A differential poset is a partially ordered set with raising and lowering operators U and D which satisfy the commutation relation DU−UD = rI for some constant r. This notion may be generalized to deal with the case in which there exist sequences of constants {qn}n≥0 and {rn}n≥0 such that for any poset element x of rank n, DU(x) = qnUD(x)+rnx. Here, we introduce natural raising and lowering ope...

A link between matroid theory and p-branes is discussed. The Schild type action for p-branes and matroid bundle notion provide the two central structures for such a link. We use such a connection to bring the duality concept in matroid theory to p-branes physics. Our analysis may be of particular interest in M-theory and in matroid bundle theory.

A graph G∗ is 1-edge fault-tolerant with respect to a graph G, denoted by 1-EFT(G), if every graph obtained by removing any edge from G∗ contains G. A 1-EFT(G) graph is optimal if it contains the minimum number of edges among all 1-EFT(G) graphs. The kth ladder graph, Lk , is defined to be the cartesian product of the Pk and P2 where Pn is the n-vertex path graph. In this paper, we present seve...

The pattern of well-known states in q 4 spectroscopy is quite different from CE and b 6. Because of the position of the heavy quark thresholds, the JP = lradial excitation ladder is well studied by formation in e+eexperiments and the L = 1 triplets are seen in 7 transitions. In the q p sector, however, the “leading” high-spin multiplets are best known (in both natural and unnatural f) and, sinc...

Let G be a connected noncompact simple Hermitian symmetric group with nite center. Let H() denote the geometric realization of an irreducible unitary highest weight representation with highest weight. Then H() consists of vector-valued holomorphic functions on G=K and the action of G on H() is given in terms of a factor of automorphy. For highest weights corresponding to ladder representations,...

We present two modelling approaches for the application of model checking to verify railway interlockings. The first translates so-called Ladder Logic into Scade language, the second models a segment of railway from scratch. The verification tool used is Scade.

A link between matroid theory and p-branes is discussed. The Schild type action for p-branes and matroid bundle notion provide the two central structures for such a link. We use such a connection to bring the duality concept in matroid theory to p-branes physics. Our analysis may be of particular interest in M-theory and in matroid bundle theory.

The chain ladder (volume-weighted average development factor) is perhaps the most widely used of the link ratio (age-to-age development factor) techniques, being popular among actuaries in many countries. The chain ladder technique has a number of interesting properties. We present one such property, which indicates that the chain ladder doesn’t distinguish between accident years and developmen...

The usual chain ladder metlwd is a deterministic claims reserving method. In the last years. o stochastic loglineor approximation to the chain ladder method hav been u~rl by several authors especially in order to quantify the variability of the estimated claims reserves. Although the reserves estimated by both merAo& are clenrly diflerent. rk logknenrapproxi-mation has been called " chain ladde...

A ladder lottery, known as “Amidakuji” in Japan, is a common way to choose one winner or to make an assignment randomly in Japan. Formally, a ladder lottery L of a permutation π = (x1, x2, . . . , xn) is a network with n vertical lines (lines for short) and many horizontal lines (bars for short) connecting two consecutive vertical lines. The top ends of lines correspond to π. See Fig. 1. Each n...