Generation of artificial knowledge graphs

Implementation of synthesis model from the paper "Synthesizing Knowledge Graphs for Link and Type Prediction Benchmarking" submitted to ESWC2017.

Knowledge graph models

The six models described in the paper are supported:

• M1: Includes distribution of types over entities plus joint distribuiton of relations, subject and object types
• M2: M1 plus non-reflexiveness, functionality and inverse functionality of relations
• M3: M2 plus horn rules
• EMi: Mi plus bias to selection of entities

Usage

For this example we use a small knowledge base from the Semantic Web dog food about the conference ESWC2015, whose horn rules are available here.

• First load the knowledge base dump into a tensor:

python load_tensor.py eswc2015.n3

this will create the file eswc2015.npz with a tensor representation of the knowledge base

• Then Learn the models:

python learn_model.py eswc2015.ext -m M1
python learn_model.py eswc2015.ext -m M2
python learn_model.py eswc2015.ext -m M3 -r eswc2015-AmieRules.txt
python learn_model.py eswc2015.ext -m e -sm M1 M2 M3

The commands need to be executed in the order above because one model is an extension of the other. The commands will create generate the models and save them in the pickle files:

• eswc2015-M1.pkl

• eswc2015-M2.pkl

• eswc2015-M3.pkl

• eswc2015-eM1.pkl, eswc2015-eM2.pkl and eswc2015-eM3.pkl

• From the learned models the knowledge base can be synthesized

python synthesize.py eswc2015-M1.pkl eswc2015-replica-M1.n3 -size 0.1

This will synthesize a replica of the dataset with 10% of the original size and dump it into eswc2015-replica-M1.n3

The bash script example.sh contains the commands of the example above.

Requirements

The knowledge base creation is done with rdflib. The tensors are handled with scipy, and the synthesis progress bar is done with tqdm. The knowledge graph model M3 requires a text file containing horn rules learned with AMIE.