Reconfigurable antenna for mobile devices

O trabalho descrito nesta dissertação de mestrado foca-se em geral na investigação de antenas impressas. São apresentados conceitos básicos, em conjunto com alguns exemplos desenvolvidos. No entanto, o principal foco prende-se com técnicas de miniaturização e reconfigurabilidade de antenas. A miniaturização de antenas é um tema de investigação de longa data, no entanto, novas técnicas e soluções são apresentadas regularmente. Nesta tese, é aplicada uma técnica recente, baseada na introdução de indutores encapsulados no elemento ressonante de uma antena, que permite miniaturizar um monopólio impresso com uma frequência de ressonância de 2.5 GHz. Outro assunto abordado neste trabalho é a reconfigurabilidade de antenas. Algumas das técnicas mais comuns na investigação actual são apresentadas e debatidas. Uma solução com recurso a díodos PIN é usada para estudar esta capacidade. Os conceitos e características deste tipo de componentes são apresentadas sendo feito o desenho e fabrico de um possível monopólio impresso reconfigurável para operação em dupla banda. Por fim, são combinadas as técnicas de miniaturização com inductor encapsulado e reconfigurabilidade através de díodos PIN, por forma a projectar uma antena reconfigurável muito pequena, para operação em duas bandas distintas. Os resultados são discutidos e com base nestes, algumas possíveis otimizações são propostas. The work reported in this dissertation is focused in the printed antenna research. Basic concepts of printed antennas are presented, along with a few examples that were developed. The main focus however, is around miniaturization and reconfigurability of antennas. Antenna miniaturization is a long time research subject, however, new techniques and solutions are presented everyday. In this thesis, a recent technique based on the introduction of chip inductors in the resonating element of a printed antenna is used in order to miniaturize a monopole with a resonating frequency at 2.5 GHz. Another issue approached in this work is antenna reconfigurability. Some common techniques used in antenna reconfiguration are presented and debated. A solution with PIN diodes is used to study this capability. The concepts and characteristics of this type of components are presented and an example of a reconfigurable printed monopole for dual-band operation is designed and fabricated. At last, miniaturization with chip inductor and reconfigurability through PIN diodes are used together to create a very small antenna for dual-band operation. The simulated and measured results are discussed and upon these, some possible optimizations are proposed.

Personalized sightseeing tours support using mobile devices

In this paper, we present PSiS (Personalized Sightseeing Tours Recommendation System) Mobile. PSiS Mobile is our proposal to a mobile recommendation and planning support system, which is designed to provide effective support during the tourist visit with context-aware information and recommendations about places of interest (POI), exploiting tourist preferences and context.

Recommendation and planning through mobile devices in tourism context

In this paper we present a mobile recommendation and planning system, named PSiS Mobile. It is designed to provide effective support during a tourist visit through context-aware information and recommendations about points of interest, exploiting tourist preferences and context. Designing a tool like this brings several challenges that must be addressed. We discuss how these challenges have been overcame, present the overall system architecture, since this mobile application extends the PSiS project website, and the mobile application architecture.

Utilization of remote experimentation in mobile devices for education

In this paper the authors intend to demonstrate the utilization of remote experimentation (RE) using mobile computational devices in the Science areas of the elementary school, with the purpose to develop practices that will help in the assimilation process of the subjects taught in classroom seeking to interlink them with the daily students? activities. Allying mobility with RE we intend to minimize the space-temporal barrier giving more availability and speed in the information access. The implemented architecture utilizes technologies and freely distributed softwares with open code resources besides remote experiments developed in the Laboratory of Remote Experimentation (RExLab) of Federal University of Santa Catarina (UFSC), in Brazil, through the physical computation platform of the ?open hardware of construction of our own. The utilization of open code computational tools and the integration of hardware to the 3D virtual worlds, accessible through mobile devices, give to the project an innovative face with a high potential for reproducibility and reusability.

Extending access to remote labs from mobile devices in educational contexts

This paper describes how to extend the access to remote experiments from mobile devices, aiming to better engage digital native students who expect a more interactive and ubiquitous access mode. The extension is based on features of HTML5 and the jQuery Mobile framework, which allow accessing the experiments from different operating systems via the browser or native applications. As a result, users have a richer interaction mode with the experiments, which includes access from simple hand-held devices such as smartphones and PDAs. Extending the access to remote experiments, from simple devices, enables its use in other educational stages, such as high schools, where teachers struggle to engage students in STEM learning. By enabling students to use their everyday "technological companions", e.g. cellular phones, to access remote experiments, we seek to increase the educational value of this technology-enhanced learning resource.

Educational application of remote experimentation for mobile devices

In this article the authors describe the application development RExMobile and the importance of remote experimentation via mobile devices, especially smartphones simple, beyond the space provided for this application in education. The article deals the creation, software and hardware that provide an interactive and dynamic way to attract more students to use these experiments remote, serving as support to teachers to science teaching from its initial series. The ease and availability of smartphones, even these students of basic education, permits the reach of new users and in different places. Thus, the practice of remote experimentation in mobile devices enables new spaces for access and interaction. Are used for developing software free or low cost, HTML5 and jQuery Mobile framework, that enable the creation of pages compatible with different mobile operating systems such as iOS, Android, Windows Phone, some Symbian, among others. Also are demonstrated patterns layouts that allow greater accessibility.

Sensors on mobile devices for AAL

Com o envelhecimento da população, as preocupações com a garantia do seu bem-estar aumentam criando a necessidade de desenvolver ferramentas que permitam monitorizar em permanência este sector da população. A utilização de smartphones pelos mais velhos pode ser crucial no seu bem-estar e na sua autonomia contribuindo para a recolha de informação importante já que estes estão muitas vezes equipados com sensores que podem dar indicações preciosas ao cuidador sobre o estado atual do paciente. Os sensores podem fornecer dados sobre a atividade física do paciente, bem como detetar quedas ou calcular a sua posição, com a ajuda do acelerómetro, do giroscópio e do sensor de campo magnético. No entanto, funcionalidades como essas requerem, obrigatoriamente, uma frequência de amostragem mínima por parte dos sensores que permita a implementação de algoritmos, que determinarão esses parâmetros da forma mais exata possível. Dado que nem sempre os pacientes se fazem acompanhar do seu smartphone quando estão na sua residência, a criação de ambientes de AAL (Ambient Assisted Living) com recurso a dispositivos externos que podem ser “vestidos” pelos pacientes pode também ser uma solução adequada. Estes contêm normalmente os mesmos sensores que os smartphones e comunicam com estes através de tecnologias sem fios, como é o caso do Bluetooth Low Energy. Neste trabalho, avaliou-se a possibilidade de alteração da frequência dos sensores em diferentes sistemas operativos, tendo sido efectuadas modificações nas instalações por defeito de alguns sistemas operativos abertos. Com o objectivo de permitir a criação de uma solução de AAL com recurso a um dispositivo externo implementaram-se serviços e perfis num dispositivo externo, o SensorTag.

Mining social individuals movements and friends based on mobile devices

Trabalho de Projeto realizado para obtenção do grau de Mestre em Engenharia Informática e de Computadores

Creating and optimizing client-server applications on mobile devices

Mobile devices are embedded systems with very limited capacities that need to be considered when developing a client-server application, mainly due to technical, ergonomic and economic implications to the mobile user. With the increasing popularity of mobile computing, many developers have faced problems due to low performance of devices. In this paper, we discuss how to optimize and create client-server applications for in wireless/mobile environments, presenting techniques to improve overall performance.

Accommodation management system using mobile devices

Os dispositivos móveis são pessoais, intransmissíveis e cada vez mais utilizados, tornando-se assim numa boa ferramenta para a realização de um conjunto de serviços na indústria hoteleira. Entre esses serviços que necessitam da identificação pessoal, encontram-se a possibilidade do cliente reservar um quarto ou utilizar o serviço de quartos. Atualmente é muito utilizado, nos locais de alojamento, um smart card que possibilite ao cliente ter acesso a alguns dos serviços disponíveis. O objetivo deste documento é apresentar uma alternativa ao sistema de cartões, utilizando para o efeito, dispositivos móveis. De modo a garantir a segurança e uma utilização semelhante ao sistema de cartões existentes foi utilizada a tecnologia NFC (Near Field Communication) que, ao permitir o modo de emulação de cartão, facilita a transação do sistema de smart card existente, para o da utilização de dispositivos móveis na realização das mesmas funções. Mais concretamente, será abordada a utilização de smartphones para o processo de abertura de portas. Para que exista uma melhor compreensão e para que haja um conhecimento das suas capacidades e limites foram estudados casos de uso da tecnologia NFC. Este documento apresenta ainda os processos de desenvolvimento de uma aplicação nativa para o sistema operativo Android, cujo objetivo é proporcionar ao cliente de um local de alojamento um novo modo de acesso ao quarto, utilizando a tecnologia NFC. Para além desta funcionalidade a aplicação permite ainda ao utilizador fazer reservas, fazer o check-in, fazer o check-out entre outras. Posteriormente serão apresentadas as conclusões e possíveis trabalhos futuros.

WIFI indoor positioning for mobile devices, an application for the UJI Smart Campus

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Combining WLAN fingerprint-based localization with sensor data for indoor navigation using mobile devices

This project proposes an approach for supporting Indoor Navigation Systems using Pedestrian Dead Reckoning-based methods and by analyzing motion sensor data available in most modern smartphones. Processes suggested in this investigation are able to calculate the distance traveled by a user while he or she is walking. WLAN fingerprint- based navigation systems benefit from the processes followed in this research and results achieved to reduce its workload and improve its positioning estimations.

The consumption of media contents through mobile devices in Finland

O campo dos media na Finlândia encontra-se num processo de mudanças aparentemente imparáveis, com os dispositivos móveis, tal como os smartphones e tablets, a influenciarem cada vez mais os padrões de produção e consumo de media. Nesta dissertação é defendido que esta situação é influenciada por factores históricos, sociais e culturais: desde os livros e jornais como meio de manter a língua finlandesa até aos benefícios da Segurança Social que permitiram que até as pessoas com menos rendimentos comprassem o jornal para se manterem a par dos desenvolvimentos do país, bem como a grande tradição de leitura que é associada aos finlandeses, assim como as condições que ao longo da história fazem fizeram com que os finlandeses sejam fascinados pelas novas tecnologias. Adicionalmente, presto especial atenção às estratégias que são adoptadas pelas cada vez mais convergentes companhias de media para enfrentarem a competição de elementos como os social media.

Identifying finger postures when interacting with the touch screen of mobile devices

This study presents the results of preliminary test on the interaction between fingertip and touch screen. The objective of this study is to identify the fingertip posture when interacting with touch screen devices. Ten participants, 7 males and 3 females, participated in this study. The participants were asked to touch targets on the mobile devices screen by tapping them sequentially and connecting them. The participants performed the tasks in a sitting posture. A tablet with 10 inches screen and a mobile phone with 4 inches screen were used in the study. The results showed that all participants dominantly used their thumb to interact with the mobile phone in single and two hands postures. The common thumb posture adopted by the participants is the combination of the 60° pitch and 0° roll angles. While for interaction with tablet in various postures observed in the study, the participants commonly used their index fingers in the combination of 60° pitch and 0° roll angles. This study also observed the participant with long finger nails touched targets on the mobile devices screen by using her index or middle fingers very low pitch.

Adaptive Privacy Management System Design For Context-Aware Mobile Devices

While mobile technologies can provide great personalized services for mobile users, they also threaten their privacy. Such personalization-privacy paradox are particularly salient for context aware technology based mobile applications where user's behaviors, movement and habits can be associated with a consumer's personal identity. In this thesis, I studied the privacy issues in the mobile context, particularly focus on an adaptive privacy management system design for context-aware mobile devices, and explore the role of personalization and control over user's personal data. This allowed me to make multiple contributions, both theoretical and practical. In the theoretical world, I propose and prototype an adaptive Single-Sign On solution that use user's context information to protect user's private information for smartphone. To validate this solution, I first proved that user's context is a unique user identifier and context awareness technology can increase user's perceived ease of use of the system and service provider's authentication security. I then followed a design science research paradigm and implemented this solution into a mobile application called "Privacy Manager". I evaluated the utility by several focus group interviews, and overall the proposed solution fulfilled the expected function and users expressed their intentions to use this application. To better understand the personalization-privacy paradox, I built on the theoretical foundations of privacy calculus and technology acceptance model to conceptualize the theory of users' mobile privacy management. I also examined the role of personalization and control ability on my model and how these two elements interact with privacy calculus and mobile technology model. In the practical realm, this thesis contributes to the understanding of the tradeoff between the benefit of personalized services and user's privacy concerns it may cause. By pointing out new opportunities to rethink how user's context information can protect private data, it also suggests new elements for privacy related business models.