- ItemDSaaS : a cloud service for persistent data structures(Institute for Systems and Technologies of Information, 2016-04) Le Roux, Pierre Bernard; Kroon, Steve; Bester, WillemIn an attempt to tackle shortcomings of current approaches to collaborating on the development of structured data sets, we present a prototype platform that allows users to share and collaborate on the development of data structures via a web application, or by using language bindings or an API. Using techniques from the theory of persistent linked data structures, the resulting platform delivers automatically version-controlled map and graph abstract data types as a web service. The core of the system is provided by a Hash Array Mapped Trie (HAMT) which is made confluently persistent by path-copying. The system aims to make efficient use of storage, and to have consistent access and update times regardless of the version being accessed or modified.
- ItemThe discrete pulse transform in two dimensions(Pattern Recognition Association of South Africa, 2009) Fabris-Rotelli, I. (Inger); Van der Walt, S. J. (Stefan J.); Annual Symposium of the Pattern Recognition Association of South Africa (20th : 30 November-1 December 2009 : Stellenbosch, South Africa); Nicolls, F.During the last three decades, the LULU operator and its close relative, the Discrete Pulse Transform (DPT), were developed and applied to signal processing problems. Its recent extension into higher dimensions paved the way for applications on signals such as images. In this paper, we present a memory-efficient implementation of the two-dimensional Discrete Pulse Transform and use it to explore the scale space exposed by the DPT.