Parallel database machine architectures have evolved from the use of exotic hardware to a software parallel dataflow architecture based on conventional shared-nothing hardware. These new designs provide impressive speedup and scaleup when processing relational database queries. This paper reviews the techniques used by such systems,…
We present a real-time robot motion planner that is fast and complete to a resolution. The technique is guaranteed to find a path if one exists at the resolution, and all paths returned are safe. The planner can handle any polyhedral geometry of robot and…
This paper describes a system architecture that supports realtime generation of complex images, efficient generation of extremely high-quality images, and a smooth trade-off between the two. Based on the paradigm of integration, the architecture extends a state-of-the-art rendering system with an additional high-precision image buffer.…
EZ is a system that integrates the facilities provided separately by traditional programming languages and operating systems. This integration is accomplished by casting services provided by traditional operating services as EZ language features. EZ is a high-level string processing language with a persistent memory. Traditional…
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…
This chapter discusses the design process for building user-centered on-line help. On-line help can be interactive and action-dependent. It can be dependent on the user's working context or on the history of a user's actions, and can take account of a user's skill level. On-line…
The time-split B-tree is an integrated index structure for a versioned timestamped database. It gradually migrates data from a current database to an historical database, records migrating when nodes split. Records valid at the split time are placed in both an historical node and a…
We investigate the interactions of subtyping and recursive types in a simply typed łambda-calculus. The two fundamental questions here are whether two (recursive) types are in the subtype relation and whether a term has a type. To address the first question, we relate various definitions…
Studies of the propagation of heat pulses, launched by a sawtooth collapse or by modulated auxiliary heating, yield information on transport properties in the tokamak. Corresponding values of the thermal conductivity are often found to be significantly larger than values obtained from power balance calculations.…
Most markets for computing are evolving towards distributed solutions. The system framework that accommodates distributed solutions most gracefully is likely to dominate in the 1990’s. A leadership distributed system includes the best of today’s centralized systems, combining their coherence and function with the better cost/performance,…
Program representation graphs are a recently introduced intermediate representation form for programs. In this paper, we develop a mathematics semantics for the graphs by interpretating them as data-flow graphs. We also study the relation between this semantics and the standard operational semantics of programs.
Recent progress in developing automatic articulatory analysis-synthesis procedures is described. The goal of the research is to find ways to fully exploit the advantages of articulatory modeling in producing natural-sounding speech from text and in low-bit-rate coding. Estimation of articulatory parameters by analysis-synthesis appears to…
