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.
Nýlega bætt við
Caffeine, Daytime Sleepiness, and Conduct Problems Among Early Adolescents : A Longitudinal Analysis
(2025-05) Kogan, Steven M.; Lilly, Christa L.; James, Jack E.; Kristjansson, Alfgeir L.; Department of Psychology
Purpose: Recent research suggests that caffeine use may promote a range of adjustment difficulties among adolescents, particularly during the middle school years. The effects of caffeine are particularly concerning given the increased use of high-dosage caffeine products, such as energy drinks, among youth. We investigated the influence of caffeine use on trajectories of conduct problems among early adolescents. Daytime sleepiness was tested as mediator of caffeine's effect. Methods: Hypotheses were tested with longitudinal (4 waves) data from 2,633 middle school students beginning in the Fall of sixth grade and concluding in the spring of seventh grade. All students in a single class cohort at 20 West Virginia middle schools were invited to participate. Results: Controlling for family affluence and management practices and pubertal development, use of more than 100 mg of caffeine significantly predicted linear increases in conduct problems over time (Est. = 0.23, p = .015). Increases in daytime sleepiness partially mediated this effect (Est. = 0.22, p = .002). Discussion: Caffeine use and daytime sleepiness are important vulnerability factors for the emergence of conduct problems.
Cellular Composition of the Brain of a Northern Minke Whale
(2025-09) Avelino-de-Souza, Kamilla; Patzke, Nina; Karlsson, Karl; Manger, Paul R.; Herculano-Houzel, Suzana; Department of Engineering
The largest mammalian brains belong to cetacean species among the cetartiodactyls. Stereological analyses have estimated cetacean numbers of cerebral cortical neurons to be more than the average 16 billion of humans, yet isotropic fractionator estimates in artiodactyls predict that even the largest cetacean brains should have no more than a few billion cortical neurons. Here, we used the isotropic fractionator to investigate these contrasting estimates of neuronal numbers by determining the numbers of neurons and non-neuronal cells forming the brain of a northern minke whale, previously estimated using stereology as containing 12.8 billion cortical neurons (Eriksen and Pakkenberg 2007), and comparing it to our dataset of several dozen mammalian species analyzed with the same method. We report that, with 3.2 billion neurons, the minke whale cerebral cortex conforms to the quantitative scaling rules that apply to other mammals, especially the closely related artiodactyls. The same brain contained a total of 57.4 billion neurons, of which 54.2 billion were cerebellar neurons, matching the expected numbers of a hypothetical artiodactyl brain of similar cerebellar mass. In addition, we found that the northern minke whale brain, with a mass of 2683.9 g, contained 173.4 billion non-neuronal cells, following the universal scaling rules that apply to the brain in all therian mammals examined to date. Thus, how non-neuronal cells are added to the mammalian brain is conserved across therian mammals and is not affected by the transition to an obligatory aquatic life history. Strikingly, we find that the minke whale is an outlier amongst mammals in having almost 18 cerebellar neurons for every neuron in the cerebral cortex, compared to the average ratio of 4, which might be related to infrasonic communication. In addition, with only approximately 88 million neurons, the remainder of the brain (brainstem/diencephalon/subcortical telencephalon) of the northern minke whale exhibited the lowest relative neuronal density of these regions reported in mammalian brains, which might be related to the absence of limbs compared to all other mammalian species. Our results indicate that the number of neurons in cetacean brains has been grossly overestimated by stereological accounts, and place whale brains on par with highly cognitively capable macaws, macaques, baboons, and elephants, but below great apes and humans, in terms of numbers of cortical neurons.
Broadband multi-layered stepped cone shaped metamaterial absorber for energy harvesting and stealth applications
(2024-11) Bağmancı, Mehmet; Wang, Lulu; Sabah, Cumali; Karaaslan, Muharrem; Paul, Liton Chandra; Rani, Tithi; Unal, Emin; Department of Engineering
In this study, a broadband polarization and angle-independent metamaterial absorber (MA) is investigated in the microwave range. It is made up of a periodic array of multi-layered metal-dielectric stepped cones. Since the dimensions of the layers forming the unit cell are different, each layer resonates at different frequencies with overlapping bands. The overall response of the structure, with its extremely wide bandwidth, can be obtained by summing all the overlapping frequency responses corresponding to each layer. In numerical simulation, it is observed that the absorption at normal incidence is above 90% in the frequency range between 9.68 and 17.45 GHz and 95% in the frequency range between 9.91 and 14.86 GHz. The energy harvesting ratios of the structure are also evaluated in a wide spectral band. A power ratio of around 90% is obtained in the same frequency range in accordance with absorption response. A noticeable harvesting efficiency of up to 82% is observed, which represents the energy level converted into electrical energy on resistors.
Beyond the west : Revealing and bridging the gap between Western and Chinese phishing website detection
(2025-01) Yuan, Ying; Apruzzese, Giovanni; Conti, Mauro; Department of Computer Science
Phishing attacks are on the rise, and phishing websites are everywhere, denoting the brittleness of security mechanisms reliant on blocklists. To cope with this threat, many works proposed to enhance Phishing Website Detectors (PWD) with data-driven techniques powered by Machine Learning (ML). Despite achieving promising results both in research and practice, existing solutions mostly focus “on the West”, e.g., they consider websites in English, German, or Italian. In contrast, phishing websites targeting “Eastern” countries, such as China, have been mostly neglected—despite phishing being rampant also in this side of the world. In this paper, we scrutinize whether current PWD can simultaneously work against Western and Chinese phishing websites. First, after highlighting the difficulties of practically testing PWD on Chinese phishing websites, we create CghPghrg—a dataset which enables assessment of PWD on Chinese websites. Then, we evaluate 72 PWD developed by industry practitioners and 10 ML-based PWD proposed in recent research on Western and Chinese websites: our results highlight that existing solutions, despite achieving low false positive rates, exhibit unacceptably low detection rates (sometimes inferior to 1%) on phishing websites of different regions. Next, to bridge the gap we brought to light, we elucidate the differences between Western and Chinese websites, and devise an enhanced feature set that accounts for the unique characteristics of Chinese websites. We empirically demonstrate the effectiveness of our proposed feature set by replicating (and testing) state-of-the-art ML-PWD: our results show a small but statistically significant improvement over the baselines. Finally, we review all our previous contributions and combine them to develop practical PWD that simultaneously work on Chinese and Western websites, achieving over 0.98 detection rate while maintaining only 0.01 false positive rate in a cross-regional setting. We openly release all our tools, disclose all our benchmark results, and also perform proof-of-concept experiments revealing that the problem tackled by our paper extends to other “Eastern” countries that have been overlooked by prior research on PWD.
Between expectations and outcomes : Technology adopters' narratives and technology discourse dynamics
(2026-12) Bunduchi, Raluca; Candi, Marina; Department of Business and Economics
Expectations propel the evolution of emerging technologies, yet existing research generally assumes that expectations are gradually displaced by concrete outcomes as technologies mature and become widely accepted. We revisit this assumption by examining how technology adopters' temporal framings of technology performance, their expressions of concrete outcomes of technology adoption, and the broader technology discourse reflected in trade-press coverage relate to one another over time. We illuminate these patterns by tracing 21 years (2002−2022) of radio-frequency identification (RFID) adoption and analysing adopters' statements in 407 case stories published in The RFID Journal, coupled with a longitudinal corpus of trade-press coverage from the same period. Manual coding of adopters' expressions of concrete realised benefits and challenges in the case stories is combined with a purpose-built dictionary that detects five temporal positions in adopters' framings of RFID performance. We find that associations between concrete outcomes and temporal framings are selective and stage-dependent. Concrete outcomes do not simply replace expectations, instead, they become associated with specific temporal framings over time. We also find that adopters' temporal framings are associated with trade-press coverage in stage-specific ways that change over time, often amplifying but also sometimes tempering broader attention to RFID. We contribute to research on technology framing and expectations dynamics by foregrounding adopters as co-constructors of technology discourse, challenging the displacement assumption with a stage-sensitive explanation of expectation–outcome dynamics, and introducing a replicable, dictionary-based approach for large-scale analysis of temporal framings in technology narratives.
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- University of Iceland
- University of Akureyri
- Bifröst University
- Hólar University College
- IRIS
- Agricultural University of Iceland
- National and University Library of Iceland
- Iceland University of the Arts