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The nonlinear N-membranes evolution problem

Rodrigues, José Francisco; Santos, Lisa; Urbano, José Miguel
Fonte: Centro de Matemática da Universidade de Coimbra Publicador: Centro de Matemática da Universidade de Coimbra
Tipo: preprint
Português
Relevância na Pesquisa
35.87%
The parabolic N-membranes problem for the p-Laplacian and the complete order constraint on the components of the solution is studied in what concerns the approximation, the regularity and the stability of the variational solutions. We extend to the evolutionary case the characterization of the Lagrange multipliers associated with the ordering constraint in terms of the characteristic functions of the coincidence sets. We give continuous dependence results, and study the asymptotic behavior as t ? ? of the solution and the coincidence sets, showing that they converge to their stationary counterparts.

A contribuição do neuromarketing para o estudo do comportamento do consumidor; Neuromarketing´s contribution to consumer behaviour studies

Colaferro, Claudia Almeida
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: dissertação de mestrado Formato: application/pdf
Publicado em 16/12/2011 Português
Relevância na Pesquisa
35.9%
À medida que se avança no século XXI observamos a diversidade humana, cada vez em maior número, convivendo e interagindo a todo o momento. As dificuldades aumentam quando a diversidade se dá além de diferentes sexos, idades, mas também por diferentes opiniões e as várias formas de expressão e comportamento das pessoas, principalmente aqueles não conscientes. Nesse contexto vive-se o desencadeamento de uma crise das metodologias clássicas de investigação, vistas como limitantes e pouco esclarecedoras para o entendimento de que, em um mesmo indivíduo, podem existir estilos de consumo distintos, não conscientes, além de que o entrevistado pode, de maneira intencional ou não intencional, compreender mal, interpretar mal ou até mesmo enganar o pesquisador. O objetivo da dissertação foi avaliar se o neuromarketing pode ser uma nova área de colaboração ao entendimento do consumidor, ser capaz de obter as informações não declaradas do indivíduo, pela captura das informações cerebrais, adicionando assim conhecimento para o processo do entendimento de seu comportamento de consumo, validando-o como uma nova área de cooperação. Por meio de revisão bibliográfica e pesquisa empírica buscou-se identificar, entender e com isso resumir conceitos básicos sobre o neuromarketing...

Peculiar trajectories around the Lagrangian equilateral points

Winter, S. M. Giuliatti; Winter, O. C.; Mourao, D. C.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 112-118
Português
Relevância na Pesquisa
26.17%
In the present work we analyse the behaviour of a particle under the gravitational influence of two massive bodies and a particular dissipative force. The circular restricted three body problem, which describes the motion of this particle, has five equilibrium points in the frame which rotates with the same angular velocity as the massive bodies: two equilateral stable points (L-4, L-5) and three colinear unstable points (L-1, L-2, L-3). A particular solution for this problem is a stable orbital libration, called a tadpole orbit, around the equilateral points. The inclusion of a particular dissipative force can alter this configuration. We investigated the orbital behaviour of a particle initially located near L4 or L5 under the perturbation of a satellite and the Poynting-Robertson drag. This is an example of breakdown of quasi-periodic motion about an elliptic point of an area-preserving map under the action of dissipation. Our results show that the effect of this dissipative force is more pronounced when the mass of the satellite and/or the size of the particle decrease, leading to chaotic, although confined, orbits. From the maximum Lyapunov Characteristic Exponent a final value of gamma was computed after a time span of 10(6) orbital periods of the satellite. This result enables us to obtain a critical value of log y beyond which the orbit of the particle will be unstable...

School dropout, problem behaviour and poor academic achievement : a longitudinal view of portuguese male offenders

Saraiva, A. Beatriz; Pereira, Beatriz Oliveira; Cruz, Judite Zamith
Fonte: Routledge Publicador: Routledge
Tipo: Artigo de Revista Científica
Publicado em //2011 Português
Relevância na Pesquisa
66.17%
This study examines school drop outs from the perspective of male adults themselves through interviews with offenders currently serving sentences. Participants were 10 Portuguese male inmates, between the ages of 19 and 46 years of age, incarcerated in two prison facilities of the Azores. Qualitative and interpretative methods were carried out using a semi-structured in-depth individual interview that was audiorecorded and conducted on the basis of a list of topics. Interview transcripts and thematic analysis were used in data treatment and analysis. The findings primarily indicate that poor academic achievement and emotional and behavioural difficulties of participants played a particular role in early school drop out. The trajectories these individuals followed within the education system presented problem behaviour, learning disabilities, and/or foster care interventions. While school drop out circumstances were apparently various, analysis showed that they were underpinned by three distinct sets of conditions generally not addressed by the education system. The analysis of the triggering factors and the maintenance dynamics of school drop outs indicated three distinct types: retention/absenteeism, life turning points and positive resolution. Implications for secondary prevention and screening practices are discussed.; FCT (SFRH/ BD/ 44245/ 2008); CIEC - unidade de investigação 317 da FCT

A modified fractional zener model to describe the behaviour of a carbon fibre reinforced polymer

Costa, M. Fernanda P.; Ribeiro, Carolina Paula Baptista
Fonte: AIP Publishing Publicador: AIP Publishing
Tipo: info:eu-repo/semantics/conferenceobject
Publicado em //2013 Português
Relevância na Pesquisa
35.87%
In this work a modified conventional Fractional Zener Model is deduced and applied to estimate the viscoelastic constitutive parameters of a Carbon Fibre Reinforced Polymer. The accuracy of this modified model was studied against conventional Fractional Zener model and Fractional Maxwell model, considering experimental data in the frequency domain. The set of parameters was found by solving a nonlinear constrained least square problem based on the variation of the storage and loss moduli with frequency.; This work was financed by FEDER funds through COMPETE (Operational Programme Thematic Factors of Competitiveness) and by portuguese funds through FCT (Foundation for Science and Technology) within the project PEst-C/MAT/UI0013/ 2011.

Artificial intelligence approaches for the generation and assessment of believable human-like behaviour in virtual characters

Asensio, Joan Marc Llargues; Donate, Juan Peralta; Arrabales, R.; Bedia, M. Gonzalez; Cortez, Paulo; Penã, A. Lopez
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em /11/2014 Português
Relevância na Pesquisa
36.19%
Having artificial agents to autonomously produce human-like behaviour is one of the most ambitious original goals of Artificial Intelligence (AI) and remains an open problem nowadays. The imitation game originally proposed by Turing constitute a very effective method to prove the indistinguishability of an artificial agent. The behaviour of an agent is said to be indistinguishable from that of a human when observers (the so-called judges in the Turing test) can not tell apart humans and non-human agents. Different environments, testing protocols, scopes and problem domains can be established to develop limited versions or variants of the original Turing test. In this paper we use a specific version of the Turing test, based on the international BotPrize competition, built in a First-Person Shooter video game, where both human players and non-player characters interact in complex virtual environments. Based on our past experience both in the BotPrize competition and other robotics and computer game AI applications we have developed three new more advanced controllers for believable agents: two based on a combination of the CERA-CRANIUM and SOAR cognitive architectures and other based on ADANN, a system for the automatic evolution and adaptation of artificial neural networks. These two new agents have been put to the test jointly with CCBot3...

Inverse problem methodology for thermal-physical properties estimation of frozen green beans

Martins, R.C.; Silva, C.L.M.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2004 Português
Relevância na Pesquisa
35.97%
Frozen green beans (Phaseolus vulgaris, L.) thermal conductivity (k) and heat capacity (Cp) were determined experimentally by a one dimensional finite difference (transient method) and differential scanning calorimetry, respectively. Thermal properties were also estimated by the inverse problem methodology (IPM). Heat capacity and thermal conductivity behaviour with temperature were modelled by the Schwartzberg equations and linear relationship, respectively below and above the melting point. These equations were used inside a finite element model (FEM) to simulate green beans phase transition under thawing conditions. The sequential simplex method was used to minimise the error vector of the FEM inverse problem, to estimate thermal capacity and thermal conductivity. The accuracy of thermal-physical properties estimated by the two methodologies was compared with data from literature. The thermo-physical properties estimated by the IPM converged for physically meaningful values. Important conclusions were obtained about errors in model predictions. Furthermore, the IPM thermal properties increased the accuracy of simulations, especially during phase transition.

Experimental study on the biaxial bending cyclic behaviour of RC columns

Rodrigues, H.; Arêde, A.; Varum, H.; Costa, A.
Tipo: conferenceobject
Português
Relevância na Pesquisa
36.03%
The available experimental studies on the inelastic 3D response of axially loaded members under biaxial bending moment loading histories are limited. Possibly, this is partially due to the uncertainty of combining bending moment’s histories in the two orthogonal directions that adds considerable complication to the problem. Three types of cantilever reinforced concrete columns with constant axial load were subjected to cyclic uniaxial and biaxial tests. It was intended to gain enhanced knowledge concerning the behaviour or RC columns that allows for the calibration of simplified non-linear models. The experimental campaign is described, test results are presented and discussed comparing the uniaxial and the biaxial tests and the effect of the different biaxial load paths in the columns behaviour.

Children’s Challenging Behaviour: Teachers’ Understanding and Intervention

Grácio, Luísa
Tipo: book
Português
Relevância na Pesquisa
35.9%
Challenging behaviours are observable behaviours that can affect the environment and often have a negative influence in the child and those around. The concept of challenging behavior (CD) refers to behavior difficulties or problems that can be shown be children, teenagers or adults. This concept appears to characterize the behavior as a challenge instead of labeling people as a problem. From this point of view, challenging behaviours are seen through the view of development psychology, and perceived as developmental struggles or delays in social, emotional and academic areas. The causes for challenging behaviours are diverse, resulting from genetic vulnerabilities and environmental stress The probable causes for disruptive and challenging behaviours can be explained through an ecological approach, based on Bronfenbrenner’s findings (1979). Challenging behaviours fulfill a function or purpose and are kept by the individual as long as they show themselves to be a successful adaptation to the environment. The pattern for challenging behaviours changes considerably according to the considered target characteristics and the age of individuals. Individuals with challenging behaviours are not all alike. We should focus on the behaviours’ target characteristics because they describe the behaviours to change.

M|G|? queue system transient behaviour and busy period

Ferreira, Manuel Alberto M.
Fonte: Slovak University of Technology Publicador: Slovak University of Technology
Tipo: info:eu-repo/semantics/conferenceobject
Publicado em //2003 Português
Relevância na Pesquisa
35.98%
This paper main subject is the M|G|? queue system transient probabilities study as time functions. We achieve it completely when the time origin is an unoccupied system instant. But we do not get such a goal when the time origin is a busy period beginning instant. We shall see that, in this last situation, the service time length distribution hazard rate function plays a very important role. And so the results got may be useful in the survival analysis field. As the M G queue system can be applied in the modelation of many social problems: sickness, unemployment, emigration, ...(see, for instance, Ferreira (1995 and 1996)), in these situations it is very important to study the busy period length distribution of that system. We show, in this work, that the solution of the problem may be in the resolution of a Ricatti equation generalizing the work of Ferreira (1998) as a consequence of the transient behaviour study.

Suicidal behaviour: a continuing cause for concern.

Aldridge, D
Tipo: text
Publicado em /11/1992 Português
Relevância na Pesquisa
26.17%
There is an increase in suicidal behaviour in the western world providing a major challenge to health care providers. There is an increase in the number of suicides among elderly people in Europe. The problem of suicides among elderly people is in itself a social problem, not solely a medical one. The general practitioner may be the only source of social contact for the elderly. Elderly individuals often present their problems to doctors as somatic complaints; these complaints must not be taken at face value but understood as expressions of psychosocial and social distress. The rise in suicide rates among young people is also alarming. The warning signs of escalating distress in adolescents are known and a treatment programme coordinating medical initiatives, such that recidivism of suicidal behaviour in adolescents is reduced, is necessary. The general practitioner is urged to sense when the problem presented by the individual stems from a source which is predominantly social, and to suggest an appropriate solution which may entail a family intervention. The general practitioner is in the front line of treatment and he or she may be better advised to treat both the social situation and the individual person in cases of attempted suicide. Medical initiatives must incorporate aspects of social medicine whereby community solutions are found for the management of individual distress. Social disruption...

Neighbourhood level and individual level SES effects on child problem behaviour: a multilevel analysis

Kalff, A; Kroes, M; Vles, J; Hendriksen, J; Feron, F; Steyaert, J; van Zeben, T M C B; Jolles, J; van Os, J
Fonte: BMJ Group Publicador: BMJ Group
Tipo: text
Publicado em /04/2001 Português
Relevância na Pesquisa
35.98%
OBJECTIVE—This study examined whether neighbourhood level socioeconomic variables have an independent effect on reported child behaviour problems over and above the effect of individual level measures of socioeconomic status.?DESIGN AND SETTING—Multilevel analysis of cross sectional survey data relating individual level child behavioural problems and parental measures of socioeconomic status with neighbourhood level measures of socioeconomic deprivation in the city of Maastricht, the Netherlands.?PARTICIPANTS—Children born in the years 1990-1991 attending the second grade of normal kindergarten schools in the city of Maastricht, the Netherlands. Out of 1417 eligible 5-7 year olds, the parents of 734 children (51.8%) agreed to participate.?MAIN RESULTS—Child behaviour problems were more frequent in families of low parental occupation and education (F=14.51, df 3, 721, p

Problem behaviour in primary health care

Lamberts, H.
Tipo: text
Publicado em /06/1979 Português
Relevância na Pesquisa
35.9%
Primary health care can be regarded as the boundary between society as a whole and the medical system. Many of the problems patients bring to doctors in primary care are concerned with their personalities and life situation, and can be considered together as problems of human behaviour.

Group-based care: does it change problem behaviour?

van Weel, Chris
Tipo: text
Publicado em /11/1980 Português
Relevância na Pesquisa
46.02%
As a result of disappointing experiences in managing problem behaviour presented by patients in general practice, a system of team or group-based care was developed at the Ommoord Health Centre in Rotterdam, the Netherlands.

Problem behaviour in primary health care

Lamberts, H.
Tipo: text
Publicado em /05/1980 Português
Relevância na Pesquisa
36.02%
Primary health care can be regarded as the boundary between society as a whole and the medical system. Many of the problems patients bring to doctors in primary care are concerned with their personalities and life situation, and can be considered together as problems of human behaviour. On being questioned in a waiting room, 15 per cent of patients considered their problem “psychosocial only”, and an additional 13 to 14 per cent “both somatic and psychosocial”.

Life Satisfaction, Positive Youth Development, and Problem Behaviour Among Chinese Adolescents in Hong Kong

Sun, Rachel C. F.; Shek, Daniel T. L.
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: text
Português
Relevância na Pesquisa
46.37%
This paper examines the relationships among life satisfaction, positive youth development, and problem behaviour. A total of 7,975 Secondary One students (4,169 boys and 3,387 girls; with most aged 12) of Chinese ethnicity recruited from 48 schools responded to validated measures of life satisfaction, positive youth development and problem behaviour. While life satisfaction was positively correlated with different measures of positive youth development, these measures were negatively correlated with measures of substance abuse, delinquency and intention to engage in problem behaviour. Based on a series of structural equation models, a non-recursive model was found to best fit the data, which suggests that adolescents having higher levels of positive youth development are more satisfied with life and have fewer problem behaviour, with life satisfaction and problem behaviour negatively reinforcing each other.

Positive Youth Development, Life Satisfaction and Problem Behaviour Among Chinese Adolescents in Hong Kong: A Replication

Sun, Rachel C. F.; Shek, Daniel T. L.
Fonte: Springer Netherlands Publicador: Springer Netherlands
Tipo: text
Português
Relevância na Pesquisa
46.37%
The purpose of this replication study was to examine the relationships among life satisfaction, positive youth development and problem behaviour. The respondents were 7,151 Chinese Secondary 2 (Grade 8) students (3,707 boys and 3,014 girls) recruited from 44 schools in Hong Kong. Validated assessment tools measuring positive youth development, life satisfaction and problem behaviour were used. As predicted, positive youth development was positively correlated with life satisfaction, and positive youth development and life satisfaction were negatively correlated with adolescent problem behaviour. Based on a series of structural equation models, the present findings replicated the previous findings that adolescents with a higher level of positive youth development were more satisfied with life and had lesser problem behaviour, with higher level of life satisfaction and lower level of problem behaviour mutually influencing each other. These replicated findings provide a further advance in the literature on positive youth development, particularly in the Chinese context. Implications for future research and intervention were discussed.

Behavioural flexibility and problem-solving in a tropical lizard

Leal, Manuel; Powell, Brian J.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: text
Português
Relevância na Pesquisa
35.9%
The role of behavioural flexibility in responding to new or changing environmental challenges is a central theme in cognitive ecology. Studies of behavioural flexibility have focused mostly on mammals and birds because theory predicts that behavioural flexibility is favoured in species or clades that exploit a diversity of habitats or food sources and/or have complex social structure, attributes not associated with ectothermic vertebrates. Here, we present the results of a series of experiments designed to test cognitive abilities across multiple cognitive modules in a tropical arboreal lizard: Anolis evermanni. This lizard shows behavioural flexibility across multiple cognitive tasks, including solving a novel motor task using multiple strategies and reversal learning, as well as rapid associative learning. This flexibility was unexpected because lizards are commonly believed to have limited cognitive abilities and highly stereotyped behaviour. Our findings indicate that the cognitive abilities of A. evermanni are comparable with those of some endothermic species that are recognized to be highly flexible, and strongly suggest a re-thinking of our understanding of the cognitive abilities of ectothermic tetrapods and of the factors favouring the evolution of behavioural flexibility.

Duration of Gestation, Size at Birth and Later Childhood Behaviour

Yang, Seungmi; Fombonne, Eric; Kramer, Michael S.
Tipo: text
Português
Relevância na Pesquisa
26.19%
Although many previous studies have reported an association between preterm birth or small size at birth and later behaviour, multiple methodological limitations threaten the validity of causal inferences from reported associations. The authors have examined the association between gestational age and gestational age-specific size at birth (weight, length, and head circumference) and behaviour in a large sample of children born healthy at term. The data were from the 6.5-year follow-up of 13,889 Belarusian children who participated in PROBIT, a cluster-randomized trial of a breastfeeding promotion intervention. Child behaviour was measured using the parent and teacher versions of Strengths and Difficulties Questionnaire (SDQ). Differences in SDQ scores by gestational age and by birthweight, birth length, and birth head circumference standardized for gestational age and sex (z-scores) were analyzed after controlling for potentially confounding maternal and family factors. There was no association between gestational age and child behaviour after adjusting for potential confounding factors. Lower birthweight for gestational age was significantly associated with higher scores in problem behaviours including total difficulties, conduct problems...

Dyadic Flexibility in Early Parent–Child Interactions: Relations with Maternal Depressive Symptoms and Child Negativity and Behaviour Problems

Lunkenheimer, Erika S.; Albrecht, Erin C.; Kemp, Christine J.
Tipo: text
Português
Relevância na Pesquisa
26.22%
Lower levels of parent–child affective flexibility indicate risk for children’s problem outcomes. This short-term longitudinal study examined whether maternal depressive symptoms were related to lower levels of dyadic affective flexibility and positive affective content in mother–child problem-solving interactions at age 3.5 years (N=100) and whether these maternal and dyadic factors predicted child emotional negativity and behaviour problems at a 4-month follow-up. Dyadic flexibility and positive affect were measured using dynamic systems-based modelling of second-by-second affective patterns during a mother–child problem-solving task. Results showed that higher levels of maternal depressive symptoms were related to lower levels of dyadic affective flexibility, which predicted children’s higher levels of negativity and behaviour problems as rated by teachers. Mothers’ ratings of child negativity and behaviour problems were predicted by their own depressive symptoms and individual child factors, but not by dyadic flexibility. There were no effects of dyadic positive affect. Findings highlight the importance of studying patterns in real-time dyadic parent–child interactions as potential mechanisms of risk in developmental psychopathology.