Small Ramsey Numbers

We present data which, to the best of our knowledge, includes all known nontrivial values and bounds for specific graph, hypergraph and multicolor Ramsey numbers, where the avoided graphs are complete or complete without one edge. Many results pertaining to other more studied cases are also presented. We give references to all cited bounds and values, as well as to previous similar compilations. We do not attempt complete coverage of asymptotic behavior of Ramsey numbers, but concentrate on their specific values

Recent developments in graph Ramsey theory

Given a graph H, the Ramsey number r(H) is the smallest natural number N such that any two-colouring of the edges of K_N contains a monochromatic copy of H. The existence of these numbers has been known since 1930 but their quantitative behaviour is still not well understood. Even so, there has been a great deal of recent progress on the study of Ramsey numbers and their variants, spurred on by the many advances across extremal combinatorics. In this survey, we will describe some of this progress

Knowledge Acquisition and Structuring by Multiple Experts in a Group Support Systems Environment

This study addresses the impact of Group Decision Support Systems (GDSS) on expert system development by multiple Domain Experts. Current approaches to building expert systems rely heavily on knowledge acquisition and prototyping by a Knowledge Engineer working directly with the Domain Expert. Although the complexity of knowledge domains and new organizational approaches demand the involvement of multiple experts, standard procedures limit the ability of the Knowledge Engineer to work with more than one expert at a time. Group Decision Support Systems offer a networked computerized environment for group work activities, in which multiple experts may express their ideas concurrently and anonymously through the electronic channel. GDSS systems have been widely used in other applications to support idea generation, conflict management, and the organizing, prioritizing, and synthesizing of ideas. The effects of many group process and technical factors on GDSS have been widely studied and documented. A review of the literature on expert systems, GDSS, and GDSS in relation to expert systems was conducted. Knowledge gained from this review was applied in the construction of an exploratory research model intended to provide the necessary breadth to identify factors worthy of future, more statistically-based, investigation. Domain Experts represented by college students were charged with developing and prioritizing ideas for creating a pre-prototypical expert system. The treatment group worked in a GDSS environment with a facilitator; a control group worked with a facilitator but without the assistance of GDSS. Each group then exchanged facilitators and technology to address another real-life problem. Additional groups worked with GDSS over time, addressing both problems. Data were gathered, analyzed and discussed relating to group efficiency factors, group process factors, attitudinal factors, and product quality factors. Independent Knowledge Engineers and Domain Experts evaluated the validity and verifiability of the group products. Analysis focused on the effect of GDSS in facilitating the acquisition and structuring of ideas for expert systems by multiple Domain Experts

Drawing out interaction: Lines around shared space.

PhdDespite advances in image, video, and motion capture technologies, human interactions are frequently represented as line drawings. Intuitively, drawings provide a useful way of filtering complex, dynamic sequences to produce concise representations of interaction. They also make it possible to represent phenomena such as topic spaces, that do not have a concrete physical manifestation. However, the processes involved in producing these drawings, the advantages and limitations of line drawings as representations, and the implications of drawing as an analytic method have not previously been investigated. This thesis explores the use of drawings to represent human interaction and is informed by the prior experience and abilities of the investigator as a practising visual artist. It begins by discussing the drawing process and how it has been used to capture human activities. Key drawing techniques are identified and tested against an excerpt from an interaction between architects. A series of new drawings are constructed to depict one scene from this interaction, highlighting the contrasts between each drawing technique and their impact on the way shared spaces are represented. A second series of original drawings are produced exploring new ways of representing these spaces, leading to a proposal for a field-based approach that combines gesture paths, fields, and human figures to create a richer analytic representation. A protocol for using this approach to analyse video in practice is developed and evaluated though a sequence of three participatory workshops for researchers in human interaction. The results suggest that the field based process of drawing facilitates the production of spatially enriched graphical representations of qualitative spaces. The thesis concludes that the use of drawing to explore non-metric approaches to shared interactional space, has implications for research in human interaction, interaction design, clinical psychology, anthropology, and discourse analysis, and will find form in new new approaches to contemporary artistic practice.Engineering and Physical Sciences Research Council (EPSRC)