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- Jaldemark, Jimmy, 1970-, et al.
(författare)
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Att förstå hur man deltar via redskap i en lärgemenskap
- 2005
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Ingår i: Att förstå lärgemenskaper och mötesplatser på nätet. - Lund : Studentlitteratur. - 9144043708 ; , s. 109-147
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Bokkapitel (refereegranskat)abstract
- Syftet med detta kapitel är att fördjupa förståelsen av ett deltagande via redskap i utbildningsrelaterade nätbaserade lärgemenskaper. För att kunna sammanfläta redskap med deltagande, och samtidigt lyfta fram hur innebörden av deltagandet kan tillskrivas ett teoretiskt perspektiv, problematiserar vi behavioristisk, kognitiv och sociokulturell teoribildning. De nämnda perspektiven utgör en tolkningsram för en generell analys och diskussion av användningen av redskap vid deltagande i utbildningsrelaterade nätbaserade lärgemenskaper. I kapitlet illustreras deltagandet via redskapen med hjälp av chatt, e-post och videokonferens. En diskussion förs kring konsekvenserna av att deltaga i en utbildningsplattform där flera redskap ingår. Skillnader mellan perspektiven tydliggörs för deltagandet.
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| 2. |
- Jaldemark, Jimmy, 1970-, et al.
(författare)
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Sharing the distance or a distance shared : Social and individual aspects of participation in ICT-supported distance-based teacher education
- 2005
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Ingår i: ICT in teacher education. - Jönköping : Jönköping University Press. - 9197495344 ; , s. 142-160
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Bokkapitel (refereegranskat)abstract
- This chapter is about ICT and participation. Our aim is to initiate a discussion about student participation in a web-based learning environment. The chapter contains some results of a philosophical hermeneutical study of a distance-based teacher education in which ICT is used for sharing materials and teaching. Data was collected by interviewing 19 students, who had been using ICT in their teacher education for more than two years. As a framework for understanding, interpretations about student participation were made based on an explicit description of three different perspectives of learning � social constructivist, social constructionist, and sociocultural - and the divergent assumptions these perspectives could be claimed to hold. The findings indicate that students participate in distance-based teacher education in such a way that their participation is not part of a social, but rather, an individual process of learning. The findings also suggest that there is a need to be more explicit about expectations inherent in the use of ICT as a learning environment, and that the current design of such environments for collaboration and learning are challenging.
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| 3. |
- Olofsson, Jörgen, 1970-
(författare)
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Developing and evaluating dose calculation models for verification of advanced radiotherapy
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A prerequisite for modern radiotherapy is the ability to accurately determine the absorbed dose (D) that is given to the patient. The subject of this thesis has been to develop and evaluate efficient dose calculation models for high-energy photon beams delivered by linear accelerators. Even though the considered calculation models are general, the work has been focused on quality assurance (QA) tools used to independently verify the dose for individual treatment plans. The purpose of this verification is to guarantee patient safety and to improve the treatment outcome. Furthermore, a vital part of this work has been to explore the prospect of estimating the dose calculation uncertainties associated with individual treatment setups. A discussion on how such uncertainty estimations can facilitate improved clinical QA procedures by providing appropriate action levels has also been included within the scope of this thesis. In order to enable efficient modelling of the physical phenomena that are involved in dose output calculations it is convenient to divide them into two main categories; the first one dealing with the radiation exiting the accelerator’s treatment head and a second one associated with the subsequent energy deposition processes. A multi-source model describing the distribution of energy fluence emitted from the treatment head per delivered monitor unit (MU) is presented and evaluated through comparisons with measurements in multiple photon beams and collimator settings. The calculations show close agreement with the extensive set of experimental data, generally within +/-1% of corresponding measurements. The energy (dose) deposition in the irradiated object has been modelled through a photon pencil kernel solely based on a beam quality index (TPR20,10). This model was evaluated in a similar manner as the multi-source model at three different treatment depths. A separate study was focused on the specific difficulties associated with dose calculations in points located at a distance from the central beam axis. Despite the minimal input data required to characterize individual photon beams, the accuracy proved to be very good when comparing the calculated results with experimental data. The evaluated calculation models were finally used to analyse how well the lateral dose distributions from typical megavoltage photon beams are optimized with respect to the resulting beam flatness characteristics. The results did not reveal any obvious reasons why different manufacturers should provide different lateral dose distributions. Furthermore, the performed lateral optimizations indicate that there is room for improved flatness performance for the investigated linear accelerators.
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