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Articles 1 - 9 of 9

Full-Text Articles in Physical Sciences and Mathematics

Optically Stimulated Luminescence (Osl) Dating Of Perenially Frozen Deposits In North-Central Siberia: Osl Characteristics Of Quartz Grains And Methodological Considerations Regarding Their Suitability For Dating, Lee Arnold, Richard Roberts Mar 2013

Optically Stimulated Luminescence (Osl) Dating Of Perenially Frozen Deposits In North-Central Siberia: Osl Characteristics Of Quartz Grains And Methodological Considerations Regarding Their Suitability For Dating, Lee Arnold, Richard Roberts

Richard G Roberts

Optically stimulated luminescence (OSL) dating of coarse-grained quartz is increasingly being used as the main chronological tool in late Quaternary palaeoenvironmental reconstructions of Siberia. However, relatively little information has been published on the suitability of OSL dating for the various types of perennially frozen sediments found in this region. Here we provide a systematic examination of the quartz luminescence characteristics of 21 perennially frozen samples from the Taimyr Peninsula and adjacent coastal lowlands of north-central Siberia, and discuss their implications for the reliability of single-grain and multi-grain OSL chronologies in such contexts. The results of this study suggest that the …


Development Of The Sar Tt-Osl Procedure For Dating Middle Pleistocene Dune And Shallow Marine Deposits Along The Southern Cape Coast Of South Africa, Zenobia Jacobs, Richard Roberts, Terry Lachlan, Panagiotis Karkanas, Curtis Marean, David Roberts Mar 2013

Development Of The Sar Tt-Osl Procedure For Dating Middle Pleistocene Dune And Shallow Marine Deposits Along The Southern Cape Coast Of South Africa, Zenobia Jacobs, Richard Roberts, Terry Lachlan, Panagiotis Karkanas, Curtis Marean, David Roberts

Richard G Roberts

Optically stimulated luminescence (OSL) dating is now commonly used to estimate the depositional age of Quaternary landforms along the southern Cape coast of South Africa. Due to the early onset of dose saturation in the quartz-rich sediments from this region, determining the age of deposits much older than the last three glacio-eustatic sea-level high stands has been a challenge. In this study, we explored the feasibility of using the thermally-transferred OSL (TT-OSL) dating method to obtain ages for aeolian and shallow marine deposits at three different localities that hold promise to further illuminate the long and complex Late Quaternary sea-level …


Middle Paleolithic Occupation On A Marine Isotope Stage 5 Lakeshore In The Nefud Desert, Saudi Arabia, Michael Petraglia, Abdullah Alsharekh, Remy Crassard, Nick Drake, Huw Groucutt, Adrian Parker, Richard Roberts Mar 2013

Middle Paleolithic Occupation On A Marine Isotope Stage 5 Lakeshore In The Nefud Desert, Saudi Arabia, Michael Petraglia, Abdullah Alsharekh, Remy Crassard, Nick Drake, Huw Groucutt, Adrian Parker, Richard Roberts

Richard G Roberts

No abstract provided.


Dirt, Dates And Dna:Osl And Radiocarbon Chronologies Of Perenially Frozen Sediments In Siberia, And Their Implications For Sedimentary Ancient Dna Studies, Lee Arnold, Richard Roberts, Ross Macphee, James Haile, Fiona Brock, Per Moller, Duane Froese, Alexei Tikhonov, Allan Chivas, M. Thomas Gilbert, Eske Willerslev Mar 2013

Dirt, Dates And Dna:Osl And Radiocarbon Chronologies Of Perenially Frozen Sediments In Siberia, And Their Implications For Sedimentary Ancient Dna Studies, Lee Arnold, Richard Roberts, Ross Macphee, James Haile, Fiona Brock, Per Moller, Duane Froese, Alexei Tikhonov, Allan Chivas, M. Thomas Gilbert, Eske Willerslev

Richard G Roberts

The sedimentary ancient DNA (sedaDNA) technique offers a potentially invaluable means of investigating species evolution and extinction dynamics in high-latitude environments. An implicit assumption of the sedaDNA approach is that the extracted DNA is autochthonous with the host deposit and that it has not been physically transported from older source deposits or reworked within the sedimentary profile by postdepositional mixing. In this paper we investigate whether these fundamental conditions are upheld at seven perennially frozen wetland sites across the Taimyr Peninsula and coastal lowlands of north-central Siberia. Optically stimulated luminescence (OSL) and radiocarbon (14C) dating are used to constrain the …


Late Acheulean Hominins At The Marine Isotope Stage 6/5e Transition In North-Central India, Michael Haslam, Richard Roberts, Ceri Shipton, J Pal, Jacqueline Fenwick, Peter Ditchfield, Nicole Boivin, A Dubey, M Gupta, Michael Petraglia Mar 2013

Late Acheulean Hominins At The Marine Isotope Stage 6/5e Transition In North-Central India, Michael Haslam, Richard Roberts, Ceri Shipton, J Pal, Jacqueline Fenwick, Peter Ditchfield, Nicole Boivin, A Dubey, M Gupta, Michael Petraglia

Richard G Roberts

Single-grain optically stimulated luminescence dating was applied to Late Quaternary sediments at two sites in the Middle Son Valley, Madhya Pradesh, India. Designated Bamburi 1 and Patpara, thesse sites contain Late Acheulean stone tool assemblages, which we associate with non-modern hominins. Age determinations of 140-120. ka place the formation of these sites at around the Marine Oxygen Isotope Stage 6-5 transition, placing them among the youngest Acheulean sites in the world. We present here the geochronology and sedimentological setting of these sites, and consider potential implications of Late Pleistocene archaic habitation in north-central India for the initial dispersal of modern …


Understanding Ageing In Older Australians: The Contribution Of The Dynamic Analyses To Optimise Ageing (Dynopta) Project To The Evidence Base And Policy, Kaarin Anstey, Allison Blelak, Carole Birrell, Colette Browning, Richard Burns, Julie Byles, Kim Kiely, Binod Nepal, Lesley Ross, David Steel, Timothy Windsor Dec 2012

Understanding Ageing In Older Australians: The Contribution Of The Dynamic Analyses To Optimise Ageing (Dynopta) Project To The Evidence Base And Policy, Kaarin Anstey, Allison Blelak, Carole Birrell, Colette Browning, Richard Burns, Julie Byles, Kim Kiely, Binod Nepal, Lesley Ross, David Steel, Timothy Windsor

Professor David Steel

Aim:  To describe the Dynamic Analyses to Optimise Ageing (DYNOPTA) project and illustrate its contributions to understanding ageing through innovative methodology, and investigations on outcomes based on the project themes. DYNOPTA provides a platform and technical expertise that may be used to combine other national and international datasets. Methods:  The DYNOPTA project has pooled and harmonised data from nine Australian longitudinal studies to create the largest available longitudinal dataset (n= 50652) on ageing in Australia. Results:  A range of findings have resulted from the study to date, including methodological advances, prevalence rates of disease and disability, and mapping trajectories of …


On The Step Response Of The Dct, Jim Andrew, Philip Ogunbona Sep 2012

On The Step Response Of The Dct, Jim Andrew, Philip Ogunbona

Professor Philip Ogunbona

We show that the discrete cosine transform (DCT) is the best orthogonal transform, in terms of energy packing efficiency, for coding input steps of uniformly distributed random phase. Over sufficiently small block sizes, edges in an image can be modeled as such step inputs. This characteristic of the DCT, coupled with its high energy packing efficiency for highly correlated data, helps explain the impressive performance of the DCT for image compression.


On The Combination Of Local Texture And Global Structure For Food Classification, Zhimin Zong, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li Sep 2012

On The Combination Of Local Texture And Global Structure For Food Classification, Zhimin Zong, Duc Thanh Nguyen, Philip Ogunbona, Wanqing Li

Professor Philip Ogunbona

This paper proposes a food image classification method using local textural patterns and their global structure to describe the food image. In this paper, a visual codebook of local textural patterns is created by employing Scale Invariant Feature Transformation (SIFT) interest point detector with the Local Binary Pattern (LBP) feature. In addition to describing the food image using local texture, the global structure of the food object is represented as the spatial distribution of the local textural structures and encoded using shape context. We evaluated the proposed method on the Pittsburgh Fast-Food Image (PFI) dataset. Experimental results showed that the …


One Million Downloads For Uow’S Research Online, Kate Mcilwain, Michael Organ, K. Michael, M. Michael Oct 2009

One Million Downloads For Uow’S Research Online, Kate Mcilwain, Michael Organ, K. Michael, M. Michael

Michael Organ

No abstract provided.