321 research outputs found
Design in Engineering: An Evaluation of Civilian and Military Unmanned Aerial Vehicle Platforms, Considering Smart Sensing with Ethical Design to Embody Mitigation Against Asymmetric Hostile Actor Exploitation
This report is written in part-fulfilment of personal output criteria for the Visiting Research Fellowship (Sir Richard Grenville Fellowship) at the Changing Character of War Centre, Pembroke College, Oxford, and the Centre for Sea Power and Strategy, Britannia Royal Naval College, Plymouth University at BRNC, Dartmouth. In this report I undertook an extensive analysis of the maritime UAV platform systems sector of a wide range of upstream manufacturing industry and downstream end user stakeholders. I consulted a global range of military and civilian users, to inform discussions around civilian UAV platforms which could be modified by hostile non-state actors, with emphasis on the littoral maritime region. This has strategic relevance to the United Kingdom, being an island-state with over 10,000 miles of coastline, c. 600 ports, and nearly 300 off-shore oil and gas platforms. In addition the UK has 14 dependencies together with a combined EEZ of 2.5 million square miles, the fifth largest in the world
Re-Examining Mortality Sources and Population Trends in a Declining Seabird: Using Bayesian Methods to Incorporate Existing Information and New Data
The population of flesh-footed shearwaters (Puffinus carneipes) breeding on Lord Howe Island was shown to be declining
from the 1970’s to the early 2000’s. This was attributed to destruction of breeding habitat and fisheries mortality in the
Australian Eastern Tuna and Billfish Fishery. Recent evidence suggests these impacts have ceased; presumably leading to
population recovery. We used Bayesian statistical methods to combine data from the literature with more recent, but
incomplete, field data to estimate population parameters and trends. This approach easily accounts for sources of variation
and uncertainty while formally incorporating data and variation from different sources into the estimate. There is a 70%
probability that the flesh-footed shearwater population on Lord Howe continued to decline during 2003–2009, and
a number of possible reasons for this are suggested. During the breeding season, road-based mortality of adults on Lord
Howe Island is likely to result in reduced adult survival and there is evidence that breeding success is negatively impacted
by marine debris. Interactions with fisheries on flesh-footed shearwater winter grounds should be further investigated
The long Galactic bar as seen by UKIDSS Galactic Plane Survey
Over the last decade there have been a series of results supporting the
hypothesis of the existence of a long thin bar in the Milky Way with a
half-length of 4.5 kpc and a position angle of around 45 deg. This is
apparently a very different structure from the triaxial bulge of the Galaxy,
which is thicker and shorter and dominates the star counts at |l|<10 deg. In
this paper, we analyse the stellar distribution in the inner Galaxy to see if
there is clear evidence for two triaxial or bar-like structures in the Milky
Way.
By using the red-clump population as a tracer of Galactic structure, we
determine the apparent morphology of the inner Galaxy. Deeper and higher
spatial resolution NIR photometry from the UKIDSS Galactic Plane Survey allows
us to use in-plane data even at the innermost Galactic longitudes, a region
where the source confusion is a dominant effect that makes it impossible to use
other NIR databases such as 2MASS or TCS-CAIN. We show that results previously
obtained with using the red-clump giants are confirmed with the in-plane data
from UKIDSS GPS. There are two different structures coexisting in the inner
Galactic plane: one with a position angle of 23.60+-2.19 deg that can be traced
from the Galactic Centre up to l=10 deg (the Galactic bulge), and other with a
larger position angle of 42.44+-2.14 deg, that ends around l=28 deg (the long
Galactic bar).Comment: (8 pages, 14 figures, accepted for publication in A&A
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