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全部话题 - 话题: model
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y***i
发帖数: 36
1
来自主题: SJTU版 - Fuel cell modeling Postdoc positions
Fuel cell modeling Postdoc positions
Two post-doc research fellow positions are available at the center of solid
oxide fuel cells at the University of South Carolina http://www.engr.sc.edu/SOFC/team.html.
The research area is about solid oxide fuel cell modeling and computation or
closely related topics. At least one of the following primary Background is
preferred:
1) fuel cell modeling, solid oxide fuel cell modeling background is of
particular interest;
2) computational fluid dynamics (CFD
y***i
发帖数: 36
2
来自主题: USTC版 - Fuel cell modeling Postdoc positions
Fuel cell modeling Postdoc positions
Two post-doc research fellow positions are available at the center of solid
oxide fuel cells at the University of South Carolina http://www.engr.sc.edu/SOFC/team.html.
The research area is about solid oxide fuel cell modeling and computation or
closely related topics. At least one of the following primary Background is
preferred:
1) fuel cell modeling, solid oxide fuel cell modeling background is of
particular interest;
2) computational fluid dynamics (CFD
y***i
发帖数: 36
3
来自主题: XJTU版 - Fuel cell modeling Postdoc positions
Fuel cell modeling Postdoc positions
Two post-doc research fellow positions are available at the center of solid
oxide fuel cells at the University of South Carolina http://www.engr.sc.edu/SOFC/team.html.
The research area is about solid oxide fuel cell modeling and computation or
closely related topics. At least one of the following primary Background is
preferred:
1) fuel cell modeling, solid oxide fuel cell modeling background is of
particular interest;
2) computational fluid dynamics (CFD
y***i
发帖数: 36
4
Fuel cell modeling Postdoc positions
Two post-doc research fellow positions are available at the center of solid
oxide fuel cells at the University of South Carolina http://www.engr.sc.edu/SOFC/team.html.
The research area is about solid oxide fuel cell modeling and computation or
closely related topics. At least one of the following primary Background is
preferred:
1) fuel cell modeling, solid oxide fuel cell modeling background is of
particular interest;
2) computational fluid dynamics (CFD
s*****o
发帖数: 48
5
Aims and Scope: Exploring and using anatomical shape properties plays an
increasingly important role in many medical imaging and image processing
applications. For examples, in medical image segmentation, prior knowledge
on the shape of interest has been used to achieve more accurate segmentation
, e.g. in case of ambiguities owing to limited image quality. In
neuroscience, the shape of certain brain structures, such as hippocampus,
has been shown to be useful for predicting the development of a... 阅读全帖
a*******5
发帖数: 3
6
是SOCIAL MEDIA公司关于USER ANALYTICS方面的职位的面试题. 本人在SCHEMA AND
LOGICAL MODEL DESIGN这方面实践经验很少,急切期待各位指点这一类问题的切入点和
解决思路。如果对任何一题有线索,或EXAMPLE,或者LINK...我都非常感激!
- Design a database schema http://en.wikipedia.org/wiki/Database_schema to be used internally for user analytics (ad hoc analysis and automated reporting) of its mobile applications.
- For a typical social network product, describe the logical data model for
related fact and dimension tables, the aggregation tables you'd want to
build for analytics,... 阅读全帖
w*******7
发帖数: 188
7
According to Julie's blog, if you use EF5 and VS2012, you can "uses a code
generator that spits out POCO entity classes managed by a DbContext by
default rather than the EntityObject based classes managed by the
ObjectCpntext as it did for VS2008 and VS2010."
http://thedatafarm.com/blog/data-access/getting-started-with-ef
I used "code first" to build a db and use "DB first" to reverse-engineering
a model (You can use such as model.tt to rebuild you data model) and
compared with previous class, b... 阅读全帖
o******n
发帖数: 511
8
谢谢你的回复。
如果我们不加kinship到model里,那么genotype就是一个有27个level的factor,R会
assume这些level是一样的,但其实它们之间的genetic distance并不一样,所以我们
想把这个信息加到model里。
让我困惑的就是怎么加。我想到一个办法就是把每个plant genotype跟其它所有
genotype的total genetic distance作为一个新的covariate放到model里。但我又觉得
,这个covariate和genotype不是collinear的吗?
plant breeding的人有时会把kinship matrix加到model里做association analysis。
不过我们的trait不是传统意义上的phenotype,也没有每株植物的SNP data,所以很多
软件/package不能用……
s*****o
发帖数: 48
9
Aims and Scope: Exploring and using anatomical shape properties plays an
increasingly important role in many medical imaging and image processing
applications. For examples, in medical image segmentation, prior knowledge
on the shape of interest has been used to achieve more accurate segmentation
, e.g. in case of ambiguities owing to limited image quality. In
neuroscience, the shape of certain brain structures, such as hippocampus,has
been shown to be useful for predicting the development of a ... 阅读全帖
s*********o
发帖数: 14
10
来自主题: Economics版 - 求助time-series models
Yes, it's location-scale model, but for most of those models, lagged Y_t's
are also in the right-hand equation (in the location term m and/or the scale
term s). While here I want some models where the right-hand side does NOT
contain any Y's. Are models like this popular? Especially are they used in
applications? Thanks.
f*******r
发帖数: 257
11
Generally there are two ways of deriving the models for binary data:
1. latent variable approach: y*=x \beta + u. Here y* is a continuous
latent variable. then u can be treated as logistically or normally
distributed, which corresponds to logit or probit model. This approach is
modeling the underline variable behind the binary variable y.
2. link function approach. This approach models the binary variable y
directly: y=g(X \beta), where g() is the inverse link function. Basically
it maps
s**l
发帖数: 869
12
来自主题: Economics版 - Gordon growth model问题请教 (转载)
【 以下文字转载自 Stock 讨论区 】
发信人: stll (Cynthia we love you), 信区: Stock
标 题: Gordon growth model问题请教
发信站: BBS 未名空间站 (Thu Apr 21 22:12:00 2016, 美东)
小弟门外汉正在学习知识中,对这个model不是很明白,向大家请教。(自己感觉是个
很傻的问题,大家莫笑)
在下面的链接中,
http://www.investopedia.com/terms/d/dcf.asp
Gordon growth model(dividend discount model (DDM)) 定义
公司的terminal value = projected cash flow for final year (1 + long-term
growth rate) / (discount rate - long-term growth rate)
这里 discount rate 我有两种理解,一种是等同于fed discount rate,也就是常说的
美联储基本拆借利率,这个目前很低是0.... 阅读全帖
q*******n
发帖数: 52
13
想找个ideal switch model, 要求有控制开关, Ron=0ohm, Roff = infinity ohms. 因
为在一些precision电路中, 希望开关换成理想的, 先算别的部分引进的误差.
在analogLib, 有个model called "switch", 但是open switch resistance, close
switch resistance 必须设成实际的数, 好象设成 0 会出错.
还看到一个model called "sp1tswitch", 这个model 好象没有控制开关, 只有静态的
设置成开或关.
最近问题太多, 感谢本版帮助.
I***a
发帖数: 704
14
我现在有1个foundry提供的spectre model,描述一个transistor的 ,但是foundry没
有提供cadence里面的cell ,我现在需要做LVS, 就把foundry提供的类似的cell复制
一个新的,然后用TOOLS->CIF->Edit修改了 Base Model Name 和 Model Name 这2个参
数。 但是LVS得到的 schematic的netlist 还是用的修改前的 model name。 如何解决
呢?
l***r
发帖数: 473
15
来自主题: EE版 - CMOS device or modeling
工作快2年了,做了1年半的CMOS device modeling,加半年多的CMOS device, 20nm
的,在NY的一家大型半导体公司,大家估计都知道。
最近在考虑换工作,现在有个机会,是一家RFIC的设计公司,做modeling/
simulation的,不过公司规模要小,在加州,地点是好很多。
比较纠结的是,职业发展方向到底是沿着device呢,还是modeling/simulation呢
? 搞device的,其实没几家公司了,就业范围比较窄,但是最近很多foundry/IDM 都
在大规模投资,貌似发展还可以。 如果转做modeling,很多fabless的公司会需要,但
是不值得前景会怎样,而去一旦转了,再回头就难了。
其实个人最理性的就是找个这两个都需要的职位,可惜opening就更少了。。。
听听大家的说法呢
k******a
发帖数: 306
16
代发,If interested, pls contact: d******[email protected]
Looking for a Director/Associate Director in Clinical Pharmacology Modeling
& Simulation for a global leading pharma in Shanghai, China
Qualifications and Responsibilities:
The role requires doctoral-level training (Ph.D., Pharm.D., or M.D.). An
analytical and inquisitive mind for problem solving and strong written and
oral communication skills are essential. You will be working across the
drug discovery pipeline from pre-candidate selectio... 阅读全帖
w*****1
发帖数: 473
17
来自主题: Pharmaceutical版 - 请问大家有关mixed model (转载)
【 以下文字转载自 Statistics 讨论区 】
发信人: wz99331 (dotti), 信区: Statistics
标 题: 请问大家有关mixed model
发信站: BBS 未名空间站 (Wed Jul 19 12:57:18 2017, 美东)
大家好,我需要用mixed model 对三个group的人群(教育程度1,2,3)进行分析,看
看这些人的认知能力在不同时间的变化有没有显著性的不同。
proc mixed data=outban;
class timepoint educ;
model rbantotal= timepoint | educ/ solution;
random int /subject=id ;
lsmeans educ*timepoint;
run;
因为我是3个group,而不是两个group,如果我想看相互作用项educ*timepoint的p-值,
是不是需要用f-test?如何在mixed model中用f-test呢?我看到现在的结果里就已经有
f-test了:
... 阅读全帖
w*****1
发帖数: 473
18
来自主题: Psychology版 - 请问大家有关mixed model (转载)
【 以下文字转载自 Statistics 讨论区 】
发信人: wz99331 (dotti), 信区: Statistics
标 题: 请问大家有关mixed model
发信站: BBS 未名空间站 (Wed Jul 19 12:57:18 2017, 美东)
大家好,我需要用mixed model 对三个group的人群(教育程度1,2,3)进行分析,看
看这些人的认知能力在不同时间的变化有没有显著性的不同。
proc mixed data=outban;
class timepoint educ;
model rbantotal= timepoint | educ/ solution;
random int /subject=id ;
lsmeans educ*timepoint;
run;
因为我是3个group,而不是两个group,如果我想看相互作用项educ*timepoint的p-值,
是不是需要用f-test?如何在mixed model中用f-test呢?我看到现在的结果里就已经有
f-test了:
... 阅读全帖
B*********h
发帖数: 800
19
Quantitative model development -Singapore (client will relocate qualified c
andidates from other locations)
Job Summary:
This is a mid level model development position aligned with a Singapore Comm
odities trading desk, which is a part of a global operation.
The candidate will develop models, implement products, and support the tradi
ng desk.
Core Responsibilities:
Develop models and implement them in software for pricing
and risk managing commodities and commodity/energy derivat
IJ
发帖数: 494
20
1.Credit Derivatives Pricing Models: Model, Pricing and Implementation -
Philipp J. Sch?nbucher
2.An Introduction to Credit Risk Modeling (Chapman & Hall/Crc Financial
Mathematics Series) - Christian Bluhm
3.Credit Risk Modelling: The Cutting-edge Collection - Technical Papers
published in Risk 1999-2003
4. Cutting-edge papers on recent Risk Maganize

market
i****e
发帖数: 78
21
I guess that you can try few ways
1) reduce the degree of freedom in your model, i.e., reduce model
parameters, use simpler model.
2) or try to calibrate to more market data. for example, if you want
to calibrate the correlation, find some liquid options, which are
sensitive to correlation.
3) or use historical data to determine the undetermined model parameters.

to
some
.g
n****8
发帖数: 23
22
来自主题: Quant版 - Predictive Power of Hull White Model
If you have both positive or negative bias, it is normal since no model can
predict the rate perfectly. But persistance positive biase means something
wrong.
HW is affine term structure models. If you use 1 factor HW, it doesn't
capture non parallel shift of the term structure. Hence the TS you forecase
could only show paralell movement, which result in persistance positive or
nagative bias.
If you use 2 factor models, it can allow non parallel shift. But there are
many format of 2 factor models
G*****o
发帖数: 1341
23
我在一个financial service 公司(starmine) 做 model, 主要是根据wallstreet 各个
投行的analyst 给出的eps estimate 的改变,来做一个monthly 投资的model, 选出
最近得到postive EPS estimate revision。 有谁做过类似的model吗?不了解市场,
也不了解自己做的model 是哪些人在用。欢迎大家讨论。
b*********e
发帖数: 2
24
Please send your resume to j********[email protected]
Job Title
Senior Quantitative Analyst I
Job Description
Using statistical packages such as MatLab, or SAS to build pipeline fallout
models for the purpose of pipeline closing ratio projection and risk
management. This includes retrieving and organizing pipeline data from
database, building statistics models, implementing, validating, documenting
models, and monitoring model performance on a regular basis. In addition,
this candicate will b
g******8
发帖数: 542
25
affine jump diffusion model 是heston model上加入compounded poisson jump on
log price and also on volatility. 我看的几篇research paper, 比如“# B.
Eraker. (2003).# Do Stock Prices and Volatility Jump? Reconciling Evidence
from Spot and Option Prices.”,里面就说转换成risk neutral meausre的affine
jump diffusion model的结果is standard in the literature.可是我没找到起源,不
知道是怎么转换的。这里有大牛指点一下么?谢谢!
C******n
发帖数: 9204
26
market肯定是incomplete的,没人能买卖任意数量。
在SV model里是incomplete,但这是this model的缺陷,因为实际上有比该模型更多的
product存在但没考虑。Potentially,任意的shock都可以write contract。正如你所
说,vol是个market,而且liquidity足够好,for the purpose of SV modeling,可以
算是complete。
我主要说的是上面童鞋想模型有点太literal,model说incomplete就能任意设置SDF,
这是不合理的。

to
a
big
k*******i
发帖数: 82
27
来自主题: Quant版 - 请问CIR model
好吧,我来科普一下吧。 First of all , this is a short rate term structure
model. If you only observe a time series of the short rate r_t, then you can
use MLE or GMM to estimate the model parameters easily because it is an
affine model whose CCF has closed form solution. Now the issue is, you don't
observe the short rate, but the treasury rates only. In principal, the
treasury
rates with different maturities are the functions of the short rate and the
model parameters. Therefore you need to do the followin... 阅读全帖
a*****a
发帖数: 286
28
我是经济学的phd,不是数学出身,快毕业了。论文主要搞the empirical estimation
of stochastic volatility models. 主要用到的方法是bayesian MCMC, 对state
space model, kalman filter or particle filter比较熟悉些。
MSCI’s Equity Risk Modeling Group里的quantitative researcher职位要是面试的
话会主要问哪方面的问题啊?论文做起来都是有深度没广度,想多准备一下职位相关的
知识,希望这里的朋友能给些建设性意见,谢谢。我目前想到的是多看看factor
models和financial time series。
y*****n
发帖数: 5016
29
来自主题: Quant版 - hiring 2 model managers (转载)
【 以下文字转载自 Statistics 讨论区 】
发信人: yuxuxin (开水泡妞), 信区: Statistics
标 题: hiring 2 model managers
发信站: BBS 未名空间站 (Fri Aug 1 23:37:10 2014, 美东)
TD bank, Wilmington DE office
will be officially posted on September 1
therefore haven't drafted official job requirements yet
however, below are the key qualifications i am looking for
hands-on modeling experience, preferably acquisition model building
model performance monitoring experience, e.g. creating and reviewing reports
financial industry experience,... 阅读全帖
t********a
发帖数: 423
30
【 以下文字转载自 JobHunting 讨论区 】
发信人: tomorrowba (明天吧), 信区: JobHunting
标 题: Irvine,CA major financial招modeling manager III and director
发信站: BBS 未名空间站 (Wed Apr 15 11:33:05 2015, 美东)
借朋友的ID发帖。
Irvine,CA major financial招modeling manager III and director
需要有predictive modeling, time series modeling experience.Director will
manager a team.
需要有身份。如果有兴趣请email your resume to [email protected]
/* */
谢谢。
l*******y
发帖数: 22
31
来自主题: Statistics版 - 求助:hierarchical linear model 的问题
你说的正是我所迷惑的地方
hierarchical linear model和random effect model 或者 multi-level model看似很
像,但是有好几个疑点
第一: 前者经常在bayesian学派的书籍中出现,后者几乎只在频率学派的书中出现,
这是否说明这两类模型是两派分别提
出来的?所以还是有所区别的吧。
第二: 有一本书《mixed models》中讲到一点这两者的区别,说他们虽然结构相似,
但是前者的prior是自己给定的,而
后者的“prior”的参数是通过各种优化算法计算出来的,比如em,newton。。
可否指点一下这两者究竟有何关系?
s**********e
发帖数: 63
32
Bayesian 的可以通过matlab 实现:
Step 1: Gibbs Sampling - take marginal probability distribution of your
Estimate Result and run Gibbs Sampler. Starting value - Your OLS result or
whatever model you used to estimate the parameters.
Step 2: Get your posterior and and use Chibs method to yield the Log
Marginal (LME) Likelihood of each model. Take the exponents of the LME, then
you would derive your Marginal likelihood (ML). (Simply taking the
exponents of the LME), Add the ML of all of your models, they s
s*********e
发帖数: 1051
33
both response and look-alike models are just buz terms. essentially, they
are logit models. the difference is how to define modeling population and
objectives.
c****s
发帖数: 63
34
MSE是用来比较几个Model之间的哪一个MSE的数值最小,如果直接用一个Gamma model的
话,一个MSE的数值恐怕不能说它是好还是不好吧。
老板要用R-square是因为看到一个 R-square就可以判断它是不是好的model了。
我虽不太同意这种做法,但确也找不到其他的这样的test来判断一个GLM Model了
真的是好郁闷呀,不知各位大虾还有没有高招了
b*******g
发帖数: 513
35
为什么在mixed models中加入random effects,response就conditionally
independent了?看了一些书上写的,random effects是用来消除corellated
responses中的correlation的。不管是general linear mixed models,还是genralized
linear mixed models,加入random effects,responses就从correlated,变为
conditionally independent了。基本上书上都这么写,但没写为什么?哪位大虾知道
?还有mixed models中都是什么样的effects能成为random effects?
f**********t
发帖数: 1001
36
来自主题: Statistics版 - 问个关于credit score model的问题
1. 想了解一下公司里做这个的时候,是以什么标准来评判一个credit score model的
好坏
的?
2. 另外,一个公司里是不是会有多个credit score model呢?这个问题还望牛人指教
。看相
关的书了解到的情况,是说对历史数据做个logistic regression,这样对于每个
factor都会
有相应的coefficient。然后新的数据到来时,已知coefficient,就能做预测。想问的
是,这
多个credit score model是如何产生的?是不是不同的binning method(相似的组归类),
factor的取舍,都会产生不同的model?
多谢~~~~
b*********l
发帖数: 466
37
来自主题: Statistics版 - Please help with ANCOVA models
Perform the following ANCOVA models:
Model 1
Dependent variable: Log(BLVALUE)
Independent variables: TREATMENT, AGEYR, SEXSNM
Model 2
Dependent variable: Log(VALUE) Use the value at visit 10
Independent variable: TREATMENT, AGEYR, SEXSNM,
log(BLVALUE) Use the natural log when doing the log transformations

Need the following results reported:
Adjusted mean for Treatment group
Adjusted mean for Placebo group
P-value from the treatment factor in the A... 阅读全帖
c*****1
发帖数: 131
38
主要做marketing modeling (data manipulation, data analysis, build campaign models, model diagnosis and model deployment), need SAS, fresh MS/Ph.D都行,和群,性格好,有潜力,希望本科是学理工科的(数学,统计,CS最好),愿意relocate到中西部, 2 years contract
Support OPT/H1B
I will not answer questions, please send your resume to s******[email protected] directly if you are interested. We will contact you if you are good candidate.
最好今天,需要这两天确定面世的人选
Thanks a lot,
F******n
发帖数: 160
39
来自主题: Statistics版 - Help: mixed model
Based on your description, I guess you could construct a dynamic model to
account for the "time-dependent" effect. There are standard constructions
for such type of dynamic models, say try google "dynamic linear models."
The specific details for setting up such models depend on your data and
prior/domain knowledge about observations/effects in your studies.

in
s*********e
发帖数: 1051
40
来自主题: Statistics版 - a risk modeling opening in my team
it is within a regional bank in cincinnati. if interested, please email your
resume to me w********[email protected]
no relocation package but likely to have some moving assistance. however, we
are very supportive to h1b and green card.
thanks.
1) advanced degree in statistics / econometrics / other quantitative fields
with a solid grasp in modern statistical modeling and data mining and the
completion of statistics courses at the graduate level.
2) high-degree proficiency in SAS base, stat, ets, and en... 阅读全帖
r****t
发帖数: 276
41
来自主题: Statistics版 - GEE model一问
诸位大虾,在下试用GENMOD with repeated option去估计一个率,看起来很简单的
model,比如这样:
proc genmod data = dsn;
class subjid y x;
model y = x/link = logit distribution = binomial;
repeated subject = subjid/type=exch;
estimate 'rate a' x 1 0;
run;
可是一旦使用了repeated option 也就是GEE model,出来的率非常邪门。如果直接
proc freq; tables y*x得到的y=1 & x=1的率是70%左右,用GEE model求出来的居然在
30%左右?我注意到用exchangeable option 出来的working correlation〉0.95,这是
不是如此离奇的rate的原因亚?那位大虾对这种情况有经验望不吝赐教,谢先
h**t
发帖数: 1678
42
来自主题: Statistics版 - random forest model
1) if i save the rf model using the training datset and want to test the rf
model by the test dataset. How does the model was used? it pass the dataset
to all 500 trees(if i use default setting) and give out the everage or it
will pick the one which is most close?
2) rf 的结果是average all trees,我可以看到rules in each tree, 怎么能看到the
final outcome, the average result? 要自己计算吗?
3)能否提供一些rf model 应用的文章
多谢!
y*****w
发帖数: 1350
43
I was running the JM package in R for a joint model for longitudinal and
survival data. I could successfully run the lme() function (for the mixed
model) and the coxph() function (for the Cox model) separately, but when I
ran the JointModel() function, the program returned the following error
message:
Error in fitter(X, Y, strats, offset, init, control, weights = weights, :
Can't fit a Cox model with 0 failures
I double checked my data and there was no any irregular point. What's the
meaning ... 阅读全帖
a*********y
发帖数: 36
44
来自主题: Statistics版 - 关于 Risk model
被问到关于risk model的问题,不太理解,请教版上有相关经验的高人。
1. risk model 用很多credit bureau 的数据,大概两百个吧,但是很多variable 的
missing value 高达90%,这种情况应该如何处理?被告知dataset里面所有的missing
value都被populate 成9999,这样是否可行?如果不可行,应该如何处理?
2. 一般用多少个independent variables 来build model, 一般最后选出来多少个?用
sas run proc logistic 的话,放200最后还是选出来50个左右,怎样可以减少到10-15
个?是不是放得太多?如果不放那么多的话,有什么好的方法可以选择出适量的
variables 放进去 run model?
问题太多,谢谢!
P*****6
发帖数: 273
45
lasso 的使用本版讨论了不少,受益不浅,不过实际应用中还是遇到一个问题,不知高
手如何解决
我的基本问题跟前一段一位老兄相似,就是run不同次结果不同
我的数据只有50个左右,variable 却有400多个
我可以理解可能有多个参数coefficent类似,不过有时参数只有1-2个(可能是最
dominant的那1-2个),有时却有10几个,差别太大,结果中一般来说参数只有1-2个的
CV.err大
另一个解释是,听说glmnet 用coordinate descent 找lamda,可能不是每次都能找到
CV.err最小的
我的问题是:
1。如果我多run几次,选择CV最小的lamda建立的model 业界是否可以接受?我这个
model只是筛选,以后还要验证,所以多引几个variable在model中没有关系
2。使用glmnet有什么技巧可以使建出的model的重复性好些,比如选出的variable都在
10个左右。CV.err也更接近
w**********y
发帖数: 1691
46
我的问题是:
1。如果我多run几次,选择CV最小的lamda建立的model 业界是否可以接受?我这个
model只是筛选,以后还要验证,所以多引几个variable在model中没有关系
--一般不推荐用min而是用lambda.1se吧?特别你的目的只是筛选..
2。使用glmnet有什么技巧可以使建出的model的重复性好些,比如选出的variable都在
10个左右。CV.err也更接近
t*******t
发帖数: 633
47
能做modeling当然做modeling
data management在我看来是最无聊的事情了。
有任何成果反正是modeler做的好,出错很多情况下要怪data有问题。
而且没有高层关心你的data具体是怎么整的。。都关心fancy的model
t********m
发帖数: 939
48
来自主题: Statistics版 - 该用cox regression model还是gee model?
多谢回复。经你这么一说,我觉得用survival analysis更合适。现在就是如何建model
的问题。正在看survival analysis using sas这本书,感觉里面的例子似乎没有一个
跟我这个情况一样,很是苦恼。我想将data改成下面这种形式,然后用了163页的model
,这种情况下有些id的age2-age8有missing value,也不知道对不对。
Obs ID MONTHS SEQ EVENT AGE1 AGE2 ..AGE8 BMI1 BMI2...BMI8
1 1 84 8 0 40 41 ....47 27.39999962..
2 2 12 2 1 50 51 ...... 28 27........
proc phreg data=test;
model seq*event(0)=age bmi;
array ag(*) ag1-ag8;
array bm(*) b... 阅读全帖
w*******9
发帖数: 1433
49
I have done a simulation study of the PK model so I know a little bit, but
never did the model fitting.
If you only want the PD parameters, things will be easier. Emax model
assumes
PD = E0 + (Emax-E0)/(1+EC50/Concentration) + error
here (E0, Emax, EC50) is subject specific and follows a joint normal model.
If you want to know more, see
http://www4.stat.ncsu.edu/~davidian/webinar.pdf

nonlinear
b*****y
发帖数: 350
50
来自主题: Statistics版 - 问大牛们一个logistic model的问题哈
这问题没那马复杂,
1. 因为C在model里不显著,保留它着不对model有任何贡献。但是,原则上C和B,应该
通过Varclus分析到底应该去掉哪个。
2. 保留C的后果,在multicollinearity存在于model中,对model精度和变量的显著性
检验都有影响。

??
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