Despite the many qualitative elements of software time-to-build estimating, some observable features can be quantified; even if the resulting set of variables observed is arbitrary. Such is the case when estimating the expected duration for database re-engineering. If we assume that for any extant database, an entity-relationship model (ERM) can be produced from which a new normalised schema is generated, then our estimating task needs to quantify both the complexity of the ensuing ERM and also the data modelling knowledge of the ‘re-engineer’. Whilst there may be additional variables to be considered, a set of primary elements required for estimating the durations of the task have been identified. The formula proposed in this paper is arbitrary but it is intended as an instrument for measuring ER model complexity, such that time-to-build estimates can be made for the task of re-engineering extant non-relational databases into relational form.
+ + +This paper discusses the method of determining heights of mountains during the original geodetic survey of Victoria. From 1840 to 1875, more particularly the 1860s, geodetic surveyors were charged with the responsibility of mapping the colony. The subject of this paper is their efforts to determine the elevations by barometric heighting. A brief introduction to other methods is given while particular attention is paid to the determination of the height of Mount Sabine in the Otway Ranges, Victoria, by Surveyor Irwin in 1865. Attempts are made to recompute his original observations.
+ + +Semantic data models comprise formally defined abstractions for representing real world relationships and aspects of the structure of real world phenomena so as to aid database design. While previous research in spatial database design has shown that semantic data models are amenable to explicitly representing some spatial concepts, this paper shows that semantic data models may usefully be applied to the design of spatial databases even without explicitly representing spatial concepts. Specifically, an entity-relationship model comprising only “is-associated-with” relationships is used as the basis from which to define thematic layers for a layer based spatial database.
+ + +This paper reports the results of a recent national survey which considered the use of CASE tools and 4GLs in commercial software development. Responses from just over 750 organisations show a high degree of product penetration, along with extensive use of package solutions. Use of 3GLs in general, and of COBOL in particular, is still relatively widespread, however. In terms of systems analysis and design techniques under a CASE/4GL environment, screen and report definition is the most preferred technique, although both dataflow analysis and data modelling also feature strongly.
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+ + +This paper argues that the introduction of western cadastral concepts into communities with different land tenure systems have involved “cultural costs.” The paper discusses these cultural costs and concludes that cadastral reformers need to re-design their product to fit the communities.
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