610 resultados para car-like vehicle visual servoing


Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper we identify the origins of stop-and-go (or slow-and-go) driving and measure microscopic features of their propagations by analyzing vehicle trajectories via Wavelet Transform. Based on 53 oscillation cases analyzed, we find that oscillations can be originated by either lane-changing maneuvers (LCMs) or car-following behavior (CF). LCMs were predominantly responsible for oscillation formations in the absence of considerable horizontal or vertical curves, whereas oscillations formed spontaneously near roadside work on an uphill segment. Regardless of the trigger, the features of oscillation propagations were similar in terms of propagation speed, oscillation duration, and amplitude. All observed cases initially exhibited a precursor phase, in which slow-and-go motions were localized. Some of them eventually transitioned into a well developed phase, in which oscillations propagated upstream in queue. LCMs were primarily responsible for the transition, although some transitions occurred without LCMs. Our findings also suggest that an oscillation has a regressive effect on car following behavior: a deceleration wave of an oscillation affects a timid driver (with larger response time and minimum spacing) to become less timid and an aggressive driver less aggressive, although this change may be short-lived. An extended framework of Newell’s CF is able to describe the regressive effects with two additional parameters with reasonable accuracy, as verified using vehicle trajectory data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Drivers' ability to react to unpredictable events deteriorates when exposed to highly predictable and uneventful driving tasks. Highway design reduces the driving task mainly to a lane-keeping manoeuvre. Such a task is monotonous, providing little stimulation and this contributes to crashes due to inattention. Research has shown that driver's hypovigilance can be assessed with EEG measurements and that driving performance is impaired during prolonged monotonous driving tasks. This paper aims to show that two dimensions of monotony - namely road design and road side variability - decrease vigilance and impair driving performance. This is the first study correlating hypovigilance and driver performance in varied monotonous conditions, particularly on a short time scale (a few seconds). We induced vigilance decrement as assessed with an EEG during a monotonous driving simulator experiment. Road monotony was varied through both road design and road side variability. The driver's decrease in vigilance occurred due to both road design and road scenery monotony and almost independently of the driver's sensation seeking level. Such impairment was also correlated to observable measurements from the driver, the car and the environment. During periods of hypovigilance, the driving performance impairment affected lane positioning, time to lane crossing, blink frequency, heart rate variability and non-specific electrodermal response rates. This work lays the foundation for the development of an in-vehicle device preventing hypovigilance crashes on monotonous roads.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It is known that the depth of focus (DOF) of the human eye can be affected by the higher order aberrations. We estimated the optimal combinations of primary and secondary Zernike spherical aberration to expand the DOF and evaluated their efficiency in real eyes using an adaptive optics system. The ratio between increased DOF and loss of visual acuity was used as the performance indicator. The results indicate that primary or secondary spherical aberration alone shows similar effectiveness in extending the DOF. However, combinations of primary and secondary spherical aberration with different signs provide better efficiency for expanding the DOF. This finding suggests that the optimal combinations of primary and secondary spherical aberration may be useful in the design of optical presbyopic corrections. © 2011 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The broad research questions of the book are: How can successful, interdisciplinary collaboration contribute to research innovation through Practice-led research? What contributes to the design, production and curation of successful new media art? What are the implications of exhibiting it across dual sites for artists, curators and participant audiences? Is it possible to create an 'intimate transaction' between people who are separated by vast distances but joined by interfaces and distributed networks? Centred on a new media work of the same name by the Transmute Collective (led by Keith Armstrong), this book provides insights from multidisciplinary perspectives. Visual, sound and performance artists, furniture designers, spatial architects, technology systems designers, and curators who collaborated in the production of Intimate Transactions discuss their design philosophies, working processes and resolution of this major new media work. Analytical and philosophical essays by international writers complement these writings on production. They consider how new media art, like Intimate Transactions, challenges traditional understandings of art, curatorial installation and exhibition experience because of the need to take into account interaction, the reconfiguration of space, co-presence, performativity and inter-site collaboration.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Acquisition of Land Act 1967 (Qld) (‘the Act’) deals with the acquisition of land by the State for public purposes and provides for compensation. The issue that arose for determination in Sorrento Medical Service Pty Ltd v Chief Executive, Dept of Main Roads [2007] QCA 73 was whether the appellant was entitled to claim compensation under the Act in respect of land resumed by the Main Roads Department over which the appellant had an exclusive contractual licence for car parking spaces for use in association with a medical centre leased by the appellant. At first instance, it was held by the Land Court that the appellant was not entitled to compensation for the resumption of the car parking spaces. The basis for this decision by the Land Court was that a right to compensation only exists where resumption has taken some proprietary interest of the claimant in the land. Following an appeal to the Land Appeal Court being dismissed, the appellant instituted the present appeal to the Queensland Court of Appeal (McMurdo P, Holmes JA and Chesterman J).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This study investigates the influence of the built environment upon residents' sense of familiarity, concept of self and thus, their facilitation of place through the theory of "The Bondage of Imposed Visual Discourse". Simone de Beauvoir's theory "The Bondage of Feminine Elegance" provides the conceptual understanding of the visual discourse between the physicality of clothing and the wearer's personal identity. This fashion theory is transposed to explore the influence of the built environment's physicality upon aged care residents' personal identity. This paper presents findings from a study of professionals' opinions in reference to the built environment of permanent residential aged care for the 'oldest-old' of Australia. The researcher conducted qualitative interviews with four participants: an architect, occupational therapist, nursing home facility manager and an aged care lobbyist in the South-East Queensland. This study is structured towards proposing "place-focused" qualitative design principles to encourage residents' sense of place through the built environment. These proposed principles are addressed with reference to existing Standards and Principles outlined by the Australian Government.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Research has demonstrated that driving a vehicle for work is potentially one of the most dangerous workplace activities. Although organisations are required to meet legislative obligations under workplace health and safety in relation to work related vehicle use, organisations are often reluctant to acknowledge and address the risks associated with the vehicle as a workplace. Recent research undertaken investigating the challenges associated with driver and organisational aspects of fleet safety are discussed. This paper provides a risk management framework to assist organisations to meet legislative requirements and reduce the risk associated with vehicle use in the workplace. In addition the paper argues that organisations need to develop and maintain a positive fleet safety culture to proactively mitigate risk in an effort to reduce the frequency and severity of vehicle related incidents within the workplace.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Inspection of solder joints has been a critical process in the electronic manufacturing industry to reduce manufacturing cost, improve yield, and ensure product quality and reliability. This paper proposes two inspection modules for an automatic solder joint classification system. The “front-end” inspection system includes illumination normalisation, localisation and segmentation. The “back-end” inspection involves the classification of solder joints using the Log Gabor filter and classifier fusion. Five different levels of solder quality with respect to the amount of solder paste have been defined. The Log Gabor filter has been demonstrated to achieve high recognition rates and is resistant to misalignment. This proposed system does not need any special illumination system, and the images are acquired by an ordinary digital camera. This system could contribute to the development of automated non-contact, non-destructive and low cost solder joint quality inspection systems.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Increasingly, national and international governments have a strong mandate to develop national e-health systems to enable delivery of much-needed healthcare services. Research is, therefore, needed into appropriate security and reliance structures for the development of health information systems which must be compliant with governmental and alike obligations. The protection of e-health information security is critical to the successful implementation of any e-health initiative. To address this, this paper proposes a security architecture for index-based e-health environments, according to the broad outline of Australia’s National E-health Strategy and National E-health Transition Authority (NEHTA)’s Connectivity Architecture. This proposal, however, could be equally applied to any distributed, index-based health information system involving referencing to disparate health information systems. The practicality of the proposed security architecture is supported through an experimental demonstration. This successful prototype completion demonstrates the comprehensibility of the proposed architecture, and the clarity and feasibility of system specifications, in enabling ready development of such a system. This test vehicle has also indicated a number of parameters that need to be considered in any national indexed-based e-health system design with reasonable levels of system security. This paper has identified the need for evaluation of the levels of education, training, and expertise required to create such a system.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, I would like to outline the approach we have taken to mapping and assessing integrity systems and how this has led us to see integrity systems in a new light. Indeed, it has led us to a new visual metaphor for integrity systems – a bird’s nest rather than a Greek temple. This was the result of a pair of major research projects completed in partnership with Transparency International (TI). One worked on refining and extending the measurement of corruption. This, the second, looked at what was then the emerging institutional means for reducing corruption – ‘national integrity systems’

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Columns are one of the key load bearing elements that are highly susceptible to vehicle impacts. The resulting severe damages to columns may leads to failures of the supporting structure that are catastrophic in nature. However, the columns in existing structures are seldom designed for impact due to inadequacies of design guidelines. The impact behaviour of columns designed for gravity loads and actions other than impact is, therefore, of an interest. A comprehensive investigation is conducted on reinforced concrete column with a particular focus on investigating the vulnerability of the exposed columns and to implement mitigation techniques under low to medium velocity car and truck impacts. The investigation is based on non-linear explicit computer simulations of impacted columns followed by a comprehensive validation process. The impact is simulated using force pulses generated from full scale vehicle impact tests. A material model capable of simulating triaxial loading conditions is used in the analyses. Circular columns adequate in capacity for five to twenty story buildings, designed according to Australian standards are considered in the investigation. The crucial parameters associated with the routine column designs and the different load combinations applied at the serviceability stage on the typical columns are considered in detail. Axially loaded columns are examined at the initial stage and the investigation is extended to analyse the impact behaviour under single axis bending and biaxial bending. The impact capacity reduction under varying axial loads is also investigated. Effects of the various load combinations are quantified and residual capacity of the impacted columns based on the status of the damage and mitigation techniques are also presented. In addition, the contribution of the individual parameter to the failure load is scrutinized and analytical equations are developed to identify the critical impulses in terms of the geometrical and material properties of the impacted column. In particular, an innovative technique was developed and introduced to improve the accuracy of the equations where the other techniques are failed due to the shape of the error distribution. Above all, the equations can be used to quantify the critical impulse for three consecutive points (load combinations) located on the interaction diagram for one particular column. Consequently, linear interpolation can be used to quantify the critical impulse for the loading points that are located in-between on the interaction diagram. Having provided a known force and impulse pair for an average impact duration, this method can be extended to assess the vulnerability of columns for a general vehicle population based on an analytical method that can be used to quantify the critical peak forces under different impact durations. Therefore the contribution of this research is not only limited to produce simplified yet rational design guidelines and equations, but also provides a comprehensive solution to quantify the impact capacity while delivering new insight to the scientific community for dealing with impacts.