8010
Unlike evaluations in the SRE series , the i-vector challenge was run entirely online and used fixed-length feature vectors projected into a low-dimensional space -LRB- i-vectors -RRB- rather than audio recordings .
 used for: fixed-length feature vectors, low-dimensional space -LRB- i-vectors -RRB-; used for: low-dimensional space -LRB- i-vectors -RRB-, i-vector challenge; compare: audio recordings, low-dimensional space -LRB- i-vectors -RRB-
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: conjunction, feature of, hyponym of, used for, part of, compare, evaluate for 
Text: {0} 
 Entity Pairs:  fixed-length feature vectors, low-dimensional space -LRB- i-vectors -RRB-; low-dimensional space -LRB- i-vectors -RRB-, i-vector challenge; audio recordings, low-dimensional space -LRB- i-vectors -RRB- 
Answer:
 used for: fixed-length feature vectors, low-dimensional space -LRB- i-vectors -RRB-; used for: low-dimensional space -LRB- i-vectors -RRB-, i-vector challenge; compare: audio recordings, low-dimensional space -LRB- i-vectors -RRB-