8,603 research outputs found
A study of the high-inclination population in the Kuiper belt - II. The Twotinos
As the second part of our study, in this paper we proceed to explore the
dynamics of the high-inclination Twotinos in the 1:2 Neptune mean motion
resonance (NMMR). Depending on the inclination , we show the existence of
two critical eccentricities and , which are lower limits of
the eccentricity for the resonant angle to exhibit libration and
asymmetric libration, respectively. Accordingly, we have determined the
libration centres for inclined orbits, which are strongly dependent
on . With initial on a fine grid of , the
stability of orbits in the 1:2 NMMR is probed by 4-Gyr integrations. It is
shown that symmetric librators are totally unstable for ; while
stable asymmetric librators exist for up to .
We further investigate the 1:2 NMMR capture and retention of planetesimals
with initial inclinations in the planet migration model
using a time-scale of yr. We find that: (1) the capture
efficiency of the 1:2 NMMR decreases drastically with the increase of ,
and it goes to 0 when ; (2) the probability of discovering
Twotinos with , beyond observed values, is roughly estimated to
be per cent; (3) more particles are captured into the leading rather
than the trailing asymmetric resonance for , but this number
difference appears to be the opposite at and is continuously
varying for even larger ; (4) captured Twotinos residing in the trailing
resonance or having are practically outside the Kozai mechanism,
like currently observed samples.Comment: 13 pages, 10 figures, Accepted by MNRAS. Comments welcome
Optimal Rates for Distributed Learning with Random Features
In recent studies, the generalization properties for distributed learning and
random features assumed the existence of the target concept over the hypothesis
space. However, this strict condition is not applicable to the more common
non-attainable case. In this paper, using refined proof techniques, we first
extend the optimal rates for distributed learning with random features to the
non-attainable case. Then, we reduce the number of required random features via
data-dependent generating strategy, and improve the allowed number of
partitions with additional unlabeled data. Theoretical analysis shows these
techniques remarkably reduce computational cost while preserving the optimal
generalization accuracy under standard assumptions. Finally, we conduct several
experiments on both simulated and real-world datasets, and the empirical
results validate our theoretical findings.Comment: Accpected at IJCAI 202
The Ideological and Political Education Values of the Constructive Postmodernism
By analyzing and criticizing the modernity, the constructive postmodernism rebuilds a postmodern worldview consistent with human beings’ spiritual needs and value pursuit, promotes human beings’ subjective spirits, and realized human beings’ subjective values. And it is just the purport of ideological and political education to highlight the significance of human beings and the value world. Keywords: constructive postmodernism; ideological and political education valueRésumé: Le postmodernisme constructif reconstruit une vision du monde postmoderne qui correspond aux besoins spirituels et à la poursuite des valeurs de l'homme en analysant et critiquant la modernité. Il met en valeur l'esprit du sujet de l'homme et la réalisation de valeur principale de l'homme. Le centre d'intérêts de l'éducation idéologique et politique est d'apporter attention au sens de l'homme et au monde de valeurs.Mots-clés: postmodernisme constructif; éducation idéologique et politiqu
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