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Communications of the ACM

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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 …

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 …

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 …

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 …

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 …

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 …

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.