2,599 research outputs found
Ranking Significant Discrepancies in Clinical Reports
Medical errors are a major public health concern and a leading cause of death
worldwide. Many healthcare centers and hospitals use reporting systems where
medical practitioners write a preliminary medical report and the report is
later reviewed, revised, and finalized by a more experienced physician. The
revisions range from stylistic to corrections of critical errors or
misinterpretations of the case. Due to the large quantity of reports written
daily, it is often difficult to manually and thoroughly review all the
finalized reports to find such errors and learn from them. To address this
challenge, we propose a novel ranking approach, consisting of textual and
ontological overlaps between the preliminary and final versions of reports. The
approach learns to rank the reports based on the degree of discrepancy between
the versions. This allows medical practitioners to easily identify and learn
from the reports in which their interpretation most substantially differed from
that of the attending physician (who finalized the report). This is a crucial
step towards uncovering potential errors and helping medical practitioners to
learn from such errors, thus improving patient-care in the long run. We
evaluate our model on a dataset of radiology reports and show that our approach
outperforms both previously-proposed approaches and more recent language models
by 4.5% to 15.4%.Comment: ECIR 2020 (short
Current-oscillator correlation and Fano factor spectrum of quantum shuttle with finite bias voltage and temperature
A general master equation is derived to describe an electromechanical
single-dot transistor in the Coulomb blockade regime. In the equation, Fermi
distribution functions in the two leads are taken into account, which allows
one to study the system as a function of bias voltage and temperature of the
leads. Furthermore, we treat the coherent interaction mechanism between
electron tunneling events and the dynamics of excited vibrational modes.
Stationary solutions of the equation are numerically calculated. We show
current through the oscillating island at low temperature appears step like
characteristics as a function of the bias voltage and the steps depend on mean
phonon number of the oscillator. At higher temperatures the current steps would
disappear and this event is accompanied by the emergence of thermal noise of
the charge transfer. When the system is mainly in the ground state, zero
frequency Fano factor of current manifests sub-Poissonian noise and when the
system is partially driven into its excited states it exhibits super-Poissonian
noise. The difference in the current noise would almost be removed for the
situation in which the dissipation rate of the oscillator is much larger than
the bare tunneling rates of electrons.Comment: 14 pages, 8 figure
Realization of GHZ States and the GHZ Test via Cavity QED
In this article we discuss the realization of atomic GHZ states involving
three-level atoms and we show explicitly how to use this state to perform the
GHZ test in which it is possible to decide between local realism theories and
quantum mechanics. The experimental realizations proposed makes use of the
interaction of Rydberg atoms with a cavity prepared in a coherent state.Comment: 16 pages and 3 figures. submitted to J. Mod. Op
Output entanglement and squeezing of two-mode fields generated by a single atom
A single four-level atom interacting with two-mode cavities is investigated.
Under large detuning condition, we obtain the effective Hamiltonian which is
unitary squeezing operator of two-mode fields. Employing the input-output
theory, we find that the entanglement and squeezing of the output fields can be
achieved. By analyzing the squeezing spectrum, we show that asymmetric detuning
and asymmetric atomic initial state split the squeezing spectrum from one
valley into two minimum values, and appropriate leakage of the cavity is needed
for obtaining output entangled fields
Methodological problem with comparing increases in different measures of body weight
<p>Abstract</p> <p>Background</p> <p>A number of studies have compared proportional increases over time in waist circumference (WC) and body mass index (BMI). However this method is flawed. Here, we explain why comparisons of WC and BMI must take into account the relationship between them. We used data from two cross-sectional US surveys (NHANES 1988-94 and 2005-06), and calculated the percentage change in the average BMI and the average WC between the two surveys, comparing the results with a regression analysis of changes in WC relative to BMI.</p> <p>Findings</p> <p>The crude percentage change in BMI (5.8%) was marginally greater than for WC (5.1%). But these percentages cannot be directly compared, as the relationship between the measures is described by a regression equation with an intercept term that does not equal zero. The coefficient of time from the regression equation will determine whether or not WC is on average larger for a given BMI at the second compared with the first time point.</p> <p>Conclusion</p> <p>Differences in the percentage change in WC and the percentage change in BMI cannot be usefully directly compared. Comparisons of increases in the two measures must account for the relationship between them as described by the regression equation.</p
Single-Atom Gating of Quantum State Superpositions
The ultimate miniaturization of electronic devices will likely require local
and coherent control of single electronic wavefunctions. Wavefunctions exist
within both physical real space and an abstract state space with a simple
geometric interpretation: this state space--or Hilbert space--is spanned by
mutually orthogonal state vectors corresponding to the quantized degrees of
freedom of the real-space system. Measurement of superpositions is akin to
accessing the direction of a vector in Hilbert space, determining an angle of
rotation equivalent to quantum phase. Here we show that an individual atom
inside a designed quantum corral can control this angle, producing arbitrary
coherent superpositions of spatial quantum states. Using scanning tunnelling
microscopy and nanostructures assembled atom-by-atom we demonstrate how single
spins and quantum mirages can be harnessed to image the superposition of two
electronic states. We also present a straightforward method to determine the
atom path enacting phase rotations between any desired state vectors. A single
atom thus becomes a real space handle for an abstract Hilbert space, providing
a simple technique for coherent quantum state manipulation at the spatial limit
of condensed matter.Comment: Published online 6 April 2008 in Nature Physics; 17 page manuscript
(including 4 figures) + 3 page supplement (including 2 figures);
supplementary movies available at http://mota.stanford.ed
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