3,731 research outputs found
Co-axial capillaries microfluidic device for synthesizing size- and morphology-controlled polymer core-polymer shell particles
An easy assembling-disassembling co-axial capillaries microfluidic device was built up for the production of double droplets. Uniform polymer core-polymer shell particles were synthesized by polymerizing the two immiscible monomer phases composing the double droplet. Thus poly(acrylamide) core-poly(tripropylenglycol-diacrylate) shell particles with controlled core diameter and shell thickness were simply obtained by adjusting operating parameters. An empirical law was extracted from experiments to predict core and shell sizes. Additionally uniform and predictable non-spherical polymer objects were also prepared without adding shape-formation procedures in the experimental device. An empirical equation for describing the lengths of rod-like polymer particles is also presented
Hilbert series for ALP EFTs
Axions and axion-like particles (ALPs) are ubiquitous in popular attempts to
solve supercalifragilisticexpialidocious puzzles of Nature. A widespread and
vivid experimental programme spanning a vast range of mass scales and decades
of couplings strives to find evidence for these elusive but theoretically
well-motivated particles. In the absence of clear guiding principle, effective
field theories (EFTs) prove to be an efficient tool in this experimental quest.
Hilbert series technologies are a privileged instrument of the EFT toolbox to
enumerate and classify operators. In this work, we compute explicitly the
Hilbert series capturing the interactions of a generic ALP to the Standard
Model particles above and below the electroweak symmetry scale, which allow us
to build bases of operators up to dimension 8. In particular, we revealed a
remarkable structure of the Hilbert series that isolates the shift-symmetry
breaking and preserving interactions. In addition, with the Hilbert series
method, we enumerate the sources of CP violation in terms of CP-even, CP-odd
and CP-violating operators. Furthermore, we provide an ancillary file of the
Hilbert series up to dimension 15 to supplement our findings, which can be used
for further analysis and exploration.Comment: 33 pages + appendices, 2 figures, 13 tables, added discussion about
CP, updated the ancillary fil
Effcient numerical methods for strongly anisotropic elliptic equations
In this paper, we study an effcient numerical scheme for a strongly anisotropic elliptic problem which arises in the modeling of ionospheric plasma dynamics. A small parameter \varepsilon induces the anisotropy of the problem, which leads to severe numerical diffculties for 0 < \varepsilo
Statistical approximations for characteristic-mode-based power flow analysis
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76404/1/AIAA-2001-1593-843.pd
Effect of surface water level fluctuations on the performance of near-bank managed aquifer recharge from injection wells
Funding: This research was supported by the National Natural Science Foundation of China (42102286, U1803241, 51779230), the Belt and Road Special Foundation of the State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering (Nanjing Hydraulic Research Institute. Grant 2020nkms05), the Open Project Program of Key Laboratory of Groundwater Resources and Environment (Jilin University), Ministry of Education (Grant No. 202105002KF), and the Natural Resources Science and Technology Project of Henan Province in 2020 (Henan Natural Resources Han [2020] No. 542-7), providing financial support for the collection of data, their analysis and the writing and publication of the results Acknowledgments: The authors acknowledge valuable comments from the reviewers, which led to significant improvement of the paper.Peer reviewedPublisher PD
Radiomics strategies for risk assessment of tumour failure in head-and-neck cancer
Quantitative extraction of high-dimensional mineable data from medical images
is a process known as radiomics. Radiomics is foreseen as an essential
prognostic tool for cancer risk assessment and the quantification of
intratumoural heterogeneity. In this work, 1615 radiomic features (quantifying
tumour image intensity, shape, texture) extracted from pre-treatment FDG-PET
and CT images of 300 patients from four different cohorts were analyzed for the
risk assessment of locoregional recurrences (LR) and distant metastases (DM) in
head-and-neck cancer. Prediction models combining radiomic and clinical
variables were constructed via random forests and imbalance-adjustment
strategies using two of the four cohorts. Independent validation of the
prediction and prognostic performance of the models was carried out on the
other two cohorts (LR: AUC = 0.69 and CI = 0.67; DM: AUC = 0.86 and CI = 0.88).
Furthermore, the results obtained via Kaplan-Meier analysis demonstrated the
potential of radiomics for assessing the risk of specific tumour outcomes using
multiple stratification groups. This could have important clinical impact,
notably by allowing for a better personalization of chemo-radiation treatments
for head-and-neck cancer patients from different risk groups.Comment: (1) Paper: 33 pages, 4 figures, 1 table; (2) SUPP info: 41 pages, 7
figures, 8 table
RoPEUS: A New Robust Algorithm for Static Positioning in Ultrasonic Systems
A well known problem for precise positioning in real environments is the presence of outliers in the measurement sample. Its importance is even bigger in ultrasound based systems since this technology needs a direct line of sight between emitters and receivers. Standard techniques for outlier detection in range based systems do not usually employ robust algorithms, failing when multiple outliers are present. The direct application of standard robust regression algorithms fails in static positioning (where only the current measurement sample is considered) in real ultrasound based systems mainly due to the limited number of measurements and the geometry effects. This paper presents a new robust algorithm, called RoPEUS, based on MM estimation, that follows a typical two-step strategy: 1) a high breakdown point algorithm to obtain a clean sample, and 2) a refinement algorithm to increase the accuracy of the solution. The main modifications proposed to the standard MM robust algorithm are a built in check of partial solutions in the first step (rejecting bad geometries) and the off-line calculation of the scale of the measurements. The algorithm is tested with real samples obtained with the 3D-LOCUS ultrasound localization system in an ideal environment without obstacles. These measurements are corrupted with typical outlying patterns to numerically evaluate the algorithm performance with respect to the standard parity space algorithm. The algorithm proves to be robust under single or multiple outliers, providing similar accuracy figures in all cases
Topography, structural and exhumation history of the Admiralty Mountains region, northern Victoria Land, Antarctica
International audience; The Admiralty Mountains region forms the northern termination of the northern Victoria Land, Antarctica. Few quantitative data are available to reconstruct the Cenozoic morpho-tectonic evolution of this sector of the Antarctic plate, where the Admiralty Mountains region forms the northern termination of the western shoulder of the Mesozoic-Cenozoic West Antarctica Rift System. In this study we combine new low-temperature thermochronological data (apatite fission-track and (U-Th-Sm)/He analyses) with structural and topography analysis. The regional pattern of the fission-track ages shows a general tendency to older ages (80â60 Ma) associated with shortened mean track-lengths in the interior, and younger fission-track ages clustering at 38â26 Ma with long mean track-lengths in the coastal region. Differently from other regions of Victoria Land, the younger ages are found as far as 50â70 km inland. Single grain apatite (U-Th-Sm)/He ages cluster at 50â30 Ma with younger ages in the coastal domain. Topography analysis reveals that the Admiralty Mountains has high local relief, with an area close to the coast, 180 km long and 70 km large, having the highest local relief of >2500 m. This coincides with the location of the youngest fission-track ages. The shape of the area with highest local relief matches the shape of a recently detected low velocity zone beneath the northern TAM, indicating that high topography of the Admiralty Mountains region is likely sustained by a mantle thermal anomaly. We used the obtained constraints on the amount of removed crustal section to reconstruct back-eroded profiles and calculate the erosional load in order to test flexural uplift models. We found that our back-eroded profiles are better reproduced by a constant elastic thickness of intermediate values (Te = 20â30 km). This suggests that, beneath the Admiralty Mountains, the elastic properties of the lithosphere are different with respect to other TAM sectors, likely due to a stationary Cenozoic upper mantle thermal anomaly in the region
FLIRT: Feedback Loop In-context Red Teaming
Warning: this paper contains content that may be inappropriate or offensive.
As generative models become available for public use in various applications,
testing and analyzing vulnerabilities of these models has become a priority.
Here we propose an automatic red teaming framework that evaluates a given model
and exposes its vulnerabilities against unsafe and inappropriate content
generation. Our framework uses in-context learning in a feedback loop to red
team models and trigger them into unsafe content generation. We propose
different in-context attack strategies to automatically learn effective and
diverse adversarial prompts for text-to-image models. Our experiments
demonstrate that compared to baseline approaches, our proposed strategy is
significantly more effective in exposing vulnerabilities in Stable Diffusion
(SD) model, even when the latter is enhanced with safety features. Furthermore,
we demonstrate that the proposed framework is effective for red teaming
text-to-text models, resulting in significantly higher toxic response
generation rate compared to previously reported numbers
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