| 1. |
- Broström, Robert
(författare)
-
Design implications for visual-manual interfaces in cars
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the past decades there has been an extensive evolution in computer and communication technologies. In the last ten years these technologies have become an integrated part of our cars via in-vehicle information systems. Considerable efforts are put into research and development of the interface between the in-vehicle information systems and the driver. Due to the fact that vision is imperative in driving, the focus is in particular on the visual-manual interface and on apt usability evaluation methods.The purpose of this thesis is to study design implications for the development of visual-manual interfaces in cars. A point of departure is that the practice of the usability concept, usability evaluation methods, and compliance tests has implications for the design process.Four papers are appended to the thesis. Paper I focuses on differences between rotary control and touch screen interfaces in terms of driving simulator and glance metrics. Paper II investigates correlations between data from customer evaluations and expert evaluations for visual-manual interfaces. Paper III searches for the presence of and possible explanations for individual glance strategies in a driving simulator study. Paper IV investigates effects of individual glance strategies on the NHTSA visual-manual distraction test in a driving simulator set-up.In the thesis it is concluded that the optimal input device is dependent on the task being performed, that is, the touch screen is more efficient for alphanumeric input while rotary control performs list scrolling more efficiently. In addition, drivers seem to adapt their glance behaviour based on the display position. It is evident that efficiency metrics correlate between several usability evaluation methods. Hence, it is possible to generalise results from expert evaluations at an early design phase, to customer survey samples based on car ownership. Concerning glance behaviour, it is clear that individual glance strategies exist. Especially interesting are two glance strategies, long glancers and frequent glancers, that affect the results of the NHTSA compliance testing. These glance strategies have to be controlled for in the test situation. Finally, a framework is proposed that combines a classification of visual-manual actions with different visual fixations. The task analysis framework has the potential to analyse actions in terms of required visual resources, thus already providing an evaluation of visual-manual interfaces in the concept phase.
|
|
| 2. |
- Broström, Robert, et al.
(författare)
-
Individual glance strategies and their effect on the NHTSA visual manual distraction test
- 2016
-
Ingår i: Transportation Research Part F. - : Elsevier BV. - 1369-8478 .- 1873-5517. ; 36, s. 83-91
-
Tidskriftsartikel (refereegranskat)abstract
- The purpose of this paper was to investigate how individual differences in glance strategy could impact the glance performance test defined in the NHTSA visual manual distraction guidelines. Better understanding of the test procedure could help development of new technology for safe driving. A custom in-vehicle information system was developed and assessed in a driving simulator by eighteen participants. The interfaces were designed according to recommendations in the NHTSA guidelines and contained manual radio-tuning tasks, sound settings tasks and six letter spelling tasks. Two of the six tested interfaces fully complied with the test. In addition, clear individual differences in glance strategy were found among the participants. Four individual glance strategies were identified. Two of these, long glancers and frequent glancers, highly affected the outcome of the compliance test. Participants belonging to the long glancers and the frequent glancers categories were identified as statistical outliers in many test cases. For example, if the individual values of these participants were replaced with sample mean, the number of complying interfaces would increase to five out of six, which is more in line with expectations for these interfaces. The results of this study show that individual variations in glance strategy exist. Also, these individual variations seem to have a non- negligible influence on the result when performance-testing of in-vehicle interfaces is done according to the NTHSA guidelines.
|
|
| 3. |
- Falk, Joel, et al.
(författare)
-
Mass flow and variability in screw feeding of biomass powders : relations to particle and bulk properties
- 2015
-
Ingår i: Powder Technology. - : Elsevier BV. - 0032-5910 .- 1873-328X. ; 276, s. 80-88
-
Tidskriftsartikel (refereegranskat)abstract
- Biomass powders often have high cohesiveness, low bulk density and poor material flow characteristics which cause interruptions and variations in feeding systems. In this study, a range of biomasses – commercial charcoal, torrefied Norway spruce stem wood, non-treated Norway spruce stem wood, and reed canary grass – were milled (screen size: 1 mm) using two different methods; cutting mill and hammer mill, to form eight types of biomass powders. The powders were analyzed for loose bulk density, Hausner ratio, compression ratio, angle of repose and for size and shape distributions. Size and shape were determined by mechanical sieving and optical particle size and shape analysis. Additionally, yield loci and wall yield loci were determined through standard bulk solid testing methods. Screw feeding properties of the eight biomass powders were determined by feeding the materials in a twin screw feeder — at constant rpm and at a constant feeding rate of 1 kg/h. Correlation analysis and principal component loadings were used to describe relations between material properties and feeding characteristics. When materials were fed at a constant rpm, feeding variability was closely correlated to the powder's angle of repose (long time) and Hausner and compression ratios (short time).
|
|
| 4. |
|
|
| 5. |
- Osz, Katalin, 1983-, et al.
(författare)
-
Building Collaborative Test Practices : Design Ethnography and WOz in Autonomous Driving Research
- 2018
-
Ingår i: IxD&A. - Rome : Interaction Design & Architectures. - 1826-9745 .- 2283-2998. ; :37, s. 12-20
-
Tidskriftsartikel (refereegranskat)abstract
- This article outlines a novel way of performing experimental "Wizard of Oz" (WOz) User Experience (UX) research that specifically targets driving in different levels of self-driving modes. The reasons for exploring the possibilities of combining experimental and ethnographic WOz-testing have been twofold. On the one hand, this mixed-method approach responds to a growing body of critique concerning how the WOz test is biased by the claim that it explores real-life behaviour in an experimental setting. On the other hand, our approach also meets the demands for innovative research methodologies that can contribute to deeper understandings of how to better evaluate and account for human expectations and experiences when automated technologies become integrated in everyday life contexts. This knowledge is inevitable for a broader understanding of the overall user experience and expectations of autonomous driving and, more specifically, building an interdisciplinary collaborative testing approach.
|
|
| 6. |
- Oxelmark, Lena, et al.
(författare)
-
Use of complementary and alternative medicine in Swedish patients with inflammatory bowel disease : a controlled study.
- 2016
-
Ingår i: European Journal of Gastroenterology and Hepathology. - London : Lippincott Williams & Wilkins. - 0954-691X .- 1473-5687. ; 28:11, s. 1320-1328
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: There is an increasing interest in complementary and alternative medicine (CAM) in patients with chronic diseases, including those with inflammatory bowel disease (IBD). Patients may turn to CAM when conventional therapies are inadequate or associated with side effects for symptomatic relief or to regain control over their disease. The objectives were to explore CAM use and perceived effects in IBD patients in comparison with a control group.METHODS: A cross-sectional, multicenter, controlled study was carried out. IBD patients were invited from 12 IBD clinics in Sweden. Controls were selected randomly from a residence registry. A study-specific questionnaire was used for data collection.RESULTS: Overall, 48.3% of patients with IBD had used some kind of CAM during the past year compared with 53.5% in controls (P=0.025, adjusted for age, sex, geographic residence, and diet). The most frequently used CAM among IBD patients was massage (21.3%), versus controls (31.4%) (adjusted P=0.0003). The second most used CAM was natural products, 18.7% in IBD patients versus 22.3% of the controls (unadjusted P=0.018). In all, 83.1% of the patients experienced positive effects from CAM and 14.4% experienced negative effects.CONCLUSION: Overall, 48.3% of Swedish IBD patients used some kind of CAM and controls used CAM significantly more. Natural products were used by one-fifth of the patients and even more by controls. This is notable from a patient safety perspective considering the possible risks of interactions with conventional medication. In all, 40% of the patients reported adverse events from conventional medicine. Patients experienced predominantly positive effects from CAM, and so did controls.
|
|
