869 resultados para médias móveis


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Recently the planar antennas have been studied due to their characteristics as well as the advantages that they offers when compared with another types of antennas. In the mobile communications area, the need for this kind of antennas have became each time bigger due to the intense increase of the mobile communications that needs of antennas which operate in multifrequency and wide bandwidth. The microstrip antennas presents narrow bandwidth due the loss in the dielectric generated by radiation. Another limitation is the radiation pattern degradation due the generation of surface waves in the substrate. In this work some used techniques to minimize the disadvantages (previously mentioned) of the use of microstrip antennas are presented, those are: substrates with PBG material - Photonic Bandgap, multilayer antennas and with stacked patches. The developed analysis in this work used the TTL - Transverse Transmission Line method in the domain of Fourier transform, that uses a component of propagation in the y direction (transverse to the direction real of propagation z), treating the general equations of electric and magnetic field as functions of y and y . This work has as objective the application of the TTL method to microstrip structures with single and multilayers of rectangular and triangular patches, to obtaining the resonance frequency and radiation pattern of each structure. This method is applied for the treatment of the fields in stacked structures. The Homogenization theory will be applied to obtaining the effective permittivity for s and p polarizations of the substrate composed of PBG material. Numerical results for the triangular and rectangular antennas with single layer, multilayers resonators with triangular and rectangular patches are presented (in photonic and isotropic substrates). Conclusions and suggestions for continuity of this work are presented

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New versions of SCTP protocol allow the implementation of handover procedures in the transport layer, as well as the supply of a partially reliable communication service. A communication architecture is proposed herein, integrating SCTP with the session initiation protocol, SIP, besides additional protocols. This architecture is intended to handle voice applications over IP networks with mobility requirements. User localization procedures are specified in the application layer as well, using SIP, as an alternative mean to the mechanisms used by traditional protocols, that support mobility in the network layer. The SDL formal specification language is used to specify the operation of a control module, which coordinates the operation of the system component protocols. This formal specification is intended to prevent ambiguities and inconsistencies in the definition of this module, assisting in the correct implementation of the elements of this architecture

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Navigation based on visual feedback for robots, working in a closed environment, can be obtained settling a camera in each robot (local vision system). However, this solution requests a camera and capacity of local processing for each robot. When possible, a global vision system is a cheapest solution for this problem. In this case, one or a little amount of cameras, covering all the workspace, can be shared by the entire team of robots, saving the cost of a great amount of cameras and the associated processing hardware needed in a local vision system. This work presents the implementation and experimental results of a global vision system for mobile mini-robots, using robot soccer as test platform. The proposed vision system consists of a camera, a frame grabber and a computer (PC) for image processing. The PC is responsible for the team motion control, based on the visual feedback, sending commands to the robots through a radio link. In order for the system to be able to unequivocally recognize each robot, each one has a label on its top, consisting of two colored circles. Image processing algorithms were developed for the eficient computation, in real time, of all objects position (robot and ball) and orientation (robot). A great problem found was to label the color, in real time, of each colored point of the image, in time-varying illumination conditions. To overcome this problem, an automatic camera calibration, based on clustering K-means algorithm, was implemented. This method guarantees that similar pixels will be clustered around a unique color class. The obtained experimental results shown that the position and orientation of each robot can be obtained with a precision of few millimeters. The updating of the position and orientation was attained in real time, analyzing 30 frames per second

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On this research we investigated how new technologies can help the process of design and manufacturing of furniture in such small manufacturers in Rio Grande do Norte state. Google SketchUp, a 3D software tool, was developed in such a way that its internal structures are opened and can be accessed using SketchUp s API for Ruby and programs written in Ruby language (plugins). Using the concepts of the so-called Group Technology and the flexibility that enables adding new functionalities to this software, it was created a Methodology for Modeling of Furniture, a Coding System and a plugin for Google s tool in order to implement the Methodology developed. As resulted, the following facilities are available: the user may create and reuse the library s models over-and-over; reports of the materials manufacturing process costs are provided and, finally, detailed drawings, getting a better integration between the furniture design and manufacturing process

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It is an investigation that seeks to reveal, record and analyze the process of appropriation and use of digital media by university students, aged between 40 and 60 years. Interested in studying how changes are perceived in the educational sphere for students Whois have gone through liberal/traditional school, ie, effected the first contact with technological devices media as adults, in the university. This investigation sought to contribute to the knowledge on the use of new learning strategies imposed by digital media by recording and analyzing the reports surveyed sample. Allowed to know the cultural universe of these women, revealing the context in which receive mediated messages and uses that maré these learning strategies within their daily academic life. Gathered in this work, reflexions guided by studies of media reception and role played by digital media as builders images and facilitators in knowledging acquisitions, it was chosen to work two main theorical notions: communication media and digital inclusion. As the research methodology, it was used the exploratory descriptive technical together with other appropriate tecniques. In ordem to approach the problem can be observed two phases: a quantitative one, which was used an investigative procedure, a survey data with closed questions; and a qualitative phase, which was used to collect data through a diary from situations encountered in the classroom. The main objective of analyzing how digital media are received, appropriated and used by university women has been fulfilled and it is remarkable that they access with dificulty and can not be considered included digitally. The results show that the problem of these agents is not the access, there are was of appropriation of digital media offered at IES, and it was possible to note that they seek to integrate to the technological world, and they even have devices that can insert them on this world. Insertion in cyberculture sets up the ability to find a favorable way to be aware of reality and production of knowledge and liberating and dignifying practices, in this case refers to an appropriation of citizenship through the field of technological devices offered as a perspective that they can interact

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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This study discusses about the practice of communication in libraries from the appropriation of the resources of web 2.0, particularly social media, establishing from the aspects of mediatization new communication scenarios in their environments. Aims at understanding how in the contemporary society, the libraries, that symbolize traditional space in the search for information and knowledge, modify their contexts through technological resources involved in your scenario, and specifically checks as the process of mediatization is inserted into the communication practices and interaction of libraries, noting the relevance of the ownership of social media, especially twitter and facebook, by the libraries of the Federal University of Rio Grande do Norte - UFRN. Use as methodological procedures, a theoretical approach concerning the conceptual research to investigate issues relating to social media, communication practice, mediatization and network society, and is characterized by being a descriptive exploratory research, of qualitative nature with adoption of the inductive method, using interviews and direct observation, analyzing reconfiguration scenario of university libraries located in UFRN. Thus, with the of the study, expected to be possible to give an overview of how to establish the use of social media in the scenario investigated by checking the new possibilities of communication, outreach services, information dissemination and interaction with user

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With the increase of processing ability, storage and several kinds of communication existing such as Bluetooth, infrared, wireless networks, etc.., mobile devices are no longer only devices with specific function and have become tools with various functionalities. In the business field, the benefits that these kinds of devices can offer are considerable, because the portability allows tasks that previously could only be performed within the work environment, can be performed anywhere. In the context of oil exploration companies, mobile applications allow quick actions could be taken by petroleum engineers and technicians, using their mobile devices to avoid potential catastrophes like an unexpected stop or break of important equipment. In general, the configuration of equipment for oil extraction is performed on the work environment using computer systems in desktop platforms. After the obtained configuration, an employee goes to equipment to be configured and perform the modifications obtained on the use desktop system. This management process equipment for oil extraction takes long time and does not guarantee the maintenance in time to avoid problems. With the use of mobile devices, management and maintenance of equipment for oil extraction can be performed in a more agile time once it enables the engineer or technician oil can perform this configuration at the time and place where the request comes for example, near in the oil well where the equipment is located. The wide variety of mobile devices creates a big difficulty in developing mobile applications, since for one application can function in several types of devices, the application must be changed for each specific type of device, which makes the development quite costly. This paper defines and implements a software product line for designing sucker-rod pumping systems on mobile devices. This product line of software, called BMMobile, aims to produce products that are capable of performing calculations to determine the possible configurations for the equipment in the design suckerrod pumping, and managing the variabilities of the various products that can be generated. Besides, this work performs two evaluations. The first evaluation will verify the consistency of the products produced by the software product line. The second evaluation will verify the reuse of some products generated by SPL developed

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Software Products Lines (SPL) is a software engineering approach to developing software system families that share common features and differ in other features according to the requested software systems. The adoption of the SPL approach can promote several benefits such as cost reduction, product quality, productivity, and time to market. On the other hand, the SPL approach brings new challenges to the software evolution that must be considered. Recent research work has explored and proposed automated approaches based on code analysis and traceability techniques for change impact analysis in the context of SPL development. There are existing limitations concerning these approaches such as the customization of the analysis functionalities to address different strategies for change impact analysis, and the change impact analysis of fine-grained variability. This dissertation proposes a change impact analysis tool for SPL development, called Squid Impact Analyzer. The tool allows the implementation of change impact analysis based on information from variability modeling, mapping of variability to code assets, and existing dependency relationships between code assets. An assessment of the tool is conducted through an experiment that compare the change impact analysis results provided by the tool with real changes applied to several evolution releases from a SPL for media management in mobile devices

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

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The media currently play a dual role in the physical and symbolic structure of social organization. It is through the media that companies have achieved control of their distribution and production. It is not only through the media, but mainly so, that certain world views circulate and are legitimized. Access to material and symbolic goods has become a mark of social distinction. The project of a more democratic society also involves the preparation of its citizens to be able both to deal with the media products that already circulate as well as to develop a critical perspective of media products. This research stemmed from the need to understand what place this study of the media occupies in training for teachers in early grades, given that children are already immersed in a media world from an early age. This research shows that this is a place which is under construction and despite the existing adverse conditions, emancipatory practices are being developed. The research is guided by the study of the media in teacher education from an emancipatory perspective. This perspective develops in a time that, in this case, has proved slow and fragmented, but not nonexistent. The process of teacher training is influenced by working conditions and educational policies that hinder both working with the media in school and also improving the critical understanding of the media. The research shows that training opportunities, even in these conditions, can allow for more meaningful criticism. The emancipatory perspective also includes a reflection on practices. These practices are being developed and this research sought to provide support for a proposed study of the media from this perspective

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The great interest observed in wireless communication systems has required the development of new configurations of microstrip antennas, because they are easily built and integrated to other microwave circuit components, which is suitable for the construction and development of planar antenna arrays and microwave integrated circuits. This work presents a new configuration of tapered microstrip antenna, which is obtained by impressing U-slots on the conducting patch combined with a transmission line matching circuit that uses an inset length. It is shown that the use of U-slots in the microstrip antenna conducting patch excites new resonating modes, that gives a multiband characteristic for the slotted microstrip antenna, that is suitable for applications in communication systems that operates several frequencies simultaneously. Up to this date, the works reported in the literature deals with the use of Uslotted microstrip rectangular antennas fed by a coaxial probe. The properties of a linear array of microstrip patch tapered antennas are also investigated. The main parameters of the U slotted tapered microstrip antennas are investigated for different sizes and locations of the slots impressed on the conducting patch. The analysis of the proposed antenna is performed by using the resonant cavity and equivalent transmission line methods, in combination with a parametric study, that is conducted by the use of the Ansoft Designer, a commercial computer aided microwave software well known by its accuracy and efficiency. The mentioned methods are used to evaluate the effect in the antennas parameters, like resonant frequency and return loss, produced by variations of the antenna structural parameters, accomplished separately or simultaneously. An experimental investigation is also developed, that consists of the design, construction and measurement of several U slotted microstrip antenna prototypes. Finally, theoretical and simulated results are presented that are in agreement with the measured ones. These results are related to the resonating modes identification and to the determination of the main characteristics of the investigated antennas, such as resonant frequency, return loss, and radiation pattern

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This study shows the results of a research developed in the coastal regions of the Maxaranguape and Touros municipalities, more specific in the mobile dune fields of the Rio Grande do Norte's eastern coast. Although the coastal zones, represent a small percentage of the earth's surface it concentrates a great part of the world's population. The Rio Grande do Norte's state coastal landscape mosaic composed by the dune fields suggest a dynamic scene of changes in the spatial and temporal arranges, with significant changes in the geometry of the sedimentary cover. Following this perspective this research has the objective to map the emerged coastal zone of the Rio Grande do Norte's eastern coast under the perspective of the time-space evolution of the mobile dune fields using geoprocessing techniques, which includes remote sensing, digital images processing and geographic information system (GIS). The results imply the issue of thematic maps: Geologic map; multitemporal evolution map of the mobile dune fields; quantification of the mobile dune fields differences map; temporal evolution of the mobile dune fields surrounds map. The El Niño episodes have directly affected the atmospheric circulation, what have enhanced the sedimentary input in the sand dune, what can justify the relative area growth between the years of 1993 and 2001. The dynamic of the landscape transition were higher than the stability of the spatial pattern of the dune and it's surrounds, as a result the Rio Grande do Norte eastern coast dune fields, specially the mobile dunes from Touros, Zumbi and Maracajau have shown a decrease on the sedimentary cover without vegetation area from 1970 to 2007. Therefore, the data acquired and the techniques used, can be, eventually applied to the mobile dune fields monitoring in order to preserve the dune ecosystems in the Rio Grande do Norte coast

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Este trabalho discute a gestão da tecnologia ern pequenas e medias empresas tradicionais da área de manufaturados. Ele analisa aspectos estratégicos e operacionais através de um modelo conceitual simplificado, com base em referências bibliográficas e pesquisa exploratória(survey). Foram detectados alguns aspectos importantes : limitada integração entre planejamento de tecnologia e de produto/mercado; vulnerabilidade tecnológica com relação a direitos de propriedade industrial; dificuldades financeiras para desenvolvimento, capacitação tecnológica limitada; e limitação de mudanças organizacionais de transição. Uma questão importante seria a construção de mecanismos externos de colaboração para essas empresas, com difusão de práticas da gestão da tecnologia e parceria para desenvolvimento de produtos.