s*****g
发帖数: 77 | 1 医院的一个朋友请我帮忙，他发一个paper，reviewer说underpower让他拿回来修改。
她做了400多个sample per group，要做一个test on proportion 去证明treatment里
面的比例要少。（baseline:（1.6%), treatment : 0.8% )
但是我做了power analysis需要至少1000多个sample才可以。因为她不可能再找更多的
sample了。所以他问我有什么办法。我也不知道，请各位大侠看下有什么方法没。
一个reviewer说可以用predictive probability.我看了下好像这个是survival
analysis里的东西，也不知道这里能不能用啊？谢谢大家帮忙了阿 |
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s*r
发帖数: 2757 | 2 for proportional data, it could be predictive value in stead of predictive
probability. google positive predictive value negative predictive value.
to raise power without increasing sample size, you have to raise type I
error bar |
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f***a
发帖数: 329 | 3 monte carlo simulation里的probability 数据
你到底指啥？ |
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a****3
发帖数: 11741 | 4 我想问问Monte Carlo Simulation和probability有什么关系？ |
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f***a
发帖数: 329 | 5 monte carlo是一种解决问题的方法
probability是一个概念
你可以把你的问题说具体点 |
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s*******2
发帖数: 791 | 6 请讲一下计算过程， 谢谢。
(2) A company classifies injuries to its workers as minor if the worker does not have to take time off and severe if the worker has to take time off. The company has two plants, A and B. In plant A 60%of the workers had no injuries, 30% had minor injuries, and 10% had severe injuries. In plant B 50% had no injuries, 35% minor injuries, and 15% severe injuries. 70% of all workers work in plant A and 30% in plant B. what is the probability that a worker who had an injury worked in p |
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s******a
发帖数: 184 | 7 根据一个已知的数据集，估算这个数据的probability distribution 一般用那些方法
？ |
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f***a
发帖数: 329 | 8 其实我觉得第一步先画个histogram看看形状，然后猜测几个candidate distributions
，再去estimate their parameters，然后再验证数据是不是fit。
至于如何验证empirical distribution和candidate distribution是不是fit的方法，
我胡乱说几个：
一当然是画图比较density function;
二可以有计算PIT (Probability integral transform)，这个主要是看
underdispersion or overdispersion的
三是可以计算EMD (Earth mover's distance)，这个是比较两个distributions之间“
距离”的。 |
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s******a
发帖数: 184 | 9 请问在R里怎么计算两个probability density 的covolution？ |
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YW
发帖数: 46 | 10 How can I use SAS to estimate adjusted probability and their differences
using logistic model and get a confidence interval?
Thank you |
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c********k
发帖数: 200 | 11 set 1 has 20 numbers:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95,
100
set 2 is identical to set 1.
randomly select a number from set 1, x1,
and randomly select a number from set 2, x2,
now the question is:
what is the probability of x1+x2=100?
much appreciate! |
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M*******r
发帖数: 165 | 12 就是最普通的probability distribution, 比如normal, 客户要求用CV检验这个
distribution的estimation是否valid，请高手指点下，这样做合理吗？我认为CV更多
是用来检验prediction model, distribution的test更多是用hypothesis test来着，
比如chi square test。 |
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h*****u
发帖数: 109 | 13 请教各位一个Monte Carlo在engineering里应用的一个问题。方法比较简单。是用
Monte Carlo产生若干个Sample，每一个Sample是系统的输入，然后看输出的性能。最
后统计Average。
问题是需要一个probability distribution来产生Sample。知道的信息只是包括最小值
和最大值。没有一个accepted的distribution。请问怎么办？可以把常用的Normal,
Uniform, Triangular等都用上，然后看结果的sensitivity吗？
多谢各位。 |
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p****x
发帖数: 1346 | 14 If I have all the consumer loans history data ready, how to create
Probability Default rate & Loss Given Default rate?
Thanks! |
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m**********r
发帖数: 122 | 15 有一个数据集，每一格数据点对应一个weight. 这个weight不一定非是probability
density,它也可能是整数。请问有什么算法可以根据这些weight 对这个数据集采样。 |
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n**m
发帖数: 156 | 16 I'm using proc glimmix to run cumulative logit model. Boss asks me to plot
the predicted probability to make the result easier to understand. But can't
find an easy approach to do it. Any one has idea? Thanks. |
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p*********g
发帖数: 453 | 17 An interesting question, can anyone help?
Team A beat Team B 3 times out of 4 games; while Team B beat Team C 3 times
out of 4 games. What's the probability that Team A beat Team C?
Thanks. |
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e*****r
发帖数: 621 | 18 就是 mlogit model run 出来以后，要用一些 hypothetical independent variable
value 来算 predicted probability。请问在Stata 12下面具体的code是什么？
我知道在以前版本的Stata下，可以用 prvalue 来算，比如
prvalue, x(a=xx b=xx c=xx) rest(mean)
可现在发现 prvalue 不被recognize了。
另外知道在 LOGIT model里面，可以用 adjust a=xx b=xx c=xx, pr 但是发现这个在
MLOGIT 下面不行。
谢谢指教！ |
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j***o
发帖数: 30 | 19 Just want to check whether someone might have this book.
A Course in Probability Theory (Kai Lai Chung)
Thanks |
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a*******n
发帖数: 247 | 20 最近在看一些paper提到Poisson distribution, coefficient of variation等等统计
术语，在想可能需要找一本书补一下相关知识。但是在图书馆搜probability theory有
好多同样的书，自我感觉从一本写得好的书入门和写得不好的书入门效果完全不同。不
知道大家能不能推荐一本相关的教材呢？多谢多谢！ |
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P*****r
发帖数: 554 | 21 applied statistics and probability for engineers
300 level的本科课的教材,难度不大,自己看看前半部分,应该比较容易 |
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B*********r
发帖数: 62 | 22 X ~ N(0,1), Y ~ N(0,1), X and Y are independent; what is conditional
probability P( X>0 | X+Y>0 )? |
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f*********3
发帖数: 313 | 23 用Proc Glimmix建立3-level random effect logistic regression后需要 predicted
probability，用output 命令只能给出每个样本对应的概率，但我需要自变量不同取值
的概率。请问大家有什么好的建议么？谢谢了。 |
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s*****r
发帖数: 223 | 24 又来学习请教了， 据说这是一个很经典的题目
suppose that in each individual of a large population there is a pair of
genes, each of which can be either x or X, that controls eye color: those
with xx have blue eyes, while heterozygotes (those with Xx or xX) and those
with XX have brown eyes. The proportion of blue-eyed individuals is p2 and
of heterozygotes is 2p(1−p), where 0
its own genes to the child; if a parent is a heterozygote, the probability
that it transmits the gene o... 阅读全帖 |
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l****u
发帖数: 199 | 25 survival analysis, censored be defied as the thing happened 1, not happened
as 0. When I get the output of Survival (used baseline covariance is the
independent variables matrix), should the probability=1-Survival or directly
Survival? Can anybody give a help? Thanks. |
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D****G
发帖数: 284 | 26 如果客户要求在50,000中选出 top20 risky target, 那岂不是不能根据estimated
probability of default 来排序取最大的20个？这样的话，模型没法用啊，project的
目的就是找出top 20 risky的target.
minimal |
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c*********4
发帖数: 8 | 27 It looks like a Bayesian question. Assuming non-informative prior for p, the
conditional probability for p=0.5 given x=55 is ... :) |
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w*******y
发帖数: 60932 | 28 Pretty sure it's YMMV since it's clearance, but if you need one it's
probably worth checking.
It's currently $749 on Amazon, so I jumped all over it when I saw the price:
Link:
http://www.amazon.com/Canon-T1i-Digital-18-55mm-3-5-5-6/dp/B001
I'm new and don't know how to make an inventory checker thing, sorry.
Link:
|
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p*****l
发帖数: 399 | 29 I read about a formula in a book today, which calculates the probablity of
going broke.
Pr(Going broke)=e的[(-2BW)/(V)]次方=EXP((-2BW)/(V))
B is the bankroll
W is the win rate
V is the variance which is equal to the standard deviation squared
For example, for a good player in a good live game, a typical win rate is 1
big bet per hour and a typical standard deviation is 10 big bets per hour,
based on the assmuption, we can calculate the risk of ruin for various size
bankrolls as follows:
Bankroll (B |
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g****g
发帖数: 1828 | 30 In probability theory, the normal (or Gaussian) distribution, is a
continuous probability distribution that is often used as a first
approximation to describe real-valued random variables that tend to cluster
around a single mean value. The graph of the associated probability density
function is “bell”-shaped, and is known as the Gaussian function or bell
curve:[nb 1]
f(x) = \tfrac{1}{\sqrt{2\pi\sigma^2}}\; e^{ -\frac{(x-\mu)^2}{2\sigma^2}
},
where parameter μ is the mean (location of the pe... 阅读全帖 |
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k**********4
发帖数: 16092 | 31 Game Rules
The numbers picked for the prizes consist of 5 numbers picked at random
from a pool of 56 numbers (the White Numbers). Then a single number (the
Mega Number) is picked from a second pool that has 46 numbers. If the
results of these random number selections match one of the winning
combinations on your lottery ticket, then you win something.
In any combinatorics problem where all possible outcomes are equally
likely, the probability of a successful outcome is determined by findin... 阅读全帖 |
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f**d
发帖数: 768 | 32 这是一本计算神经科学的优秀著作，全文拷贝这里（图和公式缺），有兴趣的同学可以
阅读
如需要，我可以分享PDF文件（－－仅供个人学习，无商业用途）
From Computer to Brain
William W. Lytton
From Computer to Brain
Foundations of Computational Neuroscience
Springer
William W. Lytton, M.D.
Associate Professor, State University of New York, Downstato, Brooklyn, NY
Visiting Associate Professor, University of Wisconsin, Madison
Visiting Associate Professor, Polytechnic University, Brooklyn, NY
Staff Neurologist., Kings County Hospital, Brooklyn, NY
In From Computer to Brain: ... 阅读全帖 |
|
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m********t
发帖数: 13072 | 34
======================================================
Fundamentals of Probability
Consider the experiment of rolling two dice: one 6-sided and one 20-sided.
1. How many possible outcomes are there for this experiment?
2. Find the probabilities of each of the following events.
(a) Rolling a 6 on the 6-sided die
(b) NOT rolling a 6 on the 6-sided die
(c) Rolling a 20 on the 20-sided die
(d) NOT rolling a 20 on the 20-sided die
(e) Rolling a 6 on the 6-sided die AND a 20 on the 20-sided die
(f) N... 阅读全帖 |
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g********n
发帖数: 2314 | 35 【 以下文字转载自 SanFrancisco 讨论区 】
发信人: dadabear (bless you), 信区: SanFrancisco
标 题: [合集] goldenrain的观点未免偏颇
发信站: BBS 未名空间站 (Thu Feb 8 16:24:51 2007), 站内
☆─────────────────────────────────────☆
MSJ (Mission San Jose) 于 (Tue Feb 6 00:42:38 2007) 提到:
看完他blog的《现在在哪里买房风险小》，我只能笑着摇摇头。在我眼里，这个列表与
其说是“风险小”列表，不如说是“房子难涨地区列表”。试论证一二：
1. 常言道“强者恒强，弱者恒弱”。NYC, SF地区房价高企不是一年两年了，支撑房价
的不是那个affordability的percentage，而是能afford的人口数和房子总数的比例。
这里看百分比是没有多大意义的。只要还有人能买得起还愿意买，即使affordability
只有15%又如何呢？
2. 正如high tech公司的P/E要远大于... 阅读全帖 |
|
发帖数: 1 | 36 Stone Cold Word
Longboat Key, Florida4m ago
AG Barr investigating a missing Twinkie is a joke.
So I am reading all these comments laughing and calling out "conspiracy
theories". It's easy to "throw shade"..... getting "shade to stick" is
another story.
I know this. A high profile prisoner, who supposedly tried to kill
himself just two weeks ago, this guy could not get near a 6 inch piece of
thread. Now that's not a "conspiracy theory".
The "shade slingers" want us to believe that this ego ... 阅读全帖 |
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B*********e
发帖数: 86 | 37 ([email protected])
回帖_BiggeyIssue_to wonderingmm jiuselu Asdfeqo et al_mitbbs_2018-03-08 ~ 03
[email protected]_1633-.docx
([email protected])
回帖_BiggeyIssue_to wonderingmm jiuselu Asdfeqo et al_mitbbs_2018-03-08 ~ 03
[email protected]_2224-.docx
([email protected])
回帖_BiggeyIssue_to wonderingmm jiuselu Asdfeqo et al_mitbbs_2018-03-08 ~ 03
[email protected][email protected]_2330-_.docx
([email protected])
回帖_BiggeyIssue_to wonderingmm jiuselu Asdfeqo et a... 阅读全帖 |
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s******l
发帖数: 6898 | 38 诺贝尔奖获得者的宗教信仰
云儿
（转自“独立评论”）
----------------------------------------------------------------------------
-------
诺贝尔物理学奖获得者的宗教信仰
闲极无聊读杂书，读到一本的《1901-2000年诺贝尔奖获得者大全》(Louise S. Sherby
, "The Who’s Who of Nobel Prize Winners 1901–2000", Oryx Press, Westport,
CT • London 2002)。突然觉得手痒，量化癖发作，随手作了一个物理学奖获得
者的宗教信仰统计。
此书编者，从公开文献中摘取物理学奖获得者的个人资料，包括宗教信仰。当文献中明
确提到获奖者的宗教信仰及其所属教派时，编者会尽可能列出细分的教派名。当编者感
觉相当肯定获奖者信仰某一宗教，但无法确认之时，就用“极可能信某教(如 Most
probably Christian)”标出。有时候，获奖者的宗教信仰有改变，编者就以“来自某
某教背景(如 From Jewish b... 阅读全帖 |
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B*********e
发帖数: 86 | 39 【 以下文字转载自 Faculty 讨论区 】
发信人: BiggeyIssue (出大事儿了..(可算)出大事儿了...), 信区: Faculty
标 题: Re: 标 题: Re: 求建议，回国还是留下
发信站: BBS 未名空间站 (Fri Feb 1 15:23:11 2019, 美东)
~~~~~~~~~~~~~~~~~~~~~~
[回复] [回信给作者] [本篇全文] [本讨论区] [修改] [删除] [转寄] [转贴] [收藏]
[举报] [ 154 ]
发信人: BiggeyIssue (出大事儿了..(可算)出大事儿了...), 信区: Faculty
标 题: Re: 求建议，回国还是留下
发信站: BBS 未名空间站 (Fri Feb 1 15:03:14 2019, 美东)
(2019-01-29#2013)
to sunnyan (羊妈妈)和爱人__to （water77 (水)__mitbbs发考题版__mitbbs发考题版
_2019-01-25#0015-0439__s#0440__1840-2333__01-26#1852-... 阅读全帖 |
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g********n
发帖数: 2314 | 40 原来是'Performance profiling' could help to catch cheater 现在是 '
Performance profiling' could help to dispel doubts.
Why great Olympic feats raise suspicions
'Performance profiling' could help to dispel doubts.
Ewen Callaway
01 August 2012 Corrected: 03 August 2012
Chinese swimmer Ye Shiwen broke the world record for the women's 400-metre
individual medley event at the Olympic Games on 28 July.
L. NEAL /AFP / GETTY IMAGES
Article tools
print
email
rights & permissions
share/bookmark
At the Olympics,... 阅读全帖 |
|
m*****n
发帖数: 1513 | 41 MH370 Malaysia plane: How maths helped find an earlier crash
Statisticians helped locate an Air France plane in 2011 which was missing
for two years. Could mathematical techniques inspired by an 18th Century
Presbyterian minister be used to locate the mysterious disappearance of
Malaysia Airlines Flight MH370?
In June 2009, Air France flight 447 went missing flying from Rio de Janeiro
in Brazil to Paris, France.
Debris from the Airbus A330 was found floating on the surface of the
Atlantic five d... 阅读全帖 |
|
a********9
发帖数: 3813 | 42 Trump’s Immigration Ban Blocks Travelers at Airports Around Globe
WASHINGTON — President Trump’s executive order on immigration
quickly
reverberated through the United States and across the globe on Saturday,
slamming the border shut for an Iranian scientist headed to a lab in Boston,
an Iraqi who had worked as an interpreter for the United States Army, and a
Syrian refugee family headed to a new life in Ohio, among countless others.
Around the nation, security officers at major international ga... 阅读全帖 |
|
a********9
发帖数: 3813 | 43 Trump’s Immigration Ban Blocks Travelers at Airports Around Globe
WASHINGTON — President Trump’s executive order on immigration
quickly
reverberated through the United States and across the globe on Saturday,
slamming the border shut for an Iranian scientist headed to a lab in Boston,
an Iraqi who had worked as an interpreter for the United States Army, and a
Syrian refugee family headed to a new life in Ohio, among countless others.
Around the nation, security officers at major international ga... 阅读全帖 |
|
a********9
发帖数: 3813 | 44 最新消息：
Trump’s Immigration Ban Blocks Travelers at Airports Around Globe
WASHINGTON — President Trump’s executive order on immigration
quickly
reverberated through the United States and across the globe on Saturday,
slamming the border shut for an Iranian scientist headed to a lab in Boston,
an Iraqi who had worked as an interpreter for the United States Army, and a
Syrian refugee family headed to a new life in Ohio, among countless others.
Around the nation, security officers at major internatio... 阅读全帖 |
|
j****m
发帖数: 8 | 45 看到有人指出在icmlc 2011会议中同一个作者发表论文达10多篇。本文深知做学术
的不易，觉得在短时间内能在同一个会议上发表10多篇论文，不是造假抄袭，就是粗制
滥造。于是随便找了一篇搜索了一下。发现不如所料，亩产万斤果然是有问题的。
请相关专业人员鉴定是否属于抄袭，以及是否还有其他未发现之处。
抄袭文（以下简称USOM文）
Le Li, Xiaohang Zhang, Zhiwen yu, Zijian Feng, Ruiping Wei, USOM: Mining
and Visualizing Uncertain Data Based on Self-Organizing Maps, Proceedings
of the 2011 International Conference on machine Learning and Cybernetics,
804-809
作者单位：
School of Computer Science and Engineering, South China University of
Technology, Guangzhou, China
... 阅读全帖 |
|
m*****n
发帖数: 1513 | 46 【 以下文字转载自 Military 讨论区 】
发信人: mitcoin (米特币), 信区: Military
标 题: BBC：Bayesian Stat.可找MH370，曾成功找到法航残骸
发信站: BBS 未名空间站 (Sat Mar 22 11:06:03 2014, 美东)
MH370 Malaysia plane: How maths helped find an earlier crash
Statisticians helped locate an Air France plane in 2011 which was missing
for two years. Could mathematical techniques inspired by an 18th Century
Presbyterian minister be used to locate the mysterious disappearance of
Malaysia Airlines Flight MH370?
In June 2009, Air France flight 447 went m... 阅读全帖 |
|
g********d
发帖数: 4174 | 47 Jump to…Top of pageAbstractIntroductionMaterials and
methodsResultsDiscussionConclusionAcknowledgementsReferences
Introduction
Top of page
Abstract
Introduction
Materials and methods
Results
Discussion
Conclusion
Acknowledgements
References
The National Blood Services of the UK have, since the early 1980s, asked men
who have ever had sex with men (MSM) to not donate blood. At first, this
action was motivated by the aim of preventing transmission by transfusion of
the infectious agent associated ... 阅读全帖 |
|
g**********2
发帖数: 2408 | 48 Question-and-Answer Session
Operator
Thank you. Ladies and gentlemen, we will now begin the question-and-answer
session. (Operator Instructions) Your first question now comes from the line
of Philip Wan from Morgan Stanley. Please ask your question.
Philip Wan - Morgan Stanley
Hi, Louis and Sisi, thanks for taking my question. My question is about your
overseas business, as you mentioned you are seeing intensifying competition
, could you elaborate a little bit more on where do you see tougher
c... 阅读全帖 |
|
g**********2
发帖数: 2408 | 49 Question-and-Answer Session
Operator
Thank you. Ladies and gentlemen, we will now begin the question-and-answer
session. (Operator Instructions) Your first question now comes from the line
of Philip Wan from Morgan Stanley. Please ask your question.
Philip Wan - Morgan Stanley
Hi, Louis and Sisi, thanks for taking my question. My question is about your
overseas business, as you mentioned you are seeing intensifying competition
, could you elaborate a little bit more on where do you see tougher
c... 阅读全帖 |
|
