Predicting Temporal Sets with Deep Neural Networks Le Yu, Leilei - - PowerPoint PPT Presentation

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Predicting Temporal Sets with Deep Neural Networks Le Yu, Leilei - - PowerPoint PPT Presentation

Proceedings of the 26th ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD 20), August 23 27, 2020, Virtual Event, CA, USA. Predicting Temporal Sets with Deep Neural Networks Le Yu, Leilei Sun*, Bowen Du, Chuanren Liu, Hui


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Predicting Temporal Sets with Deep Neural Networks

Le Yu, Leilei Sun*, Bowen Du, Chuanren Liu, Hui Xiong, Weifeng Lv Proceedings of the 26th ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD ’20), August 23–27, 2020, Virtual Event, CA, USA.

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Background

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Formalization

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Motivation CONTENTS

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Experiments

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Methodology

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Background

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Baskets in shopping

Background

Drugs in healthcare Places in traveling Courses in schools

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Information loss

Related Work

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Existing methods usually follow a two-stage strategy (Yu et al. 2016, Hu and He, 2019): (1) set embedding (2) sequential behaviors learning The two-stage approach often leads to information loss.

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A unique perspective

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How would the model perform if we make prediction of temporal sets from a different perspective? Set Embedding Sequential Behaviors Learning

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Existing methods: Lead to information loss

Learning the relationship of elements

Leverage information in elements relationship as much as possible This work:

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Formalization

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⚫ Let 𝕍 = 𝑣1, 𝑣2, ⋯ , 𝑣𝑜 , 𝕎 = {𝑤1, 𝑤2, ⋯ , 𝑤𝑛} denote the set of 𝑜 users and 𝑛 elements, a set 𝑇 ⊂ 𝕎 denotes the collection of elements. ⚫ Given:a sequence of sets 𝕋𝑗 = 𝑇𝑗

1, 𝑇𝑗 2, ⋯ , 𝑇𝑗 𝑈 that records the

historical behaviors of user 𝑣𝑗 ∈ 𝕍 ⚫ Goal:predict the next-period set of 𝑣𝑗, መ 𝑇𝑗

𝑈+1 = 𝑔 𝑇𝑗 1, 𝑇𝑗 2, ⋯ , 𝑇𝑗 𝑈, 𝑿 ,

where 𝑿 is the trainable parameter.

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Learn temporal dependencies of elements in the sequence of sets Learn set-level element relationship Fuse static and dynamic information by a gated updating mechanism

Our Method: DNNTSP

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2) Weighted Convolutions on Dynamic Graphs

𝒅𝑗,𝑘

𝑢,𝑚+1 = 𝜏

𝒄𝑚 + ෍

𝑙∈𝒪

𝑗,𝑘 𝑢 ∪{𝑘}

𝐵𝑗

𝑢 𝑘, 𝑙 · 𝑿𝑚𝒅𝑗,𝑙 𝑢,𝑚

1) Weighted Graphs Construction

Element Relationship Learning

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… … Learn element relationship in the same set.

trainable convolutional parameters

𝑤𝑗,1, 𝑤𝑗,2 , 𝑤𝑗,1, 𝑤𝑗,3 , 𝑤𝑗,2, 𝑤𝑗,1 , 𝑤𝑗,2, 𝑤𝑗,3 , 𝑤𝑗,3, 𝑤𝑗,1 , (𝑤𝑗,3, 𝑤𝑗,2) 𝑤𝑗,1, 𝑤𝑗,3 , 𝑤𝑗,1, 𝑤𝑗,4 , 𝑤𝑗,3, 𝑤𝑗,1 , 𝑤𝑗,3, 𝑤𝑗,4 , 𝑤𝑗,4, 𝑤𝑗,1 , (𝑤𝑗,4, 𝑤𝑗,3) 𝑤𝑗,1, 𝑤𝑗,2, 2 , 𝑤𝑗,1, 𝑤𝑗,3, 3 , 𝑤𝑗,1, 𝑤𝑗,4, 1 , 𝑤𝑗,2, 𝑤𝑗,1, 2 , … 𝑤𝑗,1, 𝑤𝑗,1, 1 , 𝑤𝑗,2, 𝑤𝑗,2, 1 , 𝑤𝑗,3, 𝑤𝑗,3, 1 , 𝑤𝑗,4, 𝑤𝑗,4, 1

𝑤𝑗,1, 𝑤𝑗,2, 0.67 , 𝑤𝑗,1, 𝑤𝑗,3, 1.0 , 𝑤𝑗,1, 𝑤𝑗,4, 0.33 , 𝑤𝑗,2, 𝑤𝑗,1, 0.67 , … 𝑤𝑗,1, 𝑤𝑗,1, 0.33 , 𝑤𝑗,2, 𝑤𝑗,2, 0.33 , 𝑤𝑗,3, 𝑤𝑗,3, 0.33 , 𝑤𝑗,4, 𝑤𝑗,4, 0.33

(a) (b) (c) (d)

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𝒂𝑗,𝑘 = 𝑡𝑝𝑔𝑢𝑛𝑏𝑦

𝑫𝑗,𝑘𝑿𝑟 𝑫𝒋,𝑘𝑿𝑙

T

𝐺′′

+ 𝑵𝑗 ⋅ (𝑫𝑗,𝑘𝑿𝑤)

Attention-based Temporal Dependency Learning

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Learn element temporal dependency among the sequence of sets.

𝒜𝑗,𝑘 = 𝒂𝑗,𝑘 · 𝒙𝑏𝑕𝑕

T · 𝒂𝑗,𝑘 T

a trainable parameter to learn the importance of different timestamps 𝑁𝑗

𝑢,𝑢′ = ቊ 0, 𝑗𝑔 𝑢 ≤ 𝑢′

−∞, 𝑝𝑢ℎ𝑓𝑠𝑥𝑗𝑡𝑓 is a masked matrix.

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Gated Information Fusing

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𝑭𝑗,𝐽 𝑘

𝑣𝑞𝑒𝑏𝑢𝑓 = 1 − 𝛾𝑗,𝐽 𝑘 · 𝛿𝐽 𝑘

· 𝑭𝑗,𝐽 𝑘 + (𝛾𝑗,𝐽 𝑘 · 𝛿𝐽 𝑘 ) · 𝒜𝑗,𝑘

Mine shared patterns and fuse static and dynamic representations of elements.

an indicator vector controls the importance of static and dynamic representations

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The Learning Process

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Prediction:

ෝ 𝒛𝑗 = 𝑡𝑗𝑕𝑛𝑝𝑗𝑒 𝑭𝑗

𝑣𝑞𝑒𝑏𝑢𝑓𝒙𝑝 + 𝒄𝑝

Loss function:

𝑀 = − 1 𝑂 ෍

𝑗 𝑂 1

𝑛 ෍

𝑘 𝑛

𝑧𝑗,𝑘 log ො 𝑧𝑗,𝑘 + (1 − 𝑧𝑗,𝑘) log 1 − ො 𝑧𝑗,𝑘 + 𝝁 𝑿

𝟑

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Datasets and Baselines

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Four datasets are used for evaluation, i.e. TaFeng, DC, TaoBao and TMS. Both classical and state-of-the-art methods: TOP, PersonalTOP, ElementTransfer, DREAM and Sets2Sets Three evaluation metrics: Recall, NDCG and PHR Statistics of the datasets:

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Our model outperforms existing methods with a significant margin.

Experimental Results

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Our model is applicable to scenarios with sparse data.

Experimental Results

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  • Our model is better than Sets2Sets- when no empirical information is added.
  • Our method outperforms Sets2Sets when incorporating the component for modelling

repeated behaviors.

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next-basket recommendation travel-package recommendation

… 𝑈 + 1

customer

time

? ? ?

automatic treatment

… 𝑈 + 1

patient

time

? ? ?

… 𝑈 + 1

tourist

time

? ? ?

courses planning

… 𝑈 + 1 time

? ? ?

student

Applications

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Website: https://www.brilliantasus.com/

Our Team

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Thanks!

Contact

Le Yu yule@buaa.edu.cn

Reference

Le Yu, Leilei Sun*, Bowen Du, Chuanren Liu, Hui Xiong, Weifeng Lv, Predicting Temporal Sets with Deep Neural Networks, KDD 2020

Code and data

https://github.com/yule-BUAA/DNNTSP

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