993 resultados para Armington Assumption


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This paper will investigate the suitability of existing performance measures under the assumption of a clearly defined benchmark. A range of measures are examined including the Sortino Ratio, the Sharpe Selection ratio (SSR), the Student’s t-test and a decay rate measure. A simulation study is used to assess the power and bias of these measures based on variations in sample size and mean performance of two simulated funds. The Sortino Ratio is found to be the superior performance measure exhibiting more power and less bias than the SSR when the distribution of excess returns are skewed.

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In this paper, we present a finite sample analysis of the sample minimum-variance frontier under the assumption that the returns are independent and multivariate normally distributed. We show that the sample minimum-variance frontier is a highly biased estimator of the population frontier, and we propose an improved estimator of the population frontier. In addition, we provide the exact distribution of the out-of-sample mean and variance of sample minimum-variance portfolios. This allows us to understand the impact of estimation error on the performance of in-sample optimal portfolios. Key Words: minimum-variance frontier; efficiency set constants; finite sample distribution

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This article rebuts the still-common assumption that managers of capitalist entities have a duty, principally or even exclusively, to maximise the monetary return to investors on their investments. It argues that this view is based on a misleadingly simplistic conception of human values and motivation. Not only is acting solely to maximise long-term shareholder value difficult, it displays, at best, banal single-mindedness and, at worst, sociopathy. In fact, real investors and managers have rich constellations of values that should be taken account of in all their decisions, including their business decisions. Awareness of our values, and public expression of our commitment to exemplify them, make for healthier investment and, in the long term, a healthier corporate world. Individuals and funds investing on the basis of such values, in companies that express their own, display humanity rather than pathology. Preamble I always enjoyed the discussions that Michael Whincop and I had about the interaction of ethics and economics. Each of us could see an important role for these disciplines, as well as our common discipline of law. We also shared an appreciation of the institutional context within which much of the drama of life is played out. In understanding the behaviour of individuals and the choices they make, it seemed axiomatic to each of us that ethics and economics have a lot to say. This was also true of the institutions in which they operate. Michael ·had a strong interest in 'the new institutional economics' I and I had a strong interest in 'institutionalising ethics' right through the 1990s.' This formed the basis of some fascinating and fruitful discussions. Professor Charles Sampford is Director, Key Centre for Ethics, Law, Justice and Governance, Foundation Professor of Law at Griffith University and President, International Institute for Public Ethics.DrVirginia Berry is a Research Fellow at theKey Centre for Ethics, Law,Justice andGovernance, Griffith University. Oliver Williamson, one of the leading proponents of the 'new institutional economics', published a number of influential works - see Williamson (1975, 1995,1996). Sampford (1991),' pp 185-222. The primary focus of discussions on institutionalising ethics has been in public sectorethics: see, for example, Preston and Sampford (2002); Sampford (1994), pp 114-38. Some discussion has, however, moved beyond the public sector to include business - see Sampford 200408299

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Road features extraction from remote sensed imagery has been a long-term topic of great interest within the photogrammetry and remote sensing communities for over three decades. The majority of the early work only focused on linear feature detection approaches, with restrictive assumption on image resolution and road appearance. The widely available of high resolution digital aerial images makes it possible to extract sub-road features, e.g. road pavement markings. In this paper, we will focus on the automatic extraction of road lane markings, which are required by various lane-based vehicle applications, such as, autonomous vehicle navigation, and lane departure warning. The proposed approach consists of three phases: i) road centerline extraction from low resolution image, ii) road surface detection in the original image, and iii) pavement marking extraction on the generated road surface. The proposed method was tested on the aerial imagery dataset of the Bruce Highway, Queensland, and the results demonstrate the efficiency of our approach.

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This was a two-year project focusing on internationalising the curriculum within the context of the QUT Graduate Capabilities and teaching and learning issues within three Faculties. It was based on the assumption that there is an increased need for social and cultural responsiveness in curriculum that intersects local, national and global contexts and priorities. The Internationalising the Curriculum Project sought to challenge and support staff (academic and general) and students to engage with complex concepts of identity, values, awareness and sensitivity as they relate to internationalising the curriculum. The project took a case study approach to planning, implementation and evaluation in a way that complements and enhances platforms developed and emerging from the Indigenous Perspectives and cultural diversity projects already underway in Education, Creative Industries and QUT, Carseldine.

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This article presents a survey of authorisation models and considers their ‘fitness-for-purpose’ in facilitating information sharing. Network-supported information sharing is an important technical capability that underpins collaboration in support of dynamic and unpredictable activities such as emergency response, national security, infrastructure protection, supply chain integration and emerging business models based on the concept of a ‘virtual organisation’. The article argues that present authorisation models are inflexible and poorly scalable in such dynamic environments due to their assumption that the future needs of the system can be predicted, which in turn justifies the use of persistent authorisation policies. The article outlines the motivation and requirement for a new flexible authorisation model that addresses the needs of information sharing. It proposes that a flexible and scalable authorisation model must allow an explicit specification of the objectives of the system and access decisions must be made based on a late trade-off analysis between these explicit objectives. A research agenda for the proposed Objective-based Access Control concept is presented.

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Information Retrieval is an important albeit imperfect component of information technologies. A problem of insufficient diversity of retrieved documents is one of the primary issues studied in this research. This study shows that this problem leads to a decrease of precision and recall, traditional measures of information retrieval effectiveness. This thesis presents an adaptive IR system based on the theory of adaptive dual control. The aim of the approach is the optimization of retrieval precision after all feedback has been issued. This is done by increasing the diversity of retrieved documents. This study shows that the value of recall reflects this diversity. The Probability Ranking Principle is viewed in the literature as the “bedrock” of current probabilistic Information Retrieval theory. Neither the proposed approach nor other methods of diversification of retrieved documents from the literature conform to this principle. This study shows by counterexample that the Probability Ranking Principle does not in general lead to optimal precision in a search session with feedback (for which it may not have been designed but is actively used). Retrieval precision of the search session should be optimized with a multistage stochastic programming model to accomplish the aim. However, such models are computationally intractable. Therefore, approximate linear multistage stochastic programming models are derived in this study, where the multistage improvement of the probability distribution is modelled using the proposed feedback correctness method. The proposed optimization models are based on several assumptions, starting with the assumption that Information Retrieval is conducted in units of topics. The use of clusters is the primary reasons why a new method of probability estimation is proposed. The adaptive dual control of topic-based IR system was evaluated in a series of experiments conducted on the Reuters, Wikipedia and TREC collections of documents. The Wikipedia experiment revealed that the dual control feedback mechanism improves precision and S-recall when all the underlying assumptions are satisfied. In the TREC experiment, this feedback mechanism was compared to a state-of-the-art adaptive IR system based on BM-25 term weighting and the Rocchio relevance feedback algorithm. The baseline system exhibited better effectiveness than the cluster-based optimization model of ADTIR. The main reason for this was insufficient quality of the generated clusters in the TREC collection that violated the underlying assumption.

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The call to innovate is ubiquitous across the Australian educational policy context. The claims of innovative practices and environments that occur frequently in university mission statements, strategic plans and marketing literature suggest that this exhortation to innovate appears to have been taken up enthusiastically by the university sector. Throughout the history of universities, a range of reported deficiencies of higher education have worked to produce a notion of crisis. At present, it would seem that innovation is positioned as the solution to the notion of crisis. This thesis is an inquiry into how the insistence on innovation works to both enable and constrain teaching and learning practices in Australian universities. Alongside the interplay between innovation and crisis is the link between resistance and innovation, a link which remains largely unproblematized in the scholarly literature. This thesis works to locate and unsettle understandings of a relationship between innovation and Australian higher education. The aim of this inquiry is to generate new understandings of what counts as innovation within this context and how innovation is enacted. The thesis draws on a number of postmodernist theorists, whose works have informed firstly the research method, and then the analysis and findings. Firstly, there is an assumption that power is capillary and works through discourse to enact power relations which shape certain truths (Foucault, 1990). Secondly, this research scrutinised language practices which frame the capacity for individuals to act, alongside the language practices which encourage an individual to adopt certain attitudes and actions as one’s own (Foucault, 1988). Thirdly, innovation talk is read in this thesis as an example of needs talk, that is, as a medium through which what is considered domestic, political or economic is made and contested (Fraser, 1989). Fourthly, relationships between and within discourses were identified and analysed beyond cause and effect descriptions, and more productively considered to be in a constant state of becoming (Deleuze, 1987). Finally, the use of ironic research methods assisted in producing alternate configurations of innovation talk which are useful and new (Rorty, 1989). The theoretical assumptions which underpin this thesis inform a document analysis methodology, used to examine how certain texts work to shape the ways in which innovation is constructed. The data consisted of three Federal higher education funding policies selected on the rationale that these documents, as opposed to state or locally based policy and legislation, represent the only shared policy context for all Australian universities. The analysis first provided a modernist reading of the three documents, and this was followed by postmodernist readings of these same policy documents. The modernist reading worked to locate and describe the current truths about innovation. The historical context in which the policy was produced as well as the textual features of the document itself were important to this reading. In the first modernist reading, the binaries involved in producing proper and improper notions of innovation were described and analysed. In the process of the modernist analysis and the subsequent location of binary organisation, a number of conceptual collisions were identified, and these sites of struggle were revisited, through the application of a postmodernist reading. By applying the theories of Rorty (1989) and Fraser (1989) it became possible to not treat these sites as contradictory and requiring resolution, but rather as spaces in which binary tensions are necessary and productive. This postmodernist reading constructed new spaces for refusing and resisting dominant discourses of innovation which value only certain kinds of teaching and learning practices. By exploring a number of ironic language practices found within the policies, this thesis proposes an alternative way of thinking about what counts as innovation and how it happens. The new readings of innovation made possible through the work of this thesis were in response to a suite of enduring, inter-related questions – what counts as innovation?, who or what supports innovation?, how does innovation occur?, and who are the innovators?. The truths presented in response to these questions were treated as the language practices which constitute a dominant discourse of innovation talk. The collisions that occur within these truths were the contested sites which were of most interest for the analysis. The thesis concludes by presenting a theoretical blueprint which works to shift the boundaries of what counts as innovation and how it happens in a manner which is productive, inclusive and powerful. This blueprint forms the foundation upon which a number of recommendations are made for both my own professional practice and broader contexts. In keeping with the conceptual tone of this study, these recommendations are a suite of new questions which focus attention on the boundaries of innovation talk as an attempt to re-configure what is valued about teaching and learning at university.

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The assumption that the size, anonymity and weakened social controls of urban living generates social conflict, disorganization and higher rates of crime and violence has been an article of faith in much criminological and social scientific inquiry since the nineteenth century (i.e. Tönnies 1897; Shaw and McKay 1931; Levin and Lindesmith 1937; Nisbet 1970; Baldwin and Bottoms 1976; Felson 1994). The paper challenges this article of criminological faith and questions the utility of urban centric criminological theorizing about the causes of violence in rural settings. Drawing on descriptive data that show that rural men present a relatively high risk of inflicting harm upon themselves and others, this paper explores the larger socio-criminological question as to why this might be. The question is examined in relation to the processes of community formation that shape the everyday architecture of rural life. We explore how that architecture has historically valorized violent expressions of masculinity grounded in a relationship between men's bodies and the rural landscapes they inhabit - but how the legitimacy of these violent expressions are being challenged by sweeping social, economic and political changes. One psycho-social response to these sweeping social changes to rural life, we conclude, is a resort to violence as a largely strategic practice deployed to recreate an imagined rural gender order.

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Occidentalism, which treats the other as the same, can be detected in both the criminological and rural sociological treatment of violence in the sociospatial sites of rural countrysides. Criminology tends to mistakenly assume that violence in the modern world is primarily an urban phenomenon (Baldwin & Bottoms, 1976, p. 1; Braithwaite, 1989, p. 47). If violence in rural settings is encountered it tends to be treated as a smaller scale version of the urban problem, or the importation of an otherwise urban problem - as the corrupting influence of the gesellschaft within the gemeinschaft. Within much rural sociology violence is rendered invisible by the assumption that rural communities conform to the idealised conception of the typical gemeinschaft society, small-scale traditional societies based on strong cohesiveness, intimacy and organic forms of solidarity. What these bonds conceal, rather than reveal - violence within the family - remains invisible to the public gaze. The visibility of violence within Aboriginal families and communities presents a major exception to the spatially ordered social relations which render so much white family violence hidden. The need to take into account the complexity and diversity of these sociospatial relations is concretely highlighted in our research which has taken us out of the urban context and confronted us not only with the phenomenon of the violence of other rurals, but also with fundamentally competing claims on, and conceptions of, space and place in the context of a racially divided Australian interior. This article represents the second installment of conceptual reflections on this research, with the first having been published in this journal in 1998.

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The standard Blanchard-Quah (BQ) decomposition forces aggregate demand and supply shocks to be orthogonal. However, this assumption is problematic for a nation with an inflation target. The very notion of inflation targeting means that monetary policy reacts to changes in aggregate supply. This paper employs a modification of the BQ procedure that allows for correlated shifts in aggregate supply and demand. It is found that shocks to Australian aggregate demand and supply are highly correlated. The estimated shifts in the aggregate demand and supply curves are then used to measure the effects of inflation targeting on the Australian inflation rate and level of GDP.

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US state-based data breach notification laws have unveiled serious corporate and government failures regarding the security of personal information. These laws require organisations to notify persons who may be affected by an unauthorized acquisition of their personal information. Safe harbours to notification exist if personal information is encrypted. Three types of safe harbour have been identified in the literature: exemptions, rebuttable presumptions and factors. The underlying assumption of exemptions is that encrypted personal information is secure and therefore unauthorized access does not pose a risk. However, the viability of this assumption is questionable when examined against data breaches involving encrypted information and the demanding practical requirements of effective encryption management. Recent recommendations by the Australian Law Reform Commission (ALRC) would amend the Privacy Act 1988 (Cth) to implement a data breach scheme that includes a different type of safe harbour, factor based analysis. The authors examine the potential capability of the ALRC’s proposed encryption safe harbour in relation to the US experience at the state legislature level.

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DMAPS (Distributed Multi-Agent Planning System) is a planning system developed for distributed multi-robot teams based on MAPS (Multi-Agent Planning System). MAPS assumes that each agent has the same global view of the environment in order to determine the most suitable actions. This assumption fails when perception is local to the agents: each agent has only a partial and unique view of the environment. DMAPS addresses this problem by creating a probabilistic global view on each agent by fusing the perceptual information from each robot. The experimental results on consuming tasks show that while the probabilistic global view is not identical on each robot, the shared view is still effective in increasing performance of the team.

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In this paper, the optimal allocation and sizing of distributed generators (DGs) in a distribution system is studied. To achieve this goal, an optimization problem should be solved in which the main objective is to minimize the DGs cost and to maximise the reliability simultaneously. The active power balance between loads and DGs during the isolation time is used as a constraint. Another point considered in this process is the load shedding. It means that if the summation of DGs active power in a zone, isolated by the sectionalizers because of a fault, is less than the total active power of loads located in that zone, the program start shedding the loads in one-by-one using the priority rule still the active power balance is satisfied. This assumption decreases the reliability index, SAIDI, compared with the case loads in a zone are shed when total DGs power is less than the total load power. To validate the proposed method, a 17-bus distribution system is employed and the results are analysed.

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The literature on critical thinking in higher education is constructed around the fundamental assumption that, while regarded as essential, is neither clearly or commonly understood. There is elsewhere evidence that academics and students have differing perceptions of what happens in university classrooms, particularly in regard to higher order thinking. This paper reports on a small-scale investigation in a Faculty of Education at an Australian University into academic and student definitions and understandings of critical thinking. Our particular interest lay in the consistencies and disconnections assumed to exist between academic staff and students. The presumption might therefore be that staff and students perceive critical thinking in different ways and that this may limit its achievement as a critical graduate attribute. The key finding from this study, contrary to extant findings, is that academics and students did share substantively similar definitions and understandings of critical thinking.