2,297 research outputs found
Coevolution of Camouflage
Camouflage in nature seems to arise from competition between predator and
prey. To survive, predators must find prey, and prey must avoid being found.
This work simulates an abstract model of that adversarial relationship. It
looks at crypsis through evolving prey camouflage patterns (as color textures)
in competition with evolving predator vision. During their "lifetime" predators
learn to better locate camouflaged prey. The environment for this 2D simulation
is provided by a set of photographs, typically of natural scenes. This model is
based on two evolving populations, one of prey and another of predators. Mutual
conflict between these populations can produce both effective prey camouflage
and predators skilled at "breaking" camouflage. The result is an open source
artificial life model to help study camouflage in nature, and the perceptual
phenomenon of camouflage more generally.Comment: 16 pages, 20 figure
Evaluating site induction practice efficiency and effectiveness:an organisational case study
The style of induction presentation and other processes, irrespective of duration, immediately establishes the context and attitude of the construction site team and is where initial behavioural standards are established. A case study within a large contractor investigates site induction activities in practice to better understand the operational demands on time for those involved in managing site inductions and the impact of this activity on safety behaviour on site. The research method adopted was a desk-based review of company policy through document analysis, observations of site induction practice, operations and semi structured interviews. Trade-offs between time losses/benefits, safety in practice, technology implementation and their impact on administrative processes are examined. It is argued that the use of observations has allowed the identification of the actual time commitment in practice. The principal contractor's allocated time for providing and undertaking site induction activities was underestimated by 16% to 20%. There is potential to save time through exploitation of existing and new technology solutions more fully. However, those with an H&S leadership role have indicated difficulties in keeping up with the pace of change in technology development for this purpose
Power, Protection and Magic in Thailand
This biographical study of an unusual southern policeman explores the relationship between religion and power in Thailand during the early twentieth century when parts of the country were remote and banditry was rife. Khun Phan (1898–2006), known as Lion Lawman, sometimes used rather too much lethal force in carrying out his orders. He was the most famous graduate of a monastic academy in the mid-south, whose senior teachers imparted occult knowledge favoured by fighters on both sides of the law. Khun Phan imbibed this knowledge to confront the risks and uncertainty that lay ahead and bolster his confidence and self-reliance for his struggle with adversaries. Against the background of national events, the story is rooted in the mid-south where the policeman was born and died. Based on a wide range of works in Thai language, on field trips to the region and on interviews with local and regional scholars as well as the policeman’s descendants, this generously illustrated book, accompanied by short video clips, brings to life the distinctive environment of the lakes district on the Malay Peninsula
The Monument Project (Si Monumentum Reqiuis Circumspice) Leonardo article
This paper describes the concepts, ideas, background and operations of The Monument Project (Si Monumentum Requiris Circumspice), a digital video installation that produces a continuous stream of weather-responsive panoramic images from the top of the Monument in the City of London. The work, which was commissioned by Julian Harrap Architects, was part of a £4.5 million refurbishment of the 17th-century landmark, designed by Sir Christopher Wren and Dr. Robert Hooke to commemorate the Great Fire of London in 1666
X-ray properties of an Unbiased Hard X-ray Detected Sample of AGN
The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a
sample of active galactic nuclei (AGN) based solely on their hard X-ray flux
(14-195 keV). In this paper, we present for the first time {\it XMM-Newton}
X-ray spectra for 22 BAT AGNs with no previously analyzed X-ray spectra. If our
sources are a representative sample of the BAT AGN, as we claim, our results
present for the first time global X-ray properties of an unbiased towards
absorption (n), AGN
sample. We find 9/22 low absorption (n cm), simple power
law model sources, where 4 of these sources have a statistically significant
soft component. Among these sources, we find the presence of a warm absorber
statistically significant for only one Seyfert 1 source, contrasting with the
ASCA results of \citet{rey97} and \citet{geo98}, who find signatures of warm
absorption in half or more of their Seyfert 1 samples at similar redshifts.
Additionally, the remaining sources (14/22) have more complex spectra, well-fit
by an absorbed power law at keV. Five of the complex sources are
classified as Compton-thick candidates. Further, we find four more sources with
properties consistent with the hidden/buried AGN reported by Ueda {\it et al.}
(2007). Finally, we include a comparison of the {\it XMM-Newton} EPIC spectra
with available SWIFT X-ray Telescope (XRT) observations. From these
comparisons, we find 6/16 sources with varying column densities, 6/16 sources
with varying power law indices, and 13/16 sources with varying fluxes, over
periods of hours to months. Flux and power law index are correlated for objects
where both parameters vary.Comment: 39 pages, 16 figures, accepted to Ap
Feudalism as a Trope or Discourse for the Asian Past with special reference to Thailand
The  problem that will interest me in this essay is the existence of terms for  feudalism in Asian-language discourses about past and present society and  what the writer in English -anthropologist, literary scholar, historian,  linguist, whatever -is to do with these feudalisms. Why do native speakers of  Asian languages term their own societies "feudal" (feudal = term in  language X) and how do they come to employ this term? Generally, Western  writers dismiss these Asian-language feudalisms as too culture-bound to be of  use in writing objective history. Such usage, so the argument might run, is  too embedded in internal debates within Asian societies about who should -or  should not -hold power. That is, "feudalism" is a category of social  evolution that serves revolutionary or official nationalist interests, and  such interests so skew its usage that the term cannot tell the disinterested  observer anything illuminating about the political economy of a particular  society.
Vestibular feedback maintains reaching accuracy during body movement
When using our arms to interact with the world, unintended body motion can introduce movement error. A mechanism which could detect and compensate for such motion would be beneficial. Observations of arm movements evoked by vestibular stimulation provide some support for this mechanism. However, the physiological function underlying these artificially-evoked movements is unclear from previous research. For such a mechanism to be functional, it should only operate when the arm is being controlled in an earth-fixed rather than body-fixed reference frame. In the latter case, compensation would be unnecessary and even deleterious. To test this hypothesis, subjects were gently rotated in a chair while asked to maintain their outstretched arm pointing either towards earth-fixed (EF) or body-fixed (BF) memorised targets. Galvanic vestibular stimulation (GVS) was applied concurrently during rotation to isolate the influence of vestibular input, uncontaminated by inertial factors. During the EF task, GVS produced large polarity-dependent corrections in arm position. These corrections mimicked those evoked when chair velocity was altered without any GVS, indicating a compensatory arm response to a sensation of altered body motion. In stark contrast, corrections were completely absent during the BF task, despite the same chair movement profile and arm posture. These effects persisted when we controlled for differences in limb kinematics between the two tasks. Our results demonstrate that vestibular control of the upper-limb maintains reaching accuracy during unpredictable body motion. The observation that such responses only occurred when reaching within an EF reference frame confirms the functional nature of vestibular-evoked arm movement
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