RCAAP Repository

The evidences demonstrate that the inorganic phosphate increase is strongly associated with the weakness of the contractile mechanism, due to attractiveness with the ion calcium liberated by the sarcoplasmic reticulum and the formation of the calcium phosphate. Experimental studies related to the effect of the inorganic phosphate reacting with ion calcium, usually in vitro are accomplished, in other words, with reactions that could omit substances with interfere in the conditions in vivo during the muscular contraction. It is still necessary to observe the high concentration of inorganic phosphate drives the precipitation of calcium phosphate and if these reactions can be verified in vivo, as well as, to present a methodology that allows reproductibility for futures research projects that can associate this precipitation affects, or can not, the muscular contraction. This study order to evaluated the inorganic phosphate, induced through the injection of potassium phosphate in vivo, it causes precipitation with the calcium serum, generating the product denominated insoluble phosphate of calcium and, which ideal amount to be injected indeed for such a precipitation to happen in vivo. The protocol used in that procedure consisted of the use of intraperitoneal injection of potassium phosphate, in rats Wistar separated randon and equal distributed in seven groups of seven animals, where the Group I was denominated of control and injected 0,5 ml of physiologic solution (NaCl 0,9%) and the Groups II to VII with the following doses, respectively: 0,5, 1,5, 2,5, 5,0, 7,5 g e 10,0 mg/kg. After the injection of potassium phosphate, the blood was collected of the inferior cava vein and submitted the biochemical evaluation of the creatinin, urea, calcium and inorganic phosphate. The results demonstrated that after to the regression of analysis, none of the models was significant statistically (p0,05) to represent some urea variation and of the creatinin in function of the variations of the doses of inorganic phosphate. In relation to the inorganic phosphate, the model sigmoidal of four parameters presents an excellent adjustment degree to the data and with difference significant statistically among the doses of potassium phosphate (p<0,0147). The calcium serum presented difference significant statistically (p<0,0069) among the treatment it controls and the treatment that corresponds to the application of 5,0 mg/kg of phosphate potassium. From of that value there is a tendency to the stabilization of the presented answer, where we didn't find differences significant statistically among the doses of potassium phosphate. With these results we can conclude that the potassium phosphate is a substance capable to cause precipitation of calcium serum without any lesion in the animals and that the ideal amount of potassium phosphate to be injected for increase of the concentration of inorganic phosphate and decrease of the calcium serum is of 5,0 mg/kg, and you dose superiors or inferior don't present effects in the concentration of calcium serum due to precipitation with the inorganic phosphate.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

The purpose of this study was investigate the measurement techniques of human movement and to develop a system capable of capturing and reconstructing the movement trajectory on real world. The devised system uses video cameras to record the movement and a computer program to process video footage assessing the movement trajectory and calculating its kinematical variables. Those data are showed by the program as graphics or animation which simulates the reconstructed movement. To reach these objectives, the system used techniques from image processing, computer vision and anthropometric models. In the end of this work, it is exhibited an experimental evaluation of the precision and accuracy of the system and some case studies to show its potential.

The incipient technology of wireless access networks of the IEEE 802.16 Standard aggregates to the BWA systems many advantages over concur technologies, such as radio signal wide coverage, even in difficult access regions or needy of conventional infrastructure of network, as the case of some urban and rural areas of Brazil. Moreover, enables access to the Internet in last mile with high transmission rates, attending to the more several requisites of the data, voice and video applications with minor cost in comparison to others available alternatives. Meanwhile, this technology not specifies how the packages or service flows should be the scheduled in the MAC layer. Thus, this study compares the use of mechanisms for scheduling that approximates the ideal GPS scheduler to support the provision of QoS on IEEE 802.16 PMP network. The modeling and simulation based results evidence that the considered mechanisms WRR and WF2Q get good results in the support to the provision of QoS in this network.

In globalization times, the international trade becomes part of day-by-day of the people. With this continuous increasing of the importation and exportation activities, the logistic chain starts to have vital and indispensable role. Containers Terminal is an important component of the international logistic chain; multimodal interface that handles mainly with goods of the maritime modal (ship), become one of the responsible by the agility and the cost that the goods that are destined and came from foreign commerce reaches the final consumer. One of the more important tasks of the Container Terminal operational activities is the Stowage Planning, which can be characterized as a work of the optimize resources and schedules. The large amount of variables in these optimizations becomes decision support tools indispensable. Genetic Algorithms (GA) have being successfully used in complex problems, mainly which deterministic modeling is difficult, or if this approach brings computational times that becomes solutions infeasible. The proposal of this work was the implementation of the GA that could enclose the Container Terminal reality, with the complete and the large number of variables and restrictions known for the Stowage Planning process. In the GA developed was used also a routine that seems the local search process, called repaired routine, intending to speed up the convergence to the feasible solutions space, improving the general performance. With the container set used, the simulations results showed that the employed technique is appropriate, considering the characteristics of the best solutions and the computational times. Future works suggested would become the proposal still more adherent to daily run of the Container Terminal.

The compressed air systems represent plot expressive of energy consumption of an industrial plant. However, the lack of an appropriate project and a regular maintenance causes reduction in the overall performance featuring a constant source of waste. This fact guided the subject of this dissertation research, which is directed towards the development and application of techniques for analysis of the energy efficiency of compressed air systems. The analysis will be addressed more specifically to the study of the compressor installed in the laboratory systems driving the Faculty of Electrical Engineering of the Federal University of Uberlândia. Within this focus, the activities developed and presented in this document include issues related to energy conservation, presentation of the prototype, its analysis through digital simulations in the field of time, method of diagnosis energy, and finally, a case study obtained the prototype.

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This work presents the complete study regarding a non-isolated online Uninterruptable Power Supply (UPS), which employs a PFC boost converter associated with a passive resonant cell operating at high frequency. The analysis includes the operating principles, mathematical development and design procedure of the proposed system. It can be demonstrated that the use of a resonant cell and average current mode control provides satisfactory performance in the achievement of soft switching and unity power factor, respectively. Additionally, desirable features such as high efficiency, low cost, and also reduced weight and size are obtained.

This study presents the characteristics of using genetic algorithms on the elaboration of Class Schedules for education institutions. The complexity of the problems found to define a good quality solution, in the elaboration of the Class schedule was demonstrated was demonstrated, since there are multiple objectives, multiple restrictions, and a large number of variables to be weighted. Due to the resolution complexity of this kind of problem, it is considered that genetic algorithms are appropriate for use in process automation. Although there are restrictions common to any education institution, there is a large number of restrictions specific for each institution, and this kind of restriction can impose difficulties to the generation process of a general purpose class schedule establishment. The objective of this study was to develop a genetic representation for the problem of creating a class schedule for a given institution, considering resources limitation, based on its information, and using Genetic Algorithms to reach a viable solution, where there was a specific case of staggering: Class Schedule, after the requirements of the education institution were established, FEELT Faculdade de Engenharia Elétrica da UFU Universidade Federal de Uberlândia MG. The techniques jointly used allowed the achievement of a desired solution for the problem, and as far as the application base don a case study, it can be concluded that the approach used has an acceptable result, which can be used in education institutions that have restrictions and problems with faculty acceptance in the relation to the class schedule to be established. As a major contribution of this work, the study and application of evolutive computing techniques (Genetic Algorithms) in conjunction with the restriction problems can be mentioned for the solution of the difficulty in finding schedules for the faculty, when there is a specific case of staggering and the requirements were established by the education institution FEELT Faculdade de Engenharia Elétrica da UFU Universidade ederal de Uberlândia MG.

This work presents a study for torque ripple reduction in switched reluctance motors. The work explores two strategies for torque ripple minimization, angle setting and current profile control. The strategy devised for torque ripple reduction is explained with help of diagrams which comprise the machine, the converter, power supply, current controller and torque controller. The system is simulated using MATLAB/SIMULINK/SIMPOWERSYSTEM® environment and the results are presented and discussed. An electronic board able to deliver instantaneous torque estimation was assembled and experimental results using this device are included.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Currently living in the digital age, so the manipulation of data and images is often all day. Due to the problem of space for storage of pictures and time of transmission, many compression techniques had been developed, and a great challenge is to make these techniques to bring good results in terms of compression rate, picture quality and processing time. The Fractal Compression technique developed by Fisher, was described, implemented and tested in this work and it brought great results, and considerable improvement in terms of execution time, which was rather low. Another area that has been emphasizing is the use of biometric techniques to the people recognition. A very used technique is the iris recognition that has shown enough reliability. Thus, connecting the two technologies brings great benefits. In this work, images of iris were compressed by the method implemented here and were made simulations of the technique iris recognition developed by Libor Maseck. The results show that it is possible to compress fractally the images without damage the recognition system. Comparisons were made and was possible realize that even with changes in pixels of images, the system remains very reliable, bringing benefits to storage space.

This thesis presents an architecture for distribution of virtual environments in Augmented Reality as a tool to support projects in education. Subsequently, according to the evaluators, you can see that the results showed that the prototype is effective and enforceable. In face of this, this work aims creating an interface for interaction with the user and a layer for distribution of made interactions. Thus, for the creation of the software prototype, the interface of Augmented Reality is based on a study case that represents a specific area of knowledge, in this case the plant physiology. Thus was created an interface of Augmented Reality that enables user interaction with the virtual environment through menus for interaction and also by means of labels. This interface is integrated with a layer of distribution. Thus, the layer of distribution was implemented following the methodology client / server-based objects. With the implementation, the interactions made in an environment are replicated for other environments and vice versa, thereby generating a strong system applicable to education as it can provide multiple views of virtual objects on the real objects. The system was submitted and evaluated by teachers and students of a Educational Institution, a Faculty of Itumbiara city, Goiás. Thus teachers and students of information technology and biology areas examined the prototype and answered a questionnaire based on ISONORM. Later, according to the evaluators, it could be seen that the results showed the prototype is effective and enforceable.

The growing demand for energy in electric systems has resulted in greater difficulties to operate them. This has led specialists to deal more strictly with the control of reactive power and voltage, mainly in the case of radial electric systems, for the supply of seasonal loads. For this purpose, static compensators represent an alternative of great potential to control the power flow and improve the voltage profile of electric systems. In this context, the SCRSC or Saturated Core Reactor Static Compensator - made up of a magnetic core with special characteristics and winding and a set of capacitors in series and in parallel - becomes an interesting alternative, when compared to other types of equipment being sold at present, due to its robustness, low cost, fewer maintenance requirements and good performance. Within this scenario, the purpose of the present dissertation is to research the performance of a saturated core reactor prototype connected to a supply network, in order to assess its effectiveness and the effect on its quality standards, as for example: voltage peaks and valleys, harmonic distortions, unbalance, temperature and noise. Thus, tests were carried out on a saturated core reactor prototype to evaluate the following issues: transients as a result of prototype energizing; correlation between voltage and reactive power; definition of the harmonic components of voltage and current; analysis of the thermal performance in continuous operation and noise level verification during operation.

The retrieval of similar images in databases is a wide and complex research field that shows a great demand for good performance applications. The increasing volume of information available in the Internet and the success of textual search engines motivate the development of tools that make possible image searches by content similarity. Many features can be applied in determining the similarity between images, such as size, color, shape, color variation, texture, objects and their spatial distribution, among others. Texture and color are the most important features which allow a preliminary analysis of image similarity. This dissertation presents many techniques introduced in the literature, which analyze texture and color. Some of them were implemented, their performances were compared and the results were presented. This comparison allows the determination of the best techniques, making possible the analysis of their applicability and can be used as a reference in future works. The quantitative performance analyses were done using the ANMRR metric, defined in the MPEG-7 standard, and the confusion matrices were presented for each of the tested techniques. Two groups of quantitative tests were realized: the first one was applied upon a gray scale texture database and the second one, upon a color image database. For the experiment with the gray scale texture images, the techniques PBLIRU16, MCNC and their combination presented the best performances. For the experiment with the color images, SCD, HDCIG and CSD techniques performed best.

Conselho Nacional de Desenvolvimento Científico e Tecnológico

The present work reflects a case study done at a factoring company, acting in the area of market fomenting. This work focuses on the negotiations related to financial credit done with its client businesses, notably micro and small companies. It examines the credit analysis system utilized, highlighting that, after a selected bibliographical review and a deep study of its method and analysis process, some gaps were found which give its negotiations credit concession actions of high risk. With the objective of giving support to the analysts of the aforementioned company in the analysis process, as well as conferring a more efficient directive for decision making, this work proposes a strategic credit analysis model which uses contemporary approaches with the objective of aggregating value and giving new emphasis to the model used. The proposed model is based on the utilization of two conceptual tools: subjective credit analysis, applied in a standardized way and concepts of intangible assets to qualify and quantify the portfolio management risks; and a computational tool, artificial neural network techniques specifically, to process, learn and generalize the proposed model, and from there, form a more accurate diagnosis for future clients. Therefore, after the elaboration of the method, several tests were made, the results of which were considered promising and with a good proficiency level. Not only was the contemporary approach utilized considered prominent, but also the application of neural networks demonstrated high performance handling the multivariate data given to it.

This thesis develops an alternative approach for interdisciplinary education, based on the proposition, implementation and evaluation of an online distance-learning system devoted to Neuroscience, focused on Neuroanatomy and on Cellular Neurophysiology. This system makes use of simple and common hardware/software configurations, thus enabling high-speed connections, as well as antivirus resources. The pedagogical materials involve animations, interactive classes, photos of real anatomic parts, and texts which provide explicit connections between anatomy and pathologies. The system development considers difficulties pointed out by local undergraduate students, based on a poll carried out in order to assess Internet use in our university. The thesis proposes a rigorous methodology for the evaluation of such system, including both pedagogical and informatic issues, according to IEEE regulations, by means of formal inquiries, remote monitoring and direct observation. Evaluations were carried out during one year on 136 local undergraduate students, including five different backgrounds (Biology, Biomedicine, Biomedical Engineering, Medicine and Veterinary). Results point out that, in average, at least 75% of students consider the system very important for efficient learning, as well as the need of a tutor in order to lead such pedagogical approach based on distance-learning.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior