Parton distributions and small X physics

We determine the parton distributions of the pion from a consistent next-to-leading order analysis of several high statistics π±N experiments including both Drell-Yan and prompt photon production. The results are compared with earlier distributions and with the predictions of lattice QCD. We study the general behaviour of parton distributions at small x and, in particular, the predictions of the Lipatov equation. The very-small-a; behaviour of the gluon distribution in a proton is obtained by solving this equation with a suitable nonlinear shadowing term incorporated. We find, with decreasing x, the emergence of an x(^- λ) behaviour one? the eventual taming of this singular behaviour by the shadowing term. We compare our dynamically generated gluon distribution with (i) the results of a recent next-to-leading order QCD structure function analysis which incorporated both a singular behaviour and shadowing corrections, (ii) the double-leading-leading logarithm approximation (DLLA) and (iii) the semiclassical approximation of the DLLA. Finally, we examine the proposal that deep-inelastic scattering events which contain an identified jet, with transverse momentum squared k(^2) ~Q(^2) allow an ideal determination of the QCD behaviour at very small x. We solve the relevant Lipatov equation to predict the shape of the jet spectrum in such events and discuss whether it will be possible to observe such jets at the HERA collider

Restrictions on copredication: a situation theoretic approach

This paper proposes a situation-theoretic account of polysemy: polysemous nouns denote situations that witness (i.e. contain) multiple entities of different types. For instance, lunch denotes situations that contain an eating event and some food where these stand in a patient relation. A puzzle regarding more than two ways polysemous nouns such as statement is the restrictions on copredication they exhibit, namely, where multiple, potentially incompatible predicates are applied based on a single antecedent, but not all combinations of readings are possible. Such restrictions fall naturally out of the situation-theoretic account of polysemy

Using quicksand to improve debugging practice in post-novice level students

The ability to debug existing code is an important skill to develop in student programmers. However, debugging may not receive the same amount of explicit teaching attention as other material and the main expression of debugging competence is students' ability to undo problems which they themselves have injected into their assignments. Further, as the literature points out, debugging skills do not necessarily develop at the same rate as code writing skills. This paper discusses an intervention in a second year course designed to improve students' application of simple debugging techniques. We use a puzzle based approach where students are graded based on the number of attempts they take to locate misbehaving code in a program which they did not write but whose function they understand. An existing assignment component addresses another aspect of debugging practice

Compiler optimization and ordering effects on VLIW code compression

Code size has always been an important issue for all embedded applications as well as larger systems. Code compression techniques have been devised as a way of battling bloated code; however, the impact of VLIW compiler methods and outputs on these compression schemes has not been thoroughly investigated. This paper describes the application of single- and multipleinstruction dictionary methods for code compression to decrease overall code size for the TI TMS320C6xxx DSP family. The compression scheme is applied to benchmarks taken from the Mediabench benchmark suite built with differing compiler optimization parameters. In the single instruction encoding scheme, it was found that compression ratios were not a useful indicator of the best overall code size – the best results (smallest overall code size) were obtained when the compression scheme was applied to sizeoptimized code. In the multiple instruction encoding scheme, changing parallel instruction order was found to only slightly improve compression in unoptimized code and does not affect the code compression when it is applied to builds already optimized for size

Linguistic Organisation and Native Title

Classical Aboriginal societies in Australia have commonly been described in terms of social organisation and local organisation. This book presents rich detail on a third and related domain that has not been given the same kind of attention: linguistic organisation. Basing their analyses on fieldwork among the Wik peoples of Cape York Peninsula, north Australia, Peter Sutton and Ken Hale show how cosmology, linguistic variation, language prehistory, clan totemic identities, geopolitics, land use and land ownership created a vibrant linguistic organisation in a classical Aboriginal society. This has been a society long in love with language and languages. Its people have richly imbued the domain of rights and interests in country—the foundations of their native title as recognised in Australian law—with rights and interests in the abundance of languages and dialects given to them at the start of the world