1,044 research outputs found
The Ontological Basis of Strong Artificial Life
This article concerns the claim that it is possible to create living organisms, not merely models that represent organisms, simply by programming computers ("virtual" strong alife). I ask what sort of things these computer-generated organisms are supposed to be (where are they, and what are they made of?). I consider four possible answers to this question: (a) The organisms are abstract complexes of pure information; (b) they are material objects made of bits of computer hardware; (c) they are physical processes going on inside the computer; and (d) they are denizens of an entire artificial world, different from our own, that the programmer creates. I argue that (a) could not be right, that (c) collapses into (b), and that (d) would make strong alife either absurd or uninteresting. Thus, "virtual" strong alife amounts to the claim that, by programming a computer, one can literally bring bits of its hardware to life
Parametric ordering of complex systems
Cellular automata (CA) dynamics are ordered in terms of two global
parameters, computable {\sl a priori} from the description of rules. While one
of them (activity) has been used before, the second one is new; it estimates
the average sensitivity of rules to small configurational changes. For two
well-known families of rules, the Wolfram complexity Classes cluster
satisfactorily. The observed simultaneous occurrence of sharp and smooth
transitions from ordered to disordered dynamics in CA can be explained with the
two-parameter diagram
Social Media Advocacy
Our research project’s purpose is to inform the local community on the ethics and effectiveness as well as the exploitive power of using social media to promote international and domestic causes. We will educate the public and professionals on the responsible use of social media in advocacy and the consequences of its misuse. We will achieve this goal by researching social media movements and their lasting effects in academic journals and major news outlets. We will then share these findings in a presentation, educating our audience and providing them with the knowledge necessary for responsible use. The presentation will compare, contrast and analyze four international campaigns conducted over social media, resulting in various outcomes. The campaigns are the ALS Ice Bucket Challenge, Kony 2012, the #FirstWorldProblems Hashtag Killer by Water is Life ,and #bringbackourgirls
Creation and Reproduction of Model Cells with Semipermeable Membrane
A high activity of reactions can be confined in a model cell with a
semipermeable membrane in the Schl\"ogl model. It is interpreted as a model of
primitive metabolism in a cell. We study two generalized models to understand
the creation of primitive cell systems conceptually from the view point of the
nonlinear-nonequilibrium physics. In the first model, a single-cell system with
a highly active state confined by a semipermeable membrane is spontaneously
created from an inactive homogeneous state by a stochastic jump process. In the
second model, many cell structures are reproduced from a single cell, and a
multicellular system is created.Comment: 11 pages, 7 figure
Quantitative evaluation of polymer gel dosimeters by broadband ultrasound attenuation
Ultrasound has been examined previously as an alternative readout method for irradiated polymer gel dosimeters, with authors reporting varying dose response to ultrasound transmission measurements. In this current work we extend previous work to measure the broadband ultrasound attenuation (BUA) response of irradiated PAGAT gel dosimeters, using a novel ultrasound computed tomography system
Cognitive demands of face monitoring: Evidence for visuospatial overload
Young children perform difficult communication tasks better face to face than when they cannot see one another (e.g., Doherty-Sneddon & Kent, 1996). However, in recent studies, it was found that children aged 6 and 10 years, describing abstract shapes, showed evidence of face-to-face interference rather than facilitation. For some communication tasks, access to visual signals (such as facial expression and eye gaze) may hinder rather than help children’s communication. In new research we have pursued this interference effect. Five studies are described with adults and 10- and 6-year-old participants. It was found that looking at a face interfered with children’s abilities to listen to descriptions of abstract shapes. Children also performed visuospatial memory tasks worse when they looked at someone’s face prior to responding than when they looked at a visuospatial pattern or at the floor. It was concluded that performance on certain tasks was hindered by monitoring another person’s face. It is suggested that processing of visual communication signals shares certain processing resources with the processing of other visuospatial information
Eulerian Walkers as a model of Self-Organised Criticality
We propose a new model of self-organized criticality. A particle is dropped
at random on a lattice and moves along directions specified by arrows at each
site. As it moves, it changes the direction of the arrows according to fixed
rules. On closed graphs these walks generate Euler circuits. On open graphs,
the particle eventually leaves the system, and a new particle is then added.
The operators corresponding to particle addition generate an abelian group,
same as the group for the Abelian Sandpile model on the graph. We determine the
critical steady state and some critical exponents exactly, using this
equivalence.Comment: 4 pages, RevTex, 4 figure
HD 17156b: A Transiting Planet with a 21.2 Day Period and an Eccentric Orbit
We report the detection of transits by the 3.1 M_Jup companion to the V=8.17
G0V star HD 17156. The transit was observed by three independant observers on
Sept. 9/10, 2007 (two in central Italy and one in the Canary Islands), who
obtained detections at confidence levels of 3.0 sigma, 5.3 sigma, and 7.9
sigma, respectively. The observations were carried out under the auspices of
the Transitsearch.org network, which organizes follow-up photometric transit
searches of known planet-bearing stars during the time intervals when transits
are expected to possibly occur. Analyses of the 7.9 sigma data set indicates a
transit depth d=0.0062+/-0.0004, and a transit duration t=186+/-5 min. These
values are consistent with the transit of a Jupiter-sized planet with an impact
parameter b=a*cos(i)/R_star ~ 0.8. This planet occupies a unique regime among
known transiting extrasolar planets, both as a result of its large orbital
eccentricity (e=0.67) and long orbital period (P=21.2 d). The planet receives a
26-fold variation in insolation during the course of its orbit, which will make
it a useful object for characterization of exoplanetary atmospheric dynamics.Comment: Accepted for publication to A&A, 4 pages, 2 figure
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