941 resultados para Chaotic component
Resumo:
This paper is a deductive theoretical enquiry into the flow of effects from the geometry of price bubbles/busts, to price indices, to pricing behaviours of sellers and buyers, and back to price bubbles/busts. The intent of the analysis is to suggest analytical approaches to identify the presence, maturity, and/or sustainability of a price bubble. We present a pricing model to emulate market behaviour, including numeric examples and charts of the interaction of supply and demand. The model extends into dynamic market solutions myopic (single- and multi-period) backward looking rational expectations to demonstrate how buyers and sellers interact to affect supply and demand and to show how capital gain expectations can be a destabilising influence – i.e. the lagged effects of past price gains can drive the market price away from long-run market-worth. Investing based on the outputs of past price-based valuation models appear to be more of a game-of-chance than a sound investment strategy.
Resumo:
Much research has investigated the differences between option implied volatilities and econometric model-based forecasts. Implied volatility is a market determined forecast, in contrast to model-based forecasts that employ some degree of smoothing of past volatility to generate forecasts. Implied volatility has the potential to reflect information that a model-based forecast could not. This paper considers two issues relating to the informational content of the S&P 500 VIX implied volatility index. First, whether it subsumes information on how historical jump activity contributed to the price volatility, followed by whether the VIX reflects any incremental information pertaining to future jump activity relative to model-based forecasts. It is found that the VIX index both subsumes information relating to past jump contributions to total volatility and reflects incremental information pertaining to future jump activity. This issue has not been examined previously and expands our understanding of how option markets form their volatility forecasts.
Resumo:
The development of research data management infrastructure and services and making research data more discoverable and accessible to the research community is a key priority at the national, state and individual university level. This paper will discuss and reflect upon a collaborative project between Griffith University and the Queensland University of Technology to commission a Metadata Hub or Metadata Aggregation service based upon open source software components. It will describe the role that metadata aggregation services play in modern research infrastructure and argue that this role is a critical one.
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Developmental progression and differentiation of distinct cell types depend on the regulation of gene expression in space and time. Tools that allow spatial and temporal control of gene expression are crucial for the accurate elucidation of gene function. Most systems to manipulate gene expression allow control of only one factor, space or time, and currently available systems that control both temporal and spatial expression of genes have their limitations. We have developed a versatile two-component system that overcomes these limitations, providing reliable, conditional gene activation in restricted tissues or cell types. This system allows conditional tissue-specific ectopic gene expression and provides a tool for conditional cell type- or tissue-specific complementation of mutants. The chimeric transcription factor XVE, in conjunction with Gateway recombination cloning technology, was used to generate a tractable system that can efficiently and faithfully activate target genes in a variety of cell types. Six promoters/enhancers, each with different tissue specificities (including vascular tissue, trichomes, root, and reproductive cell types), were used in activation constructs to generate different expression patterns of XVE. Conditional transactivation of reporter genes was achieved in a predictable, tissue-specific pattern of expression, following the insertion of the activator or the responder T-DNA in a wide variety of positions in the genome. Expression patterns were faithfully replicated in independent transgenic plant lines. Results demonstrate that we can also induce mutant phenotypes using conditional ectopic gene expression. One of these mutant phenotypes could not have been identified using noninducible ectopic gene expression approaches.
Resumo:
We report the long term outcome of the flangeless, cemented all polyethylene Exeter cup at a mean of 14.6 years (range 10-17) after operation. Of the 263 hips in 243 patients, 122 hips are still in situ, 112 patients (119 hips) have died, eighteen hips were revised, and three patients (four hips) had moved abroad and were lost to follow-up (1.5%). Radiographs demonstrated two sockets had migrated and six more had radiolucent lines in all three zones. The Kaplan Meier survivorship at 15 years with endpoint revision for all causes is 89.9% (95% CI 84.6 to 95.2%) and for aseptic cup loosening or lysis 91.7% (CI 86.6 to 96.8%). In 210 hips with a diagnosis of primary osteoarthritis survivorship for all causes is 93.2% (95% CI 88.1 to 98.3%), and for aseptic cup loosening 95.0% (CI 90.3 to 99.7%). The cemented all polyethylene Exeter cup has an excellent long-term survivorship.
Resumo:
Background: The “Curriculum renewal in legal education” project has been funded by the Australian Learning and Teaching Council with the core objectives being the articulation of a set of final year curriculum design principles, and the development of a model of a transferable final year program. Through these principles and the development of the model, it is anticipated that the final year experience for law students will provide greater opportunity for them to understand the relevance of their learning, and will enhance their capacity to make decisions regarding their career path. Discussion / Argument: This paper reports on the project’s progress to date, and presents an argument for the inclusion of work integrated learning (WIL) as a component of the final year experience in undergraduate law programs. The project has identified that the two principal objectives of capstone experiences are to provide closure and to facilitate transition to post-university life. Reflective practice and Bruner’s spiral curriculum model are the central theoretical foundations by which these objectives can be achieved. Experiential learning is also increasingly seen as an essential element of a capstone experience. WIL is consistent with the objectives of capstones in focusing on the transition to professional practice and providing opportunities for reflection. However, the ability of WIL to meet all of the objectives of capstones, particularly closure and integration, may be limited. Conclusions / Implications: The paper posits that while WIL should be considered as a potential component of a capstone experience, educators should ensure that WIL is not equated with a capstone experience unless it is carefully designed to ensure that all of the objectives of capstones are met. Keywords: Work-integrated learning, capstone, final year experience, law
Resumo:
Maintenance activities in a large-scale engineering system are usually scheduled according to the lifetimes of various components in order to ensure the overall reliability of the system. Lifetimes of components can be deduced by the corresponding probability distributions with parameters estimated from past failure data. While failure data of the components is not always readily available, the engineers have to be content with the primitive information from the manufacturers only, such as the mean and standard deviation of lifetime, to plan for the maintenance activities. In this paper, the moment-based piecewise polynomial model (MPPM) are proposed to estimate the parameters of the reliability probability distribution of the products when only the mean and standard deviation of the product lifetime are known. This method employs a group of polynomial functions to estimate the two parameters of the Weibull Distribution according to the mathematical relationship between the shape parameter of two-parameters Weibull Distribution and the ratio of mean and standard deviation. Tests are carried out to evaluate the validity and accuracy of the proposed methods with discussions on its suitability of applications. The proposed method is particularly useful for reliability-critical systems, such as railway and power systems, in which the maintenance activities are scheduled according to the expected lifetimes of the system components.