Context: It is challenging to develop comprehensive, consistent, analyzable requirements models for evolving requirements. This is particularly critical for certain highly interactive types of socio-technical systems that involve a wide range of stakeholders with disparate backgrounds; system success is often dependent on how well local social constraints are addressed in system design. Objecti...

In this paper, we consider a Pólya urn model containing balls of m different labels under a general replacement scheme, which is characterized by an m×m addition matrix of integers without constraints on the values of these m integers other than non-negativity. This urn model includes some important urn models treated before. By a method based on the probability generating functions, we conside...

A generalised urn model is presented in this paper. The urn contains L different types of balls and its replacement policy depends on both an urn function and a random environment. We consider the Ldimensional stochastic process {Xn} that represents the proportion of balls of each type in the urn after each replacement. This process can be expressed as a stochastic recurrent equation that fits ...

We construct an independent increments Gaussian process associated to a class of multicolor urn models. The construction uses random variables from the urn model which are different from the random variables for which central limit theorems are available in the two color case.

Shepp’s urn model is a useful tool for analyzing the stopping-rule problems in economics and finance. In [R.W. Chen, A. Zame, C.T. Lin, H. Wu, A random version of Shepp’s urn scheme, SIAM J. Discrete Math. 19 (1) (2005) 149–164], Chen et al. considered a random version of Shepp’s urn scheme and showed that a simple drawing policy (called “the k in the hole policy”) can asymptotically maximize t...

Acidic ostreolysin A/pleurotolysin B (OlyA/PlyB, formerly known as ostreolysin (Oly), and basic 20 kDa equinatoxins (EqTs) are cytolytic proteins isolated from the edible mushroom Pleurotus ostreatus and the sea anemone Actinia equina, respectively. Both toxins, although from different sources, share many similar biological activities: (i) colloid-osmotic shock by forming pores in cellular and ...