SpireX is an adjunct to the Spire acoustic-phonetic workstation [1]. The SpireX system is designed to perform statistical analysis of acoustic-phonetic parameters over a large speech database. Results are displayed in the form of histograms, density contours, and scatter plots. By concentrating on the human-engineering aspects of the user interface we intend for Spire and SpireX to increase by an order of magnitude the productivity of speech scientists as well as to bring sophisticated computational resources within the grasp of non-computer experts.

As part of our goal to design large-vocabulary, phonetically-based isolated word recognition systems, we investigated the statistical properties and constraints of the phonemic structures of English words. Our database consisted of five lexicons varying in size from 1250 to 20,000 words. The lexicons included, in addition to a phonemic transcription for each word, the word's frequency of occurrence as determined from the Brown Corpus. We studied the distributions of the phonemes, both individually and by class, within the lexicon and within the corpus. Distributions of consonant clusters were also obtained. Finally, the distribution of words in terms of patterns derived from broad categorization of the phonemes was investigated. This paper summarizes the results of these studies and discusses implications for phonetically-based isolated word recognition strategies.

DAPLEX is a database language which incorporates: This paper presents and motivates the DAPLEX language and the underlying data model on which it is based.

This paper presents a formal analysis of the concurrency control strategy of SDD-1. SDD-1, a System for Distributed Databases, is a prototype distributed database system being developed by Computer Corporation of America. In SDD-1, portions of data distributed throughout a network may be replicated at multiple sites. The SDD-1 concurrency control guarantees database consistency in the face of such distribution and replication. This paper is one of a series of companion papers on SDD-1 [2, 8].

This paper presents the concurrency control strategy of SDD-1. SDD-1, a System for Distributed Databases, is a prototype distributed database system being developed by Computer Corporation of America. In SDD-1, portions of data distributed throughout a network may be replicated at multiple sites. The SDD-1 concurrency control guarantees database consistency in the face of such distribution and replication. This paper is one of a series of companion papers on SDD-1 [4, 10, 12, 21].

This paper presents the reliability mechanisms of SDD-1, a prototype distributed database system being developed by the Computer Corporation of America. Reliability algorithms in SDD-1 center around the concept of the Reliable Network (RelNet). The RelNet is a communications medium incorporating facilities for site status monitoring, event timestamping, multiply buffered message delivery, and the atomic control of distributed transactions. This paper is one of a series of companion papers on SDD-1 [3, 4, 6, 13].

The declining cost of computer hardware and the increasing data processing needs of geographically dispersed organizations have led to substantial interest in distributed data management. SDD-1 is a distributed database management system currently being developed by Computer Corporation of America. Users interact with SDD-1 precisely as if it were a nondistributed database system because SDD-1 handles all issues arising from the distribution of data. These issues include distributed concurrency control, distributed query processing, resiliency to component failure, and distributed directory management. This paper presents an overview of the SDD-1 design and its solutions to the above problems. This paper is the first of a series of companion papers on SDD-1 (Bernstein and Shipman [2], Bernstein et al. [4], and Hammer and Shipman [14]).

This paper discusses the advantages of a functional approach to data modelling. This approach forms the basis for DAPLEX, a high-level language for data description and manipulation. We describe the DAPLEX language and the functional data model and examine the benefits they provide as tools for expressing and solving problems in database management.

An arbitrary interleaved execution of transactions in a database system can lead to an inconsistent database state. A number of synchronization mechanisms have been proposed to prevent such spurious behavior. To gain insight into these mechanisms, we analyze them in a simple centralized system that permits one read operation and one write operation per transaction. We show why locking mechanisms lead to correct operation, we show that two proposed mechanisms for distributed environments are special cases of locking, and we present a new version of lockdng that alows more concurrency than past methods. We also examine conflict graph analysis, the method used in the SDD-1 distributed database system, we prove its correctness, and we show that it can be used to substantially improve the performance of almost any synchronization mechanisn.