Density based fuzzy c-means clustering of non-convex patterns

We propose a new technique to perform unsupervised data classification (clustering) based on density induced metric and non-smooth optimization. Our goal is to automatically recognize multidimensional clusters of non-convex shape. We present a modification of the fuzzy c-means algorithm, which uses the data induced metric, defined with the help of Delaunay triangulation. We detail computation of the distances in such a metric using graph algorithms. To find optimal positions of cluster prototypes we employ the discrete gradient method of non-smooth optimization. The new clustering method is capable to identify non-convex overlapped d-dimensional clusters.

Combining extension matrix and integer programming for optimal concept learning

This paper proposes two integer programming models and their GA-based solutions for optimal concept learning. The models are built to obtain the optimal concept description in the form of propositional logic formulas from examples based on completeness, consistency and simplicity. The simplicity of the propositional rules is selected as the objective function of the integer programming models, and the completeness and consistency of the concept are used as the constraints. Considering the real-world problems that certain level of noise is contained in data set, the constraints in model 11 are slacked by adding slack-variables. To solve the integer programming models, genetic algorithm is employed to search the global solution space. We call our approach IP-AE. Its effectiveness is verified by comparing the experimental results with other well- known concept learning algorithms: AQ15 and C4.5.

The impossible infinite: Les Murray, poetry, and the sacred

In 1983, the provocative and idiosyncratic Australian poet Les Murray published a volume entitled The People's Otherworld. At the heart of that middle volume of Murray's work is a poem about grace entitled Equanimity. Here, McCredden examines how does the poetry of Murray seek to represent the sacred.

Achieving behaviour change: three generations of HIV/AIDS programming and jargon in Thailand

NGOs have played an important role worldwide in the fight to prevent the spread of HIV/AIDS through achieving behaviour change. NGOs have often been at the forefront of innovative changes, influencing government and international programming activities. This paper identifies and analyses the evolution of the HIV/AIDS programmes of one NGO in Thailand over a period of ten years. Three generations of programming are identified both through distinct approaches to this area of work and through the changing jargon used to describe the people the programmes are aimed at.

Fuzzy clustering of non-convex patterns using global optimization

This paper discusses various extensions of the classical within-group sum of squared errors functional, routinely used as the clustering criterion. Fuzzy c-means algorithm is extended to the case when clusters have irregular shapes, by representing the clusters with more than one prototype. The resulting minimization problem is non-convex and non-smooth. A recently developed cutting angle method of global optimization is applied to this difficult problem

Convex hulls as an hypothesis language bias

Classification learning is dominated by systems which induce large numbers of small axis-orthogonal decision surfaces which biases such systems towards particular hypothesis types. However, there is reason to believe that many domains have underlying concepts which do not involve axis orthogonal surfaces. Further, the multiplicity of small decision regions mitigates against any holistic appreciation of the theories produced by these systems, notwithstanding the fact that many of the small regions are individually comprehensible. We propose the use of less strongly biased hypothesis languages which might be expected to model' concepts using a number of structures close to the number of actual structures in the domain. An instantiation of such a language, a convex hull based classifier, CHI, has been implemented to investigate modeling concepts as a small number of large geometric structures in n-dimensional space. A comparison of the number of regions induced is made against other well-known systems on a representative selection of largely or wholly continuous valued machine learning tasks. The convex hull system is shown to produce a number of induced regions about an order of magnitude less than well-known systems and very close to the number of actual concepts. This representation, as convex hulls, allows the possibility of extraction of higher level mathematical descriptions of the induced concepts, using the techniques of computational geometry.

Design guidelines for children programming in school environment

This paper describes design guidelines of a programming environment for children, aiming to lower the barriers for children to learn programming. Our model called GBuilder has been developed on the basis of guidelines, with the express purpose of enabling and empowering the students to develop their own learning programs in survival literacy within enjoyable and fun environment.

Deborah Walker : hommage to the infinite

Spirtuality is at the heart of Deborah Walker's enigmatically engaging works. Drawing on the interpretive nature of a philosophical world view, Walker presents a figurative structure imbued with a calmness, stillness, and sophistication. Elegantly dressed characters are warmly depicted witha touch of theatre and drama, their serene gaze gentle, sometimes melancholy and reflective. 

Implementation of novel methods of global and nonsmooth optimization : GANSO programming library

We discuss the implementation of a number of modern methods of global and nonsmooth continuous optimization, based on the ideas of Rubinov, in a programming library GANSO. GANSO implements the derivative-free bundle method, the extended cutting angle method, dynamical system-based optimization and their various combinations and heuristics. We outline the main ideas behind each method, and report on the interfacing with Matlab and Maple packages.

Scope for further analytical solutions for constant flux infiltration into a semi-infinite soil profile or redistribution in a finite soil profile.

We attempt to generate new solutions for the moisture content form of the one-dimensional Richards' [1931] equation using the Lisle [1992] equivalence mapping. This mapping is used as no more general set of transformations exists for mapping the one-dimensional Richards' equation into itself. Starting from a given solution, the mapping has the potential to generate an infinite number of new solutions for a series of nonlinear diffusivity and hydraulic conductivity functions. We first seek new analytical solutions satisfying Richards' equation subject to a constant flux surface boundary condition for a semi-infinite dry soil, starting with the Burgers model. The first iteration produces an existing solution, while subsequent iterations are shown to endlessly reproduce this same solution. Next, we briefly consider the problem of redistribution in a finite-length soil. In this case, Lisle's equivalence mapping is generalized to account for arbitrary initial conditions. As was the case for infiltration, however, it is found that new analytical solutions are not generated using the equivalence mapping, although existing solutions are recovered.

Opportunities and challenges with J2SE 5 for introductory programming teaching

The recent release of the Java version 5.0 "Tiger" introduces some significant language changes. For educators, some of these changes provide opportunities to improve teaching, while others pose additional problems that require awareness to avoid them. The authors have recently completed the inclusion of support for all new language features into a wellknown educational IDE for Java – BlueJ – and in the course of doing so evaluated each of them for usefulness in education, and developed pedagogic strategies to handle the inherent opportunities and challenges. This has formed the basis of the design of the features in BlueJ which support the language changes. In this paper, we describe the results of our evaluation, provide recommendations on treatment of the new features in introductory courses and discuss how BlueJ may be used to illustrate important aspects.

Programming your - objects (turtles, textboxes, sliders and buttons) in microworlds

This article outlines some new-object commands of Logo Microworlds and includes the use of buttons, sliders and programmable colours. The ability to assign object properties including font, colour and frames are discussed. As is assigning object-instructions and commands such as click on and clickoff, launch and cancel. Programming the turtle, making a new turtle, running simultaneous turtles, programming graphic colours and sliders as well as understanding dotimes are explored.