Structural change in macroeconomic time series: A complex systems perspective

We demonstrate that the process of generating smooth transitions Call be viewed as a natural result of the filtering operations implied in the generation of discrete-time series observations from the sampling of data from an underlying continuous time process that has undergone a process of structural change. In order to focus discussion, we utilize the problem of estimating the location of abrupt shifts in some simple time series models. This approach will permit its to address salient issues relating to distortions induced by the inherent aggregation associated with discrete-time sampling of continuous time processes experiencing structural change, We also address the issue of how time irreversible structures may be generated within the smooth transition processes. (c) 2005 Elsevier Inc. All rights reserved.

White and gray matter development in human fetal, newborn and pediatric brains

Brain anatomy is characterized by dramatic growth from the end of the second trimester through the neonatal stage. The characterization of normal axonal growth of the white matter tracts has not been well-documented to date and could provide important clues to understanding the extensive inhomogeneity of white matter injuries in cerebral palsy (CP) patients. However, anatomical studies of human brain development during this period are surprisingly scarce and histology-based atlases have become available only recently. Diffusion tensor magnetic resonance imaging (DTMRI) can reveal detailed anatomy of white matter. We acquired diffusion tensor images (DTI) of postmortem fetal brain samples and in vivo neonates and children. Neural structures were annotated in two-dimensional (2D) slices, segmented, measured, and reconstructed three-dimensionally (3D). The growth status of various white matter tracts was evaluated on cross-sections at 19-20 gestational weeks, and compared with 0-month-old neonates and 5- to 6-year-old children. Limbic, commissural, association, and projection white matter tracts and gray matter structures were illustrated in 3D and quantitatively characterized to assess their dynamic changes. The overall pattern of the time courses for the development of different white matter is that limbic fibers develop first and association fibers last and commissural and projection fibers are forming from anterior to posterior part of the brain. The resultant DTNIRI-based 3D human brain data will be a valuable resource for human brain developmental study and will provide reference standards for diagnostic radiology of premature newborns. (c) 2006 Elsevier Inc. All rights reserved.

3D statistical shape models to embed spatial relationship information

This paper presents the creation of 3D statistical shape models of the knee bones and their use to embed information into a segmentation system for MRIs of the knee. We propose utilising the strong spatial relationship between the cartilages and the bones in the knee by embedding this information into the created models. This information can then be used to automate the initialisation of segmentation algorithms for the cartilages. The approach used to automatically generate the 3D statistical shape models of the bones is based on the point distribution model optimisation framework of Davies. Our implementation of this scheme uses a parameterized surface extraction algorithm, which is used as the basis for the optimisation scheme that automatically creates the 3D statistical shape models. The current approach is illustrated by generating 3D statistical shape models of the patella, tibia and femoral bones from a segmented database of the knee. The use of these models to embed spatial relationship information to aid in the automation of segmentation algorithms for the cartilages is then illustrated.

Stratigrafia fisica ed analisi di facies dei depositi torbiditici della Formazione delle Arenarie del Monte Cervarola tra la Val Secchia e la Val Scoltenna (Aquitaniano-Burdigaliano, Appennino Settentrionale)

The Cervarola Sandstones Formation (CSF), Aquitanian-Burdigalian in age, was deposited in an elongate, NW-stretched foredeep basin formed in front of the growing Northern Apennines orogenic wedge. The stratigraphic succession of the CSF, in the same way of other Apennine foredeep deposits, records the progressive closure of the basin due to the propagation of thrust fronts toward north-east, i.e. toward the outer and shallower foreland ramp. This process produce a complex foredeep characterized by synsedimentary structural highs and depocenters that can strongly influence the lateral and vertical turbidite facies distribution. Of consequence the main aim of this work is to describe and discuss this influence on the basis of a new high-resolution stratigraphic framework performed by measuring ten stratigraphic logs, for a total thickness of about 2000m, between the Secchia and Scoltenna Valleys (30km apart). In particular, the relationship between the turbidite sedimentation and the ongoing tectonic activity during the foredeep evolution has been describe through various stratigraphic cross sections oriented parallel and perpendicular to the main tectonic structures. On the basis of the high resolution physical stratigraphy of the studied succession, we propose a facies tract and an evolutionary model for the Cervarola Sandstones in the studied area. Thanks to these results and the analogies with others foredeep deposits of the northern Apennines, such as the Marnoso-arenacea Formation, the Cervarola basin has been interpreted as a highly confined foredeep controlled by an intense synsedimentary tectonic activity. The most important evidences supporting this hypothesis are: 1) the upward increase, in the studied stratigraphic succession (about 1000m thick), of sandstone/mudstone ratio, grain sizes and Ophiomorpha-type trace fossils testifying the high degree of flow deceleration related to the progressive closure and uplift of the foredeep. 2) the occurrence in the upper part of the stratigraphic succession of coarse-grained massive sandstones overlain by tractive structures such as megaripples and traction carpets passing downcurrent into fine-grained laminated contained-reflected beds. This facies tract is interpreted as related to deceleration and decoupling of bipartite flows with the deposition of the basal dense flows and bypass of the upper turbulent flows. 3) the widespread occurrence of contained reflected beds related to morphological obstacles created by tectonic structures parallel and perpendicular to the basin axis (see for example the Pievepelago line). 4) occurrence of intra-formational slumps, constituted by highly deformed portion of fine-grained succession, indicating a syn-sedimentary tectonic activity of the tectonic structures able to destabilize the margins of the basin. These types of deposits increase towards the upper part of the stratigraphic succession (see points 1 and 2) 5) the impressive lateral facies changes between intrabasinal topographic highs characterized by fine-grained and thin sandstone beds and marlstones and depocenters characterized by thick to very thick coarse-grained massive sandstones. 6) the common occurrence of amalgamation surfaces, flow impact structures and mud-draped scours related to sudden deceleration of the turbidite flows induced by the structurally-controlled confinement and morphological irregularities. In conclusion, the CSF has many analogies with the facies associations occurring in other tectonically-controlled foredeeps such as those of Marnoso-arenacea Formation (northern Italy) and Annot Sandstones (southern France) showing how thrust fronts and transversal structures moving towards the foreland, were able to produce a segmented foredeep that can strongly influence the turbidity current deposition.

IMPRENSA DE COMUNIDADES IMIGRANTES DE SÃO PAULO E IDENTIDADE: estudo dos jornais ibéricos Mundo Lusíada e Alborada

Entre os veículos impressos voltados para colônias de imigrantes em circulação na cidade de São Paulo, atualmente (2005/2006), estão Mundo Lusíada (português) e Alborada (espanhol). Identificar se estes dois jornais trazem em seu conteúdo, predominantemente, assuntos que favorecem a aculturação e assimilação do estrangeiro no território receptor ou a preservação de sua identidade cultural foi o principal objetivo deste trabalho, além de apurar as características editoriais e averiguar se a relação com a comunidade em questão não é apenas uma estratégia mercadológica. O estudo foi baseado em pesquisa bibliográfica, mapeamento das principais publicações voltadas para imigrantes que circulam na capital paulista e, sobretudo, em análise de conteúdo de 12 edições do Mundo Lusíada e 11 de Alborada. Entre os resultados observados destaca-se que o conteúdo de ambos os títulos fornece elementos que propiciam um contato direto com as raízes desses grupos. Este demonstra elementos que permeiam a memória coletiva dos imigrantes luso e hispânico que vieram para o Brasil há mais de um século independentemente de essa identidade ser real. Mundo Lusíada, apesar de ser um veículo voltado para a comunidade luso-brasileira é segmentado, uma vez que, entre outros fatores, se utiliza de estrutura comercial de uma micro empresa. Já Alboradapode ser considerado comunitário no sentido de servir à comunidade atendida pela Sociedade Hispano Brasileira SHB (que o mantém) embora este caráter esteja mudando. Com relação a aspectos jornalísticos verificados nos dois jornais, estes se assemelham aos da pequena imprensa, numa mistura de amadorismo e fonte de status. No entanto, ambos têm papel relevante no fortalecimento dos laços de amizade, culturais e união dos envolvidos, bem como na celebração de suas origens.(AU)

Comunicação e mobilização social para o desenvolvimento sustentável em assentamentos rurais em Bituruna (Paraná)

Esta dissertação tem como objetivo analisar o papel da comunicação no processo de mobilização e transferência de tecnologias florestais e ambientais em assentamentos rurais para o desenvolvimento sustentável. A metodologia utilizada é o Estudo de Caso, de natureza qualitativa, tendo como referencial teórico a Teoria da Mobilização Social, de Bernardo Toro e Nísia Werneck (2004), por meio de observação direta. Foram realizadas observações e entrevistas com técnicos extensionistas e assentados de Bituruna/PR sobre os papéis e níveis de comunicação: micro (pessoal), macro (público segmentado) e massa (mídia em geral). Este estudo mostra a importância da comunicação e de suas ferramentas para melhorar o processo de transferência de tecnologia entre assentados e técnicos extensionistas. Revela as dificuldades inerentes ao processo comunicativo, além da necessidade de criação de mecanismos de participação coletiva dos assentados para serem sujeitos de seu desenvolvimento. Desta forma, mostra que a comunicação pode ser melhor utilizada no processo de mobilização e precisa estar inserida no planejamento dos trabalhos realizados nos assentamentos, em uma perspectiva dialógica e participativa. A comunicação pode, então, criar sentido, formular imaginários a serem alcançados e, efetivamente, mobilizar para o desenvolvimento sustentável.(AU)

O NEGÓCIO DA COMUNICAÇÃO EM TURISMO Cluster no Núcleo de Turismo da Editora Abril

Esse trabalho examina a relação da Comunicação com o Turismo discutindo a importância dos produtos de comunicação junto ao negócio do turismo no Brasil. Tem como corpus da pesquisa o Núcleo de Turismo da Editora Abril, formado pelas publicações Guia 4 Rodas, revistas Viagem e Turismo e National Geographic Brasil, e o portal de viagens www.viajeaqui.com.br. Investiga o peso e o amadurecimento do setor de turismo na economia brasileira, o crescimento e a consolidação do mercado editorial neste segmento. Discute o papel do Cluster na área de Turismo e seus efeitos no Jornalismo. Por meio da análise de conteúdo avalia os processos de produção das publicações do Núcleo, o caminho das informações compartilhadas pelos profissionais envolvidos e o impacto dessas informações nos públicos-alvos de cada veículo. Faz ainda uma reflexão sobre os limites entre Jornalismo e Publicidade em mídias segmentadas dentro de um Cluster.(AU)

OSTEOTOMIA SEGMENTAR DE MAXILA CASO CLÍNICO

A Osteotomia Segmentar de Maxila ou Osteotomia Le Fort I Segmentada é um procedimento que tem se tornado, cada vez mais comum, nas cirugias para as correções das deformidades dentofaciais, conhecidas como Cirurgias Ortognáticas. Este procedimento é muito bem indicado para a correção das discrepâncias maxilares, nos diferentes planos e num único tempo cirúrgico, otimizando assim, o tempo de tratamento a que o paciente é submetido. A estabilidade esquelética transversal e a oclusal dos pacientes, que são submetidos a este tipo de osteotomia, tem sido objeto de estudo na literatura , assim como também, os potenciais riscos e complicações inerentes a este procedimento como, a desvitalização dentária, fístula oro-nasal, perda dentária, necrose de algum segmento da maxila ou até mesmo, de toda a maxila. O objetivo deste trabalho é apresentar o caso clínico de um paciente submetido à osteotomia segmentar de maxila, e fazer uma revisão da literatura abrangendo os últimos 10 anos, com artigos que abordam a estabilidade deste tipo de procedimento, assim como também os potenciais riscos e complicações aos pacientes submetidos a este procedimento. Utilizando algumas palavras chave na base de dados eletrônica PUBMED, 12 artigos foram selecionados para este trabalho, no período de 2002 a 2012. A Osteotomia Segmentar de Maxila é um procedimento estável e seguro, com baixo índice de complicação, quando indicado corretamente e com os devidos cuidados no pré, trans e pós operatórios.

Modeling equity market integration using smooth transition analysis:a study of Eastern European stock markets

This paper assesses the extent to which the equity markets of Hungary, Poland the Czech Republic and Russia have become less segmented. Using a variety of tests it is shown there has been a consistent increase in the co-movement of some Eastern European markets and developed markets. Using the variance decompositions from a vector autoregressive representation of returns it is shown that for Poland and Hungary global factors are having an increasing influence on equity returns, suggestive of increased equity market integration. In this paper we model a system of bivariate equity market correlations as a smooth transition logistic trend model in order to establish how rapidly the countries of Eastern Europe are moving away from market segmentation. We find that Hungary is the country which is becoming integrated the most quickly. © 2005 ELsevier Ltd. All rights reserved.

Testing for market segmentation in the A and B share markets of China

Recent research has suggested that the A and B share markets of China may be informationally segmented. In this paper volatility patterns in the A and B share market are studied to establish whether volatility changes to the A and B share markets are synchronous. A consequence of new information, when investors act upon it is that volatility rises. This means that if the A and B markets are perfectly integrated volatility changes to each market would be expected to occur at the same time. However, if they are segmented there is no reason for volatility changes to occur on the same day. Using the iterative cumulative sum of squares across the different markets. Evidence is found of integration between the two A share markets but not between the A and B markets. © 2005 Taylor & Francis Group Ltd.

Studies on the generalisation of Gaussian processes and Bayesian neural networks

The assessment of the reliability of systems which learn from data is a key issue to investigate thoroughly before the actual application of information processing techniques to real-world problems. Over the recent years Gaussian processes and Bayesian neural networks have come to the fore and in this thesis their generalisation capabilities are analysed from theoretical and empirical perspectives. Upper and lower bounds on the learning curve of Gaussian processes are investigated in order to estimate the amount of data required to guarantee a certain level of generalisation performance. In this thesis we analyse the effects on the bounds and the learning curve induced by the smoothness of stochastic processes described by four different covariance functions. We also explain the early, linearly-decreasing behaviour of the curves and we investigate the asymptotic behaviour of the upper bounds. The effect of the noise and the characteristic lengthscale of the stochastic process on the tightness of the bounds are also discussed. The analysis is supported by several numerical simulations. The generalisation error of a Gaussian process is affected by the dimension of the input vector and may be decreased by input-variable reduction techniques. In conventional approaches to Gaussian process regression, the positive definite matrix estimating the distance between input points is often taken diagonal. In this thesis we show that a general distance matrix is able to estimate the effective dimensionality of the regression problem as well as to discover the linear transformation from the manifest variables to the hidden-feature space, with a significant reduction of the input dimension. Numerical simulations confirm the significant superiority of the general distance matrix with respect to the diagonal one.In the thesis we also present an empirical investigation of the generalisation errors of neural networks trained by two Bayesian algorithms, the Markov Chain Monte Carlo method and the evidence framework; the neural networks have been trained on the task of labelling segmented outdoor images.

A study of the problem solving strategies used by expert and novice designers

This research project focused upon the design strategies adopted by expert and novice designers. It was based upon a desire to compare the design problem solving strategies of novices, in this case key stage three pupils studying technolgy within the United Kingdom National Curriculum, with designers who could be considered to have developed expertise. The findings helped to provide insights into potential teaching strategies to suit novice designers. Verbal protocols were made as samples of expert and novice designers solved a design problem and talked aloud as they worked. The verbalisations were recorded on video tape. The protocols were transcribed and segmented, with each segment being assigned to a predetermined coding system which represented a model of design problem solving. The results of the encoding were analysed and consideration was also given to the general design strategy and heuristics used by the expert and novice designers. The drawings and models produced during the generation of the protocols were also analysed and considered. A number of significant differences between the problem solving strategies adopted by the expert and novice designers were identified. First of all, differences were observed in the way expert and novice designers used the problem statement and solution validation during the process. Differences were also identified in the way holistic solutions were generated near the start of the process, and also in the cycles of exploration and the processes of integration. The way design and technological knowledge was used provided further insights into the differences between experts and novices, as did the role of drawing and modelling during the process. In more general terms, differences were identified in the heuristics and overall design strategies adopted by the expert and novice designers. The above findings provided a basis for discussing teaching strategies appropriate for novice designers. Finally, opportunities for future research were discussed.

Application of the finite element method to problems in fracture mechanics

Numerical techniques have been finding increasing use in all aspects of fracture mechanics, and often provide the only means for analyzing fracture problems. The work presented here, is concerned with the application of the finite element method to cracked structures. The present work was directed towards the establishment of a comprehensive two-dimensional finite element, linear elastic, fracture analysis package. Significant progress has been made to this end, and features which can now be studied include multi-crack tip mixed-mode problems, involving partial crack closure. The crack tip core element was refined and special local crack tip elements were employed to reduce the element density in the neighbourhood of the core region. The work builds upon experience gained by previous research workers and, as part of the general development, the program was modified to incorporate the eight-node isoparametric quadrilateral element. Also. a more flexible solving routine was developed, and provided a very compact method of solving large sets of simultaneous equations, stored in a segmented form. To complement the finite element analysis programs, an automatic mesh generation program has been developed, which enables complex problems. involving fine element detail, to be investigated with a minimum of input data. The scheme has proven to be versati Ie and reasonably easy to implement. Numerous examples are given to demonstrate the accuracy and flexibility of the finite element technique.

Automatic object segmentation from calibrated images

This paper addresses the problem of automatically obtaining the object/background segmentation of a rigid 3D object observed in a set of images that have been calibrated for camera pose and intrinsics. Such segmentations can be used to obtain a shape representation of a potentially texture-less object by computing a visual hull. We propose an automatic approach where the object to be segmented is identified by the pose of the cameras instead of user input such as 2D bounding rectangles or brush-strokes. The key behind our method is a pairwise MRF framework that combines (a) foreground/background appearance models, (b) epipolar constraints and (c) weak stereo correspondence into a single segmentation cost function that can be efficiently solved by Graph-cuts. The segmentation thus obtained is further improved using silhouette coherency and then used to update the foreground/background appearance models which are fed into the next Graph-cut computation. These two steps are iterated until segmentation convergences. Our method can automatically provide a 3D surface representation even in texture-less scenes where MVS methods might fail. Furthermore, it confers improved performance in images where the object is not readily separable from the background in colour space, an area that previous segmentation approaches have found challenging. © 2011 IEEE.

Waveform type evaluation in congenital nystagmus

Congenital nystagmus is an ocular-motor disorder characterised by involuntary, conjugated and bilateral to and fro ocular oscillations. In this study a method to recognise automatically jerk waveform inside a congenital nystagmus recording and to compute foveation time and foveation position variability is presented. The recordings were performed with subjects looking at visual targets, presented in nine eye gaze positions; data were segmented into blocks corresponding to each gaze position. The nystagmus cycles were identified searching for local minima and maxima (SpEp sequence) in intervals centred on each slope change of the eye position signal (position criterion). The SpEp sequence was then refined using an adaptive threshold applied to the eye velocity signal; the outcome is a robust detection of each slow phase start point, fundamental to accurately compute some nystagmus parameters. A total of 1206 slow phases was used to compute the specificity in waveform recognition applying only the position criterion or adding the adaptive threshold; results showed an increase in negative predictive value of 25.1% using both features. The duration of each foveation window was measured on raw data or using an interpolating function of the congenital nystagmus slow phases; foveation time estimation less sensitive to noise was obtained in the second case. © 2010.