51,787 research outputs found
Co-detection of acoustic emissions during failure of heterogeneous media: new perspectives for natural hazard early warning
A promising method for real time early warning of gravity driven rupture that
considers both the heterogeneity of natural media and characteristics of
acoustic emissions attenuation is proposed. The method capitalizes on
co-detection of elastic waves emanating from micro-cracks by multiple and
spatially separated sensors. Event co-detection is considered as surrogate for
large event size with more frequent co-detected events marking imminence of
catastrophic failure. Using a spatially explicit fiber bundle numerical model
with spatially correlated mechanical strength and two load redistribution
rules, we constructed a range of mechanical failure scenarios and associated
failure events (mapped into AE) in space and time. Analysis considering
hypothetical arrays of sensors and consideration of signal attenuation
demonstrate the potential of the co-detection principles even for insensitive
sensors to provide early warning for imminent global failure
Methodology to assess safety effects of future Intelligent Transport Systems on railway level crossings
There is consistent evidence showing that driver behaviour contributes to crashes and near miss incidents at railway level crossings (RLXs). The development of emerging Vehicle-to-Vehicle and Vehicle-to-Infrastructure technologies is a highly promising approach to improve RLX safety. To date, research has not evaluated comprehensively the potential effects of such technologies on driving behaviour at RLXs. This paper presents an on-going research programme assessing the impacts of such new technologies on human factors and drivers’ situational awareness at RLX. Additionally, requirements for the design of such promising technologies and ways to display safety information to drivers were systematically reviewed. Finally, a methodology which comprehensively assesses the effects of in-vehicle and road-based interventions warning the driver of incoming trains at RLXs is discussed, with a focus on both benefits and potential negative behavioural adaptations. The methodology is designed for implementation in a driving simulator and covers compliance, control of the vehicle, distraction, mental workload and drivers’ acceptance. This study has the potential to provide a broad understanding of the effects of deploying new in-vehicle and road-based technologies at RLXs and hence inform policy makers on safety improvements planning for RLX
Stuck in Traffic (SiT) Attacks: A Framework for Identifying Stealthy Attacks that Cause Traffic Congestion
Recent advances in wireless technologies have enabled many new applications
in Intelligent Transportation Systems (ITS) such as collision avoidance,
cooperative driving, congestion avoidance, and traffic optimization. Due to the
vulnerable nature of wireless communication against interference and
intentional jamming, ITS face new challenges to ensure the reliability and the
safety of the overall system. In this paper, we expose a class of stealthy
attacks -- Stuck in Traffic (SiT) attacks -- that aim to cause congestion by
exploiting how drivers make decisions based on smart traffic signs. An attacker
mounting a SiT attack solves a Markov Decision Process problem to find
optimal/suboptimal attack policies in which he/she interferes with a
well-chosen subset of signals that are based on the state of the system. We
apply Approximate Policy Iteration (API) algorithms to derive potent attack
policies. We evaluate their performance on a number of systems and compare them
to other attack policies including random, myopic and DoS attack policies. The
generated policies, albeit suboptimal, are shown to significantly outperform
other attack policies as they maximize the expected cumulative reward from the
standpoint of the attacker
Measuring working memory load effects on electrophysiological markers of attention orienting during a simulated drive
Intersection accidents result in a significant proportion of road fatalities, and attention allocation likely plays a role. Attention allocation may depend on (limited) working memory (WM) capacity. Driving is often combined with tasks increasing WM load, consequently impairing attention orienting. This study (n = 22) investigated WM load effects on event-related potentials (ERPs) related to attention orienting. A simulated driving environment allowed continuous lane-keeping measurement. Participants were asked to orient attention covertly towards the side indicated by an arrow, and to respond only to moving cars appearing on the attended side by pressing a button. WM load was manipulated using a concurrent memory task. ERPs showed typical attentional modulation (cue: contralateral negativity, LDAP; car: N1, P1, SN and P3) under low and high load conditions. With increased WM load, lane-keeping performance improved, while dual task performance degraded (memory task: increased error rate; orienting task: increased false alarms, smaller P3).
Practitioner Summary: Intersection driver-support systems aim to improve traffic safety and flow. However, in-vehicle systems induce WM load, increasing the tendency to yield. Traffic flow reduces if drivers stop at inappropriate times, reducing the effectiveness of systems. Consequently, driver-support systems could include WM load measurement during driving in the development phase
Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 159
This bibliography lists 257 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1976
Communication: 'What now for Britain?' The state department's intelligence assessment of the 'Special Relationship' 7 February 1968
The period 1967-1968 was a difficult one for the Anglo-American relationship, as a result of developments such as British defense cuts “East of Suez.” In the run-up to a visit to Washington by Prime Minister Harold Wilson in February 1968, the State Department's Intelligence and Research Bureau provided a lively and detailed evaluation of American bonds with Britain. The analysis maintained that the relationship was based on deeply established cooperation in defense, diplomacy and intelligence, and that despite recent problems Britain would remain of unparalleled importance as an American ally. The immediate impact of the memorandum in the White House of Lyndon B. Johnson was quite limited, but among other things the document helps to explain the ready blossoming of close high-level Anglo-American bonds during, for example, the Falklands War of 1982. The most important sections of the memorandum are reproduced, and a brief analysis is provided to put the issues in context
Human factor guidelines for the design of safe in-car traffic information services
The first version of the “Human factor guidelines for the design of safe in-car traffic information services” was compiled in 2014. In 2016 the guidelines were updated by Connecting Mobility/ DITCM, and the present version is a further update of that version. New systems have been introduced into the marked, and the role of apps on smartphones has increased. This report was updated to include recent developments such as gesture control. The guidelines are aimed at in-car traffic information services
DESIGNING AN INDUCTIVE SENSOR FOR ROAD TRAFFIC MONITORING SYSTEMS AND CONTROL
The purpose of this study is to design an inductive sensor,which detect a vehicle on the
road. The main objectives are to design an inductive sensor using an enameled copper
wire and interface it to an electronics circuit. The analyses of experiments will mainly
the important part of this project. Then, a demonstration will be held to demonstrate the
sensing process using a working model.
This sensor can change some work from manual to automatically. Examples of situation
that can implement this sensor is to control the barrier automatically on the main gates
on the roads, to monitor traffic on a narrow curved portion of the road and to count the
number of vehicles from a particular point per unit time.
At present, there are a lot of sensors available in the market that uses inductive sensor.
Many methods can be used in detecting the presence of vehicle and a complete circuit
of inductive sensor has also been developed. The result from these methods will assist
in the future work of this project
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