User tmy1018 - MathOverflowmost recent 30 from http://mathoverflow.net2013-05-23T20:24:06Zhttp://mathoverflow.net/feeds/user/10028http://www.creativecommons.org/licenses/by-nc/2.5/rdfhttp://mathoverflow.net/questions/90907/the-relationship-between-stirling-number-of-the-second-kind-and-the-polylogarithmThe relationship between Stirling number of the second kind and the polylogarithmtmy10182012-03-11T15:01:12Z2012-03-11T19:22:15Z
<p>It is shown here on <a href="http://mathworld.wolfram.com/StirlingNumberoftheSecondKind.html" rel="nofollow">Mathworld's page on Stirling number of the second kind</a> that </p>
<p>$$
\sum_{k=1}^n S(n,k) (k-1)! z^k = (-1)^n \text{Li}_{1-n}(1+\frac{1}{z})
$$</p>
<p>where $S(n,k)$ is Stirling number of the second kind and $\text{Li}_{1-n}$ is the polylogarithm.</p>
<p>Can somebody provide me some reference on where this identity came from? It isn't shown on Mathworld's page.</p>
http://mathoverflow.net/questions/85038/cover-a-line-segment-randomly-with-smaller-line-segments/86786#86786Answer by tmy1018 for Cover a line segment randomly with smaller line segmentstmy10182012-01-27T03:26:46Z2012-01-27T03:26:46Z<p>This problem can actually be solved using the exact same method as Chapter 4 of Solomon's geometric probability.</p>
http://mathoverflow.net/questions/85038/cover-a-line-segment-randomly-with-smaller-line-segmentsCover a line segment randomly with smaller line segmentstmy10182012-01-06T08:50:54Z2012-01-27T03:26:46Z
<p>Covering a circle randomly with arcs has been well studied in the past (<a href="http://books.google.com.hk/books/about/Geometric_Probability.html?id=tY8cAZFklIEC" rel="nofollow">Geometric Probability - Solomon</a>).</p>
<p>But the problem when the circle is changed to a line segment doesn't seem to have been studied before.</p>
<p>I'd like to know if there's any work out there who already obtained the probability distribution of the number and the length of the connected line segments that you get when randomly covering a line segment with another set of shorter segments, which may all be of equal length or have some kind of distribution.</p>
<p>Thanks!</p>
http://mathoverflow.net/questions/100788/degeneracy-of-the-analytic-center-of-a-set-of-linear-inequalitiesComment by tmy1018tmy10182012-06-28T02:49:45Z2012-06-28T02:49:45ZWhen you have a set of inequalities
$$ \begin{cases} x_1+x_2+x_3+x_4\leq 4\\ 3x_1+x_2+x_3+x_4\leq 6 \end{cases} $$
then it seems that the analytic center should be degenerathttp://mathoverflow.net/questions/92242/a-discrete-optimization-problem-involving-binomial-coefficientsComment by tmy1018tmy10182012-03-26T15:31:06Z2012-03-26T15:31:06ZSorry, I forgot to write the constraints on $a_1,a_2,...,a_k$, it has been corrected now.http://mathoverflow.net/questions/92015/how-to-get-a-bootstrap-confidence-interval-for-the-mle-for-the-parameter-of-a-conComment by tmy1018tmy10182012-03-23T16:06:23Z2012-03-23T16:06:23Z@BR Could you please point me to some other references, I'm afraid I can't obtain a copy of the work they referred to there.http://mathoverflow.net/questions/89872/an-enumeration-problem-arising-from-dna-sequencing-statistics/89920#89920Comment by tmy1018tmy10182012-03-01T06:16:19Z2012-03-01T06:16:19ZSorry, it should have been 144, I just fixed it.http://mathoverflow.net/questions/89364/a-good-bound-or-an-asymptotic-formula-for-a-sum-involving-binomial-coefficientsComment by tmy1018tmy10182012-02-25T06:28:00Z2012-02-25T06:28:00ZI edited this a little by adding some restrictions on the variables.http://mathoverflow.net/questions/85038/cover-a-line-segment-randomly-with-smaller-line-segmentsComment by tmy1018tmy10182012-01-10T01:20:18Z2012-01-10T01:20:18Z@fedja The problem is can be described like this: if smaller line segments are randomly picked from a longer line segment, what's the distribution of the number of connected "contigs" that consist of overlapping line segments and what's the distribution of the number of gaps? You can see Chapter 6 in in Solomon's Geometric Probability.http://mathoverflow.net/questions/85038/cover-a-line-segment-randomly-with-smaller-line-segmentsComment by tmy1018tmy10182012-01-08T03:14:33Z2012-01-08T03:14:33Z@Anthony The problem I'm talking about is [DNA sequencing](<a href="http://en.wikipedia.org/wiki/DNA_sequencing" rel="nofollow">en.wikipedia.org/wiki/DNA_sequencing</a>)