109 resultados para Comunicações de acesso múltiplo


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This thesis is resulted of a research on propagated the social representations of constructivism in the Internet, which as had estimated basic the idea of Moscovici (1961) of that the media it has determinative paper in the popularization of the scientific theories, in formation e propagation of the social representations and in the construction of behaviors human beings. Understanding the Internet as latest space of circulation of social communications, therefore, privileged field (and still not explored) for studies of social representations, we choose this half midiático as investigative field of our research, it if it constitutes in the "great ocean of the new informational planet" (LEVY, 2000, p. 126), besides making possible the interaction with different forms of images, different individuals, different ' world ', configuring itself as important space of symbolic production e of analysis of the representational process in the world contemporary. Based in these questions, we trace as objective to analyze the circulating speech propagated on-line on the constructivism, searching to apprehend the social representations shared the respect. This objective was constructed in face of the insertion of the theory constructivist in the educational way has two decades more than, as well as of its consolidation as reference in different social contexts, mainly in midiático. The question that directed the research was: as this theory obtains to penetrate in some layers of our society, to influence the world readings e the behaviors of different people? That modifications it suffers in this trajectory and which the paper of the Internet in this process? The corpus of the research was constituted of the substances on the theory found in the Internet, in pages in Portuguese of Google, in the period of 27 of July of 2004 the 17 of August of 2004. The data they had been analyzed on the basis of the project of analysis of content elaborated for Moscovici (1961) and in the estimated theoreticians of the social communication, in special of the hypermedia. The results had disclosed that the Internet participates of determinative form in the process of popularization of the constructivism theory, not only spreading out its estimated theoretician- methodological for the domain public (diffusion), but propagating positive beliefs and images of its postulates (propagation) and using them it service of interests politicians e financiers (propaganda). The popularization of the constructivism in the Internet and social representations of this theory propagated configure one process in which the theory passes of pedagogical theoretical landmark for grief, assuming a commercial character extremely and the status of solution for problems of the education and the society, stirring up attitudes and behaviors in public, most general possible, that comes to take care of to the interests politicians e marketing. Recognizing the diversity, the permanent renewal of information and the negotiation of directions gifts in the Internet, as well as the innumerable ones forms of access to the information found by it, we consider results of the research as fruits of the inherent characteristics to this way midiático, to the time where we call the attention for relativity these results, for the plasticity of knowing them and sensible propagated on-line e for the great challenge that the hypermedia imposes to the study of communication phenomena, of the social representations and in educational quarrels and for the necessity of new research that they investigate the forms of socialization of the information and communication propitiated by hypermedia and its implications in the construction of the symbolic universes and in practical social

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Inclusion of students with disabilities is a recent case that has been discussed in school contexts, but the current policy of inclusion for access and retention of students in higher education is still a problem face there is much to do, therefore, are incipient studies in which this student body is involved. Accordingly, what is happening is that the most studies deal with on these students and little is said about them. For inclusive education thus the institution should prepare to receive students, having as one of its premises their point of views about what actually experience aiming at promoting education for all. Therefore, this study deals with the process of inclusion of students with disabilities regularly enrolled in undergraduate courses at the Universidade Federal do Rio Grande do Norte - UFRN.They were used the assumptions of qualitative research enabled by the case study method and semi-structured interviews. It has been analyzed by guiding actions and teaching practices, under the views of disabled students and teachers, the conditions of access and permanence offered by UFRN. Twelve students with physical, visual, hearing disabilities participated and five teachers from the acedemic centers that in academic year 2008 taught to these students. For data analysis it was used the technique of content analysis. It was extracted two themes: access and retention of students with disabilities in UFRN, in which emerged the categories described and analyzed in the course of this work. The results show the difficulties of access and retention of students with disabilities within the UFRN, such as attitudinal, pedagogical and architectural barriers. However, as it has also turned out, initial advances in the quest for achieving more effective actions to guarantee access and permanence of these students in UFRN. It has concluded that the scope for the exercise of citizenship in the pupils with disabilities who need this Higher Education Institution has an inclusive education Project, wide and consolidated, for the actions undertaken by the Ministry of Education - MEC, by itself, are not guaranteed to all students due to mobility, autonomy and security. It has hoped this work will bring benefits for new studies to develop features that were located, but were not our focus, because then the UFRN may advance the inclusive process of disabled students

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This study focuses on the central Brazilian historiography of science, focusing specifically on the life and work of a contemporaneous mathematician-physicist, and becomes part of the set of research results that investigate, organize and describe personal, intellectual and professional itineraries of Brazilian scientists and educators. The theme chosen for the study ran from seminars on Mathematics in Pará and is up to organize and describe the life history, education, professional experience and scientific production of William Mauricio Souza Marcos de La Penha (Guilherme de La Penha), considering their academic, professional and intellectual life history, so that their academic and intellectual production be spread over the Brazilian scientific and academic community. We adopted the historical research as theoretical and methodological base for the development of this study, rising arguments about the profile of Guilherme de La Penha to characterize him as a multiskill intellectual and to reveal that his thoughts about science, technology, training scientists and educators were in accordance with their writings and their professional practice in order to build a first story about the life and work of William de La Penha. In this sense, we took the theoretical aspects related to historical research, biographies, intellectual itineraries, files and inventories as sources and historical construction vehicles in order to point out the essential elements to form a profile of the transdisciplinary intellectual historians, ie a profile scientist who carries out the research, management and administration, as well as a committed educator to the on-going training and forming process. The results pointed in different directions, among which we highlight the creation of Seção Guilherme de La Penha at Universidade da Amazonia, producing several articles about the life and work of William de La Penha presented at national and international conferences and the proposal for documentary displays which could contribute to understanding the implementation of a scientific area in Pará State, an area that would not only be restricted to the production of knowledge, but more than that, it would include the spreading, which provides various means, primarily through education. Thus it was possible to ensure that La Penha has an intellectual profile that can be considered a multi-and transdisciplinary intellectual who defends the possibility of forming a scientist one and multiple, non-linear attitudes and dialogues with all other areas in order to be understood under a model scientist for the twenty-first century based on the model clearly inspired by the scientist authors with which he identified throughout their training and professional activities, like the three that stood out in their relationship science: Archimedes, Leonhard Euler and Cliford Ambrose Truesdell

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Access is a problem of higher education in Brazil that has existed since the formalization of this has occurred since the installation of the Portuguese court in Brazil in 1808. Only 10% of young people between 18 and 24 years of age attending this level of education in 2000, arriving in 2010 just 15%, far from that determined the National Education Plan in 2001, triple that percentage by the year 2010. In addition, a majority of seats of public HEIs is populated by students from the private network, especially in high-demand courses. In this context, this study aims to identify the costs related to the trajectories of students who were successful in the vestibular UFRN editions from 2006 to 2010. Presents an overview of higher education in Brazil, a brief history of vestibular, as well as new forms of access, and some of the policies to expand such access, highlighting the argument Inclusion UFRN. Focusing on the theme of the paper presents the concepts of opportunity costs and social. After collecting data through a questionnaire and consultation of databases COMPERVE was developed to search for a descriptive and analytical, with the participation of 3,995 students, of whom 1642 (41.1%) had completed secondary education in schools public, and 2,078 (52%) in private schools. The profile indicates that 90% are single, about 50% are 21 years of age, are white and female. In the course of preparation for college entrance exams, 80% chose the course during or after completion of the last year of high school, and almost 70% said they had started preparing at that time. Findings related to the costs involved with this preparation indicate that, in most cases there were school fees and disbursements and workshops, and the purchase of books and other materials, with parents primarily responsible for this cost, the amount disbursed each month was up $ 300 for 64% of respondents and only 7% of them exceeded $ 1,000, the major non-financial costs were characterized by the following resignations: job opportunities (24%) or temporary work (20%) courses of languages (26%), leisure activities (48%), leisure travel (43%), and parties and / or shows (54%). Of social investments by the government, stand out in the tax waiver scholarships for study in private institutions, grant exemption from the registration fee of vestibular, the preparatory courses UFRN, and seminars by COMPERVE / UFRN with networks of high school. From the junction of the opportunity costs (private costs) and social costs (public costs), a new concept: the social opportunity cost, which measures the combined efforts of families and government to finance the opportunity to access higher education of an individual. This concept can and should be incorporated as a strategic vector for the sake of democratic university, which reflects the social model that is sought

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In current upbringing production, children are often conceived as rightful subjects, and concrete and singular people, marked by specificities that schools must respect, mainly their personal wholeness, their care and attention needs, as well as their abilities to learn and produce culture. In the educational practices frame, routine is considered to have a definitive roll in time, space and activities structuring, as with actions and relations of subjects involved. In that perspective, this research aims to analyze routines of zero to two years old children in the upbringing context, relating to their childish specificities. Anchored in the qualitative approach, a Case Study was developed, according the procedures of daily routine observation and semi-structured interviews with six nursery teachers of CMEI Centro Municipal de Educação Infantil, Natal-RN, the research field. The data analysis was based in Speech Analysis principles. The teachers utterances regarding routine and it s roll in the frame revealed significances related to control/regulation of actions theirs and students aiming to streamline tasks; learning relative to routine itself, time and school practices. Thus, prospects of discipline and exercise of power of teachers over students surges, reducing their possibilities to participate. These conceptions reflect the daily routine of the kids and their teachers. By analyzing the methods of routine operation in the time/space/activities frame of CMEI, it was possible to perceive its homogenization of actions and rhythms, not only of the group s children, but the whole institution, which creates, many times, a controlling character that contains/prevents children s initiative. However, it was also possible to observe that in routine recesses, when it s relaxed, and other spaces, times and actions are provided, kids have the opportunity to experience and create different ways of action and relation with time, materials, other kids and teachers, being, as such, respected their specificities. We highlight the importance of reflections regarding routine in upbringing context, as to comprehend it s functions and the need for it s construction to take a multiple character that respects the plurality of situations and singularities of children as persons

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On this qualitative study, it has been discussed the school inclusion paths done by a student with cerebral palsy, who we call Liz, and who was also the reference and indirect subject for this study. For the representation of landscapes found, it follows throughout historical, political and pedagogical paths, getting through the case study method references on the current Brazilian educational context, analyzing, which concepts are attributed to the inclusion and which practices are developed by educational managers and teachers in a regular school of the City of Natal/RN. The theory which based this research is supported on Vygotsky's central ideas (1991, 1997, 2004) and his followers. Furthermore, it was essential to bring to this investigative journey a literature which could dialogue with the most relevant aspects of the cultural-historical approach, emphasizing the assumptions of a progressive education tendency, which promotes the subject involvement of his/her work in the world and for the world. This way, it was necessary to seek for theoretical support on assistive technology and on alternative communication, in order to show the importance of establishing other communications, which is, to break away from the conventional pattern established by the school. On this journey it was used procedures for the data construction, such as: observation, conducting semistructured interviews and questionnaires; and document analysis that supported and legitimized the inclusion, besides the permanent field diaries record. On the access paths to this landscape it entered in the Youth and Adults Education (Educação de Jovens e Adultos - EJA), seeking to establish a dialogue among Youth and Adult Education and Special Education. It was verified that, still, there are large gaps in these policies articulation. Among the results obtained it was raised discussions on new scenery, in which Youth and Adults Education (EJA) emerges as prominent mode of the established relationships throughout the school inclusion process. There were target reflections on: the planning and evaluation systematic, the pedagogical articulation among the Youth and Adults Education (EJA) teachers and the multifunctional resource room teacher's actions and the continuous training importance of the educators involved. It was considered, therefore, that the necessary mediations for school inclusion may be sustained if the walkers are involved in a permanent contact with the nature of a proposal from the Special Education inclusive perspective

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This dissertation of Master of Science investigates the influence of the organization dimensions in the development of the management of the knowledge in the administrative activities developed by the tourist sector of the city of the Natal/RN. The adopted methodology was a descriptive research and exploration, using the technique of analysis of Cluster and Box Multiple Plot. The objective of if using descriptive and exploration analysis of the absolute values and the gotten percentages, are to present, on the basis of the studied dimensions, the degree of importance and the agreement related to the organization knowledge in the perception of the interviewed ones. The used instrument of research was a composed questionnaire for two parts: study of the management of the knowledge and profiles of the companies and interviewed. This questionnaire aims at the study of the organization environment, evidencing if the same it propitiates one administrative politics directed for the creation, storage and dissemination of the organization knowledge. Of this form, the general result presented a relationship of the content seen in the bibliography with the activities developed in the hotels, demonstrating that the management of the organization knowledge is of great importance for the development of this activity

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The concepts of the industrial automation are being incorporated in the medical area, in other words, they also pass to be applied in the hospital automation. In this sense, researches have been developed and have usually been approached several of the problems that are pertinent to the processes that can be automated in the hospital environment. Considering that in the automation processes, an imperative factor is the communication, because the systems are usually distributed, the network for data transference becomes itself an important point in these processes. Because this network should be capable to provide the exchange of data and to guarantee the demands that are imposed by the automation process. In this context, this doctorate thesis proposed, specified, analyzed and validated the Multicycles Protocol for Hospital Automation (MP-HA), which is customized to assist the demands in these automation processes, seeking to guarantee the determinism in the communications and to optimize the factor of use of the mean of transmission

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This thesis proposes the specification and performance analysis of a real-time communication mechanism for IEEE 802.11/11e standard. This approach is called Group Sequential Communication (GSC). The GSC has a better performance for dealing with small data packets when compared to the HCCA mechanism by adopting a decentralized medium access control using a publish/subscribe communication scheme. The main objective of the thesis is the HCCA overhead reduction of the Polling, ACK and QoS Null frames exchanged between the Hybrid Coordinator and the polled stations. The GSC eliminates the polling scheme used by HCCA scheduling algorithm by using a Virtual Token Passing procedure among members of the real-time group to whom a high-priority and sequential access to communication medium is granted. In order to improve the reliability of the mechanism proposed into a noisy channel, it is presented an error recovery scheme called second chance algorithm. This scheme is based on block acknowledgment strategy where there is a possibility of retransmitting when missing real-time messages. Thus, the GSC mechanism maintains the real-time traffic across many IEEE 802.11/11e devices, optimized bandwidth usage and minimal delay variation for data packets in the wireless network. For validation purpose of the communication scheme, the GSC and HCCA mechanisms have been implemented in network simulation software developed in C/C++ and their performance results were compared. The experiments show the efficiency of the GSC mechanism, especially in industrial communication scenarios.

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This work presents a study of implementation procedures for multiband microstrip patch antennas characterization, using on wireless communication systems. An artificial neural network multilayer perceptron is used to locate the bands of operational frequencies of the antenna for different geometrics configurations. The antenna is projected, simulated and tested in laboratory. The results obtained are compared in order to validate the performance of archetypes that resulted in a good one agreement in metric terms. The neurocomputationals procedures developed can be extended to other electromagnetic structures of wireless communications systems

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The frequency selective surfaces, or FSS (Frequency Selective Surfaces), are structures consisting of periodic arrays of conductive elements, called patches, which are usually very thin and they are printed on dielectric layers, or by openings perforated on very thin metallic surfaces, for applications in bands of microwave and millimeter waves. These structures are often used in aircraft, missiles, satellites, radomes, antennae reflector, high gain antennas and microwave ovens, for example. The use of these structures has as main objective filter frequency bands that can be broadcast or rejection, depending on the specificity of the required application. In turn, the modern communication systems such as GSM (Global System for Mobile Communications), RFID (Radio Frequency Identification), Bluetooth, Wi-Fi and WiMAX, whose services are highly demanded by society, have required the development of antennas having, as its main features, and low cost profile, and reduced dimensions and weight. In this context, the microstrip antenna is presented as an excellent choice for communications systems today, because (in addition to meeting the requirements mentioned intrinsically) planar structures are easy to manufacture and integration with other components in microwave circuits. Consequently, the analysis and synthesis of these devices mainly, due to the high possibility of shapes, size and frequency of its elements has been carried out by full-wave models, such as the finite element method, the method of moments and finite difference time domain. However, these methods require an accurate despite great computational effort. In this context, computational intelligence (CI) has been used successfully in the design and optimization of microwave planar structures, as an auxiliary tool and very appropriate, given the complexity of the geometry of the antennas and the FSS considered. The computational intelligence is inspired by natural phenomena such as learning, perception and decision, using techniques such as artificial neural networks, fuzzy logic, fractal geometry and evolutionary computation. This work makes a study of application of computational intelligence using meta-heuristics such as genetic algorithms and swarm intelligence optimization of antennas and frequency selective surfaces. Genetic algorithms are computational search methods based on the theory of natural selection proposed by Darwin and genetics used to solve complex problems, eg, problems where the search space grows with the size of the problem. The particle swarm optimization characteristics including the use of intelligence collectively being applied to optimization problems in many areas of research. The main objective of this work is the use of computational intelligence, the analysis and synthesis of antennas and FSS. We considered the structures of a microstrip planar monopole, ring type, and a cross-dipole FSS. We developed algorithms and optimization results obtained for optimized geometries of antennas and FSS considered. To validate results were designed, constructed and measured several prototypes. The measured results showed excellent agreement with the simulated. Moreover, the results obtained in this study were compared to those simulated using a commercial software has been also observed an excellent agreement. Specifically, the efficiency of techniques used were CI evidenced by simulated and measured, aiming at optimizing the bandwidth of an antenna for wideband operation or UWB (Ultra Wideband), using a genetic algorithm and optimizing the bandwidth, by specifying the length of the air gap between two frequency selective surfaces, using an optimization algorithm particle swarm

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In the globalized world modern telecommunications have assumed key role within the company, causing a large increase in demand for the wireless technology of communication, which has been happening in recent years have greatly increased the number of applications using this technology. Due to this demand, new materials are developed to enable new control mechanisms and propagation of electromagnetic waves. The research to develop new technologies for wireless communication presents a multidisciplinary study that covers from the new geometries for passive antennas, active up to the development of materials for devices that improve the performance at the frequency range of operation. Recently, planar antennas have attracted interest due to their characteristics and advantages when compared with other types of antennas. In the area of mobile communications the need for antennas of this type has become increasingly used, due to intensive development, which needs to operate in multifrequency antennas and broadband. The microstrip antennas have narrow bandwidth due to the dielectric losses generated by irradiation. Another limitation is the degradation of the radiation pattern due to the generation of surface waves in the substrate. Some techniques have been developed to minimize this limitation of bandwidth, such as the study of type materials PBG - Photonic Band Gap, to form the dielectric material. This work has as main objective the development project of a slot resonator with multiple layers and use the type PBG substrate, which carried out the optimization from the numerical analysis and then designed the device initially proposed for the band electromagnetic spectrum between 3-9 GHz, which basically includes the band S to X. Was used as the dielectric material RT/Duroid 5870 and RT/Duroid 6010.LM where both are laminated ceramic-filled PTFE dielectric constants 2.33 and 10.2, respectively. Through an experimental investigation was conducted an analysis of the simulated versus measured by observing the behavior of the radiation characteristics from the height variation of the dielectric multilayer substrates. We also used the LTT method resonators structures rectangular slot with multiple layers of material photonic PBG in order to obtain the resonance frequency and the entire theory involving the electromagnetic parameters of the structure under consideration. xviii The analysis developed in this work was performed using the method LTT - Transverse Transmission Line, in the field of Fourier transform that uses a component propagating in the y direction (transverse to the real direction of propagation z), thus treating the general equations of the fields electric and magnetic and function. The PBG theory is applied to obtain the relative permittivity of the polarizations for the sep photonic composite substrates material. The results are obtained with the commercial software Ansoft HFSS, used for accurate analysis of the electromagnetic behavior of the planar device under study through the Finite Element Method (FEM). Numerical computational results are presented in graphical form in two and three dimensions, playing in the parameters of return loss, frequency of radiation and radiation diagram, radiation efficiency and surface current for the device under study, and have as substrates, photonic materials and had been simulated in an appropriate computational tool. With respect to the planar device design study are presented in the simulated and measured results that show good agreement with measurements made. These results are mainly in the identification of resonance modes and determining the characteristics of the designed device, such as resonant frequency, return loss and radiation pattern

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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ln this work, planar quasi- Y agi antennas are investigated based on the concept of the classic Y agi_Uda antennas. These antennas represent improvements on the topologies of the antennas existing printed because they present characteristics of broad bandwidth, excellent radiation diagrams and simple construction. New configurations are adapted for the driver of the antennas, introducing patches elements into the driver. These new configurations are named Patches Elements Anteonas (PEA). This adaptation is obtained from simulations that are executed usiog the software C8T Microwave 8tudio 5. After doing the optimizations, procedures for construction and measurement ofthe prototypes are executed in order to improve the performance of the antennas in such way that they could be used in wireless communication applications, such as Bluetooth, WLAN' s and Wi-Fi. Next, the quasi- Y agi antennas are studied in order to implement them in arrangements. The arrangements construction is based 00 the best driver configuration of the antenna developed in this work. First, a linear arrangement composed by two elements of quasi¬Yagi antennas is constructed in such way that the radiation characteristics and the mutual coupling effects could be analyzed. After that, a 90° angle arrangement composed by two elements is studied to observe the effect of circular polarization. Experiments are executed in order to evaluate the arrangements performance. The experimental results show that the analysis made in this work is efficient and accurate. The numerical values obtained for the analyzed parameters of each structure developed are compared with the experimental values. 80, it is possible to observe a good concordance between them. Finally, some future works proposals are presented