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  • Reconstruction of UWB Indoor Radio Wave Propagation
02 Nov 09

Faculty Profile - Gregory David Durgin

Who wrote the book, Space-Time Wireless Channels
I only understood the basis of MIMO communication after reading this great book!!!

www.ece.gatech.edu/...publications.php - Preview

channel-modeling mimo wireless persons favorites

  • Gregory David Durgin





    Associate Professor

    Electromagnetics
28 Oct 09

Moon (2009)

To work lonely on the moon for 3 yrs is a very terrible job. Sam accepted it however found he is cloned by the company signed contract with him. The clone was isolated with his family and treated as machine. When 3 yr's contact is over, the clones are not sent back to earth as promised but killed as rubbish.

All these are for the energy problem on earth. So some one must be there working on the moon but nobody is willing to. However, clone seems to be a clever way to solve this problem. But is clone a human?

Not sure the second clone which tried to get back to earth on the cargo ship could be successful or not.

It is a very good low cost scientifiction movie.

www.imdb.com/tt1182345 - Preview

moon energy future humanity movies scientifiction clone

24 Oct 09

南方周末 - 我接受了《纽约客》的核查

  • 我在接听《纽约客》核查电话时,仿佛置身一个古老仪式
23 Oct 09

中国“反坝”运动中的媒体的力量_网易新闻中心

  • 中国“反坝”运动中的媒体的力量


    2009-10-22 10:45:00 来源: 科学新闻(北京) 跟贴 37 手机看新闻

    “世界上并没有哪个组织是真正反坝的,要么他们是因为想要保持纯原生态,要么是因为他们的某个在意的利益点被影响,才会导致他们表现出来对于大坝的反对。”一位对反坝有研究的水利水电专家对《科学新闻》解释。

20 Oct 09

WiMedia Alliance - Wikipedia, the free encyclopedia

Standardization of Ultra-bandwidth Communication
UWB本来将通过IEEE802.15 WG进行其标准化工作,各方在IEEE通过PAR,即15.3a TG的成立许可。但究竟是使用Multi-Band OFDM还是DS UWB让各参与者渐行渐远。

一方是Multi-Band OFDM的支持者,组成了WiMedia[http://www.wimedia.org/]联盟,将近乎完整的规范已提案
[http://www.wimedia.org/imwp/idms/popups /pop_download.asp?ContentID=6516]的形式投给了IEEE802.15.3a。WiMedia的主要支持者是TI、 Intel这样的老牌芯片厂商,同时也有很多初创的小企业。

另一方则是DS UWB的支持者,组成了UWB Forum,开始与WiMedia竞争。主要players是Motorola,Freescale。Freescale也是有备而来,准备使用其的 110Mbit/s技术,以推广其XS110芯片组。其实很多学术界的人都是支持直序或脉冲方式的高速通信的,UFL的Dongliang Duan的老板就是做脉冲的。个人分析,因为大家觉得最初的无线通信方式(马可尼的电报系统)就是脉冲方式的,在使用波形调制这么多年后,从哲学的角度来说,技术是该进行一次轮回的。当然,脉冲方式是有很多实质性好处的,应该较MB-OFDM简单,使得成本更低。代价是,在这个满是波形调制的现有社会中,要使用脉冲而不让干扰波及到现有系统,是很困难的。

在IEEE Member Voting中,双方势均力敌,不可开交。于是双方决定放弃在IEEE的标准化路程,通过走向市场的de facto事实标准来竞争,让用户来决定谁是赢家。另一方面,缺少一致也被认为是技术和市场均还未成熟,进行标准化尚早,也支持了15.3a的流产。

按传闻[http://www.handheld.eet-china.com /ART_8800414008_4000001_NT_4072ae1d.HTM],2006年4月,Freescale计划退出UWB Forum,主要厌倦了游说工作,认为太多肮脏政治超过了技术本身。Motorola是Freescale的兄长,自然也是保持一致地推出了。这样,UWB Forum元气大伤,只剩Pulse-Link高举大旗死扛。按照Wikipedia的描述,如今的UWB Forum已名存实亡。不过有趣的是当年MultiBand OFDM Alliance Special Interest Group (MBOA-SIG)的域名[multibandofdm.org]也已易主。

WiMedia则一番风顺,其输出标准于2005年被ECMA(欧洲计算机制造商协会)采纳为规范,ECMA-368[http://www.ecma- international.org/publications/standards/Ecma-368.htm]和ECMA-369[http: //www.ecma-international.org/publications/standards/Ecma-369.htm]。

ETSI(欧洲通信标准学会)采纳了ECMA的规范。

2007年ISO(国际标准组织)也采纳了ECMA的规范,作为ISO/IEC 26907:2007和ISO/IEC 26908:2007[http://standards.iso.org/ittf/PubliclyAvailableStandards /index.html]。

2009 年1月,WiMedia宣称中国信产部已批准MB-OFDM在中国的使用并准许其使用频谱。不过中国未必安心使用国外标准,众多国内芯片企业虎视眈眈。至少在DVB领域,中国就算是抄,也得抄出个自己的标准来。不过在DVB时代,中国是采纳了南北两套技术的。实验室邻座的小弟在徒手研究UWB信道建模,老板也开始过问起UWB标准,不知道是否是UWB中国大雨前的乌云。

WiMedia的思路倒是很先进的,同IEEE802.16的 Service-Specific Convergent Sub-Layer一样,WiMedia在上层支持多种payload的承载,自身以负责PHY传输技术为主,这样厂商甚至可以在WiMedia上架设私有的MAC协议。WiMedia的2008版也将Interference Avoidance纳入其设计考虑,这样在世界各地频谱使用不同的情况下推广要容易得多。

这些相似的重要战略步伐当然还是因为他们背后是同一批 Sophisticated 的棋手。

我们这帮做无线的就等着啥时候自己在家看电视时只用接电源线就了事,忽略信号线的时代了!

en.wikipedia.org/...WiMedia_Alliance - Preview

standards wireless UWB industry OFDM

  • Multi-band Orthogonal Frequency Division Multiplexing (MB-OFDM)

ath9k - Linux Wireless

  • FOSS wireless driver for all Atheros IEEE 802.11n PCI/PCI-Express and AHB WLAN based chipsets
27 Sep 09

Melting memory chips in mass production: Scientific American

  • required high currents and temperatures to crystallize
  • making flash and similar memories less stable at very tiny scales
25 Sep 09

17 Again (2009)

Don't lose your second chance.

www.imdb.com/tt0974661 - Preview

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20 Sep 09

Technology Review: A New Language for Phone Networks

  • A New Language for Phone Networks

    Researchers develop a better way to write applications for peer-to peer cellular networks.
19 Sep 09

Technology Review: Can You Trust Crowd Wisdom?

  • "If you have two or three people voting 500 times," says Kostakos, the results may not be representative of the community overall. He suspects this may be why ratings often tend toward extremes.
  • allowing users to vote on the helpfulness of other users' reviews.
  • 3 more annotations...
14 Sep 09

IEEE - ADMINISTRATION and Branch Officers Duties

  • Annual Plan,
    IEEE Headquarters provides
    an incentive allotment of US$100.00 (if
    your Branch has more than 50
    members or (US$50.00 if your Branch has
    less than 49 members).
  • The Annual
    Report
    is due at IEEE Student
    Services 1
    May.



    Once again, to encourage you
    to fill this out, the IEEE provides an
    incentive rebate of US$2.00 per student
    member at your Branch (based
    on your membership on Dec. 31 of the
    previous year).

  • 1 more annotations...

Flatland (2007) (V)

  • "Flatland: A Romance of Many Dimensions" was originally an 1884 novella by the theologian and mathematician Edwin A. Abbott. It is popular among mathematics and computer science students, and considered useful reading for people studying topics such as the concept of other dimensions.
  • "Flatland: A Romance of Many Dimensions" was originally an 1884 novella by the theologian and mathematician Edwin A. Abbott. It is popular among mathematics and computer science students, and considered useful reading for people studying topics such as the concept of other dimensions.
  • 1 more annotations...
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