c******a
发帖数: 6951 | 1 V. Klee and G.J. Minty. "How Good is the Simplex Algorithm?" In O. Shisha,
editor, Inequalities, III, pages 159–175. Academic Press, New York, NY,
1972
Simplex pivot rules visit all 2^n vertices before arriving at the optimal
point in an example in which the polytope P is a distortion of an n-
dimensional cube. This shows that the upper bound complexity of the
algorithm is exponential time. This is the worst case. The simplex method is
remarkably efficient in practice. |
|
w*******e
发帖数: 285 | 2 【 以下文字转载自 Java 讨论区 】
发信人: windforce (大怪兽), 信区: Java
标 题: 请问哪里有java的downhill simplex方法的源码？
发信站: BBS 未名空间站 (Fri Jan 30 15:54:08 2009), 站内
我在n维空间中有一个点，知道它到其他n+1个点的距离和他们的坐标，求当前点的坐标
使得误差的平方和最小。如果没有downhill simplex有其他的比较有效率的方法也行，
或者C++下的源码也行。谢谢了。 |
|
w*******e
发帖数: 285 | 3 【 以下文字转载自 Java 讨论区 】
发信人: windforce (大怪兽), 信区: Java
标 题: 请问哪里有java的downhill simplex方法的源码？
发信站: BBS 未名空间站 (Fri Jan 30 15:54:08 2009), 站内
我在n维空间中有一个点，知道它到其他n+1个点的距离和他们的坐标，求当前点的坐标
使得误差的平方和最小。如果没有downhill simplex有其他的比较有效率的方法也行，
或者C++下的源码也行。谢谢了。 |
|
s********n
发帖数: 5 | 4 有一个线性规划问题，想用Simplex解决,未知数X为47维
enj是47维向量，M1和M2均为1000*48维矩阵，
运行下列语句的时候
simplex(a=enj,A1=M1[,2:48],b1=t(M1[,1]),A2=M2[,2:48],b2=t(M2[,1]),maxi=TRUE)
提示错误如下
Error in as.vector(X) %*% t(as.vector(Y)) : non-conformable arguments
取消了b1和b2的转置提示同样的错误
请问有人知道是哪里写错了么，谢谢 |
|
t**i
发帖数: 688 | 5 enj = rnorm(3, mean=3,sd=1)
M1 = matrix(rnorm(40,mean=0,sd=1),ncol=4,byrow=TRUE)
M2 = matrix(rnorm(40,mean=0,sd=1),ncol=4,byrow=TRUE)
require(boot)
simplex(a=enj,A1=M1[,2:4],b1=t(M1[,1]),A2=M2[,2:4],b2=t(M2[,1]),maxi=TRUE)
Linear Programming Results
Call : simplex(a = enj, A1 = M1[, 2:4], b1 = t(M1[, 1]), A2 = M2[, 2:4],
b2 = t(M2[, 1]), maxi = TRUE)
Maximization Problem with Objective Function Coefficients
x1 x2 x3
2.088811 4.114023 2.513823
No feasible solution could be f |
|
w*******e
发帖数: 285 | 6 我在n维空间中有一个点，知道它到其他n+1个点的距离和他们的坐标，求当前点的坐标
使得误差的平方和最小。如果没有downhill simplex有其他的比较有效率的方法也行，
或者C++下的源码也行。谢谢了。 |
|
L*******g
发帖数: 913 | 7 我在用numerical recipe的simplex方法找最小值，程序片段如下：
int ntmp;
float p[3][2], y[3];
float getfunc(float x[])
{...}
void amoeba(float **p, float y[], int ndim, float ftol,
float (*funk)(float []), int *nfunk);
p[0][0]=p[0][1]=0.5;
p[1][0]=p[0][0]-0.2;
p[1][1]=p[0][1]-0.2;
p[2][0]=p[0][0]+0.2;
p[2][1]=p[0][1]-0.2;
amoeba(p, y, 2, 1.0e-5, getfunc, &ntmp);
现在问题是amoeba子程序里不能读入p的初值。是不是p的类型有问题？多谢指教！ |
|
j*********3
发帖数: 32 | 8 Does anybody know why Simplex method is exponential? Could you give me the
proof? Thank you .... |
|
R*****n
发帖数: 8658 | 9 这个参数的取值范围是什么?
就是定义simplex的vertices的domain |
|
t**i
发帖数: 688 | 10 I am not familiar with simplex(), but this error seems to stem from
iteration/convergence criteria. Either obfun> -eps or it<=n.iter gives a NA
and that caused the problem. Try to play with eps or n.iter options.
However, caution is needed because the thus-generated results may not have
been drawn from the convergence status. |
|
s*********e
发帖数: 1051 | 11 does anyone here have experience in simplex distribution?
I drafted a piece of nlmixed code based upon the density function but am not
sure it is correct or not.
proc nlmixed data = tmp1 technique = NRRIDG ;
parms b0 = 0 b1 = 0.1 sigma = 5;
bounds sigma > 0;
u = 1 / (1 + exp(-(b0 + b1 * x)));
dd = (y - u) ** 2 / (y * (1 - y) * u ** 2 * (1 - u) ** 2);
lh = (2 * constant('pi') * sigma * (y * (1 - y)) ** 3) ** (-0.5) * exp(-(2
* sigma) ** (-1) * dd);
ll = log(lh);
model y ~ general(l... 阅读全帖 |
|
j*****e
发帖数: 333 | 12 查资料说这indicates degeneracy of the Nelder--Mead simplex. 但不懂
degeneracy是什么意思，这个代表什么意思呢，为什么会这样的结果，有什么办法得到
convergence=0呢？谢谢大虾指教！ |
|
|
|
发帖数: 1 | 15 新生儿herpes也有可能是医院获得性的，由接触患儿的医护人员传染给另外的新生儿。
HSV is usually transmitted during delivery through an infected maternal
genital tract. Transplacental transmission of virus and hospital-acquired
spread from one neonate to another by hospital personnel or family may
account for some cases. Mothers of neonates with HSV infection tend to have
newly acquired genital infection, but many have not had symptoms at the time
of delivery.
Neonatal Herpes Simplex Virus (HSV) Infection
http://www.merckmanuals.com/p... 阅读全帖 |
|
l******a
发帖数: 42 | 16 Q: Because of the Walras Law,we can place price vector on a simplex in general
equilibrium analysis.
Is it true? If it is,then how can I explain it? I don't know how to connect
Walras Law with Price simplex. I know in order to prove the existence of
Walras Law,Varian uses pice simplex theory.
Thanks a lot!!! |
|
|
b****t
发帖数: 114 | 18 Hi all,
I am thinking about very interesting problem:
I want to partition a n-diemsional unit cube into a bunch of n-D simplexs;
these simplexs are disjoint and union of them is the unit cube.
Also, within the cube, I may have one way to easily detect any point belongs
to which simplex.
and finally how to calculate the volumes of any kind of simplx in n-D space.
I know the formula for this, but determinant calculations are basically too
expensive. any better alternatives?
thanks a lot.
Beet |
|
p**q
发帖数: 1130 | 19 是女孩的first name，
百度了一下，原来背后还有个故事
奥地利商人埃米尔·耶里内克（Emil Jellinek）是戴姆勒汽车公司的客户，他将爱女
的名字“梅赛德斯”（西班牙语中的女子名）作为戴姆勒汽车公司为他所定制汽车的名
称。1901年，35马力的“梅赛德斯”汽车实现了“现代汽车”的突破。这辆“梅赛德斯
”汽车在当时是极为出色的新奇产品，采用了众多的创新技术，包括强劲的发动机以及
蜂窝式散热器、长轴距和低重心。埃米尔·耶里内克将35马力的“梅赛德斯”汽车推向
了赛场，并获得了成功。不久，“梅赛德斯”之名就开始广为流传。1902年，“梅赛德
斯”作为商标，获得了法律保护。同年，戴姆勒汽车公司推出了梅赛德斯“Simplex”
系列；“Simplex”系列不仅装配了更加强劲的发动机，而且更加易于操纵。在本次展
览会中展出的1907年生产的35马力的梅赛德斯“Simplex”就是当时典型的代表。
a |
|
k*******d
发帖数: 707 | 20 刚刚google了一下，simplex herpes 二型就是生殖器herpes，会从母亲传染，如果母
亲正好是潜伏的herpes病毒发作的时候。
Causes of Birth-Acquired Herpes
The herpes simplex virus causes birth-acquired herpes. After someone
recovers from herpes, the virus lies dormant in their body for long periods
of time before it flares up and symptoms appear. When the virus reactivates,
it’s called an active infection. Women who have active herpes infections
are more likely to pass the virus on to their babies during a vaginal birth.
The infant comes into ... 阅读全帖 |
|
|
g*****j
发帖数: 1211 | 22 It can be herpes simplex, or it can be canker sore.
If you are pregnant, you need to discuss that with your OB doctor. Primary
herpes simplex virus infection might affect baby, although your case is most
likely a relapse of existing infection. A simple blood test can confirm
the difference. |
|
w*******d
发帖数: 48 | 23 Chlamydia Negative Negative Negative 07/08/2011 07/11/
2011
Hepatitis B Negative Negative Negative 07/08/2011 07/09/
2011
Hepatitis C 0.2 0.0-0.9 Negative 07/08/2011 07/09/2011
Gonorrhea Negative Negative Negative 07/08/2011 07/11/
2011
Herpes Simplex Virus Type I 4.37 0.00-0.90 Positive 07/08/
2011 07/11/2011
Herpes Simplex Virus Type II <0.91 0.00-0.90 Negative 07/08/
2011 07... 阅读全帖 |
|
|
w*******d
发帖数: 48 | 25 【 以下文字转载自 Medicine 讨论区 】
发信人: whyclosed (问题为何被关闭), 信区: Medicine
标 题: HSV1
发信站: BBS 未名空间站 (Tue Jul 12 10:22:18 2011, 美东)
Chlamydia Negative Negative Negative 07/08/2011 07/11/
2011
Hepatitis B Negative Negative Negative 07/08/2011 07/09/
2011
Hepatitis C 0.2 0.0-0.9 Negative 07/08/2011 07/09/2011
Gonorrhea Negative Negative Negative 07/08/2011 07/11/
2011
Herpes Simplex Virus Type I 4.37 0.00-0.90 Positiv... 阅读全帖 |
|
b*********d
发帖数: 2105 | 26 谢谢指导！可是我试了，还是不行。
这是我macbook的ifconfig情况：
en0: flags=8863 mtu 1500
inet6 fe80::21b:63ff:fe1c:c1c4%en0 prefixlen 64 scopeid 0x4
inet 10.1.1.2 netmask 0xffffff00 broadcast 10.1.1.255
ether 00:1b:63:1c:c1:c4
media: autoselect (1000baseT ) status:
active
en1: flags=8863 mtu 1500
inet6 fe80::21b:63ff:fe0a:2b05%en1 prefixlen 64 scopeid 0x5
... 阅读全帖 |
|
s*****l
发帖数: 116 | 27 我在网上找到一篇文章，是一个著名的案子，登在science上。还有案子提到的文章。
看到这篇文章我觉我的情况没戏了。做博士后太苦了，辛辛苦苦的研究自己连知识产权
都没份，怎么才能保护自己的权利呢。
http://www.sciencemag.org/cgi/content/full/287/5462/2399
Chou J, Kern ER, Whitley RJ, Roizman B.
Mapping of herpes simplex virus-1 neurovirulence to gamma 134.5, a gene
nonessential for growth in culture.
Science. 1990 Nov 30;250(4985):1262-6.
Chou J, Roizman B.
The herpes simplex virus 1 gene for ICP34.5, which maps in inverted repeats,
is conserved in several limited-passage isolates but not in s... 阅读全帖 |
|
j***x
发帖数: 1469 | 28 ===================================================
1.Immunobiology
Volume 158, Issue 4, April 1981, Pages 369–379
Induction of natural killer cells by herpes-simplex virus type 2 in
resistant and sensitive inbred mouse strains
D. Armerding1, 2,
H. Rossiter1
===========================================
2.The Journal of ImmunologyFebruary 1, 1987 vol. 138 no. 3 884-888
Role of NK cells in protection of mice against herpes simplex virus-1
infection.
B Rager-Zisman,
P C Quan,
M Rosner,
J R Moller... 阅读全帖 |
|
j***x
发帖数: 1469 | 29 J Infect Dis. 1978 Mar;137(3):221-6.
Experimental infection of Tupaia belangeri (tree shrews) with herpes simplex
virus types 1 and 2.
Darai G, Schwaier A, Komitowski D, Munk K.
Abstract
The susceptibility of Tupaia belangeri (tree shrews, which are primitive
prosimian primates) to infection with herpes simplex virus (HSV) and the
pathogenesis of HSV in these animals were investigated. Juvenile (28--45
days old) and adult (150 days old) animals were inoculated intravenously,
intraperitoneally, o... 阅读全帖 |
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m********e
发帖数: 1 | 30 求不等式组是否有解的问题:
我现在遇到一个问题:
一个很大的不等式组:就只有4个变量组成1296个不等式.
问是否有解.
我现在是用linear programming的方法来做.
Simplex,和interior point algorithm都试了.
计算时间是1秒左右.但我希望是小于0.1秒.
不知有什么更好的方法.
因为Simplex,和interior point algorithm中也有很多
的不同的计算方法,不知那种对我的情况最合适.
谢谢. |
|
p*n
发帖数: 134 | 31 but how do you use simplex method for an objective function
with absolute values?
simplex method |
|
f******e
发帖数: 10 | 32 Actually, I am not so sure about your question. As I know, price simplex is
used as a condition of Walras Law. But it is also used to prove the the
existence of Walrasian Equilibrium independently. I don't see very clearly
about the cause-effect relationship between Walras law and the use of price
vector simplex, that's why I am inclined to say that the statement is false.
connect |
|
k*****y
发帖数: 744 | 33 在R^{n+1}空间中x_1 + x_2 + ... + x_{n+1} = 1, x_i >=0，这个就是一个regular的n-simplex。http://en.wikipedia.org/wiki/Simplex
考虑三角形的情况可以看得清楚点，你把三角形的中心沿着跟它垂直的另一个维度移动(在R^3里面看)，那么这个面上点到中心的夹角可以是比arccos(-1/2)任意小的角。
你可以做同样的事情，取四面体的中点，增加一个垂直维度(在R^4里面看)，然后沿着它移动中点，可以证明交角可以为任意比arccos(-1/3)小的角。 |
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R**T
发帖数: 784 | 34 非常感谢！我大概知道你的意思了，三角形为出发点的的情况比较好理解，
四面体的那个涉及到R^4就没辙了，不过大概的意思我好像了解了
我当才算了一遍行列是，验证了一下结果。看来以后高维的情况我还是老实算行列式吧
：）
的n-simplex。http://en.wikipedia.org/wiki/Simplex
动(在R^3里面看)，那么这个面上点到中心的夹角可以是比arccos(-1/2)任意小的角。
着它移动中点，可以证明交角可以为任意比arccos(-1/3)小的角。 |
|
b******a
发帖数: 704 | 35 Common Causes of Pneumonia
In a young patient without coexisting illnesses, there are many potential
infectious causes of pneumonia.1 The patient's history gives us several
clues that help in reducing the list of possible pathogens. This patient
underwent bronchoscopy and bronchoalveolar lavage. Negative bacterial
cultures argue against common, easy-to-culture bacterial pathogens.
Furthermore, the patient did not have a response to multiple, broad-spectrum
antibacterial therapy including erythro... 阅读全帖 |
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d********n
发帖数: 279 | 36 俺说国内处于起步阶段是指的应用，就理论而言，过去几十年没什么大的发展。
Interior Point Method也就那么回事，从另外一个角度思考问题而已，现在的商业软
件用得多的还是SIMPLEX。
要解工业问题，首先还是得要数据，背后那个信息系统建立不起来，买什么包都不行。
还有就是一个观念问题，是不是VALUE这个东西。 |
|
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m***d
发帖数: 1050 | 38 How to post a video??
https://www.youtube.com/watch?v=hcq1nDynzuE
Dec 18, 2010, Navin boarded the Mumbai-New York plane. Due to snow
storm, his plane been grounded in Brussels. He talked to co-passengers,
Olesya Elisa Dukhota of Brooklyn. Navin said "There was this crazy Ukrainian
nurse who wanted to kiss me but I pushed her off and told her to keep away.
I have a beautiful Chinese girlfriend. She got offended."He said "She has
blisters/cold sores around her lip and mouth due to Herpes S... 阅读全帖 |
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f******k
发帖数: 297 | 39 classic problem. to sample uniformly from a n-dim simplex, first draw n
random variables independently from the exponential distribution, then
normalize. |
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s********l
发帖数: 439 | 40 那个“锥体的底面”叫simplex，n >= 3的时候不是平面
xn |
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I*a
发帖数: 297 | 41 你在国内读过数学吗，我知道叫simplex，在国内,这种东西就叫n维空间的超平面。
基本上在一个线形空间x1, x2, ..., xn
形如
a1x1+..,+anxn=c
就定义了n维空间的一个（超）平面 |
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s********l
发帖数: 439 | 42 靠，你应该早点把具体的问题说出来。你这样子当然要sample一个simplex（中文叫单
纯形）上面的均匀分布，具体做法前面已经给了，或者用N个i.i.d 指数分布做
rescaling，或者就是N-1个均匀分布排序做[0 1]之间的等分点。
你sample 10000个当然是看不到这种1个0.99，其他9个都特别小的情况的。要知道维数
越高，单纯形的一个角占总体积的比例越小。如果是10个的话这种正好在单纯形一个角
上的概率大概是10^-18这个量级。
另外return和投资组合之间总应该有一点连续性的。随机取一个点然后用BiCG或者BFGS
之类的方法去找这个点周围的局部最优。多选几个随机的出发点，找到整体最优不会太
困难，至少比你这种在高维空间做穷举法简单太多了。
sample |
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w*********g
发帖数: 10097 | 43 cold sore是herpes simplex virus引起的，性传播
canker sore不传染 |
|
m*****t
发帖数: 16663 | 44 Approximately 80 percent of oral herpes cases are caused by HSV-1, while the
remaining 20 percent are caused by HSV-2, and 75%-80% of Americans carry at
least one Herpes Simplex Virus (Type 1 or 2). |
|
发帖数: 1 | 45 进华博弈只有日本人在做了吧，天天在一个simplex里面解微分方程，目前很难看到使
用价值
个。 |
|
f**********d
发帖数: 4960 | 46 这是显而易见的，但不是所有K-1 simplex都满足，注意有第二点。 |
|
g********d
发帖数: 4174 | 47 Results
Top of page
Abstract
Introduction
Materials and methods
Results
Discussion
Conclusion
Acknowledgements
References
Review of epidemiological data from donors and other sources
The prevalence of anti-HIV in blood donors is very low. Both the number and
the proportion of anti-HIV-positive donors, reported as MSM, have fallen
over the years (Fig. 1). However, this route of infection still constituted
approximately 27% of anti-HIV-positive donations during 1998–2000. Sexual
intercourse betwee... 阅读全帖 |
|
A********e
发帖数: 354 | 48 【 以下文字转载自 Biology 讨论区 】
发信人: albertsmwk (.)(.), 信区: Biology
标 题: 第一批“青年千人计划”生物类@publication列表@
发信站: BBS 未名空间站 (Thu Aug 18 15:04:16 2011, 美东)
花了一个小时，深深的鄙视一下自己的无聊行径！！
125 蔡亮 男 1980年11月 复旦大学 生命
科学 2007年12月毕业于[美国]北卡大学 [美国]加州大学旧金山分校 博士后
Cai L, Mostov K. Polarity is destiny. Cell. 2009 Nov 13;139(4):660-2. PubMed
PMID: 19914162; PubMed Central PMCID: PMC2900917.
Cai L, Makhov AM, Schafer DA, Bear JE. Coronin 1B antagonizes cortactin and
remodels Arp2/3-containing actin branche... 阅读全帖 |
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T**********y
发帖数: 157 | 49 http://www.ccse.uestc.edu.cn/teacher/teacher.aspx?id=414
所有已经发表论文清单
（发表时间序）
【1】 周涛，傅忠谦，周佩玲，张建荣，张德学，”基于遗传算法的大规模流量
工程问题求解”，计算机应用，2003年第6期，43－45
【2】 杨春霞，周涛，周佩玲，刘隽，基于Multi_Agent的股市经济系统建模与
分析，自动化理论、技术与应用卷十，中国科学技术大学出版社，2003年，596-601（
中国自动化学会第18届青年学术年会会议论文集）
【3】 周佩玲，许民，赵亮，周涛，”混沌信号奇异性检测与外界冲击度量”，
数据采集与处理，Vol.19，195-198，2004
【4】 周涛，徐俊明，刘隽，”图直径和平均距离极值问题研究”，中国科学技
术大学学报，Vol.34，410-413，2004
【5】 周佩玲，杨春霞，周涛，李立文，”虚拟股市建模与混沌分析”，中国科
学技术大学学报，Vol.34，442-448，2004
【6】 T. Zhou, P. ... 阅读全帖 |
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