6,096 research outputs found
Behavior of the Dripping Faucet over a Wide Range of the Flow Rate
The time interval of successive water-drips from a faucet was examined over a
wide range of the flow rate. The dripping interval alternately exhibits a
stable state and a chaotic state as the flow rate increases. In the stable
state, the volume of the drip is kept constant at fixed flow rates, and the
constant volume increases with the flow rate. In the chaotic state, in addition
to a mechanics that the drip is torn by its own weight, the vibration of the
drip on the faucet takes part in the strange behavior of the interval.Comment: 7 pages, 7 figures, to be published in J. Phys. Soc. Jpn vol
68-2(1999
Convex Independence in Permutation Graphs
A set C of vertices of a graph is P_3-convex if every vertex outside C has at
most one neighbor in C. The convex hull \sigma(A) of a set A is the smallest
P_3-convex set that contains A. A set M is convexly independent if for every
vertex x \in M, x \notin \sigma(M-x). We show that the maximal number of
vertices that a convexly independent set in a permutation graph can have, can
be computed in polynomial time
{RefinedC}: {A}utomating the Foundational Verification of {C} Code with Refined Ownership Types
Experimental harvesting of fish populations drives genetically based shifts in body size and maturation
Size-selective harvesting in commercial fisheries can induce rapid changes in biological traits. While experimental and wild harvested populations often exhibit clear shifts in body size and maturation associated with fishing pressure, the relative contributions of genetic and environmental factors to these shifts remain uncertain and have been much debated. To date, observations of so-called fisheries-induced evolution (FIE) have been based solely on phenotypic measures, such as size data. Genetic data are hitherto lacking. Here, we quantify genetic versus environmental change in response to size-selective harvesting for small and large body size in guppies (Poecilia reticulata) across three generations of selection. We document for the first time significant changes at individual genetic loci, some of which have previously been associated with body size. In contrast, variation at neutral microsatellite markers was unaffected by selection, providing direct genetic evidence for rapid evolution induced by size-selective harvesting. These findings demonstrate FIE in an experimental system, with major implications for the sustainability of harvested populations, as well as impacts on size-structured communities and ecosystem processes. These findings highlight the need for scientists and managers to reconsider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation. © 2013 The Ecological Society of America
Quasinormal modes prefer supersymmetry ?
One ambiguity in loop quantum gravity is the appearance of a free parameter
which is called Immirzi parameter. Recently Dreyer has argued that this
parameter may be fixed by considering the quasinormal mode spectrum of black
holes, while at the price of changing the gauge group to SO(3) rather than the
original one SU(2). Physically such a replacement is not quite natural or
desirable. In this paper we study the relationship between the black hole
entropy and the quasi normal mode spectrum in the loop quantization of N=1
supergravity. We find that a single value of the Immirzi parameter agrees with
the semiclassical expectations as well. But in this case the lowest
supersymmetric representation dominates, fitting well with the result based on
statistical consideration. This suggests that, so long as fermions are included
in the theory, supersymemtry may be favored for the consistency of the low
energy limit of loop quantum gravity.Comment: 3 page
Compilation of extended recursion in call-by-value functional languages
This paper formalizes and proves correct a compilation scheme for
mutually-recursive definitions in call-by-value functional languages. This
scheme supports a wider range of recursive definitions than previous methods.
We formalize our technique as a translation scheme to a lambda-calculus
featuring in-place update of memory blocks, and prove the translation to be
correct.Comment: 62 pages, uses pi
Simulation of a Dripping Faucet
We present a simulation of a dripping faucet system. A new algorithm based on
Lagrangian description is introduced. The shape of drop falling from a faucet
obtained by the present algorithm agrees quite well with experimental
observations. Long-term behavior of the simulation can reproduce period-one,
period-two, intermittent and chaotic oscillations widely observed in
experiments. Possible routes to chaos are discussed.Comment: 20 pages, 15 figures, J. Phys. Soc. Jpn. (in press
M/L, H-alpha Rotation Curves, and HI Measurements for 329 Nearby Cluster and Field Spirals: II. Evidence for Galaxy Infall
We have conducted a study of optical and HI properties of spiral galaxies
(size, luminosity, H-alpha flux distribution, circular velocity, HI gas mass)
to explore the role of gas stripping as a driver of morphological evolution in
clusters. We find a strong correlation between the spiral and S0 fractions
within clusters, and the spiral fraction scales tightly with cluster X-ray gas
luminosity. We explore young star formation and identify spirals that are (1)
asymmetric, with truncated H-alpha emission and HI gas reservoirs on the
leading edge of the disk, on a first pass through the dense intracluster medium
in the cores of rich clusters; (2) strongly HI deficient and stripped, with
star formation confined to the inner 5 kpc/h and 3 disk scale lengths; (3)
reddened, extremely HI deficient and quenched, where star formation has been
halted across the entire disk. We propose that these spirals are in successive
stages of morphological transformation, between infalling field spirals and
cluster S0s, and that the process which acts to remove the HI gas reservoir
suppresses new star formation on a similarly fast timescale. These data suggest
that gas stripping plays a significant role in morphological transformation and
rapid truncation of star formation across the disk.Comment: 24 pages, 12 figures; accepted for publication in AJ;
higher-resolution figures available at http://astronomy.nmsu.edu/nicol
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