300 research outputs found
Assessment of 48 Stock markets using adaptive multifractal approach
Stock market comovements are examined using cointegration, Granger causality
tests and nonlinear approaches in context of mutual information and
correlations. Underlying data sets are affected by non-stationarities and
trends, we also apply AMF-DFA and AMF-DXA. We find only 170 pair of Stock
markets cointegrated, and according to the Granger causality and mutual
information, we realize that the strongest relations lies between emerging
markets, and between emerging and frontier markets. According to scaling
exponent given by AMF-DFA, , we find that all underlying data sets
belong to non-stationary process. According to EMH, only 8 markets are
classified in uncorrelated processes at confidence interval. 6 Stock
markets belong to anti-correlated class and dominant part of markets has memory
in corresponding daily index prices during January 1995 to February 2014.
New-Zealand with and Jordan with are far
from EMH. The nature of cross-correlation exponents based on AMF-DXA is almost
multifractal for all pair of Stock markets. The empirical relation, , is confirmed. Mentioned relation for is also
satisfied while for there is a deviation from this relation confirming
behavior of markets for small fluctuations is affected by contribution of major
pair. For larger fluctuations, the cross-correlation contains information from
both local and global conditions. Width of singularity spectrum for
auto-correlation and cross-correlation are and , respectively. The
wide range of singularity spectrum for cross-correlation confirms that the
bilateral relation between Stock markets is more complex. The value of
indicates that all pairs of stock market studied in this time
interval belong to cross-correlated processes.Comment: 16 pages, 13 figures and 4 tables, major revision and match to
published versio
Complex tasks, delegation, and flexibility: What role for engagement and shared leadership?
Task complexity is one of the main factors studied by academics and is at the center of leaders’ concerns. It is related to delegation and flexibility, which are enhanced by workers’ engagement and depend on how leadership is shared. In this context, this research was carried out with the main objective of testing the serial mediating effect of engagement and shared leadership on the relationship between task complexity and flexibility and the relationship between task complexity and delegation. The sample for this study consists of 368 participants, all of whom work in organizations based in Portugal. The results indicate that task complexity is positively and significantly associated with engagement, shared leadership, flexibility, and delegation. Shared leadership has a positive and significant association with flexibility and delegation. The serial mediating effect of engagement and shared leadership on the relationship between task complexity and flexibility was confirmed. The serial mediating effect of engagement and shared leadership on the relationship between task complexity and delegation was not confirmed.info:eu-repo/semantics/publishedVersio
Stability in the Pseudo-state Formalism of Discrete Systems Controlled in the Presence of Intermittent Sensor Faults
Trabalho apresentado em IFAC Workshop on Adaptation and Learning in Control and Signal Processing, 26-28 de Agosto de 2010, Antalya, Turquia.N/
Stability of Discrete Systems Controlled in the Presence ofIntermittent Sensor Faults
info:eu-repo/semantics/publishedVersio
Molecular dynamics in polymeric systems
It is well known that the properties of polymeric materials depend strongly upon their chemical structure. Other more specific factors that may be related to the chemical structure also determine the macroscopic behaviour of such materials, namely the relative position of the different segments of the polymeric chain, the molecular architecture (molecular weight distribution, branching, copoly-mer organisation, cross-linking extent, etc.), the crystalline environment and the pressure/temperature conditions. All these factors have a common impact in the material: they are strongly correlated to the mobility on the molecular level. That is why a huge amount of work has been devoted to the study of translational/rota-tional mobility that occurs within the polymeric chains. This review is intended to provide a brief survey on such kinds of mobilities, how they can be studied and what are their main characteristics. Examples on systems studied in our groups will be provided, obtained by dielectric and mechanical spectroscopies and differential scanning calorimetry. It will be mainly focused on molecular motions that occur in the solid phase (i.e., to temperatures up to the rubbery plateau). The dynamics in blends or copolymers will be avoided here, as they would deserve a special dis-cussion in their own context. Special attention will be paid to the glass transition and the mobility that occurs below and above it. The dynamics that are observed in peculiar systems, such as semi-crystalline or liquid crystalline polymers, will be addressed
Computing Parity Space Residuals’ Computational Form With MIMO Predictive Models
Trabalho apresentado em 12th Mediterranean Conference on Control and Automation MED’04, 6-9 de Junho de 2004, Kusadasi, Turquia.N/
Renovascular hypertension: a case with atypical neurological signs
Secondary hypertension is the most frequent form of hypertension in children. Renovascular disease accounts for 5-10% of all childhood hypertension and should be suspected in the presence of severe hypertension found difficult to manage with medical therapy. Uncontrolled hypertension can lead to severe target organ damage. We describe the case of a 13-month-old baby boy with failure to thrive, recent muscular weakness of the lower extremities and irritability. Hypertension was detected and he was admitted to the paediatric intensive care unit with a refractory hypertensive emergency, despite multiple antihypertensive therapies. Bilateral renal artery stenosis was diagnosed through renal angiography and balloon dilation was performed, leading to lower blood pressure. He is currently withdrawing from antihypertensive medication, and slowly gaining weight and recovering from target organ damage. However, weakness of the lower extremities persists and he has been diagnosed with a neurogenic bladde
Determination of phytoextraction potential of plant speciesfor toxic elements in soils of abandoned sulphide-mining areas
This study has determined contamination levels in soils and plants from the SaËœo Domingos mining area, Portugal, by k0-INAA. Total concentrations of As, Sb, Cr, Hg, Cu, Zn and Fe in soils were very high, exceeding the maximum limits in Portuguese legislation. Concentrations of toxic elements like As, Sb and Zn were highest in roots of Erica andevalensis, Juncus acutus, Agrostis castellana and Nicotiana glauca. Additionally, As, Br, Cr, Fe, Sb and Zn in all organs of most plants were above toxicity levels.
Those species that accumulated relatively high concentrations of toxic elements in roots (and tops) may be cultivated for phytostabilisation of similar areas
Formação e literatura : relatos sem fronteiras
O presente texto, resultado de uma pesquisa de caráter qualitativo-interpretativo, tem por objetivo contribuir para (re)pensar o papel do Ensino Superior na formação do professor de LÃngua Portuguesa, especificamente, na constituição do leitor literário, considerando a importância da experiência contÃnua e dinâmica na formação dos alunos de Letras – futuros mediadores de leitura literária em instituições de Educação Básica. Para tanto, se fez necessário compreender quais as razões que levam os alunos de
Letras, em fase de conclusão de curso, no perÃodo de Estágio Supervisionado, a expressarem insegurança, medo e despreparo para desenvolver práticas pedagógicas de leitura literária. Como foco de investigação, buscou-se perceber como esses alunos se veem, como veem o curso de Letras e o conteúdo estudado na Universidade frente ao contexto profissional e de formação em que se encontram. Assim, foram ouvidos dez estudantes brasileiros da Universidade Federal da Bahia e cinco alunos portugueses da Universidade do Minho, Braga. A entrevista semiestruturada e o diário de campo foram os recursos utilizados para a coleta dos dados. Como aporte teórico, os estudos de Leahy-Dios e Menezes(2001), DionÃsio (1990, 2004), Zilberman (1991), Todorov (2009), Perrone-Moisés (1998), Canário (2001), foram considerados. Os resultados desse estudo evidenciam a crise revelada pelos alunosprofessores, uma vez que, quando se encontram em perÃodo de Estágio Supervisionado, em práticas de ensino, na fase conclusiva da formação acadêmica para lecionar LÃngua Portuguesa, não conseguem estabelecer diálogo entre as teorias aprendidas nas aulas
de literatura e a prática pedagógica requerida para a mediação e formação de novos leitores literários.CAPES, B
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