2,742 research outputs found
The Rising Stellar Velocity Dispersion of M87 from Integrated Starlight
We have measured the line-of-sight velocity distribution from integrated
stellar light at two points in the outer halo of M87 (NGC 4486), the
second-rank galaxy in the Virgo Cluster. The data were taken at R = 480" ( kpc) and R = 526" ( kpc) along the SE major axis. The second
moment for a non-parametric estimate of the full velocity distribution is km/s and km/s respectively. There is intriguing evidence
in the velocity profiles for two kinematically distinct stellar components at
the position of our pointing. Under this assumption we employ a two-Gaussian
decomposition and find the primary Gaussian having rest velocities equal to M87
(consistent with zero rotation) and second moments of km/s and
km/s respectively. The asymmetry seen in the velocity profiles
suggests that the stellar halo of M87 is not in a relaxed state and confuses a
clean dynamical interpretation. That said, either measurement (full or two
component model) shows a rising velocity dispersion at large radii, consistent
with previous integrated light measurements, yet significantly higher than
globular cluster measurements at comparable radial positions. These integrated
light measurements at large radii, and the stark contrast they make to the
measurements of other kinematic tracers, highlight the rich kinematic
complexity of environments like the center of the Virgo Cluster and the need
for caution when interpreting kinematic measurements from various dynamical
tracers.Comment: 16 pages, 5 figures; accepted for publication in The Astrophysical
Journa
A Method Worth Telling:Using Story Completion to Understand Social Work Responses to Discriminatory Abuse
Story completion methods have not yet been used in social work research, but the method has significant potential in this area. This paper reports on findings of a qualitative story completion study, which set out to understand professional responses to discriminatory abuse in English safeguarding adults practice. Fifty-six social worker and social care worker participants responded to a ‘story stem’, which refers to the opening lines of a story, continuing a story they choose to tell in response. In this instance, the story stem introduces a fictional scenario involving a social worker who is visiting an adult who has experienced discriminatory abuse. Story completion was chosen because it does not require self-report and this was useful given the under-reporting of discriminatory abuse. Story completion is appropriate for studying taboo or sensitive topics because it is less exposing, producing stories rather than accounts of one’s practice. Story completion also allowed contrast and comparison across different characteristics that might be targeted in discriminatory abuse, spotlighting divergent responses to discrimination based on transgender identity, race and mental ill-health. Dramaturgical narrative analysis was used to make sense of the resulting stories and three narratives were identified: anxious allies, affirmative advocates and administrative assessors. There were a small number of outliers who did not complete stories based on the guidelines provided. The results suggest workforce development needs in relation to discriminatory abuse. The article concludes with a reflection on the ways in which social work research can draw on story completion methods in the future
Reinforcement Learning for Battery Management in Dairy Farming
Dairy farming is a particularly energy-intensive part of the agriculture
sector. Effective battery management is essential for renewable integration
within the agriculture sector. However, controlling battery
charging/discharging is a difficult task due to electricity demand variability,
stochasticity of renewable generation, and energy price fluctuations. Despite
the potential benefits of applying Artificial Intelligence (AI) to renewable
energy in the context of dairy farming, there has been limited research in this
area. This research is a priority for Ireland as it strives to meet its
governmental goals in energy and sustainability. This research paper utilizes
Q-learning to learn an effective policy for charging and discharging a battery
within a dairy farm setting. The results demonstrate that the developed policy
significantly reduces electricity costs compared to the established baseline
algorithm. These findings highlight the effectiveness of reinforcement learning
for battery management within the dairy farming sector.Comment: This paper has been accepted at the 2023 Artificial Intelligence for
Sustainability (AI4S) Workshop, at 26th European Conference on Artificial
Intelligence ECAI 202
A Multi-Agent Systems Approach for Peer-to-Peer Energy Trading in Dairy Farming
To achieve desired carbon emission reductions, integrating renewable
generation and accelerating the adoption of peer-to-peer energy trading is
crucial. This is especially important for energy-intensive farming, like dairy
farming. However, integrating renewables and peer-to-peer trading presents
challenges. To address this, we propose the Multi-Agent Peer-to-Peer Dairy Farm
Energy Simulator (MAPDES), enabling dairy farms to participate in peer-to-peer
markets. Our strategy reduces electricity costs and peak demand by
approximately 30% and 24% respectively, while increasing energy sales by 37%
compared to the baseline scenario without P2P trading. This demonstrates the
effectiveness of our approach.Comment: Proc. of the Artificial Intelligence for Sustainability, ECAI 2023,
Eunika et al. (eds.), Sep 30- Oct 1, 2023,
https://sites.google.com/view/ai4s. 202
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