| [ QuizWit ] in KIDS 글 쓴 이(By): mkjung () 날 짜 (Date): 2000년 2월 3일 목요일 오후 01시 45분 23초 제 목(Title): GPS Pseudo-random sequences of 1's and 0's are key components in Global Positioning System (GPS) receivers, digital cellular telephones, industrial and military stream ciphers, and radar synchronization systems. Such sequences may be rapidly generated using simple, inexpensive, off-the-shelf "shift register" hardware. Most applications require shift registers to be configured so that their output sequences will have enormous periods and will pass various statistical tests for randomness. How do we determine which connections to make on the shift register so that the output sequence has these desirable properties? It turns out that shift register sequences may be analyzed using Galois theory, elliptic curve theory, and p-adic arithmetic. Until recently these branches of mathematics were generally considered to be largely "useless", but today they are so important that the US even places export restrictions on certain software which performs computations of this type. In this talk we will describe the basic shift register hardware and show how some of the questions which arise may be solved using Galois theory and elliptic curves. Conferencier: MARK GORESKY Speaker: Institute for Advanced Study (IAS) 학교에서 쎄미나 업스트랙트가 재미있어서 긁어왔습니다. |