420 research outputs found
High performance implementation of 3D FEM for nonlocal Poisson problem with different ball approximation strategies
Nonlocality brings many challenges to the implementation of finite element
methods (FEM) for nonlocal problems, such as large number of queries and invoke
operations on the meshes. Besides, the interactions are usually limited to
Euclidean balls, so direct numerical integrals often introduce numerical
errors. The issues of interactions between the ball and finite elements have to
be carefully dealt with, such as using ball approximation strategies. In this
paper, an efficient representation and construction methods for approximate
balls are presented based on combinatorial map, and an efficient parallel
algorithm is also designed for assembly of nonlocal linear systems.
Specifically, a new ball approximation method based on Monte Carlo integrals,
i.e., the fullcaps method, is also proposed to compute numerical integrals over
the intersection region of an element with the ball
SGLD-Based Information Criteria and the Over-Parameterized Regime
Double-descent refers to the unexpected drop in test loss of a learning
algorithm beyond an interpolating threshold with over-parameterization, which
is not predicted by information criteria in their classical forms due to the
limitations in the standard asymptotic approach. We update these analyses using
the information risk minimization framework and provide Akaike Information
Criterion (AIC) and Bayesian Information Criterion (BIC) for models learned by
stochastic gradient Langevin dynamics (SGLD). Notably, the AIC and BIC penalty
terms for SGLD correspond to specific information measures, i.e., symmetrized
KL information and KL divergence. We extend this information-theoretic analysis
to over-parameterized models by characterizing the SGLD-based BIC for the
random feature model in the regime where the number of parameters and the
number of samples tend to infinity, with fixed. Our experiments
demonstrate that the refined SGLD-based BIC can track the double-descent curve,
providing meaningful guidance for model selection and revealing new insights
into the behavior of SGLD learning algorithms in the over-parameterized regime
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Job Satisfaction Among Methadone Maintenance Treatment Clinic Service Providers in Jiangsu, China: A Cross-sectional Survey.
ObjectiveService providers' job satisfaction is critical to the stability of the work force and thereby the effectiveness of methadone maintenance treatment (MMT) programs. This study aimed to explore MMT clinic service providers' job satisfaction and associated factors in Jiangsu, China.MethodsThis secondary study used baseline data of a randomized interventional trial implemented in Jiangsu, China. A survey was conducted among 76 MMT service providers using the computer-assisted self-interview (CASI) method. Job satisfaction responses were assessed via a 30-item scale, with a higher score indicating a higher level of job satisfaction. Perceived institutional support and perceived stigma due to working with drug users were measured using a 9-item scale. Correlation and multiple linear regression analyses were performed to identify factors associated with job satisfaction.ResultsCorrelation analyses found a significant association between job satisfaction and having professional experience in the prevention and control of HIV, other sexually transmitted infections, or other infectious diseases (P = 0.046). Multiple regression analyses revealed that working at MMT clinics affiliated with Center for Disease Control and Prevention sites was associated with a lower level of job satisfaction (P = 0.014), and perception of greater institutional support (P = 0.001) was associated with a higher level of job satisfaction.ConclusionJob satisfaction among MMT clinic service providers was moderate in our study. Our findings suggest that institutional support for providers should be improved, and that acquisition of additional expertise should be encouraged
Content Creator versus Brand Advertiser? The Effect of Inserting Advertisements in Videos on Influencers Engagement
Influencer advertising has become an indispensable component of online marketing due to the exponential growth of social influencers and their influence. Whereas the effectiveness of using influencer endorsements is well studied from the brand or company perspective, how the commercial endorsements affect influencers themselves is an important yet unrevealed question. We empirically examine the instantaneous (measured using live comment sentiment) and longer-term (measured using video feedback and follower number change) influence of inserting advertisements in videos on influencers’ reputation. We further investigate how this effect can be moderated when influencers demonstrate stronger endorsement by showing their faces during advertisements. Our result suggests that inserting advertisements have a negative impact on both instantaneous and longer-term viewer engagement; advertisements with influencers’ face showing moderate the negative effect of advertisements on viewers’ instantaneous response, while the different impact between advertisements with/out influencers showing their faces is not significant in the longer term
On the Active Components in Crystalline Li-Nb-O and Li-Ta-O Coatings from First Principles
Layered-oxide (NMC) positive electrodes
with high Nickel content, deliver high voltages and energy densities. However,
a high nickel content, e.g., = 0.8 (NMC 811), can lead to high surface
reactivity, which can trigger thermal runaway and gas generation. While claimed
safer, all-solid-state batteries still suffer from high interfacial resistance.
Here, we investigate niobate and tantalate coating materials, which can
mitigate the interfacial reactivities in Li-ion and all-solid-state batteries.
First-principles calculations reveal the multiphasic nature of Li-Nb-O and
Li-Ta-O coatings, containing mixtures of and
, or of and . The
concurrence of several phases in Li-Nb-O or Li-Ta-O modulates the type of
stable native defects in these coatings. Li-Nb-O and Li-Ta-O coating materials
can form favorably lithium vacancies and antisite
defects
() combined into
charge-neutral defect complexes. Even in defective crystalline
(or ), we reveal poor Li-ion conduction
properties. In contrast, and that are
introduced by high-temperature calcinations can provide adequate Li-ion
transport in these coatings. Our in-depth investigation of the
structure-property relationships in the important Li-Nb-O and Li-Ta-O coating
materials helps to develop more suitable calcination protocols to maximize the
functional properties of these niobates and tantalates
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