57 research outputs found
Setting up a Reinforcement Learning Task with a Real-World Robot
Reinforcement learning is a promising approach to developing hard-to-engineer
adaptive solutions for complex and diverse robotic tasks. However, learning
with real-world robots is often unreliable and difficult, which resulted in
their low adoption in reinforcement learning research. This difficulty is
worsened by the lack of guidelines for setting up learning tasks with robots.
In this work, we develop a learning task with a UR5 robotic arm to bring to
light some key elements of a task setup and study their contributions to the
challenges with robots. We find that learning performance can be highly
sensitive to the setup, and thus oversights and omissions in setup details can
make effective learning, reproducibility, and fair comparison hard. Our study
suggests some mitigating steps to help future experimenters avoid difficulties
and pitfalls. We show that highly reliable and repeatable experiments can be
performed in our setup, indicating the possibility of reinforcement learning
research extensively based on real-world robots.Comment: Submitted to 2018 IEEE/RSJ International Conference on Intelligent
Robots and Systems (IROS
The insertion and assembly of membrane proteins (including subunits of the ATP synthase) by the bacterial holo-translocon
Black holes vs. naked singularities formation in collapsing Einstein's clusters
Non-static, spherically symmetric clusters of counter-rotating particles, of
the type first introduced by Einstein, are analysed here. The initial data
space can be parameterized in terms of three arbitrary functions, namely;
initial density, velocity and angular momentum profiles. The final state of
collapse, black hole or naked singularity, turns out to depend on the order of
the first non-vanishing derivatives of such functions at the centre. The work
extends recent results by Harada, Iguchi and Nakao.Comment: 13 pages, LaTeX format. To appear in Physical Review
Efeito fitotóxico do óleo volátil de Cleome guianensis Aubl. sobre o crescimento inicial de Senna occidentalis L.
The impact of risk perceptions and belief in conspiracy theories on COVID-19 pandemic-related behaviours
Throughout the COVID-19 pandemic, conspiracy theories about the virus spread rapidly, and whilst governments across the globe put in place different restrictions and guidelines to contain the pandemic, these were not universally adhered to. This research examined the association between pandemic related risk perceptions, belief in conspiracy theories, and compliance with COVID-19 public guidelines amongst a UK sample (n = 368). Participants rated their level of concern for a series of potential risks during the pandemic (to the economy, personal health, freedom, media integrity and health risk to others). Participants also rated their level of belief in different conspiracy theories and self-reported their behaviour during the first UK lockdown. Mediational analyses showed that stronger belief in conspiracy theories was associated with perceptions of lower risk to health and higher risk to the economy and freedom, which in turn were associated with lower compliance with COVID-19 related governmental guidelines. Perception of information transparency risks did not mediate the association between belief in conspiracy theories and compliant behaviours. These results highlight the key role that risk perception may play in translating belief in conspiracy theories into low compliance with governmental COVID-19 related guidelines. Our findings suggest new patterns with respect to the relationship between conspiracy theory adherence and salience of different risk perceptions amidst the pandemic, which could have implications for the development of public health messaging and communication interventions
Malaya, 1948: Britain’s Asian Cold War?
Between 8:30 and 9:00 a.m. on 16 June 1948, three Europeans were shot dead in the Sungei Siput area of Perak in northern Malaya. The three were estate managers of rubber plantations, and the perpetrators were guerrillas in the “mobile corps” of the Malayan Communist Party (MCP). The shootings were the culmination of a long series of attacks and “outrages” against estate managers in Penang, Selangor, and the southern state of Johore. Late that afternoon, the colonial government declared a state of emergency in Perak and Johore that was extended, two days later, to the whole ofMalaya. An immediate casualty was respect for civil liberties. Under emergency regulations the
authorities enacted a range of draconian measures, including a ban on “seditious” publications; the introduction of coercive powers of detention, arrest,
trial, deportation, and “banishment”; the establishment of the death penalty for anyone carrying unauthorized ªrearms; and the registration of the entire adult population
The insertion and assembly of membrane proteins (including subunits of the ATP synthase) by the bacterial holo-translocon
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