Identification of aggressive driving from naturalistic data in car-following situations

Introduction: Aggressive driving has been associated as one of the causes for crashes, sometimes with very serious consequences. The objective of this study is to investigate the possibility of identifying aggressive driving in car-following situations on motorways by simple jerk metrics derived from naturalistic data. Method: We investigate two jerk metrics, one for large positive jerk and the other for large negative jerk, when drivers are operating the gas and brake pedal, respectively. Results: The results obtained from naturalistic data from five countries in Europe show that the drivers from different countries have a significantly different number of large positive and large negative jerks. Male drivers operate the vehicle with significantly larger number of negative jerks compared to female drivers. The validation of the jerk metrics in identifying aggressive driving is performed by tailgating (following a leading vehicle in a close proximity) and by a violator/non-violator categorization derived from self-reported questionnaires. Our study shows that the identification of aggressive driving could be reinforced by the number of large negative jerks, given that the drivers are tailgating, or by the number of large positive jerks, given that the drivers are categorized as violators. Practical applications: The possibility of understanding, classifying, and quantifying aggressive driving behavior and driving styles with higher risk for accidents can be used for the development of driver support and coaching programs that promote driver safety and are enabled by the vast collection of driving data from modern in-vehicle monitoring and smartphone technology.     

The hybrid model of empirical wavelet transform and relevance vector regression for monthly wind speed prediction

ABSTRACT

In order to improve the prediction ability for the monthly wind speed of RVR, the hybrid model of empirical wavelet transform and relevance vector regression (EWT-RVR) is proposed for monthly wind speed prediction in this study. Compared with empirical mode decomposition (EMD), empirical wavelet transform (EWT) can obtain a more consistent decomposition and have a mathematical theory. In order to testify the superiority of EWT-RVR, several traditional RVR models are used to compare with the proposed EWT-RVR method under the situation of the same embedding dimensions. The experimental results show that the proposed EWT-RVR method has a better prediction ability for monthly wind speed than RVR. It can be concluded that the proposed EWT-RVR method for monthly wind speed is effective.     

Validation of the propensity for angry driving scale

Problem: This study examined the validity of the Propensity for Angry Driving Scale (PADS; DePasquale, J. P., Geller, E. S., Clarke, S. W., and Littleton, L. C. (2001). Measuring road rage: Development of the Propensity for Angry Driving Scale. Journal of Safety Research, 32, 1–16) in predicting aggressive driving. Method: The PADS and the Driving Anger Scale (DAS; Deffenbacher, J. L., Oetting, E. R., and Lynch, R. S. (1994). Development of a driving anger scale. Psychological reports, 74, 83–91.) were administered to 232 college student volunteers with measures of aggressive and risky driving. Results: Convergent and discriminant validity of the PADS were supported through relationships among measures of similar constructs. The PADS significantly (p<.05) predicted moving tickets, minor accidents, aggressive driving, risky driving, and maladaptive driving anger expression, above and beyond gender, miles driven per week, and trait anger. Discussion: Findings suggest that the PADS is a useful predictor of aggressive driving and has some advantages over the DAS. Impact on Industry: The PADS is an effective predictor of aggressive driving that complements established measures like the DAS and provides researchers with another valuable tool for the assessment of aggressive driving.     

Aggressive behavior while driving as predictor of self-reported car crashes

PROBLEM: In Greece, there is a lack of scientific evidence on the relationship between aggressive behavior while driving and young drivers' involvement in car crashes; this study examined this potential relationship. METHODS: The randomly selected samples of 356 young drivers (18-24 years old) were interviewed through a questionnaire of self-reported car crash involvement, which mainly focused on their behavior on the road and the number of car crashes in which they had been involved. RESULTS: The statistical methods used were principal components analysis (PCA) and multiple regression analysis. Two factors relevant to aggressive driving emerged: (a) driving violations and (b) irritability while driving. The multivariate model suggested that driving just for fun (joyriding) and irritability were predictors of young drivers' involvement in car crashes. It was found that younger age was negatively associated with young drivers' involvement in car crashes. IMPACT ON GOVERNMENT AND INDUSTRY: The findings of this study can contribute in the formation of public policies aiming to prevent young drivers' car crashes. These findings can also be the starting point of some health promotion interventions trying to reduce car crashes and casualties on the road. Finally, the insurance companies may be interested in applying these findings into their field of interest.     

Chemical ornaments of male lizards <Emphasis Type="Italic">Psammodromus algirus</Emphasis> may reveal their parasite load and health state to females

Evidence for parasite-mediated sexual selection has been found in many species that use visual ornaments to attract females. However, in many animals, variation in female responses to scents of parasitized males suggests that parasitic infections might also affect information conveyed by pheromones (i.e., chemical ornaments). Thus, pheromones might also function in parasite-mediated sexual selection. We show here that female lizards Psammodromus algirus responded differently to femoral gland secretions of males according to the parasite load and health of these males. Scents of healthier males elicited more tongue flicks (a chemosensory behavior) by females, suggesting that these scents were more attractive. Chemical analyses showed that parasite load and the T-cell-mediated immune response were related to the variability in the proportions of some lipids in secretions of males. Further trials testing the chemosensory responses of females to chemical standards indicated that females actually discriminated the chemicals related to males’ health from other chemicals found in secretions. We suggest that these chemical ornaments may provide reliable information on the health and degree of parasitic infection of a male.     

Diet quality affects an attractive white plumage pattern in dark-eyed juncos (Junco hyemalis)

Sexually selected traits that act as signals of quality often display some degree of condition dependence. In birds, condition dependence of ornamental plumage is often mediated by production costs related to acquisition or allocation of dietary resources. White plumage ornaments, however, have often been assumed to be inexpensive because their production requires neither pigment nor specialized feather structure. In male dark-eyed juncos (Junco hyemalis), the size of a white patch on the tail contributes to attractiveness and mating success. Using captive males, we examined the effects of diet quality on the size and brightness of the tail-white patch. After removing four tail feathers to induce replacement, we maintained subjects on a subsistence (low-protein) or enriched (high-protein) diet while induced feathers grew. Birds that received an enriched diet grew their feathers more quickly and grew larger, brighter white patches. Feather growth rate was positively correlated with the increase in the size of the tail-white patch, a relationship that was stronger in the subsistence diet group. However, within diet treatments, faster-grown feathers were slightly duller. Taken together, these results suggest that variation in diet quality may lead to condition-dependent expression of tail white and that condition dependence may be stronger in more stressful environments. We suggest a mechanism by which increased feather growth rate may lead to an increase in the size of the tail-white patch and discuss potential trade-offs between signal size and brightness.     

Unusual echolocation behavior in a small molossid bat, <Emphasis Type="Italic">Molossops temminckii,</Emphasis> that forages near background clutter

When searching for flying insects, Molossops temminckii uses unusual echolocation calls characterized by upward modulation of frequency vs time (UFM). Call frequency increases asymptotically in the relatively long (∼8 ms) pulses from a starting frequency of ∼40 kHz to a long narrowband tail at ∼50 kHz. When approaching a prey, the bat progressively increases the duration of calls and intersperses in the sequence broadband downwardly frequency-modulated signals with a terminal frequency of about 53 kHz, which totally replaces the UFM signals at the end of the approach phase. The sequence progresses to a capture buzz resembling those from other molossid and vespertilionid bats. The M. temminckii wing morphology is characterized by an average aspect ratio and a high wing loading, suggesting that it is more maneuverable than the typical Molossidae but less than typical Vespertilionidae. M. temminckii regularly forages near clutter, where it needs to pay attention to the background and might face forward and backward masking of signals. We hypothesize that the UFM echolocation signals of M. temminckii represent an adaptation to foraging near background clutter in a not very maneuverable bat needing a broad attention window. The broadband component of the signal might serve for the perception of the background and the narrowband tail for detection and perhaps classification of prey. Bats may solve the signal masking problems by separating emission and echoes in the frequency domain. The echolocation behavior of M. temminckii may shed light on the evolution of the narrowband frequency analysis echolocation systems adopted by some bats foraging within clutter.     

The evolution of Müllerian mimicry

It is now 130 years since Fritz Müller proposed an evolutionary explanation for the close similarity of co-existing unpalatable prey species, a phenomenon now known as Müllerian mimicry. Müller's hypothesis was that unpalatable species evolve a similar appearance to reduce the mortality involved in training predators to avoid them, and he backed up his arguments with a mathematical model in which predators attack a fixed number (n) of each distinct unpalatable type in a given season before avoiding them. Here, I review what has since been discovered about Müllerian mimicry and consider in particular its relationship to other forms of mimicry. Müller's specific model of associative learning involving a "fixed n" in a given season has not been supported, and several experiments now suggest that two distinct unpalatable prey types may be just as easy to learn to avoid as one. Nevertheless, Müller's general insight that novel unpalatable forms have higher mortality than common unpalatable forms as a result of predation has been well supported by field experiments. From its inception, there has been a heated debate over the nature of the relationship between Müllerian co-mimics that differ in their level of defence. There is now a growing awareness that this relationship can be mediated by many factors, including synergistic effects between co-mimics that differ in their mode of defence, rates of generalisation among warning signals and concomitant changes in prey density as mimicry evolves. I highlight areas for future enquiry, including the possibility of Müllerian mimicry systems based on profitability rather than unprofitability and the co-evolution of defence.     

Life history costs of olfactory status signalling in mice

Large body size confers a competitive advantage in animal contests but does not always determine the outcome. Here we explore the trade-off between short-term achievement of high social status and longer-term life history costs in animals which vary in competitive ability. Using laboratory mice, Mus musculus, as a model system, we show that small competitors can initially maintain dominance over larger males by increasing investment in olfactory status signalling (scent-marking), but only at the cost of reduced growth rate and body size. As a result they become more vulnerable to dominance reversals later in life. Our results also provide the first empirical information about life history costs of olfactory status signals. Received: 15 December 1999 / Revised: 6 June 2000 / Accepted: 24 June 2000     

Dufour gland secretion in the harvester ant genus <Emphasis Type="Italic">Pogonomyrmex</Emphasis>

Summary. Dufour gland secretions of the harvester ants Pogonomyrmex barbatus, P. rugosus and P. maricopa were investigated. The glandular blends exhibit species specific patterns, but more importantly, based on indiviual profiles of Dufour gland contents of colony members it is possible to separate the colonies from each other in each species. It is possible that these collective colony specific cues serve as longer lasting trunk route markers. Behavioral tests demonstrate that workers of P. rugosus prefer homing routes marked by members of their own colony to routes marked by a foreign conspecific colony.