The certainty-factor (CF) model is a commonly used method for managing uncertainty in rule-based systems. We review the history and mechanics of the CF model, and delineate precisely its theoretical and practical limitations. In addition, we examine the belief network, a representation that is similar…
As automatic speech recognition systems are finding their way into practical applications it is becoming increasingly clear that they must be able to accommodate a variety of acoustical environments. This paper describes two algorithms that provide robustness for automatic speech recognition systems in a fashion…
Computers are increasingly the enabling devices of the information revolution, and computing is becoming ubiquitous in every corner of society, from manufacturing to telecommunications to pharmaceuticals to entertainment. Even more importantly, the face of computing is changing rapidly, as even traditional rivals such as IBM…
It is often conjectured that articulatory modelling of speech is desirable, if training data can be obtained. Articulatory parameters are likely to interpolate over long intervals, and reproduce many acoustic details from simple constraints governed by physical laws. For text-to-speech application, it may be easier…
The use of different kinds of feedback in preventing mode errors was investigated. Two experiments examined the frequency of mode errors in a text editing task where a mode error was defined as an attempt to issue navigation commands while in insert mode, or an…
I planned to lock my door but not to put the chain on. I locked the door and proceeded to put the chain on all the while thinking that it wasn’t what I wanted to do.
This paper reports the results of two studies carried out on memory problems at work. The first study used a diary method to collect a corpus of memory problems. A taxonomy of memory problems was developed and implications for technological support for memory at work…
The recent development of virtual communities, sites of social interaction predominantly mediated by computers and telecommunications networks, provides a unique opportunity to study the mechanisms by which collectivities generate and maintain the commitment of their participants in a new social terrain. Using the analytical framework…
B-spline surfaces, although widely used, are incapable of arbitrary topological type. It is not possible to model a general closed surface or a surface with handles as a single non-degenerate B-spline. In practice such surfaces are often needed. In this thesis, a generalization of bicubic…
Here's the first self-contained reference to provide an in-depth discussion of the theory and applications of Lapped Transforms (LTs). The text explains how LTs can lead to a better complexity/performance tradeoff than other transforms or filter banks used in signal processing. It addresses the increased…
This paper describes the management of register spills in a retargetable C compiler. Spills are rare, which means that testing is a bigger problem than performance. The trade-offs have been arranged so that the common case (no spills) generates respectable code quickly and the uncommon…
The elements of the Hessian matrix consist of the second derivatives of the error measure with respect to the weights and thresholds in the network. They are needed in Bayesian estimation of network regularization parameters, for estimation of error bars on the network outputs, for…
