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| 2. |
- Kircher, Albert, et al.
(författare)
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Knowledge representation forms for data mining methodologies as applied in thoracic surgery
- 2000
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Ingår i: AMIA,2000. - Philadelphia : Hanley & Belfus Inc. - 156053480X ; , s. 428-432
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Konferensbidrag (refereegranskat)abstract
- Typical ways of disseminating and using results of clinical research are scientific journals and reports. Presentation forms are condensed and comprehensible mainly to the experts following the specific topics. A vast amount of information remains unutilized due to the complex form of presenting the knowledge. Subject of this research is to explore possibilities of representation and also visualization of the results obtained using data mining methodologies. The intention is to formulate more than scientific ways to communicate facts that are of interest for the clinicians, medical students and even patients. Internet technologies as already widely established media support knowledge representation forms such as hypertext documents and structured knowledge components. The "Assist Me" decision support system for surgical treatment of cardiac patients integrates several forms of data mining and representation methodologies. We are showing a feasibility study in which scientific outcomes were forwarded to a broad group of potential users.
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| 3. |
- Kircher, Albert, et al.
(författare)
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Mobile telephone simulator study
- 2004
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The study consists of four separate experiments conducted in the VTI drivingsimulator. The common theme was to investigate how driver behaviour andtraffic safety are influenced when the driver attends to another technicaldevice while driving. The experiments were concerned with handsfree orhandheld mobile phone conversation and dialling, receiving mobile phone SMSmessages and watching a DVD film (the latter two being minor pilotexperiments). In three of the experiments (mobile phone conversation, SMS,DVD) the participants drove a route which led through urban and ruralenvironments, ranging from 90 km/h rural to 50 km/h urban environments. Theurban environments differed in complexity (three levels). The drivingdistance was about 70 km. The dialling experiment used a rural environmentwith a speed limit of 110 km/h. The driving distance was about 15 km. In themain experiment dealing with mobile phone conversation, a number of drivingperformance measures were analysed: driving speed, variation in lateralposition, deceleration, brake reaction time, headway, time to collision, etc.PDT (Peripheral Detection Task) was used as a measure of mental workload.Mobile phone conversation was found demanding in terms of mental workload. Italso had effects on driving. Most effects were quite similar for the twophone modes (handsfree, handheld). Impaired reaction time performance wasdemonstrated in one of the situations for handheld mode. However, effectswere found which could be interpreted as attempts to compensate for theincreased workload caused by the mobile phone conversation: speed was reduced(more so for handheld than for handsfree mode), and time and distance headwayincreased. In spite of these compensatory behaviours, mental workload wasstill markedly increased by phone use. In the SMS experiment the participantsbraked later in one situation when reading the SMS message. No other effectswere found in this minor experiment. In the DVD experiment, mental workloadincreased when watching the film, although this was compensated for to someextent by the increased distance headway to a lead vehicle. No compensationin terms of reduced driving speed, however, was apparent in this experiment.In the dialling experiment negative effects on traffic safety were evidentfrom the larger variance of lateral car position during the dialling task forthe handsfree phone mode. The mental workload also increased with thedialling task. Compensation in terms of reduced driving speed was apparentfor both phone modes. Other aspects of mobile phone use while driving stillremain to be analysed in more detail, such as starting or finishing a call,looking for a phone number to dial, mishaps like dropping the phone, etc.
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| 5. |
- Kircher, Albert, et al.
(författare)
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Vehicle control and drowsiness
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The report consists of two parts. The first part is a literature study aimed at identifying the most relevant indicators for predicting and detecting fatigue induced impaired driving. The aim was to identify possible performance based technologies, such as the lateral control of the car. Thus, less attention was devoted to e.g. psycho-physiological measures like EEG. A large number of research reports describing various approaches have been reviewed. The survey clearly indicates that no single indicator can be used to detect drowsy driving.A combination of different measures is recommended e.g. analysis of lateral control performance and eye blink pattern. Furthermore, it should be noted that so far there is no commercial system available that provides a sufficiently reliable method to detect a drowsy driver. In the second part, experimental data from previous driving simulator experiments were analysed by means of signal processing and statistical analyses. Specific attention was paid to investigate the potential of lateral vehicle position data as a mean to estimate driver drowsiness. The analysis of experimental data did not reveal any clear answer to what indicators are the most prominent with respect to detect drowsy driving behaviour. Further investigations and analyses of driving behaviour data are needed. However, the data analysis conforms in large to the findings in the literature survey.
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| 6. |
- Kircher, Albert, 1975, et al.
(författare)
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Vehicle control and drowsiness
- 2002
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- It is known that drivers' drowsiness and fatigue is accompanied by deteriorated vehicle control. Albert Kircher, VTI, and Marcus Uddman and Jesper Sandin, Virtual Technology, have investigated which factors are possible to use for the prediction and detection of fatigue induced impaired driving. In this study focus was on variables directly related to lateral control and steering behaviour aiming at a method capable of detection and prediction of impaired driving performance in real time and in an automated manner. Psycho-physiological variables, subjective rating scales, etc. are only briefly discussed. The first part of the report is a literature study. It served to examine the available knowledge in the field and to identify the most promising indicators of impaired driving. A large number of publications describing various approaches have been reviewed. The survey clearly indicates that no single indicator can be used to reliably detect drowsy driving. A combination of different measures is recommended, e.g. analysis of lateral control performance and eye blink patterns. Furthermore, it should be noted that even though there are a small number of commercial drowsiness detection systems available, no system provides a sufficiently reliable and scientifically proven method to detect a drowsy driver. In the second part of the report experimental data from previous driving simulator experiments were analysed. Signal processing techniques, such as frequency analysis by means of Fourier transforms, and statistical analyses were used to disclose if data could be used to determine drivers' drowsiness as rated on subjective rating scales (Karolinska Sleepiness Scale). Specific attention was paid to investigate the potential of lane control data (steering performance) as a mean to estimate driver drowsiness. Measures related to lateral vehicle position, such as time to line crossing and deviation of lateral position, were also analysed, but were not found useful. The analysis of experimental data did not reveal any clear answer to what driver behaviour indicators are the most prominent to detect drowsy driving behaviour. However, the data analysis conforms in large to the findings in the literature survey: a single variable is hardly usable as drowsiness predictor. More advanced signal processing techniques could be more proficient for the aspired goal. Further investigations and analyses of driving behaviour data are needed. Combination of different variables, such as eye blink patterns and lane control measures, are expected to be more successful.
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| 8. |
- Patten, Christopher, 1968-, et al.
(författare)
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Using mobile telephones : cognitive workload and attention resource allocation
- 2004
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Ingår i: Accident Analysis and Prevention. - 0001-4575 .- 1879-2057. ; 36:3, s. 341-350
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Tidskriftsartikel (refereegranskat)abstract
- Driver distraction is recognized as being one of the central causes of road traffic incidents and mobile telephones are tangible devices (among many other electronic devices) that can distract the driver through changes in workload. Forty participants completed a motorway route characterized by a low level of road complexity in the form of vehicle handling and information processing. A peripheral detection task (PDT) was employed to gauge mental workload. We compared effects of conversation type (simple versus complex) and telephone mode (hands-free versus handheld) to baseline conditions. The participants' reaction times increased significantly when conversing but no benefit of hands-free units over handheld units on rural roads/motorways were found. Thus, in regard to mobile telephones, the content of the conversation was far more important for driving and driver distraction than the type of telephone when driving oil a rnotorway or similar type of road. The more difficult and complex the conversation, the greater the possible negative effect on driver distraction. (C) 2003 Elsevier Ltd. All rights reserved.
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| 9. |
- Vogel, Katja, et al.
(författare)
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Traffic sense : which factors influence the ability to predict the development of traffic scenes?
- 2003
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Ingår i: Accident Analysis and Prevention. - 0001-4575 .- 1879-2057. ; 35:5, s. 749-762
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Tidskriftsartikel (refereegranskat)abstract
- A study was conducted to evaluate the skill to predict the development of traffic situations. A stop-controlled intersection was filmed over several days, and 12 scenes with varying traffic complexity were selected. In half of the scenes, the traffic rules were violated, in half of the scenes, the rules were observed. A total of 36 participants were asked to watch the scenes and predict how the scene would most likely develop in the 2 s after the film was paused. Additionally, the participants rated how certain they were about their prediction, and how complex and dangerous they assessed the scenes to be. With the method used here, experienced drivers were not found to make more correct predictions of situational development, and no difference in skill to predict could be found between genders. Nevertheless, more experienced drivers were more certain in their judgements and evaluated the situations on average as less complex and dangerous than did less experienced drivers. Scenes in which the traffic rules were violated were more difficult to predict correctly. The scenes in which the participants predicted violations were rated as more complex and dangerous. It is concluded that the low-cost method used here is more useful for examining which scenes are generally easy or difficult to predict and how they are experienced subjectively than to investigate differences in performance for different driver categories.
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