181,150 research outputs found
GenRule : Learning of Shortcut-Oriented Diagnostic Problem Solving in the MOLTKE 3 Workbench
GenRule is the offline processing component of the MOLTKE3 workbench’s learning mechanism. It learns from diagnostic cases, i.e. protocols of the diagnostic behavior of an experienced service technician. The result of a learning step are so called shortcut rules, which allow the derivation of symptom values from other already known values. Furthermore, these rules are used to direct the diagnostic strategy applied by the MOLTKE3 shell. The presented mechanism appears to be well suited for modeling the typical diagnostic behavior of a service technician
MDNet: A Semantically and Visually Interpretable Medical Image Diagnosis Network
The inability to interpret the model prediction in semantically and visually
meaningful ways is a well-known shortcoming of most existing computer-aided
diagnosis methods. In this paper, we propose MDNet to establish a direct
multimodal mapping between medical images and diagnostic reports that can read
images, generate diagnostic reports, retrieve images by symptom descriptions,
and visualize attention, to provide justifications of the network diagnosis
process. MDNet includes an image model and a language model. The image model is
proposed to enhance multi-scale feature ensembles and utilization efficiency.
The language model, integrated with our improved attention mechanism, aims to
read and explore discriminative image feature descriptions from reports to
learn a direct mapping from sentence words to image pixels. The overall network
is trained end-to-end by using our developed optimization strategy. Based on a
pathology bladder cancer images and its diagnostic reports (BCIDR) dataset, we
conduct sufficient experiments to demonstrate that MDNet outperforms
comparative baselines. The proposed image model obtains state-of-the-art
performance on two CIFAR datasets as well.Comment: CVPR2017 Ora
Quantitative characterization of viscoelastic behavior in tissue-mimicking phantoms and ex vivo animal tissues.
Viscoelasticity of soft tissue is often related to pathology, and therefore, has become an important diagnostic indicator in the clinical assessment of suspect tissue. Surgeons, particularly within head and neck subsites, typically use palpation techniques for intra-operative tumor detection. This detection method, however, is highly subjective and often fails to detect small or deep abnormalities. Vibroacoustography (VA) and similar methods have previously been used to distinguish tissue with high-contrast, but a firm understanding of the main contrast mechanism has yet to be verified. The contributions of tissue mechanical properties in VA images have been difficult to verify given the limited literature on viscoelastic properties of various normal and diseased tissue. This paper aims to investigate viscoelasticity theory and present a detailed description of viscoelastic experimental results obtained in tissue-mimicking phantoms (TMPs) and ex vivo tissues to verify the main contrast mechanism in VA and similar imaging modalities. A spherical-tip micro-indentation technique was employed with the Hertzian model to acquire absolute, quantitative, point measurements of the elastic modulus (E), long term shear modulus (η), and time constant (τ) in homogeneous TMPs and ex vivo tissue in rat liver and porcine liver and gallbladder. Viscoelastic differences observed between porcine liver and gallbladder tissue suggest that imaging modalities which utilize the mechanical properties of tissue as a primary contrast mechanism can potentially be used to quantitatively differentiate between proximate organs in a clinical setting. These results may facilitate more accurate tissue modeling and add information not currently available to the field of systems characterization and biomedical research
The influence of coronal EUV irradiance on the emission in the He I 10830 A and D3 multiplets
Two of the most attractive spectral windows for spectropolarimetric
investigations of the physical properties of the plasma structures in the solar
chromosphere and corona are the ones provided by the spectral lines of the He I
10830 A and 5876 A (or D3) multiplets, whose polarization signals are sensitive
to the Hanle and Zeeman effects. However, in order to be able to carry out
reliable diagnostics, it is crucial to have a good physical understanding of
the sensitivity of the observed spectral line radiation to the various
competing driving mechanisms. Here we report a series of off-the-limb non-LTE
calculations of the He I D3 and 10830 A emission profiles, focusing our
investigation on their sensitivity to the EUV coronal irradiation and the model
atmosphere used in the calculations. We show in particular that the intensity
ratio of the blue to the red components in the emission profiles of the He I
10830 A multiplet turns out to be a good candidate as a diagnostic tool for the
coronal irradiance. Measurements of this observable as a function of the
distance to the limb and its confrontation with radiative transfer modeling
might give us valuable information on the physical properties of the solar
atmosphere and on the amount of EUV radiation at relevant wavelengths
penetrating the chromosphere from above.Comment: 19 pages, 11 figures (pre-print format). Accepted for publication in
Ap
Stellar convective cores as dark matter probes
The recent detection of a convective core in a main-sequence solar-type star
is used here to test particular models of dark matter (DM) particles, those
with masses and scattering cross sections in the range of interest for the DM
interpretation of the positive results in several DM direct detection
experiments. If DM particles do not effectively self-annihilate after
accumulating inside low-mass stars (e.g. in the asymmetric DM scenario) their
conduction provides an efficient mechanism of energy transport in the stellar
core. For main-sequence stars with masses between 1.1 and 1.3 Msun, this
mechanism may lead to the suppression of the inner convective region expected
to be present in standard stellar evolution theory. The asteroseismic analysis
of the acoustic oscillations of a star can prove the presence/absence of such a
convective core, as it was demonstrated for the first time with the Kepler
field main-sequence solar-like pulsator, KIC 2009505. Studying this star we
found that the asymmetric DM interpretation of the results in the CoGeNT
experiment is incompatible with the confirmed presence of a small convective
core in KIC 2009505.Comment: to appear on Physical Review
- …