1,862 research outputs found
On the assessment of angiogenesis: it is time to change (go further) from an estimate to a measurement
Higher rank numerical ranges of normal matrices
The higher rank numerical range is closely connected to the construction of
quantum error correction code for a noisy quantum channel. It is known that if
a normal matrix has eigenvalues , then its higher
rank numerical range is the intersection of convex polygons with
vertices , where . In this paper, it is shown that the higher rank numerical range of a
normal matrix with distinct eigenvalues can be written as the intersection
of no more than closed half planes. In addition, given a convex
polygon a construction is given for a normal matrix
with minimum such that . In particular, if
has vertices, with , there is a normal matrix with such that .Comment: 12 pages, 9 figures, to appear in SIAM Journal on Matrix Analysis and
Application
Recursive Encoding and Decoding of Noiseless Subsystem and Decoherence Free Subspace
When the environmental disturbace to a quantum system has a wavelength much
larger than the system size, all qubits localized within a small area are under
action of the same error operators. Noiseless subsystem and decoherence free
subspace are known to correct such collective errors. We construct simple
quantum circuits, which implement these collective error correction codes, for
a small number of physical qubits. A single logical qubit is encoded with
and , while two logical qubits are encoded with . The recursive
relations among the subspaces employed in noiseless subsystem and decoherence
free subspace play essential r\^oles in our implementation. The recursive
relations also show that the number of gates required to encode logical
qubits increases linearly in .Comment: 9 pages, 3 figure
Cephalometric comparisons of Chinese and Caucasian surgical class III patients
published_or_final_versio
Effective age for application of orthopedic maxillary protraction
Abstract no. 1374published_or_final_versio
Reviewer Integration and Performance Measurement for Malware Detection
We present and evaluate a large-scale malware detection system integrating
machine learning with expert reviewers, treating reviewers as a limited
labeling resource. We demonstrate that even in small numbers, reviewers can
vastly improve the system's ability to keep pace with evolving threats. We
conduct our evaluation on a sample of VirusTotal submissions spanning 2.5 years
and containing 1.1 million binaries with 778GB of raw feature data. Without
reviewer assistance, we achieve 72% detection at a 0.5% false positive rate,
performing comparable to the best vendors on VirusTotal. Given a budget of 80
accurate reviews daily, we improve detection to 89% and are able to detect 42%
of malicious binaries undetected upon initial submission to VirusTotal.
Additionally, we identify a previously unnoticed temporal inconsistency in the
labeling of training datasets. We compare the impact of training labels
obtained at the same time training data is first seen with training labels
obtained months later. We find that using training labels obtained well after
samples appear, and thus unavailable in practice for current training data,
inflates measured detection by almost 20 percentage points. We release our
cluster-based implementation, as well as a list of all hashes in our evaluation
and 3% of our entire dataset.Comment: 20 papers, 11 figures, accepted at the 13th Conference on Detection
of Intrusions and Malware & Vulnerability Assessment (DIMVA 2016
Light atom quantum oscillations in UC and US
High energy vibrational scattering in the binary systems UC and US is
measured using time-of-flight inelastic neutron scattering. A clear set of
well-defined peaks equally separated in energy is observed in UC, corresponding
to harmonic oscillations of the light C atoms in a cage of heavy U atoms. The
scattering is much weaker in US and only a few oscillator peaks are visible. We
show how the difference between the materials can be understood by considering
the neutron scattering lengths and masses of the lighter atoms. Monte Carlo ray
tracing is used to simulate the scattering, with near quantitative agreement
with the data in UC, and some differences with US. The possibility of observing
anharmonicity and anisotropy in the potentials of the light atoms is
investigated in UC. Overall the observed data is well accounted for by
considering each light atom as a single atom isotropic quantum harmonic
oscillator.Comment: 10 pages, 8 figure
Optimal Income Transfers and Tariffs.
This paper investigates the optimality of international income transfers in a two-country model in which each country engages in non-cooperative trade policy behaviour. It is shown that unconditional income transfers can never be optimal for the donor country, which not only suffers the loss of income but is harmed as the recipient responds optimally by raising tariffs. It is further shown that it is possible for the donor to attach carefully designed conditionality rules to the aid package to ensure that the recipient will agree to the package and that the donor's welfare is improved. In fact, the use of conditional income transfers is shown to result in a Pareto efficient equilibrium.
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