Exploiting multi-word units in history-based probabilistic generation

We present a simple history-based model for sentence generation from LFG f-structures, which improves on the accuracy of previous models by breaking down PCFG independence assumptions so that more f-structure conditioning context is used in the prediction of grammar rule expansions. In addition, we present work on experiments with named entities and other multi-word units, showing a statistically significant improvement of generation accuracy. Tested on section 23 of the PennWall Street Journal Treebank, the techniques described in this paper improve BLEU scores from 66.52 to 68.82, and coverage from 98.18% to 99.96%

Application of shape grammar theory to underground rail station design and passenger evacuation

This paper outlines the development of a computer design environment that generates station ‘reference’ plans for analysis by designers at the project feasibility stage. The developed program uses the theoretical concept of shape grammar, based upon principles of recognition and replacement of a particular shape to enable the generation of station layouts. The developed novel shape grammar rules produce multiple plans of accurately sized infrastructure faster than by traditional means. A finite set of station infrastructure elements and a finite set of connection possibilities for them, directed by regulations and the logical processes of station usage, allows for increasingly complex composite shapes to be automatically produced, some of which are credible station layouts at ‘reference’ block plan level. The proposed method of generating shape grammar plans is aligned to London Underground standards, in particular to the Station Planning Standards and Guidelines 5th edition (SPSG5 2007) and the BS-7974 fire safety engineering process. Quantitative testing is via existing evacuation modelling software. The prototype system, named SGEvac, has both the scope and potential for redevelopment to any other country’s design legislation

Investigating the washback effects on improving the writing performance of Iranian EFL university student

Because of the complex nature of writing as a social, cultural and cognitive phenomenon, and the variety of challenges faced by both learners and teachers, learning and teaching writing in EFL context, this study aimed to investigate the washback effects on improving Iranian EFL students' writing performance. Two research questions were addressed. The first was whether the test-oriented writing classes provide teachers with a taxonomy of more common errors in university EFL learners' scripts or not. The second aimed at investigating the significance of the difference in the writing performance of university EFL learners receiving washback treatment and those taught by the traditional method. The subjects of the research were ninety Iranian university EFL students, making up two intact classes of thirdyear majors. There were forty-five students per class, which consisted almost entirely female. The control group continued the traditional way of practicing writing in the classroom. The experimental group received washback–based instruction. The instructional program was then steered toward improving the areas of difficulty and focusing on the aspects that require more practice. The study showed that the rate of grammatical and lexico-semantic errors was more than errors in keeping cohesion, coherence and rhetorical organization.The diagnostic instructional program based on washback effect was satisfactory in improving the students' writing performance