Let n E Z+ and let K be a field. Let ~ be a partial order on {1, 2, ... , n}. Let An(:::;) be the matrix incidence algebra consisting of those n x n matrices A = (ai,j) with entries in K, satisfying ai,j 0 whenever i 1:. j. For a subset £ ~ An (::5), a necessary and sufficient condition that the algebra generated by £ u {I} is An(::5) is that (i) for every 1 :::; i, j :::; n with i =1= j, there...

We present a partial classification of those finite linear spaces S on which an almost simple group G with socle PSL(3, q) acts line-transitively. A linear space S is an incidence structure consisting of a set of points Π and a set of lines Λ in the power set of Π such that any two points are incident with exactly one line. The linear space is called non-trivial if every line contains at least ...

We study the restriction of the Fourier transform to quadratic surfaces in vector spaces over finite fields. In two dimensions, we obtain the sharp result by considering the sums of arbitrary two elements in the subset of quadratic surfaces on two dimensional vector spaces over finite fields. For higher dimensions, we estimate the decay of the Fourier transform of the characteristic functions o...

A linear space is a point line incidence geometry with the property that every pair of points is on exactly one line and every line has at least two points. We consider finite linear spaces, i.e. linear spaces with a finite number of points. In [2], the current authors enumerated all linear spaces of order at most 12. More specific types of linear spaces have also been studied. We denote the se...

Malignant Melanoma is one of the rare and the deadliest form of skin cancer if left untreated. Death rate due to this cancer is three times more than all other skin-related malignancies combined. Incidence rates of melanoma have been increasing, especially among young adults, but survival rates are high if detected early. There is a need for an automated system to assess a patient’s risk of mel...

Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 2009, 17(Suppl 2):O1 doi:10.1186/1757-7241-17-S2-O1 Danish Society for Emergency Medicine: Research Symposium 2009 editor>Mikkel Brabrand, Peter Hallas and Kjetil G Ringdal Publication of this sup lement was supported by Akuttjournalen Ar na AS <no...

A new type of diffraction range finder is disclosed that places the primary grating at an angle of grazing incidence relative to the receiver. The new design offers improvements over earlier prototypes in reduced package size, reduced chirp depth and a highly anamorphic behavior that provides a high profile to depth ratio. Demonstrations with transmission and reflection types of diffraction gra...

In this paper we discuss three closely related problems on the incidence structure between n points and m hyperplanes in d-dimensional space: the maximal number of incidences if there are no big bipartite subconfigurations, a compressed representation for the incidence structure, and a lower bound for any algorithm that determines the number of incidences (counting version of Hopcroft’s problem...