11,587 research outputs found
Influence of data type and rate on short arc lunar orbit determination
Error analysis for selecting optimum rates for taking counted doppler rate and range data for tracking short arc of lunar satellite orbi
Coordinate systems for differential correction
System of state transition partial derivatives for which tracking information normal matrix for lunar orbiter is nearly diagonalize
Fearless: Casey Butrico and Melanie Emerson
Casey Butrico (‘16) and Melanie Emerson (‘16) recently started a discussion group called Students for Reproductive Justice. This group is dedicated to the belief that women should control all aspects of their reproduction, including education about and access to safe birth control. They also aim to focus on gynecological care, pre-natal care, and abortion as human rights. These two fearless first-years have made a mission to educate and raise awareness about local and national issues that relate to women’s reproductive autonomy and the legal restrictions threatening it. [excerpt
Scalable Noise Estimation with Random Unitary Operators
We describe a scalable stochastic method for the experimental measurement of
generalized fidelities characterizing the accuracy of the implementation of a
coherent quantum transformation. The method is based on the motion reversal of
random unitary operators. In the simplest case our method enables direct
estimation of the average gate fidelity. The more general fidelities are
characterized by a universal exponential rate of fidelity loss. In all cases
the measurable fidelity decrease is directly related to the strength of the
noise affecting the implementation -- quantified by the trace of the
superoperator describing the non--unitary dynamics. While the scalability of
our stochastic protocol makes it most relevant in large Hilbert spaces (when
quantum process tomography is infeasible), our method should be immediately
useful for evaluating the degree of control that is achievable in any prototype
quantum processing device. By varying over different experimental arrangements
and error-correction strategies additional information about the noise can be
determined.Comment: 8 pages; v2: published version (typos corrected; reference added
The On The Fly Imaging Technique
The On-The-Fly (OTF) imaging technique enables single-dish radio telescopes
to construct images of small areas of the sky with greater efficiency and
accuracy. This paper describes the practical application of the OTF imaging
technique. By way of example the implementation of the OTF imaging technique at
the NRAO 12 Meter Telescope is described. Specific requirements for data
sampling, image formation, and Doppler correction are discussed.Comment: 10 pages, 13 figures, accepted A&
Convergence Conditions for Random Quantum Circuits
Efficient methods for generating pseudo-randomly distributed unitary
operators are needed for the practical application of Haar distributed random
operators in quantum communication and noise estimation protocols. We develop a
theoretical framework for analyzing pseudo-random ensembles generated through a
random circuit composition. We prove that the measure over random circuits
converges exponentially (with increasing circuit length) to the uniform (Haar)
measure on the unitary group and describe how the rate of convergence may be
calculated for specific applications.Comment: 4 pages (revtex), comments welcome. v2: reference added, title
changed; v3: published version, minor changes, references update
Model Checking CTL is Almost Always Inherently Sequential
The model checking problem for CTL is known to be P-complete (Clarke,
Emerson, and Sistla (1986), see Schnoebelen (2002)). We consider fragments of
CTL obtained by restricting the use of temporal modalities or the use of
negations---restrictions already studied for LTL by Sistla and Clarke (1985)
and Markey (2004). For all these fragments, except for the trivial case without
any temporal operator, we systematically prove model checking to be either
inherently sequential (P-complete) or very efficiently parallelizable
(LOGCFL-complete). For most fragments, however, model checking for CTL is
already P-complete. Hence our results indicate that, in cases where the
combined complexity is of relevance, approaching CTL model checking by
parallelism cannot be expected to result in any significant speedup. We also
completely determine the complexity of the model checking problem for all
fragments of the extensions ECTL, CTL+, and ECTL+
Winning Cores in Parity Games
We introduce the novel notion of winning cores in parity games and develop a
deterministic polynomial-time under-approximation algorithm for solving parity
games based on winning core approximation. Underlying this algorithm are a
number properties about winning cores which are interesting in their own right.
In particular, we show that the winning core and the winning region for a
player in a parity game are equivalently empty. Moreover, the winning core
contains all fatal attractors but is not necessarily a dominion itself.
Experimental results are very positive both with respect to quality of
approximation and running time. It outperforms existing state-of-the-art
algorithms significantly on most benchmarks
Organ failure, outcomes and deprivation status among critically ill cirrhosis patients — a one-year cohort study
No abstract available
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