4,773 research outputs found
Study of motivation in portuguese students
In adolescence, motivation is a predictive factor in academic success. Motivated students have higher levels of satisfaction in school, mobilizing interests and skills in various domains (Galinha, 2006). This study aimed to assess the existence of improvements in motivational dynamics in Portuguese adolescents by investigating if students who participated in the P-DMAR Programme displayed higher motivation levels relative to the control group in the domains present in the QME questionnaire. The School Motivation Questionnaire - QME (Cordeiro, 2010) was administered to two groups (experimental vs control) at two different phases, before and after participation in the P-DMAR. A sample of 86 students (n = 43 experimental group, n = 43 control group) were involved in the study. The statistical methodology consisted of a quantitative analysis of the QME using hypothesis tests for independent and paired samples. An α = 5% was set. The results showed that males were predominant (51.2%) with 29.1% of the respondents repeating. There was a statistically significant improvement in the six dimensions evaluated in the QME in the experimental group as opposed to the control group (p values <0.01). It was verified that the P-DMAR is a valuable programme with statistical significance (p <0.01) because the students participating in it saw their motivational capacities enhanced in the following six domains measured in the QME: strategies, extrinsic objectives of the teacher, extrinsic objectives of the student with external regulation, intrinsic objectives of the teacher, extrinsic objectives of the student with internal regulation and intrinsic objectives of the student.info:eu-repo/semantics/publishedVersio
Ancient tin production: Slags from the Iron Age Carvalhelhos hillfort (NW Iberian Peninsula)
Provenance and production of tin in the Ancient World has since long been a major topic of discussion among archaeologists. In Western Europe, where significant tin ore (cassiterite) deposits are known, only a few remains of ancient tin production, such as tin slags, have been detected. In the present work, elemental and microstructural analyses by WDXRF, SEM-EDS and XRD were performed on recently recognised tin slags from the Iron Age Carvalhelhos hillfort located in NW Iberia, a territory that represents the largest extension with tin mineralisation in Western Europe. Elemental and microstructural characterisation of cassiterite collected in a pilot field survey in the region of the hillfort are presented and discussed, as well as two ceramic fragments that could be part of a smelting structure and an iron slag from the settlement. Results show that the tin slags have variable but high contents in Sn, similarly to Pre-Medieval tin slags found in other Western European areas, but also high contents of Ta and Nb, which specifically distinguish them from other tin slags, such as those found in SW Britain. Tin ores from the hillfort region frequently have Ta and Nb in cassiterite solid solution or as inclusions of columbite group minerals, relating well with the Carvalhelhos tin slags. Up to present, the Carvalhelhos slags are amongst the very few ancient tin slags known in Western Europe, and their study can contribute to a better knowledge on ancient tin sources and trade routes
Bounds for Invariance Pressure
This paper provides an upper for the invariance pressure of control sets with
nonempty interior and a lower bound for sets with finite volume. In the special
case of the control set of a hyperbolic linear control system in R^{d} this
yields an explicit formula. Further applications to linear control systems on
Lie groups and to inner control sets are discussed.Comment: 16 page
Age Structure Explaining a Large Shift in Homicides: The Case of the State of São Paulo
After reaching a historic peak by the end of the 1990s, homicides in large cities in the state of São Paulo dropped sharply. Several explanations have been advanced, most prominently improvements in policing, adoption of policies such as dry laws, and increased incarceration. In this paper, we show that demographic changes play a large role in explaining the dynamics of homicide. More specifically, we present evidence of a strong co-movement between the proportion of males on the 15-25 age bracket and homicides at the statewide and at city levels, and argue that the relationship is causal. We estimate that a 1% increase in the proportion of 15-to-24-year-old males causes a 4.5% increase in homicides.Age Structure, Demographic Change, Homicides
Tools and libraries to model and manipulate circular programs
This paper presents techniques to model circular lazy programs in a strict, purely functional setting. Circular lazy programs model any algorithm based on multiple traversals over a recursive data structure as a single traversal function. Such elegant and concise circular programs are defined in a (strict or lazy) functional language and they are transformed into efficient strict and deforested, multiple traversal programs by using attribute grammars-based techniques. Moreover, we use standard slicing techniques to slice such circular lazy programs. We have expressed these transformations as an Haskell library and two tools have been constructed: the HaCirctool that refactors Haskell lazy circular programs into strict ones, and the OCirctool that extends Ocaml with circular definitions allowing programmers to write circular programs in Ocaml notation, which are transformed into strict Ocaml programs before they are executed. The first benchmarks of the different implementations are presented and show that for algorithms relying on a large number of traversals the resulting strict, deforested programs are more efficient than the lazy ones, both in terms of runtime and memory consumption.(undefined
Manufacturing employment and exchange rates in the Portuguese economy: the role of openness, technology and labour market rigidity
Integration into the world economy, specialization in low-technology sectors and labour market rigidity have been singled out as structural features of the Portuguese economy that are crucial for the understanding of its performance. In this paper, we explore empirically the role of openness, technology and labour market rigidity in the determination of the effect of the exchange rate on the dynamics of employment in Portugal. Our estimates indicate that employment in low-technology sectors with a high degree of trade openness and facing less rigidity in the labour market is more sensitive to movements in exchange rates. Therefore, our results provide additional evidence on the relevance of those structural features for explaining the evolution of the Portuguese economy in the last decades. In this paper the degree of labour market rigidity is measured at the sector level by means of a novel index. According to this index, high-technology sectors face less labour market rigidity. These sectors are also more exposed to international competition. However, the bulk of employment destruction has occurred in low-technology sectors. This suggests that productivity/technology may be the key variable to reduce the economy's exposure to external shocks.exchange rates, international trade, job flows, labour market rigidity, technology
Manufacturing Employment and Exchange Rates in the Portuguese Economy: The Role of Openness, Technology and Labour Market Rigidity
In this paper, we explore empirically the role of openness, technology and labour market rigidity in the determination of the effect of the exchange rate on employment in Portugal. We develop an index that allows us to measure labour market flexibility at the sector level. This index shows that labour market flexibility has been increasing in all manufacturing sectors and that the labour market in high technology sectors is more flexible than in low technology sectors. We use this index in the estimation of an employment regression, focusing on the effect of exchange rate movements. Our estimates indicate that employment in low-technology sectors, with a high degree of trade openness and facing less rigidity in the labour market are more sensitive to movements in exchange rates.exchange rates, international trade, job flows, labour market rigidity, technology
Employment and Exchange rates: the Role of Openness and Technology
Real exchange rate movements are important drivers of the reallocation of resources between sectors of the economy. Economic theory suggests that the impact of exchange rates should vary with the degree of exposure to international competition and with the technology level. This paper contributes by bringing together these two views, both theoretically and empirically. We show that both the degree of openness and the technology level mediate the impact of exchange rate movements on labour market developments. According to our estimations, whereas employment in high-technology sectors seems to be relatively immune to changes in real exchange rates, these appear to have sizable and significant effects on highly open low-technology sectors. The analysis of job flows suggests that the impact of exchange rates on these sectors occurs through employment destruction.Exchange Rates, International Trade, Job Flows.
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