1937
Even these methods can obtain a manufacturable TO layout , the boundaryproblems brought by a density based TO method still pose challenges for AM processes .
 concept or principle: manufacturable; concept or principle: layout; machanical property: density; manufacturing process: AM processes
Given options, please tell me the categories of all the listed entity words.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} 
 Entities: manufacturable, layout, density, AM processes 
Answer:
 concept or principle: manufacturable; concept or principle: layout; machanical property: density; manufacturing process: AM processes