Desenvolvimento de estruturas integradas de filtros e antenas para aplicações em sistemas de comunicações sem fio

This paper presents a study of the integration of filters and microstrip antennas, yielding devices named as filtennas for applications in wireless communications systems. The design of these structures is given from the observation of filtennas based integration between horn antennas and frequency selective surfaces (FSS), used in the band X. The choice of microstrip line structures for the development of a new configuration filtennas justifies the wide application of these transmission lines, in recent decades, always resulting in the production of circuit structures with planar light-weight, compact size, low cost, easy to construct and particularly easy to integrate with other microwave circuits. In addition, the antenna structure considered for the composition of filtennas consists of a planar monopole microstrip to microstrip filters integrated in the feed line of the antenna. In particular, are considered elliptical monopole microstrip (operating in UWB UWB) microstrip filters and (in structures with associated sections in series and / or coupled). In addition, the monopole microstrip has a proper bandwidth and omnidirectional radiation pattern, such that its integration with microstrip filters results in decreased bandwidth, but with slight changes in the radiation pattern. The methods used in the analysis of monopoles, and filters were filtennas finite elements and moments by using commercial software Ansoft Designer and HFSS Ansoft, respectively. Specifically, we analyze the main characteristics of filtennas, such as radiation pattern, gain and bandwidth. Were designed, constructed and measures, several structures filtennas, for validation of the simulated results. Were also used computational tools (CAD) in the process of building prototypes of planar monopoles, filters and filtennas. The prototypes were constructed on substrates of glass-fiber (FR4). Measurements were performed at the Laboratory for Telecommunications UFRN. Comparisons were made between simulated and measured, and found good agreement in the cases considered

Aplicação de tecnologias eletroquímicas (oxidação via radicais hidroxila, oxidação mediada via cloro ativo e eletrocoagulação) para o tratamento de efluentes reais ou sintéticos

In this work the degradation of real and synthetic wastewater was studied using electrochemical processes such as oxidation via hydroxyl radicals, mediated oxidation via active chlorine and electrocoagulation. The real effluent used was collected in the decanter tank of the Federal University of Rio Grande do Norte (ETE-UFRN) of Effluent Treatment Plant and the other a textile effluent dye Ácido Blue 113 (AB 113) was synthesized in the laboratory. In the electrochemical process, the effects of anode material, current density, the presence and concentration of chloride as well as the active chlorine species on site generated were evaluated. Electrodes of different compositions, Ti/Pt, Ti/Ru0,3Ti0,7O2, BDD, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 were used as anodes. These electrodes were subjected to electroanalytical analysis with the goal of checking how happen the anodic and cathodic processes across the concentrations of NaCl and supporting electrolyte used. The potential of oxygen evolution reaction were also checked. The effect of active chlorine species formed under the process efficiency was evaluated by removing the organic matter in the effluent-ETE UFRN. The wastewater treatment ETE-UFRN using Ti/Pt, DDB and Ti/Ru0,3Ti0,7O2 electrodes was evaluated, obtaining good performances. The electrochemical degradation of effluent-UFRN was able to promote the reduction of the concentration of TOC and COD in all tested anodes. However, Ti/Ru0,3Ti0,7O2 showed a considerable degradation due to active chlorine species generated on site. The results obtained from the electrochemical process in the presence of chloride were more satisfactory than those obtained in the absence. The addition of 0.021 M NaCl resulted in a faster removal of organic matter. Secondly, was prepared and characterized the electrode Ti/TiO2-nanotubes/PbO2 according to what the literature reports, however their preparation was to disk (10 cm diameter) with surface area and higher than that described by the same authors, aiming at application to textile effluent AB 113 dye. SEM images were taken to observe the growth of TiO2 nanotubes and confirm the electrodeposition of PbO2. Atomic Force Microscope was also used to confirm the formation of these nanotubes. Furthermore, was tested and found a high electrochemical stability of the electrode Ti/TiO2-nanotubes/PbO2 for applications such as long-term indicating a good electrocatalytic material. The electrochemical oxidation of AB 113 using Ti/Pt, Pb/PbO2 and Ti/TiO2-nanotubes/PbO2 and Al/Al (electrocoagulation) was also studied. However, the best color removal and COD decay were obtained when Ti/TiO2-nanotubes/PbO2 was used as the anode, removing up to 98% of color and 92,5% of COD decay. Analysis of GC/MS were performed in order to identify possible intermediates formed in the degradation of AB 113.

ArchWiSeN: uma estratégia baseada em modelos para desenvolvimento de aplicações para redes de sensores e atuadores sem fio

Wireless Sensor and Actuator Networks (WSAN) are a key component in Ubiquitous Computing Systems and have many applications in different knowledge domains. Programming for such networks is very hard and requires developers to know the available sensor platforms specificities, increasing the learning curve for developing WSAN applications. In this work, an MDA (Model-Driven Architecture) approach for WSAN applications development called ArchWiSeN is proposed. The goal of such approach is to facilitate the development task by providing: (i) A WSAN domain-specific language, (ii) a methodology for WSAN application development; and (iii) an MDA infrastructure composed of several software artifacts (PIM, PSMs and transformations). ArchWiSeN allows the direct contribution of domain experts in the WSAN application development without the need of specialized knowledge on WSAN platforms and, at the same time, allows network experts to manage the application requirements without the need for specific knowledge of the application domain. Furthermore, this approach also aims to enable developers to express and validate functional and non-functional requirements of the application, incorporate services offered by WSAN middleware platforms and promote reuse of the developed software artifacts. In this sense, this Thesis proposes an approach that includes all WSAN development stages for current and emerging scenarios through the proposed MDA infrastructure. An evaluation of the proposal was performed by: (i) a proof of concept encompassing three different scenarios performed with the usage of the MDA infrastructure to describe the WSAN development process using the application engineering process, (ii) a controlled experiment to assess the use of the proposed approach compared to traditional method of WSAN application development, (iii) the analysis of ArchWiSeN support of middleware services to ensure that WSAN applications using such services can achieve their requirements ; and (iv) systematic analysis of ArchWiSeN in terms of desired characteristics for MDA tool when compared with other existing MDA tools for WSAN.

Estudo de arranjos de antenas de microfita com Patch quase-fractal para comunicações sem fio

In this dissertation, are presented two microstrip antennas and two arrays for applications in wireless communication systems multiband. Initially, we studied an antenna and a linear array consisting of two elements identical to the patch antenna isolated. The shape of the patch used in both structures is based on fractal geometry and has multiband behavior. Next a new antenna is analyzed and a new array such as initial structure, but with the truncated ground plane, in order to obtain better bandwidths and return loss. For feeding the structures, we used microstrip transmission line. In the design of planar structures, was used HFSS software for the simulation. Next were built and measures electromagnetic parameters such as input impedance and return loss, using vector network analyzer in the telecommunications laboratory of Federal University of Rio Grande do Norte. The experimental results were compared with the simulated and showed improved return loss for the first array and also appeared a fourth band and increased directivity compared with the isolated antenna. The first two benefits are not commonly found in the literature. For structures with a truncated ground planes, the technique improved impedance matching, bandwidth and return loss when compared to the initial structure with filled ground planes. Moreover, these structures exhibited a better distribution of frequency, facilitating the adjustment of frequencies. Thus, it is expected that the planar structures presented in this study, particularly arrays may be suitable for specific applications in wireless communication systems when frequency multiband and wideband transmission signals are required.

Modelagem do consumo de energia de redes de sensores sem fio usando SystemC-AMS e stateflow

This work aims at modeling power consumption at the nodes of a Wireless Sensor Network (WSN). For doing so, a finite state machine was implemented by means of SystemC-AMS and Stateflow modeling and simulation tools. In order to achieve this goal, communication data in a WSN were collected. Based on the collected data, a simulation environment for power consumption characterization, which aimed at describing the network operation, was developed. Other than performing power consumption simulation, this environment also takes into account a discharging model as to analyze the battery charge level at any given moment. Such analysis result in a graph illustrating the battery voltage variations as well as its state of charge (SOC). Finally, a case study of the WSN power consumption aims to analyze the acquisition mode and network data communication. With this analysis, it is possible make adjustments in node-sensors to reduce the total power consumption of the network.

Ferramenta para avaliação e inferência de parâmetros de redes industriais sem fio

Wireless sensor networks (WSN) have gained ground in the industrial environment, due to the possibility of connecting points of information that were inaccessible to wired networks. However, there are several challenges in the implementation and acceptance of this technology in the industrial environment, one of them the guaranteed availability of information, which can be influenced by various parameters, such as path stability and power consumption of the field device. As such, in this work was developed a tool to evaluate and infer parameters of wireless industrial networks based on the WirelessHART and ISA 100.11a protocols. The tool allows quantitative evaluation, qualitative evaluation and evaluation by inference during a given time of the operating network. The quantitative and qualitative evaluation are based on own definitions of parameters, such as the parameter of stability, or based on descriptive statistics, such as mean, standard deviation and box plots. In the evaluation by inference uses the intelligent technique artificial neural networks to infer some network parameters such as battery life. Finally, it displays the results of use the tool in different scenarios networks, as topologies star and mesh, in order to attest to the importance of tool in evaluation of the behavior of these networks, but also support possible changes or maintenance of the system.

FTE-LEACH: um protocolo energeticamente eficiente e tolerante a falhas aplicado às redes industriais de sensores sem fio

A Wireless Sensor Network (WSN) consists of distributed devices in an area in order to monitor physical variables such as temperature, pressure, vibration, motion and environmental conditions in places where wired networks would be difficult or impractical to implement, for example, industrial applications of difficult access, monitoring and control of oil wells on-shore or off-shore, monitoring of large areas of agricultural and animal farming, among others. To be viable, a WSN should have important requirements such as low cost, low latency, and especially low power consumption. However, to ensure these requirements, these networks suffer from limited resources, and eventually being used in hostile environments, leading to high failure rates, such as segmented routing, mes sage loss, reducing efficiency, and compromising the entire network, inclusive. This work aims to present the FTE-LEACH, a fault tolerant and energy efficient routing protocol that maintains efficiency in communication and dissemination of data.This protocol was developed based on the IEEE 802.15.4 standard and suitable for industrial networks with limited energy resources

No fio da meada: um estudo acerca da precarização do trabalho na indústria têxtil

In line with the process of financialization and globalization of capital, which has intensified in all latitudes of the globe, the world of work is permeated by his determinations arising and also has been (re) setting from numerous changes expressed by example, in the unbridled expansion of temporary forms of work activities, and flexible outsourced by the growth of informality, forming a new morphology of work. However, regardless of how these forms are expressed in concrete materiality, there is something that unifies: all of them are marked by exponentiation of insecurity and hence the numerous negative effects on the lives of individuals who need to sell their labor power to survive. Given this premise, the present work is devoted to study, within the framework of the Brazilian particularities of transition between Fordism and Toyotism, what we call composite settings of the conditions and labor relations processed within the North river- textile industry Grande. To this end, guided by historical and dialectical materialism, we made use of social research in its qualitative aspect, using semi-structured interviews, in addition to literature review, information retrieval and use of field notes. From our raids, we note that between the time span stretching from the 1990s to the current year, the Natal textile industry has been undergoing a process of successive and intense changes in their modus operandi, geared specifically to the organization and labor management causing, concomitantly, several repercussions for the entire working class.

No fio da meada: um estudo acerca da precarização do trabalho na indústria têxtil

In line with the process of financialization and globalization of capital, which has intensified in all latitudes of the globe, the world of work is permeated by his determinations arising and also has been (re) setting from numerous changes expressed by example, in the unbridled expansion of temporary forms of work activities, and flexible outsourced by the growth of informality, forming a new morphology of work. However, regardless of how these forms are expressed in concrete materiality, there is something that unifies: all of them are marked by exponentiation of insecurity and hence the numerous negative effects on the lives of individuals who need to sell their labor power to survive. Given this premise, the present work is devoted to study, within the framework of the Brazilian particularities of transition between Fordism and Toyotism, what we call composite settings of the conditions and labor relations processed within the North river- textile industry Grande. To this end, guided by historical and dialectical materialism, we made use of social research in its qualitative aspect, using semi-structured interviews, in addition to literature review, information retrieval and use of field notes. From our raids, we note that between the time span stretching from the 1990s to the current year, the Natal textile industry has been undergoing a process of successive and intense changes in their modus operandi, geared specifically to the organization and labor management causing, concomitantly, several repercussions for the entire working class.

A economia criativa como estratégia de desenvolvimento para a cidade de Natal/RN

Globalization, the enormous speed of information exchange, technology updated in a speed never before and the growth of the cultural industry places us in a new reality in which we must adapt ourselves puting issues concerning to culture and technology at the center of development discussions. The Creative Economy, therefore, is inserted in this dicussion bringing these new elements to the center of the debate. The development potential of this new economy are real in Natal / RN, from, especially their link withim tourism. Thus, the intention of the work is to answer the questions: What is the weight of the creative economy in Natal? What are the issues that accelerate or hinder their development? To answer these questions we mapping the creative sectors on Natal’s economy, stressing labor and income figures, exercise already done by national and international organizations. The issues that connect the Creative Economy to education, R & D, cultural policy and tourism is also discussed. The review of the indicators related to these topics will be used to explain how they are configured as obstacle for the development of the creative economy in Natal/RN.

Estudo e desenvolvimento de algoritmos criptográficos para redes de sensores sem fio, utilizando técnicas de programação genética

Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.

Estudo e desenvolvimento de algoritmos criptográficos para redes de sensores sem fio, utilizando técnicas de programação genética

Cryptography is the main form to obtain security in any network. Even in networks with great energy consumption restrictions, processing and memory limitations, as the Wireless Sensors Networks (WSN), this is no different. Aiming to improve the cryptography performance, security and the lifetime of these networks, we propose a new cryptographic algorithm developed through the Genetic Programming (GP) techniques. For the development of the cryptographic algorithm’s fitness criteria, established by the genetic GP, nine new cryptographic algorithms were tested: AES, Blowfish, DES, RC6, Skipjack, Twofish, T-DES, XTEA and XXTEA. Starting from these tests, fitness functions was build taking into account the execution time, occupied memory space, maximum deviation, irregular deviation and correlation coefficient. After obtaining the genetic GP, the CRYSEED and CRYSEED2 was created, algorithms for the 8-bits devices, optimized for WSNs, i.e., with low complexity, few memory consumption and good security for sensing and instrumentation applications.

Projeto CLIK2GET - sistema agregador de tecnologias que facilitem a integração de aplicativos gamificados

Relatório de estágio para obtenção de grau de mestre na área de Educação e Comunicação Multimédia

Formação inicial do professor de matemática com uso de tecnologias da informação e comunicação no contexto da escola pública

This paper intends to analyze which contribution for teachers formative training the participation on extension projects can bring to the bachelors in Mathematics teaching. The research was conducted during the developing of a Project from the Program of Extension - Programa de Extensão UFU/Comunidade (PEIC) in a municipal school located in a country zone from Uberlândia-MG. The research was constituted by a series of activities with students from the ninth year of the Fundamental Education, Middle School. The main focus is the work developed by two bachelors of Mathemactics teaching from the Federal University from Uberlândia who were part of the PEIC team. This present research intends to answer the following question: How the extension project “Information technology and communication on Mathematics problem resolution in country zone schools” has contribited to reinforce and to (re)criate the fomative experiences of students from the Mathematics teaching course who have developed such project? The presente study is from a qualitative nature and has made use of the partaker searching methodology. The presente paper was organized in three chapters. On chapter I evidence is given to theoretical discussion made, having as main references the works of Larrosa, Ponte e Shön. Chapter II brings the description of the three activities that were developed and aplied during the PEIC Project, which are: Problems in the Park, Inaccessible Hight and Lili Game. On chapter III, the data analysis is presented. The data was obtained through instruments of registration such as: camera recording, photografic material, meetings reports, field notes, surveys and semi-structured interviews. The initial hypothesis aim is on the fact that the participation on extention projects during the graduation course can bring rich contribution for the teachers to be, since it’s going to provide the knowledge and chalenge close to the one from the future profession. With the analysis of the obtained results from the colected data, it was possible to conclude that the PEIC has provided the bachelors in Mathematics teching the opportunity of recreate and potenciate their formative experiences. Such opportunity happened in situations that involved, for example, planning makings, development of colective work, softwares usage, different school spaces and the direct interaction with school bureaucracy. Beyond that, it was possible to work with the cocepts of reflection in action in a way to contribute to the professional development of the future Mathematics teachers. Thereby, in our final considerations, is possible to conclude that extension projects performed during the graduation course can bring great contributions to the professional formation of the bachelors in Mathematics teaching, among them we highlight the potentiation of the previous formative experiences and the development of colective work and behavior related to a reflexive teacher.

Projectos de consultoria em SAP e tecnologias microsoft: análise e desenvolvimento de soluções de software à medida

À medida que a sociedade evolui, também as profissões evoluem com ela. Uma profissão que tem crescido de forma notável é a de consultor na área das tecnologias de informação. De facto, há alguns anos atrás, esta profissão não tinha o relevo que tem na actualidade, pois com a evolução das tecnologias da informação, as ferramentas ao dispor das empresas diversificaram-se e como tal, a mão-de-obra vai-se especializando nestas ferramentas. As empresas, na impossibilidade de contratar mão-de-obra para instalar, manter e evoluir todas as suas ferramentas, recorrem cada vez mais à experiência de consultores externos; estes são contratados para realizar tarefas específicas que as empresas não têm capacidade de executar com os próprios recursos e a sua ligação com estas entidades termina após a conclusão destas tarefas. Cada vez mais as empresas procuram tirar o máximo partido das ferramentas informáticas à sua disposição e os sistemas de Enterprise Resource Planning não são excepção. À medida que os utilizadores vão usufruindo dos sistemas, surgem novas necessidades que, depois de colmatadas, permitem a sua optimização. Além disso, com a alteração das leis, é preciso adaptar os sistemas para que estes evoluam e possam reflectir os novos requisitos legais. Com o aumento da regulação bancária, as entidades bancárias são obrigadas a comunicar informação sobre as suas finanças ao Banco de Portugal, de modo a que o banco possa analisar a saúde financeira das entidades e emitir recomendações sobre a sua forma de actuar. Esta nova forma de comunicação será efectuada por meio de relatórios em eXtended Business Reporting Language (XBRL). Pretende-se caracterizar a profissão de consultor e apresentar alguns projectos realizados enquanto consultor numa consultora de grande dimensão.