105 research outputs found
A Contamination Sensor Based on an Array of Microfibers with Nanoscale-Structured Film
A contamination sensor based on an array of microfibers with nanoscale-structured film using evanescent field is proposed and demonstrated theoretically and experimentally. When the molecular contaminants deposit on the nanoscale-structured film, the refractive index of the film will change and the additional loss will be produced due to the disturbance of evanescent field. The possibility of the sensor is demonstrated theoretically by using three-dimensional finite-difference time domain (3D-FDTD). The corresponding experiments have also been carried out in order to demonstrate the theoretical results. Microfibers are fabricated by using hydrogen-oxygen flame-heated scanning fiber drawing method and the nanoscale-structured film coated on the surface of microfibers is deposited by using dip coating process. Then an array of microfibers is assembled to demonstrate the feasibility of the device. The experimental results show that contaminants detection with the device can agree well with the results measured by the laser-scattering particle counter, which demonstrates the feasibility of the new type of contaminant sensor. The device can be used to monitor contaminants on-line in the high-power laser system
Lifelong Sequential Modeling with Personalized Memorization for User Response Prediction
User response prediction, which models the user preference w.r.t. the
presented items, plays a key role in online services. With two-decade rapid
development, nowadays the cumulated user behavior sequences on mature Internet
service platforms have become extremely long since the user's first
registration. Each user not only has intrinsic tastes, but also keeps changing
her personal interests during lifetime. Hence, it is challenging to handle such
lifelong sequential modeling for each individual user. Existing methodologies
for sequential modeling are only capable of dealing with relatively recent user
behaviors, which leaves huge space for modeling long-term especially lifelong
sequential patterns to facilitate user modeling. Moreover, one user's behavior
may be accounted for various previous behaviors within her whole online
activity history, i.e., long-term dependency with multi-scale sequential
patterns. In order to tackle these challenges, in this paper, we propose a
Hierarchical Periodic Memory Network for lifelong sequential modeling with
personalized memorization of sequential patterns for each user. The model also
adopts a hierarchical and periodical updating mechanism to capture multi-scale
sequential patterns of user interests while supporting the evolving user
behavior logs. The experimental results over three large-scale real-world
datasets have demonstrated the advantages of our proposed model with
significant improvement in user response prediction performance against the
state-of-the-arts.Comment: SIGIR 2019. Reproducible codes and datasets:
https://github.com/alimamarankgroup/HPM
A Deep Prediction Network for Understanding Advertiser Intent and Satisfaction
For e-commerce platforms such as Taobao and Amazon, advertisers play an
important role in the entire digital ecosystem: their behaviors explicitly
influence users' browsing and shopping experience; more importantly,
advertiser's expenditure on advertising constitutes a primary source of
platform revenue. Therefore, providing better services for advertisers is
essential for the long-term prosperity for e-commerce platforms. To achieve
this goal, the ad platform needs to have an in-depth understanding of
advertisers in terms of both their marketing intents and satisfaction over the
advertising performance, based on which further optimization could be carried
out to service the advertisers in the correct direction. In this paper, we
propose a novel Deep Satisfaction Prediction Network (DSPN), which models
advertiser intent and satisfaction simultaneously. It employs a two-stage
network structure where advertiser intent vector and satisfaction are jointly
learned by considering the features of advertiser's action information and
advertising performance indicators. Experiments on an Alibaba advertisement
dataset and online evaluations show that our proposed DSPN outperforms
state-of-the-art baselines and has stable performance in terms of AUC in the
online environment. Further analyses show that DSPN not only predicts
advertisers' satisfaction accurately but also learns an explainable advertiser
intent, revealing the opportunities to optimize the advertising performance
further
A Knowledge-Enhanced Recommendation Model with Attribute-Level Co-Attention
Deep neural networks (DNNs) have been widely employed in recommender systems
including incorporating attention mechanism for performance improvement.
However, most of existing attention-based models only apply item-level
attention on user side, restricting the further enhancement of recommendation
performance. In this paper, we propose a knowledge-enhanced recommendation
model ACAM, which incorporates item attributes distilled from knowledge graphs
(KGs) as side information, and is built with a co-attention mechanism on
attribute-level to achieve performance gains. Specifically, each user and item
in ACAM are represented by a set of attribute embeddings at first. Then, user
representations and item representations are augmented simultaneously through
capturing the correlations between different attributes by a co-attention
module. Our extensive experiments over two realistic datasets show that the
user representations and item representations augmented by attribute-level
co-attention gain ACAM's superiority over the state-of-the-art deep models
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