由买买提看人间百态

topics

全部话题 - 话题: sigma
1 2 3 4 5 6 7 8 9 10 下页 末页 (共10页)
s**********8
发帖数: 25265
1
来自主题: MedicalDevice版 - six sigma
Six Sigma
From Wikipedia, the free encyclopediaJump to: navigation, search
Not to be confused with Sigma 6.
The often-used Six Sigma symbol.Part of a series of articles on
Industry
Manufacturing methods
Batch production • Job production
Continuous production
Improvement methods
LM • TPM • QRM • VDM
TOC • Six Sigma • RCM
Information & communication
ISA-88 • ISA-95 • ERP
SAP • IEC 62264 • B2MML
Process control
PLC • DCS
Six Sigma is... 阅读全帖
p***e
发帖数: 29053
2
50MM镜头大比拼,CANON 50L SIGMA 50MM ART, ZEISS 50MM F2
我前段时间纠结买CANON 50 1.2好还是SIGMA 50MM 1.4 ART 好,网上看到一篇文章说
sigma光圈有点标高(就一篇说了),就犹豫了,买了50L,当天晚上对50L挺失望的,
YZB又贴了个SIGMA 50MM 1.4 ART黑科技的 deal,手一抖就买了,准备卖了50L。后来给
冠西骂醒了,第2天发信去SIGMA cancel ORDER,但是cancel 失败,结果还是寄给我了。
既然拿到,就测试测试吧,拿到的sigma镜头是sigma refurbished,但是拿到手知道这
个头是新的头。一点灰尘都没有
测试环境
SIGMA没有滤镜,其他都是hoya 滤镜,都没有调焦,小3中间点对焦
相机是5D3,室外室内。按照刘大师的建议,室外选择有前景有后景加一点逆光
机JPG直接出,FLICKR自己压缩
室外ISO 100 AV挡 (阳光有一点变化),快门有点不同,也测一下镜头在相机有点自
动下的表现
室内ISO 800 M挡保证快门光圈ISO一样
主要对比sigma... 阅读全帖
w*******y
发帖数: 60932
3
Abe's of Maine has the following Sigma lenses on sale after applying the
codes "ABES50" and "LOYALTY15" in the shopping cart. The $50 off code
appears to be valid from 7/1-7/7 but it may expire before then. Based on
posts from the previous FP deal on these lenses ($434 and $399, respectively
, at that time) there may be a several day delay in shipping them out.
Shipping is free for the standard 5-6 business day shipping option and tax
is only added for customers in NJ.
50mm f/1.4 for Canon, Niko... 阅读全帖
w****f
发帖数: 1420
4
来自主题: PhotoGear版 - Sigma 出 Art 系列的策略
今天看了看自己的镜头群和预购list,忽然明白了一个道理:
Sigma 内有高人!
就定焦而言,sigma列出1.4的list,而非1.2,显然是更针对nikon,而非canon。当然
一定会顺便出canon口。
正所谓大三元大四喜:这大四喜在G子头时代无非就是:
24/1.4G
35/1.4G
50/1.4G (或58/1.4G)
85/1.4G
当然200/2也很牛,但我们仅分析2000刀内的,F/1.4的头。
sigma打算抗衡这四个头,第一炮必须打响,给art系列铺路!否则整个计划都会大打折
扣!
那么为什么第一发瞄准35/1.4G呢? 原因很简单:要向拼过原厂,价格必须低,性能必
须高!而8514和2414已经很好了,怎么办?去拼5014?虽然5014很烂,但丫价格低啊,
所以最聪明的办法就是先出3514,用一半的价格去pk性能一般的3514G。一举成名后,
art系列立刻名震天下!成为最超值,性能最好的dslr 35mm头。
接着出5014,这个art论素质打败5014G是一点悬念都没有。但价格不见得比5014G低。
这就是sigma聪明的策略。试想第一开始出5014art... 阅读全帖
y*b
发帖数: 3190
5
http://sigma-rumors.com/2015/02/sigma-lens-rumors-possibilities
"24-70mm f/2.8 DG OS Art & 70-200mm f/2.8 DG OS Sports
Last year, Sigma’s CEO admitted that the 24-70mm f/2.8 EX and 70-200mm f/2.
8 EX had to be updated. At this stage, and given how important these zooms
are in a lens lineup, it makes little doubt that both are in development.
Canon, Tamron and even Tokina have announced/updated their own 24-70mm f/2.8
recently. Sigma should follow suit.
Mr. Yamaki also expressed how he was impres... 阅读全帖
y*b
发帖数: 3190
6
来自主题: PhotoGear版 - sigma 85ART, 24-70ART, 70-200SPort in 2016
Sigma 85mm f/1.4 Art, 24-70mm f/2.8 Art OS, 70-200mm f/2.8 OS Sport to be
Announced in 2016
"Sigma recently has announced the new Sigma 20mm f/1.4 DG HSM Art lens. The
widest f/1.4 lens in the world. According to CanonRumors, in next year 2016,
Sigma will announce at least three other prime and zoom lenses for
Photokina 2016.
These three lenses are: Sigma 85mm f/1.4 DG HSM Art Lens, Sigma 24-70mm f/2.
8 DG HSM OS Art Lens, Sigma 70-200mm f/2.8 DG HSM OS Sport lens.
The Sigma 85mm f/1.4 art lens ... 阅读全帖
b*********n
发帖数: 1258
7
USCIS AAO 已经 Rule 了
AAO Decision on EB1b about“Who’s Who in America” and Sigma Xi membership

http://www.uscis.gov/err/B3%20-%20Outstanding%20Professors%20an

With respect to “Who’s Who in America”, USCIS is more inclined to
consider it as “vanity press publications”.
On page 5, last paragraph in the bottom, it reads
“Initially, counsel asserted that the qualifying evidence being submitted
under 8 C.F.R.5 204.5(i)(3)(i)(A) included inclusion in large biographic
directories such as Who's Who in... 阅读全帖

发帖数: 1
8
来自主题: PhotoGear版 - 【2018总结】迷上Sigma Art的一年
2018第一个镜头是一个很屌丝的镜头,Yongnuo 35mm F/2. 非常轻巧的镜头。图轻松的
时候,我就会用这个镜头。优点,便宜,轻。缺点,LR不能识别,用它拍视频时间长了
,D750会出错。
2018第二个镜头是Tokina 17-35mm F/4 AT-X Pro FX Lens。优点,便宜,轻。缺点,
不够锐,不够广。用了一段时间卖了。
2018第三个镜头是Sigma 24-70mm F2.8 DG OS HSM Art Lens。调焦之后,还是比较锐
的,缺点,贵,重,要自己调焦。个人感觉,Sigma art 24-70 F2.8成像的质量明显比
Tamron 24-70 F2.8 G1要好。后者用了一段时间卖了。
2018第四个镜头是Sigma Art 50mm f/1.4 HSM DG Lens。真是锐。和领导晚上去Six
flag玩,她面对一个灯箱,F1.4,焦对在眼睛上,照片里睫毛根根清晰可见。缺点,要
自己调焦。定焦镜头调焦不难调,但是不调就不锐。
2018第五个镜头是Sigma Art 85mm f/1.4 HSM DG Lens。锐。但是用的不多,站的近了
... 阅读全帖

发帖数: 1
9
来自主题: JobHunting版 - Airbnb,Facebook, Two Sigma求建议
报几个最近的offer,因为马上要做决定了,来请教一下各位大大的意见
先列一下pkg,然后说一下我自己的见解
facebook @ Bay Area
base: 115K
bonus: 10%
signon: 75K
rsu: 160K/4years
relo: 25K
我让fb compete,hr像上级尝试了一次失败,现在在尝试第二次,我是不抱希望。
airbnb @ seattle
base: 125K
signon: 20K
rsu: 2000 shares(210K)/4years
relo: 11K
two sigma @ nyc
base: 140K
bonus: 60K
signon: 45K
relo: 15K
我是new grad,所以希望各位前辈给出意见的时候还是从new grad提升能力及未来发展
空间方面入手~
facebook和airbnb都是进去以后再分组,two sigma是去enterprise下的legal&
compliance team,做internal tool的
airbnb整个面试都是按sfo来的,结果被分到seattle,被告知sfo满... 阅读全帖

发帖数: 1
10
来自主题: JobHunting版 - Airbnb,Facebook, Two Sigma求建议
报几个最近的offer,因为马上要做决定了,来请教一下各位大大的意见
先列一下pkg,然后说一下我自己的见解
facebook @ Bay Area
base: 115K
bonus: 10%
signon: 75K
rsu: 160K/4years
relo: 25K
我让fb compete,hr像上级尝试了一次失败,现在在尝试第二次,我是不抱希望。
airbnb @ seattle
base: 125K
signon: 20K
rsu: 2000 shares(210K)/4years
relo: 11K
two sigma @ nyc
base: 140K
bonus: 60K
signon: 45K
relo: 15K
我是new grad,所以希望各位前辈给出意见的时候还是从new grad提升能力及未来发展
空间方面入手~
facebook和airbnb都是进去以后再分组,two sigma是去enterprise下的legal&
compliance team,做internal tool的
airbnb整个面试都是按sfo来的,结果被分到seattle,被告知sfo满... 阅读全帖
f******x
发帖数: 201
11
最近在面试的时候,一起面试的小伙伴都会提起Two Sigma这家公司,据说base和bonus
加起来一年不得了,都是去申申看,用来negotiate硅谷的IT公司。
因为楼主现在住在西海岸,飞纽约一趟时间和精力成本很大,所以想问问这种做法的靠
谱性。
楼主的顾虑如下:
1. 听说Snapchat的package挺高的,是不是申请了Snapchat就可以不申请Two Sigma了?
2. Two Sigma的offer本身会有几个弊端。首先,听说进去了就很难出去,因为他们会
告离职的员工;其次,金融公司搞的东西本身就没什么意思;最后,如果看中IT公司的
发展潜力,发股票的package会比发钱的package更有吸引力。我想IT公司的recruiter
肯定吃定了我们不会真正去Two Sigma,所以会对基于Two Sigma的negotiation不予理
会?
3. 听说Two Sigma要找三个推荐人,但楼主并不想让导师知道楼主在干这种事。。
请问各位大大,楼主的顾虑有道理吗?是不是应该申一下Two Sigma?
谢谢!
闪电狐狸

发帖数: 1
12
来自主题: JobHunting版 - Facebook, Two Sigma Offer求比较
各位大牛好,想咨询一个offer比较的问题~现在在fb和two sigma之间纠结。
fb的package: base 115K, bonus 10%, signon 75K, rsu 160K/4years, relocation
25K
two sigma的package是:base 140K, bonus 60K, signon 45K, relocation 15K,地点
是nyc,组是做enterprise internal tool,所以和核心的trading及modeling无关。。
可以看出,现在的package FB比two sigma要低不少,已经和hr negotiate了,不过要1
月才能联系到她的manager给我答复,电话里听她的口气好像只有signon能加,rsu比较
困难,但signon极限100K, 如果rsu不能加的话,感觉package上还是match不了,不知
熟悉行情的大大能给点信息不~
如果fb的package能match或者差的不多的话,我是倾向于fb的,接下来谈谈钱以外的东
西。。
fb:
i)地处湾区,CS的归宿。IT领域下的新技术,新... 阅读全帖
G*******g
发帖数: 3729
13
新版本
The Sigma 120-300mm f/2.8 DG OS HSM Lens for Canon is a telephoto zoom lens
featuring a fast, constant f/2.8 maximum aperture. This lens is the first
lens designed under Sigma's new Sports line of lenses, making it well-suited
for fast-moving subjects such as wildlife, nature, aviation, racing, and
other similar situations.
Featuring a dust- and splash-proof construction, this lens is ideally-suited
for use in outdoor and adverse conditions. Its design features rubber focus
and zoom rings as... 阅读全帖
y*b
发帖数: 3190
14
Nikon reached a settlement for the patent infringement lawsuit against Sigma
"Nikon reports that it reached a settlement for the patent infringement
lawsuit against Sigma filed in Japan in 2011. The amount of the settlement
Nikon received from Sigma was not disclosed:
Nikon Corporation (Kazuo Ushida, President, Tokyo, hereafter referred to as
“Nikon”) announces that it reached a judicial settlement as of April 21,
2015 with regard to the patent infringement lawsuit (hereafter referred to
as “Law... 阅读全帖
z****e
发帖数: 2024
15
来自主题: Mathematics版 - 请教:algebra VS. sigma algebra
多谢。
赞。
“If "a" is the algebra generated by "C", then the sigma algebra generated by "a" and by "C" are the same.”
一看就是行家。
我理解了,如果用你说的 sigma-algebra contains algebra (both of them 阿are generated by the same "C"), 我就能理解你上面这句话了。因为可以证明
sigma-algebra generated by "C"=sc;
sigma-algebra generated by "a"=sa;
sc, sa 相互 contain. 对吧?
但是我没有理解,为什么 sigma-algebra generated by "C" is larger than the algebra generated by "C"?
按照定义,我怎么觉得 sigma-algebra 是一种带有那个可数集限制条件的,一种特殊的 algebra 呢?
问题1:
我觉得怎么 algebra 比 sigma-al
h****e
发帖数: 2125
16
高亢过的好惨:“
Two Sigma’s most prominent criminal case against an employee involves
Chinese national Kang Gao, a then 28-year-old researcher who gave notice to
the hedge fund in 2014. Gao had worked at Two Sigma since 2010, after
graduating from MIT with degrees in physics and engineering.
In early 2014, when Gao was preparing to leave, Two Sigma claims, he e-
mailed himself some of the firm’s trading models. After exploring his
options, he ultimately accepted a position at Citadel but agreed not to
... 阅读全帖
h****e
发帖数: 2125
17
高亢过的好惨:“
Two Sigma’s most prominent criminal case against an employee involves
Chinese national Kang Gao, a then 28-year-old researcher who gave notice to
the hedge fund in 2014. Gao had worked at Two Sigma since 2010, after
graduating from MIT with degrees in physics and engineering.
In early 2014, when Gao was preparing to leave, Two Sigma claims, he e-
mailed himself some of the firm’s trading models. After exploring his
options, he ultimately accepted a position at Citadel but agreed not to
... 阅读全帖
z*****a
发帖数: 3809
18
来自主题: JobHunting版 - Two Sigma新鲜CS master 20万 (转载)
【 以下文字转载自 Quant 讨论区 】
发信人: swordmans (风云第一刀), 信区: Quant
标 题: Two Sigma新鲜CS master 20万
发信站: BBS 未名空间站 (Wed May 7 22:50:30 2014, 美东)
这么搞法以后连个developer都搞不了了
Two Sigma VS Yahoo
今年五月份计算机硕士毕业。
现在有两个公司在process offer,deadline应该还有段时间,不过还是想请教各位比
较一下这两家公司。
Two Sigma是纽约做hedge fund的金融公司,他们的理念是tech drives business,我
有可能去的组是broker dealer,是做high frequence trading的。Yahoo的组是
communication/mail组。
Two Sigma的薪水应该是125k的base和50k的bonus,relocation和signon一个10k,一个
15k。 Yahoo还不是很清楚。
我自己有一些想法,不过想先看看大家的看法。我的疑惑是以后还是打算回国,不知道... 阅读全帖
n*********o
发帖数: 574
19
Sigma SD1的对焦系统和O的完全一样,都是十一点双十字,布局和感光范围也一样
据传是Sigma和Olympus的技术交换,O不再做单反了,将技术给Sigma,作为交换,Sigma
将为Olympus生产 m4/3芯片,这样sigma的成本也可以摊薄,而O是被panasonic坑了很
久,现在估计也要另寻出路了
http://www.43rumors.com/photokina-news-sigma-surprise-finepix-x100-for-1-000-only/
t******k
发帖数: 5617
20
http://sigma-rumors.com/2014/06/sigma-dp2-quattro-all-the-sampl
I will be updating this post regularly as new sample images from the Sigma
dp2 Quattro emerge.
If you find some, feel free to post the link in the comments so I can
complete the list below. Thanks!
- See more at: http://sigma-rumors.com/2014/06/sigma-dp2-quattro-all-the-sample-images/#sthash.jDYOMdN4.dpuf
y*b
发帖数: 3190
21
来自主题: PhotoGear版 - sigma price watch
Sigma Rumors’ comprehensive price guide is now live, and can be found in
the top menu under Price Watch!
Without further ado, let’s see what it’s all about.
Features
Prices of all Sigma products* fetched from ten online stores (US and EU).
Each price is a link that will lead you to the retailer’s product page for
that specific Sigma product.
Auto update every 30 minutes, 24/7.
Easy differentiation of in stock and not in stock items (two colors).
Possibility to subscribe to an unavailable product... 阅读全帖
y*b
发帖数: 3190
22
来自主题: PhotoGear版 - Sigma 85mm f/1.4 Art Lens Next? [CR2]
"
We’re told the next Art series lens from Sigma will be an 85mm f/1.4 DG HSM
Art. However, it’s not coming any time soon. There’s still a small
possibility that a new 135mm Art series lens will arrive first, but Sigma
feels there will be a higher sales volume likelihood with the 85mm focal
length, and will do their best to get it to market first.
A new 24-70 f/2.8 OS DG HSM Art is also a possibility, as the chance of an f
/2 version has diminished due to costs of development and production. One... 阅读全帖
x*********a
发帖数: 5
23
【 以下文字转载自 JobHunting 讨论区 】
发信人: xiaodemajia (xiaomajia), 信区: JobHunting
标 题: 求助offer 选择 google vs two sigma
发信站: BBS 未名空间站 (Mon Nov 4 09:28:42 2013, 美东)
大家好,本人是cs phd。找了好长一段时间工作,拿到了几个fgt和two sigma的offer
。offer deadline是在明天,目前主要在google和two sigma之间选择,很难下定决心
。请大家给些意见。
两个offer目前给的相当,可能长远看two sigma会多些。主要想听听大牛们从career
path和技术
层面分析下这个问题。google的技术实力比较强,去了可以学到不少东西。我match到
的组做的东西我也很喜欢。two sigma的经历是我面试以来最愉快的一次,感觉做的确
实非常有意思。如果直接浪费了会比较可惜,毕竟现在还有时间可以未知领域去闯荡下。
我主要有几个问题:
1. 如果去了two sigma,但是做的不开心,想再回到加州是不是比较难?
... 阅读全帖
c*******h
发帖数: 1096
24
Looking back, I feel that I've made the right decision with Two Sigma.
Paying generously, the company is brutal in protecting its IP. For those who
deem publishing an achievement and who aspire to be a figure in the course
of human civilization, please, work for yourself and make your intellectual
contribution public.
Cited from the Forbes article:
Two Sigma’s most prominent criminal case against an employee involves
Chinese national Kang Gao, a then 28-year-old researcher who gave notice to
the... 阅读全帖
x*********a
发帖数: 5
25
来自主题: JobHunting版 - 求助offer 选择 google vs two sigma
大家好,本人是cs phd。找了好长一段时间工作,拿到了几个fgt和two sigma的offer
。offer deadline是在明天,目前主要在google和two sigma之间选择,很难下定决心
。请大家给些意见。
两个offer目前给的相当,可能长远看two sigma会多些。主要想听听大牛们从career
path和技术
层面分析下这个问题。google的技术实力比较强,去了可以学到不少东西。我match到
的组做的东西我也很喜欢。two sigma的经历是我面试以来最愉快的一次,感觉做的确
实非常有意思。如果直接浪费了会比较可惜,毕竟现在还有时间可以未知领域去闯荡下。
我主要有几个问题:
1. 如果去了two sigma,但是做的不开心,想再回到加州是不是比较难?
2. 对金融领域没有了解,很多未知的东西,会不会对工作造成影响?
y****e
发帖数: 23
26
来自主题: JobHunting版 - Two Sigma VS Yahoo
Two Sigma VS Yahoo
今年五月份计算机硕士毕业。
现在有两个公司在process offer,deadline应该还有段时间,不过还是想请教各位比
较一下这两家公司。
Two Sigma是纽约做hedge fund的金融公司,他们的理念是tech drives business,我
有可能去的组是broker dealer,是做high frequence trading的。Yahoo的组是
communication/mail组。
Two Sigma的薪水应该是125k的base和50k的bonus,relocation和signon一个10k,一个
15k。 Yahoo还不是很清楚。
我自己有一些想法,不过想先看看大家的看法。我的疑惑是以后还是打算回国,不知道
two sigma在国内的名气怎么样,如果以后想跳槽其他公司会不会很承认这家公司出来
的人,还有two sigma的HR讲的感觉以后发展空间比较大,包括薪水方面,不知道Yahoo
怎么样?
谢谢!
现在还有最后一个面试,面完之后来更新找工作遇见的题目。
h********3
发帖数: 2075
27
来自主题: JobHunting版 - Two Sigma VS Yahoo
认可度显然不如Yahoo。
这里的人总是喜欢对自己不熟悉的领域或公司有种莫名的崇拜。其实真正做过金融IT行
业的就知道,two sigma并没有传说中那么神奇。high frequency trading的公司很早
就有了,最近还要被禁了,在中国更是被视为市场操控,所以two sigma在实际范围没
多大品牌。
two sigma所谓的tech driven的金融,在金融行业只是很小很小一块蛋糕。金融领域的
大鳄太多了,two sigma在自己圈子就算做得再好,也不会有多大名气。
在New York City,像two sigma这样依靠IT技术在某个应用领域做的出色的中小型公司太
多了。基本上都做不大,但是也饿不死。
h*******y
发帖数: 864
28
我同意绝大多数企业都没有把握lean six sigma精髓, 但是这个问题不是顾问行业能解
决的. 绝大多数企业都不知道他们自己的value proposition. 更重要的是,管理层也没
有动力和政治魄力去面对这些问题. 没有管理层的绝对支持,lean six sigma没有成功
的可能. 多数企业即使执行了也就是依样画葫芦罢了. 这就是为什么号称要学lean six
sigma的公司多,学会的几乎一个也没有(除非原来就这么做的公司).
Buffett最近说CEO应该是Chief Risk Officer,这个我很赞同. 因为风险控制是公司的
根本. 但是,lean six sigma的精髓,说穿了也是公司的根本. 不由CEO兼职,我觉得还不
如不搞. 尤其国内这环境,大家捞现钱还来不及呢,谁想这么远? 想这么远对自己有什么
好处? 如果,你这个行当到最后对谁都没有好处,你说还有什么前途? Lean six sigma的
起始点不就是用户需要么? 光有技术没有用户有什么用?
S******n
发帖数: 5022
29
来自主题: PhotoGear版 - Sigma的无敌镜头
1. Sigma 35mm f/1.4 DG HSM Lens (口径67mm)含1枚FLD和4枚SLD镜片
2. Sigma 18-35mm f/1.8 APS-C Zoom Lens (口径72mm)含5枚SLD镜片
3. Sigma 180mm f/2.8 EX DG APO HSM OS Macro Lens (口径86mm)含3枚FLD镜片
http://qicai.fengniao.com/316/3164467.html 深度评测
4. Sigma 120-300mm f/2.8 DG OS HSM Zoom Lens (口径105mm)含2枚FLD和1枚SLD镜片
5. Sigma 200-500mm f/2.8 EX Zoom Lens (口径237mm)内含3枚ELD和1枚SLD镜片
大家补充。。。
S******n
发帖数: 5022
30
The Tokyo district court ordered Sigma to pay 1.5 billion JPY (around 14.5
million dollars) compensation to Nikon as a result of the patent
infringement case for lenses with VR technology that was filed back in 2011.
The lawsuit was based on six Sigma lenses with image stabilization
technology. Initially Nikon was looking for a compensations of 12 billion
yen (around 116 million dollars).
Here is the summary of the judgment:
"Nikon obtained the patent related to VR technology in 2002. The conten... 阅读全帖
J*********n
发帖数: 6974
31
http://sigma-rumors.com/2015/02/sigma-12-24mm-dg-hsm-canon-11-2
Canon EF 11-24mm f/4L USM (left: 11mm, right: 24mm)
Sigma 12-24mm f/4.5-5.6 DG HSM (left: 12mm, right: 24mm)
Thick lines (Canon) / Red lines (Sigma): Measurements at 10 LP/mm
Thin lines (Canon) / Green lines (Sigma): Measurements at 30 LP/mm
Blue lines (Canon only) F=8
y*b
发帖数: 3190
32
来自主题: PhotoGear版 - SIGMA 20MM F/1.4 DG HSM ART APPEARS
"A new Sigma Art series lens has leaked. It looks like Sigma is adding a
20mm f/1.4 DG Art to their already stellar Art series lineup.
Sigma 20mm f/1.4 DG Art Specifications:
Designed for 24×36 DSLR cameras
Lens construction: 15 elements in 11 groups
One large-diameter aspherical element
Two FLD elements and five SLD elements to best correct chromatic aberrations
In-lens HSM autofocus motor. New mechanism for full-time manual override in
autofocus mode
Total length: 129.8mm
Maximum diameter: 90.... 阅读全帖
y*b
发帖数: 3190
33
来自主题: PhotoGear版 - Sigma 50-100mm f/1.8 DC HSM Art On the Way
"Sigma will announce a 50-100mm f/1.8 DC HSM Art lens next week ahead of CP+
. This is another unique fast zoom lens coming from Sigma. This one is for
crop sensor cameras.
Sigma 50-100mm f/1.8 DC HSM Art Specifications (Google Translated)
Lens construction: 15 group 21 sheets – three FLD glass. One SLD glass. One
high-refractive-index, high-dispersion glass. High refractive index SLD
glass three
Filter Size: 82mm
Minimum shooting distance: 95cm
Maximum magnification of 1: 6.7
Total length: 170.... 阅读全帖
a***s
发帖数: 616
34
来自主题: Mathematics版 - 请教:algebra VS. sigma algebra

the algebra generated by "C", right? I'm not sure.
No. The sigma-algebra generated by "C" is larger than the algebra generated
by
"C". You can say "a" is an algebra containing "C".
algebra? I think "a" is unique since it is the "smallest". But then "C"
generates the same algebra and sigma-algebra, right?
It's the unique sigma-algebra.
same algebra? is this generated algebra still "a"? does "a" and "C" generate
the same sigma-algebra? is this generated sigma-algebra contained by "a"?
The algebra
s*******s
发帖数: 1568
35
来自主题: Quant版 - Two Sigma新鲜CS master 20万
这么搞法以后连个developer都搞不了了
Two Sigma VS Yahoo
今年五月份计算机硕士毕业。
现在有两个公司在process offer,deadline应该还有段时间,不过还是想请教各位比
较一下这两家公司。
Two Sigma是纽约做hedge fund的金融公司,他们的理念是tech drives business,我
有可能去的组是broker dealer,是做high frequence trading的。Yahoo的组是
communication/mail组。
Two Sigma的薪水应该是125k的base和50k的bonus,relocation和signon一个10k,一个
15k。 Yahoo还不是很清楚。
我自己有一些想法,不过想先看看大家的看法。我的疑惑是以后还是打算回国,不知道
two sigma在国内的名气怎么样,如果以后想跳槽其他公司会不会很承认这家公司出来
的人,还有two sigma的HR讲的感觉以后发展空间比较大,包括薪水方面,不知道Yahoo
怎么样?
谢谢!
n***e
发帖数: 69
36
我一直按照着 概率题 + brain teaser + coding 的模式在准备,最近面了几家HFT也
都是这个模式,也比较顺利,我以为 two sigma应该也是这个模式就申了(我知道我错
了。。)这里“概率题”指的是抛硬币掷色子玩扑克那一类的问题,区别于下面提到的
“统计题”
拿到面试之后上网一查,有几个帖子说two sigma问的基本全是统计题,特别是
sampling、假设检验和Stochastic Calculus,由于是CS背景,我在统计上面比较弱,
尤其是Stochastic Calculus。
因为这几个帖子都比较老而且数量少(大部分two sigma面经都是码工的),不知道有
没有在two sigma或者面过two sigma quant的前辈能够确认一下?如果真的全是统计题
我也好有个心理准备。。。
非常感谢!
n***e
发帖数: 69
37
我一直按照着 概率题 + brain teaser + coding 的模式在准备,最近面了几家HFT也
都是这个模式,也比较顺利,我以为 two sigma应该也是这个模式就申了(我知道我错
了。。)这里“概率题”指的是抛硬币掷色子玩扑克那一类的问题,区别于下面提到的
“统计题”
拿到面试之后上网一查,有几个帖子说two sigma问的基本全是统计题,特别是
sampling、假设检验和Stochastic Calculus,由于是CS背景,我在统计上面比较弱,
尤其是Stochastic Calculus。
因为这几个帖子都比较老而且数量少(大部分two sigma面经都是码工的),不知道有
没有在two sigma或者面过two sigma quant的前辈能够确认一下?如果真的全是统计题
我也好有个心理准备。。。
非常感谢!
w*******y
发帖数: 60932
38
10% off automatically added in cart (DEAL10)
Combinable with $15 off $400 coupon (LOYALTY15)
Some examples I found:
Sigma 10-20mm f/4-5.6 for Canon, Nikon $416.10
Sigma 30mm f/1.4 for Canon (showing as backordered), Nikon $425.10
Sigma 17-50 f/2.8 $587.10
Sigma 50 f/1.4 $434.10
Sigma 85mm f/1.4 (backordered for Canon) $857.10
Link:
http://www.abesofmaine.com/
s*****d
发帖数: 1749
39
二手交易风险自负!请自行验证是否合法和一手卡!:
我想卖的物品:
Sigma DP1S digital camera+Sigma HA-11 hood
单张面值:
可接受价格(必须明码标价!):
$300 + shipping
物品新旧要求:
Used for about 6 months, less than 2000 shots
邮寄方式要求:
FedEx or UPS
买卖双方谁承担邮寄损失(Required if not code only):
Buyer
付款方式说明:
BOA or non-credit card paypal
其他补充说明:
reference link on amazon:
http://www.amazon.com/Sigma-FOVEON-Sensor-Digital-Camera/dp/B00
广告的有效期:
until sold
物品来源(Required for All Cards!):
Bought new from Amazon.com
我的联系方式:
站内联系
Warranty期限:
能否证明是合法的一手卡?(Required for A... 阅读全帖
s*****d
发帖数: 1749
40
二手交易风险自负!请自行验证是否合法和一手卡!:
我想卖的物品:
Sigma DP1S digital camera+Sigma HA-11 hood
单张面值:
可接受价格(必须明码标价!):
$300 + shipping
物品新旧要求:
Used for about 6 months, less than 2000 shots
邮寄方式要求:
FedEx or UPS
买卖双方谁承担邮寄损失(Required if not code only):
Buyer
付款方式说明:
BOA or non-credit card paypal
其他补充说明:
reference link on amazon:
http://www.amazon.com/Sigma-FOVEON-Sensor-Digital-Camera/dp/B00
广告的有效期:
until sold
物品来源(Required for All Cards!):
Bought new from Amazon.com
我的联系方式:
站内联系
Warranty期限:
能否证明是合法的一手卡?(Required for A... 阅读全帖
c********7
发帖数: 8
41
Fresh master, offer from Amazon, Microsoft, SAS, Two Sigma
Amazon: SDE position in Seattle. 常规Amazon compensation, 95k + 7.5k
relocation + bonus + RSU
Microsoft: SDET position in Seattle. 常规Microsoft compensation , 95k + 7.5k
relocation + bonus + RSU
SAS: SDE position in Boston. No.1 on 2011 FORTUNE "100 Best Companies to
Work For" list. 90k base, 其他未知。 Information Retrieval + research 职位
,自己比较擅长也比较喜欢这个职位并且公司氛围和team都很好。
Two Sigma: A Technology Hedge fund company. SDET position in New York City.... 阅读全帖
r**n
发帖数: 39
42
来自主题: Immigration版 - 求Sigma Xi Membership推荐
正在申请EB1B,想把Sigma Xi Membership放到contribution里面。
苦于一片一作的文章也没有,担心直接在网上申请sigma xi不通过,汗...(sigma xi网
上说要两篇一作,thesis算一篇,我也就只有thesis算得上了...其它都是2作和3作的
)。
版上哪位好人是sigma xi的full member,也愿意当我的norminator的?
请站内联系,不甚感激!

发帖数: 1
43
弱case 申请eb1a 律师强烈建议弄个sigma xi 的membership。之前看到很多人说,如
果弄了sigma xi的membership,必遭rfe. 跟律师沟通过我的想法,可是律师又非常坚
持让我去办一个sigma x。 请大家来给我出出主意吧!!!根据最近的情形来看,有了
sigma xi就一定会被
ref吗?
谢谢大家了!
G****a
发帖数: 10208
44
【 以下文字转载自 JobHunting 讨论区 】
发信人: jcissb (jcissb), 信区: JobHunting
标 题: offer选择+ 分享找工作经历 更新two sigma面经
发信站: BBS 未名空间站 (Wed Feb 29 16:35:37 2012, 美东)
我是cs master,今年5月毕业,在东部cs top30的学校。1月中旬开始投的简历(投了
15家听说过的大公司,挂了一个简历在monster),到现在拿到3个offer
1. nvidia:暑假实习的公司,湾区总部,还没谈待遇,我在网上看有人报105k base。
在他家主要做GPU的驱动的开发,少量测试,debug,语言主要是c/c++, 偶尔可能有
java c#的tool要写。优点是manager人很好,知识渊博,对我非常非常nice,组里面
的活也不紧不慢的,大环境比较熟悉。缺点是现在组里6个人(包括manager)全部都是
印度人,我要去了就是唯一一个中国女生,其实暑假跟他们相处到没感觉有传说中那么
可怕,不过公司里印度人确实太多了,看上去实在像个大火坑。
2. two sigma... 阅读全帖
o**d
发帖数: 267
45
器材名称
Sigma Zoom Telephoto 120-300mm f/2.8 EX APO DG IF HSM Autofocus Lens for
Nikon AF
Sigma 2X Teleconverter EX APO DG for Nikon AF
付款方式(需要其他付款方式请联系卖家)
boa,paypal
卖家联系方式
pm
器材具体描述、价格、运费:
俗称“巨黑”,性价比最高的328(没有之一)。适合打鸟、体育和人像。请注意是无
OS版。
Used, 9/10, 有正常使用的痕迹,光学部分完好,附件齐全(前后盖+皮套+镜头筒)。
到手后一直没有合适的器材配合,发挥不出镜头的潜力,现家中急需用钱才不得不变现
,有意者站内信箱联系(可提供照片),谢谢!
镜头$1500 or BO(均为现金/BOA或non-cc paypal价)+YL
增距镜$150+YL
两个一起$1600+YL
老ID优先。买镜头附送Sigma 105mm UV Filter(~$100 value)
c*****l
发帖数: 1493
46
来自主题: PhotoGear版 - Sigma 出 Art 系列的策略
lz的大前提是sigma的战略针对的尼康。
但是,每个sigma镜头要发布多个卡口的版本,而1.2大光圈对老尼的机身比较有难度,
所以退而求其次,选择1.4.
在常用焦段35 50 85中,只有35mm同时存在CN两只牛头,而且是1.4光圈。
从这次盗版Otus可见,sigma copy paste的功力很高,对s来说,选择35mm还有个好处,
两只现成的镜头可以一起借鉴。
说到镜头分辨率,s35胜过35g不假,但是同样秒了35L。
DXO的评分中35L配6d和5d3分别是29,30分;35G在d600/d800上是33分。
要评估s35对谁家的冲击大,我认为应该看两种卡口和对手销售量的对比。
而nikon最近在新机身上拒绝支持sigma,估计是输了官司后的反应。
(当年intel cpu拼不过amd就申请销售禁令,amd胜诉后也失了先机,为什么nikon没这
一招)
nikon就像以前是个好孩子后来学坏了,而佳能一直是挤牙膏的德行,大家已经习惯了
。有点冤。
J*********n
发帖数: 6974
47
来自主题: PhotoGear版 - sigma CP+要放大招
http://sigma-rumors.com/2014/01/something-groundbreaking-from-s
Back in December, the Japanese magazine Impress Japan published an interview
(in Japanese) with Sigma CEO, Kazuto Yamaki.
Of course, Mr. Yamaki was rather coy when responding to the unavoidable
questions about future products, but an interesting bit of info emerged.
It appears Sigma has something “groundbreaking” up their sleeves, which is
“not a camera”. Still, it may be related to the Foveon, or it may be a
new feature to be incor... 阅读全帖
a******g
发帖数: 725
48
来自主题: PhotoGear版 - ref 的SIGMA warranty 只有90天?
SIGMA OUTLET WARRANTY
We don't foresee any issues with the products purchased through the Sigma
Outlet, but sometimes things happen. If you find a manufacturer's defect
with your product, we'll repair it for you free of charge with the return
shipping on us. All Sigma cameras, lenses, and flashes qualify for a 90-day
warranty. If you should need to send your product to us for repair, simply
pack it up with a copy of your original proof of purchase and the warranty
card, fill out the Sigma Servic... 阅读全帖
y*b
发帖数: 3190
49
来自主题: PhotoGear版 - Sigma Art Primes on 50 Megapixels
Sigma Art Primes on 50 Megapixels: RAW Sample Images
"Photography Blog has posted a bunch of sample photos made with the Sigma
24mm, 35mm and 50mm f/1.4 Art lenses on a production Canon EOS 5Ds 50MP DSLR
. Among the 113 shots are 20 RAW (.CR2) images taken at various apertures
and distances."
http://sigma-rumors.com/2015/06/sigma-art-prime-lenses-canon-eo
http://www.canonrumors.com/2015/06/canon-eos-5ds-samples-with-s
http://www.canonwatch.com/canon-eos-5ds-sample-pictures-shot-wi
y*b
发帖数: 3190
50
http://photorumors.com/2015/06/18/sigma-24-35mm-f2-dg-hsm-art-l
http://sigma-rumors.com/2015/06/sigma-24-35mm-f2-dg-hsm-art-ann
Sigma will announce a new 24-35mm f/2 DG HSM Art full frame lens (pictures
via digicame-info). Stay tuned for details.
1 2 3 4 5 6 7 8 9 10 下页 末页 (共10页)