We consider the action of the 2-dimensional projective general linear group PGL(2, q) on the projective line PG(1, q). A subset S of PGL(2, q) is said to be an intersecting family if for every g1, g2 ∈ S, there exists α ∈ PG(1, q) such that αg1 = αg2 . It was proved by Meagher and Spiga that the intersecting families of maximum size in PGL(2, q) are precisely the cosets of point stabilizers. We...

Control laws' design strategies are developed to stabilize a class of BIBO integro-differential systems with two distributed delays by using an extended system.

Small and Medium sized Enterprises (SMEs) make a major contribution to most western economies. They are often supported by government policies and in UK the government encourages banks to lend to them. It is generally believed that the credit crunch will have had an impact on performance of SMEs. This study looks at the impact of the crunch using large samples from 2007 through to 2010. It look...

The law of multiplicative error is presented for independent observations and correlated observations represented by the q-product, respectively. We obtain the standard log-normal distribution in the former case and the log-q-normal distribution in the latter case. Queirós’ q-log normal distribution is also reconsidered in the framework of the law of error. These results are presented with math...

We introduce the exact core and the biexact core of a strategic game form. Those are solutions which lie between the usual b-core and the set of strong equilibrium outcomes. We define the corresponding notion of exact and biexact stability. We prove that a game form is exactly stable if and only if it is exact, tight and subadditive and that it is biexactly stable if and only if in addition it ...

We identify the normal subgroups of the orientation preserving subgroup [3, 5, 3] of the Coxeter group [3, 5, 3], with the factor group isomorphic to PSL2(Fq) with particular congruence subgroups of an arithmetic subgroup of PSL2(C) derived from a quaternion algebra over a quartic field. 1 Motivation – Hurwitz groups and HurwitzMacbeath surfaces It is a well known fact that up to isomorphy, the...

A method based on conceptual tools of predictive control is described for tackling tracking problems of uncertain linear systems wherein pointwise-in-time input and/or state inequality constraints are present. The method consists of adding to a primal compensated system a nonlinear device called Predictive Reference Filter (PRF) which manipulates the desired reference in order to fullll the pre...

This paper introduces and studies the notion of output-input stability, which represents a variant of the minimum-phase property for general smooth nonlinear control systems. The definition of outputinput stability does not rely on a particular choice of coordinates in which the system takes a normal form or on the computation of zero dynamics. In the spirit of the “input-to-state stability” ph...

Graphene is one of the new materials which has shown a large impact on the electronic industry due to its versatile properties, such as high specific surface area, high electrical conductivity, chemical stability, and large spectrum of electrochemical properties. The graphene material-based electronic industry has provided flexible devices which are inexpensive, simple and low power-consuming s...

in the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. in 2-d analysis, effect of convex and concave walls are neglected, however concave slopes are believed to be more stable than straight walls due to t...