177 research outputs found
Knowledge-aware Complementary Product Representation Learning
Learning product representations that reflect complementary relationship
plays a central role in e-commerce recommender system. In the absence of the
product relationships graph, which existing methods rely on, there is a need to
detect the complementary relationships directly from noisy and sparse customer
purchase activities. Furthermore, unlike simple relationships such as
similarity, complementariness is asymmetric and non-transitive. Standard usage
of representation learning emphasizes on only one set of embedding, which is
problematic for modelling such properties of complementariness. We propose
using knowledge-aware learning with dual product embedding to solve the above
challenges. We encode contextual knowledge into product representation by
multi-task learning, to alleviate the sparsity issue. By explicitly modelling
with user bias terms, we separate the noise of customer-specific preferences
from the complementariness. Furthermore, we adopt the dual embedding framework
to capture the intrinsic properties of complementariness and provide geometric
interpretation motivated by the classic separating hyperplane theory. Finally,
we propose a Bayesian network structure that unifies all the components, which
also concludes several popular models as special cases. The proposed method
compares favourably to state-of-art methods, in downstream classification and
recommendation tasks. We also develop an implementation that scales efficiently
to a dataset with millions of items and customers
Wrinkled few-layer graphene as highly efficient load bearer
Multilayered graphitic materials are not suitable as load-bearers due to
their inherent weak interlayer bonding (for example, graphite is a solid
lubricant in certain applications). This situation is largely improved when
two-dimensional (2-D) materials such as a monolayer (SLG) graphene are
employed. The downside in these cases is the presence of thermally or
mechanically induced wrinkles which are ubiquitous in 2-D materials. Here we
set out to examine the effect of extensive large wavelength/ amplitude
wrinkling on the stress transfer capabilities of exfoliated simply-supported
graphene flakes. Contrary to common belief we present clear evidence that this
type of "corrugation" enhances the load bearing capacity of few-layer graphene
as compared to 'flat' specimens. This effect is the result of the significant
increase of the graphene/polymer interfacial shear stress per increment of
applied strain due to wrinkling and paves the way for designing affordable
graphene composites with highly improved stress-transfer efficiency.Comment: 20 pages, 6 figure
The Role of Preprocessing for Word Representation Learning in Affective Tasks
Affective tasks, including sentiment analysis, emotion classification, and sarcasm detection have drawn a lot of attention in recent years due to a broad range of useful applications in various domains. The main goal of affect detection tasks is to recognize states such as mood, sentiment, and emotions from textual data (e.g., news articles or product reviews). Despite the importance of utilizing preprocessing steps in different stages (i.e., word representation learning and building a classification model) of affect detection tasks, this topic has not been studied well. To that end, we explore whether applying various preprocessing methods (stemming, lemmatization, stopword removal, punctuation removal and so on) and their combinations in different stages of the affect detection pipeline can improve the model performance. The are many preprocessing approaches that can be utilized in affect detection tasks. However, their influence on the final performance depends on the type of preprocessing and the stages that they are applied. Moreover, the preprocessing impacts vary across different affective tasks. Our analysis provides thorough insights into how preprocessing steps can be applied in building an effect detection pipeline and their respective influence on performance
Conversation Derailment Forecasting with Graph Convolutional Networks
Online conversations are particularly susceptible to derailment, which can
manifest itself in the form of toxic communication patterns like disrespectful
comments or verbal abuse. Forecasting conversation derailment predicts signs of
derailment in advance enabling proactive moderation of conversations. Current
state-of-the-art approaches to address this problem rely on sequence models
that treat dialogues as text streams. We propose a novel model based on a graph
convolutional neural network that considers dialogue user dynamics and the
influence of public perception on conversation utterances. Through empirical
evaluation, we show that our model effectively captures conversation dynamics
and outperforms the state-of-the-art models on the CGA and CMV benchmark
datasets by 1.5\% and 1.7\%, respectively.Comment: WOAH, AC
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