On the Life and Work of S. Helgason

This article is a contribution to a Festschrift for S. Helgason. After a biographical sketch, we survey some of his research on several topics in geometric and harmonic analysis during his long and influential career. While not an exhaustive presentation of all facets of his research, for those topics covered we include reference to the current status of these areas.Comment: Final versio

Ground Beetle Range Extensions: Six New Ohio Records (Coleoptera: Carabidae)

We newly report six ground beetles from Ohio, comprising Badister parviceps, Stenolophus dissimilis, Harpalus somnulentus, Pentagonica fiavipes, Agonum albicrus, and Lebia collaris

Mode coupling and multiquantum vibrational excitations in Feshbach-resonant positron annihilation in molecules

The dominant mechanism of low-energy positron annihilation in polyatomic molecules is through positron capture in vibrational Feshbach resonances (VFR). In this paper we investigate theoretically the effect of anharmonic terms in the vibrational Hamiltonian on the positron annihilation rates. Such interactions enable positron capture in VFRs associated with multiquantum vibrational excitations, leading to enhanced annihilation. Mode coupling can also lead to faster depopulation of VFRs, thereby reducing their contribution to the annihlation rates. To analyze this complex picture, we use coupled-cluster methods to calculate the anharmonic vibrational spectra and dipole transition amplitudes for chloroform, chloroform-$d_1$, 1,1-dichloroethylene, and methanol, and use these data to compute positron resonant annihilation rates for these molecules. Theoretical predictions are compared with the annihilation rates measured as a function of incident positron energy. The results demonstrate the importance of mode coupling in both enhancement and suppression of the VFR. There is also experimental evidence for the direct excitation of multimode VFR. Their contribution is analyzed using a statistical approach, with an outlook towards more accurate treatment of this phenomenon.Comment: 16 pages, 10 figures, submitted to Phys. Rev.

Exploring reflective design: an approach to digital archives

In this short paper we discuss our explorations with adopting reflective design as an approach to designing a digital archive for the performing arts. The stakeholders in this project are diverse, comprised of members of the partner organisation, the public, the design team and government funding agencies. Each stakeholder has different expectations and skills to bring to the project. It is proposed that reflective design with its mix of critical reflection with a human centred design and prototyping approach provides a methodological framework that enables the complexities of the project to be integrated into an action orientated design exploration

Development of a generic activities model of command and control

This paper reports on five different models of command and control. Four different models are reviewed: a process model, a contextual control model, a decision ladder model and a functional model. Further to this, command and control activities are analysed in three distinct domains: armed forces, emergency services and civilian services. From this analysis, taxonomies of command and control activities are developed that give rise to an activities model of command and control. This model will be used to guide further research into technological support of command and control activities

Distinguishing Observed Inattentive Behaviors in the College Classroom as they Correlate to Brain Wave Activity Utilizing a Wireless Electroencephalograph

A significant amount of research has been devoted to the behavioral correlates of inattention in children (A.P.A., 2000; Arnold, 2000; Gordon & Barkley, 1998). It is proposed by the authors that college students, in their several years of experience, are much more capable of masking these trademark behaviors. When a child loses interest they will begin to openly look around the room, shift in their seat, or chat with their neighbors (Sandberg, Rutter & Taylor, 1978; Arnold, 2000). College students however, are proposed to candidly fidget, shift in their seat, or even maintain eye contact with their instructor while “daydreaming”. Therefore, an additional physiological aid is required to better assess inattentive periods in college subjects. Given the invasive nature of past devices commonly used, such as the Electroencephalograph (EEG), accurate measurement proves to be very difficult in a natural setting (Boyd & Campbell, 1998). This study used a modified version of an EEG called the Attention Trainer (AT). The AT is smaller in size, and wireless thus alleviating distraction and allowing more reliable field assessment. The study found positive correlations (Table 1) between suggested and previously validated behaviors. Contrary to prior research, significant correlations were found between all four frequency bands (Beta, Theta, Delta, and SMR), suggesting the device may be inaccurate (Figure 1). While results can neither confirm nor discredit biofeedback applications for the AT, further research is needed for validation

Distributed situation awareness in dynamic systems: Theoretical development and application of an ergonomics methodology

The purpose of this paper is to propose foundations for a theory of situation awareness based on the analysis of interactions between agents (i.e., both human and non-human) in subsystems. This approach may help promote a better understanding of technology-mediated interaction in systems, as well as helping in the formulation of hypotheses and predictions concerning distributed situation awareness. It is proposed that agents within a system each hold their own situation awareness which may be very different from (although compatible with) other agents. It is argued that we should not always hope for, or indeed want, sharing of this awareness, as different system agents have different purposes. This view marks situation awareness as a 1 dynamic and collaborative process that binds agents together on tasks on a moment-by-moment basis. Implications of this viewpoint for development of a new theory of, and accompanying methodology for, distributed situation awareness are offered