960 resultados para mediation and moderation models


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BACKGROUND: Homeopathy is a major modality in complementary and alternative medicine. Significant tensions exist between homeopathic practice and education, evident in the diversity of practice styles and pedagogic models. Utilizing clinical reasoning knowledge in conventional medicine and allied health sciences, this article seeks to identify and critique existing research in this important area. MATERIALS AND METHODS: A literature search utilizing MEDLINE,(®) Allied and Complementary Medicine (AMED), and CINAHL(®) (Cumulative Index to Nursing and Allied Health Literature) was conducted. Key terms including clinical thinking, clinical reasoning, decision-making, homeopathy, and complementary medicine were utilized. A critical appraisal of the evidence was undertaken. RESULTS: Four (4) studies have examined homeopathic clinical reasoning. Two (2) studies sought to measure and quantify homeopathic reasoning. One (1) study proposed a reasoning model, based on pattern recognition, hypothetico-deductive reasoning, intuition, and remedy-matching (PHIR-M), resembling much that has been previously mapped in conventional medical reasoning research. The fourth closely investigated the meaning and use of intuition in homeopathic decision-making. CONCLUSIONS: Taken together, these four studies provide valuable insight into what is currently known about homeopathic clinical reasoning. However, despite the history and breadth of practice, little is known about homeopathic clinical reasoning and decision-making. Building on the research would require viewing clinical reasoning not only as a cognitive phenomenon but also as a situated and interactive one. Further research into homeopathic clinical reasoning is indicated.

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PEOPLE COMMUNICATE AND MAKE meaning through the use of the signs, codes and rules of their community and its language/s. On the way to learning these signs, codes and rules, children often create or invent their own unique and sometimes temporary systems of meaning making. In this paper we use Vygotsky’s concept of semiotic mediation and Bernstein’s code theory to reflect on some examples of children’s creative approaches to communication that involved the creation and use of signs. We will argue that young language learners’ invention of their own languages and creative use of drawing as a form of sign creation are symbolic expressions of their intent to generate and reinforce desired social and cultural situations of learning. We conclude that individuals mediate social and individual functioning in order to make meaning of their world, and argue for a move away from viewing second language learning and emergent writing as static sets of abilities to a more dynamic interpretation.

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Model transformations are a crucial part of Model-Driven Engineering (MDE) technologies but are usually hard to specify and maintain for many engineers. Most current approaches use meta-model-driven transformation specification via textual scripting languages. These are often hard to specify, understand and maintain. We present a novel approach that instead allows domain experts to discover and specify transformation correspondences using concrete visualizations of example source and target models. From these example model correspondences, complex model transformation implementations are automatically generated. We also introduce a recommender system that helps domain experts and novice users find possible correspondences between large source and target model visualization elements. Correspondences are then specified by directly interacting with suggested recommendations or drag and drop of visual notational elements of source and target visualizations. We have implemented this approach in our prototype tool-set, CONVErT, and applied it to a variety of model transformation examples. Our evaluation of this approach includes a detailed user study of our tool and a quantitative analysis of the recommender system.

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This work presents a hybrid controller based on the combination of fuzzy logic control (FLC) mechanism and internal model-based control (IMC). Neural network-based inverse and forward models are developed for IMC. After designing the FLC and IMC independently, they are combined in parallel to produce a single control signal. Mean averaging mechanism is used to combine the prediction of both controllers. Finally, performance of the proposed hybrid controller is studied for a nonlinear numerical plant model (NNPM). Simulation result shows the proposed hybrid controller outperforms both FLC and IMC.

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This paper describes a multi-level system dynamics (SD) / discrete event simulation (DES) approach for assessing planning and scheduling problems within an aviation training continuum. The aviation training continuum is a complex system, consisting of multiple aviation schools interacting through interschool student and instructor flows that are affected by external triggers such as resource availability and the weather.
SD was used to model the overall training continuum at a macro level to ascertain relationships between system entities. SD also assisted in developing a shared understanding of the training continuum, which involves constructing the definitions of the training requirements, resources and policy objectives. An end-to-end model of the continuum is easy to relate to, while dynamic visualisation of system behaviour provides a method for exploration of the model.
DES was used for micro level exploration of an individual school within the training continuum to capture the physical aspects of the system including resource capacity requirements, bottlenecks and student waiting times. It was also used to model stochastic events such as weather and student availability. DES has the advantage of being able to represent system variability and accurately reflect the limitations imposed on a system by resource constraints.
Through sharing results between the models, we demonstrate a multi-level approach to the analysis of the overall continuum. The SD model provides the school’s targeted demand to the DES model. The detailed DES model is able to assess schedules in the presence of resource constraints and variability and provide the expected capacity of a school to the high level SD model, subjected to constraints such as instructor availability or budgeted number of training systems. The SD model allows stakeholders to assess how policy and planning affect the continuum, both in the short and the long term.
The development of this approach permits moving the analysis of the continuum between SD and DES models as appropriate for given system entities, scales and tasks. The resultant model outcomes are propagated between the continuum and the detailed DES model, iteratively generating an assessment of the entire set of plans and schedule across the continuum. Combining data and information between SD and DES models and techniques assures relevance to the stakeholder needs and effective problem scoping and scaling that can also evolve with dynamic architecture and policy requirements.
An example case study shows the combined use of the two models and how they are used to evaluate a typical scenario where increased demand is placed on the training continuum. The multi-level approach provides a high level indication of training requirements to the model of the new training school, where the detailed model indicates the resources required to achieve those particular student levels.

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The evidence underpinning the developmental origins of health and disease (DOHaD) is overwhelming. As the emphasis shifts more towards interventions and the translational strategies for disease prevention, it is important to capitalize on collaboration and knowledge sharing to maximize opportunities for discovery and replication. DOHaD meetings are facilitating this interaction. However, strategies to perpetuate focussed discussions and collaborations around and between conferences are more likely to facilitate the development of DOHaD research. For this reason, the DOHaD Society of Australia and New Zealand (DOHaD ANZ) has initiated themed Working Groups, which convened at the 2014-2015 conferences. This report introduces the DOHaD ANZ Working Groups and summarizes their plans and activities. One of the first Working Groups to form was the ActEarly birth cohort group, which is moving towards more translational goals. Reflecting growing emphasis on the impact of early life biodiversity - even before birth - we also have a Working Group titled Infection, inflammation and the microbiome. We have several Working Groups exploring other major non-cancerous disease outcomes over the lifespan, including Brain, behaviour and development and Obesity, cardiovascular and metabolic health. The Epigenetics and Animal Models Working Groups cut across all these areas and seeks to ensure interaction between researchers. Finally, we have a group focussed on 'Translation, policy and communication' which focusses on how we can best take the evidence we produce into the community to effect change. By coordinating and perpetuating DOHaD discussions in this way we aim to enhance DOHaD research in our region.

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This study presents an approach to combine uncertainties of the hydrological model outputs predicted from a number of machine learning models. The machine learning based uncertainty prediction approach is very useful for estimation of hydrological models' uncertainty in particular hydro-metrological situation in real-time application [1]. In this approach the hydrological model realizations from Monte Carlo simulations are used to build different machine learning uncertainty models to predict uncertainty (quantiles of pdf) of the a deterministic output from hydrological model . Uncertainty models are trained using antecedent precipitation and streamflows as inputs. The trained models are then employed to predict the model output uncertainty which is specific for the new input data. We used three machine learning models namely artificial neural networks, model tree, locally weighted regression to predict output uncertainties. These three models produce similar verification results, which can be improved by merging their outputs dynamically. We propose an approach to form a committee of the three models to combine their outputs. The approach is applied to estimate uncertainty of streamflows simulation from a conceptual hydrological model in the Brue catchment in UK and the Bagmati catchment in Nepal. The verification results show that merged output is better than an individual model output. [1] D. L. Shrestha, N. Kayastha, and D. P. Solomatine, and R. Price. Encapsulation of parameteric uncertainty statistics by various predictive machine learning models: MLUE method, Journal of Hydroinformatic, in press, 2013.

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The Short-term Water Information and Forecasting Tools (SWIFT) is a suite of tools for flood and short-term streamflow forecasting, consisting of a collection of hydrologic model components and utilities. Catchments are modeled using conceptual subareas and a node-link structure for channel routing. The tools comprise modules for calibration, model state updating, output error correction, ensemble runs and data assimilation. Given the combinatorial nature of the modelling experiments and the sub-daily time steps typically used for simulations, the volume of model configurations and time series data is substantial and its management is not trivial. SWIFT is currently used mostly for research purposes but has also been used operationally, with intersecting but significantly different requirements. Early versions of SWIFT used mostly ad-hoc text files handled via Fortran code, with limited use of netCDF for time series data. The configuration and data handling modules have since been redesigned. The model configuration now follows a design where the data model is decoupled from the on-disk persistence mechanism. For research purposes the preferred on-disk format is JSON, to leverage numerous software libraries in a variety of languages, while retaining the legacy option of custom tab-separated text formats when it is a preferred access arrangement for the researcher. By decoupling data model and data persistence, it is much easier to interchangeably use for instance relational databases to provide stricter provenance and audit trail capabilities in an operational flood forecasting context. For the time series data, given the volume and required throughput, text based formats are usually inadequate. A schema derived from CF conventions has been designed to efficiently handle time series for SWIFT.

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New business and technology platforms are required to sustainably manage urban water resources [1,2]. However, any proposed solutions must be cognisant of security, privacy and other factors that may inhibit adoption and hence impact. The FP7 WISDOM project (funded by the European Commission - GA 619795) aims to achieve a step change in water and energy savings via the integration of innovative Information and Communication Technologies (ICT) frameworks to optimize water distribution networks and to enable change in consumer behavior through innovative demand management and adaptive pricing schemes [1,2,3]. The WISDOM concept centres on the integration of water distribution, sensor monitoring and communication systems coupled with semantic modelling (using ontologies, potentially connected to BIM, to serve as intelligent linkages throughout the entire framework) and control capabilities to provide for near real-time management of urban water resources. Fundamental to this framework are the needs and operational requirements of users and stakeholders at domestic, corporate and city levels and this requires the interoperability of a number of demand and operational models, fed with data from diverse sources such as sensor networks and crowsourced information. This has implications regarding the provenance and trustworthiness of such data and how it can be used in not only the understanding of system and user behaviours, but more importantly in the real-time control of such systems. Adaptive and intelligent analytics will be used to produce decision support systems that will drive the ability to increase the variability of both supply and consumption [3]. This in turn paves the way for adaptive pricing incentives and a greater understanding of the water-energy nexus. This integration is complex and uncertain yet being typical of a cyber-physical system, and its relevance transcends the water resource management domain. The WISDOM framework will be modeled and simulated with initial testing at an experimental facility in France (AQUASIM – a full-scale test-bed facility to study sustainable water management), then deployed and evaluated in in two pilots in Cardiff (UK) and La Spezia (Italy). These demonstrators will evaluate the integrated concept providing insight for wider adoption.

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In this paper, we test a version of the conditional CAPM with respect to a local market portfolio, proxied by the Brazilian stock index during the period 1976-1992. We also test a conditional APT modeI by using the difference between the 3-day rate (Cdb) and the overnight rate as a second factor in addition to the market portfolio in order to capture the large inflation risk present during this period. The conditional CAPM and APT models are estimated by the Generalized Method of Moments (GMM) and tested on a set of size portfolios created from individual securities exchanged on the Brazilian markets. The inclusion of this second factor proves to be important for the appropriate pricing of the portfolios.

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This paper presents evidence on the key role of infrastructure in the Andean Community trade patterns. Three distinct but related gravity models of bilateral trade are used. The first model aims at identifying the importance of the Preferential Trade Agreement and adjacency on intra-regional trade, while also checking the traditional roles of economic size and distance. The second and third models also assess the evolution of the Trade Agreement and the importance of sharing a common border, but their main goal is to analyze the relevance of including infrastructure in the augmented gravity equation, testing the theoretical assumption that infrastructure endowments, by reducing trade and transport costs, reduce “distance” between bilateral partners. Indeed, if one accepts distance as a proxy for transportation costs, infrastructure development and improvement drastically modify it. Trade liberalization eliminates most of the distortions that a protectionist tariff system imposes on international business; hence transportation costs represent nowadays a considerably larger barrier to trade than in past decades. As new trade pacts are being negotiated in the Americas, borders and old agreements will lose significance; trade among countries will be nearly without restrictions, and bilateral flows will be defined in terms of costs and competitiveness. Competitiveness, however, will only be achieved by an improvement in infrastructure services at all points in the production-distribution chain.

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This paper studies the Bankruptcy Law in Latin America, focusing on the Brazilian reform. We start with a review of the international literature and its evolution on this subject. Next, we examine the economic incentives associated with several aspects of bankruptcy laws and insolvency procedures in general, as well as the trade-offs involved. After this theoretical discussion, we evaluate empirically the current stage of the quality of insolvency procedures in Latin America using data from Doing Business and World Development Indicators, both from World Bank and International Financial Statistics from IMF. We find that the region is governed by an inefficient law, even when compared with regions of lower per capita income. As theoretical and econometric models predict, this inefficiency has severe consequences for credit markets and the cost of capital. Next, we focus on the recent Brazilian bankruptcy reform, analyzing its main changes and possible effects over the economic environment. The appendix describes difficulties of this process of reform in Brazil, and what other Latin American countries can possibly learn from it.

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Behavioral finance, or behavioral economics, consists of a theoretical field of research stating that consequent psychological and behavioral variables are involved in financial activities such as corporate finance and investment decisions (i.e. asset allocation, portfolio management and so on). This field has known an increasing interest from scholar and financial professionals since episodes of multiple speculative bubbles and financial crises. Indeed, practical incoherencies between economic events and traditional neoclassical financial theories had pushed more and more researchers to look for new and broader models and theories. The purpose of this work is to present the field of research, still ill-known by a vast majority. This work is thus a survey that introduces its origins and its main theories, while contrasting them with traditional finance theories still predominant nowadays. The main question guiding this work would be to see if this area of inquiry is able to provide better explanations for real life market phenomenon. For that purpose, the study will present some market anomalies unsolved by traditional theories, which have been recently addressed by behavioral finance researchers. In addition, it presents a practical application of portfolio management, comparing asset allocation under the traditional Markowitz’s approach to the Black-Litterman model, which incorporates some features of behavioral finance.

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Asset allocation decisions and value at risk calculations rely strongly on volatility estimates. Volatility measures such as rolling window, EWMA, GARCH and stochastic volatility are used in practice. GARCH and EWMA type models that incorporate the dynamic structure of volatility and are capable of forecasting future behavior of risk should perform better than constant, rolling window volatility models. For the same asset the model that is the ‘best’ according to some criterion can change from period to period. We use the reality check test∗ to verify if one model out-performs others over a class of re-sampled time-series data. The test is based on re-sampling the data using stationary bootstrapping. For each re-sample we check the ‘best’ model according to two criteria and analyze the distribution of the performance statistics. We compare constant volatility, EWMA and GARCH models using a quadratic utility function and a risk management measurement as comparison criteria. No model consistently out-performs the benchmark.

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A quantificação do risco país – e do risco político em particular – levanta várias dificuldades às empresas, instituições, e investidores. Como os indicadores econômicos são atualizados com muito menos freqüência do que o Facebook, compreender, e mais precisamente, medir – o que está ocorrendo no terreno em tempo real pode constituir um desafio para os analistas de risco político. No entanto, com a crescente disponibilidade de “big data” de ferramentas sociais como o Twitter, agora é o momento oportuno para examinar os tipos de métricas das ferramentas sociais que estão disponíveis e as limitações da sua aplicação para a análise de risco país, especialmente durante episódios de violência política. Utilizando o método qualitativo de pesquisa bibliográfica, este estudo identifica a paisagem atual de dados disponíveis a partir do Twitter, analisa os métodos atuais e potenciais de análise, e discute a sua possível aplicação no campo da análise de risco político. Depois de uma revisão completa do campo até hoje, e tendo em conta os avanços tecnológicos esperados a curto e médio prazo, este estudo conclui que, apesar de obstáculos como o custo de armazenamento de informação, as limitações da análise em tempo real, e o potencial para a manipulação de dados, os benefícios potenciais da aplicação de métricas de ferramentas sociais para o campo da análise de risco político, particularmente para os modelos qualitativos-estruturados e quantitativos, claramente superam os desafios.