Blockchain,by 邓斌斌,What is blockchain?,trade,默克尔树,Each transaction in the set that makes up a block is fed through a program that creates an encrypted code known as the hash value. Hash values are further combined in a system known as a Merkle Tree. The result of all this hashing goes into the blocks header , along with a hash of the previous blocks header and a time-stamp. The header then becomes part of a cryptographic puzzle solved by manipulating a number called the nonce. Once a solution is found the new block is added to the blockchain.,代码加密,时间戳,加密,Number once,What are the application of blockchain?,Distribution Shopping Trust Internet Transaction Security ,,,分布式账本,添加幻灯片标题 - 1,,decentralization,去中心化,If youre a hacker You will Attack?,BANK,Block chain,欺诈,,Traditional,data globalization,Block chain,Security,Thank you!,Black Technology in American election,毛承蔚,Pay less but gain more？？！,300 million400 million？,Thanks to big data,hiahiahia,Nate Silver,In 2008，It predicted 49 of the 50 states elections correctly.,In 2012，It predicted all 50 states elections correctly.,Then... Proposed big data research and development initiative Invest more than 200 million dollars.,Improve collection, storage, retention, management, analysis and The core technologies needed to share vast amounts of data.,So... now... There are more than 772 data centers is running, With more than 70,000 servers, And about 7 million computer terminals.,GOOD JOB!!,who is the next ?,A election with strong big data gene .,In this election, the technology team that served Mrs Clintons election has more than 50 people, the equivalent of a small silicon valley tech start-up.,Hillary Clinton, $240 million.,PageRank,李存益,PageRank -A wonderful way to identify the level and importance of a we page,The basic algorithm: 1.every web page will get the same PageRank at first 2.Execute the following cycle:Each page assigns its current PageRank equally to the outward links on this page, so that each link gets the corresponding PageRank. For each cycle, the new PageRank is obtained by summation of all the PageRank that is passed in inward links of this page. 3.After several cycle,the PageRank of every web page wont change any more.And the more higher the PageRank , the more important the web page .,Simplified Algorithm,L:the number of outward liknks PR:the PageRank in this cycle q:Damping factor: the probability that a user reaches a web page and continues to browse backwards at any time.,Advantage:It is a static algorithm which is independent of the query. And the PageRank of all web pages is obtained by offline calculation. It effectively reduce the amount of computation in online query, greatly reduce the query response time. disadvantage:Peoples queries always have thematic features.But PageRank ignores thematic relevance, resulting in the reduction of the correlation and thematic for results.,。