We implement our code in Tensorflow and the code is tested under a server with 40-core Intel Xeon E5-2630 v4 @ 2.20GHz CPU, 256G RAM and Nvidia GTX 1080 GPUs (with TensorFlow 1.13 and Python 3).
The preprocessed datasets are in the data directory (e.g. data/ml1m.txt). Each line of the txt format data contains
a user id and an item id, where both user id and item id are indexed from 1 consecutively. Each line represents one interaction between the user
and the item. For every user, their interactions were sorted by timestamp.
Our paper has been accepted to ACM Recommender Systems Conference 2020 and selected for Best Long Paper Candidates (https://dl.acm.org/doi/10.1145/3383313.3412258) and our pre-print version is on arxiv or our ICLR borderline-rejected version https://openreview.net/forum?id=HkeuD34KPH.
One can cite one of below for now:
@inproceedings{wu2020sse,
title={SSE-PT: Sequential Recommendation Via Personalized Transformer},
author={Wu, Liwei and Li, Shuqing and Hsieh, Cho-Jui and Sharpnack, James},
booktitle={Fourteenth ACM Conference on Recommender Systems},
pages={328--337},
year={2020}
}
or
@misc{
wu2020ssept,
title={{\{}SSE{\}}-{\{}PT{\}}: Sequential Recommendation Via Personalized Transformer},
author={Liwei Wu and Shuqing Li and Cho-Jui Hsieh and James Sharpnack},
year={2020},
url={https://openreview.net/forum?id=HkeuD34KPH}
}
It is worth noting that a new regualrization technique called SSE is used. One can refer to the paper below for more details: Stochastic Shared Embeddings: Data-driven Regularization of Embedding Layers. The paper has been accepted to NeurIPS 2019. We will present the work at Vancouver, Canada. Another git repo is at https://github.com/wuliwei9278/SSE.
@article{wu2019stochastic,
title={Stochastic Shared Embeddings: Data-driven Regularization of Embedding Layers},
author={Wu, Liwei and Li, Shuqing and Hsieh, Cho-Jui and Sharpnack, James},
journal={arXiv preprint arXiv:1905.10630},
year={2019}
}
The training of the SSE-PT model is handled by the main.py script that provides the following command line arguments.
--dataset STR Name of dataset. Default is "ml1m".
--train_dir STR Train directory. Default is "default".
--batch_size INT Batch size. Default is 128.
--lr FLOAT Learning rate. Default is 0.001.
--maxlen INT Maxmum length of sequence. Default is 50.
--user_hidden_units INT Hidden units of user. Default is 50.
--item_hidden_units INT Hidden units of item. Default is 50.
--num_blocks INT Number of blocks. Default is 2.
--num_epochs INT Number of epochs to run. Default is 2001.
--num_heads INT Number of heads. Default is 1.
--dropout_rate FLOAT Dropout rate value. Default is 0.5.
--threshold_user FLOAT SSE probability of user. Default is 1.0.
--threshold_item FLOAT SSE probability of item. Default is 1.0.
--l2_emb FLOAT L2 regularization value. Default is 0.0.
--gpu INT Name of GPU to use. Default is 0.
--print_freq INT Print frequency of evaluation. Default is 10.
--k INT Top k for NDCG and Hits. Default is 10.
To train our model on the default ml1m data with default parameters:
python3 main.py
To train a SSE-PT model on ml1m data using a maxlen of 200, a dropout rate of 0.2, a SSE probability of 0.92 for user side
and a SSE probability of 0.1 for item side.
python3 main.py --maxlen=200 --dropout_rate 0.2 --threshold_user 0.08 --threshold_item 0.9
The following is the plot of NDCG@10 versus training time (Seconds) for SASRec, SSE-PT and SSE-PT++. Our proposed SSE-PT and SSE-PT++ outperform SASRec.
We based our codes on SASRec.