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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Neural and Behavioral Evidence for a Link Between Mobile Technology Usage and Intertemporal Preference

Wilmer, Henry Hawthorne January 2017 (has links)
Mobile electronic devices such as smartphones are playing an increasingly pervasive role in our daily activities. A growing body of literature is beginning to investigate how mobile technology habits might relate to individual differences in cognitive traits. The present study is an investigation into how individual differences in intertemporal preference, impulse control, and reward sensitivity, are predictive of the degree to which people engage with their smartphones, in two separate experiments. Experiment 1 utilized behavioral and self-reported measures for each of the aforementioned cognitive traits to examine their relationships with Mobile Technology Engagement (MTE) as defined in Wilmer & Chein (2016). The results replicated earlier work demonstrating that mobile technology engagement is positively correlated with a tendency to discount delayed rewards. A positive relationship was also observed between MTE and reward sensitivity. In an attempt to investigate the neural origins of the relationship observed in Experiment 1, Experiment 2 examined the association between mobile technology usage and white matter connectivity from the ventral striatum (vSTR) to the ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC), pathways that have been previously implicated as biological markers for individual differences in intertemporal preference. Regression analyses revealed that both pathways predicted delay discounting performance, but only vSTR-vmPFC predicted mobile technology engagement. Taken together, the results of these two experiments provide important foundational evidence for both neural and cognitive factors that predict how individuals engage with mobile technology. / Psychology
212

The Enhancement of Women’s Safety Through Smartphones

Sophie, Hopkins January 2022 (has links)
This study aims to understand how, and if, women use smartphones to enhance their safety when out of the home. Proven safety is difficult to measure, especially through a cross-sectional study; this research will assess how and if women feel safer through adapting how they use their smartphone. The primary research is predominately focused on gathering data from within the UK to understand and assess smartphone behaviours there and the impact these behaviours have on safety.  Existing research also focuses on the UK but takes lessons and development findings from across the globe to be applied as a proxy to the study and to better inform the research in the wider communication for development spectrum.   The key questions being addressed are to understand if women feel their safety is enhanced using their smartphone and if so, how they think this safety is being improved by using their smartphone. The final question addresses how these issues are answered and how communication could be enhanced to promote future safety developments within the sphere of women’s physical safety.    Data was conducted through carrying out primary research through quantitative online surveys and qualitative focus groups. The first offered robust data collection for men and women across age ranges, the second enabled for more detailed finding to be uncovered. This research was carried out in the UK (which is the initial focus of the study); this was a practical approach in terms of geographical location and language barriers, but in follow up analysis, it was also possible to find UK specific information on both smartphone usage and women’s safety. This resulted in there being a range of data to work with and analyse. This was useful to then apply comdev theories to and understand potential ways existing approaches could be developed and utilised around the world. Existing literature within the fields of women’s safety and smartphone usage was assessed to glean a more robust understanding and worldly viewpoint. Theoretical themes were addressed through literature research.    The results indicated that women were wary of their physical environments and adjusted or adapted their behaviours through their smartphone usage more so than men did to improve their safety   As this can be considered a broad and complex topic, there are several theories incorporated. For many women across the globe, the digital revolution, and smartphones, have acted as a means of empowerment. They enable humans to connect with one another regardless of where they are. For women, this has had a massive impact on safety by being able to quickly connect with other, they used messaging options with selected friends/family to notify their whereabouts to enhance their safety, others chose location sharing apps; both of which tie in with the idea of an invited space (Tufte); in this case a virtual space of safety, where the outside physical space may pose as danger. To coincide with this, many of the apps mentioned work through participatory methods, whereby users opt in to improve their safety and the safety of others.
213

Mathematical network models applied to the analysis of mobile applications behavior

Alegre Sanahuja, Juan 11 July 2016 (has links)
[EN] The network topologies are present in different social, political, economic and technological phenomena. These network structures allow to share information, alliances generation, behavior influence, opinion spread and virus transmission, among other aspects. Online networks are a reflection of the offline world and they also show these kind of network structures, in such a way that they allow the information transmission, social circle or community detection, affinity prediction between individuals, generation of recommendations, detection of influence people and generation of viral phenomena. Although all of these networks exhibit heterogeneity, they have enough underlying structure to allow their modelization for the study and analysis of all the listed phenomena. Nowadays, the line between the offline world and the online world is becoming more diffuse and there are network structures where both natures are mixed: There are almost as many mobile phones as individuals and in developed societies, the pervasiveness of smartphones on day-to-day is unquestionable in such a way that almost everybody is almost always connected everywhere. This permanent connection means that the individual, simultaneously and in a continuous mode, is a node belonging to its social network and its social network online. A key aspect of smartphones are the mobile applications that can be downloaded to the device. There are many applications for a host of different uses and the user behavior with these applications is the factor that determines how these applications behave. Also, mobile applications are the main source of infection of viruses on smartphones and, in this case, also the user behavior is what determines the transmission of these viruses. That is, the number of downloads of the application, the retention time of the application without being uninstalled, weekly minutes of usage, the popularity of the application, the transmission of viruses between smartphones, etc., depend on user behavior and, since the user is part of a social "offline" network and a social online network, in which the information is shared, communities are generated, behavior is influenced, opinion is spread and viruses are transmitted, we can intuit that the application behaviors can be modeled considering the network structure which user belongs to, so it is possible to analyze and study issues such as predicting the retention and download of applications and/or the transmission of viruses between smartphones. The purpose of this thesis is to analyze the behavior of mobile applications through mathematical network models. The behavior of mobile applications will be defined by the network of the users, taking into account parameters such as user behavior and technical issues of the mobile devices, so for model the networks both factors will be taken into account. / [ES] Las estructuras de redes están presentes en multitud de fenómenos sociales, políticos, económicos y tecnológicos. Estas estructuras permiten compartir información, constituir alianzas, influir en comportamientos, generar corrientes de opinión, y transmitir virus, entre otros aspectos. Las redes online son un reflejo del mundo "analógico" y también presentan este tipo de estructura de red, de tal forma que permiten transmitir información, detectar comunidades, predecir afinidades entre individuos, generar recomendaciones, identificar individuos influyentes o producir fenómenos virales. Aunque todas estas redes son de naturaleza heterogénea, la estructura subyacente que presentan permiten su modelización para el estudio y análisis de los fenómenos indicados. Actualmente, la línea que divide el mundo "analógico" y el mundo online es cada vez más difusa produciéndose estructuras de redes donde se entremezclan ambas naturalezas: Existen casi tantos teléfonos móviles como individuos y, en las sociedades desarrolladas, la omnipresencia de los smartphones en el día día es incuestionable de tal forma que cualquier persona está conectada casi en todo momento y lugar. Esta conexión permanente conlleva que el individuo constituya simultáneamente y de un modo continuo un nodo de su estructura de red social y de su red social online. Una parte fundamental de los smartphones son las aplicaciones que se pueden descargar en el dispositivo. Existen multitud de aplicaciones para infinidad de utilidades distintas y el comportamiento del usuario frente a esas aplicaciones es el que determina cómo se comportan dichas aplicaciones. Asimismo, las aplicaciones móviles son la principal fuente de contagio de virus en los smartphones y en este caso, también el comportamiento del usuario es el que determina la transmisión de esos virus. Es decir, el número de descargas de la aplicación, el tiempo de retención de la aplicación sin ser desinstalada, los minutos semanales de uso, la popularidad de la aplicación, la transmisión de virus en smartphones, etc., dependen del comportamiento del usuario y, puesto que el usuario forma parte de una red social "offline" y una red social online, en las cuales se comparte y transmite información, se constituyen comunidades, se influye en los comportamientos, se generan corrientes de opinión y se transmiten virus, podemos intuir que los comportamientos de las aplicaciones pueden ser modelizados considerando la estructura de red de la que el usuario forma parte, de tal forma que sea posible analizar y estudiar aspectos tales como predecir la descarga y retención de aplicaciones y/o la transmisión de virus entre smartphones. El propósito de la presente tesis doctoral es modelizar y analizar el comportamiento de las aplicaciones móviles mediante estructuras de red. El comportamiento de las aplicaciones móviles vendrá definido por la red formada por los usuarios, teniendo en cuenta tanto parámetros de comportamiento de los usuarios como parámetros relacionados con aspectos técnicos de los dispositivos móviles, por lo que para la modelización de las redes se tendrán en cuenta ambos factores. / [CA] Les estructures de xarxes estàn presents en multitud de fenòmens socials, pol'itics, econòmics i tecnològics. Estes estructures permeten compartir informació, constituir aliances, influir en comportaments, generar corrents d'opinió, i transmetre virus, entre altres aspectes. Les xarxes online són un reflex del món analògic i també presenten este tipus d'estructura de xarxa, de tal forma que permet transmetre informació, detectar comunitats, predir afinitats entre individus, generar recomanacions, identificar individus influents o produir fenòmens virals. Encara que totes estes xarxes són de naturalesa heterogènia, l'estructura subjacent que presenten permeten la seua modelització per a l'estudi i anàlisi dels fenòmens indicats. Actualment, la línia que dividix el món analògic i el món online és cada vegada més difusa produintse estructures de xarxes on s'entremesclen ambós naturaleses: Existixen quasi tants telèfons mòbils com individus i, en les societats desenvolupades, l'omnipresència dels smartphones en el dia a dia és inqüestionable de tal forma que qualsevol persona està connectada quasi en tot moment i lloc. Esta connexió permanent comporta que l'individu constituïsca simultàniament i d'una manera contínua un node de la seua estructura de xarxa social i de la seua xarxa social online. Una part fonamental dels smartphones són les aplicacions que es poden descarregar en el dispositiu. Hi ha multitud d'aplicacions per a infinitat d'utilitats distintes i el comportament de l'usuari enfront d'eixes aplicacions és el que determina com es comporten aquestes aplicacions. Així mateix, les aplicacions mòbils són la principal font de contagi de virus en els smartphones i en este cas, també el comportament de l'usuari és el que determina la transmissió d'eixos virus. És a dir, el nombre de descàrregues de l'aplicació, el temps de retenció de l'aplicació sense ser esborrada, els minuts setmanals d'ús, la popularitat de l'aplicació, la transmissió de virus entre smartphones, etc., depenen del comportament de l'usuari i, ja que l'usuari forma part d'una xarxa social "offline" i una xarxa social online, en les quals es compartix i es transmet informació, es constituïxen comunitats, s'influïx en els comportaments, es generen corrents d'opinió i es transmeten virus, podem intuir que els comportaments de les aplicacions poden ser modelitzats considerant l'estructura de xarxa de què l'usuari forma part, de tal forma que siga possible analitzar i estudiar aspectes com ara predir la descàrrega i retenció d'aplicacions i/o la transmissió de virus entre smartphones. El propòsit de la present tesi doctoral és modelitzar i analitzar el comportament de les aplicacions mòbils per mitjà d'estructures de xarxa. El comportament de les aplicacions mòbils vindrà definit per la xarxa formada pels usuaris, tenint en compte tant paràmetres de comportament dels usuaris com paràmetres relacionats amb aspectes tècnics dels dispositius mòbils, per la qual cosa per a la modelització de les xarxes es tindràn en compte ambdós factors. / Alegre Sanahuja, J. (2016). Mathematical network models applied to the analysis of mobile applications behavior [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/67389
214

Dielectric-Insensitive Phased Array with Improved Characteristics for 5G Mobile Handsets

Ojaroudi Parchin, Naser, Basherlou, H.J., Abd-Alhameed, Raed 01 October 2020 (has links)
Yes / In this manuscript, a high-performance beam-steerable phased array antenna is introduced for fifth-generation (5G) mobile handsets. The configuration of the design is arranged by employing eight dielectric-insensitive L-ring/slot-loop radiators in a linear form on the top edge of the handset mainboard. The beam-steerable array design exhibits high radiation performances even though it is implemented on a lossy FR-4 material. The proposed design exhibits an impedance bandwidth of 18-20 GHz with the center frequency of 19 GHz. It provides satisfactory characteristics such as wide beam-steering, high gain and efficiency characteristics indicating its promising potential for beam-steerable 5G smartphones. The characteristics of the antenna array are insensitive for different types of dielectrics. Furthermore, the designed antenna array offers quite good radiation behavior in the presence of hand phantom.
215

Análise da influência da vizinhança no comportamento individual relativo a viagens através de dados em painel / Analysis of neighborhood influence on travel behaviour through panel data

Assirati, Lucas 04 September 2018 (has links)
O comportamento individual relativo a viagens sofre a influência de fatores individuais e do meio urbano. Assim, a vizinhança seria uma das variáveis a serem consideradas na análise comportamental relacionada aos deslocamentos. O objetivo principal deste trabalho é analisar a influência da vizinhança no comportamento individual relativo a viagens, através de dados em painel. Dados em painel constituem importante ferramenta em análises comportamentais subjacentes a viagens urbanas, uma vez que propiciam maior quantidade de informações quando comparados aos dados seccionais. Padrões de viagens são mais bem evidenciados, através de dados em painel, caracterizando as habituais rotinas de atividades e viagens, além de melhor identificar comportamentos atípicos. Todavia, a obtenção desses dados comumente não é atividade trivial, demandando recursos monetários e de tempo. Um dos objetivos secundários deste trabalho é apresentar uma maneira prática e pouco onerosa de obtenção de dados em painel através de Smartphones. Tais dados, posteriormente, são aplicados à classificação de indivíduos segundo comportamento relacionado às viagens. A potencialidade da proposta sugerida é validada por meio de um estudo de caso relativo aos estudantes universitários do município de São Carlos - SP, Brasil. Através dos dados em painel, fornecidos pelos estudantes, utilizou-se o algoritmo k-médias considerando quatro variáveis relativas aos deslocamentos. As três categorias obtidas apresentam estrutura espacial e, portanto, possibilitam análises espaciais exploratórias e confirmatórias, almejando a compreensão de influências da vizinhança nas dinâmicas cotidianas. Este trabalho atesta a existência de autocorrelação espacial do conjunto de dados por meio de dois indicadores: Moran e SivarG (Global Spatial Indicator Based on Variogram). A corroboração da dependência espacial, apontada pelos indicadores globais, é confirmada por meio de dois modelos de escolha discreta. Um contendo apenas variáveis originais da base de dados. Outro, análogo ao primeiro, porém adicionado de covariáveis regionais, obtidas por preceitos da geoestatística. A incorporação das covariáveis regionais aumenta a precisão do modelo e promove um incremento das taxas de acertos em validações cruzadas. / Individual travel behaviour is influenced by individual factors and the urban environment. Thus, the neighborhood influence would be one of the variables to be considered in travel behavior analysis related to urban displacements. The main objective of this work is to analyze the influence of neighborhood on travel behavior by panel data. Panel data is an important tool in urban travel behavioral analyzes, since they provide a greater amount of information when compared to sectional data. Travel patterns are more evident through panel data, characterizing the usual routines of activities, as well the atypical behaviors. However, obtaining these data is not a simple task, requiring monetary and time resources. Secondary goals of this work aim to present a practical and inexpensive way to obtain panel data through Smartphones. These data are then applied to the classification of individuals according to travel behavior. The potential of the proposal is validated by a case of study concerning undergraduate and PhD students from São Carlos - SP, Brazil. Using the data provided by the students, a k-means algorithm was used considering four variables regarding displacements. These three categories have spatial structure and allow exploratory and confirmatory spatial data analyzes aiming the comprehension of the nearby influence of data at daily dynamics. This work attests to the existence of spatial autocorrelation of the data set by two indicators: Moran and SivarG (Global Spatial Indicator Based on Variogram). Corroboration of spatial dependence, pointed by the global indicators, is confirmed by two discrete choice models. The first one includes just the original database variables. The second one, analogous to the first, but added of regional covariates obtained by geostatistical concepts. The addition of regional variables leads to a more accurate model, increasing cross-validations hit rates.
216

Estimativa das observáveis GPS da portadora L2 por meio de Redes Neurais Artificiais a partir de dados obtidos em dispositivos móveis / Estimation of the GPS L2 observables by use of Artificial Neural Networks from data obtained in mobile devices

Negri, Cassio Vinícius Carletti 19 December 2018 (has links)
Ao longo dos anos, o posicionamento por satélites artificiais através da geotecnologia Global Navigation Satellite System (GNSS) e, principalmente, por meio do sistema americano Global Positioning System (GPS), ganhou importante espaço na área de Geomática. A qualidade das soluções está diretamente relacionada, entre outros fatores, ao tipo de receptor utilizado no trabalho: dispositivos mais caros (geodésicos), capazes de gerar as portadoras L1 e L2 ou L1, L2 e L5, produzem os melhores resultados; por outro lado, receptores topográficos que rastreiam apenas a frequência L1 são mais baratos, mas tornam o processamento dos dados dependente de um modelo ionosférico para reduzir parcialmente os efeitos dessa origem. Visando melhorar as soluções de posicionamento com dispositivos de baixo custo e evitar despesas adicionais do usuário que, eventualmente, necessitaria de utilizar aparelhos mais onerosos, este trabalho tem como objetivo principal propor a implementação de uma Rede Neural Artificial (RNA) para estimar as observações da portadora L2 do sistema GPS com base nas observáveis da L1, buscando-se também aprimorar o método de predição destes dados elaborado em outras pesquisas. Para tanto, selecionou-se um modelo de rede através da técnica de Validação Cruzada (CV), estimaram-se as observações a partir das rastreadas tanto em um receptor geodésico como em um smartphone Android, e comparou-se a acurácia das soluções que foram processadas com e sem as observáveis artificiais criadas pela RNA. A técnica CV demonstrou que uma Multilayer Perceptron (MLP) de quatro camadas escondidas e outra de uma camada intermediária são as configurações mais apropriadas para estimação das observáveis do código e da fase da portadora L2, respectivamente. O tempo de aprendizagem em todos os experimentos não ultrapassou poucos segundos e o processamento dos arquivos RINEX de dupla frequência, criados neste trabalho, revelou melhorias significativas das soluções de posicionamento na maioria dos testes, reduzindo os desvios planos e espaciais em torno de 40 a 50% em relação aos resultados atingidos com apenas os dados originais da portadora L1, sendo que em alguns experimentos foi possível realizar a combinação iono-free (L3) e em outros atender a normativa de georreferenciamento de imóveis rurais do Instituto Nacional de Colonização e Reforma Agrária (INCRA). Os resultados apontam, portanto, que a proposta metodológica da presente investigação atua de forma bastante promissora e como uma alternativa ao uso de receptores mais caros. / Over the years, positioning by artificial satellites through the Global Navigation Satellite System (GNSS) and, mainly, through the American Global Positioning System (GPS), has become increasingly important in Geomatics. The quality of the solutions is directly related, among other factors, to the receiver type used in the work: more expensive (geodetic) devices, capable of generating the carriers L1 and L2 or L1, L2 and L5, produce the best results; conversely, topographic receivers which only trace the L1 frequency are cheaper, but make data processing dependent on an ionospheric model to partially reduce the effects of that source. In order to improve the positioning solutions with low cost devices and avoid additional financial costs to the user who would ultimately need to use more expensive devices, the main objective of this work is to propose the implementation of an Artificial Neural Network (ANN) to estimate the GPS L2 observations from the L1 observables, aiming also to improve the prediction method elaborated in other research. This was done by using the Cross-Validation (CV) technique to select a network model. The observations were estimated from observables tracked on both a geodetic receiver and an Android smartphone, and we compared the accuracy of the solutions that were processed with and without the artificial observations created by the ANN. The CV technique demonstrated that a Multilayer Perceptron (MLP) of four hidden layers and another of an intermediate layer are the most appropriate configurations for the estimation of the L2 code and phase observables, respectively. The learning time in all the tests did not exceed a few seconds and the processing of the dual frequency RINEX files, which were created in this work, revealed significant improvements in the positioning solutions in all the experiments. The plane and spatial deviations were reduced by around 40% to 50% in relation to the results obtained with only the original L1 carrier data. In some tests it was possible to perform the iono-free combination (L3) and in others to meet the georeferencing regulations for rural properties of the National Institute of Colonization and Agrarian Reform (INCRA). The results indicate, therefore, that the methodological proposal of the present investigation acts in a very promising way and as an alternative to the use of more expensive receivers.
217

Análise da influência da vizinhança no comportamento individual relativo a viagens através de dados em painel / Analysis of neighborhood influence on travel behaviour through panel data

Lucas Assirati 04 September 2018 (has links)
O comportamento individual relativo a viagens sofre a influência de fatores individuais e do meio urbano. Assim, a vizinhança seria uma das variáveis a serem consideradas na análise comportamental relacionada aos deslocamentos. O objetivo principal deste trabalho é analisar a influência da vizinhança no comportamento individual relativo a viagens, através de dados em painel. Dados em painel constituem importante ferramenta em análises comportamentais subjacentes a viagens urbanas, uma vez que propiciam maior quantidade de informações quando comparados aos dados seccionais. Padrões de viagens são mais bem evidenciados, através de dados em painel, caracterizando as habituais rotinas de atividades e viagens, além de melhor identificar comportamentos atípicos. Todavia, a obtenção desses dados comumente não é atividade trivial, demandando recursos monetários e de tempo. Um dos objetivos secundários deste trabalho é apresentar uma maneira prática e pouco onerosa de obtenção de dados em painel através de Smartphones. Tais dados, posteriormente, são aplicados à classificação de indivíduos segundo comportamento relacionado às viagens. A potencialidade da proposta sugerida é validada por meio de um estudo de caso relativo aos estudantes universitários do município de São Carlos - SP, Brasil. Através dos dados em painel, fornecidos pelos estudantes, utilizou-se o algoritmo k-médias considerando quatro variáveis relativas aos deslocamentos. As três categorias obtidas apresentam estrutura espacial e, portanto, possibilitam análises espaciais exploratórias e confirmatórias, almejando a compreensão de influências da vizinhança nas dinâmicas cotidianas. Este trabalho atesta a existência de autocorrelação espacial do conjunto de dados por meio de dois indicadores: Moran e SivarG (Global Spatial Indicator Based on Variogram). A corroboração da dependência espacial, apontada pelos indicadores globais, é confirmada por meio de dois modelos de escolha discreta. Um contendo apenas variáveis originais da base de dados. Outro, análogo ao primeiro, porém adicionado de covariáveis regionais, obtidas por preceitos da geoestatística. A incorporação das covariáveis regionais aumenta a precisão do modelo e promove um incremento das taxas de acertos em validações cruzadas. / Individual travel behaviour is influenced by individual factors and the urban environment. Thus, the neighborhood influence would be one of the variables to be considered in travel behavior analysis related to urban displacements. The main objective of this work is to analyze the influence of neighborhood on travel behavior by panel data. Panel data is an important tool in urban travel behavioral analyzes, since they provide a greater amount of information when compared to sectional data. Travel patterns are more evident through panel data, characterizing the usual routines of activities, as well the atypical behaviors. However, obtaining these data is not a simple task, requiring monetary and time resources. Secondary goals of this work aim to present a practical and inexpensive way to obtain panel data through Smartphones. These data are then applied to the classification of individuals according to travel behavior. The potential of the proposal is validated by a case of study concerning undergraduate and PhD students from São Carlos - SP, Brazil. Using the data provided by the students, a k-means algorithm was used considering four variables regarding displacements. These three categories have spatial structure and allow exploratory and confirmatory spatial data analyzes aiming the comprehension of the nearby influence of data at daily dynamics. This work attests to the existence of spatial autocorrelation of the data set by two indicators: Moran and SivarG (Global Spatial Indicator Based on Variogram). Corroboration of spatial dependence, pointed by the global indicators, is confirmed by two discrete choice models. The first one includes just the original database variables. The second one, analogous to the first, but added of regional covariates obtained by geostatistical concepts. The addition of regional variables leads to a more accurate model, increasing cross-validations hit rates.
218

Estimativa das observáveis GPS da portadora L2 por meio de Redes Neurais Artificiais a partir de dados obtidos em dispositivos móveis / Estimation of the GPS L2 observables by use of Artificial Neural Networks from data obtained in mobile devices

Cassio Vinícius Carletti Negri 19 December 2018 (has links)
Ao longo dos anos, o posicionamento por satélites artificiais através da geotecnologia Global Navigation Satellite System (GNSS) e, principalmente, por meio do sistema americano Global Positioning System (GPS), ganhou importante espaço na área de Geomática. A qualidade das soluções está diretamente relacionada, entre outros fatores, ao tipo de receptor utilizado no trabalho: dispositivos mais caros (geodésicos), capazes de gerar as portadoras L1 e L2 ou L1, L2 e L5, produzem os melhores resultados; por outro lado, receptores topográficos que rastreiam apenas a frequência L1 são mais baratos, mas tornam o processamento dos dados dependente de um modelo ionosférico para reduzir parcialmente os efeitos dessa origem. Visando melhorar as soluções de posicionamento com dispositivos de baixo custo e evitar despesas adicionais do usuário que, eventualmente, necessitaria de utilizar aparelhos mais onerosos, este trabalho tem como objetivo principal propor a implementação de uma Rede Neural Artificial (RNA) para estimar as observações da portadora L2 do sistema GPS com base nas observáveis da L1, buscando-se também aprimorar o método de predição destes dados elaborado em outras pesquisas. Para tanto, selecionou-se um modelo de rede através da técnica de Validação Cruzada (CV), estimaram-se as observações a partir das rastreadas tanto em um receptor geodésico como em um smartphone Android, e comparou-se a acurácia das soluções que foram processadas com e sem as observáveis artificiais criadas pela RNA. A técnica CV demonstrou que uma Multilayer Perceptron (MLP) de quatro camadas escondidas e outra de uma camada intermediária são as configurações mais apropriadas para estimação das observáveis do código e da fase da portadora L2, respectivamente. O tempo de aprendizagem em todos os experimentos não ultrapassou poucos segundos e o processamento dos arquivos RINEX de dupla frequência, criados neste trabalho, revelou melhorias significativas das soluções de posicionamento na maioria dos testes, reduzindo os desvios planos e espaciais em torno de 40 a 50% em relação aos resultados atingidos com apenas os dados originais da portadora L1, sendo que em alguns experimentos foi possível realizar a combinação iono-free (L3) e em outros atender a normativa de georreferenciamento de imóveis rurais do Instituto Nacional de Colonização e Reforma Agrária (INCRA). Os resultados apontam, portanto, que a proposta metodológica da presente investigação atua de forma bastante promissora e como uma alternativa ao uso de receptores mais caros. / Over the years, positioning by artificial satellites through the Global Navigation Satellite System (GNSS) and, mainly, through the American Global Positioning System (GPS), has become increasingly important in Geomatics. The quality of the solutions is directly related, among other factors, to the receiver type used in the work: more expensive (geodetic) devices, capable of generating the carriers L1 and L2 or L1, L2 and L5, produce the best results; conversely, topographic receivers which only trace the L1 frequency are cheaper, but make data processing dependent on an ionospheric model to partially reduce the effects of that source. In order to improve the positioning solutions with low cost devices and avoid additional financial costs to the user who would ultimately need to use more expensive devices, the main objective of this work is to propose the implementation of an Artificial Neural Network (ANN) to estimate the GPS L2 observations from the L1 observables, aiming also to improve the prediction method elaborated in other research. This was done by using the Cross-Validation (CV) technique to select a network model. The observations were estimated from observables tracked on both a geodetic receiver and an Android smartphone, and we compared the accuracy of the solutions that were processed with and without the artificial observations created by the ANN. The CV technique demonstrated that a Multilayer Perceptron (MLP) of four hidden layers and another of an intermediate layer are the most appropriate configurations for the estimation of the L2 code and phase observables, respectively. The learning time in all the tests did not exceed a few seconds and the processing of the dual frequency RINEX files, which were created in this work, revealed significant improvements in the positioning solutions in all the experiments. The plane and spatial deviations were reduced by around 40% to 50% in relation to the results obtained with only the original L1 carrier data. In some tests it was possible to perform the iono-free combination (L3) and in others to meet the georeferencing regulations for rural properties of the National Institute of Colonization and Agrarian Reform (INCRA). The results indicate, therefore, that the methodological proposal of the present investigation acts in a very promising way and as an alternative to the use of more expensive receivers.
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Tecnologias móveis na formação de professores que ensinam matemática / Mobile Technologies in the formation of teachers teaching mathematics

Freitas, Raphael de Oliveira 12 May 2017 (has links)
The present work deals with a qualitative research in the modality of a case study on the insertion of the mobile technologies (tablets and smartphones) as didactic strategy, in order to investigate how these resources favor the learning of the mathematical contents of the additive field and the multiplicative field in elementary school. The study was carried out with the students of the courses of Pedagogy and of the Degree in Mathematics in the classroom mode of the Federal University of Alagoas (UFAL), Campus AC Simões in Maceió - Alagoas, Institute of Mathematics - IM, in the Laboratory of Mathematics Teaching - LMAT. The analysis of the data was based on the work of Gerard Vernaug (2014), Borba (2014) and Bairral (2015), in order to base analyzes on the training of mathematics teachers with mobile technologies. Of official MEC Brazil documents (1997, 1998, 1999, 2002a, 2002b, 2006a, 2006b and 2015). To collect data, we used two questionnaires: direct and participative observation, field diary, interview, pedagogical workshop and course documents as didactic resource. The results obtained indicated the students' interest in the possibilities and limitations of the use of mobile technologies as teaching and learning resources, as well as the understanding of the mathematical contents of the conceptual fields worked through their participation in the discussions and reflections of the activities proposed during the workshop. In the analysis of the interviews it is indicated by the students that much of the training received is lacking a curriculum that addresses the educational context in which these individuals are inserted (digital information society), because the pedagogical practices still focus on "traditional" didactics and curriculum , Whose classes are often based on a reproduction / transfer of knowledge and not on a formation in which the future teacher acts in an innovative way and with a meaningful learning approach. / O presente trabalho trata de uma pesquisa qualitativa na modalidade de um estudo de caso sobre a inserção das tecnologias móveis (tablets e smartphones) como estratégia didática, a fim de investigar como esses recursos favorecem a aprendizagem dos conteúdos matemáticos do campo aditivo e do campo multiplicativo no ensino fundamental. O estudo foi realizado com os alunos dos cursos de Pedagogia e da Licenciatura em Matemática na modalidade presencial da Universidade Federal de Alagoas (UFAL), Campus A.C. Simões em Maceió - Alagoas, no Instituto de Matemática – IM, no Laboratório de Ensino de Matemática - LEMA. As análises dos dados foram pautadas nos trabalhos de, Carvalho (2009, 2015), Gerard Vernaug (2014), além de Borba (2014) e Bairral (2015) para fundamentar as análises sobre a formação de professores de matemática com tecnologias móveis, além de documentos oficiais do MEC Brasil (1997, 1998, 1999, 2002a, 2002b, 2006a, 2006b e 2015). Para a coleta de dados, utilizamos como instrumentos dois questionários, observação direta e participativa, diário de campo, entrevista, oficina pedagógica e documentos do curso como recurso didático. Os resultados obtidos sinalizaram o interesse dos alunos, em formação, nas possibilidades e limitações do uso das tecnologias móveis como recursos de ensino e aprendizagem, da mesma forma, a compreensão dos conteúdos matemáticos dos campos conceituais trabalhados por meio de sua participação nas discussões e reflexões das atividades propostas durante a oficina. Nas análises das entrevistas é indicado pelos alunos que boa parte da formação recebida é carente de um currículo que aborde o contexto educacional no qual esses indivíduos estão inseridos (sociedade da informação digital), pois as práticas pedagógicas ainda focam em didática e currículo ―tradicionais‖, cujas aulas muitas vezes são baseadas em uma reprodução/transferência de conhecimentos e não numa formação na qual o futuro professor atue de maneira inovadora e com uma abordagem de aprendizagem significativa.
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Bridging the gap between Privacy by Design and mobile systems by patterns / Modèles pour les environnements de terminaux nomades "Privacy by Design"

Sokolova, Karina 27 April 2016 (has links)
De nos jours, les smartphones et les tablettes génèrent, reçoivent, mémorisent et transfèrent vers des serveurs une grande quantité de données en proposant des services aux utilisateurs via des applications mobiles facilement téléchargeables et installables. Le grand nombre de capteurs intégrés dans un smartphone lui permet de collecter de façon continue des informations très précise sur l'utilisateur et son environnement. Cette importante quantité de données privées et professionnelles devient difficile à superviser.L'approche «Privacy by Design», qui inclut sept principes, propose d'intégrer la notion du respect des données privées dès la phase de la conception d’un traitement informatique. En Europe, la directive européenne sur la protection des données privées (Directive 95/46/EC) intègre des notions du «Privacy by Design». La nouvelle loi européenne unifiée (General Data Protection Régulation) renforce la protection et le respect des données privées en prenant en compte les nouvelles technologies et confère au concept de «Privacy by Design» le rang d’une obligation légale dans le monde des services et des applications mobiles.L’objectif de cette thèse est de proposer des solutions pour améliorer la transparence des utilisations des données personnelles mobiles, la visibilité sur les systèmes informatiques, le consentement et la sécurité pour finalement rendre les applications et les systèmes mobiles plus conforme au «Privacy by (re)Design» / Nowadays, smartphones and smart tablets generate, receive, store and transfer substantial quantities of data, providing services for all possible user needs with easily installable programs, also known as mobile applications. A number of sensors integrated into smartphones allow the devices to collect very precise information about the owner and his environment at any time. The important flow of personal and business data becomes hard to manage.The “Privacy by Design” approach with 7 privacy principles states privacy can be integrated into any system from the software design stage. In Europe, the Data Protection Directive (Directive 95/46/EC) includes “Privacy by Design” principles. The new General Data Protection Regulation enforces privacy protection in the European Union, taking into account modern technologies such as mobile systems and making “Privacy by Design” not only a benefit for users, but also a legal obligation for system designers and developers.The goal of this thesis is to propose pattern-oriented solutions to cope with mobile privacy problems, such as lack of transparency, lack of consent, poor security and disregard for purpose limitation, thus giving mobile systems more Privacy by (re) Design

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