938 resultados para nonlinear Thomas-Fermi theory


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Communication between cultures that do not share similar norms, values, beliefs, experiences, attitudes and practices has long proven to be a difficult exercise (Balsmeier & Heck, 1994). These difficulties can have serious consequences when the miscommunication happens in the justice system; the innocent can be convicted and witnesses undermined. Much work has been carried out on the need for better communication in the courtroom (Eades, 1993; Lauchs, 2010; Supreme Court of Queensland, 2010; Supreme Court of Western Australia, 2008) but far less on language and interactions between police and indigenous Australians (Powell, 2000). It is ethically necessary that officers of the law be made aware of linguistic issues to ensure they conduct their investigations in a fair and effective manner. Despite years of awareness raising issues still arise. Issues of clashes between police and indigenous peoples are still prevalent (Heath, 2012; Remeikis, 2012). This paper will attempt to explain the reason for this discrepancy and, in doing so, suggest some solutions to the problem. This paper draws on cultural schema theory in an attempt to determine if cultural difference in language could be negatively affecting communication between Aboriginal people and the police of South East Queensland. Findings from this research are significant in determining if miscommunication is adding to the already unequal standing of Aboriginal people within the Criminal Justice system, and encouraging the already volatile relationship between Aboriginal people and police.

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Hybrid system representations have been exploited in a number of challenging modelling situations, including situations where the original nonlinear dynamics are too complex (or too imprecisely known) to be directly filtered. Unfortunately, the question of how to best design suitable hybrid system models has not yet been fully addressed, particularly in the situations involving model uncertainty. This paper proposes a novel joint state-measurement relative entropy rate based approach for design of hybrid system filters in the presence of (parameterised) model uncertainty. We also present a design approach suitable for suboptimal hybrid system filters. The benefits of our proposed approaches are illustrated through design examples and simulation studies.

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This book sensitizes the reader to the fact that there is substantial disagreement within the academic community, and among policymakers and the general public, over what behaviors, conditions (e.g., physical attributes), and people should be designated as deviant or criminal. Normative conceptions, the societal reaction/labeling approach, and the critical approach are offered as frameworks within which to study these definitions. A comprehensive explanation of theory and social policy on deviance is constructed.

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Advancing Critical Criminology constitutes a timely addition to the growing body of knowledge on critical criminology scholarship. DeKeseredy and Perry have assembled a volume that provides scholars with an in-depth review of the extant literature on several major branches of criminology as well as examples of how critical criminologists apply their theoretical perspectives to substantive topics, such as drugs, interpersonal violence, and rural crime. Accordingly, this work is divided into two main sections: overviews of theories and applications. Each chapter provides a summary of work in a specific area, along with suggestions for moving the field forward. This reader is unique in its choice of topics, which have often been overlooked in the past. An expert collection of international scholars, Advancing Critical Criminology is certain to stimulate lively debates and generate further critical social scientific work in this field.

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Left realists contend that people lacking legitimate means of solving the problem of relative deprivation may come into contact with other frustrated disenfranchised people and form subcultures, which in turn, encourage criminal behaviors. Absent from this theory is an attempt to address how, today, subcultural development in North America and elsewhere is heavily shaped simultaneously by the recent destructive consequences of right-wing Friedman or Chicago School economic policies and marginalized men's attempts to live up to the principles of hegemonic masculinity. The purpose of this paper, then, is to offer a new left realist theory that emphasizes the contribution of these two key determinants.

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"There once was a man who aspired to be the author of the general theory of holes. When asked ‘What kind of hole—holes dug by children in the sand for amusement, holes dug by gardeners to plant lettuce seedlings, tank traps, holes made by road makers?’ he would reply indignantly that he wished for a general theory that would explain all of these. He rejected ab initio the—as he saw it—pathetically common-sense view that of the digging of different kinds of holes there are quite different kinds of explanations to be given; why then he would ask do we have the concept of a hole? Lacking the explanations to which he originally aspired, he then fell to discovering statistically significant correlations; he found for example that there is a correlation between the aggregate hole-digging achievement of a society as measured, or at least one day to be measured, by econometric techniques, and its degree of techno- logical development. The United States surpasses both Paraguay and Upper Volta in hole-digging; there are more holes in Vietnam than there were. These observations, he would always insist, were neutral and value-free. This man’s achievement has passed totally unnoticed except by me. Had he however turned his talents to political science, had he concerned himself not with holes, but with modernization, urbanization or violence, I find it difficult to believe that he might not have achieved high office in the APSA." (MacIntyre 1971, 260)

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This volume aims to 'bring the state back into terrorism studies' and fill the notable gap that currently exists in our understanding of the ways in which states employ terrorism as a political strategy of internal governance or foreign policy. Within this broader context, the volume has a number of specific aims. First, it aims to make the argument that state terrorism is a valid and analytically useful concept which can do much to illuminate our understanding of state repression and governance, and illustrate the varieties of actors, modalities, aims, forms, and outcomes of this form of contemporary political violence. Secondly, by discussing a rich and diverse set of empirical case studies of contemporary state terrorism this volume explores and tests theoretical notions, generates new questions and provides a resource for further research. Thirdly, it contributes to a critical-normative approach to the study of terrorism more broadly and challenges dominant approaches and perspectives which assume that states, particularly Western states, are primarily victims and not perpetrators of terrorism. Given the scarceness of current and past research on state terrorism, this volume will make a genuine contribution to the wider field, particularly in terms of ongoing efforts to generate more critical approaches to the study of political terrorism. This book will be of much interest to students of critical terrorism studies, critical security studies, terrorism and political violence and political theory in general.

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A major challenge in modern photonics and nano-optics is the diffraction limit of light which does not allow field localisation into regions with dimensions smaller than half the wavelength. Localisation of light into nanoscale regions (beyond its diffraction limit) has applications ranging from the design of optical sensors and measurement techniques with resolutions as high as a few nanometres, to the effective delivery of optical energy into targeted nanoscale regions such as quantum dots, nano-electronic and nano-optical devices. This field has become a major research direction over the last decade. The use of strongly localised surface plasmons in metallic nanostructures is one of the most promising approaches to overcome this problem. Therefore, the aim of this thesis is to investigate the linear and non-linear propagation of surface plasmons in metallic nanostructures. This thesis will focus on two main areas of plasmonic research –– plasmon nanofocusing and plasmon nanoguiding. Plasmon nanofocusing – The main aim of plasmon nanofocusing research is to focus plasmon energy into nanoscale regions using metallic nanostructures and at the same time achieve strong local field enhancement. Various structures for nanofocusing purposes have been proposed and analysed such as sharp metal wedges, tapered metal films on dielectric substrates, tapered metal rods, and dielectric V-grooves in metals. However, a number of important practical issues related to nanofocusing in these structures still remain unclear. Therefore, one of the main aims of this thesis is to address two of the most important of issues which are the coupling efficiency and heating effects of surface plasmons in metallic nanostructures. The method of analysis developed throughout this thesis is a general treatment that can be applied to a diversity of nanofocusing structures, with results shown here for the specific case of sharp metal wedges. Based on the geometrical optics approximation, it is demonstrated that the coupling efficiency from plasmons generated with a metal grating into the nanofocused symmetric or quasi-symmetric modes may vary between ~50% to ~100% depending on the structural parameters. Optimal conditions for nanofocusing with the view to minimise coupling and dissipative losses are also determined and discussed. It is shown that the temperature near the tip of a metal wedge heated by nanosecond plasmonic pulses can increase by several hundred degrees Celsius. This temperature increase is expected to lead to nonlinear effects, self-influence of the focused plasmon, and ultimately self-destruction of the metal tip. This thesis also investigates a different type of nanofocusing structure which consists of a tapered high-index dielectric layer resting on a metal surface. It is shown that the nanofocusing mechanism that occurs in this structure is somewhat different from other structures that have been considered thus far. For example, the surface plasmon experiences significant backreflection and mode transformation at a cut-off thickness. In addition, the reflected plasmon shows negative refraction properties that have not been observed in other nanofocusing structures considered to date. Plasmon nanoguiding – Guiding surface plasmons using metallic nanostructures is important for the development of highly integrated optical components and circuits which are expected to have a superior performance compared to their electronicbased counterparts. A number of different plasmonic waveguides have been considered over the last decade including the recently considered gap and trench plasmon waveguides. The gap and trench plasmon waveguides have proven to be difficult to fabricate. Therefore, this thesis will propose and analyse four different modified gap and trench plasmon waveguides that are expected to be easier to fabricate, and at the same time acquire improved propagation characteristics of the guided mode. In particular, it is demonstrated that the guided modes are significantly screened by the extended metal at the bottom of the structure. This is important for the design of highly integrated optics as it provides the opportunity to place two waveguides close together without significant cross-talk. This thesis also investigates the use of plasmonic nanowires to construct a Fabry-Pérot resonator/interferometer. It is shown that the resonance effect can be achieved with the appropriate resonator length and gap width. Typical quality factors of the Fabry- Pérot cavity are determined and explained in terms of radiative and dissipative losses. The possibility of using a nanowire resonator for the design of plasmonic filters with close to ~100% transmission is also demonstrated. It is expected that the results obtained in this thesis will play a vital role in the development of high resolution near field microscopy and spectroscopy, new measurement techniques and devices for single molecule detection, highly integrated optical devices, and nanobiotechnology devices for diagnostics of living cells.