Opin vísindi
Opin vísindi er varðveislusafn vísindaefnis og doktorsritgerða í opnum aðgangi á vegum íslenskra háskóla og Landsbókasafns Íslands - Háskólabókasafns.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
Opinn aðgangur að rannsóknaniðurstöðum er í samræmi við 10. gr. laga nr. 3/2003 um opinberan stuðning við vísindarannsóknir sem og kröfur innlendra og erlendra rannsóknasjóða. Markmiðið með opnum aðgangi er að niðurstöður rannsókna séu aðgengilegar sem flestum óhindrað og án endurgjalds á rafrænu formi. Vistun í varðveislusafninu er varanleg og ætlað að tryggja aðgang að vísindaefni íslenskra háskóla í opnum aðgangi um ókomna tíð. Varðveislusafnið Opin vísindi er tengt við rannsóknagáttina IRIS og rannsóknaniðurstöður í opnum aðgangi sem eru skráðar í IRIS eru um leið vistaðar og gerðar aðgengilegar til framtíðar í varðveislusafninu. Með því að safna þessu efni saman í eitt safn verður aðgangur að því einfaldur og þægilegur fyrir alla sem vilja kynna sér það og geta þannig notið þess öfluga vísindastarfs sem fram fer í háskólum landsins.
Varðveislusafnið er OpenAIRE / OpenAIREplus samhæft og samrýmist kröfum sem gerðar eru um birtingu rannsóknaniðurstaðna úr verkefnum sem styrkt eru úr evrópsku rannsóknaáætlununum FP7 og H2020.
Varðveislusafnið notar opna hugbúnaðinn DSpace.
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Strategy Implementation in Icelandic Fisheries : Obstacles, key success factors and competitive advantages
(2025-09-26) Vigfússon, Kristján Reykjalín; Jóhannsdóttir, Lára; Ólafsson, Snjólfur; Köseoğlu, Mehmet Ali; Department of Business and Economics
Strategy implementation is crucial for companies and organizations to utilize resources effectively and facilitate business results. The fishery industry is a major global sector that creates millions of jobs; globally, more than half a billion people earn their livelihoods from fishing. Fisheries also provide essential nutrition for people and serve as an important link in alleviating poverty and ensuring global food security. This doctoral thesis comprises four published academic articles examining strategy implementation in the Icelandic fishing industry, focusing on key success factors, obstacles, and competitive advantages. The thesis is situated within the broader landscape of strategic management, offering valuable insights into industry-specific conditions and strategic principles. The first article of this thesis is a systematic literature review. It exclusively analyzes empirical studies on strategy implementation. Articles two, three, and four are industry-focused case studies on the fisheries sector. These articles are drawn on both primary and secondary data. The first article of the thesis presents a comprehensive review of existing research on strategy implementation, synthesizing findings to generate new insights. The paper reviews 35 peer-reviewed articles published between 1980 and 2020. The aim is to highlight the main success factors and obstacles hindering strategy implementation while paying particular attention to existing literature gaps. The results indicate that previous research identified 16 obstacles and 18 success factors influencing strategy implementation. Furthermore, this brings forth certain dualistic factors showing that some obstacles can simultaneously be viewed as success factors and vice versa. The second article focuses on the challenges Icelandic fisheries face in implementing their strategy. The study aims to identify and understand the critical internal and external obstacles companies encounter during the strategy implementation process, as perceived by their Chief Executive Officers (CEOs). Through elite interviews with the CEOs of some of the largest fisheries companies in Iceland, the research uncovers several noteworthy findings. It reveals two previously identified internal obstacles, language barriers, and the complexities of managing a multicultural workforce. Additionally, the study identifies external obstacles not commonly documented in earlier research, including the absence of a clear governmental vision for the industry, confrontations with regulatory bodies, persistent changes in industry regulations, high levels of political uncertainty, time-consuming lobbying efforts, and often, unsupportive political and media discourse. These results have theoretical significance and deepen knowledge of strategy implementation by identifying and classifying internal and external obstacles that reduce the likelihood of successful implementation. These findings contribute to a better understanding of the fisheries challenges and provide valuable insights for policymakers and CEOs in the industry. The third article focuses on the key success factors necessary for efficient strategy implementation within the Icelandic fisheries industry. The article aims to classify and identify the main success factors that influence strategy implementation, with the secondary goal of evaluating the focus and importance of the United Nations’ Sustainable Development Goals (SDGs) for the Icelandic fisheries industry. The article is based on interviews with the CEOs of some of the largest fisheries in Iceland. The results indicated four important areas where strategy implementation can be improved: including all employees in the implementation process; promoting innovation and communication between employees and managers; aligning company policies with the United Nations’ SDGs; and implementing action plans with clear, measurable, and prioritized goals and timelines. The findings have a theoretical contribution as the study identifies success factors of strategy implementation, enriching existing literature through a conceptual framework. In addition to the study‘s theoretical contributions, the framework provides fisheries industry practitioners with actionable insights to enhance policy implementation, improving strategic alignment and organizational performance. The fourth article investigates factors contributing to competitive advantage in Icelandic fisheries. This study is based on interviews with CEOs of some of the largest fisheries in Iceland. The findings suggest a transition from a resource-based view to a market-based view that strengthens the companies competitive advantage in the industry. These changes, however, occur gradually due to obstacles such as a lack of expertise and experience necessary to navigate the consumer market, insufficient investment within the market, and restricted growth possibilities within the Individual Transferable Quota management system. The identified future competitive advantage integrates strengths from the resource-based view with a market perspective for the industry. The theoretical contribution of the study proposes a conceptual framework showing the prospective competitive advantage of the industry. This study offers actionable insights and recommendations for CEOs and stakeholders in Icelandic and international fisheries, highlighting a shift from a resource-based view to a market-based view while underscoring the importance of internal resource integration for sustaining competitiveness. An important overall contribution to the thesis is to introduce and propose a framework that outlines a five-phase approach to strategy implementation. The framework logic aligns with widely accepted principles of strategic management. It sequentially moves from creating enabling conditions (Phase 1) to defining strategy (Phase 2), preparing for execution (Phase 3), implementing strategy (Phase 4), and sustaining accountability through monitoring (Phase 5). In addition, the findings of this thesis identify the characteristics of a future fisheries company and propose a framework that leverages internal strengths, such as management expertise, access to fishing stocks, and sustainability emphasis, alongside market-based approaches to industry growth. While aiming to provide a comprehensive perspective on strategy implementation in the fisheries industry, special emphasis is placed on industry obstacles and on the important incentives that facilitate implementation. Additionally, the development of the industry's competitive advantage is evaluated from both resource-based theory and market-based perspectives. This thesis offers valuable insights for industries reliant on natural resources, highlighting the dynamic interplay between internal resources and external market forces in shaping competitiveness. The theoretical contribution of the thesis lies in strengthening and further developing the conceptual framework of strategy implementation, with particular emphasis on organizational and institutional theories. Additionally, it advances theoretical understanding by employing the lens of resource-based theory and the market-based perspective to evaluate competitive advantage within the industry. The integration of these four articles offers practical contributions to our understanding of strategy implementation and competitive advantages, particularly within resource-dependent industries. The thesis proposes frameworks and models bridging the theoretical knowledge gap and practical implementation, offering actionable insights for industry leaders and policymakers. Keywords: Strategy, implementation, key success factors, obstacles, fishery, CEOs, competitive advantage
Modelling metabolomic changes in human bone marrow derived mesenchymal stem cells during oesteogenic differentiation via genome scale metabolic models to further their use in regenerative medicine
(Reykjavík University, 2021) Sigmarsdottir, Thora Bjorg; Sigurjónsson, Ólafur E.
In recent years the fields of regenerative and translational medicine have become the subjects of significantly growing interest due to their offer of previously unimaginable therapeutics. Within these fields are several novel tools believed to hold the keys to furthering existing and new developments and one of those tools is human mesenchymal stem cells. One of the applications hMSCs have been studied for is enhanced osteogenic regeneration or reconstruction of new bone tissue. Although various studies have been performed and some strides been made towards a plausible clinical application there is still lot left to be discovered. A methodical studying and relatively detailed in silico genome scale metabolic modelling occurring changes and the accompanying metabolic phenotypes could provide a means to fill in the existing knowledge gaps (from the protein level all the way to the genomic level) and, additionally, a means to perform hypotheses testing with a significant reduction when it comes to the accompanying cost. The objective of this thesis was to study the metabolomic changes in hMSCs during osteogenic differentiation using original transcriptomic, intracellular and extracellular metabolomic data in order try and define possible metabolic stages over the course of the differentiation and use genome scale network reconstruction to create in silico models. In the first part of this work extracellular and intracellular data were used to define possible stages to osteogenic differentiation and hypothesise which pathways may characterise the different metabolic phenotypes. Three stages were suggested based on the data and labelled intracellular metabolomics indicated a decrease in glycolytic dependencies throughout the differentiation period with an increase in mitochondria related energy producing functions as the osteogenesis progressed. This will help focus specific time points of interest and relevance when it comes to mapping the significant metabolomic changes. In the second part of this work extracellular metabolomic data collected from BM-hMSCs during proliferation, adipogenic and osteogenic differentiation was used along with experimentally specific data to create three directly comparable genome scale metabolic models, two of which have no comparable predecessors, for those cell lineages during the first 7 days of cell culture. Models were biologically feasible and showed all lineage specific characteristic reactions as active. By analysis and comparison, the various enriched subsystems and pathways most significant for each lineage were found. Results were varied for proliferating cells, which matches that they have to synthesise various metabolites and substances to expand, whilst fatty acid oxidation and fatty acid synthesis was most prominent in adipogenesis with fatty acid oxidation as well as transport reactions characteristic for osteogenesis. These models can be used for model-driven experimental design to engineer osteogenesis and, with modifications, to create disease model for osteoporosis. In the third part presented we summarized the various characteristics and possibilities that lie in using MSCs as a tool in tissue engineering and regenerative medicine and how, via implementation of genome scale metabolic model reconstruction, their possibilities could possibly be taken much further in a faster, more methodical manner while reducing the related experimental cost. To summarise, this work has provided real strides when it comes to closing the existing gap regarding metabolomic changes during differentiation of hMSCs as well as providing novel tools that can be used to make further studies more efficient and cost effective.
„Riddarinn hallast við brotinn brand, bleik er hans unga kinn“: Um birtingarmyndir berkla í skáldskap
(Hugvísindastofnun Háskóla Íslands, 2025-09-30) Egilsson, Sveinn Yngvi; Íslensku- og menningardeild (HÍ); Faculty of Icelandic and Comparative Cultural Studies (UI); Hugvísindasvið (HÍ); School of Humanities (UI)
Í greininni er fjallað um skáldskap sem tengist berklum. Hún hefst á almennum inngangi um sögu berkla og menningarlega þýðingu þeirra sem „rómantísks sjúkdóms“. Síðan eru dregnar saman helstu niðurstöður erlendra rannsókna á berklabókmenntum. Susan Sontag og Katherine Byrne hafa bent á skáldskapareinkenni á borð við blómamál, lit og litleysi (roða, fölva), hita og kulda, hernaðarmál (bardaga, berkla sem óvin) og persónugervingar berkla eða dauðans (vofa, svipur, beinagrind). Auk þess hafa þær sýnt að í skáldskapnum birtist oft sterkar andstæður eins og lífsþorsti og dauðaþrá, fegurð og ljótleiki, ást og hatur eða beiskja, ástríður og deyfð, sköpunarkraftur og lamandi depurð, virkni og þolandaháttur, líkami og andi. Í greininni er leitað svara við þeirri spurningu hvort hliðstæð einkenni megi finna í íslenskri ljóðagerð. Könnunin beinist sérstaklega að völdum kvæðum eftir skáldin Jóhann Gunnar Sigurðsson (1882–1906), Stefán Sigurðsson frá Hvítadal (1887–1933) og Guðfinnu Jónsdóttur frá Hömrum (1899–1946). Einnig er hugað að þeim hugmyndaklasa sem tengist sjúkdómum eins og berklum og getur falið í sér æsku, fegurð, gáfur, hnignun, depurð og dæmda ást eða ill örlög. Helstu niðurstöðurnar eru þær að í ljóðum þessara þriggja skálda, sem öll dóu úr berklum, megi greina hliðstæð einkenni og bent hefur verið á í erlendum berklaskáldskap. Áðurnefndar andstæður setja sterkan svip á kvæði þeirra allra. Mikið ber á myndmáli kulda og þrá eftir hlýju og birtu. Haust- og vetrarlandslag myndar þá gjarnan andstæðu við vor- og sumarmyndir. Í kvæðum Jóhanns Gunnars birtast veikindin oft í myndhverfingum og ummyndunum eins og þekkt er úr kvæðum eftir erlend skáld eins og John Keats (1795–1821) sem berklar drógu til dauða. Þeir yrkja báðir um föla riddara sem eru milli heims og helju (kvæðin La Belle Dame sans Merci og Í val). Jóhann Gunnar sækir stef og stíl í þjóðkvæði og lætur ljóðrænan óhugnað þeirra endurspegla vanlíðan og ótta þeirra sem eru alvarlega veik. Stefán frá Hvítadal yrkir á beinskeyttari hátt þó að hann beiti líka myndmáli til að lýsa þeirri líðan og tilfinningum sem fylgja því að vera haldinn lífshættulegum sjúkdómi. Kvæði Stefáns einkennast af hispurslausri tjáningu og tilfinningasveiflum sem lýsa von um bata og ótta við dauðann. Guðfinna frá Hömrum skapar ákveðinn ljóðheim sem helgast af fegurð, samhljómi og birtu. Tónlist setur sterkan svip á skáldskapinn og myndar eins konar hljómgrunn í lýsingum á náttúrunni og tilfinningum. Guðfinna yrkir um dulúðuga tóna og hljóma sem óma í sköpunarverkinu og tengja má hugmyndinni um „hljómlist hvolfanna“ (lat. Musica universalis, e. Music of the spheres). Keats yrkir á svipaðan hátt í Ode on a Grecian Urn og skapar í ljóðum sínum heim fegurðar og samhljóms. Nálægðin við dauðann og undirliggjandi depurð koma víða fram í ljóðum Guðfinnu og geta tekið á sig tónlistarmyndir. Þannig má greina ýmis einkenni berklabókmennta í ljóðum Guðfinnu en í samanburði við skáldskap Jóhanns Gunnars og Stefáns er ljóðheimur hennar fagurfræðilegri og hljómrænni. Í lok greinarinnar er hvatt til frekari rannsókna á íslenskum bókmenntum sem tengjast berklum.
Dual-Polarized Super-Wideband Antenna with Artificial Materials-Enhanced Gain for 5G Millimeter-Wave and Remote Sensing Applications
(2026) Esmail, Bashar A.F.; Isleifson, Dustin; Koziel, Slawomir; Pietrenko-Dabrowska, Anna; Department of Engineering
This paper presents a high-performance dual-polarized super-wideband (SWB) antenna that employs optimized slots and an Artificial Material (AM) array to achieve remarkable enhancements in both bandwidth and gain. The proposed design features a compact Vivaldi configuration with integrated arrow-shaped slots, enabling SWB operation while maintaining a low-profile size of 0.66× 0.49× 0.01λ3. A constrained trust-region gradient-based optimization is used to refine the slot geometry and antenna parameters, achieving an operating range from 8.4 to 42.8 GHz with a stable gain of approximately 10 dBi at frequencies above 17 GHz. The incorporation of AMs further enhances the gain and extends the bandwidth. The AM antenna, with dimensions of 0.94× 0.49× 0.01λ3 , achieves peak gains of 13.3 dBi at 24 and 38 GHz and covers a wide operating range of 8.3-45 GHz. Dual polarization is realized by employing two orthogonally oriented Vivaldi elements, resulting in a high polarization isolation exceeding 25 dB across the entire operating bandwidth. The experimental results demonstrate excellent agreement with the simulation-based findings. Featuring SWB performance, high gain, strong polarization isolation, polarization diversity, and a compact low-profile structure, the proposed antenna is well suited for 5G millimeter-wave (MMW) and satellite remote sensing applications.
Dual adversarial attacks : Fooling humans and classifiers
(2023-06) Schneider, Johannes; Apruzzese, Giovanni; Department of Computer Science
Adversarial samples mostly aim at fooling machine learning (ML) models. They often involve minor pixel-based perturbations that are imperceptible to human observers. In this work, adversarial samples should fool both humans and ML models, which is important in two-stage decision processes. We perform changes on a higher abstraction level so that a target sample exhibits properties of a desired sample. Technically, we contribute by deriving a regularization scheme for autoencoders incorporating a classifier loss for smoothly interpolating between wildly different samples. The realism and effectiveness of generated samples are confirmed with a user study and other evaluations. Our experiments consider neural networks of four architectures, assessed on MNIST, FashionMNIST, QuickDraw and CIFAR-10. Results show that our scheme leads to superior performance compared to existing interpolation techniques: on average, other methods have an 11% higher failure rate when producing a sample that is of any of two interpolated classes. Furthermore, our attacks work in both white- and black-box settings.
Error fetching top-level communities