309 research outputs found

    A Steering Wheel Reversal Rate Metric for Assessing Effects of Visual and Cognitive Secondary Task Load

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    This paper presents a steering wheel reversal rate metric intended for assessment of the effects of secondary tasks, such as interacting with in-vehicle information systems, on vehicle lateral control performance. The metric was compared to a number of other common steering wheel metrics with respect to the sensitivity to visual and cognitive secondary task load. It was shown that the proposed reversal rate metric, together with the existing steering entropy metric, was the most sensitive across experimental conditions. Different parameter settings for the metric were systematically investigated and suitable values for capturing the effects of visual and cognitive secondary task load recommended

    Modeling driver control behavior in both routine and near-accident driving

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    Building on ideas from contemporary neuroscience, a framework is proposed in which drivers’ steering and pedal behavior is modeled as a series of individual control adjustments, triggered after accumulation of sensory evidence for the need of an adjustment, or evidence that a previous or ongoing adjustment is not achieving the intended results. Example simulations are provided. Specifically, it is shown that evidence accumulation can account for previously unexplained variance in looming detection thresholds and brake onset timing. It is argued that the proposed framework resolves a discrepancy in the current driver modeling literature, by explaining not only the short-latency, well-tuned, closed-loop type of control of routine driving, but also the degradation into long-latency, ill-tuned open-loop control in more rare, unexpected, and urgent situations such as near-accidents

    Detection of aphid migrations in Finland

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    Our insect immigration warning system was built on the atmospheric dispersion model that has been used in predicting long-range transport of airborne pollen. We observed immigrations with a trap network consisting of rotating tow-nets, yellow sticky traps, and suction traps. Based on our studies the aphids can be detected with radars when they occur in large numbers

    What is behind the seeming cessation of the increase in sleep medicine consumption in Finland during the last years?

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    In Finland, between 2003 and 2010 and parallel to the increase in the prevalence of insomnia-related symptoms among the general population, there has been a cessation of growth and even a decrease in the consumption of traditional hypnotics. The reasons behind this seemingly paradoxical situation are not known. We analyzed trends over the period 2000-2010 in the estimated consumption of traditional hypnotics and some new drugs that are destined for use in insomnia treatment. We used the annual wholesale statistical database compiled by the Finnish Medicine Agency, FIMEA, and data from the Finnish Drug Prescription Register. We found evidence to support two parallel trends in Finnish outpatient care. First, there seems to be a trend in which physicians increasingly comply with official guidelines for insomnia treatment, which partly accounts for the decrease in the consumption of traditional hypnotics. Second, at the same time, the first trend seems to be resulting in an increasing trend to treat insomnia patients with some new drugs that were not originally developed for insomnia treatment by prescribing these non-hypnotic drugs in small, sub-clinical doses. The current trend in practice may have contradictory effects on the treatment of insomnia. The long-term consequences of using low doses of drugs other than hypnotics to treat insomnia are not known and the situation should, therefore, be followed-up in subsequent studies. However, pharmacological treatment should never be a substitute for non-pharmacological treatments of insomnia

    Impacts of winter feeding of reindeer on vegetation and soil in the sub-Arctic: insights from a feeding experiment

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    The overall impacts of winter feeding, including the effects of both forage and reindeer (Rangifer tarandus), were studied in an experiment in the Hammastunturi herding cooperative (68°N), Finland, with 300 reindeer in a sub-xeric heath forest (35 ha) during March/April 2009 and 2010. The feeding practices on the 50 plots were: (1) feeding with grass silage+hay with leftovers cleared in the spring; (2) feeding with grass silage+hay with leftovers not cleared; and (3) feeding with pellets. In addition, (4) unfenced and (5) fenced control plots were included, on which the reindeer were not fed. No invasive plant species introduced through grass silage+hay were observed on the plots. The coverage of Deschampsia flexuosa increased on grass silage+hay plots after the first winter, and both coverage and height of the grass increased after the second winter. The coverage of Dicranum sp. and Pleurozium schreberi was lower on plots where reindeer were fed with grass silage (leftover silage not cleared) vs. controls. Some dwarf shrubs, e.g., Calluna vulgaris, showed a similar response after the second winter. The N content of Empetrum nigrum was higher on grass silage plots (leftover silage not cleared) after the first winter vs. controls. After two winters, the N content of both E. nigrum and Vaccinium myrtillus was increased. Of the soil variables studied, C/N decreased on grass silage+hay plots vs. fenced controls. We conclude that even a moderate level of feeding may cause changes that can lead to a gradual shift from nutrient-poor heath forest towards a more nutrient-rich type

    Local Versus Centralized Control of Flexbile Loads in Power Grid

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    An adaptive technique for content-based image retrieval

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    We discuss an adaptive approach towards Content-Based Image Retrieval. It is based on the Ostensive Model of developing information needs—a special kind of relevance feedback model that learns from implicit user feedback and adds a temporal notion to relevance. The ostensive approach supports content-assisted browsing through visualising the interaction by adding user-selected images to a browsing path, which ends with a set of system recommendations. The suggestions are based on an adaptive query learning scheme, in which the query is learnt from previously selected images. Our approach is an adaptation of the original Ostensive Model based on textual features only, to include content-based features to characterise images. In the proposed scheme textual and colour features are combined using the Dempster-Shafer theory of evidence combination. Results from a user-centred, work-task oriented evaluation show that the ostensive interface is preferred over a traditional interface with manual query facilities. This is due to its ability to adapt to the user's need, its intuitiveness and the fluid way in which it operates. Studying and comparing the nature of the underlying information need, it emerges that our approach elicits changes in the user's need based on the interaction, and is successful in adapting the retrieval to match the changes. In addition, a preliminary study of the retrieval performance of the ostensive relevance feedback scheme shows that it can outperform a standard relevance feedback strategy in terms of image recall in category search

    Incidence and prevalence of mental disorders among immigrants and native Finns: a register-based study

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    Migrants appear to have a higher risk of mental disorders, but findings vary across country settings and migrant groups. We aimed to assess incidence and prevalence of mental disorders among immigrants and Finnish-born controls in a register-based cohort study.A register-based cohort study of 184.806 immigrants and 185.184 Finnish-born controls (1.412.117 person-years) was conducted. Information on mental disorders according to ICD-10 was retrieved from the Hospital Discharge Register, which covers all public health care use.The incidence of any mental disorder was lower among male (adjusted HR 0.82, 95% CI 0.77-0.87) and female (aHR 0.76, 95% CI 0.72-0.81) immigrants, being lowest among Asian and highest among North African and Middle Eastern immigrants. The incidence of bipolar, depressive and alcohol use disorders was lower among immigrants. Incidence of psychotic disorders was lower among female and not higher among male immigrants, compared with native Finns. Incidence of PTSD was higher among male immigrants (aHR 4.88, 95% CI 3.38-7.05).The risk of mental disorders varies significantly across migrant groups and disorders and is generally lower among immigrants than native Finns
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