3,402 research outputs found
Stabilization diagrams to distinguish physical modes and spurious modes for structural parameter identification
A novel clustering stabilization diagram combined with self adaptive differential evolution algorithm is proposed to identify the modal parameters of civil engineering structures. Compared with the traditional stabilization diagram, the clustering diagram has drawn more attention because it can distinguish physical and spurious modes due to its automatic performance. In this paper, a self adaptive differential evolution algorithm is proposed to optimize the initial clustering centers so as to improve the clustering stabilization diagram. Moreover, this paper presents a new idea that the modal assurance criterion (MAC) composed of mode shapes is selected as the Y-axis to replace the model orders or damping ratios in existing stabilization diagrams. The results of a benchmark test of bridge Z24 and the numerical simulation of a continuous beam and a cable-stayed bridge demonstrate the advantages of the proposed approaches and the reliability of detecting the modal parameters
A Pairwise Likelihood Augmented Estimator for the Cox Model Under Left-Truncation
Survival data collected from prevalent cohorts are subject to left-truncation and the analysis is challenging. Conditional approaches for left-truncated data under the Cox model are inefficient as they typically ignore the information in the marginal likelihood of the truncation times. Length-biased sampling methods can improve the estimation efficiency but only when the stationarity assumption of the disease incidence holds, i.e., the truncation distribution is uniform; otherwise they may generate biased estimates. In this paper, we propose a semi-parametric method for the Cox model under general left-truncation, where the truncation distribution is unspecified. Our approach is to make inference based on the conditional likelihood augmented with a pairwise likelihood which eliminates the unspecified truncation distribution, yet retains the information about the regression coefficients and the baseline hazard function in the marginal likelihood. An iterative algorithm is provided to solve for the regression coefficients and the baseline hazard simultaneously. The proposed estimator is consistent and asymptotically normal with a closed-form consistent variance estimator. Simulations show a substantial efficiency gain in both the regression coefficients and the cumulative baseline hazard over the conditional approach estimator. Even when the stationarity assumption holds, our estimator results in better efficiency than some length-biased sampling estimators. An application to the analysis of a chronic kidney disease cohort study illustrates the utility of the method
Application effect of dual disease management theory in patients with alcoholic cardiomyopathy and heart failure
This paper explores the effect of application of dual disease management theory
in the discharge readiness service for patients with alcoholic cardiomyopathy and
heart failure. A retrospective study of 70 male patients with heart failure due
to alcoholic cardiomyopathy was conducted. All patients were admitted in the
hospital from September 2021 to September 2022. The control group was identified
through an odd number, and the even number was the observation group, with 35
cases in each group. The control group received routine nursing care, and the
observation group received a nursing model based on dual disease management
theory, developed on the basis of the control group. The assessment criteria
including the discharge readiness, binary coping score, self-efficacy score,
self-care ability score and nursing compliance were compared between the two
groups. The discharge readiness, patient and caregiver support coping score,
self-efficacy and self-care ability scores of the observation group improved,
compared to those of the control group, the difference was statistically
significant (p < 0.05). The nursing compliance of the observation
group was 91.4 %, statistically significantly higher (p < 0.05),
compared to that of the control group (71.4%). The findings in this paper
suggest that dual disease management theory applicable to the routine
nursing can improve the nursing compliance and self-efficacy of patients with
alcoholic cardiomyopathy and heart failure and self-care ability. Therefore, the
dual management theory can effectively contribute to improving the level of
patient support, response and patient care compliance
Feature Proliferation -- the "Cancer" in StyleGAN and its Treatments
Despite the success of StyleGAN in image synthesis, the images it synthesizes
are not always perfect and the well-known truncation trick has become a
standard post-processing technique for StyleGAN to synthesize high-quality
images. Although effective, it has long been noted that the truncation trick
tends to reduce the diversity of synthesized images and unnecessarily
sacrifices many distinct image features. To address this issue, in this paper,
we first delve into the StyleGAN image synthesis mechanism and discover an
important phenomenon, namely Feature Proliferation, which demonstrates how
specific features reproduce with forward propagation. Then, we show how the
occurrence of Feature Proliferation results in StyleGAN image artifacts. As an
analogy, we refer to it as the" cancer" in StyleGAN from its proliferating and
malignant nature. Finally, we propose a novel feature rescaling method that
identifies and modulates risky features to mitigate feature proliferation.
Thanks to our discovery of Feature Proliferation, the proposed feature
rescaling method is less destructive and retains more useful image features
than the truncation trick, as it is more fine-grained and works in a
lower-level feature space rather than a high-level latent space. Experimental
results justify the validity of our claims and the effectiveness of the
proposed feature rescaling method. Our code is available at https://github.
com/songc42/Feature-proliferation.Comment: Accepted at ICCV 202
Deep-potential enabled multiscale simulation of gallium nitride devices on boron arsenide cooling substrates
High-efficient heat dissipation plays critical role for high-power-density
electronics. Experimental synthesis of ultrahigh thermal conductivity boron
arsenide (BAs, 1300 W m-1K-1) cooling substrates into the wide-bandgap
semiconductor of gallium nitride (GaN) devices has been realized. However, the
lack of systematic analysis on the heat transfer across the BAs-GaN interface
hampers the practical applications. In this study, by constructing the accurate
and high-efficient machine learning interatomic potentials, we performed
multiscale simulations of the BAs-GaN heterostructures. Ultrahigh interfacial
thermal conductance (ITC) of 265 MW m-2K-1 is achieved, which lies in the
well-matched lattice vibrations of BAs and GaN. Moreover, the competition
between grain size and boundary resistance was revealed with size increasing
from 1 nm to 100 {\mu}m. Such deep-potential equipped multiscale simulations
not only promote the practical applications of BAs cooling substrates in
electronics, but also offer new approach for designing advanced thermal
management systems
Di-μ-sulfato-κ4 O:O′-bisÂ[diaquaÂ(1H-imidazo[4,5-f][1,10]phenanthroline-κ2 N 7,N 9)cobalt(II)] dihydrate
In the centrosymmetric dinuclear title compound, [Co2(SO4)2(C13H8N4)2(H2O)4]·2H2O, the CoII atom is coordÂinÂated by two N atoms from two 1H-imidazo[4,5-f][1,10]phenanthroline ligands, two O atoms from two sulfate anions and two O atoms from water molÂecules in a distorted octaÂhedral geometry. The Co⋯Co separation is 5.1167 (7) Å. The coordinated and uncoordinated water molÂecules engage in N—H⋯O and O—H⋯O hydrogen-bonding interÂactions
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