5731
Different active contours segmentation methods are compared , and the sources of variability of the resulting measurements are investigated in terms of repeatability , part-to-part and build-to-build variability .
 contours, variability, repeatability, variability
Please list all entity words in the text that fit the category. Output format is "word1, 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:
 contours, variability, repeatability, variability