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Dimension Reduction Methods with Application to ... - Rice University

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L 2 -L 2 RP: IMPROVEMENT ON ACHLIOPTAS<br />

BOUND<br />

Rojo and Nguyen (2009b): Method 3<br />

◮ Pinelis inequality<br />

———————————————————————<br />

Let U i ’s be independent rademacher random variables. Let<br />

d 1 , . . . , d m be real numbers such that ∑ m<br />

i=1 d2 i = 1. Let<br />

S m = ∑ m<br />

i=1 d iU i , then for any t > 0,<br />

( )<br />

1<br />

P[|S m | ≥ t] ≤ min<br />

t , 2(1 − Φ(t − 1.495/t)) 2<br />

———————————————————————<br />

◮ Method 3: lower bound for k: 15% improvement (ɛ = 0.1)<br />

k ≥ 2(p − 1)a2 n<br />

pɛ 2 , (24)<br />

where a n = Qn+√ Q 2 n +4(1.495)<br />

2<br />

, and Q n = Φ −1 ( 1 − 1<br />

n 2+β )<br />

.<br />

44 / 86

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