j*c
发帖数: 97 | 1 integration of x^n exp[-x] (actually my problem is to integration
x^n exp[-(x-x0)/a],however, it can be rewrite as the sum of several
x^n exp[-x]).0<=n<=4, x is any region (xi,xf) between 1e-6 and 1e8, with
xf/xi~1.2. Since we have large error tolerance (0.01), we can use
approximations for x<0.05 and x>20. The remain problem is for 0.05
The most important issue here is that we can't use double precision for
the executing time limitation.
So the problem is: to find a fast method to solve t |
|
j*c
发帖数: 97 | 2
~~~~~~~~~~~~~~~~~~~~~~
just thought that the large (0.1) error of the final results may occur
when sum these integrations together. this implies a more accuracy
integration of x^n exp[-x], maybe 0.001 or 0.0001 |
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J**Y
发帖数: 34 | 3 In Bayesian econometrics, we need estimate the moments of functions of
interests, for example, the expecttation of f(a): E[f(a)|D], where
a is a random number and D is observed data.
E[f(a)|D]=Integrate[(f(a)*p(a|d)),{a}]. Where p(a|D) is posterior
density of a. Generally, we can not find
the closed form of the integration, so some numeriacl methods is neccessary.
The first method is Laplace's method. This method changes the problem
to a numerical derivative, which is much easier. However, this |
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j***u
发帖数: 26 | 4 Thanks eejob for your reply. In fact, I did have a buffer connecting between
the integrator output and ESD pad. So the leakage of ESD should not be an
issue. And the buffer offset has been considered when measurement. Well, the
integrator will be used in a large system. I just hope this offset is not
caused by the leakage of the transistors due to such small tail current. I
will make the measurement again using oscilloscope to make sure high
impedance mode. Really thanks for your reply.
By the w |
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I***a
发帖数: 704 | 5 我做asynchronous digital VLSI的，这学期上了semiconductor device这门课，感觉
很有用。
请问Integrated Circuit Fabrication Technology这门课有用吗？
课程介绍在这里:
Theory and techniques of integrated circuit fabrication technology; crystal
growth, chemical vapor deposition, impurity diffusion, oxidation, ion
implantation, photolithography and medullization. Design and analysis of
device fabrication using SUPREM and SEDAN. In-process analysis techniques. |
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f***r
发帖数: 344 | 6 有一个Process integration engineer位置面试的机会，本人PHD毕业不久，对各BEOL
的process都熟悉，但还没有捞到工业界processing工作的经验。
请问: Process integration engineer位置的面试一般会涉及哪些方面的问题呢？会很
具体到某一个流程中某种材料的选择之类的吗？
请有经验的前辈指点，也可站内信，感激不尽！ |
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Y*P
发帖数: 519 | 7 【 以下文字转载自 JobHunting 讨论区 】
发信人: YeP (也不), 信区: JobHunting
标 题: Signal Integrity Intern Opportunity
发信站: BBS 未名空间站 (Wed Apr 3 12:20:07 2013, 美东)
My team has a Signal Integrity Intern opportunity in bay area. The intern
will work with senior team member on SI of server development. Please
message me if you are interested. Thank you. |
|
s********5
发帖数: 2 | 8 大家好，小弟在一水校读phd，今天是第二年，目前在找暑期
实习，但是对工业界的岗位分类不太明白，有点疑惑。
现在自己在做的是on-chip RF/MM-WAVE IC 的passive circuits modeling，比如
transmission line， interconnects，spiral inductor，filter之类的。课程背景主
要是一些IC的课，比如analog circuit， RF/microwave IC等active circuit之类的。
虽然课程上的还行，无奈研究都没涉及active 方面的，流的片也只有passive circuit
，投IC的position也没啥底气。想做本行但是发现职位基本没有单独招passive
circuit的。目前看来只有做signal integrity的比较靠边了，比如大家都会用到VNA，
TDR，还有常用的EM solver，像ADS, HFSS, Maxwell,Q3D之类的。
所以想请教一些在公司工作的前辈，我这种情况是不是主要投signal integrity的
position比较靠谱呢？
Thanks... 阅读全帖 |
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v*c
发帖数: 42 | 9 suppose we know x_hat is aymptotic distributed with mean x and variance
sigma2.
here, x_hat is an estimator of x.
Now, we have integral (x_hat)dx, x from 0 to 1. Then how to obtain the
aymptotic distribution of this integral?
Thanks, |
|
B********e
发帖数: 10014 | 10 it seems that no explicit expression exists.
you can substitue y for the exponent ,solve x for y then end up with the dec
oupled integrations. one of the integration is like:
\int{exp(k\sqrt{1-x^2})dx}. but as simple as this one it's difficult to get
explicit anti-deri. |
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H****h
发帖数: 1037 | 11 没听说过direct Riemann integrable。 |
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n******t
发帖数: 4406 | 12 经典的Riemann广义积分一般定义成 lim_{x->inf}\int_0^x f(t)dt.
direct Riemann Integrable 是指直接在(0,\inf)上定义Riemann上和
和下和，然后要求上和和下和收敛且相等。
例子比如说sin(x)/x. |
|
b***e
发帖数: 3337 | 13 Integral of exp{-(a*x^2+b*x+c)} from 0 to infinite
i know the answer of Integral of exp{-(a*x^2+b*x+c)} from -inf to inf
= sqrt(pi/a)*exp((b^2-4ac)/4a)
thanks!! |
|
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m******t
发帖数: 273 | 15 【 以下文字转载自 Statistics 讨论区 】
发信人: myregmit (myregmit), 信区: Statistics
标 题: solve an optimization model with integral as constraints
发信站: BBS 未名空间站 (Wed Mar 19 22:21:44 2014, 美东)
I need to solve a mathematical optimization model with integral as
constraints.
Min. | s1 - k1 | + | s2- k2 |
s.t.
integral_from_0_to_M of f(x) = 1
s1 = integral_from_0_to_M of x * f(x)
s2 = integral_from_0_to_M of x^2 * f(x)
M, k1 and k2 are positive numbers
f(x) is a proba... 阅读全帖 |
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s*******s
发帖数: 133 | 16 有谁用ANSYS算过J INTEGRAL?
J INTEGRAL里面那个DISPLACEMENT GRADIENT怎么从ANSYS里得到?
最后的RESULT里一般都是整个的SHEAR STRAIN啊. 谢谢 |
|
e**********n
发帖数: 57 | 17 刚接到一个从Integration International Inc. (I3)recruiter打来的电话，有一个
contractor 的位置。
想问一问大家，有谁和Integration International Inc. (I3)打过交道？
没有contractor 的经验，因为刚要Ph.D.毕业，想听听大家的意见？ |
|
h*****n
发帖数: 2023 | 18 【 以下文字转载自 Statistics 讨论区 】
发信人: haibian (dahai), 信区: Statistics
标 题: 如何免费登入Thomson Reuters Integrity？
发信站: BBS 未名空间站 (Wed Dec 23 13:04:00 2015, 美东)
在美国，有没有办法免费使用Thomson Reuters Integrity?请问各位前辈 |
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m*******s
发帖数: 3142 | 19 最近在看 path integral，发现一旦涉及Grassmann variable的部分差不多都是一个样
，反正看不明白，不知道大家能不能推荐把Fermion path integral讲得比较好的书，
谢谢！ |
|
r*****t
发帖数: 286 | 20 ☆─────────────────────────────────────☆
KuangTer (KuangTer=Quant) 于 (Sun Apr 15 16:26:33 2007) 提到:
We know:
X(t) = 1 + I[sigma*(X(s)^0.5)]dW(s) + bt, and tao = inf{t: X(t)=0}
Sorry, I can't type integral notation, so I use the "I[f(s)]dW(s)" in the
formula to denote Ito integral for function f(s) from 0 to t.
Question is:
Give necessary and sufficient conditions on sigma and b>0, such that P{tao<
infinite}>0
Can anyone help to calculate it, thank you!
My answer is 0<2b/(sigma^2)<1, is it ri |
|
B*********h
发帖数: 800 | 21 ☆─────────────────────────────────────☆
maglion (da木头) 于 (Tue Mar 6 12:10:29 2007) 提到:
X^X
☆─────────────────────────────────────☆
maglion (da木头) 于 (Tue Mar 6 15:43:08 2007) 提到:
nobody knows?
☆─────────────────────────────────────☆
sinme4 (天空是我家) 于 (Tue Mar 6 15:53:14 2007) 提到:
I know the derivative. But not sure if the same method applies to the
integral.
maybe you can use exp(integral{ln()}).
☆─────────────────────────────────────☆
cocojumbo (Nick) 于 (Tue Mar 6 16:10:35 |
|
x********o
发帖数: 228 | 22 integral of 1/(1+x^2)^(1/2) dx
用substitution 还是 integral by parts?
另外，differential equation有没有什么在线得中文辅助材料可以看？ |
|
t*******e
发帖数: 172 | 23 You need to carefully think about what is Ito integral...
after your do some integral, you get a R.V. if you know the distribution,
then you definitely know the R.V. , what eles do you want?
In your e.g. you actually get a R.V is 1/2 (X^{2}-T) where X is a N.R.V with
mean 0 variance T. If you want you can write X as W_{T}, but what is the
difference? |
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t*******e
发帖数: 172 | 24 I think what he asked is about can we find a exlicit form as function of W.
In this sense, the answer is no, and knowing the variance is enough. Just
like the(some) definite elliptic integral cannot be written as elemntay
function. But we know all the property of the integral well.
Besides this, is it important or useful for "canonical" way in analysis
world?
is
... |
|
m******t
发帖数: 273 | 25 【 以下文字转载自 Statistics 讨论区 】
发信人: myregmit (myregmit), 信区: Statistics
标 题: solve an optimization model with integral as constraints
发信站: BBS 未名空间站 (Wed Mar 19 22:21:44 2014, 美东)
I need to solve a mathematical optimization model with integral as
constraints.
Min. | s1 - k1 | + | s2- k2 |
s.t.
integral_from_0_to_M of f(x) = 1
s1 = integral_from_0_to_M of x * f(x)
s2 = integral_from_0_to_M of x^2 * f(x)
M, k1 and k2 are positive numbers
f(x) is a proba... 阅读全帖 |
|
m******t
发帖数: 273 | 26 I need to calculate an integral in python.
I have imported sympy.
g(a,z) = integral_from_z_to_inf of ( t^(a-1) * e^(-1))
in python:
x,a,z = symbols('x a z')
g = integrate(x**(a-1) * exp(-x), z, oo)
I got error:
ValueError: Invalid limits given: (z, oo)
Any help would be appreciated !
Thanks ! |
|
B***y
发帖数: 83 | 27
I am not sure about what problem might occur in the numeric
integration. Just
some suggestions:
1) when r is quite large, sin(kr) is oscillating quite fast, thus
usually you
need to take smaller time-steps to take care of it.
2) since you choose g(k) =1, then \int_0^\infty 1/k sin(kr) dk is not
absolutely
integrable, thus there might be some problem when k is small, where
1/k is quite
large, causing some numeric problem.
good luck. |
|
m****o
发帖数: 31 | 28 想问问为什么运行完integrate命令后，会出现如下的错误：
Error in integrate(basefunction, lower = 0, upper = 5, subdivisions = 100) :
maximum number of subdivisions reached
然后我将 subdivisions 处改为10000（subdivisions = 10000），但是还是提示：
maximum number of subdivisions reached
麻烦高人指点，小妹刚刚接触R，有点摸头不着恼的，谢谢了！ |
|
w*******y
发帖数: 60932 | 29 Sony BRAVIA KDL46EX523 46-Inch 1080p LED HDTV with Integrated WiFi, Black
Price in Cart $898.98
link:
http://www.amazon.com/Sony-BRAVIA-KDL46EX523-46-Inch-Integrated
Technical Details
46-inch display with full HD (1080p) picture quality (1920 x 1080 native
panel resolution)
LED backlighting for incredible contrast, slim design, and energy efficiency
Sony's X-Reality Engine sharpens images for a clear, vivid, life-like
picture
Wireless Internet TV for wide variety of streaming media and other Int... 阅读全帖 |
|
w*******y
发帖数: 60932 | 30 Kodak Mini HD 720p Waterproof Ultra Slim Camcorder 1.8" LCD Display,
Integrated USB & Video Editing Software!
1saleaday.com:
http://1saleaday.com/family/
Specs
Condition: Factory Refurbished
Packaging: Brown Box
Warranty: 90 Day
Manufacturer: Kodak
Model: ZM2
Features Include:
o Waterproof to 10 feet
o 1.8" color LCD screen, 61.4K pixels
o 1/4" CMOS sensor
o 720p HD video (1280x720@24fps), VGA (640x480@30fps)
o 40mm lens
o 1.6 foot - Infinity fixed focus
o 3x digital zoom
o ... 阅读全帖 |
|
w*******y
发帖数: 60932 | 31 Sears.Com
Pyramid Technologies Pr330A 2-Channel Receiver With Integrated Amplifier
$8.20 plus shipping, which was $17 for me. Possible price / pricing error.
You could also try the shipvantage 30 day trial to get free shipping. I
tried, but got charged shipping anyway and had to call for a refund. They
also cancelled my shipvantage and I can't use it again via the website
without a phone call. Not that big a deal, as I don't shop for delivery
there very often. If you select the shipvantage t... 阅读全帖 |
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k***e
发帖数: 7933 | 32 看了一下那个sh文件，好像是用来config
gv和sipgate的。
这个文件开头说This assumes you've install asterisk
and google voice integration already
这里的google voice integration指的是什么？
我现在已经装了dd-wrt，optware，asteriks14，python
下面就在昨天怎么config了。
我把ddwrt-lite-config里面的copy到相应的目录了，
下一步是不是就是运行这个sh文件把gv，sipgate的
user/pwd放上去？
还有几个问题请教一下：
用什么命令可以查asterisk是不是正常起来了？
最后和我的pap2怎么接起来？
谢谢！ |
|
l*****7
发帖数: 8463 | 33 Bill Gates is a very honest, respectful man with integrity and dignity
http://www.thegatesnotes.com/en/Books/Personal/Why-Nations-Fail
February 26, 2013 | Review by Bill Gates
Why Nations Fail: The Origins of Power, Prosperity, and Poverty (Book Review)
Normally, I’m fairly positive about the books I review, but here’s one I
really took issue with.
Why have some countries prospered and created great living conditions for
their citizens, while others have not? This is a topic I care a lot about,
... 阅读全帖 |
|
C********g
发帖数: 1548 | 34 Sorry I cannot type Chinese at work.
We have a remote-hosted application (so-called SaaS) and need integrate it
with our in-house LDAP server. The LDAP team asks to install a ssl cert in
the remote server. Can anyone advise what to do in their server? It is
Ubuntu server. And does the vendor have a reason for security concern if we
install our own cert in their server? |
|
t*******a
发帖数: 4055 | 35 The Trump administration has changed the focus of a Department of Homeland
Security immigrant citizenship training program managed by USCIS to “
assimilation,” a significant shift from the Obama era focus on “
integration.” |
|
s******r
发帖数: 5309 | 36 疮破撒谎成性，开赌场，嫖妓女，逃兵役太有dignity，honor，integrity 和decency
赢得疮轮跪舔。 |
|
n*******n
发帖数: 407 | 37 Let X1 and X2 be two independent Poisson variables with respective
parameters λ1 and λ2.
Let F1(t) and F2(t) be their respective cumulative functions.
What is F1(t)-F2(t)? What is ∫(F1(t)-F2(t))dt? What is finite integral of
F1(t)-F2(t) from 0 to N? |
|
b**********y
发帖数: 7371 | 38 这个即把轮胎 - 固特异的INTEGRITY 235/70R16- 雨天简直没法开啊，抓地力真TNND差
， SKID & SLIDE all over the road
即把固特异的服务也超烂， 明摆着还有50%+的TREAD， 没个合理的解释， 只是一个劲
的推销它的新胎， MLGBDBD |
|
|
P*******Y
发帖数: 1038 | 40 Smart phone integration 基本都有吧
Led灯基本4matic 上的车都配，led headlight 要加价850好像。
那个两排天窗的没什么用吧，还是大家都很喜欢?
不过高配的都有，感觉浪费1500找难受，这里太热，天窗是副作用。 |
|
r*****t
发帖数: 2860 | 41 可以手机app通过蓝牙连接听歌。不需要任何package
：最近气的爆炸， 定了的车等了两个多月 都没有到， 只有去买现车了。很多现车没
有 Smart Phone Integration Package。
： |
|
a******s
发帖数: 1812 | 42 2个Sonos PLAY:3 All-in-One Wireless Music Player with 3 Integrated Speakers
(White)
$235 each
northeast |
|
d******0
发帖数: 22800 | 43 你要看它匹配不，像楼上说的。
一般receiver如果是integrated amplifier， 已经有了power amp， 而且，缺德带冒
烟的，不给出中间产物pre-amp的输出。要走hifi的话，还是pre-amp和power amp分开
买，加上电源净化， 就可以不停地分开升级各个部件。 |
|
p********e
发帖数: 16048 | 44 Jwalk:
krell's integrated amp.. well, it was designed for a specific price point.
its circuit design and production does not have the soul of a real Krell. It
is desinged to capture the $2500~ market, which is what most "sane" person
would spend on an amp, and the price market is significantly bigger than the
>$2500...
but IMHO, it is not really a krell... |
|
p**u
发帖数: 30 | 45 【 以下文字转载自 Statistics 讨论区 】
发信人: pepu (pepu), 信区: Statistics
标 题: 请问用sas做data integrity
发信站: BBS 未名空间站 (Tue Nov 24 18:32:04 2009, 美东)
onsite面试，需要做一个sas skill test
很久没用sas做data部分了，需要复习准备一下
有人熟悉这部分编程吗，大概会碰到什么样子的data做什么样子的处理
多谢 |
|
a*******j
发帖数: 72 | 46 It is with a well-established company in the bay area. This is an urgent
position and needs to be filled soon!
RF System Integration Engineer (Automated Test Specialist)
Job Description
· Develop and optimize RF design validation systems
· Contribute to a multi-facetted validation software suite
based on C
* Candidate will interpret wireless standards documents to develop
automated validation solutions
* Analyze validation results in conjunction with RF design and
va |
|
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f******r
发帖数: 148 | 48 We have one opening for Signal Integrity Engineer located in Bayarea, the
person will work in the hardware group for server systems. New graduate only
, master (preferred) or PhD, need to be available this May.
Please send me a message if you're interested. Thanks. |
|
Y*P
发帖数: 519 | 49 My team has a Signal Integrity Intern opportunity in bay area. The intern
will work with senior team member on SI of server development. Please
message me if you are interested. Thank you. |
|
i*****h
发帖数: 1534 | 50 借版上的人气问一下，这是什么意思？
之前读了个学位没找到工作，现在转专业并且用CPT在工作，今年申请的H1B，但是收到
RFE说要提供证明how CPT is an integral part of the degree？ 一般问这个是什么
意思？ 有经验的请指点下，谢谢！ |
|
