455 research outputs found
Lunar Polar Coring Lander
Plans to build a lunar base are presently being studied with a number of considerations. One of the most important considerations is qualifying the presence of water on the Moon. The existence of water on the Moon implies that future lunar settlements may be able to use this resource to produce things such as drinking water and rocket fuel. Due to the very high cost of transporting these materials to the Moon, in situ production could save billions of dollars in operating costs of the lunar base. Scientists have suggested that the polar regions of the Moon may contain some amounts of water ice in the regolith. Six possible mission scenarios are suggested which would allow lunar polar soil samples to be collected for analysis. The options presented are: remote sensing satellite, two unmanned robotic lunar coring missions (one is a sample return and one is a data return only), two combined manned and robotic polar coring missions, and one fully manned core retrieval mission. One of the combined manned and robotic missions has been singled out for detailed analysis. This mission proposes sending at least three unmanned robotic landers to the lunar pole to take core samples as deep as 15 meters. Upon successful completion of the coring operations, a manned mission would be sent to retrieve the samples and perform extensive experiments of the polar region. Man's first step in returning to the Moon is recommended to investigate the issue of lunar polar water. The potential benefits of lunar water more than warrant sending either astronauts, robots or both to the Moon before any permanent facility is constructed
III. Comparison of the findings of the two studies
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67190/2/10.1177_002200276400800407.pd
The dynamic crossover in water does not require bulk water
Many of the anomalous properties of water may be explained by invoking a second critical point that terminates the coexistence line between the low- and high-density amorphous states in the liquid. Direct experimental evidence of this point, and the associated polyamorphic liquid–liquid transition, is elusive as it is necessary for liquid water to be cooled below its homogeneous-nucleation temperature. To avoid crystallization, water in the eutectic LiCl solution has been studied but then it is generally considered that “bulk” water cannot be present. However, recent computational and experimental studies observe cooperative hydration in which case it is possible that sufficient hydrogen-bonded water is present for the essential characteristics of water to be preserved. For femtosecond optical Kerr-effect and nuclear magnetic resonance measurements, we observe in each case a fractional Stokes–Einstein relation with evidence of the dynamic crossover appearing near 220 K and 250 K respectively. Spectra obtained in the glass state also confirm the complex nature of the hydrogen-bonding modes reported for neat room-temperature water and support predictions of anomalous diffusion due to “worm-hole” structure
The Proliferation of Special Accounting Items: A Threat to Corporate Credibility
Betty L. Brewer, DBA, CFP, is associate professor of finance, Department of Business and Economics, North Carolina A&T State University, Greensboro, NC 27411.
Robert J. Angell, DBA, is professor of finance, Department of Business Administration, School of Business and Economics, North Carolina A&T State University, Greensboro, NC 27411.
R. David Mautz, Jr., Ph.D., CPA, is associate professor of accounting, Department of Accounting, School of Business and Economics, North Carolina A&T State University, Greensboro, NC 27411
MadRadar: A Black-Box Physical Layer Attack Framework on mmWave Automotive FMCW Radars
Frequency modulated continuous wave (FMCW) millimeter-wave (mmWave) radars
play a critical role in many of the advanced driver assistance systems (ADAS)
featured on today's vehicles. While previous works have demonstrated (only)
successful false-positive spoofing attacks against these sensors, all but one
assumed that an attacker had the runtime knowledge of the victim radar's
configuration. In this work, we introduce MadRadar, a general black-box radar
attack framework for automotive mmWave FMCW radars capable of estimating the
victim radar's configuration in real-time, and then executing an attack based
on the estimates. We evaluate the impact of such attacks maliciously
manipulating a victim radar's point cloud, and show the novel ability to
effectively `add' (i.e., false positive attacks), `remove' (i.e., false
negative attacks), or `move' (i.e., translation attacks) object detections from
a victim vehicle's scene. Finally, we experimentally demonstrate the
feasibility of our attacks on real-world case studies performed using a
real-time physical prototype on a software-defined radio platform
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Emotion regulation in depression, anxiety and stress: a focus on catastrophising
Emotion regulation is fundamental to how we all feel, think about and experience our daily lives. So far the majority of studies into emotion regulation have focused on theories relating to strategies such as rumination, suppression and reappraisal. The first study focused
on developing a wider understanding of how emotion is regulated through developing emotion regulation profiles of depression, anxiety and stress. The second study developed an emotion regulation questionnaire designed for experimental use. Unlike existing emotion
regulation questionnaires it was designed to be atheoretical and considerably broader in scope. The relationship between catastrophising and other mental health traits was highlighted in the initial study and found to be mostly unexplored by the emotion regulation literature. The final three studies aimed to build on existing understanding of catastrophising. The first of
these used a catastrophising induction developed for the study. The results suggested that in laboratory conditions, catastrophising reduces positive mood and increases negative mood compared to a control group. The forth study created and successfully validated the
Catastrophising Questionnaire. This found catastrophising to generally fall into two groups, general catastrophising and health and safety catastrophising, where the later tended to be less associated with poor mental health outcomes. The final study developed a two-week intervention to reduce catastrophising, which was
delivered to a community sample through a mobile phone or tablet based application. Where participants were randomly assigned to the control or the experimental group. Participants in the experimental condition were found to catastrophise comparatively less. They also
reported less negative mood, more positive mood and improved more on mental health indicators than the control group
A Modular Platform For Collaborative, Distributed Sensor Fusion
Leading autonomous vehicle (AV) platforms and testing infrastructures are,
unfortunately, proprietary and closed-source. Thus, it is difficult to evaluate
how well safety-critical AVs perform and how safe they truly are. Similarly,
few platforms exist for much-needed multi-agent analysis. To provide a starting
point for analysis of sensor fusion and collaborative & distributed sensing, we
design an accessible, modular sensing platform with AVstack. We build
collaborative and distributed camera-radar fusion algorithms and demonstrate an
evaluation ecosystem of AV datasets, physics-based simulators, and hardware in
the physical world. This three-part ecosystem enables testing next-generation
configurations that are prohibitively challenging in existing development
platforms
Supercooled Lennard-Jones Liquids and Glasses: a Kinetic Monte Carlo Approach
A kinetic Monte Carlo (KMC) method is used to study the structural properties
and dynamics of a supercooled binary Lennard-Jones liquid around the glass
transition temperature. This technique permits us to explore the potential
energy surface and barrier distributions without suffering the exponential
slowing down at low temperature that affects molecular dynamics simulations. In
agreement with previous studies we observe a distinct change in behaviour
around , close to the dynamical transition temperature of mode
coupling theory (MCT). Below this temperature the number of different local
minima visited by the system for the same number of KMC steps decreases by more
than an order of magnitude. The mean number of atoms involved in each jump
between local minima and the average distance they move also decreases
significantly, and new features appear in the partial structure factor. Above
the probability distribution for the magnitude of the atomic
displacement per KMC step exhibits an exponential decay, which is only weakly
temperature dependent.Comment: Accepted for J. Non-Cryst. Solid
The favoured cluster structures of model glass formers
We examine the favoured cluster structures for two new potentials, which both
behave as monatomic model glass-formers in bulk. We find that the oscillations
in the interatomic potential lead to global minima that are non-compact
arrangements of linked 13-atom icosahedra. We find that the structural
properties of the clusters correlate with the glass-forming propensities of the
potentials, and with the fragilities of the corresponding supercooled liquids.Comment: 9 pages, 7 figures; new section added and error in potential
parameters correcte
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