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  • 301. Höglund, L
    et al.
    Holtz, P O
      Pettersson, H
    Asplund, C
    Wang, Q
    RISE., Swedish ICT, Acreo.
    Malm, H
    Almqvist, S
    Petrini, E
    Andersson, J Y
    RISE., Swedish ICT, Viktoria.
    Optical pumping as artificial doping in quantum dots-in-a-well infrared photodetectors2009Ingår i: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 94, s. 53503-Artikel i tidskrift (Refereegranskat)
  • 302. Iglesias Olmedo, M.
    et al.
    Pang, Xiaodan
    RISE., Swedish ICT, Acreo.
    Schatz, R.
    Zibar, D.
    Tafur Monroy, I.
    Jacobsen, G
    Popov, S
    Digital signal processing approaches for semiconductor phase noise tolerant coherent transmission systems2015Ingår i: Proceedings of SPIE - The International Society for Optical Engineering, 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    We discuss about digital signal processing approaches that can enable coherent links based on semiconductor lasers. A state-of-the art analysis on different carrier-phase recovery (CPR) techniques is presented. We show that these techniques are based on the assumption of lorentzian linewidth, which does not hold for monolithically integrated semiconductor lasers. We investigate the impact of such lineshape on both 3 and 20 dB linewidth and experimentally conduct a systematic study for 56-GBaud DP-QPSK and 28-GBaud DP-16QAM systems using a decision directed phase look loop algorithm. We show how carrier induced frequency noise has no impact on linewidth but a significant impact on system performance; which rises the question on whether 3-dB linewidth should be used as performance estimator for semiconductor lasers. © 2015 SPIE.

  • 303.
    Irukulapati, Maga
    et al.
    Ericsson AB, Sweden.
    Secondini, Marco
    TeCIP Institute, Italy.
    Agrell, Erik
    Chalmers University of Technology, Sweden.
    Johannisson, Pontus
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Wymeersch, Henk
    Chalmers University of Technology, Sweden.
    Improved Lower Bounds on Mutual Information Accounting for Nonlinear Signal--Noise Interaction2018Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 36, nr 22, s. 5152-5159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In fiber-optic communications, evaluation of mutual information (MI) is still an open issue due to the unavailability of an exact and mathematically tractable channel model. Traditionally, lower bounds on MI are computed by approximating the (original) channel with an auxiliary forward channel. In this paper, lower bounds are computed using an auxiliary backward channel, which has not been previously considered in the context of fiber-optic communications. Distributions obtained through two variations of the stochastic digital backpropagation (SDBP) algorithm are used as auxiliary backward channels and these bounds are compared with bounds obtained through the conventional digital backpropagation (DBP). Through simulations, higher information rates were achieved with SDBP, which can be explained by the ability of SDBP to account for nonlinear signal--noise interactions

  • 304. Isaksson, J
    et al.
    Kjäll, P
    RISE., Swedish ICT, Acreo.
    Nilsson, D
    Robinson, N
    Berggren, M
    Richter-Dahlfors, A
    Electronic control of Ca2+ signalling in neuronal cells using an organic electronic ion pump2007Ingår i: Nature Materials_x000D_, Vol. 6, nr 9, s. 673-Artikel i tidskrift (Refereegranskat)
  • 305. Isaksson, J
    et al.
    Nilsson, D
    Kjall, P
    RISE., Swedish ICT, Acreo.
    Robinson, N D
    Richter-Dahlfors, A
    Berggren, M
    Electronically Controlled Ph Gradients Proton Oscillations2008Ingår i: Organic electronics, ISSN 1566-1199, E-ISSN 1878-5530, Vol. 9, s. 303-309Artikel i tidskrift (Refereegranskat)
  • 306.
    Jacobsen, G
    RISE., Swedish ICT, Acreo.
    Error-rate floors in intradyne QPSK systems with quadruple phase extraction – comparison of block sliding Processor Unit update2011Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 31, s. 180-3Artikel i tidskrift (Refereegranskat)
  • 307.
    Jacobsen, G
    RISE., Swedish ICT, Acreo.
    Laser phase noise induced error-rate floors in differential n-level phase-shift-keying coherent receivers2010Ingår i: Electronics Letters, ISSN 0013-5194, E-ISSN 1350-911X, Vol. 46, nr 10, s. 698-700Artikel i tidskrift (Refereegranskat)
  • 308.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Aurelius, A
    Berntson, A
    RISE., Swedish ICT, Acreo.
    BER Model for Rx ISI Effects in WDM Systems Accounting for General LPF Impulse Responses for Correlation of Quadrature Polarization Noise Contributions2007Ingår i: Journal of Optical Communications, Vol. 28, nr 1, s. 52-57Artikel i tidskrift (Refereegranskat)
  • 309.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Carlsson, A
    Berntson, A
    RISE., Swedish ICT, Acreo.
    New rigorous model for Rx ISI effects in WDM systems2004Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 25, nr 6, s. 241-45Artikel i tidskrift (Refereegranskat)
  • 310.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Gillner, L
    Fransson, O
    On the use of OSNR for BER monitoring in optical networks2000Ingår i: Journal of Optical Communication, Vol. 21, s. 20-Artikel i tidskrift (Refereegranskat)
  • 311.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Kazovsky, LG
    Xu, T
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Phase noise influence in optical OFDM systems employing RF pilot tone for phase noise cancellation2011Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 32, s. 141-5Artikel i tidskrift (Refereegranskat)
  • 312.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Lidon, M
    Xu, T
    Popov, S
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    Influence of Pre- Post-compensation of Chromatic Dispersion on Equalization Enhanced Phase Noise in Coherent Multilevel Systems2011Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 32Artikel i tidskrift (Refereegranskat)
  • 313.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Persson, U
    Gillner, L
    Vanin, E
    RISE., Swedish ICT, Acreo.
    Wingstrand, S
    Pump power dependent black box EDFA model2000Ingår i: Journal of Optical Communication, Vol. 21, s. 675-Artikel i tidskrift (Refereegranskat)
  • 314.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Vanin, E
    RISE., Swedish ICT, Acreo.
    Novel optical direct-detection D16PSK Gray code receiver using two interferometers simple multilevel electrical processing2009Ingår i: J. Opt. Commun., Vol. 31, nr 1Artikel i tidskrift (Refereegranskat)
  • 315.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Vanin, E
    RISE., Swedish ICT, Acreo.
    Forzati, M
    RISE., Swedish ICT, Acreo.
    Wang, L
    Practical design model of DnPSK systems using direct BER counting rigorous BER modeling2008Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 29, nr 4, s. 226-Artikel i tidskrift (Refereegranskat)
  • 316.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Wildhagen, P
    A general rigorous WDM receiver model targeting 10 - 40 Gb/s channel bit-rates2001Ingår i: IEEE transactions on intelligent transportation systems (Print), ISSN 1524-9050, E-ISSN 1558-0016, Vol. 19, s. 966-Artikel i tidskrift (Refereegranskat)
  • 317.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, T
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    EEPN CD study for coherent optical nPSK nQAM systems with RF pilot based phase noise compensation2012Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 20, nr 8, s. 8862-70Artikel i tidskrift (Refereegranskat)
  • 318.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, T
    Popov, S
    Li, J
    RISE., Swedish ICT, Acreo.
    Friberg, AT
    Zhang, Y
    RISE., Swedish ICT, Acreo.
    Receiver implemented RF pilot tone phase noise mitigation in coherent optical nPSK nQAM systems2011Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 19, nr 15, s. 14487-94Artikel i tidskrift (Refereegranskat)
  • 319.
    Jacobsen, G
    et al.
    RISE., Swedish ICT, Acreo.
    Xu, T
    Popov, S
    Sergeyev, S
    Phase noise influence in coherent optical DnPSK systems with DSP based dispersion compensation2014Ingår i: Journal of optical communications, ISSN 0173-4911, E-ISSN 2191-6322, Vol. 35, nr 1, s. 57-Artikel i tidskrift (Refereegranskat)
  • 320. Jaskorzynska, B
    et al.
    Sergeyev, S
    RISE., Swedish ICT, Acreo.
    Swillo, M
    Khoptyar, D
    Nonlinear upconversion rate in Er-doped fibers2001Ingår i: Acta Physica Polonica A_x000D_, Vol. 99, s. 147-Artikel i tidskrift (Refereegranskat)
  • 321. Jason, J
    et al.
    Rugel, P
    Tarasenko, O
    RISE., Swedish ICT, Acreo.
    Margulis, W
    RISE., Swedish ICT, Acreo.
    Nilsson, HE
    Temperature characteristics of the birefringence properties of filled side-hole fibers2013Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 52, nr 21, s. 5208-15Artikel i tidskrift (Refereegranskat)
  • 322. Jason, Johan
    et al.
    Rugeland, Patrik
    RISE., Swedish ICT, Acreo.
    Tarasenko, Oleksandr
    RISE., Swedish ICT, Acreo.
    Margulis, Walter
    RISE., Swedish ICT, Acreo.
    Nilsson, Hans-Erik
    Temperature characteristics of the birefringence properties of filled side-hole fibers.2013Ingår i: Applied Optics, ISSN 0003-6935, E-ISSN 1539-4522, Vol. 52, nr 21, s. 5208-5215Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The temperature characteristics of the birefringence of side-hole fibers filled with liquids or metal are investigated, aiming at providing a basis for on/off temperature sensing. Short pieces of fiber are filled and the change in birefringence is registered using measurements in reflective mode of the transmitted power through a linear polarizer at 1550 nm. The rapid change in the birefringence behavior of the fiber at the temperature of the phase transition of the filler substance is shown, and from the measurement data the phase transition temperatures can be determined as well as an estimation of the birefringence change with temperature. The experimental results are supported by numerical simulations.

  • 323. Jelger, P
    et al.
    Engholm, M
    Norin, L
    RISE., Swedish ICT, Acreo.
    Laurell, F
    Degradation-resistant lasing at 980 nm in a Yb/Ce/Al-doped silica fiber2010Ingår i: Journal of the Optical Society of America. B, Optical physics, ISSN 0740-3224, E-ISSN 1520-8540, Vol. 27, nr 2, s. 338-42Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    n this work we measure how photodarkening affects the optical efficiency for three different Yb/Al -doped silica fibers operating at 980€‰nm , one of which is codoped with cerium. A volume Bragg grating is used for linewidth control added rejection of amplified spontaneous emission. Several hours of degradation-resistant operation is obtained with the Ce-codoped fiber, while for the Yb/Al doped fibers a large drop in efficiency is observed within the first hour of operation. Our results show that Yb/Ce/Al -doped fibers could be excellent candidates for high-power 980€‰nm fiber laser sources._x000D_

  • 324.
    Jia, Shi
    et al.
    Zhejiang University, China.
    Pang, Xiaodan
    KTH Royal Institute of Technology, Sweden.
    Ozolins, Oskars
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Yu, Xiobin
    Zhejiang University, China.
    Hu, Hao
    DTU Technical University of Denmark, Denmark.
    Yu, Jinlong
    Tianjin University, China.
    Guan, Pengyu
    DTU Technical University of Denmark, Denmark.
    Da Ros, Francesco
    DTU Technical University of Denmark, Denmark.
    Popov, Sergei
    KTH Royal Institute of Technology, Sweden.
    Jacobsen, Gunnar
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Galili, Michael
    DTU Technical University of Denmark, Denmark.
    Morioka, Toshio
    DTU Technical University of Denmark, Denmark.
    Zibar, Darko
    DTU Technical University of Denmark, Denmark.
    Oxenloewe, Leif K.
    DTU Technical University of Denmark, Denmark.
    0.4 THz Photonic-Wireless Link with 106 Gbit/s Single Channel Bitrate2018Ingår i: Journal of Lightwave Technology, ISSN 0733-8724, E-ISSN 1558-2213, Vol. 36, nr 2, s. 610-616Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To accommodate the demand of exponentially increased global wireless data traffic, the prospective data rates for wireless communication in the market place will soon reach 100 Gbit/s and beyond. In the lab environment, wireless transmission throughput has been elevated to the level of over 100 Gbit/s attributed to the development of photonic-assisted millimeter wave (MMW) and THz technologies. However, most of recent demonstrations with over 100 Gbit/s data rates are based on spatial or frequency division multiplexing techniques, resulting in increased system's complexity and energy consumption. Here, we experimentally demonstrate a single channel 0.4 THz photonic-wireless link achieving a net data rate of beyond 100 Gbit/s by using a single pair of THz emitter and receiver, without employing any spatial/frequency division multiplexing techniques. The high throughput up to 106 Gbit/s within a single THz channel is enabled by combining spectrally efficient modulation format, ultra-broadband THz transceiver and advanced digital signal processing (DSP) routine. Besides that, our demonstration from system-wide implementation viewpoint also features high transmission stability, and hence shows its great potential to not only decrease the system's complexity, but also meet the requirements of prospective data rates for bandwidth-hungry short-range wireless applications.

  • 325. Jian, Q.
    et al.
    Yang, J.
    Yu, Y.
    Bjorkholm, P.
    RISE., Swedish ICT, Acreo.
    McKelvey, T.
    Detection of breathing and heartbeat by using a simple UWB radar system2014Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, 2014, s. 3078-3081Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present the development on an ultra-wideband (UWB) radar system and its signal processing algorithms for detecting human breathing and heartbeat in the paper. The UWB radar system consists of two (Tx and Rx) antennas and one compact CMOS UWB transceiver. Several signal processing techniques are developed for the application. The system has been tested by real measurements. .

  • 326.
    Johannisson, P
    et al.
    RISE., Swedish ICT, Acreo.
    Anderson, D
    Berntson, A
    RISE., Swedish ICT, Acreo.
    Mårtensson, J
    RISE., Swedish ICT, Acreo.
    Generation dynamics of ghost pulses in strongly dispersion-managed fiber-optic communication systems2001Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 26, s. 1227-29Artikel i tidskrift (Refereegranskat)
  • 327.
    Johannisson, P
    et al.
    RISE., Swedish ICT, Acreo.
    Anderson, D
    Marklund, M
    Berntson, A
    RISE., Swedish ICT, Acreo.
    Forzati, M
    RISE., Swedish ICT, Acreo.
    Mårtensson, J
    RISE., Swedish ICT, Acreo.
    Suppression of nonlinear effects by phase alternation in strongly dispersion-managed optical transmission2002Ingår i: Optics Letters, ISSN 0146-9592, E-ISSN 1539-4794, Vol. 27, nr 12Artikel i tidskrift (Refereegranskat)
  • 328.
    Johannisson, Pontus
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ohlsson, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Rusu, Cristina
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Impact-driven up-conversion in piezoelectric MEMS energy harvesters with pulsed excitation2018Ingår i: Journal of Physics: Conference Series, 2018, nr 1, artikel-id 012106Konferensbidrag (Refereegranskat)
    Abstract [en]

    The potential of impact-driven frequency up-conversion in a MEMS EH is evaluated using numerical simulations. The investigated design is compared to a conventional cantilever EH in terms of output power and loss rate. The upshifting can lead to significantly increased output power at a similar loss rate but as the time scale for the loss is long, the benefit is limited. This also requires an effective upshifting process. The design of the impact introduces a length scale that must be selected with excitation, gravity, and pre-stress taken into account. This makes this type of EH application-dependent as a non-optimal choice may result in low output power.

  • 329.
    Johannisson, Pontus
    et al.
    RISE., Swedish ICT, Acreo.
    Ohlsson, Fredrik
    RISE., Swedish ICT, Acreo.
    Rusu, Cristina
    RISE., Swedish ICT, Acreo.
    Multi-axis piezoelectric energy harvesting using MEMS components with slanted beams2016Ingår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 773, nr 1, artikel-id 012080Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    During the manufacturing of MEMS components, slanted beams can be produced in the etching process. We show that this can be used to produce skew motion that causes deflection of a proof mass out of the device plane also when the excitation is confined to the device plane. This allows construction of an energy harvester that uses a planar manufacturing process and produces power also with in-plane excitation. To obtain this with traditional methods it would be necessary to manufacture separate components and then mount them with their sensitive axes orthogonal to each other.

  • 330.
    Johansson, C
    RISE., Swedish ICT, Acreo.
    Magnetic properties of magnetic nanoparticles in New materials for micro-scale sensors actuators : An engineering review2007Ingår i: Materials science Engineering reports, Vol. 56, nr 1, s. 1-129Artikel i tidskrift (Refereegranskat)
  • 331.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Aklint, T
    Hanson, M
    Andersson, M
    Tarras-Wahlberg, N
    Olsson, E
    Kalska, B
    Wäppling, R
    Rosen, A
    Deposited nano-metre sized iron clusters1999Ingår i: Nanostructured Materials, Vol. 12, s. 287-Artikel i tidskrift (Refereegranskat)
  • 332.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Influence of sample geometry in a vibrating sample magnetometer1994Ingår i: IEEE Trans. Magn., Vol. 30, s. 1064-Artikel i tidskrift (Refereegranskat)
  • 333.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Hendriksen, PV
    Marup, S
    The magnetization of magnetic liquids containing amorphous Fe1-xCx particles1993Ingår i: J. Magn. Magn. Mat., Vol. 122, s. 125-Artikel i tidskrift (Refereegranskat)
  • 334.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Lundqvist, P
    Field induced anisotropy in a magnetic liquid1996Ingår i: J. Magn. Magn. Mat., Vol. 157, s. 599-Artikel i tidskrift (Refereegranskat)
  • 335.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Pedersen, MS
    Marup, S
    High field magnetization of magnetic liquids containing amorphous iron carbon particles1994Ingår i: J. Magn. Magn. Mat., Vol. 134, s. 25-Artikel i tidskrift (Refereegranskat)
  • 336.
    Johansson, C
    et al.
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Pedersen, MS
    Marup, S
    Magn, J
    Magnetic properties of magnetic liquids with iron-oxide particles - the influence of anisotropy interactions1997Ingår i: J. Magn. Magn. Mat., Vol. 173, s. 5-Artikel i tidskrift (Refereegranskat)
  • 337.
    Johansson, Christer
    et al.
    RISE, Swedish ICT, Acreo, Sensor Systems.
    Ahrentorp, Fredrik
    Metod och anordning för detektering av förändringar av magnetisk respons hos magnetiska partiklar försedda med yttre skikt i bärarvätska2002Patent (Övrig (populärvetenskap, debatt, mm))
  • 338.
    Johansson, Dongni
    et al.
    University of Gothenburg, Sweden.
    Ericsson, Anders
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Johansson, Anders
    Karolinska Institutet, Sweden.
    Medvedev, Alexander
    Uppsala University, Sweden.
    Nyholm, Dag
    Uppsala University, Sweden.
    Ohlsson, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Senek, Marina
    Uppsala University, Sweden.
    Spira, Jack
    Sensidose AB, Sweden.
    Thomas, Ilias
    Dalarna University, Sweden.
    Westin, Jerker
    Dalarna University, Sweden.
    Bergquist, Fredrik
    University of Gothenburg, Sweden.
    Individualization of levodopa treatment using a microtablet dispenser and ambulatory accelerometry2018Ingår i: CNS Neuroscience & Therapeutics, ISSN 1755-5930, E-ISSN 1755-5949, Vol. 24, nr 5, s. 439-447Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aim: This 4-week open-label observational study describes the effect of introducing a microtablet dose dispenser and adjusting doses based on objective free-living motor symptom monitoring in individuals with Parkinson's disease (PD). Methods: Twenty-eight outpatients with PD on stable levodopa treatment with dose intervals of ≤4 hour had their daytime doses of levodopa replaced with levodopa/carbidopa microtablets, 5/1.25 mg (LC-5) delivered from a dose dispenser device with programmable reminders. After 2 weeks, doses were adjusted based on ambulatory accelerometry and clinical monitoring. Results: Twenty-four participants completed the study per protocol. The daily levodopa dose was increased by 15% (112 mg, P < 0.001) from period 1 to 2, and the dose interval was reduced by 12% (22 minutes, P = 0.003). The treatment adherence to LC-5 was high in both periods. The MDS-UPDRS parts II and III, disease-specific quality of life (PDQ-8), wearing-off symptoms (WOQ-19), and nonmotor symptoms (NMS Quest) improved after dose titration, but the generic quality-of-life measure EQ-5D-5L did not. Blinded expert evaluation of accelerometry results demonstrated improvement in 60% of subjects and worsening in 25%. Conclusions: The introduction of a levodopa microtablet dispenser and accelerometry aided dose adjustments improve PD symptoms and quality of life in the short term.

  • 339.
    Johansson, Dongni
    et al.
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Ohlsson, Fredrik
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Krýsl, David
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Rydenhag, Bertil
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Czarnecki, Madeleine
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Gustafsson, Niclas
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Wipenmyr, Jan
    RISE - Research Institutes of Sweden, ICT, Acreo.
    McKelvey, Tomas
    Sahlgrenska University Hospital, Sweden.
    Malmgren, Kristina
    University of Gothenburg, Sweden; Sahlgrenska University Hospital, Sweden.
    Tonic-clonic seizure detection using accelerometry-based wearable sensors: A prospective, video-EEG controlled study2019Ingår i: Seizure, ISSN 1059-1311, E-ISSN 1532-2688, Vol. 65, s. 48-54Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: The aim of this prospective, video-electroencephalography (video-EEG) controlled study was to evaluate the performance of an accelerometry-based wearable system to detect tonic-clonic seizures (TCSs) and to investigate the accuracy of different seizure detection algorithms using separate training and test data sets. Methods: Seventy-five epilepsy surgery candidates undergoing video-EEG monitoring were included. The patients wore one three-axis accelerometer on each wrist during video-EEG. The accelerometer data was band-pass filtered and reduced using a movement threshold and mapped to a time-frequency feature space representation. Algorithms based on standard binary classifiers combined with a TCS specific event detection layer were developed and trained using the training set. Their performance was evaluated in terms of sensitivity and false positive (FP) rate using the test set. Results: Thirty-seven available TCSs in 11 patients were recorded and the data was divided into disjoint training (27 TCSs, three patients) and test (10 TCSs, eight patients) data sets. The classification algorithms evaluated were K-nearest-neighbors (KNN), random forest (RF) and a linear kernel support vector machine (SVM). For the TCSs detection performance of the three algorithms in the test set, the highest sensitivity was obtained for KNN (100% sensitivity, 0.05 FP/h) and the lowest FP rate was obtained for RF (90% sensitivity, 0.01 FP/h). Conclusions: The low FP rate enhances the clinical utility of the detection system for long-term reliable seizure monitoring. It also allows a possible implementation of an automated TCS detection in free-living environment, which could contribute to ascertain seizure frequency and thereby better seizure management.

  • 340. Johansson, S
    et al.
    Bjurshagen, S
    Canalias, C
    Pasiskevicius, V
    Laurell, F
     Koch, R
    RISE., Swedish ICT, Acreo.
    An all solid-state UV source based on a frequency quadrupled, passively Q-switched 946 nm laser2007Ingår i: Optics Express, ISSN 1094-4087, E-ISSN 1094-4087, Vol. 15, nr 2, s. 449-58Artikel i tidskrift (Refereegranskat)
  • 341.
    John, Wolfgang
    et al.
    Ericsson AB, Sweden.
    Marchetto, Guido
    Politecnico di Torino, Italy.
    Németh, Felician
    Budapest University of Technology and Economics, Hungary.
    Sköldström, Pontus
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Steinert, Rebecca
    RISE - Research Institutes of Sweden, ICT, SICS.
    Meirosu, Catalin
    Ericsson AB, Sweden.
    Papafili, Ioanna
    Hellenic Telecommunications Organization, Greece.
    Pentikousis, Kostas
    Travelping, Germany.
    Service provider DevOps2017Ingår i: IEEE Communications Magazine, ISSN 0163-6804, E-ISSN 1558-1896, Vol. 55, nr 1, s. 204-211, artikel-id 7823363Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Although there is consensus that software defined networking and network functions virtualization overhaul service provisioning and deployment, the community still lacks a definite answer on how carrier-grade operations praxis needs to evolve. This article presents what lies beyond the first evolutionary steps in network management, identifies the challenges in service verification, observability, and troubleshooting, and explains how to address them using our Service Provider DevOps (SP-DevOps) framework. We compendiously cover the entire process from design goals to tool realization and employ an elastic version of an industry-standard use case to show how on-the-fly verification, software-defined monitoring, and automated troubleshooting of services reduce the cost of fault management actions. We assess SP-DevOps with respect to key attributes of software-defined telecommunication infrastructures both qualitatively and quantitatively, and demonstrate that SP-DevOps paves the way toward carrier-grade operations and management in the network virtualization era.

  • 342.
    John, Wolfgang
    et al.
    Ericsson Research, Sweden.
    Moradi, Fernaz
    Ericsson Research, Sweden.
    Pechenot, Bertrand
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Sköldström, Pontus
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Meeting the observability challenges for VNFs in 5G systems2017Ingår i: Proceedings of the IM 2017 - 2017 IFIP/IEEE International Symposium on Integrated Network and Service Management, 2017, s. 1127-1130Konferensbidrag (Refereegranskat)
    Abstract [en]

    5G mobile communication systems will need to accommodate a variety of use-cases, resulting in a diverse set of requirements. To meet these requirements, 5G systems take advantage of modern virtualization possibilities offered by Network Function Virtualization (NFV), enabling deployment agility and dynamicity of virtualized network functions. With the transformation of telecom towards virtualized environments, advanced observability possibilities gain increasing importance as one of the essential prerequisites, especially for successful DevOps operations. However, deployment agility also puts specific requirements on monitoring solutions in order to adapt automatically and continuously to frequent changes in service deployments. In this short-paper, we establish and discuss essential properties of observability systems for virtual network functions in a 5G context. We take these properties as guiding design principles for our software-defined monitoring framework and outline how to evolve our existing components towards a flexible, scalable, and programmable observability solution for microservice-based NFV with features for increased manageability.

  • 343.
    Jonasson, Christian
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Benselfelt, Tobias
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ilver, Dag
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Olofsson, Linda
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Utvärdering av onlinesystem för tidig varning avfekal påverkan i råvattenBaserad på interferensmoduleradflödescytometr2015Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Projektet har utvärderat ny mätteknik för att man snabbare ska kunna upptäcka påverkan av fekalier på råvatten. E. coli har använts som indikatorbakterie. Det använda instrumentet har stor potential att mäta halten E.colii råvatten online, och lämpar sig därför bra som ett tidigt varningssystem.Online-mätning av råvattenkvaliteten kan förhindra vattenburen smitta,något som är intressant för både dricksvattenproducenter och samhället istort.Metoden baseras på att bakterier märks med antikroppar som har fluorescenstaggats med en molekyl som gör att de efter bestrålning sänder utkortvarigt ljus. Ett optiskt instrument har utvecklats för att räkna enstakabakterier i ett provflöde. Mätsystemet har konstruerats för att dels matchaen industriell miljö, dels hålla nere kostnaden för att göra instrumentet ekonomiskt rimligt för aktörer inom dricksvattenproduktionDe fluorescerande markörerna skickar ut ljus som uppfångas av en detektor. Ursprungligen valdes markörerna för att skicka ut ljus i det synliga området. Men det visade sig att bakgrundsfluorescensen i det synliga området varhög, från klorofyll i alger och cyanobakterier. Därför beslutade projektgruppen att i stället välja markörer som fluorescerade i nära infraröda våglängder.Bytet av våglängdsområde löste problemen med bakgrundsfluorescens ochär ett avgörande steg mot ett fungerande instrument. Men anpassningen avoptiken för det nya våglängdsområdet medförde nya utmaningar, särskilt pådetektorsidan.Fälttester som genomfördes på Överby Vattenverk i Trollhättan visade attinstrumentet fungerar bra i den industriella miljön, och man kunde kopplain det mot en råvattenledning. Mätningar utförda i labb på råvatten ochrenat avloppsvatten visade på tydliga skillnader i koncentrationen av E. coli,men i de flesta fall var den uppmätta halten lägre än förväntat.Den kanske största begränsningen med den nya mättekniken är att få entillräckligt hög genomströmning av vattenprov i instrumentet. Detta är viktigt för att få en bra uppskattning av koncentrationen E. coli inom rimlig tid(minuter). Man kan öka genomflödet genom att öka dimensionen hos denoptiska flödeskanalen. Nackdelen är att känsligheten minskar. I en störreflödeskanal tittar man på ett större område och signalen från en enstakabakterie gentemot bakgrunden blir mindre. Här finns en viktig avvägningför framtida utveckling.Projektet har letts av Trollhättan Energi i samarbete med Göteborgs stad,Norrvatten, Vivab och DRICKS-programmet på Chalmers. Större delen avutvecklingsarbetet har utförts av Acreo Swedish ICT. Projektet har ingåttsom en del i ett större Vinnovafinansierat projekt inom utmaningsdriveninnovation med titeln Online sensorsystem för resurseffektiv vattenhantering (SENSATION) som avslutades 2014 och var fokuserat på en helhetslösning för mätning av vattenkvalitet.

  • 344.
    Jonasson, Christian
    et al.
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Schaller, Vincent
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Zeng, Lunjie
    Chalmers University of Technology, Sweden.
    Olsson, Eva
    Chalmers University of Technology, Sweden.
    Frandsen, Cathrine
    DTU Technical University of Denmark, Denmark.
    Castro, Alejandra
    Solve AB, Sweden.
    Nilsson, Lars
    Solve AB, Sweden.
    Bogart, Lara
    University College London, UK.
    Southern, Paul
    University College London, UK.
    Pankhurst, Quentin
    University College London, UK.
    Morales, Puerto
    Institute of Material Science of Madrid, Spain.
    Johansson, Christer
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Modelling the effect of different core sizes and magnetic interactions inside magnetic nanoparticles on hyperthermia performance2018Ingår i: Journal of Magnetism and Magnetic Materials, ISSN 0304-8853, E-ISSN 1873-4766, Vol. 477, s. 198-202Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We present experimental intrinsic loss power (ILP) values, measured at an excitation frequency of 1 MHz and at relatively low field amplitudes of 3.4 to 9.9 kA/m, as a function of the mean core diameter, for selected magnetic nanoparticle (MNP). The mean core sizes ranged from ca. 8 nm to 31 nm. Transmission electron microscopy indicated that those with smaller core sizes (less than ca. 22 nm) were single-core MNPs, while those with larger core sizes (ca. 29 nm to 31 nm) were multi-core MNPs. The ILP data showed a peak at ca. 20 nm. We show here that this behaviour correlates well with the predicted ILP values obtained using either a non-interacting Debye model, or via dynamic Monte-Carlo simulations, the latter including core-core magnetic interactions for the multi-core particles. This alignment of the models is a consequence of the low field amplitudes used. We also present interesting results showing that the core-core interactions affect the ILP value differently depending on the mean core size.

  • 345.
    Jonsson, Per
    et al.
    FOI Swedish Defence Reasearch Agency, Sweden.
    Lindgren, David
    FOI Swedish Defence Reasearch Agency, Sweden.
    Asplund, Mailn
    Tekniska verken i Linköping AB, Sweden.
    Stavjklint, Helenea
    Tekniska verken i Linköping AB, Sweden.
    Magounakis, Malin
    Tekniska verken i Linköping AB, Sweden.
    Mokhlesi, Saeed
    Chalmers University of Technology, Sweden.
    Pettersson, Thomas
    Chalmers University of Technology, Sweden.
    Winquist, Fredrik
    Linköping University, Sweden.
    Eriksson, Mats
    Linköping University, Sweden.
    Jonasson, Christian
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Ilver, Dag
    RISE - Research Institutes of Sweden, ICT, Acreo.
    Strömbeck, Niclas
    Luode Consulting Oy, Sweden.
    Svenskt Vatten UtvecklingElektronisk tunga och andra onlinesensorer för detektion av föroreningar i dricksvattennätet – en utvärdering2018Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Projektet har utvärderat olika onlinesensorer för att upptäcka föroreningar från avloppsvatten i dricksvattennätet. Flera kommersiella sensorer kunde detektera inläckage vid koncentrationer av avloppsvatten på cirka 0,7 procent, men bäst var den nyutvecklade sensor som kallas elektronisk tunga. Den kunde med låg sannolikhet för falsklarm detektera ner till åtminstone 0,05 procent avloppsvatten. Vanliga problem som kan ge upphov till smitta via dricksvatten är gamla och läckande ledningsnät som ger tryckfall, eller felaktiga kopplingar som gör att ytvatten och avloppsvatten kan förorena dricksvattnet. Risken för inläckage av avloppsvatten ansågs i projektet vara det högst prioriterade scenariot. Med ett nätverk av sensorer i dricksvattennätet och ett effektivt övervakningssystem skulle man kunna upptäcka och lokalisera föroreningskällan och ingripa med nödvändiga åtgärder innan det förorenade vattnet når kunderna.

    Projektet utfördes av Tekniska verken i Linköping i samverkan med Totalförsvarets forskningsinstitut (FOI) och ett stort antal andra aktörer. I en referensgrupp ingick ett antal svenska dricksvattenproducenter som ställde upp viktiga kriterier för onlinesensorer i dricksvattennätet. Sensorerna ska vara billiga, robusta, driftsäkra, anpassade för driftmiljön och kräva lite underhåll. De ska inte behöva förbehandling eller reagenser och bör helst mäta direkt på det trycksatta nätet. De bör helst vara generella, det vill säga upptäcka alla typer av föroreningar, men det är ett stort mervärde om de kan klassificera typen av förorening. Den elektroniska tungan har vidareutvecklats inom Vinnovaprojektet Sensation III. Även de nya sensorerna flödescytometer och elektronisk näsa testades i projektet, liksom standardsensorer för konduktivitet, pH och kloröverskott, samt en avancerad sensor baserad på optisk absorbans. Testerna skedde i en rigg på avloppsreningsverket i Linköping under ett par månader då olika koncentrationer av avloppsvatten tillfördes. Även syntetiskt avloppsvatten och råvatten tillfördes vid några tillfällen. Två elektroniska tungor testades även vid en tryckstegringsstation respektive vid vattentornet under cirka ett år. Olika typer av signalbehandling undersöktes för att optimera larmalgoritmerna.

    Resultaten visar att det är möjligt att upptäcka inläckage av avloppsvatten i dricksvattnet med hjälp av onlinesensorer. Även standardsensorer för konduktivitet och pH kunde detektera inläckage av avloppsvatten, men bäst resultat gav den elektroniska tungan. Sensorn för optisk absorbans hade en detektionsgräns mellan den elektroniska tungan och standardsensorerna. I anläggningar med större utspädning av avloppsvattnet än i Linköping kommer sensorerna förmodligen att ha en högre detektionsgräns.

    För att det ska bli möjligt att övervaka dricksvattenkvaliteten med hjälp av onlinesensorer krävs det nära samverkan mellan sensortillverkare, dricksvattenproducenter och -distributörer, eftersom det behövs fortsatta tester och är så svårt att kravställa och bestämma prestandan för sensorerna för alla tänkbara vatten.

  • 346. Junique, S
    et al.
    Agren, D
    Wang, Q
    RISE., Swedish ICT, Acreo.
    Almqvist, S
    Noharet, B
    Andersson, J
    RISE., Swedish ICT, Viktoria.
    A Modulating Retro-Reflector for Free-Space Optical Communication2006Ingår i: IEEE Photonics Technology Letters, ISSN 1041-1135, E-ISSN 1941-0174, Vol. 18, nr 1, s. 85-87Artikel i tidskrift (Refereegranskat)
  • 347. Junique, S
    et al.
    Wang, Q
    RISE., Swedish ICT, Acreo.
    Almqvist, S
    Guo, J
    Martijn, H
    Noharet, B
    Andersson, JY
    RISE., Swedish ICT, Viktoria.
    GaAs-based multiple-quantum-well spatial light modulators fabricated by a wafer-scale process2005Ingår i: Applied Optics, ISSN 1559-128X, E-ISSN 2155-3165, Vol. 44, nr 9, s. 1635-41Artikel i tidskrift (Refereegranskat)
  • 348. Juszczyk, S
    et al.
    Johansson, C
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Gogolowicz, M
    Noncollinear spin structure in Zn0.825Cu0.175Cr2Se41994Ingår i: Physics Letters A, Vol. 192, s. 429-Artikel i tidskrift (Refereegranskat)
  • 349. Juszczyk, S
    et al.
    Johansson, C
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Malecki, G
    Magnetic properties of Cr2[Ni2(CN)4]31994Ingår i: J. Magn. Magn. Mat., Vol. 136, s. 45-Artikel i tidskrift (Refereegranskat)
  • 350. Juszczyk, S
    et al.
    Johansson, C
    RISE., Swedish ICT, Acreo.
    Hanson, M
    Ratuszna, A
    Malecki, G
    Structural magnetic properties of Me2[Fe(CN)6] compounds, where Me are 3d transition metals1994Ingår i: J. Magn. Magn. Mat., Vol. 138, s. 281-Artikel i tidskrift (Refereegranskat)
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