4,594 research outputs found

    PRHOLO: 360¬ļ Interactive Public Relations

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    In the globalized world, possessing good products may not be enough to reach potential clients unless creative marketing strategies are well delineated. In this context, public relations are also important when it comes to capture the client‚Äôs attention, making the first contact between the clients and the company‚Äôs products, while being persuasive enough to make them confident that the company has the right products to fit their needs. Three virtual public relations installations were purposed in this chapter, combining technology with a human like public relations ability, capable of interacting with potential clients located in front of the installation, at angles of up to 57¬ļ (degrees), 180¬ļ and 360¬ļ, respectively. From one to several Microsoft Kinects were used to develop the three interaction models, which allows tracking and recognition of users‚Äô gestures and positions (heat map), sound sources, voice commands and face and body extraction of the user interacting with the installation.info:eu-repo/semantics/publishedVersio

    Optimal deployment of mobile gateways in LoRaWAN environments

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    The recent growth of the Internet of Things (IoT) has given rise to new applications and technologies. Of these technologies, LoRa is the one that has stood out recently due to its ability to transmit packets over long distances at low energy costs. In addition to this, this technology also uses unlicensed frequency bands, and all these factors make it possible to build low energy cost networks with large coverage areas at low monetary cost. This makes LoRa very appealing for environments where multiple square kilometers need to be covered for monitoring, such as agriculture. This thesis focuses primarily on positioning gateways in a Lo- RaWAN in order to achieve energy fairness in the network.The target in question is an environmental sensor network that monitors conditions inside tree canopies in an orange orchard in the Algarve, south of Portugal.The peculiar characteristics of these orange trees, with heights up to 3.5 m and very dense foliage, makes it a very challenging environment for radio waves propagation and causes a rapid drop in signal quality. The power consumption of the end-nodes of the network is defined by 7 combinations of spreading factor and bandwidth (0 to 6) where 0 represents the slowest and most reliable transmission at the cost of higher power consumption while 6 represents the opposite. The combination of bandwidth and spreading factor is denominated data rate. Environmental factors can negatively impact the quality of LoRa packets and the necessary power adjustments of the end-node to overcome this, and increase signal reliability, can easily define whether a device is able to transmit for 1 year or 10! The main factors that can affect signal quality are obstruction, distance and meteorology. In the case study, of these 3 factors, obstruction affects transmission quality the most. Most of the literature suggests solutions within the framework of optimizing the datarate optimization algorithm (ADR). ADR aims to minimize energy consumption while ensuring the best possible packet transmission rate and achieves this by changing the data rate based on the quality of the last 20 packets received.However, this optimization is done directly to individual end-nodes and does not solve the problem of energy fairness over the whole network because, regardless of how optimized this algorithm is, the algorithm cannot transcend the physical constraints imposed by the devices and the technology itself. Distance and obstruction will always be obstacles to signal quality. Since these physical constraints will always be present in a network and the solutions proposed by the literature only improve performance at the level of individual devices, this ends up creating a large lifetime discrepancy between devices depending on their placement. In the case of LHT65s, the discrepancy in device life expectancy is high. For example the difference between using a data rate of 0 or 5 is about 10 years. The solution proposed in this thesis to overcome this problem is to precompute the optimal position for the gateways in order to guarantee the highest life expectancy for the network. Given a number of available positions for the gateways and having a certain number of gateways less than the number of positions, the goal is to compute the optimal positioning of the gateways in order to maximize the overall network life expectancy by ensuring a fair energy consumption among different end-nodes. The first step in this process was to collect information about signal quality from a real case LoRaWAN deployment. This allowed to better understand the constraints and problems associated with its implementation. This was done using 25 LTH65 devices, 1 RAK 7244 gateway and Chirpstack as the framework to manage the network. Regarding the study of the algorithm before applying it to the practical case, a simulator was used to collect data. The simulator chosen for the development of the application was OMNet++, which besides being easier to use is also better documented than the other options considered. This simulator also offers a graphical interface with great detail that allows you to easily observe the behavior of the network. Using the Flora module it was simulated a LoRaWAN network with the structure suggested by the LoRa Alliance¬ģ with 25 devices using Oulu‚Äôs path loss model. The information obtained from this simulation was used as input and test for the algorithm that was compiled by CPLEX. In each simulation about 10,000 packets were sent per device and each experiment was repeated 30 times. The results show that the optimization model has the ability to identify the best placement for the gateway given a predefined locations and network geometry. This is due to the fact that the algorithm identifies the lowest value in the highest energy consumption per packet, and minimizing this value creates a balance of consumption among the devices and consequently extends the life expectancy of the network. It can then be concluded that this methodology is indeed efficient for deployments where changing network devices cannot be done frequently. Although it is not easy to relocate gateways in already implemented networks, but in new environments where monitoring and optimization are requirements, and these new environments are built considering the network structure, we can use this methodology since it has proven to be able to improve network life expectancy.O recente crescimento da Internet das Coisas (IoT) deu origem a novas aplicac¬ł ňúoes e tecnologias. Destas tecnologias, a LoRa ¬īe a que se tem destacado recentemente devido `a sua capacidade de transmitir pacotes a longas distňÜancias a baixos custos energ¬īeticos. Al¬īem disso, esta tecnologia tamb¬īem utiliza bandas de frequňÜencia nňúao licenciadas, e todos estes factores tornam poss¬īńĪvel a construc¬ł ňúao de redes de baixo custo energ¬īetico com grandes ¬īareas de cobertura a baixo custo monet¬īario. Isto torna LoRa muito apelativo para ambientes onde v¬īarios quil¬īometros quadrados precisam de ser cobertos para monitorizac¬ł ňúao, tais como a agricultura. Esta tese centra-se principalmente no posicionamento de gateways numa rede LoRaWAN, a fim de alcan√ßar a energy fairness na rede.(...)This work was supported by FCT (Foundation for Science and Technology) from Portugal within CEOT (Center for Electronic, Optoelectronic and Telecommunications) and UID/MULTI/00631/2020 project

    Cellulose Nanocrystal Based Chiral Structures for Photonic Applications

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    This thesis documents the fabrication and characterization of flexible ultraviolet (UV) sensors based on cellulose nanocrystals (CNC) as photonic films, for circularly polarized light sensing. The produced films exhibit an inherent left-handed chiral nematic structure which can be used as a filter for CPL in the visible range, where left CPL is reflected and right CPL is transmitted (LCPL and RCPL, respectively), creating a photonic bandgap. This property will be one of the focuses of the final device, allowing the production of specific electronic outputs depending on the polarization of the irradiating light. One of the main objectives of this work is the modulation of the photonic bandgap using potassium hydroxide, allowing for the tuna-bility of the workable spectrum (near-UV to red visible light). The second objective is the im-plementation of the photonic film into a UV sensor capable of distinguishing between R- and LCPL. The sensing layer is a zinc oxide (ZnO) ink with carbon contacts, deposited by screen-printing. The device was then encapsulated between cellulose acetate and characterized. Op-tical characterization shows a blue shift of the photonic bandgap with the addition of potas-sium hydroxide (from 700 nm with no substitutions to 430 nm with 150% substitution) result-ing in a near-linear relation between the photonic bandgap and increasing addition of the hy-droxide without relevant modification in the structure of the crystal. Electrical characterization presents an electronic signal distinction between left and right CPL ranging from 5-15%.A seguinte tese documenta a fabrica√ß√£o e caracteriza√ß√£o de sensores ultravioleta (UV) em substrato flex√≠vel com base em celulose nano-cristalina na forma de filmes fot√≥nicos, tornando poss√≠vel reconhecer diferentes polariza√ß√Ķes de luz circularmente polarizada (LCP). Os filmes produzidos exibem uma estrutura quiral nem√°tica esquerda capaz de filtrar LCP na gama da luz vis√≠vel, onde LCP direita √© refletida e LCP esquerda √© transmitida (LCPD e LCPE, respetivamente), criando assim um hiato fot√≥nico. Esta propriedade vai ser o foco do funcionamento do dispositivo final, possibilitando a produ√ß√£o de sinais eletr√≥nicos distintos para as diferentes polariza√ß√Ķes de luz incidida. Um dos principais objetivos deste trabalho √© a modifica√ß√£o do hiato fot√≥nico usando hidr√≥xido de pot√°ssio, possibilitando uma modula√ß√£o do espetro trabalhado (gama entre near-UV e vis√≠vel). O segundo objetivo √© a implementa√ß√£o do filme fot√≥nico num sensor UV capaz de distinguir entre LCPD e LCPE. A camada sens√≠vel √© produzida usando tinta de √≥xido de zinco (ZnO) e contactos de carbono, depositados atrav√©s de screen-printing. O dispositivo foi encapsulado entre acetato de celulose e caracterizado. Analisando os resultados da caracteriza√ß√£o √≥tica foi poss√≠vel identificar uma transi√ß√£o do hiato fot√≥nico para o azul com a adi√ß√£o do hidr√≥xido de pot√°ssio (de um hiato nos 700 nm sem substitui√ß√Ķes para 430 nm com a substitui√ß√£o de 150%) resultando numa rela√ß√£o qu√°silinear entre o hiato fot√≥nico e o aumento de hidr√≥xido de pot√°ssio adicionado, sem altera√ß√Ķes relevantes na estrutura do cristal. Caracteriza√ß√£o el√©trica revela uma distin√ß√£o de sinal el√©trico entre as duas polariza√ß√Ķes entre 5-15%

    Dialectical Polyptych: an interactive movie installation

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    Most of the known video games developed by important software companies usually establish an approach to the cinematic language in an attempt to create a perfect combination of narrative, visual technique and interaction. Unlike most video games, interactive film narratives normally involve an interruption in time whenever the spectator has to make choices. ‚ÄúDialectical Polyptych‚ÄĚ is an interactive movie included in a project called ‚ÄúCharacters looking for a spectactor‚ÄĚ, which aims to give the spectator on-the-fly control over film editing, thus exploiting the role of the spectator as an active subject in the presented narrative. This paper presents an installation based on a mobile device, which allows seamless real-time interactivity with the movie. Different finger touches in the screen allow the spectator to alternate between two parallel narratives, both producing a complementary narrative, and change the angle or shot within each narrative.info:eu-repo/semantics/publishedVersio

    Cadavre Exquis: motion-controlled interactive film

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    This interactive film, a variation on the surrealist game Cadavre Exquis, seeks the possibility of subverting the filmic discourse by exploring psychosomatic processes that may give the viewer different perceptions of cinematic time, by providing the possibility of intervening into the narrative in a disruptive way.info:eu-repo/semantics/publishedVersio

    Personagens que saem e que entram no ecr√£: interatividade e cinema

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    Este trabalho prop√Ķe-se analisar aspetos relativos a processos de intera√ß√£o nas rela√ß√Ķes entre espetador e personagem cinematogr√°fica. Quando, em 1903, Justus D. Barnes, dispara o seu rev√≥lver na dire√ß√£o do p√ļblico, inaugura uma longa tradi√ß√£o de chamamento do espetador para um papel mais ativo na narrativa f√≠lmica. Neste sentido, dividimos em dois momentos este estudo: um primeiro, onde ser√£o identificados alguns exemplos de filmes em que as personagens abandonam uma narrativa agrilhoada ao ecr√£ e procuram, explicitamente, o espetador, umas vezes atrav√©s de estrat√©gias morfol√≥gicas, outras atrav√©s de solu√ß√Ķes t√©cnicas e/ou tecnol√≥gicas; e um segundo momento, que aprofunda essas possibilidades tecnol√≥gicas e, ao inv√©s de ir ao encontro do espetador, prefere seduzi-lo e gui√°-lo para dentro da narrativa. Nesta fase, encontramos diferentes n√≠veis de interatividade homem-m√°quina, onde o espetador tem algum poder de decis√£o sobre a narrativa. A estrutura linear pr√©-definida tende a esbater-se e a ideia de imers√£o na narrativa ganha uma nova dimens√£o. Na √ļltima parte do artigo, visitaremos mais de perto um caso concreto: o filme interativo Neblina, o primeiro filme da trilogia Os Caminhos que se bifurcam que procura transferir o espetador, atrav√©s de um processo de imers√£o, de um n√≠vel extradiag√©tico para um n√≠vel intradiag√©tico.info:eu-repo/semantics/publishedVersio

    Rela√ß√Ķes Virtuais: da sedu√ß√£o de Baudrillard √† representa√ß√£o de papeis no Second Life

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    As comunidades virtuais proporcionam anonimato e privacidade, formando espa√ßos l√ļdicos ideais para a experimenta√ß√£o sexual. Estes laborat√≥rios virtuais possibilitam a recria√ß√£o, interpreta√ß√£o e aniquila√ß√£o de todos os tabus. Os ciber-amantes gozam de uma liberdade total, por vezes extrema e obscura. √Č o caso de um clube (criado por mulheres) inspirado em RPGs (rol playing games), cujo tema √© a viola√ß√£o. Estas mulheres exp√Ķem-se, atrav√©s da Internet, a viola√ß√Ķes realizadas por elas pr√≥prias. De acordo com Sherry Turkle (TURKLE, 1995) a realidade virtual s√≥ pode ser interessante se for baseada na realidade. No entanto, tamb√©m √© necess√°rio concretizar virtualmente o que n√£o √© concretiz√°vel na vida real. Este espa√ßo pleno de significa√ß√£o sexual e social √© prop√≠cio √† simula√ß√£o de situa√ß√Ķes que no, plano actual, n√£o seriam concretiz√°veis.info:eu-repo/semantics/publishedVersio

    Disrupting the rent-a-car market through sharing economies

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    The World is changing. As Tom Goodwin, Senior Vice President of Strategy and Innovation at Havas Media, would eloquently put it: ‚ÄúUber, the world‚Äôs largest taxi company, owns no vehicles. Facebook, the world‚Äôs most popular media owner, creates no content‚Ķ And Airbnb, the world‚Äôs largest accommodation provider, owns no real estate‚ÄĚ. In that line of thought ‚ÄúDisrupting the Rent-a-Car Market Through Sharing Economies‚ÄĚ is a Directed Research Work Project with the purpose of building a Business Plan for launching a Mobile Peer-to-Peer Car Rental Platform in Portugal, while creating Consumer Value and driving sustainable competitive advantage
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