An analysis of relational complexity in an air traffic control conflict detection task

Theoretical analyses of air traffic complexity were carried out using the Method for the Analysis of Relational Complexity. Twenty-two air traffic controllers examined static air traffic displays and were required to detect and resolve conflicts. Objective measures of performance included conflict detection time and accuracy. Subjective perceptions of mental workload were assessed by a complexity-sorting task and subjective ratings of the difficulty of different aspects of the task. A metric quantifying the complexity of pair-wise relations among aircraft was able to account for a substantial portion of the variance in the perceived complexity and difficulty of conflict detection problems, as well as reaction time. Other variables that influenced performance included the mean minimum separation between aircraft pairs and the amount of time that aircraft spent in conflict.

A flaw in the use of minimal defining sets for secret sharing schemes

It is shown that in some cases it is possible to reconstruct a block design D uniquely from incomplete knowledge of a minimal defining set for D. This surprising result has implications for the use of minimal defining sets in secret sharing schemes.

Candidatus "Anammoxoglobus propionicus" a new propionate oxidizing species of anaerobic ammonium oxidizing bacteria

The bacteria that mediate the anaerobic oxidation of ammonium (anammox) are detected worldwide in natural and man-made ecosystems, and contribute up to 50% to the loss of inorganic nitrogen in the oceans. Two different anammox species rarely live in a single habitat, suggesting that each species has a defined but yet unknown niche. Here we describe a new anaerobic ammonium oxidizing bacterium with a defined niche: the co-oxidation of propionate and ammonium. The new anammox species was enriched in a laboratory scale bioreactor in the presence of ammonium and propionate. Interestingly, this particular anammox species could out-compete other anammox bacteria and heterotrophic denitrifiers for the oxidation of propionate in the presence of ammonium, nitrite and nitrate. We provisionally named the new species Candidatus "Anammoxoglobus propionicus".

Generalized Perk-Schultz models: solutions of the Yang-Baxter equation associated with quantized orthosymplectic superalgebras

The Perk-Schultz model may be expressed in terms of the solution of the Yang-Baxter equation associated with the fundamental representation of the untwisted affine extension of the general linear quantum superalgebra U-q (gl(m/n)], with a multiparametric coproduct action as given by Reshetikhin. Here, we present analogous explicit expressions for solutions of the Yang-Baxter equation associated with the fundamental representations of the twisted and untwisted affine extensions of the orthosymplectic quantum superalgebras U-q[osp(m/n)]. In this manner, we obtain generalizations of the Perk-Schultz model.

Managing knowledge in tourism planning: How to assess your capability

This paper explores the theme of strategic planning in a State Tourism Organization (STO) from a knowledge management perspective. It highlights the value of knowledge in strategy making and the importance of an organisation's knowledge management agenda in facilitating a strategic planning process. In particular, it considers the capability of an STO to implement knowledge management as the key to a successful strategic planning exercise. In order to develop greater insight into the factors that impact on planning competence, the key aim of this paper is to develop a framework on which the capability of a STO to implement a knowledge-based agenda in strategic planning can be assessed. Research on knowledge management in the field of tourism is limited and there is little practical account of the application of knowledge management principles in tourism planning. Further, there is no apparent tool or instrument that allows for the assessment of an STO's capability to implement knowledge management in planning initiatives. Based on a literature review, a three-point framework of assessment is developed. The three elements of the framework are identified as: 1. Integration of knowledge management objectives with strategic imperatives; 2. A planning approach that balances top-down (outcome focused) with bottom-up (process focused) planning processes; and 3. Organisational capacity, including leadership, people and culture, process, technology, content and continuous improvement. The framework is tested through application to a practical case study - a planning initiative undertaken by a leading tourism STO in Australia. The results demonstrate that the framework is a useful means to evaluate organisational capability in knowledge-led strategic planning exercises and would be of practical value as a point of reference for future knowledge- based strategic planning projects. Copyright © by The Haworth Press, Inc. All rights reserved.