52 research outputs found
Movement Analytics: Current Status, Application to Manufacturing, and Future Prospects from an AI Perspective
Data-driven decision making is becoming an integral part of manufacturing
companies. Data is collected and commonly used to improve efficiency and
produce high quality items for the customers. IoT-based and other forms of
object tracking are an emerging tool for collecting movement data of
objects/entities (e.g. human workers, moving vehicles, trolleys etc.) over
space and time. Movement data can provide valuable insights like process
bottlenecks, resource utilization, effective working time etc. that can be used
for decision making and improving efficiency.
Turning movement data into valuable information for industrial management and
decision making requires analysis methods. We refer to this process as movement
analytics. The purpose of this document is to review the current state of work
for movement analytics both in manufacturing and more broadly.
We survey relevant work from both a theoretical perspective and an
application perspective. From the theoretical perspective, we put an emphasis
on useful methods from two research areas: machine learning, and logic-based
knowledge representation. We also review their combinations in view of movement
analytics, and we discuss promising areas for future development and
application. Furthermore, we touch on constraint optimization.
From an application perspective, we review applications of these methods to
movement analytics in a general sense and across various industries. We also
describe currently available commercial off-the-shelf products for tracking in
manufacturing, and we overview main concepts of digital twins and their
applications
The VLT-FLAMES Tarantula Survey XXII. Multiplicity properties of the B-type stars
We investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with
multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative
radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations
(and with an amplitude larger than 16 km sā1
) are classified as spectroscopic binaries. We find an observed spectroscopic binary
fraction (defined by periods of <103.5
d and mass ratios > 0.1) for the B-type stars, fB(obs) = 0.25 Ā± 0.02, which appears constant
across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary
fractions of 0.08 Ā± 0.08 and 0.10 Ā± 0.09, respectively. Using synthetic populations and a model of our observed epochs and their
potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in
30 Dor. We obtain a present-day binary fraction fB(true) = 0.58 Ā± 0.11, with a flat period distribution. Within the uncertainties, the
multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS
The VLT-FLAMES Tarantula Survey: XXX. Red stragglers in the clusters Hodge 301 and SL 639
Aims: We estimate physical parameters for the late-type massive stars observed as part of the VLT-FLAMES Tarantula Survey (VFTS) in the 30 Doradus region of the Large Magellanic Cloud (LMC).
Methods: The observational sample comprises 20 candidate red supergiants (RSGs) which are the reddest ((Bā
āā
V) > 1 mag) and brightest (V < 16 mag) objects in the VFTS. We use optical and near-infrared (near-IR) photometry to estimate their temperatures and luminosities, and introduce the luminosityāage diagram to estimate their ages.
Results: We derive physical parameters for our targets, including temperatures from a new calibration of (Jā
āā
Ks)0 colour for luminous cool stars in the LMC, luminosities from their J-band magnitudes (thence radii), and ages from comparisons with current evolutionary models. We show that interstellar extinction is a significant factor for our targets, highlighting the need to take it into account in the analysis of the physical parameters of RSGs. We find that some of the candidate RSGs could be massive AGB stars. The apparent ages of the RSGs in the Hodge 301 and SL 639 clusters show a significant spread (12ā24 Myr). We also apply our approach to the RSG population of the relatively nearby NGC 2100 cluster, finding a similarly large spread.
Conclusions We argue that the effects of mass transfer in binaries may lead to more massive and luminous RSGs (which we call āred stragglersā) than expected from single-star evolution, and that the true cluster ages correspond to the upper limit of the estimated RSG ages. In this way, the RSGs can serve as a new and potentially reliable age tracer in young star clusters. The corresponding analysis yields ages of 24-3+5 Myr for Hodge 301, 22-5+6 Myr for SL 639, and 23-2+4 Myr for NGC 2100
Land-use and sustainability under intersecting global change and domestic policy scenarios: trajectories for Australia to 2050
Understanding potential future influence of environmental, economic, and social drivers on land-use and sustainability is critical for guiding strategic decisions that can help nations adapt to change, anticipate opportunities, and cope with surprises. Using the Land-Use Trade-Offs (LUTO) model, we undertook a comprehensive, detailed, integrated, and quantitative scenario analysis of land-use and sustainability for Australia’s agricultural land from 2013–2050, under interacting global change and domestic policies, and considering key uncertainties. We assessed land use competition between multiple land-uses and assessed the sustainability of economic returns and ecosystem services at high spatial (1.1 km grid cells) and temporal (annual) resolution. We found substantial potential for land-use transition from agriculture to carbon plantings, environmental plantings, and biofuels cropping under certain scenarios, with impacts on the sustainability of economic returns and ecosystem services including food/fibre production, emissions abatement, water resource use, biodiversity services, and energy production. However, the type, magnitude, timing, and location of land-use responses and their impacts were highly dependent on scenario parameter assumptions including global outlook and emissions abatement effort, domestic land-use policy settings, land-use change adoption behaviour, productivity growth, and capacity constraints. With strong global abatement incentives complemented by biodiversity-focussed domestic land-use policy, land-use responses can substantially increase and diversify economic returns to land and produce a much wider range of ecosystem services such as emissions abatement, biodiversity, and energy, without major impacts on agricultural production. However, better governance is needed for managing potentially significant water resource impacts. The results have wide-ranging implications for land-use and sustainability policy and governance at global and domestic scales and can inform strategic thinking and decision-making about land-use and sustainability in Australia. A comprehensive and freely available 26 GB data pack (http://doi.org/10.4225/08/5604A2E8A00CC) provides a unique resource for further research. As similarly nuanced transformational change is also possible elsewhere, our template for comprehensive, integrated, quantitative, and high resolution scenario analysis can support other nations in strategic thinking and decision-making to prepare for an uncertain future
A comparison of branch-and-bound algorithms for a family scheduling problem with identical parallel machines
Simulation and Optimization
A comparison of branch-and-bound algorithms for a family scheduling problem with identical parallel machine
Optimal road design through ecologically sensitive areas considering animal migration dynamics
With increasing land transportation requirements in both urban and rural areas, roads are
encroaching ever more on animal habitats, where collisions with vehicles are a leading
contributor to wildlife mortality. While road designers recognise the importance of
accounting for such impacts at the design level, existing approaches simply either ignore
viable habitat or avoid such regions entirely. Respectively, this can result in road alignments
that are overly damaging to vulnerable species or prohibitively expensive to build
and operate. The research presented in this paper investigates the effects of explicitly
accounting for animal mortality on the design of a road through an ecologically sensitive
area. The model presented achieves this by incorporating a spatially-explicit animal migration
and road mortality model into an accepted optimal road alignment algorithm to propose
low-cost roads that maintain the animal population above a minimum threshold by
the end of a specified design horizon. The new method was applied to an example scenario
to demonstrate the effect of setting a minimum required animal population on the road
design. This model was able to consistently produce a road that met a minimum required
species conservation benefit. This reflected a major improvement over the model that
ignored animal habitats while only requiring a minor increase in construction and operating
costs compared to the model that avoids habitat.This research was funded through an Australian Government Research Training Program Scholarship
Container packing problem for stochastic inventory and optimal ordering through integer programming
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