This paper describes a design for an authentication service for a very large scale, very long lifetime, distributed system. The paper introduces a methodology for describing authentication protocols that makes explicit the trust relationships amongst the participants. The authentication protocol is based on the primitive…
This paper describes a system which locates and grasps parts from a pile. The system uses photometric stereo and binocu lar stereo as vision input tools. Photometric stereo is used to make surface ...
Over the last several years, teams working on expert systems have been exploring formal approaches for belief revision and information acquisition. The formalization of major components of expert systems operation is useful for understanding and characterizing system behavior and for predicting changes with modification. Formalization…
The advantages of user-defined distfix operators – a syntactic convenience that enhances the readability of programs – can be obtained as an extension of almost any programming language without requiring dynamic changes to the parser.
For some time I had been looking for a mutual exclusion algorithm that satisfied my complete list of desirable properties. I finally found one--the N!-bit algorithm described in this paper. The algorithm is wildly impractical, requiring N! bits of storage for N processors, but practicality…
The paper examines the stability of a model divertor tokamak equilibrium to MHD ballooning and interchange modes. The combined effects of the magnetic separatrix and a finite edge current density can result in coalescence of the first and second stable regions. This leads to a…
This paper reports on results of theoretical studies dealing with: (1) the use of microinstability-based thermal transport models to interpret the anomalous confinement properties observed in key tokamak experiments such as TFTR and (2) the likely consequences of the presence of such instabilities for future…
We have been working on a design for an authentication service for a distributed system. The design has three goals that we fed have not been met simultaneously by any previous design. First, the service must be able to grow to cover an arbitrarily large…
We examine the problem of explaining expert system recommendations derived from complex reasoning strategies. We focus on the difficulty of justifying advice generated by hypothesis-directed reasoning. In this context, we discuss research on the PATHFINDER system for the diagnosis of lymph node pathology. We present…
One of the most striking features of the H-mode, in contrast to the L-mode, is the existence of very steep pressure gradients in a narrow layer just inside the plasma boundary. In this paper, it is shown how the existence of H- and L-regimes, together…
This paper is an overview of the software environment (called AGORA) that is being developed at Carnegie-Mellon University to support the devlopment of connected, speaker independent, speech recognition systems. This includes the design, implemenentation, testing and fast (parallel) execution of speech recognition programs composed of…
We present a logical relationship between a small number of intuitive properties for measures of belief and the axioms of probability theory. The relationship was first demonstrated several decades ago but has remained obscure. We introduce the proof and discuss its relevance to research on…
