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
A Low-Profile Hybrid Decoupling Method for Ultra-Compact Planar Antenna Arrays
(2026) Taheri, Sina Hasibi; Lalbakhsh, Ali; Zahur, Nabeel; Koziel, Slawomir; Szczepanski, Stanislaw; Zareanborji, Amirhassan; Department of Engineering
This paper presents a novel and compact decoupling methodology for ultra-compact planar antenna arrays with center-to-center spacing smaller than 0.3 λ. In such densely packed configurations, strong multidirectional mutual coupling significantly degrades the array performance. To address this challenge, a comprehensive decoupling strategy is proposed for a 2 × 2 array operating in the 5.8-6 GHz band. The approach integrates three coordinated mechanisms: I-shaped metallic strips for coupling-path cancellation, a dumbbell-shaped defected ground structure (DGS) for ground-current suppression, and dielectric perturbation for reducing substrate-mediated coupling. The proposed structure achieves effective two-dimensional decoupling while maintaining a low-profile and easy-to-fabricate configuration. By performing a systematic parametric study and Genetic Algorithm (GA) the structure is optimized in the multidimensional design space. Both simulated and measured results demonstrate that the proposed method successfully reduces the transmission coefficients between array elements to below -20 dB across the target frequency band, satisfying the critical design requirement. The achieved isolation enhancement does not degrade the impedance matching, and the measured radiation patterns further demonstrate that the proposed decoupling structure improves the realized gain by 2.85 dB and 4.34 dB at the lower and upper edges of the operating frequency band, respectively.
Advancing Meibography Assessment and Automated Meibomian Gland Detection Using Gray Value Profiles
(2025-05) Forni, Riccardo; Maruotto, Ida; Zanuccoli, Anna; Nicoletti, Riccardo; Trimigno, Luca; Corbellino, Matteo; Travé-Huarte, Sònia; Giannaccare, Giuseppe; Gargiulo, Paolo; Department of Engineering
Objective: This study introduces a novel method for the automated detection and quantification of meibomian gland morphology using gray value distribution profiles. The approach addresses limitations in traditional manual and deep learning-based meibography analysis, which are often time-consuming and prone to variability. Methods: This study enrolled 100 volunteers (mean age 40 ± 16 years, range 18–85) who suffered from dry eye and responded to the Ocular Surface Disease Index questionnaire for scoring ocular discomfort symptoms and infrared meibography for capturing imaging of meibomian glands. By leveraging pixel brightness variations, the algorithm provides real-time detection and classification of long, medium, and short meibomian glands, offering a quantitative assessment of gland atrophy. Results: A novel parameter, namely “atrophy index”, a quantitative measure of gland degeneration, is introduced. Atrophy index is the first instrumental measurement to assess single- and multiple-gland morphology. Conclusions: This tool provides a robust, scalable metric for integrating quantitative meibography into clinical practice, making it suitable for real-time screening and advancing the management of dry eyes owing to meibomian gland dysfunction.
Adapting in times of crisis : how social media marketing of gambling changed in response to major shifts in the gambling landscape
(2026) Houghton, Scott; Boy, Frederic; Bradley, Alexander; James, Richard J.E.; Wardle, Heather; Dymond, Simon; Department of Psychology
Gambling marketing on social media in countries like Great Britain (GB) is relatively well understood. Little is known, however, about how such marketing is impacted by major changes to the gambling landscape, like the COVID-19 pandemic. Here, we assessed changes in the frequency, sentiment, and content of gambling marketing on Twitter by Great Britain (GB) gambling operators and affiliates. We analysed n = 353,134 tweets from 10 operators and affiliates posted between January 2020 and July 2022. Using machine learning, we categorised tweets based on content and tracked how social media use by operators and affiliates changed during the pandemic. Findings revealed decreases in the frequency of tweets posted during the first national lockdown, particularly for affiliates, and a greater proportion of sports content related tweets, compared to direct advertising, as the pandemic continued. Postings by affiliates tended to include more positive sentiments. Our findings highlight the speed at which gambling operators and affiliates adapted their social media marketing campaigns to large structural changes like the COVID-19 lockdowns.
A computational 3D analysis for assessing bone remodeling following total hip arthroplasty : a longitudinal study spanning six years
(2025-10-01) Betti, Valentina; Jónsson, Halldór; Cristofolini, Luca; Gíslason, Magnús Kjartan; Gargiulo, Paolo; Department of Engineering
Objectives: This study aimed to enhance the comprehension of volumetric bone mineral density (vBMD) changes following Total Hip Arthroplasty (THA) by establishing a protocol to (i) precisely locate alterations in the proximal femur in three dimensions and (ii) evaluate these changes over an extended period. Methods: Twelve individuals who underwent unilateral THA, using either cemented or uncemented prostheses, were recruited. CT-scans of the proximal femur were acquired at three distinct time points: 24 h, 1 and 6 years post-surgery. Utilizing the acquired data, 3D models of the proximal femur were generated, and a novel algorithm was developed to categorize them into Gruen zones. Comparative analysis of density values among the three sets of scans allowed the calculation of bone density gains/losses for the entire proximal femur and specific regions. Results: A lower trabecular bone quantity was observed in the cemented group compared to the uncemented cohort, with discernible differences in vBMD evolution observed in the overall femur and certain Gruen zones. Noteworthy inter-patient variability was evident, ranging from physiological bone remodeling to unexpected increases/decreases in vBMD (e.g.,+340% after one year). Conclusions: This analysis proves to be a valuable tool to understand the long-term vBMD evolution in THA patients.
A Compact Half-Mode Substrate Integrated Waveguide Based Dual-Wideband Antenna
(2024-05) Agrawal, Meha; Kumar, Trivesh; Saraswat, Kapil; Department of Engineering
A dual-wide-band triple resonance half mode substrate integrated waveguide (HMSIW) cavity-backed antenna with an extra shorting via is presented in this paper. Three modes of the HMSIW cavity are utilized to generate the dual-wide-band resonances. The HMSIW cavity along with three rectangular slots is fed coaxially which helps in achieving triple resonance and size miniaturization. An additional shorting via is loaded at the position of electric null between the 2nd and 3rd modes to bring the modes closer and couple them. The antenna exhibits one narrow band and one wide-band response. The dual-wide-band antenna is fabricated and tested on a low-profile substrate of 0.05 λg. A relative bandwidth of 1.03% (10.58–10.69 GHz) and 6.12% (12.47–13.25 GHz) is attained by the two bands. A stable broadside and unidirectional radiation pattern is achieved with a peak gain of 4.5 dBi, 5.81 dBi, and 6.18 dBi at 10.6 GHz, 12.68 GHz, and 13.2 GHz, respectively. Thus, the proposed dual-wide-band antenna can be effectively utilized for satellite applications.
Flokkar í Opnum vísindum
Veldu flokk til að skoða.
- 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