The thesis comprises five papers and an introductory overview of applied models and methods. The papers concern interdependences and interrelations in models applied to empirical analyses of various problems related to production, consumption, location and trade. Among different definitions of 'structural analysis' one refers to the study of the properties of economic models on the assumption of invariant structural relations, this definition is close to what is aimed at in lire present case. Although the subjects cover widely differing aspects of the economic system, applied models and methods, i.e. entropy maximizing (information minimizing) models and random utility maximizing models, are in many cases closely connected. Tlic first paper reports on a regional input-ouput study applied to Norrbotten, Sweden. The paper is mainly concentrated on developing and estimating an econometric model, describing the structural interdependences in the Norrbotten economy. The chapter is composed of three parts. The first part concerns the theoretical basis of the model, the main fields of application and principal problems in connection with the estimation. The core of the estimated model is defined by the intersectoral dependences in the Norrbotten economy. This model can be viewed as a part of a more general model of the regional economy, and such a general model is briefly outlined. The second part reports on the collection and arranging of data, and the methods used for the estimation of the model. In the third part the results are presented. A special interest concerns the effects of production changes in the basic industries in the county, as to the expected impact on different industries and occupational groups. The second paper concerns some aspects of the problem of predicting trade flows in the forest sector. The model, based on information theory, is predicting current trade flows by adjusting the historical, a priori, trade flows to satisfy current export and import totals. In the third paper an entropy model is employed to decompose the interregional and intraregional employment change in Sweden and Stockholm, during the period 1960 - 1980, into effects attributed to regions (zones), industries, occupations and interaction effects. The fourth paper presents an empirical analysis of housing choice, based on individual data of households in Stockholm. The consumer choice is regarded as a complex choice from a finite set of discrete alternatives and a probabilistic choice mode! (multinomial logit) is employed, where secondary dwelling is included in the housing choice decision. In the final paper spectral analysis is used for identifying the significant components of cycle behaviour in time series of Swedish exports of forest products over a twenty year time period. / digitalisering@umu

Rapid and deep transport of solutes in soils can potentially pollute groundwater resources. Field estimates of solute leaching depth based on randomized sampling provide extremely variable field average estimates that confound the treatment effects of the leaching study with the high spatial variation of soil hydraulic properties. The purpose of this study was to investigate the spatial scale of variation of solute (Bromide) leaching depth, and apply this scale of variation to study the leaching depth of Bromide as a function of a sinusoidal application of transport causing factors, i.e., rainfall amount, intensity and application time delay. Solute leaching depth varied over different spatial scales. The deepest leaching was observed on plots where the Br center of mass ranged from 19-30 cm depth. Deep leaching occurred with large quantities of low intensity precipitations (5.5 to 6 cm/day) and short time delays (≤ 17 hours), respectively. The hydraulic gradient presented cyclic variation at 8 m wavelength across the 10-30cm depth compartment. Spectral analysis indicated that spatial variation of the leaching depth was mainly affected by precipitation amount and intensity and only a small portion of the leaching depth variation was caused by time delay. Cross-spectral analysis identified common cyclic variation between the Br leaching depth and precipitation amount, intensity and time delay over 32, 32 and 8 m wavelengths, respectively. Simulated Br concentration over depth and horizontal distance and soil water matric potential ψm were in good agreement with experimental observations, the latter revealing a satisfactory Br and water mass balance.

Feeding problems in preterm neonates stem from complications of early delivery. Attainment of independent feeding is a prerequisite for Neonatal Intensive Care Unit (NICU) discharges. Some quantitative studies of infant feeding involve excessive amounts of time for data processing. Multivariate spectral analysis was used to minimize time for investigation of variability in these rhythms. Auto and Cross-spectral parameters of the rhythms were correlated with Gestational Age (GA), Postmenstrual Age (PMA), Birthweight (BW), Days of Life (DOL), and Time Since First Nipple feeding (TSFN). Auto-spectral analysis showed 25.55% increase in Bandwidth of suck (bw-su) for a 2-week increase in GA (DOL fixed) and 8.99% increase in bw-su for a 10-day increase in DOL (GA fixed). Crossspectral analysis showed a decrease of 0.158Hz of Bandwidth of Suck-Swallow (bw-SS) for a 2-week increase in GA for GA later than 28 weeks. For GA earlier than 28 weeks, peak coherence decreased by 0.774 for a 2-week increase in GA (PMA fixed) and decreased by 0.126 for a 2-week increase in PMA (GA fixed). The method describes the progression of feeding rhythms through correlations with clinical indexes, thus providing clinicians with an understanding of the development of infant feeding and helps predict long-term developmental outcomes.

No description available.

Infants with hearing loss (HL) are being diagnosed and fitted with amplification earlier than ever before. In order to acquire speech and language abilities that are on par with their normal-hearing (NH) peers, hearing-impaired (HI) infants require amplification that provides appropriate exposure to the sounds of their native language. To date, no research has addressed this issue and thus, there is a need to examine the type of amplification that is most suitable for infants during the early stages of language acquisition. In this thesis, three different amplification types were compared: one that preserves the natural spectral shape of speech (unmodified speech); a second that emphasises high-frequency speech information (positive spectral tilt); and a third that emphasises low-frequency information (negative spectral tilt). NH infants were tested to examine how each of these amplification types affects speech perception and to explore whether infants at different stages of language acquisition find modified spectral tilt a help or hindrance in perceiving native-language speech contrasts. A visual habituation (VH) procedure was used to test 288 6- and 9-month-old NH infants on their ability to discriminate the high-frequency fricative contrast /f/- /s/; the mid-frequency approximant contrast /l/-/r/; and the low-frequency vowel contrast /5/-/N/ under modified spectral tilt conditions. For each speech contrast, 96 infants were tested in one of three conditions: (a) unmodified spectral tilt (n = 32); (b) with a positive 6 dB/octave spectral tilt (n = 32); or (c) with a negative 6 dB/octave spectral tilt (n = 32). The results showed that both 6- and 9-month-olds discriminated the three speech contrasts in the unmodified condition. However, when the contrasts were spectrally modified, a consistent developmental trend emerged. Six-month-olds’ discrimination performance improved when the spectral tilt modification amplified the relevant frequency information. That is, for the consonant contrasts (fricatives /f/-/s/ and approximants /l/-/r/) 6-month-olds performed best when high-frequency information was emphasised, whereas for the vowel contrast (/5/-/N/) the best discrimination performance was found when low-frequency information was enhanced. Nine-month-olds, on the other hand, showed no evidence of discriminating any of the contrasts when spectral tilt was modified. For all three contrasts, the older infants’ best discrimination performance was in the unmodified spectral tilt condition. The findings reflect the early stages of linguistic development. Six-month olds, whose acoustically driven speech perception operates in a language-general mode, demonstrated a broad-based ability to discriminate speech sounds. They not only accommodated speech with positive or negative spectral tilt, but a facilitation effect was observed when relevant frequency information was amplified. In contrast, 9-month-olds, whose perception is linguistically driven, found that spectral tilt modifications hinder speech perception. It seems that because older infants are attuning to native phonemic categories, their attention is constrained to native language spectral profiles only. Thus, even those spectral tilt modifications that should have been beneficial for perception were eschewed by 9-month-olds because they were incompatible with the older infants���� narrow focus on spectrally intact native speech sounds. Only NH infants were tested in this study, so it is not possible draw firm conclusions about amplification schemes until HI infants are tested too. Nevertheless, the results have a number of implications for infants with HL. The demonstration that spectral tilt modifications interfere with older NH infants’ speech perception suggests that future research should investigate whether HI infants also show this developmental pattern. That is, do HI infants progressively attune to the native language, and if so, does this affect their perception of spectrally modified speech sounds? Moreover, if HI infants are to attune to the native language and acquire speech and language in the same way as their NH peers, then the research reported here suggests that, throughout infancy, HI infants will need access to amplified speech that maintains the spectral shape of natural speech. Thus, the current research demonstrates, for the first time, a developmental difference in the way that infants perceive spectrally modified speech, one that is closely linked to the infant’s stage of native-language attunement. This research provides a solid foundation on which to conduct further research with HI infants and offers preliminary suggestions with regard to amplification and intervention to ensure that HI infants have the opportunity to emulate the native-language attunement process and subsequently achieve language development outcomes comparable with their NH peers. / Doctor of Philosophy (PhD)

Doctor of Philosophy / This dissertation provides an overview of my research over the last five years into the spectral analysis involved in human sound localization. The work involved conducting psychophysical tests of human auditory localization performance and then applying analytical techniques to analyze and explain the data. It is a fundamental thesis of this work that human auditory localization response directions are primarily driven by the auditory localization cues associated with the acoustic filtering properties of the external auditory periphery, i.e., the head, torso, shoulder, neck, and external ears. This work can be considered as composed of three parts. In the first part of this work, I compared the auditory localization performance of a human subject and a time-delay neural network model under three sound conditions: broadband, high-pass, and low-pass. A “black-box” modeling paradigm was applied. The modeling results indicated that training the network to localize sounds of varying center-frequency and bandwidth could degrade localization performance results in a manner demonstrating some similarity to human auditory localization performance. As the data collected during the network modeling showed that humans demonstrate striking localization errors when tested using bandlimited sound stimuli, the second part of this work focused on human sound localization of bandpass filtered noise stimuli. Localization data was collected from 5 subjects and for 7 sound conditions: 300 Hz to 5 kHz, 300 Hz to 7 kHz, 300 Hz to 10 kHz, 300 Hz to 14 kHz, 3 to 8 kHz, 4 to 9 kHz, and 7 to 14 kHz. The localization results were analyzed using the method of cue similarity indices developed by Middlebrooks (1992). The data indicated that the energy level in relatively wide frequency bands could be driving the localization response directions, just as in Butler’s covert peak area model (see Butler and Musicant, 1993). The question was then raised as to whether the energy levels in the various frequency bands, as described above, are most likely analyzed by the human auditory localization system on a monaural or an interaural basis. In the third part of this work, an experiment was conducted using virtual auditory space sound stimuli in which the monaural spectral cues for auditory localization were disrupted, but the interaural spectral difference cue was preserved. The results from this work showed that the human auditory localization system relies primarily on a monaural analysis of spectral shape information for its discrimination of directions on the cone of confusion. The work described in the three parts lead to the suggestion that a spectral contrast model based on overlapping frequency bands of varying bandwidth and perhaps multiple frequency scales can provide a reasonable algorithm for explaining much of the current psychophysical and neurophysiological data related to human auditory localization.

Made available in DSpace on 2016-08-17T18:39:51Z (GMT). No. of bitstreams: 1 6222.pdf: 2879821 bytes, checksum: 010a3c6abf3b0c6f2ec81ebf9ff59ef0 (MD5) Previous issue date: 2014-08-21 / Universidade Federal de Sao Carlos / Aging causes changes in several human subsystems such as the cardiovascular and immune systems. The objective of this study was to evaluate the relationship between baroreflex function through linear algorithm (cross-spectral analysis) and proinflammatory cytokines in the aging process and also assess the baroreflex sensitivity, TNF-α, IL-6 and hsCRP in different ages and in the aging process. One hundred and ten apparently healthy subjects divided into 5 groups with 22 individuals each, according to age were evaluated: 21-30 years, 30-40 years, 40-50 years, 50-60 years, 60-70 years. The experimental protocol consisted of a blood samples collection for analysis of inflammatory markers and in the same day were collected ECG, blood pressure and respiratory movements for 15 minutes in the supine position and in standing position, after the active postural change for 15 minutes. For the analysis of baroreflex sensitivity cross spectral analysis (coherence, phase and gain) was used and ELISA method for analysis of TNF-α and IL-6 was used. Data were analyzed using analysis of variance one-way ANOVA test with Tukey test post-hoc or Kruskal-Wallis oneway ANOVA with Dunn's post-hoc according to the normality of the data and the Spearman correlation test. The level of significance for the tests was 5%. The main results were: 1) reduced baroreflex sensitivity during the aging process; 2) increased levels of inflammatory markers in the aging process; 3) negative correlation between IL-6 and BF gain and phase; 4) negative relationship between hsCRP and coherence, phase and gain in BF. It can be concluded that the human natural aging causes a loss of baroreflex sensitivity and increased serum levels of inflammatory markers studied, although the decrease in baroreflex sensitivity as function of the decreasing of vagal autonomic function occurred in the 41-50 age range, and only in the next age was observed changes in inflammatory markers. / O envelhecimento causa alterações em diversos subsistemas humanos como o cardiovascular e imunológico. O objetivo deste trabalho foi avaliar a relação entre a função barorreflexa, por meio de algoritmo linear (análise espectral cruzada) e citocinas próinflamatórias no processo de envelhecimento e ainda, avaliar a sensibilidade barorreflexa, IL- 6, TNF-α e PCRus em diversas faixas etárias e no processo de envelhecimento. Foram avaliados 110 indivíduos aparentemente saudáveis divididos em 5 grupos com 22 indivíduos cada, de acordo com a faixa etária: 21-30 anos, 30-40 anos, 40-50 anos, 50-60 anos, 60-70 anos. O protocolo experimental consistiu em uma coleta de amostras de sangue para a análise dos marcadores inflamatórios e no mesmo dia foram coletados o eletrocardiograma (ECG), a pressão arterial de pulso e a respiração por 15 minutos na postura supina, logo após foi realizada a mudança postural ativa de supino para ortostatismo, permanecendo 15 minutos nesta posição a coleta de sangue. Para a análise da sensibilidade barorreflexa foi utilizada a analise espectral cruzada e o método ELISA para análise das citocinas TNF-α e IL-6. Os dados foram analisados por meio do teste de análise de variância ANOVA one-way com posthoc de Tukey ou Kruskal-Wallis ANOVA one-way com post-hoc de Dunn s de acordo com a normalidade dos dados e teste de Correlação de Spearman. O nível de significância estabelecido para os testes foi de 5%. Os principais resultados foram: 1) redução da sensibilidade barorreflexa durante o processo de envelhecimento; 2) aumento dos níveis dos marcadores inflamatórios no processo de envelhecimento; 3) relação negativa entre a IL-6 e fase e ganho em BF; 4) relação negativa entre PCRus e coerência, fase e ganho em BF. Podese concluir que o envelhecimento natural humano causa a redução da sensibilidade barorreflexa e aumento dos níveis séricos dos marcadores inflamatórios estudados, ainda a diminuição da sensibilidade barorreflexa em consequência da diminuição da função autonômica vagal correu na faixa etária 41-50 e somente na faixa etária seguinte foi observada alterações nos marcadores inflamatórios.

Este trabalho apresenta um estudo comparativo entre análises no domínio do tempo e análises espectrais, como forma de sugerir uma abordagem alternativa para o projeto de pontes de seção celular submetidas à ação de terremotos. Com esse propósito, desenvolveu-se um programa em linguagem JAVA para a geração de sismos artificiais, usando como base o Eurocode 8. A saída do programa foi utilizada para o desenvolvimento de um estudo de caso, que consiste em uma modelagem simplificada no software ADINA, de um vão de 21 m da Ponte Alverca, em Portugal. Após a extração e comparação de resultados dos dois métodos, é possível perceber que o método alternativo proposto - no domínio do tempo, que consiste na aplicação de acelerogramas artificiais ao modelo - possui resultados bastante coerentes com a análise espectral, além de ser mais recomendado se efeitos geométricos ou fisicamente não lineares forem considerados na modelagem. / This work presents a comparative study between time-domain analysis and spectral analysis, as a way of suggesting an alternative approach for treating cell section bridges subjected to earthquakes. To reach this goal, it was developed a program in JAVA language for the artificial earthquakes generation, using the Eurocode 8 as a basis. The program output was used for a case study that consists in a simplified modeling using ADINA software, of a twenty-one-meter-long span of Alverca Bridge, in Portugal. After the results extraction of both methods, it is possible to notice that the alternative method - in the time-domain, which consists of the application of artificial accelerograms to the model - has fairly consistent results with spectral analysis, not to mention that it is the most suitable one, in case geometrical or physical non-linearities are considered in the modelling.

Sob o regime de metas de inflação cabe à autoridade monetária balisar seus instrumentos de política de forma a manter a estabilidade do nível geral de preços. Neste aspecto, pelo caráter volátil dos índices de inflação cheia os bancos centrais de todo o mundo utilizam o conceito de núcleo da inflação para tentar capturar com maior acurácia a tendência subjacente da taxa de inflação. Muitas vezes os índices de preços ao consumidor estão altamente sujeitos a volatilidades decorrentes de fatores temporários e muitas vezes localizados. E já que o objetivo da autoridade monetária está em zelar pela estabilidade \"real\" (ou de fato) do nível geral de preços, mudanças temporárias ou localizadas não afetam as taxas de inflação no longo prazo e, consequentemente, não cabe à autoridade monetária responder a tais mudanças, pois isso poderia gerar uma volatilidade desnecessária à política monetária com consequência sobre as flutuações da atividade econômica no período. Dessa forma, Bancos Centrais do mundo inteiro fazem uso de núcleos de inflação. Este trabalho aplica uma nova metodologia de cálculo de núcleo para a inflação brasileira, utilizando o modelo de fatores dinâmicos generalizados. Esta abordagem permite diferenciar fatores localizados (idiossincráticos) dos choques comuns (generalizados) em um grande conjunto de dados. Usamos o IPCA em seu nível mais desagregado e geramos o choque comum entre este conjunto. E a este choque chamamos de núcleo da inflação. Sua eficiência em termos de antecedência à inflação cheia no curto prazo foi testada por meio de uma cointegração, VEC, tais resultados foram comparados com o desempenho do núcleo por Exclusão, mostrando uma maior eficiência do núcleo aqui encontrado. / Under the inflation target system lies to the monetary authority the evaluation of the best tools to keep general price stability. In this context, due to the volatile character of the inflation, central banks around the world use the concept of the inflation core in attempt to capture in a more accurately way the prices trends. Several times, consumer prices indexes are subjected to very volatile prices, due to temporary or localized factors. As the vigilance of the monetary authority relies on the real stability of the general prices level, temporary or localized changes doesn\'t affect the inflation indexes in the long run and, therefore, it\'s not an issue to the central bank to respond to this variations, this could indeed create an unnecessary volatility to the monetary politics with consequences to the economic activity in the period. This way, central banks around the world calculate and use inflation core. This paper applies a new methodology to calculate the inflation core to the Brazilian inflation, using the generalized dynamic factor model. With this approach it\'s possible to differentiate the localized factors from the common (generalized) shocks in a great data set. We use IPCA on its more disaggregated level and create a common shock in the data set, and we name this shock the inflation core. We test the advance of this core to the inflation in the short run using a VEC, and compare with the results of the Exclusion core, we show that your core by using dynamic factor model is more effcient then Exclusion core.

A monitoração do processo de fermentação alcoólica para a obtenção de etanol é um tema de grande interesse pelo fato deste ser utilizado como fonte sustentavel de energia na indústria. Os processo de monitoração convencionalmente utilizados na indústria são dispendiosos, baseados em medições supervisionadas de densidade e estimativas de parâmetros químicos mediante procedimentos offline. O uso de técnicas de monitoração não invasivas baseadas em ultra-som vem sendo desenvolvidas para esse fim, fazendo uso de estimativas de parâmetros clássicos como a velocidade de propagação acústica e a atenuação. No entanto, a evolução do processo fermentativo não é bem descrita por esses parâmetros. Devido a isso, o presente trabalho propõe um sistema híbrido de processamento de sinais de ultra-som que utiliza um conglomerado de parâmetros para uma caracterização mais eficiente do processo fermentativo. O sistema incorpora procedimentos computacionais para a detecção, caracterização e classificação das fases do mosto em fermentação, visto como uma suspensão sólido-líquido (fase dispersa e contínua). Esses procedimentos foram baseadas em estimativas de estacionariedade dos sinais de retroespalhamento de ultra-som ( teste de hipotese não paramétrico - Teste de Run), ajuste de curvas sobre a largura de banda espectral (técnica de curve fitting), assim como a extração de atributos espectrais tais como : frequência central, largura de banda e valores de amplitude da componente fundamental, entre outros, além de parâmetros ultra-sônicos como o coeficiente de atenuação (slope) e o coeficiente integrado de retro-espalhamento (IBC). Para a classificação foi utilizado o algoritmo K-means. Os resultados obtidos mostraram a viabilidade na caracterização multiparamétrica não invasiva do fluido em fermentação, permitindo a identificação das principais fases do processo fermentativo. O trabalho contribui com uma metodología alternativa para a avaliação da cinética do crescimento microbiano como indicador da evolução da fermentação alcoólica. / Monitoring of alcoholic fermentation process for the ethanol production is a topic of great interest because it can be used as a sustainable energy source in the industry. The monitoring process conventionally used in industry are expensive, based on supervised measurements of density and parameter estimates by chemical offline procedures. The use of noninvasive monitoring techniques based on ultrasound are being developed for this purpose, using estimates of classical parameters as the acoustic propagation velocity and attenuation. However, the time evolution of the fermentation process is not well described by these parameters. For this reason, this study proposes a hybrid system of ultrasound signal processing that uses a conglomerate of parameters aiming a more efficient characterization about the fermentation process. The system incorporates computational procedures for the detection, characterization and classification of the fermentation must phases, seen as a solid-liquid suspension (dispersed and continuous phases). These procedures were based on estimates of stationarity for ultrasound backscattered signals (non-parametric statistical test - Run Test), curve fitting on the spectral bandwidth, as well as spectral attributes extraction such as center frequency, bandwidth and energy values of the fundamental frequency and so on, plus ultrasonic parameters as the attenuation coefficient (slope) and the integrated back-scattering coefficient (IBC). For classification we used the k-means algorithm. The results showed the feasibility for the multiparametric noninvasive characterization of fluid in fermentation, identifying the main stages of the fermentation process. This work contributes with an alternative methodology to evaluate the kinetics of microbial growth as an indicator of the alcoholic fermentation evolution.