1,656 research outputs found
Organizational transformation through knowledge management : an internship at Luxembourg-slovenian business club
Internship Report presented as the partial requirement for obtaining a Master's degree in Information Management, specialization in Knowledge Management and Business IntelligenceThe purpose of this report is to describe a five month internship that the student did at the Slovenian non-profit organization Luxembourg-Slovenian Business Club (LSBC). This internship report stands as partial requirement for obtaining the Master Degree in Information Management with specialization in Knowledge Management and Business Intelligence. Methodologies and the framework followed were largely based on knowledge acquired through the guidance of Nova IMS Information Management Master.
The main objective of this internship was to better understand the impact of information on a business context and how to foment a knowledge-based environment. In-depth, the aim was determining the information flow as it stands, identify bottlenecks and help growing a knowledge creation culture while shortening the gap inside the organization and between the organization and its members (both individuals and organizations). The main areas affected by this internship were Knowledge Management, Information Systems and Enterprise 2.0.
This report starts by giving an introduction to context and goals where the internship is inserted upon, followed by a detailed description of the background of the organization itself. After this section, it follows literature background focused on Knowledge Management areas - all subjects that were relevant for the internship practical work. Subsequently, an explanation of the of internship objectives and the path to achieve them is further discussed. Also, a presentation of the completed tasks results, followed by a critical opinion about them. Finally, possible future work endeavours that can follow up this project are then present as well as a pragmatic reflexion of the internship.
As a result of this report, improvements in information handling and some applied methodologies regarding Knowledge Management will be integrated in the organization. Hopefully, it will also bring to this organization new opportunities to develop business, to establish new partnerships while simultaneously expanding LSBC network of contacts
Study and implementation of an advanced transceiver for 5G
With the years passing by, the users of mobile networks present higher needs and
demands when it comes to e ective download and upload data rates. The fth generation
of mobile communications assumes the concretization of binary rates above 1
Gbps to be achieved by any ordinary user. To ful l this requirement, it was necessary to
undertake a study and development of a system using the 4th Generation of Mobile Communications
(4G) waveform to lessen the need for adding new modules and increasing
the complexity of mobile network systems. The main goal is to develop an Orthogonal
Frequency Division Multiplexing (OFDM) waveform simulator for 5th Generation of Mobile
Communications (5G) using Quadrature Amplitude Modulation (QAM), simulate
its performance to compare with the theoretical one and perform laboratorial tests. In
this study the channel estimation is carried out and we evaluated the performance of Bit
Error Rate (BER) and Error Vector Magnitude (EVM) as study metrics and parallels
the usual transmission loss models for indoor and free-space communications. The study
and experiments end in resulting mobile uncoded and convolutional hard decision OFDM
communications up to 5.9 Gbps of e ective data rate and the results and measurements
were obtained inside the laboratory environment, with a signal carrier of 3.5GHz and 2dB
of both antennas gain and 26dB of ampli er gain at distances up to 4 meters between the
two antennas. The best result obtained considering the highest data rate achieved was a
256-QAM uncoded OFDM communication at 5.9 Gbps on a 4 meters distance between
antennas.A quinta geração de redes móveis prevê a concretização de ritmos binários acima
de 1 Gbps ao acesso de qualquer utilizador comum. Para concretizar esse requisito,
foi necessário levar a cargo um estudo e desenvolvimento de um sistema que utilize a
forma de onda do 4a Geração de Comunicações Móveis (4G) para diminuir eventuais
necessidades de adição de novos módulos e aumento da complexidade dos sistemas de
redes móveis. O objetivo concreto é o desenvolvimento de um simulador de forma de
onda de Multiplexação por Divisão de Frequência Ortogonal (OFDM) que atinja as
taxas efetivas de dados para a 5a Geração de Comunicações Móveis (5G) utilizando
Modulação de Amplitude em Quadratura (QAM), realizar simulações para averiguar o
normal funcionamento de acordo com a teoria e realizar testes laboratoriais. Neste estudo
é efetuada a estimação de canal, são avaliadas as performances da Taxa de Erro de Bits
(BER) e da Magnitude do Vetor de Erro (EVM) como métricas de estudo e efetuado um
paralelismo com os modelos de perdas de transmissão usuais para comunicações indoor e
de espaço livre. O estudo e os testes laboratoriais concluem-se em comunicações OFDM
não codi cado e com decisão abrupta em códigos convolucionais efetuadas até velocidades
efetivas de 5.9 Gbps de dados e foram obtidos os resultados e medições num ambiente de
laboratório, com uma portadora de 3.5 GHz, com o ganho de ambas as antenas de 2dB
e um ampli cador com um ganho de 26dB em distâncias até aos 4 metros entre as duas
antenas. O melhor resultado obtido em termos de velocidade de transmissão de dados
foi a comunicação 256-QAM OFDM não codi cado atingindo os 5.9 Gbps com 4 metros
de distância entre antenas
Tourism in Portugal: dynamics, persistence and impact
This study presents an empirical evaluation of the impact of tourism on the Portuguese
economy. We use a two-step FAVAR with a ve principal component
estimation to nest the e ect of tourism in other 127 macroeconomic variables.
Our ndings point to some channels in which tourism can help an economy develop
and recover from a crisis. The overall e ect on the variables is positive, but
the most prominent dynamics concern the labour market. The variance decomposition,
with an R2 ranging from 29.7% to 89.0%, is more robust in indicators
such as Unemployment (14.0%) and Industrial Employment Index (18.3%). It
also accounts for 3.7% of the overall Economic Sentiment Indicator, showing
improvements in economic agents' expectations. Finally, the representation of
tourism shocks along time backs the hypothesis of tourism helping the Portuguese
economy in recovering from a nancial crisi
Use of Pd-Ag membrane reactors in the water-gas shift reaction for producing ultra-pure hydrogen
Tese de doutoramento. Engenharia Química e Biológica. Faculdade de Engenharia. Universidade do Porto. 201
The most valued social media attributes of Portuguese consumers
The exponential growth of the entertainment and media industry has revolutionized the social media landscape. Increasingly more people use social media platforms in their daily lives for different reasons. The goal of this research is, in particular, to determine what are the attributes of Facebook Instagram and Tik Tok they value the most, as well as having an overview on how Portuguese consumers perceive such platformsandwhat influences its engagement. To reach such goals,reasons why people use social media were identified,aperceptual map with two dimensions was plotted, and a conjoint analysis was performed. On the associations found to be linked with social media, all three social media platforms do not need to readjust their positioning strategy to occupy a specific position in the market, but there is still room for attributes improvement, to engage with potential Portuguese valuable consumers, considering the different needs, preferences, and behaviors. The most important feature and counterpart for the usage of social media is linked with privacy concerns
Smart-contract Blockchain with Secure Hardware
In recent years, blockchains have grown in popularity and the main reason for this
growth is the set of properties that they provide, such as user privacy and a public record
of transactions. This popularity is verifiable by the number of cryptocurrencies currently
available and by the current market value of Bitcoin currency. Since its introduction,
blockchain has evolved and another concept closely linked with it is smart-contract, which
allows for more complex operations over the blockchain than simple transactions.
Nevertheless, blockchain technologies have significant problems that prevent it to be
adopted as a mainstream solution, or at least as an alternative to centralized solutions
such as banking systems. The main one is its inefficiency, which is due to the need of a
consensus algorithm that provides total order of transactions. Traditional systems easily
solve this by having a single central entity that orders transactions, which can’t be done
in decentralized systems. Thus, blockchain’s efficiency and scalability suffer from the
need of time-costly consensus algorithms, which means that they can’t currently compete
with centralized systems that provide a much greater amount of transactional processing
power.
However, with the emergence of novel processor architectures, secure hardware and
trusted computing technologies (e.g. Intel SGX and ARM TrustZone), it became possible
to investigate new ways of improving the inefficiency issues of blockchain systems, by
designing better and improved blockchains.
With all this in mind, this dissertation aims to build an efficient blockchain system
that leverages trusted technologies, namely the Intel SGX. Also, a previous thesis will
serve as a starting point, since it already implements a secure wallet system, that allows
authenticated transactions between users, through the Intel SGX. As such, this wallet
system will be extended to provide traceability of its transactions through a blockchain.
This blockchain will use Intel SGX to provide an efficient causal consistency mechanism
for ordering transactions. After this, the following step will be to support the execution
of smart-contracts, besides regular transactions.Nos últimos anos, as blockchains tornaram-se bastante populares e o motivo é o conjunto
de propriedades que fornecem, como a privacidade dos utilizadores e um registo público
de transações. Essa popularidade é verificável pelo número de criptomoedas existentes
e pelo atual valor de mercado da moeda Bitcoin. Desde a sua introdução, o conceito de
blockchain evoluiu bastante e surgiu o conceito de smart-contract, que permite realizar
operações mais complexas sobre uma blockchain, além de simples transações.
Contudo, existem problemas que impedem blockchains de serem adotadas como so luções convencionais ou como uma alternativa a soluções centralizadas, como o caso de
sistemas bancários. O seu principal problema é ineficiência, resultante da necessidade
de um algoritmo de consensus que forneça ordem total das transações. Os sistemas tradi cionais resolvem esse problema facilmente, sendo que têm uma única entidade central
que ordena transações, o que não pode ser feito em sistemas descentralizados. Assim,
a eficiência e a escalabilidade das blockchains sofrem com a utilização de algoritmos de
consensus dispendiosos, o que significa que não conseguem competir atualmente com
sistemas centralizados que fornecem uma maior quantidade de poder de processamento
transacional.
No entanto, com o aparecimento de novas arquiteturas de processadores, hardware
seguro e tecnologias de computação confiável (por exemplo, Intel SGX e ARM TrustZone),
tornou-se possível investigar novas formas de melhorar os problemas de ineficiência dos
sistemas de blockchain e a construção de sistemas melhores e mais eficientes.
Assim sendo, esta dissertação visa construir uma blockchain eficiente com recurso
ao Intel SGX. O ponto de partida será um sistema de wallet, que permite transações
autenticadas entre usuários através do Intel SGX, desnvolvido numa dissertação anterior.
Como tal, esse sistema será estendido para fornecer rastreabilidade das transações através
de uma blockchain. Esta blockchain utilizará o Intel SGX para fornecer um mecanismo
de consistência causal eficiente para a ordenação das transações. Depois disto, o passo
seguinte será suportar a execução de smart-contract, além de simples transações
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