h*********r
发帖数: 10182 | 1 Corrosion[edit]
Whether ethanol causes unacceptable levels of corrosion in internal
combustion engines has been a cause of some debate.[52][53] In general, E10
blends (see above section) pose no problems.[54] At higher blends, ethanol's
different chemistry from oil derivates makes it corrosive for certain
engine parts. These are replaced to create the flex-fuel vehicles that
accept up to E85.[55]
Fuel economy[edit]
Ethanol contains approx. 34% less energy per unit volume than gasoline, and
there... 阅读全帖 |
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h**l
发帖数: 4883 | 2 Yeah. Only done it in manikins, never on humans. hehe. I lack of practical
experience.
But I read compression is way more important than giving breaths. So at
least you can try compression on pets if mouth-to-mouth breathing is not
acceptable. Or you can get a barrier device like face shield or mask.
Sometimes you can even try napkins.
Pets |
|
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z*****n
发帖数: 7639 | 4 Do you mean GPRS or EDGE? GPRS gives maximum raw bit rate
around 171kbps with all time-slots allocated to you, but
this never happens because the operator usually sets MAX=4.
I had been using it for almost 5 years, sucked.
In most time it gave me only 20-30kbps bandwidth.
EDGE, as far as I know, is not deployed in most GSM networks.
COMPRESSION doesn't work for .zip and those already compress
video/audio/picture files, most of downloads are unfortunately of this type. |
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z**r
发帖数: 17771 | 5 EDGE. ppl don't intend to use cellular network to download right? so they
most likely just surf the internet, access emails... these content can get
very good compression ratio.
btw, the compression part usually is done with bytemobile stuff, a
reinvented squid.
type. |
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c***r
发帖数: 4631 | 6 转一个国内的OS X Mavericks评测，看着写得还不错，难得。
原帖地址：
http://macshuo.com/?p=845
http://macshuo.com/?p=833
http://macshuo.com/?p=812
品评 OS X Mavericks ——唯快不破（下）
性能：唯快不破
一个操作系统除了功能性和安全性之外，考虑最多的就是训疾如风的响应速度和持久的
续航能力，这次 Mavericks 的升级使用了多种技术保证了 OS X 的快和节能。
（一）Kernel
OS X 的内核基于 FreeBSD和 Mash3.0构建，可以通过32位或64位内核启动系统，并充
分发挥32位或64位应用程序的运行效能。在64位内核的情况下，Mavericks 经测试可以
最大支持 128G 的物理内存，这特么就是个服务器版本啊。
（二）Compressed Memory（内存压缩）
内存压缩技术是 Mavericks 新增加的底层技术，这货彻底提升了整个系统的使用容量
和响应速度，也就是说你可以开启几十个应用程序，在联动内存超过80%，物理内存使
用几乎达到100%的时候，... 阅读全帖 |
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c**********t
发帖数: 99 | 7 CS research focuses on two areas: 1) the nature of computer itself (compiler/O
S/architecture/language...) 2) the object which the computer deals with,the op
erations over the object (image processing/graphics/data compression/cryptogra
hy/networking ....).
The object which the computer deals with is data or information. How to repres
ent data in different info domains is the research in the following areas: gra
phics, image processing, speech, data compression, crypto, HCI. How to communi
cate |
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R********n
发帖数: 519 | 8 coding theory, or compressive sensing确实EE和CS都在做，不过我更偏向是EE这边。
这里coding theory我主要说的是纠错码，代数几何编码等等。CS编码不太了解，主要
是?
至于compressive sensing,最早的Donoho是statistics；Tao is pure math guy,Cand
ès is Applied Math&Statistics, Romberg 是唯一的工科背景，EE背景。并且关键性
paper都是在TIT，SP or Annals of Stat.上，应用上目前最活跃的就是Rice的ECE
这怎么能算是CS领域，只是插上去做一下罢了 |
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R********n
发帖数: 519 | 9 再补充下，CS做coding的人工作看得很少，不好说。STOC等上面自然有coding的paper
，但就很理论吗？EE的coding发到TIT上面的很多，有不少很好的工作，还有些的发到
代数方面的数学journal，这些才能说是更理论的
但可以目前CS做compressive sensing的暂时没有做出很有意义的工作，当然跟风挖坑
还是少不了的。因为自己就在CS，希望这边能有更多基于深入了解了compressive
sensing，or sparse representation之后，用到CS这边的工作出现
google |
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i****a
发帖数: 36252 | 10 If you are using pre SQL 2008, you can look into Quest Litespeed logshipping
, it compresses the log file. if you have SQL 2008, then enable compression.
how big is the database? if it's smaller than the log file then do a backup
and restore as suggested.
and finally, what is the business requirement? with limited bandwidth, can you do
replication, and do rebuild index on the off-site server seperatly? |
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g***l
发帖数: 18555 | 11 总结一下SQL SERVER的DISASTER RECOVERY PLAN吧，不管你是DBA还是DEVELOPER,公司
大小，如果DB CRASH不能恢复，说明你的RECOVERY PLAN就是不WORK的，平时的功夫都
白搭了，DBA需要被FIRE掉
创建DB的时候就要考虑，三年内变多大，能不能BACKUP，月的星期的，或者每天的。
FULL BACKUP DIFFERIETIAL TRANSACTION LOG配合使用FOR OLTP，这个书里经常讲了
如果数据量大，考虑用FILEGROUP,常更新的数据放在一个GROUP里，经常BACKUP一下，
不常更新的放到一个GROUP里，不常BACKUP
临时TABLE放到一个GROUP里，不BACKUP
如果空间有限制，考虑BACKUP COMPRESSION,2008企业版自带COMPRESSION，否则考虑购
买第三方产品
不要忘了JOB先BACKUP然后再DELETE OLD BACKUP，所以至少要有两个BACKUP的空间。
PLAN是需要TEST的，随便PICK一天,RESTORE一个BACKUP，看看WORK不WORK，有... 阅读全帖 |
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l******t
发帖数: 660 | 12 【 以下文字转载自 JobHunting 讨论区 】
发信人: dongfeiwww (人人都是艺术家), 信区: JobHunting
标 题: hadoop面试和学习总结
发信站: BBS 未名空间站 (Thu Mar 1 04:05:10 2012, 美东)
随着大数据的盛行，Hadoop也流行起来。我面过很多hadoop相关的公司，包括一线公司
(hadoop就是公司主要产品)如cloudera, hortonworks, mapr, teradata, greenplum,
二线的（使用hadoop)：apple, expedia，comScore. 当然还有很多公司facebook,
twitter, baidu, 感觉这块还是机会挺多的，我就把我知道的一些给大家分享一下。
书籍和paper
: 里面内容非常好，既有高屋建瓴，又有微观把握，
比如mapreduce各个子阶段，经常问道join在里面也有代码实现，
google的三量马车，GFS, MapReduce, BigTable
入门：
知道MapRedu... 阅读全帖 |
|
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g*********n
发帖数: 43 | 14 Good point. The subquery
select age,hobby_id, count(*) ct
from Users
group by 1,2;
can compress table Users into a, then we join "a" and "hobbies".
This indeed helps. But the thing is, even after the compression, table a
still has 25k rows:), and the join is still 25k * 200 = 5 million rows. |
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z**r
发帖数: 17771 | 15 Sprint也是用的的cdma，美国两家大公司用，verizon和sprint。大约都是从2000年左右
开始做proof concept，2002年左右开始roll out。不过这两家公司特点不同，Verizon一
般是一个市场一个市场的上，一般可以看到某个新技术在某个市场出现了，但是别的地方
还不行。Sprint一动就是全美国都上。
刚开始的时候，大家都是1xrtt，峰值大约140-150的样子，平均速度可以到70kbps左右，
当时sprint的air card用户比较占便宜，因为sprint在distribution site放了
compression，东西跟现在大家谈论的application switch类似，可以优化tcp，对一些协
议进行压缩，实际速度可以达到200-400kbps。verizon决定率先上evdo，sprint最初想
bypass evdo，直接上evdv，但是看到自己的1xrtt+compression不能完全跟evdo竞争，其
实俺觉得这个在air card上似乎区别不是特别大，主要是手机上的很多多媒体应用没办法
上，sprint后来也决定上ev |
|
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a***e
发帖数: 27968 | 17 那个啥memory compression狂吃CPU
网上各种解决方案，尼玛啥奇葩都有
俺这个似乎和两个因素有关，开始是update，瞎整一下好了一阵子
现在发现打开pagefile丫就消停了
看上去像内存调度没了swap就不小心进入倒腾的死循环了？尼玛俺还80%内存free你
compress个鸟蛋，这飞翔的内存管理
尼玛俺16GB的上网机需要屁虚拟内存
再说虚拟内存对SSD怎么看着不靠谱的样子
同修们推荐一个可以放pagefile的ramdrive？
★ 发自iPhone App: ChineseWeb 11 |
|
发帖数: 1 | 18 谁叫自己上了嵌入式的贼船，工资低呢。。。C看多了，也不能刷题转码搞互联网
为什么摄像头领域不能有像开源openwrt一样的项目呢？
把海康的dmesg贴出来，大家可以参考，他们用安霸S3L，https://www.ambarella.com/
products/security-ip-cameras/security-ip-camera-products#S3L
[ 0.000000] Booting Linux on physical CPU 0x0
[ 0.000000] Linux version 3.10.73+ ([email protected]) (gcc version 5
.2.1 20151005 (Linaro GCC 5.2-2015.11-2) ) #1 PREEMPT Mon Jan 23 10:38:22
CST 2017
[ 0.000000] CPU: ARMv7 Processor [414fc091] revision 1 (ARMv7), cr=
10c53c7d
[ 0.000000] CPU: PIPT / ... 阅读全帖 |
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F***Q
发帖数: 6599 | 19
so, you are not "processing" 2 million emails, really, you just want to
process new incoming emails to an Inbox with 2 mil existing emails.
in that case, all you need to do is to create a new folder, move most of the
existing emails to the folder, and the compress. after that, your default
inbox will be responsive again.
also, delete junks and compress regularly, I doubt all your emails are worth
keeping. |
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m*****z
发帖数: 2 | 20 uncheck software compression
将辅助DNS设为207.197.0.10
uncheck IP header compression
Everything will be working as before then. |
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p***e
发帖数: 29053 | 21 老师这样和我说：
double click on the program after you install “JAVA Virtual Machine”。
文件是xxx.jar
我装了JAVA Virtual Machine 但是还是不能运行那个文件。
后来一个同学和我说：
You just double click the NetEdit23.jar. If it does not work, you need to
some work.
This file is a compressed file. So if it is associated to some compress
programs such as Winrar,
you need to modify it.
1. Right click the NetEdit23.jar
2. Click the property
3. Click the change in General Tap
4. Select javaw
但是尽管装了JAVA Virtual Machine，但是没有那个选项啊，好像没有装过那样
开始 |
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m******t
发帖数: 2416 | 22
You guys... this isn't even about writing into a compressed file -
who says there is a compressed file to begin with? What if the class
is loaded from a URL? What if the class is loaded from a jar that
is loaded from a URL? |
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S*******h
发帖数: 7021 | 23 之前有网友推荐这些. 我还没去仔细看过 你参考看看吧 有用的话上来吱一声
---------
发信人: dongfeiwww (人人都是艺术家), 信区: JobHunting
标 题: hadoop面试和学习总结
发信站: BBS 未名空间站 (Thu Mar 1 04:05:10 2012, 美东)
随著大数据的盛行，Hadoop也流行起来。我面过很多hadoop相关的公司，包括一线公司
(hadoop就是公司主要产品)如cloudera, hortonworks, mapr, teradata, greenplum,
二线的（使用hadoop)：apple, expedia，comScore. 当然还有很多公司facebook,
twitter, baidu, 感觉这块还是机会挺多的，我就把我知道的一些给大家分享一下。
书籍和paper
: 里面内容非常好，既有高屋建瓴，又有微观把握，
比如mapreduce各个子阶段，经常问道join在里面也有代码实现，
google的三量马车，GFS, MapReduce, B... 阅读全帖 |
|
h***z
发帖数: 233 | 24 Why do you want to write ascii file as binary file? If it's for space
savings, easiest way is to just compress it using a standard compression
format that you have libraries for in all 3 languages. |
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a****s
发帖数: 524 | 25 I hope you know what you are talking about.
As far as I know:
a coding is more redundant when it has low entropy, therefore eliminating
part of them does not lose as much information as does a coding with high
entropy.
Chinese has higher entropy, therefore it is harder to compress. But, hell,
that also means it is already well compressed.
has
it
ambiguities.
is |
|
r*****3
发帖数: 143 | 26 中文名: Python标准库示例
原名: Python Standard Library by Example
作者: Doug Hellmann
图书分类: 软件
资源格式: PDF
版本: 英文文字版/更新EPUB版本
出版社: Addison-Wesley Professional
书号: 9780321767349
发行时间: 2011年
地区: 美国
语言: 英文
简介:
内容介绍：
You’ll find practical code for working with text, data types, algorithms,
math, file systems, networking, the Internet, XML, email, cryptography,
concurrency, runtime and language services, and much more. Each section
fully covers one module, and links to valuable additional resources, making
this bo... 阅读全帖 |
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w***g
发帖数: 5958 | 27 我听过类似的是random projection.
就是把高维通过随机线性变换降维(相对的,PCA是优化出来的一组基),
能大致保持距离.
关于nearest neighbor的结论是, 一般而言, 随着维度升高
r/R -> 1
r: nearest neighbor distance
R: fartherst neighbor distance
这个可以解释为什么有人找老公/买房子越来越下不了决心.
因为看到的维度越来越多, 就会发现其实并没有特别好的.
或者说, 一般来说, 在极高维做nearest neighbor search没有意义.
实际数据表观维度很高, 但是维度之间有相关性, 所以往往
内蕴的维度并不是太高.
所以你说的compressed sensing的重要性应该是"一定的统计条件"是
什么. 我没学过compressed sensing, 完全根据你的贴子猜的.
(网站已经起来了) |
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f**a
发帖数: 330 | 28 in winrar, select the "store" (not very sure) compression method, and
specify the volume size. winrar just cuts the file into several pieces
without compression. |
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L********r
发帖数: 59 | 29 Job description:
Senior Software Engineer, who is a self motivated team player, will work on
next generation video/audio encoding and multiplexing platform. This senior
level position will be responsible for adding features to our existing
software architecture. He will involve working with the HW teams in support
of new custom board designs and adding application level device driver
support. The successful candidate must have good communication and
documentation skills, a willingness to learn a... 阅读全帖 |
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r****t
发帖数: 10904 | 30 1) can be achieved by \usepackage[sort&compressed]{natbib}
^^^ should be sort&compress
But you probably need to run "latex makebst" to get a good format.
2) if using natbib, then \citep{xxx} will give you that. |
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m*****e
发帖数: 126 | 31 I have some experimental data which is in binary format. The size
of the files is about 10M each. When I rewrite them into ascii,
the size is about 36M. When I compress the ascii file by bzip2,
it takes very long time to run and finally generate a file just
1.5M. Is that possible? Does bzip2 have any special algorithm
to do the compression? |
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s****e
发帖数: 68 | 32 i dl some paper from online with *.ps.gz format.
i thought they are compressed files and tried to use
gzip or gnuzip to decompress but always comes out like
" they are not in gzip format"
then later i found they are simply postscript files or
some "compressed ps files" and can be viewed directly
by ghostview.
anyone knows why or what is it? thanks. |
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s****e
发帖数: 68 | 33 however, i use IE...
i still think there is some kind of "Compressed Postcript"
which may be viewed directly by ghostview, maybe because
ghostview has build-in decompressor. maybe i am wrong.
i think they are compressed by something else but not
regular pkzip, gzip, gnuzip... |
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I**A
发帖数: 96 | 34 I have a huge directory.
I want to archive it.
I used tar:
tar -cvf Myproject.tar Myproject
then used gzip:
gzip Myproject.tar
to generate .gz file.
But, the intermediate myproject.tar is too big, like 400GB.
I want to know how I can compress the directory directly.
Because the file is very huge, I doubt if tar pipe gzip works.
I saw there is tar -z can compress directly when we tar it. But my ksh does
not have this -z option. |
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B*******e
发帖数: 3882 | 35 I guest is ia virus or trojan. Search ur computer for this ntfs.exe
Windows 2000 or windows xp does not have ntfs.exe.
some info that may be related:
Trojan.Win32.Filecoder
Filecoder is a trojan program that renames and encrypts files into subdirect
ories of local and network drives. It is written in Delphi and compressed by
the UPX utility. The compressed size is 137 KB; the uncompressed size is 35
3 KB.
This virus program is sent via e-mail, proclaiming itself to be "a very usef
ul tool".
Inst |
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c******x
发帖数: 438 | 36 1. A New Constitutive Model for the Compressibility of Elastomers at Finite
Deformations
Jeffrey E. Bischoff, Ellen M. Arruda, and Karl Grosh
Rubber Chem. Technol. 74, 541 (2001)
2. The mechanical properties of poly(ether-ether-ketone) (PEEK) with
emphasis on the large compressive strain response
P.J. Raea, , , E.N. Browna and E.B. Orlerb
Polymer, Volume 48, Issue 2, 12 January 2007, Pages 598-615
3. The strain-rate and temperature dependence of the mechanical properties
of polyetherketone and p... 阅读全帖 |
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R**********n
发帖数: 1109 | 37 Dear Friends:
Sorry I can not input Chinese from this computer. My boss gave me half of a
day to do some research and tell him what is the difference between column
and wall (I think he meant shear wall, not retaining wall). He ask me to
research it from structural engineering view instead of geometrical view.
What come to my mind is: column mainly support axial compression force and
governed by compression; shear wall mainly support lateral force and
governed by shear.
Could you give me some su |
|
b****e
发帖数: 4 | 38
has
Yes, image compression is a big part of image communications.
The scope of image communication usually covers:
Entropy Coding
Quantization
Transform Coding
Rate Control Techniques
Filter Banks and Wavelets
Scalable Compression
Standards: JBIG, JPEG, JPEG-2000
Motion-compensated coding,
MPEG standards
Digital video broadcasting
Internet video streaming |
|
l*****n
发帖数: 239 | 39 本人是一个很一般的学校数学系的在读PhD,第四年了但是由于和之间老板出了些问题,
所以有了转学的打算.目前在做Compressed sensing,老板是牛人但是毕竟是做数学的,
只对理论方面感兴趣.所以我做的也很理论.
想转到好学校的EE,接着做Compressed sensing或者DSP(rocessing)这些比较偏数学的
方向.
我觉得我的优势可能是数学背景比较好,毕竟数学系的qual都混过来了.劣势也很明显,
没有任何EE的基础,所以可能比较指望现在老板的推荐信.
转学的想法也是最近才有,不知道EE方面的情况.请问版里的XDJM有什么建议没有?数学
转EE可行性吗? |
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t***o
发帖数: 4 | 40 master期间的研究方向主要是signal and image processing及其在imaging system中
的应用，submit过一篇paper是关于基于compressive sensing的confocal microscopy.
目前考虑的申请方向有：
1. 和compressive sensing的应用相关的方向（我不想做纯理论的)
rice这个做的挺多的，不晓得还有哪些group？这个和我的背景最match
2. biomedical imaging
对这个领域的唯一了解就是confocal microscopy
3. computer vision
本科时在一个做face recognition的组作毕设时接触过而已
不晓得以上三个方向哪个比较好?
另外,我这样的背景还有什么方向可以试一试吗? |
|
