2055
Similar to structure topology optimization , surface structure design and optimization face more difficulties in the modelling , simulation and embracing of AM constraints .
 concept or principle: structure; concept or principle: optimization; engineering feature: surface structure; engineering feature: design; concept or principle: optimization face; enabling technology: modelling; enabling technology: simulation; manufacturing process: AM
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 concept or principle: structure; concept or principle: optimization; engineering feature: surface structure; engineering feature: design; concept or principle: optimization face; enabling technology: modelling; enabling technology: simulation; manufacturing process: AM