4,598 research outputs found
PRHOLO: 360º Interactive Public Relations
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’s attention, making the first contact between the clients and the company’s 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 57º (degrees), 180º and 360º, respectively.
From one to several Microsoft Kinects were used to develop the three interaction models, which allows
tracking and recognition of users’ 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
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® with 25
devices using Oulu’s 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¸ ˜oes
e tecnologias. Destas tecnologias, a LoRa ´e a que se tem destacado recentemente
devido `a sua capacidade de transmitir pacotes a longas distˆancias a baixos custos
energ´eticos. Al´em disso, esta tecnologia tamb´em utiliza bandas de frequˆencia n˜ao
licenciadas, e todos estes factores tornam poss´ıvel a construc¸ ˜ao de redes de baixo
custo energ´etico com grandes ´areas de cobertura a baixo custo monet´ario. Isto
torna LoRa muito apelativo para ambientes onde v´arios quil´ometros quadrados
precisam de ser cobertos para monitorizac¸ ˜ao, tais como a agricultura. Esta tese
centra-se principalmente no posicionamento de gateways numa rede LoRaWAN,
a fim de alcançar 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
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 fabricação e caracterização de sensores ultravioleta (UV) em substrato flexível com base em celulose nano-cristalina na forma de filmes fotónicos, tornando possível reconhecer diferentes polarizações de luz circularmente polarizada (LCP). Os filmes produzidos exibem uma estrutura quiral nemática esquerda capaz de filtrar LCP na gama da luz visível, onde LCP direita é refletida e LCP esquerda é transmitida (LCPD e LCPE, respetivamente), criando assim um hiato fotónico. Esta propriedade vai ser o foco do funcionamento do dispositivo final, possibilitando a produção de sinais eletrónicos distintos para as diferentes polarizações de luz incidida. Um dos principais objetivos deste trabalho é a modificação do hiato fotónico usando hidróxido de potássio, possibilitando uma modulação do espetro trabalhado (gama entre near-UV e visível). O segundo objetivo é a implementação do filme fotónico num sensor UV capaz de distinguir entre LCPD e LCPE. A camada sensível é produzida usando tinta de óxido de zinco (ZnO) e contactos de carbono, depositados através de screen-printing. O dispositivo foi encapsulado entre acetato de celulose e caracterizado. Analisando os resultados da caracterização ótica foi possível identificar uma transição do hiato fotónico para o azul com a adição do hidróxido de potássio (de um hiato nos 700 nm sem substituições para 430 nm com a substituição de 150%) resultando numa relação quásilinear entre o hiato fotónico e o aumento de hidróxido de potássio adicionado, sem alterações relevantes na estrutura do cristal. Caracterização elétrica revela uma distinção de sinal elétrico entre as duas polarizações entre 5-15%
Dialectical Polyptych: an interactive movie installation
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. “Dialectical
Polyptych” is an interactive movie included in a project called “Characters looking for a spectactor”, 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
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 ecrã: interatividade e cinema
Este trabalho propõe-se analisar aspetos relativos a processos de interação nas
relações entre espetador e personagem cinematográfica. Quando, em 1903, Justus D.
Barnes, dispara o seu revólver na direção do público, inaugura uma longa tradição de
chamamento do espetador para um papel mais ativo na narrativa fílmica. Neste sentido,
dividimos em dois momentos este estudo: um primeiro, onde serão identificados alguns
exemplos de filmes em que as personagens abandonam uma narrativa agrilhoada ao ecrã
e procuram, explicitamente, o espetador, umas vezes através de estratégias
morfológicas, outras através de soluções técnicas e/ou tecnológicas; e um segundo
momento, que aprofunda essas possibilidades tecnológicas e, ao invés de ir ao encontro
do espetador, prefere seduzi-lo e guiá-lo para dentro da narrativa. Nesta fase,
encontramos diferentes níveis de interatividade homem-máquina, onde o espetador tem
algum poder de decisão sobre a narrativa. A estrutura linear pré-definida tende a
esbater-se e a ideia de imersão na narrativa ganha uma nova dimensão. Na última 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, através de um processo de imersão, de um nível extradiagético para um nível
intradiagético.info:eu-repo/semantics/publishedVersio
Relações Virtuais: da sedução de Baudrillard à representação de papeis no Second Life
As comunidades virtuais proporcionam anonimato e privacidade, formando
espaços lúdicos ideais para a experimentação sexual. Estes laboratórios virtuais
possibilitam a recriação, interpretação e aniquilação de todos os tabus.
Os ciber-amantes gozam de uma liberdade total, por vezes extrema e obscura. É
o caso de um clube (criado por mulheres) inspirado em RPGs (rol playing games), cujo
tema é a violação. Estas mulheres expõem-se, através da Internet, a violações realizadas
por elas próprias.
De acordo com Sherry Turkle (TURKLE, 1995) a realidade virtual só pode ser
interessante se for baseada na realidade. No entanto, também é necessário concretizar
virtualmente o que não é concretizável na vida real. Este espaço pleno de significação
sexual e social é propício à simulação de situações que no, plano actual, não seriam
concretizáveis.info:eu-repo/semantics/publishedVersio
Disrupting the rent-a-car market through sharing economies
The World is changing.
As Tom Goodwin, Senior Vice President of Strategy and Innovation at Havas Media, would eloquently put it: “Uber, the world’s largest taxi company, owns no vehicles. Facebook, the world’s most popular media owner, creates no content… And Airbnb, the world’s largest accommodation provider, owns no real estate”. In that line of thought “Disrupting the Rent-a-Car Market Through Sharing Economies” 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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