3,891 research outputs found
Modeling Life as Cognitive Info-Computation
This article presents a naturalist approach to cognition understood as a
network of info-computational, autopoietic processes in living systems. It
provides a conceptual framework for the unified view of cognition as evolved
from the simplest to the most complex organisms, based on new empirical and
theoretical results. It addresses three fundamental questions: what cognition
is, how cognition works and what cognition does at different levels of
complexity of living organisms. By explicating the info-computational character
of cognition, its evolution, agent-dependency and generative mechanisms we can
better understand its life-sustaining and life-propagating role. The
info-computational approach contributes to rethinking cognition as a process of
natural computation in living beings that can be applied for cognitive
computation in artificial systems.Comment: Manuscript submitted to Computability in Europe CiE 201
Concepts of mental disorders in the United Kingdom : Similarities and differences between the lay public and psychiatrists
BACKGROUND: The lay public often conceptualise mental disorders in a different way to mental health professionals, and this can negatively impact on outcomes when in treatment. AIMS: This study explored which disorders the lay public are familiar with, which theoretical models they understand, which they endorse and how they compared to a sample of psychiatrists. METHODS: The Maudsley Attitude Questionnaire (MAQ), typically used to assess mental health professional's concepts of mental disorders, was adapted for use by a lay community sample (N = 160). The results were compared with a sample of psychiatrists (N = 76). RESULTS: The MAQ appeared to be accessible to the lay public, providing some interesting preliminary findings: in order, the lay sample reported having the best understanding of depression followed by generalised anxiety, schizophrenia and finally antisocial personality disorder. They best understood spiritualist, nihilist and social realist theoretical models of these disorders, but were most likely to endorse biological, behavioural and cognitive models. The lay public were significantly more likely to endorse some models for certain disorders suggesting a nuanced understanding of the cause and likely cure, of various disorders. Ratings often differed significantly from the sample of psychiatrists who were relatively steadfast in their endorsement of the biological model. CONCLUSION: The adapted MAQ appeared accessible to the lay sample. Results suggest that the lay public are generally aligned with evidence-driven concepts of common disorders, but may not always understand or agree with how mental health professionals conceptualise them. The possible causes of these differences, future avenues for research and the implications for more collaborative, patient-clinician conceptualisations are discussed.Peer reviewedFinal Accepted Versio
Addition-Deletion Networks
We study structural properties of growing networks where both addition and
deletion of nodes are possible. Our model network evolves via two independent
processes. With rate r, a node is added to the system and this node links to a
randomly selected existing node. With rate 1, a randomly selected node is
deleted, and its parent node inherits the links of its immediate descendants.
We show that the in-component size distribution decays algebraically, c_k ~
k^{-beta}, as k-->infty. The exponent beta=2+1/(r-1) varies continuously with
the addition rate r. Structural properties of the network including the height
distribution, the diameter of the network, the average distance between two
nodes, and the fraction of dangling nodes are also obtained analytically.
Interestingly, the deletion process leads to a giant hub, a single node with a
macroscopic degree whereas all other nodes have a microscopic degree.Comment: 8 pages, 5 figure
Secondary user relations in emerging mobile computing environments
Mobile technologies are enabling access to information in diverse environ.ments, and are exposing a wider group of individuals to said technology. Therefore, this paper proposes that a wider view of user relations than is usually considered in information systems research is required. Specifically, we examine the potential effects of emerging mobile technologies on end-‐user relations with a focus on the ‘secondary user’, those who are not intended to interact directly with the technology but are intended consumers of the technology’s output. For illustration, we draw on a study of a U.K. regional Fire and Rescue Service and deconstruct mobile technology use at Fire Service incidents. Our findings provide insights, which suggest that, because of the nature of mobile technologies and their context of use, secondary user relations in such emerging mobile environments are important and need further exploration
Mining predicted crystal structure landscapes with high throughput crystallisation: old molecules, new insights
Organic molecules tend to close pack to form
dense structures when they are crystallized from organic solvents. Porous
molecular crystals defy this rule: they typically crystallize with lattice
solvent in the interconnected pores. However, the design and discovery of such structures
is often challenging and time consuming, in part because it is difficult to
predict solvent effects on crystallization. Here, we combine crystal structure
prediction (CSP) with a high-throughput crystallization screening method to
accelerate the discovery of stable hydrogen-bonded frameworks. We exemplify
this strategy by finding new phases of two well-studied molecules in a
computationally targeted way. Specifically, we find a new porous polymorph of
trimesic acid, δ-TMA,
that has a guest free hexagonal pore structure, as well as three new solvent-stabilized
diamondoid frameworks of
adamantane-1,3,5,7-tetracarboxylic acid (ADTA)
First Passage Properties of the Erdos-Renyi Random Graph
We study the mean time for a random walk to traverse between two arbitrary
sites of the Erdos-Renyi random graph. We develop an effective medium
approximation that predicts that the mean first-passage time between pairs of
nodes, as well as all moments of this first-passage time, are insensitive to
the fraction p of occupied links. This prediction qualitatively agrees with
numerical simulations away from the percolation threshold. Near the percolation
threshold, the statistically meaningful quantity is the mean transit rate,
namely, the inverse of the first-passage time. This rate varies
non-monotonically with p near the percolation transition. Much of this behavior
can be understood by simple heuristic arguments.Comment: 10 pages, 9 figures, 2-column revtex4 forma
Deployment of ultrasonic through-transmission inspection using twin cooperative industrial robots
The uptake of composite materials in the aerospace sector has led to a number of automated inspections systems based on industrial robots to be developed, including the IntACom project at TWI Technology Centre Wales. These new materials present challenges not only due to their intrinsic material properties but also due to the higher complexity of their surface geometries. Robotic inspections are designed using Off-Line Programing (OLP) software to describe a path on a computer-aided design (CAD) model of the object to be inspected using the pulse-echo ultrasonic method. By synchronising the movements of two robots, a second robot can be used to follow the path of the first, allowing for ultrasonic through-transmission inspections. Investigations carried out at TWI Technology Centre Wales have identified key challenges encountered in alignment and synchronisation when carrying out through-transmission inspections of various components. Reasons behind these challenges include inherent latency in the communication between the two robots and tool misalignment. Another challenge typically encountered arises from the relative pose between probes remaining fixed which makes it difficult to inspect geometries with varying thicknesses. The current paper discusses the above mentioned challenges and presents on-going work at TWI to tackle these issues. The effects of misalignment on the received ultrasonic signal are discussed and experimentally verified. The robot velocity and acceleration profiles are also taken into account for geometries with high curvature and their effects on through-transmission inspections are discussed. Finally an inspection of a component with varying thickness is presented and the results are compared for different robot cooperation methods
The design, development and evaluation of an array-based FES system with automated setup for the correction of drop foot
Functional electrical stimulation has been shown to be a safe and effective means of correcting drop foot of central neurological origin. However, despite recent technological advances, the set-up of surface stimulators remains a challenge for many users with drop foot. The automation of the setup process through the use of electrode arrays has been proposed as a way to address this problem. This paper describes a series of research and clinical studies which have led to the first demonstration of unsupervised automated setup of an electrode-array based drop foot stimulator. Finally, future research plans are discussed
Apparent wave function collapse caused by scattering
Some experimental implications of the recent progress on wave function
collapse are calculated. Exact results are derived for the center-of-mass wave
function collapse caused by random scatterings and applied to a range of
specific examples. The results show that recently proposed experiments to
measure the GRW effect are likely to fail, since the effect of naturally
occurring scatterings is of the same form as the GRW effect but generally much
stronger. The same goes for attempts to measure the collapse caused by quantum
gravity as suggested by Hawking and others. The results also indicate that
macroscopic systems tend to be found in states with (Delta-x)(Delta-p) =
hbar/sqrt(2), but microscopic systems in highly tiltedly squeezed states with
(Delta-x)(Delta-p) >> hbar.Comment: Final published version. 20 pages, Plain TeX, no figures. Online at
http://astro.berkeley.edu/~max/collapse.html (faster from the US), from
http://www.mpa-garching.mpg.de/~max/collapse.html (faster from Europe) or
from [email protected]
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