With the ubiquity of mobile devices, there has been increased interest in determining how they can be used with location-based services. These types of services work best when the device has the ability to sense its location frequently, while still maintaining enough battery life to carry out its normal daily functions. Since the life of the battery on a mobile device is already so limited, ways of preserving that energy has become an important issue. The goal of this thesis is to demonstrate that Bluetooth can assist in providing energy efficient mobile device localization. This goal is achieved through a proposed Bluetooth Location Service Discovery framework which provides an API that can be incorporated into third party applications. The API allows BlackBerry devices to use surrounding Bluetooth devices in order to make a prediction about its current location. Predictions are completed with the assistance of the K-Nearest Neighbour data mining algorithm, and can be used as an alternative to invoking the GPS. The results obtained through experiments demonstrate that the results are comparable to those obtained with GPS.

The handset product has been styled in successive years to reach more compact sizes and there has as a result been a reduction in volume available to house antennas; therefore size/performance trade-offs have had to become accommodated. Some of the issues antenna engineers are currently confronted with include; frequency shifting due to the antenna not being isolated from the handset, far field pattern deformation due to close proximity effects from the energy absorbing human tissues, distortion caused by noise from electronic components that share the handheld platform. What is required is antenna technology, which maintains a high enough performance despite the escalating restrictions imposed by the demands of the market. Research is performed on a twisted loop antenna topology that possesses an integral balun as part of its structure. Two rudimentary designs are utilised in the research, a simple bifilar structure that can be adapted for GSM, peN, Bluetooth and W-LAN applications, and a quadrifilar helix structure for use in GPS. Both structures are based on existing industrial dielectricloaded antenna structures but are modelled as novel air-loaded structures using a commercially available Method of Moments (MoM) electromagnetic simulator. In this fashion, the antennas could be generated quickly with low computational requirements. A parametric study is performed on the bifilar antenna structure to gain an enhanced understanding of the twisted loop topology. Once this understanding is achieved proposed modifications to the structure are implemented to improve the performance of the antenna. The main subject of improvement is the broadening of bandwidth as normally dielectric-loaded antennas have inherent narrow bandwidth. Any improvements made on the air-loaded structures could be tested on dielectric structures in future research. The most successful novel approach attempted to increase the bandwidth in the twisted loop structure was the insertion of parasitic helices to create a coupled multi-pole filter response. In conjunction with the work performed on the bifilar, an air-loaded GPS quadrifilar helix antenna was also modelled. A method for inducing circular polarisation is proposed and then by the insertion of parasitics into the quadrifilar helix design a novel dual-band dual-polarised antenna is presented. Finally measurements are made to demonstrate the advantageous properties the dielectric-loaded GPS antenna has over conventional GPS antennas.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xvii, 148 p.; also includes graphics (some col.). Includes bibliographical references (p. 143-148).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains xi, 94 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 87-89).

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references. Also available in electronic version. Access restricted to campus users.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 63-66). Also available in electronic version. Access restricted to campus users.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2005. / Includes bibliographical references. Also available in electronic version.

Developing apps for both Android and iOS has previously necessitated two different code bases in the platforms’ native languages. Creating an app would be a quicker and easier process if they could be written once and run on both platforms, and such solutions have been appearing over the last few years. One of them is React Native, which we will investigate in this paper. To investigate React Native’s capabilities, we are going to look into the feasibility of porting the Android and iOS versions of an already existing fitness app, developed by a software consulting company. The original app uses Bluetoothfunctionality to record users’ heart-rate during exercise. They want to know if they can switch to React Native and a single code-base for future installments, lessening the workload and making it more maintainable. In order to find out if it is advisable to recreate the app with React Native we attempt a port of the app, looking at performance, functionality, and the codebase. The code-base investigation focuses on what parts can become completely platform independent and where we need to fill in the gaps with code targeted to a certain platform, and how large our port is in relation to the equivalent code in the original app. We end up finding that performance is severely worse on iOS, with much higher CPU utilization when the Bluetooth functionality is in use. On Android the difference is noticeable but not quite as big. For functionality we could get everything working with a single code-base except for handling Bluetooth while the app is in the background on Android. The code-base is mostly platform independent, and where it is not this is due to differing Bluetooth implementations for the platforms. It is also larger than either of the original apps, but smaller than the two put together. Lastly, we conclude that React Native has a largely platform-independent codebase, and for simpler apps where less complex functionality is needed we suspect the code-base can be completely platform-independent. The cause and remedies to iOS performance ought to be further investigated, but React Native is capable for this particular use-case.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia Elétrica. / Made available in DSpace on 2012-10-23T02:40:50Z (GMT). No. of bitstreams: 1 241199.pdf: 2590430 bytes, checksum: 5aea6945f791b1635acd3d37b75972d2 (MD5) / O presente trabalho aborda o desenvolvimento de um protótipo para ensaio de desempenho de incubadoras neonatais de forma semi-automática, tendo como base as prescrições da Norma NBR IEC 601- 2- 19/1999, Seção 8. O sistema implementado realiza a aquisição dos dados através de um sistema microcontrolado e envia os dados amostrados ao PC via protocolo Bluetooth. Este sistema compreende cinco módulos: Sensores, aquisição, comunicação, software de controle e banco de dados. O primeiro módulo contém cinco sensores de temperatura, um de umidade e um de fluxo de ar. O software sendo executado no PC é responsável pelo gerenciamento da obtenção de dados, bem como, pela orientação do usuário sobre os procedimentos a serem adotados durante o ensaio. Esta orientação é realizada através de mensagens e alerta sonoros após o término de cada etapa do ensaio. Os dados adquiridos são armazenados no banco de dados que podem ser acessados localmente. Os resultados dos ensaios são apresentados na forma de relatório. Este contém gráfico sobre a evolução da temperatura, umidade e fluxo de ar durante todo o período de ensaio. Os sensores foram calibrados utilizando como padrão de referência padrões rastreados. Exemplo de ensaio realizado com o sistema desenvolvido é apresentado.