Re: Question on modular algebra
 From: "Dani Camps" <danicamps81@xxxxxxxxx>
 Date: 19 Mar 2007 06:56:25 0700
On Mar 17, 1:12 am, Mike Amling <nos...@xxxxxxxxxx> wrote:
Dani Camps wrote:
On 16 mar, 10:54, "Dani Camps" <danicamp...@xxxxxxxxx> wrote:
On 15 mar, 16:46, Peter Pearson <ppear...@xxxxxxxxxxxxxxx> wrote:
On 14 Mar 2007 08:43:26 0700, Dani Camps <danicamp...@xxxxxxxxx> wrote:Hi,
[snip]
I have a sequence generated with the following expression[snip]
A(x)=(d + a*x) (mod n)
Where 0<=d<n, and a and n are coprimes, i.e gcd(a,n)=1.
Consider r consecutive values of the sequence A(x)An approximate solution would be simple. Do you need an
starting from 0, so {A(0) ... A(r1)} where 0<=r<n. What I
want to know is how many values of the subset {A(0)
... A(r1)} are above my threshold j.
exact solution? Faster than just counting them?

To email me, substitute nowhere>spamcop, invalid>net.
What I am looking for is the exact value in a close formula. I need
this in order to proof something, so I am not interested in an
algorithm. Do you have any idea ? An approximation, or better a bound,
can be a starting point.
Best Regards
Dani
Actually what I need to proof is that r/(m1) is bigger than sth, so I
need a lower bound for r/(m1). Where r is the lentgh of the sequence,
and m is the number of elements in the sequence {A(0) ... A(r1)}
above/below the threshold j.
"m is the number ... above/below ..." Well, which is it?
If m is the number of values above the threshold, then for a=1, d=0,
we find the first j values below the threshold j, so r/(m1) is r for
1<=r<=j, and the lower bound is no higher than j.
If m is the number of values below the threshold, then for a=1,
d=j+1, we find the first nj1 values above the threshold, so r/(m1) is
r for 1<=r<=nj1, and the lower bound is no higher than n+j+1.
Or is the lower bound to be taken over some other domain than all
(a,d,r) combinations?
Mike Amling
Hi,
I want to show that r/(m1) is bigger than sth, let's say A. A is not
directly related with (a,d,j,n), that's why I wanted first to find a
lower bound for r/(m1) as a function of (a,d,j,n), hoping that then I
would be able to compare the expression with A.
Regarding m it should be the number of elements below the threshold,
but I said above/below is because it really does not matter, if
instead of m I find the number of elements above j, lets say b, then m
is simply rb.
Regards
Dani
.
 References:
 Question on modular algebra
 From: Dani Camps
 Re: Question on modular algebra
 From: Peter Pearson
 Re: Question on modular algebra
 From: Dani Camps
 Re: Question on modular algebra
 From: Dani Camps
 Re: Question on modular algebra
 From: Mike Amling
 Question on modular algebra
 Prev by Date: Re: Jim Reed's Hagelin Cryptanalysis article
 Next by Date: Re: A sort of reverse SAT
 Previous by thread: Re: Question on modular algebra
 Next by thread: JSH: Sobering invention, surrogate factoring
 Index(es):
Relevant Pages
