1072
In this study , a new real-time defect identification method is proposed for Al alloys in robotic arc welding , using arc optical spectroscopy and an integrated learning method .
 concept or principle: defect; material: Al alloys; manufacturing process: arc welding; concept or principle: arc; concept or principle: spectroscopy
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: defect; material: Al alloys; manufacturing process: arc welding; concept or principle: arc; concept or principle: spectroscopy