A number of methods utilize an extra type of information as the observed features for entities, by either merging, concatenating, or averaging the entity and its features to compute its embeddings, such as numerical values BIBREF26 (we use KBLN from this work to compare it with our approach using only numerical as extra attributes), images BIBREF27 , BIBREF28 (we use IKRL from the first work to compare it with our approach using only images as extra attributes), text BIBREF29 , BIBREF30 , BIBREF31 , BIBREF32 , BIBREF33 , BIBREF34 , and a combination of text and image BIBREF35 . Further, BIBREF7 address the multilingual relation extraction task to attain a universal schema by considering raw text with no annotation as extra feature and using matrix factorization to jointly embed KB and textual relations BIBREF36 . In addition to treating the extra information as features, graph embedding approaches BIBREF37 , BIBREF38 consider observed attributes while encoding to achieve more accurate embeddings. 
 Question: What other multimodal knowledge base embedding methods are there?
merging, concatenating, or averaging the entity and its features to compute its embeddings graph embedding approaches matrix factorization to jointly embed KB and textual relations