6,852 research outputs found

    Spousal Concordance in Academic Achievements and Intelligence and Family-Based Association Studies Identified Novel Loci Associated with Intelligence.

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    Assortative Mating, the tendency for mate selection to occur on the basis of similar traits, plays an essential role in understanding the genetic variation on academic achievements and intelligence (IQ). It is an important mechanism explaining spousal concordance. We used principal component analysis (PCA) for spousal correlation. There is a significant positive correlation between spouses by the new variable PC1 (correlation coefficient=0.515, p\u3c0.0001). We further research the genetic factor that affects IQ by using the same data. We performed a low density genome-wide association (GWA) analysis with a family-based association test to identify genetic variants that associated with intelligence as measured by WAIS full-score IQ (FSIQ). NTM at 11q25 (rs411280, p=0.000764) and NR3C2 at 4q31.23 (rs3846329, p=0.000675) were 2 novel genes that haven\u27t been associated with IQ from other studies. This study may serve as a resource for replication in other populations and a foundation for future investigations

    A Finite Time Analysis of Two Time-Scale Actor Critic Methods

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    Actor-critic (AC) methods have exhibited great empirical success compared with other reinforcement learning algorithms, where the actor uses the policy gradient to improve the learning policy and the critic uses temporal difference learning to estimate the policy gradient. Under the two time-scale learning rate schedule, the asymptotic convergence of AC has been well studied in the literature. However, the non-asymptotic convergence and finite sample complexity of actor-critic methods are largely open. In this work, we provide a non-asymptotic analysis for two time-scale actor-critic methods under non-i.i.d. setting. We prove that the actor-critic method is guaranteed to find a first-order stationary point (i.e., ∥∇J(θ)∥22≤ϵ\|\nabla J(\boldsymbol{\theta})\|_2^2 \le \epsilon) of the non-concave performance function J(θ)J(\boldsymbol{\theta}), with O~(ϵ−2.5)\mathcal{\tilde{O}}(\epsilon^{-2.5}) sample complexity. To the best of our knowledge, this is the first work providing finite-time analysis and sample complexity bound for two time-scale actor-critic methods.Comment: 45 page

    Inception vs Completion: Comparing the Effects of Two Treatments on the Acquisition of le

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    This study aims to explore the effects of two instructional treatments on adult English-speaking Chinese learners’ learning of the Chinese particle le. Previous studies reveal that adult English-speaking Chinese learners’ performance on le structures is subject to the influence of the time grammar of English. Drawing upon Input Processing theory, English-speaking Chinese learners’ performance on le structures correlates to their awareness of the syntactic uniqueness of le, and the awareness may vary according to the way le is introduced. That is, the influence of time grammar on learners may be either strengthened or weakened depending on how learners’ attention is directed at the stage of input. In this sense, this study hypothesizes that the time-analysis based (completion-oriented) instruction will differ from the fact-analysis based (inception-oriented) instruction in effects on English-speaking Chinese learners’ learning of the Chinese particle le. Specifically, learners exposed to the inception-oriented treatment will develop processing strategies that are less subject to time grammar. Relatively, learners exposed to the completion-oriented treatment will be more susceptible to the influence of time grammar transfer in the processing of le structures. An experiment was conducted to compare the effects of the two instructional treatments, and the results of the experiment support the conclusion that the instructional treatments caused differences the two groups’ performances

    Advanced DSP Techniques for High-Capacity and Energy-Efficient Optical Fiber Communications

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    The rapid proliferation of the Internet has been driving communication networks closer and closer to their limits, while available bandwidth is disappearing due to an ever-increasing network load. Over the past decade, optical fiber communication technology has increased per fiber data rate from 10 Tb/s to exceeding 10 Pb/s. The major explosion came after the maturity of coherent detection and advanced digital signal processing (DSP). DSP has played a critical role in accommodating channel impairments mitigation, enabling advanced modulation formats for spectral efficiency transmission and realizing flexible bandwidth. This book aims to explore novel, advanced DSP techniques to enable multi-Tb/s/channel optical transmission to address pressing bandwidth and power-efficiency demands. It provides state-of-the-art advances and future perspectives of DSP as well

    Energy cascade in the Garrett-Munk spectrum of internal gravity waves

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    We study the spectral energy transfer due to wave-triad interactions in the Garrett-Munk spectrum of internal gravity waves (IGWs) based on a numerical evaluation of the collision integral in the wave kinetic equation. Our numerical evaluation builds on the reduction of the collision integral on the resonant manifold for a horizontally isotropic spectrum. We directly evaluate the downscale energy flux available for ocean mixing, whose value is in close agreement with the empirical finescale parameterization. We further decompose the energy transfer into contributions from different mechanisms, including local interactions and three types of nonlocal interactions, namely parametric subharmonic instability (PSI), elastic scattering (ES) and induced diffusion (ID). Through analysis on the role of each type of interaction, we resolve two long-standing paradoxes regarding the mechanism for forward cascade in frequency and zero ID flux for GM76 spectrum. In addition, our analysis estimates the contribution of each mechanism to the energy transfer in each spectral direction, and reveals new understanding of the importance of local interactions and ES in the energy transfer
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