1,894 research outputs found
Optimizing Long-term Value for Auction-Based Recommender Systems via On-Policy Reinforcement Learning
Auction-based recommender systems are prevalent in online advertising
platforms, but they are typically optimized to allocate recommendation slots
based on immediate expected return metrics, neglecting the downstream effects
of recommendations on user behavior. In this study, we employ reinforcement
learning to optimize for long-term return metrics in an auction-based
recommender system. Utilizing temporal difference learning, a fundamental
reinforcement learning algorithm, we implement an one-step policy improvement
approach that biases the system towards recommendations with higher long-term
user engagement metrics. This optimizes value over long horizons while
maintaining compatibility with the auction framework. Our approach is grounded
in dynamic programming ideas which show that our method provably improves upon
the existing auction-based base policy. Through an online A/B test conducted on
an auction-based recommender system which handles billions of impressions and
users daily, we empirically establish that our proposed method outperforms the
current production system in terms of long-term user engagement metrics
GCC: Graph Contrastive Coding for Graph Neural Network Pre-Training
Graph representation learning has emerged as a powerful technique for
addressing real-world problems. Various downstream graph learning tasks have
benefited from its recent developments, such as node classification, similarity
search, and graph classification. However, prior arts on graph representation
learning focus on domain specific problems and train a dedicated model for each
graph dataset, which is usually non-transferable to out-of-domain data.
Inspired by the recent advances in pre-training from natural language
processing and computer vision, we design Graph Contrastive Coding (GCC) -- a
self-supervised graph neural network pre-training framework -- to capture the
universal network topological properties across multiple networks. We design
GCC's pre-training task as subgraph instance discrimination in and across
networks and leverage contrastive learning to empower graph neural networks to
learn the intrinsic and transferable structural representations. We conduct
extensive experiments on three graph learning tasks and ten graph datasets. The
results show that GCC pre-trained on a collection of diverse datasets can
achieve competitive or better performance to its task-specific and
trained-from-scratch counterparts. This suggests that the pre-training and
fine-tuning paradigm presents great potential for graph representation
learning.Comment: 11 pages, 5 figures, to appear in KDD 2020 proceeding
Meta-analysis of gene–environment-wide association scans accounting for education level identifies additional loci for refractive error
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users will need to obtain permission from the license holder to reproduce the material.
To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/Myopia is the most common human eye disorder and it results from complex genetic and environmental causes. The rapidly increasing prevalence of myopia poses a major public health challenge. Here, the CREAM consortium performs a joint meta-analysis to test single-nucleotide polymorphism (SNP) main effects and SNP × education interaction effects on refractive error in 40,036 adults from 25 studies of European ancestry and 10,315 adults from 9 studies of Asian ancestry. In European ancestry individuals, we identify six novel loci (FAM150B-ACP1, LINC00340, FBN1, DIS3L-MAP2K1, ARID2-SNAT1 and SLC14A2) associated with refractive error. In Asian populations, three genome-wide significant loci AREG, GABRR1 and PDE10A also exhibit strong interactions with education (P<8.5 × 10(-5)), whereas the interactions are less evident in Europeans. The discovery of these loci represents an important advance in understanding how gene and environment interactions contribute to the heterogeneity of myopia
A common variant near TGFBR3 is associated with primary open angle glaucoma
Primary open angle glaucoma (POAG), a major cause of blindness worldwide, is a complex disease with a significant genetic contribution. We performed Exome Array (Illumina) analysis on 3504 POAG cases and 9746 controls with replication of the most significant findings in 9173 POAG cases and 26 780 controls across 18 collections of Asian, African and European descent. Apart from confirming strong evidence of association at CDKN2B-AS1 (rs2157719 [G], odds ratio [OR] = 0.71, P = 2.81 × 10−33), we observed one SNP showing significant association to POAG (CDC7–TGFBR3 rs1192415, ORG-allele = 1.13, Pmeta = 1.60 × 10−8). This particular SNP has previously been shown to be strongly associated with optic disc area and vertical cup-to-disc ratio, which are regarded as glaucoma-related quantitative traits. Our study now extends this by directly implicating it in POAG disease pathogenesis
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