3,767 research outputs found
Earned value management applied to an engineered-to-order multiple project environment
University of Technology, Sydney. Faculty of Engineering and Information Technology.The supply of Engineered-to-Order pressure equipment in Australia has established a place in the global market. Local manufacturing requires innovation to maintain its position in this supply chain. Changes at the manufacturing level looked to project management to connect the end productās development and delivery with the end userās needs. Earned Value Management (EVM) offers project management a best practice in project control and its application to this niche market was considered worthy of investigation as a response to market changes.
EVM has a long history of application in large and complicated projects. This provided researchers with material to study application detail across the cost and time domains, resulting in well-established theories about performance outputs and forecasting. EVM implementation has also been the subject of research offering guidance to the user. An area of EVM that remains in the background is the application, implementation and benefits of the method in the smaller manufacturing sector. This research applies EVM to a project orientated organisation that designs and manufactures customised pressure equipment. The objective of this practice-based research is to address questions of EVM application, implementation and benefits when applied to a multiple project environment set within an operations context.
A series of twelve projects carried out by the host organisation were subject to EVM application. This provided data to assess the response of EVM to the short duration project and to explore various forecasting behaviours from both the cost and time domains under different reporting frequencies. The process of application was also used to establish qualitative information on implementation and organisational effects as a result of the methods presence.
Results indicated EVM is adaptable to the sampled manufacturing projects and tracking capabilities were positive on the few larger projects in the sample. Net benefit to the internal project management function is not represented by EVM tracking, when restricted to the short duration project. Forecasting of both cost and time was adversely affected by high material costs, but displayed stability after this project phase. Exclusion of materials simplified application by reducing administration effort however it did exaggerate deviation of progress from the plan.
High project and organisational value is realised by access to EVMās data sources and structure. It was therefore concluded EVM methodology, coupled to organisational project management and business system theories can deliver substantial operational gains for the project orientated manufacturer
Improved spatial resolution of elemental maps through inversion of LA-ICP-MS data
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) provides the spatial distribution of elements within crystals and therefore can constrain the rates of geological processes. Spatial resolution of LA-ICP-MS is limited by the requirement to ablate sufficient material to surpass the detection limit of the instrument: too little material and the concentration cannot be measured; too much material from the same spatial location and the possibility of depth dependent variations in concentration increases. Because of this requirement and typical analytical setup, this commonly places a lower bound on the diameter of an ablation āspotā size of approximately 20 Ī¼m for elements with ppm concentration. Here we present a means to achieve sub-spot size resolution using inverse methods. We discretize the space sampled in an analysis into pixels and note that the average concentration of the pixels sampled by a spot equals the measured concentration. As multiple overlapping spots sample some of the same pixels, we can combine discrete expressions for each spot as a system of linear equations. Through linear inversion with smoothness constraints we can solve for unknown pixel concentrations. We highlight this approach with two natural examples in which diffusive processes are important: magmatic ascent speeds and (U-Th)/He noble gas thermochronometry. In these examples, accurate results require that the true concentration gradients can be recovered from LA-ICP-MS data. We show that the ability to infer rapid rates of magma ascent is improved from months to weeks and that we are able to interpret previously un-interpretable thermochronometric data
Computed tomography colonography: Radiographer independent preliminary clinical evaluation for intraluminal pathology
This is the author accepted manuscript; the final version is available from Elsevier via the DOI in this recordIntroduction: We evaluated the reporting competency of radiographers providing preliminary clinical evaluations (PCE) for intraluminal pathology of computed tomography colonography (CTC). Method: Following validation of a suitable tool, audit was undertaken to compare radiographer PCE against radiology reports. A database was designed to capture radiographer and radiologist report data. The radiographer's PCE of intraluminal pathology was given a score, the āpathology discrepancy and significanceā (PDS) score based on the pathology present, any discrepancy between the PCE and the final report, and the significance of that discrepancy on the management of the patient. Agreement was assessed using percentage agreement and Kappa coefficient. Significant discrepancies between findings were compared against endoscopy and pathology reports. Results: There was agreement or insignificant discrepancy between the radiographer PCE and the radiology report for 1736 patients, representing 97.0% of cases. There was a significant discrepancy between findings in 2.8% of cases and a major discrepancy recorded for 0.2% of cases. There was a 98.4% agreement in the 229 cases where significant pathologies were present. Conclusion: From a database of 1815 studies acquired over three years and representing work done in a clinical environment, this study indicates a potential for trained radiographers to provide a PCE of intraluminal pathology
The C@merata Task at MediaEval 2014: Natural Language Queries on Classical Music Scores
This paper summarises the C@merata task in which participants built systems to answer short natural language queries about classical music scores in MusicXML. The task thus combined natural language processing with music information retrieval. Five groups from four countries submitted eight runs. The best submission scored Beat Precision 0.713 and Beat Recall 0.904
The C@merata Task at MediaEval 2015: Natural Language Queries on Classical Music Scores
This was the second year of the C@merata task [16,1] which relates natural language processing to music inform ation retrieval. Participants each build a system which takes as input a query and a music score and produces as output one or more ma tching passages in the score. This year, questions were mo re difficult and scores were more complex. Participants were the same as last year and once again CLAS was the best with a Beat F-Score of 0.620
Detrital Thermochronometry Reveals That the Topography Along the Antarctic Peninsula is Not a Pleistocene Landscape
Using offshore detrital apatite (UāTh)/He thermochronometry and 3D thermoākinematic modeling of the catchment topography, we constrain the timing of major topographic change at Bourgeois Fjord, Antarctic Peninsula (AP). While many midālatitude glacial landscapes developed primarily in response to global cooling over the last ~2.6 Ma, we find that kilometerāscale landscape evolution at Bourgeois Fjord began ~30ā12 Ma ago and <2 km of valley incision has occurred since ~16 Ma. This early onset of major topographic change occurred following the initiation of alpine glaciation at this location and prior to the development of a regional polythermal ice sheet inferred from sedimentary evidence offshore of the AP. We hypothesize that topographic change relates to (i) feedbacks between an evolving topography and glacial erosion processes, (ii) effects of glacialāinterglacial variability, and (iii) the prevalence of subglacial meltwater. The timing and inferred spatial patterns of longāterm exhumation at Bourgeois Fjord are consistent with a hypothesis that glacial erosion processes were suppressed at the AP during global PlioāPleistocene cooling, rather than enhanced. Our study examines the longāterm consequences of glacial processes on catchmentāwide erosion as the local climate cooled. Our findings support the hypothesis that landscapes at different latitudes had different responses to global cooling. Our results also suggest that erosion is enhanced along the plateau flanks of Bourgeois Fjord today, which may be due to periglacial processes or mantling via subglacial till. If regional warming persists and meltwater becomes more pronounced, we predict that enhanced erosion along the plateau flank will accelerate topographic change
Late Cenozoic deepening of Yosemite Valley, USA
Although Yosemite Valley, USA, catalyzed the modern environmental movement and fueled foundational debates in geomorphology, a century of investigation has failed to definitively determine when it formed. The non-depositional nature of the landscape and homogeneous bedrock have prevented direct geological assessments. Indirect assumptions about the age of downcutting have ranged from pre-Eocene to Pleistocene. Clarity on this issue would not only satisfy public interest but also provide a new constraint for contentious debates about the Cenozoic tectonic and geomorphologic history of the Sierra Nevada in California. Here we use thermochronometric analysis of radiogenic helium in apatite crystals, coupled with numerical models of crustal temperatures beneath evolving topography, to demonstrate significant late Cenozoic deepening of Tenaya Canyon, Yosemiteās northeastern branch. Approximately 40%ā90% of the current relief has developed since 10 Ma and most likely since 5 Ma. This coincides with renewed regional tectonism, which is a long-hypothesized but much debated driver of Sierran canyon development. Pleistocene glaciation caused spatially variable incision and valley widening in Yosemite Valley, whereas little contemporaneous erosion occurred in the adjacent upper Tuolumne watershed. Such variations probably arise from glacial erosionās dependence on topographic focusing of ice discharge into zones of rapid flow, and on the abundance of pre-existing fractures in the substrate. All available data, including those from our study, are consistent with a moderately high and slowly eroding mid-Cenozoic Sierra Nevada followed by significant late Cenozoic incision of some, but not all, west-side canyon
Westernmost Grand Canyon incision: Testing thermochronometric resolution
The timing of carving of Grand Canyon has been debated for over 100 years with competing endmember hypotheses advocating for either a 70 Ma (āoldā) or <6 Ma (āyoungā) Grand Canyon. Several geological constraints appear to support a āyoungā canyon model, but thermochronometric measures of cooling history and corresponding estimates of landscape evolution have been in debate. In particular, 4He/3He thermochronometric data record the distribution of radiogenic 4He (from the 238U, 235U and 232Th decay series) within an individual apatite crystal and thus are highly sensitive to the thermal history corresponding to landscape evolution. However, there are several complicating factors that make interpreting such data challenging in geologic scenarios involving reheating. Here, we analyze new data that provide measures of the cooling of basement rocks at the base of westernmost Grand Canyon, and use these data as a testbed for exploring the resolving power and limitations of 4He/3He data in general. We explore a range of thermal histories and find that these data are most consistent with a āyoungā Grand Canyon. A problem with the recovered thermal history, however, is that burial temperatures are under predicted based on sedimentological evidence. A solution to this problem is to increase the resistance of alpha recoil damage to annealing, thus modifying He diffusion kinetics, allowing for higher temperatures throughout the thermal history. This limitation in quantifying radiation damage (and hence crystal retentivity) introduces non-uniqueness to interpreting timeātemperature paths in rocks that resided in the apatite helium partial retention zone for long durations. Another source of non-uniqueness, is due to unknown U and Th distributions within crystals. We show that for highly zoned with a decrease in effective U of 20 ppm over the outer 80% of the radius of the crystal, the 4He/3He data could be consistent with an āoldā canyon model. To reduce this non-uniqueness, we obtain U and Th zonation information for separate crystals from the same rock sample through LA-ICP-MS analysis. The observed U and Th distributions are relatively uniform and not strongly zoned, thus supporting a āyoungā canyon model interpretation of the 4He/3He data. Furthermore, we show that for the mapped zonation, the difference between predicted 4He/3He data for a uniform crystal and a 3D model of the crystal are minimal, highlighting that zonation is unlikely to lead us to falsely infer an āoldā Grand Canyon
Neither phylogenomic nor palaeontological data support a Palaeogene origin of placental mammals.
O'Leary et al. (O'Leary et al. 2013 Science 339, 662-667. (doi:10.1126/science.1229237)) performed a fossil-only dating analysis of mammals, concluding that the ancestor of placentals post-dated the Cretaceous-Palaeogene boundary, contradicting previous palaeontological and molecular studies that placed the ancestor in the Cretaceous. They incorrectly used fossil ages as species divergence times for crown groups, while in fact the former should merely form minimum-age bounds for the latter. Statistical analyses of the fossil record have shown that crown groups are significantly older than the oldest ingroup fossil, so that fossils do not directly reflect the true ages of clades. Here, we analyse a 20 million nucleotide genome-scale alignment in conjunction with a probabilistic interpretation of the fossil ages from O'Leary et al. Our combined analysis of fossils and molecules demonstrates that Placentalia originated in the Cretaceous.This work was financially supported by BBSRC grant no. BB/J009709/1
A helium-based model for the effects of radiation damage annealing on helium diffusion kinetics in apatite
Widely used to study surface processes and the development of topography through geologic time, (UāTh)/He thermochronometry in apatite depends on a quantitative description of the kinetics of 4He diffusion across a range of temperatures, timescales, and geologic scenarios. Empirical observations demonstrate that He diffusivity in apatite is not solely a function of temperature, but also depends on damage to the crystal structure from radioactive decay processes. Commonly-used models accounting for the influence of thermal annealing of radiation damage on He diffusivity assume the net effects evolve in proportion to the rate of fission track annealing, although the majority of radiation damage results from Ī±-recoil. While existing models adequately quantify the net effects of damage annealing in many geologic scenarios, experimental work suggests different annealing rates for the two damage types. Here, we introduce an alpha-damage annealing model (ADAM) that is independent of fission track annealing kinetics, and directly quantifies the influence of thermal annealing on He diffusivity in apatite. We present an empirical fit to diffusion kinetics data and incorporate this fit into a model that tracks the competing effects of radiation damage accumulation and annealing on He diffusivity in apatite through geologic time. Using timeātemperature paths to illustrate differences between models, we highlight the influence of damage annealing on data interpretation. In certain, but not all, geologic scenarios, the interpretation of low-temperature thermochronometric data can be strongly influenced by which model of radiation damage annealing is assumed. In particular, geologic scenarios involving 1ā2 km of sedimentary burial are especially sensitive to the assumed rate of annealing and its influence on He diffusivity. In cases such as basement rocks in Grand Canyon and the Canadian Shield, (UāTh)/He ages predicted from the ADAM can differ by hundreds of Ma from those predicted by other models for a given thermal path involving extended residence between ā¼40ā80āĀ°C
- ā¦