Este trabalho aborda o estudo de um sistema de referência inercial de posição e atitude e um sistema de controle para um helicóptero autônomo utilizando, como base para formulação e testes, o modelo linearizado da aeronave Yamaha R-MAX. Um sistema de referência inercial (INS) e um sistema de referência de atitude e orientação (AHRS) são utilizados para estimar a posição e atitude da aeronave, e estimadores robustos baseados no filtro de Kalman são empregados para minimizar os efeitos de incertezas paramétricas. É utilizada uma estratégia de controle em cascata com três malhas consistindo de uma malha interna para garantir a estabilidade do helicóptero (são utilizadas as técnicas LQR e H \'INFINITO\', separadamente), uma malha intermediária baseada em linearização por realimentação (FLC) para desacoplar os pares entrada/saída e uma malha externa baseada em um controlador proporcional-derivativo (PD) para permitir o rastreamento da trajetória. Resultados de simulação são apresentados para avaliar o desempenho de cada abordagem. / This work concerns the study of an inertial reference system and a control system for an autonomous helicopter using, as basis for the formulation and testing, the linearized mo del of the aircraft Yamaha R-MAX. An inertial navigation system (INS) and an attitude and orientation reference system (AHRS) are used to estimate the position and attitude of the aircraft and robust estimators based on Kalman filter are employed to minimize the effects of parametric uncertainties. A cascaded control architecture with three control methodologies is used, consisting of an inner-loop to ensure stability of the helicopter (the LQR and H \'INFINITE\' techniques are used, separately), a mid-loop based on linearization feedback (FLC) to decouple the dynamics ofthe lateral, longitudinal, vertical and heading axes and an outer-loop based on a proportional-derivative (PD) controller to enable trajectory tracking. Simulation results are presented to evaluate the performance of each approach.

A market survey conducted on students currently studying at different universities in Sweden showed that a majority of students either were in need or previously had been in need of a platform where solely students can buy and sell everyday services to each other. Furthermore, the survey showed that a majority of the students in question found it very important that a web application is easily navigated and that they can find what they are looking for with as few clicks as possible. The purpose of this study was to examine how different aspects of a web application intended for students in Sweden affects navigability in terms of the number of clicks needed to perform various tasks on said web application. This was done by iteratively developing and assessing a website based on research within the area, navigability measures as well as qualitative and quantitative feedback from user testing. The results suggest that a higher degree of navigability was obtained when the structure of the web application was made broader through more direct links to and from different nodes. It also seems to be of importance that users were certain of where a click of a button would take them in the overall structure, through effective labeling and placement.

Denna studie utforskar fotgängares möjligheter att orientera sig och ta sig fram i stadsmiljöer. Orienterbarhet kan förväntas få en allt större betydelse i samband med att gångtrafiken får en viktigare roll i städers transportsystem. Samtidigt vistas allt fler människor i omgivningar de är sämre förtrogna med, till följd av den ökade mobiliteten som globaliseringen har medfört. Uppgiften för denna studie är därför att utforska orienterbarhetens betydelse för staden och dess invånare, att kartlägga orienteringssituationen i Stockholm och att undersöka hur den kan förbättras. Studien inleds med en genomgång av teorier och resonemang gällande orienterbarhet, vil- ken fungerar som en teoretisk bakgrund till de efterföljande delarna. Orienterbarhet definieras här som en egenskap som beskriver svårighetsgraden att bestämma sin position och planera sin rörelse i en stadsmiljö. Hur själva orienteringen går till beskrivs som en process där hjärnan strukturerar sinnesintrycken i en kognitiv representation av verkligheten; en mental karta eller bild. Om denna process underlättas av god orienterbarhet kan staden gynnas inom fyra identifierade huvudområden; stadens gångvänlighet, individens välbefinnande, tillgänglighet till stadens funktioner samt besökarvänlighet. Förbättrad orienterbarhet kan inom dessa områden väntas ge ekonomiska, sociala och ekologiska vinster. Stockholms orienteringssituation kartläggs sedan med ett brett tillvägagångssätt. Orienterbarhetens betydelse i planeringen undersöks, liksom viktiga aktörers arbetssätt och synsätt. Grundförutsättningarna för orientering bedöms med hjälp av rumsliga analyser, och en undersökning av hur fotgängare upplever stadens orienterbarhet görs. Av undersökningarna framgår det att grundförutsättningarna för orientering är relativt goda i Stockholm som helhet, men att Cityområdet innehåller ett flertal brister. Det finns med andra ord ett behov av åtgärder för förbättrad orienterbarhet. Det tredje kapitlet presenterar tre informationssystem för fotgängare, hämtade från tre andra europeiska städer av varierande storlek och karaktär. De tre projekten illustrerar hur orienterbarheten kan förbättras med hjälp av orienteringsinformation. Även om grundförutsättningarna för orientering är förhållandevis goda, visar projekten att det kan finnas starka incitament för att stödja fotgängares orientering. Informationssystem för fotgängare krävs när stadsmiljön i sig inte räcker till, men är också av nytta när grundförutsättningarna är tillräckliga. Studien avslutas med en diskussion kring de slutsatser som gjorts, och vilken innebörd de kan tänkas ha för Stockholm som ”promenadstad”. Det konstateras att de utländska projektens tillvägagångssätt i viss mån även skulle kunna tillämpas i Stockholm. Slutligen ges ett antal rekommendationer av åtgärder som kan förbättra orienteringssituationen. Dessa innefattar utveckling och planering av ett informationssystem för fotgängare, som till en början omfattar Cityområdet. / This master thesis explores the conditions under which pedestrians navigate in urban environments. The importance of urban navigability is likely to increase, as walking becomes a more prioritised transport mode. There is also a tendency of more pedestrians moving beyond their accustomed bounds, as a result of the increased mobility of a more globalised world. The task of this thesis is to explore the effects of urban navigability on the city and its inhabitants, as well as to examine the wayfinding situation in Stockholm and possible ways to improve it. The thesis begins with a review of theories and reasonings concerning urban navigability, which forms the theoretical framework for the following parts. Urban navigability is defined as a property determining the ease, at which orientation and movement is possible in an urban environment. The pedestrian capability of reading the environment is described as a process where sensory impressions form a cognitive representation; a mental map or image. If this process is facilitated by the urban navigability, gains can be made in four main fields; urban walkability, individual wellbeing, accessibility and visitor friendliness. This is expected to bring economical, social and environmental benefits. The wayfinding situation is subsequently examined with a wide approach. The presence of wayfinding issues is examined in planning documents and among organisations engaged with city development. The physical conditions for pedestrian wayfinding are assessed with different methods of spatial analysis. In addition, a pedestrian survey is carried out to examine how people in general experience wayfinding in Stockholm. The studies reveal that the physical conditions for wayfinding are fairly good in Stockholm as a whole, while some weaknesses still can be found in the ‘City’ district. This implies a need of improvement; at least in the innermost part of the city. The third chapter presents three pedestrian wayfinding systems, selected from three other european cities. The three projects show how urban navigability can be improved by means of spatial information. Even in cases where physical conditions for wayfinding are acceptable, there may be strong incentives to facilitate pedestrian wayfinding. Wayfinding systems are needed when the environment lacks legibility in itself, but they are also profitable in cases where the physical conditions are ‘sufficient’. The thesis ends with a discussion about the findings and their possible meanings for Stockholm as a walkable city. It is suggested that some of the previously presented approaches are applicable in Stockholm as well. Finally some recommendations are given regarding improvements of the current wayfinding situation. These include the development of a pedestrian wayfinding system, which initially would cover the ‘City’ district of Stockholm.

The primary aim of this study was to examine the effects of a web application’s navigability on user satisfaction. This was studied by developing a web application for the rental of pri- vate belongings such as tools, party equipment, outfits, et cetera. The study’s scope was hav- ing students at Linköping University as the target group. During the development phase, two different user tests were conducted on two different versions of the web application to obtain feedback on important factors within navigability such as functionalities, design, and layout. Said factors were tested with methods such as Concurrent Think-Aloud (CTA), Smith’s Mea- sure of Lostness, and Likert-styled questions. The first test provided a variety of feedback that, by applying retrospective probing, resulted in major improvements for the second user test. The study shows that in designing user tests it is important to have a widespread test group, test users without relations, and longer than one week between different iterations of a test. The study concludes that a thumbnail system is preferred over displaying products in a list. Moreover, tests showed that feedback and communication from the system improved the user experience. / Studiens huvudsakliga syfte var att undersöka hur en webbapplikations navigerbarhet påverkar användarupplevelsen. Detta gjordes genom att en webbapplikation för uthyrning av privatägda prylar såsom verktyg, festutrustning, utklädnader, etcetera utvecklades. Stu- dien hade en tydlig omfattning med studenter från Linköpings Universitet som målgrupp. Under utvecklingsfasen utfördes användartester på två olika iterationer av webbapplikatio- nen vid separata tillfällen. Detta gjordes för att samla in respons och åsikter kring centrala faktorer inom navigerbarhet, såsom funktionalitet, design och layout. Dessa faktorer testades med en rad metoder, till exempel Concurrent Think-Aloud (CTA), Smith’s Measure of Lost- ness och Likert-Styled questions. Det första testet tillhandahöll respons som då retrospektiv sondering applicerades medförde betydande förbättringar av webbapplikationen inför det andra testet. Studien visar på en rad premisser som är centrala då användartester utförs. Det är då viktigt att ha en hög variation på testgruppens deltagare, att utföra tester på deltagare som inte har någon relation till varandra, samt att vänta längre än en vecka mellan olika test. Ett antal slutsatser dras från studien. En av dessa är att thumbnail-system föredras över att visa produkterna i en lista. Testen visade också att tydlig kommunikation från systemet ökade användarvänligheten.

A survey, carried out and answered by students at Linköping University proved that 92.6% of the surveyees are interested in buying second-hand course literature. Numerous retailers exist for this market, however the problems with the solutions at the time of the survey are clear; lack of structure and absence of filtering and search functions. Therefore, the thesis aims to create an e-commerce for second-hand course literature with good usability with regards to good navigability for students by applying scientific theories and the feedback of user tests at two separate iterations. The result was Bokhyllan, a web application where buyers and sellers meet to exchange second-hand course literature for money. The conclusion was that the navigation bar, visual confirmations after actions, useful search and filtering functions, and the layout and placement of links make up decisive roles in the navigability of web applications. A relevant addition to this report within the key area would be to investigate different age groups, as this report solely delimits to students. / En enkätundersökning som utfördes och besvarades av studenter vid Linköpings universitet påvisade att 92,6% av enkätbesvararna är intresserade av att köpa begagnad kurslitteratur. Ett flertal aktörer existerar för denna marknad men problemen med lösningarna vid enkätens tillfälle är tydliga; brist på struktur och avsaknad av filtrerings- och sökfunktioner. Arbetet ämnar därmed att skapa en e-shop för begagnad kurslitteratur med god användbarhet med avseende på god navigerbarhet för studenter genom att applicera vetenskapliga teorier samt återkopplingen från användartester vid två olika iterationer. Resultatet blev Bokhyllan, en webbapplikation där köpare och säljare möts för att utbyta begagnad kurslitteratur mot pengar. Slutsatsen drogs att navigationsmenyn, visuell bekräftelse vid handlingar, användbara sök- och filtreringsfunktioner samt länkars utformning och placering utgör avgörande roller för webbapplikationers navigerbarhet. En relevant påbyggnad för detta arbete inom huvudområdet skulle vara att undersöka olika åldersgrupper, då denna rapport endast avgränsar sig till studenter.

The purpose of this study was to develop a web application where users can advertise home-cooked meals for other users to buy while focusing on identifying the critical design and technological features that enhance navigability and credibility in a web application designed for advertising and selling home-cooked lunch boxes to students, and how these features contribute to optimising the purchasing process. Based on a pre-study where market analysis, user testing on similar applications, and prototypes were examined the team defined an outline for the agile development process. The development followed some best practices regarding version handling, development methodology, database management, etc. The research culminated in a fully functional and aesthetically pleasing web application where the results and conclusions were solidified by extensive user and unit testing. Concluded by the research study, a navigable and credible web application can be created by implementing a simple base layout with a few interactive elements, carefully chosen colours, and creating credibility through user ratings and high-quality pictures. Moreover, the analysed factors are proved to streamline the purchasing process. / Denna forskning genomfördes som en kandidatuppsats vid Linköpings universitet. Syftet var att utveckla en webbapplikation där användare kan annonsera hemlagade måltider för andra användare att köpa. Fokuset låg på forskningsfrågan där analysen syftar till att identifiera kritiska design- och teknikaspekter som förbättrar navigerbarheten och trovärdigheten i en webbapplikation utformad för att annonsera och sälja hemlagade lunchlådor till studenter, och hur dessa funktioner bidrar till att optimera köpprocessen. Baserat på en förstudie där marknadsanalys, användartester på liknande applikationer och prototyper undersöktes, definierade teamet en agil utvecklingsprocess. Utvecklingen följde vissa ”best practices” avseende versionshantering, utvecklingsmetodik, databashantering etc. Forskningen kulminerade i en fullt fungerande och estetiskt tilltalande webbapplikation där resultaten och slutsatserna stärktes genom omfattande användar- och enhetstester. Konkluderat var att en navigerbar och trovärdig webbapplikation kan skapas genom att implementera en enkel baslayout med ett fåtal interaktiva element, noggrant utvalda färger och skapad trovärdighet genom användarbetyg och högkvalitativa bilder. Dessutom visade sig de analyserade faktorerna effektivisera köpprocessen.

Este trabalho apresenta um sistema de navegação autônoma para veículos terrestres com foco em ambientes não estruturados, tendo como principal meta aplicações em campos abertos com vegetação esparsa e em cenário agrícola. É aplicada visão computacional como sistema de percepção principal utilizando uma câmera estéreo em um veículo com modelo cinemático de Ackermann. A navegação é executada de forma deliberativa por um planejador baseado em malha de estados sobre um mapa de custos e localização por odometria e GPS. O mapa de custos é obtido através de um modelo de ocupação probabilístico desenvolvido fazendo uso de uma OctoMap. É descrito um modelo sensorial para atualizar esta OctoMap a partir da informação espacial proveniente de nuvens de pontos obtidas a partir do método de visão estéreo. Os pontos são segmentados e filtrados levando em consideração os ruídos inerentes da aquisição de imagens e do processo de cálculo de disparidade para obter a distância dos pontos. Os testes foram executados em ambiente de simulação, permitindo a replicação e repetição dos experimentos. A modelagem do veículo foi descrita para o simulador físico Gazebo de acordo com a plataforma real CaRINA I (veículo elétrico automatizado do LRM-ICMC/USP), levando-se em consideração o modelo cinemático e as limitações deste veículo. O desenvolvimento foi baseado no ROS (Robot Operating System) sendo utilizada a arquitetura básica de navegação deste framework a partir da customização dos seus componentes. Foi executada a validação do sistema no ambiente real em cenários com terreno irregular e obstáculos diversos. O sistema apresentou um desempenho satisfatório tendo em vista a utilização de uma abordagem baseada em apenas uma câmera estéreo. Nesta dissertação são apresentados os principais componentes de um sistema de navegação autônoma e as etapas necessárias para a sua concepção, assim como resultados de experimentos simulados e com o uso de um veículo autônomo real / This work presents a system for autonomous vehicle navigation focusing on unstructured environments, with the primary goal applications in open fields with sparse vegetation, unstructured environments and agricultural scenario. Computer vision is applied as the main perception system using a stereo camera in a car-like vehicle with Ackermann kinematic model. Navigation is performed deliberatively using a path planner based on a lattice state space over a cost map with localization by odometry and GPS. The cost map is obtained through a probabilistic occupation model developed making use of an OctoMap. It is described a sensor model to update the spatial occupancy information of the OctoMap from a point cloud obtained by stereo vision. The points are segmented and filtered taking into account the noise inherent in the image acquisition and calculation of disparity to obtain the distance from points. Tests are performed in simulation, allowing replication and repetition of experiments. The modeling of the vehicle is described to be used in the Gazebo physics simulator in accordance with the real platform CaRINA I (LRM-ICMC/USP automated electrical vehicle) taking into account the kinematic model and the limitations of this vehicle. The development is based on ROS (Robot Operating System) and its basic navigation architecture is customized. System validation is performed on real environment in scenarios with different obstacles and uneven terrain. The system shows satisfactory performance considering a simple configuration and an approach based on only one stereo camera. This dissertation presents the main components of an autonomous navigation system and the necessary steps for its conception as well as results of experiments in simulated and using a real autonomous vehicle

Este trabalho apresenta um sistema de navegação autônoma para veículos terrestres com foco em ambientes não estruturados, tendo como principal meta aplicações em campos abertos com vegetação esparsa e em cenário agrícola. É aplicada visão computacional como sistema de percepção principal utilizando uma câmera estéreo em um veículo com modelo cinemático de Ackermann. A navegação é executada de forma deliberativa por um planejador baseado em malha de estados sobre um mapa de custos e localização por odometria e GPS. O mapa de custos é obtido através de um modelo de ocupação probabilístico desenvolvido fazendo uso de uma OctoMap. É descrito um modelo sensorial para atualizar esta OctoMap a partir da informação espacial proveniente de nuvens de pontos obtidas a partir do método de visão estéreo. Os pontos são segmentados e filtrados levando em consideração os ruídos inerentes da aquisição de imagens e do processo de cálculo de disparidade para obter a distância dos pontos. Os testes foram executados em ambiente de simulação, permitindo a replicação e repetição dos experimentos. A modelagem do veículo foi descrita para o simulador físico Gazebo de acordo com a plataforma real CaRINA I (veículo elétrico automatizado do LRM-ICMC/USP), levando-se em consideração o modelo cinemático e as limitações deste veículo. O desenvolvimento foi baseado no ROS (Robot Operating System) sendo utilizada a arquitetura básica de navegação deste framework a partir da customização dos seus componentes. Foi executada a validação do sistema no ambiente real em cenários com terreno irregular e obstáculos diversos. O sistema apresentou um desempenho satisfatório tendo em vista a utilização de uma abordagem baseada em apenas uma câmera estéreo. Nesta dissertação são apresentados os principais componentes de um sistema de navegação autônoma e as etapas necessárias para a sua concepção, assim como resultados de experimentos simulados e com o uso de um veículo autônomo real / This work presents a system for autonomous vehicle navigation focusing on unstructured environments, with the primary goal applications in open fields with sparse vegetation, unstructured environments and agricultural scenario. Computer vision is applied as the main perception system using a stereo camera in a car-like vehicle with Ackermann kinematic model. Navigation is performed deliberatively using a path planner based on a lattice state space over a cost map with localization by odometry and GPS. The cost map is obtained through a probabilistic occupation model developed making use of an OctoMap. It is described a sensor model to update the spatial occupancy information of the OctoMap from a point cloud obtained by stereo vision. The points are segmented and filtered taking into account the noise inherent in the image acquisition and calculation of disparity to obtain the distance from points. Tests are performed in simulation, allowing replication and repetition of experiments. The modeling of the vehicle is described to be used in the Gazebo physics simulator in accordance with the real platform CaRINA I (LRM-ICMC/USP automated electrical vehicle) taking into account the kinematic model and the limitations of this vehicle. The development is based on ROS (Robot Operating System) and its basic navigation architecture is customized. System validation is performed on real environment in scenarios with different obstacles and uneven terrain. The system shows satisfactory performance considering a simple configuration and an approach based on only one stereo camera. This dissertation presents the main components of an autonomous navigation system and the necessary steps for its conception as well as results of experiments in simulated and using a real autonomous vehicle

Background: In the last decade, flow diversion (FD) has been established as hemodynamic treatment for cerebral aneurysms arising from proximal and distal cerebral arteries. However, two significant limitations remain—the need for 0.027” microcatheters required for delivery of most flow diverting stents (FDS), and long-term dual anti-platelet therapy (DAPT) in order to prevent FDS-associated thromboembolism, at the cost of increasing the risk for hemorrhage. This study reports the experience of three neurovascular centers with the p64MW-HPC, a FDS with anti-thrombotic coating that is implantable via a 0.021” microcatheter. Materials and methods: Three neurovascular centers contributed to this retrospective analysis of patients that had been treated with the p64MW-HPC between March 2020 and March 2021. Clinical data, aneurysm characteristics, and follow-up results, including procedural and post-procedural complications, were recorded. The hemodynamic effect was assessed using the O’Kelly–Marotta Scale (OKM). Results: Thirty-two patients (22 female, mean age 57.1 years) with 33 aneurysms (27 anterior circulation and six posterior circulation) were successfully treated with the p64MW-HPC. In 30/32 patients (93.75%), aneurysmal perfusion was significantly reduced immediately post implantation. Follow-up imaging was available for 23 aneurysms. Delayed aneurysm perfusion (OKM A3: 8.7%), reduction in aneurysm size (OKM B1-3: 26.1%), or sufficient separation from the parent vessel (OKM C1-3 and D1: 65.2%) was demonstrated at the last available follow-up after a mean of 5.9 months. In two cases, device thrombosis after early discontinuation of DAPT occurred. One delayed rupture caused a caroticocavernous fistula. The complications were treated sufficiently and all patients recovered without permanent significant morbidity. Conclusion: Treatment with the p64MW-HPC is safe and feasible and achieves good early aneurysm occlusion rates in the proximal intracranial circulation, which are comparable to those of well-established FDS. Sudden interruption of DAPT in the early post-interventional phase can cause in-stent thrombosis despite the HPC surface modification. Deliverability via the 0.021” microcatheter facilitates treatment in challenging vascular anatomies.

S’inscrivant à l’intersection des champs du marketing expérientiel et des théories des systèmes d’information et d’interaction homme-machine, ce travail de recherche doctorale étudie les spécificités de l’expérience de shopping dans un environnement commercial en 3D enrichi de dispositifs de réalité virtuelle. Particulièrement, il étudie les facteurs d’accès à l’expérience d’immersion et de présence dans cet environnement et ses conséquences sur les intentions comportementales. La revue de la littérature et la phase qualitative triangulée ont permis de mettre en évidence l’importance de trois facteurs clés d’accès à l’expérience et à son enrichissement ainsi que le rôle central du processus immersion – présence. Une expérimentation mise en oeuvre dans un « véritable » environnement commercial en 3D nous a permis d’étudier de manière concomitante les effets des différents facteurs à savoir : la navigabilité du site web (par le biais d’une manipulation liée à la présence/l’absence d’un map interactif), la richesse sensorielle de l’environnementcommercial (par le biais de la manipulation des couleurs et de la musique diffusée) et la sociabilité (par le biais de la manipulation de la présence/l’absence d’un vendeur virtuel) sur l’immersion sensorielle et la présence. Les conséquences sur les intentions comportementales ont également été investiguées. Les contributions théoriques, méthodologiques et managériales sont nombreuses. / As part of the intersection of the fields of experiential marketing and the theories of information systems and human-computer interaction, this doctoral research work investigates the specificities of the shopping experience in a 3D commercial environment enriched with virtual reality devices. In particular, it studies the factors of access to the immersion and presence experience in thisenvironment and its consequences on behavioral intentions. The review of the literature and the triangulated qualitative phase made it possible to highlight the importance of three key factors of access to the experience and its enrichment as well as the central role of the immersion - presence process. An experiment implemented in a "real" commercial environment in 3D allowed us to studyconcomitantly the effects of the various factors namely: the navigability of the website (through a manipulation related to the presence / l lack of an interactive map), the sensory wealth of the commercial environment (through the manipulation of colors and diffused music) and sociability (through the manipulation of the presence / absence of 'a virtual seller) on sensory immersion and presence. The consequences on behavioral intentions have also been investigated. Theoretical,methodological and managerial contributions are numerous.