RCAAP Repository

The aim of this research was to evaluate and compare the behavior of temperature inside poultry sheds with bell jar type gas conventional heating and heating in the floor with use of a heat exchanger. It was used the public domain program FEMM 4.2 for the analysis of temperature through the use of finite elements techniques with data collected from two lots. Heating in the floor is made with the hot water flowing through a heat exchanger, which is installed below the bed; this hot water is from solar heaters. From the results obtained with the simulations can be observed that the heating through the floor provides a more homogeneous distribution breast when compared with the bell jar type heating. The flow of heat is upwards supplying thus the most needed heating of the bird that is the pectoral part. Energy consumption evaluation was made with use of LPG; this has enabled a comparative analysis of the quantity of electric energy necessary to provide the same thermal energy and the financial expenses obtained with the heating though LPG or electric energy for each lot.

The present work aims to create a prototype called SISPIMA - forecast system in the incidence of malaria, to generate estimates of the incidence of malaria in Roraima state in three different periods: short term (3 months), medium term (6 months) and long term (12 months). To develop the system, were employed techniques of artificial neural networks and time series analysis. The SISPIMA consists of four steps: collection and storage of data, preprocessing, training and predicting the incidence of malaria. Data were obtained through access to the site SIVEP-Malaria Health Ministry. These were filtered, normalized and classified by SISPIMA in the pre-processing before performing the training and prediction. For training and forecasting, used artificial neural networks. The architecture of artificial neural network used was the multilayer perceptron (MLP) with a variation of the backpropagation training algorithm, called of Resilient Propagation (RPROG). To validate the results and assess the performance and accuracy of the proposed system, we use the ARIMA model as a comparison because of its wide application in epidemiological time series forecasting.

The automatic recognition of individuals through the iris characteristics is an e±cient biometric technique that is widely studied and applied around the world. Many image processing stages are necessary to make possible the representation and the interpretation of the iris information. This work presents the state of the art in iris recognition systems where the most re- markable works and the di®erent techniques applied to perform each process- ing stage are quoted. The implementations of each processing stage using traditional techniques are presented and, afterwards, two innovator methods are proposed with the common objective of bringing bene¯t to the system. The ¯rst processing stage should be the localization of the iris region in an eye image. The ¯rst method proposed in this work presents an algorithm to achieve the iris localization through the utilization of the called Memetic Algorithms. The new method is compared to a classical method and the obtained results show advantages concerning e±ciency and processing time. In another processing stage there must be a pixels sampling from the iris region, from where the information used to di®erentiate the individuals is extracted. Traditionally, this sampling process is accomplished in an uni- form way along the whole iris region. It is proposed a pre-processing method which suggests a non uniform pixels sampling from the iris region with the objective of selecting the group of pixels which carry more information about the iris structure. The search for this group of pixels is done through Ge- netic Algorithms. The application of the new method improves the e±ciency of the system and also, allows the generation of smaller templates. In this work, a study on the called Active Shape Models is also accomplished and its application to perform the iris region segmentation is evaluated. To execute the simulations and the evaluation of the methods, it was used two public and free iris images database: UBIRIS database and MMU database.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

This work develops a new mathematical model to the salient pole synchronous machines (SPSM), based on the abc reference system. The model considers the distribution and coil pitch factors of windings and develops a new function for the variable air gap, generated by the curvature of the polar mass. As a result, the development of the modeling takes into account the spatial harmonic components of: magneto motive force MMF(θ)h, electromagnetic ux density B(θ)h and variation function of the air gap g(θ)h. It is also proposed a new and simplied methodology using the locked rotor tests, volt-ampere method, to obtain the constants of the synchronous machine design, which allow the calculation of the modeling parameters and the terminals magnitudes determination. It presents also contributions to traditional methods of obtaining experimental inductances, using the locked rotor test. Yet it develops procedures and makes the simulation of the main temporal magnitudes at the generator terminals connected to the utility grid, electrical torque, speed, voltage and current. The model is validated through the theoretical and experimental confrontation of inductances, and also of the voltages and currents at the generator terminals connected to the utility grid.

The main problem of tremor is the damage caused to the quality of the life of patients, especially those at more advanced ages. There is not a consensus yet about the origins of this disorder, but it can be examined in the correlations between the biological signs of aging and the tremor characteristics. This work sought correlations between the osmotic fragility of erythrocytes and features extracted from electromyographic (EMG) activity resulting from physiological tremor in healthy volunteers (N=44) at different age groups (24-87 years). The osmotic fragility was spectrophotometrically evaluated by the dependence of hemolysis, provided by the absorbance in 540 nm (A54o), on the concentration of NaCl. The data were adjusted to curves of sigmoidal regression and characterized by the half transition point (H50), amplitude of lysis transition (dx) and values of A540 in the curve regions that characterize the presence of lysed (A1) and preserved erythrocytes (A2). The amplitude, frequency and approximate entropy was estimated from EMG signals detected with surface electrodes fixed on the extensor carpi ulnaris muscle during the movement of the hand of subjects holding up a laser pen towards an Archimedes spiral, fixed in a whiteboard, and from an acelerometer fixed at the pen. The evaluations were carried out with the laser pen at rest, at the center of the spiral, and in movement from the center to the outside and from outside to the center. The correlations among the parameters of osmotic fragility, tremor, gender and age were tested. Negative correlations with age were found for A1 and dx. With the hand at rest, a positive correlation with H50 was found for the approximate entropy. Negative correlations with H50 were found for the entropy with the hand in movement, as from the center to the outside or from the outside to the center of the spiral. In neurological healthy individuals, the increase in the erythrocyte osmotic fragility was associated with a decrease in the approximate entropy for rest tremor and with an increase of the entropy for movement tremor. This suggests that the neuromuscular degeneration associated with tremor entails also the mechanisms involved in the breakdown of structural homeostasis of the erythrocyte membrane.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Software development processes are now essential for an organization to obtain acceptable levels of productivity and quality. The integration of agile and traditional development processes is an open and few explored research area, which has attracted the interest of industrial and academic communities in order to take advantage of the strengths of both approaches. However, little is known about the real benefits of existing proposals, as studies are still preliminary and evidence is very sparse. This research aims to investigate the best options for agile and traditional integration by defining a hybrid process that takes advantage of both approaches. A proposal to integrate the practices of Scrum agile method within a development process based on RUP Rational Unified Process was made based on some indications and results in the literature. An empirical study aiming to evaluate the productivity impact of that hybrid Scrum-RUP proposal was also carried out. Five groups of similar projects from a CMMI-ML2 medium-sized company were compared with respect to productivity, some of which were developed using the new Scrum-RUP process and others were developed using the other RUP-based process the company was used to employ. Also interviews were held with developers who participated in the projects to identify the causes of productivity results. Quantitative results have shown that four out of five project groups showed significant productivity increase in Scrum-RUP projects. The results of the interviews have shown that the main causes of productivity increase were related to process, of which the most frequent were communication, collaboration and reduction of documentation. The study shows that it is possible to integrate Scrum practices in the software development process without losing the rigor needed in the desired subprocesses and still get real development productivity gain.

This work presents a computer mathematical model of the human neuromusculoskeletal system specially designed to study the postural balance in standing. In addition to the extrafusal muscle tissue properties commonly used in traditional muscle models applied to study human movement and posture, this model includes two components physiologically important of postural control system: the intrafusal muscle tissue properties and intrinsic reflex responses provided by three neuromuscular organs (muscle spindles, Golgi tendon and Rhenshaw cells). The global model treats the body as a single-link inverted pendulum supported by a pair of muscle-reflex actuators (Winters, 1995) controlled by a proportional-integral-derivative controller. Model simulations were made with and without the contribution of the modelled reflex responses. The results were compatible with those presented in other investigations based on experimental data. In this manner, three fundamental properties of somatosensory feedback system were mathematically had been proven: (i) its anticipatory characteristic, (ii) its capacity to maintain alone the human body in standing posture and (iii) the incapacity of the body in supporting itself in that position in the absence of the modelled reflex responses. This model analysis allows one to conclude that the modelled reflex responses plays a fundamental role when a subject maintains an upright posture. This model can be used to formulate hypothesis about the origin of the feedback somatosensory deficits on human postural control in standing.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The machine learning in datasets that have unbalanced classes, has received considerable attention in the scientific community, because the traditional classification algorithms don t provide a satisfactory performance. This low performance can be explained by the fact that the traditional techniques of machine learning consider that each class present in the database has an approximately equal number of instances. However, most real datasets, have classes with an unbalanced distribution, where one class is over represented in comparison with the others. This gives rise to classifiers with high accuracy to predict the majority class and low accuracy for predicting the minority class. Therefore, the minority class is ignored by the classifier. This predisposition of the classifier for the majority class occurs, because the classifiers are designed to maximize accuracy in relation to the database being used for training. In training the classifier, it is assumed that when making the prediction of data not yet seen, they have the same distribution of the data that were used in training. This limits its ability to recognize examples of the minority class. Several improvements in the traditional classification algorithms have been proposed in the literature, where considerations were made at the level of data and algorithms. The former uses various ways of resampling, such as oversampling of examples from the minority class, undersampling the majority class or a combination of both. The latter attempt to adapt (by inserting dierent costs in the minority class examples and majority, changing kernels and other techniques) the existing classification algorithms to improve the performance of minority class. Several algorithms in the form of a ensemble machine, are also reported as meta-techniques for working with unbalanced classes. This thesis studies the main algorithms that deal with unbalanced class, highlighting its main features as: the generation of new synthetic examples instead of replicating data at random, in the process of oversampling; the use of dierent penalties to misclassification of the minority and majority class; and the use of ensembles for that the generated classifiers have a greater ability to generalize. After assessing the contributions that each algorithm provides, a study was done if one could get something more of the characteristics of each one. It was made a modification in the algorithm that generates new synthetic examples of way that reduces the possibility of generating new elements in the incorrect region. As with highly unbalanced datasets, the generation of synthetic elements is not enough to balance the whole, there was a need to develop a new algorithm to perform an undersampling the majority class examples. And to enhance the generalization ability of the generated classifier, was also made a change to an ensemble algorithm. Using these three steps, we obtained an compound algorithm that has a hit rate of data classification better than the algorithms on which it was relied.

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

This thesis is aimed to show the analysis, measurement and evaluation performance of the indoor power line communication (PLC) network operating at popular houses. For the PLC channel the analysis was made of the attenuation considering the parameters condition of the transmitter, receiver and load. Considering the transfer of date through power line, this work shows the results of noise signal from household appliance and the effects caused by the appliances in the PLC network. The measurements show that popular houses are able to receive signal by PLC system.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Guidelines provided by the Brazilian Electricity Distribution Agency and the National Operator Grid considers, amongst other power quality indicators, issues associated to harmonic distortions. Such documents, as far as harmonics are concerned, are focused to different goals such as definitions, measurement procedures, reference values, etc. Having in mind these orientations and by recognizing that mitigation techniques to adequate the harmonic levels to the recommended values are frequently linked to high costs emerges the necessity of ways to find, at a given PCC, the harmonic distortion percentile due to the utility and the consumer itself. Within this context, a few publications have attempted to provide means to share the responsibility upon a measured voltage distortion and, usually, the approaches are based on frequency domain procedures and superposition principles. These have shown to be promising but the final methodology is still to be fulfilled. Although the simplicity of such approaches it has been found that the difficulties at obtaining the required supply system and consumer equivalent harmonic impedance are quite limiting to the use of such strategies. Aiming at achieving a manner of overcome such matters emerges this thesis which context is dedicated to the search of a systematic manner of sharing the responsibilities for a given busbar distortion. The work is then developed towards the investigation of the current methods limitations and inaccuracy and to propose a new mechanism that allows for attributing the percentile origin of the distortions. This has been called by Modified Superposition Method and its fundamentals, procedures, computational results, etc. are fully described in the work.

Universidade Federal do Triângulo Mineiro

The epilepsy is not a recent phenomenon, even its has being approached and Inves- tigated, this area still demands several researches and it is far away from being totally explained. The obtaining of the primordial features to di®erentiate the epileptic events of the others, in coming signs EEG of scalp, it represents a great challenge, since exist to many artifacts, and these are confused with epileptic events. In this sense, this study presents the development of architectures destined to detect events of epilepsy in coming signs EEG of scalp, capable to aid the professionals of the health in the study of this pathology To accomplish the objectives, ¯rstly was developed an application capable to visualize EEG and to segment the electroencephalogram plan to form the base of data Concerning to the detection of the pathological signs, four architectures were proposed. The architecture with analysis multi-resolution used the \ wavelet " (WT) for extraction of features, as well as neural networks and specialist system for recognition. For that architecture the best gotten results obtained a rate of 71,6 % of success, with 28,3 % of error. The sensibility was around 83,3 %, the speci¯city 70,5 % and the precision 76,9 %. The statistical architecture is directly composed of tools for features extraction of the sign. The best success rate was around 85,3 %, the obtained error was of 14,3 % and the inde¯nite ones around 1 %. The sensibility was of 97,4 %, the speci¯city 82,1 % and the precision 89,75 %. The architecture of analysis multi-resolution and AR possesses two stages for extraction of feature: the \ wavelet ", following by the AR models. For that architecture they used two AR models . The best success rate for the \ Yule-Walker"model was around 87,9 %, with order 10. Already in the results of the \ Burg"model, the best success rate was of 88,5 % with order 7. For the last architecture is a hybrid model with several tools of extraction of features in the domain of the time, frequency (FFT) and time-frequency (WT). In that architecture the success rate was in 95,1 %, the error 4,1 % the inde¯nite ones 5,5 %. The speci¯city was of 91,5 %, the obtained sensibility was of 90,5 % and the precision around 91,1 %. Therefore all of the developed systems presented quite coherent results among the phenomena demarcated by the professionals of the medical area and those revealed by the architectures, mainly for the case of the hybrid architecture that presented the best rates.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Fundação de Amparo a Pesquisa do Estado de Minas Gerais

Fundação de Amparo a Pesquisa do Estado de Minas Gerais