我想看一级黄色片_欧美性爱无遮挡电影_色丁香视频网站中文字幕_视频一区 视频二区 国产,日本三级理论日本电影,午夜不卡免费大片,国产午夜视频在线观看,18禁无遮拦无码国产在线播放,在线视频不卡国产在线视频不卡 ,,欧美一及黄片,日韩国产另类

????非洲的城市化進(jìn)程為成千上萬人帶來了巨大的希望,，前提是基礎(chǔ)設(shè)施能保持建設(shè)力度,。而技術(shù)手段則大有希望提高非洲基礎(chǔ)設(shè)施建設(shè)進(jìn)程的速度和效率。

????非洲大陸的人口多達(dá)9.55億人,，是僅次于亞洲的世界第二大人口密集大陸,。與其他各大洲的居民相比，他們正在經(jīng)歷速度更快的城市化進(jìn)程。盡管超過半數(shù)的非洲人仍然生活在貧困線以下,，但按照德克薩斯大學(xué)（University of Texas）教授,，也是《非洲崛起》（Africa Rising）一書的作者維賈伊?馬哈揚的估測，約有35%的非洲人已邁入中產(chǎn)階級,。

????今天,，非洲大陸上人口逾百萬的城市已經(jīng)有37座。約有41%的非洲人居住在城市里,，而據(jù)為聯(lián)合國（the United Nations）所做的一份報告預(yù)測,，到2020年，將有超過半數(shù)的非洲人在城市安家,。這些人之所以遷往城市,，是因為他們希望獲得比在鄉(xiāng)村和農(nóng)場更高的安全感和更好的發(fā)展機(jī)會,。但是他們往往發(fā)現(xiàn),，城市并沒有做好準(zhǔn)備來滿足他們的基本需求，比如潔凈的飲水和烹煮食物的燃料,。

????建設(shè)基礎(chǔ)設(shè)施,，保證新進(jìn)入城市的居民安居樂業(yè)并能創(chuàng)造更大價值，已經(jīng)成為這些城市和國家領(lǐng)導(dǎo)人的重大責(zé)任,。

????雖然多數(shù)非洲城市的基礎(chǔ)設(shè)施十分匱乏,，但正因為如此，公共與私營部門的領(lǐng)袖們才有機(jī)會建設(shè)新型的供水系統(tǒng),、電網(wǎng)和交通控制系統(tǒng),。與世界發(fā)達(dá)地區(qū)老化的基礎(chǔ)設(shè)施相比，這些系統(tǒng)會更高效,，也更節(jié)能,。電子傳感器和控制器等技術(shù)可對電力進(jìn)行可變定價，對用水消耗量進(jìn)行精確計量,。與美國適應(yīng)汽車需求的大規(guī)模道路和停車場系統(tǒng)相比,，智能交通系統(tǒng)將更好地管理非洲的交通。

????目前,，非洲已經(jīng)在一個關(guān)鍵的基礎(chǔ)設(shè)施領(lǐng)域取得了快速發(fā)展,，這就是通訊業(yè)。

????代表全球通訊業(yè)利益的全球移動通信系統(tǒng)協(xié)會（Groupe Speciale Mobile Association (GSMA)稱,，各家無線通訊公司將在未來5年內(nèi)在撒哈拉以南非洲地區(qū)投資500億美元,。一項由GSMA和德勤公司（Deloitte）聯(lián)合開展的研究估測，在發(fā)展中國家,，移動通訊滲透率每增加10%,，其國內(nèi)生產(chǎn)總值（GDP）年增長率就可提高1.2%。移動通訊滲透率是指擁有移動通信覆蓋并直接聯(lián)接到移動通訊系統(tǒng)的人數(shù)。

????在非洲向城市生活和現(xiàn)代經(jīng)濟(jì)體系轉(zhuǎn)型的過程中,，無線通訊革命正在迎來發(fā)展的轉(zhuǎn)折點,。在各種技術(shù)中，無線通訊技術(shù)能夠跳過建設(shè)大量基礎(chǔ)設(shè)施的階段,，從而確保獲得最快的投資回報,，同時帶來提高生產(chǎn)力的最快捷途徑。蜂窩網(wǎng)絡(luò)和最終的無線寬帶無需昂貴的物理聯(lián)接就可確保通訊,、信息,、教育和金融實現(xiàn)互聯(lián)。

????The urbanization of Africa offers great hope for hundreds of millions of people -- if the infrastructure can keep up. And technology holds huge promise to make building that infrastructure faster and more efficient.

????The 955 million people in Africa -- the world's second most populous continent after Asia -- are urbanizing more rapidly than residents of any other region. While more than half Africa's population lives below the poverty line, an estimated 35% have entered the middle class according to University of Texas Professor Vijay Mahajan, author of the book, Africa Rising.

????Today there are 37 cities on the African continent with more than one million people. An estimated 41% of the people in Africa live in cities and, by 2020 more than half will, according to estimates done for the United Nations. Those people are moving to the continent's cities because they expect more security and better opportunities than they have in rural villages and farms. But often they find that cities aren't prepared to provide basic needs like clean water and fuel for cooking.

????Establishing an infrastructure that will allow newly arrived settlers to thrive and become more productive is a key responsibility for the leaders of those cities and nations.

????While infrastructure in most African cities is adversely inadequate, public and private sector leaders have an opportunity to build basic water systems, electricity grids and traffic control systems that will be much more efficient and less energy intensive than the aged infrastructure in developed parts of the world. Technology such as electronic sensors and controls would permit variable pricing for power and finely-tuned measures of water consumption. Smart transit systems could manage traffic far more efficiently than the massive road and parking-lot systems required by vehicles in the U.S., for example.

????And Africa is already moving rapidly in one key infrastructure area: communications.

????Groupe Speciale Mobile Association (GSMA) -- which represents the interests of the global communication industry -- says wireless companies will invest $50 billion in sub-Saharan Africa over the next five years. A GSMA and Deloitte study estimates that an increase of 10% in mobile penetration -- the number of people who have mobile coverage and are directly connected to the mobile system -- can increase the annual GDP growth rate up to 1.2% in a developing country.

????The wireless communications revolution is coming at a turning point in Africa's transition to urban life and a modern economic system. By bypassing the need to build extensive physical infrastructure, wireless telecommunications promise the fastest payback and quickest route to improved productivity of any technology. Cellular networks and eventually wireless broadband promise communications, information, education and finance connectivity that bypass costly physical connections.