900 resultados para other numerical approaches


Relevância:

30.00% 30.00%

Publicador:

Resumo:

This issue of Settler Colonial Studies comes out of a long-term collaboration between the guest editors which began, in earnest, with a panel on the theme of ‘Other People’s Country: Law, Water, Entitlement’ at the Cultural Studies Association of Australasia conference held at the University of Sydney in December 2012. The panel’s topic was drawn from our own work on encounters between settler and indigenous ‘laws’ over specific waters, including Lake Omapere in the Hokianga district of Aotearoa/New Zealand, Lake Okanagan in British Columbia, Canada, Lake Cayuga in upper New York State, and the Wenlock, Archer, Stewart and Lockhart rivers in far north Queensland, Australia.1 Further, the conference’s provocative title (Materialities: Economies, Empiricism, & Things) corresponded to our own interest in thinking through the entangled objects of law – legislation, policies, institutions, treaties and so on – that ‘govern’ waters and that make bodies of water ‘lawful’ within these settler colonial sites today. Informed by the theoretical interventions of cosmopolitics and political ecology, each opening up new approaches to questions of politics and ‘the political’, we were interested in attempting to locate these insights within material settler colonial ‘places’ rather than abstract structures of domination. A claim to water is not simply a claim to a resource. It is a claim to knowledge and to the constitution of place and therefore, in the terms of Isabelle Stengers, to the continued constitution of the past, present and future of a ‘real world’.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

There is a long-standing interest in behavioural ecology, exploring the causes and correlates of consistent individual differences in mean behavioural traits ('personality') and the response to the environment ('plasticity'). Recently, it has been observed that individuals also consistently differ in their residual intraindividual variability (rIIV). This variation will probably have broad biological and methodological implications to the study of trait variation in labile traits, such as behaviour and physiology, though we currently need studies to quantify variation in rIIV, using more standardized and powerful methodology. Focusing on activity rates in guppies (Poecilia reticulata), we provide a model example, from sampling design to data analysis, in how to quantify rIIV in labile traits. Building on the doubly hierarchical generalized linear model recently used to quantify individual differences in rIIV, we extend the model to evaluate the covariance between individual mean values and their rIIV. After accounting for time-related change in behaviour, our guppies substantially differed in rIIV, and it was the active individuals that tended to be more consistent (lower rIIV). We provide annotated data analysis code to implement these complex models, and discuss how to further generalize the model to evaluate covariances with other aspects of phenotypic variation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this work we analyze an optimal control problem for a system of two hydroelectric power stations in cascade with reversible turbines. The objective is to optimize the profit of power production while respecting the system’s restrictions. Some of these restrictions translate into state constraints and the cost function is nonconvex. This increases the complexity of the optimal control problem. The problem is solved numerically and two different approaches are adopted. These approaches focus on global optimization techniques (Chen-Burer algorithm) and on a projection estimation refinement method (PERmethod). PERmethod is used as a technique to reduce the dimension of the problem. Results and execution time of the two procedures are compared.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this article, the author discusses how she applied autoethnography in a study of the design of hypermedia educational resources and shows how she addressed problematic issues related to autoethnographic legitimacy and representation. The study covered a 6-year period during which the practitioner’s perspective on the internal and external factors influencing the creation of three hypermedia CD-ROMs contributed to an emerging theory of design. The author highlights the interrelationship between perception and reality as vital to qualitative approaches and encourages researchers to investigate their reality more fully by practicing the art of autoethnography.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

We generalize the classical notion of Vapnik–Chernovenkis (VC) dimension to ordinal VC-dimension, in the context of logical learning paradigms. Logical learning paradigms encompass the numerical learning paradigms commonly studied in Inductive Inference. A logical learning paradigm is defined as a set W of structures over some vocabulary, and a set D of first-order formulas that represent data. The sets of models of ϕ in W, where ϕ varies over D, generate a natural topology W over W. We show that if D is closed under boolean operators, then the notion of ordinal VC-dimension offers a perfect characterization for the problem of predicting the truth of the members of D in a member of W, with an ordinal bound on the number of mistakes. This shows that the notion of VC-dimension has a natural interpretation in Inductive Inference, when cast into a logical setting. We also study the relationships between predictive complexity, selective complexity—a variation on predictive complexity—and mind change complexity. The assumptions that D is closed under boolean operators and that W is compact often play a crucial role to establish connections between these concepts. We then consider a computable setting with effective versions of the complexity measures, and show that the equivalence between ordinal VC-dimension and predictive complexity fails. More precisely, we prove that the effective ordinal VC-dimension of a paradigm can be defined when all other effective notions of complexity are undefined. On a better note, when W is compact, all effective notions of complexity are defined, though they are not related as in the noncomputable version of the framework.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, a space fractional di®usion equation (SFDE) with non- homogeneous boundary conditions on a bounded domain is considered. A new matrix transfer technique (MTT) for solving the SFDE is proposed. The method is based on a matrix representation of the fractional-in-space operator and the novelty of this approach is that a standard discretisation of the operator leads to a system of linear ODEs with the matrix raised to the same fractional power. Analytic solutions of the SFDE are derived. Finally, some numerical results are given to demonstrate that the MTT is a computationally e±cient and accurate method for solving SFDE.