| Literature DB >> 35659292 |
Hoang-Quynh Le1, Duy-Cat Can2, Nigel Collier3.
Abstract
BACKGROUND: Most previous relation extraction (RE) studies have focused on intra sentence relations and have ignored relations that span sentences, i.e. inter sentence relations. Such relations connect entities at the document level rather than as relational facts in a single sentence. Extracting facts that are expressed across sentences leads to some challenges and requires different approaches than those usually applied in recent intra sentence relation extraction. Despite recent results, there are still limitations to be overcome.Entities:
Keywords: Convolutional neural network; Deep learning; Graph; Multiple paths; Relation extraction
Mesh:
Year: 2022 PMID: 35659292 PMCID: PMC9166375 DOI: 10.1186/s13326-022-00267-3
Source DB: PubMed Journal: J Biomed Semantics
Summary of the BioCreative V CDR dataset
| Subset | Abs | Disease | Chemical | CID | ||||
|---|---|---|---|---|---|---|---|---|
| Ment | ID | IAA | Ment | ID | IAA | |||
| Training | 500 | 4182 | 1965 | 0.8600 | 5203 | 1467 | 0.9523 | 1038 |
| Development | 500 | 4244 | 1865 | 0.8742 | 5347 | 1507 | 0.9577 | 1012 |
| Test | 500 | 4424 | 1988 | 0.8875 | 5385 | 1435 | 0.9630 | 1066 |
Abs Abstracts, Ment Mentions, CID Chemical-induced disease relations
Fig. 1Proposed model for inter sentence relation classification. Red dotted and striped nodes indicate two types of disease. Blue filled nodes indicate one type of chemical
Fig. 2Examples of two unexpected problems while generating the instance from document subgraph
Fig. 3Diagram illustrating of a swCNN architecture
Tuned hyper-parameter of the proposed model
| Information | Configuration | Parameters | |
|---|---|---|---|
| Dependency embeddings | Dependency type | LUT | 10800 |
| Dependency direction | LUT | 300 | |
| Token embeddings | FastText embeds | Pre-trained 300−dim vector | − |
| Character embeddings | LUT | 4250 | |
| biLSTM with 50 units | 40400 | ||
| POS tag | LUT | 2850 | |
| WordNet embeds | Fixed spare 45−dim vector | − | |
| Augmented information | Base distance embeds | 32−dim vector | 32 |
| Self attention score | 833 | ||
| Heuristic attention | Linear | − | |
| Kernel filters | 100 filters size 832×1 | 83300 | |
| Shared weight-CNN | 128 filters each region-size (1,2,3) | 2056320 | |
| Classifier | Fully-connected MLP | Do not use | − |
| Softmax | 2 classes | 768 | |
| Total number of parameters | 2199853 | ||
Embed: Embedding, Dim: Dimension
Ablation test results for added virtual edges in the document subgraph
| Precision | Recall | F1 | |
|---|---|---|---|
| Without TITLE | 62.24 | ||
| Without NEXT-SENT | |||
| Without COREF-sent | 63.80 | 61.85 | |
| Without COREF-to-title | 62.60 | 61.73 | |
| Without COREF-from-title | 64.27 | 62.53 | |
| Without KB-CTD | 64.28 | 61.98 |
Results are reported in %
Decreased results are highlighted in bold
Fig. 4Ablation test results for virtual edges of the document subgraph. The vertical axis shows the performance in %. Experiments are conducted with 3 shortest paths
Fig. 5The change of results with different size of sliding window. The vertical axis shows the performance in % while the horizontal axis shows the size of w. Only fastText word embedding is used to represent words. Experiments are conducted with 3 shortest paths
Results of the document subgraph with different sizes of the sliding window for training and testing
| Precision | Recall | F1 | ||
|---|---|---|---|---|
| 1 | 1 | 55.50 | 60.02 | |
| 2 | 62.20 | 57.22 | 59.61 | |
| 3 | 61.47 | 58.27 | 59.83 | |
| 4 | 61.92 | 54.86 | 58.18 | |
| 5 | 57.13 | 59.76 | 58.42 | |
| 2 | 1 | 61.95 | 60.19 | 61.06 |
| 2 | 61.25 | 61.26 | 61.25 | |
| 3 | 61.97 | 60.30 | 61.12 | |
| 4 | 61.30 | 58.52 | 59.88 | |
| 5 | 60.99 | 59.36 | 60.16 | |
| 3 | 1 | 61.05 | 61.74 | 61.39 |
| 2 | 60.65 | 61.74 | 61.19 | |
| 3 | 60.70 | 61.88 | 61.28 | |
| 4 | 62.30 | 59.47 | 60.85 | |
| 5 | 61.10 | 59.81 | 60.45 | |
| 4 | 1 | 60.30 | 64.01 | 62.10 |
| 2 | 57.88 | 61.67 | ||
| 3 | 58.31 | 65.27 | 61.59 | |
| 4 | 58.40 | 63.86 | 61.01 | |
| 5 | 59.97 | 61.71 | 60.83 | |
| 5 | 1 | 61.15 | 63.76 | 62.43 |
| 2 | 60.13 | 65.89 | ||
| 3 | 58.56 | 65.79 | 61.96 | |
| 4 | 58.64 | 62.42 | 60.47 | |
| 5 | 57.92 | 62.36 | 60.06 |
Results are reported in %
The highest result in each column is highlighted in bold
Ablation test results for various components of the document subgraph based model
| Component removed/changed | Precision | Recall | F1 | Change of F1 |
|---|---|---|---|---|
| Without subgraph | 57.68 | 55.16 | 56.39 | -6.49 |
| Without TITLE | 61.12 | 54.12 | 57.41 | -5.47 |
| Without NEXT-SENT | 62.36 | 58.33 | 60.28 | -2.60 |
| Without instance merging technique | 52.40 | 69.26 | 59.66 | -3.22 |
| Without swCNN and top- | 59.92 | 62.19 | 61.03 | -1.84 |
| Choose top- | 58.56 | 66.96 | 62.48 | -0.40 |
| Use w=2 for both training and testing (instead of different | 61.25 | 61.26 | 61.25 | -1.62 |
| Without using class weight | 59.60 | 65.92 | 62.60 | -0.28 |
| Without attention mechanism | 59.13 | 64.85 | 61.86 | -1.02 |
Results are reported in %
Column ‘Change of F1’ shows the decrease of F1 when removing/changing components from the model
Highest result in each column is highlighted in bold
The performance of document subgraph-based model and some comparative models
| Method/model | Precision | Recall | F1 | |
|---|---|---|---|---|
| hybridDNN (Zhou et al., 2016 [ | Syntactic features | 62.15 | 47.28 | 53.70 |
| + Context | 62.39 | 47.47 | 53.92 | |
| + Position | 62.86 | 47.47 | 54.09 | |
| ASM (Panyam et al., 2018 [ | Dependency graph | 49.00 | 67.40 | 56.80 |
| MASS (Le et al., 2018 [ | Multi channel CNN-LSTM | 58.90 | 54.90 | 56.90 |
| + Ensemble | 56.80 | 57.90 | 57.30 | |
| + Post processing | 52.80 | 71.10 | 60.60 | |
| UET-CAM (Le et al., 2016 [ | SVM + coreference | 53.41 | 49.41 | 51.60 |
| + Data | 57.63 | 60.23 | 58.90 | |
| SVM (Peng et al., 2016 [ | SVM + Rich feature set | 64.24 | 52.06 | 57.51 |
| + Data | 56.94 | 61.01 | ||
| CNN+ME (Gu et al., 2017 [ | Hybrid model | 60.90 | 59.50 | 60.20 |
| + Post-processing | 55.70 | 68.10 | 61.30 | |
| LSTM-CNN (Zheng et al., 2018 [ | Sequence of sentences | 24.00 | 52.00 | 32.80 |
| + Entity replacing | 54.30 | 65.90 | 59.50 | |
| BRAN (Verga et al., 2018 [ | CNN + abstract attention | 55.60 | 70.80 | 62.10 |
| + Data | 64.00 | 69.20 | 66.20 | |
| + Ensemble | 65.40 | 71.80 | 68.40 | |
| Graph CNN (Sahu et al., 2019 [ | Document-level Graph | 52.80 | 66.00 | 58.60 |
| Our results | Document subgraph | 60.13 | 65.89 | 62.88 |
| + Data | 62.95 | 68.52 | ||
| + Ensemble | 64.79 | 74.05 | ||
Results are reported in %
Highest result in each column is highlighted in bold
The detailed results of the document subgraph-based model
| Precision | Recall | F1 | |
|---|---|---|---|
| Full result | 64.79 | 74.05 | 69.11 |
| intra sentence relation result | 72.91 | 85.73 | 78.80 |
| inter sentence relation result | 46.12 | 47.28 | 46.69 |
Results are reported in %
Only evaluated on Intra- or inter sentence relations
Examples of errors on the BC5 CDR test set
| # | PMID | Chemical-Disease | Golden label | RbSP | SGM | Type | Effect | Error type |
|---|---|---|---|---|---|---|---|---|
| 1 | 2131034 | D003561–D020258 | CID | NONE | CID | Intra | FN → TP | |
| 2 | 18801087 | D000638–D009369 | NONE | CID | NONE | Intra | FP → TN | |
| 3 | 44072 | C024986–D001145 | CID | CID | NONE | Intra | TP → FN | |
| 4 | 15265979 | D005947–D006529 | NONE | NONE | CID | Intra | TN → FP | |
| 5 | 1655018 | D000305–D006528 | CID | NONE | NONE | Intra | − | FN |
| 6 | 35781 | D010423–D002375 | NONE | CID | CID | Intra | − | FP |
| 7 | 7644931 | D017239–D018771 | CID | − | CID | Inter | FN → TP | |
| 8 | 10327032 | D005472–D008107 | NONE | − | CID | Inter | TN → FP | |
| 9 | 2710809 | D001712–D003680 | CID | − | − | Inter | − | FN |
| 10 | 11745287 | D016190–D015431 | CID | − | NONE | Inter | − | FN |
| 11 | 10087562 | D004280–D008133 | NONE | CID | CID | Intra | FN | |
| 12 | 24464946 | D015251–D006331 | NONE | − | CID | Inter | TN → FP |
The re-implemented intra sentence RbSP model (Can et al. [30]) - without subgraph model in Table 5
subgraph model’s prediction
*Errors due to the imperfect annotation
CID Chemical-induced disease, NONE Unrelated, ‘ −’: Cannot generate path, TP True Positive, TN True Negative, FP False Positive, FN False Negative
Cases where the SBM model gives correct results are highlighted in bold