首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
With age, a decline in attention capacity may occur and this may impact driving performance especially while distracted. Although the effect of distraction on driving performance of older drivers has been investigated, the moderating effect of attention capacity on driving performance during distraction has not been investigated yet. Therefore, the aim was to investigate whether attention capacity has a moderating effect on older drivers’ driving performance during visual distraction (experiment 1) and cognitive distraction (experiment 2). In a fixed-based driving simulator, older drivers completed a driving task without and with visual distraction (experiment 1, N = 17, mean age 78 years) or cognitive distraction (experiment 2, N = 35, mean age 76 years). Several specific driving measures of varying complexity (i.e., speed, lane keeping, following distance, braking behavior, and crashes) were investigated. In addition to these objective driving measures, subjective measures of workload and driving performance were also included. In experiment 1, crash occurrence increased with visual distraction and was negatively related to attention capacity. In experiment 2, complete stops at stop signs decreased, initiation of braking at pedestrian crossings was later, and crash occurrence increased with cognitive distraction. Interestingly, for a measure of lane keeping (i.e., standard deviation of lateral lane position (SDLP)), effects of both types of distraction were moderated by attention capacity. Despite the decrease of driving performance with distraction, participants estimated their driving performance during distraction as good. These results imply that attention capacity is important for driving. Driver assessment and training programs might therefore focus on attention capacity. Nonetheless, it is crucial to eliminate driver distraction as much as possible given the deterioration of performance on several driving measures in those with low and high attention capacity.  相似文献   

2.
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.  相似文献   

3.
4.
Scientometrics - The goal of the study here is to model and analyze the relation between research funding and citation-based performance in science to predict the diffusion of new scientific...  相似文献   

5.
6.
Gender is less of an issue in nanotechnology than in other areas of science and technology but, as Chris Toumey explains, public attitudes to nanotech do depend on gender.  相似文献   

7.
An invited panel discussed with the participants of the Symposium their views on the impact of non-targeted effects on the relationship between microdosimetry and risk. The discussion was wide ranging and lively, with divergences of opinion. At one end was the view that understanding microscopic features and distributions of radiation was an essential component to understanding risk, especially at low doses, and additionally that substantial questions and uncertainties arose from lack of information on the mechanisms and consequences of non-targeted effects. At the other end, it was held that microdosimetry and non-targeted effects are irrelevant to practical radiation protection because protection practice is already securely founded on macroscopic organ doses and direct epidemiological observations of risk. A summary of the discussion is provided in the sequence in which it took place. The session illustrated the underlying mixture of fundamental and practical issues and the need for increased scientific knowledge.  相似文献   

8.
《功能材料》2012,43(16)
基于Maxwell电磁理论中电解质悬浮液中粒子质量分数和电导率之间的关系,提出了一种判定纳米流体悬浮稳定性的方法,并进行了实验验证。实验中,采用"两步法"经超声振荡制备了CuO/去离子水纳米流体。利用电导率仪测量了不同质量分数时纳米流体的电导率,建立了质量分数与电导率的关系,同时研究了温度对电导率的影响。结果表明电导率随着颗粒质量分数的增加而增加,随着质量分数的减小而减小;随着温度的增长,电导率只有微小变化,可以忽略温度对电导率的影响。  相似文献   

9.
Australia is a vast country with an average distance of 1911 km between its eight state capital cities. The quantitative impact of this distance on collaboration practices between Australian universities and between different types of Australian universities has not been examined previously and hence our knowledge about the spatial distribution effects, if any, on collaboration practices and opportunities is very limited. The aim of the study reported here was therefore to analyse the effect of distance on the collaboration activities of humanities, arts and social science scholars in Australia, using co-authorship as a proxy for collaboration. In order to do this, gravity models were developed to determine the distance effects on external collaboration between universities in relation to geographic region and institutional alliance of 25 Australian universities. Although distance was found to have a weak impact on external collaboration, the strength of the research publishing record within a university (internal collaboration) was found to be an important factor in determining external collaboration activity levels. This finding would suggest that increasing internal collaboration within universities could be an effective strategy to encourage external collaboration between universities. This strategy becomes even more effective for universities that are further away from each other. Establishing a hierarchical structure of different types of universities within a region can optimise the location advantage in the region to encourage knowledge exchange within that region. The stronger network could also attract more collaboration between networks.  相似文献   

10.
Does relationship marketing exist in cyberspace?   总被引:1,自引:1,他引:0  
Abstract and Key Results
–  ▪ A central tenet of relationship marketing is that exchanges can be classified on a continuum ranging from episodic transactions to relational exchanges embedded in social bonds.
–  ▪ The aim of this study is to assess whether the unique transacting properties of the Internet (e.g., interactivity, connectivity) promote or hinder the development of exchange relationships.
–  ▪ The study reveals that exchanges conducted in unregulated cyber-markets are invested with similar expectations and norms regarding cooperative behavior as more traditional marketplace exchanges.
This project was supported by the Hong Kong University Grants Council (G-V639).  相似文献   

11.
The persistent overrepresentation of young drivers in road crashes is universally recognised. A multitude of factors influencing their behaviour and safety have been identified through methods including crash analyses, simulated and naturalistic driving studies, and self-report measures. Across the globe numerous, diverse, countermeasures have been implemented; the design of the vast majority of these has been informed by a driver-centric approach. An alternative approach gaining popularity in transport safety is the systems approach which considers not only the characteristics of the individual, but also the decisions and actions of other actors within the road transport system, along with the interactions amongst them. This paper argues that for substantial improvements to be made in young driver road safety, what has been learnt from driver-centric research needs to be integrated into a systems approach, thus providing a holistic appraisal of the young driver road safety problem. Only then will more effective opportunities and avenues for intervention be realised.  相似文献   

12.
Transferring and applying manufacturing principles and practices to improve both service efficiency and service quality is an important area of research in service operations. This paper advances this stream of research by examining the compatibility of operating efficiency and service quality. Specifically, our research addresses the following questions: (1) Do operating efficiency and service quality have to be traded off, or can they exist in unison (are they compatible)? and (2) What aspects of service quality have a stronger association with operating efficiency? In disentangling these important issues, we utilise a combination of data envelopment analysis (DEA) and survey-based empirical research methods. Additionally, our focus lies on a novel type of service industry where such research has been sparse. We evaluate the relative operating efficiencies of service driving agencies based on actual transaction data and subsequently analyse differences in service quality dimensions based on efficiencies. Overall, our analyses suggest important strategic decision-making implications for service operations managers and provide novel insights for academic research.  相似文献   

13.
Does exposure to residential radon increase the risk of lung cancer?   总被引:1,自引:0,他引:1  
In assessing the risks of exposure to ionising radiation, it is important to neither overstate nor understate the effects of the hazard. These requirements are often difficult to satisfy, especially since much of our knowledge about the effects of low levels of radiation is subject to rather large uncertainties. Our participants have given their opinions about the risk of lung cancer induction resulting from exposure to radon in residences. Each agrees that exposures to high concentrations of radon are hazardous. However, as with low level exposures to other types of ionising radiation, quantifying relatively small risks is quite difficult. The national and international standards setting bodies have recommended a fairly conservative approach that may overestimate the 'true' magnitude of deleterious effects and their dependence upon exposure, but this is to be expected given the uncertainties in the data and the need to avoid underestimates. A conservative approach can have both positive and negative consequences, and it is also important to neither overstate nor understate these consequences.  相似文献   

14.
A range of polymer–nanotube nanocomposites were produced using different processing routes. Both polymer-grafted and as-grown nanotubes were used and latex and polystyrene matrices investigated. The microstructures of the nanocomposites were studied, mainly by electron microscopy, in terms of the dispersion state of the nanotubes and the polymer–nanotube interface. The mechanical and electrical properties of the composites were also measured. The relationship between the microstructures observed and the resulting physical properties are discussed. It is found that composites with apparently similar microstructures can exhibit similar mechanical properties but very different electrical behaviours. Moreover, the nanocomposites produced using polymer-grafted nanotubes exhibit a clear improvement of the stress at large deformation. Thus, from our results, it appears that the mechanical and electrical properties do not necessarily depend on the same microstructural parameters. However it is still a challenge to simultaneously improve both physical properties.  相似文献   

15.
Abstract

In this paper we examine the relationship between the state trajectory deviation caused by system parameter variation and the normality of the system matrix for autonomous linear time‐invariant systems. Starting from two rational definitions of the state trajectory deviation, we derive upper bounds for the state trajectory deviation. All the results developed indicate that the normality of the system matrix is the dominant factor in the trajectory sensitivity to the system parameter variation.  相似文献   

16.
There is a rich literature on how science and technology are related to each other. Patent citation analysis is amongst the most frequently used to tool to track the strengths of links. In this paper we explore the relationship between patent citations and citation impact in nanoscience. Our observations indicate that patent-cited papers perform better in terms of standard bibliometric indicators than comparable publications that are not linked to technology in this way. More specifically, we found that articles cited in patents are more likely to be cited also by other papers. The share of highly cited papers is the most striking result. Instead of the average of 4% of all papers, 13.8% of the papers cited once or twice in patents fall into this category and even 23.5% of the papers more frequently cited in patents receive citation rates far above the standard. Our analyses further demonstrate the presence and the relevance of bandwagon effects driving the development of science and technology.  相似文献   

17.
Pallari  Elena  Lewison  Grant 《Scientometrics》2022,127(9):5159-5174
Scientometrics - Cancer and cardiovascular disease (CVD) are now two of the leading components of the global burden of disease, especially in high- and upper-middle-income countries. Causes of the...  相似文献   

18.
19.
The motorcar accident pattern of culpable young (18-25 years old) and middle-aged (35-55 years old) male and female drivers was studied in Finland. The aim was to see whether the difference in accident patterns between males and females has remained constant or whether it has changed over a 16-year period. Two different sets of traffic accident data were used. The first set of data covered all motorcar accidents for which damages were paid between 1987 and 2000, a total of 140802 accidents. The second set of data covered all fatal motor vehicle accidents in Finland during the time period between 1984 and 2000, a total of 2401 accidents. The results are analysed and discussed in the framework of a four-level hierarchical model of driving behaviour [Keskinen, E., 1996. Why do young drivers have more accidents? In: Junge, F., Fahrerinnen (Eds.), Young Drivers (in German and in English). Berichte der Bundesanstalt für Strabetaenwesen, Mensch und Sicherheit, Heft M 52, Bergisch Gladbach, Germany; Hatakka, M., Keskinen, E., Gregersen, N.P., Glad, A., Hernetkoski, K., 2002. From control of the vehicle to personal self-control; broadening the perspectives to driver education. Transportation Res. Part F 5 (3), 201-215]. Female drivers had proportionally more accidents that were connected to vehicle manoeuvring and control of traffic situations, e.g. reversing and loss-of-control accidents in a sober state and when not speeding. Male drivers, and especially young male drivers, had proportionally more accidents connected to higher levels of driving behaviour like motives for driving and attitudes. Factors that characterised these accidents were speeding and alcohol consumption. Male drivers also had previous traffic offences more often than female drivers. The study concludes that the difference in accident patterns between male and female drivers has remained constant, i.e. the accident pattern of female drivers was as dissimilar to the accident pattern of male drivers in the year 2000 as in the middle of the 1980s.  相似文献   

20.
For the calculation of effective dose (E), tissue weighting factors (wT) are needed to represent the varying radiosensitivity of the tissues in the human body with respect to the induction of stochastic effects. The wT-values have been determined by the International Commission on Radiological Protection according to the stochastic detriment of human populations during their postnatal life. This study discusses whether these wT-values can also be used for the embryo/fetus. For this purpose, the epidemiological data and some results from animal experiments on carcinogenesis after prenatal radiation exposures have been reviewed. Most human data have been obtained from studies of childhood cancers (<19 y of age) after exposures during prenatal development. These tumours differ from those observed later in life after radiation exposures of children and adults. From animal data and more recent results from the atomic bomb survivors, it appears that not only childhood cancers but also cancers occurring during adulthood would have to be considered for the determination of possible wT-values after prenatal irradiation. From the present data it is concluded that sufficient data for defining wT-values following exposure of the embryo/fetus are not available at present.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号