299 research outputs found
The Librating Companions in HD 37124, HD 12661, HD 82943, 47 Uma and GJ 876: Alignment or Antialignment?
We investigated the apsidal motion for the multi-planet systems. In the
simulations, we found that the two planets of HD 37124, HD 12661, 47 Uma and HD
82943 separately undergo apsidal alignment or antialignment. But the companions
of GJ 876 and And are only in apsidal lock about .
Moreover, we obtained the criteria with Laplace-Lagrange secular theory to
discern whether a pair of planets for a certain system are in libration or
circulation.Comment: 13 Pages, 3 figures, 2 tables, Published by ApJ Letters, 591, July 1,
2003 (Figures now included to match the publication
The Dynamical Simulations of the Planets Orbiting GJ 876
We have performed simulations to investigate the dynamics of the M dwarf star
GJ 876 in an attempt to reveal any stabilizing mechanism for sustaining the
system.We simulated different coplanar and noncoplanar configurations of
two-planet systems and other cases.From the simulations,we found that the 2 :1
mean-motion resonance between two planets can act as an effective mechanism for
maintaining the stability of the system.This result is explained by a proposed
analytical model.Using this model,we studied the region of motion of the inner
planet by varying the parameters of the system,and we detected that the
analytical results are well consistent with the numerical simulations.Comment: 17 pages, 8 figures available through authors, to be published in
ApJ, June 20,2002 (V572, see figures
Direct Preference Optimization for Neural Machine Translation with Minimum Bayes Risk Decoding
Minimum Bayes Risk (MBR) decoding can significantly improve translation
performance of Multilingual Large Language Models (MLLMs). However, MBR
decoding is computationally expensive and in this paper, we show how recently
developed Reinforcement Learning (RL) technique, Direct Preference Optimization
(DPO) can be used to fine-tune MLLMs so that we get the gains from MBR without
the additional computation in inference. Our fine-tuned models have
significantly improved performance on multiple NMT test sets compared to base
MLLMs without preference optimization. Our method boosts the translation
performance of MLLMs using relatively small monolingual fine-tuning sets
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