934 research outputs found
Cryptanalysis of group-based key agreement protocols using subgroup distance functions
We introduce a new approach for cryptanalysis of key agreement protocols
based on noncommutative groups. This approach uses functions that estimate the
distance of a group element to a given subgroup. We test it against the
Shpilrain-Ushakov protocol, which is based on Thompson's group F
The groupoidal analogue Theta~ to Joyal's category Theta is a test category
We introduce the groupoidal analogue \tilde\Theta to Joyal's cell category
\Theta and we prove that \tilde\Theta is a strict test category in the sense of
Grothendieck. This implies that presheaves on \tilde\Theta model homotopy types
in a canonical way. We also prove that the canonical functor from \Theta to
\tilde\Theta is aspherical, again in the sense of Grothendieck. This allows us
to compare weak equivalences of presheaves on \tilde\Theta to weak equivalences
of presheaves on \Theta. Our proofs apply to other categories analogous to
\Theta.Comment: 41 pages, v2: references added, Remark 7.3 added, v3: metadata
update
Evaluation of an Artificial Intelligence Coronary Artery Calcium Scoring Model from Computed Tomography
OBJECTIVES: Coronary artery calcium (CAC) scores derived from computed tomography (CT) scans are used for cardiovascular risk stratification. Artificial intelligence (AI) can assist in CAC quantification and potentially reduce the time required for human analysis. This study aimed to develop and evaluate a fully automated model that identifies and quantifies CAC. METHODS: Fully convolutional neural networks for automated CAC scoring were developed and trained on 2439 cardiac CT scans and validated using 771 scans. The model was tested on an independent set of 1849 cardiac CT scans. Agatston CAC scores were further categorised into five risk categories (0, 1–10, 11–100, 101–400, and > 400). Automated scores were compared to the manual reference standard (level 3 expert readers). RESULTS: Of 1849 scans used for model testing (mean age 55.7 ± 10.5 years, 49% males), the automated model detected the presence of CAC in 867 (47%) scans compared with 815 (44%) by human readers (p = 0.09). CAC scores from the model correlated very strongly with the manual score (Spearman’s r = 0.90, 95% confidence interval [CI] 0.89–0.91, p < 0.001 and intraclass correlation coefficient = 0.98, 95% CI 0.98–0.99, p < 0.001). The model classified 1646 (89%) into the same risk category as human observers. The Bland–Altman analysis demonstrated little difference (1.69, 95% limits of agreement: −41.22, 44.60) and there was almost excellent agreement (Cohen’s κ = 0.90, 95% CI 0.88–0.91, p < 0.001). Model analysis time was 13.1 ± 3.2 s/scan. CONCLUSIONS: This artificial intelligence–based fully automated CAC scoring model shows high accuracy and low analysis times. Its potential to optimise clinical workflow efficiency and patient outcomes requires evaluation. KEY POINTS: • Coronary artery calcium (CAC) scores are traditionally assessed using cardiac computed tomography and require manual input by human operators to identify calcified lesions. • A novel artificial intelligence (AI)–based model for fully automated CAC scoring was developed and tested on an independent dataset of computed tomography scans, showing very high levels of correlation and agreement with manual measurements as a reference standard. • AI has the potential to assist in the identification and quantification of CAC, thereby reducing the time required for human analysis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00330-022-09028-3
Hadron Production in Heavy Ion Collisions
We review hadron production in heavy ion collisions with emphasis on pion and
kaon production at energies below 2 AGeV and on partonic collectivity at RHIC
energies.Comment: 31 pages, 26 figures, accepted for publication in Landolt-Boernstein
Volume 1-23
Fear of the unknown: a pre-departure qualitative study of Turkish international students
This paper presents findings from eleven in-depth interviews with Turkish undergraduate students, who were, by the time of data collection, about to spend a semester at a European university under the Erasmus exchange scheme. The students all agreed to be interviewed about their feelings about studying in a foreign culture, and were found to be anxious prior to departure about the quality of accommodation in the new destination, their language ability and the opportunity to form friendships. Fears were expressed about possible misconceptions over Turkey as a Muslim and a developing country. Suggestions are made for HEI interventions to allay student travellers’ concerns
Role of baryonic resonances in the dilepton emission in nucleon-nucleon collisions
Within an effective Lagrangian model, we present calculations for cross
sections of the dilepton production in proton-proton and proton-neutron
collisions at laboratory kinetic energies in 1-5 GeV range. Production
amplitudes include contributions from the nucleon-nucleon bremsstrahlung as
well as from the mechanism of excitation, propagation, and radiative decay of
Delta(1232) and N*(1520) intermediate baryonic resonances. It is found that the
delta isobar terms dominate the cross sections in the entire considered beam
energy range. Our calculations are able to explain the data of the DLS
collaboration on the dilepton production in proton-proton collisions for beam
energies below 1.3 GeV. However, for incident energies higher than this the
inclusion of contributions from other dilepton sources like Dalitz decay of pi0
and eta mesons, and direct decay of rho and omega mesons is necessary to
describe the data.Comment: 22 pages, 7 figures, more details of the calculations added, version
to appear in Phys. Rev
A systematic review of health-related quality of life in cutaneous melanoma
Melanoma can be considered an emerging chronic disease that may considerably affect patients’ lives. The authors systematically reviewed the available literature on health-related quality of life (HRQOL) and melanoma. Of reviews and the selected studies, reference lists were hand-searched. The quality of the eligible studies was appraised based on 14 previously published criteria. Of the 158 abstracts, 44 articles were appraised, resulting in 13 selected studies written in English (published between 2001 and 2008). Most studies assessed patients from specialised centres with varying, but relatively advanced, disease stages. The most commonly used instruments were the SF-36 and EORTC QLQ-C30. Recently, a melanoma-specific HRQOL questionnaire [FACT-Melanoma (FACT-M)] was introduced for clinical trial purposes. It showed that approximately one-third of melanoma patients experienced considerable levels of distress, mostly at the time of diagnosis and following treatment. Systemic therapies affected HRQOL negatively in the short term, but to a lesser extent in the long term. Health status and patients’ psychological characteristics are associated with higher levels of HRQOL impairment. The authors found that the impact of melanoma on patients’ HRQOL is comparable to that of other cancers. Accurately assessing HRQOL impairment in melanoma patients is pivotal, as it may affect disease management, including therapy and additional counselling, future preventive behaviour and perhaps even prognosis
Hadronic observables from SIS to SPS energies - anything strange with strangeness ?
We calculate and (+) rapidity
distributions and compare to experimental data from SIS to SPS energies within
the UrQMD and HSD transport approaches that are both based on string, quark,
diquark () and hadronic degrees of freedom. The
two transport models do not include any explicit phase transition to a
quark-gluon plasma (QGP). It is found that both approaches agree rather well
with each other and with the experimental rapidity distributions for protons,
's, and . Inspite of this apparent agreement both
transport models fail to reproduce the maximum in the excitation function for
the ratio found experimentally between 11 and 40 AGeV. A
comparison to the various experimental data shows that this 'failure' is
dominantly due to an insufficient description of pion rapidity distributions
rather than missing 'strangeness'. The modest differences in the transport
model results -- on the other hand -- can be attributed to different
implementations of string formation and fragmentation, that are not
sufficiently controlled by experimental data for the 'elementary' reactions in
vacuum.Comment: 46 pages, including 15 eps figures, to be published in Phys. Rev.
Felix Alexandrovich Berezin and his work
This is a survey of Berezin's work focused on three topics: representation
theory, general concept of quantization, and supermathematics.Comment: LaTeX, 27 page
Search for and Using Genetic Programming Event Selection
We apply a genetic programming technique to search for the double Cabibbo
suppressed decays and .
We normalize these decays to their Cabibbo favored partners and find
\Lambda_c^+ \to p K^+ \pi^-\Lambda_c^+ \to p K^-
\pi^+ and D_s^+ \to K^+ K^+
\pi^-D_s^+ \to K^+ K^- \pi^+ where
the first errors are statistical and the second are systematic. Expressed as
90% confidence levels (CL), we find and respectively.
This is the first successful use of genetic programming in a high energy
physics data analysis.Comment: 10 page
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