Sensor Simulation and position calibration for the CMS pixel detector

In this paper a detailed simulation of irradiated pixel sensors was used to investigate the effects of radiation damage on charge sharing and position determination. The simulation implements a model of radiation damage by including two defect levels with opposite charge states and trapping of charge carriers. We show that charge sharing functions extracted from the simulation can be parameterized as a function of the inter-pixel position and used to improve the position determination. For sensors irradiated to Phi=5.9x10^14 n/cm^2 a position resolution below 15 um can be achieved after calibration.Comment: Presented at the 14th Int. Workshop on Vertex Detectors (Vertex 2005), November 7-11 2005, Chuzenji Lake, Nikko, Japan. 4 pages, 1 figur

g-elements, finite buildings and higher Cohen-Macaulay connectivity

The main result is a proof that the g-vector of a simplicial complex with a convex ear decomposition is an M-vector. This is a generalization of similar results for matroid complexes. We also show that a finite building has a convex ear decomposition. This leads to connections between higher Cohen-Macaulay connectivity and increasing h-vectors.Comment: To appear in JCT A. 20 page

Reconnaissance of the Distribution and Abundance of Schistosomatium Douthitti, a Possible Human Disease Agent in Surface Waters in Alaska

Studies during the summer and early fall of 1967 show that Schistosomatium douthitti, a blood fluke which may pose a health hazard to man, is well established in the surface waters and surrounding terrestrial environments in the Fairbanks area. It is almost certain that this situation exists throughout Interior Alaska. Ecologically and geologically, the lakes and ponds in which it has been found are the most abundant types in the Interior and both the specific lakes and the types which they represent are abundantly used by man. The life cycle of the worm in this area is probably sustained mostly in small mammals, especially in Microtus pennsvlvanicus but also in Clethrionomys rutilus. The infection certainly over-winters in the mammal host but probably also survives in the snail host under the ice. Although the fluke was only found in two of the nine mammalian species examined, it is probable that it occurs in other than Microtus pennsvlvanicus and Clethrionomys rutilus.The work upon which this report is based was supported in part by funds provided by the U. S. Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Research Act of 1964. Project Number: A-O20- ALAS Agreement Number: 14-01-0001-89

g-elements of matroid complexes

Let K be the face ring of the independence complex of a matroid. We show that if T is a generic linear system of parameters, then K/T satisfies a weak form of the Hard Lefschetz Theorem. As a result, the first half of the h-vector of the complex satisfies inequalities similar to the g-theorem for simplicial polytopes.Comment: 6 pages. Will appear in J. Comb. Theory Ser.