| 1. |
- Anund, Anna, 1964-, et al.
(författare)
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Night-time scenarios in simulators : a prestudy of needs, knowledge and possible solutions
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study in this publication investigates the need and potential for night-time scenarios in driving simulators, determines how such night-time scenarios could be reproduced and identifies the objects most important to reproduce. Although on average 12 out of every 24 hours are dark and considering that most situations are more demanding for drivers in dark conditions, simulations of driving scenarios with different degrees of darkness are not common. The project work comprised a pre-study that involved an investigation of the need and potential of night-time scenarios with the help of input from different stakeholders, consolidation of what is known up to now through benchmarking and state of the art, and a review of available technical solutions. The objective was to identify pros and cons with existing solutions and aspects that are important to consider in order to reproduce the most important components in realistic night-time scenarios. Based on the results, six important use cases were identified and two of these (‘Driver fatigue’ and ‘Objects without light sources’) were studied in more detail. It was concluded that for night-time scenarios there is enough darkness in general in the simulator environment. The question is whether it is possible to create sufficient contrast for objects that are meant to be observable. For daytime scenarios, the light levels in the simulator are clearly unrealistically low and this limitation might even trigger unwanted sleepiness.
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| 2. |
- Forsberg, Bertil, et al.
(författare)
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En analys av Göteborgs luft över 40 år - halter och dödlighet
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Det primära syftet med detta projekt har varit att insamla, digitalisera och sammanställa historiska data för sot och svaveldioxid från Göteborg, samt att studera korttidshalternas samband med dagligt antal dödsfall. Genom insamlandet av mätresultat från olika arkiv har en samlad digitaliserad databas upprättats, som går tillbaka till 1959, innehållande dygnsdata för sot och svaveldioxid. Under studieperiodens början låg halterna av sot och svaveldioxid i Göteborg liksom på många andra platser i Europa, allmänt 5-10 gånger högre än idag. Under 60-talet var det ganska vanligt med dygnsmedelhalter för sot på över 125 μg/m3 och enstaka dagar låg sothalten över 200 μg/m3. Svaveldioxidhalten kunde under 60-talet som dygnsmedelvärde enstaka dygn uppgå till 500-600 μg/m3. För de epidemiologiska analyserna har bildats fem delperioder huvudsakligen definierade av teknik- och mätplatsbyten för sotmätningarna i Göteborg. Medelvärdet för sot var under de fem delperioderna cirka 39, 22, 14, 8 respektive 6 μg/m3. Dödligheten tycks öka med sothalten främst under den första delperioden, då den kumulativa effekten av halten de senaste 14 dagarna är statistiskt säkerställd, och effekten av halten de senaste 7 respektive 21 dygnen också är nära att vara statistiskt säkerställda.
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| 3. |
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| 4. |
- Högberg, Thomas, 1947-, et al.
(författare)
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A prospective population-based management program including primary surgery and postoperative risk assessment by means of DNA ploidy and histopathology. Adjuvant radiotherapy is not necessary for the majority of patients with FIGO stage I-II endometrial cancer
- 2004
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Ingår i: International Journal of Gynecological Cancer. - : BMJ. - 1048-891X .- 1525-1438. ; 14:3, s. 437-450
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Tidskriftsartikel (refereegranskat)abstract
- A management program for FIGO stage I-II nonserous, nonclear-cell adenocarcinomas was evaluated. Histopathology and DNA ploidy were used to estimate postoperatively the risk of progression or death of disease and to tailor treatment. The patient material was a population-based consecutive cohort of all women with endometrial cancer in the Southern Swedish Health Care Region diagnosed between June 1993 and June 1996 (n = 553). Of these, 335 were eligible for the management program. Patients estimated to be at low risk were treated by surgery only, while high-risk patients also received vaginal brachytherapy. A large low-risk group consisting of 84% (n = 283) of the patients with an estimated disease-specific 5-year survival of 96% (95% CI = 93-98%) was identified. The high-risk group (n = 52, 16%) showed a worse outcome with an 80% 5-year disease-specific survival (95% CI = 65-89%). The difference in survival between the groups was highly significant (P < 0.0001). Half of the progressions were distant in the high-risk group. Although there is a clear indication for adjuvant therapy for this group, locoregional radiotherapy could be expected to fail in cases with distant progression. Thus, effective systemic treatments need to be developed. Low-risk patients, constituting the majority (84%) of the patients, can be safely treated by surgery only.
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| 5. |
- Lian, Ming, et al.
(författare)
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Lidar mapping of atmospheric atomic mercury in the Wanshan area, China
- 2018
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Ingår i: Environmental Pollution. - : Elsevier BV. - 0269-7491. ; 240, s. 353-358
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Tidskriftsartikel (refereegranskat)abstract
- A novel mobile laser radar system was used for mapping gaseous atomic mercury (Hg0) atmospheric pollution in the Wanshan district, south of Tongren City, Guizhou Province, China. This area is heavily impacted by legacy mercury from now abandoned mining activities. Differential absorption lidar measurements were supplemented by localized point monitoring using a Lumex RA-915M Zeeman modulation mercury analyzer. Range-resolved concentration measurements in different directions were performed. Concentrations in the lower atmospheric layers often exceeded levels of 100 ng/m3 for March conditions with temperature ranging from 5 °C to 20 °C. A flux measurement of Hg0 over a vertical cross section of 0.12 km2 resulted in about 29 g/h. Vertical lidar sounding at night revealed quickly falling Hg0 concentrations with height. This is the first lidar mapping demonstration in a heavily mercury-polluted area in China, illustrating the lidar potential in complementing point monitors.
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| 6. |
- Nilsson, Emma, 1982, et al.
(författare)
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Effects of cognitive load on response time in an unexpected lead vehicle braking scenario and the detection response task (DRT)
- 2018
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Ingår i: Transportation Research Part F: Traffic Psychology and Behaviour. - : Elsevier BV. - 1369-8478. ; 59, s. 463-474
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Tidskriftsartikel (refereegranskat)abstract
- The effects of cognitive distraction on traffic safety and driver performance are unclear and under debate. Based on increased response times to stimuli or events in controlled driving experiments, concerns, primarily about cell phone usage during driving, have been raised. But while cognitive load repeatedly have been shown to increase response times in artificial tasks such as the Detection Response Task (DRT), the generalizability of the results to response times in critical traffic situations is questionable. Method: Two experiments were conducted. In Experiment 1, response times in the DRT were measured during simulated driving with and without execution of a cognitively loading secondary task. In Experiment 2, brake response times in an unexpected lead vehicle braking scenario were measured with and without the same cognitively loading task. Results: In Experiment 1, DRT response times increased with increased level of cognitive load. In Experiment 2, brake response times were unaffected by cognitive load. Conclusion: The response time results from the artificial DRT did not generalize to the critical lead vehicle braking scenario. This finding can possibly be explained by the cognitive control hypothesis, which suggests that cognitive load selectively impairs driving subtasks that rely on cognitive control (i.e. novel or inconsistent tasks) but leaves automatic performance unaffected (Engström, Markkula, Victor, & Merat, 2017). While the DRT responses, because of the task novelty, can be assumed to require cognitive control, responses to visually expanding objects, such as a braking lead vehicle with short time headway, are triggered automatically. Common interpretations of the effect of cognitive load on traffic safety thus need to be re-examined. It seems inappropriate to generalize from effects of cognitive load on DRT, or other artificial laboratory tasks that rely on cognitive control, to unexpected real-world situations where responses are triggered primarily by looming cues.
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| 7. |
- Nilsson, Emma, 1982, et al.
(författare)
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Let Complexity Bring Clarity: A Multidimensional Assessment of Cognitive Load Using Physiological Measures
- 2022
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Ingår i: Frontiers in Neuroergonomics. - : Frontiers Media SA. - 2673-6195. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- The effects of cognitive load on driver behavior and traffic safety are unclear and in need of further investigation. Reliable measures of cognitive load for use in research and, subsequently, in the development and implementation of driver monitoring systems are therefore sought. Physiological measures are of interest since they can provide continuous recordings of driver state. Currently, however, a few issues related to their use in this context are not usually taken into consideration, despite being well-known. First, cognitive load is a multidimensional construct consisting of many mental responses (cognitive load components) to added task demand. Yet, researchers treat it as unidimensional. Second, cognitive load does not occur in isolation; rather, it is part of a complex response to task demands in a specific operational setting. Third, physiological measures typically correlate with more than one mental state, limiting the inferences that can be made from them individually. We suggest that acknowledging these issues and studying multiple mental responses using multiple physiological measures and independent variables will lead to greatly improved measurability of cognitive load. To demonstrate the potential of this approach, we used data from a driving simulator study in which a number of physiological measures (heart rate, heart rate variability, breathing rate, skin conductance, pupil diameter, eye blink rate, eye blink duration, EEG alpha power, and EEG theta power) were analyzed. Participants performed a cognitively loading n-back task at two levels of difficulty while driving through three different traffic scenarios, each repeated four times. Cognitive load components and other coinciding mental responses were assessed by considering response patterns of multiple physiological measures in relation to multiple independent variables. With this approach, the construct validity of cognitive load is improved, which is important for interpreting results accurately. Also, the use of multiple measures and independent variables makes the measurements (when analyzed jointly) more diagnostic—that is, better able to distinguish between different cognitive load components. This in turn improves the overall external validity. With more detailed, diagnostic, and valid measures of cognitive load, the effects of cognitive load on traffic safety can be better understood, and hence possibly mitigated.
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| 8. |
- Nilsson, Emma, 1982, et al.
(författare)
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On-to-off-path gaze shift cancellations lead to gaze concentration in cognitively loaded car drivers: A simulator study exploring gaze patterns in relation to a cognitive task and the traffic environment
- 2020
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Ingår i: Transportation Research Part F: Traffic Psychology and Behaviour. - : Elsevier BV. - 1369-8478. ; 75, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Appropriate visual behaviour is necessary for safe driving. Many previous studies have found that when performing non-visual cognitive tasks, drivers typically display an increased amount of on-path glances, along with a deteriorated visual scanning pattern towards potential hazards at locations outside their future travel path (off-path locations). This is often referred to as a gaze concentration effect. However, what has not been explored is more precisely how and when gaze concentration arises in relation to the cognitive task, and to what extent the timing of glances towards traffic-situation relevant off-path locations is affected. To investigate these specific topics, a driving simulator study was carried out. Car drivers’ visual behaviour during execution of a cognitive task (n-back) was studied during two traffic scenarios; one when driving through an intersection and one when passing a hidden exit. Aside from the expected gaze concentration effect, several novel findings that may explain this effect were observed. It was found that gaze shifts from an on-path to an off-path location were inhibited during increased cognitive load. However, gaze shifts in the other direction, that is, from an off-path to an on-path location, remained unaffected. This resulted in on-path glances increasing in duration, while off-path glances decreased in number. Furthermore, the inhibited off-path glances were typically not compensated for later. That is, off-path glances were cancelled, not delayed. This was the case both in relation to the cognitive task (near-term) and the traffic environment (far-term). There was thus a general reduction in the number of glances towards situationally relevant off-path locations, but the timing of the remaining glances was unaffected. These findings provide a deeper understanding of the mechanism behind gaze concentration and can contribute to both understanding and prediction of safety relevant effects of cognitive load in car drivers.
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| 9. |
- Nilsson, Emma, et al.
(författare)
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Vehicle Driver Monitoring : sleepiness and cognitive load
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- To prevent road crashes, it is important to understand driver related contributing factors. The overall aim of the Vehicle Driver Monitoring project was to advance the understanding of two such factors; sleepiness and cognitive distraction. The project aimed at finding methods to measure the two states, with focus on physiological measures, and to study their effect on driver behaviour. The data collection was done in several laboratory and driving simulator experiments. Much new knowledge and insights were gained in the project. Significant effects of cognitive load as well as of sleepiness were found in several physiological measures. The results also showed that context, including individual and environmental factors, has a great impact on driver behaviours, measures and driver experiences.
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| 10. |
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