[主题活动] 【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】 1-23 [复制链接]

草木也知愁
UID: 2487572

永久会员

Rank: 16

声望: 3963
寄托币: 23288
注册时间: 2008-1-2
精华: 50
帖子: 2141

电梯直达

楼主

发表于 2009-9-8 00:56:20 |只看该作者 |倒序浏览

【CASK EFFECT】0910G阅读能力基础自测（速度、难度、深度、越障、真题、RAM）
https://bbs.gter.net/forum.php?mod=viewthread&tid=910464&highlight

【CASK EFFECT】0910F阅读全方位锻炼--越障【SCI】汇总贴
https://bbs.gter.net/thread-982020-1-1.html

规则：
我每天贴出1000字左右的一篇文字
没有别的要求，只要大家坚持读完就可以
如果你能坚持一个月，你会发现自己的阅读进化了~

[注]
1、直接在电脑屏幕面前做，虽然GRE阅读是在纸上考，但是这个过程会遏制你做笔记，同时给你的阅读造成视觉障碍，也就是把难度训练和抗干扰训练同步结合，增加效率（初期会很累，但是既然大家想要成为高手，那么就别对自己太温柔）

Radio for Responders

As multiband radio for public safety proceeds, digital spectrum for it still lags
BY LARRY GREENEMEIER

One lesson in the 9/11 attacks eight years ago was the importance of police officers, firefighters and other first responders being able to communicate with one another. Many died because they did not get the call to evacuate from the World Trade Center towers that were about to collapse. To tackle this problem, the U.S. Department of Homeland Security will begin a pilot program this month to test multiband radios designed to let responders communicate across a number of different radio frequencies. Meanwhile a long-touted nationwide public safety broadband network, made possible by the freeing of broadcast spectrum in the country’s switch to digital television this past June, continues to stagnate.

The radios of public safety agencies currently operate on separate, discrete frequencies, making it impossible for a firefighter, for example, to communicate with a police officer. “There’s no single band with enough room for all of the public responders,” says David Boyd, director of command, control and interoperability in the Homeland Security’s Science and Technology Directorate. As a result, public safety agencies have been forced to spread their signals throughout the four different frequency bands available to them—namely, at megahertz frequencies of 150, 400, 700 and 800.

Several manufacturers are developing multiband radios, but currently only a version made by Thales Communications in Clarksburg, Md., meets criteria set by Homeland Security—that is, the device is roughly the same size and weight as the radios that police and other responders carry today, and it costs no more than $5,000, similar to the high-end single-band radios now on the market, Boyd says. (They must also work with an auxiliary power pack that can be charged by a battery.)

This summer the security personnel of several organizations—including Amtrak along its Northeast Corridor, the Metro Area Transit Authority in Washington, D.C., the 2010 U.S. Olympic Security Planning Committee and 11 others—began using the Thales radio as part of Homeland Security’s program. Each agency will evaluate the radio in the field through pilot tests lasting at least 30 days, with the government publishing the results early next year, Boyd says. This test is actually the last of a three-phase program to determine the radio’s viability; it already passed a lab test and a nonemergency demonstration on May 2 at the Kentucky Derby.

Although the radio voice-communication part of the public safety efforts is proceeding, first responders will not have an emergency broadband data network anytime soon. The 700-megahertz band (actually covering 698 to 806 megahertz), freed up from the switch to digital TV, has space designated by the Federal Communications Commission for data. Called the D block, it will be used for a national wireless public safety broadband network to enable local, state and federal emergency responders to send text messages and large amounts of data, such as digital images and streaming video. “Public safety doesn’t currently have this broadband ability,” Boyd remarks.

But the move to make use of the D block has hit some snags. Because establishing a nationwide network on it would be costly, the government wants a public-private partnership to develop the block. The proposed wireless broadband network would be built and used by both public-sector emergency responders and private-sector businesses, which would also be able to license part of the network for commercial purposes.

Although the FCC succeeded in selling the right to use the old television spectrum in an auction last year (it raked in $20 billion, twice as much as it expected), it ultimately refused to sell a D block license because it had not been offered enough money by any of D block’s suitors, Boyd says. Harlin McEwen, chair of the Public Safety Spectrum Trust (PSST) Corporation—formed in 2007 by the FCC to work with industry to develop the national wireless public safety broadband network—gave a more pointed reason: the companies bidding for the space wanted priority access to the D block space over first responders, even in times of emergency.

Without a proper suitor and with a new FCC chair, Julius Genachowski, confi rmed only in late June, McEwen says the FCC has delayed bidding for the D block indefi nitely. He plans to meet with Genachowski to discuss the agency officials’ options for the D block. “They can schedule another D block auction with the rule that the winner has to work with the PSST,” McEwen says. “Or they can auction the block without restriction, which they are unlikely to do.”

Although broadband data access is important during emergencies, some experts do not think that the delays in its implementation will seriously undermine public safety. Voice communication will continue to be the most important lifeline among responders, Boyd states, which is why the Homeland Security’s upcoming multiband pilot program is so important. “Data are not going to replace voice as the fundamental emergency communication, because voice is interactive in a way that text will never be,” he notes as an example. “In environments where you have to use your eyes and hands for other things, you have to be able to talk.”