32,023 research outputs found
Two-dimensional electron system in high magnetic fields: Wigner crystal vs. composite-fermion liquid
The two dimensional system of electrons in a high magnetic field offers an
opportunity to investigate a phase transition from a quantum liquid into a
Wigner solid. Recent experiments have revealed an incipient composite fermion
liquid in a parameter range where theory and many experiments had previously
suggested the Wigner crystal phase, thus calling into question our current
understanding. This Letter shows how very small quantitative corrections (< 1%)
in the energy due to the weak interaction between composite fermions can cause
a fundamental change in the nature of the ground state, thus providing insight
into the puzzling experimental results.Comment: 4 pages, 2 figure
Use of Skylab S190B imagery
There are no author-identified significant results in this report
Effects of construction and staged filling of reservoirs on the environment and ecology
There are no author-identified significant results in this report
On Match Lengths, Zero Entropy and Large Deviations - with Application to Sliding Window Lempel-Ziv Algorithm
The Sliding Window Lempel-Ziv (SWLZ) algorithm that makes use of recurrence
times and match lengths has been studied from various perspectives in
information theory literature. In this paper, we undertake a finer study of
these quantities under two different scenarios, i) \emph{zero entropy} sources
that are characterized by strong long-term memory, and ii) the processes with
weak memory as described through various mixing conditions.
For zero entropy sources, a general statement on match length is obtained. It
is used in the proof of almost sure optimality of Fixed Shift Variant of
Lempel-Ziv (FSLZ) and SWLZ algorithms given in literature. Through an example
of stationary and ergodic processes generated by an irrational rotation we
establish that for a window of size , a compression ratio given by
where depends on and approaches 1 as
, is obtained under the application of FSLZ and SWLZ
algorithms. Also, we give a general expression for the compression ratio for a
class of stationary and ergodic processes with zero entropy.
Next, we extend the study of Ornstein and Weiss on the asymptotic behavior of
the \emph{normalized} version of recurrence times and establish the \emph{large
deviation property} (LDP) for a class of mixing processes. Also, an estimator
of entropy based on recurrence times is proposed for which large deviation
principle is proved for sources satisfying similar mixing conditions.Comment: accepted to appear in IEEE Transactions on Information Theor
Investigation of the effects of construction and stage filling of reservoirs on the environment and energy
There are no author-identified significant results in this report
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