首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
One thing that distinguishes the online world from the real one is that it is very easy to find things. To find a copy of The Ec
One thing that distinguishes the online world from the real one is that it is very easy to find things. To find a copy of The Ec
admin
2010-05-14
35
问题
One thing that distinguishes the online world from the real one is that it is very easy to find things. To find a copy of The Economist in print, one has to go to a news-stand, which may or may not carry it. Finding it online, though, is a different proposition. Just go to Google, type in "economist" and you will be instantly directed to economist.com. Though it is difficult to remember now, this was not always the case. Indeed, until Google, now the world’s most popular search engine, came on to the scene in September 1998, it was not the case at all. As in the physical world, searching online was a hit-or-miss affair.
Google was vastly better than anything that had come before: so much better, in fact, that it changed the way many people use the web. Almost overnight, it made the web far more useful, particularly for non- specialist users, many of whom now regard Google as the internet’ s front door. The recent fuss over Google’s stock market flotation obscures its far wider social significance: few technologies, after all, are so influential that their names become used as verbs.
Google began in 1998 as an academic research project by Sergey Brin and Lawrence Page, who were then graduate students at Stanford University in Palo Alto, California. It was not the first search engine, of course. Existing search engines were able to scan or "crawl" a large portion of the web, build an index, and then find pages that matched particular words. But they were less good at presenting those pages, which might number in the hundreds of thousands, in a useful way.
Mr Brin’s and Mr Page’s accomplishment was to devise a way to sort the results by determining which pages were likely to be most relevant. They did so using a mathematical recipe, or algorithm, called PageRank. This algorithm is at the heart of Google’s success, distinguishing it from all previous search engines and accounting for its apparently magical ability to find the most useful web pages.
Untangllng the web
PageRank works by analysing the structure of the web itself. Each of its billions of pages can link to other pages, and can also, in turn, be linked to. Mr Brin and Mr Page reasoned that if a page was linked to many other pages, it was likely to be important. Furthermore, if the pages that linked to a page were important, then that page was even more likely to be important. There is, of course, an inherent circularity to this formula--the importance of one page depends on the importance of pages that link to it, the importance of wb4ch depends in turn on the importance of pages that link to them. But using some mathematical tricks, this circularity can be resolved, and each page can be given a score that reflects its importance.
The simplest way to calculate the score for each page is to perform a repeating or "iterative" calculation (see article). To start with, all pages are given the same score. Then each link from one page to another is counted as a "vote" for the destination page. Each page’s score is recalculated by adding up the contribution from each incoming link, which is simply the score of the linking page divided by the number of outgoing links on that page. (Each page’s score is thus shared out among the pages it links to.)
Once all the scores have been recalculated, the process is repeated using the new scores, until the scores settle down and stop changing (in mathematical jargon, the calculation "converges"). The final scores can then be used to rank search results: pages that match a particular set of search terms are displayed in order of descending score, so that the page deemed most important appears at the top of the list.
The most important factor in Google’s success is ______.
选项
A、its unique mathematical recipe
B、the popularity of its brand among users
C、that it was the first search engine in the world
D、its stock market flotation
答案
A
解析
Google成功的关键在于它采用了独特的数理运算法则,可以高效地根据重要性大小搜索到最有价值的网页。
转载请注明原文地址:https://kaotiyun.com/show/1dqO777K
0
专业英语八级
相关试题推荐
Modernintelligencetestingbeganin【B1】______.FrenchpsychologistBinetbasedhistestonthetheorythatintelligenceincreas
A、Damswillprotectthecityfrommoderatelyintensehurricanesthistime.B、ThereisanewlakecalledLakeNewOrleansemergin
Ifirstly【B1】______towritetheletterwhentheproducercalledbecauseFOOCwasaboutotherpeople’s【B2】______and【B3】______.
ForquiteafewyearswehavebeentalkingaboutaddictiontotheInternet.Nowweareputtingtogether【C1】______thosestudents
ForquiteafewyearswehavebeentalkingaboutaddictiontotheInternet.Nowweareputtingtogether【C1】______thosestudents
Fromitsbirth,threepowerfulimageshavecolouredideasofwhattheUnitedStateswasandwhatitstoodfor.Onewas"acityo
Toseehowbigcarrierscouldcontroltheonlineworld,youmustunderstanditsstructures.EarthlinkgivesJenniferaccesst
A、calmandquiet.B、nervousandnumb.C、timidandconfused.D、shockedandangry.A本题也是考查总体理解。虽然被访者经历了一个terriblesituation,但她还是较
Toseehowbigcarrierscouldcontroltheonlineworld,youmustunderstanditsstructures.EarthlinkgivesJenniferaccesstot
Rabiesisanordinarilyinfectiousdiseaseofthecentralnervoussystem,causedbyavirusand,asarule,spreadchieflybydo
随机试题
A.二硫化碳B.苯胺C.二氯乙烷D.一氧化碳E.铅、汞
消化性溃疡最常见的并发症是()
键盘主要分为()等区域。
会计资料是在会计核算过程中形成的、记录和反映实际发生的经济业务事项的资料,包括()。
企业资产负债表上“存货”项目的期末数应包括()。
一般情况下,骨折现场急救处理的第一步是()。
由于七和弦中出现了不协和的七度音程,所以所有的七和弦都是不协和和弦。()
在全球气候变暖的背景下,我国东北长白山高山苔原带矮小灌木的冻害反而加剧。调查发现长白山雪期缩短;冻害与坡度密切相关,而与海拔基本无关;西北坡为冻害高发区。据此完成下列问题。长白山西北坡比其他坡向冻害高发,是因为该坡()。
下面代码的输出结果是>>>True—False
TheordinaryfamilyincolonialNorthAmericawasprimarilyconcernedwithsheerphysicalsurvivalandbeyondthat,itsownecon
最新回复
(
0
)