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  • 18101.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Mchedlidze, T.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Utsumi, A.
    Furukawa, Y.
    Moon, S.
    Wakahara, A.
    Yonezu, H.
    Effect of nitrogen ion bombardment on defect formation and luminescence efficiency of GaNP epilayers grown by molecular-beam epitaxy2006In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 88, no 10, p. 101904-Article in journal (Refereed)
    Abstract [en]

    Radiative efficiency of GaNP epilayers grown on GaP substrates by solid-source molecular beam epitaxy is significantly improved by reduced nitrogen ion bombardment during the growth. Based on the results of temperature-dependent photoluminescence (PL) and optically detected magnetic resonance studies (ODMR), the observed improvements are attributed to reduced formation of defects, such as a Ga interstitial related defect and an unidentified defect revealed by ODMR. We demonstrate that these defects act as competing recombination centers, which promote thermal quenching of the PL intensity and result in a substantial (34×) decrease in room-temperature PL intensity. © 2006 American Institute of Physics.

  • 18102.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Utsumi, A.
    Furukawa, Y.
    Wakahara, A.
    Yonezu, H.
    Formation of grown-in defects in molecular beam epitaxial Ga(In)NP: effects of growth conditions and post-growth treatments2008In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 103, p. 063519-Article in journal (Refereed)
    Abstract [en]

    Effects of growth conditions and post-growth treatments, such as presence of N ions, N2 flow, growth temperature, In alloying, and postgrowth rapid thermal annealing (RTA), on formation of grown-in defects in Ga(In)NP prepared by molecular beam epitaxy are studied in detail by the optically detected magnetic resonance (ODMR) technique. Several common residual defects, such as two Ga-interstitial defects (i.e., Gai-A and Gai-B) and two unidentified defects with a g factor around 2 (denoted by S1 and S2), are closely monitored. Bombardment of impinging N ions on grown sample surface is found to facilitate formation of these defects. Higher N2 flow is shown to have an even more profound effect than a higher number of ions in introducing these defects. Incorporation of a small amount of In (e.g., 5.1%) in GaNP seems to play a minor role in the formation of the defects. In GaInNP with 45% of In; however, the defects were found to be abundant. Effect of RTA on the defects is found to depend on initial configurations of Gai-related defects formed during the growth. In the alloys where the Gai-A and Gai-B defects are absent in the as-grown samples (i.e., GaNP grown at a low temperature of 460 °C), the concentrations of the two Gai defects are found to increase after postgrowth RTA. This indicates that the defects originally introduced in the as-grown alloys have been transformed into the more thermally stable Gai-A and Gai-B during RTA. On the other hand, when the Gai-A and Gai-B are readily abundant (e.g., at higher growth temperatures (>=500 °C), RTA leads to a slight reduction of the Gai-A and Gai-B ODMR signals. The S2 defect is also shown to be thermally stable upon the RTA treatment.

  • 18103.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Effect of hydrogen on defects in dilute nitride2013In: Hydrogenated dilute nitride semiconductors: theory, properties, applications / [ed] G. Ciatto, Pan Stanford Publishing, 2013, p. 75-98Chapter in book (Other academic)
  • 18104.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Huang, Yuqing
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Tu, C. W.
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California, USA .
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Japan .
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Dual-wavelength excited photoluminescence spectroscopy of deep-level hole traps in Ga(In)NP2015In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 117, p. 015701-Article in journal (Refereed)
    Abstract [en]

    By employing photoluminescence(PL) spectroscopy under dual-wavelength optical excitation, we uncover the presence of deep-level hole traps in Ga(In)NP alloys grown by molecular beam epitaxy(MBE). The energy level positions of the traps are determined to be at 0.56 eV and 0.78 eV above the top of the valance band. We show that photo-excitation of the holes from the traps, by a secondary light source with a photonenergy below the bandgapenergy, can lead to a strong enhancement (up to 25%) of the PL emissions from the alloys under a primary optical excitation above the bandgapenergy. We further demonstrate that the same hole traps can be found in various MBE-grown Ga(In)NP alloys, regardless of their growth temperatures, chemical compositions, and strain. The extent of the PL enhancement induced by the hole de-trapping is shown to vary between different alloys, however, likely reflecting their different trap concentrations. The absence of theses traps in the GaNP alloy grown by vapor phase epitaxy suggests that their incorporation could be associated with a contaminant accompanied by the N plasma source employed in the MBEgrowth, possibly a Cu impurity.

  • 18105.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Puttisong, Yuttapoom
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Japan .
    Ptak, A. J.
    National Renewable Energy Laboratory, Golden, Colorado, USA.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Effects of substrate defects on photoluminescence of GaNP and GaNAs epitaxial layers: optically detected magnetic resonance study2012Conference paper (Other academic)
  • 18106.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Puustinen, J.
    Guina, M.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Study of grown-in defects in GaBiAs grown at low temperatures by molecular beam epitaxy2013In: : , 2013Conference paper (Other academic)
  • 18107.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Puustinen, J.
    Tampere University of Technology, Finland .
    Guina, M.
    Tampere University of Technology, Finland .
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Identification of an isolated arsenic antisite defect in GaAsBi2014In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 104, no 5, p. 052110-Article in journal (Refereed)
    Abstract [en]

    Optically detected magnetic resonance and photoluminescence spectroscopy are employed to study grown-in defects in GaAs0.985Bi0.015 epilayers grown by molecular beam epitaxy. The dominant paramagnetic defect is identified as an isolated arsenic antisite, As-Ga, with an electron g-factor of 2.03 +/- 0.01 and an isotropic hyperfine interaction constant A (900 +/- 620) x 10(-4) cm(-1). The defect is found to be preferably incorporated during the growth at the lowest growth temperature of 270 degrees C, but its formation can be suppressed upon increasing growth temperature to 315 degrees C. The As-Ga concentration is also reduced after post-growth rapid thermal annealing at 600 degrees C.

  • 18108.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Ren, Q. J.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Murayama, A.
    Graduate School of Information Science and Technology, Hokkaido University, Japan.
    Antiferromagnetic coupling in CdSe/ZnMnSe quantum dot structures2012In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 101, no 5, p. 052405-1-052405-Article in journal (Refereed)
    Abstract [en]

    Spin polarization of nonmagnetic CdSe quantum dots (QDs) coupled to adjacent ZnMnSe diluted magnetic semiconductor (DMS) is investigated by CW and time-resolved magneto-optical spectroscopy under tunable laser excitation. Efficient enhancement in the degree of σ circular polarization of photoluminescence from the CdSe QDs is observed under optical excitation at the σ+-active exciton state of the DMS. The fact that the enhancement persists much longer than the exciton lifetime of the DMS rules out a role of the DMS excitons. A possible explanation is discussed in terms of antiferromagnetic coupling between the excitons in QDs and aligned Mn ions in DMS.

  • 18109.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Ren, Q. J.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Furuta, T.
    Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan.
    Hyomi, K.
    Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan.
    Souma, I.
    Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan.
    Murayama, A.
    Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Evidence for interlayer magnetic coupling in coupled CdSe/ZnMnSe nanostructures2012Conference paper (Other academic)
  • 18110.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Stehr, Jan E.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Yu Egorov, A
    St Petersburg Academic University, Russia .
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Optically detected magnetic resonance studies of point defects in quaternary GaNAsP epilayers grown by vapor phase epitaxy2013In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 102, no 2, p. 021910-Article in journal (Refereed)
    Abstract [en]

    Defect properties of quaternary GaNAsP/GaP epilayers grown by vapor phase epitaxy (VPE) are studied by photoluminescence and optically detected magnetic resonance techniques. Incorporation of more than 0.6% of nitrogen is found to facilitate formation of several paramagnetic defects which act as competing carrier recombination centers. One of the defects (labeled as Ga-i-D) is identified as a complex defect that has a Ga interstitial (Ga-i) atom residing inside a Ga tetrahedron as its core. A comparison of Ga-i-D with other Ga-i-related defects known in ternary GaNP and GaNAs alloys suggests that this defect configuration is specific to VPE-grown dilute nitrides.

  • 18111.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Tu, C. W.
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California, USA .
    Polimeni, A.
    INFM and Dipartimento di Fisica, Università di Roma “La Sapienza”, Roma, Italy.
    Capizzi, M.
    INFM and Dipartimento di Fisica, Università di Roma “La Sapienza,” Roma, Italy .
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Effect of thermal annealing on defects in post-growth hydrogenated GaNP2013In: Physica Status Solidi. C, Current topics in solid state physics, ISSN 1610-1634, E-ISSN 1610-1642, Vol. 10, no 4, p. 561-563Article in journal (Refereed)
    Abstract [en]

    Effect of thermal annealing on paramagnetic centers in post-growth hydrogenated GaN0.0081P0.9919 epilayer is examined by means of photoluminescence and optically detected magnetic resonance (ODMR) techniques. In recent studies, several Ga-interstitial (Gai) related centers were found to be activated by the presence of hydrogen in the hydrogenated GaNP alloys. These centers compete with near-band edge radiative recombination. Annealing at 400 ºC in Ar-ambient is found to cause quenching of the Gai-related ODMR signals that were activated by post-growth hydrogenation. We tentatively ascribe this effect to dissociation of the H-Gai complexes and subsequent out-diffusion of H.

  • 18112.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Vorona, I. P
    Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine.
    Vlasenko, L. S.
    A. F. Ioffe Physico-Technical Institute, St. Petersburg, Russia.
    Wang, X. J.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Utsumi, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Furukawa, Y.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Wakahara, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Buyanova, I. A.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, Faculty of Science & Engineering.
    Chen, W. M.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, Faculty of Science & Engineering.
    Evidence for a phosphorus-related interfacial defect complex at a GaP/GaNP heterojunction2010In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 81, p. 115334-Article in journal (Refereed)
    Abstract [en]

    Optically detected magnetic resonance (ODMR) studies of molecular beam epitaxial GaNP/GaP structures reveal presence of a P-related complex defect, evident from its resolved hyperfine interaction between an unpaired electronic spin (S=1/2) and a nuclear spin (I = ½) of a 31P atom. The principal axis of the defect is concluded to be along a <111> crystallographic direction from angular dependence of the ODMR spectrum, restricting the P atom (either a PGa antisite or a Pi interstitial) and its partner in the complex defect to be oriented along this direction. The principal values of the electronic g-tensor and hyperfine interaction tensor are determined as: g=2.013, g=2.002, and A=130´10-4 cm-1, A=330´10-4 cm-1, respectively. The interface nature of the defect is clearly manifested by the absence of the ODMR lines originating from two out of four equivalent <111> orientations. Defect formation is shown to be facilitated by nitrogen ion bombardment under non-equilibrium growth conditions and the defect is thermally stable upon post-growth thermal annealing.

  • 18113.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Vorona, Igor P
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Vlasenko, Leonid S
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Wang, Xingjun
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Utsumi, A
    University of Technology, Toyohashi, Aichi, Japan.
    Furukawa, Y
    University of Technology, Toyohashi, Aichi, Japan.
    Wakahara, A
    University of Technology, Toyohashi, Aichi, Japan.
    Yonezu, H
    University of Technology, Toyohashi, Aichi, Japan.
    Buyanova, Irina A
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Phosphorus-related interfacial defect complex at a GaP/GaNP heterojunction2010Conference paper (Other academic)
    Abstract [en]

    For full exploration of dilute nitrides in device applications, a better understanding and control of defects located at interfaces involving e.g. Ga(In)NP are required. In this work we report on the first identification of a point defect situated at an interface between two semiconductors: GaNP and GaP. The defect is concluded to be a complex involving a P antisite or a P interstitial in its core, partnered with a neighboring impurity/defect aligned along a <111> direction, from detailed angular dependence studies of the optically detected magnetic resonance (ODMR) spectra at both X- and Q-band microwave frequencies. The principal g and A values, g=2.013, g=2.002, A=130x10-4 cm-1 and A=330x10-4 cm-1, are obtained from a spin Hamiltonian analysis. The interface nature of the defect is clearly evident from the absence of the ODMR lines originating from two out of four equivalent <111> orientations. Defect formation is shown to be facilitated by severe nitrogen ion bombardment under non-equilibrium growth conditions during solid-source molecular beam epitaxy and the defect is thermally stable upon post-growth thermal annealing.

  • 18114.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Vorona, Igor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Wang, X
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials.
    Geelhaar, L.
    Infineon Technologies, Corporate Research, Munich, Germany .
    Riechert, H.
    Infineon Technologies, Corporate Research, Munich, Germany .
    Optically detected cyclotron resonance studies of InGaNAs/GaAs structures2007In: Physics of semiconductors : 28th International Conference on the Physics of Semiconductors, ICPS 2006, Vienna, Austria, 24-28 July 2006, American Institute of Physics (AIP), 2007, p. 383-384Conference paper (Other academic)
    Abstract [en]

    We report on our recent results from a systematic study of layered structures containing an InGaNAs/GaAs quantum well (QW), by the optically detected cyclotron resonance (ODCR) technique. By monitoring photoluminescence (PL) emissions from various layers the predominant ODCR peak is shown to be related to carriers with a 2D character and an effective mass of 0.51 me. The responsible carriers are ascribed to be electrons in GaAs/AlAs superlattices (SL) that are employed in the laser structures to prevent carrier leak by sandwiching the InGaNAs/GaAs QW. This conclusion is based on the following observations: (a) the ODCR peak is only observed in the structures containing the SL; (b) the effective mass value determined by the ODCR peak is independent of In and N compositions; (c) the same ODCR peak is also observed by monitoring PL from the SL. Unfortunately no ODCR signal related to InGaNAs was observed

  • 18115.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Vorona, Igor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Geelhaar, L.
    Riechert, H.
    Optically detected cyclotron resonance studies of InxGa1-xNyAs1-y/GaAs quantum wells sandwiched between type-II AlAs/GaAs superlattices.2007In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 101, p. 073705-Article in journal (Refereed)
    Abstract [en]

      We report on our results from a systematic study of layered structures containing an InGaNAs/GaAs single quantum well (SQW) enclosed between staggered type II AlAs/GaAs superlattices (SL), by the photoluminescence (PL) and optically detected cyclotron resonance (ODCR) techniques. Besides the ODCR signal known to originate from electrons in GaAs, the predominant ODCR peak is shown to be related to carriers with a two-dimensional character and a cyclotron resonance effective mass of m*[approximate](0.51-0.56)m0. The responsible carriers are ascribed to electrons on the ellipsoidal equienergy surface at the AlAs X point of the Brillouin zone within the SL, based on results from angular and spectral dependences of the ODCR signal. No ODCR signal related to the InGaNAs SQW was detected, presumably due to low carrier mobility despite the high optical quality. Multiple absorption of photons with energy below the band gap energy of the SL and the GaAs barriers was observed, which bears implication on the efficiency of light-emitting devices based on these structures.

  • 18116.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Vorona, I.P.
    Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine .
    Nosenko, G.
    Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev 03028, Ukraine .
    Wang, X. J.
    National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, China .
    Tu, C. W.
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California, USA .
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Japan .
    Polimeni, A.
    INFM and Dipartimento di Fisica, Università di Roma “La Sapienza”, Roma, Italy.
    Capizzi, M.
    INFM and Dipartimento di Fisica, Università di Roma “La Sapienza”, Piazzale A. Moro 2, I-00185 Roma, Italy .
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    An optically detected magnetic resonance study of effects of hydrogenation on non-radiative defects in GaNP and GaNAs alloys2012Conference paper (Other academic)
  • 18117.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Vorona, I.P.
    Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine .
    Nosenko, G.
    Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Kiev, Ukraine .
    Wang, X. J.
    National Laboratory for Infrared Physics, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, China .
    Tu, C. W.
    Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, California, USA .
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Japan .
    Polimeni, A.
    INFM and Dipartimento di Fisica, Università di Roma “La Sapienza”, Roma, Italy.
    Capizzi, M.
    INFM and Dipartimento di Fisica, Universita` di Roma “La Sapienza”, Piazzale A. Moro 2,.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Effects of hydrogenation on non-radiative defects in GaNP and GaNAs alloys: An optically detected magnetic resonance study2012In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 111, no 023501Article in journal (Refereed)
    Abstract [en]

    Photoluminescence and optically detected magnetic resonance techniques are utilized to study defect properties of GaNP and GaNAs alloys subjected to post-growth hydrogenation by low-energy sub-threshold ion beam irradiation. It is found that in GaNP H incorporation leads to activation of new defects, which has a Ga interstitial (Ga-i) atom at its core and may also involve a H atom as a partner. The observed activation critically depends on the presence of N in the alloy, as it does not occur in GaP with a low level of N doping. In sharp contrast, in GaNAs hydrogen is found to efficiently passivate Ga-i-related defects present in the as-grown material. A possible mechanism responsible for the observed difference in the H behavior in GaNP and GaNAs is discussed.

  • 18118.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Wang, X. J.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Tu, C. W.
    Department of Electrical and Computer Engineering, University of California, La Jolla, California 92093, USA.
    Polimeni, A.
    INFM and Dipartimento di Fisica,Università di Roma “La Sapienza”, Piazzale A. Moro 2, I-00185 Roma, Italy.
    Capizzi, M.
    INFM and Dipartimento di Fisica,Università di Roma “La Sapienza”, Piazzale A. Moro 2, I-00185 Roma, Italy.
    Buyanova, I. A
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Activation of defects in GaNP by post-growth hydrogen treatmentManuscript (preprint) (Other academic)
    Abstract [en]

    Effect of post-growth hydrogen treatment on defects and their role in carrier recombination in molecular beam epitaxial GaNP alloys is examined by means of photoluminescence and optically detected magnetic resonance. We present direct experimental evidence for effective activation of several different defects in carrier recombination by the hydrogen treatment. Among them, two defect complexes are identified to contain a Ga interstitial (Gai). None of the activated Gai complexes was previously observed in GaNP. Possible mechanisms for the hydrogen-induced defect activation are discussed.

  • 18119.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Utsumi, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Furukawa, Y.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Wakahara, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Effect of growth conditions on grown-in defect formation and luminescence efficiency in GaInNP epilayers grown by molecular-beam epitaxy.2008In: Physica status solidi (c)Special Issue: E-MRS 2007 Spring Meeting – Symposium F and Conference on Photonic Materials, Weinheim: Wiley-VCH Verlagsgesellschaft, 2008, Vol. 5, p. 460-463Conference paper (Refereed)
    Abstract [en]

    A detailed study of the impact of different growth conditions (i.e. ion bombardment, nitrogen flow and In content) on the defect formation in Ga(In)NP epilayers grown on GaP substrates by solid-source molecular beam epitaxy is performed. Reduced nitrogen ion bombardment during the growth is shown to significantly reduce formation of defects acting as competing recombination centers, such as a Ga interstitial defect and other unidentified defects revealed by optically detected magnetic resonance. Further, high nitrogen flow is found to be even more effective than the ion bombardment in introducing the defects. The incorporation of In by 5.1% is, on the other hand, found not to affect the introduction of defects. The results provide a useful insight into the formation mechanism of the defects that will hopefully shed light on a control of the defect introduction in the alloys by optimizing growth conditions.

  • 18120.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Wang, Xingjun
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Tu, C W
    University of California San Diego.
    Polimeni, A
    University Roma La Sapienza.
    Capizzi, M
    University Roma La Sapienza.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Buyanova, Irina
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Effect of postgrowth hydrogen treatment on defects in GaNP2011In: APPLIED PHYSICS LETTERS, ISSN 0003-6951, Vol. 98, no 14, p. 141920-Article in journal (Refereed)
    Abstract [en]

    Effect of postgrowth hydrogen treatment on defects and their role in carrier recombination in GaNP alloys is examined by photoluminescence (PL) and optically detected magnetic resonance. We present direct experimental evidence for effective activation of several defects by low-energy subthreshold hydrogen treatment (andlt;= 100 eV H ions). Among them, two defect complexes are identified to contain a Ga interstitial. Possible mechanisms for the H-induced defect activation and creation are discussed. Carrier recombination via these defects is shown to efficiently compete with the near band-edge PL, explaining the observed degraded optical quality of the alloys after the H treatment.

  • 18121.
    Dagnelund, Daniel
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Wang, Xingjun
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Tu, C.W.
    University of California.
    Polimeni, A.
    University Roma La Sapienza.
    Capizzi, M.
    University Roma La Sapienza.
    Buyanova, Irina A
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Chen, Weimin
    Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials. Linköping University, The Institute of Technology.
    Activation of defects in GaNP by low-energy hydrogen treatment2011In: Abstract book of the 9th Int. Conf. on Nitride Semiconductors, Glasgow, UK, 2011, p. PC3.36-Conference paper (Other academic)
  • 18122.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Vorona, Igor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Utsumi, A.
    Furukawa, Y.
    Moon, S.
    Wakahara, A.
    Yonezu, H.
    Critical issue of defects in Ga(In)NP alloys: a new and promising material system for integration of III-V-based optoelectronics with Si-based microelectronics.2007In: 31th Workshop on Compound Semiconductor Devices and Integrated Circuits WOCSDICE 2007,2007, 2007, p. 149-151Conference paper (Other academic)
  • 18123.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Vorona, Igor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Utsumi, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Furukawa, Y.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Moon, S.
    Wakahara, A.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Yonezu, H.
    Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Toyohashi, Aichi, Japan.
    Effect of growth conditions on grown-in defects in Ga(In)NP alloys2007Conference paper (Other academic)
  • 18124.
    Dagnelund, Daniel
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Wang, Xingjun
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Vorona, Igor
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Buyanova, Irina
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Chen, Weimin
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Functional Electronic Materials.
    Utsumi, A.
    Furukawa, Y.
    Moon, S.
    Wakahara, A.
    Yonezu, H.
    Spin resonance spectroscopy of grown-in defects in Ga(In)NP alloys2008In: 7th International Conference on Physics of Light-Matter Coupling in Nanostructures, 2007, Elsevier Ltd. , 2008, p. 620-625Conference paper (Refereed)
    Abstract [en]

    We employ the optically detected magnetic resonance (ODMR) technique to study and identify important grown-in defects in Ga(In)NP grown by molecular-beam epitaxy (MBE). Several types of defects were revealed from ODMR studies. The dominant defects were found to be related to Ga interstitials, evident form their characteristic hyperfine interaction arising from the spin interaction between the electron and the Ga nucleus. Some other as yet unidentified intrinsic defects were also found to be commonly present in the alloys. The effects of growth conditions (ion bombardment, N2 gas flow, etc.) and post-growth rapid thermal annealing on the formation of these defects were studied in detail, shedding light on the formation mechanism of defects.

  • 18125.
    Dagson, Josef
    et al.
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Nissilä Källström, Samuel
    Linköping University, Department of Electrical Engineering, Vehicular Systems. Linköping University, The Institute of Technology.
    Air Leakage Diagnosis in Heavy Duty Truck Engines with EGR and VGT2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Scania CV AB is a leading company within development and production of buses, trucks as well as industrial and marine engines.

    New environmental and safety legislations continuously demand higher quality from the products. An upcoming European legislation, Euro 6, implies that gas leakages from truck engines should be detected while driving. If the source of the leakage is not only detected, but also isolated, that is separated from other faults, the adjustments in the workshop goes faster since there is no need for leakage localisation. A faster reparation increases the up-time, i.e. the amount of time that the truck can be used.

    This master thesis work uses current methods developed at Scania for residual generation to perform model-based leakage diagnosis. In this work, measurements are gathered for dierent sensor faults and two leakages. The measurements are used to evaluate the actual performance of the resulting diagnosis system.

    The result, based on the residuals generated by the method, shows that leakages on the boost-side and the exhaust-side can be detected, and isolated from faults in the pressure sensors on the boost-side and the exhaust-side. The isolation of these four faults is considered the hardest to achieve among sensor faults and leakages why the full isolation performance is promising. Further measurements are needed to determine the full isolation performance of the diagnosis system.

    The resulting system is reasoned to be suitable for execution in real time on-board the truck.

  • 18126.
    Dagöö, Jesper
    et al.
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Persson Asplund, Robert
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Andersson Bsenko, Helene
    Umeå University, Sweden .
    Hjerling, Sofia
    Uppsala University, Sweden .
    Holmberg, Anna
    Mid Sweden University, Sweden .
    Westh, Susanne
    Mid Sweden University, Sweden .
    Oberg, Louise
    Lund University, Sweden .
    Ljotsson, Brjann
    Karolinska Institute, Sweden .
    Carlbring, Per
    Stockholm University, Sweden .
    Furmark, Tomas
    Uppsala University, Sweden .
    Andersson, Gerhard
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Cognitive behavior therapy versus interpersonal psychotherapy for social anxiety disorder delivered via smartphone and computer: A randomized controlled trial2014In: Journal of Anxiety Disorders, ISSN 0887-6185, E-ISSN 1873-7897, Vol. 28, no 4, p. 410-417Article in journal (Refereed)
    Abstract [en]

    In this study, a previously evaluated guided Internet-based cognitive behavior therapy for social anxiety disorder (SAD) was adapted for mobile phone administration (mCBT). The treatment was compared with a guided self-help treatment based on interpersonal psychotherapy (mIPT). The treatment platform could be accessed through smartphones, tablet computers, and standard computers. A total of 52 participants were diagnosed with SAD and randomized to either mCBT (n = 27) or mIPT (n = 25). Measures were collected at pre-treatment, during the treatment, post-treatment and 3-month follow-up. On the primary outcome measure, the Liebowitz Social Anxiety Scale - self-rated, both groups showed statistically significant improvements. However, mCBT performed significantly better than mIPT (between group Cohens d = 0.64 in favor of mCBT). A larger proportion of the mCBT group was classified as responders at post-treatment (55.6% versus 8.0% in the mIPT group). We conclude that CBT for SAD can be delivered using modern information technology. IPT delivered as a guided self-help treatment may be less effective in this format.

  • 18127. Dahl, Andreas
    et al.
    Gharibi, Arash
    Swietlicki, Erik
    Gudmundsson, Anders
    Bohgard, Mats
    Ljungman, Anders
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Occupational and Environmental Medicine.
    Blomqvist, Göran
    Gustafsson, Mats
    Traffic-generated emissions of ultrafine particles from pavement-tire interface2006In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 40, no 7, p. 1314-1323Article in journal (Refereed)
    Abstract [en]

    In a road simulator study, a significant source of sub-micrometer fine particles produced by the road-tire interface was observed. Since the particle size distribution and source strength is dependent on the type of tire used, it is likely that these particles largely originate from the tires, and not the road pavement. The particles consisted most likely of mineral oils from the softening filler and fragments of the carbon-reinforcing filler material (soot agglomerates). This identification was based on transmission electron microscopy studies of collected ultrafine wear particles and on-line thermal treatment using a thermodesorber. The mean particle number diameters were between 15-50 nm, similar to those found in light duty vehicle (LDV) tail-pipe exhaust. A simple box model approach was used to estimate emission factors in the size interval 15-700 nm. The emission factors increased with increasing vehicle speed, and varied between 3.7×1011 and 3.2×10 12 particles vehicle-1 km-1 at speeds of 50 and 70 km h-1. This corresponds to between 0.1-1% of tail-pipe emissions in real-world emission studies at similar speeds from a fleet of LDV with 95% gasoline and 5% diesel-fueled cars. The emission factors for particles originating from the road-tire interface were, however, similar in magnitude to particle number emission factors from liquefied petroleum gas-powered vehicles derived in test bench studies in Australia 2005. Thus the road-tire interface may be a significant contributor to particle emissions from ultraclean vehicles. © 2005 Elsevier Ltd. All rights reserved.

  • 18128. Dahl, Christian
    et al.
    Kjölhede, Preben
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Obstetrics and gynecology. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Gynecology and Obstetrics in Linköping.
    Obstetric anal sphincter rupture in older primiparous women: A case-control study2006In: Acta Obstetricia et Gynecologica Scandinavica, ISSN 0001-6349, E-ISSN 1600-0412, Vol. 85, no 10, p. 1252-1258Article in journal (Refereed)
    Abstract [en]

    Objective. To determine if maternal age (35 years of age or older) in primiparous women is a risk factor for the development of obstetric anal sphincter rupture (OASR) and to identify obstetric factors associated with it. Material and methods. This is a retrospective case-control study. The study population was made up of the 5,345 primiparous women aged 24-45 years who delivered vaginally with singleton live-born neonates during 1990-99 at the Department of Obstetrics and Gynecology, Linköping University Hospital, Sweden. As cases the 327 primiparous women aged 35-45 years at delivery were selected. For each case two primiparous controls ten years younger were selected, matched for gestational age and year of delivery, in all 654 controls. Maternal, obstetrical, and neonatal data were obtained from the delivery records. Obstetric factors for the development of OASR were assessed with multivariate logistic regression analysis. Results. No significant association was found between the primiparous age category and OASR. Vacuum extraction, forceps delivery, and the head circumference of the neonate were found to be independent risk factors for OASR, while the use of mediolateral episiotomy or epidural analgesia were independent protective factors for developing OASR. Conclusions. Primiparous women, 35 years of age or older, do not seem to have a greater risk of OASR than younger primiparous women. Risk factors for OASR are instrumental vaginal delivery and the size of the neonate. Mediolateral episiotomy and epidural analgesia seem to reduce the risk for OASR. © 2006 Taylor & Francis.

  • 18129.
    Dahl, Christoffer
    Linköping University, Department of Management and Engineering, Commercial and Business Law.
    Skadestånd och Europakonventionen: Särskilt angående privaträttsliga subjekt på arbetsmarknaden2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Syftet med uppsatsen är att kritiskt diskutera vad fallet NJA 2015 s. 899 får för konsekvenserför den svenska skadeståndsrättsliga traditionen.Grunden för skadeståndsyrkandet i fallet var bland annat att fackförbundet genom blockadenhade kränkt byggföretagets rättigheter enligt Europakonventionen, närmare bestämtföreningsfriheten artikel 11 EKMR och skyddet för äganderätten artikel 1 i förstatilläggsprotokollet. Högsta domstolen tog upp fallet med mellandomstemat: Är SvenskaByggnads, om förbundets stridsåtgärder skulle vara oförenliga med artikel 11 iEuropakonventionen respektive artikel 1 i det första tilläggsprotokollet till konventionen, ioch för sig skyldigt att betala ersättning till Henrik Gustavsson för de skador somByggföretaget kan ha orsakats till följd av stridsåtgärderna? HD besvarande frågan nekandemen öppnade för att kvalificerat otillbörligt handlande, som slagits fast i NJA 2005 s. 608,kan göras gällande i vissa situationer.Vad HD hade att pröva i målet var om de i mellandomstemat förutsattakonventionskränkningarna i sig var tillräckliga för att utlösa ett skadeståndsansvar.Prövningen innefattade följaktligen inte frågan om några rättighetskränkningar faktisktförekommit, och inte heller frågan om Byggnads i detta specifika fall var skadeståndsskyldigt.Tre viktiga frågor som HD tog ställning till utöver mellandomstemat var följande:1. Om den grundlagsskyddade rätten för arbetsmarknadens parter att vidta stridsåtgärderenligt 2 kap. 14 § RF utgjorde ett generellt hinder mot ett skadeståndsansvar för stridsåtgärdersom kränker Europakonventionen.2. Om Byggnads i ansvarshänseende kunde jämställas med stat eller kommun alternativt omByggnads kunde åläggas ett skadeståndsansvar såsom enskild genom direkt horisontell effektav Europakonventionen.3. Om skadestånd kan utgå med en tillämpning av allmänna skadeståndsrättsliga principer.HD besvarade fråga 1 och 2 nekande tillsammans med mellandomstemat men fråga 3besvarades jakande. HD konstaterade att en kränkning av Europakonventionen i sig inte äriiitillräckligt för att utlösa skadeståndsansvar om inte det rättighetskränkande agerandet är attanse som kvalificerat otillbörligt. Avslutningsvis innehåller avgörandet många intressantainslag som talar för att HD bara har påbörjat utvecklingen inom detta mycket svårtillgängligaområde inom svensk skadeståndsrätt.

  • 18130.
    Dahl, Daniel
    et al.
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    Nordström, Michaela
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    Varumärkeskommunikation och positionering med en begränsad marknadsföringsbudget: Marknadsföring med små medel i ett bilpoolsföretag2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This Thesis deals with the two concepts branding and position, more precisely how companies with a small marketing budget needs to work with these two concepts. The purpose of this thesis is to understand how these companies are able to assert a position  on their specific market. The thesis treats theories and empirical data to be  able to answer the purposes of the thesis and for the authors to be able to give recommendations of how companies in this situation can improve their marketing strategies. To be able to give these recommendations a more in depth study had been made of a carsharing company, Sunfleet. This to be able to se how a specific company works with branding and positioning as well as what can be improved. The authors have given recommendations on how improvements can be done.

  • 18131.
    Dahl, Elin
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy companies becoming energy service providers: A comparative study between Denmark and Sweden2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Energy efficiency is important – but an energy saving potential has yet to reach its full range. Energy services are means to reach that potential and energy companies are stressed as important actors into creating an established market for energy services. Energy services are tools that include providing in-direct services such as energy statistics, audits, declarations, consultations and analysis. It also includes a number of more complex and direct services, for example energy efficiency measurements or service contracts.

    This report is a result of a study on Danish and Swedish energy companies offering energy services, based on the market they act upon. It aims to find their driving forces for providing energy services. It also looks closer into whether publically and privately owned energy companies differ and if there exist contradictions to both supply energy and energy services at the same time. It also looks into how energy companies are affected and feel about national regulatory instruments.

    Energy companies in both countries offering energy services are reaching a wide spectrum of client segments and energy services. They often have the possibility to combine and package energy supply with energy services and they can reduce many of the theoretical barriers to energy efficiency by offering energy services. They are driven by a client demand and a closer client relationship, both leading to a decreased supply client fluctuation. A new business opportunity and a green profile strategy are also driving factors. Energy services also help energy companies to decrease heavy investment on existing equipment by having more control over their clients’ energy use and reducing energy utilization tops.

    Danish energy companies are tied to an energy saving obligation scheme, providing them with conditions, which their market is based, whilst Swedish energy companies offering energy services act on a market that is created by them and their competitors derive from different business backgrounds. There exist an assertive regulatory instrument in Denmark affecting driving factors for public and private energy companies and clients. In Sweden regulatory instruments, such as energy efficiency programmes, subsidises for energy audits and voluntary agreements for industries affect energy companies in a less way than in Denmark, mostly increasing a client demand for energy services. The regulatory instruments in Denmark increase a trust for energy companies as energy service providers as in Sweden they are trusted upon their existing substantial role on the energy market, a reputation of knowledge and experience and a strategy aiming towards visualisation, motivation and education for the clients.

    Public energy companies feel a responsibility towards their public owners to offer an efficient energy supply and by having a local connection to the municipality they are able to increase competiveness in the region by offering energy services. Private companies are substantially larger than public companies and have a great potential to reach out to a larger number of clients through their existing supply client stock. This is of substantial higher relevance in Sweden than Denmark. 

  • 18132.
    Dahl, Emmy
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Män pratar miljö: Diskursiva maskuliniteter i mäns samtal om klimatförändringar och miljövänliga resor2011In: Tidskrift för Genusvetenskap, ISSN 1654-5443, E-ISSN 2001-1377, no 4, p. 109-137Article in journal (Refereed)
    Abstract [en]

    The fact that actions such as driving, shopping and travellingcontribute to climate change is something that individuals mayregard in various ways. Research indicates that the concern andwillingness of individuals to change their everyday life in order toreduce their impact on the climate might be gendered. Men inSweden appear to be less worried and in addition travel in a lessenvironmentally-friendly way than women. This article investigateslinkages between masculinities, femininities and individuals’ viewson climate change by analyzing focus group conversations withmen. The ways that these men made use of, reproduced or challenged discoursesof masculinities, when positioning themselves in relation toclimate change and sustainable travel, were scrutinized. Threediverse discursive practices were found, each one enabling variousways of positioning regarding the individual’s responsibility fortravelling sustainably. A discourse about men’s affection for carswas used as well as challenged by the men talking about sustainabletravelling. Some men used the discourse in order to justifyunsustainable travelling. Other men used it to position themselvesas different kinds of men. Furthermore, ecofeminist discoursesabout women as having a “closer” relation to the environment ornature as feminine were not recreated during the conversations. Thearticle contributes to a deeper understanding of men’s reasoning onclimate change and sustainable travel. It thus challenges narrowassumptions of men as environmental rouges and masculinity asproblematic in relation to environmental issues.

  • 18133.
    Dahl, Emmy
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Om miljöproblemen hänger på mig: Individer förhandlar sitt ansvar för miljön2014Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Over the last decade, the behaviors and lifestyles of the Swedish public have been depicted as having important environmental effects by both politicians and the media in Sweden. In this thesis, this is regarded as part of an ongoing tendency to individualize environmental responsibilities. Using a feminist poststructuralist point of departure, this individualized environmental responsibility is understood as a particular discourse that frames individuals as essential actors in handling environmental problems. How individuals position themselves in relation to the reasonableness and meaning of these responsibilities, however, is still an open question.

    The aim is to explore how individuals make scnse of and negotiate the discourse of individual environmental responsibility in group discussions. Twelve focus group conversations involving people in various life situations and with various expericnces of environmental issues and travelling are analyzed. The analysis investigates how the focus group participants position themselves in relation to the discoursc and, thus, negotiate its meaning and relevance. The analysis seeks to understand what other discourses support, compete with, or challenge the discourse of individual environmental responsibility in order to illuminate how individuals can incorporate or resist this particular discursive description of the world. The thesis also investigates what subject positions are made troubled or untroubled by the focus group participants, which reveals how gender and dass discourses position individuals as in various ways or to various degrees responsible for their individual impact on the environment.

    The analysis suggests that the discourse of individual environmental responsibility privileges independent, self-governing individuals, that is, people who assume responsibility without demanding either societal or social support. Some focus group participants depict individual environmental responsibility as morally significant and beneficial, while others depict it as unrealistic and unacceptable. The discourse seems to engender competition between individuals. Both people acting as highly environmentally responsible and people acting as unable or unwilling to take environmental responsibility are framed as troubled individuals in the conversations. Concurrently, other potential environmentally responsible actors and political scenes are often neglected. The discourse of individual environmental responsibility dominates; for some focus group participants, this discourse leads toa lack of faith in societal ability to handle environmental problems.

  • 18134.
    Dahl, Emmy
    et al.
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Henriksson, Malin
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Levin, Lena
    VTI, Statens väg- och transportforskningsinstitut, Sweden.
    Konstruktioner av maskulinitet i samtal om kollektivtrafik2012In: Norma, ISSN 1890-2138, E-ISSN 1890-2146, Vol. 07, no 2, p. 160-181Article in journal (Refereed)
    Abstract [en]

    This article highlights how environmental issues influence transport planning, andhow they make transport planners rethink previous categorizations of user groups.The introduction of an environmental discourse leads to a questioning of men’stravel activities, i.e. car driving. However, the critique against men’s travelling doesnot address all men. Instead, two types of masculinities are constructed in the localplanning discourse: the first one is a ‘problematic’ obsolete old driver. The secondone is a young ‘quality conscious’ man who opts for new technological solutions.The relationship between these two constructions of masculinities is hierarchical.The transport planners interpret it as their responsibility to make sure that publictransport is regarded as attractive to younger men and their imagined ‘needs’. Theelderly men however, are made scapegoats and are blamed for their unsustainabletravelling. These rather stereotypical constructions of men also include a negativeperception of elderly men. The analysis is based on discussions in eight focusgroups, accomplished in 2009 with 36 transport planners and politicians (24 menand 12 women) working with the planning of the future public transport system in Malmö city in the south of Sweden.

  • 18135.
    Dahl Jensen, Lasse
    et al.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Cao, Ziquan
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences.
    Nakamura, Masaki
    Karolinska Institute, Sweden .
    Yang, Yunlong
    Karolinska Institute, Sweden .
    Brautigam, Lars
    Karolinska Institute, Sweden .
    Andersson, Patrik
    Karolinska Institute, Sweden .
    Zhang, Yin
    Karolinska Institute, Sweden .
    Wahlberg, Eric
    Linköping University, Department of Medical and Health Sciences, Vascular surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Hosaka, Kayoko
    Karolinska Institute, Sweden .
    Cao, Yihai
    Linköping University, Department of Medical and Health Sciences, Division of Cardiovascular Medicine. Linköping University, Faculty of Health Sciences. Department of Microbiology, Tumor and Cell Biology, Karolinska Institute, Stockholm, Sweden.
    Opposing Effects of Circadian Clock Genes Bmal1 and Period2 in Regulation of VEGF-Dependent Angiogenesis in Developing Zebrafish2012In: Cell Reports, ISSN 2211-1247, Vol. 2, no 2, p. 231-241Article in journal (Refereed)
    Abstract [en]

    Molecular mechanisms underlying circadian-regulated physiological processes remain largely unknown. Here, we show that disruption of the circadian clock by both constant exposure to light and genetic manipulation of key genes in zebrafish led to impaired developmental angiogenesis. A bmal1-specific morpholino inhibited developmental angiogenesis in zebrafish embryos without causing obvious nonvascular phenotypes. Conversely, a period2 morpholino accelerated angiogenic vessel growth, suggesting that Bmal1 and Period2 display opposing angiogenic effects. Using a promoter-reporter system consisting of various deleted vegf-promoter mutants, we show that Bmal1 directly binds to and activates the vegf promoter via E-boxes. Additionally, we provide evidence that knockdown of Bmal1 leads to impaired Notch-inhibition-induced vascular sprouting. These results shed mechanistic insight on the role of the circadian clock in regulation of developmental angiogenesis, and our findings may be reasonably extended to other types of physiological or pathological angiogenesis.

  • 18136.
    Dahl Jensen, Lasse
    et al.
    Linköping University, Department of Medical and Health Sciences, Cardiology. Linköping University, Faculty of Health Sciences.
    Rouhi, Pegah
    Karolinska Institute.
    Cao, Ziquan
    Karolinska Institute.
    Länne, Toste
    Linköping University, Department of Medical and Health Sciences, Physiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Thoracic and Vascular Surgery.
    Wahlberg, Eric
    Linköping University, Department of Medical and Health Sciences, Vascular surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Cao, Yihai
    Karolinska Institute.
    Zebrafish Models to Study Hypoxia-Induced Pathological Angiogenesis in Malignant and Nonmalignant Diseases2011In: Birth Defects Research. Part C: Embryo Today Reviews, ISSN 1542-975X, Vol. 93, no 2, p. 182-193Article, review/survey (Refereed)
    Abstract [en]

    Most in vivo preclinical disease models are based on mouse and other mammalian systems. However, these rodent-based model systems have considerable limitations to recapitulate clinical situations in human patients. Zebrafish have been widely used to study embryonic development, behavior, tissue regeneration, and genetic defects. Additionally, zebrafish also provides an opportunity to screen chemical compounds that target a specific cell population for drug development. Owing to the availability of various genetically manipulated strains of zebrafish, immune privilege during early embryonic development, transparency of the embryos, and easy and precise setup of hypoxia equipment, we have developed several disease models in both embryonic and adult zebrafish, focusing on studying the role of angiogenesis in pathological settings. These zebrafish disease models are complementary to the existing mouse models, allowing us to study clinically relevant processes in cancer and nonmalignant diseases, which otherwise would be difficult to study in mice. For example, dissemination and invasion of single human or mouse tumor cells from the primary site in association with tumor angiogenesis can be studied under normoxia or hypoxia in zebrafish embryos. Hypoxia-induced retinopathy in the adult zebrafish recapitulates the clinical situation of retinopathy development in diabetic patients or age-related macular degeneration. These zebrafish disease models offer exciting opportunities to understand the mechanisms of disease development, progression, and development of more effective drugs for therapeutic intervention.

  • 18137.
    Dahl, Jimmy
    Linköping University, Department of Computer and Information Science.
    Virtuell träningscoach för webben2010Independent thesis Advanced level (degree of Master (Two Years)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Targitude Handelsbolag har en konceptuell idé om att erbjuda användare en webbaserad träningsdagbok med ett innovativt gränssnitt och ett system som kan ge användaren förslag på passande träning beroende på användarens kondition. En träningsdagbok är vanligtvis utformad som en vanlig dagbok och är ett hjälpmedel för träningsaktiva att följa upp sin träning. Syftet med detta examensarbete var att leverera en fungerande produkt till uppdragsgivaren för att på så sätt visa att deras koncept fungerar. En viktig del i projektet har varit att integrera produktens inloggningssystem med webbshop-systemet OpenCart, vilken uppdragsgivaren önskar använda parallellt. Uppdragsgivarens önskan var att en användare bara  skulle behöva logga in i ett av systemen för att bli inloggad i båda. På detta vis slipper användaren logga in på nytt vid navigation från det ena systemet till det andra.

    Produkten implementerades som en hemsida där användargränssnittet byggdes i HTML och CSS, logiken skrevs i PHP och Javascript och data lagrades i en MySQL-databas. Användare, som har ett konto i systemet, kan logga in och presenteras ett veckoschema och en lista med förslag på vad användaren borde träna under den vecka som visas baserat på användarens konditionsnivå. Användaren kan själv planera sin vecka genom att med hjälp av musen dra träningspassen till passande plats i schemat.

    Så fort systemet uppfattades som tillräckligt klart för att fungera testades det av en av uppdragsgivaren inbjuden grupp testanvändare. Uppdragsgivaren utvärderade sedan produkten baserat på vad testgruppen tyckte. Denna testperiod fungerade även som slutligt test av källkoden för att hitta och åtgärda eventuella fel, endast två fel uppdagades och de åtgärdades med en gång.

    Efter testomgången och utvärderingen var uppdragsgivaren nöjd med den produkt som levererades. Samtliga av uppdragsgivaren ställda krav uppfylldes och projektet föll väl ut. Efter projektets genomförande kunde jag visa på att uppdragsgivarens koncept fungerade och de båda systemen hade en synkroniserad inloggningshantering. Dock levererades ingen fullständigt genomarbetad produkt. Innan den kan anses komplett krävs viss vidareutveckling, främst med komplettering av ytterligare funktionalitet för att ge användaren ett komplett verktyg men även med avseende på systemets säkerhet och hur systemet hanterar inloggningsuppgifter.

  • 18138.
    Dahl, Johan
    et al.
    Linköping University, Department of Behavioural Sciences.
    Bendelin, Nina
    Linköping University, Department of Behavioural Sciences.
    Patienters upplevelser av internetbaserad kognitiv beteendeterapeutisk självhjälpsbehandling mot depression2006Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [sv]

    Patienters upplevelser av internetbaserad självhjälpsbehandling är ett obeforskat område inom psykoterapiforskningen. I syfte att utforska upplevelser av att genomgå internetadministrerad kognitiv beteendeterapeutisk självhjälpsbehandling mot depression intervjuades 12 deltagare. Tematisk analys genererade de övergripande kategorierna:

    Läsa och göra; Någon som.. bryr sig; Det svåra är det givande samt Orden man bär med sig. Mönster av upplevelser och förändringsprocesser i informanternas berättelser föll ut i tre grupperingar: Noviser, Lärjungar och Mästare. Dessa mönster av upplevelser kan förstås utifrån tidigare studier av förändringsprocesser i psykoterapi. Kvalitativa studier på autonomi, kontext och funktionen av terapeutkontakt behövs för att ytterligare utreda förändringsprocesser i internetbaserad självhjälpsbehandling.

  • 18139.
    Dahl, Jonas
    et al.
    Linköping University, Department of Management and Economics.
    Porelius, Jesper
    Linköping University, Department of Management and Economics.
    ABC+SCM=Sant?2006Independent thesis Advanced level (degree of Magister), 10 points / 15 hpStudent thesis
    Abstract [en]

    Background:

    Companies of today commonly search to gain competitive advantages throughout different forms of co-operation, one of which is referred to as Supply Chain Management. Although little research has been assigned to the topic of how to manage and control this type of relation, lately a growing number of academics has been arguing that ABC is an appropriate mean of controlling this type of relationships.

    Purpose:

    The purpose of this thesis is to investigate to what degree the ongoing debate on the use of ABC as a mean of control within SCM correspond to the present theories related to ABC and SCM respectively.

    Research method:

    The thesis takes it’s starting point within the literature, meaning that the empirical information consists of published articles in the ongoing debate. This information is put in relation to the original theories concerning both topics.

    Conclusions:

    The results shown in the thesis in some content agrees with the ongoing debate referring to the positive aspects that could result from using ABC as a mean of control within SCM. However the main result of the study is the discovery of a lack of discussion concerning the problems that implementing ABC within SCM might implicate, a fact that we believe contributes to the mainly positive view on using ABC within Supply Chain Management.

  • 18140.
    Dahl, Kristina
    Linköping University, Department of Culture and Communication.
    Kommunikativt samspel inom social interaktion elev och lärare emellan2009Independent thesis Advanced level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    I denna uppsats berörs ämnet kommunikativt samspel mellan lärare och elev under dramalektioner, där intresset ligger i att se hur dessa personer uppfattar varandra utifrån det som den andre personen har sagt. Kommunikation är något som sker oavbrutet hela tiden både genom ord och kroppsspråk mellan olika individer. Alla har vi våra olika förutsättningar för att ge uttryck av oss själva, och därför kan det ibland vara svårt att veta att det som jag har sagt verkligen når ut som jag vill att det skall nås ut. Detta är en kvalitativ intervjustudie där fokus på det kommunikativa samspelet ligger och vad det sen kan få för konsekvenser när man inte når ut med sitt budskap till mottagaren.

  • 18141.
    Dahl, Kristoffer
    Linköping University, Department of Physics, Chemistry and Biology.
    Management effects on butterfly and bumblebee abundance in Swedish semi-natural grasslands2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The amount of semi-natural grasslands has decreased in the agricultural landscape and because of this many grassland species are declining. Semi-natural grasslands are dependent on management, but different studies suggest that different management methods are most favorable to species richness and abundance. The aim of this study was to compare the effects of mowing and grazing on butterfly and bumblebee abundance in Swedish semi-natural grasslands. We used data collected through the Swedish environmental monitoring program NILS. We identified 31 comparable meadows and chose 1-10 pastures in the area surrounding each meadow. For six different species groups we calculated the number of individuals found per 100 m. By standardizing the values of the difference between the means for meadows and pastures we were able to compare the effects of the two methods on abundance in each species group. No species group showed a preference for pastures. A significant preference for meadows was found for two butterfly species groups. The four other groups showed a trend to prefer meadows before pastures. According to our study the recommended management method should be mowing, considering protection of butterflies and bumblebees.

  • 18142. Dahl, Thomas
    et al.
    Lindgren, Anne-Li
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute, Department of Child Studies.
    Gullberg, Eva
    Lindgren, Cecilia
    Axelsson, Thom
    Qvarsebo, Jonas
    Sandin, Bengt
    Areschoug, Judith
    Linköping University, Faculty of Arts and Sciences. Linköping University, The Tema Institute.
    Conference Review: Chilhood and the State - the State of Childhood. The Society for the History of Children and Youth (SHCY) Bi-Annual Conference 26-29 June2003In: H-Education, Vol. OctoberArticle in journal (Other academic)
  • 18143.
    Dahl, Valerie
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Davidsson, Mikael
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Route flow estimation based on time-dependent route choice sets and historical travel times2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Since congestion leads to variations in travel time which gives a variation in the traffic flow, it is interesting to estimate the traffic flow in larger cities where cars drive in a limited space. In order to estimate the traffic flow, different traffic models are usually used. These models often use volume-delay functions which calculate the travel times for each link depending on the current traffic flow. However, in these models, the process for reaching equilibrium can be time consuming and it is hard to calibrate the volume-delay functions for a road network with a large set of links. Instead, we assume that it is relatively simply to measure or collect historical time-dependent travel times on a large set of links. With this assumption, a method that uses time-dependent route choice sets and time-dependent travel times in order to estimate time-dependent route flows, is developed.

    In this thesis, the method was applied to Stockholm County where it is interesting to study the route choice since congestion occurs in the area which generate variations in travel time. In order to estimate time-dependent route flows, a time-sliced OD-matrix was created by dividing the matrix for the peak hour using two different time-slicing distributions.

    The time-dependent route choice set with time-dependent travel times was created by using an existing route planning tool. These routes were mapped to the links in a road network in order to estimate link flows. The mapping was done by using map matching and a shortest path algorithm. Route shares were decided by using a method that splits the demand equally among the routes in the route choice set for an OD-pair, and with a logit model that takes travel time into account with the assumption that the travel time can affect a traveler’s route choice.

    The evaluation of the resulting link flows was done by comparing these link flows with observed link flows using different time-slicing distributions and route share models. Furthermore, the method’s resulting link flows was evaluated against the resulting link flows from a scenario where all travelers are assumed to choose the shortest path, in terms of free flow travel time, between each OD-pair.

    The developed method can estimate link flows so that 27.9 % of the links have a GEH value less than 5, which can be compared to the commonly used acceptance criteria of 85 %. This shows that the method needs to be developed further in order to achieve link flow estimations that fulfills the acceptance criteria. Even though the overall result show that the developed method does not fulfill the acceptance criteria, the method works well on some individual links. Furthermore, the resulting link flows from the developed method match the observed link flows better than the resulting link flows from the scenario where all travelers are assumed to choose the shortest path.

  • 18144. Dahl, Å
    et al.
    Nyberg, H
    Edell-Gustafsson, Ulla
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Nurses' clinical experiences of the inverse bed position on a neurointensive care unit - A phenomenographic study2003In: Intensive & Critical Care Nursing, ISSN 0964-3397, E-ISSN 1532-4036, Vol. 19, no 5, p. 289-298Article in journal (Refereed)
    Abstract [en]

    Our knowledge of unstable critically ill patients placed in an inverse bed position on the neurointensive care unit (NICU) is fairly limited. The purpose of this study was to ascertain the variation in nurses' conceptions of the impact of clinical experiences on the care and working environments among patients with the head towards the centre of the room on an NICU. An important research question was: how is the nursing care of patients facing inwards on an NICU perceived? Interviews were conducted and analysed with 15 nurses, using the method of phenomenography. From a nursing perspective, four descriptive categories were found, which partly distinguished the nursing psychosocial environment from the physical environment. These were safety and security of mobile computer tomography (CT) on the NICU, availability and overview, integrated holistic view in an open nursing psychosocial environment and adaptation of practical equipment. In conclusion, inverse bed position is important for more individualised neurointensive nursing care among unstable patients subjected to frequent CT scans on the unit. More stable patients should be turned back to the traditional bed position in order to promote their recovery process. This new knowledge is important for the development of quality assurance, with regard to, amongst other things, the patient's dignity. ⌐ 2003 Elsevier Ltd. All rights reserved.

  • 18145. Dahl, Å
    et al.
    Nyberg, H
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Thoracic Surgery.
    Edéll-Gustafsson, Ulla
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Nursing Science.
    Omvårdnadsaspekter vid omvänt sängläge2002In: Studiedagar för Neuro-sjuksköterskor, Linköping 2002,2002, 2002Conference paper (Refereed)
  • 18146.
    Dahlander, Lina
    et al.
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    Hultkrantz, Tove
    Linköping University, Department of Management and Engineering, Business Administration. Linköping University, Faculty of Arts and Sciences.
    Råd från en robot?: En komparativ studie av storbankers och nischaktörers utformning av finansiell rådgivning2017Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Background: As a result of regulations, internationalization and technical development major changes in the financial sector have occurred which have impacted financial institutions. New digital players, fintechs and niche banks, have introduced alternatives to traditional financial advisory. The new digital and self-directed financial advice which is based on algorithms is called robotic-advice. This poses challenges to older and established banks, which have had a strong market position in the past. The changes in society and competition from new innovative players creates a complex challenge which is likely to be of great importance for financial institutions in the future. Therefore, it is of interest to investigate how different companies in the financial sector are responding to the change of financial advisory.

    Aim: The aim of the study is to analyze how different financial institutions design financial advisory in the light of digitalization and automatization.

    Methodology: The study is designed in accordance with a qualitative research strategy. Empirical data have been collected from respondents divided into two different groups, major banks and niche players in Sweden. The study consists of six semi- structured interviews.

    Conclusion: The findings in the study indicate differences and similarities in the major banks and niche players offers of financial advisory. The traditional financial companies, such as the major banks and Söderberg & Partners, offer personal financial advisory and emphasizes the expertise of advisors as a competitive advantage. Digital niche-players offers alternatives to traditional financial advisory that are digital and self-directed and their competitive advantage is their simplicity and transparency. The financial advisory is not affected by the players age and size, but rather the companies’ attitudes towards the development of digitalization and what they consider financial advisory should include. Furthermore, the development of financial advisory is affected by current regulations, however, new regulations will facilitate for digital and innovative niche players. Therefore, the competition will increase and it is essential for the established banks to review their strategies and offers of financial advisory to maintain their market position.

  • 18147.
    Dahlberg , Tore
    Linköping University, The Institute of Technology. Linköping University, Department of Management and Engineering, Solid Mechanics .
    Modelling of the dynamic behaviour of in situ concrete railway sleepers2008In: Proceedings of the Institution of Mechanical Engineers. P. F, Journal of rail and rapid transit, ISSN 0954-4097 , Vol. 222, no 4, p. 433-440Article in journal (Refereed)
    Abstract [en]

    An analytical Solution to the problem of a vibrating beam on an elastic foundation is presented. An application example of a concrete railway sleeper embedded in an elastic medium (the ballast) is provided. The sleeper is also elastically connected to the rails. The Rayleigh-Timoshenko (R-T) beam theory for a beam on an elastic foundation is used and eigenfrequencies are calculated. The beam (sleeper) is divided into three sections that have piecewise constant properties. The central portion of the beam is slightly thinner than the outer parts, and each one of the three parts may or may not be supported by the elastic foundation. The elastic connections to the rails are situated at the two joinings of the three sleeper sections.

    Conclusions drawn are that the Euler-Bernoulli beam theory can be used to calculate two, or maximum three, eigenfrequencies of the sleeper. For higher frequencies, the R-T beam theory should be used. The foundation stiffness influences the lowest bending-mode eigenfrequency the most; higher eigenfrequencies are practically unaffected by the foundation stiffness. The influence of railpad (and rail) stiffness on the sleeper eigenfrequencies is negligible.

  • 18148.
    Dahlberg, Anders
    Linköping University, Department of Electrical Engineering.
    Evaluation of a Floating Point Acoustic Echo Canceller Implementation2007Independent thesis Basic level (professional degree), 20 points / 30 hpStudent thesis
    Abstract [en]

    This master thesis consists of implementation and evaluation of an AEC, Acoustic Echo Canceller, algorithm in a floating-point architecture. The most important question this thesis will try to answer is to determine benefits or drawbacks of using a floating-point architecture, relative a fixed-point architecture, to do AEC. In a telephony system there is two common forms of echo, line echo and acoustic echo. Acoustic echo is introduced by sound emanating from a loudspeaker, e.g. in a handsfree or speakerphone, being picked up by a microphone and then sent back to the source. The problem with this feedback is that the far-end speaker will hear one, or multiple, time-delayed version(s) of her own speech. This time-delayed version of speech is usually perceived as both confusing and annoying unless removed by the use of AEC. In this master thesis the performance of a floating-point version of a normalized least-mean-square AEC algorithm was evaluated in an environment designed and implemented to approximate live telephony calls. An instruction-set simulator and assembler available at the initiation of this master thesis were extended to enable; zero-overhead loops, modular addressing, post-increment of registers and register-write forwarding. With these improvements a bit-true assembly version was implemented capable of real-time AEC requiring 15 million instructions per second. A solution using as few as eight mantissa bits, in an external format used when storing data in memory, was found to have an insignificant effect on the selected AEC implementation’s performance. Due to the relatively low memory requirement of the selected AEC algorithm, the use of a small external format has a minor effect on the required memory size. In total this indicates that the possible reduction of the memory requirement and related energy consumption, does not justify the added complexity and energy consumption of using a floating-point architecture for the selected algorithm. Use of a floating-point format can still be advantageous in speech-related signal processing when the introduced time delay by a subband, or a similar frequency domain, solution is unacceptable. Speech algorithms that have high memory use and small introduced delay requirements are a good candidate for a floating-point digital signal processor architecture.

  • 18149.
    Dahlberg, Christer
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Utveckling av en dynamisk webbsajt med interaktiva möjligheter2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sales Partner Group is a company located in Nyköping. It is focused on education and recruitment in the sales market. The company contacted Linköpings University as they were in need of a new graphical profile, especially for the Internet. A new user-friendly and dynamic website with the purpose of grouping costumers, salesmen and employees together in one place, was what they asked for. In addition to a dynamic and user-friendly website they also wanted a website which should be easy to update, offer interactivity and give certain users a possibility to discuss and have access to important information in a personal community.

    The result is a database driven website that is combined of HTML, CSS, PHP and MySQL. The design is created in view of usability rules for the Internet and general guides for layout and design. To make the website accessible to a great extent, it is developed and tested in the two main web browsers Internet Explorer and Mozilla Firefox. An interface for administrating the website has been created as one of the requirements was an easy-to-update website. According to that a help manual in digital and printed format has been created to facilitate the use of the interface.

    The work took a great amount of time which mostly depends on the requirements of the website which changed throughout the project and the fact that things proceeded more slowly than expected. A clear and strict plan could have prevented this, but as similar project hasn’t been done before, it was hard to measure the amount of time each part of the project would take. Even though, both Sales Partner Group and I are very satisfied with the result.

  • 18150.
    Dahlberg, David
    Linköping University, Department of Thematic Studies.
    Att motverka mobbning i skolan- ett problem sett ur lärarperspektiv2004Independent thesis Advanced level (degree of Magister)Student thesis
    Abstract [sv]

    Uppsatsens syfte är att diskutera vad lärare anser att de kan göra för att motverka mobbning i skolan. Studien är av kvalitativ art och har genomförts med hjälp av en hermeneutisk tolkningsmetod. Studien är baserad på åtta stycken lärarintervjuer. Undersökningen visar att lärarna anser att samtal och diskussioner med eleverna har stor betydelse när det gäller att motverka mobbning. Likaså framhålls vikten av att upprätta gemensamma regler och att vara tydlig som lärare genom att sätta gränser och markera när ett beteende inte accepteras. Det finns en stor enighet hos informanterna om att det är mycket betydelsefullt att läraren visar upp ett kraftfullt engagemang mot mobbning genom att inta ett tydligt förhållningssätt mot detsamma. I studien framgår även att flera av lärarna anser sig få för lite fortbildning inom ämnesområdet mobbning, vilket gör det problematiskt att agera i mobbningssituationer. Undersökningen visar även att lärarna talar mycket om akuta mobbningsfall inom arbetslaget, men inte så mycket om vad som kan eller borde göras i förebyggande syfte.

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