| 1. |
- Aggerstam, Thomas, et al.
(författare)
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GaN/AlN multiple quantum well structures grown by MBE on GaN templates for 1.55 mu m intersubband absorption
- 2007
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Ingår i: Quantum Sensing and Nanophotonic Devices IV. - : SPIE. - 9780819465924 ; 6479, s. 64791E-
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Konferensbidrag (refereegranskat)abstract
- We have used MBE to grow MQW structures on MOVPE GaN/sapphire templates. The MQW devices are intended for high speed intersubband electroabsorption modulator devices operating at 1.55-mu m. The GaN/AlN multiple quantum well material was systematically studied regarding the surface morphology, structural characterization and optical property by atomic force microscopy, X-ray diffraction and Fourier transform infrared spectroscopy, respectively. The intersubband resonance energy was also calculated considering many-body effects in n-type doped structures. The multiple quantum well structure showed superior performance in terms of linewidth when grown on GaN templates as compared on sapphire. GaN quantum well and AlN barriers with a thickness of 3.3 and 4.2 nm respectively resulted in FWHM of the intersubband absorption peak as low as 93 meV at an absorption energy of 700 meV. This is promising for intersubband modulator applications.
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| 2. |
- Andersson, Thorvald, 1946, et al.
(författare)
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Macroscopic defects in GaN/AlN multiple quantum well structures grown by MBE on GaN templates
- 2009
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Ingår i: Microelectronics Journal. - : Elsevier BV. - 0026-2692. ; 40:2, s. 360-362
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Tidskriftsartikel (refereegranskat)abstract
- We have used MBE to grow in AlN/GaN superlattices, with different number of periods, on 2.5-mu m-thick MOVPE-GaN templates to study the development of defects such as surface deformation due to strain. After growth the samples were studied by atomic force microscopy (AFM), transmission electron microscopy (TEM), XRD and Fourier transform infrared spectroscopy (FT-IR). The strain increased with the number of quantum wells (QWs) and eventually caused defects such as microcracks visible by optical microscopy at four or more QW periods. High-resolution TEM images showed shallow recessions on the surface (surface deformation) indicating formation of microcracks in the MQW region. The measured intersubband (IS) absorption linewidth from a four period structure was 97 meV, which is comparable with the spectrum from a 10 period structure at an absorption energy of similar to 700 meV. This indicates that the interface quality of the MQW is not substantially affected by the presence of cracks.
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| 3. |
- Augustsson, Nils-Petter, 1972-, et al.
(författare)
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From Technological Transitions to Service Transitions : A Study of Attenuation Effects in IT Service Provisioning
- 2015
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Ingår i: Journal of Information Technology Services. - 1975-4256. ; 14:2, s. 337-354
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Tidskriftsartikel (refereegranskat)abstract
- In a day and age when contemporary businesses are transformed, driven by a service-dominance logic and dependent upon IT, we need to understand how firms cope with technological adaptations and how such technological adaptations can lead to service adaptations. Drawing on a framework on technological transitions and an interpretive longitudinal case study of the services provided by a team within a large public IT firm, this article addresses the following questions：How do service transitions come about? Can we distinguish particular patterns in service transition processes? This research unveils how technological and social dimensions mutually constitute each other within development and implementation of service provisioning. The findings show how：(a) IT plays a fundamental role in service provisioning; (b) technological transitions are the necessary but insufficient preconditions for service transitions; and (c) there are attenuation effects when it comes to the move from technology transition to service transition.
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| 4. |
- Augustsson, Nils-Petter, 1972-, et al.
(författare)
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Living on the edge : balancing rigor and relevance within an action research context
- 2010
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Ingår i: Industrial informatics design use and innovation. - Hershey : IGI Global. - 9781615206926 - 9781616923143 - 9781615206933 ; , s. 102-109
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- This paper describes the efforts in ensuring research relevance by means of an industrial PhD project. The project is aiming at strengthening the relevance of research and development by educating scientists with an insight into the practical aspects of research and development and by developing networks in which knowledge can be effectively disseminated between industry and university. The project is taking its stand with an empirical and industrial centre with a technical solution called Dynamo, which is delivered by the company Logica. Dynamo, an intelligent portal that seamlessly connects systems, user information, roles and rule sets, and its context will provide a rich and useful empirical source from which to launch the action research process. The project contains two distinct stakeholders – industry and academy – jointly guiding the project and making sure that both worlds get a result that is in line with and contributes to their business. To this end two key stakeholders that have taken on the role as gatekeepers of rigor and relevance respectively. Taking position in the middle of the action is the PhD student who, by living the life of both researcher and consultant, will take on the role of balancing rigor and relevance. The chosen research approach together with the complex implementation context together with makes it crucial to take on an open minded selection.
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| 5. |
- Augustsson, Nils-Petter, 1972-, et al.
(författare)
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Managing digital infrastructures: negotiating control and drift in service provisioning
- 2019
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Ingår i: International Journal of Business Information Systems. - : InderScience Publishers. - 1746-0972 .- 1746-0980. ; 30:1, s. 51-78
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Tidskriftsartikel (refereegranskat)abstract
- The digital infrastructure literature provides important perspectives on the intrinsic relations between information systems in today’s organisations. However, little attention has been paid to the challenges involved in providing requisite digital infrastructure services to organisations. In this paper, we argue digital infrastructure service providers operate in highly complex and uncertain environments. Rather than adopting a traditional approach to control, providers must therefore continuously negotiate a balance between control and drift as two complementary strategies. Our argument is based on a retrospective longitudinal case study of a Swedish infrastructure service team within a large international firm. Using the encounter-episode process model as structuring principle and focusing on the tension between control and drift, we analyse the evolution of the provider’s efforts to manage a portfolio of digital infrastructure services over a period of ten years. Based on these analyses, we uncover the involved complexities and dynamics, how control efforts and drift were constituted and how the infrastructure services were managed by continuously balancing control and drift. In conclusion, we relate the findings to extant literature to discuss new insights into provider management of digital infrastructure services. Copyright © 2019 Inderscience Enterprises Ltd.
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| 6. |
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| 7. |
- Augustsson, Nils-Petter, 1972-, et al.
(författare)
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The role of context in managing information infrastructure services
- 2010
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Ingår i: ICIS 2010 Proceedings. - : AIS Electronic Library (AISeL). - 9780615418988
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Contemporary organizations are increasingly dependent on information infrastructures to deliver their services. However, information infrastructures are highly complex and dynamic, which lead to considerable management challenges. This research aims to contribute to our understanding of these challenges through an in-depth investigation of a team responsible for information infrastructure services at a large business and technology service company. The complexity and dynamics faced by the team emphasizes the important role of context in managing its information infrastructure services and underlying technology platform. To investigate the team’s practice we therefore adopt contextualist inquiry in combination with a pluralist approach based on four complementary theoretical lenses; technological frames of references, risk management, control versus drift, and dynamic capabilities. As contributions, this research has the dual goal to improve the teams’ practices while at the same time providing new theoretical insights about the role of context in management of information infrastructure services.
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| 8. |
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| 9. |
- Berglind, Eilert, et al.
(författare)
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On the Possibilities to Create a Negative Permittivity Metamaterial with Zero Imaginary Part of the Permittivity at a Specific Frequency-Electrical Network Theory Approach
- 2012
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Ingår i: IEEE Journal of Quantum Electronics. - 0018-9197 .- 1558-1713. ; 48:4, s. 507-511
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Tidskriftsartikel (refereegranskat)abstract
- A permittivity function suggested in the literature describing a material that exhibits negative permittivity and no loss at a specific frequency (and losses at other frequencies) is analyzed using electrical network theory. An equivalent circuit of the polarization admittance consisting of RLC components is derived. Further, a proof is given showing that if the admittance is lossless at a specific frequency, then all components with losses (resistances) in the circuit have to be short circuited or blocked or virtually disconnected at this frequency by the use of ideal lossless resonant LC circuits. However, in the literature, inductors in metamaterials are associated with inherently lossy metal nanoparticles, hence invalidating the suggested permittivity function unless a lossless inductor at optical frequencies is found or proved possible.
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| 10. |
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