O**M
发帖数: 29 | 1 1. Click menu "SPECIAL -> DOMAIN -> CHANGE DOMAIN"
Select "Examples" and click OK. This step is needed
only once each time you start tgif.
2. Click menu "SPECIAL -> INSTANTIATE"
Select "eq4-ps2epsi.sym" and click OK.
You will see a small empty equation box floating around.
Place it where you want, and you will see blue Latex code
on top of it.
3. Double click the blue Latex code (not the equation box
itself), the equation is visible now.
4. Select the equat |
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t*******y
发帖数: 11968 | 2 学ODE, 下列这些书里,如果只选一本, 应该选那本学. 如果大家觉得非要看两三本才可
以, 也请推荐一下. 谢谢
1 Perko, Lawrence. Differential Equations and Dynamical Systems. Texts in
Applied Mathematics, No. 7, Springer-Verlag, 2001.
2 Chicone, Carmen. Ordinary Differential Equations with Applications. Texts
in Applied Mathematics, No. 34, Springer-Verlag, 1999.
3 Arnold, V.I. Ordinary Differential Equations.
4 Walter and Thompson. Ordinary Differential Equations. Graduate Texts in
Mathematics. Springer-Verlag.
5 Coddington and Levinson. Theory |
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G********n
发帖数: 615 | 3 http://www.ams.org/news?news_id=1166
这俩人一个20岁拿到博士一个23岁拿到博士
Christodoulou and Hamilton Receive 2011 Shaw Prize
Demetrios Christodoulou of the ETH-Zurich and Richard Hamilton of Columbia
University have jointly been awarded the Shaw Prize of US$1 million "for
their highly innovative works on nonlinear partial differential equations in
Lorentzian and Riemannian geometry and their applications to general
relativity and topology." The work of the two prizewinners exemplifies the
power of geometric me... 阅读全帖 |
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i****g
发帖数: 3896 | 4 能不能不要只盯着这些无聊的生活细节啊？他的学生对他评价都很高，绝对是一位优秀
的老师：
This man taught me calculus. A wonderful gentleman and a phenomenal
instructor.
[+]Temorse 282 points283 points284 points 12 hours ago (11 children)
[–]Temorse 282 points283 points284 points 12 hours ago
I was also lucky enough to have him as my calc professor, twice. The first
thing he would tell us at the beginning of each term was, "My name is Yitang
Zhang, but in China, you would call me Zhang Yitang." Then he would erase
both names off the white ... 阅读全帖 |
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L*m
发帖数: 235 | 5 统计了近十余年来中国大陆高校在四大刊物上的发文，有些是挂名的，但不管如何，还
是都统计了。全名单如下
Annals of Mathematics
A proof of Demailly’s strong openness conjecture
Qi'an Guan（关启安 北京大学） Xiangyu Zhou（周向宇 中科院）
A solution of an L2 extension problem with an optimal estimate and
applications
Qi'an Guan（关启安 北京大学） Xiangyu Zhou（周向宇 中科院）
Construction of Cauchy data of vacuum Einstein field equations evolving to
black holes
Junbin Li（黎俊彬 中山大学） Pin Yu（于品 清华大学）
Special test configuration and K-stability of Fano varieties
Chi Li(李驰 普林斯顿大学 现stony broo... 阅读全帖 |
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n*********3
发帖数: 534 | 6 y=1+x+x^2+x^3+x^4+.... equation a
y=1+x(1+x+x^2+x^3+x^4+....)
y=1+xy
y=1/(1-x) equation b
now
equation a converges for when -1
but equation b converges for all x except when x=1.
How to understand or resolve this contradiction? which one is correct?
anyone?
many thanks in advance |
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x********g
发帖数: 595 | 7 Because the classical system was first quantized by canonical quantization
in which the Hamiltonian plays the main role.The canonical quantization is
based on Hamilton's equation of motion and the fundamental commutation
relations [p, q] =...( all of which come from the definition of Possion's
bracket).Thus the resulting equations, the Heisenberg's equation of motion
and the Schordinger's equation, contain the Hamiltonian operator.
Another quantization process, the path integral quantization, m |
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e*******n
发帖数: 4912 | 8 1.在这个系列里我打算写一些我在各种文章和书中看到的八卦
希望能博大家一笑
有一次littlewood问hardy,为什么他每次到一个旅馆就会把镜子用毛巾盖起来?
回答是:因为他长得太丑了
2.Hadamard,Jacques去意大利Bologna开1928年国际数学家大会,期间要坐火车去一个地
方
车厢里有很多人在聊天,他觉得十分累,就出了道困难的数学题,众人思考这道题,
车厢里马上安静下来了,于是Hadamard就可以睡觉了
3.Bourbaki是一个法国数学家的集体代名词
Bourbaki的第一篇文章发表在comptes Rendus(法国科学院的一个杂志)上
在1949年Journal of symbolic logic上的一篇文章
"Foundations of mathematics for the working mathematican"
中,Bourbaki教授的地址是University of Nancago
一个杜撰的地址,分别是Nancy和Chicago(weil在那里)前后组合
1940年,Boas,Ralph(MR的主编)曾经在Encyclopa... 阅读全帖 |
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i****k
发帖数: 39 | 9 Some naive questions come to my mind when I try to understand the derivation
of Black-Scholes equation.
1). Why we assume stock price S follows GBM? I know data suggest S~GBM, but
is there any fundamental reason?
2). Is it a MUST to assume S ~ GBM to derive B-S? If I assume stock price
follows BM (not GBM), what equation will European call option satisfy? Will
it still be BS or not? Why? How to prove?
3). A more general question is for any asset S, assume we don't know what
process it follows. W... 阅读全帖 |
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r******g
发帖数: 13 | 10 very confused about the Straight algebraic substitution by MatthewM in the
link, tried to do the same things, not sure is there anything I missed,
1) how to get equation (8) using the two roots? why
2) both equations (1), (2) and (6) show equation between (2) and (3) is 0,
what's wrong with it? but equation (10) gives (12)
thought the algebraic substitution was easy and straight forward, scratching my head to find out what's I did wrong, wasting several papers, still not clue, many thanks for th... 阅读全帖 |
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m**D
发帖数: 134 | 11 1. MELVYL Catalog
Abel's equation and the cauchy integral equation of the second kind, by a s
peters., 1966. 1 v.
2. MELVYL Catalog
Anderson, Christopher Radcliff. Integral equation preconditioning for the
solution of Poisson's equation on geometrically complex regions /, Christopher
R. Anderson, Archie C. Li. Los Angeles, CA : Dept. of Mathematics, University
of California, Los Angeles, [1997] 19 p. : ill. ; 28 cm.
Series title: CAM report ; 97-25, CAM report (University of California, Los
Ang |
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l*********d
发帖数: 254 | 12 在选择regression model的时候，用到step() function ：step forward, step
backward and step both.
在以上三种step() function 选择model的过程中，都用到了AIC value作为选择的标准
.因而在step() function中，是包含了计算AIC的equation的。另一方面，AIC()
function同样也是计算AIC值的，但是所得到的AIC与从step()function得到的AIC是不
同的。因为它们用了不同的equation 来计算AIC. 问题是，我要怎样才能在R中看到这
两个不同的equation呢？换句话说，我应该用什么样的code才能找到这两个equation呢
？ 请各位高手指点！谢谢！ |
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M*P
发帖数: 6456 | 13 why do you have a equation for y(i) and a different equation for y = p*(x^m)
?
there is no regression here. I feel that the "empirical relation" between y
and x is the actual equation, the linear equation y(i) = k(i)*x(i) + b(i) is
empirical approximation.
n |
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m*********g
发帖数: 11102 | 14 【 以下文字转载自 TeX 讨论区 】
发信人: cockroach (冬冬), 信区: TeX
标 题: Re: 公式编号前面怎么加入一个字母？
发信站: BBS 未名空间站 (Wed Aug 12 10:35:00 2009, 美东)
the following is the quick solution:
\numberwithin{equation}{section}
if you really want to use the letter 'S' instead of the section number
appended by a dot, you can do the following instead:
\renewcommand{\theequation}{S\arabic{equation}}
btw, you may also want to reset the equation counter in your supporting
material:
\setcounter{equation}{0} |
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l*****y
发帖数: 5 | 15 I have such type of matrix problems: An unknow matrix X \in R^{nxn} satisfies
an equation with X in quadratic form (power to two). For example, X is real
symmetric and the equation is:
( P * X * P' + Q ) = X * R * (P * X * P' + Q ) + X
P, Q, and R are given constant matrices. My question is: what is the approach
to generally solve such type of equations? it is really a simple quadratic
equation for any scalar X (middle school problem). But how about if X is an
unknown matrix? Is such type of mat |
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d**e
发帖数: 2420 | 16 【 以下文字转载自 Mathematics 讨论区 】
发信人: dade (leno), 信区: Mathematics
标 题: 见识一下数学文章的一稿多投
发信站: BBS 未名空间站 (Tue Mar 15 15:03:30 2011, 美东)
文章仍然可以下载，打上了RETRACTED标识。第一次见着数学论文一稿多投，三波人，
居然在那么短时间内两次投同一个杂志Journal of Computational and Applied
Mathematics，看来缺少沟通呀，太搞了。
http://xys.org/xys/ebooks/others/science/dajia12/wanglijuan.txt
一鱼三吃、五人共享
作者：卿本佳人
一篇文发到三份期刊刊登，都被撤文了。涉及抄袭的五人是：
北京首都师范大学数学系 及 浙江嘉兴 嘉兴学院 数理与信息工程学院 王立娟
湖南省常德市 湖南文理学院 数学与计算科学学院 彭乐群
浙江嘉兴 嘉兴学院 数理与信息工程学院 王文涛
浙江嘉兴 嘉兴学院 数理与信息工程学院 乐光学
广东广州 广东工业大学 应用数学学院 欧春霞
... 阅读全帖 |
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h*****9
发帖数: 6643 | 17 Is the Big-Bang a Religious Hoax?
Huascar Terra do Valle
Science is the opposite of religion. Right? No! Wrong! Religion is always
trying to infiltrate into religion. Sometimes it succeeds. For instance, in
the Big Bang theory.
Today it is almost unanimous among the orthodox astronomers and astrophysics
that the world was created some 12 billions ago from a magnificent
explosion of a primodial atom. In a few seconds, as the theory goes, all the
universe was created from this primordial explosion... 阅读全帖 |
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d*****l
发帖数: 8441 | 18 http://rhart.org/algebra/
https://jhupbooks.press.jhu.edu/content/chinese-roots-linear-algebra
The Chinese Roots of Linear Algebra
Roger Hart
A monumental accomplishment in the history of non-Western mathematics, The
Chinese Roots of Linear Algebra explains the fundamentally visual way
Chinese mathematicians understood and solved mathematical problems. It
argues convincingly that what the West "discovered" in the sixteenth and
seventeenth centuries had already been known to the Chinese for 1,000... 阅读全帖 |
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w****y
发帖数: 2952 | 19 1950 Shiing-shen Chern, Differential Geometry of Fiber Bundles.
1970 Shiing-shen Chern, Differential Geometry: Its Past and Its Future.
1978 Shing-Tung Yau, The Role of Partial Differential Equations in
Differential Geometry.
1983 Wu-chung Hsiang, Geometric Applications of Algebraic K-Theory.
1983 Yum-Tong Siu, Some Recent Developments in Complex Differential Geometry.
2002 Sun-Yung Alice Chang and Paul Chien-Ping Yang, Non-linear Partial
Differential Equations in Conformal Geometry.
2002 Yum-To... 阅读全帖 |
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d*********2
发帖数: 48111 | 20 你觉得一个刷盘子的有必要认识这些人吗？
Mathematics
Peter Lax (1943)[1] fluid dynamics, differential equations; elected 1970
to the United States National Academy of Sciences, 1987 Wolf Prize, 1992
Steele Prize, 2005 Abel Prize, (New York University, emeritus)
Bertram Kostant (1945)[2] Lie groups and representation theory; elected
in 1978 to the United States National Academy of Sciences, (Massachusetts
Institute of Technology).
D. J. Newman (1947)[3] analytic number theory, long-time editor of
problems... 阅读全帖 |
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h*****d
发帖数: 244 | 21 国内人无知也就算了，号称万能的军版也这水平，太掉价了
http://www.smithsonianmag.com/history/charles-proteus-steinmetz
Charles Proteus Steinmetz, the Wizard of Schenectady
His contributions to mathematics and electrical engineering made him one of
the most beloved and instantly recognizable men of his time.
By Gilbert King
smithsonian.com
August 16, 2011
Steinmetz and his contemporaries (Tesla, Einstein and others) at the Marconi
wireless station in New Jersey. Image courtesy of Wikicommons
He stood just four feet tall, hi... 阅读全帖 |
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b***y
发帖数: 14281 | 22 what the hell are you talking about? If m=0, the same equation reduce to e^2
=p^2, and yes that's how you verify the rest mass of a particle is zero. Of
course, in reality you can only confirm from experiments that m^2
where epsilon is the upper bound of the photon mass.
Why do you think my equation is wrong? I suppose you mean p should be
replaced by pc? In high energy theory, people usually set c=1 so equations
look simpler. This simply amounts to a change of unit of time so there is n... 阅读全帖 |
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i******r
发帖数: 1175 | 23 鱉完成的這量子計算模擬落後有10年了吧。量子計算領先梯隊裏沒有中國團隊。沒有一
樣重要研究成果是中國人的。
Timeline[edit]
Main article: Timeline of quantum computing
In 1959 Richard Feynman in his lecture "There's Plenty of Room at the Bottom
" states the possibility of using quantum effects for computation.
In 1980 Paul Benioff described quantum mechanical Hamiltonian models of
computers[57] and the Russian mathematician Yuri Manin motivated the
development of quantum computers.[58]
In 1981, at a conference co-organized by MIT and IBM, physicist ... 阅读全帖 |
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T*******x
发帖数: 8565 | 24 Gamma函数的积分定义可以计算z的实部大于0处的函数值，再加上递推公式Gamma(z+1)=
z Gamma(z)，可以推导任意z处函数值。
黎曼Zeta函数积分定义为Alpha(z)/Gamma(z)。其中Alpha函数为另一个积分，和Gamma
非常相像。但是只能定义在z实部大于1的地方，因此黎曼Zeta函数的积分定义也只能定
义在实部大于1的地方。黎曼Zeta函数的其他定义，比如级数定义，乘积定义，都是如
此。这也不奇怪，因为黎曼Zeta函数在z=1点趋于无穷，定义不过去。
黎曼Zeta函数也有functional equation，
Zeta(z)=f(z)Zeta(1-z)，
根据z实部大于1处的函数值可以退出z实部小于0处函数值，但是z实部在01之间的Zeta
函数值推不出来，要另想办法。
最有效的应该还是一种functional equation。这种functional equation是非常有用的
，黎曼零点的计算肯定也依靠它。
理论上也应该考虑一下，泰勒展开也就是解析函数的解析展开，的radius of
convergence。比如考虑Alpha函数，也就是黎曼Z... 阅读全帖 |
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T*******x
发帖数: 8565 | 25 谢谢。你给这个链接不错。这个证明我以前没见过。
看来functional equation可能还需要一个convex条件才能得出唯一的函数。在gamma函
数的例子中，如果没有这个ln(f)的convex条件，可能还得不出必为gamma的结论，至少
这个证明不成立了。
不过我还是觉得functional equation已经是非常非常强的限制了，再加上解析函数的
要求，即使没有某种convex条件，这么强的限制下还能有什么腾挪的空间吗？如果有，
那这个空间也挺有意思的。
你的回帖有一点小错误：如果C=ln(gamma)的话，C(p)=C(p-1)+ln(p-1).
我这个题是有例子的：
let A(p)=integral of x^p ln(1-x) over (0,1)
let B(p)=A(p-1)
let C(p)= -p B(p)
这个C(p)就有我说的性质：解析函数，满足我说的functional equation.
我确实是想知道它是不是唯一的。 |
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T*******x
发帖数: 8565 | 26 黎曼zeta函数可用的技巧只有两个，一个是functional equation，一个是Euler
product。
Functional equation建立的是函数在不同点的值之间的关系。它不同于differential
equation。微分方程建立的是一种动力学系统，描述的是函数值是如何影响另外一个动
力学变量，然后这个动力学变量又反过来影响函数值（在另一处的值）。
Euler product，把黎曼函数表示成素数点乘积的形式。Dirichlet深挖了这个方法，发
明了Dirichlet Character和L函数，证明了等差数列中有无穷多素数的问题。至今这个
东西还在解析数论的中心位置。
然后就是把这两个技巧各种各样的包装，抽象。 |
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l****z
发帖数: 29846 | 27 呵呵,早知道底线突破后, 什么乱七八糟的东东都接着要来了. 反正是born this way嘛.
Gawker’s Soft Peddling Pedophilia
September 10, 2012 Posted by Warner Todd Huston
Recently, Gawker.com, a left-leaning and sometimes profane general interest
website, posted a story that makes excuses for child rape, calling it an “
orientation” instead of a crime and stating that raping children is “a
sexual relationship,” as opposed to the violation that it truly is.
The piece entitled, “Born This Way: Sympathy and Science for Those Who Want
to... 阅读全帖 |
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w********t
发帖数: 12853 | 28 (转载）
What’s the Matter With Connecticut?
By Annie Lowrey
A funny-sad back-and-forth appeared in the pages of the Hartford Courant
last month.
It started when one Christopher Edge wrote into the letters section to say
he had had it and was moving out in a brief tirade entitled “Farewell,
Connecticut.” More positive residents then chimed in with their support for
the Nutmeg State. “Running away is not the solution,” chided one Patricia
Karwoski.
But what problems could Edge possibly be trying to d... 阅读全帖 |
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w**5
发帖数: 316 | 29 Try to ask your students: 3/0.5 = ?
Many of students could not get it.
About half of the students in my school (3rd tier public university) failed
College algebra, finite math, and intro statistics.
For my finance class, I have to give out the same equation in different
format during an exam or quiz because students could not move a term from
one side of the equation to other side. They consider them all different
equation. I was upset at first. But after 10+ years of teaching those kind
of stud... 阅读全帖 |
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T********n
发帖数: 528 | 30 面经已经上礼拜发了 （http://www.mitbbs.com/article_t0/JobHunting/31809237.html）
这个礼拜在考虑从那家的时候，理所当然的试试negotiate一下offer。
虽然要求一度被拒绝，最后还是成功的negotiate了一点。而且是本来就最准备从的一
家，所以可以说是捡到的。高兴！发个经验看看对大家有没有帮助。
上礼拜，收到这家的一个offer。金融界名气挺大的，不是quant - 工作属于理财组/
institutional方向中的technology product management.
当时，HM就约了时间当天谈谈我对offer的感想。
聊的时候我沉不住气，提出我觉得对收到offer感到兴奋，可是base比想象中少一点。
HM就说：
1）这个total comp已经比你上一个工作高很多了（没错，高了～30-40%）
2）福利比你上一个工作多的太多了。他指出vacation天多了，还有因为是从小公司来
，所以很多这个公司给的profit sharing plan on top of base+bonus， tuition
rei... 阅读全帖 |
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a****a
发帖数: 186 | 31 Given a number find whether the digits in the number can be used to form an
equation with + and '='. That is if the number is 123, we can have a
equation of 1+2=3. But even the number 17512 also forms the equation 12+5=17
.就是随便排列数字，用+和=构造等式。加号只能用一次，数字不需要是连续的。
想法：对给定的数进行排列，分成三个数,然后sum两小的是不是等于大的。另外，分的
时候对最大数进行长度限制，貌似可以减少搜索空间。
还有什么其他的好方法吗？我记得好像这个题被讨论过，谁记得那个连接，谢谢！ |
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t**********w
发帖数: 478 | 32 two variables, two equations, give you the closed form solution.
data mean offers an equation,
stdev,same as variance, gives you another equation.
two variables, shape and scale.
Am I missing anything? |
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m******t
发帖数: 273 | 33 【 以下文字转载自 Quant 讨论区 】
发信人: myregmit (myregmit), 信区: Quant
标 题: solve integral eq. embeeded with another integral eq.
发信站: BBS 未名空间站 (Sun Mar 23 14:20:18 2014, 美东)
I need to solve an integral equation embedded with another integral equation
by python 3.2 in win7.
There are 2 integral equations.
The code is here:
import numpy as np
from scipy.optimize.minpack import fsolve
from numpy import exp
from scipy.integrate.quadpack import quad
import matplotlib.pyplot as plt
impor... 阅读全帖 |
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a*****a
发帖数: 19262 | 34 normal equation
or first-order equation?
其实，我觉得即便不知道这个equation的名字，你说出来解法就足够了，如果因为这个
而觉得你不qualify，这样的职位不要也罢。 |
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D***t
发帖数: 64 | 35 Position description
The successful candidate is expected to lead the development and application
of mathematical models which are required to describe the performance of
equipment and processes in the materials processing industries (chemicals,
petrochemicals, coal, etc.). A majority of the work involves the development
and application of process model libraries and systems modeling frameworks
to support process development and optimization.
Job responsibilities
Projects typically involve model... 阅读全帖 |
|
a*****g
发帖数: 19398 | 36 IL 教师对 PARCC 发表的意见
【注：PARCC是基于Common Core的 Assessment】
Dear ICTM colleagues:
With the recent, extensive field test of PARCC test items now completed and
some sample items posted on the PARCC web site, teachers now have a better s
ense of the kinds of test items that PARCC will be asking. (Practice items
form the Grades 3-8 performance-based tests will be released in Fall 2014.)
I raise here one concern about plans for the performance (open response) ite
ms in the hope of generating some discuss... 阅读全帖 |
|
a*****g
发帖数: 19398 | 37 IL 教师对 PARCC 发表的意见
【注：PARCC是基于Common Core的 Assessment】
Dear ICTM colleagues:
With the recent, extensive field test of PARCC test items now completed and
some sample items posted on the PARCC web site, teachers now have a better s
ense of the kinds of test items that PARCC will be asking. (Practice items
form the Grades 3-8 performance-based tests will be released in Fall 2014.)
I raise here one concern about plans for the performance (open response) ite
ms in the hope of generating some discuss... 阅读全帖 |
|
t*******r
发帖数: 22634 | 38 小调跟复调不是一个范畴的概念。
小调是对应大调而言。指瓢虫型旋律和弦蹦音符机左递归文法规则。。。
好比线代里，如何构造每单个 linear equation 的问题。
复调是对应主调而言，指多个瓢虫型旋律和弦蹦音符机之间的配合
姿势问题。。。就好比线代里，如何选择各个 linear equation
构造成 simultaneous equation 的问题。。。或者矩阵代数里，
变量系数的稀疏矩阵，是咋个稀疏的样子。 |
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t*******r
发帖数: 22634 | 39 感谢推荐 Help Your Kids with Math。俺把 Amazon Link 贴在下面：
http://www.amazon.com/dp/1465421661/ref=rdr_ext_tmb
另一方面，我觉得，书有时候要两三本一起看看，才最佳。。。我在 Amazon
上面看了一下。。。你介绍这本书图文并茂非常好。。。但不是没有缺点，
比如在 solve quadratic equation 那章，没有提到那个凑 (x-a)^2 = b
的通解解法（基于 quadratic expression 的 vertex form，当然最后还是
基于 distributive property）。。。而理解那个比 quadratic equation
solution formula 更基本，揭示代数的简洁性和（符号系统的）优越性。
当然，quadratic equation solution formula 也很重要，显示代数
作为 following proved known routine procedure without understanding
的简洁形式。。。（我这... 阅读全帖 |
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t*******r
发帖数: 22634 | 40 在中小学数学和物理里，比记忆力更重要的是时空想象力。。。这么说，你无法让瞎子
去记住风的形状，记忆力再好都没用，因为瞎子一辈子也没看见过风的形状。。 。
对于中小学数学，时空想象力主要是 mathematical structure (空间) 和
mathematical logics (时间)
(1) visual modelling
(2) equation (equation 其实是 tree structure, simultaneous equation 其实是
forest)
(3) decision tree
(4) 娃版 foundation of mathematics (mathematical logic)
(5) 其它的娃版 mathematical logic
所以俺推娃时，最担心这个。。。驾校司机爷爷说，你基本没法让瞎子开车。。。而腿
短的话，大不了支根小棍。。。 |
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a*****g
发帖数: 19398 | 41 （注意——大概有２５０条）
By John K. Jonak
Reflection is a significant part of growth. At Westmont Junior High School,
in Westmont, Illinois, my 8th grade Literacy classes took the PARCC test
this past March. My amazing two 8th grade Literacy teachers understood
there was an interesting lesson within the ongoing discussions about PARCC
testing in both school and political forums. Ms. Nancy Bartosz and Ms.
Colleen Walsh recognized that their students, being stakeholders involved in
this testing process, h... 阅读全帖 |
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t******l
发帖数: 10908 | 42 我对美帝数学八年级进度不熟。但如果不是 math accelerated track，algebra 1 是
九年级上的？八年级不会 simultaneous equation 是不是情有可原？
不过问题也真的在于，如果 prealgebra 底子不行的话，九年级很可能过不了
simultaneous equation 和 quadratic equation 的两道关口。
我看完美帝小说型 prealgebra 课本后，我都觉得不用说啥了。我打定主意自己用 AMC
8 -> AMC 10 加料，帮娃推过 algebra 那关，其他都是浮云。 |
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g****t
发帖数: 31659 | 43 【 以下文字转载自 Mathematics 讨论区 】
发信人: kennkqzhang (kenn), 信区: Mathematics
标 题: 最puzzling藕的还是空间和物质的可分性
发信站: BBS 未名空间站 (Fri Dec 4 02:42:43 2009, 美东)
最puzzling藕的还是空间和物质的可分性；
物质不断地分下去，是什么？
这个古老的问题，已经puzzling藕N年了。。。
这个不需要物理学知识，完全是个纯逻辑问题、纯哲学问题，或者说纯数学问提；
空间的可分性，也很paradoxical；
其它的比较简单了；
藕斗胆评论几个：
1 ether exists；
以太无处不在；建议研究以太动力学，ether dynamics；
以太很难被直接观测，但是，在weak interaction的时候，是以太造成了W＋，W－，Z
2 电荷到底是什么？
什么东西都被看成是运动了、能量了，连质量都没有被放过；只有电荷是个例外；
what the hell is the charge？
藕speculate，电荷也是一种运动形式，跟spin自旋 很项似；
3... 阅读全帖 |
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a*****g
发帖数: 19398 | 44 IL 教师对 PARCC 发表的意见
【注：PARCC是基于Common Core的 Assessment】
Dear ICTM colleagues:
With the recent, extensive field test of PARCC test items now completed and
some sample items posted on the PARCC web site, teachers now have a better s
ense of the kinds of test items that PARCC will be asking. (Practice items
form the Grades 3-8 performance-based tests will be released in Fall 2014.)
I raise here one concern about plans for the performance (open response) ite
ms in the hope of generating some discuss... 阅读全帖 |
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l*****9
发帖数: 9501 | 45 Life in the Fast Lane
Is Jeremy Lin the new talent code for the NBA?
by Kurt Brungardt
The basketball world is wondering… Is Jeremy Lin for real? Now, another
piece of the Lin puzzle has emerged.
Lin’s pre-Draft speed numbers have surfaced, giving fans new information
and suggesting a new talent code for NBA success. The equation goes like
this: Four years of college + a high BAM score for speed = JEREMY LIN.
Basic Athletic Measurement (BAM) is the company that administers athletic
tests for the... 阅读全帖 |
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m*****g
发帖数: 12253 | 46 ☆─────────────────────────────────────☆
Bosnower (Bosnower) 于 (Tue Mar 13 14:46:36 2012, 美东) 提到:
且不论NYK全场输在篮板上，但至少第四节时双方还是没拉开不是？尽管JR脑残的上来
乱搞一气，尽管什么防守也没有，但好在bulls没篮。
小林全场都很好，只是第四节没有把两个猩猩调动起来，小s难得的积极和精准，第三
节砍下不少分，但第四节小林基本就没往他那看过一眼，搞的小s没怎么出手；melo做
为巨猩，虽然手感不是很好，但在篮下多次出现mismatch，就算不是一对一中投，也是
三秒区内上篮的机会，但小林也没有多少个直接给瓜的。
但做为拿全对1%薪水的PG来说，全场综合表现已经很好了，而且基本rose没在他身上占
到便宜，反而送给小林生涯中高光的blocks。
如果小胡子一定要让小林和斯瓜一起上场的话，小林一定要想办法把球送到两人手里，
目前发现小林更喜欢往fields和钱手里送，这不单是机会的问题，还有下意识的感应。
☆────────────────────────────────... 阅读全帖 |
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m*****g
发帖数: 12253 | 47 ☆─────────────────────────────────────☆
bia (bia) 于 (Wed Jun 20 01:04:27 2012, 美东) 提到:
俩人兑子，靠西部和哈登打爆热火
☆─────────────────────────────────────☆
sioc (煎饼爱果子) 于 (Wed Jun 20 01:05:12 2012, 美东) 提到:
恩，看好赌神5分钟后就坐板凳了
☆─────────────────────────────────────☆
savylee ( New Life) 于 (Wed Jun 20 01:05:53 2012, 美东) 提到:
为什么试试让ibaka防呢？多给lbj几个look也好啊。
☆─────────────────────────────────────☆
tetee (fatfish) 于 (Wed Jun 20 01:06:09 2012, 美东) 提到:
不是防过了么？防不了这场才换回来sefo的
☆───────────────────────────... 阅读全帖 |
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e*f
发帖数: 1709 | 48 Is Jeremy Lin the new talent code for the NBA?
by Kurt Brungardt
Thursday, March 1st, 2012
The basketball world is wondering… Is Jeremy Lin for real? Now, another
piece of the Lin puzzle has emerged.
Lin’s pre-Draft speed numbers have surfaced, giving fans new information
and suggesting a new talent code for NBA success. The equation goes like
this: Four years of college + a high BAM score for speed = JEREMY LIN.
Basic Athletic Measurement (BAM) is the company that administers athletic
tests for... 阅读全帖 |
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G****e
发帖数: 11198 | 49 http://rivals.yahoo.com/ncaa/football/news;_ylt=Akf5WuT..vL_nbX
Illegitimate BCS process holds game hostage
By Dan Wetzel, Yahoo! Sports
Nov 29, 11:19 pm EST
The BCS formula is an exercise in nonsense.
It always has been; it’s just more obvious this season, when there is a
heated debate over the second-best team, the one that would meet LSU for the
title.
Alabama, Oklahoma State, Virginia Tech and others are making their pitches,
pointing out this strength and that argument to get a crack at the... 阅读全帖 |
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T***N
发帖数: 1835 | 50 第一次在movie版发帖。。。
趁着科幻热，又看了一遍黑客帝国123。
第一遍是高中看，感觉就是爽，
第二遍大学时看的，感觉很疑惑。
第三遍刚来美国看的，感觉后背发麻。
第四遍刚看的，最后感到充满了希望。
转载一篇解析吧，解释的很好，观点也都基本同意。。。
《黑客帝国》完全解析
发布时间: 2012-01-14 22:46 阅读: 27771 次 推荐: 43 原文链接 [收藏]
万事皆有始亦有终——《The Matrix》影评之终结篇
一、前言
从 Matrix I 到 Matrix III，整整四年，一对名叫沃卓斯基（导演加编剧）的兄
弟给科幻电影带来一次史无前例的冲击，无论从思想上还是视觉效果上都超过了以往任
何一部科幻电影，从来没有一部科幻电影能够创造这么多的 Fans 也没有任何一部科幻
电影能像 Matrix 这样引发如此大规模的讨论——讨论剧情，讨论主题，讨论特效，讨
论演员，笔者绝不敢自称 100% 的看懂了（我把看懂定义为“理解沃卓斯基兄弟眼中剧
情和主题的原意”，以免就这个“看懂”一词遭来无数的非议），但是我愿意把我所理
解的 The Matrix 的... 阅读全帖 |
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