People with severe motor disabilities may communicate using their eye movements aided by a virtual keyboard and an eye tracker. Text entry by gaze may also benefit users immersed in virtual or augmented realities, when they do not have access to a physical keyboard or touchscreen. Thus, both users with and without disabilities may take advantage of the ability to enter text by gaze. However, methods for text entry by gaze are typically slow and uncomfortable. In this thesis we propose EyeSwipe as a step further towards fast and comfortable text entry by gaze. EyeSwipe maps gaze paths into words, similarly to how finger traces are used on swipe-based methods for touchscreen devices. A gaze path differs from the finger trace in that it does not have clear start and end positions. To segment the gaze path from the user\'s continuous gaze data stream, EyeSwipe requires the user to explicitly indicate its beginning and end. The user can quickly glance at the vicinity of the other characters that compose the word. Candidate words are sorted based on the gaze path and presented to the user. We discuss two versions of EyeSwipe. EyeSwipe 1 uses a deterministic gaze gesture called Reverse Crossing to select both the first and last letters of the word. Considering the lessons learned during the development and test of EyeSwipe 1 we proposed EyeSwipe 2. The user emits commands to the interface by switching the focus between regions. In a text entry experiment comparing EyeSwipe 2 to EyeSwipe 1, 11 participants achieved an average text entry rate of 12.58 words per minute (wpm) with EyeSwipe 1 and 14.59 wpm with EyeSwipe 2 after using each method for 75 minutes. The maximum entry rates achieved with EyeSwipe 1 and EyeSwipe 2 were, respectively, 21.27 wpm and 32.96 wpm. Participants considered EyeSwipe 2 to be more comfortable and faster, while less accurate than EyeSwipe 1. Additionally, with EyeSwipe 2 we proposed the use of gaze path data to dynamically adjust the gaze estimation. Using data from the experiment we show that gaze paths can be used to dynamically improve gaze estimation during the interaction. / Pessoas com deficiências motoras severas podem se comunicar usando movimentos do olhar com o auxílio de um teclado virtual e um rastreador de olhar. A entrada de texto usando o olhar também beneficia usuários imersos em realidade virtual ou realidade aumentada, quando não possuem acesso a um teclado físico ou tela sensível ao toque. Assim, tanto usuários com e sem deficiência podem se beneficiar da possibilidade de entrar texto usando o olhar. Entretanto, métodos para entrada de texto com o olhar são tipicamente lentos e desconfortáveis. Nesta tese propomos o EyeSwipe como mais um passo em direção à entrada rápida e confortável de texto com o olhar. O EyeSwipe mapeia gestos do olhar em palavras, de maneira similar a como os movimentos do dedo em uma tela sensível ao toque são utilizados em métodos baseados em gestos (swipe). Um gesto do olhar difere de um gesto com os dedos em que ele não possui posições de início e fim claramente definidas. Para segmentar o gesto do olhar a partir do fluxo contínuo de dados do olhar, o EyeSwipe requer que o usuário indique explicitamente seu início e fim. O usuário pode olhar rapidamente a vizinhança dos outros caracteres que compõe a palavra. Palavras candidatas são ordenadas baseadas no gesto do olhar e apresentadas ao usuário. Discutimos duas versões do EyeSwipe. O EyeSwipe 1 usa um gesto do olhar determinístico chamado Cruzamento Reverso para selecionar tanto a primeira quanto a última letra da palavra. Levando em consideração os aprendizados obtidos durante o desenvolvimento e teste do EyeSwipe 1 nós propusemos o EyeSwipe 2. O usuário emite comandos para a interface ao trocar o foco entre as regiões do teclado. Em um experimento de entrada de texto comparando o EyeSwipe 2 com o EyeSwipe 1, 11 participantes atingiram uma taxa de entrada média de 12.58 palavras por minuto (ppm) usando o EyeSwipe 1 e 14.59 ppm com o EyeSwipe 2 após utilizar cada método por 75 minutos. A taxa de entrada de texto máxima alcançada com o EyeSwipe 1 e EyeSwipe 2 foram, respectivamente, 21.27 ppm e 32.96 ppm. Os participantes consideraram o EyeSwipe 2 mais confortável e rápido, mas menos preciso do que o EyeSwipe 1. Além disso, com o EyeSwipe 2 nós propusemos o uso dos dados dos gestos do olhar para ajustar a estimação do olhar dinamicamente. Utilizando dados obtidos no experimento mostramos que os gestos do olhar podem ser usados para melhorar a estimação dinamicamente durante a interação.

People with severe motor disabilities may communicate using their eye movements aided by a virtual keyboard and an eye tracker. Text entry by gaze may also benefit users immersed in virtual or augmented realities, when they do not have access to a physical keyboard or touchscreen. Thus, both users with and without disabilities may take advantage of the ability to enter text by gaze. However, methods for text entry by gaze are typically slow and uncomfortable. In this thesis we propose EyeSwipe as a step further towards fast and comfortable text entry by gaze. EyeSwipe maps gaze paths into words, similarly to how finger traces are used on swipe-based methods for touchscreen devices. A gaze path differs from the finger trace in that it does not have clear start and end positions. To segment the gaze path from the user\'s continuous gaze data stream, EyeSwipe requires the user to explicitly indicate its beginning and end. The user can quickly glance at the vicinity of the other characters that compose the word. Candidate words are sorted based on the gaze path and presented to the user. We discuss two versions of EyeSwipe. EyeSwipe 1 uses a deterministic gaze gesture called Reverse Crossing to select both the first and last letters of the word. Considering the lessons learned during the development and test of EyeSwipe 1 we proposed EyeSwipe 2. The user emits commands to the interface by switching the focus between regions. In a text entry experiment comparing EyeSwipe 2 to EyeSwipe 1, 11 participants achieved an average text entry rate of 12.58 words per minute (wpm) with EyeSwipe 1 and 14.59 wpm with EyeSwipe 2 after using each method for 75 minutes. The maximum entry rates achieved with EyeSwipe 1 and EyeSwipe 2 were, respectively, 21.27 wpm and 32.96 wpm. Participants considered EyeSwipe 2 to be more comfortable and faster, while less accurate than EyeSwipe 1. Additionally, with EyeSwipe 2 we proposed the use of gaze path data to dynamically adjust the gaze estimation. Using data from the experiment we show that gaze paths can be used to dynamically improve gaze estimation during the interaction. / Pessoas com deficiências motoras severas podem se comunicar usando movimentos do olhar com o auxílio de um teclado virtual e um rastreador de olhar. A entrada de texto usando o olhar também beneficia usuários imersos em realidade virtual ou realidade aumentada, quando não possuem acesso a um teclado físico ou tela sensível ao toque. Assim, tanto usuários com e sem deficiência podem se beneficiar da possibilidade de entrar texto usando o olhar. Entretanto, métodos para entrada de texto com o olhar são tipicamente lentos e desconfortáveis. Nesta tese propomos o EyeSwipe como mais um passo em direção à entrada rápida e confortável de texto com o olhar. O EyeSwipe mapeia gestos do olhar em palavras, de maneira similar a como os movimentos do dedo em uma tela sensível ao toque são utilizados em métodos baseados em gestos (swipe). Um gesto do olhar difere de um gesto com os dedos em que ele não possui posições de início e fim claramente definidas. Para segmentar o gesto do olhar a partir do fluxo contínuo de dados do olhar, o EyeSwipe requer que o usuário indique explicitamente seu início e fim. O usuário pode olhar rapidamente a vizinhança dos outros caracteres que compõe a palavra. Palavras candidatas são ordenadas baseadas no gesto do olhar e apresentadas ao usuário. Discutimos duas versões do EyeSwipe. O EyeSwipe 1 usa um gesto do olhar determinístico chamado Cruzamento Reverso para selecionar tanto a primeira quanto a última letra da palavra. Levando em consideração os aprendizados obtidos durante o desenvolvimento e teste do EyeSwipe 1 nós propusemos o EyeSwipe 2. O usuário emite comandos para a interface ao trocar o foco entre as regiões do teclado. Em um experimento de entrada de texto comparando o EyeSwipe 2 com o EyeSwipe 1, 11 participantes atingiram uma taxa de entrada média de 12.58 palavras por minuto (ppm) usando o EyeSwipe 1 e 14.59 ppm com o EyeSwipe 2 após utilizar cada método por 75 minutos. A taxa de entrada de texto máxima alcançada com o EyeSwipe 1 e EyeSwipe 2 foram, respectivamente, 21.27 ppm e 32.96 ppm. Os participantes consideraram o EyeSwipe 2 mais confortável e rápido, mas menos preciso do que o EyeSwipe 1. Além disso, com o EyeSwipe 2 nós propusemos o uso dos dados dos gestos do olhar para ajustar a estimação do olhar dinamicamente. Utilizando dados obtidos no experimento mostramos que os gestos do olhar podem ser usados para melhorar a estimação dinamicamente durante a interação.

A measurement of the primordial B-mode polarisation of the Cosmic Microwave Background would provide direct evidence of inflation in the early universe. The extremely weak nature of the B-mode signal necessitates an instrument with a high sensitivity and precise control over systematic effects. Multi-mode antenna feed horns offer higher sensitivity than their single-mode counterparts, however their behaviour is much more complex. The Short Wavelength Instrument for the Polarisation Explorer (SWIPE) onboard the Large Scale Polarisation Explorer (LSPE) is one instrument planning to implement multi-mode feed horns. SWIPE will attempt to detect the primordial B-mode at large angular scales, measuring the sky in three bands at 140, 220 and 240 GHz. A single on-axis High-Density PolyEthylene (HDPE) lens and polarisation-splitting wire grid combine to focus the radiation from the sky onto two focal planes of multi-mode horns feeding bolometric detectors. A large diameter rotating metal-mesh half-wave plate allows both polarisations to be measured by the same pixel, therefore bypassing many detector systematics. Simulations are performed to predict the sky beam for two key pixels: closest to and furthest from the centre of the focal plane. For the 140 GHz channel the cross-polarisation is predicted, and the optimum location at which to place the telescope’s focus behind the horn aperture to maximise gain and optimise beam shape is investigated. A measurement of the multi-mode horn is performed using a room-temperature bolometer. An investigation is also conducted to assess to what extent the same measurements can be performed using a coherent measurement system such as a vector network analyser. A working coherent measurement technique is devised, however it is limited to horns carrying only the first 3 modes.

The perception of a good user experience can be fundamental in an app for users to be willing to engage in it and use it more than one time. An important part of the user experience is the interactions of the used interface. In this study, the goal has been to answer the question 'How can swipe gestures be used in a book recommendation system to introduce users to new content and allow them to sample it'. To answer the question, a user study with 18 participants has been done in which prototypes based on three different swipe gestures, defined by Google, have been tested: edge swipe, overscroll collapse and paging swipe. The study is based on the previous studies 'Clicking, Assessing, Immersing, and Sharing' by Oh et al. and 'Power of the Swipe: Why Mobile Websites Should Add Horizontal Swiping to Tapping, Clicking, and Scrolling Interaction Techniques' by Dou and Sundar. The study shows that it is possible to design swipe gestures in a recommendation tool for books in such a fashion that it engages the users. The study also shows that the participants thought that the prototype with the paging swipe was statistically significantly more easy to browse and that their attention was less diverted while browsing the content of that prototype. How swipe gestures can be used in a book recommendation system for the intended purpose depends on the purpose and the context of the tool. One way to do it would be to create a tool based on the paging swipe gesture with factors such as content, attractiveness and intuitiveness of the interface in mind. / Upplevelsen av god användarvänlighet kan vara fundamental i en app för att användare ska vilja engagera sig i den och använda den fler än en gång. En viktig del av användarupplevelsen är interaktionerna i det använda gränssnittet. Målet i den här studien har varit att besvara frågan 'Hur kan swipegester användas i ett bokrekommendationsverktyg för att introducera användare till nytt material och låta dem sampla det'. För att besvara frågan har en användarstudie med 18 deltagare genomförts i vilken prototyper baserade på tre, av Google definierade, swipegester har testats: edge swipe, overscroll collapse och paging swipe. Studien är primärt baserad på de tidigare studierna 'Clicking, Assessing, Immersing, and Sharing' av Oh et al. och 'Power of the Swipe: Why Mobile Websites Should Add Horizontal Swiping to Tapping, Clicking, and Scrolling Interaction Techniques' av Dou och Sundar. Studien visar att det är möjligt att designa swipegester i ett bokrekommendationsverktyg på ett sådant sätt att det engagerar användare. Studien visar också att deltagarna fann prototypen med paging swipe statistiskt signifikant enklare att utforska och att deras uppmärksamhet var mindre delad när de utforskade innehållet i den prototypen. Studien skulle dock behöva genomföras med fler deltagare. Hur swipegester kan användas i ett bokrekommendationsverktyg beror på verktygets syfte liksom på kontexten det ska användas i. Ett sätt som swipegester skulle kunna användas på är i ett verktyg baserat på paging swipegester i vilket hänsyn tagits till faktorer som innehåll, attraktionskraft och gränssnittets intuitivitet.

Each year about 400,000 trucks are involved in motor vehicle crashes. Crashes involving a car and truck have always been a major concern due to the heavy fatality rates. These types of crashes result in about 60 percent of all fatal truck crashes and two-thirds of all police-reportable truck crashes. Car-truck crashes need to be analyzed further to study the trends for a car-truck crash and develop some countermeasures to lower these crashes. Various types of car-truck crashes are analyzed in this study and the effects of various roadway/environment factors and variables related to driver characteristics in these car-truck crashes are investigated. To examine the crash characteristics and to investigate the significant factors related to a car-truck crash, this study analyzed five years of data (2000-2004) of the General estimates system of National Sampling System (GES) and the Fatality Analysis Reporting system database (FARS). All two vehicle crashes including either a car or truck (truck-truck cases excluded because of their low percentage composition) were obtained from these databases. Based on the five year data (GES/FARS) the percentage of car-truck angle collisions constituted the highest percent of frequency of all types of car-truck collisions. Furthermore, based on the 2004 GES data there is a clear trend that the frequency of angle collision increases with the increase in driver injury severity. When analyzing the GES data it was observed that the percentage of angle collisions was the highest followed by the rear end and sideswipe (same direction) collisions respectively. When the fatalities were considered (FARS database used), the percentage of angle collisions was the highest followed by head-on and rear-end collisions. The nominal multinomial logit model and logistic regression models were utilized for this analysis. Divided section, alcohol involvement, adverse weather conditions, dark lighting condition and old age of drivers had a significant effect on the car-truck crashes and were likely to increase the likelihood of a car-truck crash. Whereas dark but light conditions, young aged drivers showed a less likelihood of involving in a car-truck crash. This research is significant in providing an insight into various car-truck crash types and provides with results, which have impacted the car-truck crashes. A better understanding of the factors impacting these crashes will help in providing better countermeasures, which would result in reducing the car-truck crashes.

At the time of writing, touch is revolutionizing the market with devices that have touch as the primary input modality. In this thesis we have been able to explore how another input modality, touchless, can complement touch in everyday applications. Touchless refers to an input method that is able to recognize hand gestures and act upon them. To investigate how these two input modalities can be combined, an Android prototype application featuring both touch and touchless was created. We chose to create a recipe reader because we found that a lot of people can relate to having soggy hands in the kitchen. The outcome of this thesis is assembled to form design principles that we find worthy to consider when designing multimodal input interfaces that includes both touch and touchless.

O uso das amostragens ambientais para fins de salvaguardas vêm sendo aplicadas pela Agência Internacional de Energia Atômica AIEA desde 1996 e estão sendo rotineiramente utilizadas como uma medida de fortalecimento complementar aos procedimentos tradicionais de salvaguardas de materiais nucleares. O intuito é verificar se os Estados signatários aos acordos de salvaguardas não estão divergindo suas atividades nucleares pacíficas para atividades nucleares não declaradas. O presente trabalho apresenta um novo protocolo de coleta e análise de esfregaços para identificação de assinaturas nucleares que possam relacionar-se com as atividades nucleares desenvolvidas na instalação inspecionada. Neste trabalho foi utilizada como estudo de caso uma planta real de reconversão de urânio do ciclo do combustível nuclear do IPEN. A estratégia analítica proposta utiliza diferentes técnicas, como medidor de radiação alfa, MEVEDS e ICPMS para identificar assinaturas do urânio aderido ao esfregaço. Na análise dos esfregaços, foi possível identificar partículas de UO2F2 e UF4 através da comparação morfológica e análises semi-quantitativas utilizando a técnica de MEVEDS. Nesse trabalho, utilizaram-se métodos que como resultado tem-se a composição isotópica média da amostra, onde o enriquecimento (fração atômica molar) variou de 1,453 ± 0,023% a 18,24 ± 0,15% no isótopo 235U. Através das coletas realizadas externamente, uma forma não intrusiva de amostragem, foi possível à identificação de atividades de manuseio de material enriquecido com medidas de fração atômica molar de 1,453 ± 0,023% a 6,331 ± 0,055% no isótopo 235U, bem como uso de material reprocessado, através da identificação do isótopo 236U. As incertezas obtidas neste trabalho para a razão n(235U)/n(238U) variaram de 0,40% a 1,68%. / The use of environmental samplings for safeguards purposes has been applied by the International Atomic Energy AgencyIAEA since 1996 and they are routinely used as a complementary measure to strengthen the traditional nuclear safeguards procedures. The aim is verify if the signatory states to the safeguards agreements are not diverging their peaceful nuclear activities to undeclared nuclear activities. This work describes a new protocol of collect and analysis of swipe samples in order to achieve identification of nuclear signatures, which may be related to the nuclear activities developed in the inspected facility. In this work, as a case of study, a real uranium reconversion plant of the nuclear fuel cycle of IPEN was used. The strategy proposed uses different analytical techniques, such as alpha radiation meter, SEM-EDX and ICP-QMS to identify signatures of the uranium adhered to the swipe samples. In the swipe samples analysis, it was possible to identify particles of UO2F2 and UF4 through the morphological comparison and semi-quantitative analysis performed by SEM-EDX technique. The methods used in this work bring the average isotopic composition of the sample as a result, in which the enrichment (molar atomic fraction) ranged from 1.453 ± 0.023% to 18.24 ± 0.15% in the 235U isotope. Through of the external collections, a non-intrusive sampling, it was possible to identify handling activities of enriched material with molar atomic fraction of 1.453 ± 0.023% to 6.331 ± 0.055% in the 235U isotope, as well as the use of reprocessed material by means of the 236U isotope identification. The uncertainties obtained in this work to the n(235U)/n(238U) ratio varied from 0.40% to 1.68%.

O uso das amostragens ambientais para fins de salvaguardas vêm sendo aplicadas pela Agência Internacional de Energia Atômica AIEA desde 1996 e estão sendo rotineiramente utilizadas como uma medida de fortalecimento complementar aos procedimentos tradicionais de salvaguardas de materiais nucleares. O intuito é verificar se os Estados signatários aos acordos de salvaguardas não estão divergindo suas atividades nucleares pacíficas para atividades nucleares não declaradas. O presente trabalho apresenta um novo protocolo de coleta e análise de esfregaços para identificação de assinaturas nucleares que possam relacionar-se com as atividades nucleares desenvolvidas na instalação inspecionada. Neste trabalho foi utilizada como estudo de caso uma planta real de reconversão de urânio do ciclo do combustível nuclear do IPEN. A estratégia analítica proposta utiliza diferentes técnicas, como medidor de radiação alfa, MEVEDS e ICPMS para identificar assinaturas do urânio aderido ao esfregaço. Na análise dos esfregaços, foi possível identificar partículas de UO2F2 e UF4 através da comparação morfológica e análises semi-quantitativas utilizando a técnica de MEVEDS. Nesse trabalho, utilizaram-se métodos que como resultado tem-se a composição isotópica média da amostra, onde o enriquecimento (fração atômica molar) variou de 1,453 ± 0,023% a 18,24 ± 0,15% no isótopo 235U. Através das coletas realizadas externamente, uma forma não intrusiva de amostragem, foi possível à identificação de atividades de manuseio de material enriquecido com medidas de fração atômica molar de 1,453 ± 0,023% a 6,331 ± 0,055% no isótopo 235U, bem como uso de material reprocessado, através da identificação do isótopo 236U. As incertezas obtidas neste trabalho para a razão n(235U)/n(238U) variaram de 0,40% a 1,68%. / The use of environmental samplings for safeguards purposes has been applied by the International Atomic Energy AgencyIAEA since 1996 and they are routinely used as a complementary measure to strengthen the traditional nuclear safeguards procedures. The aim is verify if the signatory states to the safeguards agreements are not diverging their peaceful nuclear activities to undeclared nuclear activities. This work describes a new protocol of collect and analysis of swipe samples in order to achieve identification of nuclear signatures, which may be related to the nuclear activities developed in the inspected facility. In this work, as a case of study, a real uranium reconversion plant of the nuclear fuel cycle of IPEN was used. The strategy proposed uses different analytical techniques, such as alpha radiation meter, SEM-EDX and ICP-QMS to identify signatures of the uranium adhered to the swipe samples. In the swipe samples analysis, it was possible to identify particles of UO2F2 and UF4 through the morphological comparison and semi-quantitative analysis performed by SEM-EDX technique. The methods used in this work bring the average isotopic composition of the sample as a result, in which the enrichment (molar atomic fraction) ranged from 1.453 ± 0.023% to 18.24 ± 0.15% in the 235U isotope. Through of the external collections, a non-intrusive sampling, it was possible to identify handling activities of enriched material with molar atomic fraction of 1.453 ± 0.023% to 6.331 ± 0.055% in the 235U isotope, as well as the use of reprocessed material by means of the 236U isotope identification. The uncertainties obtained in this work to the n(235U)/n(238U) ratio varied from 0.40% to 1.68%.

Smarttelefoner med applikationer har öppnat upp för nya kommunikationsmöjligheter. Denna studie undersöker den kontaktskapande applikationen Tinder, utifrån användarnas upplevelse av applikationen. Tinder är en positionsbaserad kontaktskapande realtidsapplikation som har flera miljoner användare världen över. Varje användare måste koppla upp sin profil mot Facebook, varifrån profilbilder, namn, ålder och gemensamma vänner hämtas. I studien undersöktes hur unga vuxna i åldern 18-30år, bosatta i Stockholm förhåller sig till hur Tinders funktioner och gränssnitt bidragit till applikationens genomslag. Studien baseras på Normans sex designprinciper, enkätsvar från 120 personer samt intervjuer med användare inom målgruppen. Resultatet visade att anledningen till Tinders framgång är en kombination av tre faktorer. Den första är att applikationen förhåller sig till Normans designprinciper. Den andra är att det skapas en trygghetskänsla hos användarna genom att i Tinders fall koppla varje användare till dennes Facebook-konto, samt att marknadsföra applikationen på rätt sätt. Tinder lyckades med det sistnämnda genom att marknadsföra och utforma applikationen som en kontaktskapande applikation snarare än en dejtingapplikation, vilket lockar en något annorlunda målgrupp. / Smartphones with applications have created new communication opportunities. This study explores the application Tinder by examining the user experience. Tinder is a location-based application which has millions of users worldwide. Each user has to connect their profile to Facebook, from which Tinder gets the users' profile pictures, names, age and mutual friends. In the thesis, we examine how young adults of age 18 to 30, living in Stockholm, relate to how Tinder's functions and interface have contributed to the success of the application. The study is based on the six design principles created by Norman, a survey with 120 respondants that has used the application and interviews. The results show that the reason for Tinder's success is a combination of three factors. The first is that the application relates to Norman's six design principles. The second reason is that a sense of security created for the users of the profile's connection to Facebook. The third is that Tinder has been marketing their application not as a datingapplication, but as a way for people to meet others, which attracts a slightly different target group.