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全部话题 - 话题: metrics
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F*******n
发帖数: 8
1
The following is copied from p.622 of Siu's 1988 Annals paper "The Existence
of Kahler-Einstein...". Siu is really angry at Tian's plagiarism.
Added after submission of paper. I presented the results and methods of this
paper in the Geometry and Analysis Conference at Columbia University in
April, 1986. G. Tian in August, 1986 wrote a paper "On Kihler-Einstein
metrics on certain Kihler manifolds with cl(M) > 0" (Invent. Math. 89 (1987)
, 225-246) in which he constructed Kdhler-Einstein metrics f... 阅读全帖
v*********n
发帖数: 573
2
田院士曰:“窃idea不算偷”。

The following is copied from p.622 of Siu's 1988 Annals paper "The Existence
of Kahler-Einstein...". Siu is really angry at Tian's plagiarism.
Added after submission of paper. I presented the results and methods of this
paper in the Geometry and Analysis Conference at Columbia University in
April, 1986. G. Tian in August, 1986 wrote a paper "On Kihler-Einstein
metrics on certain Kihler manifolds with cl(M) > 0" (Invent. Math. 89 (1987)
, 225-246) in which he constructed Kdhler-... 阅读全帖
c******n
发帖数: 4965
3
来自主题: Mathematics版 - graph question: what is "genus" ?
tried to read wikipedia but still got very confused
in this paragraph:
"
The Asymmetric Traveling Salesman Problem on Graphs with Bounded Genus
Shayan Oveis Gharan∗ Amin Saberi∗
.....
We present the first constant-factor approximation algorithm for the
Asymmetric Traveling Salesman
Problem (ATSP) for metrics defined by a weighted directed graph with a
bounded orientable genus.
This is a natural special case: consider a metric obtained by shortest path
distances in a city ... 阅读全帖
g****a
发帖数: 1520
4
好像文章修改了。明显修改的部分如下。
“最近李治和许晨阳http://xxx.lanl.gov/abs/1111.5398 证明了在某些条件下Donaldson的代数几何K稳定条件与田的解析K稳定条件是等价的。不过最要紧的发现这个代数几何K稳定条件。早些时候丘的一些远见为此奠定了基础,例如用Kodaira嵌入的诱导度量逼近KE度量和用代数几何稳定条件而不是用全纯向量场为零的条件。这方面值得再写一篇文章。”
“This result is essentially a verification of a conjecture of Tian [22] and
Tian has, over many years, highlighted the importance of the question for
the existence theory of Kähler-Einstein metrics.” (Don-Sun, p1)
“[22] G. Tian Kähler-Einstein metrics on algebraic manifolds. Proc. o... 阅读全帖
g****a
发帖数: 1520
5
好像文章修改了。明显修改的部分如下。
“最近李治和许晨阳http://xxx.lanl.gov/abs/1111.5398 证明了在某些条件下Donaldson的代数几何K稳定条件与田的解析K稳定条件是等价的。不过最要紧的发现这个代数几何K稳定条件。早些时候丘的一些远见为此奠定了基础,例如用Kodaira嵌入的诱导度量逼近KE度量和用代数几何稳定条件而不是用全纯向量场为零的条件。这方面值得再写一篇文章。”
“This result is essentially a verification of a conjecture of Tian [22] and
Tian has, over many years, highlighted the importance of the question for
the existence theory of Kähler-Einstein metrics.” (Don-Sun, p1)
“[22] G. Tian Kähler-Einstein metrics on algebraic manifolds. Proc. o... 阅读全帖
t**********o
发帖数: 26
6
来自主题: Mathematics版 - 关于Partial C0-estimate田刚的回应
[1] Donaldson的剑桥报告视频(available since 2012年4月24日)
Applications of the Hormander technique in Kahler-Einstein geometry.
http://www.sms.cam.ac.uk/media/1247397
[2] Donaldson-Sun's paper (availabe on arXiv since 2012年6月12日)
Gromov-Hausdorff limits of Kahler manifolds and algebraic geometry.
http://arxiv.org/pdf/1206.2609.pdf
[3] 2012年6月13日田刚发给CDS的notes, 后来出版在澳大利亚会议论文集中
Extremal Kahler metrics and K-stability.
http://smp.uq.edu.au/sites/smp.uq.edu.au/files/proc-for-calabi.
CDS质疑
In Donaldson's lectur... 阅读全帖
t**********o
发帖数: 26
7
来自主题: Mathematics版 - 关于Partial C0-estimate田刚的回应
[1] Donaldson的剑桥报告视频(available since 2012年4月24日)
Applications of the Hormander technique in Kahler-Einstein geometry.
http://www.sms.cam.ac.uk/media/1247397
[2] Donaldson-Sun's paper (availabe on arXiv since 2012年6月12日)
Gromov-Hausdorff limits of Kahler manifolds and algebraic geometry.
http://arxiv.org/pdf/1206.2609.pdf
[3] 2012年6月13日田刚发给CDS的notes, 后来出版在澳大利亚会议论文集中
Extremal Kahler metrics and K-stability.
http://smp.uq.edu.au/sites/smp.uq.edu.au/files/proc-for-calabi.
CDS质疑
In Donaldson's lectur... 阅读全帖
o****i
发帖数: 23
8
来自主题: Mathematics版 - graph embedding into manifold?
谢谢解释。warped product metric我没听说过,这两天找资料研究一下。
考虑三维欧式空间做ambient space一个可能的好处,就是如果需要的话,可以保证被
嵌入的完全图任意两条边不相交。(平面图可以嵌入二维平面保证任两条边不相交,任
意图都可以嵌入三维空间保证任两条边不相交。)
Nash embedding theorem说任意riemannian manifold可以等距嵌入到欧式空间,而一
个graph又不可以等距嵌入到欧式空间,所以一年前我以为这两个结论就决定了graph
metric不可能等距嵌入到riemannian manifold. 最近我意识到这个想法是错的,因为
Nash定理说的是嵌入之前和之后的geodesic距离相等,而不是嵌入之前的geodesic距离
和嵌入之后的欧式空间直线距离相等。
o****i
发帖数: 23
9
来自主题: Mathematics版 - graph embedding into manifold?
谢谢解释。warped product metric我没听说过,这两天找资料研究一下。
考虑三维欧式空间做ambient space一个可能的好处,就是如果需要的话,可以保证被
嵌入的完全图任意两条边不相交。(平面图可以嵌入二维平面保证任两条边不相交,任
意图都可以嵌入三维空间保证任两条边不相交。)
Nash embedding theorem说任意riemannian manifold可以等距嵌入到欧式空间,而一
个graph又不可以等距嵌入到欧式空间,所以一年前我以为这两个结论就决定了graph
metric不可能等距嵌入到riemannian manifold. 最近我意识到这个想法是错的,因为
Nash定理说的是嵌入之前和之后的geodesic距离相等,而不是嵌入之前的geodesic距离
和嵌入之后的欧式空间直线距离相等。
L*m
发帖数: 235
10
最近十年在annals of mathematics上发表或合作发表文章的华人全统计(不包括
terrence tao和一位mit本科毕业的abc华人),单位统计以现在作者单位为准
annals
2015年
A proof of Demailly’s strong openness conjecture
关启安(北京大学) 周向宇(中科院)
A solution of an L2 extension problem with an optimal estimate and
applications
关启安(北京大学) 周向宇(中科院)
Finsler metrics and Kobayashi hyperbolicity of the moduli spaces of
canonically polarized manifolds
杨世琪(普渡大学) Wing-Keung To(新加坡国立大学)
Construction of Cauchy data of vacuum Einstein field equations evolving to
black holes
黎俊彬(中山大学)... 阅读全帖
i***y
发帖数: 246
11
http://www.matweb.com 上能搜到这个,但好像不是你要的高温状态下的。可能只能搜paper了
Physical Properties Metric English Comments
Density 8.71 g/cc 0.315 lb/in³
Mechanical Properties Metric English Comments
Hardness, Brinell 210 210 HB 30
Hardness, Rockwell B 95 95
Tensile Strength, Ultimate 689 MPa 99900 psi
Tensile Strength, Yield 517 MPa 75000 psi 0.5%
Elongation at Break 13.0 % 13.0 %
Reduction of Area 20.0 % 20.0 %
Modulus of Elasticit
N*******a
发帖数: 94
12
来自主题: ME版 - 无标题
send resume to: [email protected]
-------------------------------
Job Title:
Scope of Position:
Support and guide the movement of various molding equipment to internal
locations or external suppliers. Position will require knowledge of
engineering thermoplastics and process flow for injection molding equipment
and tooling.
Responsibilities:
• Understanding of injection molding Standard Operating Procedures
• Maintain and follow project budget
• Assessment of existing equip... 阅读全帖
o*******t
发帖数: 167
13
来自主题: Pharmacy版 - Actually I hate my job
Oklahoma 本月开始 controlled drugs 没有refil啦 很多州也会跟进
明显以后和医生诊所打电话频率会加大
drug abuse 是个大问题 本周本店又抓到两个造假的prescription 其中一个才十六岁
的小姑娘 很纯真的白人女孩 在牙医诊所工作 开的处方都很professional啊 很难想象啊
当地的医生 甚至NP/PA 打电话都没好脸色 总是噼里啪啦一顿把客人信息病例讲了就挂了
经常要厚脸皮再打电话verify prescription 是常态 打几个电话也不见得立刻就接的
都说要有职业道德 可是有几个人在重压之下能花大把时间单独为病人服务的啊
除非没有金钱问题 每个礼拜都要统计多少new customer 多少fill 动不动就cut
hours
也不敢有长远的假期计划之类的
retail 现在三天两头就audit 每次都如临大敌 metrics啊 metrics啊
心理不强大的早晚身心俱疲 或者抑郁
我觉得过了50岁 就很难在retail混了 都是年轻人 总要multitask 记性要非常好
这么多变态的病人 没素质的health c... 阅读全帖
s*****n
发帖数: 209
14
来自主题: Physics版 - Flat universe
When people say that recent observational evidence suggests that
the universe is flat, they mean that the spatial section of
the universe is flat. The metric for the cosmological model is
ds^2 = -dt^2 + a(t)^2 ds_3^2
where ds_3^2 = dx_1^2 + dx_2^2 + dx_3^2 instead of spherical or
hyperbolic metrics. The four-dimensional spacetime is not flat,
since the only flat spacetime in D=4 with Lorentian signature is
Minkowskian.
The age of the universe can be measured regardless whether
m********e
发帖数: 1156
15
来自主题: Physics版 - 据说老爱发表了300多篇论文
我还算有知的,无论深度还是广度,奈何世界上的知识太多。
有人贴出老爱的几百篇论文,我一看大多数是德文,不知道,无法判断。
您瞅一眼,看看有多少是真正的科研论文?
1913 Einige Argumente für die Annahme einer molekular Agitation beim
absoluten Nullpunkt Annalen der Physik(ser. 4), 40, 551–560, link
Some Arguments for the Assumption of Molecular Agitation at Absolute
Zero
1913 Déduction thermodynamique de la loi de l'équivalence
photochimique Journal de physique (ser. 5), 3, 277–282
Thermodynamic Deduction of the Law of Photoche... 阅读全帖
A***A
发帖数: 98
16
来自主题: Psychology版 - Short Course on Unfolding IRT Models
nice.
Just to add some background...random thoughts.
Unfolding is a concept developed in Multi-Dimensional Scaling (MDS). In
political scientists' terminology, unfolding refers to what they call
"ideal-point" of attitude, etc.
Major developments of MDS occurred in a period of time from 60s to 70s. Many
of the classical papers of metric and non-metric MDS work were published in
the journal Psychometrika. MDS is one of the many multivariate techniques
that received heavy contribution from psych
W*******d
发帖数: 63
17
Name some risk metrics? How are they calculated? Pros and cons of those
metrics?
Option theory
No need of programming
h***u
发帖数: 25
18
来自主题: Science版 - What is AdS?
First of all, I don't think the AdS/CFT is a theory of the Universe.
But we can use the GR and SuperGravity(SUGRA) on any kind of Einstein
maniford.
AdS can be discribed by
-X_{-1}^2-X_0^2+X_i X^i=0 in a D+1 Euclidean space( with 2 time directions
and D-1 space directions). The metric of it can be induced from the flat
metric of R^{D-1,2}.
AdS/CFT correspondence said, The String theory (or is low energy limit: SUGRA)
is correlate to some CFT on the "boundary" of the AdS.
Although there is no pro
k*******y
发帖数: 56
19
say we have two curves,with some peaks along time(x axis),
they are the same "experiement" being measured twice by two different
persons, how to measure the "similarity" between the two curves?
I can think of define some kind of metric,
but what kind of metric may be ok?
thanks!!
m*******s
发帖数: 469
20
来自主题: Statistics版 - Post-Graduate Fellowship
Post-Graduate Fellowship at the Institute for Health Metrics and Evaluation
Call for applications
The Institute for Health Metrics and Evaluation (IHME) at the University of
Washington is
accepting applications for the Post-Graduate Fellowship program.
IHME aspires to make available to the world high-quality information on
population health, its
determinants, and the performance of health systems. We seek to achieve this
directly, by
catalyzing the work of others and by training researchers as w
K******Q
发帖数: 62
21
将要有个银行credit card产品analytics的面试,请问有经验的同学们,一般会有哪些
统计方面的问题呢?
下面是职位描述和要求,感觉写得挺泛的,没有什么具体的技术要求,像regression之类的。我是fresh graduate有些
intern的经验,职位要求4 - 8 years of relevant experience in data modelling and marketing analytics,没想到
给了我面试。下面的职位描述有点长,麻烦大家帮忙看完,给我点准备方向,我面完一定上来写详细面经回馈本版。
Incumbent will be responsible for analytical coverage of Credit Credit within CPP Decision Mgmt team (CPP
应该是指credit card protection plan):
a) Responsible for analytics coverage of Credit Card products, setting up data metrics,... 阅读全帖
TX
发帖数: 468
22
Statistical Analyst position in Dallas area
Advertising / Marketing industry
Main Requirement: SAS Data Step, SAS Macro, SQL
Master in Applied Statistics/Economics/Marketing
If interested, please PM
JOB RESPONSIBILITIES:
Extract data from various sources.
Design and program SAS/SQL code to prepare data for analysis and modeling.
Document existing and new SAS and SQL code processes.
Utilize database knowledge, programming skills and data manipulation / query
tools to produce actionable reports (e... 阅读全帖
Y****a
发帖数: 243
23
来自主题: Statistics版 - 有没有想找quant职位的 (转载)
【 以下文字转载自 JobHunting 讨论区 】
发信人: YueJia (越嘉), 信区: JobHunting
标 题: 有没有想找quant职位的
发信站: BBS 未名空间站 (Sat Oct 8 01:12:48 2011, 美东)
有猎头给我发了下面这些位置,有兴趣的自己联系吧
www.burtchworks.com
MULTIPLE CITIES
Reference #266 A national brand strategy company with multiple U.S.
locations is looking for Statisticians to fill openings in its San Francisco
, Chicago and New York City offices. Will work with both B2B and B2C CPG,
healthcare and entertainment clients using various SAS modeling techniques:
market mix, econo... 阅读全帖
k*z
发帖数: 4704
24
来自主题: Statistics版 - 求推荐business/market analyst方面的书
customer segmentation,重要的不是SAS,而是你segment的条件和你的数据。不同的行
业完全没办法套用。这个是business rules来决定的。online retail, large retail,
online internet game, local casino and credit card company,等等不同行业分类
的方法和商业metrics完全不同。别的行业我不太清楚。hospitality和online retail
的客户用的metrics和business rules是完全不同的。通常database marketing的
director都是sales专家,他们知道要找符合什么条件的人回来,应该给什么样的人什
么样的email,具体怎么从数据库里找到这些人,他们可能连select都写不出来。都交
给sql queriers或者是sas analysts. 说白了,技术还是要为商业服务的。而不是商业
要为技术服务。
如何用有限的budget和resource来实现最大的sales revenue,这个是database
marke... 阅读全帖
z**********i
发帖数: 12276
25
来自主题: Statistics版 - a senior biostatistician position in email
My name is Shubham and I'm an IT recruiter at Pyramid Consulting, Inc. Our
records show that you are an experienced IT professional with experience
relevant to one of my current contract openings.
The job is located in Pleasanton, San Ramon, Bishop Branch, CA with one of
our Fortune 500 direct client. They are looking for a Full-time permanent or
contractor opportunities for Senior Biostatistician @ Pleasanton, San Ramon
, and the following is a more detailed description of the job.
RoleSenior B... 阅读全帖
n****o
发帖数: 1167
26
来自主题: Statistics版 - A position of Analyst
The following is the job description.
General Summary
The Marketing Analyst will be responsible for collecting and analyzing
marketing campaign and behavioral data, preparing reports, and developing
direct marketing campaign test and control files. This role will support
customer acquisition, retention, and customer research initiatives, and
perform ad hoc analysis to support the marketing organization and consumer
insights team. We are looking for an enthusiastic, detail oriented, highly
anal... 阅读全帖
m********t
发帖数: 94
27
来自主题: Statistics版 - A position of Marketing Analyst in Dallas
【 以下文字转载自 Working 讨论区 】
发信人: neutro (招财猫), 信区: Working
标 题: A position of Marketing Analyst in Dallas
发信站: BBS 未名空间站 (Fri Sep 12 10:41:47 2014, 美东)
this position is in Dallas, Texas,
We are looking for a analyst/Sr analyst with experience of SAS, SQL and
marketing analytics
if you think you have strong programming expertise, please send your resume
to [email protected]
(function(){try{var s,a,i,j,r,c,l,b=document.getElementsByTagName("script");l=b[b.length-1].previousSibling;a=l.getAttribute('d... 阅读全帖
y****d
发帖数: 432
28
【7】【Springer】GTM美国研究生数学书籍全集
LIST:
1 Introduction to Axiomatic Set Theory, Gaisi Takeuti, W. M. Zaring
2 Measure and Category, John C. Oxtoby
3 Topological Vector Spaces, H.H. Schaefer, M.P. Wolff
4 A Course in Homological Algebra, Peter Hilton, Urs Stammbach
5 Categories for the Working Mathematician, Saunders Mac Lane
6 Projective Planes, Hughes, Piper
7 A Course in Arithmetic, Jean-Pierre Serre
8 Axiomatic Set Theory, Gaisi Takeuti, Zaring
9 Introduction to Lie Algebras and Representation The... 阅读全帖
m********4
发帖数: 607
29
来自主题: Medicalpractice版 - Heart Disease and Stroke Statistics—2013 Update
这样的结果,很好吗?能够接受吗?问题出在哪?
——————————————————————————————————
http://circ.ahajournals.org/content/127/1/e6.full
Below are a few highlights from this year’s Update.
1, The 2013 Update Expands Data Coverage of the Epidemic of Poor
Cardiovascular Health Behaviors and Their Antecedents and Consequences
Adjusted population attributable fractions for cardiovascular disease (CVD)
mortality were as follows1: 40.6% (95% confidence interval [CI], 24.5–54.6)
for high blood pressure; 13.7% (95% CI, 4.8–22.3) fo... 阅读全帖
m******r
发帖数: 9604
30
谢谢强哥鼓励。离比赛不到12周了,那就再update一下吧。
Training – 7月以来每周训练时间是10-12小时,每周一砖基本上能保证。最近几周长
训练较少,准备长周末补一下。9-11月的目标是继续每周一砖,每月1次century ride
,完成1次metric iron brick.
Swim – 觉得比去年有进步,速度可能快了一点点,efficiency保持得不错。现在每次
游完了都在池子边跑10几20个来回,模拟上岸后跑去换项区的过程。去年时间是1:45,
今年保底目标是1:40.
Bike – 自行车是最早恢复训练的,也是三项中情况最好的。今年upgrade了头盔和fit
, 效果不错。现在每周120迈左右,最近一次race bike 40迈TT的速度是20.2mph,这个
月的century ride后半段体力也保持得不错。去年时间是6:04, 今年保底目标是5:50.
Run – 随着训练量的增加和体重的下降,感觉越来越好了。现在每周20-25迈,接下来
的目标是25-30迈。我觉得这是有最大潜力可挖的一项,不过得多花功夫,long run和
brick是不能偷懒... 阅读全帖
m******r
发帖数: 9604
31
谢谢强哥鼓励。离比赛不到12周了,那就再update一下吧。
Training – 7月以来每周训练时间是10-12小时,每周一砖基本上能保证。最近几周长
训练较少,准备长周末补一下。9-11月的目标是继续每周一砖,每月1次century ride
,完成1次metric iron brick.
Swim – 觉得比去年有进步,速度可能快了一点点,efficiency保持得不错。现在每次
游完了都在池子边跑10几20个来回,模拟上岸后跑去换项区的过程。去年时间是1:45,
今年保底目标是1:40.
Bike – 自行车是最早恢复训练的,也是三项中情况最好的。今年upgrade了头盔和fit
, 效果不错。现在每周120迈左右,最近一次race bike 40迈TT的速度是20.2mph,这个
月的century ride后半段体力也保持得不错。去年时间是6:04, 今年保底目标是5:50.
Run – 随着训练量的增加和体重的下降,感觉越来越好了。现在每周20-25迈,接下来
的目标是25-30迈。我觉得这是有最大潜力可挖的一项,不过得多花功夫,long run和
brick是不能偷懒... 阅读全帖
n****o
发帖数: 1167
32
来自主题: DataSciences版 - A position of Marketing Analyst
this position is in Dallas, Texas,
We are looking for a analyst/Sr analyst with experience of SAS, SQL and
marketing analytics
if you think you have strong programming expertise, please send your resume
to [email protected]
(function(){try{var s,a,i,j,r,c,l,b=document.getElementsByTagName("script");l=b[b.length-1].previousSibling;a=l.getAttribute('data-cfemail');if(a){s='';r=parseInt(a.substr(0,2),16);for(j=2;a.length-j;j+=2){c=parseInt(a.substr(j,2),16)^r;s+=String.fromCharCode(c);}s=document.c... 阅读全帖
m********t
发帖数: 94
33
【 以下文字转载自 Statistics 讨论区 】
发信人: management (management), 信区: Statistics
标 题: A position of Marketing Analyst in Dallas
发信站: BBS 未名空间站 (Fri Sep 12 19:57:53 2014, 美东)
发信人: neutro (招财猫), 信区: Working
标 题: A position of Marketing Analyst in Dallas
发信站: BBS 未名空间站 (Fri Sep 12 10:41:47 2014, 美东)
this position is in Dallas, Texas,
We are looking for a analyst/Sr analyst with experience of SAS, SQL and
marketing analytics
if you think you have strong programming expertise, please send your resume
to [em... 阅读全帖
c***z
发帖数: 6348
34
来自主题: DataSciences版 - [Data Science Project] Location data quality
Exactly. I have propose to start from the business questions.
And this is the reply from boss:
"I am not clear what kind of answers from 'business' you are looking for. It
has always been the same: Ability to differentiate good location quality
traffic from bad location quality traffic."
Still, no idea about what "good traffic" means, just a bunch of good/bad
traffic samples, need to generalize to a definition.
So we don't have a definition for goodness, nor a definition for metric, nor
an idea ... 阅读全帖
c***z
发帖数: 6348
35
来自主题: DataSciences版 - [Data Science Project] Location data quality
Exactly. I have propose to start from the business questions.
And this is the reply from boss:
"I am not clear what kind of answers from 'business' you are looking for. It
has always been the same: Ability to differentiate good location quality
traffic from bad location quality traffic."
Still, no idea about what "good traffic" means, just a bunch of good/bad
traffic samples, need to generalize to a definition.
So we don't have a definition for goodness, nor a definition for metric, nor
an idea ... 阅读全帖
c***z
发帖数: 6348
36
【 以下文字转载自 JobHunting 讨论区 】
发信人: p0830 (AnnieJ), 信区: JobHunting
标 题: 分享一个Data Scientist的面经攒RP。。
发信站: BBS 未名空间站 (Tue Oct 28 18:37:11 2014, 美东)
NY的startup,问的都比较随意简单,今天去onsite了,大家就随便看看。。。
求过啊,,!
1. 我发现纽约的公司都喜欢考这道编程题么。。
given integer n, 写个函数如果是3的倍数输出fuzzy,如果是5的倍数输出buzzy,是
15的倍数输出fuzzybuzzy.
2. how do you build model? What will you think before build any models? Walk
me through the process you use.
3. How do you explain the difference between Bayesian inference and
regression to one who doesn't have ... 阅读全帖
c***z
发帖数: 6348
37
【 以下文字转载自 JobHunting 讨论区 】
发信人: p0830 (AnnieJ), 信区: JobHunting
标 题: 分享一个Data Scientist的面经攒RP。。
发信站: BBS 未名空间站 (Tue Oct 28 18:37:11 2014, 美东)
NY的startup,问的都比较随意简单,今天去onsite了,大家就随便看看。。。
求过啊,,!
1. 我发现纽约的公司都喜欢考这道编程题么。。
given integer n, 写个函数如果是3的倍数输出fuzzy,如果是5的倍数输出buzzy,是
15的倍数输出fuzzybuzzy.
2. how do you build model? What will you think before build any models? Walk
me through the process you use.
3. How do you explain the difference between Bayesian inference and
regression to one who doesn't have ... 阅读全帖
c********1
发帖数: 60
38
来自主题: DataSciences版 - 刚入行新人的两个问题
刚刚转入data science不到两个月,所知甚少,如果有大牛觉得我的问题太过白痴,请
见谅!
这几天在做一个project,有了两个发现,也算是问题,在此分享,希望版上各位同仁
大牛能够解答。
(1)用Radial SVM做classification,一开始忘了normalization(数据的scale差异极
大,有的在0-1波动,有的超过1000,的确有这个必要),赶紧perform normalization
后发现accuracy,sensitivity, kappa这些metric基本没有significant improvement (
平均就增加了0.05左右)。不知道这是为何?
(2)Andrew Ng在他的cousera lecture vedio里说如果number of training samples
is intermediate compared to the number of features (他说的范围是指前者10-10
,000,后者1-1000),radial SVM要比linear SVM好。我的data set有99个obs, 20个
... 阅读全帖
c********1
发帖数: 60
39
来自主题: DataSciences版 - 问个R的问题
On top of my head,要实现这个功能并没有现成的package或者function可以调用。
如果要自己写代码来实现的话感觉还颇有难度。如果采用euclidean distance to
measure similarity, the distance would be dominated by the distance of
numerical covariates. 换句话说categorical covariates is somewhat ignored in
the similarity metrics.
谷歌了下,关于similarity metrics of categorical variables没有简单现成的答案
,基本都是paper。不知版上诸多大牛是否有好的解决方法?
s***h
发帖数: 26
40
来自主题: DataSciences版 - 求问一道关于NLP的面试题
表示是某IT的DS intern,已挂但还是想为了以后的面试认真准备下
假设我们用topic models(比如LDA)搞出了一些主题,如何evaluate topic quality?
如果我们打算用Precision & Recall来衡量,你怎么建metrics来计算topic的relevant
(我觉得是topic和我们文章的relevant)。
我已经咨询了本校的一些博士,但是没有能够给我一个比较validate的idea。
我个人有点疑惑的点在于:LDA原本是unsupervised(当然也有Supervised版本),这
么干的话需要有一些label data帮助你做evaluate。在我们的情况下(ie 奥观海政治
相关文本),那么我们是不是在知道background情况下找一些感觉相关(ie 奥观海其
他同阶段政治文本)的documents 做training sets,然后想办法build metrics 然后
在test set上检验? 这种在工业上是不是可行,有没有可能给个文本毫无任何
background那这样的话这套quality evaluation可行吗... 阅读全帖
z*******n
发帖数: 1034
41
来自主题: MobileDevelopment版 - Big Data and mobile analytics: Ready to rule 2015
2014 was a big year for big data, a term that gradually gained momentum to
become one of the most talked-about subjects in the tech world. With 2015
fast approaching, prepare for big data’s total domination, as it, along
with the Internet of Things, is set to be the focus of web and mobile.
It will become standard for businesses to try and benefit from it by
analyzing as much as possible.
But what it actually is and what it does isn’t always clear to app
publishers.
Boom-beach-general-2375 mobil... 阅读全帖
x*b
发帖数: 5723
42
哈,是我弄混了weight之间的转换,我也自我纠正一下,顺便给大家发点FYI:
Curb Weight = Weight of Car with standard accessories, full fluids, NO
driver
Unladen EU Weight = Weight of Car with 90% fuel, 68 kg driver, 7 kg cargo
Unladen DIN Weight = Weight of Car with 90% fuel, NO driver, no cargo
1 US Gallon = 3.8 liters
Weight of 1 US Gallon of Gasoline = 6.35 pounds (2.87 kg)
Weight of 1 liter of Gasoline = 1.67 pounds (0.76 kg)
Equations for Weight Conversion:
Curb Weight (metric) = EU1 Weight - 68kg for driver - 7 kg for cargo... 阅读全帖
w*******y
发帖数: 60932
43
Link:
http://www.sears.com/shc/s/p_10153_12605_00934558000P
This 18 pc. set includes both inch and metric sizes for all of your needs
around the house and garage. It includes 9 pc. 12pt deep inch sizes and 9 pc
. 12pt deep metric sizes. It also comes in a plastic tray for easy
portability and storage.
at less than a buck a pop this is a steal for anyone for Christmas or for
yourself. It will add great dimension to a standard socket set and reach
deep and lifetime warranty.
pick up at store for n... 阅读全帖
w*******y
发帖数: 60932
44
I hit my local Harbor Freight and found them getting rid of several things I
could not pass up:
3/8" deep wall Metric socket set $3.77 link:
http://www.harborfreight.com/8-piece-3-8-eighth-inch-metric-deep-wall-impact-socket-set-3655.html
3/8" deep wall SAE socket set $3.77 link:
http://www.harborfreight.com/8-piece-3-8-eighth-inch-sae-deep-wall-impact-sockets-2583.html
7 Piece Impact Adapter set $5.97 link:
http://www.harborfreight.com/7-piece-impact-socket-adapter-set-34046.html
3 Piece Impact... 阅读全帖
w*******y
发帖数: 60932
45
Staples has the WD 1TB Elements Portable WDBABV0010BBK for $99.99. Free
shipping. If you don't have a $25 off $75 coupon buy one at ejunkie or ebay.
Possibly get another 5% back through Shop Discover or 2% through e-bates.
Compatibility
* Formatted NTFS for Windows XP, Windows Vista, Windows 7,
* Mac OS X, Tiger, Leopard, Snow Leopard (requires reformatting)
Package Contents
* USB 2.0 portable hard drive
* USB cable
* Quick Install Guide
Serial Transfer Rate
USB 2.0
S... 阅读全帖
w*******y
发帖数: 60932
46
Link:
http://itunes.apple.com/app/id369324269?mt=8#
#" rel="nofollow" target="_blank" onclick="_gaq.push(['_trackEvent', 'thread
', 'click', '2617717 - kinetic-run-walk-cycle-gps-tracking-for-iphone-free-
today']);">http://itunes.apple.com/app/id369324269?mt=8#
Kinetic is designed specifically to help measure and improve fitness and get
in shape. Kinetic is ideal for outdoor activities such as running, cycling,
hiking, walking or exploring new places. Suitable for everyone from novice
to expert... 阅读全帖
w*******y
发帖数: 60932
47
Craftsman 154 pc. Mechanics Tool Set:
http://www.kmart.com/shc/s/p_10151_10104_005W730703110001P
Select pick up in store to save on shipping
Use Code SAVEBIG for $10 off
Final price $76
Lifetime warranty
Product Description
The 154 piece Mechanics Tool Set includes 93 sockets in 1/4, 3/8 and 1/2 in.
drive sizes, both metric and standard sizes, deep and standard depths. The
set also includes 12 combination wrenches in metric and standard sizes, 3
quick-release ratchets (each drive), 2 extension b... 阅读全帖
w*******y
发帖数: 60932
48
Craftsman 154 pc. Mechanics Tool Set:
http://www.kmart.com/shc/s/p_10151_10104_005W730703110001P
- $77 picked up in store
1) add the Craftsman 154 pc. Mechanics Tool Set:
http://www.kmart.com/shc/s/p_10151_10104_005W730703110001P
, select pick up in store to save on shipping
2) go to c o u p o n c a b i n (dot) com and click their link for the
JOLLYKM coupon, it will actually apply 10% off, not $5 off like it says.
price will go from 85.50 down to 76.95 pre tax if store pickup is chosen.
Lifet... 阅读全帖
w*******y
发帖数: 60932
49
Sears has the 7 Pc. GearWrench Flex Head Ratcheting Wrench Sets (Metric or
Standard) for $27 + free store pickup. Add to cart to see the lower price.
Coupons will not apply to these items.
Metric: Link:
http://www.sears.com/shc/s/p_10153_12605_00944006000P
Standard: Link:
http://www.sears.com/shc/s/p_10153_12605_00944005000P
w*******y
发帖数: 60932
50

Kobalt 10-Piece SAE 1/4"
Drive 6-Point Socket Set for 5.98 Regularly 19.99:
http://www.lowes.com/ProductDisplay?partNumber=338636-25428-852
Kobalt 10-Piece Metric 1/4" Drive 6-Point Socket Set for 5.98 Reg 19.98:
http://www.lowes.com/ProductDisplay?partNumber=338637-25428-852
Kobalt 6-Piece SAE Combina... 阅读全帖

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