a weakness of hashing Problem: For any hash function h, a set of keys exists that can cause the average access time of a hash table to skyrocket An adversary can pick all keys from tkeU: h(k)=i for some slot i IDEA Choose the hash function at random independently of the keys
Translation(English to Chinese) 1. I was greatly impressed by its natural beauty when I took a study tour there two years ago 两年前,我在那里做过野外考查,那里的自然风光给我印象极深
Ch. 23 Cointegration 1 Introduction An important property of (1) variables is that there can be linear combinations of theses variables that are I(O). If this is so then these variables are said to be cointegrated. Suppose that we consider two variables Yt and Xt that are I(1) (For example, Yt= Yt-1+ St and Xt= Xi-1+nt.)Then, Yt and Xt are said to be cointegrated if there exists a B such
II. Listening Skills Listening to People talk about health 1. M: I haven't been to see my doctor for a very long time. I'm worried that he'll be angry with me for not having a physical examination for so long w: Which is more important, the doctors feelings or your health? Youd better go if you want to make sure everything is all right with you. It seems that the man worries more about the doctor's feelings than his own healtl
