k*******l
发帖数: 69 | 1 那本书还行吧
哪儿bt了？我都看的懂(除了引用的parabolic PDE的结果） |
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l****f
发帖数: 88 | 2 来自主题: Mathematics版 - 请教PDE 哪位知道：
对于parabolic equation with Neumann boundary condition, 解的上下界是什
么？其中的系数和区域有什么关系？
谢了！ |
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s*********4
发帖数: 54 | 3 来自主题: Mathematics版 - 救命,求助 Use a triple integral to Calculate the volume of the solid E enclosed by
the parabolic cyclinder z=1−x^2 and the planes z=0,y=0, and y+z=2. |
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c*****t
发帖数: 520 | 4 我是原作者。谢谢各位的指点。
我刚接触这个领域，正看E.Risler（maths.insa-lyon.fr/~risler/）近期的相关文章
，是通过energy functional发展在1977年P.Fife和J.B.McLeod做的有关global
convergence and stability of travelling wave solutions of nonlinear
diffusion equations的结论。
我想自己现在也不见得需要看很系统和深刻的专著，只是想了解这个方向大体的背景知
识和研究状况，以便在读文章时更好地理解。根据BlackKnife推荐，我已下载了3 个
Volpert 合写的Traveling Wave Solutions of Parabolic Systems 。
另外，虽然E.Risler的文章没有涉及什么应用，但是我看到相关的文章说这类方程有
biological dynamics 方面的应用，有些被算作做生物数学的人，也在做相关的工作。
不知道有没有人了解这方面的前景？ |
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F********E
发帖数: 1025 | 5 Hi all:
I want to do a least square fitting, but I need to apply a constraint--which
is that the fitting line has to exactly cut through one specific data point
in my data set. For example, I want the parabolic line pass the origin, or
I need the following equation to fit in my data:
*************
a*x^2+b*x
**************
instead of the regular one:
*************
a*x^2+b*x+c
**************
Does anybody know any function in PYLAB OR PYTHON or other suite which can
do this? Thanks a lot! |
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g****t
发帖数: 31659 | 6 你读读matlab的polyfit函数的帮助。
这个不是问题。和原来的最小二乘法没区别。
如果是更复杂的约束就麻烦些。
Hi all:
I want to do a least square fitting, but I need to apply a constraint--which
is that the fitting line has to exactly cut through one specific data point
in my data set. For example, I want the parabolic line pass the origin, or
I need the following equation to fit in my data:
*************
a*x^2+b*x
**************
instead of the regular one:
*************
a*x^2+b*x+c
**************
Does anybody know any function in PYLAB OR PYT |
|
|
B********e
发帖数: 10014 | 8 maybe start with
heat eqn/green function/decay rate...
or maximal principle
or from semi-group theory
then semilinear/quasilinear case |
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m*****9
发帖数: 166 | 9 概言之，如果你能证明 u 和 |gradient u| 是一致有界的话，那
u 就是光滑的。 |
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c*****t
发帖数: 520 | 10 Thank you very much for your reply. But I do not understand this conclusion.
I think it is too strong. I want to know it in detail. Can you recommend
some books on this topic?
In the paper "The Approach of Solutions of Nonlinear Diffusion Equations to
Travelling Front Solutions", by Paul C. Fife and J.B. McLeod in 1977, the
authors discussed the following equation:
u_t=u_xx+f(u), -\infty0.
f\in C^1[0,1], f(0)=f(1)=0.
If the initial data u(x,0)\in[0,1], then u(x,t)\in[0,1] for any t>... 阅读全帖 |
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x******a
发帖数: 6336 | 11 她好像有本薄一些的讲义100多页，你可以翻翻然后把讲义的习题做做 |
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c*****t
发帖数: 520 | 12 谢谢。
您说的讲义是Analytic Semigroups and Reaction-Diffusion Problems，Internet
Seminar 2004–2005 吧。
我之前看到这份讲义开头的例子，spatial domain和time domain 都是bounded ，而书
里不少内容似乎没有提及，就没有继续看。因为我主要做unbounded domain上的问题，
不知道此讲义是否讨论了相关情况。Lunardi 的书里似乎是考虑了unbounded domain的
情况吧。
既然讲义有习题，我把讲义和书配合起来看吧。 |
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c*****t
发帖数: 520 | 13 Wolf Prize in Mathematics 2012: Michael Aschbacher and Luis Caffarelli.
http://www.simply-smart.com/wolf/Wolf_Prize_2012-ENG_PR.pdf
Michael Aschbacher is a principal architect of the classification of finite
simple groups. His Impact on the theory of finite groups is extraordinary in
its breadth, depth and beauty.
Luis Caffarelli produced outstanding, visionary, original and fundamental
work on partial differential equations, in particular on regularity for
elliptic and parabolic equations, free... 阅读全帖 |
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a*1
发帖数: 120 | 14 版上有做PDE的朋友吗，我的问题是
For u（x,t）
u_t + a(x,t)*u_xx+b(x,t)*u_x=0
在什么情况下有解？ 比如a,b关于x是holder continuous的情况是是否有解？ |
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L*******t
发帖数: 2385 | 17 来广告一下我的工作，至少quasi-linear parabolic PDE，我能找到普适的解法。 |
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L*m
发帖数: 235 | 18 近十年JAMS上的华人作者，JAMS上的文章相对更多，搜的没那么仔细，有可能不完全。
大家也看看有没有漏的
2015
Kähler-Einstein metrics on Fano manifolds. I: Approximation of metrics
with cone singularities
Xiuxiong Chen, Simon Donaldson and Song Sun.
Kähler-Einstein metrics on Fano manifolds. II: Limits with cone angle
less than 2π
Xiuxiong Chen, Simon Donaldson and Song Sun.
Kähler-Einstein metrics on Fano manifolds. III: Limits as cone angle
approaches 2π and completion of the main proof
Xiuxiong Chen, Simon Donaldson... 阅读全帖 |
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n*********3
发帖数: 534 | 19 Given a river with a parabolic flow profile, zero velocity on the edge and
maximum in the center, a ship with constant speed, but the direct can be
adjusted, what is the path the ship should take (angle relative to the edge
as a function of position in the river) so that the time crossing the river
is the shortest? |
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n*********3
发帖数: 534 | 20 Given a river with a parabolic flow profile, zero velocity on the edge and
maximum in the center, a ship with constant speed, but the direct can be
adjusted, what is the path the ship should take (angle relative to the edge
as a function of position in the river) so that the time crossing the river
is the shortest? |
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x********i
发帖数: 905 | 21 http://iccm.mcm.ac.cn/dct/page/1
Invited Lectures
Group 1
Fan Qin: Cluster algebras and monoidal categorification
Fang Li: Positivity of acyclic sign-skew-symmetric cluster algebras via
unfolding method and some related topics
Cheng-Chiang Tsai: An attempt for affine Springer theory
Li Cai: The Gross-Zagier formula: arithmetic applications
Ming-Hsuan Kang: Geometric zeta functions on reductive groups over non-
archimedean local fields
Huanchen Bao: Canonical bases arising... 阅读全帖 |
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f*******r
发帖数: 204 | 22 First choice: Use Autolisp or ObjectArx. Read help and try to program yourself.
Alternatively, you can use SPline to fit your curve, since 3 points are enough
to define a parabolic curve. |
|
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b***k
发帖数: 2673 | 24 ☆─────────────────────────────────────☆
accumulator (power) 于 (Fri Dec 7 23:07:33 2007) 提到:
Does anyone know the answer for this question? Thanks a lot.
1) If you are solving a parabolic partial differential equation by using
explicit finite difference method, is it worse to have too many time steps
or too fine a grid in the space dimension? Why?
2) To get 3 heads in a row, what is the expected minimum times of coin
tosses needed?
☆─────────────────────────────────────☆
moreroads (做好自己的 |
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a*********r
发帖数: 139 | 25 PDE and its numerical methods are important because the solutions of many
SDEs are PDE. For example, to solve the classic Black-Scholes option pricing
equation, one need to solve the back-forward parabolic PDE. The good news
is that PDE is very easy to learn. A solid background in freshman calculus
is sufficient. However, to really understand SDE, you need much more
preparation. |
|
|
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x******a
发帖数: 6336 | 28 it is really nothing compared with Lieberman's 'Second order parabolic
differential equations'
I |
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L*******t
发帖数: 2385 | 29 请教版上的各位大神，高维的Parabolic（最好是一般的nonlinear PDE) PDE有什么比
较好的curse of dimension free 的数值解法？
我目前在读一篇Option pricing的文章上面说到了sparse grid和expansion。但我不确
定这个是最好的方法。。
还请各位大牛指点！ |
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L*******t
发帖数: 2385 | 30 谢谢！我要的就是线性高维parabolic的解法：）是不是Galerkin也是一种可行的方法
呢？ |
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L*******t
发帖数: 2385 | 31 其实也没啥用，要用解quasilinear Parabolic PDE的地方都可以试试看嘛 |
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a*********r
发帖数: 116 | 32 These two papers have nothing to do with the present
problem. They
are all about parabolic potential. And they are standard
citations in
the textbook on paramagnetic property. |
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M*********m
发帖数: 2024 | 33 You must have seen this sort of things before. For free electron gas, if you
apply magnetic field to it, the orbital angular momentum around the magnetic
field is quantized. Since the electron number is conserved, so the density of
state changes from a parabolic to steps. It was proposed by L.D. Landau in
1930 and was measured by de Haas and van Alphen at the same year. For HTSC,
the electrons are considered mainly confined in 2D cuprate layer, and
therefore the Landau levels are co-centric circ |
|
F********E
发帖数: 1025 | 34 Hi all:
I want to do a least square fitting, but I need to apply a constraint--which
is that the fitting line has to exactly cut through one specific data point
in my data set. For example, I want the parabolic line pass the origin, or
I need the following equation to fit in my data:
*************
a*x^2+b*x
**************
instead of the regular one:
*************
a*x^2+b*x+c
**************
Does anybody know any function in PYLAB OR PYTHON or other suite which can
do this? Thanks a lot! |
|
f**d
发帖数: 768 | 35 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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S*********g
发帖数: 24893 | 36 【 以下文字转载自 StephenKing 俱乐部 】
发信人: StephenKing (金博士), 信区: StephenKing
标 题: 不系安全带，John Nash今天车祸死了
发信站: BBS 未名空间站 (Sun May 24 11:17:59 2015, 美东)
John Forbes Nash, Jr.
Born June 13, 1928
Bluefield, West Virginia, U.S.
Died May 23, 2015 (aged 86) [1]
Residence United States
Nationality American
Fields
Mathematics
Economics
Institutions
Massachusetts Institute of Technology
Princeton University
Alma mater
Princeton University
Carnegie Institute of Te... 阅读全帖 |
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S******s
发帖数: 5376 | 37 Understanding Jigging Rod Ratings
Most rods are rated in three ways by the GRAM (jig weight) and the PE Rating
(line Rating) & Style.
Gram rating: The gram rating on your rod is a max rating therefore a 400g
rod is rated from roughly half that rating to the exact gram. So in essence
if I use 250g-400g jigs would be ideal. I generally always buy 400g rods
because I use anywhere from 200-400 jigs and the tips on my rods are always
parabolic in nature therefore I am safe. The blanks are designed to... 阅读全帖 |
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w*******y
发帖数: 60932 | 38 Amazon has the streamlight 73001 led light for 6.99 shipped w/prime.
Link:
http://www.amazon.com/Streamlight-73001-Miniature-Keychain-Flashlight/dp/B0011UIPIW/
Seems to have fairly goodreviews.
Keep in mind this light is tiny, but the light itself is very good.
Case material is machined aircraft aluminum with anodized finish
Parabolic shaped LED area optimizes beam performance
5mm white LED, impervious to shock with a 100,000 hour lifetime
Up to 8 hours declining usable output
1.47-Inches length |
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w*******y
发帖数: 60932 | 39 OMG!!! this is a deal! This is the HQI metal halide lighting one.. not the
CF one
Nano-Cube HQI Aquarium w/FREE Nano Cube Stand for 314.99 plus 8.99 shipping
50 percent off!
28 gallon Nano Cube HQI Aquarium
Mega Illumination
JBJ Lighting is proud to offer the 28 gallon Nano-Cube HQI, boasting a
whopping 5.35 watts of power per gallon. Combined with a German parabolic
reflector, it casts sparkling, shimmering rays to every corner of the
aquarium. The 28 gallon Nano-Cube HQI is definitely the choi... 阅读全帖 |
|
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N***i
发帖数: 2063 | 41 来自主题: _Stockcafeteria版 - VISN cool
parabolic move?! |
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B*S
发帖数: 1328 | 42 I know I am not supposed to do this here. But both the view point and
the conclusion are interesting...
************************************************************************
In a recent report Stöferle went on to say:
1) The Dow/gold ratio suggests a possible future $10,400 price
for gold.
At 8.5x the Dow/gold ratio is currently slightly above the long-term
median of 8x. This means that gold is still relatively inexpensive in
comparison with the Dow Jones. Bull markets tend to en... 阅读全帖 |
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L****a
发帖数: 572 | 43 say what ? cree ? it's just simple, one sentence :
it's a maker of LED components and LED lamps.
But it looks like a parabolic run here. |
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C****a
发帖数: 1639 | 44 我也不是经常put, 我觉得两种setting 用来put比较保险吧
1，range stock, 在上沿put, 这种不会怎么大跌，可以保险一点比如几个月的ATM。
2. parabolic move + volume increase, 这种就是赌大跌，上便宜的far OTM, 比如
SLV那样的。
不过专家们好象都不推荐单边赌期权。。。 |
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