18,786 research outputs found
Investigative Simulation: Towards Utilizing Graph Pattern Matching for Investigative Search
This paper proposes the use of graph pattern matching for investigative graph
search, which is the process of searching for and prioritizing persons of
interest who may exhibit part or all of a pattern of suspicious behaviors or
connections. While there are a variety of applications, our principal
motivation is to aid law enforcement in the detection of homegrown violent
extremists. We introduce investigative simulation, which consists of several
necessary extensions to the existing dual simulation graph pattern matching
scheme in order to make it appropriate for intelligence analysts and law
enforcement officials. Specifically, we impose a categorical label structure on
nodes consistent with the nature of indicators in investigations, as well as
prune or complete search results to ensure sensibility and usefulness of
partial matches to analysts. Lastly, we introduce a natural top-k ranking
scheme that can help analysts prioritize investigative efforts. We demonstrate
performance of investigative simulation on a real-world large dataset.Comment: 8 pages, 6 figures. Paper to appear in the Fosint-SI 2016 conference
proceedings in conjunction with the 2016 IEEE/ACM International Conference on
Advances in Social Networks Analysis and Mining ASONAM 201
Parametrization of electron impact ionization cross sections for CO, CO2, NH3 and SO2
The electron impact ionization and dissociative ionization cross section data of CO, CO2, CH4, NH3, and SO2, measured in the laboratory, were parameterized utilizing an empirical formula based on the Born approximation. For this purpose an chi squared minimization technique was employed which provided an excellent fit to the experimental data
Tax-Deferred Retirement Savings of Farm Households: An Empirical Investigation
This study examines factors affecting tax-deferred retirement savings among farm households. A double-hurdle model is estimated using 2003 Agricultural Resource Management Survey (ARMS) farm-level national data. Results indicate that demographic factors, total household income, off-farm work, and risk preference play important roles in retirement savings plan participation. Retirement savings increase with household size, intensity of off-farm work by farm operator and spouse, and size of farming operation. We find that the amount of retirement savings decreases with operator’s age and increases with spouse’s age, and that cash grain and dairy farmers have lower retirement savings.double-hurdle estimation, farm households, probit, retirement savings, risk preference, total household income, Agricultural Finance, Consumer/Household Economics,
Monte Carlo Study of the Spin Transport in Magnetic Materials
The resistivity in magnetic materials has been theoretically shown to depend
on the spin-spin correlation function which in turn depends on the
magnetic-field, the density of conduction electron, the magnetic ordering
stability, etc. However, these theories involved a lot of approximations, so
their validity remained to be confirmed. The purpose of this work is to show by
extensive Monte Carlo (MC) simulation the resistivity of the spin current from
low- ordered phase to high- paramagnetic phase in a ferromagnetic film.
We take into account the interaction between the itinerant spins and the
localized lattice spins as well as the interaction between itinerant spins
themselves. We show that the resistivity undergoes an anomalous behavior at the
magnetic phase transition in agreement with previous theories in spite of their
numerous approximations. The origin of the resistivity peak near the phase
transition in ferromagnets is interpreted here as stemming from the existence
of magnetic domains in the critical region. This interpretation is shown to be
in consistence with previous theoretical pictures. Resistivity in a simple
cubic antiferromagnet is also shown. The absence of a peak in this case is
explained
Is Lavelle-McMullan transformation a really new symmetry in QED?
Lavelle-McMullan symmetry of QED is examined at classical and quantum levels.
It is shown that Lavelle-McMullan symmetry does not give any new non-trivial
information in QED by examining the Ward-Takahashi identities. Being inspired
by the examination of Ward-Takahashi identity, we construct the generalized
non-local and non-covariant symmetries of QED.Comment: LATEX, 9 pages, two figures generated by Feynma
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