2,310 research outputs found
Construction and Refinement of Coarse-Grained Models
A general scheme, which includes constructions of coarse-grained (CG) models,
weighted ensemble dynamics (WED) simulations and cluster analyses (CA) of
stable states, is presented to detect dynamical and thermodynamical properties
in complex systems. In the scheme, CG models are efficiently and accurately
optimized based on a directed distance from original to CG systems, which is
estimated from ensemble means of lots of independent observable in two systems.
Furthermore, WED independently generates multiple short molecular dynamics
trajectories in original systems. The initial conformations of the trajectories
are constructed from equilibrium conformations in CG models, and the weights of
the trajectories can be estimated from the trajectories themselves in
generating complete equilibrium samples in the original systems. CA calculates
the directed distances among the trajectories and groups their initial
conformations into some clusters, which correspond to stable states in the
original systems, so that transition dynamics can be detected without requiring
a priori knowledge of the states.Comment: 4 pages, no figure
On the origin of the asymmetric dwarf galaxy distribution around Andromeda
The dwarf galaxy distribution surrounding M31 is significantly anisotropic in
nature. Of the 30 dwarf galaxies in this distribution, 15 form a disc-like
structure and 23 are contained within the hemisphere facing the Milky Way.
Using a realistic local potential, we analyse the conditions required to
produce and maintain these asymmetries. We find that some dwarf galaxies are
required to have highly eccentric orbits in order to preserve the presence of
the hemispherical asymmetry with an appropriately large radial dispersion.
Under the assumption that the dwarf galaxies originate from a single
association or accretion event, we find that the initial size and specific
energy of that association must both be relatively large in order to produce
the observed hemispherical asymmetry. However if the association was large in
physical size, the very high-energy required would enable several dwarf
galaxies to escape from the M31 and be captured by the Milky Way. Furthermore,
we find that associations that result in this structure have total specific
energies concentrated around --
, implying that the initial velocity and initial
position needed to produce the structure are strongly correlated. The overlap
of initial conditions required to produce the radial dispersion, angular
dispersion, and the planar structure is small and suggests that either they did
not originate from a single accretion event, or that these asymmetric
structures are short-lived.Comment: 12 pages, 10 figures, accepted by MNRA
Exponentiation of the Drell-Yan cross section near partonic threshold in the DIS and MSbar schemes
It has been observed that in the DIS scheme the refactorization of the
Drell-Yan cross section leading to exponentiation of threshold logarithms can
also be used to organize a class of constant terms, most of which arise from
the ratio of the timelike Sudakov form factor to its spacelike counterpart. We
extend this exponentiation to include all constant terms, and demonstrate how a
similar organization may be achieved in the MSbar scheme. We study the
relevance of these exponentiations in a two-loop analysis.Comment: 20 pages, JHEP style, no figure
Mid-Upper Arm Circumference based Nutrition Programming: evidence for a new approach in regions with high burden of Acute Malnutrition
In therapeutic feeding programs (TFP), mid-upper arm circumference (MUAC) shows advantages over weight-for-height Z score (WHZ) and is recommended by the World Health Organization (WHO) as an independent criterion for screening children 6-59 months old. Here we report outcomes and treatment response from a TFP using MUAC ≤118 mm or oedema as sole admission criteria for severe acute malnutrition (SAM)
Post-Disaster Housing Reconstruction in Sri Lanka: What Methodology?
Research methodology is the procedural framework within which the research is conducted. This includes the overall
approach to a problem that could be put into practice in a research process, from the theoretical underpinning to the
collection and analysis of data. Choice of methodology depends on the primary drivers: topic to be researched and the
specific research questions. Hence, methodological perspectives of managing stakeholder expectations of PDHR context
are composed of research philosophies, research strategy, research design, and research techniques. This research belonged
to social constructivism or interpretivism within a philosophical continuum. The nature of the study was more toward
subjectivism where human behavior favored voluntary stance. Ontological, methodological, epistemological, and axiological
positioning carried the characteristics of idealism, ideographic, anti-positivism, and value laden, respectively. Data collection
comprises two phases, preliminary and secondary. Exploratory interviews with construction experts in the United Kingdom
and Sri Lanka were carried out to refine the interview questions and identify the case studies. Case study interviews during
the secondary phase took place in Sri Lanka. Data collected at the preliminary stage were used to assess the attributes of
power, legitimacy/proximity, and urgency of stakeholders to the project using Stakeholder Circle™ software. Moreover,
the data collected at secondary phase via case studies will be analyzed with NVivo 8. This article aims to discuss these
methodological underpinnings in detail applied in a post-disaster housing reconstruction context in Sri Lanka
On tacit knowledge for philosophy of education
This article offers a detailed reading Gascoigne and Thornton’s book Tacit Knowledge (2013), which aims to account for the tacitness of tacit knowledge (TK) while preserving its status as knowledge proper. I take issue with their characterization and rejection of the existential-phenomenological Background—which they presuppose even as they dismiss—and their claim that TK can be articulated “from within”—which betrays a residual Cartesianism, the result of their elision of conceptuality and propositionality. Knowledgeable acts instantiate capacities which we might know we have and of which we can be aware, but which are not propositionally structured at their “core”. Nevertheless, propositionality is necessary to what Robert Brandom calls, in Making It Explicit (1994) and Articulating Reasons (2000), “explicitation”, which notion also presupposes a tacit dimension, which is, simply, the embodied person (the knower), without which no conception of knowledge can get any purchase. On my view, there is no knowledgeable act that can be understood as such separately from the notion of skilled corporeal performance. The account I offer cannot make sense of so-called “knowledge-based” education, as opposed to systems and styles which supposedly privilege “contentless” skills over and above “knowledge”, because on the phenomenological and inferentialist lines I endorse, neither the concepts “knowledge” nor “skill” has any purchase or meaning without the other
Large constraint length high speed viterbi decoder based on a modular hierarchial decomposition of the deBruijn graph
A method of formulating and packaging decision-making elements into a long constraint length Viterbi decoder which involves formulating the decision-making processors as individual Viterbi butterfly processors that are interconnected in a deBruijn graph configuration. A fully distributed architecture, which achieves high decoding speeds, is made feasible by novel wiring and partitioning of the state diagram. This partitioning defines universal modules, which can be used to build any size decoder, such that a large number of wires is contained inside each module, and a small number of wires is needed to connect modules. The total system is modular and hierarchical, and it implements a large proportion of the required wiring internally within modules and may include some external wiring to fully complete the deBruijn graph. pg,14
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