Localizar objetos ou pessoas no interior de um edifício é de grande interesse. Contudo, diferentemente do que ocorre no exterior de edificações, não há metodologia consagrada para a determinação da posição desses entes nos edifícios. Para o posicionamento em locais abertos existem tecnologias consolidadas, como GNSS (Global Navigation Satellite System), a dificuldade em fazê-lo em interiores é maior. Nesses casos, o GNSS não pode ser utilizado, pois os sinais de rádio dos satélites não conseguem penetrar através das estruturas, enquanto que outras tecnologias são apenas incipientes nesse quesito. Abordagens habituais para a resolução dessa demanda têm se baseado na utilização de propagadores das ondas de rádio do GNSS, no uso da potência de sinais de redes sem fio ou, ainda, no emprego de transmissores infravermelhos. No entanto, uma técnica diferente pode ser empreendida para essa finalidade. Usando-se a assinatura das potências de rádio das redes sem fio nas imediações e no interior da edificação, é possível criar um mapa com base nesses sinais, permitindo a determinação da posição de um objeto. No presente trabalho foram desenvolvidos um sistema para geração do mapa de sinais, com critério de parada e um método de cálculo de posicionamento. Procedeu-se, também, à análise de quatro critérios para o cálculo final da posição do objeto, baseados no uso da distância euclidiana com os conjuntos de roteadores disponíveis. Concluiu-se que, quando o mapa de sinais é pequeno, o posicionamento fracassou. Entretanto, quando a quantidade de sinais geradores do mapa aumenta, os resultados apresentaram melhora significativa, com resultados próximos a 100% de assertividade. Desse modo foi possível determinar uma estimativa boa para o número mínimo de roteadores presentes na base e estabelecer um critério de parada para a fase de criação do mapa de sinais. / Locate objects or person inside a building is a subject that matters. Although what occurs outdoor of a building, there is no consolidate methodology to define a position in an indoor environment. For outdoor positioning there is the GNSS (Global Navigation Satellite System) a consolidate technology for outdoor usage with a lot of challenges to make this work in an indoor environment. In such cases, the GNSS cannot be used due to the lack of the sattelite radio signal, which cannot penetrate the walls and buildings structures, meanwhile other technologies are just incipient. Usual approaches using this approach are based in propagation of the GNSS radio signal, wi-fi based location or infrared transmitter. A different technique can be applied for indoor positioning. Using the wireless fingerprint in an indoor environment we created a radio map based on those signals, allowing the location of a mobile station. In the present research, we developed a system that generates a radio map (with a stop criteria) and a positioning calculation method. We concluded that when the radio map is small (with only a few measurements) the method cannot calculate accurately. However, with more measurements, the method succeeded and have a performance near a 100% of precision. In this way it was posible to estimate a number of access points needed for a building\'s range and define the stop criteria used in the radio map phase.

Localizar objetos ou pessoas no interior de um edifício é de grande interesse. Contudo, diferentemente do que ocorre no exterior de edificações, não há metodologia consagrada para a determinação da posição desses entes nos edifícios. Para o posicionamento em locais abertos existem tecnologias consolidadas, como GNSS (Global Navigation Satellite System), a dificuldade em fazê-lo em interiores é maior. Nesses casos, o GNSS não pode ser utilizado, pois os sinais de rádio dos satélites não conseguem penetrar através das estruturas, enquanto que outras tecnologias são apenas incipientes nesse quesito. Abordagens habituais para a resolução dessa demanda têm se baseado na utilização de propagadores das ondas de rádio do GNSS, no uso da potência de sinais de redes sem fio ou, ainda, no emprego de transmissores infravermelhos. No entanto, uma técnica diferente pode ser empreendida para essa finalidade. Usando-se a assinatura das potências de rádio das redes sem fio nas imediações e no interior da edificação, é possível criar um mapa com base nesses sinais, permitindo a determinação da posição de um objeto. No presente trabalho foram desenvolvidos um sistema para geração do mapa de sinais, com critério de parada e um método de cálculo de posicionamento. Procedeu-se, também, à análise de quatro critérios para o cálculo final da posição do objeto, baseados no uso da distância euclidiana com os conjuntos de roteadores disponíveis. Concluiu-se que, quando o mapa de sinais é pequeno, o posicionamento fracassou. Entretanto, quando a quantidade de sinais geradores do mapa aumenta, os resultados apresentaram melhora significativa, com resultados próximos a 100% de assertividade. Desse modo foi possível determinar uma estimativa boa para o número mínimo de roteadores presentes na base e estabelecer um critério de parada para a fase de criação do mapa de sinais. / Locate objects or person inside a building is a subject that matters. Although what occurs outdoor of a building, there is no consolidate methodology to define a position in an indoor environment. For outdoor positioning there is the GNSS (Global Navigation Satellite System) a consolidate technology for outdoor usage with a lot of challenges to make this work in an indoor environment. In such cases, the GNSS cannot be used due to the lack of the sattelite radio signal, which cannot penetrate the walls and buildings structures, meanwhile other technologies are just incipient. Usual approaches using this approach are based in propagation of the GNSS radio signal, wi-fi based location or infrared transmitter. A different technique can be applied for indoor positioning. Using the wireless fingerprint in an indoor environment we created a radio map based on those signals, allowing the location of a mobile station. In the present research, we developed a system that generates a radio map (with a stop criteria) and a positioning calculation method. We concluded that when the radio map is small (with only a few measurements) the method cannot calculate accurately. However, with more measurements, the method succeeded and have a performance near a 100% of precision. In this way it was posible to estimate a number of access points needed for a building\'s range and define the stop criteria used in the radio map phase.

Chim, Ho Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 58-62). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Objectives --- p.1 / Chapter 1.2 --- Motivations --- p.1 / Chapter 1.3 --- Problem Statement --- p.2 / Chapter 1.4 --- Camera Self-Localization Approaches --- p.3 / Chapter 1.4.1 --- Based on Calibration Patterns --- p.3 / Chapter 1.4.2 --- Based on Self-calibration --- p.3 / Chapter 1.4.3 --- Based on Shape and Motion --- p.4 / Chapter 1.4.4 --- The Proposed Approach - Based on Junctions --- p.5 / Chapter 1.5 --- Thesis Organization --- p.6 / Chapter 2 --- Previous Work --- p.7 / Chapter 2.1 --- Camera Self-Localization --- p.7 / Chapter 2.1.1 --- Parallel Plane Features --- p.7 / Chapter 2.1.2 --- Parallelepiped Features --- p.8 / Chapter 2.1.3 --- Single View Geometric Features --- p.8 / Chapter 2.1.4 --- Shape and Motion --- p.8 / Chapter 2.1.5 --- Other Estimation Methods --- p.9 / Chapter 2.2 --- Feature Correspondences Establishment --- p.9 / Chapter 2.2.1 --- Feature-based Object Recognition --- p.9 / Chapter 2.2.2 --- Model-based Object Recognition --- p.10 / Chapter 3 --- Preliminaries --- p.11 / Chapter 3.1 --- Perspective Camera Model --- p.11 / Chapter 3.2 --- Camera Pose from Point Correspondences --- p.15 / Chapter 3.3 --- Camera Pose from Direction Correspondences --- p.16 / Chapter 4 --- A Junction-based Approach --- p.18 / Chapter 4.1 --- Use of Junction Correspondences for Determining Camera Pose --- p.18 / Chapter 4.1.1 --- Constraints from Point Information --- p.19 / Chapter 4.1.2 --- Constraint from Direction Information --- p.21 / Chapter 4.1.3 --- Junction Triplet Correspondences --- p.22 / Chapter 4.2 --- Extraction of Junctions and Junction Triplets from Image --- p.24 / Chapter 4.2.1 --- Handling Image Data --- p.24 / Chapter 4.2.2 --- Bridging Lines --- p.25 / Chapter 4.2.3 --- """L""-junctions" --- p.26 / Chapter 4.2.4 --- """Y"" and ""Adjunctions" --- p.27 / Chapter 4.2.5 --- Junction Triplets --- p.28 / Chapter 4.3 --- Establishment of the First Junction Triplet Correspondence --- p.30 / Chapter 4.3.1 --- Ordered Junction Triplets from Model --- p.30 / Chapter 4.3.2 --- A Junction Hashing Scheme --- p.31 / Chapter 4.4 --- Establishment of Points Correspondence --- p.33 / Chapter 4.4.1 --- Viewing Sphere Tessellation --- p.33 / Chapter 4.4.2 --- Model Views Synthesizing --- p.35 / Chapter 4.4.3 --- Affine Coordinates Computation --- p.35 / Chapter 4.4.4 --- Hash Table Filling --- p.38 / Chapter 4.4.5 --- Hash Table Voting --- p.38 / Chapter 4.4.6 --- Hypothesis and Confirmation --- p.39 / Chapter 4.4.7 --- An Example of Geometric Hashing --- p.40 / Chapter 5 --- Experimental Results --- p.43 / Chapter 5.1 --- Results from Synthetic Image Data --- p.43 / Chapter 5.2 --- Results from Real Image Data --- p.45 / Chapter 5.2.1 --- Results on Laboratory Scenes --- p.46 / Chapter 5.2.2 --- Results on Outdoor Scenes --- p.48 / Chapter 6 --- Conclusion --- p.51 / Chapter 6.1 --- Contributions --- p.51 / Chapter 6.2 --- Advantages --- p.52 / Chapter 6.3 --- Summary and Future Work --- p.52 / Chapter A --- Least-Squares Method --- p.54 / Chapter B --- RQ Decomposition --- p.56 / Bibliography --- p.58

Largely driven by advances in communication and information technology, such as the increasing availability and accuracy of GPS technology and the miniaturization of wireless communication devices, Location–Based Services (LBS) are continuously gaining popularity. Innovative LBSes integrate knowledge about the users into the service. Such knowledge can be derived by analyzing the location data of users. Such data contain two unique dimensions, space and time, which need to be analyzed. The objectives of this thesis are three–fold. First, to extend popular data mining methods to the spatio–temporal domain. Second, to demonstrate the usefulness of the extended methods and the derived knowledge in two promising LBS examples. Finally, to eliminate privacy concerns in connection with spatio–temporal data mining by devising systems for privacy–preserving location data collection and mining.   To this extent, Chapter 2 presents a general methodology, pivoting, to extend a popular data mining method, namely rule mining, to the spatio–temporal domain. By considering the characteristics of a number of real–world data sources, Chapter 2 also derives a taxonomy of spatio–temporal data, and demonstrates the usefulness of the rules that the extended spatio–temporal rule mining method can discover. In Chapter 4 the proposed spatio–temporal extension is applied to find long, sharable patterns in trajectories of moving objects. Empirical evaluations show that the extended method and its variants, using high–level SQL implementations, are effective tools for analyzing trajectories of moving objects. Real–world trajectory data about a large population of objects moving over extended periods within a limited geographical space is difficult to obtain. To aid the development in spatio–temporal data management and data mining, Chapter 3 develops a Spatio–Temporal ACTivity Simulator (ST–ACTS). ST–ACTS uses a number of real–world geo–statistical data sources and intuitive principles to effectively generate realistic spatio–temporal activities of mobile users.   Chapter 5 proposes an LBS in the transportation domain, namely cab–sharing. To deliver an effective service, a unique spatio–temporal grouping algorithm is presented and implemented as a sequence of SQL statements. Chapter 6 identifies ascalability bottleneck in the grouping algorithm. To eliminate the bottleneck, the chapter expresses the grouping algorithm as a continuous stream query in a data stream management system, and then devises simple but effective spatio–temporal partitioning methods for streams to parallelize the computation. Experimental results show that parallelization through adaptive partitioning methods leads to speed–ups of orders of magnitude without significantly effecting the quality of the grouping. Spatio–temporal stream partitioning is expected to be an effective method to scale computation–intensive spatial queries and spatial analysis methods for streams.   Location–Based Advertising (LBA), the delivery of relevant commercial information to mobile consumers, is considered to be one of the most promising business opportunities amongst LBSes. To this extent, Chapter 7 describes an LBA framework and an LBA database that can be used for the management of mobile ads. Using a simulated but realistic mobile consumer population and a set of mobile ads, the LBA database is used to estimate the capacity of the mobile advertising channel. The estimates show that the channel capacity is extremely large, which is evidence for a strong business case, but it also necessitates adequate user controls.   When data about users is collected and analyzed, privacy naturally becomes a concern. To eliminate the concerns, Chapter 8 first presents a grid–based framework in which location data is anonymized through spatio–temporal generalization, and then proposes a system for collecting and mining anonymous location data. Experimental results show that the privacy–preserving data mining component discovers patterns that, while probabilistic, are accurate enough to be useful for many LBSes.   To eliminate any uncertainty in the mining results, Chapter 9 proposes a system for collecting exact trajectories of moving objects in a privacy–preserving manner. In the proposed system there are no trusted components and anonymization is performed by the clients in a P2P network via data cloaking and data swapping. Realistic simulations show that under reasonable conditions and privacy/anonymity settings the proposed system is effective. / QC 20120215

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.

In response to a growing recognition of the importance of spatial information, the concept of Spatial Data Infrastructure (SDI) has evolved. Designed to facilitate an environment that promotes access and sharing of spatial information, SDI development has benefited from, and in due course adopted, advances in information technology (particularly improvements in desktop computing capabilities and communication networks such as the Internet). / The never ceasing progression of technology now enables communication and data access via mobile phones and a myriad of portable, networked computing devices. Indeed over the last few years, the proliferation of mobile phones has exceeded many expectations and is enabling nomadic users to communicate and access data services with ease. Location is one of the unique characteristics of mobility that is encompassed by this form of wireless communication and has been capitalised on in the form of enhanced safety initiatives. In turn, the infrastructure required for these safety services has encouraged additional Location Based Services (LBS) to flourish / LBS act as spatial decision making tools, providing information to end users based on their location, or on the location of some target. LBS are not restricted to the wireless environment however this is their current area of promotion. The principles of accessing spatial information that are encompassed by LBS mirror those of SDIs, and as a result SDI models need to accommodate for this new medium of information access and delivery. This research aimed to expand the SDI model to support applications that assist with spatial decision making, such as LBS. Focused specifically on LBS that are accessible for wirelessly networked, portable devices, this research implemented a theoretical and practical approach to identify the additional requirements for SDIs in this domain. A prototype LBS application for public transport information and navigation was developed and evaluated as part of this process. It is proposed that the resulting model (which details the additional requirements as well as their relative importance) act as an example framework for future LBS implementations so that they may gain the benefits from a standard, integrated infrastructure as offered by SDIs.

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 58-60).

With the rapid growth of mobile, ubiquitous and wearable computing, location-based services become an indispensable part of mobile internet. These services rely on the geographical position of the mobile devices and provide location-dependent contents or services to users, such as location-based in- stant messaging, POI browsing, map navigation, and location-based virtual reality games. Most existing systems implement these location-based services by always storing and transmitting raw, plaintext GPS coordinates. However, location information is arguably a private asset of individual user, and the disclosure of such information could lead to severe privacy disclosure of other even more sensitive information, such as religion, sexuality, medical condition, or political affiliation. To address this issue, researchers have proposed a series of techniques to protect user location privacy against location-based service providers. How- ever, it is challenging to apply these theoretical and sophisticated techniques ii to practical location systems because of the computational or network over- head imposed on the mobile devices as well as the complexity of the secure protocols and algorithms for application developers. In this thesis, I will study two real-life privacy-preserving location systems and show how they can be adopted by developers with little security background. The rst is outdoor proximity detection that determines whether two users (or a user and an ob- ject) are within a given distance threshold. This is a fundamental service in many geo-social or map services. For example, \People nearby" in Wechat and QQ interconnect users because of their locality and/or mutual interests in some topics, such as food and movies. The second is indoor location mon- itoring and tracking. Wearable devices such as smart watch and bracelets continually broadcast Bluetooth Low Energy signals, which can be easily cap- tured by monitoring devices such as WiFi routers and Bluetooth scanners. As more and more wearable devices emerge, unauthorized monitoring and track- ing by adversary becomes great privacy threats not only in the cyberworld, but also in the physical world. To protect location privacy, I develop a real- life location monitoring system that is based on Bluetooth Low Energy (BLE) privacy feature that changes the device physical address periodically. To en- able users to better control their privacy level while still providing monitoring and tracking service to authorized parties (e.g., for child and elderly care), I extend BLE privacy by enriching its privacy semantics with a comprehensive set of metrics, such as simple opt-in/out, k-anonymity, and granularity-based anonymity. Both systems have been posted online and evaluated in terms of accuracy and user study.

Mobile commerce (m-commerce) has created the opportunity to transact anywhere, anytime, transcending barriers of space and time. However, this freedom has been found to be intrusive in the lives of mobile users, acting counterproductively to trust building and exacerbating the reluctance to adopt m-commerce. The research design was a quantitative study that pivoted around the concept of location-based services (LBS) for mobile users and was focused on understanding specific behaviours around usage and trust under pre-determined conditions of connecting (particular place, particular time), push and pull mechanisms, brand loyalty and social network recommendations. The study was conducted through an online questionnaire with a non-probability sample of 189 individuals. Factors including push and pull LBS mechanisms, brand loyalty and social network recommendations were found to exhibit significant influence on mobile users trust and propensity to transact in m-commerce. No empirical support was found between the connecting conditions with mobile users and adoption of m-commerce, eliciting future research in this area. These results contribute to the body of research regarding mobile commerce by extending the existing understanding of its use through application with push and pull location-based services. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted

Privacy has been discussed throughout the ages as the world has developed and changed however privacy concerns have been reignited by the development of technology. One of these technologies, Location Based Services (LBS), together with how organisations are using these technologies is pushing the consumers’ privacy boundaries. In order for this technology to become widely adopted these privacy concerns need to be understood and addressed. It is therefore the purpose of this research to examine whether consumers’ privacy concern can be negated through consumers receiving a benefit which caused them to forego this concern.The research used scenarios to evaluate consumers’ comfort levels for four different intrusion levels and five different discounts offered. Due to the nature of the scenarios a repeated measures ANOVA design was used in order to allow for the analysis of each of the scenarios, intrusion levels and discount offered for each respondent.It was found that although privacy concerns can and were influenced by the offers made to the respondents, consumers have not yet gained a complete sense of comfort with the privacy boundaries that are being challenged. / Dissertation (MBA)--University of Pretoria, 2013. / Gordon Institute of Business Science (GIBS) / unrestricted