| 1. |
- Espinoza, Fredrik, et al.
(författare)
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GeoNotes: social and navigational aspects of location-based information systems
- 2001. - 1
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Ingår i: UBICOMP 2001. - : Swedish Institute of Computer Science.
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Location-based information systems allow the user to access information in relation to the user's position in geographical space. This paper outlines navigational and social aspects of such systems. It is argued that location-based systems must allow users to participate as content providers in order to achieve a social and dynamic information space. Moreover, as these systems allow commercial and private users to annotate space with information on a mass-scale, information filtering techniques will become essential in order to prevent information overload and user disturbance. We present a number of content-based and social filtering techniques to support this. We discuss implications for implementation and we describe a system (GeoNotes), which takes some of these aspects into account.
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| 2. |
- Fagerberg, Petra, et al.
(författare)
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What is a place? Allowing users to name and define places
- 2003. - 1
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Konferensbidrag (refereegranskat)abstract
- From working with location-based information systems we know that positioning is problematic. A different approach was tested, where users themselves were allowed to name and define the places they wanted to use. The question was if they would do so, and if they would understand the notion of “place”. In a user study, 78 users created 84 place labels. The user study also gave us some unexpected input to the users’ perception of place: not only physical, but also virtual places were created.
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| 3. |
- Hallén, Anders., et al.
(författare)
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Ion implantation of silicon carbide
- 2002
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Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - 0168-583X .- 1872-9584. ; 186, s. 186-194
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Tidskriftsartikel (refereegranskat)abstract
- Ion implantation is an important technique for a successful implementation of commercial SiC devices. Much effort has also been devoted to optimising implantation and annealing parameters to improve the electrical device characteristics. However, there is a severe lack of understanding of the fundamental implantation process and the generation and annealing kinetics of point defects and defect complexes. Only very few of the most elementary intrinsic point defects have been unambiguously identified so far. To reach a deeper understanding of the basic mechanisms SiC samples have been implanted with a broad range of ions, energies, doses, etc., and the resulting defects and damage produced in the lattice have been studied with a multitude of characterisation techniques. In this contribution we will review some of the results generated recently and also try to indicate where more research is needed. In particular, deep level transient spectroscopy (DLTS) has been used to investigate point defects at very low doses and transmission electron microscopy (TEM) and Rutherford backscattering spectrometry (RBS) are used for studying the damage build-up at high doses.
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| 4. |
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| 5. |
- Persson, Per, et al.
(författare)
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GeoNotes: social enhancement of physical space
- 2001. - 1
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Ingår i: Proceeding CHI EA '01 CHI '01 Extended Abstracts on Human Factors in Computing Systems. - Seattle, Washington, USA : ACM Publications.
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Konferensbidrag (refereegranskat)abstract
- The GeoNotes system allows users to annotate physical locations with virtual 'notes', which are then pushed to or accessed by other users when in the vicinity. GeoNotes employs a number of social filtering techniques, which all rely on logging of usage rather than content.
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| 6. |
- Persson, Per, et al.
(författare)
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GeoNotes: social enhancement of physical space
- 2001. - 1
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Ingår i: ERCIM News. ; :47
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- Positioning technology is often associated with locating people in geographical space. The GeoNotes system, however, positions pieces of information. GeoNotes allows all users to annotate physical locations with virtual "notes", which are then pushed to or accessed by other users when in the vicinity.
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| 7. |
- Svensson, BG, et al.
(författare)
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Doping of silicon carbide by ion implantation
- 2001
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Ingår i: Materials Science Forum, Vols. 353-356. - : Trans Tech Publications Inc.. - 9780878498734 - 0878498737 ; , s. 549-554, s. 549-554
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Konferensbidrag (refereegranskat)abstract
- A brief survey is given of some recent results on doping of 4H- and 6H-SiC by ion implantation. The doses and energies used are between 10(9) and 10(15) cm(-2) and 100 keV and 5 MeV, respectively, and B and Al ions (p-type dopants) are predominantly studied. After low dose implantation (less than or equal to 10(10) cm(-2)) a strong compensation is observed in n-type samples and this holds irrespective of implantation temperature up to 600 degreesC. However, at higher doses (10(14)-10(15) Al/cm(2)) the rate of defect recombination (annihilation) increases substantially during hot implants (greater than or equal to 200 degreesC) and in these samples one type of structural defect dominates after past-implant annealing at 1700-2000 degreesC. The defect is identified as a dislocation loop composed of clustered interstitial atoms inserted on the basal plane in the hexagonal crystal structure. Finally, transient enhanced diffusion (TED) of ion-implanted boron in 4H-samples is discussed.
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