Analysis and control of transient spectra using time-dependent density functional theory.

215 p.

Error analyses reveal contrasting deficits in “theory of mind”: neuropsychological evidence from a 3-option false belief task

Perspective taking is a crucial ability that guides our social interactions. In this study, we show how the specific patterns of errors of brain-damaged patients in perspective taking tasks can help us further understand the factors contributing to perspective taking abilities. Previous work (e.g., Samson, Apperly, Chiavarino, & Humphreys, 2004; Samson, Apperly, Kathirgamanathan, & Humphreys, 2005) distinguished two components of perspective taking: the ability to inhibit our own perspective and the ability to infer someone else’s perspective. We assessed these components using a new nonverbal false belief task which provided different response options to detect three types of response strategies that participants might be using: a complete and spared belief reasoning strategy, a reality-based response selection strategy in which participants respond from their own perspective, and a simplified mentalising strategy in which participants avoid responding from their own perspective but rely on inaccurate cues to infer the other person’s belief. One patient, with a self-perspective inhibition deficit, almost always used the reality-based response strategy; in contrast, the other patient, with a deficit in taking other perspectives, tended to use the simplified mentalising strategy without necessarily transposing her own perspective. We discuss the extent to which the pattern of performance of both patients could relate to their executive function deficit and how it can inform us on the cognitive and neural components involved in belief reasoning.

Room temperature photo-response of titanium supersaturated silicon at energies over the bandgap

Silicon samples were implanted with high Ti doses and subsequently processed with the pulsed-laser melting technique. The electronic transport properties in the 15–300 K range and the room temperature spectral photoresponse at energies over the bandgap were measured. Samples with Ti concentration below the insulator-metal (I-M) transition limit showed a progressive reduction of the carrier lifetime in the implanted layer as Ti dose is increased. However, when the Ti concentration exceeded this limit, an extraordinary recovery of the photoresponse was measured. This result supports the theory of intermediate band materials and is of utmost relevance for photovoltaic cells and Si-based detectors.

Danger theory: the link between AIS and IDS?

We present ideas about creating a next generation Intrusion Detection System (IDS) based on the latest immunological theories. The central challenge with computer security is determining the difference between normal and potentially harmful activity. For half a century, developers have protected their systems by coding rules that identify and block specific events. However, the nature of current and future threats in conjunction with ever larger IT systems urgently requires the development of automated and adaptive defensive tools. A promising solution is emerging in the form of Artificial Immune Systems (AIS): The Human Immune System (HIS) can detect and defend against harmful and previously unseen invaders, so can we not build a similar Intrusion Detection System (IDS) for our computers? Presumably, those systems would then have the same beneficial properties as HIS like error tolerance, adaptation and self-monitoring. Current AIS have been successful on test systems, but the algorithms rely on self-nonself discrimination, as stipulated in classical immunology. However, immunologist are increasingly finding fault with traditional self-nonself thinking and a new ‘Danger Theory’ (DT) is emerging. This new theory suggests that the immune system reacts to threats based on the correlation of various (danger) signals and it provides a method of ‘grounding’ the immune response, i.e. linking it directly to the attacker. Little is currently understood of the precise nature and correlation of these signals and the theory is a topic of hot debate. It is the aim of this research to investigate this correlation and to translate the DT into the realms of computer security, thereby creating AIS that are no longer limited by self-nonself discrimination. It should be noted that we do not intend to defend this controversial theory per se, although as a deliverable this project will add to the body of knowledge in this area. Rather we are interested in its merits for scaling up AIS applications by overcoming self-nonself discrimination problems.

Trade Shocks and Local Labor Markets' Linkages: Theory and Evidence

In the past few years, there has been a concern among economists and policy makers that increased openness to international trade affects some regions in a country more than others. Recent research has found that local labor markets more exposed to import competition through their initial employment composition experience worse outcomes in several dimensions such as, employment, wages, and poverty. Although there is evidence that regions within a country exhibit variation in the intensity with which they trade with each other and with other countries, trade linkages have been ignored in empirical analyses of the regional effects of trade, which focus on differences in employment composition. In this dissertation, I investigate how local labor markets' trade linkages shape the response of wages to international trade shocks. In the second chapter, I lay out a standard multi-sector general equilibrium model of trade, where domestic regions trade with each other and with the rest of the world. Using this benchmark, I decompose a region's wage change resulting from a national import cost shock into a direct effect on prices, holding other endogenous variables constant, and a series of general equilibrium effects. I argue the direct effect provides a natural measure of exposure to import competition within the model since it summarizes the effect of the shock on a region's wage as a function of initial conditions given by its trade linkages. I call my proposed measure linkage exposure while I refer to the measures used in previous studies as employment exposure. My theoretical analysis also shows that the assumptions previous studies make on trade linkages are not consistent with the standard trade model. In the third chapter, I calibrate the model to the Brazilian economy in 1991--at the beginning of a period of trade liberalization--to perform a series of experiments. In each of them, I reduce the Brazilian import cost by 1 percent in a single sector and I calculate how much of the cross-regional variation in counterfactual wage changes is explained by exposure measures. Over this set of experiments, employment exposure explains, for the median sector, 2 percent of the variation in counterfactual wage changes while linkage exposure explains 44 percent. In addition, I propose an estimation strategy that incorporates trade linkages in the analysis of the effects of trade on observed wages. In the model, changes in wages are completely determined by changes in market access, an endogenous variable that summarizes the real demand faced by a region. I show that a linkage measure of exposure is a valid instrument for changes in market access within Brazil. By using observed wage changes in Brazil between 1991-2000, my estimates imply that a region at the 25th percentile of the change in domestic market access induced by trade liberalization, experiences a 0.6 log points larger wage decline (or smaller wage increase) than a region at the 75th percentile. The estimates from a regression of wages changes on exposure imply that a region at the 25th percentile of exposure experiences a 3 log points larger wage decline (or smaller wage increase) than a region at the 75th percentile. I conclude that estimates based on exposure overstate the negative impact of trade liberalization on wages in Brazil. In the fourth chapter, I extend the standard model to allow for two types of workers according to their education levels: skilled and unskilled. I show that there is substantial variation across Brazilian regions in the skill premium. I use the exogenous variation provided by tariff changes to estimate the impact of market access on the skill premium. I find that decreased domestic market access resulting from trade liberalization resulted in a higher skill premium. I propose a mechanism to explain this result: that the manufacturing sector is relatively more intensive in unskilled labor and I show empirical evidence that supports this hypothesis.

Are Videogames Art?

My dissertation defends a positive answer to the question: “Can a videogame be a work of art? ” To achieve this goal I develop definitions of several concepts, primarily ‘art’, ‘games’, and ‘videogames’, and offer arguments about the compatibility of these notions. In Part One, I defend a definition of art from amongst several contemporary and historical accounts. This definition, the Intentional-Historical account, requires, among other things, that an artwork have the right kind of creative intentions behind it, in short that the work be intended to be regarded in a particular manner. This is a leading account that has faced several recent objections that I address, particular the buck-passing theory, the objection against non-failure theories of art, and the simultaneous creation response to the ur-art problem, while arguing that it is superior to other theories in its ability to answer the question of videogames’ art status. Part Two examines whether games can exhibit the art-making kind of creative intention. Recent literature has suggested that they can. To verify this a definition of games is needed. I review and develop the most promising account of games in the literature, the over-looked account from Bernard Suits. I propose and defend a modified version of this definition against other accounts. Interestingly, this account entails that games cannot be successfully intended to be works of art because games are goal-directed activities that require a voluntary selection of inefficient means and that is incompatible with the proper manner of regarding that is necessary for something to be an artwork. While the conclusions of Part One and Part Two may appear to suggest that videogames cannot be works of art, Part Three proposes and defends a new account of videogames that, contrary to first appearances, implies that not all videogames are games. This Intentional-Historical Formalist account allows for non-game videogames to be created with an art-making intention, though not every non-ludic videogame will have an art-making intention behind it. I then discuss examples of videogames that are good candidates for being works of art. I conclude that a videogame can be a work of art, but that not all videogames are works of art. The thesis is significant in several respects. It is a continuation of academic work that has focused on the definition and art status of videogames. It clarifies the current debate and provides a positive account of the central issues that has so far been lacking. It also defines videogames in a way that corresponds better with the actual practice of videogame making and playing than other definitions in the literature. It offers further evidence in defense of certain theories of art over others, providing a close examination of videogames as a new case study for potential art objects and for aesthetic and artistic theory in general. Finally, it provides a compelling answer to the question of whether videogames can be art. This project also provides the groundwork for new evaluative, critical, and appreciative tools for engagement with videogames as they develop as a medium. As videogames mature, more people, both inside and outside academia, have increasing interest in what they are and how to understand them. One place many have looked is to the practice of art appreciation. My project helps make sense of which appreciative and art-critical tools and methods are applicable to videogames.

Radio Frequency Superconducting Quantum Interference Device Meta-atoms and Metamaterials: Experiment, Theory, and Analysis

Metamamterials are 1D, 2D or 3D arrays of articial atoms. The articial atoms, called "meta-atoms", can be any component with tailorable electromagnetic properties, such as resonators, LC circuits, nano particles, and so on. By designing the properties of individual meta-atoms and the interaction created by putting them in a lattice, one can create a metamaterial with intriguing properties not found in nature. My Ph. D. work examines the meta-atoms based on radio frequency superconducting quantum interference devices (rf-SQUIDs); their tunability with dc magnetic field, rf magnetic field, and temperature are studied. The rf-SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties. At relatively low rf magnetic field, a magnetic field tunability of the resonant frequency of up to 80 THz/Gauss by dc magnetic field is observed, and a total frequency tunability of 100% is achieved. The macroscopic quantum superconducting metamaterial also shows manipulative self-induced broadband transparency due to a qualitatively novel nonlinear mechanism that is different from conventional electromagnetically induced transparency (EIT) or its classical analogs. A near complete disappearance of resonant absorption under a range of applied rf flux is observed experimentally and explained theoretically. The transparency comes from the intrinsic bi-stability and can be tuned on/ off easily by altering rf and dc magnetic fields, temperature and history. Hysteretic in situ 100% tunability of transparency paves the way for auto-cloaking metamaterials, intensity dependent filters, and fast-tunable power limiters. An rf-SQUID metamaterial is shown to have qualitatively the same behavior as a single rf-SQUID with regards to dc flux, rf flux and temperature tuning. The two-tone response of self-resonant rf-SQUID meta-atoms and metamaterials is then studied here via intermodulation (IM) measurement over a broad range of tone frequencies and tone powers. A sharp onset followed by a surprising strongly suppressed IM region near the resonance is observed. This behavior can be understood employing methods in nonlinear dynamics; the sharp onset, and the gap of IM, are due to sudden state jumps during a beat of the two-tone sum input signal. The theory predicts that the IM can be manipulated with tone power, center frequency, frequency difference between the two tones, and temperature. This quantitative understanding potentially allows for the design of rf-SQUID metamaterials with either very low or very high IM response.

Ideological Complex Systems: Mathematical Theory

The goal of this article is to build an abstract mathematical theory rather than a computational one of the process of transmission of ideology. The basis of much of the argument is Patten's Environment Theory that characterizes a system with its double environment (input or stimulus and output or response) and the existing interactions among them. Ideological processes are semiotic processes, and if in Patten's theory, the two environments are physical, in this theory ideological processes are physical and semiotic, as are stimulus and response.

The use of Integral Theory to evaluate architectural sustainability - a case study

DeKay’s concept of Integral Sustainable Design (ISD) is based on Integral Theory, a framework proposed by the American philosopher, Ken Wilber. It offers four simultaneous perspectives (represented by quadrants) which each take a different view of the problem. The ‘experiences’ quadrant focuses on individual human experiences. The ‘behaviours’ quadrant looks at environmental performance. The ‘cultures’ perspective focuses on the collective interpretation of meaning, symbolism and worldviews and the ‘systems’ quadrant investigates the response and interaction with context. Integral Theory can act as a reminder for architects of the different perspectives that a sustainable building should address. In order to evaluate ISD, the Waterfront Campus Building of Deakin University has been used as a case study. The building, its performance, impact and perception, has been evaluated using both quantitative and qualitative data. Two surveys have been conducted to gather qualitative data to: (i) determine the experience of building users (staff and students) and (ii) the perception of non-users (Geelong residents and tourists). Data from building services and a site analysis has enabled quantitative assessments to be made. These inputs have been analysed, guided by ISD, to evaluate the usefulness of ISD as a sustainability assessment tool.

Theory of mind in major depressive disorder: a meta-analysis

OBJECTIVE: Social cognitive deficits can contribute to risk for depression and to psychosocial impairment during depression. However, available evidence suggests that emotion recognition is only marginally impaired in major depressive disorder (MDD). Recent studies have investigated theory of mind (ToM) abilities, a cognitively more demanding aspect of social cognition. METHODS: We conducted a meta-analysis of studies comparing ToM abilities in MDD and healthy controls. 18 studies comparing 613 patients with MDD and 529 healthy controls were included. RESULTS: MDD patients significantly underperformed healthy controls in ToM (d=0.51-0.58). ToM impairment in MDD was evident in response to different types of ToM tasks (verbal/visual and cognitive/affective and reasoning/decoding). ToM impairment was significantly related to severity of depressive symptoms. CONCLUSION: Theory of mind abilities are impaired during depression and can potentially contribute to psychosocial difficulties during depression. There is a need to investigate ToM abilities in different subtypes and stages of depression, especially in remitted patients.

A succession of theories : purging redundancy from disturbance theory

The topics of succession and post-disturbance ecosystem recovery have a long and convoluted history. There is extensive redundancy within this body of theory, which has resulted in confusion, and the links among theories have not been adequately drawn. This review aims to distil the unique ideas from the array of theory related to ecosystem change in response to disturbance. This will help to reduce redundancy, and improve communication and understanding between researchers. We first outline the broad range of concepts that have developed over the past century to describe community change in response to disturbance. The body of work spans overlapping succession concepts presented by Clements in 1916, Egler in 1954, and Connell and Slatyer in 1977. Other theories describing community change include state and transition models, biological legacy theory, and the application of functional traits to predict responses to disturbance. Second, we identify areas of overlap of these theories, in addition to highlighting the conceptual and taxonomic limitations of each. In aligning each of these theories with one another, the limited scope and relative inflexibility of some theories becomes apparent, and redundancy becomes explicit. We identify a set of unique concepts to describe the range of mechanisms driving ecosystem responses to disturbance. We present a schematic model of our proposed synthesis which brings together the range of unique mechanisms that were identified in our review. The model describes five main mechanisms of transition away from a post-disturbance community: (i) pulse events with rapid state shifts; (ii) stochastic community drift; (iii) facilitation; (iv) competition; and (v) the influence of the initial composition of a post-disturbance community. In addition, stabilising processes such as biological legacies, inhibition or continuing disturbance may prevent a transition between community types. Integrating these six mechanisms with the functional trait approach is likely to improve the predictive capacity of disturbance theory. Finally, we complement our discussion of theory with a case study which emphasises that many post-disturbance theories apply simultaneously to the same ecosystem. Using the well-studied mountain ash (Eucalyptus regnans) forests of south-eastern Australia, we illustrate phenomena that align with six of the theories described in our model of rationalised disturbance theory. We encourage further work to improve our schematic model, increase coverage of disturbance-related theory, and to show how the model may link to, or integrate with, other domains of ecological theory.

A realist case study of a regional hospital's response to improve emergency department access in the context of Australian healthcare reforms

Introduction: Major health-care reforms have extended across all Australian public hospitals in recent years. Improving emergency department (ED) access has been a focus of these reforms.

Objective: This study evaluates how the national reforms have led to improvement in ED access in a regional hospital in remote Australia.Methods: Assessing a complex scenario such as national reforms and the challenges faced by the regional hospital to implement these reforms requires in-depth analysis. A realist evaluation theory-based approach was employed, allowing investigation of what, how, why, and for whom change occurred. A case study mixed methods design was adopted within the realist framework to answer these questions about change.

Results and Conclusion: The study identified moderate improvement in ED access as a result of the reforms (investment in infrastructure and workforce and the introduction of ED targets). Clinical leadership and support from management were essential for the improvement. Without ongoing investment and clinical redesign activities, however, sustainability of the improvement may prove difficult.

Enhancing collaboration in BIM-based construction networks through organisational discontinuity theory: a case study of the new Royal Adelaide Hospital

This paper discusses a case study of Australia’s most technologically advanced health facility to address an identified gap in the body of the knowledge. That is, no comprehensive study has hitherto attempted to draw upon virtual team working theories to enhance collaboration in BIM-based construction networks (BbCNs). In response to this, the present study seeks to raise awareness of organisational discontinuity theory (ODT) as a recent theory for virtual teams, which enables BbCNs to embrace collaboration. To this end, the major challenges encountered and corresponding solutions adopted on a mega-project have been closely monitored and investigated. The study contributes to the field through the conceptualisation of typical barriers to collaboration in BbCNs from the perspective of ODT. Additionally, the discussions presented outline practical implications by demonstrating how the identified issues of collaboration in BbCNs could be effectively dealt with.

Neuroscience and Hindu Aesthetics: A Critical Analysis of V.S. Ramachandran’s “Science of Art”

Neuroaesthetics is the study of the brain’s response to artistic stimuli. The neuroscientist V.S. Ramachandran contends that art is primarily “caricature” or “exaggeration.” Exaggerated forms hyperactivate neurons in viewers’ brains, which in turn produce specific, “universal” responses. Ramachandran identifies a precursor for his theory in the concept of rasa (literally “juice”) from classical Hindu aesthetics, which he associates with “exaggeration.” The canonical Sanskrit texts of Bharata Muni’s Natya Shastra and Abhinavagupta’s Abhinavabharati, however, do not support Ramachandran’s conclusions. They present audiences as dynamic co-creators, not passive recipients. I believe we could more accurately model the neurology of Hindu aesthetic experiences if we took indigenous rasa theory more seriously as qualitative data that could inform future research.

Molecular Origins of Higher Harmonics in Large-Amplitude Oscillatory Shear Flow: Shear Stress Response

Recent work has focused on deepening our understanding of the molecular origins of the higher harmonics that arise in the shear stress response of polymeric liquids in large-amplitude oscillatory shear flow. For instance, these higher harmonics have been explained by just considering the orientation distribution of rigid dumbbells suspended in a Newtonian solvent. These dumbbells, when in dilute suspension, form the simplest relevant molecular model of polymer viscoelasticity, and this model specifically neglects interactions between the polymer molecules [R.B. Bird et al., J Chem Phys, 140, 074904 (2014)]. In this paper, we explore these interactions by examining the Curtiss-Bird model, a kinetic molecular theory designed specifically to account for the restricted motions that arise when polymer chains are concentrated, thus interacting and specifically, entangled. We begin our comparison using a heretofore ignored explicit analytical solution [Fan and Bird, JNNFM, 15, 341 (1984)]. For concentrated systems, the chain motion transverse to the chain axis is more restricted than along the axis. This anisotropy is described by the link tension coefficient, ε, for which several special cases arise: ε = 0 corresponds to reptation, ε > 1/8 to rod-climbing, 1/2 ≥ ε ≥ 3/4 to reasonable predictions for shear-thinning in steady simple shear flow, and ε = 1 to the dilute solution without hydrodynamic interaction. In this paper, we examine the shapes of the shear stress versus shear rate loops for the special cases ε = (0,1/8, 3/8,1) , and we compare these with those of rigid dumbbell and reptation model predictions.