4 research outputs found
CEPHA29: Automatic Cephalometric Landmark Detection Challenge 2023
Quantitative cephalometric analysis is the most widely used clinical and
research tool in modern orthodontics. Accurate localization of cephalometric
landmarks enables the quantification and classification of anatomical
abnormalities, however, the traditional manual way of marking these landmarks
is a very tedious job. Endeavours have constantly been made to develop
automated cephalometric landmark detection systems but they are inadequate for
orthodontic applications. The fundamental reason for this is that the amount of
publicly available datasets as well as the images provided for training in
these datasets are insufficient for an AI model to perform well. To facilitate
the development of robust AI solutions for morphometric analysis, we organise
the CEPHA29 Automatic Cephalometric Landmark Detection Challenge in conjunction
with IEEE International Symposium on Biomedical Imaging (ISBI 2023). In this
context, we provide the largest known publicly available dataset, consisting of
1000 cephalometric X-ray images. We hope that our challenge will not only
derive forward research and innovation in automatic cephalometric landmark
identification but will also signal the beginning of a new era in the
discipline
A review of N+ observations in the ionosphere-magnetosphere system
Most studies have yet to consider and assess the transport and energization of N+ ions throughout the ionosphere-magnetosphere system, in addition to that of O+ and other heavy ion species. The limited observational record of N+ presence in near-Earth plasma, partly due to instrument limitations to distinguish ion species of similar masses, has obscured its significant contribution to the near-Earth plasma. This letter reviews the most notable observations of N+ ions, starting from the early low altitude measurements from Sputnik III in the ionosphere to the measurements reported by the Enhanced Polar Outflow Probe (e-POP) mission. The available observational data set suggests that nitrogen ions are constant companions of outflowing oxygen ions, and their abundances vary with season, solar cycle, time of day, and geomagnetic activity. This strong record of nitrogen presence in the ionosphere-magnetosphere system raises the question of ionic composition and the need for caution when interpreting O+ measurements from current missions
'Aariz: A Benchmark Dataset for Automatic Cephalometric Landmark Detection and CVM Stage Classification
The accurate identification and precise localization of cephalometric
landmarks enable the classification and quantification of anatomical
abnormalities. The traditional way of marking cephalometric landmarks on
lateral cephalograms is a monotonous and time-consuming job. Endeavours to
develop automated landmark detection systems have persistently been made,
however, they are inadequate for orthodontic applications due to unavailability
of a reliable dataset. We proposed a new state-of-the-art dataset to facilitate
the development of robust AI solutions for quantitative morphometric analysis.
The dataset includes 1000 lateral cephalometric radiographs (LCRs) obtained
from 7 different radiographic imaging devices with varying resolutions, making
it the most diverse and comprehensive cephalometric dataset to date. The
clinical experts of our team meticulously annotated each radiograph with 29
cephalometric landmarks, including the most significant soft tissue landmarks
ever marked in any publicly available dataset. Additionally, our experts also
labelled the cervical vertebral maturation (CVM) stage of the patient in a
radiograph, making this dataset the first standard resource for CVM
classification. We believe that this dataset will be instrumental in the
development of reliable automated landmark detection frameworks for use in
orthodontics and beyond
Effect of temperature anisotropy on various modes and instabilities for a magnetized non-relativistic bi-Maxwellian plasma
Using kinetic theory for homogeneous collisionless magnetized plasmas, we
present an extended review of the plasma waves and instabilities and discuss
the anisotropic response of generalized relativistic dielectric tensor and
Onsager symmetry properties for arbitrary distribution functions. In general,
we observe that for such plasmas only those electromagnetic modes whose
magnetic field perturbations are perpendicular to the ambient magneticeld,
i.e.,B1 \perp B0, are effected by the anisotropy. However, in oblique
propagation all modes do show such anisotropic effects. Considering the
non-relativistic bi-Maxwellian distribution and studying the relevant
components of the general dielectric tensor under appropriate conditions, we
derive the dispersion relations for various modes and instabilities. We show
that only the electromagnetic R- and L- waves, those derived from them and the
O-mode are affected by thermal anisotropies, since they satisfy the required
condition B1\perpB0. By contrast, the perpendicularly propagating X-mode and
the modes derived from it (the pure transverse X-mode and Bernstein mode) show
no such effect. In general, we note that the thermal anisotropy modifies the
parallel propagating modes via the parallel acoustic effect, while it modifies
the perpendicular propagating modes via the Larmor-radius effect. In oblique
propagation for kinetic Alfven waves, the thermal anisotropy affects the
kinetic regime more than it affects the inertial regime. The generalized fast
mode exhibits two distinct acoustic effects, one in the direction parallel to
the ambient magnetic field and the other in the direction perpendicular to it.
In the fast-mode instability, the magneto-sonic wave causes suppression of the
firehose instability. We discuss all these propagation characteristics and
present graphic illustrations