Planar graphs as L-intersection or L-contact graphs

The L-intersection graphs are the graphs that have a representation as intersection graphs of axis parallel shapes in the plane. A subfamily of these graphs are {L, |, --}-contact graphs which are the contact graphs of axis parallel L, |, and -- shapes in the plane. We prove here two results that were conjectured by Chaplick and Ueckerdt in 2013. We show that planar graphs are L-intersection graphs, and that triangle-free planar graphs are {L, |, --}-contact graphs. These results are obtained by a new and simple decomposition technique for 4-connected triangulations. Our results also provide a much simpler proof of the known fact that planar graphs are segment intersection graphs

Performance anxiety in actors: symptoms, explanations and an Indian approach to treatment

There are numerous examples of renowned performers across the arts (actors and musicians) and in sports, which become news items in the media due to their performance anxiety (also called stage fright in English, or Lampenfieber in German). Given the number of celebrity actors suffering from stage fright, the number of those actors who do not make the news headlines in relation to their stage fright but nevertheless suffer from it must be even higher. In t his essay we provide an up to date account of the symptoms of stage fright, possible explanations for it and a range of known approaches to treatment. This is followed by an original approach to treating stage fright, based on Indian performance techniques, using details of a study undertaken in 2005.This multi-author journal article provides an in-depth analysis into the nature and treatment available for performance anxiety. The article offers examples of numerous artists and singers, including Sir Laurence Olivier, who had experienced stage fright for the duration of his performances of the title role in Ibsen’s The Master Builder (1965). The article run a clear analysis of the symptoms of stage fright and explain the nature of this psychophysical anxiety using clinical evidences and therapeutic methods. The key focus of the article is to compare and contrast two therapeutic methods for deducing stage anxiety: NLP, a well-established method, and SIT, which is an emerging method developed by Sreenath Nair using South Indian Bodily traditions. The article is based on a project carried out by Emerita Elizabeth Valentine and Daniel Meyer-Dinkgräfe in 2005, funded by the British Academy and the University of Wales Aberystwyth. The project compared two distinct methods of reducing stage fright in stage actors (Valentine et.al. 2006), one of them based on Indian approaches (South Indian Techniques, SIT) and the other Neuro Linguistic Programming (NLP). The SIT approach makes use of a range of psychophysical approaches deriving from the martial and performance traditions of Kerala. The study concludes that although many of the results were not statistically significant, ten of the eleven main effects were in the predicted direction, i.e. a greater effect for SIT than NLP. This multi-author journal article provides an in-depth analysis into the nature and treatment available for performance anxiety. The article offers examples of numerous artists and singers, including Sir Laurence Olivier, who had experienced stage fright for the duration of his performances of the title role in Ibsen’s The Master Builder (1965). The article run a clear analysis of the symptoms of stage fright and explain the nature of this psychophysical anxiety using clinical evidences and therapeutic methods. The key focus of the article is to compare and contrast two therapeutic methods for deducing stage anxiety: NLP, a well-established method, and SIT, which is an emerging method developed by Sreenath Nair using South Indian Bodily traditions. The article is based on a project carried out by Emerita Elizabeth Valentine and Daniel Meyer-Dinkgräfe in 2005, funded by the British Academy and the University of Wales Aberystwyth. The project compared two distinct methods of reducing stage fright in stage actors (Valentine et.al. 2006), one of them based on Indian approaches (South Indian Techniques, SIT) and the other Neuro Linguistic Programming (NLP). The SIT approach makes use of a range of psychophysical approaches deriving from the martial and performance traditions of Kerala. The study concludes that although many of the results were not statistically significant, ten of the eleven main effects were in the predicted direction, i.e. a greater effect for SIT than NLP. The study is a practice-based research demonstrating a highly relevant contribution to a therapeutic practice reducing stage fright. The research combines science and humanities indicating direct and wider impact

Bridging the Gap Between Traditional Metadata and the Requirements of an Academic SDI for Interdisciplinary Research

Metadata has long been understood as a fundamental component of any Spatial Data Infrastructure, providing information relating to discovery, evaluation and use of datasets and describing their quality. Having good metadata about a dataset is fundamental to using it correctly and to understanding the implications of issues such as missing data or incorrect attribution on the results obtained for any analysis carried out. Traditionally, spatial data was created by expert users (e.g. national mapping agencies), who created metadata for the data. Increasingly, however, data used in spatial analysis comes from multiple sources and could be captured or used by nonexpert users – for example academic researchers ‐ many of whom are from non‐GIS disciplinary backgrounds, not familiar with metadata and perhaps working in geographically dispersed teams. This paper examines the applicability of metadata in this academic context, using a multi‐national coastal/environmental project as a case study. The work to date highlights a number of suggestions for good practice, issues and research questions relevant to Academic SDI, particularly given the increased levels of research data sharing and reuse required by UK and EU funders

Laser induced Zero-Group Velocity resonances in Transversely Isotropic cylinder

The transient response of an elastic cylinder to a laser impact is studied. When the laser source is a line perpendicular to the cylinder axis, modes guided along the cylinder are generated. For a millimetric steel cylinder up to ten narrow resonances can be locally detected by laser interferometry below 8 MHz. Most of these resonances correspond to Zero-Group Velocity guided modes while a few others can be ascribed to thickness modes. We observe that the theory describing the propagation of elastic waves in an isotropic cylinder is not sufficient to precisely predict the resonance spectrum. In fact, the texture of such elongated structure manifest as elastic anisotropy. Thus, a transverse isotropic (TI) model is used to calculate the dispersion curves and compare them with the measured one, obtained by moving the source along the cylinder. The five elastic constants of a TI cylinder are adjusted leading to a good agreement between measured and theoretical dispersion curves. Then, all the resonance frequencies are satisfactorily identified.Comment: 23 pages, 7 figures, submitted to the JAS

Laser beam shaping for enhanced Zero-Group Velocity Lamb modes generation

Optimization of Lamb modes induced by laser can be achieved by adjusting the spatial source distribution to the mode wavelength ($\lambda$). The excitability of Zero-Group Velocity (ZGV) resonances in isotropic plates is investigated both theoretically and experimentally for axially symmetric sources. Optimal parameters and amplitude gains are derived analytically for spot and annular sources of either Gaussian or rectangular energy profiles. For a Gaussian spot source, the optimal radius is found to be $\lambda_{ZGV}/\pi$. Annular sources increase the amplitude by at least a factor of 3 compared to the optimal Gaussian source. Rectangular energy profiles provide higher gain than Gaussian ones. These predictions are confirmed by semi-analytical simulation of the thermoelastic generation of Lamb waves, including the effect of material attenuation. Experimentally, Gaussian ring sources of controlled width and radius are produced with an axicon-lens system. Measured optimal geometric parameters obtained for Gaussian and annular beams are in good agreement with theoretical predictions. A ZGV resonance amplification factor of 2.1 is obtained with the Gaussian ring. Such source should facilitate the inspection of highly attenuating plates made of low ablation threshold materials like composites.Comment: 11 pages, 12 figure

Cost-effectiveness analysis in R using a multi-state modelling survival analysis framework: a tutorial

This tutorial provides a step-by-step guide to performing cost-effectiveness analysis using a multi-state modelling approach. Alongside the tutorial we provide easy-to-use functions in the statistics package R. We argue this multi-state modelling approach using a package such as R has advantages over approaches where models are built in a spreadsheet package. In particular, using a syntax-based approach means there is a written record of what was done and the calculations are transparent. Reproducing the analysis is straightforward as the syntax just needs to be run again. The approach can be thought of as an alternative way to build a Markov decision analytic model, which also has the option to use a state-arrival extended approach if the Markov property does not hold. In the state-arrival extended multi-state model a covariate that represents patients’ history is included allowing the Markov property to be tested. We illustrate the building of multi-state survival models, making predictions from the models and assessing fits. We then proceed to perform a cost-effectiveness analysis including deterministic and probabilistic sensitivity analyses. Finally, we show how to create two common methods of visualising the results, namely cost-effectiveness planes and cost-effectiveness acceptability curves. The analysis is implemented entirely within R. It is based on adaptions to functions in the existing R package mstate, to accommodate parametric multi-state modelling which facilitates extrapolation of survival curves