- Call for papers XA2010
XA2010
"EUROPEAN CONFERENCE ON
COMPUTER SCIENCES & APPLICATIONS"
3rd Edition
Timi ?oara, Rom?nia, September 24-25, 2010
AIM
The 3rd European Conference on Computer Sciences and Applications
intends to stimulate the research activity and to establish
interactions between Romanian and foreign researchers, teachers, B.
- Nine papers published by Geometry & Topology Publications
Seven papers have been published by Algebraic & Geometric Topology
(1) Algebraic & Geometric Topology 10 (2010) 525-530
Faithfulness of a functor of Quillen
by William G Dwyer, Andrei Radulescu-Banu and Sebastian Thomas
URL: [link]
DOI: 10.2140/agt.2010.10.525
- Re: decomposing rationals
If a and b are rational,
this becomes an integer linear programming problem in two variables.
Such things are solvable in polynomial time.
I don't remember details.
I think that you can solve the linear relaxation
and plug away with Gomory fractional cuts.
Selecting the approximations could be tricky.
- Re: minimum height of a 0-1 simplex
The above is roughly 1/n, but there are worse examples:
e_j for j in 1..k
k
SUM e_j + e_L for L in k+1..n
j=1
k n
The vertices satisfy SUM x_j + (1-k) SUM x_j = 1
j=1 j=k+1
For k=2n/3, the distance to zero is roughly sqrt(27/(4n**3)).
- Call for Papers Reminder (extended): The World Congress on Engineering WCE 2010
CFP: The World Congress on Engineering WCE 2010
WCE 2010: London, U.K., 30 June - 2 July, 2010
[link]
Draft Paper Submission Deadline (extended): 18 March, 2010
The WCE 2010 is organized by International Association of Engineers
(IAENG), a non-profit international association for the engineers and
- Re: minimum height of a 0-1 simplex
That is what I get, also.
The base satisfies the linear equation
n-1
SUM x[j] + (2-n)*x[n] = 1
j=1
Lower bound, anyone?
- Re: minimum height of a 0-1 simplex
I'm not sure what this means,
but I think that it is not true even in three dimension.
that a minimal-height-defining line segment of a
tetrahedron lies within the tetrahedron.
Consider a tetrahedron with the following vertices:
(0, 0, 0), (3, 2, 0), (3, -2, 0) and (4, 0, 1).
Its minimal-height-defining segment is (4, 0, 1)_(4, 0, 0).
- Re: minimum height of a 0-1 simplex
Yes, but it seems I made a mistake there, as the height-defining
segment
does not always lie inside the simplex.
However, it does so, if the simplex has the property that all angles
between
edges are at most \pi/2.
Now for a simplex with vertices in {0,1}^n this condition is
satisfied!
By symmetry, it is enough to check this at the vertex zero.
- Re: minimum height of a 0-1 simplex
no, is not.
For example, consider the simplex spanned by zero, e=e_1+...+e_n, e_1,
e_2,...,e_{n-1},
where e_1,...,e_n is the standard basis.
A calculation shows that the vertex at zero has height equal to 1/
sqrt(n-1+(n-2)^2)
which for n>3 is less that 1/sqrt(n).
- Whitehead Groups of Short Exact Sequence
Hello, all!
The Whitehead group of a group G, Wh(G), is a functor from the category
of (finitely presented?) groups to the category of Abelian groups. A
reference is _A Course in Simple Homotopy Theory_ by Cohen.
If I have a short exact sequence of finitely presented groups 1 -> K -> G
-> Q -> 1, and I take the Whitehead torsion of the sequence, forming Wh
- Re: minimum height of a 0-1 simplex
Excellent news. Thanks much.
I'm having trouble following the proof, though.
I'll get back to it when I'm not supposed to be working.
The crucial point that I didn't think of.
Once I can prove that both ends of the height-defining segment are in
n-cube,
the rest is easy.
- Re: Do free abelian groups embed into connected semisimple complex lie groups?
Any such Lie group contains a complex torus isomorphic to C^*.
This group contains a subgroup isomorphic to the additive group R
of reals. Now let n be a natural number and choose v_1,...,v_n in R
which are linearly independent over Q.
Then the group Z v_1 + ... + Z v_n is free abelian of rank n and
- Re: minimum height of a 0-1 simplex
The lower bound is 1/sqrt(n).
Proof as follows. Let e_1,...,e_n be the standard basis of R^n.
Let s be a simplex of dimension n in R^n.
The minimal height is taken at a vertex v_1 which lies opposite to a
face F of maximal area.
(This is so since the volume of the simplex is height times area(F)
times dimension factor.)
- minimum height of a 0-1 simplex
What is the minimum height of a full dimensional n-simplex whose
vertices are members {0, 1}**n ?
Equivalently, what is the minimum non-zero distance to the origin from
a hyperplane defined by members of {0, 1}**n ?
The answer is at most 1/sqrt(n) .
The corner simplex provides an example.
A smaller answer might be possible if the simplex is oblique enough
- Re: delta function as a continuous linear map?
Oh now I see. Thanks G.A and Dan for pointing out the caveat in my
argument.
- Ten papers published by GT Publications
Five papers have been published by Algebraic & Geometric Topology
(1) Algebraic & Geometric Topology 10 (2010) 315-342
An involution on the K-theory of bimonoidal categories with anti-involution
by Birgit Richter
URL: [link]
DOI: 10.2140/agt.2010.10.315
- Call for Paper The International Journal of Computer Science (IJCS)
Call for Paper
The International Journal of Computer Science (IJCS) publishes
original papers on all subjects relevant to computer science,
communication network, and information systems. The highest priority
will be given to those contributions concerned with a discussion of
the background of a practical problem, the establishment of an
- Re: delta function as a continuous linear map?
On Wed, 03 Mar 2010 13:40:02 -0600, Dan Luecking
wrote:
I really meant n,m>0
and I meant \sum_{k <= n, j <= m}
And here || f ||_{n,m}
And here || f ||_{0,0}
Dan
To reply by email, change LookInSig to luecking
- Re: delta function as a continuous linear map?
On Tue, 2 Mar 2010 22:12:35 -0800 (PST), mahdiarnt
You have provided a proof that the delta function
is not continuous on L^2. To prove it _is_ continuous
on S, you have to use the topology on S, which is
provided by the fammily of seminorms || f ||_{n,m},
n >= 0, where || f ||_{n,m} is defined to be
- Re: delta function as a continuous linear map?
In article
<5b79b21d-efa8-4f42-979b-f3518 b89c...@g8g2000pri.googlegroup s.com>,
So, you refer to ||f||_S , but what is that? Of course, to determine
whether some function is continuous on S we need to know what is the
topology on S. In fact, this topology is not given by a norm.
- Ten papers published by GT Publications
Five papers have been published by Algebraic & Geometric Topology
(1) Algebraic & Geometric Topology 10 (2010) 315-342
An involution on the K-theory of bimonoidal categories with anti-involution
by Birgit Richter
URL: [link]
DOI: 10.2140/agt.2010.10.315
- delta function as a continuous linear map?
Hi
I've come across a claim that has made me confused. In
[link] (which is for people like me)
it's claimed on page 17 that the delta function defined on functions
of Schwartz space S as
delta: S -> R, delta_{x_0} f = f(x_0)
is continuous. I think it's true, as implicitly mentioned there as
- Do free abelian groups embed into connected semisimple complex lie groups?
Question:
Let A be a connected semisimiple complex lie group. Is it true that
any free abelian group G of finite rank can be embedded in A?
I know that it is the case that any free groups of finite rank can be
embedded into any connected complex semisimple lie group.
Do we have to make any assumptions about the dimension of A for the
- Call For Manuscripts: International Journal of Signal Processing (IJSP)
Call For Manuscripts
The International Journal of Signal Processing (IJSP) is currently
accepting original high-quality research manuscripts for publication.
The Journal welcomes the submission of manuscripts that meet the
scientific criteria of significance and academic excellence. All
research articles submitted for the journal will be peer-reviewed
- Re: Three Elementary Planar Convexity Problems
D'oh! and sincere regrets at errors due to haste in posting.
Long and thin rectangles show that both (i) and (ii) are incorrect.
Although it is possible to avoid that case by restricting the minimal
width of X it is probably best to consider case (iii) only.
- Re: Schnirelmann (Was Re: Goldbach Conjecture and Schnirelmann's "300,000 primes")
As promised, I offer here a translation of an article about L. G.
Schnirel'mann, written by
V. Tikhomirov and V. Uspenskii. It appeared in the Russian magazine
Kvant in 1996, No 2. pp. 2-6. The
translation took longer than I expected, (for various reasons, mainly
laziness), but here it is.
The article is ostensibly written for high school students, and in a
- Three Elementary Planar Convexity Problems
It is well known that for compact subsets, X, of the Euclidean plane,
with interior points, X is convex if and only if each frontier point
has at least one support line: see Eggleston, [1], Theorems 8 and 9.
For other relevant convexity terminology and background also see [1].
Assume in the rest of this communication that X is a planar, compact
- Re: Cesaro-like summability
Yes, of course that case will work, because in any L1 L2 consecutive
integers each a(i), i=1..L1, gets matched once with each b(j), j=1..L2,
resulting in
a(1) b(1) + ... + a(n L1 L2) b(n L1 L2)
= n (a(1) + ... + a(L1))(b(1) + ... + b(L2)) = n L1 L2 M c
- Re: Cesaro-like summability
On 26 fév, 23:00, Robert Israel
wrote:
Yes of course but I still consider b to be nonperiodic with the
additional condition (b(1)+...+b(n))/n--> some limit
There is a general case for which it seems working. If a and b are 2
periodic sequences with period lenght L1 and L2 respectively and such
- Re: Cesaro-like summability
That can't work. Consider e.g.
a(n) = b(n) = 1 if n is even, 2 if n is odd
(a(1) + ... + a(n))/n -> M = 3/2,
(a(1) b(1) + ... + a(n) b(n))/(b(1) + ... + b(n)) -> 5/3
and b(1) + ... + b(n) = 3/2 n + O(1).
- Re: Nine papers published by Geometry & Topology Publications
On Feb 15, 10:50 am, Geometry and Topology
wrote:
Sir,
I wrote 2 papers on Euclidian geomety. Its about proof of 2
theorems which simplify the Euclidian Geometry. I am an undergraduate
student of Computer Sc Engineering. How & where i shall publish those
papers,if you kindly inform me.
- Re: Cesaro-like summability
On 24 fév, 15:00, Robert Israel
wrote:
Thank you very much,
The complicated conditions are fine but useless for me since V(n,n+P)
takes a finite number of values among more than P distinct values.
I suppose the weaker condition:
(b(1)+b(2)+...+b(n))/n-->c>0 as n-->infty is not sufficient. If so, do
- Re: Mosteller and Wallace
In article ,
I don't have a specific recommendation, but you might want to check out
the list of references in the following paper by Koppel, Schler, and
Argamon ("Computational methods in authorship attribution"):
[link]
- Re: decomposing rationals
If [a,b] contains zero, then it's easy. Also if b < 0 we can work with
[-b,-a]. So we can assume 0 < a < b. Also we might as well assume x >
0.
Suppose y1 < y2, and m1 and m2 are both positive or both negative.
Then we can replace m1.y1 + m2.y2 with (m1+m2)y, where
y = (m1.y1 + m2.y2)/(m1 + m2) is a rational number in [y1,y2]. So we
- Mosteller and Wallace
Can anyone recommend a modern text, at a level suitable for an
undergraduate economics major, that describes the sort of textual
analysis that Mosteller and Wallace did of the Federalists papers in
the 1960's? (Given a text with two possible authors, and information
about their typical use of certain key words and phrases, determining
- Re: Cesaro-like summability
One simple sufficient condition is lim_{n -> infty} b(n) = c > 0.
There are more complicated conditions. For integers A < B, let
V(A,B) = max_{A <= j < B} b(j) / min_{A <= j < B} b(j). Then
a sufficient condition is that
1) lim_{n->infty} V(n,n+P) = 1, where P is the period of the
sequence {a(n)}, and
- Re: Is the sum of two countable nowhere dense sets of non-negative real numbers nowhere dense?
In article , xsfxsf
No. Counterexample suggested by the Cantor set...
Let X = Y = numbers in [0,1) with finite expansions base 3 with only
digits 0 and 2. Then X + Y is dense in [0,2].
- decomposing rationals
Hello
let x be any rational number, and also given an arbitrary interval [a,
b] that does not contain x. Is there a systematic way to find a set
of integers m1, m2, ..mK and corresponding rationals y1, y2,...yK all
in the interval [a, b] such that their linear combination is x,
x= m1.y1 + m2 . y2 + ....+ mK . yK
- Re: Factorization into Primes using Gray code and full parity
sorry for the big delayed reply. Got swamped with work. Please see my
reply embedded below.
yes, I recall. You originally said any binary numbering sequence would work
for your function. I'm really surprised why the math group is not
interested in this binary prime factorization method based on gray code and
- Is the sum of two countable nowhere dense sets of non-negative real numbers nowhere dense?
(Suggested by a Putnam problem).
A set X of real numbers is nowhere dense if every nonempty open
interval in R contains a nonempty open subinterval disjoint from X.
Let X and Y be countable nowhere dense sets of non-negative real
numbers.
Let X+Y denote {x+y | x \in X and y\in Y}.
Is X+Y necessarily nowhere dense? If so, does this remain true if X
- Cesaro-like summability
Hi,
Suppose a(n)>0 is a periodic sequence with (a(1)+a(2)+..+a(n))/n--> M
as n-->infty.
Let b(n)>0 be a nonperiodic bounded sequence.
are there simple conditions to add to b(n) in order to have:
(a(1)b(1)+a(2)b(2)+...+a(n)b(n ))/(b(1)+b(2)+....+b(n))-->M as n--
Thanks for help.
- Nine papers published by Geometry & Topology Publications
Papers (1)-(6) continue the publication of AGT Volume 10 issue 1 and
papers (7)-(9) complete issue 1 of GT Volume 14.
Six papers have been published by Algebraic & Geometric Topology
(1) Algebraic & Geometric Topology 10 (2010) 87-136
Bar constructions and Quillen homology of modules over operads
- Draft paper submission deadline is extended: TMFCS-10, Orlando, USA
It would be highly appreciated if you could share this announcement
with your colleagues, students and individuals whose research is in
theoretical computing, complexity theory, algorithms, computational
science and related areas.
Draft paper submission deadline is extended: TMFCS-10, Orlando, USA
The 2010 International Conference on Theoretical and Mathematical
- tensor products preserving reflexivity
It was shown by Aharoni and Saphar that, if $E$ and $F$ are reflexive
Banach spaces, then the tensor product $E \otimes_{g_2} F$ is reflexive,
too.
Are there any other "canonical" Banach space tensor products that
peserve reflexivity?
Best,
Volker Runde.
- Re: Can we associated to every closed salient convex cone C a hyperplane which intersects each ray exactly once?
Cm wrote:
I don't know how you are defining a "hyperplane" in a Banach space, but
taking the characterization you give (a level set of a bounded R-linear
functional into R, or equivalently a translate of a closed subspace of
codimension 1 [where all spaces are over the reals as coefficient
field]) as the definition, existence of a hyperplane satisfying the
- The problem written on the black board in "A beautiful mind" film.
Would anybody remember the precise mathematical statement of the
problem written by John Nash (interpreted by Russell Crowe) on the
black board during his math lesson and that Alicia, his future wife,
tried to solve it ?
Thanks.
- assitencia computadores enseada do sua vitoria-es 32469
Contato: pcnetsecurity @ gmail.com
Assist ncia TŽcnica
Prestamos assist ncia tŽcnica nos computadores de sua empresa ou resid ncia, e tambŽm possu’mos uma equipe qualificada para fazer a manuten ‹o no pr—prio local.
- Contratos de Suporte e Manuten ‹o
Reduza os custos de sua empresa com solicita ›es de visitas tŽcnicas para seus computadores, elaboramos um contrato de manuten ‹o integrado para sua empresa onde disponibilizamos: tŽcnicos, equipamentos de suporte e substitui ‹o, e atendimento no hor‡rio comercial ou plant‹o sob an‡lise.
- Re: Factorization into Primes using Gray code and full parity
The method I described in the other post can be used
to derive an IsPrime() function for Gray code:
cba
---
000 = 0
001 = 1
011 = 2
010 = 3
110 = 4
111 = 5
101 = 6
110 = 7
Take the inverse of the non-prime numbers
to create the clauses for the CNF IsPrime():
IsPrimeGray() =
(c+b+a){0} & (c+b+~a){1} & (~c+~b+a){4} & (~c+b+~a){6} =
- Re: Weierstrass factorization
You have : f(z) = sqrt(2) * sin(pi/4-z).
Cid75
- Weierstrass factorization
I am interested in obtaining the factorization of f(z) = cos (z) - sin
(z). Thank you.
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