Smarter bridges,why and how?

Bridge safety, especially during extreme events, is enhanced by measurement and monitoring of critical bridge components. Enhanced safety, reliability and efficient maintenance can result from improved incident detection and assessment enabled by ‘smarter’ bridges. This article considers the problems, and discusses some solutions being investigated by the US Federal Highway Administration.     

Who,what, why? An exploration of JoVE scientific video publications in tweets

This paper investigates how and why scientific video articles are communicated on Twitter. We use video articles published in the Journal of Visualized Experiments (JoVE) as our objects of study. We harvested tweets from October 2011 to November 2015 that contained one or more JoVE links. These tweets “citing” JoVE articles were analyzed both statistically and qualitatively. In this paper, we present the distribution of these tweets, with a closer look at the affordance use of Twitter including hashtags and mentions. In addition, we conducted a content analysis of the sampled Twitter accounts and tweets. We present the coding schemes and results of both Twitter user accounts and tweets text. In addition to the analysis of the coding results, we discuss the content of the tweets with particular attention to issues including the video/visual feature mentioned, the role of Twitter bots, and self-promotion of different stakeholders in the Twitter communication of JoVE video publications.     

ResearchGate and Google Scholar: how much do they differ in publications,citations and different metrics and why?

ResearchGate has emerged as a popular professional network for scientists and researchers in a very short span. Similar to Google Scholar, the ResearchGate indexing uses an automatic crawling algorithm that extracts bibliographic data, citations, and other information about scholarly articles from various sources. However, it has been observed that the two platforms often show different publication and citation data for the same institutions, journals, and authors. While several previous studies analysed different aspects of ResearchGate and Google Scholar, the quantum of differences in publications, citations, and metrics between the two and the probable reasons for the same are not explored much. This article, therefore, attempts to bridge this research gap by analysing and measuring the differences in publications, citations, and different metrics of the two platforms for a large data set of highly cited authors. The results indicate that there are significantly high differences in publications and citations for the same authors captured by the two platforms, with Google Scholar having higher counts for a vast majority of the cases. The different metrics computed by the two platforms also differ in their values, showing different degrees of correlation. The coverage policy, indexing errors, author attribution mechanism, and strategy to deal with predatory publishing are found to be the main probable reasons for the differences in the two platforms.

     

Who are the traffic offenders among ethnic groups and why?

Marginalized populations, particularly ethnic minorities, are often at a higher risk of being involved in traffic crashes and committing traffic violations. Prominent explanations for this “ethnic traffic risk gap” include cultural and socioeconomic factors, usually measured at an aggregate level. In particular, it has been hypothesized that ethnic minorities commit traffic violations as a form of social resistance to what they perceive to be an oppressing regime. The current study examined the mechanisms underlying traffic violations at the individual level within a single ethnic minority, Israeli-Arabs. The study sample (n = 231) included a group of known offenders (n = 60) and non-offenders (n = 171), all of which completed the Traffic Violation Questionnaire. The results show that offenders and non-offenders tended to have different types of occupations, although these did not translate into significant differences in level of income. Offenders reported significantly lower levels of trust in some hegemonic institutions (the police, government ministries) but not others (parliament, the juridical system). However, offenders displayed remarkably different daily activity patterns, including much higher exposure to traffic (3 h/day vs. 0.75) and more complex trip patterns. Our results find little support for the social resistance hypothesis, as it fails to explain the differential treatment of hegemonic institutions. Daily activity patterns stand out as a central mechanism influencing the risk of violations. These results suggest policymakers should adopt a holistic approach for traffic safety interventions but avoid monolithic views of ethnic minorities which may lead to an inefficient use of resources.     

Deformable wing kinematics in the desert locust: how and why do camber,twist and topography vary through the stroke?

Here, we present a detailed analysis of the wing kinematics and wing deformations of desert locusts (Schistocerca gregaria, Forskål) flying tethered in a wind tunnel. We filmed them using four high-speed digital video cameras, and used photogrammetry to reconstruct the motion of more than 100 identified points. Whereas the hindwing motions were highly stereotyped, the forewing motions showed considerable variation, consistent with a role in flight control. Both wings were positively cambered on the downstroke. The hindwing was cambered through an ‘umbrella effect’ whereby the trailing edge tension compressed the radial veins during the downstroke. Hindwing camber was reversed on the upstroke as the wing fan corrugated, reducing the projected area by 30 per cent, and releasing the tension in the trailing edge. Both the wings were strongly twisted from the root to the tip. The linear decrease in incidence along the hindwing on the downstroke precisely counteracts the linear increase in the angle of attack that would otherwise occur in root flapping for an untwisted wing. The consequent near-constant angle of attack is reminiscent of the optimum for a propeller of constant aerofoil section, wherein a linear twist distribution allows each section to operate at the unique angle of attack maximizing the lift to drag ratio. This implies tuning of the structural, morphological and kinematic parameters of the hindwing for efficient aerodynamic force production.     

Diversity and interdisciplinarity: how can one distinguish and recombine disparity,variety, and balance?

Scientometrics - The dilemma which remained unsolved using Rao-Stirling diversity, namely of how variety and balance can be combined into “dual concept diversity” (Stirling in SPRU...     

Where, and how, does a nanowire break?

Using molecular dynamics (MD) simulation, we studied the structural transformation and breaking mechanism of a single crystalline copper nanowire under continuous strain. At a certain strain rate, an ensemble of relaxed initial states of the nanowire can preferentially go through one or more paths of deformation. In each deformation path, disordered atoms can be generated at the specific positions of the nanowire, where necking and breaking take place afterward. Such a breaking position is not predetermined; multiple initial states lead to a strain-rate-dependent, statistical distribution of breaking positions.     

Prediction of driving ability: Are we building valid models?

The prediction of on-road driving ability using off-road measures is a key aim in driving research. The primary goal in most classification models is to determine a small number of off-road variables that predict driving ability with high accuracy. Unfortunately, classification models are often over-fitted to the study sample, leading to inflation of predictive accuracy, poor generalization to the relevant population and, thus, poor validity. Many driving studies do not report sufficient details to determine the risk of model over-fitting and few report any validation technique, which is critical to test the generalizability of a model. After reviewing the literature, we generated a model using a moderately large sample size (n = 279) employing best practice techniques in the context of regression modelling. By then randomly selecting progressively smaller sample sizes we show that a low ratio of participants to independent variables can result in over-fitted models and spurious conclusions regarding model accuracy. We conclude that more stable models can be constructed by following a few guidelines.     

Suspicious minds? – users’ perceptions of autonomous and connected driving

Abstract

In this article, the public perception and acceptance of novel vehicle technologies – autonomous driving (AD) and connected driving (CD) – is investigated. Following a multistep empirical procedure, we explore participants’ cognitions towards AD and CD. Therefore, a questionnaire study was run in which the perceived benefits and barriers of the technologies were evaluated by 443 participants in a wide age range (18–76 years). In addition, we took a closer look at the impact of user diversity (gender, age, need for privacy, control, risk taking tolerance and technical self-efficacy) on the evaluation of both driving technologies. Finally, cluster analyses were used out to identify evaluation profiles in both benefits and barriers, respectively. Overall, CD is seen significantly more positive compared to AD. With increasing risk taking tolerance and technical self-efficacy, the perception of the benefits was higher. In contrast, the perception of barriers in novel vehicle technologies was independent of personality factors and attitudes. Here, privacy and data protection issues were seen as key disadvantages. The findings can be used to develop timely and individually tailored public information and communication strategies for automated and connected vehicle technologies.     

Are drivers aware of sleepiness and increasing crash risk while driving?

Drivers are advised to take breaks when they feel too tired to drive, but there is question over whether they are able to detect increasing fatigue and sleepiness sufficiently to decide when to take a break. The aim of this study was to investigate the extent to which drivers have access to cognitive information about their current state of sleepiness, likelihood of falling asleep, and the implications for driving performance and the likelihood of crashing. Ninety drivers were recruited to do a 2 h drive in a driving simulator. They were divided into three groups: one made ratings of their sleepiness, likelihood of falling asleep and likelihood of crashing over the next few minutes at prompts occurring at 200 s intervals throughout the drive, the second rated sleepiness and likelihood of falling asleep at prompts but pressed a button on the steering wheel at any time if they felt they were near to crashing and the third made no ratings and only used a button-press if they felt a crash was likely. Fatigue and sleepiness was encouraged by monotonous driving conditions, an imposed shorter than usual sleep on the night before and by afternoon testing. Drivers who reported that they were possibly, likely or very likely to fall asleep in the next few minutes, were more than four times more likely to crash subsequently. Those who rated themselves as sleepy or likely to fall asleep had a more than 9-fold increase in the hazards of a centerline crossing compared to those who rated themselves as alert. The research shows clearly that drivers can detect changes in their levels of sleepiness sufficiently to make a safe decision to stop driving due to sleepiness. Therefore, road safety policy needs to move from reminding drivers of the signs of sleepiness and focus on encouraging drivers to respond to obvious indicators of fatigue and sleepiness and consequent increased crash risk.     

Are anxiety and fear separable emotions in driving? A laboratory study of behavioural and physiological responses to different driving environments

Research into anxiety and driving has indicated that those higher in anxiety are potentially more dangerous on the roads. However, simulator findings suggest that conclusions are mixed at best. It is possible that anxiety is becoming confused with fear, which has a focus on more clearly defined sources of threat from the environment, as opposed to the internal, thought-related process associated with anxiety. This research aimed to measure feelings of fear, as well as physiological and attentional reactions to increasing levels of accident risk. Trait anxiety was also measured to see if it interacted with levels of risk or its associated reactions. Participants watched videos of driving scenarios with varying levels of accident risk and had to rate how much fear they would feel if they were the driver of the car, whilst skin conductance, heart rate, and eye movements were recorded. Analysis of the data suggested that perceptions of fear increased with increasing levels of accident risk, and skin conductance reflected this pattern. Eye movements, when considered alongside reaction times, indicated different patterns of performance according to different dangerous situations. These effects were independent of trait anxiety, which was only associated with higher rates of disliking driving and use of maladaptive coping mechanisms on questionnaires. It is concluded that these results could provide useful evidence in support for training-based programmes; it may also be beneficial to study trait anxiety within a more immersive driving environment and on a larger scale.     

Rise of multi-authored papers in economics: Demise of the ‘lone star’ and why?

Scientometrics - This paper builds on previous work by reviewing the key literature relating to the rise in co-authorship in economics and by presenting further new evidence on several features of...     

With whom do researchers collaborate and why?

Although research collaboration has been studied extensively, we still lack understanding regarding the factors stimulating researchers to collaborate with different kinds of research partners including members of the same research center or group, researchers from the same organization, researchers from other academic and non-academic organizations as well as international partners. Here, we provide an explanation of the emergence of diverse collaborative ties. The theoretical framework used for understanding research collaboration couples scientific and technical human capital embodied in the individual with the social organization and cognitive characteristics of the research field. We analyze survey data collected from Slovenian scientists in four scientific disciplines: mathematics; physics; biotechnology; and sociology. The results show that while individual characteristics and resources are among the strongest predictors of collaboration, very different mechanisms underlie collaboration with different kinds of partners. International collaboration is particularly important for the researchers in small national science systems. Collaboration with colleagues from various domestic organizations presents a vehicle for resource mobilization. Within organizations collaboration reflects the elaborated division of labor in the laboratories and high level of competition between different research groups. These results hold practical implications for policymakers interested in promoting quality research.     

Some questions on the corrosion of steel in concrete—Part I: when,how and how much steel corrodes

It is widely accepted that concrete-embedded steel is in a passive state. However, there are some exceptional circumstances that induce corosion in an active state within concrete structures, thereby severely reducing their durability. This two-part paper analyses some major questions which, however elementary they may be, are still controversial in scientific, technical and economic terms. The first part provides answers to the following questions on the steel/concrete/environment system:

1. How does steel in concrete normally behave?
2. What are the initiating factors for depassivation?
3. What are the effects of corrosion?
4. What is the morphology of corrosion in the active state? and
5. What is the corrosion rate threshold above which the durability of reinforced concrete structures is impaired? The answers to these questions are provided in light of experimental results, most of which were obtained by the authors themselves.

     

The effectiveness of enforcement and publicity campaigns on serious crashes involving young male drivers: Are drink driving and speeding similar?

This study re-evaluated the effectiveness of the anti-drink driving and anti-speeding enforcement and publicity campaigns implemented in the Australian State of Victoria which have thus far yielded mixed results in several evaluations. As opposed to previous evaluations, this study focused on the effects of these campaigns on young male drivers who formed the primary target and examined the combined effects of the campaigns on the total number of serious crashes. Our results showed that the anti-drink driving enforcement and publicity campaigns had a significant independent effect in reducing crashes but their interactive effect was anti-complementary. Conversely, the anti-speeding enforcement and publicity campaigns had no independent effect but their interactive effect was significant in reducing serious crashes involving young male drivers.     

Transport networks and their use: how real can modelling get?

The context for modelling transport systems and their use is set out. Such modelling is based on representing the transport system by a network of nodes and links, and the characteristics of this representation needed to reflect the principal realities of the system are outlined. The characteristics of use of the system that need to be reflected are described. Purposes of the modelling are set out and its evolution is described, starting from the basic traffic assignment model and discussing its generalizations and extensions in the search for greater realism-first in steady-state modelling for fixed demand, and then considering variable demand and time dependence. Further progress towards appropriate realism is seen as requiring communication and cooperation between the modellers and the users of models, helped perhaps by combining the advantages of analytical modelling and microsimulation.     

Are child occupants a significant source of driving distraction?

Driver distraction represents a well-documented and growing contribution to the road safety problem. This study used a naturalistic, observational approach to examine if children in vehicles are a significant source of driving distraction. Families with children aged between 1 and 8 years drove an instrumented “study vehicle” on their regular trips for 3 weeks. A discrete video recording system in the vehicle provided images of the driver and front seat passenger, the rear seat child passengers and the traffic ahead. The video-recordings inside and outside the vehicle were analysed to identify potential distracting activities, where ‘distraction’ was broadly defined as any activity that distracted the driver or competed for their attention while driving. In addition, all potentially distracting activities that involved the driver looking away from the forward roadway for more than 2 s while the vehicle was in motion were also coded. Video-recordings were analysed for 92 driving journeys undertaken by 12 families including 25 children and 19 drivers. The mean journey duration was approximately 16 min (range: 2 min–3 h 34 min). Most journeys were undertaken during the day (89%), with the mother driving (65%) and without a front seat passenger (64%). Driving journeys were predominantly undertaken in urban areas (97%), on suburban roads/streets (94%), and under low complexity traffic conditions (91%). Most journeys involved some source of potential driver distraction (98%), with drivers distracted for 18% of the driving journey. The most frequent types of distracting activities that drivers engaged in included: touching their head or their face (35%), interacting with child passengers in the rear seat (12%), and engaging with the front seat passenger (9%). Almost three-quarters of these potentially distracting activities were engaged in by the driver while the study vehicle was in motion (72%) and 14% of all potentially distracting activities involved the driver's eyes off the roadway for greater than 2 s while the vehicle was in motion, thereby potentially doubling their crash risk. The most frequent child-related activities that drivers engaged in included: turning to look at the rear seated occupants or viewing the children using the rear-view mirror (76.4%), engaging in conversation with their children (16%), assisting their children (e.g., passing food and drink [7%]) and playing with their children (1%). Drivers spent significantly longer periods of time engaged in non-child occupant-related activities compared with child occupant-related activities and were significantly more likely to have their eyes off the forward roadway for greater than 2 s while engaged in non-child occupant-related activities (14%) compared to child occupant-related activities (10%). The results suggest that drivers need to be educated about the potential crash and injury risks associated with both child occupant-related and non-child occupant-related activities while driving their vehicle.     

Are aggressive people aggressive drivers? A study of the relationship between self-reported general aggressiveness, driver anger and aggressive driving

In this study the relationships among self-reported general aggressiveness, impulsiveness, driver anger, and aggressive responses to anger-provoking situations on the road were studied. The British version of a driver anger scale (UK DAS), aggression questionnaire (AQ), and an impulsiveness questionnaire (I7) together with background questions (gender, age, annual mileage) were administered to a sample of 270 British drivers. Variation in strength of correlations between anger and aggressive reactions in the 21 UK DAS items showed that the relationship between driver anger and aggression depends in part on the characteristics of the situation. In addition, three path models for describing the relationships among the measures were constructed separately for women and men. The models suggested that the effects of verbal aggressiveness on self-reported driver aggression were mediated by driver anger whereas physical aggressiveness was directly related to aggressive behaviour. Age was negatively related to both driver anger and aggression among men whereas annual mileage was negatively related to aggression among women. The models constructed indicate that aggressive driver behaviour is a complex phenomenon with a range of psychological causes.