Delirium is common among old patients admitted to hospital, but is often a neglected problem in patient care. The principal aim of this thesis was to evaluate aspects of delirium in relation to incidence, risk factors, behavioural changes, cognitive function and health-related quality of life (HRQOL). A further aim was to describe patients’ experiences of being delirious. The study was prospective, descriptive and comparative, with repeated measures (six-month follow up). The sample consisted of 225 consecutive patients, aged 65 years or older, who were to be operated on due to hip fracture or hip replacement. Exclusion criteria were serious cognitive disorder or delirium on admission. Data were collected via frequent daily observations, cognitive functioning tests (MMSE), HRQOL questionnaires (SF-36) and interviews. Delirium was assessed according to the DSM-IV criteria. A total of 45/225 became delirious, with an incidence of 24.3% among patients undergoing hip fracture surgery and 11.7% among those with hip replacement surgery. A predictive model for delirium included four factors: impaired hearing, passivity, low cognitive functioning, and waiting more than 18h for hip fracture surgery. Disorientation and urgent calls for attention were the most frequent behavioural changes in the prodromal phase prior to delirium. Delirium in connection with hip fracture revealed deteriorated HRQOL and cognitive functioning when measured at a six-month follow-up. The experience of being delirious was described by the patients as a sudden change of reality. Such an experience gave rise to strong emotional feelings, as did recovery from delirium. Nurses’ observations of behavioural changes in old patients with impaired cognitive function may be the first step in managing and reducing delirium. The predictive model of delirium ought to be tested further before use in clinical practice.

This thesis is targeted at precoding methods and resource allocation for the downlink of fixed multi-user multi-antenna broadband wireless systems. We explore different utilizations of precoders in transmission over frequency-selective channels. We first consider the weighted sum-rate (WSR) maximization problem for multi-carrier systems using linear precoding and propose a low complexity algorithm which exhibits near-optimal performance. Moreover, we offer a novel rate allocation method that utilizes the signalto- noise-ratio (SNR) gap to capacity concept to choose the rates to allocate to each data stream. We then study a single-carrier transmission scheme that overcomes known impairments associated with multi-carrier systems. The proposed scheme utilizes timereversal space-time block coding (TR-STBC) to orthogonalize the downlink receivers and performs the required pre-equalization using Tomlinson-Harashima precoding (THP).We finally discuss the strengths and weaknesses of the proposed method.

This thesis is targeted at precoding methods and resource allocation for the downlink of fixed multi-user multi-antenna broadband wireless systems. We explore different utilizations of precoders in transmission over frequency-selective channels. We first consider the weighted sum-rate (WSR) maximization problem for multi-carrier systems using linear precoding and propose a low complexity algorithm which exhibits near-optimal performance. Moreover, we offer a novel rate allocation method that utilizes the signalto- noise-ratio (SNR) gap to capacity concept to choose the rates to allocate to each data stream. We then study a single-carrier transmission scheme that overcomes known impairments associated with multi-carrier systems. The proposed scheme utilizes timereversal space-time block coding (TR-STBC) to orthogonalize the downlink receivers and performs the required pre-equalization using Tomlinson-Harashima precoding (THP).We finally discuss the strengths and weaknesses of the proposed method.

Reducing interference noise in a noisy speech recording has been a challenging task for many years yet has a variety of applications, for example, in handsfree mobile communications, in speech recognition, and in hearing aids. Traditional single-channel noise reduction schemes, such as Wiener filtering, do not work satisfactorily in the presence of non-stationary background noise. Alternatively, supervised approaches, where the noise type is known in advance, lead to higher-quality enhanced speech signals. This dissertation proposes supervised and unsupervised single-channel noise reduction algorithms. We consider two classes of methods for this purpose: approaches based on nonnegative matrix factorization (NMF) and methods based on hidden Markov models (HMM).  The contributions of this dissertation can be divided into three main (overlapping) parts. First, we propose NMF-based enhancement approaches that use temporal dependencies of the speech signals. In a standard NMF, the important temporal correlations between consecutive short-time frames are ignored. We propose both continuous and discrete state-space nonnegative dynamical models. These approaches are used to describe the dynamics of the NMF coefficients or activations. We derive optimal minimum mean squared error (MMSE) or linear MMSE estimates of the speech signal using the probabilistic formulations of NMF. Our experiments show that using temporal dynamics in the NMF-based denoising systems improves the performance greatly. Additionally, this dissertation proposes an approach to learn the noise basis matrix online from the noisy observations. This relaxes the assumption of an a-priori specified noise type and enables us to use the NMF-based denoising method in an unsupervised manner. Our experiments show that the proposed approach with online noise basis learning considerably outperforms state-of-the-art methods in different noise conditions.  Second, this thesis proposes two methods for NMF-based separation of sources with similar dictionaries. We suggest a nonnegative HMM (NHMM) for babble noise that is derived from a speech HMM. In this approach, speech and babble signals share the same basis vectors, whereas the activation of the basis vectors are different for the two signals over time. We derive an MMSE estimator for the clean speech signal using the proposed NHMM. The objective evaluations and performed subjective listening test show that the proposed babble model and the final noise reduction algorithm outperform the conventional methods noticeably. Moreover, the dissertation proposes another solution to separate a desired source from a mixture with arbitrarily low artifacts.  Third, an HMM-based algorithm to enhance the speech spectra using super-Gaussian priors is proposed. Our experiments show that speech discrete Fourier transform (DFT) coefficients have super-Gaussian rather than Gaussian distributions even if we limit the speech data to come from a specific phoneme. We derive a new MMSE estimator for the speech spectra that uses super-Gaussian priors. The results of our evaluations using the developed noise reduction algorithm support the super-Gaussianity hypothesis. / <p>QC 20130916</p>

Le langage parlé complété (LPC) est un système de communication visuel qui utilise des formes de main placés dans différentes positions près du visage, en combinaison avec le discours de la lecture labiale naturel, pour améliorer la perception de la parole à partir de l'entrée visuelle pour les personnes sourdes. Cependant l'un des défis importants est la question de la communication de la parole entre les personnes normo-entendant qui ne pratiquent pas LPC mais produisent discours acoustique et les personnes sourdes qui utilisent la lecture labiale complété par code LPC pour la perception de la parole sans audition résiduelle. Dans notre travail, nous appliquons la méthode de régression linéaire multiple (MLR) et modèle gaussien de mélange (GMM) approche pour mapper des paramètres spectraux acoustiques à la position de la main dans LPC et la forme de la lèvre d'accompagnement. Nous donc contribué à la mise au point d'un système de traduction automatique dans le cadre de la synthèse de la parole visuelle.Cela prouve que l'approche MLR est bonne pour l'estimation des paramètres pour les lèvres à partir des paramètres spectraux car il y a forte corrélation linéaire entre les paramètres des lèvres et des paramètres spectraux. Cependant, la performance de l'approche MLR pour estimer la position de la main est faible car il n'y a pas de relation entre les positions de la main et des paramètres spectraux. En introduisant un espace intermédiaire, il s'avère que la structure de topologie similaire est la clé de la MLR. Afin de libérer de la contrainte linéaire de l'approche MLR, nous appliquons la méthode de cartographie basée sur GMM qui possède à la fois les propriétés de classification et de régression. Les paramètres de GMM sont estimés par les méthodes de formation supervisées, non supervisées et semi- supervisés séparément dans la vue de la théorie de l'apprentissage de la machine. La méthode de formation supervisée montre une grande efficacité et une bonne robustesse. Le Minimum Mean Square Error (MMSE) et Maximum A Posteriori Probabilité (MAP) sont utilisés comme critères de régression séparément dans l'approche de la cartographie basée sur GMM. Cela prouve que l'approche MLR est un cas particulier de l'approche de GMM lorsque le nombre de gaussiennes est égal à un. Ainsi, l'approche de la cartographie sur GMM peut améliorer la performance significative en comparaison avec le MLR en augmentant le nombre de gaussiennes. Enfin, les différentes approches de cartographie utilisées dans ce travail sont comparées dans une transition continue. Il montre que l'approche sur GMM peut effectuer bien grâce à la propriété de classification lorsque les données source et cible n'a pas de " relation" comme dans le cas de l'estimation de la position de la main, et il peut également améliorer les performances par la propriété de régression local lorsque la source et les données cible a forte corrélation comme dans le cas du paramètre de lèvre estimation. En outre, une prédiction directe de la géométrie des lèvres comporte de l'image naturelle de la bouche région d'intérêt (ROI) sur la base de la 2D transformée en cosinus discrète (DCT) combinée à une analyse en composante principale (ACP) est proposé. Les résultats montrent la possibilité d'estimer les caractéristiques géométriques de la lèvre avec une bonne précision en utilisant un ensemble réduit de prédicteurs dérivés des coefficients DCT.

Ubiquitous location-aware systems and services are becoming a reality as made evident by the widely known Global Position System (GPS). However, indoor location-aware sensing systems are not yet commercially viable since: (i) for a GPS-based system, the signals attenuate and can multipath indoors causing weak signal and poor location (ii) for a Radiolocation-based system, the propagation of radio signals are complex and difficult to model. In this paper, we present RadLoco, a location-sensing system that uses IEEE 802.11 Wireless LAN survey techniques to create a radio Received Signal Strength (RSS) map of the propagation environment. To provide accurate location estimation, we make use of a kernel-window estimation algorithm that is used to approximate the probability density function of RSS measurement and location. Unlike parametric estimators, this non-parametric kernel approach requires less knowledge of the distributions of location and measurements, and also makes use of the prior knowledge of mobile terminal location to reduce the estimation error. The novelty of the system is an innovative radio/ultrasonic sensory network which allows for rapid data collection whereas the standard technique of defining a grid of survey points with measuring rulers, chalk, and tape would require a great amount of manpower. Using this sensory network, a 2000m sq. office building is surveyed in four hours by a single technician. Our experimental results indicate the mobile terminal is located on the correct oor with over 98% accuracy and with a mean error of less than 2.5m from the true location.

Made available in DSpace on 2014-12-17T14:13:33Z (GMT). No. of bitstreams: 1 PatriciaEMM_Tese.pdf: 847319 bytes, checksum: 45c87b0995e32e622482e82ba5c34d31 (MD5) Previous issue date: 2009-10-09 / The aim of the present study was to assess the presence of depressive symptomatology among elderly residents in long-stay institutions (LSI) and in the community of Recife, Brazil. In total, 81 long-stay elderly patients (mean age of 75.55 ? 9.18 years) and 132 elderly (mean age of 73.14 ? 8.27 years) individuals from the community were evaluated. Depressive symptomatology was assessed by the Geriatric Depression Scale (GDS-15), cognitive status by the Mini Mental State Examination (MMSE) and capacity to perform the activities of daily living (ADL) by the Katz Index. Comorbities and the use of medication were recorded. The LSI elderly exhibited more depressive symptoms (p < 0.001) and more dependency (p< 0.001). We observed no differences in MMSE (p = 0.058). The elderly in the community displayed more comorbidities and the LSI elderly consumed more medication (p < 0.001 and p < 0.001, respectively). According to multivariate analysis (logistic regression), being male, having no spouse and having a low schooling level are risk factors for depressive symptoms. In conclusion, most elderly with depressive symptoms received no medication fordepression. / Avaliar a preval?ncia de sintomas depressivos entre idosos e pacientes portadores de doen?a pulmonar obstrutiva cr?nica (DPOC) e suas rela??es com os n?veis de TNF-&#945; e IL-2 e o horm?nio cortisol, comorbidades, consumo de medicamentos, composi??o corporal e desempenho no teste de caminhada de seis minutos (TC6min). Metodologia: Foram avaliados idosos e pacientes com DPOC quanto a presen?a de sintomas depressivos (GDS-15), cogni??o (MMSE), atividades de vida di?ria (AVD), composi??o corporal (Bioimped?ncia El?trica), TC6min, cortisol s?rico (Eletroquimioluminesc?ncia), TNF-&#945; e IL-2 plasm?tico (Elisa). Resultados: Artigo 1. Os idosos das institui??es de longa perman?ncia (ILP) apresentaram mais sintomas depressivos, depend?ncia e maior consumo de medicamentos enquanto os da comunidade apresentaram mais comorbidades. Na an?lise multivariada, pertencer ao sexo masculino, n?o ter companheiro e ter baixa escolaridade se apresentaram como fatores de risco para a sintomatologia depressiva. Artigo 2.Os sintomas depressivos ocorreram em 22,5% dos pacientes com DPOC do sexo masculino. A deple??o muscular ocorreu a partir do n?vel leve de obstru??o entre aqueles sem sintomas e moderado entre aqueles com depress?o. A dist?ncia percorrida ficou abaixo do previsto e o tempo de caminhada com encorajamento foi maior no grupo sem sintomas. Artigo 3. A preval?ncia de sintomas depressivos foi maior no grupo dos pacientes DPOC. O n?mero de comorbidades foi maior entre aqueles com sintomas depressivos. N?o foram encontradas diferen?as quanto aos n?veis de TNF-&#945;, IL-2, cortisol, n?mero de anos de fumo e ma?os-ano entre os grupos. O grupo DPOC apresentou maior freq??ncia de deple??o nutricional em rela??o aos idosos. Conclus?o: Os sintomas depressivos foram mais prevalentes entre idosos das ILP e com DPOC, e esses n?o foram acompanhados de tratamento com antidepressivos. N?o foram observadas diferen?as entre os n?veis de TNF-&#945;, IL-2 e cortisol entre idosos da comunidade e com DPOC

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-04-10T14:24:23Z No. of bitstreams: 1 denisemendoncademelo.pdf: 507802 bytes, checksum: c3b5542230bfc09c6418bdaf6d4288e2 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-04-11T11:35:29Z (GMT) No. of bitstreams: 1 denisemendoncademelo.pdf: 507802 bytes, checksum: c3b5542230bfc09c6418bdaf6d4288e2 (MD5) / Made available in DSpace on 2017-04-11T11:35:29Z (GMT). No. of bitstreams: 1 denisemendoncademelo.pdf: 507802 bytes, checksum: c3b5542230bfc09c6418bdaf6d4288e2 (MD5) Previous issue date: 2016-12-07 / O Mini Exame do Estado Mental (MEEM) é o instrumento de rastreio do status cognitivo mais utilizado no mundo. Apesar de sua relevância, suas propriedades psicométricas não têm sido suficientemente analisadas no Brasil. O objetivo principal desta tese foi analisar as propriedades psicométricas da versão brasileira dessa medida proposta por Brucki et al (2003) com Teoria Clássica dos Testes e com Teoria de Resposta ao Item (TRI), enfatizando a escolaridade. Para tanto, foram desenvolvidos dois estudos. Antes, porém, realizou-se uma revisão sistemática das pesquisas empíricas indexadas na base de dados SciELO que utilizaram o MEEM com idosos no Brasil (N=74), que identificou 11 versões do MEEM. Mais da metade desses estudos adotou a escolaridade para estabelecer pontos de corte. Constatou-se que as propriedades psicométricas dessa medida têm sido pouco investigadas no país e, consequentemente, faltam padronização e evidências de validade. O segundo estudo teve como objetivo obter evidências de validade baseadas na estrutura interna para essa medida por meio de análise de componentes principais (ACP) e de análise fatorial confirmatória (AFC). Uma amostra de 2734 idosos participantes do estudo FIBRA Unicamp foi pesquisada. Na ACP, uma solução com cinco componentes foi a mais adequada. Quatro modelos de estrutura interna foram testados com AFC. Dois modelos com estrutura multidimensional de cinco fatores e um fator de segunda ordem apresentaram índices de ajuste satisfatórios, o que não ocorreu com o modelo unidimensional. Assim, há evidências de que se trata de uma medida multidimensional. O terceiro estudo apresentou uma análise com TRI para avaliar o funcionamento diferencial dos itens (DIF), a dificuldade e a discriminação dos itens. Constatou-se que quatro itens do sete seriado foram os mais difíceis e os itens nove, 13, 22 e 23, os mais fáceis. O nível de habilidade das pessoas foi maior do que o nível de dificuldade dos itens. Observou-se DIF para escolaridade (27 itens), sexo (18 itens) e idade (16 itens). Conclui-se que o uso do MEEM com idosos da comunidade deve ser cauteloso devido ao grande número de itens enviesados, principalmente pela escolaridade. Em suma, a versão do MEEM analisada apresentou evidências de validade baseadas na estrutura interna, e é fortemente influenciada pela escolaridade. / The Mini Mental State Examination (MMSE) is the screening tool of cognitive status most used in the world. Despite its relevance, its psychometric properties have not been sufficiently analyzed in Brazil. The main purpose of this thesis was to analyze the psychometric properties of a Brazilian version of this measure suggested by Brucki et al (2003) with Classical Theory of Tests and Item Response Theory (IRT), emphasizing education. For this, two studies were developed. First, however, there was a systematic review of empirical research indexed in SciELO database that used the MMSE with elderly (N = 74), which identified 11 versions of the MMSE. More than half of these studies adopted the school to establish cutoffs. It was found that the psychometric properties of this measure have been little investigated in the country and, consequently, lack standardization and evidence of validity. The second study aimed to obtain evidence of validity based on the internal structure for this measure by principal component analysis (PCA) and confirmatory factor analysis (CFA). A sample of 2734 elderly participants of the FIBRA Unicamp study was researched. In the PCA, a solution with five components was the most appropriate. Four internal structure models were tested with CFA. Two models with multidimensional structure of five factors and a factor of second order showed satisfactory fit indices, which did not happen with the unidimensional model. Therefore, there is evidence that it is a multidimensional measurement. The third study presents an analysis with IRT to evaluate the differential item functioning (DIF), difficulty and discrimination of the items. It was found that four items of serial seven were the most difficult and the items 9, 13, 22 and 23 were the easiest ones. The skill level of the people was higher than the level of difficulty of the items. There was DIF for education (27 items), sex (18 items) and age (16 items). We conclude that the use of MMSE with community dwelling elderly should be cautious due to the large number of biased items, especially for education. In conclusion, the version of the MMSE analyzed the version of MMSE analyzed obtained validity evidences regarding the internal structure, and is strongly influenced by education.

The present study investigated the criterion-based validity of the Mini-Mental State Examination (MMSE), the Cognitive Capacity Screening Examination (CCSE), and the Neurobehavioral Cognitive Status Examination (NCSE) in a sample of older adults with suspected cognitive impairment. As cognitive screening tests, the MMSE, CCSE, and NCSE should predict performance relative to a more thorough testing procedure. In the present study, performance on the Halstead-Reitan Neuropsychological Test Battery (HRNTB) was employed as the criterion measure. Scores on the General Neuropsychological Deficit Scale (G-NDS), a global performance measure computed from the HRNTB, served as the standard by which to judge the presence of cognitive impairment. The sensitivity, specificity, and predictive value of each screening test, as well as how well each screening test correlated with the G-NDS, were investigated. Results of this investigation found that, although the MMSE, CCSE, and NCSE were all significantly correlated with the G-NDS, only the NCSE demonstrated an appropriate balance between high sensitivity and specificity. When a rigorous neuropsychological evaluation was employed as the criterion standard, the NCSE accurately detected the presence of cognitive impairment: in 82% of the cases. The MMSE and CCSE, however, failed to detect cognitive deficits in approximately 80% of the cases. These findings strongly suggest that the MMSE and CCSE may have limited utility in the identification of cognitive impairment in older adults. The heightened sensitivity of the NCSE appears to be the result of several unigue features of the instrument, including a multidimensional scoring system and a graded series of increasingly difficult items within each ability area. Future studies need to examine the utility of the NCSE in other geriatric settings, as well as with more diverse populations suffering from a variety of organic mental syndromes.

This thesis presents a comparison of a GPU implementation of the Conjugate Residual method as a sequence of generic library kernels against implementations ofthe method with custom kernels to expose the performance gains of a keyoptimization strategy, kernel fusion, for memory-bound operations which is to makeefficient reuse of the processed data. For massive MIMO the iterative solver is to be employed at the linear detection stageto overcome the computational bottleneck of the matrix inversion required in theequalization process, which is 𝒪(𝑛3) for direct solvers. A detailed analysis of howone more of the Krylov subspace methods that is feasible for massive MIMO can beimplemented on a GPU as a unified kernel is given. Further, to show that kernel fusion can improve the execution performance not onlywhen the input data is large matrices-vectors as in scientific computing but also inthe case of massive MIMO and possibly similar cases where the input data is a largenumber of small matrices-vectors that must be processed in parallel.In more details, focusing on the small number of iterations required for the solver toachieve a close enough approximation of the exact solution in the case of massiveMIMO, and the case where the number of users matches the size of a warp, twodifferent approaches that allow to fully unroll the algorithm and gradually fuse allthe separate kernels into a single, until reaching a top-down hardcodedimplementation are proposed and tested. Targeting to overcome the algorithms computational burden which is the matrixvector product, further optimization techniques such as two ways to utilize the faston-chip memories, preloading the matrix in shared memory and preloading thevector in shared memory, are tested and proposed to achieve high efficiency andhigh parallelism.