LOGICAL AND PHYSICAL TEMPORAL-DATABASE DESIGN

This paper examines problems and approaches to logical and physical temporal-database design. The logical model is used to determine the functionality required of the physical design. Due to the special nature of temporal data, existing database structures are inadequate. The nature of physical design problems are examined and some solutions proposed. A multi-dimensional file partitioning algorithm is proposed; this algorithm is appropriate for certain temporal-database environments

Optimal Arrangements of Cartridges In Carousel Type Mass Storage Systems

Optimal arrangements of cartridges and file partitioning schemes are examined in carousel type mass storage systems using Markov decision theory. It is shown that the Organ-Pipe Arrangement is optimal under different storage configurations for both the anticipatory as well as the non-anticipatory versions of the problem. When requests arrive as per an arbitrary renewal process this arrangement is also shown to minimize the mean queueing delay and the time spent in the system by the requests.Information Systems Working Papers Serie

Contrasting Approaches to Implementing an Evolving Technology: Internet-EDI

This paper traces the evolution of Internet-EDI technology in the last 3 years through two illustrative cases of it\u27s implementation -an Internet-EDI pilot project by Bank of America (BofA) and Lawrence Livermore National Labs (LLNL) in 1994, and a robust, production level Internet-EDI implementation by McKesson in 1996. While BofA took a proof of concept approach in its early implementation, McKesson applied the traditional life cycle model in the system design and purchased much of its Internet-EDI capability up front, albeit at a prohibitive cost. The rapid evolution of the technology has resulted in the availability of browser-based systems in early 1997. By facilitating entry of small to mid size companies into EDI networks, these inexpensive systems could transform the competitive landscape within these network

Laparoscopic Removal of an Intrauterine Device Following Colon Perforation

Intestinal perforation by a migrating intrauterine device is a serious complication and may be corrected by using a laparoscopic approach

The Partial Least Squares Approach for Causal Modeling in IS Research

Thc objective of the tutorial is to present a state of the art overview of &e Partial Least Squares method and position it among other analytic techniques as well as within IS research. Furthermore, this tutorial will highlight the philosophid and operational issues that should be considered when employing causa! modeling

Optimal Arrangements of Cartridges In Carousel Type Mass Storage Systems

Optimal arrangements of cartridges and file partitioning schemes are examined in carousel type mass storage systems using Markov decision theory. It is shown that the Organ-Pipe Arrangement is optimal under different storage configurations for both the anticipatory as well as the non-anticipatory versions of the problem. When requests arrive as per an arbitrary renewal process this arrangement is also shown to minimize the mean queueing delay and the time spent in the system by the requests.Information Systems Working Papers Serie

Efficient Indexing Methods for Temporal Relations

Abstract-The size of temporal databases and the semantics cases are subsequently investigated: 1) Dynamic structures for of temporal queries pose challenges for the design of efhcient indexing methods. The primary issues that affect the design of indexing methods are examined, and propose several structures and algorithms for specific cases. Indexing methods for timebased queries are developed, queries on the surrogate or timesurrogate and time indexing (ST); 2) Static and dynamic partitioning algorithms for the time-line in the context of temporal attribute and time indexing; and 3) Time-indexing for append-only database. In all the designs, the focus is on invariant key and time, and temporal attribute and time. In the the role of the time attribute. latter case, several methods are presented that partition the timeline, in order to balance the distribution of tuple-pointers within the index. The methods are analyzed against alternatives, and present appropriate empirical results. Index Terms-Indexing, physical organization, query processing, searching, temporal databases. The paper is organized as follows. In Section II, we discuss the relational representation of data in the temporal context, followed by a framework for analyzing the physical design of a temporal database. In Section III, we introduce the APtree, which is designed for time-based query operations on an append-only database, and is subsequently incorporated into our surrogate-time index of Section IV. In Section V, we I