| 21. |
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| 22. |
- Johansson, Mikael
(författare)
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Quality functions for requirements engineering methods
- 1996
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objectives for this thesis is to establish what aspects of Requirements Engineering (RE) methods are considered important by the users. The thesis is to study an alternative RE method (Action Design), present evaluation results and establish general quality characteristics for RE methods. It is also an attempt to invoke the need to reflect over quality aspects of use and development of methods within the field of RE.The research is based on a grounded theory perspective where the studies together form the final results. The data collection was performed by interviews and focus groups. The analysis of data was done by using (1) Action Design (AD) methodology as an instrument to evaluate AD itself, (2) Quality Function Deployment to structure and rank quality characteristics, and (3) by phenomenological analyses.The results show the importance of considering social and organizational issues, user participation, project management and method customizing in the process of RE.Further, the results suggest that support which integrate different methods, or parts of methods to achieve a suitable collection of instruments tailored for a specific project is needed. It is also found that RE is to be considered, not only in the early parts of the software development cycle, but as an integrated part of the whole software development cycle.The conclusion is that RE methods beside the integration, need to be approached differently in the future. The integrated view of RE (as a part of the entire development process) could also be a way to solve some of the current problems that are discussed in relation to requirements in software development.
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| 23. |
- Johansson, Mikael
(författare)
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Scanning Tunnelling Microscopy and Spectroscopy of Adsorbates on Aluminium and Silicon
- 1997
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The main topic of this thesis is the investigation of atomic andmolecular adsorbates on single crystal surfaces of silicon and aluminiumusing the techniques of scanning tunnelling microscopy (STM) andspectroscopy (STS). The emphasis has been to use atomic-resolutionspectroscopy and imaging to determine the relationship between thesurfaces' geometric and electronic structures. The STM results have beenprofitably compared with synchrotron-based valence band and core levelphotoelectron spectroscopy (PES) data to provide a more complete picturethan any single technique could provide. On Si(001) a peak seen in valence band PES at Li coverages up to 0.4 MLwas explained by STM images showing a local perturbation of theSi(001)-2x1 reconstruction by the Li atoms. STM also showed that Liadsorption on p-type substrates created localised electron traps whichinduced negative differential resistance in tunnel spectra. The formation of 3D islands of metallic MoSi2 was shown to be a generalfeature of annealing 0.1 - 10 ML Mo films on Si(001) and Si(111) at 800 C.STM and STS showing the growth of the silicide islands at the expense ofatomic-scale features formed at lower temperatures was correlated withPES data showing the changes in the Si bonding on the surface. STS of Rb on Al(111) revealed that the (Root(3)xRoot(3))R30 overlayer formedat room temperature confined electrons to a 2D quantum well state. STM ofthe growing layer supported existing models for the (Root(3)xRoot(3))R30reconstruction and a complex structure formed at lower coverages, as well asdemonstrating the existence of kinetic barriers to atomic motion on thesurface. STM of C60 on Al(111) showed details of the growth of a (2Root(3)x2Root(3))R30ordered overlayer at room temperature. Spectroscopy of an annealedsurface proved that inequivalent molecules in its (6x6) unit cell havedifferent molecular energy levels and bonding to the substrate.
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| 24. |
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| 25. |
- Johansson, Mikael, et al.
(författare)
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Tumor blood flow and the cytotoxic effects of estramustine and its constituents in a rat glioma model
- 1997
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Ingår i: Neurosurgery. - : Oxford University Press. - 0148-396X .- 1524-4040. ; 41:1, s. 237-244
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Estramustine (EaM) is a conjugate of nor-nitrogen mustard (NNM) and 17 beta-estradiol (E2) that has cytotoxic and radiosensitizing effects on experimental malignant glioma. Its mechanism of action is only partly understood. To further investigate the mechanism in vivo, the effects on tumor blood flow (TBF) and tumor growth were analyzed.METHODS: TBF was measured by radioactive microspheres, and tumor growth was measured by weight. Apoptosis was evaluated by in situ end labeling and gel electrophoresis. The effects of the constituents NNM and E2 were also evaluated.RESULTS: EaM increased TBF to 153.8 ml/100 g/min after 3 days and to 153.9 ml/100 g/min after 10 days of treatment, compared with 94.0 ml/100 g/min in untreated controls. Cerebral blood flow did not change after EaM treatment. NNM increased TBF but also showed a tendency to increase cerebral blood flow. E2 increased TBF, whereas cerebral blood flow was unchanged. EaM resulted in a rapid reduction in tumor weight from 230 mg in untreated animals to 146 mg after 3 days of treatment. EaM induced an early transient fragmentation of deoxyribonucleic acid in glioma but not in the normal brain. Neither NNM nor E2 affected tumor weight.CONCLUSION: EaM increases TBF in the BT4C rat glioma model with a concomitant rapid antitumoral effect. The increase in TBF could partially be induced by an estrogen-like action of EaM, but the rapid cytotoxic effect of the drug is obviously attributed to the intact EaM compound. This cytotoxic effect might be attributable to the induction of programmed cell death.
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| 26. |
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| 27. |
- Johansson, Rolf, et al.
(författare)
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Discrimination of Patients with Acoustic Neuroma and Peripheral Vestibular Lesions with Human Posture Dynamics
- 1995
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Ingår i: Acta Oto-Laryngologica. - : Informa UK Limited. - 1651-2251 .- 0001-6489. ; 115:S520, s. 27-28
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Tidskriftsartikel (refereegranskat)abstract
- A group of normal subjects (n = 17) was compared with groups of patients with a diagnosis of vestibular neuritis (n = 18), and acoustic neuromas (n = 35). Fisher linear discriminant analysis was applied to distinguish clusters of parameters characteristic for each disease. Hence it was possible to distinguish the vestibular neuritis patients from the normal group with statistical significance (p < 0.01). Also the patients with an acoustic neuroma could be distinguished from the normal subjects with statistical significance (p < 0.05).
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| 28. |
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| 29. |
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| 30. |
- Karlberg, Mikael, et al.
(författare)
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Dizziness of Suspected Cervical Origin Distinguished by Posturographic Assessment of Human Postural Dynamics
- 1996
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Ingår i: Journal of Vestibular Research. - 1878-6464. ; 6:1, s. 37-47
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Tidskriftsartikel (refereegranskat)abstract
- Useful clinical tests are lacking for the controversial entity "cervical vertigo". In earlier studies patients assumed to suffer from cervical vertigo or dizziness manifested disturbed postural control as compared to healthy subjects, but were hard to distinguish from patients with other balance disorders. Using posturography in which stance was perturbed by a vibratory stimulus applied towards the calf muscles, we studied 16 consecutive patients with recent onset of neck pain and concomitant complaints of vertigo or dizziness, but normal findings at otoneurological examination and electronystagmography; 18 patients with recent vestibular neuritis; and 17 healthy subjects. We performed system identification of a model of the control of upright human stance, using the vibratory stimulus as input and the recorded body sway as output. According to values for the three normalized parameters of the transfer function of the model (i.e., swiftness, stiffness, and damping), cervical vertigo patients were distinguished both from healthy subjects (P < 0.001), and from vestibular neuritis patients (P < 0.001). It was also possible to distinguish the vestibular neuritis group from the group of healthy subjects (P < 0.01). The results show disturbed postural control in patients with cervical vertigo to differ from that in patients with recent vestibular neuritis, and indicate posturographic assessment of human posture dynamics to be a possible future tool for use in diagnosing cervical vertigo.
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