506 research outputs found
Exponential attractor for the Higher-order Kirchhoff-type equation with nonlinear strongly damped term
We investigate the existence of exponential attractor for the Higher-order Kirchhoff-type equation with nonlinear strongly damped term: .For strong nonlinear damping σ(s) and φ(s) ,we assumptions .Under of the proper assume H1-H3, we first prove the squeezing property of the nonlinear semigroup associated with this equation, then the existence of exponential attractor is proved
Exploring Security Commits in Python
Python has become the most popular programming language as it is friendly to
work with for beginners. However, a recent study has found that most security
issues in Python have not been indexed by CVE and may only be fixed by 'silent'
security commits, which pose a threat to software security and hinder the
security fixes to downstream software. It is critical to identify the hidden
security commits; however, the existing datasets and methods are insufficient
for security commit detection in Python, due to the limited data variety,
non-comprehensive code semantics, and uninterpretable learned features. In this
paper, we construct the first security commit dataset in Python, namely
PySecDB, which consists of three subsets including a base dataset, a pilot
dataset, and an augmented dataset. The base dataset contains the security
commits associated with CVE records provided by MITRE. To increase the variety
of security commits, we build the pilot dataset from GitHub by filtering
keywords within the commit messages. Since not all commits provide commit
messages, we further construct the augmented dataset by understanding the
semantics of code changes. To build the augmented dataset, we propose a new
graph representation named CommitCPG and a multi-attributed graph learning
model named SCOPY to identify the security commit candidates through both
sequential and structural code semantics. The evaluation shows our proposed
algorithms can improve the data collection efficiency by up to 40 percentage
points. After manual verification by three security experts, PySecDB consists
of 1,258 security commits and 2,791 non-security commits. Furthermore, we
conduct an extensive case study on PySecDB and discover four common security
fix patterns that cover over 85% of security commits in Python, providing
insight into secure software maintenance, vulnerability detection, and
automated program repair.Comment: Accepted to 2023 IEEE International Conference on Software
Maintenance and Evolution (ICSME
Optimal Hemoglobin Extinction Coefficient Data Set for Near-Infrared Spectroscopy
Extinction coefficient (ε) is a critical parameter for quantification of oxy-, deoxy-, and total-hemoglobin concentrations (Δ[HbO2], Δ[Hb], Δ[tHb]) from optical measurements of Near-infrared spectroscopy (NIRS). There are several different ε data sets which were frequently used in NIRS quantification. A previous study reported that even a small variation in ε could cause a significant difference in hemodynamic measurements. Apparently the selection of an optimal ε data set is important for NIRS. We conducted oxygen-state-varied and blood-concentration-varied model experiments with 57 human blood samples to mimic tissue hemodynamic variations. Seven reported ε data sets were evaluated by comparisons between quantifications and assumed values. We found that the Moaveni et al (1970)’ ε data set was the optimal one, the NIRS quantification varied significantly among different ε data sets and parameter Δ[tHb] was most sensitive to ε data sets selection
Hepatic angiosarcoma arising in an adult mesenchymal hamartoma
The histogenesis of the hepatic sarcoma and its association with hamartoma is not well understood. We hereby present a Chinese patient with hepatic angiosarcoma arising from an adult mesenchymal hamartoma of liver. A 33-yr-old woman was diagnosed hepatic hamartoma eight years ago and presented with epigastric distention recently. Now she was admitted to our hospital with some unusual features: (a) this patient was diagnosed in mid-twenties, (b) the tumor occupied the whole liver and most importantly (c) the hepatic angiosarcoma appeared 8 years after the diagnosis of hamartoma. Based on this case and some reports, hepatic hamartoma may develop to hepatic angiosarcoma
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