1995
In this way , special properties should be assigned to the representative volumes and then we can apply traditional TO or other structure optimization methods to operate the special volumes .
 concept or principle: properties; material: be; concept or principle: structure optimization
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: properties; material: be; concept or principle: structure optimization