r**k
发帖数: 1402 | 1 The Selective Service System is an independent agency of the United States
government that maintains information on those potentially subject to
military conscription. Most male U.S. citizens and male immigrant non-
citizens between the ages of 18 and 25 are required by law to have
registered within 30 days of their 18th birthdays and must notify Selective
Service within ten days of any changes to any of the information they
provided on their registration cards, like a change of address. A 2010 ... 阅读全帖 |
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s*****n
发帖数: 536 | 2 You can complain at first to the present one.
And then select a new one.
Or, just select a BF. |
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b*s
发帖数: 82482 | 3 Select next alphabetical file name
This is done by pressing the tab key. All files visible in the desktop,
current window, including those displayed in hierarchically open folders,
are included in this selection. |
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b*s
发帖数: 82482 | 4 Command-down arrow opens the selected file or folder, unless the selected
file or folder is already open, in which case this key combination brings
its window to the front.
Command-o does the same work. |
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c*********t
发帖数: 2921 | 6 哪里有关于server selection problem好的overview 或survey的paper?哪些group在这方
面很有研究?尤其是dynamic server selection.
通常这个问题是跟content distribution相连的(e.g. 一个web page 放在多个servers上
，当有用户需要访问这个 web page 时，找个optimal server).
我更考虑real-time方面的要求，比如server 和请求用户间的delay, available
bandwidth， 以及如何实时得到这些 delay, available bandwidth只用reasonable
overhead.
谢谢! |
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h***n
发帖数: 276 | 7 My problem is as follows:
1) I have N strings and all strings has the same length L.
2) To be simplified, each string is composed by english letters.
How to select a set of M (M < N) strings that are most dissimilar?
My questions are as follows:
1) For any two strings, we can calculate the "edition distance" as the dissi
milarity. If there are more than 2, say M, strings, how to characterize the
dissimilarity of the whole set?
2) If the first question is well addressed, how to select the best M |
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c***c
发帖数: 6234 | 8 我有个group的table。我想在select出的结果的最前面加一行“ALL"。有办法吗？
当然我可以在table里加个All，然后再其他queries里限制别选“All”。但那样太蠢了
吧。
比如
select group from groups
我想的结果是
all
group1
group2
group3
....
..... |
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c*****u
发帖数: 562 | 9 select group from groups union select "all"? |
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v*****r
发帖数: 1119 | 10 select 'all' from dual
union
select group from groups; |
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y****9
发帖数: 144 | 11
tree.
log
YOu are probably right. this maybe the first time I need to think in big O
notation after school. Even in school I was not goot at algorithm anaysis.
If we put therotical algorithm complexity anaysis aside, from a practical
point of view,Is it safe to say the speed of select based on PK index is
almost same regardless of table lengh? I just checked the bigest table in
one of my Oracle db, it has 2 billion row. the consistent gets is 4.
So it should be index root block, branch block... 阅读全帖 |
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h******y
发帖数: 25 | 12 具体例子如下：
select * from table -- gives the following output
server col2 col3 col4 col5 col6 col7 col8 col9 col10
1 1234 null null 678 987 890 null 567 null
1 4565 null null 234 67 56 null 345 null
2 null null 578 567 234 null 73 18 null
2 null null 626 289 395 null 84 399 null
3 567 null 845 null 987 674 null null... 阅读全帖 |
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l******9
发帖数: 579 | 13 【 以下文字转载自 JobHunting 讨论区 】
发信人: light009 (light009), 信区: JobHunting
标 题: SQL select one value column for each distinct value another col
发信站: BBS 未名空间站 (Fri Jun 27 10:29:25 2014, 美东)
On SQL server 2008 R2, I would like to select one value of a column for each
distinct value of another column.
e.g.
name id_num
Tom 53
Tom 60
Tom 27
Jane 16
Jane 16
Bill 97
Bill 83
I need to get one id_num for each distinct name, such as
name id_num
Tom 27
Jane 16
Bill ... 阅读全帖 |
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a**d
发帖数: 4285 | 14 刚查的，周五下午，做题为找工作准备。
select col1, col2
from
(
select col1, col2,
ROW_NUMBER() over (partition by col1 order by newid())rn
from table1
)temp_t
where rn=1
each |
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n***l
发帖数: 143 | 15 Google 了一下，For XML Path is able to concatenate columns in a group by
clause.
Here is the result:
Recipe Components
1 2, 3
2 1, 2, 4
3 1, 2
Here is the link:
http://stackoverflow.com/questions/273238/how-to-use-group-by-t
The adapted script:
SELECT
[ID] as [Recipe],
STUFF((
SELECT ', ' + CAST([component] AS VARCHAR(MAX))
FROM recipe
WHERE (ID = Results.ID)
FOR XML PATH(''),TYPE).value('(./text())[1]','VARCHAR(MAX)')
,1,2,'') AS [Components]
FROM recipe Results
GR... 阅读全帖 |
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c****o
发帖数: 265 | 16 thanks for your answer.
这些东西部分基本上是纯javascript的
只是他们要求用更新count显示当option数量变化
改变option数量的button和link很多处
而且这种select也不少，以后可能还要用
哎 那我现在基本确定没有什么其他办法拉
想到的只能重新做一个类出来封装显示的span和select
结果已有的很多code要改
只能说改完后以后用有些好处
烦死!cry!为什么就没有那么一个事件呢！
counter
code- |
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i*****r
发帖数: 1302 | 17 新买的部件自己装,装完后开机黑屏出现两行字
reboot and select proper boot device
or insert boot media in selected boot device and press a key
重启后我按del去Bios看,sata硬盘很光驱都能检测到,第一启动光驱第二硬盘
但是IDE configuration里面
primary IDE master : not detected
primary IDE slave: not detected
secondary IDE master: CDROM
secondary IDE slave: not detected
third IDE master: not detected
fourth IDE master: Hard Disk
是不是hard disk一定要第一master? 还是别的问题,我检查了线好几遍都没有松
是什么问题啊? |
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t*******e
发帖数: 684 | 18 If I understand you correctly, what you refer to is theta-join. Here is a
SQL example.
SELECT *
FROM employee
JOIN department
ON employee.DepartmentID = department.DepartmentID;
In JPQL,
SELECT *
FROM employee e, department d
where e.DepartmentID = d.DepartmentID;
it |
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p**p
发帖数: 3386 | 19 我明白了。刚刚看了看man page，发现select是要修改timeout值的，只有pselect不会
。因此每次调用select以后都需要重新设置timeout.否则下次调用的时候相当于
timeout被设置为0，就会出现上面的问题了。 |
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c**A
发帖数: 1474 | 20 from the work of my hand:
genarally speaking, select blindly you will get 1 out of 2 working, 1 out of
5 will working really good ( >80% knock down)
But i also know a guy select 19 sites, and none of them work.. hehe,
poor guy... |
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m******5
发帖数: 1383 | 21 expression plasmid linealized,不带任何selection gene
遂决定共转其与一个selection plasmid制作stable transfect cell line
求protocol
最好电转可用的 |
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s*****g
发帖数: 87 | 22 有做stem cell 的大侠做过 FIAU (Fialuridine) counter selection 吗？
我用的 puroΔtk selection marker， 加了FIAU（0.25uM）之后为什么细胞不死呢？ |
|
发帖数: 1 | 23 也就是说如果shearing的好 就不用做size selection？
[在 finixtree (alix) 的大作中提到：]
:不能这么说，这size不是真正意义上的selection，比如next500，基本500bp以上的都
:会丢失掉，放在里面只是浪费了loading的量而已
:<br>: 凡是要选size的都是伪科学
:<br>: beads。
:<br> |
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e****a
发帖数: 25 | 24 【 以下文字转载自 EE 讨论区 】
发信人: Yale (椰子), 信区: EE
标 题: Re: what is time selective channel?
发信站: BBS 未名空间站 (Sun Dec 31 01:14:13 2006), 转信
Doppler spread <--> coherent time T_co
if T_symbol >T_co,a time selection will occur |
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s*****n
发帖数: 209 | 25 Your problem was not well defined. It can be better defined as follows:
The n hotels are randomly selected from a set of hotels whose quality
is known to you. (Repetition is possible because otherwise n will have
to be small.)
The answer: Since the hotels are randomly selected and randomly distributed,
each encounter of a hotel is an independent random event, and hence there
is no strategy. You cannot use past experience to learn about future
for independent random event, other than its |
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z****a
发帖数: 150 | 26 ☆─────────────────────────────────────☆
youcc (麦地有喜) 于 (Thu Dec 4 17:28:52 2008) 提到:
从AAFP上看到一些好东西。
附件里是AAFP提供的tips on residency selection，其中很多面世及match的技巧对今
年的同学们很实用，其他tips就是明年的同学们要留意的了。
更多相关信息参见
http://fmignet.aafp.org/online/fmig/index/residency/research.html
以下是其中一篇
Selecting Your Residency Program
Written by Jeff González, M.D., Resident, Department of Medicine, Hospital
of the University of Pennsylvania; MAC Governing Council, Resident and Fellow
Section Representative
This topic is d |
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p****o
发帖数: 229 | 27 Elsevier sell some of the best medical reference books available. With half-
off they are less expensive than through the hospital here in NC...
50% savings valid only on selected titles purchased from this promotion
through March 31, 2007
Discount will be reflected in the shopping cart
www.us.elsevierhealth.com
This offer valid for qualifying purchases of select titles based on pre-tax
amount. Offer expires on March 31, 2007. Offer is not valid on bulk orders,
previous purchases, or in combinat |
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p****o
发帖数: 229 | 28 Elsevier sell some of the best medical reference books available. With half-
off they are less expensive than through the hospital here in NC...
50% savings valid only on selected titles purchased from this promotion
through March 31, 2007
Discount will be reflected in the shopping cart
www.us.elsevierhealth.com
This offer valid for qualifying purchases of select titles based on pre-tax
amount. Offer expires on March 31, 2007. Offer is not valid on bulk orders,
previous purchases, or in combinat... 阅读全帖 |
|
l******9
发帖数: 579 | 29 【 以下文字转载自 JobHunting 讨论区 】
发信人: light009 (light009), 信区: JobHunting
标 题: SQL select one value column for each distinct value another col
发信站: BBS 未名空间站 (Fri Jun 27 10:29:25 2014, 美东)
On SQL server 2008 R2, I would like to select one value of a column for each
distinct value of another column.
e.g.
name id_num
Tom 53
Tom 60
Tom 27
Jane 16
Jane 16
Bill 97
Bill 83
I need to get one id_num for each distinct name, such as
name id_num
Tom 27
Jane 16
Bill ... 阅读全帖 |
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l*****k
发帖数: 587 | 30 classifier selection
use selected classifier for prediction
最好有例子, sas or R, both are fine |
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c****s
发帖数: 63 | 31 我的问题是：
我现在有cost为outcome的数据，要用gamma distribution来fit,
但是难题是predictors有1000个,所以又要同时选择predictor.
我的想法:
1.如果用stepwise方法来选，就可以既fit gamma 又同时select variables. 在R中可
以实现，但老板所stepwise不好，让用lasso来select variables.
2.如果直接先用lasso选变量，再去fit model，好像也不太对。因为lasso fit的
是least Angle regression, 不是基于gamma distribution. 应该不能适用于cost
data.
不知道大家遇到这种问题该怎么办，SAS, Stata or R, 那个能解决这个问题呢？
或者有什么好的建议，先谢谢了！ |
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S******y
发帖数: 1123 | 32 I am new to Gene Expression problem. But I am very interested in the
field.
But is Gene Expression problem (most of time) equivalent to variable
selection problem?
Have the following methods been widely used in Gene Expression problem?
- SSVS (Stochastic search variable selection)
- LASSO
- Stepwise
Thanks! |
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o****o
发帖数: 8077 | 33 proc sql;
create view tempv as
select *
from yourdata(where=(return^=0))
order by id, date
;
quit;
data selected;
set tempv;
by id date;
if first.id;
run; |
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d*******y
发帖数: 1154 | 34 backward selection > forward selection b/c you can have a global look on
variable.
stepwise should be similar to backward |
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A*******s
发帖数: 3942 | 35 Subset Selection in Regression这本书讲了不少细节，不过我觉得内容有点老。网上
有电子书。
简单来说GLM的automatic selection都是基于likelihood的，一般来说是likelihood
ratio test with pre-specified significance level，当然也可以用AIC，BIC，
cross validation之类的。
leaps
forward |
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M***e
发帖数: 531 | 36 有个问题是怎么用VIF做feature selection.
有上千个feature，要求是最后的logistic regression model的feature VIF要小于2.
想了解一下大家用VIF做feature selection的过程。
1. 是stepwise的方式，每次去掉有最大VIF的feature，然后重新计算余下feature的
VIF,不断循环直到最后余下的feature VIF<2.
2. 是分几步，先去掉VIF>100的，然后重新计算余下feature的VIF，再去掉VIF>10的，
然后重新计算余下feature的VIF.
因为数据量比较大，1的办法太耗时，所以在用2的办法。但是risk就是在VIF>100去掉
的feature里有本该留下的，结果一刀切都去掉了。
求助，多谢 |
|
M***e
发帖数: 531 | 37 有个问题是怎么用VIF做feature selection.
有上千个feature，要求是最后的logistic regression model的feature VIF要小于2.
想了解一下大家用VIF做feature selection的过程。
1. 是stepwise的方式，每次去掉有最大VIF的feature，然后重新计算余下feature的
VIF,不断循环直到最后余下的feature VIF<2.
2. 是分几步，先去掉VIF>100的，然后重新计算余下feature的VIF，再去掉VIF>10的，
然后重新计算余下feature的VIF.
因为数据量比较大，1的办法太耗时，所以在用2的办法。但是risk就是在VIF>100去掉
的feature里有本该留下的，结果一刀切都去掉了。
求助，多谢 |
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T*****u
发帖数: 7103 | 38 feature selection和variable selection有啥区别啊？ |
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l*******m
发帖数: 1096 | 39 Lasso, for instance, selects features for dense features. However, it
selects variables for sparse features (eg categorical features) |
|
T*****u
发帖数: 7103 | 40 feature selection和variable selection有啥区别啊？ |
|
l*******m
发帖数: 1096 | 41 Lasso, for instance, selects features for dense features. However, it
selects variables for sparse features (eg categorical features) |
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t*****e
发帖数: 364 | 42 They are not really feature selection methods, but dimension reduction
methods. If you mean using loadings of PCA to do feature selection, the
biggest cons are that it's an unsupervised method, which most likely will
give inferior predictive performance. |
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c********1
发帖数: 60 | 43 刚拿到的一个Project:11 features,200 observations.The response variable (
ordinal and categorical) takes on only three possible values. The goal is to
learn if there are some common characteristics which help predict the
classification of the response variable.
I apply filter-based feature selection first: I run pairwise statistic tests
for all combinations of response and predictors. I select those significant
features, run VIF tests to get rid of multicollinearity, and fit the data
to an ordered logi... 阅读全帖 |
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M***e
发帖数: 531 | 44 有个问题是怎么用VIF做feature selection.
有上千个feature，要求是最后的logistic regression model的feature VIF要小于2.
想了解一下大家用VIF做feature selection的过程。
1. 是stepwise的方式，每次去掉有最大VIF的feature，然后重新计算余下feature的
VIF,不断循环直到最后余下的feature VIF<2.
2. 是分几步，先去掉VIF>100的，然后重新计算余下feature的VIF，再去掉VIF>10的，
然后重新计算余下feature的VIF.
因为数据量比较大，1的办法太耗时，所以在用2的办法。但是risk就是在VIF>100去掉
的feature里有本该留下的，结果一刀切都去掉了。
一般大家都怎么做的呢？
求助，多谢 |
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