6597
The results from the synchronized three-spot method using different scanning strategies improved the layer surface roughness Ra by 3.2 μm .
 concept or principle: scanning strategies; process parameter: layer; machanical property: roughness
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: scanning strategies, layer, roughness 
Answer:
 concept or principle: scanning strategies; process parameter: layer; machanical property: roughness