Thesis (M.S.)--Ohio University, June, 2004. / Title from PDF t.p. Includes bibliographical references (p. 133-136)

Thesis (M.S.)--Ohio University, August, 2004. / Title from PDF t.p. Includes bibliographical references (p. 110-111)

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (p. 123-132).

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 226-244).

abstract: It is broadly accepted that physical activity provides substantial health benefits. Despite strong evidence, approximately 60% to 95% of US adults are insufficiently active to obtain these health benefits. This dissertation explored five projects that examined the measurement properties and methodology for a variety of physical activity assessment methods. Project one identified validity evidence for the new MyWellness Key accelerometer in sixteen adults. The MyWellness Key demonstrated acceptable validity evidence when compared to a criterion accelerometer during graded treadmill walking and in free-living settings. This supports the use of the MyWellness Key accelerometer to measure physical activity. Project two evaluated validity (study 1) and test-retest reliability evidence (study 2) of the Global Physical Activity Questionnaire (GPAQ) in a two part study. The GPAQ was compared to direct and indirect criterion measures including object and subjective physical activity instruments. These data provided preliminary validity and reliability evidence for the GPAQ that support its use to assess physical activity. Project three investigated the optimal h.d-1 of accelerometer wear time needed to assess daily physical activity. Using a semi-simulation approach, data from 124 participants were used to compare 10-13 h.d-1 to the criterion 14 h.d-1. This study suggested that a minimum accelerometer wear time of 13 h.d-1 is needed to provide a valid measure of daily physical activity. Project four evaluated validity and reliability evidence of a novel method (Movement and Activity in Physical Space [MAPS] score) that combines accelerometer and GPS data to assess person-environment interactions. Seventy-five healthy adults wore an accelerometer and GPS receiver for three days to provide MAPS scores. This study provided evidence for use of a MAPS score for future research and clinical use. Project five used accelerometer data from 1,000 participants from the 2005-2006 National Health and Nutrition Examination Study. A semi-simulation approach was used to assess the effect of accelerometer wear time (10-14 h.d-1) on physical activity data. These data showed wearing for 12 h.d-1 or less may underestimate time spent in various intensities of physical activity. / Dissertation/Thesis / Ph.D. Physical Activity, Nutrition and Wellness 2011

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

Made available in DSpace on 2014-06-11T19:32:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-07Bitstream added on 2014-06-13T20:43:48Z : No. of bitstreams: 1 rodrigues_va_dr_botfca.pdf: 2236066 bytes, checksum: d841afc89e110a9ee9b1e23ccdb0b643 (MD5) / Universidade Estadual Paulista (UNESP) / A necessidade de georreferenciar os projetos científicos, os trabalhos topográficos e ter, em todos os campus da UNESP, vértices confiáveis para levantamentos com GPS, motivaram a realização da Rede GPS UNESP com 09 vértices, integrando-a com a rede GPS USP e ITESP espalhados por todo o Estado de São Paulo, visando assim atender às necessidades da UNESP, bem como colaborando com o adensamento da Rede GPS do Estado de São Paulo. O objetivo deste trabalho foi buscar uma solução que contemplasse todo o rigor cientifico e técnico para o ajustamento de redes GPS, além de atender as normas estabelecidas pelo órgão gestor da Geodésia Brasileira, o IBGE. No planejamento do rastreio, alguns aspectos de otimização de redes GPS foram considerados: no levantamento de campo utilizou-se para rastrear os vértices o equipamento Receptor GPS Topcon Hiper GGD e a rede RBMC; e no processamento dos dados, o software Topcon Tools versão 6.04 realizou a solução da ambigüidade, bem como o tratamento das injunções durante o ajustamento da rede. Os resultados obtidos conduziram a implantação de uma rede consistente e de acurácia melhor ou igual a 1 ppm pela rede RBMC, atendendo assim às especificações do IBGE. / The necessity of geo referring the scientific project, the topographic works and have in all the campus at UNESP, reliable height to lifting with GPS motivated the realization from NET GPS UNESP, with 09 height, integrand with the net GPS USP and Itesp spread all off the State of São Paulo, aim at to attend the necessity from UNESP, as well as collaborating with the densification from NET GPS from State of São Paulo. The objective of this work was to search one solution that contemplate the whole scientific and technicist strength for de adjustment from NETS GPS, besides to attend determine norm by manager organ from Brazilian Geodesic, the IBGE. In the planning of to harrow, some aspects of optimization from NET GPS was considerate: the lifting of field was used to harrow the height the equipment Receiver GPS Topcon Hiper GGD and the net RBMC, and at data processing the software Topcon Tools 6.04 version, besides was realized the ambiguity solution, as well as the treatment of injunctions during the net adjustment. The results analyses showed the implantation of the consistent net and accuracy better or equal the 1ppm by net RBMC, attending in this specification of IBGE.

Made available in DSpace on 2014-06-11T19:24:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-07Bitstream added on 2014-06-13T20:12:58Z : No. of bitstreams: 1 tragueta_nl_me_botfca.pdf: 596662 bytes, checksum: f79930749f3e9ad077ff75e918264150 (MD5) / O Sistema de Posicionamento Global (GPS – Global Positioning System) permite o conhecimento da posição, via satélite, de localidades específicas como um ponto topográfico, um carro em movimento ou de uma pessoa caminhando. A precisão do posicionamento pode variar, já que ela está diretamente relacionada ao tipo de receptor utilizado e aos objetivos em questão. Os receptores de navegação, por apresentarem menos precisão, são normalmente utilizados na obtenção de dados aproximados, que não exigem a mesma acurácia dos receptores topográficos ou geodésicos. No entanto, diante da existência de diferentes elipsóides para diferentes regiões do globo terrestre, admitiu-se a hipótese de que a configuração de um elipsóide inadequado para nossas condições poderia provocar erros ainda maiores na determinação de um posicionamento. Neste contexto, foi desenvolvido o presente trabalho, tendo como principais objetivos avaliar, comparar e analisar o desempenho de seis receptores GPS de navegação idênticos com respeito ao cálculo de áreas, perímetros e afastamentos horizontais. Em função dos resultados obtidos, nas condições em que o trabalho foi conduzido, conclui-se que a utilização de receptor GPS de navegação sem conhecimento de suas limitações e configurações básicas, pode levar o usuário a considerar direções e distâncias incompatíveis com o trajeto pretendido ou demarcado. O usuário comum deve saber, no mínimo, que elipsóide está considerando. Quando comparados com o posicionamento real da área (receptor geodésico configurado para SAD 69), a utilização de receptor de navegação configurado para os elipsóides SAD 69, WGS 84 e Córrego Alegre apresentam deslocamento da área no sentido médio de 224º54’43”, 225º10’51” e 206º04’24”, respectivamente, com distância média de 67,49 m; 129,67 m e 90,57 m, respectivamente... / The Global Positioning System allows the knowledge of the position, through satellite, of specific places as a topographical point, a car in movement or of a person walking. The precision of the positioning may vary, because it is directly related to the type of used receiver and to the objectives in subject. The navigation receivers, for present less precision, are usually used in the obtaining of approximate data, that don't demand accuracy compared to the topographical or geodesic receivers. However, in function of the existence of different ellipsoids for different regions of the earth, the hypothesis admitted was that the configuration of an inadequate ellipsoid for our conditions could still provoke big mistakes in the determination of a positioning. In this context, the present work was developed, having as main objectives to evaluate, to compare and to analyze the performance of six identical navigation GPS receivers with regard to the calculation of areas, perimeters and horizontal removals. In function of the obtained results, in the conditions in that the work was developed, it is ended that the use of navigation GPS receivers without knowledge of its limitations and basic configurations, it can take the user to consider directions and incompatible distances with the intended itinerary or demarcated. The common user should know, at least, what ellipsoid is considering. When compared with the real positioning of the area (geodesic receiver configured for SAD 69), the use of navigation receiver configured for the ellipsoids SAD 69, WGS 84 and Córrego Alegre present displacement of the area on the average sense of 224º54'43, 225º10'51 and 206º04'24, respectively, with on the average distance of 67,49 m; 129,67 m and 90,57 m, respectively. The area and perimeters values obtained by navigation GPS receivers, when compared to the area and perimeter obtained by geodesic...(Complete abstract, click electronic access below)

Thesis (MTech (Information Technology))--Cape Peninsula University of Technology, 2015. / Recently, the deployment and availability of wireless technology have led to the development of location and positioning services. These Location Based Services (LBSs) are attracting the attention of researchers and mobile service providers. With the importance of ubiquitous computing, the main challenge seen in the LBS is in the mobile positioning or localization within reasonable and certain accuracy. The Global Positioning System (GPS), as a widely known and used navigation system, is only appropriate for use in outdoor environments, due to the lack of line-of-sight (LOS) in satellite signals that they cannot be used accurately inside buildings and premises. Apart from GPS, Wi-Fi is among others, a widely used technology as it is an already existing infrastructure in most places. This work proposes and presents an indoor positioning system. As opposed to an Ad-hoc Positioning System (APS), it uses a Wireless Mesh Network (WMN). The system makes use of an already existing Wi-Fi infrastructure. Moreover, the approach tests the positioning of a node with its neighbours in a mesh network using multi-hopping functionality. The positioning measurements used were the ICMP echo requests, RSSI and RTS/CTS requests and responses. The positioning method used was the trilateral technique, in combination with the idea of the fingerprinting method. Through research and experimentation, this study developed a system which shows potential as a positioning system with an error of about 2 m – 3 m. The hybridization of the methods proves an enhancement in the system though improvements are still required

Orientador: Lincoln Gehring Cardoso / Banca: Zacarias Xavier de Barros / Banca: Sérgio Campos / Banca: Rutênio José Latanze / Banca: Sérgio Pascoal de Campos / Resumo: A necessidade de georreferenciar os projetos científicos, os trabalhos topográficos e ter, em todos os campus da UNESP, vértices confiáveis para levantamentos com GPS, motivaram a realização da Rede GPS UNESP com 09 vértices, integrando-a com a rede GPS USP e ITESP espalhados por todo o Estado de São Paulo, visando assim atender às necessidades da UNESP, bem como colaborando com o adensamento da Rede GPS do Estado de São Paulo. O objetivo deste trabalho foi buscar uma solução que contemplasse todo o rigor cientifico e técnico para o ajustamento de redes GPS, além de atender as normas estabelecidas pelo órgão gestor da Geodésia Brasileira, o IBGE. No planejamento do rastreio, alguns aspectos de otimização de redes GPS foram considerados: no levantamento de campo utilizou-se para rastrear os vértices o equipamento Receptor GPS Topcon Hiper GGD e a rede RBMC; e no processamento dos dados, o software Topcon Tools versão 6.04 realizou a solução da ambigüidade, bem como o tratamento das injunções durante o ajustamento da rede. Os resultados obtidos conduziram a implantação de uma rede consistente e de acurácia melhor ou igual a 1 ppm pela rede RBMC, atendendo assim às especificações do IBGE. / Abstract: The necessity of geo referring the scientific project, the topographic works and have in all the campus at UNESP, reliable height to lifting with GPS motivated the realization from NET GPS UNESP, with 09 height, integrand with the net GPS USP and Itesp spread all off the State of São Paulo, aim at to attend the necessity from UNESP, as well as collaborating with the densification from NET GPS from State of São Paulo. The objective of this work was to search one solution that contemplate the whole scientific and technicist strength for de adjustment from NETS GPS, besides to attend determine norm by manager organ from Brazilian Geodesic, the IBGE. In the planning of to harrow, some aspects of optimization from NET GPS was considerate: the lifting of field was used to harrow the height the equipment Receiver GPS Topcon Hiper GGD and the net RBMC, and at data processing the software Topcon Tools 6.04 version, besides was realized the ambiguity solution, as well as the treatment of injunctions during the net adjustment. The results analyses showed the implantation of the consistent net and accuracy better or equal the 1ppm by net RBMC, attending in this specification of IBGE. / Doutor