Orientador: Eduardo Alves do Valle Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T09:45:59Z (GMT). No. of bitstreams: 1 HidalgoFlores_PaulJoseph_M.pdf: 28047685 bytes, checksum: 055aafb9f31fc0ba5c1cfac1cc7a79b3 (MD5) Previous issue date: 2015 / Resumo: Aplicações de busca visual em aparelhos móveis (Mobile Visual Search ¿ MVS) tornaram-se possíveis devido ao alto poder computacional e a multiplicidade de sensores dos novos dispositivos móveis (smart-phones, tablets). Além disso, o estado da arte em recuperação de informação multimídia baseada no conteúdo (Content Based Image Retrieval - CBIR) alcançou uma maturidade que permite realizar estas tarefas de forma eficiente. Nesta dissertação, apresentamos um estudo das principais técnicas em CBIR visual das imagens. Uma vasta investigação da literatura foi realizada, que inclui desde os descritores baseados em gradiente mais comuns aos mais recentes descritores binários e compactos. Como resultado da análise comparativa entre as principais técnicas no contexto de MVS, apresentamos as alternativas mais apropriadas para serem utilizadas em tais aplicações / Abstract: Mobile Visual Search (MVS) applications became possible due to the computational power and multiple sensors on current mobile devices (smart-phones, tablets). In addition, the state-of-the-art in content based image retrieval (CBIR) has reached a maturity to perform these tasks efficiently. In this dissertation, we present a study of the major techniques in CBIR. An extensive study of literature, including the most common descriptors based on gradients and the recently proposed binary descriptors. As a result of comparative analysis between the main techniques in the context of MVS, we present the most appropriate alternatives to use in such applications / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

Research has been conducted on the effectiveness of mobile devices in education; however, few scholars have addressed how faculty members perceive the use of mobile devices in the classroom. Mobile devices in higher education have the potential to support innovative teaching modalities. The purpose of this qualitative case study was to explore faculty perceptions of using the mobile device as an instructional aid in a higher educational institution in the United Arab Emirates (UAE). The conceptual framework was Zhao and Frank's metaphorical use of ecology and the ecosystem. Three research questions focused on faculty members' perceptions of uses, challenges, and cultural effects of integrating mobile devices into teaching. A purposeful sampling method was used to find participants for the study. Criterion based logic, semistructured, face-to-face interviews were conducted to collect data from 8 full-time, expatriate faculty members (4 from the federal university and 4 from the private university of UAE) teaching in UAE for at least 2 years who were avid users of mobile technology for classroom instruction. Interviews were transcribed, and the data were coded to identify patterns and major themes. The results showed that faculty used mobile devices for instructional purposes, increasing engagement, improving collaboration and pedagogical practices, and promoting UAE culture. Faculty also reported challenges with mobile technology such as distraction and cheating. The results of the study can lead to a positive social change by guiding higher education faculty on how to improve the status quo and assist in planning pedagogy and facilitating mobile-enhanced learning environments.

La reconnaissance biométrique a été utilisée longtemps dans des espaces confinés, généralement à l'intérieur, où les opérations de sécurité exigeaient des systèmes de haute précision, par exemple dans les postes de police, les banques, les entreprises, les aéroports. Les activités de terrain, au contraire, exigent plus de flexibilité et portabilité conduisant au développement de dispositifs pour l'acquisition des traits biométriques et des algorithmes pour la reconnaissance biométrique dans des conditions moins contraintes. L'application de la reconnaissance biométrique "portable" est limitée dans des domaines spécifiques, par exemple pour le contrôle de l'immigration, et exige des dispositifs dédiés. Pour étendre l'utilisation de la biométrie sur les appareils personnels, des tentatives ont été faites par l’intégration des scanners d'empreintes digitales dans les ordinateurs portables ou les smartphones. Mais la reconnaissance biométrique sur les appareils personnels a été utilisée seulement pour un nombre limité de tâches, comme le déverrouillage d'écrans à l'aide des empreintes digitales au lieu de mots de passe. Les activités décrites dans cette thèse se sont portées sur le développement de solutions pour la reconnaissance de l'iris sur les appareils mobiles: - Acquisition: collection de la base de données MICHE, contenant des images d'iris capturée par des appareils mobiles; - Segmentation: développement d'un algorithme de segmentation innovante; - Extraction de caractéristiques: la reconnaissance de l'iris a été combinée avec le visage et la reconnaissance du smartphone.Enfin, la reconnaissance du regard a été étudiée afin de vérifier sa possible fusion avec l'iris / Biometric recognition for a long time has been used in confined spaces, usually indoor, where security-critical operations required high accuracy recognition systems, e.g. in police stations, banks, companies, airports. Field activities, on the contrary, required more portability and flexibility leading to the development of devices for less constrained biometric traits acquisition and consequently of robust algorithms for biometric recognition in less constrained conditions. However, the application of "portable" biometric recognition, was still limited in specific fields e.g. for immigration control, and still required dedicated devices. A further step would be to spread the use of biometric recognition on personal devices, as personal computers, tablets and smartphones. Some attempts in this direction were made embedding fingerprint scanners in laptops or smartphones. So far biometric recognition on personal devices has been employed just for a limited set of tasks, as to unlock the screen using fingerprints instead of passwords. The research activities described in this thesis were focused on studying and developing solutions for iris recognition on mobile devices. This topic has been analyzed in all its main phases: - Acquisition: collection of the MICHE database, containing pictures of irises acquired by mobile devices; - Segmentation: development of an innovative iris segmentation algorithm; - Feature extraction and matching: iris recognition has been combined with the face and with sensor (smartphone) recognition. Finally, the use of gaze analysis for human recognition has been investigated in order to verify its possible fusion with iris.

Mobile and other internet-connected devices infiltrate society, including K-12 classrooms. A large body of research indicated that these devices might distract students; however, other studies have revealed many benefits when the devices are used for educational purposes. This study aimed to examine the relationships between the use of mobile devices and student performance in mathematics (MA) and English Language Arts (ELA). The study compared two districts, one that had implemented a 1:1 technology infrastructure for learning and one that had not. Archival data on the Mississippi Academic Assessment Program (MAAP) standardized test were accessed from the two districts, containing fourth-grade students' MA and ELA scores from the assessment. Additional data included students' gender and i-Ready diagnostic test scores in the 1:1 technology district. One-way analysis of variance (ANOVA) tests revealed that MAAP MA scores were significantly higher for students in the 1:1 technology district than for students in the non-technology district. However, no difference was found in students' ELA scores. A Pearson's rho correlation analysis indicated a significant association between i-Ready and MAAP MA and ELA scores for students in the 1:1 technology district. Linear regression analysis revealed that gender explained a small but significant variance in MAAP ELA scores across the two districts. The study provided mixed results for using mobile devices for student learning. Students may benefit more from mobile technology in mathematics than in ELA, possibly because specific mathematics skills can be isolated, taught, and practiced using technology. Additionally, because this study took place during the COVID-19 pandemic, future research should attempt to focus on mobile technology and its presence post-COVID-19. Finally, more research should explore making the most effective use of technology solutions to support student learning.

No description available.

No description available.

<p>This work describes a design of a multimedia content delivery system based on context, to provide multimedia information and other services according to the user location and his preferences. It focuses on mobility and the problem of different coherent and cohesive presentations depending on the available resources of the presentation environment.</p>

This work describes a design of a multimedia content delivery system based on context, to provide multimedia information and other services according to the user location and his preferences. It focuses on mobility and the problem of different coherent and cohesive presentations depending on the available resources of the presentation environment.

In recent years there have been many breakthroughs in software and hardware, which has increased the demand for mobile application development. Technology and innovation today has a big impact on how we live our lives as cell phones and the internet have taken market share and has become a part of everything we do, which is forcing companies to become more digitalized. The goal of this thesis is to develop a mobile application that will be used as a communication tool to streamline the work/communication within service industries. The work begins with a quantitative study where two restaurants were interviewed, TGI Friday and Grand Hotel, with the goal to get an image of the problem that needs to be solved. During the development phase Scrum is used as a project method to plan the progress of the project. In the end of the development a usability test is performed and the system is evaluated using Semat Kernel. The project results in a mobile application written in Objective C and Swift programming languages using the integrated development environment Xcode with ability to create account login using Facebook, and a map that displays the users current location and the ability to call the waitress anywhere in the restaurant. / De senaste åren har det varit många genombrott inom mjukvara och hårdvara, vilket har ökat kraven på mobilapplikationsutveckling. Teknik och innovation har idag en stor inverkan på hur vi lever våra liv eftersom mobiltelefoner och internet har intagit marknadsandelar och blivit en del av allt vi gör. Något som tvingar företag att bli mer digitaliserade. Målet med detta kandidatexamensarbete var att utveckla en mobilapplikation som ska användas som ett kommunikationsverktyg för att effektivisera arbetet och kommunikationen inom restaurangbranschen. Arbetet inleds med en kvantitativ förstudie där intervjuer genomfördes på två restauranger, T.G.I Friday och Grand Hôtel, med mål att få en bild kring problemet som ska lösas. Under utvecklingsfasen används Scrum som arbetsmetod i projektet. I slutet av utvecklingsfasen genomfördes en testanalys för att utvärdera användargränssnittet. Sedan används Semat Kernels utvärderingskriterier för att utvärdera systemet. Projektet resulterar i en mobilapplikation skriven i Objektive C och Swift programmeringsspråk med utvecklingsmiljö Xcode. Systemet möjliggör skapandet av konto och inloggning med Facebook samt en karta som visar användarens nuvarande position samt att användaren kan exempelvis kalla på personalen med hjälp av en knapp.

With the wide spread of mobile phones, PDAs, and Smartphones, M-Commerce has become a major application domain for mobile devices, unlike conventional wired networks, mobile devices allow the user to conduct online transactions regardless of the time and the place as long as there is mobile network coverage. However, online transactions require adequate level of security to insure the confidentiality, the integrity, and the availability of the user’s information. Security measures consume a considerable amount of energy and require more time in processing. The aim of this thesis is to optimise the energy and the resources consumption of mobile phones when applying variant symmetric and asymmetric schemes. This aim can be achieved through developing A System State Security Management Framework, SSSM, which will implement encryption schemes, symmetric and asymmetric, and will provide different options to enable the user to choose the type of encryption, the key size, and number of rounds of computation to optimise the energy consumption level of the mobile phone. This thesis compares the power and the resources consumed by the most commonly used encryption algorithms such as CAST, IDEA, Triple-DES, RSA, and AlGamal. This comparison helps to draw the advantages and disadvantages of each algorithm scheme used in reference to the security level it provides and the power it consumes. Implementing this mechanism will enhance the performance of mobile phones by increasing the security levelsprovided by the encryption schemes and utilising the limited power and resources efficiency. Therefore, confidentiality will be presented in mobile phones and variant encryption schemes, symmetric and asymmetric, and changeable key sizes and rounds, will ensure the authenticity of both senders and recipients depending on their needs as well as resources available. This research makes contributions in two major areas; the first area consists of the novel Energy Aware Encryption polices generated by this work, the second area of contribution is the energy measurements and experimental results which validate the approach presented in the research.