596 research outputs found
Reflecting on loss in Papua New Guinea
This article takes up the conundrum of conducting anthropological fieldwork with people who claim that they have 'lost their culture,' as is the case with Suau people in the Massim region of Papua New Guinea. But rather than claiming culture loss as a process of dispossession, Suau claim it as a consequence of their own attempts to engage with colonial interests. Suau appear to have responded to missionization and their close proximity to the colonial-era capital by jettisoning many of the practices characteristic of Massim societies, now identified as 'kastom.' The rejection of kastom in order to facilitate their relations with Europeans during colonialism, followed by the mourning for kastom after independence, both invite consideration of a kind of reflexivity that requires action based on the presumed perspective of another
Exploring parallel MPI fault tolerance mechanisms for phylogenetic inference with RAxML-NG
Motivation
Phylgenetic trees are now routinely inferred on large scale high performance computing systems with thousands of cores as the parallel scalability of phylogenetic inference tools has improved over the past years to cope with the molecular data avalanche. Thus, the parallel fault tolerance of phylogenetic inference tools has become a relevant challenge. To this end, we explore parallel fault tolerance mechanisms and algorithms, the software modifications required and the performance penalties induced via enabling parallel fault tolerance by example of RAxML-NG, the successor of the widely used RAxML tool for maximum likelihood-based phylogenetic tree inference.
Results
We find that the slowdown induced by the necessary additional recovery mechanisms in RAxML-NG is on average 1.00â±â0.04. The overall slowdown by using these recovery mechanisms in conjunction with a fault-tolerant Message Passing Interface implementation amounts to on average 1.7â±â0.6 for large empirical datasets. Via failure simulations, we show that RAxML-NG can successfully recover from multiple simultaneous failures, subsequent failures, failures during recovery and failures during checkpointing. Recoveries are automatic and transparent to the user
Functional evolution of quantum cylindrical waves
Kucha{\v{r}} showed that the quantum dynamics of (1 polarization) cylindrical
wave solutions to vacuum general relativity is determined by that of a free
axially-symmetric scalar field along arbitrary axially-symmetric foliations of
a fixed flat 2+1 dimensional spacetime. We investigate if such a dynamics can
be defined {\em unitarily} within the standard Fock space quantization of the
scalar field.
Evolution between two arbitrary slices of an arbitrary foliation of the flat
spacetime can be built out of a restricted class of evolutions (and their
inverses). The restricted evolution is from an initial flat slice to an
arbitrary (in general, curved) slice of the flat spacetime and can be
decomposed into (i) `time' evolution in which the spatial Minkowskian
coordinates serve as spatial coordinates on the initial and the final slice,
followed by (ii) the action of a spatial diffeomorphism of the final slice on
the data obtained from (i). We show that although the functional evolution of
(i) is unitarily implemented in the quantum theory, generic spatial
diffeomorphisms of (ii) are not. Our results imply that a Tomanaga-Schwinger
type functional evolution of quantum cylindrical waves is not a viable concept
even though, remarkably, the more limited notion of functional evolution in
Kucha{\v{r}}'s `half parametrized formalism' is well-defined.Comment: Replaced with published versio
Using Building Information Modelling (BIM) to design flexible spaces with design standards in healthcare facilities
This paper explored key factors that can enhance the designer's role when designing space for flexibility with the focal use
of building information modelling (BIM) and design standardisation. An exploratory study was conducted using a questionnaire
survey. The questionnaire was piloted to a Web-based Group (48 responses) and then it was distributed to the top 100 UK
architectural firms (10 responses) based on the Building Magazine, (2010). Both descriptive and inferential statistics were used. The
questionnaire survey included both open ended and close ended questions. The paper provides empirical insights about how design
standardisation and flexibility can be applied with BIM. It suggests that embedding flexibility can be enhanced with BIM by
supporting the generation of different design options and scheduling design tasks with different information attached. The results also
showed that strategies such as âadapting,â âcontractingâ and âexpandingâ are more beneficial than other flexible strategies.
Regarding standardisation and flexibility, the results showed that although standardisation is not the panacea of providing flexible
solutions, it is indeed applied and applicable in construction projects that require flexibility. The chosen research approach measures,
records and reports the perceptions and worldviews of the respondents. Therefore, the research findings are based on how reality is
formed by the participants and their experiences. With that in mind, the information identified was used to draw some noteworthy
findings that provide detailed information on embedding flexibility in healthcare buildings
Space standardisation and flexibility on healthcare refurbishment
One of the most common features and aims of a
flexible solution is to help all stakeholders throughout
the lifecycle of a healthcare facility, own or take (full
or part) responsibility of reducing, mitigating or
abating the redundancy impacts throughout a
buildingâs lifecycle with the integration of flexibility
and standardisation into healthcare refurbishment,
this can be achieved effectively with task partitioning.
This paper has acknowledged that there are barriers
to task partitioning. Flexibility and standardisation
strategies have been implemented globally across
different sectors and industries. Refurbishment is
usually undertaken to improve the current state or
functionality of a building in order to extend its
valuable life span. Flexible designs are intended to
provide future proof solutions. This requires
providing the ability to adapt to unforeseen future
changes at a specific place and time. Standardisation
can and should be used to improve efficiency and
reduce errors, it has been implemented in many
manufacturing processes such as the automobile
industry, but the question is how will it impact
buildings especially existing healthcare spaces?
This paper is aimed at identifying the impact of
space standardisation and flexibility on healthcare
refurbishment, with the view to identifying best
practice and prescribing possible processes for
integrating and optimising space standardisation and
flexibility during the refurbishment of healthcare
facilities
Supplemental Feeding for Ecotourism Reverses Diel Activity and Alters Movement Patterns and Spatial Distribution of the Southern Stingray, \u3cem\u3eDasyatis americana\u3c/em\u3e
Southern stingrays, Dasyatis americana, have been provided supplemental food in ecotourism operations at Stingray City Sandbar (SCS), Grand Cayman since 1986, with this site becoming one of the worldâs most famous and heavily visited marine wildlife interaction venues. Given expansion of marine wildlife interactive tourism worldwide, there are questions about the effects of such activities on the focal species and their ecosystems. We used a combination of acoustic telemetry and tag-recapture efforts to test the hypothesis that human-sourced supplemental feeding has altered stingray activity patterns and habitat use at SCS relative to wild animals at control sites. Secondarily, we also qualitatively estimated the population size of stingrays supporting this major ecotourism venue. Tag-recapture data indicated that a population of at least 164 stingrays, over 80% female, utilized the small area at SCS for prolonged periods of time. Examination of comparative movements of mature female stingrays at SCS and control sites revealed strong differences between the two groups: The fed animals demonstrated a notable inversion of diel activity, being constantly active during the day with little movement at night compared to the nocturnally active wild stingrays; The fed stingrays utilized significantly (
Supplemental Feeding for Ecotourism Reverses Diel Activity and Alters Movement Patterns and Spatial Distribution of the Southern Stingray, Dasyatis americana
Southern stingrays, Dasyatis americana, have been provided supplemental food in ecotourism operations at Stingray City Sandbar (SCS), Grand Cayman since 1986, with this site becoming one of the worldâs most famous and heavily visited marine wildlife interaction venues. Given expansion of marine wildlife interactive tourism worldwide, there are questions about the effects of such activities on the focal species and their ecosystems. We used a combination of acoustic telemetry and tag-recapture efforts to test the hypothesis that human-sourced supplemental feeding has altered stingray activity patterns and habitat use at SCS relative to wild animals at control sites. Secondarily, we also qualitatively estimated the population size of stingrays supporting this major ecotourism venue. Tag-recapture data indicated that a population of at least 164 stingrays, over 80% female, utilized the small area at SCS for prolonged periods of time. Examination of comparative movements of mature female stingrays at SCS and control sites revealed strong differences between the two groups: The fed animals demonstrated a notable inversion of diel activity, being constantly active during the day with little movement at night compared to the nocturnally active wild stingrays; The fed stingrays utilized significantly (
Electron gas polarization effect induced by heavy H-like ions of moderate velocities channeled in a silicon crystal
We report on the observation of a strong perturbation of the electron gas
induced by 20 MeV/u U ions and 13 MeV/u Pb ions channeled in
silicon crystals. This collective response (wake effect) in-duces a shift of
the continuum energy level by more than 100 eV, which is observed by means of
Radiative Electron Capture into the K and L-shells of the projectiles. We also
observe an increase of the REC probability by 20-50% relative to the
probability in a non-perturbed electron gas. The energy shift is in agreement
with calculations using the linear response theory, whereas the local electron
density enhancement is much smaller than predicted by the same model. This
shows that, for the small values of the adiabaticity parameter achieved in our
experiments, the density fluctuations are not strongly localized at the
vicinity of the heavy ions
Optimization by Quantum Annealing: Lessons from hard 3-SAT cases
The Path Integral Monte Carlo simulated Quantum Annealing algorithm is
applied to the optimization of a large hard instance of the Random 3-SAT
Problem (N=10000). The dynamical behavior of the quantum and the classical
annealing are compared, showing important qualitative differences in the way of
exploring the complex energy landscape of the combinatorial optimization
problem. At variance with the results obtained for the Ising spin glass and for
the Traveling Salesman Problem, in the present case the linear-schedule Quantum
Annealing performance is definitely worse than Classical Annealing.
Nevertheless, a quantum cooling protocol based on field-cycling and able to
outperform standard classical simulated annealing over short time scales is
introduced.Comment: 10 pages, 6 figures, submitted to PR
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