1,378 research outputs found
Non-potential field formation in the X-shaped quadrupole magnetic field configuration
Some types of solar flares are observed in X-shaped quadrupolar field
configuration. To understand the magnetic energy storage in such a region, we
studied non-potential field formation in an X-shaped quadrupolar field region
formed in the active region NOAA 11967, which produced three X-shaped M-class
flares on February 2, 2014. Nonlinear force-free field modeling was applied to
a time series of vector magnetic field maps from the Solar Optical Telescope on
board Hinode and Helioseismic and Magnetic Imager on board Solar Dynamics
Observatory. Our analysis of the temporal three-dimensional magnetic field
evolution shows that the sufficient free energy had already been stored more
than 10 hours before the occurrence of the first M-class flare and that the
storage was observed in a localized region. In this localized region,
quasi-separatrix layers (QSLs) started to develop gradually from 9 hours before
the first M-class flare. One of the flare ribbons that appeared in the first
M-class flare was co-spatial with the location of the QSLs, suggesting that the
formation of the QSLs is important in the process of energy release. These QSLs
do not appear in the potential field calculation, indicating that they were
created by the non-potential field. The formation of the QSLs was associated
with the transverse photospheric motion of the pre-emerged flux and the
emergence of a new flux. This observation indicates that the occurrence of the
flares requires the formation of QSLs in the non-potential field in which free
magnetic energy is stored in advance.Comment: Accepted for publication in Ap
Source File Set Search for Clone-and-Own Reuse Analysis
Clone-and-own approach is a natural way of source code reuse for software
developers. To assess how known bugs and security vulnerabilities of a cloned
component affect an application, developers and security analysts need to
identify an original version of the component and understand how the cloned
component is different from the original one. Although developers may record
the original version information in a version control system and/or directory
names, such information is often either unavailable or incomplete. In this
research, we propose a code search method that takes as input a set of source
files and extracts all the components including similar files from a software
ecosystem (i.e., a collection of existing versions of software packages). Our
method employs an efficient file similarity computation using b-bit minwise
hashing technique. We use an aggregated file similarity for ranking components.
To evaluate the effectiveness of this tool, we analyzed 75 cloned components in
Firefox and Android source code. The tool took about two hours to report the
original components from 10 million files in Debian GNU/Linux packages. Recall
of the top-five components in the extracted lists is 0.907, while recall of a
baseline using SHA-1 file hash is 0.773, according to the ground truth recorded
in the source code repositories.Comment: 14th International Conference on Mining Software Repositorie
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Association between physician characteristics and payments from industry in 2015-2017: observational study.
OBJECTIVE:To investigate the association between physician characteristics and the value of industry payments. DESIGN:Observational study. SETTING AND PARTICIPANTS:Using the 2015-2017 Open Payments reports of industry payments linked to the Physician Compare database, we examined the association between physician characteristics (physician sex, years in practice, medical school attended and specialty) and the industry payment value, adjusting for other physician characteristic and institution fixed effects (effectively comparing physicians practicing at the same institution). MAIN OUTCOME MEASURES:Our primary outcome was the value of total industry payments to physicians including (1) general payments (all forms of payments other than those classified for research purpose, eg, consulting fees, food, beverage), (2) research payments (payments for research endeavours under a written contract or protocol) and (3) ownership interests (eg, stock or stock options, bonds). We also investigated each category of payment separately. RESULTS:Of 544 264 physicians treating Medicare beneficiaries, a total of $5.8 billion in industry payments were made to 365 801 physicians during 2015-2017. The top 5% of physicians, by cumulative payments, accounted for 91% of industry payments. Within the same institution, male physicians, physicians with 21-30 years in practice and physicians who attended top 50 US medical schools (based on the research ranking) received higher industry payments. Across specialties, orthopaedic surgeons, neurosurgeons and endocrinologists received the highest payments. When we investigated individual types of payment, we found that orthopaedic surgeons received the highest general payments; haematologists/oncologists were the most likely to receive research payments and surgeons were the most likely to receive ownership interests compared with other types of physicians. CONCLUSIONS:Industry payments to physicians were highly concentrated among a small number of physicians. Male sex, longer length of time in clinical practice, graduated from a top-ranked US medical school and practicing certain specialties, were independently associated with higher industry payments
Stratified Ehrhart ring theory on periodic graphs
We investigate the "stratified Ehrhart ring theory" for periodic graphs,
which gives an algorithm for determining the growth sequences of periodic
graphs. The growth sequence is defined for a
graph and its fixed vertex , where is
defined as the number of vertices of at distance from .
Although the sequences for periodic graphs are
known to be of quasi-polynomial type, their determination had not been
established, even in dimension two. Our algorithm and the proofs are based on
algebraic combinatorics, analogous to the Ehrhart theory. As an application of
the algorithm, we determine the growth sequences in several new examples.Comment: 46 pages. arXiv admin note: text overlap with arXiv:2305.0817
Machine-learning-based high-benefit approach versus conventional high-risk approach in blood pressure management
高血圧診療における次世代の個別化医療戦略を提唱 --機械学習により個人の治療効果を予測する時代へ--. 京都大学プレスリリース. 2023-04-05.[Background] In medicine, clinicians treat individuals under an implicit assumption that high-risk patients would benefit most from the treatment (‘high-risk approach’). However, treating individuals with the highest estimated benefit using a novel machine-learning method (‘high-benefit approach’) may improve population health outcomes. [Methods] This study included 10 672 participants who were randomized to systolic blood pressure (SBP) target of either 0) versus the high-risk approach (treating individuals with SBP ≥130 mmHg). Using transportability formula, we also estimated the effect of these approaches among 14 575 US adults from National Health and Nutrition Examination Surveys (NHANES) 1999–2018. [Results] We found that 78.9% of individuals with SBP ≥130 mmHg benefited from the intensive SBP control. The high-benefit approach outperformed the high-risk approach [average treatment effect (95% CI), +9.36 (8.33–10.44) vs +1.65 (0.36–2.84) percentage point; difference between these two approaches, +7.71 (6.79–8.67) percentage points, P-value <0.001]. The results were consistent when we transported the results to the NHANES data. [Conclusions] The machine-learning-based high-benefit approach outperformed the high-risk approach with a larger treatment effect. These findings indicate that the high-benefit approach has the potential to maximize the effectiveness of treatment rather than the conventional high-risk approach, which needs to be validated in future research
Incommensurate-commensurate transitions in the monoaxial chiral helimagnet driven by the magnetic field
Under the terms of the Creative Commons Attribution license.-- et al.The zero-temperature phase diagram of the monoaxial chiral helimagnet in the magnetic-field plane formed by the components parallel and perpendicular to the helical axis is thoroughly analyzed. The nature of the transition to the commensurate state depends on the angle between the field and the helical axis. For field directions close to the directions parallel or perpendicular to the helical axis the transition is continuous, while for intermediate angles the transition is discontinuous and the incommensurate and commensurate states coexist on the transition line. The continuous and discontinuous transition lines are separated by two tricritical points with specific singular behavior. The location of the continuous and discontinuous lines and of the tricritical points depend strongly on the easy-plane anisotropy, the effect of which is analyzed. For high anisotropy the conical approximation locates the transition line very accurately, although it does not predict the continuous transitions and the tricritical behavior. It is shown that for high anisotropy, as in CrNb3S6, the form of the transition line is universal, that is, independent of the sample, and obeys a simple equation. The position of the tricritical points, which is not universal, is theoretically estimated for a sample of CrNb3S6.J.C. and V.L. acknowledge Grant No. MAT2015-68200-C2-2-P from the Spanish Ministry of Economy and Competitiveness. The work of A. S. Ovchinnikov was supported by the Government of the Russian Federation Program (02.A03.21.0006) and by the Ministry of Education and Science of the Russian Federation (Project Nos. 1437 and 2725).Peer Reviewe
Incommensurate--commensurate transitions in the mono-axial chiral helimagnet driven by the magnetic field
The zero temperature phase diagram of the mono-axial chiral helimagnet in the
magnetic field plane formed by the components parallel and perpendicular to the
helical axis is thoroughly analyzed. The nature of the transition to the
commensurate state depends on the angle between the field and the helical axis.
For field directions close to the directions parallel or perpendicular to the
helical axis the transition is continuous, while for intermediate angles the
transition is discontinuous and the incommensurate and commensurate states
coexist on the transition line. The continuous and discontinuous transition
lines are separated by two tricritical points with specific singular behaviour.
The location of the continuous and discontinuous lines and of the tricritical
points depend strongly on the easy-plane anisotropy, the effect of which is
analyzed. For large anisotropy the conical approximation locates the transition
line very accurately, although it does not predict the continuous transitions
nor the tricitical behaviour. It is shown that for large anisotropy, as in
CrNb3S6, the form of the transition line is universal, that is, independent of
the sample, and obeys a simple equation. The position of the tricritical
points, which is not universal, is theoretically estimated for a sample of
CrNb3S6Comment: 10 pages, 9 figure
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