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
53
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.
We can infer from the lst paragragh that by "hit-or-miss" it is meant______.
选项
A、before Google, searching online was impossible
B、before Google, searching online lacked accuracy
C、before Google, searching online was difficult
D、Google is easy to use
答案
B
解析
hit-or-miss(Marked by a lack of care,accuracy,or organization;random.)意思是缺乏精确度,没有规律,不够严密,用来形容Google出现之前网络搜索的实际情况。
转载请注明原文地址:https://kaotiyun.com/show/hdqO777K
0
专业英语八级
相关试题推荐
PlansforoneofBritain’sbiggesthousingdevelopments,of5,000homesworthhundredsofmillionsofpounds,mayhavetobeab
Modernintelligencetestingbeganin【B1】______.FrenchpsychologistBinetbasedhistestonthetheorythatintelligenceincreas
A、Hedeniesthecurrentstalemateandthebrewingconfrontation.B、TheUnitedStatesthreatstoimposenewsanctionsagainstIra
ForquiteafewyearswehavebeentalkingaboutaddictiontotheInternet.Nowweareputtingtogether【C1】______thosestudents
Goodmorning.Thediscussiontopicfortoday’sseminaris"HomelessnessinAmerica."IntheUnitedStates,homelessnesshas【C1】
Goodmorning.Thediscussiontopicfortoday’sseminaris"HomelessnessinAmerica."IntheUnitedStates,homelessnesshas【C1】
Inourlooks-obsessedsociety,manypeoplethinkthatbeingoverweightisanappearanceissue.Butbeingoverweightisactually
Inourlooks-obsessedsociety,manypeoplethinkthatbeingoverweightisanappearanceissue.Butbeingoverweightisactually
A、calmandquiet.B、nervousandnumb.C、timidandconfused.D、shockedandangry.A
AftersomanyyearsofstudyingEnglish,youmaystillgetconfusedlikeyoufirstcomeherejustbecauseoftheslangthestude
随机试题
A.Osier吉节B.Negri小体C.Aschoff小体D.环形红斑E.McCallum斑风湿性心内膜炎可有
在土方工程施工中,若采用观察法验槽,则其重点不应选择在()。
施工图预算是______阶段确定建设工程项目造价的依据。()
因铁路、公路、水上、航空事故请求损害赔偿提起的诉讼,由运输始发地、目的地、纠纷发生地或被告住所地人民法院管辖。()
初一语文课上,李老师正情绪激昂地带领学生学习毛泽东的《沁园春.雪》,大家都很投入。这时李老师无意中发现王明正对着语文课本傻笑。李老师走到王明身边才发现他正在偷偷玩手机。李老师非常生气,当即没收了王明的手机,并对他说:“看你以后还认不认真听讲!”李老师的做法
规范
一本书内有3篇文章,第一篇的页数分别是第二篇页数和第三篇页数的2倍和3倍.已知第3篇比第2篇少10页,则这本书共有().
(2004年试题,三(7))设z=f(x2-y2,exy,其中f具有连续二阶偏导数,求
下列关于派生类构造函数和析构函数的说法中,错误的是()。
AboutHomeownershipinAmericaIsthereahousing(住房供给)crisisinAmerica?Orarewesimplyinneedofadjustingasystemtha
最新回复
(
0
)