1037
At the core of each structural TO problem lies an objective function that needs to be minimized or maximized while being subjected to a set of constraints such as volume , displacement or frequency .
 machine or equipment: core; material: be; application: set; material: as
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:
 machine or equipment: core; material: be; application: set; material: as