John G. Keating

A visualisation tool to aid exploration of students' interactions in asynchronous online communication

Much research in recent years has focused on the introduction of virtual learning environments (VLEs) to universities, documenting practice, and sharing experience (Armitage, Browne, & Jenkins, 2001; Browne & Jenkins, 2003; Moron-Garcia, 2004; Weller, 2007). Attention has been directed towards the importance of online dialogue for learning as a defining feature of the VLE. Communicative tools are an important means by which VLEs have the potential to transform learning with computers from being passive and transmissive in nature, to being active and constructivist (Pavey & Garland, 2004). However, practical methods of reviewing and analysing online communication to trace cycles of real dialogue (and learning) have proved somewhat elusive. Qualitative methods are also under-used for VLE discussions, since they demand new sets of research skills for those unfamiliar with them, and can be time intensive. This paper describes a visualisation tool to aid the analysis of online communication. The tool has two purposes: first, it can be used on a day-to-day basis by teachers or forum moderators to review the development of a discussion and to support appropriate interventions. Second, the tool can support research activities since the visualisations generated provide the basis for further qualitative and quantitative analysis of online dialogue. The visualisation software is designed to encode interaction types simply and quickly. The software was tested and then used to analyse data from a sample of forums within the Moodle VLE. The paper discusses both the method of visualisation and analysis of the online interactions as a pilot for further research analysing interaction in discussion forums.

The influence of inhomogeneity on the propagation of ultrasound in wood

The use of ultrasound for determining the elastic constants of materials is a well-established science for homogeneous materials such as metals. However, its extension to anisotropic, inhomogeneous materials such as wood has proved more problematic. Wood is modelled as an orthorhombic material with the influence of inhomogeneities generally being neglected. For this paper the potential influence of inhomogeneities on waves propagating in the radial direction was considered. Within ring density and ultrasonic velocity measurements were made. A model for ultrasound propagation in the radial direction was then constructed which treats the annual ring structure in the radial direction as a layered structure and predicts the occurrence of stop bands in the frequency domain. Evidence for the existence of such stop bands is considered.

General-purpose acousto-optic connectionist processor

We present a reconfigurable optical implementation of an acousto-optic algebra processor, based on a calomel (single crystal mercurous chloride) matrix-vector multiplier. Two successful applications are demonstrated: neural network training and curve detection. In the first, a perceptron learns two-input Boolean functions. in the second, a connec- tionist model of the Hough transform is generalized to handle arbitrary curves. Experiments for line detection and circle detection are performed, and the Hough transforms throughput is solely limited by the update latency of the acousto-optic unit.

A case study on the adaptive maintenance of an internet application

We describe an Internet application for providing mobile phone tariff information for Northern Ireland and the Republic of Ireland. Using this application it is possible to accurately and easily determine and compare mobile phone packages offered by different service providers. One of the important features of such an Internet application is the potential for high maintenance associated with the data in the system and more importantly the structure of the system given the inevitable changes in the corresponding mobile phone market. We have identified the maintenance tasks associated with our system to reflect changes in the mobile phone market and outline an evaluation technique for describing the systems ability to cope with change. In particular, we evaluate the actual change required to our software system to implement various maintenance tasks. We have found that there is an upper bound (∼5%) on the maintenance effort associated with the system which is both acceptable and manageable for maintenance purposes. We show that at most the changes required to our system are no greater than 3.07%, when a complete new service provider is added or removed. We conclude that the development of a maintenance model in conjunction with system design is essential for estimating the maintenance effort associated with similar Internet applications.

Optical implementation of the Kak neural network

We show that the Kak neural network is suitable for optical implementation using a bipolar matrix vector multiplier. We demonstrate how the CC4 algorithm, with suitable modifications to the structure and training algorithm, may be used to build an optical neural network implementing N-Parity.

Noisy Optical Detection of Chaos-Based Watermarks

In this paper we investigate the limits on optical detection of noisy watermarks that use a chaotic function, the logistic difference equation, in the watermark generation scheme. By varying the function seed, different chaotic sequences exhibiting lowpass and highpass characteristics, can be obtained for the same function, offering an added security advantage over watermarks generated using pseudorandom sequences. Watermark Detection is the process of determining whether an image is watermarked with a certain watermark. In this paper, we model and investigate an optical correlator suitable for watermark detection for certain classes of high-pass or low-pass watermarks. Once in the public domain a watermarked image may be subjected to noise and other attacks, deliberate and unintentional. Additionally,an optical correlator system will also be subject to shot noise. The effects of shot noise on optically transmitted watermarks are modeled in this paper and we examine how the watermark detection scheme performs in such situations. We quantify the degree of noise that may be present in the watermark detection scheme in order to obtain reliable detection or rejection of a watermark using an optical-correlator.

Chaotic maps and pattern recognition - the XOR problem

In this report, we describe a novel application of the Bakers map. We demonstrate that the chaotic properties of this map can be used to implement basic operations in Boolean logic. This observation leads naturally to the possibility of new computational models and implementations for conventional computational systems. Here we show that by considering the variation of the fractal dimension of its attractor, and using varying parameter values as inputs, the generalised Bakers map can be used as a natural exclusive OR (XOR) gate. Further, this map can also be used to create other logical functions such as the AND gate. The efficacy of our results are demonstrated by means of a concrete application; namely by designing, to the best of our knowledge, for the frst time, a half-adder that is constructed entirely by utilising chaotic dynamics.

An online image analysis tool for science education

This paper describes an online image analysis tool developed as part of an iterative, user-centered development of an online Virtual Learning Environment (VLE) called the Education through Virtual Experience (EVE) Portal. The VLE provides a Web portal through which schoolchildren and their teachers create scientific proposals, retrieve images and other resources, and produce collaborative scientific papers summarizing their learning experiences. The VLE underwent substantive formative testing involving over 200 schoolchildren producing over 50 collaboratively written research papers. Detailed analysis of these research papers identified some shortfalls toward the goal of producing authentic scientific engagement. The absence of data collection and data analysis within these research papers was disappointing despite having scheduled time for this activity and having several professional imaging tools available. The post-evaluation analyses have enabled the development team to identify specific design flaws in the previous VLE and have shaped the design of the new custom-built tool. The success of the tool will be born out through content analysis of future collaboratively written student papers.

The VTIE Collaborative Writing Environment

This paper discusses the design of the VTIE Collaborative Writing Environment (CWE) and the functionality of the various components that make up this environment. The advantages of supporting collaborative writing are also discussed as well as different organizational schemes that can be used when structuring collaborative writing exercises. The paper also contains technical details on the implementation of the VTIE CWE.

Science investigation system for telescopes in education research

The Virtual Telescopes in Education (VTIE) project, is providing tools for teaching astronomy in K-12 classrooms using remotely controlled telescopes. VTIEs main goal is to promote scientific literacy, including a conceptual understanding of the physical world and the scientific process itself. This paper describes an essential component of VTIE: the scientific investigation system for telescopes in education research (SISTER). Students are aided in the preparation of their observing proposal by a glossary tool for dynamically inducing hyperlinks tailored to a students reading level, a proposal generation interface to guide them through the process of formulating a scientific question, and a paper writing tool to report the results of the analysis of the data. In this paper we present the architecture and methodology for SISTER.