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Dr Stephen MᶜAteer

Auxiliary Library Explorer (ALEX) development

Interior of the George Peabody Library in Baltimore

Alex Bunting, Stephen Mc Ateer and Justin Beck

This report describes the development of the Auxiliary Library Explorer (ALEX) which was carried out as part of a DST Group summer vacation scholarship in 2013–14 by Alex Bunting. ALEX is a tool motivated by Google Scholar which uses the DST Group FOUO internal report database as its input. It provides DST Group researchers with an additional discovery capability and is available from the internal DST Group website. Since its development it has been used by hundreds of DST Group researchers.

(DSTO technical note: not to be cited without approval, title and summary approved for public release, image credit: Matthew Petroff)

Fusing navigational and meteorological data for prediction of hull slamming in Navy patrol boats (honours thesis)

ATLANTIC OCEAN (Feb. 9, 2010) Waves crash against the hull of the Military Sealift Command fleet replenishment oiler USNS Leroy Grumman (T-AO 195) during a refueling-at-sea with the Nimitz-class aircraft carrier USS Carl Vinson (CVN 70). Carl Vinson is taking part in Southern Seas 2010 as part of a scheduled homeport shift from Norfolk to San Diego. (U.S. Navy photo by Mass Communication Specialist 2nd Class Daniel Barker/Released)

Katrina Kelleher (supervised by Stephen Mc Ateer)

Abstract: Driving a boat in high seas causes hull strain, which in turn can cause fatigue and costly damage. This paper investigates the feasibility of using weather data to predict hull strain measurements (in the form of slam counts) in the Royal Australian Navy fleet of Armidale Class Patrol Boats (ACPBs). Weather data containing the values of various wave attributes across the world’s oceans is combined with patrol boat GPS location data to develop a weather experience profile for a given ship.

This study uses interpolation, linear regression and big data techniques such as machine learning to investigate the interrelation of the datasets. A reliable correlation between the ship speed, wave frequency and slam counts is found and the null hypothesis rejected at the 99.9% confidence level. Several strategies for slam prediction are developed and tested however prediction accuracy is limited by insufficient data.

The approach discussed in this paper would allow maintenance inefficiencies to be reduced as a ship would potentially only require manual inspection when its weather experience profile indicates it is necessary. The ACPB fleet has an approximate whole of life cost of $650 million so finding efficiencies in the maintenance cycle has the potential to save the RAN millions of dollars.

(Submitted November 2015. Image credit: Daniel Barker, US Navy)

A diagrammatic approach to factorizing F-matrices in XXZ and XXX spin chains

su(3) F-matrix

Stephen Gerard Mc Ateer (supervised by Omar Foda)

Abstract: The aim of this thesis is a better understanding of certain mathematical structures which arise in integrable spin chains. Specifically, we are concerned with XXZ and XXX Heisenberg spin-$\frac{1}{2}$ chains and their generalizations.

The mathematical structures in question are the $F$-matrix (a symmetrising, change-of-basis operator) and the Bethe eigenvectors (the eigenvectors of the transfer matrix of integrable spin chains). A diagrammatic tensor notation represents these operators in a way which is intuitive and allows easy manipulation of the relations involving them. The sun F-matrix is a representation of a Drinfel’d twist of the $R$-matrix of the quantum algebra $U_q(\mathfrak{su}_n)$ and its associated Yangian $Y(su_n)$. The $F$-matrices of these algebras have proven useful in the calculation of scalar products and domain wall partition functions in the spin-$\frac{1}{2}$ XXZ model. In this thesis we present a factorized diagrammatic expression for the $\mathfrak{su}_2$ $F$-matrix equivalent to the algebraic expression of Maillet and Sanchez de Santos. Next we present a fully factorized expression for the $\mathfrak{su}_n$& $F$-matrix which is of a similar form to that of Maillet and Sanchez de Santos [18] for the $\mathfrak{su}_2$ $F$-matrix and equivalent to the unfactorized expression of Albert, Boos, Flume and Ruhlig [2] for the $\mathfrak{su}_n$ $F$-matrix.

Using a diagrammatic description of the nested algebraic Bethe Ansatz, we present an expression for the eigenvectors of the $\mathfrak{su}_n$ transfer matrix as components of appropriately selected $\mathfrak{su}_n$ $F$-matrices. Finally, we present expressions for the sun elementary matrices (and therefore the local spin operators in the case of $\mathfrak{su}_2$) in terms of components of the $\mathfrak{su}_n$ monodromy matrix.

(PhD thesis, available here, submitted October 2015.)

Usage of wharf space in Cairns and Darwin by RAN vessels (DSTO client report)

Darwin's Stokes Hill Wharf January 2010

Justin D. Beck, Stephen G. Mc Ateer and Timothy J. Surendonk

Summary: In this report, navigational and operational data is used to provide estimates on Royal Australian Navy (RAN) vessel numbers in Cairns and Darwin.

(DSTO client report: DSTO-CR-2013-0238, not to be cited without approval, title and summary approved for public release, image credit: Ken Hodge)

Supporting Defence decision making with big data: less talk, more data! (DSTO discussion paper)

US Navy 050123-N-2653P-001 Officer-in-Charge of Navy Oceanographic Office Fleet Survey Team One and Two, Lt. Cmdr. Todd Barnhill, left, compares data with teammates Lt. Deborah Mabey, right, and Forrest Noll, aboard the guided...

Timothy J. Surendonk, Justin D. Beck and Stephen G. Mc Ateer

Summary: In this paper, we discuss big data in the context of Defence science.

(DSTO discussion paper: DSTO-DP-1255, not to be cited without approval, title and summary approved for public release, image credit: U.S. Navy photo by Journalist 1st Class James Pinsky)

Going around in circles: a heuristic method for path categorisation

This is a photograph of the key-ring model of the Hopf fibration. I created this image with a digital camera.

S.G. Mc Ateer and J.D. Beck

Abstract: In this paper, we describe a heuristic method for the categorisation of paths in a timed geospatial data set. Based on their shape and speed, paths are categorised as ‘slow’, ‘straight’, ‘miscellaneous’ or ‘overlapping’. The method is demonstrated using Global Positioning System (GPS) data obtained from HMAS GLENELG during patrols and transits near Christmas Island. The method enables analysis and categorisation of paths without reference to an external data source (such as ship’s logs) which explicitly indicates activities over time.

(Australian Defence Operations Research Review 2012, 94-109, title and abstract approved for public release, image credit: Davidarichter)

HMAS Glenelg speed profiling using operational categorisation: analysis details (DSTO technical report)

HMAS Albany 2010

S.G. Mc Ateer and J.D. Beck

Abstract: The Defence White Paper 2009 instructed Defence to develop proposals to rationalise Australia's small vessel capability by replacing several classes of vessel with a single rerolable class—the future Offshore Combatant Vessel (OCV) (Project SEA 1180). Global Positioning System (GPS) readings from current Armidale Class Patrol Boat HMAS GLENELG were combined with operational data and a heuristic categorisation method to provide speed profiles broken down by type of operation. The results of this study inform the future requirements through the generation of speed profiles using operational categorisation.

(DSTO Report Series, 2013, report number: DSTO-TR-2896, title and abstract approved for public release, image credit: Ken Hodge)

On factorizing $F$-matrices in $\mathcal{Y}(sl_n)$ and $\mathcal{U}_q(\widehat{sl}_n)$ spin chains

su(2) F-matrix

S.G. Mc Ateer and M. Wheeler*

Abstract: We consider quantum spin chains arising from $N$-fold tensor products of the fundamental evaluation representations of $\mathcal{Y}(sl_n)$ and $\mathcal{U}_q(\widehat{sl}_n)$. Using the partial $F$-matrix formalism from the seminal work of Maillet and Sanchez de Santos, we derive a completely factorized expression for the $F$-matrix of such models and prove its equivalence to the expression obtained by Albert, Boos, Flume and Ruhlig. A new relation between the $F$-matrices and the Bethe eigenvectors of these spin chains is given.

(Journal of Statistical Mechanics: theory and experiment, also available from arXiv:1112.0839 [math-ph], 30 April 2012, *alphabetical)

Factorizing $F$-matrices and the XXZ spin-$\frac{1}{2}$ chain: A diagrammatic perspective

su(2) F-matrix

S.G. Mc Ateer and M. Wheeler*

Abstract: Using notation inherited from the six-vertex model, we construct diagrams that represent the action of the factorizing $F$-matrices associated to the finite length $XXZ$ spin-$\frac{1}{2}$ chain. We prove that these $F$-matrices factorize the tensor $R^{\sigma}_{1... n}$ corresponding with elements of the permutation group. We consider in particular the diagram for the tensor $R^{\sigma_c}_{1... n}$, which cyclically permutes the spin chain. This leads us to a diagrammatic construction of the local spin operators $S_i^{\pm}$ and $S_i^{z}$ in terms of the monodromy matrix operators.

(Nuclear Physics B, also available from arXiv:1103.4488 [math-ph], 30 May 2011, *alphabetical)

Unjamming as structural instability

A collection of interacting disks viewed as a mechanical system.

S.G. Mc Ateer

Abstract: The transition from solid-like to liquid-like behaviour of granular materials is investigated through analysis of mechanical stability beyond the scale of the individual contact: i.e on the scale of clusters of particles in the mesoscopic domain. This solid-liqiud like phase transition, otherwise known as "unjamming" in the physics community or "failure" in the engineering community, nucleates from inside the material. Mesoscopic structures emerge inside the material during deformation: like any structure, these are subject to instabilities that ultimately lead to failure. The failure of such structures on the mesoscale serves as "trigger events" or precursors to unjamming of the granular material on the macroscopic scale.

(honours thesis, Available here in PDF format, Submitted 23 November 2007)

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