4,696 research outputs found
Frequentist statistics as a theory of inductive inference
After some general remarks about the interrelation between philosophical and
statistical thinking, the discussion centres largely on significance tests.
These are defined as the calculation of -values rather than as formal
procedures for ``acceptance'' and ``rejection.'' A number of types of null
hypothesis are described and a principle for evidential interpretation set out
governing the implications of -values in the specific circumstances of each
application, as contrasted with a long-run interpretation. A variety of more
complicated situations are discussed in which modification of the simple
-value may be essential.Comment: Published at http://dx.doi.org/10.1214/074921706000000400 in the IMS
Lecture Notes--Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Prosodic transcription of Glasgow English: an evaluation study of GlaToBI
GlaToBI, a version of the ToBI prosodic transcription system which can be used to transcribe the intonation patterns of western Scottish (Glasgow) English, is currently under development. An assessment of GlaToBI, similar to the evaluation studies that were undertaken for the original ToBI system [7], and for GToBI, a version developed for German [4], has been carried out to test the new system 's reliability, learnability and comprehensiveness. The results of this study show that this adaptation of the ToBI system can be applied with the expected level of reliability to the transcription of Glasgow English. 1. INTRODUCTION Very little corpus based work has been done on the prosodic features of English dialects other than Standard American and southern British (Received Pronunciation). However, with the creation of databases such as the University of Edinburgh's HCRC Map Task corpus [1], the predominant dialect of which is western Scottish (Glasgow) English, the opportunity has arisen..
Noncooperatively Optimized Tolerance: Decentralized Strategic Optimization in Complex Systems
We introduce noncooperatively optimized tolerance (NOT), a generalization of
highly optimized tolerance (HOT) that involves strategic (game theoretic)
interactions between parties in a complex system. We illustrate our model in
the forest fire (percolation) framework. As the number of players increases,
our model retains features of HOT, such as robustness, high yield combined with
high density, and self-dissimilar landscapes, but also develops features of
self-organized criticality (SOC) when the number of players is large enough.
For example, the forest landscape becomes increasingly homogeneous and
protection from adverse events (lightning strikes) becomes less closely
correlated with the spatial distribution of these events. While HOT is a
special case of our model, the resemblance to SOC is only partial; for example,
the distribution of cascades, while becoming increasingly heavy-tailed as the
number of players increases, also deviates more significantly from a power law
in this regime. Surprisingly, the system retains considerable robustness even
as it becomes fractured, due in part to emergent cooperation between
neighboring players. At the same time, increasing homogeneity promotes
resilience against changes in the lightning distribution, giving rise to
intermediate regimes where the system is robust to a particular distribution of
adverse events, yet not very fragile to changes
Fronts in randomly advected and heterogeneous media and nonuniversality of Burgers turbulence: Theory and numerics
A recently established mathematical equivalence--between weakly perturbed
Huygens fronts (e.g., flames in weak turbulence or geometrical-optics wave
fronts in slightly nonuniform media) and the inviscid limit of
white-noise-driven Burgers turbulence--motivates theoretical and numerical
estimates of Burgers-turbulence properties for specific types of white-in-time
forcing. Existing mathematical relations between Burgers turbulence and the
statistical mechanics of directed polymers, allowing use of the replica method,
are exploited to obtain systematic upper bounds on the Burgers energy density,
corresponding to the ground-state binding energy of the directed polymer and
the speedup of the Huygens front. The results are complementary to previous
studies of both Burgers turbulence and directed polymers, which have focused on
universal scaling properties instead of forcing-dependent parameters. The
upper-bound formula can be heuristically understood in terms of renormalization
of a different kind from that previously used in combustion models, and also
shows that the burning velocity of an idealized turbulent flame does not
diverge with increasing Reynolds number at fixed turbulence intensity, a
conclusion that applies even to strong turbulence. Numerical simulations of the
one-dimensional inviscid Burgers equation using a Lagrangian finite-element
method confirm that the theoretical upper bounds are sharp within about 15% for
various forcing spectra (corresponding to various two-dimensional random
media). These computations provide a new quantitative test of the replica
method. The inferred nonuniversality (spectrum dependence) of the front speedup
is of direct importance for combustion modeling.Comment: 20 pages, 2 figures, REVTeX 4. Moved some details to appendices,
added figure on numerical metho
Oxidation and formation of deposit precursors in hydrocarbon fuels
The oxidation of two jet turbine fuels and some pure hydrocarbons was studied at 130 C with and without the presence of small amounts of N-methyl pyrrole (NMP) or indene. Tendency to form solid-deposit precursors was studied by measuring soluble gum formation as well as dimer and trimer formation using field ionization mass spectrometry. Pure n-dodecane oxidized fastest and gave the smallest amount of procursors. An unstable fuel oil oxidized much slower but formed large amounts of precursors. Stable Jet A fuel oxidized slowest and gave little precursors. Indene either retarded or accelerated the oxidation of n-dodecane, depending on its concentration, but always caused more gum formation. The NMP greatly retarded n-dodecane oxidation but accelerated Jet A oxidation and greatly increased the latter's gum formation. In general, the additive reacted faster and formed most of the gum. Results are interpreted in terms of classical cooxidation theory. The effect of oxygen pressure on gum formation is also reported
Size Gap for Zero Temperature Black Holes in Semiclassical Gravity
We show that a gap exists in the allowed sizes of all zero temperature static
spherically symmetric black holes in semiclassical gravity when only
conformally invariant fields are present. The result holds for both charged and
uncharged black holes. By size we mean the proper area of the event horizon.
The range of sizes that do not occur depends on the numbers and types of
quantized fields that are present. We also derive some general properties that
both zero and nonzero temperature black holes have in all classical and
semiclassical metric theories of gravity.Comment: 4 pages, ReVTeX, no figure
Black hole polarization and new entropy bounds
Zaslavskii has suggested how to tighten Bekenstein's bound on entropy when
the object is electrically charged. Recently Hod has provided a second tighter
version of the bound applicable when the object is rotating. Here we derive
Zaslavskii's optimized bound by considering the accretion of an ordinary
charged object by a black hole. The force originating from the polarization of
the black hole by a nearby charge is central to the derivation of the bound
from the generalized second law. We also conjecture an entropy bound for
charged rotating objects, a synthesis of Zaslavskii's and Hod's. On the basis
of the no hair principle for black holes, we show that this last bound cannot
be tightened further in a generic way by knowledge of ``global'' conserved
charges, e.g., baryon number, which may be borne by the object.Comment: 21 pages, RevTex, Regularization of potential made clearer. Error in
energy of the particle corrected with no consequence for final conclusions.
New references adde
A Solidarity Machine? Hong Kong Labour NGOs in Guangdong
Although the literature on labour NGOs (LNGOs) in China has significantly expanded, few scholars have attempted to subject the work of these organizations to a Marxist perspective. This article draws on a recently developed Marxian theoretical framework on social movements to analyse the pioneering work of Hong Kong LNGOs and their partners in the province of Guangdong, China. Over the past 15 years, the Hong Kong groups, as they are known collectively, have been ideally placed to develop specific interventions in response to migrant workers’ pursuance of wage claims and improved working conditions during a time of increased rights awareness and widespread labour shortages. While consistently careful to remain the right side of China’s restrictive laws on freedom of association and demonstrations, the Hong Kong LNGOs were able to contribute to a narrative of class-based collective solidarity that has yielded significant gains for workers
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