---
license: apache-2.0
language: en
library_name: transformers
tags:
  - sdgs
  - sustainability
  - multi-label-classification
  - text-classification
  - luke
datasets:
  - osdg/osdg-community
  - SDG-AI-Lab/sdgi_corpus
pipeline_tag: text-classification
---

# SDG Classifier: A Fine-Tuned LUKE Model for Multi-Label SDG Classification

This repository contains the pre-trained model weights (`best_model.pt`) for the paper: **"Bridging the Sustainable Development Goals: A Multi-Label Text Classification Approach for Mapping and Visualizing Nexuses in Sustainability Research"**.

➡️ **GitHub Repository (Code):** [https://github.com/Green-Engineers-Lab/SDGs-classifier/]  
➡️ **Paper Link:** [Link to Published Paper will be added upon publication]

## 📝 Model Description

This model is a fine-tuned version of `studio-ousia/luke-large-lite` for multi-label text classification of the 17 UN Sustainable Development Goals (SDGs). It has been trained on a uniquely diverse, multi-sectoral, and multilingual corpus designed to achieve high generalization performance across various domains (academic, policy, civil society, etc.).

The model takes a text input (up to 512 tokens) and outputs a probability score for each of the 17 SDGs, indicating the relevance of the text to each goal.

## 🚀 How to Use

This model was trained with a custom classification head in PyTorch. To use it, you need to define the model architecture first and then load the downloaded weights (`best_model.pt`).

Below is a complete example of how to load the model and perform a prediction.

```python
import torch
from torch import nn
from transformers import AutoTokenizer, AutoModel
from huggingface_hub import hf_hub_download
from pathlib import Path

# --- 1. Define the Model Architecture ---
# This class must match the architecture used during training.
# You can copy this class from the original training script.
class SDGClassifier(nn.Module):
    def __init__(self, model_path, pooler_dropout, class_number):
        super(SDGClassifier, self).__init__()
        self.bert = AutoModel.from_pretrained(model_path)
        self.dropout = nn.Dropout(pooler_dropout)
        self.pooler = nn.Sequential(nn.Linear(in_features=self.bert.config.hidden_size, out_features=self.bert.config.hidden_size))
        self.tanh = nn.Tanh()
        self.cls = nn.Linear(in_features=self.bert.config.hidden_size, out_features=class_number)

    def forward(self, input_ids, attention_mask, token_type_ids, position, labels):
        # Note: 'position' and 'labels' are dummy inputs required by the forward signature,
        # but are not used for inference if labels are not provided.
        bert_output = self.bert(input_ids, attention_mask, token_type_ids=token_type_ids, output_attentions=True, output_hidden_states=True)
        average_hidden_state = (bert_output.last_hidden_state * attention_mask.unsqueeze(-1)).sum(1) / attention_mask.sum(1, keepdim=True)
        pooler_output = self.tanh(self.pooler(self.dropout(average_hidden_state)))
        logits = self.cls(pooler_output)
        return logits, average_hidden_state, bert_output.attentions

# --- 2. Setup and Load Model ---
device = torch.device("cuda" if torch.cuda.is_available() else "cpu")

# Model configuration
BASE_MODEL = 'studio-ousia/luke-large-lite'
NUM_CLASSES = 17
DROPOUT_RATE = 0.26 # This is the optimized dropout rate from the paper's training

# Instantiate the model
model = SDGClassifier(model_path=BASE_MODEL, pooler_dropout=DROPOUT_RATE, class_number=NUM_CLASSES).to(device)
model.eval() # Set to evaluation mode

# Download the fine-tuned weights from this Hub
model_weights_path = hf_hub_download(
    repo_id="GE-Lab/SDGs-classifier",
    filename="best_model.pt"
)

# Load the weights into the model
model.load_state_dict(torch.load(model_weights_path, map_location=device))

print("Model loaded successfully!")

# --- 3. Prepare Input ---
tokenizer = AutoTokenizer.from_pretrained(BASE_MODEL)
text = "Our research focuses on renewable energy solutions to combat climate change and ensure a sustainable future for all."

inputs = tokenizer.encode_plus(
    text,
    None,
    add_special_tokens=True,
    max_length=512,
    padding='max_length',
    return_token_type_ids=True,
    truncation=True,
    return_tensors='pt'
).to(device)

# The model's forward pass requires these additional dummy inputs
inputs['position'] = torch.arange(0, inputs['input_ids'].shape[1]).unsqueeze(0).to(device)
inputs['labels'] = torch.zeros(1, NUM_CLASSES).to(device) # Dummy labels for inference

# --- 4. Get Predictions ---
with torch.no_grad():
    logits, _, _ = model(**inputs)
    probabilities = torch.sigmoid(logits).cpu().numpy()[0]
    predictions = (probabilities > 0.5).astype(int)

# --- 5. Interpret the Results ---
goal_contents = ['Goal 1: No Poverty','Goal 2: Zero Hunger','Goal 3: Good Health and Well-being','Goal 4: Quality Education','Goal 5: Gender Equality','Goal 6: Clean Water and Sanitation','Goal 7: Affordable and Clean Energy','Goal 8: Decent Work and Economic Growth','Goal 9: Industry, Innovation and Infrastructure','Goal 10: Reduced Inequalities','Goal 11: Sustainable Cities and Communities','Goal 12: Responsible Consumption and Production','Goal 13: Climate Action','Goal 14: Life Below Water','Goal 15: Life on Land','Goal 16: Peace, Justice and Strong Institutions','Goal 17: Partnerships for the Goals']

print(f"\nText: '{text}'")
print("\n--- Predicted SDGs (Threshold > 0.5) ---")
predicted_goals = [goal_contents[i] for i, pred in enumerate(predictions) if pred == 1]
if predicted_goals:
    for goal in predicted_goals:
        print(goal)
else:
    print("No SDGs detected with a probability > 0.5")

print("\n--- All SDG Probabilities ---")
for i, prob in enumerate(probabilities):
    print(f"{goal_contents[i]:<55}: {prob:.2%}")

```

## 📈 Training and Evaluation

### Training Data
The model was trained on a novel, heterogeneous corpus of 23,969 multi-labeled documents from 11 diverse sources, including government, academia, industry, and civil society, with some sources translated from Japanese. This approach was designed to address the "interpretive diversity" of SDG-related language.

For full details on reconstructing the training corpus, please refer to **Supplementary Information S4** in our paper.

### Evaluation
This model was selected based on its superior generalization performance (especially recall) on external datasets like the OSDG Community Dataset and the SDGi Corpus. On a human-coded sample of scientific articles, the model achieved a macro-averaged **F1-score of 0.623**. For a full breakdown of performance metrics, please see the paper.

## 📜 Citation

If you use this model in your research, please cite our paper:

```bibtex
@article{Miyashita2025,
  author    = {Naoto Miyashita and Takanori Matsui and Chihiro Haga and Naoki Masuhara and Shun Kawakubo},
  title     = {Bridging the Sustainable Development Goals: A Multi-Label Text Classification Approach for Mapping and Visualizing Nexuses in Sustainability Research},
  journal   = {Sustainability Science},
  year      = {2025},
  % TODO: Add Volume, Pages, DOI upon publication
}
```