Spatial subscriptions have been used to specify locations of interest in Distributed Event-based Systems (DEBSs). However, current DEBSs representations to support spatial subscriptions are not expressive enough to describe some forms of subscriptions in mobile settings. For instance, users are not allowed to specify a spatial subscription that refers to other more well-known locations, in case they are not familiar with the names of their current locations. In addition, the middleware in existing DEBSs does not support changes at runtime, and modification to these middleware systems to support spatial subscriptions are highly coupled with specific DEBS infrastructures. In this thesis, I argue that by enhancing the expressiveness of spatial subscriptions, a new model of mobile spatial subscriptions for location-aware services can be defined and a reusable plug-in implementation approach that supports existing DEBSs can be developed. This thesis first summarizes the essential abstractions to specify mobile spatial subscriptions, and analyze the expressiveness of existing DEBSs to support these abstractions. Second, it proposes a three-level mobile spatial subscription model, which supports the essential abstractions used to specify spatial subscriptions. The first level of the model handles subscriptions consisting of geometric coordinates; the second level supports subscriptions with location labels; the third level interprets subscriptions which specify locations by stating their dynamic properties. Next, a plug-in implementation approach is introduced, and hence, the three-level model can be integrated with different DEBSs with minimal modification to the middleware. The subscription model is implemented as a subscriber/publisher component, instead of directly modifying the existing DEBS. Finally, I develop a prototype system, Dynamic Mobile Subscription System (DMSS), and illustrate the usefulness and applicability of the three-level model and the plug-in implementation approach.

With the increasing demand on multimedia applications over the Internet, and the growing number of mobile smart devices people are using, it is helpful to develop a mobile network architecture that can support multimedia transmission without using infrastructures. We propose that service overlay networks over MANETs can serve as a supplement to the existing 3G/4G networks and Wi-Fi access point networks. In this thesis we present experiment results that show the feasibility of mobile service overlay networks to meet the requirements of multimedia streaming. And also, we improved one of the existing overlay protocols. The improved protocol takes physical location into consideration when establishing connections in the overlay network. It also limits the number of neighbors each node can have, which prevents a particular node from becoming the bottleneck of the network, when connected to too many neighbors. Evaluation results show the new protocol reduces network packet loss rate.

With the increasing demand on multimedia applications over the Internet, and the growing number of mobile smart devices people are using, it is helpful to develop a mobile network architecture that can support multimedia transmission without using infrastructures. We propose that service overlay networks over MANETs can serve as a supplement to the existing 3G/4G networks and Wi-Fi access point networks. In this thesis we present experiment results that show the feasibility of mobile service overlay networks to meet the requirements of multimedia streaming. And also, we improved one of the existing overlay protocols. The improved protocol takes physical location into consideration when establishing connections in the overlay network. It also limits the number of neighbors each node can have, which prevents a particular node from becoming the bottleneck of the network, when connected to too many neighbors. Evaluation results show the new protocol reduces network packet loss rate.

国立情報学研究所で電子化したコンテンツを使用している。

Conventional Wi-Fi location estimation techniques using radio fingerprinting typically require a lengthy initial site survey. It is suggested that the lengthy site survey is a barrier to adoption of the radio fingerprinting technique. This research investigated two methods for reducing or eliminating the site survey and instead build the radio map on-the-fly. The first approach utilized a deterministic algorithm to predict the user's location near each access point and subsequently construct a radio map of the entire area. This deterministic algorithm performed only fairly and only under limited conditions, rendering it unsuitable for most typical real-world deployments. Subsequently, a probabilistic algorithm was developed, derived from a robotic mapping technique called simultaneous localization and mapping. The standard robotic algorithm was augmented with a modified particle filter, modified motion and sensor models, and techniques for hardware-agnostic radio measurements (utilizing radio gradients and ranked radio maps). This algorithm performed favorably when compared to a standard implementation of the radio fingerprinting technique, but without needing an initial site survey. The algorithm was also reasonably robust even when the number of available access points were decreased.

My foray into location based gaming started because as a web designer, I felt that I wanted to expand my practice from one that consisted of straightforward interface design, to one that encompassed a wider variety of skills by improving on my knowledge and expertise in the burgeoning field of interaction design. This allowed me at the same time, to incorporate other aspects of design that include the usercentred design of tools for collaboration, content creation and community creation. I take a particular interest in the opportunities afforded by the convergence of web and game based technologies, especially when mobile interaction is afforded by such convergences. This exegesis describes the theoretical underpinnings that have informed the creation of a series of graphical interfaces that serve to bridge the gap between system capabilities as envisaged by the developers and a user's experience facilitated by an interface. The actual research into creation of the interface was preceded by an exploration of the field of location based gaming from which the initial area of interest was derived. Due to the fact that location based gaming is still an emerging field, it required the creation of a custom taxonomy for the works to be systematically separated into their various elements for analysis. The taxonomy to be created involved the combination of three smaller individual taxonomies in a way that has not been attempted previously and in a way that would give a balanced account of what makes up a location based game. The area of interested identified was how location based games might be made more readily available for a wider audience. Cipher Cities, which was a system in development at the time, was one that was already designed for such an application, but now required an interface that would appropriately represent what it aimed to achieve. I joined the team as their interface designer and it became clear that due to the location centric nature of the game, the only feasible way to go about democratising the participation in such games was to make it easy for people to build their own. The issue that arose was how an interface could encourage the creation of as well as participation in location based games. This required reference from current Web 2.0 applications that use members as creators of content as well as research into the theories behind community building, content creation and distribution in support of such an interface. These theories were put into practice and implemented before being evaluated and verified through a series of user testing sessions that served to refine the system in terms of user interface design and system functions. The result of the research is the first interface ever created that works to support a system for the creation of location based games by the public. More importantly, it is a robust, interface that is attractive as well as usable.

NOLÊTO, Carleandro de Oliveira. Uma ferramenta de autoria para o desenvolvimento de jogos móveis baseados em localização com realidade aumentada. 2015. 114 f. Dissertação (Mestrado em ciência da computação)- Universidade Federal do Ceará, Fortaleza-CE, 2015. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-12T19:17:21Z No. of bitstreams: 1 2015_dis_conoleto.pdf: 20398755 bytes, checksum: 8d852ec08a3b16e5ddd6271407f0c027 (MD5) / Approved for entry into archive by Rocilda Sales (rocilda@ufc.br) on 2016-07-25T11:29:03Z (GMT) No. of bitstreams: 1 2015_dis_conoleto.pdf: 20398755 bytes, checksum: 8d852ec08a3b16e5ddd6271407f0c027 (MD5) / Made available in DSpace on 2016-07-25T11:29:03Z (GMT). No. of bitstreams: 1 2015_dis_conoleto.pdf: 20398755 bytes, checksum: 8d852ec08a3b16e5ddd6271407f0c027 (MD5) Previous issue date: 2015 / Location-based mobile games are a special type of game where location technologies are employed to track players and to alter the rules of the games. Such games are a subclass of pervasive games whose playability advances according to the location of players. This work proposes an authoring tool to develop location-based mobile games enhances with augmented reality features. This tool was conceived from research studies on authoring tools and pervasive games. By analysing the related works, we have compiled the most common features of location-based mobile games and the main aspects presented in authoring tools for developing these games. Moreover, we have used focus groups to both enhance the creation of new scenarios for location-based mobile games and improve the usage of augmented reality in such games. Ultimately, we have compiled a set of requirements to design a software architecture for the development of an authoring tool. The designed architecture is composed of a server to manage running games, a web based system for developing these games, and a mobile application in which the games are executed. The main goal of this work is to provide a software solution that allows non-programmers to design, build and execute location-based mobile games. To assess the proposed work, we have designed and implemented a game called "Battle for Fortaleza" using the authoring tool. Besides, we have conducted interviews with users to validate the utility and the easiness of the tool to develop location-based mobile games. / Jogos móveis baseados em localização são aqueles que fazem uso de tecnologias de localização e que agregam a posição de seus jogadores nas regras do jogo. Estes jogos são uma subclasse de jogos pervasivos em que a jogabilidade progride de acordo com a localização do jogador. Neste trabalho é proposta uma ferramenta de autoria para a criação de jogos móveis baseados em localização, acrescidos com recursos de realidade aumentada. A concepção desta ferramenta foi feita com base em uma revisão da literatura sobre ferramentas de autoria e jogos pervasivos. A partir de trabalhos relacionados, buscou-se recolher as características comuns de jogos móveis baseados em localização e características de ferramentas de autoria para estes jogos. Além disso, utilizou-se grupos focais para refinar os novos cenários para jogos móveis baseados em localização, em particular a respeito de como a realidade aumentada pode ser utilizada nestes jogos. Com o estudo de ambos, na revisão da literatura e nos grupos focais foi produzido um conjunto de requisitos para projetar uma arquitetura de software para o desenvolvimento de uma ferramenta de criação. Esta arquitetura é composta de um servidor para gerenciar os jogos em execução, uma aplicação baseada na web que permite a autoria dos jogos e um aplicativo para dispositivos móveis onde são executados os jogos desenvolvidos. Nosso principal objetivo é fornecer uma solução de software para permitir que usuários não-programadores possam projetar, construir e executar jogos móveis baseados em localização. A fim de avaliar a nossa ferramenta, foi projetado e implementado um jogo chamado “Batalha por Fortaleza”, em que as funcionalidades da ferramentas são demonstradas. Além disso, buscou-se validar, com usuários, se a ferramenta proposta consegue auxiliar na criação de jogos de maneira fácil e intuitiva.

Nowadays, with the rapid development of GPS-equipped mobile devices, location-based social networks have been emerging to bridge the gap between the physical world and online social networking services. Various types of data, such as personal locations, check-ins, microblogs and social relations, have been available in location-based social networks. Efficiently managing and analyzing such data to meet users' daily query requirements become a challenging task. Among all the existing works in location-based social networks, group query is one of the most important research topics. In this thesis, we investigate query techniques for location-based services in social networking applications. Specifically, considering a location-based social network, we study spatial-aware interest group queries, geo-social {dollar}k{dollar}-cover group queries, and social-aware ridesharing group queries. Firstly, we study the spatial-aware interest group queries in location-based social networks. Recently, most of the location-based social networks release check-in services that allow users to share their visiting locations with their friends. These locations, considered as spatial objects, are usually associated with a few tags that describe the features of those locations. Utilizing such information, we propose a new type of \emph{Spatial-aware Interest Group} (SIG) query that retrieves a user group of size {dollar}k{dollar} where each user is interested in the query keywords and the users are close to each other in the Euclidean space. We prove this query problem is NP-complete, and develop two efficient algorithms IOAIR and DOAIR based on the IR-tree for the processing of SIG queries. We also validate the performance efficiency of the proposed query processing algorithms by empirical evaluation. Secondly, we study the problem of geo-social {dollar}k{dollar}-cover group queries for collaborative spatial computing. In this problem, we propose a novel type of geo-social queries, called \emph{Geo-Social K-Cover Group} (GSKCG) query, which is based on spatial containment and a new modeling of social relationships. Intuitively, given a set of spatial query points and an underlying social network, a GSKCG query finds a minimum user group in which the members satisfy certain social relationship and their associated regions can jointly cover all the query points. Albeit its practical usefulness, the GSKCG query problem is NP-complete. We consequently explore a set of effective pruning strategies to derive an efficient algorithm for finding the optimal solution. Moreover, we design a novel index structure tailored to our problem to further accelerate query processing. Extensive experiments demonstrate that our algorithm achieves desirable performance on real-life datasets. Thirdly, we study the problem of social-aware ridesharing group queries. With the deep penetration of smartphones and geo-locating devices, ridesharing is envisioned as a promising solution to transportation-related problems such as congestion and air pollution for metropolitan cities. Despite the potential to provide significant societal and environmental benefits, ridesharing has not so far been as popular as expected. Notable barriers include the social discomfort and safety concerns when traveling with strangers. To overcome these barriers, in this thesis, we propose a new type of \emph{Social-aware Ridesharing Group} (SaRG) query which retrieves a group of riders by taking into account their social connections besides traditional spatial proximities. Because the SaRG query problem is NP-hard, we design an efficient algorithm with a set of powerful pruning techniques to tackle this problem. We also present several incremental strategies to accelerate the search speed by reducing the repeated computations. Moreover, we propose a novel index tailored to the proposed problem to further speed up the query processing. Experimental results on real datasets show that our proposed algorithms achieve desirable performance. The works of this thesis show that the group query processing techniques are effective, which would facilitate the wider deployment of such query services in real applications

O fenômeno metafórico, caro às ciências da linguagem, tem recentemente adentrado também os estudos cognitivos, visto que se tem advogado que a metáfora não ocorre apenas na linguagem, mas constitui processos do pensamento. Argumento aqui que a metaforização articula singularidades que operam na contiguidade entre linguagem e cognição e, nela, na invenção de si e do mundo. Para tanto, um projeto de pesquisa-intervenção foi cartografado, através da criação de um método com retalhos, denominado pat(c)hwork. No projeto, desenvolvido pelo Núcleo de Pesquisas em Ecologias e Políticas Cognitivas (NUCOGS-UFRGS), um jogo digital móvel baseado em localização foi produzido para ser jogado no Parque Jardim Botânico de Porto Alegre, em um contexto não formal de aprendizagem. O jogo foi testado por estudantes do 4º e 5º ano do ensino fundamental de uma escola pública conveniada com o parque e com o grupo de pesquisa, através de oficinas. O foco cartográfico enfatizou o linguajar como agir humano na linguagem, com especial atenção à hipótese de que o mesmo caracteriza-se também pela metaforicidade O referencial teórico apóia-se na teoria autopoiética, por meio da concepção de linguagem como linguajar, entrelaçada ao emocionar e ao conversar, compondo redes de conversação; na teoria da enação, mediante a noção de cognição incorporada; na linguística cognitiva, especialmente na teoria da metáfora conceitual, como processo de fabricação e organização que pressupõe a corporeidade; e na cognição inventiva, pela costura dos conceitos de políticas, ecologias e tecnologias cognitivas. Ao cartografarmos retalhos linguageiros de conexões entre os domínios físico e digital, necessários à jogabilidade de um jogo móvel de localização, esperamos contribuir para uma compreensão do fenômeno metafórico como modulador da linguagem e da cognição como ações corporificadas, emergentes e acentradas, processos e produtos de recorrências e recursões operadas no entrelaçamento linguajar-conhecer ao longo do viver. / The metaphorical phenomenon, dear to the sciences of language, has also recently entered the cognitive studies, since it has been argued that metaphor does not occur only in language, but constitutes processes of thought. I argue here that metaphorization articulates singularities that operate in the contiguity between language and cognition and, within it, in the invention of oneself and of the world. For this, a research-intervention project was mapped through the creation of a patchwork method, called pat(c)hwork. In the project, developed by the research group Núcleo de Ecologias e Políticas Cognitivas (NUCOGS-UFRGS), a location-based mobile game was produced to be played at the Botanical Garden of Porto Alegre, in a non-formal learning context. The game was tested by students from the 4th and 5th grades of an elementary public school that entered a partnership with the park and the research group, through workshops. The cartographic focus emphasized languaging as human action in language, with special attention to the hypothesis that it is also characterized by metaphoricity The theoretical research framework is based on autopoietic theory, through the conception of language as languaging, intertwined with emotion and conversation, composing conversation networks; on enactivism, through the notion of incorporated cognition; on cognitive linguistics, especially on the theory of conceptual metaphor, as a process of fabrication and organization that presupposes corporeality; and on inventive cognition, by sewing the concepts of cognitive policies, ecologies and technologies. By mapping patches of connections between the physical and the digital domains, necessary for the gameplay of a location-based mobile game, we hope to contribute to an understanding of the metaphorical phenomenon as a modulator of embodied, emerging and decentralized language and cognition as modes of actions, processes and products of recurrences and recursions operated in the intertwining of languaging and knowing along living.

abstract: The rapid urban expansion has greatly extended the physical boundary of our living area, along with a large number of POIs (points of interest) being developed. A POI is a specific location (e.g., hotel, restaurant, theater, mall) that a user may find useful or interesting. When exploring the city and neighborhood, the increasing number of POIs could enrich people's daily life, providing them with more choices of life experience than before, while at the same time also brings the problem of "curse of choices", resulting in the difficulty for a user to make a satisfied decision on "where to go" in an efficient way. Personalized POI recommendation is a task proposed on purpose of helping users filter out uninteresting POIs and reduce time in decision making, which could also benefit virtual marketing. Developing POI recommender systems requires observation of human mobility w.r.t. real-world POIs, which is infeasible with traditional mobile data. However, the recent development of location-based social networks (LBSNs) provides such observation. Typical location-based social networking sites allow users to "check in" at POIs with smartphones, leave tips and share that experience with their online friends. The increasing number of LBSN users has generated large amounts of LBSN data, providing an unprecedented opportunity to study human mobility for personalized POI recommendation in spatial, temporal, social, and content aspects. Different from recommender systems in other categories, e.g., movie recommendation in NetFlix, friend recommendation in dating websites, item recommendation in online shopping sites, personalized POI recommendation on LBSNs has its unique challenges due to the stochastic property of human mobility and the mobile behavior indications provided by LBSN information layout. The strong correlations between geographical POI information and other LBSN information result in three major human mobile properties, i.e., geo-social correlations, geo-temporal patterns, and geo-content indications, which are neither observed in other recommender systems, nor exploited in current POI recommendation. In this dissertation, we investigate these properties on LBSNs, and propose personalized POI recommendation models accordingly. The performance evaluated on real-world LBSN datasets validates the power of these properties in capturing user mobility, and demonstrates the ability of our models for personalized POI recommendation. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2014