A spatially shifted beam approach to subwavelength focusing

Although negative-refractive-index metamaterials have successfully achieved subwavelength focusing, image resolution is limited by the presence of losses. In this Letter, a metal transmission screen with subwavelength spaced slots is proposed that focuses the near-field beyond the diffraction limit and furthermore, is easily scaled from microwave frequencies to the optical regime. An analytical model based on the superposition of shifted beam patterns is developed that agrees very well with full-wave simulations and is corroborated by experimental results at microwave frequencies.Comment: 5 pages, 7 figures. Content updated following reviewer comments to match final published pape

Effect of Achromycin Ointment on Healing Following Periodontal Surgery

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141040/1/jper0368.pd

A General Model of Dynamics on Networks with Graph Automorphism Lumping

In this paper we introduce a general Markov chain model of dynamical processes on networks. In this model, nodes in the network can adopt a finite number of states and transitions can occur that involve multiple nodes changing state at once. The rules that govern transitions only depend on measures related to the state and structure of the network and not on the particular nodes involved. We prove that symmetries of the network can be used to lump equivalent states in state-space. We illustrate how several examples of well-known dynamical processes on networks correspond to particular cases of our general model. This work connects a wide range of models specified in terms of node-based dynamical rules to their exact continuous-time Markov chain formulation

Exact analysis of summary statistics for continuous-time discrete-state Markov processes on networks using graph-automorphism lumping

We propose a unified framework to represent a wide range of continuous-time discrete-state Markov processes on networks, and show how many network dynamics models in the literature can be represented in this unified framework. We show how a particular sub-set of these models, referred to here as single-vertex-transition (SVT) processes, lead to the analysis of quasi-birth-and-death (QBD) processes in the theory of continuous-time Markov chains. We illustrate how to analyse a number of summary statistics for these processes, such as absorption probabilities and first-passage times. We extend the graph-automorphism lumping approach [Kiss, Miller, Simon, Mathematics of Epidemics on Networks, 2017; Simon, Taylor, Kiss, J. Math. Bio. 62(4), 2011], by providing a matrix-oriented representation of this technique, and show how it can be applied to a very wide range of dynamical processes on networks. This approach can be used not only to solve the master equation of the system, but also to analyse the summary statistics of interest. We also show the interplay between the graph-automorphism lumping approach and the QBD structures when dealing with SVT processes. Finally, we illustrate our theoretical results with examples from the areas of opinion dynamics and mathematical epidemiology

Match-fixing: working towards an ethical framework

How does match-fixing, or other unfair manipulation of matches, that involves under-performance by players, or refereeing and umpiring that prevents fair competition, be thought of in ethical terms? In this article, I outline the different forms that match-fixing can take and seek to comprehend these disparate scenarios within Kantian, Hegelian and contractualist ethical frameworks. I tentatively suggest that, by developing an ethical opposition to match-fixing in sport, we can give much greater substance to popular phrases such as ‘respect for the game’, encompassing the value of sport itself and respect for other players, fans, sponsors and organisers. Arguing that match-fixing denies recognition to these ‘others’ demonstrates how fundamentally match-fixing ‘hollows out’ sport because a fixed match is of no worth: the whole value of the game has literally been evacuated

Expanding understandings of wellbeing through researching women's experiences of intergenerational somatic dance classes

Engaging a feminist ethnographic methodology, this article offers a discussion of women’s embodied experiences of wellbeing in intergenerational somatic dance classes. Somatic dance classes aim to develop embodied awareness, support ease and freedom in movement, and offer opportunities for creativity, agency and reflection. Drawing on in-depth interviews, observation and autoethnographic vignettes, three themes emerged from the empirical material that expand understandings of wellbeing as a fluid and dynamic experience, reveal the value for women in moving for movement’s sake, and identify the significance of intergenerational contexts for moving together. As a consequence, this research offers insight into ways in which women participating in somatic dance classes have re-interpreted wellbeing practices, ‘re-claiming’ wellbeing from circulating neoliberal, self-improvement and productivity agendas, and instead, dancing into wellbeing

On the Accuracy of Analytical Models of TCP Throughput

peer reviewedBased on a large set of TCP sessions we first study the accuracy of two well-known analytical models (SQRT and PFTK) of the TCP average rate. This study shows that these models are far from being accurate on average. Actually, our simulations show that 70% of their predictions exceed the boundaries of TCP-Friendliness, thus questioning their use in the design of new TCP-Friendly transport protocols. Our study also shows that the inaccuracy of the PFTK model is largely due to its inability to make the distinction between the two packet loss detection methods used by TCP: triple duplicate acknowledgments or timeout expirations. We then use supervised learning techniques to infer models of the TCP rate. These models show important accuracy improvements when they take into account the two types of losses. This suggests that analytical model of TCP throughput should certainly benefit from the incorporation of the timeout loss rate.PAI MOTIO