28202446
A demonstrably correct compiler
As critical applications grow in size and complexity, high level languages, rather than better-trusted assembly languages, will be used in their development. This adds potential for extra errors to creep in, especially in the now necessary compiler. To avoid these new errors, it is necessary to have a formal specification of the high level language, and a formal development of its compiler. We outline what we believe is a practical route for achieving a demonstrably correct compiler, and describe a prototype compiler we have built by this route for a small, but non-trivial, language.
2090341
Z in practice
Using Z. Structure, Process, Fluency. The Established Strategy. Security Properties. Other Approaches to Z Specification. Validation. Putting Together Your Method. House Style. A Word Counting Utility. Roles in Space. Structuring a Video Shop. Promoting Snakes and Ladders. Refining the Tower of Hanoi. Be Abstract. Sets or Functions?. Sets, Quantifiers, or Toolkit?. Sequences are Functions are Relations are Sets. Error Handling Styles. Promotion. Using Free Types. Using Bags. A Function Calculator. Making Schemas Work for you. Exploiting the Power of the Language. A Real Number Toolkit. and Finally...
36913632
E-Publishing Portal: A New Approach to Faculty Outreach
The recent journal price increases and state-wide budget cuts have forced librarians at the University of Maryland (UMD) to make outright cancellations to journals. The implementation of an in-house system for preserving scholarly work of faculty was necessary not only because of budgetary stringency. The ongoing “scholarly communication crisis”, the recognition that the library system needs to be changed, the need for archiving e-journal content has prompted the construction of an institutional repository. This poster aims to identify issues encountered during the design process of a digital repository and suggests possible solutions. New roles of the users of this newly implemented system are described. The main elements of the service are outlined, outreach methodologies are discussed, and faculty concerns are addressed.
46025440
The use of binary search trees in external distribution sorting
Abstract A new method of external distribution sorting called tree partitioning is suggested. It involves the use of a binary tree to split an incoming file into successively smaller partitions until these are small enough to be sorted internally. The tree is generated from a sample of data of the same type as those to be sorted using that tree. The method is therefore suitable in cases where some regularity in the data is to be expected, as is the case, for example, with words from a textual or bibliographic database. The number of disc accesses during a tree partitioning sort were calculated in a simulation using files of up to 900,000 text words extracted from British National Bibliography catalogue files. These were compared with the actual numbers of disc accesses used by a standard sort-merge utility. Although the differences were in general not large, the comparison was favourable to tree partitioning in the majority of cases.
60884961
The benefit of information technology in managing outcomes focused curriculum development across related degree programs
This paper describes an interactive, web-based tool that provides access to an Outcomes Database for managing an Outcomes Focused curriculum plan. The approach provides a rapid way to involve subject specialists, course controllers, curriculum designers and educational consultants in the curriculum design and review process. The Outcomes Database is used to capture the relationships between units (i.e. subjects), Unit Learning Outcomes, Course Learning Outcomes, Generic Graduate Attributes and assessments. This is undertaken across courses (i.e. undergraduate degree programs) sharing common units in Information Technology, Computer Science, and Software Engineering. Automatically generated database reports that show how units contribute to the development of the generic graduate attributes are compared to those derived manually on a unit-by-unit basis. Preliminary experience with this IT-based approach demonstrates that automatically generated database reports effectively highlight areas requiring further attention during subsequent curriculum development iterations. The tools and approach described here show how the Outcomes Database can assist in making the transition from an existing program to one using an Outcomes Focused approach.
41108071
Using geometric properties of correspondence vectors for the registration of free-form shapes
The registration of free-form shapes by the iterative closest point algorithm (ICP) has attracted much attention from the computer vision and image processing community since it was first proposed in 1992. Many methods, mainly based on incorporating invariants described in a single coordinate frame have been devised to improve the accuracy and efficiency of the algorithm. In this paper, a novel method to improve image registration is proposed based on rigid constraints derived from geometric properties of correspondence vectors synthesised into a singe coordinate frame. False matches, which occur in almost every iteration of the ICP algorithm are eliminated through properties of the motion. For an accurate estimation of the geometric parameters of the motion, the Monte Carlo method is used in conjunction with a median filter. Experimental results based on both synthetic data and real images show that the improved method can effectively eliminate false matches, is accurate, robust, and efficient for the registration of free-form shapes with small motions.
35983610
Sorting of textual data bases: A variety generation approach to distribution sorting
Abstract A method of sorting large textual data-bases by computer using external storage is proposed. The range of sort-keys in a sample of data to be sorted is divided into a fixed set of partitions, which should also give an adequate representation of new data from a similar source. The partitions are composed of ordered key ranges. An incoming data stream is distributed into a series of bins according to the partition in which the key lies, and the bins are then seperately sorted, using an internal sort, to give an ordered file. It is shown how the number of disc accesses needed depends on the manner in which the bins become filled, and thus on statistics of the data. Experiments using an INSPEC data-base give information on which estimates of the efficiency of the method can be based.