Endre søk
Begrens søket
123456 1 - 50 of 278
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Abbasi, Abdul Gahafoor
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Khan, Zaheer
    University of the West of England, UK.
    Veidblock: Verifiable identity using blockchain and ledger in a software defined network2017Inngår i: UCC 2017 Companion - Companion Proceedings of the 10th International Conference on Utility and Cloud Computing, Association for Computing Machinery, Inc , 2017, s. 173-179Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Blockchain and verifiable identities have a lot of potential in future distributed software applications e.g. smart cities, eHealth, autonomous vehicles, networks, etc. In this paper, we proposed a novel technique, namely VeidBlock 1 , to generate verifiable identities by following a reliable authentication process. These entities are managed by using the concepts of blockchain ledger and distributed through an advance mechanism to protect them against tampering. All identities created using VeidBlock approach are verifiable and anonymous therefore it preserves user’s privacy in verification and authentication phase. As a proof of concept, we implemented and tested the VeidBlock protocols by integrating it in a SDN based infrastructure. Analysis of the test results yield that all components successfully and autonomously performed initial authentication and locally verified all the identities of connected components.

  • 2.
    Abrahamsson, Tobias
    et al.
    Linköping University, Sweden.
    Poxson, David J
    Linköping University, Sweden.
    Gabrielsson, Erik O
    Linköping University, Sweden.
    Sandberg, Mats
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Simon, Daniel T
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Formation of Monolithic Ion-Selective Transport Media Based on "Click" Cross-Linked Hyperbranched Polyglycerol.2019Inngår i: Frontiers in chemistry, ISSN 2296-2646, Vol. 7, artikkel-id 484Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the emerging field of organic bioelectronics, conducting polymers and ion-selective membranes are combined to form resistors, diodes, transistors, and circuits that transport and process both electronic and ionic signals. Such bioelectronics concepts have been explored in delivery devices that translate electronic addressing signals into the transport and dispensing of small charged biomolecules at high specificity and spatiotemporal resolution. Manufacturing such "iontronic" devices generally involves classical thin film processing of polyelectrolyte layers and insulators followed by application of electrolytes. This approach makes miniaturization and integration difficult, simply because the ion selective polyelectrolytes swell after completing the manufacturing. To advance such bioelectronics/iontronics and to enable applications where relatively larger molecules can be delivered, it is important to develop a versatile material system in which the charge/size selectivity can be easily tailormade at the same time enabling easy manufacturing of complex and miniaturized structures. Here, we report a one-pot synthesis approach with minimal amount of organic solvent to achieve cationic hyperbranched polyglycerol films for iontronics applications. The hyperbranched structure allows for tunable pre multi-functionalization, which combines available unsaturated groups used in crosslinking along with ionic groups for electrolytic properties, to achieve a one-step process when applied in devices for monolithic membrane gel formation with selective electrophoretic transport of molecules.

  • 3.
    Ahlgren, Bengt
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Hurtig, Per
    Karlstad University, Sweden.
    Abrahamsson, Henrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Grinnemo, Karl-Johan
    Karlstad University, Sweden.
    Brunstrom, Anna
    Karlstad University, Sweden.
    ICN congestion control for wireless links2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Information-centric networking (ICN) with its design around named-based forwarding and in-network caching holds great promises to become a key architecture for the future Internet. Many proposed ICN hop-by-hop congestion control schemes assume a fixed and known link capacity, which rarely - if ever - holds true for wireless links. Firstly, we demonstrate that although these congestion control schemes are able to fairly well utilise the available wireless link capacity, they greatly fail to keep the delay low. In fact, they essentially offer the same delay as in the case with no hop-by-hop, only end-to-end, congestion control. Secondly, we show that by complementing these schemes with an easy-to-implement, packet-train capacity estimator, we reduce the delay to a level significantly lower than what is obtained with only end-to-end congestion control, while still being able to keep the link utilisation at a high level.

  • 4.
    Ahniyaz, Anwar
    et al.
    Stockholm University, Sweden.
    Seisenbaeva, Gulaim A.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Häggström, Lennart
    Uppsala University, Sweden.
    Kamali, Saeed
    Uppsala University, Sweden.
    Kessler, Vadim G.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Nordblad, Per
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Johansson, Christer
    RISE., Swedish ICT, Acreo.
    Bergström, Lennart
    Stockholm University, Sweden.
    Preparation of iron oxide nanocrystals by surfactant-free or oleic acid-assisted thermal decomposition of a Fe(III) alkoxide2008Inngår i: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 320, s. 781-787Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new non-hydrolytic, alkoxide-based route was developed to synthesize iron oxide nanocrystals. Surfactant-free thermal decomposition of the iron 2-methoxy-ethoxide precursors results in the formation of uniform iron oxide nanocrystals with an average size of 5.6 nm. Transmission electron microscope study shows that the nanocrystals are protected against aggregation by a repulsive surface layer, probably originating from the alkoxy-alkoxide ligands. Addition of oleic acid resulted in monodisperse nanocrystals with an average size of 4 nm. Mössbauer analysis confirmed that the nanocrystals mainly consisted of maghemite. Analysis of the magnetic hysteresis loop measurements and the zero field and field cooled measurements displayed an excellent fit to established theories for single-domain superparamagnetic nanocrystals and the size of the magnetic domains correlated well to the crystallite size obtained from transmission electron microscope.

  • 5.
    Ahrentorp, Fredrik
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Blomgren, Jakob
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jonasson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sarwe, Anna
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sepehri, Sobhan
    Chalmers University of Technology, Sweden.
    Eriksson, Emil
    Chalmers University of Technology, Sweden.
    Kalaboukhov, Alexei
    Chalmers University of Technology, Sweden.
    Jesorka, Aldo
    Chalmers University of Technology, Sweden.
    Winkler, Dag
    Chalmers University of Technology, Sweden.
    Schneiderman, Justin F.
    University of Gothenburg, Sweden.
    Nilsson, Mats
    Stockholm University, Sweden.
    Albert, Jan
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden.
    de la Torre, Theresa Z. G.
    Uppsala University, Sweden.
    Strømme, Maria
    Uppsala University, Sweden.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sensitive magnetic biodetection using magnetic multi-core nanoparticles and RCA coils2017Inngår i: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 427, s. 14-18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We use functionalized iron oxide magnetic multi-core particles of 100 nm in size (hydrodynamic particle diameter) and AC susceptometry (ACS) methods to measure the binding reactions between the magnetic nanoparticles (MNPs) and bio-analyte products produced from DNA segments using the rolling circle amplification (RCA) method. We use sensitive induction detection techniques in order to measure the ACS response. The DNA is amplified via RCA to generate RCA coils with a specific size that is dependent on the amplification time. After about 75 min of amplification we obtain an average RCA coil diameter of about 1 µm. We determine a theoretical limit of detection (LOD) in the range of 11 attomole (corresponding to an analyte concentration of 55 fM for a sample volume of 200 µL) from the ACS dynamic response after the MNPs have bound to the RCA coils and the measured ACS readout noise. We also discuss further possible improvements of the LOD.

  • 6.
    Alcusa-Saez, E. P.
    et al.
    University of Valencia, Spain.
    Diez, A.
    University of Valencia, Spain.
    Rivera-Perez, E.
    University of Valencia, Spain.
    Margulis, Walter
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Norin, Lars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Andres, M. V.
    University of Valencia, Spain.
    All-fiber acousto-optic tunable filter in polyimide coated optical fibers2017Inngår i: International Conference on Transparent Optical Networks, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We present the experimental demonstration of in-fiber acousto-optic coupling in a polyimide-coated optical fiber. Although the presence of the polyimide coating increases is significantly the attenuation of the acoustic wave, we show that acousto-optic interaction can still be produced with reasonable efficiency. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. To our knowledge, this is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.

  • 7.
    Alcusa-Sáez, E. P.
    et al.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Díez, Antonio
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Rivera-Pérez, E.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Margulis, Walter
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Norin, L.
    RISE - Research Institutes of Sweden, ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Andrés, M. V.
    ICMUV Departamento de Física Aplicada y Electromagnetismo, Spain.
    Acousto-optic interaction in polyimide coated optical fibers with flexural waves2017Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 25, nr 15, s. 17167-17173Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Acousto-optic coupling in polyimide-coated single-mode optical fibers using flexural elastic waves is demonstrated. The effect of the polyimide coating on the acousto-optic interaction process is analyzed in detailed. Theoretical and experimental results are in good agreement. Although the elastic attenuation is significant, we show that acousto-optic coupling can be produced with a reasonably good efficiency. To our knowledge, it is the first experimental demonstration of acousto-optic coupling in optical fibers with robust protective coating.

  • 8.
    Allison, R.S.
    et al.
    York University, Canada.
    Brunnstrom, Kjell
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chandler, D.M.
    Shizuoka University, Japan.
    Colett, H.
    Intel Corp, USA.
    Corriveau, P.
    Intel Corp, USA.
    Daly, S.
    Dolby Laboratories Inc, USA.
    Goel, J.
    Qualcomm Technologies, USA.
    Long, J.Y.
    Intel Corp, USA.
    Wilcox, L.M.
    York University, Canada.
    Yaacob, Y.
    Shizuoka University, Japan.
    Yang, S. N.
    Pacific University, USA.
    Zhang, Y.
    Xi’an Jiaotong University, China.
    Perspectives on the definition of visually lossless quality for mobile and large format displays2018Inngår i: Journal of Electronic Imaging, ISSN 10179909, Vol. 27, nr 5, artikkel-id 053035Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Advances in imaging and display engineering have given rise to new and improved image and videoapplications that aim to maximize visual quality under given resource constraints (e.g., power, bandwidth).Because the human visual system is an imperfect sensor, the images/videos can be represented in a mathematicallylossy fashion but with enough fidelity that the losses are visually imperceptible—commonly termed“visually lossless.” Although a great deal of research has focused on gaining a better understanding ofthe limits of human vision when viewing natural images/video, a universally or even largely accepted definitionof visually lossless remains elusive. Differences in testing methodologies, research objectives, and targetapplications have led to multiple ad-hoc definitions that are often difficult to compare to or otherwise employ inother settings. We present a compendium of technical experiments relating to both vision science and visualquality testing that together explore the research and business perspectives of visually lossless image quality,as well as review recent scientific advances. Together, the studies presented in this paper suggest that a singledefinition of visually lossless quality might not be appropriate; rather, a better goal would be to establish varyinglevels of visually lossless quality that can be quantified in terms of the testing paradigm.

  • 9.
    Alt Murphy, Margit
    et al.
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Andersson, Sofi
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Danielsson, Anna
    University of Gothenburg, Sweden.
    Wipenmyr, Jan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ohlsson, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Comparison of accelerometer-based arm, leg and trunk activity at weekdays and weekends during subacute inpatient rehabilitation after stroke2019Inngår i: Journal of Rehabilitation Medicine, ISSN 1650-1977, E-ISSN 1651-2081, Vol. 51, nr 6, s. 426-433Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: To determine whether there are differences in arm, leg and trunk activity measured by acceleration between weekdays and weekends in people undergoing rehabilitation in the subacute stage after stroke. Design: Cross-sectional study. Patients: Twenty-eight individuals with stroke (mean age 55.4 years; severe to mild impairment) and 10 healthy controls. Methods: A set of 5 3-axial accelerometers were used on the trunk, wrists and ankles during 2 48-h sessions at weekdays and over a weekend. Day-time acceleration raw data were expressed as the signal magnitude area. Asymmetry between the affected and less-affected limb was calculated as a ratio. Results: Participants with stroke used their both arms and legs less at weekends than on weekdays (p<0.05, effect size 0.32–0.57). Asymmetry between the affected and less-affected arm was greater at weekends (p < 0.05, effect size 0.32). All activity measures, apart from the less-affected arm on weekdays, were lower in stroke compared with controls (p<0.05, effect size 0.4–0.8). No statistically significant differences were detected between weekday and weekend activity for the control group. One-third of participants perceived the trunk sensor as inconvenient to wear. Conclusion: Increased focus needs to be applied on activities carried out during weekends at rehabilitation wards.

  • 10.
    Alt Murphy, Margit
    et al.
    University of Gothenburg, Sweden.
    Bergquist, Filip
    University of Gothenburg, Sweden.
    Hagström, Bengt
    RISE - Research Institutes of Sweden, Material och produktion, IVF. Chalmers University of Technology, Sweden.
    Hernández, Niina
    University of Borås, Sweden.
    Johansson, Dongni
    University of Gothenburg, Sweden.
    Ohlsson, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sandsjö, Leif
    University of Borås, Sweden; Chalmers University of Technology, Sweden.
    Wipenmyr, Jan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Malmgren, Kristina
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    An upper body garment with integrated sensors for people with neurological disorders – early development and evaluation2019Inngår i: BMC Biomedical Engineering, Vol. 1, artikkel-id 3Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background

    In neurology and rehabilitation the primary interest for using wearables is to supplement traditional patient assessment and monitoring in hospital settings with continuous data collection at home and in community settings. The aim of this project was to develop a novel wearable garment with integrated sensors designed for continuous monitoring of physiological and movement related variables to evaluate progression, tailor treatments and improve diagnosis in epilepsy, Parkinson’s disease and stroke.

    Methods

    In this paper the early development and evaluation of a prototype designed to monitor movements and heart rate is described. An iterative development process and evaluation of an upper body garment with integrated sensors included: identification of user needs, specification of technical and garment requirements, garment development and production as well as evaluation of garment design, functionality and usability. The project is a multidisciplinary collaboration with experts from medical, engineering, textile, and material science within the wearITmed consortium. The work was organized in regular meetings, task groups and hands-on workshops. User needs were identified using results from a mixed-methods systematic review, a focus group study and expert groups. Usability was evaluated in 19 individuals (13 controls, 6 patients with Parkinson’s disease) using semi-structured interviews and qualitative content analysis.

    Results

    The garment was well accepted by the users regarding design and comfort, although the users were cautious about the technology and suggested improvements. All electronic components passed a washability test. The most robust data was obtained from accelerometer and gyroscope sensors while the electrodes for heart rate registration were sensitive to motion artefacts. The algorithm development within the wearITmed consortium has shown promising results.

    Conclusions

    The prototype was accepted by the users. Technical improvements are needed, but preliminary data indicate that the garment has potential to be used as a tool for diagnosis and treatment selection and could provide added value for monitoring seizures in epilepsy, fluctuations in PD and activity levels in stroke. Future work aims to improve the prototype further, develop algorithms, and evaluate the functionality and usability in targeted patient groups. The potential of incorporating blood pressure and heart-rate variability monitoring will also be explored.

  • 11.
    Amin, Sidra
    et al.
    Luleå University of Technology, Sweden; University of Sindh, Pakistan´; Shaheed Benazir Bhutto University, Pakistan .
    Tahira, Aneela
    Luleå University of Technology, Sweden .
    Solangi, Amber
    University of Sindh, Pakistan.
    Beni, Valerio
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Morante, JR
    Catalonia Institute for Energy Research, Spain.
    Liu, Xianjie
    Linköping University, Sweden.
    Falhman, Mats
    Linköping University, Sweden.
    Mazzaro, Raffaello
    Luleå University of Technology, Sweden .
    Ibupoto, Zafar
    Luleå University of Technology, Sweden .
    Vomiero, Alberto
    Luleå University of Technology, Sweden .
    A practical non-enzymatic urea sensor based on NiCo 2 O 4 nanoneedles2019Inngår i: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, nr 25, s. 14443-14451Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo 2 O 4 ) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 μM) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo 2 O 4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo 2 O 4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo 2 O 4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co 3 O 4 . The GCE-modified electrode is highly sensitive towards urea, with a linear response (R 2 = 0.99) over the concentration range 0.01-5 mM and with a detection limit of 1.0 μM. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.

  • 12.
    Andersson Ersman, Peter
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Westerberg, David
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Tu, Deyu
    Linköping University, Sweden.
    Nilsson, Marie
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Åhlin, Jessica
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Eveborn, Annelie
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Lagerlöf, Axel
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Nilsson, David
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sandberg, Mats
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Norberg, Petronella
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Berggren, Magnus
    Linköping University, Sweden.
    Forchheimer, Robert
    RISE - Research Institutes of Sweden, ICT, SICS.
    Gustafsson, Göran
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Screen printed digital circuits based on vertical organicelectrochemical transistors2017Inngår i: Flex. Print. Electron., Vol. 2, artikkel-id 045008Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vertical organic electrochemical transistors (OECTs) have been manufactured solely using screenprinting. The OECTs are based on PEDOT:PSS (poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonic acid)), which defines the active material for both the transistor channel and the gateelectrode. The resulting vertical OECT devices and circuits exhibit low-voltage operation, relativelyfast switching, small footprint and high manufacturing yield; the last three parameters are explainedby the reliance of the transistor configuration on a robust structure in which the electrolyte verticallybridges the bottom channel and the top gate electrode. Two different architectures of the verticalOECT have been manufactured, characterized and evaluated in parallel throughout this report. Inaddition to the experimental work, SPICE models enabling simulations of standalone OECTs andOECT-based circuits have been developed. Our findings may pave the way for fully integrated, lowvoltageoperating and printed signal processing systems integrated with e.g. printed batteries, solarcells, sensors and communication interfaces. Such technology can then serve a low-cost basetechnology for the internet of things, smart packaging and home diagnostics applications.

  • 13.
    Andersson, Jens A.
    et al.
    Lund University, Sweden.
    Arvidsson, Åke
    Ericsson AB, Sweden.
    Du, Manxing
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zhang, Huimin
    RISE., Swedish ICT, Acreo.
    Kihl, Maria
    Lund University, Sweden.
    Höst, Sefan
    Lund University, Sweden.
    Lagerstedt, Chhristina
    RISE., Swedish ICT, Acreo.
    User profiling for pre-fetching or caching in a catch-up TV network2016Inngår i: 2016 IEEE International Symposium on Broadband Multimedia Systems and Broadcasting (BMSB), 2016, artikkel-id 7521984Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We investigate the potential of different pre-fetching and/or caching strategies for different user behaviour with respect to surfing or browsing in a catch-up-TV network. To this end we identify accounts and channels associated with strong or weak surfing or browsing respectively and study the distributions of hold times for the different types of behaviour. Finally we present results from a request prediction model and a caching simulation for the different types of behaviour and find that the results are relatively similar.

  • 14.
    Araujo, Jefferson
    et al.
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Reis, Andre
    Observatório Nacional, Brazil.
    Oliveira, Vanderlei
    Observatório Nacional, Brazil.
    Santos, Amanda
    University of California, US.
    Luz-Lima, Cleaneo
    Universidade Federal do Piauí, Brazil.
    Yokoyama, Elder
    University of Brasília, Brazil.
    Mendoza, Leonardo
    Universidade Estadual do Rio de Janeiro, Brazil.
    Pereira, Joao
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Bruno, Antonio
    Pontifical Catholic University of Rio de Janeiro, Brazil.
    Characterizing complex mineral structures in thin sections of geological samples with a scanning hall effect microscope2019Inngår i: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 19, nr 7, artikkel-id 1636Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We improved a magnetic scanning microscope for measuring the magnetic properties of minerals in thin sections of geological samples at submillimeter scales. The microscope is comprised of a 200 µm diameter Hall sensor that is located at a distance of 142 µm from the sample; an electromagnet capable of applying up to 500 mT DC magnetic fields to the sample over a 40 mm diameter region; a second Hall sensor arranged in a gradiometric configuration to cancel the background signal applied by the electromagnet and reduce the overall noise in the system; a custom-designed electronics system to bias the sensors and allow adjustments to the background signal cancelation; and a scanning XY stage with micrometer resolution. Our system achieves a spatial resolution of 200 µm with a noise at 6.0 Hz of 300 nT rms /(Hz) 1/2 in an unshielded environment. The magnetic moment sensitivity is 1.3 × 10 −11 Am 2 . We successfully measured the representative magnetization of a geological sample using an alternative model that takes the sample geometry into account and identified different micrometric characteristics in the sample slice.

  • 15.
    Arndt, Holger
    et al.
    Spring Techno GmbH & Co, Germany..
    Burkard, Stefan
    Spring Techno GmbH & Co, Germany..
    Talavera, Guillermo
    Universitat Autònoma de Barcelona, Spain.
    Garcia, Joan
    Universitat Autònoma de Barcelona, Spain.
    Castells, David
    Universitat Autònoma de Barcelona, Spain.
    Codina, Marc
    Universitat Autònoma de Barcelona, Spain.
    Hausdorff, Jeffrey
    Mirelman, Anat
    Tel Aviv Sourasky Medical Center, Israel.
    Harte, Richard
    National University of Ireland, Ireland.
    Casey, Monica
    National University of Ireland, Ireland.
    Glynn, Liam
    National University of Ireland, Ireland.
    Di Rosa, Mirko
    Istituto Nazionale Riposo e Cura per Anziani, Italy.
    Rossi, Lorena
    Istituto Nazionale Riposo e Cura per Anziani, Italy.
    Stara, Vera
    Istituto Nazionale Riposo e Cura per Anziani, Italy.
    Rösevall, John
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Rusu, Cristina
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Carenas, Carlos
    EURECAT, Spain.
    Breuil, Fanny
    EURECAT, Spain.
    Reixach, Elisenda
    EURECAT, Spain.
    Carrabina, Jordi
    Universitat Autònoma de Barcelona, Spain.
    Real-time constant monitoring of fall risk index by means of fully-wireless insoles2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Constant monitoring of gait in real life conditions is considered the best way to assess Fall Risk Index (FRI) since most falls happen out of the ideal conditions in which clinicians are currently analyzing the patient's behavior. This paper presents the WIISEL platform and results obtained through the use of the first full-wireless insole devices that can measure almost all gait related data directly on the feet (not in the upper part of the body as most existing wearable solutions). The platform consists of a complete tool-chain: insoles, smartphone & app, server & analysis tool, FRI estimation and user access. Results are obtained by combining parameters in a personalized way to build individual fall risk index assessed by experts with the help of data analytics. New FRI has been compared with standards that validate the quality of its prediction in a statistically significant way. That qualitatively relevant information is being provided to the platform users, being either end-users/patients, relatives or caregivers and the related clinicians to ideally assess about their long term evolution. © 2017 The authors and IOS Press.

  • 16.
    Arndt, Sebastian
    et al.
    Technical University of Berlin, Germany.
    Brunnström, Kjell
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Cheng, Eva
    RMIT University, Australia.
    Engelke, Ulrich
    CSIRO Commonwealth Scientific and Industrial Research Organisation, Australia.
    Moller, Sebastian
    Technical University of Berlin, Germany.
    Antons, Jan-Niklas
    Technical University of Berlin, Germany.
    Review on using physiology in quality of experience2016Inngår i: Electronic Imaging: Human Vision and Electronic Imaging 2016, 2016, s. 197-205Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In the area of Quality of Experience (QoE), one challenge is to design test methodologies in order to evaluate the perceived quality of multimedia content delivered through technical sys-tems. Traditionally, this evaluation is done using subjective opinion tests. However, sometimes it is difficult for observers to communicate the experienced quality through the given scale. Fur-thermore. those tests do not give insights into how the user is reacting on an internal physiological level. To overcome these issues, one approach is to use physiological measures, in order to derive a direct non-verbal response of the recipient. In this paper, we review studies that have been performed in the domain of QoE using physiological measures and we look into current activities in standardization bodies. We present challenges this research faces. and give an overview on what researchers should be aware of when they want to start working in this research area.

  • 17.
    Baresel, Christian
    et al.
    IVL Swedish Environmental Research Institute AB, Sweden.
    Schaller, Vincent
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jonasson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Bordes, Romain
    Chalmers University of Technology, Sweden.
    Chauhan, Vinay
    Chalmers University of Technology, Sweden.
    Sugunan, Abhilash
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Welling, Sebastian
    IVL Swedish Environmental Research Institute AB, Sweden.
    Functionalized magnetic particles for water treatment2019Inngår i: Heliyon, ISSN 2405-8440, Vol. 5, nr 8, artikkel-id e02325Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, we have taken the concept of water treatment by functionalized magnetic particles one step forward by integrating the technology into a complete proof of concept, which included the preparation of surface modified beads, their use as highly selective absorbents for heavy metals ions (Zinc, Nickel), and their performance in terms of magnetic separation. The separation characteristics were studied both through experiments and by simulations. The data gathered from these experimental works enabled the elaboration of various scenarios for Life Cycle Analysis (LCA). The LCA showed that the environmental impact of the system is highly dependent on the recovery rate of the magnetic particles. The absolute impact on climate change varied significantly among the scenarios studied and the recovery rates. The results support the hypothesis that chelation specificity, magnetic separation and bead recovery should be optimized to specific targets and applications. 

  • 18.
    Bender, P.
    et al.
    University of Cantabria, Spain.
    Balceris, C.
    University of Cantabria, Spain.
    Ludwig, F.
    TU Braunschweig, Germany.
    Posth, O.
    Physikalisch-Technische Bundesanstalt, Germany.
    Bogart, L. K.
    University College London, UK.
    Szczerba, W.
    Bundesanstalt für Materialforschung und -prüfung, Germany; AGH University of Science and Technology, Poland.
    Castro, A.
    SOLVE Research and Consultancy AB, Sweden.
    Nilsson, L.
    SOLVE Research and Consultancy AB, Sweden; Lund University, Sweden.
    Costo, R.
    Instituto de Ciencia de Materiales de Madrid, Spain.
    Gavilán, H.
    Instituto de Ciencia de Materiales de Madrid, Spain.
    González-Alonso, D.
    University of Cantabria, Spain.
    Pedro, I. D.
    University of Cantabria, Spain.
    Barquin, L. F.
    University of Cantabria, Spain.
    Johansson, C.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Distribution functions of magnetic nanoparticles determined by a numerical inversion method2017Inngår i: New Journal of Physics, ISSN 1367-2630, E-ISSN 1367-2630, Vol. 19, nr 7, artikkel-id 073012Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present study, we applied a regularized inversion method to extract the particle size, magnetic moment and relaxation-time distribution of magnetic nanoparticles from small-angle x-ray scattering (SAXS), DC magnetization (DCM) and AC susceptibility (ACS) measurements. For the measurements the particles were colloidally dispersed in water. At first approximation the particles could be assumed to be spherically shaped and homogeneously magnetized single-domain particles. As model functions for the inversion, we used the particle form factor of a sphere (SAXS), the Langevin function (DCM) and the Debye model (ACS). The extracted distributions exhibited features/peaks that could be distinctly attributed to the individually dispersed and non-interacting nanoparticles. Further analysis of these peaks enabled, in combination with a prior characterization of the particle ensemble by electron microscopy and dynamic light scattering, a detailed structural and magnetic characterization of the particles. Additionally, all three extracted distributions featured peaks, which indicated deviations of the scattering (SAXS), magnetization (DCM) or relaxation (ACS) behavior from the one expected for individually dispersed, homogeneously magnetized nanoparticles. These deviations could be mainly attributed to partial agglomeration (SAXS, DCM, ACS), uncorrelated surface spins (DCM) and/or intra-well relaxation processes (ACS). The main advantage of the numerical inversion method is that no ad hoc assumptions regarding the line shape of the extracted distribution functions are required, which enabled the detection of these contributions. We highlighted this by comparing the results with the results obtained by standard model fits, where the functional form of the distributions was a priori assumed to be log-normal shaped.

  • 19.
    Bender, P.
    et al.
    University of Cantabria, Spain .
    Bogart, L. K.
    University College London, UK .
    Posth, O.
    Physikalisch-Technische Bundesanstalt, Germany .
    Szczerba, W.
    BAM Bundesanstalt für Materialforschung Und-prüfung, Germany ; AGH University of Science and Technology, Poland .
    Rogers, S. E.
    ISIS-STFC Neutron Scattering Facility, UK.
    Castro, A.
    SOLVE Research and Consultancy AB, Sweden .
    Nilsson, L.
    SOLVE Research and Consultancy AB, Sweden; Lund University, Sweden.
    Zeng, L. J.
    Chalmers University of Technology, Sweden.
    Sugunan, Abhilash
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Sommertune, Jens
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Fornara, A.
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    González-Alonso, D.
    University of Cantabria, Spain .
    Fernández Barquín, L.
    University of Cantabria, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Structural and magnetic properties of multi-core nanoparticles analysed using a generalised numerical inversion method2017Inngår i: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 7, artikkel-id 45990Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The structural and magnetic properties of magnetic multi-core particles were determined by numerical inversion of small angle scattering and isothermal magnetisation data. The investigated particles consist of iron oxide nanoparticle cores (9 nm) embedded in poly(styrene) spheres (160 nm). A thorough physical characterisation of the particles included transmission electron microscopy, X-ray diffraction and asymmetrical flow field-flow fractionation. Their structure was ultimately disclosed by an indirect Fourier transform of static light scattering, small angle X-ray scattering and small angle neutron scattering data of the colloidal dispersion. The extracted pair distance distribution functions clearly indicated that the cores were mostly accumulated in the outer surface layers of the poly(styrene) spheres. To investigate the magnetic properties, the isothermal magnetisation curves of the multi-core particles (immobilised and dispersed in water) were analysed. The study stands out by applying the same numerical approach to extract the apparent moment distributions of the particles as for the indirect Fourier transform. It could be shown that the main peak of the apparent moment distributions correlated to the expected intrinsic moment distribution of the cores. Additional peaks were observed which signaled deviations of the isothermal magnetisation behavior from the non-interacting case, indicating weak dipolar interactions.

  • 20.
    Bender, P.
    et al.
    University of Cantabria, Spain.
    Fock, J.
    DTU Technical University of Denmark, Denmark.
    Hansen, M. F.
    DTU Technical University of Denmark, Denmark.
    Bogart, L. K.
    UCL University College London, UK.
    Southern, P.
    UCL University College London, UK.
    Ludwig, F.
    Technische Universität Braunschweig, Germany.
    Wiekhorst, F.
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Szczerba, W.
    Bundesanstalt für Materialforschung und -prüfung, Germany; AGH University of Science and Technology, Poland.
    Zeng, L. J.
    Chalmers University of Technology, Sweden.
    Heinke, D.
    nanoPET Pharma GmbH, Germany.
    Gehrke, N.
    nanoPET Pharma GmbH, Germany.
    Díaz, M. T. F.
    Institut Laue Langevin, France.
    González-Alonso, D.
    University of Cantabria, Spain.
    Espeso, J. I.
    University of Cantabria, Spain.
    Fernández, J. R.
    University of Cantabria, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Influence of clustering on the magnetic properties and hyperthermia performance of iron oxide nanoparticles2018Inngår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 29, nr 42, artikkel-id 425705Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Clustering of magnetic nanoparticles can drastically change their collective magnetic properties, which in turn may influence their performance in technological or biomedical applications. Here, we investigate a commercial colloidal dispersion (FeraSpin™R), which contains dense clusters of iron oxide cores (mean size around 9 nm according to neutron diffraction) with varying cluster size (about 18-56 nm according to small angle x-ray diffraction), and its individual size fractions (FeraSpin™XS, S, M, L, XL, XXL). The magnetic properties of the colloids were characterized by isothermal magnetization, as well as frequency-dependent optomagnetic and AC susceptibility measurements. From these measurements we derive the underlying moment and relaxation frequency distributions, respectively. Analysis of the distributions shows that the clustering of the initially superparamagnetic cores leads to remanent magnetic moments within the large clusters. At frequencies below 105 rad s-1, the relaxation of the clusters is dominated by Brownian (rotation) relaxation. At higher frequencies, where Brownian relaxation is inhibited due to viscous friction, the clusters still show an appreciable magnetic relaxation due to internal moment relaxation within the clusters. As a result of the internal moment relaxation, the colloids with the large clusters (FS-L, XL, XXL) excel in magnetic hyperthermia experiments.

  • 21.
    Bender, P.
    et al.
    University of Cantabria, Spain.
    Wetterskog, E.
    Uppsala University, Sweden.
    Honecker, D.
    Institut Laue-Langevin, France.
    Fock, J.
    DTU Technical University of Denmark,, Denmark.
    Frandsen, C.
    DTU Technical University of Denmark, Denmark.
    Moerland, C.
    Technische Universiteit Eindhoven, The Netherlands.
    Bogart, L. K.
    University College London, UK.
    Posth, O.
    Physikalisch-Technische Bundesanstalt, Germany.
    Szczerba, W.
    Bundesanstalt für Materialforschung und-prüfung,Germany; AGH University of Science and Technology, Poland.
    Gavilán, H.
    Instituto de Ciencia de Materiales de Madrid, Spain.
    Costo, R.
    Fernández-Díaz, M. T.
    Institut Laue-Langevin, France.
    González-Alonso, D.
    University of Cantabria, Spain.
    Fernández Barquín, L.
    University of Cantabria, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Dipolar-coupled moment correlations in clusters of magnetic nanoparticles2018Inngår i: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 98, nr 22, artikkel-id 224420Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Here, we resolve the nature of the moment coupling between 10-nm dimercaptosuccinic acid-coated magnetic nanoparticles. The individual iron oxide cores were composed of >95% maghemite and agglomerated to clusters. At room temperature the ensemble behaved as a superparamagnet according to Mössbauer and magnetization measurements, however, with clear signs of dipolar interactions. Analysis of temperature-dependent ac susceptibility data in the superparamagnetic regime indicates a tendency for dipolar-coupled anticorrelations of the core moments within the clusters. To resolve the directional correlations between the particle moments we performed polarized small-angle neutron scattering and determined the magnetic spin-flip cross section of the powder in low magnetic field at 300 K. We extract the underlying magnetic correlation function of the magnetization vector field by an indirect Fourier transform of the cross section. The correlation function suggests nonstochastic preferential alignment between neighboring moments despite thermal fluctuations, with anticorrelations clearly dominating for next-nearest moments. These tendencies are confirmed by Monte Carlo simulations of such core clusters.

  • 22.
    Bender, Philipp
    et al.
    Universidad de Cantabria, Spain.
    Fock, Jeppe
    DTU Technical University of Denmark, Denmark.
    Frandsen, Cathrine
    DTU Technical University of Denmark, Denmark.
    Hansen, Mikkel F.
    DTU Technical University of Denmark, Denmark.
    Balceris, Christoph
    TU Braunschweig, Germany.
    Ludwig, Frank
    TU Braunschweig, Germany.
    Posth, Oliver
    Physikalisch-Technische Bundesanstalt, Germany.
    Wetterskog, Erik
    Uppsala University, Sweden.
    Bogart, Lara K.
    University College London, UK.
    Southern, Paul
    University College London, UK.
    Szczerba, Wojciech
    Bundesanstalt für Materialforschung und -prüfung, Germany; AGH University of Science and Technology, Poland.
    Zeng, Lunjie
    Chalmers University of Technology, Sweden.
    Witte, Kerstin
    University of Rostock, Germany; Micromod Partikeltechnologie GmbH, Germany.
    Gruettner, Cordula
    Micromod Partikeltechnologie GmbH, Germany.
    Westphal, Fritz
    Micromod Partikeltechnologie GmbH, Germany.
    Honecker, Dirk
    Institut Laue-Langevin, France.
    Gonzalez-Alonso, David
    Universidad de Cantabria, Spain.
    Fernandez Barquin, Luis
    Universidad de Cantabria, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Relating Magnetic Properties and High Hyperthermia Performance of Iron Oxide Nanoflowers2018Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, nr 5, s. 3068-3077Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigated, in depth, the interrelations among structure, magnetic properties, relaxation dynamics and magnetic hyperthermia performance of magnetic nanoflowers. The nanoflowers are about 39 nm in size, and consist of densely packed iron oxide cores. They display a remanent magnetization, which we explain by the exchange coupling between the cores, but we observe indications for internal spin disorder. By polarized small-angle neutron scattering, we unambiguously confirm that, on average, the nano flowers are preferentially magnetized along one direction. The extracted discrete relaxation time distribution of the colloidally dispersed particles indicates the presence of three distinct relaxation contributions. We can explain the two slower processes by Brownian and classical Neel relaxation, respectively. The additionally observed very fast relaxation contributions are attributed by us to the relaxation of disordered spins within the nanoflowers. Finally, we show that the intrinsic loss power (ILP, magnetic hyperthermia performance) of the nanoflowers measured in colloidal dispersion at high frequency is comparatively large and independent of the viscosity of the surrounding medium. This concurs with our assumption that the observed relaxation in the high frequency range is primarily a result of internal spin relaxation, and possibly connected to the disordered spins within the individual nanoflowers.

  • 23.
    Berto, Marcello
    et al.
    Università di Modena e Reggio Emilia, Italy.
    Diacci, Chiara
    Linköping University, Sweden.
    Theuer, Lorenz
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Di Lauro, Michele
    Università di Modena e Reggio Emilia, Italy.
    Simon, Daniel T.
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Biscarini, Fabio
    Università di Modena e Reggio Emilia, Italy;Instituto Italiano di Tecnologia—Center for Translational Neurophysiology, Italy.
    Beni, Valerio
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Bortolotti, Carlo A.
    Università di Modena e Reggio Emilia, Italy.
    Label free urea biosensor based on organic electrochemical transistors2018Inngår i: Flexible and Printed Electronics, ISSN 2058-8585, Vol. 3, nr 2, artikkel-id 024001Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The quantification of urea is of the utmost importance not only in medical diagnosis, where it serves as a potential indicator of kidney and liver disfunction, but also in food safety and environmental control. Here, we describe a urea biosensor based on urease entrapped in a crosslinked gelatin hydrogel, deposited onto a fully printed PEDOT:PSS-based organic electrochemical transistor (OECT). The device response is based on the modulation of the channel conductivity by the ionic species produced upon urea hydrolysis catalyzed by the entrapped urease. The biosensor shows excellent reproducibility, a limit of detection as low as 1 μM and a response time of a few minutes. The fabrication of the OECTs by screen-printing on flexible substrates ensures a significant reduction in manufacturing time and costs. The low dimensionality and operational voltages (0.5 V or below) of these devices contribute to make these enzymatic OECT-based biosensors as appealing candidates for high-throughput monitoring of urea levels at the point-of-care or in the field.

  • 24.
    Bi, Zhaoxia
    et al.
    Lund University, Sweden.
    Lenrick, Filip
    Lund University, Sweden.
    Colvin, Jovana
    Lund University, Sweden.
    Gustafsson, Anders
    Lund University, Sweden.
    Hultin, Olof
    RISE - Research Institutes of Sweden, ICT, Acreo. Lund University, Sweden.
    Nowzari, Ali
    Lund University, Sweden.
    Lu, Taiping
    RISE - Research Institutes of Sweden, ICT, Acreo. Lund University, Sweden.
    Wallenberg, Reine
    Lund University, Sweden.
    Timm, Rainer
    Lund University, Sweden.
    Mikkelsen, Anders
    Lund University, Sweden.
    Ohlsson, Jonas
    Lund University, Sweden.
    Storm, Kristian
    RISE - Research Institutes of Sweden.
    Monemar, Bo
    Lund University, Sweden.
    Samuelson, Lars
    Lund University, Sweden.
    InGaN Platelets: Synthesis and Applications toward Green and Red Light-Emitting Diodes2019Inngår i: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 19, nr 5, s. 2832-2839Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work, we present a method to synthesize arrays of hexagonal InGaN submicrometer platelets with a top c-plane area having an extension of a few hundred nanometers by selective area metal-organic vapor-phase epitaxy. The InGaN platelets were made by in situ annealing of InGaN pyramids, whereby InGaN from the pyramid apex was thermally etched away, leaving a c-plane surface, while the inclined {101Ì1} planes of the pyramids were intact. The as-formed c-planes, which are rough with islands of a few tens of nanometers, can be flattened with InGaN regrowth, showing single bilayer steps and high-quality optical properties (full width at half-maximum of photoluminescence at room temperature: 107 meV for In 0.09 Ga 0.91 N and 151 meV for In 0.18 Ga 0.82 N). Such platelets offer surfaces having relaxed lattice constants, thus enabling shifting the quantum well emission from blue (as when grown on GaN) to green and red. For single InGaN quantum wells grown on the c-plane of such InGaN platelets, a sharp interface between the quantum well and the barriers was observed. The emission energy from the quantum well, grown under the same conditions, was shifted from 2.17 eV on In 0.09 Ga 0.91 N platelets to 1.95 eV on In 0.18 Ga 0.82 N platelets as a result of a thicker quantum well and a reduced indium pulling effect on In 0.18 Ga 0.82 N platelets. On the basis of this method, prototype light-emitting diodes were demonstrated with green emission on In 0.09 Ga 0.91 N platelets and red emission on In 0.18 Ga 0.82 N platelets.

  • 25.
    Blomgren, Jakob
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ahrentorp, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ilver, Dag
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jonasson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sepehri, Sobhan
    Chalmers University of Technology, Sweden.
    Kalaboukhov, Alexei
    Chalmers University of Technology, Sweden.
    Winkler, Dag
    Chalmers University of Technology, Sweden.
    de la Torre, Tereza
    Uppsala University, Sweden.
    Strømme, Maria
    Uppsala University, Sweden.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Development of a sensitive induction-based magnetic nanoparticle biodetection method2018Inngår i: Nanomaterials, ISSN 2079-4991, Vol. 8, nr 11, artikkel-id 887Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We developed a novel biodetection method for influenza virus based on AC magnetic susceptibility measurement techniques (the DynoMag induction technique) together with functionalized multi-core magnetic nanoparticles. The sample consisting of an incubated mixture of magnetic nanoparticles and rolling circle amplified DNA coils is injected into a tube by a peristaltic pump. The sample is moved as a plug to the two well-balanced detection coils and the dynamic magnetic moment in each position is read over a range of excitation frequencies. The time for making a complete frequency sweep over the relaxation peak is about 5 minutes (10 Hz–10 kHz with 20 data points). The obtained standard deviation of the magnetic signal at the relaxation frequency (around 100 Hz) is equal to about 10−5 (volume susceptibility SI units), which is in the same range obtained with the DynoMag system. The limit of detection with this method is found to be in the range of 1 pM.

  • 26.
    Bosse, Sebastian
    et al.
    Fraunhofer, Germany.
    Brunnstrom, Kjell
    RISE - Research Institutes of Sweden, ICT, Acreo. Mid Sweden University, Sweden.
    Arndt, Sebastian
    NTNU Norwegian University of Science and Technology, Norway.
    Martini, Maria G.
    Kingston University, UK.
    Ramzan, Naeem
    University of the West of Scotland, UK.
    Engelke, Ulrich
    CSIRO, Australia.
    A common framework for the evaluation of psychophysiological visualquality assessment2019Inngår i: Quality and User Experience, ISSN 2366-0139, E-ISSN 2366-0147, Vol. 4, nr 3Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The assessment of perceived quality based on psychophysiological methods recently gained attraction as it potentiallyovercomes certain flaws of psychophysical approaches. Although studies report promising results, it is not possible toarrive at decisive and comparable conclusions that recommend the use of one or another method for a specific applicationor research question. The video quality expert group started a project on psychophysiological quality assessment to studythese novel approaches and to develop a test plan that enables more systematic research. This test plan comprises of a specificallydesigned set of quality annotated video sequences, suggestions for psychophysiological methods to be studied inquality assessment, and recommendations for the documentation and publications of test results. The test plan is presentedin this article.

  • 27.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Wetter, Göran
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Lövberg, Andreas
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Tegehall, Per-Erik
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Andersson, Dag
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF AB.
    Goncalves, Johnny
    NOTE Norrtelje AB, Sweden.
    Söderlund, Jonas
    NOTE Norrtelje AB, Sweden.
    Strandberg, Jan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Kwarnmark, Mikael
    Cogra Pro AB, Sweden.
    Feasibility of PCB-integrated vibration sensors for condition monitoring of electronic systems2018Inngår i: ASME 2018 International Technical Conference and Exhibition on Packaging and Integration of Electronic and Photonic Microsystems, InterPACK 2018, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The increasing complexity of electronics in systems used in safety critical applications, such as for example self-driving vehicles requires new methods to assure the hardware reliability of the electronic assemblies. Prognostics and Health Management (PHM) that uses a combination of data-driven and Physics-of-Failure models is a promising approach to avoid unexpected failures in the field. However, to enable PHM based partly on Physics-of-Failure models, sensor data that measures the relevant environment loads to which the electronics is subjected during its mission life are required. In this work, the feasibility to manufacture and use integrated sensors in the inner layers of a printed circuit board (PCB) as mission load indicators measuring impacts and vibrations has been investigated. A four-layered PCB was designed in which piezoelectric sensors based on polyvinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) were printed on one of the laminate layers before the lamination process. Manufacturing of the PCB was followed by the assembly of components consisting of BGAs and QFN packages in a standard production reflow soldering process. Tests to ensure that the functionality of the sensor material was unaffected by the soldering process were performed. Results showed a yield of approximately 30 % of the sensors after the reflow soldering process. The yield was also dependent on sensor placement and possibly shape. Optimization of the sensor design and placement is expected to bring the yield to 50 % or better. The sensors responded as expected to impact tests. Delamination areas were present in the test PCBs, which requires further investigation. The delamination does not seem to be due to the presence of embedded sensors alone but rather the result of a combination of several factors. The conclusion of this work is that it is feasible to embed piezoelectric sensors in the layers of a PCB.

  • 28.
    Brinkfeldt, Klas
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Wetter, Göran
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Lövberg, Andreas
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Tegehall, Per-Erik
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Andersson, Dag
    RISE - Research Institutes of Sweden, Material och produktion, IVF.
    Strandberg, Jan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Goncalves, Johnny
    NOTE Norrtelje AB, Sweden.
    Söderlund, Jonas
    NOTE Norrtelje AB, Sweden.
    Kwarnmark, Mikael
    Cogra Pro AB, Sweden.
    Feasibility of Printed Circuit Board-Integrated Vibration Sensors for Condition Monitoring of Electronic Systems2019Inngår i: Journal of Electronic Packaging, ISSN 1043-7398, E-ISSN 1528-9044, Vol. 141, nr 3, artikkel-id 031010Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The increasing complexity of electronics in systems used in safety critical applications, such as self-driving vehicles, requires new methods to assure the hardware reliability of the electronic assemblies. Prognostics and health management (PHM) that uses a combination of data-driven and physics-of-failure models is a promising approach to avoid unexpected failures in the field. However, to enable PHM based partly on physics-of-failure models, sensor data that measure the relevant environment loads to which the electronics are subjected during its mission life are required. In this work, the feasibility to manufacture and use integrated sensors in the inner layers of a printed circuit board (PCB) as mission load indicators measuring impacts and vibrations has been investigated. A four-layered PCB was designed in which piezoelectric sensors based on polyvinylidenefluoride-co-trifluoroethylene (PVDF-TrFE) were printed on one of the laminate layers before the lamination process. Manufacturing of the PCB was followed by the assembly of components consisting of ball grid arrays (BGAs) and quad flat no-leads (QFN) packages in a standard production reflow soldering process. Tests to ensure that the functionality of the sensor material was unaffected by the soldering process were performed. Results showed a yield of approximately 30% of the sensors after the reflow soldering process. The yield was also dependent on sensor placement and possibly shape. Optimization of the sensor design and placement is expected to bring the yield to 50% or better. The sensors responded as expected to impact tests. Delamination areas were present in the test PCBs, which requires further investigation. The delamination does not seem to be due to the presence of embedded sensors alone but rather the result of a combination of several factors. The conclusion of this work is that it is feasible to embed piezoelectric sensors in the layers of a PCB.

  • 29.
    Brooke, Robert
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. Linkoping University, Sweden.
    Edberg, Jesper
    RISE - Research Institutes of Sweden, ICT, Acreo. Linkoping University, Sweden.
    Crispin, Xavier
    Linkoping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Engquist, Isak
    Linkoping University, Sweden.
    Jonsson, Magnus
    Linkoping University, Sweden.
    Greyscale and paper electrochromic polymer displays by UV patterning2019Inngår i: Polymers, ISSN 2073-4360, E-ISSN 2073-4360, Vol. 11, nr 2, artikkel-id 267Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrochromic devices have important implications as smart windows for energy efficient buildings, internet of things devices, and in low-cost advertising applications. While inorganics have so far dominated the market, organic conductive polymers possess certain advantages such as high throughput and low temperature processing, faster switching, and superior optical memory. Here, we present organic electrochromic devices that can switch between two high-resolution images, based on UV-patterning and vapor phase polymerization of poly(3,4- ethylenedioxythiophene) films. We demonstrate that this technique can provide switchable greyscale images through the spatial control of a UV-light dose. The color space was able to be further altered via optimization of the oxidant concentration. Finally, we utilized a UV-patterning technique to produce functional paper with electrochromic patterns deposited on porous paper, allowing for environmentally friendly electrochromic displays.

  • 30.
    Brooke, Robert
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Edberg, Jesper
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Say, Mehmet
    Linköping University, Sweden.
    Sawatdee, Anurak
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Grimoldi, Andrea
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Åhlin, Jessica
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Gustafsson, Göran
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Berggren, Magnus
    Linköpings University, Sweden.
    Engquist, Isak
    Linköpings University, Sweden.
    Supercapacitors on demand: All-printed energy storage devices with adaptable design2019Inngår i: Flexible and Printed Electronics, ISSN 2058-8585, Vol. 4, nr 1, artikkel-id 015006Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Demands on the storage of energy have increased for many reasons, in part driven by household photovoltaics, electric grid balancing, along with portable and wearable electronics. These are fast-growing and differentiated applications that need large volume and/or highly distributed electrical energy storage, which then requires environmentally friendly, scalable and flexible materials and manufacturing techniques. However, the limitations on current inorganic technologies have driven research efforts to explore organic and carbon-based alternatives. Here, we report a conducting polymer:cellulose composite that serves as the active material in supercapacitors which has been incorporated into all-printed energy storage devices. These devices exhibit a specific capacitance of ≈90 F g -1 and an excellent cyclability (&gt;10 000 cycles). Further, a design concept coined 'supercapacitors on demand' is presented, which is based on a printing-cutting-folding procedure, that provides us with a flexible production protocol to manufacture supercapacitors with adaptable configuration and electrical characteristics.

  • 31.
    Brooke, Robert
    et al.
    Linköping University, Sweden.
    Mitraka, Evangelie
    Linköping University, Sweden.
    Sardar, Samim
    Linköping University, Sweden.
    Sandberg, Mats
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Sawatdee, Anurak
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Berggren, Magnus
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Crispin, Xavier
    Linköping University, Sweden.
    Jonsson, Magnus P.
    Linköping University, Sweden.
    Infrared electrochromic conducting polymer devices2017Inngår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 5, nr 23, s. 5824-5830Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) is well known for its electrochromic properties in the visible region. Less focus has been devoted to the infrared (IR) wavelength range, although tunable IR properties could enable a wide range of novel applications. As an example, modern day vehicles have thermal cameras to identify pedestrians and animals in total darkness, but road and speed signs cannot be easily visualized by these imaging systems. IR electrochromism could enable a new generation of dynamic road signs that are compatible with thermal imaging, while simultaneously providing contrast also in the visible region. Here, we present the first metal-free flexible IR electrochromic devices, based on PEDOT:Tosylate as both the electrochromic material and electrodes. Lateral electrochromic devices enabled a detailed investigation of the IR electrochromism of thin PEDOT:Tosylate films, revealing large changes in their thermal signature, with effective temperature changes up to 10 °C between the oxidized (1.5 V) and reduced (-1.5 V) states of the polymer. Larger scale (7 × 7 cm) vertical electrochromic devices demonstrate practical suitability and showed effective temperature changes of approximately 7 °C, with good optical memory and fast switching (1.9 s from the oxidized state to the reduced state and 3.3 s for the reversed switching). The results are highly encouraging for using PEDOT:Tosylate for IR electrochromic applications.

  • 32.
    Brunnstrom, Kjell
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. Mid Sweden University, Sweden.
    Barkowsky, Marcus
    University of Applied Sciences, Germany.
    Statistical quality of experience analysis: on planning the sample size and statistical significance testing2018Inngår i: Journal of Electronic Imaging (JEI), ISSN 1017-9909, E-ISSN 1560-229X, Vol. 27, nr 5, artikkel-id 053013Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper analyzes how an experimenter can balance errors in subjective video quality tests betweenthe statistical power of finding an effect if it is there and not claiming that an effect is there if the effect is not there,i.e., balancing Type I and Type II errors. The risk of committing Type I errors increases with the number ofcomparisons that are performed in statistical tests. We will show that when controlling for this and at thesame time keeping the power of the experiment at a reasonably high level, it is unlikely that the number oftest subjects that are normally used and recommended by the International Telecommunication Union (ITU),i.e., 15 is sufficient but the number used by the Video Quality Experts Group (VQEG), i.e., 24 is more likelyto be sufficient. Examples will also be given for the influence of Type I error on the statistical significance ofcomparing objective metrics by correlation. We also present a comparison between parametric and nonparametricstatistics. The comparison targets the question whether we would reach different conclusions on the statisticaldifference between the video quality ratings of different video clips in a subjective test, based on thecomparison between the student T-test and the Mann–Whitney U-test. We found that there was hardly a differencewhen few comparisons are compensated for, i.e., then almost the same conclusions are reached. Whenthe number of comparisons is increased, then larger and larger differences between the two methods arerevealed. In these cases, the parametric T-test gives clearly more significant cases, than the nonparametrictest, which makes it more important to investigate whether the assumptions are met for performing a certaintest.

  • 33.
    Brunnstrom, Kjell
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. Mid Sweden University, Sweden.
    Dima, Elijs
    Mid Sweden University, Sweden.
    Andersson, Mattias
    Mid Sweden University, Sweden.
    Sjöström, Mårten
    Mid Sweden University, Sweden.
    Qureshi, Tahir
    HIAB, Sweden.
    Johanson, Mathias
    Alkit Communications AB, Sweden.
    Quality of Experience of hand controller latency in a Virtual Reality simulator2019Inngår i: Human Vision and Electronic Imaging 2019 / [ed] Damon Chandler, Mark McCourt and Jeffrey Mulligan, 2019, artikkel-id 3068450Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this study, we investigate a VR simulator of a forestry crane used for loading logs onto a truck, mainly looking at Quality of Experience (QoE) aspects that may be relevant for task completion, but also whether there are any discomfort related symptoms experienced during task execution. A QoE test has been designed to capture both the general subjective experience of using the simulator and to study task performance. Moreover, a specific focus has been to study the effects of latency on the subjective experience, with regards to delays in the crane control interface. A formal subjective study has been performed where we have added controlled delays to the hand controller (joystick) signals. The added delays ranged from 0 ms to 800 ms. We found no significant effects of delays on the task performance on any scales up to 200 ms. A significant negative effect was found for 800 ms added delay. The Symptoms reported in the Simulator Sickness Questionnaire (SSQ) was significantly higher for all the symptom groups, but a majority of the participants reported only slight symptoms. Two out of thirty test persons stopped the test before finishing due to their symptoms.

  • 34.
    Brunnstrom, Kjell
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. Mid Sweden University, Sweden.
    Wang, Kun
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Tavakoli, Samira
    Universidad Politecnica de Madrid, Spain.
    Andren, Börje
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Symptoms analysis of 3D TV viewing based on Simulator SicknessQuestionnaires2017Inngår i: Quality and User Experience, ISSN 2366-0139, E-ISSN 2366-0147, Vol. 2Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Stereoscopic 3D TV viewing puts differentvisual demands on the viewer compared to 2D TV viewing.Previous research has reported on viewers’ fatigue anddiscomfort and other negative effects. This study is toinvestigate further how severe and what symptoms mayarise from somewhat longish 3D TV viewing. The MPEG3DV project is working on the next-generation videoencoding standard and in this process, MPEG issued a callfor proposal of encoding algorithms. To evaluate thesealgorithms a large scale subjective test was performedinvolving Laboratories all over the world [(MPEG 2011;Baroncini 2012)]. For the participating Labs, it wasoptional to administer a slightly modified Simulator SicknessQuestionnaire (SSQ) before and after the test. One ofthe SSQ data sets described in this article is coming fromthis study. The SSQ data from the MPEG test is the largestdata set in this study and also contains the longest viewingtimes. Along with the SSQ data from the MPEG test, wehave also collected questionnaire data in three other 3D TVstudies. We did two on the same 3D TV (passive filmpattern retarder) as in the MPEG test, and one was using aprojector system. As comparison SSQ data from a 2Dvideo quality experiment is also presented. This investigationshows a statistically significant increase in symptomsafter viewing 3D TV primarily related to the visual or Oculomotor system. Surprisingly, 3D video viewing usingprojectors did not show this effect.

  • 35.
    Brunnström, Kjell
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Allison, R. S.
    York University, Canada.
    Chandler, D. M.
    Shizuoka University, Japan.
    Colett, H.
    Intel Corp, USA.
    Corriveau, P.
    Intel Corp, USA.
    Daly, S.
    Dolby Laboratories, USA.
    Goel, J.
    Qualcomm, Canada.
    Knopf, J.
    Intel Corp, USA.
    Wilcox, L. M.
    York University, Canada.
    Yaacob, Y.
    Shizuoka University, Japan.
    Yang, S. -N
    Pacific University, USA.
    Zhang, Y.
    Shizuoka University, Japan.
    Industry and business perspectives on the distinctions between visually lossless and lossy video quality: Mobile and large format displays2017Inngår i: IS and T International Symposium on Electronic Imaging Science and Technology, 2017, s. 118-133Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will explore the mobile and business perspectives of visually lossless image quality, as well as review recent scientific advances. It is the outcome from the Special Session on Visually Lossless Video Quality for Modern Devices: Research and Industry Perspectives organized at the Human Vision and Electronic Imaging 2017 by IS&T at San Francisco Airport, Burlingame, California, USA, Jan 29 - Feb 2, 2017. It summarizes four presentations and a panel discussion.

  • 36.
    Brunnström, Kjell
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Barkowsky, Marcus
    Balancing type I errors and statistical power in video quality assessment2017Inngår i: IS and T International Symposium on Electronic Imaging Science and Technology, 2017, s. 91-96Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper analyzes how an experimenter can balance errors in subjective video quality tests between the statistical power of finding an effect if it is there and not claiming that an effect is there if the effect it is not there i.e. balancing Type I and Type II errors. The risk of committing Type I errors increases with the number of comparisons that are performed in statistical tests. We will show that when controlling for this and at the same time keeping the power of the experiment at a reasonably high level, it will require more test subjects than are normally used and recommended by international standardization bodies like the ITU. Examples will also be given for the influence of Type I error on the statistical significance of comparing objective metrics by correlation.

  • 37.
    Camara, A.
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo. Pontifícia Universidade Católica do Rio de Janeiro,Brazil.
    Tarasenko, O.
    RISE., Swedish ICT, Acreo.
    Margulis, W.
    RISE., Swedish ICT, Acreo. KTH Royal Institute of Technology, Sweden.
    Study of thermally poled fibers with a two-dimensional model2014Inngår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 22, s. 17700-15Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A two-dimensional (2D) numerical model is implemented to describe the movement of ions under thermal poling for the specific case of optical fibers. Three types of cations are considered (representing Na+, Li + and H3O+) of different mobility values. A cross-sectional map of the carrier concentration is obtained as a function of time. The role of the various cations is investigated. The assumptions of the model are validated by comparing the predictions to experimental data of the time evolution of the nonlinearity induced. A variational analysis of poling parameters including temperature, poling voltage, sign of the bias potential and initial ionic concentrations is performed for a particular fiber geometry. The analysis allows identifying the impact of these parameters on the induced secondorder nonlinearity in poled fibers.

  • 38.
    Carlsson, Raul
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, SWECAST.
    Elmquist, Lennart
    RISE - Research Institutes of Sweden, Material och produktion, SWECAST.
    Johansson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Cast metal with intelligence - from passive to intelligent cast components2017Inngår i: 8th Conference on Smart Structures and Materials, SMART 2017 and 6th International Conference on Smart Materials and Nanotechnology in Engineering, SMN 2017, 2017, s. 550-560Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper describes an innovation project aiming to embed sensors into cast metal during the casting process. Important measurands are e.g. elongation, shear, temperature and vibration. In practice this means to turn metal components into also being digital components. This will respond to some of metal industrýs challenges; resource efficient design, increased value added for the casting sector, and general access to different possibilities of digitalization. Technical challenges lie in choices of sensor material to integrate during the casting process that maintains its sensor functionality after casting processing without degrading the mechanical strength of the metal component. Other challenges relate to signal interaction and interference between sensor and metal. To handle the technical challenges the innovation project gathers competence about metal casting and sensor technology. One goal of this innovation project is to develop an innovation platform that elevates the material based casting industry into a wholly or partially value and service based industry. Integration of sensors into cast components makes sensing functionality a natural property of metal, which in turn may turn metal into key components for the industrial digitalization.

  • 39.
    Carlsson, Raul
    et al.
    RISE - Research Institutes of Sweden, Material och produktion, SWECAST.
    Elmquist, Lennart
    RISE - Research Institutes of Sweden, Material och produktion, SWECAST.
    Thore, Andreas
    RISE - Research Institutes of Sweden, Material och produktion, SWECAST.
    Ahrentorp, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Israelsson, Björn
    SKF Mekan AB, Sweden.
    Connecting sensors inside smart castings2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper presents ongoing research on smart metal castings, meaning the technologicalinnovation of elevating cast metal components into metal components with integratedsensor functionality. Since the innovation targets aim straight at low cost industrial serialproduction, specific high cost and high-end solutions like inclusion of advancedelectronic equipment and after mounted sensors are not part of this innovationdevelopment. Integrating signal carriers inside metal castings to achieve metal castingswith sensor functionality requires robust solutions for connecting the sensor signal to thesensor interrogator and interpreter. The actual transmission of the signal may be donewirelessly or by wire. However, for several reasons there is a challenge with establishingan isolated and distinct connection between the sensor contact, and the contact at theexternal connection, regardless of whether it is to an antenna for wireless transmission orto a wire. This paper presents metallurgical challenges associated with choices ofmaterials, and combinations of metallurgical challenges and production process relatedchallenges, including the high melting temperatures. Aims are to find the rightcombinations of metal alloys, production simplicity, signal stability and robustness. Thepaper will present some of the tests made in the project so far. The project is run in aconsortium of the two Sweden-based industrial companies Husqvarna and SKF, and thetwo Swedish research institutes Swerea SWECAST and RISE Acreo.

  • 40.
    Chamania, Mohit
    et al.
    ADVA Optical Networking, Germany.
    Szyrkowiec, Thomas
    ADVA Optical Networking, Germany.
    Santuari, Michele
    CREATE-NET Research Center, Italy.
    Siracusa, Dominico
    CREATE-NET Research Center, Italy.
    Autenrieth, Achim
    ADVA Optical Networking, Germany.
    Lopez, Victor
    Telefónica I+D, Spain.
    Sköldström, Pontus
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Junique, Stephane
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Intent-based in-flight service encryption in multi-layer transport networks2017Inngår i: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We demonstrate multi-layer encrypted service provisioning via the ACINO orchestrator. ACINO combines a novel intent interface with an ONOS-based SDN orchestrator to facilitate encrypted services at IP, Ethernet and optical network layers.

  • 41.
    Che, C.
    et al.
    Linköping University, Sweden.
    Vagin, M.
    Linköping University, Sweden.
    Ail, U.
    Linköping University, Sweden.
    Gueskine, V.
    Linköping University, Sweden.
    Phopase, J.
    Linköping University, Sweden.
    Brooke, Robert
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Gabrielsson, R.
    Linköping University, Sweden.
    Jonsson, M. P.
    Linköping University, Sweden.
    Mak, W. C.
    Linköping University, Sweden.
    Berggren, M.
    Linköping University, Sweden.
    Crispin, X.
    Linköping University, Sweden.
    Twinning Lignosulfonate with a Conducting Polymer via Counter-Ion Exchange for Large-Scale Electrical Storage2019Inngår i: Advanced Sustainable Systems, ISSN 2366-7486, Vol. 3, nr 9, artikkel-id 1900039Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lignosulfonate (LS) is a large-scale surplus product of the forest and paper industries, and has primarily been utilized as a low-cost plasticizer in making concrete for the construction industry. LS is an anionic redox-active polyelectrolyte and is a promising candidate to boost the charge capacity of the positive electrode (positrode) in redox-supercapacitors. Here, the physical-chemical investigation of how this biopolymer incorporates into the conducting polymer PEDOT matrix, of the positrode, by means of counter-ion exchange is reported. Upon successful incorporation, an optimal access to redox moieties is achieved, which provides a 63% increase of the resulting stored electrical charge by reversible redox interconversion. The effects of pH, ionic strength, and concentrations, of included components, on the polymer–polymer interactions are optimized to exploit the biopolymer-associated redox currents. Further, the explored LS-conducting polymer incorporation strategy, via aqueous synthesis, is evaluated in an up-scaling effort toward large-scale electrical energy storage technology. By using an up-scaled production protocol, integration of the biopolymer within the conducting polymer matrix by counter-ion exchange is confirmed and the PEDOT-LS synthesized through optimized strategy reaches an improved charge capacity of 44.6 mAh g−1. 

  • 42.
    Chen, Shangzhi
    et al.
    Linköping University, Sweden.
    Kühne, Philipp
    Linköping University, Sweden.
    Stanishev, Vallery
    Linköping University, Sweden.
    Knight, Sean
    University of Nebraska-Lincoln, US.
    Brooke, Robert
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Petsagkourakis, Ioannis
    Linköping University, Sweden.
    Crispin, Xavier
    Linköping University, Sweden.
    Schubert, Mathias
    Linköping University, Sweden; University of Nebraska-Lincoln, US; Leibniz-Institut für Polymerforschung Dresden e.V., Germany.
    Darakchieva, Vanya
    Linköping University, Sweden.
    Jonsson, Magnus
    Linköping University, Sweden.
    On the anomalous optical conductivity dispersion of electrically conducting polymers: Ultra-wide spectral range ellipsometry combined with a Drude-Lorentz model2019Inngår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 7, nr 15, s. 4350-4362Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electrically conducting polymers (ECPs) are becoming increasingly important in areas such as optoelectronics, biomedical devices, and energy systems. Still, their detailed charge transport properties produce an anomalous optical conductivity dispersion that is not yet fully understood in terms of physical model equations for the broad range optical response. Several modifications to the classical Drude model have been proposed to account for a strong non-Drude behavior from terahertz (THz) to infrared (IR) ranges, typically by implementing negative amplitude oscillator functions to the model dielectric function that effectively reduce the conductivity in those ranges. Here we present an alternative description that modifies the Drude model via addition of positive-amplitude Lorentz oscillator functions. We evaluate this so-called Drude-Lorentz (DL) model based on the first ultra-wide spectral range ellipsometry study of ECPs, spanning over four orders of magnitude: from 0.41 meV in the THz range to 5.90 eV in the ultraviolet range, using thin films of poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:Tos) as a model system. The model could accurately fit the experimental data in the whole ultrawide spectral range and provide the complex anisotropic optical conductivity of the material. Examining the resonance frequencies and widths of the Lorentz oscillators reveals that both spectrally narrow vibrational resonances and broader resonances due to localization processes contribute significantly to the deviation from the Drude optical conductivity dispersion. As verified by independent electrical measurements, the DL model accurately determines the electrical properties of the thin film, including DC conductivity, charge density, and (anisotropic) mobility. The ellipsometric method combined with the DL model may thereby become an effective and reliable tool in determining both optical and electrical properties of ECPs, indicating its future potential as a contact-free alternative to traditional electrical characterization.

  • 43.
    Chen, XÍ
    et al.
    Huazhong University of Science and Technology, China.
    Lin, Rui
    Huazhong University of Science and Technology, China.
    Cui, Jingxian
    Huazhong University of Science and Technology, China.
    Gan, Li
    Huazhong University of Science and Technology, China.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Udalcovs, Aleksejs
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jiang, Tao
    Huazhong University of Science and Technology, China.
    Schatz, Richard
    KTH Royal Institute of Technology, Sweden.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Chena, Jiajia
    KTH Royal Institute of Technology, Sweden.
    Tang, Ming
    Huazhong University of Science and Technology, China.
    Fu, Songnian
    Huazhong University of Science and Technology, China.
    Liu, Deming
    Huazhong University of Science and Technology, China.
    TDHQ Enabling Fine-granularity Adaptive Loading for SSB-DMT Systems2018Inngår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 30, nr 19, s. 1687-1690Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this letter, we introduce time domain hybrid quadrature amplitude modulation (TDHQ) for the single sideband (SSB) discrete multi-tone (DMT) systems. Experimental results reveal that with a single precoding set and the proposed adaptive loading algorithm, the TDHQ scheme can achieve finer granularity and therefore smoother continuous growth of data rate than that with the conventional quadrature amplitude modulation (QAM). Besides, thanks to the frame construction and the tailored mapping rule, the scheme with TDHQ has an obviously better peak to average power ratio (PAPR).

  • 44.
    Cherian, Dennis
    et al.
    Linköping University, Sweden.
    Armgarth, Astrid
    Linköping University, Sweden.
    Beni, Valerio
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Linderhed, Ulrika
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Tybrandt, Klas
    Linköping University, Sweden.
    Nilsson, David
    Simon, Daniel T
    Linköping University, Sweden.
    Berggren, Magnus
    Linköping University, Sweden.
    Large-area printed organic electronic ion pumps2019Inngår i: Flexible and Printed Electronics, Vol. 4, nr 2Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Biological systems use a large variety of ions and molecules of different sizes for signaling. Precise electronic regulation of biological systems therefore requires an interface which translates the electronic signals into chemically specific biological signals. One technology for this purpose that has been developed during the last decade is the organic electronic ion pump (OEIP). To date, OEIPs have been fabricated by micropatterning and labor-intensive manual techniques, hindering the potential application areas of this promising technology. Here we show, for the first time, fully screen-printed OEIPs. We demonstrate a large-area printed design with manufacturing yield >90%. Screen-printed cation- and anion-exchange membranes are both demonstrated with promising ion selectivity and performance, with transport verified for both small ions (Na+, K+, Cl) and biologically-relevant molecules (the cationic neurotransmitter acetylcholine, and the anionic anti-inflammatory salicylic acid). These advances open the 'iontronics' toolbox to the world of printed electronics, paving the way for a broader arena for applications.

  • 45.
    Colvin, Jovana
    et al.
    Lund University, Sweden.
    Ciechonski, Rafal
    Glo AB, Sweden.
    Lenrick, Filip
    Lund University, Sweden.
    Hultin, Olof
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Khalilian, Maryam
    Lund University, Sweden.
    Mikkelsen, Anders
    Lund University, Sweden.
    Gustafsson, Anders
    Lund University, Sweden.
    Samuelson, Lars
    Lund University, Sweden.
    Timm, Rainer
    Lund University, Sweden.
    Ohlsson, Jonas
    Hexagem AB, Sweden.
    Surface and dislocation investigation of planar GaN formed by crystal reformation of nanowire arrays2019Inngår i: Physical Review Materials, ISSN 2475-9953, Vol. 3, nr 9, artikkel-id 093604Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper we present a process of forming monolithic GaN surface from an ordered nanowire array by means of material redistribution. This process, referred to as reformation, is performed in a conventional MOVPE crystal growth system with the gallium supply turned off and allows a crystal nanostructure to change shape according to differences in surface energies between its facets. Using reformation, coalescence may proceed closer to thermodynamic equilibrium, which is required for fabrication of high-quality substrate material. Scanning probe techniques are utilized, complemented by cathodoluminescence and electron microscopy, to investigate structural and electrical properties of the surface after reformation, as well as to assess densities, location, and formation of different types of defects in the GaN film. Spatial variations in material properties such as intrinsic majority-carrier types can be attributed to the radical changes in growth conditions required for sequential transition between nanowire growth, selective shell growth, and reformation. These properties enable us to assess the impact of the process on densities, locations, and formation of different types of dislocations in the GaN film. We find a fraction of the nanowires to comprise of a single electrically neutral edge dislocation, propagating from the GaN buffer, while electrically active dislocations are found at coalesced interfaces between nanowires. By decreasing the mask aperture size and changing the nucleation conditions the prevalence of nanowires comprising edge dislocation was significantly reduced from 6% to 3%, while the density of interface dislocations was reduced from 6×108 to 4×107cm-2. Using a sequential reformation process was found to create inversion domains with low surface potential N-polar regions in an otherwise Ga-polar GaN film. The inversion domains were associated with pinned dislocation pairs, and were further confirmed by selective wet etching in NaOH. This lateral polarity inversion was thoroughly eliminated in samples formed by a continuous reformation process. These results reveal a path and challenges for growing GaN substrates of superior crystal quality through nanowire reformation. 

  • 46.
    Cristofori, Valentina
    et al.
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francesco
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed Essghair
    University of Rennes 1, France.
    Bramerie, Laurent
    University of Rennes 1, France.
    Ding, Yunhong
    DTU Technical University of Denmark, Denmark.
    Pang, Xiaodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Shen, Alexandre
    III-V Lab, France.
    Gallet, Antonin
    III-V Lab, France.
    Duan, Guanghua
    III-V Lab, France.
    Hassan, Karim
    CEA, France.
    Olivier, Segolene Gol Ne
    CEA, France.
    Popov, Sergei Yu
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Oxenlöwe, Leif Katsuo
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    University of Rennes 1, France.
    25-Gb/s transmission over 2.5-km SSMF by silicon MRR enhanced 1.55-μm III-V/SOI DML2017Inngår i: 30th Annual Conference of the IEEE Photonics Society, IPC 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, s. 357-360Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The use of a micro-ring resonator (MRR) to enhance the modulation extinction ratio and dispersion tolerance of a directly modulated laser (DML) is experimentally investigated with a bit rate of 25 Gb/s as proposed for the next generation data center communications. The investigated system combines a 11-GHz 1.55-m directly modulated hybrid III-V/SOI DFB laser realized by bonding III-V materials (InGaAlAs) on a silicon-on-insulator (SOI) wafer and a silicon MRR also fabricated on SOI. Such a transmitter enables error-free transmission (BER&lt; 10 -9 )at 25 Gb/s data rate over 2.5-km SSMF without dispersion compensation nor forward error correction (FEC). As both laser and MRR are fabricated on the SOI platform, they could be combined into a single device with enhanced performance, thus providing a cost-effective transmitter for short reach applications.

  • 47.
    Cristofori, Valentina
    et al.
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francescos
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed E.
    FOTON Laboratory, France.
    Bramerie, Laurent
    FOTON Laboratory, France.
    Ding, Yunhong
    DTU Technical University of Denmark, Denmark.
    Pang, Xiadon
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Shen, Alexandre
    Thales, France.
    Gallet, Antonin
    Thales, France.
    Duan, Guang-Hua
    Thales, France.
    Hassan, Karem
    III-V Lab, France.
    Olivier, Segolene
    III-V Lab, France.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    Oxenløwe, Leif K.
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    FOTON Laboratory, France.
    25-Gb/s transmission over 2.5-km SSMF by silicon MRR enhanced 1.55-μm III-V/SOI DML2017Inngår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 29, nr 12, s. 960-963, artikkel-id 7917280Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The use of a micro-ring resonator (MRR) to enhance the modulation extinction ratio and dispersion tolerance of a directly modulated laser is experimentally investigated with a bit rate of 25 Gb/s as proposed for the next generation data center communications. The investigated system combines a 11-GHz 1.55-μm directly modulated hybrid III-V/SOI DFB laser realized by bonding III-V materials (InGaAlAs) on a silicon-on-insulator (SOI) wafer and a silicon MRR also fabricated on SOI. Such a transmitter enables error-free transmission (BER &lt; 10-9) at 25 Gb/s data rate over 2.5-km standard single mode fiber without dispersion compensation nor forward error correction. As both laser and MRR are fabricated on the SOI platform, they could be combined into a single device with enhanced performance, thus providing a cost-effective transmitter for short reach applications.

  • 48.
    Czegledi, Christian B.
    et al.
    Chalmers University of Technology, Sweden.
    Karlsson, Magnus
    Chalmers University of Technology, Sweden.
    Johannisson, Pontus
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Agrell, Erik
    Chalmers University of Technology, Sweden.
    Temporal stochastic channel model for absolute polarization state and polarization-mode dispersion2017Inngår i: 2017 Optical Fiber Communications Conference and Exhibition, OFC 2017 - Proceedings, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We propose and validate a discrete-time channel model for the temporal drift of the absolute polarization state and polarization-mode dispersion for coherent fiber optic systems. The model can be used in simulations to test and develop DSP for coherent receivers.

  • 49.
    Da Ros, Francesco
    et al.
    DTU Technical University of Denmark, Denmark.
    Cristofori, Valentina
    DTU Technical University of Denmark, Denmark.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Chaibi, Mohamed E.
    University of Rennes, France.
    Pang, Xiodan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Galili, Michael
    DTU Technical University of Denmark, Denmark.
    Oxenløwe, Leif K.
    DTU Technical University of Denmark, Denmark.
    Peucheret, Christophe
    University of Rennes, France.
    4-PAM dispersion-uncompensated transmission with micro-ring resonator enhanced 1.55-μm DML2017Inngår i: Optics InfoBase Conference Papers, 2017, artikkel-id STu1M.5.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Real-time transmission of 14-GBd 4-PAM signal is demonstrated by combining a commercial 1.55-μm DML with a silicon MRR. BER below the HD-FEC threshold is measured after 26-km SSMF transmission without offline digital signal processing.

  • 50.
    Debela, A. M.
    et al.
    Sorbonne University, France.
    Ortiz, Mayreli
    Rovira i Virgili University, Spain.
    Beni, Valerio
    RISE - Research Institutes of Sweden, ICT, Acreo. Linköping University, Sweden.
    Lesage, Denis
    Sorbonne University, France.
    Cole, Richard B.
    Sorbonne University, France.
    O'Sullivan, Ciara K.
    Rovira i Virgili University, Spain; Institució Catalana de Recerca i Estudis Avançais, Spain.
    Thorimbert, Serge
    Sorbonne University, France.
    Hasenknopf, Bernold
    Sorbonne University, France.
    Functionalized deoxynucleotides and DNA primers for electrochemical diagnostics of disease predispostions2017Inngår i: ECS Transactions, Electrochemical Society Inc. , 2017, nr 11, s. 1873-1883Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Redox labeled DNAs are of increasing interest for the fabrication of next generation molecular tools. In the present work we are investigating the use of various redox labeled dNTPs, ddNTPs and DNA primers for use in detection of diseases. We have reported the use of Polyoxometalate (POM) labeled DNA primers and dNTPs for use in PCR and subsequently used for direct electrochemical detection of PCR products. The use of POM labeled DNAs in PCR enabled us to check the compatibility with polymerases and PCR incorporability of the modified DNAs. Furthermore we have investigated the solid-phase array based primer extension (é-PEX) with redox labelled ddNTPs (ferrocene (Fc), anthraquinone (AQ) phenothiazine (PTZ) and methylene blue (MB)) to prove the strategy of detection of single nucleotide polymorphisms using the labeled ddNTPs. This strategy will allow the development of cost-effective, rapid and user-friendly platform for the screening of known and unknown genetic mutations.

123456 1 - 50 of 278
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
v. 2.35.7