We describe a monad for checked, explicitly typed exceptions, which provides as a simple Haskell library what for other languages is a native feature. Multi parameter type classes and overlapping instances are the only essential extensions to Haskell 98 required.

The implicitly restarted Arnoldi method implicitly applies a polynomial lter to the Arnoldi vectors by use of orthogonal transformations. In this paper, an implicit ltering by rational functions is proposed for the rational Krylov method. This ltering is performed in an eecient way. Two applications are considered. The rst one is the ltering of unwanted eigenvalues using exact shifts. This appr...

A set of eye movement data from a visual search task using realistically complex and numerous stimuli was modeled with the EPIC architecture, which provides direct support for oculomotor constraints and visual availability constraints due to retinal non-homogeneity. The results show how the quantitative details of visual search can be explained within an architectural framework, and have useful...

EPIC (Executive Process-Interactive Control) is a human information-processing architecture especially suited for modeling human multiple-task performance. The EPIC architecture includes peripheral sensorymotor processors surrounding a production-rule cognitive processor, and is being used to construct precise computational models for basic multiple-task situations. Some of these models are bri...