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全部话题 - 话题: converging
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l****o
发帖数: 2909
1
1. Mishra SK, Wang SY, Lai KK, Explicitly B-preinvex fuzzy mappings,
INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS , 83 (1): 39-47 JAN 2006.
2. Lean Yu, Shouyang Wang, K.K. Lai, An Integrated Data Preparation Scheme
for Neural Network Data Analysis, IEEE Transactions on Knowledge and Data
Engineering, 18, pp.1-13, 2006.
3. Kin Keung Lai, Lean Yu, Shouyang Wang, Multi-agent Web Text Mining on the
Grid for Enterprise Decision Support, Lecture Notes in Computer Science,
3842, pp. 540 - 544, 2006.
4... 阅读全帖
M****i
发帖数: 58
2
来自主题: Quant版 - 问个随机积分的问题
My idea:
If the function c(t) verifies:
i) c(t)>=0;
ii) \int_0^s c(t) dt<\infty, for every s>=0;
iii) \int_0^\infty c(t) dt=\infty;
iv) \int_0^\infty c(t)^2 dt<\infty.
Then the integral
I(t)=\int_0^t c(s)*exp(-\int_s^t c(r)dr) dB(s)
converges to 0 in probability.
Example: c(t) = 1/(t+1).
Proof: The idea is to show that I(t) is L^2 convergent to 0, which implies
convergence in probability. For this purpose,
by Ito isometry (since iv) holds) we get
E(I(t)^2)
=\int_0^t c(s)^2*\exp(-2\int_s^t c(r) ... 阅读全帖
w*********i
发帖数: 77
3
来自主题: Quant版 - af0215面经中的一道题
"every convergent sequence is also absolutely convergent" wrong.
1 - 1/2 + 1/3 - 1/4 + 1/5 - 1/6.... converges but
1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6.... diverges.

sequence is also absolutely convergent.
will be
complex
a_n is
|a_n|=n^(-1/3) and (a_
divergent.
t**********y
发帖数: 374
4
I did some test runs using built-in dataset and got different outputs:
1. ===
> test=lmer(Reaction~Days+(Days|Subject),sleepstudy)
> summary(test)
Linear mixed model fit by REML ['lmerMod']
Formula: Reaction ~ Days + (Days | Subject)
Data: sleepstudy
REML criterion at convergence: 1743.6
Scaled residuals:
Min 1Q Median 3Q Max
-3.9536 -0.4634 0.0231 0.4634 5.1793
Random effects:
Groups Name Variance Std.Dev. Corr
Subject (Intercept) 612.09 24.740
... 阅读全帖
o**********e
发帖数: 18403
5
【 以下文字转载自 Seattle 讨论区 】
发信人: hiki (风卷草), 信区: Seattle
标 题: 华为在Seattle开分部:诚招Cloud Computing Chief Architect &
发信站: BBS 未名空间站 (Tue Jul 22 03:17:59 2014, 美东)
待朋友转发。负责人这两天在这边,有兴趣的请尽快联系。负责人邮件联系方式在下面。
内容贴上来之后格式全乱了,大家将就着看吧。原文在这里。
https://docs.google.com/document/d/1lEcQE7al4fEvwtQvzmRKWbT9SZXHPGMp_
BNACFMGp-U/edit#
https://docs.google.com/document/d/1sO2OSD5NmKy-aDm0szJ1Jct-
yNCQSW2wPDmcXuRCtOM/edit#
=================================
Cloud Computing Chief Architect
Huawei Technologies
About the positio... 阅读全帖
m******x
发帖数: 35
6
有些是lz自己面的有些是各处收集来的 红/绿皮书的题就不贴了 可能有些时间的原因
难免可能记错一些 请大家
包含!~
待lz想起来会不定期更新
---
explain EM algorithm, use EM algorithm to find SVD of a given matrix
---
Assume if you write an online training model, estimate how many obs the
parameters start to converge
Whats the convergence rate of online training algorithm (e.g. stochastic
gradient descent)
Convergence rate of gradient descent?
How many points are needed to converge give dim of feature space ?
Derive gradient descent formula
---
reservoir sampling... 阅读全帖
r****t
发帖数: 10904
7
在这里为后来考古的同学注释一下:这帮人其实证明了用有限远点光源的影子是
converging 的。但是他们以为 conspiracist 认为必须有多光源才能有 converging
shadow, 结果他们认为自己证明了单光源可以让影子 converging,就 busted
conspiracy 了。
看完这个以后,mythbuster 的 credit 完全丧失了。
w****n
发帖数: 113
8
来自主题: Military版 - 实数性质
可能我比较dumb吧,呵呵。想了半天,没想到一个简单的证明。
法利分割本质上和连分数是差不多的。大意就是0到1之间所有分母小于一个给定数的既
约分数排列会满足的一些性质,比如相邻两数差等于分母乘积分之一,分母之和大于给
定的界等等。
最简单的用"己知结果"来证明就是用连分数性质了。a到第n个convergent h
(n)/k(n)的距离是小于1/(k(n)*k(n 1))的。k(n 1)
大于k(n),所以这就是小于1/k(n)^2的。Convergents是在a两侧交错逼近a的,所以这个
ka小数部分小于1/k对一半的convergents(所有偶indices的或所有奇indices的)来说都
满足。k(n 1)跟k(n)关系和连分数展开直接有关。最差可能就是a的连分数展开在有限
步后都是1,1,1,...这在a和黄金分割数有关时出现。所以1/k可以改成(根号(5)-1)/(2k
),但不能再改进。


: 哦你是说此问题很难?Farrey dissection没查到。

: 感觉应该不难啊。

T*********I
发帖数: 10729
9
Re
好视频。
Convergence是否意味着国家的界限会削弱?当时在左下角的时候也converge。但是那
时候poor,不够productive。现在大家convergent+富裕了,是否有这种可能。
这个月的一篇文章:
《华尔街日报》:面对中国,加拿大美国应合并
s***c
发帖数: 50
10
来自主题: JobHunting版 - 微软onsite面经
刚从微软onsite回来。 当天面试了6轮,从11点直到下午6点,最后都快撑不住了。有
一个算法问题,都不太难,但有很多open design的问题有些难度。我记得的问题有几
个:
1. two arrays of strings A and B, find intersections, union, A-B and B-A.
如果array小于mem size,我的思路是: scan A array, 建立hash table; 然后scan
array B, 对每一个元素
检查是否在A 的hash table存在。在白板上code实现。
如果array 大于mem size, 导致hash table也大于mem size, 则对每个array做
external sort:
把array分割成多块,每块都小于mem size, load到memory, sort, 写回disk;然后
merge sort.
之后,顺序扫描另个array,比较每个元素是否相同。
面试官还问,如果用SSD,该如何改进。我的答案是建立index table,但这是把index
table存在... 阅读全帖
l****u
发帖数: 95
11
来自主题: JobMarket版 - Cupertino 公司招 C 程序员
最好有1年以上工作经验,优秀的new grads也可考虑。
公司办理H1B和绿卡。公司由海归于2000年在上海成立。
站内联系。
*Description*
We are hiring software engineer position at SIHUA Technologies in Silicon
Valley focusing on hyper-converged storage. In this team, you will have
opportunity to architect, design and develop prototypes for proof of concept
. The candidate will have to be a self-motivated and passionate professional
and you will be interacting and working closely with Cloud platform team to
deliver high value hyper-converged IT archite... 阅读全帖
s*****r
发帖数: 1032
12
来自主题: Parenting版 - 乘法怎么练才好啊?
I actually have a different definition of 发散性思维. Divergent thinking
is usually mentioned along with convergent thinking which follows a set
of logical steps to arrive at one solution. Divergent thinking is
somewhat the opposite of convergent thinking. It uses creative
methods(many kinds, brainstorm is only one of them) to reach multiple
solutions. It is usually used in the first steps of design thinking
which later applies convergent thinking techniques to arrive at an
optimal solution.
As f... 阅读全帖
h***a
发帖数: 1773
13
【 以下文字转载自 JobHunting 讨论区 】
发信人: repeat112 (windfantasy), 信区: JobHunting
标 题: 微软onsite面试悲剧,附面经并求分析,多谢~
发信站: BBS 未名空间站 (Thu May 8 18:31:09 2014, 美东)
一周之内面了微软两个组,刚刚收到结果双双悲剧,一个组的HR说It's a tough call
,另一个组的HR说very close,不知道是不是套话,总之很沮丧……来版上求问一下大
家问题可能出在哪,并且附上大概的面试过程和coding题目。
第一组:
第1轮:是一个SDE II,看名字像是中东人。coding题目是给定2棵树,判定是否其中一
棵是另一棵的subtree,同时用了DFS和BFS,写完code讨论了几个testcases和复杂度就
结束了。
第2轮:一个白哥Senior Lead,问的题目是一个maze(用2D matrix表示,有的坐标上
有障碍),给定起点和终点,找出从起点到终点的path,还是用的常规的DFS解法,搜
索过程排除有障碍的和访问过的坐标。
第3轮:一个小黑... 阅读全帖
v*****u
发帖数: 1796
14
//comfort 应该是真的close,要不然老大不会花时间的吧。好好准备,拿个比软
软好的offer

【 以下文字转载自 JobHunting 讨论区 】
发信人: repeat112 (windfantasy), 信区: JobHunting
标 题: 微软onsite面试悲剧,附面经并求分析,多谢~
发信站: BBS 未名空间站 (Thu May 8 18:31:09 2014, 美东)
一周之内面了微软两个组,刚刚收到结果双双悲剧,一个组的HR说It's a tough call
,另一个组的HR说very close,不知道是不是套话,总之很沮丧……来版上求问一下大
家问题可能出在哪,并且附上大概的面试过程和coding题目。
第一组:
第1轮:是一个SDE II,看名字像是中东人。coding题目是给定2棵树,判定是否其中一
棵是另一棵的subtree,同时用了DFS和BFS,写完code讨论了几个testcases和复杂度就
结束了。
第2轮:一个白哥Senior Lead,问的题目是一个maze(用2D matrix表示,有的坐标上
有障碍),给定起点和终点,找... 阅读全帖
t******l
发帖数: 10908
15
来自主题: Go版 - 第三局估计也没啥可看了
你忘了狗可以跟克隆狗对练,一步步提升战力,产生无数职业棋手级别的内部对局。
(前提是 learning 算法参数结果稳定能 converge,估计一伙马工天天对付这个。
另外是不能有 search space 里的重大遗漏,不过可能肉算也看不出来就是了。)。
只要在狗咬狗的 learning 阶段能保持稳定 converge,一群狗的战力不断相互提升。
克服这个弱点也就是费多少电的问题。
或者从某个角度看,一群狗咬狗,其实好比是高层 learning 的不断 iterative 的算
法。
话说当年牛鼻顿不就是用 iterative newton solver 把欧几里德阿基米德打得满地找
牙?虽然 iterative newton solver 的每一步都很蠢,不超过泰勒展开的二次微分项。
但只要保持 converge,来上五百万步,啥高次多次超级次方程,都是屎。

1M
t*******r
发帖数: 22634
16
“爱恨情仇”这种函数既不是 convex 又不是 concave,基本
不太容易 converge。
万一哪天运气好 converge 了,用屁股想想就知道 converge
在床上某点。
这种破函数实在没啥研究的价值。。。
g****g
发帖数: 1828
17
来自主题: WaterWorld版 - Normal distribution
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
I***e
发帖数: 1136
18
来自主题: WaterWorld版 - 数学问题
You misread the question.
The success rate at the n'th round is p^n.
So, the probability of no success up to step n is:
(1-p)(1-p^2)...(1-p^n).
To understand whether this converges to 0, we take log. We have:
sum(log(1-p^n))
As n->infty, this is O(sum(p^n)). This converges to a finite number
for all choices of p, except if p=1, which is a trivial case.
That means, the original sequence does not converge to zero. Even if p=.99999, there is still a non-zero probability of never hitting a... 阅读全帖
d********1
发帖数: 3828
19
来自主题: WaterWorld版 - 韩寒初中作文欣赏
证据讲究的是convergence。方舟子的证据都converge到“造假”。
而韩粉丝毫不甘示弱。对于韩粉,所有的证据都converge到“天才”。
天才,能够解释一切。

粉。
t******n
发帖数: 2939
20
来自主题: WaterWorld版 - [合集] 数学问题
☆─────────────────────────────────────☆
zblgaoxin (又是半年) 于 (Mon Nov 7 14:18:38 2011, 美东) 提到:
发个包子吧 就有答案了 呵呵

☆─────────────────────────────────────☆
dd322508 (银河) 于 (Mon Nov 7 14:25:18 2011, 美东) 提到:
很实际的题目,有些人考多少次都不行,有些人考一次不行考两次就可以了。
楼主加油,给你两次机会你就能做出来答案了。
☆─────────────────────────────────────☆
Songp (宋平宋青书) 于 (Mon Nov 7 16:35:59 2011, 美东) 提到:
pass概率小于1/9
☆─────────────────────────────────────☆
Tro11 (乔安山) 于 (Mon Nov 7 16:39:34 2011, 美东) 提到:
1.一定能过
2. 既然经过无数次了,说明他还没过
☆───... 阅读全帖
d**********o
发帖数: 1321
21
来自主题: WebRadio版 - 潜水员冒泡兼征版友意见
第一个项目report
这时偶刚到CSAC工作不久,与小A同学还不熟,我用的还是latex。随着贴的作业越来越
多,应该是用有共同爱好的小伙伴更亲密些。这次贴latex,下次才再org-mode。
\documentclass[b5paper,11pt, abstraction, titlepage]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{CJKutf8}
\usepackage{multirow}
\usepackage{multicol}
\usepackage{listings}
\usepackage{geometry}
\geometry{b5paper}
\usepackage{graphicx,floatrow}
\usepackage{graphicx,subfigure}
\newsavebox{\abstractbox}
\renewenvironment{abstract}
{\begin{lrbox}{0}\begin{minipage}{\t... 阅读全帖
d**********o
发帖数: 1321
22
来自主题: WebRadio版 - 潜水员冒泡兼征版友意见
第二次作业report
#+latex_class: cn-article
#+latex_header: \usepackage{CJKutf8}
#+latex_header: \begin{CJK}{UTF8}{gbsn}
#+latex_header: \lstset{language=c++,numbers=left,numberstyle=\tiny,
basicstyle=\ttfamily\small,tabsize=4,frame=none,escapeinside=``,
extendedchars=false,keywordstyle=\color{blue!70},commentstyle=\color{red!55!
green!55!blue!55!},rulesepcolor=\color{red!20!green!20!blue!20!}}
#+title: CS572 Project 2 Report
#+author: (me~~~)
#+begin_abstract
|---------------------------+------------... 阅读全帖
d**********o
发帖数: 1321
23
来自主题: WebRadio版 - 潜水员冒泡兼征版友意见
第一个项目report
这时偶刚到CSAC工作不久,与小A同学还不熟,我用的还是latex。随着贴的作业越来越
多,应该是用有共同爱好的小伙伴更亲密些。这次贴latex,下次才再org-mode。
\documentclass[b5paper,11pt, abstraction, titlepage]{scrartcl}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{CJKutf8}
\usepackage{multirow}
\usepackage{multicol}
\usepackage{listings}
\usepackage{geometry}
\geometry{b5paper}
\usepackage{graphicx,floatrow}
\usepackage{graphicx,subfigure}
\newsavebox{\abstractbox}
\renewenvironment{abstract}
{\begin{lrbox}{0}\begin{minipage}{\t... 阅读全帖
d**********o
发帖数: 1321
24
来自主题: WebRadio版 - 潜水员冒泡兼征版友意见
第二次作业report
#+latex_class: cn-article
#+latex_header: \usepackage{CJKutf8}
#+latex_header: \begin{CJK}{UTF8}{gbsn}
#+latex_header: \lstset{language=c++,numbers=left,numberstyle=\tiny,
basicstyle=\ttfamily\small,tabsize=4,frame=none,escapeinside=``,
extendedchars=false,keywordstyle=\color{blue!70},commentstyle=\color{red!55!
green!55!blue!55!},rulesepcolor=\color{red!20!green!20!blue!20!}}
#+title: CS572 Project 2 Report
#+author: (me~~~)
#+begin_abstract
|---------------------------+------------... 阅读全帖
f******k
发帖数: 297
25
well, the guarantee of SA for convergence to global optimum exists and it is
convergence in
probability, though the major weakness is the speed of convergence, which can
be extremely slow.
b***p
发帖数: 700
26
来自主题: EmergingNetworking版 - BGP 多线切换问题。。。
From a quick google, IP FRR is to target 50-ms level traffic convergence. If
I was you, I will leave it to 2nd phase after some experiment and tests,
because your bfd consideration is 1-sec level convergence. you can try some
tech to tune your IGP to have a fast convergence at seconds level.
s******y
发帖数: 28562
27
“Also to use convergent evolution to argue for evolution being directional does not stand”
我强烈反对这个论点。我觉得你们搞基因的人过于focus on 序列比较了.
基因的具体序列当然重要,但是,convergent evolution 正好说明了:
不管什么基因序列什么来源,表型(包括morphology)的进化 才是真正派上用场的东西所以是有方向性的。我上面举的章鱼,它的眼睛相关基因和人的眼睛相关基因完全不是一回事,你如果去比较他们的序列,那就会发现几乎没有什么homology。但是它们通过不同的基因组合,最后都得出了一个非常类似的“解”(solution) .如果完全否认里面的方向性的话,那得多么多么多么巧合才能“偶然”的在不同途径出现相似的解啊!
另外,我不明白你为什么认为convergent evolution 是rare event. 在我看来例子实在是太多了,根本就不"rare".

of
use
suggest
m*********s
发帖数: 368
28
来自主题: Mathematics版 - [合集] one problem about infinite products
☆─────────────────────────────────────☆
okla (IP~IC~IQ卡,统统告诉我密码) 于 (Sun Aug 14 17:07:39 2005) 提到:
Ahlfors said that the convergence of \sum a_n is neither sufficient nor
necessary condition for the convergence of \prod (1+a_n).
(a_n are complex numbers)
I've worked out the example that \prod (1+a_n) converges but \sum a_n doesn't.
For example, a_n=-1/(n+1), \sum a_n -> -\infty, but \prod (1+a_n) -> 0
Actually, as long as for all a_n, -1 < a_n < 0, then \prod (1+a_n) is positive
and decreasi
v**i
发帖数: 50
29
你说的convergence in law可能我理解错了。到底是 convergence in Probability (
依概率收敛),还是 convergence in distribution (依分布收敛)?
p*****n
发帖数: 758
30
来自主题: Mathematics版 - 问个复分析题
suppose a_n is a sequence of complex number such that sum of a_n converges (
but not converge absolutely). f is an analytic function in open unit disk.
prove that sum of a_nf(z^n) converge to an analytic function in open unit
disk.
B********e
发帖数: 10014
31
来自主题: Mathematics版 - 问个傅立叶级数的问题
find any college textbook named <>, go to the Fourier series part,
check the key word "Fourier series covnergence theorem" you will get the
answer.
a standard description for piecewise continuous function with cts first
derivative is, its fourier serier converges to its function value at cts
point, while it converges to the average value of left/right limits at
discontinuous points.
namely, yes you can talk about pointwise convergence(stronger than L2)
n**h
发帖数: 22
32
来自主题: Mathematics版 - Slutsky theorem for stochastic process
请问对于stochastic process有没有类似slutsky的theorem?比如:X_n(t) weakly
converges到一个tight的G(t) process,同时Y_n(t) uniformly converges到一个
deterministic的process H(t),那么可不可以推出X_n(t)*Y_n(t) converges到G(t)*H
(t)?
多谢!
d*e
发帖数: 843
33
来自主题: Quant版 - 问个随机积分的问题
You got the same answer as me.
Convergence in L^2 is OK, which implies convergence in prob, OK too.
But how about convergence in probability 1 (almost sure)?
a********e
发帖数: 508
34
来自主题: Quant版 - 面经
牛人!有这么多面试经历。effective c++确实非常不错
有两个问题不太确定
1. What is the cash flow of the future's margin account if the stock price
doesn't change.
这个cash flow应该是model depedent的吧,是不是有什么假设?要不最多只能说
cash flow是negative的吧
20. Is there a sequence a_n such that, a_n is convergent but not absolutely
convergent and (a_n)^3 is not convergent?
这个是不存在吗?
a********e
发帖数: 508
35
来自主题: Quant版 - af0215面经中的一道题
20. Is there a sequence a_n such that, a_n is convergent but not absolutely
convergent and (a_n)^3 is not convergent?
这个是不存在吗?各位高手有何高见?
M****i
发帖数: 58
36
来自主题: Quant版 - af0215面经中的一道题
If your post is correct, the answer is "NO" because every convergent sequence is also absolutely convergent.
If the "sequence" in your question is changed into "series", then it will be
more interesting and a partial answer is "YES" provided that the complex
numbers are allowed.
Example: a_n=exp(i2n\pi/3)/n^(1/3). Then the convergence of \Sigma_n a_n is
ensured by Dirichlet's criterion. Moreover, it is easily seen that |a_n|=n^(-1/3) and (a_
n)^3=1/n, hence the series \Sigma_n |a_n| and \Sigma_n... 阅读全帖
y****e
发帖数: 28
37
来自主题: Quant版 - af0215面经中的一道题
In fact, MathFi's real number series and my proposed solution are very
similar to each other except that his real number series do not get
immediate attention due to a little bit more computation. After seeing this
, I probably got some some inspirations from his solution for complex series
without realizing it.
In the spirit of giving a simple and clean answer, I rewrite my solution as
the following,
Define a={1,1,1, 1/2,1/2,1/2, 1/3,1/3,1/3, ...}
b={-2,1,1, -2,1,1, -2,1,1, ...}
Let ... 阅读全帖
D**********d
发帖数: 849
38
来自主题: Quant版 - af0215面经中的一道题
\sum a_n is convergent ==> |a_n| --> 0 ==> |a_n|^2 --> 0
a_n^3 = |a_n|^2 * a_n and \sum a_n is convergent
\sum a_n^3 must be convergent.

absolutely
z****g
发帖数: 1978
39
Also, you may need to check the basic analytically form of Ito integral. I
remember the definition is quite loose as it does not require the summation
converges on 'arbitrary' partition of t, in this sense you can choose a sub-
sequence of partition that will converge almost everywhere. Also, I remember
the integral itself converges only in terms of measure.
L*******t
发帖数: 2385
40
来自主题: Quant版 - question on monte carlo simulation
I guess one should obtain convergence result first. at least for those
discretization schemes. It's required by many numerical schemes...
For example, Takahashi and Fujii proposed many series expansion solutions to
FBSDE's, but they did not post any convergence results until recently. What
they did back then was just to compare their methods with the closed form
solutions of some FBSDE's, and claimed their methods worked, but they also
wrote a sentence in their paper that they were not responsib... 阅读全帖
P****D
发帖数: 11146
41
来自主题: Statistics版 - proc mixed的问题。
CONVF<=number>、CONVG<=number>、CONVH<=number>都可以用来放宽convergence
criteria,不过贱妾的老板不是很推荐。别人都用默认的CONVH=1E-8为标准,你不用这
个,跟别人不好比较。
不converge的可能原因太太太多了。贱妾现在能想起来的就一个variance-covariance
matrix的问题。上次贱妾有一个很小的dataset,用unstructured就不能converge,用
AR(1)就好了。
s********1
发帖数: 54
42
来自主题: Statistics版 - 再贴一遍,招人
______________________________________________________________________
In terms of the variance structure
______________________________________________________________________
Normal structure depend on each individual,Spatial structure depends on the
distances between two points and compound, etc.
______________________________________________________________________
In terms of the likelihood:
______________________________________________________________________
The PL method is based on Wol... 阅读全帖
n**h
发帖数: 22
43
来自主题: Statistics版 - Slutsky theorem for stochastic process
请问对于stochastic process有没有类似slutsky的theorem?比如:X_n(t)weakly
converges到一个tight的G(t)process,同时Y_n(t)uniformly converges到一个
deterministic的process H(t),那么可不可以推出X_n(t)*Y_n(t) converges到G(t)*H
(t)?
多谢!
c****s
发帖数: 5892
44
据星报消息,加拿大人只用手机者日渐增加,传统有线电话迟早会消失。
30岁的软件设计师李纽斯基(Mark Litnewski)说,有线电话每月要40-50元加税、要付长途电话费等,1年下来数目可观。对大部分有手机的人而言,有线电话只是浪费钱。科技研究公司IDC Canada的调查结果显示,像李纽斯基的人已占12%,比前1年增加4个百分点。Convergence Consulting Group则预测,2014年将有26%的加拿大人放弃有线电话。
美国已有25%消费者只用手机,Convergence创办人艾利(Brahm Eiley)指出,原因在于美国的低价、无限制的手机计划已大量存在5年之久。加拿大的无线服务相对昂贵,但Mobilicity、Public Mobile、WIND Mobile及魁省的Videotron开始大力推广不限通话及传讯的成套计划,情况出现转机。
SeaBoard Group分析师卡密纳(Amit Kaminer)指出,2007年时,加拿大只有3家无线服务商,用手机传送10亿位元的数据大概要花2,500元。现在则贝尔、罗渣士及研科也推出新品牌促销,革命已经开始。他补
r****t
发帖数: 10904
45
Not at all. That is exactly the opposite of what I want to prove. I like to
show:
that the NASA photo *cannot* be taken with direction of the parallel light
from the sun. What we have proved so far is that the shadows on NASA image
are not actually parallel in reality (since starting from assumed actual
parallel shadows as you did, we reached discrepancies using edges of
envelope or other truly parallel edges by noticing that the convergent point
is not a disappear point.)
So it is likely that t... 阅读全帖
u***r
发帖数: 4825
46
http://www.economist.com/blogs/graphicdetail/2012/01/energy
What will be fueling the world in 2030
THE world will consume 40% more energy in 2030 than it does today, according
to BP's World Energy Outlook, though the rate of growth will decrease from
around 2.5% a year over the past decade to an annual rate of 1.3% in 2020-30
. One source of power has always dominated the energy mix—wood in the pre-
industrial age, coal in the industrial revolution and then oil in the 20th
century. But by 2030 t... 阅读全帖
v****o
发帖数: 978
47
Chinese economic reform and development: achievements, emerging challenges
and unfinished tasks
Jane Golley and Ligang Song
The economic transformation that has taken place in China since the late
1970s is now regarded as one of the most significant social changes in human
history. Within just three decades, China has succeeded in transforming
itself from a centrally-planned closed economy into one of the world’s most
dynamic and globally-integrated market economies. The dynamics unleashed by
De... 阅读全帖
T**E
发帖数: 1892
48
来自主题: Military版 - 美国公布2013年GDP:16.8万亿美元
When will the Chinese GDP surpass America?
Past Guesses:
International Monetary Fund(2011): 2016
The Economist(Dec2011): 2018.
The Economist(Feb2010): 2019.
Price Waterhouse Cooper(2010): 2020
Goldman Sachs(2008): 2027.
Goldman Sachs(2003): 2041.
Apparently it is a moving finish line. Each successive estimate, moves the
date up sooner and sooner. And this past 2008 Recession had frozen growth in
America which was wholly unanticipated.
The closer we get to future, the more the future converges to... 阅读全帖
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