Critical slowing down and hyperuniformity on approach to jamming

Hyperuniformity characterizes a state of matter that is poised at a critical point at which density or volume-fraction fluctuations are anomalously suppressed at infinite wavelengths. Recently, much attention has been given to the link between strict jamming and hyperuniformity in frictionless hard-particle packings. Doing so requires one to study very large packings, which can be difficult to jam properly. We modify the rigorous linear programming method of Donev et al. [J. Comp. Phys. 197, 139 (2004)] in order to test for jamming in putatively jammed packings of hard-disks in two dimensions. We find that various standard packing protocols struggle to reliably create packings that are jammed for even modest system sizes; importantly, these packings appear to be jammed by conventional tests. We present evidence that suggests that deviations from hyperuniformity in putative maximally random jammed (MRJ) packings can in part be explained by a shortcoming in generating exactly-jammed configurations due to a type of "critical slowing down" as the necessary rearrangements become difficult to realize by numerical protocols. Additionally, various protocols are able to produce packings exhibiting hyperuniformity to different extents, but this is because certain protocols are better able to approach exactly-jammed configurations. Nonetheless, while one should not generally expect exact hyperuniformity for disordered packings with rattlers, we find that when jamming is ensured, our packings are very nearly hyperuniform, and deviations from hyperuniformity correlate with an inability to ensure jamming, suggesting that strict jamming and hyperuniformity are indeed linked. This raises the possibility that the ideal MRJ packings have no rattlers. Our work provides the impetus for the development of packing algorithms that produce large disordered strictly jammed packings that are rattler-free.Comment: 15 pages, 11 figures. Accepted for publication in Phys. Rev.

C2MS: Dynamic Monitoring and Management of Cloud Infrastructures

Server clustering is a common design principle employed by many organisations who require high availability, scalability and easier management of their infrastructure. Servers are typically clustered according to the service they provide whether it be the application(s) installed, the role of the server or server accessibility for example. In order to optimize performance, manage load and maintain availability, servers may migrate from one cluster group to another making it difficult for server monitoring tools to continuously monitor these dynamically changing groups. Server monitoring tools are usually statically configured and with any change of group membership requires manual reconfiguration; an unreasonable task to undertake on large-scale cloud infrastructures. In this paper we present the Cloudlet Control and Management System (C2MS); a system for monitoring and controlling dynamic groups of physical or virtual servers within cloud infrastructures. The C2MS extends Ganglia - an open source scalable system performance monitoring tool - by allowing system administrators to define, monitor and modify server groups without the need for server reconfiguration. In turn administrators can easily monitor group and individual server metrics on large-scale dynamic cloud infrastructures where roles of servers may change frequently. Furthermore, we complement group monitoring with a control element allowing administrator-specified actions to be performed over servers within service groups as well as introduce further customized monitoring metrics. This paper outlines the design, implementation and evaluation of the C2MS.Comment: Proceedings of the The 5th IEEE International Conference on Cloud Computing Technology and Science (CloudCom 2013), 8 page

Adjustable Jig and Method for Targeting Interlocking Holes of an Intramedullary Nail

A targeting jig apparatus for targeting interlocking holes of an intramedullary nail. The targeting jig includes a support-arm extending substantially parallel to the intramedullary nail. A targeting mechanism including a pair of targeting mechanism drill-guide orifices is adjustably disposed on the support arm for aligning the targeting mechanism drill-guide orifice with the interlocking holes of the intramedullary nail. The targeting mechanism includes a saddle having a U-shape including a base and parallel legs that are slidable along the support-arm. A connection mechanism includes a horizontal slot on the support-arm aligned with a vertical slot on the targeting mechanism and a pivot screw extending through the slots for facilitating adjustment of the targeting mechanism relative to the support arm

(Un)Becoming

This document provides written support for the thesis exhibition, (Un)Becoming. The body of work uses taxidermy and specimen collection techniques to explore the relationship between the Westward Expansion of the late 19th and early 20th centuries and modern conceptions of masculinity. Through jewelry and sculptural objects, I unravel my personal experiences as a queer individual growing up in a deeply repressive environment--specifically, I examine how the culture and the history of the Mormon Church, Idaho, and the American West more generally have come to define manhood, and how those definitions have shaped how I perceive myself. Using the visual languages of woodcarving, taxidermy, and ornamentation, I create reimagined versions of hunting and botanical objects through a queer lens

The pattern of a life: on a new concept of mind in twentieth century philosophy

The goal of this investigation is to uncover, within the works under analysis, a concept of mind not as a thing, but a self-constituting pattern of perceptual activity. This work examines that concept in the context of several different philosophical investigations, particularly that of Patricia and Paul Churchland, and Maurice Merleau-Ponty. The goal is to blend ideas from several contemporary philosophical schools to create a non-reductive philosophy of mind that is nonetheless physicalist all the way through. It is a kind of proof by counter-example that physicalism need not be reductive. -- The Churchlands create a new approach to human nature they call neurophilosophy. Their account of thinking and perception understands such activities as the continuing formation and transformation of ordered patterns of neuroelectrical activity in the brain. Yet the Churchlands' particular brand of physicalism, which they call 'eliminative materialism,' considers non-neurological ways of understanding perceiving and thinking to be mistaken - so philosophy will be replaced by neurology. My first chapter ends with a critique of the Churchlands' epistemology which points out the flaw in the eliminative understanding of knowledge. -- The second chapter examines the functionalist philosophy of the recent work of Jaegwon Kim, and borrows the idea of the pattern as it occurs in an essay of David Lewis. Kim offers an approach to the nature of scientific understanding that gives relevance to the functional talk of propositional attitudes, even as we accept that a belief is itself a complex patterning and re-patterning in the extremely multi-layered neural network that is the brain. Lewis' metaphor gives one the clearest image of the particular kind of existence of the mind, when the mind is considered to be a continually re-constituting pattern of activity of a body perceiving the world and moving around in it. -- The final chapter examines what I think is a very direct engagement with the concept of the individual as a pattern constituted in the activity of a body perceiving the world and moving in it. This is precisely Merleau-Ponty's concept of ‘bodily life,’ as he expresses it in his book, The Phenomenology of Perception. The analysis of this concept takes up the first half of the last chapter. Finally, I examine the work of Evan Thompson, particularly his recent Mind in Life, which articulates Merleau-Ponty's concept of bodily life in a physicalist context. For the purposes of this thesis, this work also provides an answer to the extreme reductive character of the Churchlands' eliminative physicalism. He asks what kind of physical body can carry out the activities constitutive of mind, perception and motion, and finds this to be any body constituted in a metabolic chemical activity. The human style of mind is a highly complex articulation of the perceptual and motive activity

The BSL Sentence Reproduction Test: Exploring age of acquisition effects in British deaf adults

Here we present initial findings from a BSL sentence reproduction test, adapted from a test originally created for ASL (Hauser et al., 2008), with the aim of creating a screen that can be used to distinguish signers with native-like vs. non-native-like skills. The stimulus items, based on a set of 49 sentences from Hauser et al. (2008), included 40 BSL sentences varying in length and complexity, presented on video by a deaf native BSL signer. Participants were instructed to copy the signed sentence to camera, exactly as they saw it, regardless of phonological or lexical variants for the same concepts that they might prefer. Participants were 20 deaf adults: 10 deaf native signers, 5 deaf early learners first exposed to BSL between ages 2 and 6, and 5 late learners first exposed to BSL at age 11 or later. Responses were scored by a team of deaf and hearing sign language researchers. Responses which were agreed by all scorers as identical to the stimulus were given a score of 1; responses which included any phonological, morphological, lexical or syntactic deviations were given a score of 0 (except for a few specific, agreed-upon acceptable deviations). Results indicate that native signers scored significantly higher than non-native signers. For non-native signers there was no significant differences between early and late learners. We explore implications of these findings for use of the BSL-SRT as a screening test for assessing fluency in deaf adults and for exploring age-of-acquisition effects more generally. Hauser, P., Paludneviciene, R., Supalla, T., & Bavelier, D. (2008). American Sign Language – Sentence Reproduction Test: Development & Implications. In R. M. d. Quadros (Ed.), Sign Languages: Spinning and Unraveling the Past, Present and Future. TISLR 9, Forty-five Papers and Three Posters from the 9th Theoretical Issues in Sign Language Research Conference (pp. 155-167). Petrópolis/RJ. Brazil: Editora Arara Azul

Bringing new tools, a regional focus, resource-sensitivity, local engagement and necessary discipline to mental health policy and planning

Background: While reducing the burden of mental and substance use disorders is a global challenge, it is played out locally. Mental disorders have early ages of onset, syndromal complexity and high individual variability in course and response to treatment. As most locally-delivered health systems do not account for this complexity in their design, implementation, scale or evaluation they often result in disappointing impacts. Discussion: In this viewpoint, we contend that the absence of an appropriate predictive planning framework is one critical reason that countries fail to make substantial progress in mental health outcomes. Addressing this missing infrastructure is vital to guide and coordinate national and regional (local) investments, to ensure limited mental health resources are put to best use, and to strengthen health systems to achieve the mental health targets of the 2015 Sustainable Development Goals. Most broad national policies over-emphasize provision of single elements of care (e.g. medicines, individual psychological therapies) and assess their population-level impact through static, linear and program logic-based evaluation. More sophisticated decision analytic approaches that can account for complexity have long been successfully used in non-health sectors and are now emerging in mental health research and practice. We argue that utilization of advanced decision support tools such as systems modelling and simulation, is now required to bring a necessary discipline to new national and local investments in transforming mental health systems. Conclusion: Systems modelling and simulation delivers an interactive decision analytic tool to test mental health reform and service planning scenarios in a safe environment before implementing them in the real world. The approach drives better decision-making and can inform the scale up of effective and contextually relevant strategies to reduce the burden of mental disorder and enhance the mental wealth of nations