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Contribuição à análise da estabilidade global de estruturas em concreto pré-moldado de múltiplos pavimentos; Contribution in the analysis of global stability of multi-storey precast concrete framed structures

Marin, Marcelo Cuadrado
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 04/12/2009 PT
Relevância na Pesquisa
35.87%
No presente trabalho são avaliados os principais parâmetros de projeto na análise da estabilidade global de estruturas em concreto pré-moldado de múltiplos pavimentos, considerando a não-linearidade física (NLF), não-linearidade geométrica (NLG) e ligações semi-rígidas. Os sistemas estruturais analisados são constituídos por pórticos com ligação viga-pilar semi-rígida e pilares engastados na fundação. As ligações viga-pilar têm sua tipologia definida por chumbadores retos e capa de concreto moldado in loco com armadura de continuidade. A NLF é avaliada segundo a construção dos diagramas M x N x 1/r, onde foi considerado de forma consistente o efeito da força normal, da armadura passiva, da armadura ativa e a reologia do concreto. São propostas funções e definidos coeficientes redutores de rigidez que foram comparados com valores apontados em expressões normativas que contemplam de forma aproximada a NLF. A NLG é avaliada com o auxílio do programa ANSYS e na forma aproximada segundo o coeficiente z e o método da carga lateral fictícia (P-). Apresentam-se modelos analíticos de caracterização de rigidez e resistência de ligações viga-pilar ao momento fletor negativo e positivo. Na análise numérica é feito um estudo de caso completo de uma estrutura típica de múltiplos pavimentos em concreto pré-moldado com o auxílio do programa ANSYS...

Aspectos adaptativos da variabilidade comportamental operante em um procedimento de omissão de reforço; Adaptive aspects of operant behavioral variability on a reinforcement omission procedure

Caldeira, Karine Marques
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 14/08/2014 PT
Relevância na Pesquisa
35.83%
Trabalhos recentes têm investigado como diferentes manipulações nas contingências de reforçamento podem afetar a variabilidade de respostas. Uma possível manipulação na liberação do reforço é a omissão de um reforço esperado. O objetivo do Experimento 1 foi investigar se a omissão do reforço pode afetar o comportamento de organismos reforçados por apresentar repetição ou diferentes níveis de variação de respostas operantes. Foram utilizados 32 ratos machos adultos Wistar. Foi realizado um treino de variabilidade e repetição operantes e a resposta considerada foi uma sequência de quatro pressões a qualquer de duas barras. Durante essa condição, os animais que passaram pelo treino de variabilidade foram reforçados de acordo com o esquema dependente da frequência. Havia um grupo com alta exigência de variação, um grupo com baixa exigência de variação e um grupo com exigência intermediária de variação para a liberação do reforço. Um quarto grupo foi reforçado continuamente por repetir a sequência DEEE e um quinto grupo recebeu os reforços de acordo com a distribuição dos reforços dos sujeitos do grupo de alta variabilidade, mas sem que precisassem variar suas respostas para isso. Após atingir um responder estável na condição de treino...

Um estudo do comportamento social de duplas de ratos (Rattus norvegicus); A study of social behavior in pairs of rats (Rattus norvegicus)

Bonuti, Rafael Carvalho
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 04/12/2014 PT
Relevância na Pesquisa
35.8%
Uma das dificuldades de se estudar o comportamento social é que para que ele ocorra são necessários pelo menos dois sujeitos, o que dificulta medidas de um deles, sem que seja necessário levar em conta o comportamento do outro. O presente trabalho investiga o comportamento social de duplas de ratos separados por uma grade, para minimizar o efeito que o comportamento de um rato possa ter sobre o outro. Como equipamento, foi utilizado um campo aberto de madeira (120 x 120 x 40 cm) forrado de fórmica marrom escuro. Uma das paredes podia estar intacta ou apresentar uma abertura por onde se podia acoplar uma gaiola de pássaros (34 x 22 x 26 cm). Todas as sessões se iniciavam pela colocação de um rato no centro do campo aberto e da gravação de seu comportamento por 10 minutos (exceto quando mencionado diferente) por uma câmara de vídeo. Para o registro, o piso do campo aberto na tela da TV foi dividido em 36 quadrados de 20 cm. Para cada quadrado, foram registradas a frequência e a duração dos seguintes comportamentos: (1) entradas e tempo gasto nos quadrados do campo aberto (compondo as áreas: quadrado da gaiola, cantos, periferia e centro), (2) frequência e tempo gasto farejando, limpando-se, levantando-se, esticando-se...

Stability of quaternionic linear systems

Pereira, Ricardo; Vettori, Paolo
Fonte: IEEE Publicador: IEEE
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
35.93%
The main goal of this paper is to characterize stability and bounded-input-bounded-output (BIBO)-stability of quaternionic dynamical systems. After defining the quaternion skew-field, algebraic properties of quaternionic polynomials such as divisibility and coprimeness are investigated. Having established these results, the Smith and the Smith-McMillan forms of quaternionic matrices are introduced and studied. Finally, all the tools that were developed are used to analyze stability of quaternionic linear systems in a behavioral framework.

Algebraic tools for the study of quaternionic behavioral systems

Pereira, Ricardo; Rocha, Paula; Vettori, Paolo
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
35.9%
In this paper we study behavioral systems whose trajectories are given as solutions of quaternionic difference equations. As happens in the commutative case, it turns out that quaternionic polynomial matrices play an important role in this context. Therefore we pay special attention to such matrices and derive new results concerning their Smith form. Based on these results, we obtain a characterization of system theoretic properties such as controllability and stability of a quaternionic behavior.

Bibo-stability of quaternionic systems

Pereira, Ricardo; Rocha, Paula; Vettori, Paolo
Fonte: IFAC Publicador: IFAC
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
36.04%
The main goal of this paper is to characterize BIBO-stability of input/output quaternionic systems. After defining and investigating properties of quaternionic polynomials and rational functions, the Smith and the Smith-McMillan forms of quaternionic matrices are studied. Finally, the stability of quaternionic behavioral systems is analyzed using these tools.

Transitions between dynamical states of differing stability in the human brain

Meyer-Lindenberg, Andreas; Ziemann, Ulf; Hajak, Göran; Cohen, Leonardo; Berman, Karen Faith
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
36.16%
What mechanisms underlie the flexible formation, adaptation, synchronization, and dissolution of large-scale neural assemblies from the 1010 densely interconnected, continuously active neurons of the human brain? Nonlinear dynamics provides a unifying perspective on self-organization. It shows that the emergence of patterns in open, nonequilibrium systems is governed by their stability in response to small disturbances and predicts macroscopic transitions between patterns of differing stability. Here, we directly demonstrate that such transitions can be elicited in the human brain by interference at the neural level. As a probe, we used a classic motor coordination paradigm exhibiting well described movement states of differing stability. Functional neuroimaging identified premotor (PMA) and supplementary motor (SMA) cortices as having neural activity linked to the degree of behavioral instability. These regions then were transiently disturbed with graded transcranial magnetic stimulation, which caused sustained and macroscopic behavioral transitions from the less stable out-of-phase to the stable in-phase movement, whereas the stable pattern could not be affected. Moreover, the strength of the disturbance needed (a measure of neural stability) was linked to the degree of behavioral stability...

Stability criteria

Killeen, Peter R.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1978 EN
Relevância na Pesquisa
35.8%
Three approaches to the determination of behavioral stability were examined. In the first, a learning curve was fit to acquisition data (from Cumming and Schoenfeld, 1960), and the “experiment” stopped when the data approached sufficiently close to the theoretical asymptote. In the second, the data were analyzed for variability and linear and quadratic trend. In the third, the experiment was stopped when the magnitude of the daily changes in the data fell below a criterion. Accuracy was measured as deviation between the average value of the dependent variable when the experiment was stopped, and the average value over the last 100 sessions. The first approach was most accurate, but at the cost of requiring the most sessions and being the most difficult to apply. Both the second and third approaches provided acceptable criteria with a reasonable cost-accuracy tradeoff. The second approach permits a continuous adjustment of the criteria to accommodate the variability intrinsic in the experimental paradigm. The third, nomothetic, approach also takes into account the decreasing marginal utility of extended training sessions.

Dynamic Stability of Gait Cycles as a Function of Speed and System Constraints

Buzzi, Ugo H.; Ulrich, Beverly D.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /07/2004 EN
Relevância na Pesquisa
36.07%
The purpose of this study was to examine the dynamic stability of two groups of children with different dynamic resources in changing contexts. The stability of the lower extremity segments of preadolescent children (8–10 years old) with and without Down syndrome (DS) was evaluated as children walked on a motorized treadmill at varying speeds. Tools from nonlinear dynamics, maximum Lyapunov exponent, and approximate entropy were used to assess the behavioral stability of segmental angular displacements of the thigh, shank, and foot. Our results suggest that children with DS show decreased dynamic stability during walking in all segments and that this might be a consequence of inherently different subsystem constraints between these groups. Differences between groups also varied, though not uniformly, with speed, suggesting that inherent differences could further constrain the behavioral response to changing task demands.

Myelin-associated glycoprotein and complementary axonal ligands, gangliosides, mediate axon stability in the CNS and PNS: Neuropathology and behavioral deficits in single- and double-null mice

Pan, Baohan; Fromholt, Susan E.; Hess, Ellen J.; Crawford, Thomas O.; Griffin, John W.; Sheikh, Kazim A.; Schnaar, Ronald L.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/2005 EN
Relevância na Pesquisa
26.12%
Complementary interacting molecules on myelin and axons are required for long-term axon-myelin stability. Their disruption results in axon degeneration, contributing to the pathogenesis of demyelinating diseases. Myelin-associated glycoprotein (MAG), a minor constituent of central and peripheral nervous system myelin, is a member of the Siglec family of sialic acid-binding lectins, and binds to gangliosides GD1a and GT1b, prominent molecules on the axon surface. Mice lacking the ganglioside biosynthetic gene Galgt1 fail to express complex gangliosides, including GD1a and GT1b. In the current studies, CNS and PNS histopathology and behavior of Mag-null, Galgt1-null and double-null mice were compared on the same mouse strain background. When backcrossed to >99% C57BL/6 strain purity, Mag-null mice demonstrated marked CNS, as well as PNS, axon degeneration, in contrast to prior findings using mice of mixed strain background. On the same background, Mag- and Galgt1-null mice exhibited quantitatively and qualitatively similar CNS and PNS axon degeneration, and nearly identical decreases in axon diameter and neurofilament spacing. Double-null mice had qualitatively similar changes. Consistent with these findings, Mag-, Galgt1-null mice had similar motor behavioral deficits...

Behavioral Stability Across Time and Situations: Nonverbal Versus Verbal Consistency

Weisbuch, Max; Slepian, Michael L.; Clarke, Asha; Ambady, Nalini; Veenstra-VanderWeele, Jeremy
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/03/2010 EN
Relevância na Pesquisa
35.94%
Behavioral consistency has been at the center of debates regarding the stability of personality. We argue that people are consistent but that such consistency is best observed in nonverbal behavior. In Study 1, participants’ verbal and nonverbal behaviors were observed in a mock interview and then in an informal interaction. In Study 2, medical students’ verbal and nonverbal behaviors were observed during first- and third-year clinical skills evaluation. Nonverbal behavior exhibited consistency across context and time (a duration of 2 years) whereas verbal behavior did not. Discussion focuses on implications for theories of personality and nonverbal behavior.

Striatal Activity during Intentional Switching Depends on Pattern Stability

De Luca, Cinzia; Jantzen, Kelly J.; Comani, Silvia; Bertollo, Maurizio; Kelso, J. A. Scott
Fonte: Society for Neuroscience Publicador: Society for Neuroscience
Tipo: Artigo de Revista Científica
Publicado em 03/03/2010 EN
Relevância na Pesquisa
26.07%
The theoretical framework of coordination dynamics posits complementary neural mechanisms to maintain complex behavioral patterns under circumstances that may render them unstable and to voluntarily switch between behaviors if changing internal or external conditions so demand. A candidate neural structure known to play a role in both the selection and maintenance of intentional behavior is the basal ganglia. Here, we use functional magnetic resonance imaging to explore the role of basal ganglia in intentional switching between bimanual coordination patterns that are known to differ in their stability as a function of movement rate. Key measures of pattern dynamics and switching were used to map behavior onto the associated neural circuitry to determine the relation between specific behavioral variables and activated brain areas. Results show that putamen activity is highly sensitive to pattern stability: greater activity was observed in bilateral putamen when subjects were required to switch from a more to a less stable pattern than vice versa. Since putamen activity correlated with pattern stability both before and during the switching process, its role may be to select desired actions and inhibit competing ones through parametric modulation of the intrinsic dynamics. Though compatible with recent computational models of basal ganglia function...

Contributions of COMT Val158Met to cognitive stability and flexibility in infancy

Markant, Julie; Cicchetti, Dante; Hetzel, Susan; Thomas, Kathleen M.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
26.22%
Adaptive behavior requires focusing on relevant tasks while remaining sensitive to novel information. In adult studies of cognitive control, cognitive stability involves maintaining robust cognitive representations while cognitive flexibility involves updating of representations in response to novel information. Previous adult research has shown that the Met allele of the COMT Val158Met gene is associated with enhanced cognitive stability whereas the Val allele is associated with enhanced cognitive flexibility. Here we propose that the stability/flexibility framework can also be applied to infant research, with stability mapping onto early indices of behavioral regulation and flexibility mapping onto indices of behavioral reactivity. From this perspective, the present study examined whether COMT genotype was related to 7-month-old infants’ reactivity to novel stimuli and behavioral regulation. Cognitive stability and flexibility were assessed using (1) a motor approach task, (2) a habituation task, and (3) a parental-report measure of temperament. Val carriers were faster to reach for novel toys during the motor approach task and received higher scores on the temperament measure of approach to novelty. Met carriers showed enhanced dishabituation to the novel stimulus during the habituation task and received higher scores on the temperament measures of sustained attention and behavioral regulation. Overall...

On-Call Duty Effects on Sleep-State Physiological Stability in Male Medical Interns

Lin, Yu-Hsuan; Ho, Yen-Cheng; Lin, Sheng-Hsuan; Yeh, Yao-Hsien; Liu, Chia-Yih; Kuo, Terry B. J.; Yang, Cheryl C. H.; Yang, Albert C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
35.93%
Background: On-call duty among medical interns is characterized by sleep deprivation and stressful working conditions, both of which alter cardiac autonomic modulation. We hypothesized that sleep stability decreased in medical interns during on-call duty. We used cardiopulmonary-coupling (CPC) analysis to test our hypothesis. Methods: We used electrocardiogram (ECG)-based CPC analysis to quantify physiological parameters of sleep stability in 13 medical interns during on-call and on-call duty-free periods. There were ten 33.5-h on-call duty shifts per month for interns, each followed by 2 on-call duty-free days, over 3 months. Measurements during sleep were collected before, during, and after an on-call shift. Measurements were repeated 3 months later during an on-call duty-free period. Results: The medical interns had significantly reduced stable sleep, and displayed increased latency to the first epoch of stable sleep during the on-call night shift, compared to the pre-call and on-call duty-free nights. Interns also had significantly increased rapid-eye-movement (REM) sleep during the on-call night shift, compared to the pre-call and on-call duty-free nights. Conclusion: Medical interns suffer disrupted sleep stability and continuity during on-call night shifts. The ECG-based CPC analysis provides a straightforward means to quantify sleep quality and stability in medical staff performing shift work under stressful conditions.

Continuity and discontinuity in behavioral inhibition : influences of a maltreating environment

Holmes, Beth Cerrito (1977 - ); Rogosch, Fred A.
Fonte: University of Rochester. Publicador: University of Rochester.
Tipo: Tese de Doutorado Formato: Number of Pages:xii, 165 leaves
ENG
Relevância na Pesquisa
26.3%
Thesis (Ph. D.)--University of Rochester. Dept. of Clinical and Social Sciences in Psychology, 2008.; Behavioral inhibition is one of the most frequently studied traits of child temperament. Although consistent with theoretical views of temperament, the biological and physiological underpinnings of behavioral inhibition have often been highlighted to the exclusion or minimization of environmental factors. Nevertheless, a growing literature suggests that environment plays a role in the development and expression of temperamental traits. Further, given a developmental psychopathology framework, the processes of normal development can be elucidated by the examination of maladaptive or otherwise atypical developmental patterns or environments (Cicchetti, 1984; 1990; Sroufe, 1990). The current study addresses the above issues in two ways – by examining the rates and stability of traditional behavioral inhibition across the second year of life in children from maltreating and nonmaltreating families and by proposing an alternate method of classifying behavioral inhibition for possible greater precision in non-normative, higher-risk samples. Behavioral inhibition was assessed through a standard laboratory paradigm when children were 14 and 26-months of age. Trained raters coded data for both fear behaviors (i.e....

Comportamento social de botos-cinza, sotalia guianensis, na praia de Pipa, RN, Brasil: dinâmica, sequência, sincronia e respostas ao turismo de observação

Lunarde, Diana Gonçalves
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicobiologia; Estudos de Comportamento; Psicologia Fisiológica Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Psicobiologia; Estudos de Comportamento; Psicologia Fisiológica
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
26.21%
Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics...

Impact of Behavioral Issues on Green Growth Policies and Weather-Related Disaster Reduction in Developing Countries

Kunreuther, Howard; Michel-Kerjan, Erwann
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
35.83%
This paper focuses on how developing countries can change the way they prepare for disasters so they are better equipped to sustain economic growth. It discusses the importance of considering the goals of key decision makers and the need to understand the perceptions, systematics biases, and heuristics used by the relevant interested parties (the affected public, private and public sector organizations, and nongovernmental organizations) in choosing between alternatives. The paper highlights the importance of undertaking benefit-cost analysis to evaluate disaster risk reduction measures, recognizing that decision makers might not make meaningful use of this policy tool given their behavioral biases and simplified heuristics. To address these issues, the authors propose green growth strategies that involve multi-year contracts coupled with short-term incentives that have a chance of being implemented. The strategies focus on the role of multi-year micro-insurance, long-term loans, and multi-year catastrophe bonds that reflect the institutional arrangements in the developing country. The paper illustrates this proposal in the case of farmers' agricultural practices and investment decisions that reduce losses to property from catastrophic disasters such as drought.

Respostas fisiológicas e comportamentais de recém-nascidos pré-termos submetidos a duas técnicas de banho de imersão: ensaio clínico cruzado; Physiological and behavioral responses of preterm newborn underwent to two immersion baths techniques: cross-over clinical trial

Freitas, Patricia de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 28/05/2015 PT
Relevância na Pesquisa
36.01%
Introdução: a revisão de literatura aponta que os recém-nascidos submetidos ao banho de imersão produzem menor variação térmica pós-banho comparado aos submetidos ao banho com esponja. No Brasil, o Ministério da Saúde vem capacitando profissionais que atuam em unidades de internação neonatal para implementar o Método Mãe Canguru e, entre outras práticas, recomenda que o recém-nascido pré-termo (RNPT) e com baixo peso seja submetido ao banho de imersão envolto em cueiro ou lençol, sugerindo mudança da prática hegemônica do banho com esponja ou banho de imersão convencional. No entanto, a técnica de banho de imersão recomendada carece de evidências científicas quanto a sua segurança em relação às repercussões na estabilidade da temperatura corporal (T), frequência cardíaca (FC), cortisol salivar (CS) e comportamental em RNPT. Hipótese: os RNPT submetidos ao banho de imersão envoltos em lençol (BIE) apresentam respostas fisiológicas e comportamentais similares aos submetidos à técnica de banho de imersão convencional (BIC), nos primeiros 20 minutos pós-banho. Objetivo: avaliar os parâmetros fisiológicos e comportamentais de RNPT submetidos ao banho de imersão envolto em lençol (BIE) e banho de imersão convencional (BIC). Método: ensaio clínico randomizado cruzado com amostra composta por 43 RNPT...

Behavioral Health Service Utilization and Cost for North Carolina’s Foster Children: A Report for Partnering For Excellence

Foosness, Susan
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Masters' project
Publicado em 18/04/2014
Relevância na Pesquisa
36.2%
Executive Summary Introduction The foster care population in North Carolina, which hovered around 8,882 children as of August 2013, is of special interest to policymakers, politicians, Medicaid officials, child welfare professionals, and healthcare providers. This group of infants through young adults faces unique challenges in their educational, social, emotional, developmental, and physical growth. Their elevated needs put extra pressure on already stressed systems with limited financial resources. High levels of behavioral health and emotional problems lead to placement disruptions, costly interventions, and require extra diligence on the part of caseworkers, foster parents, and professionals to manage crises and keep foster children safe. It is essential to identify strategies to address the behavioral health needs of foster children within the constraints of limited resources, and in ways that take advantage of the most recent research on evidence-based treatments. These strategies should aim to reduce placement disruptions and promote healthy outcomes for foster children. By using existing data collection systems within the Department of Social Services and Local Management Entity-Managed Care Organizations (LME-MCOs), we can gain important insight into this population’s health and mental health needs...

Estabilidad de precios de acciones en el mercado de capitales brasileño: un estudio en que se aplican redes neuronales y exponentes de Lyapunov; Stability of stock prices in the Brazilian capital market: a study applying neural networks and the Lyapunov exponent; Estabilidade de preços de ações no mercado de capitais brasileiro: um estudo aplicando redes neurais e expoentes de Lyapunov

Oliveira, Mauri Aparecido de; Montini, Alessandra de Ávila; Mendes-Da-Silva, Wesley; Bergmann, Daniel Reed
Fonte: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade Publicador: Universidade de São Paulo. Faculdade de Economia, Administração e Contabilidade
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Artigo Avaliado pelos Pares Formato: application/pdf
Publicado em 01/06/2011 POR
Relevância na Pesquisa
35.95%
En este trabajo se estudia la estabilidad de los precios de mercado de acciones para dos categorías de empresas: industrial y otros sectores, en el período comprendido entre el 2 de enero de 1995 y el 2 de enero de 2008. Es decir, se analiza la estabilidad de los precios de mercado para el período anterior a la crisis de 2008, que comenzó con los títulos subprime de Estados Unidos. Se analizan las implicaciones de la estabilidad del proceso de generación de retorno por paradigmas de racionalidad. La verificación de la estabilidad se realizó por medio de la aplicación de exponentes de Lyapunov. Se presentan los resultados sobre la estabilidad de los precios para las dos categorías de empresas: las industrias, formadas por Acesita, Ambev, Aracruz, Braskem, Duratex, Fosfertil, Gerdau, Klabin, Randon, Sadia, Sid Nacional, Souza Cruz, Unipar, Usiminas, y VCP; y las empresas de la categoría otros sectores, formadas por Ampla Energia, Bradesco, Brasil Telecom, Cemig, Eletrobrás, Itaubanco, Itausa, JB Duarte, Pronor, Besc, Alfa Financeira e Inepar. Un diagrama de dispersión del logaritmo de los precios de registro sin tendencia frente a los retornos de las dos categorías (o carteras) mostró un patrón caótico en los precios de las acciones...