A Transaction System for the NCUBE

We present the design of a transaction system which supports tuple-oriented database operations in the concurrent environment. An implementation of this system for the NCUBE Corporation NCUBE-7 hypercube processor is described. The implementation includes both the basic kernel to support the database operations and two software packages to assist users of the system

Amalgamation of South Africa’s rural municipalities: is it a good idea?

The majority of South African municipalities facing the challenges of unemployment, poverty and weak infrastructure are in rural areas. To fulfil their mandate, they depend significantly on financial transfers.  This is something that the government is focused on minimising as evidenced by the recent Department of Cooperative Governance and Traditional Affairs proposal of amalgamating many municipalities to make them self-reliant and functional.  This paper asks the question: ‘will amalgamations of rural municipalities correct for financial viability and functionality’? Using case studies of amalgamated municipalities, the paper observes that amalgamations will not make all rural municipalities self-sufficient and functional

Good Words - May 2003, vol. 5, no. 1

Adam Ncube, editor of Good Words / Amazwi Amahl

Good Words - December 2002, vol. 3, no. 6

Adam Ncube, editor of Good Words / Amazwi Amahl

Performance of a parallel code for the Euler equations on hypercube computers

The performance of hypercubes were evaluated on a computational fluid dynamics problem and the parallel environment issues were considered that must be addressed, such as algorithm changes, implementation choices, programming effort, and programming environment. The evaluation focuses on a widely used fluid dynamics code, FLO52, which solves the two dimensional steady Euler equations describing flow around the airfoil. The code development experience is described, including interacting with the operating system, utilizing the message-passing communication system, and code modifications necessary to increase parallel efficiency. Results from two hypercube parallel computers (a 16-node iPSC/2, and a 512-node NCUBE/ten) are discussed and compared. In addition, a mathematical model of the execution time was developed as a function of several machine and algorithm parameters. This model accurately predicts the actual run times obtained and is used to explore the performance of the code in interesting but yet physically realizable regions of the parameter space. Based on this model, predictions about future hypercubes are made

On the engineering of systems of systems: key challenges for the requirements engineering community!

Software intensive systems of the future will be ultra large-scale systems of systems. Systems of Systems Engineering focuses on the interoperation of many independent, self-contained constituent systems to achieve a global need. The scale and complexity of systems of systems possess unique challenges for the Requirements Engineering community. Current requirements engineering techniques are inadequate in addressing these challenges and new concepts, methods, techniques, tools and processes are required. This paper identifies some immediate key challenges for the Requirements Engineering community that need to be scoped and describes some road-mapping activities that aim to address these challenges

Adaptive Parallel Iterative Deepening Search

Many of the artificial intelligence techniques developed to date rely on heuristic search through large spaces. Unfortunately, the size of these spaces and the corresponding computational effort reduce the applicability of otherwise novel and effective algorithms. A number of parallel and distributed approaches to search have considerably improved the performance of the search process. Our goal is to develop an architecture that automatically selects parallel search strategies for optimal performance on a variety of search problems. In this paper we describe one such architecture realized in the Eureka system, which combines the benefits of many different approaches to parallel heuristic search. Through empirical and theoretical analyses we observe that features of the problem space directly affect the choice of optimal parallel search strategy. We then employ machine learning techniques to select the optimal parallel search strategy for a given problem space. When a new search task is input to the system, Eureka uses features describing the search space and the chosen architecture to automatically select the appropriate search strategy. Eureka has been tested on a MIMD parallel processor, a distributed network of workstations, and a single workstation using multithreading. Results generated from fifteen puzzle problems, robot arm motion problems, artificial search spaces, and planning problems indicate that Eureka outperforms any of the tested strategies used exclusively for all problem instances and is able to greatly reduce the search time for these applications

Good Words - December 2002, vol. 4, no. 3

Adam Ncube, editor of Good Words / Amazwi Amahl

Good Words - August 2002, vol. 4, no.2

Adam Ncube, editor of Good Words / Amazwi Amahl