Reducing the effects of driving fatigue with magnitopuncture stimulation

The purpose of this study was to assess the effects of reducing driving fatigue with magnitopuncture stimuli on Dazhui (DU14) point and Neiguan (PC6) points using heart rate (HR), reaction time (RT) testing, right rate (RR), critical flicker fusion frequency (CFF) and subjective evaluation. Forty healthy subjects were randomly divided into two groups: study and control groups. All subjects were required to be well rested before the experiment. The subjects were engaged in high speed driving at a constant vehicle velocity of 80 km/h continuously for 3h on a test course simulating an expressway. During the driving magnitopunctures (Haci Five Elements Needle, 250 mT, made by Haci Company limited) were applied to the Dazhui (DU14) point and Neiguan (PC6) points for the study group when the subject performed the task for 2.5h, and for the control group magnitopunctures were applied to non-acupuncture points during the same time session. The results of this study show a significant effect of magnitopuncture stimuli on RT, RR and CFF. Subjective evaluation also exhibited significant differences (P < 0.05) between the two groups after the driving task. The findings showed that magnitopuncture stimuli on DU14 point and PC6 points could reduce the effects of driving fatigue.     

Peripheral refractive errors in myopic,emmetropic, and hyperopic young subjects

To gain more insight into the relationship between foveal and peripheral refractive errors in humans, spheres, cylinders, and their axes were binocularly measured across the visual field in myopic, emmetropic, and hyperopic groups of young subjects. Both automated infrared photorefraction (the "PowerRefractor"; www. plusoptix.de) and a double-pass technique were used because the PowerRefractor provided extensive data from the central 44 deg of the visual field in a very convenient and fast way. Two-dimensional maps for the average cross cylinders and spherical equivalents, as well as for the axes of the power meridians of the cylinders, were created. A small amount of lower-field myopia was detected with a significant vertical gradient in spherical equivalents. In the central visual field there was little difference among the three refractive groups. The established double-pass technique provided complementary data also from the far periphery. At 45 deg eccentricity the double-pass technique revealed relatively more hyperopic spherical equivalents in myopic subjects than in emmetropic subjects [+/-2.73 +/- 2.85 D relative to the fovea, p < 0.01 (+/- standard deviation)] and more myopic spherical equivalents in hyperopic subjects (-3.84 +/- 2.86 D relative to the fovea, p < 0.01). Owing to the pronounced peripheral astigmatism, spherical equivalents (refractions with respect to the plane of the circle of least confusion) became myopic relative to the fovea in all three groups. The finding of general peripheral myopia was unexpected. Its possible roles in foveal refractive development are discussed.     

Mental workload when driving in a simulator: Effects of age and driving complexity

Driving errors for older drivers may result from a higher momentary mental workload resulting from complex driving situations, such as intersections. The present study examined if the mental workload of young and older active drivers vary with the difficulty of the driving context. We adopted the probe reaction time (RT) technique to measure the workload while driving in a simulator. The technique provided clear instructions about the primary (driving) and secondary (RT) tasks. To avoid structural interference, the secondary task consisted of responding as rapidly as possible with a vocal response (“top”) to an auditory stimulus. Participants drove through a continuous 26.4-km scenario including rural and urban sections and probes (stimuli) were given in a baseline static condition and in three different driving contexts embedded into the overall driving scenario. Specifically, stimuli were given randomly when (a) driving on straight roads at a constant speed, (b) approaching intersections for which the driver had to stop the car, and (c) when overtaking a slower vehicle. Unless a driving error was made, drivers did not need any emergency responses. Reaction time was defined as the temporal interval between the auditory stimulus and the onset of the corresponding verbal response detected from the analog signal of a piezo-electric microphone fixed on a headset (ms accuracy). Baseline RTs were similar for both groups. Both groups showed longer RTs when driving and RTs increased as the complexity of the driving contexts increased (driving straights, intersections, overtaking maneuvers). Compared to younger drivers, however, older drivers showed longer RTs for all driving contexts and the most complex driving context (overtaking maneuvers) yielded a disproportionate increase. In conclusion, driving leads to a greater mental workload for the older drivers than for the younger drivers and this effect was exacerbated by the more complex driving context (overtaking maneuvers).     

The Driver Prioritisation Questionnaire: Exploring drivers’ self-report visual priorities in a range of driving scenarios

Previous research has noted that novice drivers are at greatest risk of an accident. One reason that has been reported for this is that they have not developed the optimum visual search strategies of their more experienced counterparts. One might expect that new drivers might be taught the appropriate visual skills while learning to drive, though this requires instructors to have introspection into their own visual skills before they can be passed on to the student. In addition novice drivers should be able to acquire the instructed skills. This study used an image-based questionnaire to assess driving instructors’ and novice drivers’ priority ratings for attending to different areas of the driving scene across nine scenarios. It was predicted that if instructors and novices have introspection into the relative importance of these different areas, there should be agreement across the sample of participants. Additionally it was considered important to assess which areas of the visual scene are important across all different scenarios and which areas change in priority with a change in scenario. Results showed that for both groups the opinions regarding visual field prioritisation were highly consistent when compared to chance. Despite the rating consistencies, group differences were found, across all scenarios with “Rear View Mirrors” being the visual field with the most frequent observed group differences. Certain categories (“Road Ahead” and “Mirrors”) were highly ranked across all scenarios, while other categories were more scenario specific. We conclude that both groups have insight into some elements of visual search. However, in many occasions the prioritisation was different between driving instructors and novice drivers. It appears that during the learning process the novice drivers did not adopt the prioritisation strategies seen in driving instructors. This has important implications for the teaching of visual skills in driving.     

Critical currents of NbTi tapes with differently oriented anisotropic defects

In the paper we present a theory predicting the angular dependence of the critical current in NbTi tapes with elongated defects of different orientation with respect to the tape axis. Corresponding experiments were carried out on samples made from two NbTi foils with different critical current densities.The role of the self-field as well as of the small additional perpendicular field on the critical current is also investigated.     

Dynamical use of different sources of information in heading judgments from retinal flow.

The optic flow arising in the eyes of an observer during self-motion is influenced by the occurrence of eye movements. The determination of heading during eye movements may be based on the pattern of retinal image motion (the retinal flow) or on an additional use of an extraretinal eye-movement signal. Previous research has presented support for either of these hypotheses, depending on the movement geometry and the layout of the visual scene. A special situation in which all previous studies unequivocally have agreed that an extra-retinal signal is required occurs when the visual scene consists of a single frontoparallel plane. In this situation eye movements shift the center of expansion on the retina to a location that does not correspond to the direction of self-movement. Without extraretinal input, human observers confuse the center of expansion with their heading and show a systematical heading estimation error. We reexamined and further investigated this situation. We presented retinal flow stimuli on a large projection screen in the absence of extra-retinal input and varied stimulus size, presentation duration, and orientation of the plane. In contrast to previous studies we found that in the case of a perpendicular approach toward the plane, heading judgments can be accurate. Accurate judgments were observed when the field of view was large (90 degrees x 90 degrees) and the stimulus duration was short (< or = 0.5 s). For a small field of view or a prolonged stimulus presentation, a systematic and previously described error appeared that is related to the radial structure of the flow field and the location of the center of expansion. An oblique approach toward the plane results in an ambiguous flow field with two mathematically possible solutions for heading. In this situation, when the stimulus duration was short, subjects reported a perceived heading midway between these two solutions. For longer flow sequences, subjects again chose the center of expansion. Our results suggest a dynamical change in the analysis or interpretation of retinal flow during heading perception.     

Shifting attention across near and far spaces: Implications for the use of hands-free cell phones while driving

In three experiments, participants performed two tasks concurrently during driving. In the peripheral detection task, they responded manually to visual stimuli delivered through a LED placed on the internal rear mirror; in the conversation task, they were engaged in a conversation with a passenger, or through earphone-operated, loudspeaker-operated, or hand-held cell phones. Results showed that drivers were slower at responding to the visual stimuli when conversing through a hand-held cell phone or an earphone-operated cell phone than when conversing through a loudspeaker-operated cell phone or with a passenger. These results suggest that due to the brain coding the space into multiple representations, devices that make phone conversations taking place in the near, personal space make drivers slower at responding to visual stimuli, compared to devices that make the conversation occurring in a far space.     

A practice-orientated study of the complex „processing and handling–application–resultant properties”︁ of autopolymerizing PMMA bone cements

Bone cements which are used for the fixation of alloplasties as well as for filling and/or bridging of bone defects had been intensively investigated during the past 15 years. Scientists payed close attention to the subjects of “biocompatibility in view of chemical and thermal effects; polymerization process; structure and properties of bone cements”. As a rule, especially tests for the evaluation of strength properties were carried out with more or less standardized and relatively small specimen. The fund of experience, obtained by the methods mentioned above, don't let us hope to have any further significant progress concerning the transferability of these results to practise. A possible step further in the approximation of model experiments with respect to practical problems in the author's opinion should be the methodically combination of the known single aspects to a larger total complex. As a start in this direction a testing method was developed which enables processing and insertion of bone cements as well as the implantation of endoprostheses-shafts into tubular spaces under similar geometrical and thermal conditions as they are present in big tubular bones. Shape and dimensions of the originated bone cement- “quivers” or “jackets” are chosen in a way that experiments are practicable for the comparison of different types of bone cements and implantating methods as well as the testing of intended or unintended admixtures (for example X-ray contrast agent, antibiotics, blood) with respect to the mechanical loading capacity. Furthermore comparisons with the results of conventional mechanical material testings are possible. The contruction of the testing apparatus and the testing procedure will be presented. Its applicability for tests to compare different types of bone cements with respect to the parameters “processing and insertion method”, “implantating endoprostheses-shafts” and “admixtures” will be discussed by means of obtained results. Finally the question is asced wether a method like this can be an aid for training and objectively valuation of the methodical abilities of budding operating surgeons in this field.     

Visual risk factors for driving difficulty among older drivers

This study sought to evaluate associations between visual function and self-reported difficulty with driving tasks. Drivers (N=384) between the ages of 55 and 85 were selected from ophthalmology practices and optometry clinics; three out of four of the sample had cataracts and the remaining were cataract-free. Information on driving exposure and difficulty was obtained via self-report. Visual functional status of all participants was measured with respect to acuity, contrast sensitivity, disability glare and useful field of view. Cognitive impairment was evaluated using the Mattis Organic Mental Syndrome Screening Examination. The results show a pattern of difficulty in high-risk driving situations among those with decreased visual acuity and contrast sensitivity, even after adjustments for age, gender, weekly mileage, and cognitive impairment.     

Viewing Strategy and Window Effects on Dynamic Visual-Inspection Accuracy

Equally-spaced product units, moving on a belt at a uniform velocity, were exposed for visual inspection over a fixed viewing window. Viewing windows were equal to the product unit interspacing and twice this distance to give respectively 1 and 2 product units within the window. Three different belt speeds were used. Subjects performed short runs of visual inspection using their self-directed strategies of viewing the sequence of product units and then these subjects repeated all conditions of this task using a “directed viewing strategy.” Improved viewing discipline was expected from this “directed” strategy and eye motion monitoring was employed to verify that the subjects used the “directed” strategy. Inspection errors of each type were observed under twelve experimental conditions. Both types of errors were found to be greater with: 1) the smaller viewing window, 2) self-directed viewing strategies in contrast to the “directed” strategy, and 3) higher belt velocities. Contrasts were also made between error types and between high- and low-performing subject groups. Inferences on the apparent cost of each error type were made from these data and compared with rational objectives. Economic implications are shown for these viewing-strategy and viewing window effects.     

Interactive Measurement of Hierarchically Related Consumers’ Images

A new scaling technique was developed in the present work to investigate the image integration of consumers, taking advantage of the recent visual and object-oriented programming technology. Employed visual stimuli were the logos (and the accompanying symbolic marks, if any) of the four leading cosmetic makers, the logos of their brands and the photos of their product packages of skincare items targeted at young females. 19 females subjects evaluated the stimuli with respect to four, five and eight items for the corporate (Clmg), the brand (Blmg) and the package (Plmg) images. The image inheritance was analyzed on the internally anchored items. In addition, external anchores were employed to facilitate the Kansei processing in part of the Bimg evaluations. The major findings included the contrasting patterns exhibited by two makers both in the maker/brand discrepancies and in the image inheritances. Among the important issues to be considered in the future work are the mediation effect of the matching task and the class structure of evaluative items like those employed in AHP.

     

Monotony of road environment and driver fatigue: a simulator study

Studies have shown that drowsiness and hypovigilance frequently occur during highway driving and that they may have serious implications in terms of accident causation. This paper focuses on the task induced factors that are involved in the development of these phenomena. A driving simulator study was conducted in order to evaluate the impact of the monotony of roadside visual stimulation using a steering wheel movement (SWM) analysis procedure. Fifty-six male subjects each drove during two different 40-min periods. In one case, roadside visual stimuli were essentially repetitive and monotonous, while in the other one, the environment contained disparate visual elements aiming to disrupt monotony without changing road geometry. Subject's driving performance was compared across these conditions in order to determine whether disruptions of monotony can have a positive effect and help alleviate driver fatigue. Results reveal an early time-on-task effect on driving performance for both driving periods and more frequent large SWM when driving in the more monotonous road environment, which implies greater fatigue and vigilance decrements. Implications in terms of environmental countermeasures for driver fatigue are discussed.     

The visual and driving performance of monocular and binocular heavy-duty truck drivers

This study compared the performance of 40 monocular and 40 binocular tractor-trailer drivers on measures of both visual and driving performance. On the visual measures, the mononuclear drivers were significantly deficient in contrast sensitivity, visual acuity under low illumination and glare, and binocular depth perception. They were not significantly deficient in static or dynamic visual acuity, visual field of individual eyes, or glare recovery. Driving measures of visual search, lane keeping, clearance judgment, gap judgment, hazard detection, and information recognition showed no differences between monocular and binocular drivers. Monocular drives were poorer than binocular drivers only in sign reading distance in both daytime and nighttime driving. This decrement correlated significantly with the binocular depth perception measure. There were large individual differences within each group for most of the visual and driving performance measures. It was concluded that monocular drivers have some significant reductions in selected visual capabilities and in certain driving functions dependent on these abilities, compared with binocular drivers. However, monocular drivers are not significantly worse than binocular drivers in the safety of most day-to-day driving functions. Implications of these findings and the large individual differences within each group are discussed.     

Experimental characterization of Ti6Al4V T joints welded through linear friction welding technique: microstructure and NDE

Linear friction welding (LFW) is an innovative solid-state welding technique that allows to manufacture joints with high mechanical properties. This technology has various applications in the aerospace field; in particular it is used to weld massive structural components made of Ti6Al4V. This paper deals with the experimental study of Ti6Al4V T-joints welded through LFW, with particular focus on the effectiveness of ultrasonic control in detecting and distinguishing welding defects within the joints. Aiming to this scope, joints with different properties were manufactured and tested:some were free from defects but with different metallurgy, and some had different types of defects. The results obtained proved that the ultrasonic control was an effective method to detect and identify defects in linear friction welded titanium joints, moreover it was possible to get information regarding the microstructure and in particular the extension of the different metallurgical zones induced by the welding process.     

Selective sorption in filler-bitumen systems

Factors affecting selective sorption in the bitumen-filler interface and the difference in the capacity of various fillers for selective sorption of the chemical groups combining the bitumen are investigated and described. The effect, in this respect, of the type of diluent, the environmental conditions and the experimental methods are also studied.Quantitative evaluation of selective sorption was made using a chromatographic method, by percolation of diluted bitumen through columns of different types of filler. Among the fillers investigated, hydrated lime and limestone were the most effective, basalt was intermediate, while sandstone and mainly glass beads showed almost no capacity for selective sorption. In addition, the changes in the composition of the chemical groups, while percolating bitumen through a hydrated lime layer, were investigated and reported in this paper.The evaluation of selective sorption capacity of the filler is of great importance in bituminous mixture technology. Since the filler constitutes the ingredient with the highest specific surface in the granular mass of the bituminous mixture, its surface activity properties influence the mechanical properties of the bitumen-filler system and the behaviour of the mixture. Therefore, the capacity of selective sorption can serve as an indication to the future effect of the filler on the aggregate-bitumen-filler adhesion and the stability and deformability of the bituminous mixture. In this respect, the behaviour of sand asphalt mixtures with different types of filler was studied. Actual results were in agreement with the behaviour of the different fillers under selective sorption.     

Modeling lateral control in driving studies

In driving studies based on simulators and instrumented vehicles, specific models are needed to capture key aspects of driving data such as lateral control. We propose a model that uses weighted polynomial projections to predict each data point from the previous three time points, and accommodates the attempts of the drivers to re-center the vehicle before crossing the borders of the traffic lane. Our model also allows the possibility that average position within the lane may vary from driver to driver. We demonstrate how to fit the model using standard statistical procedures available in software packages such as SAS. We used a fixed-base driving simulator to obtain data from 67 drivers with Alzheimer's disease and 128 elderly drivers without dementia. Using these data, we estimated the subject-specific parameters of our model, and we compared the two groups with respect to these parameters. We found that the parameters based on our model were able to distinguish between the groups in an interpretable manner. Hence, this model may be a useful tool to define outcome measures for observational and interventional driving studies.     

Age dependence of attitudes and knowledge in cyclists

A number of factors related to bicycle accidents were studied, namely, knowledge of priority rules, attitude and self-reported behavior regarding traffic rules, and general opinions about the safety of the traffic behavior of cyclists and drivers. In order to get an indication of the influence of these factors at different stages of the life span, subjects ranging from 9 to 83 years of age were represented in the study. The relationship between age and the various measures was found to be U-shaped in most cases. The older cyclists and the 9 to 11 year olds, the two groups that are most at risk, were deficient regarding knowledge while showing the most positive attitudes. Implications with respect to possible counter measures are discussed.     

Factors related to driving difficulty and habits in older drivers

OBJECTIVES: To evaluate the association between chronic medical conditions, functional, cognitive, and visual impairments and driving difficulty and habits among older drivers. DESIGN: Cross-sectional study. SETTING: Mobile County, Alabama. PARTICIPANTS: A total of 901 residents of Mobile County, Alabama aged 65 or older who possessed a driver's license in 1996. MEASUREMENTS: Information on demographic characteristics, functional limitations, chronic medical conditions, driving habits, and visual and cognitive function were collected via telephone. The three dependent variables in this study were difficulty with driving, defined as any reported difficulty in > or = 3 driving situations (e.g. at night), low annual estimated mileage, defined as driving less than 3000 miles in 1996, and low number of days ( < or = 3) driven per week. RESULTS: A history of falls, kidney disease or stroke was associated with difficulty driving. Older drivers with a history of kidney disease were more likely to report a low annual mileage than subjects without kidney disease. Low annual mileage was also associated with cognitive impairment. In general, older drivers with a functional impairment were more likely to drive less than 4 days per week. Older drivers with a history of cataracts or high blood pressure were more likely to report a low number of days driven per week, while subjects with visual impairment were at increased risk of experiencing difficulty driving as well as low number of days driven per week. CONCLUSIONS: The results underscore the need to further understand the factors negatively affecting driving independence and mobility in older drivers, as well as the importance of improved communication between older adults and health care professionals regarding driving.     

Driver distraction: the effects of concurrent in-vehicle tasks, road environment complexity and age on driving performance

This paper presents the findings of a simulator study that examined the effects of distraction upon driving performance for drivers in three age groups. There were two in-vehicle distracter tasks: operating the vehicle entertainment system and conducting a simulated hands-free mobile phone conversation. The effect of visual clutter was examined by requiring participants to drive in simple and complex road environments. Overall measures of driving performance were collected, together with responses to roadway hazards and subjective measures of driver perceived workload. The two in-vehicle distraction tasks degraded overall driving performance, degraded responses to hazards and increased subjective workload. The performance decrements that occurred as a result of in-vehicle distraction were observed in both the simple and complex highway environments and for drivers in different age groups. One key difference was that older drivers traveled at lower mean speeds in the complex highway environment compared with younger drivers. The conclusions of the research are that both in-vehicle tasks impaired several aspects of driving performance, with the entertainment system distracter having the greatest negative impact on performance, and that these findings were relatively stable across different driver age groups and different environmental complexities.     

Induction effects for heterochromatic brightness matching, heterochromatic flicker photometry, and minimally distinct border: implications for the neural mechanisms underlying induction

Brightness induction refers to the finding that the apparent brightness of a stimulus changes when surrounded by a black versus a white stimulus. In the current study, we investigated the effects of black/white surrounding stimuli on settings made between red and green stimuli on three different tasks: heterochromatic brightness matching (HBM), heterochromatic flicker photometry (HFP), and minimally distinct border (MDB). For HBM, subjects varied the relative luminance between the red and green stimuli so that the brightness of the two colors appeared equal. For the two other tasks, matches were made based on minimizing red/green flicker (HFP) or the saliency of a red/green border (MDB). For all three tasks, the presence of black/white surrounding stimuli significantly altered red/green settings, demonstrating the existence of induction effects. These results are discussed in terms of which underlying color pathways (L+ M versus L-M) may contribute to induction effects for the different tasks.