January 1990 - Vol. 33 No. 1
Features
Generalized predictive TCQ of speech
Trellis coded quantization (TCQ) is incorporated into a noise feedback coding structure for encoding sampled speech. The effects of varying the encoding delay and the number of symbols released per trace-back on system performance and complexity are investigated.
Bounding delay on a multifarious token ring network
Interest in integrating voice and data on local computer networks has been building in recent years. Subsequently, much research has been devoted to various techniques that are implementable on existing networks using current standards. This exposition discusses the design issues in implementing a document retrieval system on a token ring network.
Multicast tree construction in bus-based networks
Because of the multiple-access property of the media, the problem of constructing multicast trees in bus-based networks differs fundamentally from that in point-to-point networks. This article investigates the multicast tree construction for both general and specific network topologies.
Cube structures for multiprocessors
The exact structural relationship between the hypercube and multistage interconnection networks for multiprocessors is characterized here. By varying the node architecture, structures other than these two interconnection schemes can be derived.
An incremental constraint solver
An incremental constraint solver, the DeltaBlue algorithm maintains an evolving solution to the constraint hierarchy as constraints are added and removed. DeltaBlue minimizes the cost of finding a new solution after each change by exploiting its knowledge of the last solution.
DATAPLEX: an access to heterogeneous distributed databases
Diverse database management systems are used in large organizations. The heterogeneous distributed database system (DDS) can provide a flexible intergration of diverse databases for users and applications. This is because it allows for retrieval and update of distributed data under different data systems giving the illusion of accessing a single centralized database system.
Phoenix: a safe in-memory file system
Phoenix contains two timestamped versions of the in-memory file system allowing for a reserve version that ensures safety for diskless computers with battery-powered memeory.
Two fast implementations of the “minimal standard” random number generator
Although superficially time-consuming, on 32-bit computers the minimal standard random number generator can be implemented with surprising economy.
