Made available in DSpace on 2018-03-22T15:59:43Z (GMT). No. of bitstreams: 1 tese_11695_Tese Final St_fanie Cristina de Oliveira.pdf: 1556297 bytes, checksum: e9a76ba058e80aec74bb5fddd6159037 (MD5) Previous issue date: 2017-12-21 / Entre as espécies Coffea, existe um híbrido natural denominado "Híbrido de Timor" (HT), encontrado na Ilha de Timor em 1927. HT 'CIFC 4106', o qual representa a primeira planta, possui 2n = 3x = 33 cromossomos e valor 1C DNA igual a 1C = 2.10 pg. O número cromossômico, o conteúdo de DNA e evidências geográficas, suportam uma possível origem alotriploide a partir da fusão de uma célula reprodutiva reduzida de Coffea arabica (2n = 4x = 44) com outra célula, também reduzida, de Coffea canephora (2n = 2x = 22). C. arabica, outro alopoliploide pertencente ao gênero, acumula estudos que buscam desvendar seus progenitores. Dados moleculares e cariotípicos sugerem que este alotetraploide verdadeiro seja formado a partir de uma célula reprodutiva reduzida de C. canephora (CC) e C. eugenioides (EE), seguido por um evento de poliploidização. Neste sentido, acredita-se que o genoma de C. arabica seja representado como CaCaEaEa. Com base nas evidências mencionadas, formulamos a seguinte hipótese: o genoma de HT 'CIFC 4106' é CCaEa? O presente estudo caracterizou citogenicamente C. eugenioides, C. canephora, C. arabica e HT 'CIFC 4106'. A combinação de dados morfométricos, conteúdo de DNA nuclear e cromossômico e hibridização in situ fluorescente (FISH) com rDNA 5S, expandiu o conhecimento sobre a origem evolutiva e a estrutura do genoma de HT 'CIFC 4106'. O cariograma de HT 'CIFC 4106' evidenciou pares e grupos cromossômicos delimitados de acordo com o tamanho total, classes e conteúdos de DNA cromossômicos. Com base nessas características cariotípicas, foi possível inferir a presença de dois genomas idênticos em HT 'CIFC 4106', possivelmente de C. canephora (CC) e um genoma distinto (C. eugenioides, E). Os cromossomos de HT 'CIFC 4106' apresentaram classe, conteúdo de DNA idênticos aos cromossomos de C. eugenioides, C. canephora e C.arabica. Padrões de distribuição de sinais 5S em HT 'CIFC 4106' foram similares aos encontrados nos possíveis progenitores C. eugenioides e C. canephora. Os dados revelados neste estudo corroboram com a hipótese CCaEa do genoma de HT 'CIFC 4106'.

With the development of Wi-Fi networks, Wi-Fi connection become a very important part of people‟s life, it seems that Wi-Fi networks are everywhere, especially in China. However, Wi-Fi networks not only bring convenience to users, but also bring some security threats. Nowadays, Wi-Fi security problems become increasingly acute. This thesis investigates the differences between male and female users regarding Wi-Fi network security. By distributing a questionnaire in China, specific questions have been asked about key factors within the area of Wi-Fi security. The questions focus on the usage situation, information security awareness and the knowledge level in Wi-Fi related fields. The found result is: Wi-Fi security issues are more prominent for female users than for male users.

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-09-14T22:19:42Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Eric Ribas Moraes Machado.pdf: 4900184 bytes, checksum: c948644abc8216ef6e5e18dedb37a22f (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-09-18T16:02:00Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Eric Ribas Moraes Machado.pdf: 4900184 bytes, checksum: c948644abc8216ef6e5e18dedb37a22f (MD5) / Made available in DSpace on 2018-09-18T16:02:00Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Eric Ribas Moraes Machado.pdf: 4900184 bytes, checksum: c948644abc8216ef6e5e18dedb37a22f (MD5) Previous issue date: 2017-06-05 / Redes Wi-Fi estão presentes desde as residências aos ambientes corporativos e instituições de ensino e pesquisa. Contudo, a qualidade de serviço (QoS) percebida pelo usuário pode ser degradada quando em ambientes congestionados, como em lugares confinados com grande quantidade de usuários. Para lidar com esse problema várias empresas oferecem soluções verticalmente integradas e fechadas, no entanto, os custos de capital (CAPEX), com a aquisição de equipamentos e licenças, e operacionais (OPEX) decorrente do seu gerenciamento são muito altos. O surgimento das redes definidas por software (SDN) viabilizou o desenvolvimento de varias soluções abertas para melhorar o gerenciamento das redes em geral, possibilitando ao administrador da rede programar rotinas dinâmicas de monitoramento, correção de problemas e otimização do uso dos recursos disponíveis, através de um controlador centralizado com visão geral da rede. Considerando a necessidade de soluções abertas para os Institutos Federais de Educação, Ciência e Tecnologia e o potencial da programabilidade das redes sem fio definidas por software, várias soluções foram desenvolvidas para lidar com o problema da degradação do QoS, entretanto, das inúmeras soluções existentes na literatura para o gerenciamento e balanceamento de carga nestas redes, a maioria delas não visam ambientes confinados com baixa mobilidade e/ou requerem modificações no dispositivo móvel, criando burocracia para o setor de tecnologia da informação e gerando desconforto aos usuários, que muitas vezes possuem dispositivos que não suportam as mudanças necessárias. Diante deste cenário esta dissertação propõe um arcabouço para balanceamento de carga em redes sem fio (Wi-Fi) utilizando a arquitetura SDN. Existem outras propostas que promovem o balanceamento de carga em redes Wi-Fi, mas são, normalmente, orientadas ao usuário. O foco do arcabouço proposto nesta dissertação é prover uma solução orientada à infraestrutura para ambientes de rede sem fio confinados, densos e com baixa mobilidade como auditórios, salas de aula, anfiteatros, dentre outros. O modelo promove a melhoria da QoS das aplicações dos usuários através do monitoramento de dados estatísticos da rede, coletados a partir da controladora SDN e de rádios de baixo custo com firmware modificado (OpenWRT) e da análise da carga gerada por cada usuário, mitigando assim a assimetria de rede por meio da realocação da carga. Para analisar o arcabouço proposto foi desenvolvido um software, utilizado o controlador SDN Ryu, foram configurados pontos de acesso (AP) e definidos cenários de congestionamento e assimetria em um ambiente de redes sem fio. A partir dos experimentos, foi observado que, os usuários tiveram uma melhoria de QoS considerável enquanto o sistema estava ativado. / Wi-Fi networks are present from residences to corporate environments and education and research institutions. However, user perceived quality of service (QoS) can be degraded when in congested environments, such as in confined spaces with large numbers of users. To deal with this problem several companies offer vertically integrated and closed solutions, but, the capital expenditure (CAPEX), with the acquisition of equipment and licenses, and operational expenditure (OPEX) due to its management are very high. The emergence of software-defined networking (SDN) enabled the development of several open solutions to improve network management, enabling the network administrator to program dynamic monitoring routines, problem correction and optimization of the use of available resources through centralized controller with network overview. Considering the need for open solutions for federal institutes and the potential for programmability of SDN, several solutions have been developed to deal with the QoS degradation problem, nevertheless, of the numerous solutions in the literature for managing and balancing the load on these networks, most of them do not target confined environments with low mobility and / or require modifications in the mobile device, creating bureaucracy for the IT sector and generating discomfort to the users, which often have devices that do not support the necessary changes. Considering this scenario, this dissertation proposes a framework for load balancing in wireless networks (Wi-Fi) using the SDN architecture. There are other proposals that promote load balancing on Wi-Fi networks, they are usually user-oriented. In this dissertation the proposed framework focus is to provide an infrastructure-oriented solution for confined, dense, low mobility wireless network environments such as auditoriums, classrooms and amphitheaters. The proposal improves the QoS of the users’ applications by the monitoring of statistical data from network, collected through the controller SDN and low cost radios with modified firmware (OpenWRT) and analysis of the load generated by each user, thus mitigating the asymmetry through load reallocation. In order to analyze the proposed framework, a software was developed, using the Ryu SDN controller, configured access points (AP) and defined congestion and asymmetry scenarios in a wireless environment. From the experiments, it was observed that, users had a considerable QoS improvement while the system was activated.

This thesis is focused on the use of light and LEDs for communication between the light and the user. In the introduction, the principles of VLC, which Li-Fi is part of, are described. The work also contains issues on the topics of Li-Fi, such as methods of modulation of carrier signals for data transmission, comparisons between other wireless communications, individual elements of optical frontends, current versions of Li-Fi and other possible uses of this technology. The work also contains the designing of a system working on the principle of Li-Fi.

The diploma thesis gives the overall information about the field of wireless networks of standards 802.11 and Quality of Service (QoS). The practical measurements describe the reactions of multimedia dataflows in the networks 802.11a/b/g/n. The individual standards, offered services, access methods and the network architecture are analyzed in the theoretical part. In the following part there is written about QoS and its basic parameters. Moreover, the standard 802.11e and the question of QoS in the wireless networks are explained in a detailed way. The first part of the practical measurement is focused on the networks 802.11b/g/n. All main network statistics are measured when using the wireless stations and routers. The projection and implementation of the wireless network in the Opnet Modeler is included in the next part. The individual simulations WLAN in the Opnet Modeler are comparing the networks 802.11a/b/g. The analysis of the key QoS statistics is undertaken; the measured data are clearly displayed in the charts and schemes. The interpreted results are concluded and justified.

This thesis is focused on the design of panel antennas for band 5,6 GHz. Antennas have been examined and optimized with a view to impedance, broadband and directional characteristics by using designing software CST Design Environment. Optimized antennas were produced, and their measured parameters achieved required values.

This project is concerned with the security of Wi-Fi network. It defines security and introduces the principles of some security systems which are consequently instructed for its breakthrough, out of which follows the nature of security failures. The main emphasis is put on the current security issue of Wi-Fi Protected Setup (WPS) technology. Consequently, it is concerned with the putting into service of this technology in GNU/Linux distribution OpenWrt on Wi-Fi router TP-LINK TL-WR1043ND. The project is concluded with the suggestions for the correction of the security failure.

Detta kandidatarbete undersöker Pierre Schaeffers (2012 [1952]) begrepp musique concrète samt dess metoder och tekniker. Musique concrète kan beskrivas som en samling kompositionsmetoder som utgår från inspelade ljud av omvärlden utan inblandning av musikinstrument, musikteori, eller ljud genererade från elektroniska källor. Vi använde Schaffers begrepp reduced listening, vilket är en lyssningsmetod där man bortser från ljudets källa och fokuserar på dess akustiska egenskaper, (vilket Michel Chion (1994) senare expanderade på). Jøran Rudi (2011) skriver om R. Murray Schafer’s begrepp Hi-Fi och Lo-Fi, vilket vi använde för att kategorisera ljuden som användes och platserna som spelades in. I designprocessen applicerade och experimenterade vi med metoder och tekniker från den aktuella forskningen för att utforska och dokumentera arbetsprocessen i gestaltningsprototyperna. Detta arbete resulterade i en samling kompositioner utefter Lo-Fi och Hi-Fi inom musique concrète där vi fick en bredare förståelse för de aktuella metoderna och teknikerna. / This bachelor thesis examines Pierre Schaeffer’s (2012 [1952]) term musique concrète as well as it’s methods and techniques. Musique concrète can be described as a collection of compositional methods that uses recorded sounds from the surrounding world as a startingpoint, without the use of musical instruments, music theory, or electronically produced sounds. We used Schaeffer’s term reduced listening (which Michel Chion (1994) later expanded upon). Jøran Rudi (2011) writes about R. Murray Schafer’s term Hi-Fi and Lo-Fi,and these terms were later used by us to categorise and record sounds from the environment. Investigation and experimentation with the various methods and techniques ensued in the design process in order to explore and document the work process of the prototypes. This process resulted in a collection of musique concrète compositions stemming from the Lo-Fi och Hi-Fi processes through which we gained more knowledge and understanding of themethods and techniques involved.

No description available.

This study sought to determine students’ satisfaction with technology, particularly Wi-Fi, and how it may impact retention at one university in the southeast. Differences in satisfaction were analyzed for students who planned to stay versus those who planned to leave, transfer versus native students, and for students of various ages, genders, races, and classifications. Analyses were done to examine the data quantitatively. Significant differences were found between the perceptions of satisfaction with Wi-Fi internet services of native students and transfer student in several categories. Most of the students examined in this study (88.0%) planned to return to the same school with approximately 12.0% of students indicating that they did not plan to return to the same school. The students also provided the reasons for their unwillingness to return to this school. The reasons provided by the students were personal finances, location, family reasons, issues with faculty, staff, or student, tuition cost, graduated, feeling of loneliness, COVID-19, internship, personal problems, decided to transfer, needed a break, and the fact that they did not like the school. Technology is a major factor in the academic structure as faculty, staff, and students rely heavily on technology. Investing in stable Internet/Wi-Fi in the classroom and offices can support enrollment and retention. Retention of students is considered one of the greatest weaknesses in distance education. Retention is a function of collaboration of institutional, personal, and social factors. Retention is a major factor when measuring an institution’s accountability, effectiveness, and quality. Overall, students were very satisfied with the quality of Wi-Fi on campus, and no differences in satisfaction were found between students who planned to return and those who did not. Transfer students were more satisfied with W-Fi on campus than were native students. Satisfaction with Wi-Fi on campus was higher for older students, female students, and graduate students. There were no differences in satisfaction with Wi-Fi on campus for students based on race.