ritgerð fjallar um ummerki og hegðun fornra ísstrauma á Norðausturlandi. Tilgátur hafa áður verið settar fram um ísstrauma í hinum íslenska meginjökli á síðasta jökulskeiði en takmarkaðar rannsóknir hafa verið gerðar á landmótun þeirra. Markmið verkefnisins var því að auka skilning á landmótun, útbreiðslu og virkni fornra ísstrauma og þróun þeirra á síðasta jökulskeiði með því að kortleggja og rannsaka jökulræn landform. Rannsóknir á innri byggingu landforma munu auka skilning okkar á tilurð og myndun þeirra ásamt hegðun ísstraumanna.
Í rannsókninni er lögð áhersla á straumlínulaga landform (jökulöldur og risakembur), sprungufyllingar og rifjagarða, en malarásar, leysingafarvegir, jökulgarðar og haugaruðningar eru einnig kortlagðir. Útbreiðsla og stefna straumlínulaga landforma benda til nokkurra ísstrauma sem hafa verið virkir á mismunandi tíma og færst til, ásamt ísaskilum. Á hámarki síðasta jökulskeiðs var ísflæði á rannsóknarsvæðinu til norðurs, án tilheyrandi áhrifa af undirliggjandi landslagi, en samhliða þynningu jökulþekjunnar varð ísflæðinu stjórnað æ meir af landslaginu. Sprungufyllingarnar og rifjagarðarnir eru til marks um stöðnun ísstrauma sem voru virkir á síðjökultíma. Breytileika í lögun og dreifingu landformanna er hægt að nýta til að skilja legu og virkni ísstraumanna.
Niðurstöðurnar veita nýja innsýn í útbreiðslu og virkni fornra ísstrauma á Íslandi og gagnast til að skorða líkanareikninga af íslenska meginjöklinum. Rannsóknin leggur grunn að áframhaldandi kortlagningu á fornum ísstraumum á Íslandi og eykur skilning á hegðun nútíma og fornra meginjökla og viðbrögðum óstöðugra ísstrauma við hlýnandi loftlagi.The University of Iceland Doctoral Research Fund, the Icelandic Center for Research, the Doctoral Teaching Assistant Grant, the Energy Research Fund of Landsvirkjun, the Research Fund of the Icelandic Road and coastal administration, and the Aðalsteinn Kristjánsson Memorial Fund