2,841 research outputs found
Fluctuation Scaling, Taylor’s Law, and Crime
Fluctuation scaling relationships have been observed in a wide range of processes ranging from internet router traffic to measles cases. Taylor’s law is one such scaling relationship and has been widely applied in ecology to understand communities including trees, birds, human populations, and insects. We show that monthly crime reports in the UK show complex fluctuation scaling which can be approximated by Taylor’s law relationships corresponding to local policing neighborhoods and larger regional and countrywide scales. Regression models applied to local scale data from Derbyshire and Nottinghamshire found that different categories of crime exhibited different scaling exponents with no significant difference between the two regions. On this scale, violence reports were close to a Poisson distribution (α = 1.057±0.026) while burglary exhibited a greater exponent (α = 1.292±0.029) indicative of temporal clustering. These two regions exhibited significantly different pre-exponential factors for the categories of anti-social behavior and burglary indicating that local variations in crime reports can be assessed using fluctuation scaling methods. At regional and countrywide scales, all categories exhibited scaling behavior indicative of temporal clustering evidenced by Taylor’s law exponents from 1.43±0.12 (Drugs) to 2.094±0081 (Other Crimes). Investigating crime behavior via fluctuation scaling gives insight beyond that of raw numbers and is unique in reporting on all processes contributing to the observed variance and is either robust to or exhibits signs of many types of data manipulation
Foundations of multiple black hole evolutions
We present techniques for long-term, stable, and accurate evolutions of
multiple-black-hole spacetimes using the `moving puncture' approach with
fourth- and eighth-order finite difference stencils. We use these techniques to
explore configurations of three black holes in a hierarchical system consisting
of a third black hole approaching a quasi-circular black-hole binary, and find
that, depending on the size of the binary, the resulting encounter may lead to
a prompt merger of all three black holes, production of a highly elliptical
binary (with the third black hole remaining unbound), or disruption of the
binary (leading to three free black holes). We also analyze the classical
Burrau three-body problem using full numerical evolutions. In both cases, we
find behaviors distinctly different from Newtonian predictions, which has
important implications for N-body black-hole simulations. For our simulations
we use analytic approximate data. We find that the eighth-order stencils
significantly reduce the numerical errors for our choice of grid sizes, and
that the approximate initial data produces the expected waveforms (after a
rescaling of the puncture masses) for black-hole binaries with modest initial
separations.Comment: Revtex 4, 13 pages, 15 figure
Quasi-Local Linear Momentum in Black-Hole Binaries
We propose a quasi-local formula for the linear momentum of black-hole
horizons inspired by the formalism of quasi-local horizons. We test this
formula using two complementary configurations: (i) by calculating the large
orbital linear momentum of the two black holes in an unequal-mass, zero-spin,
quasi-circular binary and (ii) by calculating the very small recoil momentum
imparted to the remnant of the head-on collision of an equal-mass,
anti-aligned-spin binary. We obtain results consistent with the horizon
trajectory in the orbiting case, and consistent with the net radiated linear
momentum for the much smaller head-on recoil velocity.Comment: 5 pages, 3 figures, revtex
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Penelitian ini meneliti tentang pengaruh terpaan artikel fashion dan beauty fashion blogger www.luce-dale.com terhadap remaja putri di dalam blog. Adapun tujuan dari penelitian ini adalah untuk mencari hubungan antara artikel fashion dan beauty yang diproduksi oleh www.luce-dale.com terhadap penegetahuan remaja putri mengenai dunia gaya dan kecantikan. Teori yang digunakan adalah teori efek terbatas, teori terpaan, dan teori SMCR, Blog, Fashion dan media, serta pengetahuan. Dimana ingin mengetahui seberapa besar pengaruh media blog terhadap audiensnya. Populasi dalam penelitia ini adalah pengguna jaringan blog yang follow atau mengikuti blog www.luce-dale.com pada periode tahun 2012 dimana berjumlah 4500 followers. Jumlah sampel ditetapkan sebanyak 98 dikarenakan jumlah tersebut merepresentasikan populasi. Metode yang digunakan adalah deskriptif kuantitatif yakni meneliti pengaruh terpaan artikel fashion dan beauty dari blog www.luce-dale.com terhadap pengetahuan remaja putri. Pengumpulan data dengan cara membuat pertanyaan-pertanyaan dalam bentuk kuisioner. Dengan menggunakan teknik analaisis deskriptif dan uji korelasional maka bahwa peneliti mendapatkan hubungan antara artikel fashion dan beauty terhadap pengetahuan remaja putri sebanyak 0,035 yaitu Ha diterima
The Birth-Death-Mutation process: a new paradigm for fat tailed distributions
Fat tailed statistics and power-laws are ubiquitous in many complex systems.
Usually the appearance of of a few anomalously successful individuals
(bio-species, investors, websites) is interpreted as reflecting some inherent
"quality" (fitness, talent, giftedness) as in Darwin's theory of natural
selection. Here we adopt the opposite, "neutral", outlook, suggesting that the
main factor explaining success is merely luck. The statistics emerging from the
neutral birth-death-mutation (BDM) process is shown to fit marvelously many
empirical distributions. While previous neutral theories have focused on the
power-law tail, our theory economically and accurately explains the entire
distribution. We thus suggest the BDM distribution as a standard neutral model:
effects of fitness and selection are to be identified by substantial deviations
from it
Nonlocal competition and logistic growth: patterns, defects and fronts
Logistic growth of diffusing reactants on spatial domains with long range
competition is studied. The bifurcations cascade involved in the transition
from the homogenous state to a spatially modulated stable solution is
presented, and a distinction is made between a modulated phase, dominated by
single or few wavenumbers, and the spiky phase, where localized colonies are
separated by depleted region. The characteristic defects in the periodic
structure are presented for each phase, together with the invasion dynamics in
case of local initiation. It is shown that the basic length scale that controls
the bifurcation is the width of the Fisher front, and that the total population
grows as this width decreases. A mix of analytic results and extensive
numerical simulations yields a comprehensive examination of the possible phases
for logistic growth in the presence of nonlocal competition
Testing minimal lepton flavor violation with extra vector-like leptons at the LHC
Models of minimal lepton flavor violation where the seesaw scale is higher
than the relevant flavor scale predict that all lepton flavor violation is
proportional to the charged lepton Yukawa matrix. If extra vector-like leptons
are within the reach of the LHC, it will be possible to test the resulting
predictions in ATLAS/CMS.Comment: 19 pages, 8 figure
Large Merger Recoils and Spin Flips From Generic Black-Hole Binaries
We report the first results from evolutions of a generic black-hole binary,
i.e. a binary containing unequal mass black holes with misaligned spins. Our
configuration, which has a mass ratio of 2:1, consists of an initially
non-spinning hole orbiting a larger, rapidly spinning hole (specific spin a/m =
0.885), with the spin direction oriented -45 degrees with respect to the
orbital plane. We track the inspiral and merger for ~2 orbits and find that the
remnant receives a substantial kick of 454 km/s, more than twice as large as
the maximum kick from non-spinning binaries. The remnant spin direction is
flipped by 103 degrees with respect to the initial spin direction of the larger
hole. We performed a second run with anti-aligned spins, a/m = +-0.5 lying in
the orbital plane that produces a kick of 1830 km/s off the orbital plane. This
value scales to nearly 4000 km/s for maximally spinning holes. Such a large
recoil velocity opens the possibility that a merged binary can be ejected even
from the nucleus of a massive host galaxy.Comment: 4 pages. Accepted for publication in ApJ
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