1,721,845 research outputs found
Eliciting expert judgement for the probability of AUV loss in contrasting operational environments
Full text linkEach time an autonomous underwater vehicle (AUV)
is used in the sea there is a non-zero probability of
loss. Quantifying probability of loss is not an exact
science; therefore much depends on the fault history
of the vehicle, the operational environment and the
complex relationships between the consequences of
faults or incidents and the environment. While this
problem may be stated in scientific terms, in practice,
there is no solution through scientific means alone.
This is an example of ‘trans-science’. We suggest that
an approach based on the formal process of eliciting
expert judgement may be an effective means of
approaching this problem, as the process has been
used successfully for other trans-scientific questions.
The paper provides an introduction to the process of
eliciting expert judgement, outlines four exemplar
environments: coastal, open water, under sea ice and
under shelf ice, and gives a worked example of one
expert’s judgement on the probability of loss in the
four environments arising from a real fault with the
Autosub1 AUV. Using the fault history of the
Autosub3 AUV, included in the Annex, we ask
experts from among UUST attendees (and others) to
take part in this expert judgement elicitation. Based
on the results of this elicitation we aim to publish a
paper in the peer-reviewed literature
Griffiths, G (Gordon), NX28271
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/389178Surname: GRIFFITHS. Given Name(s) or Initials: G (GORDON). Military Service Number or Last Known Location: NX28271. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 35918.212913
Item: [2016.0049.21471] "Griffiths, G (Gordon), NX28271
Griffiths, G J, VX5526
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/389209Surname: GRIFFITHS. Given Name(s) or Initials: G J. Military Service Number or Last Known Location: VX5526. Missing, Wounded and Prisoner of War Enquiry Card Index Number: 4324.212978
Item: [2016.0049.21502] "Griffiths, G J, VX5526
Analysis of causation of loss of communication with marine autonomous systems: a probability tree approach
Full text linkThe last decade has seen the eagerly anticipated introduction of marine autonomous systems as a pragmatic tool for ocean observation. However, outstanding reliability problems means that these vehicles are not yet fulfilling their true potential. Of the classes of problems, loss of communication with a marine autonomous system is both fundamental and difficult to diagnose. In our view, this is due to two reasons: first in many cases users are not technologists and secondly if a vehicle is lost the task of diagnosing the root cause is subject to epistemic uncertainty that users are often reluctant to quantify in a formal manner. As a result users may accept the first hypothesis considered as the main root cause for loss of communication. We show that this approach can result in an increased unreliability of marine autonomous systems through failure to ascertain and then address the true root causes. Consequently, we propose a probability tree approach to help diagnose root cause(s) for loss of communication with a marine autonomous system (MAS). The model was developed based on the results of two detailed investigations and a body of failure data collected from 205 undersea glider operations
Autosub under ice
Full text linkAutosub made headlines recently when it became trapped under 200m of ice in Antarctica. Here we explore the ideas behind the £5.86 million research programme, and look back at an earlier expedition which took place last summer off the coast of Greenland
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