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Orientadores: Helder Anibal Hermini, Cecilia Amelia de Carvalho Zavaglia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-13T00:54:31Z (GMT). No. of bitstreams: 1 Gaino_MartaRegianeCorrocher_M.pdf: 3846558 bytes, checksum: b58ca2b460c15132afc714592bd49e5e (MD5) Previous issue date: 2009 / Resumo: O rolamento dos pés é fundamental para uma marcha humana eficiente, mas o envelhecimento traz alterações em todos os sistemas corporais, causando também modificação no rolamento dos pés durante a deambulação e uma diminuição na eficiência da marcha. Este trabalho se propôs a criar um dispositivo para, simultaneamente, captar e registrar a sequência da distribuição de cargas na região plantar dos pés durante a marcha e fornecer estímulos sonoros que auxiliem o indivíduo na compreensão da seqüência correta de rolamento dos pés. O dispositivo foi idealizado e desenvolvido por uma equipe multidisciplinar, sendo testado inicialmente nos pés da equipe e em seguida em três sujeitos acima de 60 anos de idade, para realização de ajustes. Os dados colhidos pelo protótipo foram colocados em uma planilha Excel para análise. Em vista dos resultados, são sugeridas melhorias e formas de utilização do dispositivo, que pode ser uma alternativa para uso clínico, tanto para verificação das condições de rolamento do pé na marcha, quanto para o treinamento do mesmo através do "biofeedback" sonoro. Foi encontrada uma vantagem adicional no uso dos sensores de película sensíveis ao toque, uma vez que os mesmos forneceram também um estímulo para a sensibilidade plantar. Em conclusão sugerem-se possibilidades de aprimoramento e propõem-se novos testes. / Abstract: Feet roll-over is fundamental to assure an efficient human gait but aging brings body system's alterations that cause modifications in gait's feet roll-over and diminishes gait's efficiency. This work's proposal was to elaborate and develop a device in order to simultaneously acquire e record plantar load distribution during gait and to give sound stimuli that help aged people to understand the correct feet roll-over mechanism. The device has been idealized and developed by a multidisciplinary team. In order to verify the device efficiency or problems, it has been tried on by the researchers and in three persons above 60 years old, aiming to make adjustments. The collected data have been gathered in Excel spreadsheet in order to be analyzed. Improvements and use possibilities are suggested based in the results. The device can be an alternative to clinical procedures, both to feet roll-over verification or training with sound biofeedback. An additional advantage has been found since the touch pellicle sensors showed to be a good source of sensitive stimuli to the feet's plantar region. In conclusion, improvements and tests of usage possibilities have been suggested. / Mestrado / Projeto Mecanico / Mestre em Engenharia Mecânica

Yes / Understanding the detailed differences between posed and spontaneous smiles is an important topic with a range of applications such as in human-computer interaction, automatic facial emotion analysis and in awareness systems. During the past decade or so, there have been very promising solutions for accurate automatic recognition and detailed facial emotion analysis. To this end, many methods and techniques have been proposed for distinguishing between spontaneous and posed smiles. Our aim here is to go beyond the present state of the art in this field. Hence, in this work, we are concerned with understanding the exact distribution of a smile – both spontaneous and posed – across the face. To do this, we utilise a lightweight computational framework which we have developed to analyse the dynamics of human facial expressions. We utilise this framework to undertake a detailed study of the smile expression. Based on computing the optical flow across the face – especially across key parts of the face such as the mouth, the cheeks and around the eyes – we are able to accurately map the dynamic weight distribution of the smile expression. To validate our computational model, we utilise two publicly available datasets, namely the CK + dataset in which the subjects express posed smiles and the MUG dataset in which the subjects express genuine smiles. Our results not only confirm what already exists in the literature – i.e. that the spontaneous genuine smile is truly in the eyes – but it also gives further insight into the exact distribution of the smile across the face.

No / This chapter presents an application of computational smile analysis framework discussed earlier. Here we discuss how one could utilise a computational algorithm to distinguish between genuine and posed smiles. We utilise aspects of the computational framework discussed in Chap. 2 to process and analyse the smile expression looking for clues to determine the genuineness of it. Equally, we discuss how the exact distribution of a smile across the face, especially the distinction in the weight distribution between a genuine and a posed smile can be achieved.

The purpose of this dissertation was to examine the existence of force production and strength symmetry while concentrating on its role with performance. Specifically, in this dissertation I sought to determine if differences in symmetry exist between male and female athletes as well as between athletes of different strength levels. Various symmetry assessments were used and the amount of carryover between tests was also evaluated. Furthermore, the relationship between asymmetry magnitude and various aspects of jump performance was also assessed. The results showed that female athletes were more asymmetrical than their male counterparts for most assessments. Interestingly, weaker athletes regardless of gender were more asymmetrical than stronger athletes for all assessments. Symmetry characteristics appeared to carryover between all tests and conditions with the exception of the bilateral strength assessment. When separated by strength level, good carryover of explosive strength symmetry characteristics was noted. A trend of negative relationships was noted between jump performance and kinetic asymmetry, measured during jumps and weight distribution. Isometric mid-thigh pull force production asymmetry did not relate to jump performance as it had previously. Kinetic asymmetry was shown to influence the direction of center of mass displacement (COMd). Specifically, asymmetrical rate of force development showed the most ability to differentiate between values of COMd in the mediolateral direction. The finding that female athletes are more likely to produce force asymmetrically may indicate that they are more susceptible to the performance detriments that accompany force production asymmetry. This may also indicate that female athletes are more susceptible to injury if force asymmetry is an injury predictor. However, differences in asymmetry magnitude between the sexes may be due to differences in strength level between the sexes in the current study, as weaker athletes were shown to be more asymmetrical than their stronger counterparts. Thus, it may be inadequate strength level that is a risk factor to performance detriments and possible injury. It also appears that force production asymmetry can both alter and hinder optimal jump performance. In order to optimize performance and possibly reduce injury risk, it is recommended that weaker athletes focus on bilateral strengthening exercises.

Background: Obesity is a chronic disease characterized by a body mass index (BM1) of ≥ 30 kg/m2 which negatively impacts the musculoskeletal system and has been found to be a major contributing factor to obesity-induced biomechanical alterations during activities of daily living (ADLs). A certain level of mobility is required for all populations to maintain independence and a good quality of life becomes more difficult with excess weight. Using a reduced weight-bearing activity, such as the Alter Gravity treadmill, would be beneficial in an obese population to reduce the load on the joints and potentially decrease the risk of weight bearing injury while maintaining normal gait mechanics. The purpose of this dissertation was to determine the biomechanical effects of excess weight and weight distribution on ADLs. To address this, two different weight gain models were created to simulate central (CL) and peripheral (PL) weight gain compared to an obese group (OW), and normal weight group (UL) during different activities of daily living (ADLs). The purpose of the third study was to compare lower extremity joint kinematics and muscle activation patterns between obese and normal individuals at different levels of body support (100, 75, and 50%) while walking in the AlterG treadmill. Methods: 14 normal weight (BMI: 22.4 ± 1.8 kg/m2, age: 23.4 ± 3.6 yrs) and 17 obese (BMI: 33.2 ± 2.3 kg/m2, age: 31.6 ± 8.0 years) adults participated in different ADLs (gait and descending a set of stairs). Normal weight participants were loaded with two different external loads sufficient to increase their BMI by 5 kg/m2 (~22.6% body mass). Kinematic and kinetic data were collected with 3D motion analysis. Frontal plane hip and knee angles and moments were calculated. Results: During gait, the obese group walked at a significantly slower velocity compared to UL. Step length was 8.7% longer in UL and 7.4% longer in the CL compared to the OW. PL more closely mirrored the OW group in step length, flexion moment and extension moment and the CL more closely mirrored the obese group in sagittal plane knee and hip excursion, and peak hip flexion moment and extension moment during gait During the transition from descending stair walking to level gait, it was found that the PL, but not CL, decreased step length, increased step width, and increased proportion of the gait cycle spent in stance. During the transition from walking down the stairs to level gait it was found that CL and PL affect temporal spatial variables differently. PL also reduced peak hip adduction angle, increased peak hip flexion moment, decreased peak hip extension, decreased sagittal plane hip excursion, and decreased frontal plane hip excursion. Conversely, CL reduced peak hip flexion moment and trended to reduce peak hip extension moment. To determine the effects of reduced body mass per se on improved biomechanics, we needed a model that would prevent associated changes in segmental volume. Therefore, using an AlterG treadmill facilitated this method. At 100 % BW support, mean ST and VM EMG activity were significantly higher in the obese compared to the normal weight groups. There were also differences found at 75 % BW support in ST in the obese being greater than the normal. Conclusions: Combined, the overall results of this dissertation suggest that weight gain is able to be modeled but is variable and task specific. The CL has proven to be the weight gain model that which elicits a better biomechanical obese response when normal weight individuals are loaded. Further work is needed to understand how to truly mimic obesity with an external load.

There are two main goals of this thesis: to investigate the flow-induced crystallization behaviour of Polybutene-1 (PB-1 samples, and to study the effects of molecular parameters on the crystallization behaviour While flow-induced crystallization is not a new area in polymer research, well-defined experimental methods that allow access to high flow rate range comparable to that encountered in real processing are still lacking. Two types of flow are considered: shear and uniaxial elongational. Regarding the second aim, several molecular parameters considered are: molecular weight, molecular weight distribution, isotacticity, presence of nucleating agents, and copolymer content. For this purpose an array of PB-1 samples were used. It is found that each of these parameters can have significant effect on the crystallization behaviour. Mainly rheological methods were utilized to conduct the flow-induced crystallization experiments. Crystallization onset time is define d from the change in viscosity or other related parameters. The experiments begin with low shear rate range, to ensure that the results are comparable with literature data. In this range we encounter the quasi-quiescent onset time at very small. shear rates, which draws an interesting comparison with another physical parameter, the gel time. Beyond a critical flow rate a decrease in the onset time is seen, and a plateau-and-slope trend is evident for a curve of onset time vs. shear rate. Using a combination of three experimental methods, shear rates ranging from Q0001 - 500 s-1 are successfully achieved, and a good agreement between these methods is observed. Furthermore, a normalization procedure is introduced, which yields temperature-invariant curves for the mentioned range of shear rate. For the uniaxial elongation flow, the Elongational Viscosity Fixture (EVF) is employed, with the strain rate ranging from 0.0001 - 10 s'. A greater reduction in onset time as compared to shear (at the same shear/strain r ate) is observed, and the difference in the onset times for shear and elongation already reaches more than one decade for a flow rate of 10 5. This quantitative comparison is particularly important; since not so many data on elongation-induced crystallization are available in the literature. Finally, the thesis compares several flow induced crystallization models that can be useful as prediction tools and selects one of these models to be compared with the experimental data. A qualitative agreement is found, however, for better quantitative prediction the model still needs to be.

Battail [1989] shows that an appropriate criterion for the design of long block codes is the closeness of the normalized weight distribution to a Gaussian distribution. A subsequent work shows that iterated product of single parity check codes satisfy this criterion [1994]. Motivated by these earlier works, in this thesis, we study the effect of the interleaver on the performance of turbo codes for large block lengths, $N\rightarrow\infty$. A parallel concatenated turbo code that consists of two or more component codes is considered. We demonstrate that for $N\rightarrow\infty$, the normalized weight of the systematic $\widehat{w_1}=\displaystyle\frac{w_1}{\sqrt{N}}$, and the parity check sequences $\widehat{w_2}=\displaystyle\frac{w_2}{\sqrt{N}}$ and $\widehat{w_3}=\displaystyle\frac{w_3}{\sqrt{N}}$ become a set of jointly Gaussian distributions for the typical values of $\widehat{w_i},i=1,2,3$, where the typical values of $\widehat{w_i}$ are defined as $\displaystyle\lim_{N\rightarrow\infty}\frac{\widehat{w_i}}{\sqrt{N}}\neq 0,1$ for $i=1,2,3$. To optimize the turbo code performance in the waterfall region which is dominated by high-weight codewords, it is desirable to reduce $\rho_{ij}$, $i,j=1,2,3$ as much as possible, where $\rho_{ij}$ is the correlation coefficient between $\widehat{w_i}$ and $\widehat{w_j}$. It is shown that: (i)~$\rho_{ij}>0$, $i,j=1,2,3$, (ii)~$\rho_{12},\rho_{13}\rightarrow 0$ as $N\rightarrow\infty$, and (iii)~$\rho_{23}\rightarrow 0$ as $N\rightarrow\infty$ for "almost" any random interleaver. This indicates that for $N\rightarrow\infty$, the optimization of the interleaver has a diminishing effect on the distribution of high-weight error events, and consequently, on the error performance in the waterfall region. We show that for the typical weights, this weight distribution approaches the average spectrum defined by Poltyrev [1994]. We also apply the tangential sphere bound (TSB) on the Gaussian distribution in AWGN channel with BPSK signalling and show that it performs very close to the capacity for code rates of interest. We also study the statistical properties of the low-weight codeword structures. We prove that for large block lengths, the number of low-weight codewords of these structures are some Poisson random variables. These random variables can be used to evaluate the asymptotic probability mass function of the minimum distance of the turbo code among all the possible interleavers. We show that the number of indecomposable low-weight codewords of different types tend to a set of independent Poisson random variables. We find the mean and the variance of the union bound in the error floor region and study the effect of expurgating low-weight codewords on the performance. We show that the weight distribution in the transition region between Poisson and Gaussian follows a negative binomial distribution. We also calculate the interleaver gain for multi-component turbo codes based on these Poisson random variables. We show that the asymptotic error performance for multi-component codes in different weight regions converges to zero either exponentially (in the Gaussian region) or polynomially (in the Poisson and negative binomial regions) with respect to the block length, with the code-rate and energy values close to the channel capacity.

Battail [1989] shows that an appropriate criterion for the design of long block codes is the closeness of the normalized weight distribution to a Gaussian distribution. A subsequent work shows that iterated product of single parity check codes satisfy this criterion [1994]. Motivated by these earlier works, in this thesis, we study the effect of the interleaver on the performance of turbo codes for large block lengths, $N\rightarrow\infty$. A parallel concatenated turbo code that consists of two or more component codes is considered. We demonstrate that for $N\rightarrow\infty$, the normalized weight of the systematic $\widehat{w_1}=\displaystyle\frac{w_1}{\sqrt{N}}$, and the parity check sequences $\widehat{w_2}=\displaystyle\frac{w_2}{\sqrt{N}}$ and $\widehat{w_3}=\displaystyle\frac{w_3}{\sqrt{N}}$ become a set of jointly Gaussian distributions for the typical values of $\widehat{w_i},i=1,2,3$, where the typical values of $\widehat{w_i}$ are defined as $\displaystyle\lim_{N\rightarrow\infty}\frac{\widehat{w_i}}{\sqrt{N}}\neq 0,1$ for $i=1,2,3$. To optimize the turbo code performance in the waterfall region which is dominated by high-weight codewords, it is desirable to reduce $\rho_{ij}$, $i,j=1,2,3$ as much as possible, where $\rho_{ij}$ is the correlation coefficient between $\widehat{w_i}$ and $\widehat{w_j}$. It is shown that: (i)~$\rho_{ij}>0$, $i,j=1,2,3$, (ii)~$\rho_{12},\rho_{13}\rightarrow 0$ as $N\rightarrow\infty$, and (iii)~$\rho_{23}\rightarrow 0$ as $N\rightarrow\infty$ for "almost" any random interleaver. This indicates that for $N\rightarrow\infty$, the optimization of the interleaver has a diminishing effect on the distribution of high-weight error events, and consequently, on the error performance in the waterfall region. We show that for the typical weights, this weight distribution approaches the average spectrum defined by Poltyrev [1994]. We also apply the tangential sphere bound (TSB) on the Gaussian distribution in AWGN channel with BPSK signalling and show that it performs very close to the capacity for code rates of interest. We also study the statistical properties of the low-weight codeword structures. We prove that for large block lengths, the number of low-weight codewords of these structures are some Poisson random variables. These random variables can be used to evaluate the asymptotic probability mass function of the minimum distance of the turbo code among all the possible interleavers. We show that the number of indecomposable low-weight codewords of different types tend to a set of independent Poisson random variables. We find the mean and the variance of the union bound in the error floor region and study the effect of expurgating low-weight codewords on the performance. We show that the weight distribution in the transition region between Poisson and Gaussian follows a negative binomial distribution. We also calculate the interleaver gain for multi-component turbo codes based on these Poisson random variables. We show that the asymptotic error performance for multi-component codes in different weight regions converges to zero either exponentially (in the Gaussian region) or polynomially (in the Poisson and negative binomial regions) with respect to the block length, with the code-rate and energy values close to the channel capacity.

The objective of this work is to develop mathematical models to predict molecular weight distributions (MWDs) of ethylene copolymers produced in an industrial gas-phase reactor using a Ziegler-Natta (Z-N) catalyst. Because of the multi-site nature of Z-N catalysts, models of Z-N catalyzed copolymerization tend to be very large and have many parameters that need to be estimated. It is important that the data that are available for parameter estimation be used effectively, and that a suitable balance is achieved between modeling rigour and simplification. In the thesis, deconvolution analysis is used to gain an understanding of how the polymer produced by various types of active sites on the Z-N catalyst responds to changes in the reactor operating conditions. This analysis reveals which reactions are important in determining the MWD and also shows that some types of active sites share similar behavior and can therefore share some kinetic parameters. With this knowledge, a simplified model is developed to predict MWDs of ethylene/hexene copolymers produced at 90 °C. Estimates of the parameters in this isothermal model provide good initial guesses for parameter estimation in a subsequent more complex model. The isothermal model is extended to account for the effects of butene and temperature. Estimability analysis and cross-validation are used to determine which parameters should be estimated from the available industrial data set. Twenty model parameters are estimated so that the model provides good predictions of MWD and comonomer incorporation. Finally, D-, A-,and V-optimal experimental designs for improving the quality of the model predictions are determined. Difficulties with local minima are addressed and a comparison of the optimality criteria is presented. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2009-05-28 20:43:58.37