Earnings overseas and cash holdings

I investigate the impact of foreign pre-tax income on the total amount of cash held by companies and on the amount of cash that is held in companies’ foreign subsidiaries. I also investigate the impact of the existence and amount of cash held on companies’ foreign subsidiaries in the composition of cash holdings in terms of risk and liquidity. Using a sample of 100 largest U.S. non-financial and non-utilities companies I find that companies with higher earnings overseas present higher cash reserves and invest a higher fraction of their cash in risky assets. My evidence suggests that companies have a different optimization strategy for cash overseas, in which precautionary motives are not the main driver for holding cash.

Construction sector: Need for strategic reorientation

The construction sector in Portugal declined sharply over the past 10 years. The current crisis can wiped out the entire industry. Can the industry survive? What lessons can we learn? What can be done to revive the sector? These are questions this study intends to answer. By analyzing the best practices of the industry and of the largest construction companies in Portugal, as well as the difficulties and constrains that they all faced, I found that retrenchment (operational costs and selling assets) are the main measures companies resort to, and that strategic reorientation is essential to turnaround. I found that internationalization is a key driver on strategic reorientation and diversification and concentration are complementary strategies that can enforce and strengthen the main one.

Trust, alliance management capability and the alliance management function: A comparative analysis of Portuguese SMEs

Strategic alliances represent a key driver for internationalization and growth, being the purpose of this work project to better understand the intertwined relationship between trust and the existence of an alliance management position. Previous research supports the positive impact of such position in stock market returns. However, little attention has been given to the impact of such position on the level of trust in the collaborative arrangement, which is deemed to be a key driver for alliance success. A qualitative comparative case-study of three Portuguese SMEs is used to draw conclusions from the literature to real life business cases and it demonstrates the positive impact of an alliance management position on trust.

E-loyalty in e-commerce: A study at GIRISSIMA.COM

Few studies have been conducted on causal antecedents for electronic loyalty regarding the online fashion industry. In Portugal there is no systematic empirical research in this area. This study aims to examine e-satisfaction and e-trust that potentially impact eloyalty. It also examines the impact of price, website design and selection of brands. A research study was performed at GIRISSIMA.COM and survey responses were 77. The findings show that e-satisfaction is the main driver of e-loyalty. E-trust, website design and price affect positively e-loyalty. Additionally, selection of brands was proved to impact e-loyalty through e-satisfaction and e-trust.

Using an LED as a sensor and visible light communication device in a smart illumination system

The need for more efficient illumination systems has led to the proliferation of Solid-State Lighting (SSL) systems, which offer optimized power consumption. SSL systems are comprised of LED devices which are intrinsically fast devices and permit very fast light modulation. This, along with the congestion of the radio frequency spectrum has paved the path for the emergence of Visible Light Communication (VLC) systems. VLC uses free space to convey information by using light modulation. Notwithstanding, as VLC systems proliferate and cost competitiveness ensues, there are two important aspects to be considered. State-of-the-art VLC implementations use power demanding PAs, and thus it is important to investigate if regular, existent Switched-Mode Power Supply (SMPS) circuits can be adapted for VLC use. A 28 W buck regulator was implemented using a off-the-shelf LED Driver integrated circuit, using both series and parallel dimming techniques. Results show that optical clock frequencies up to 500 kHz are achievable without any major modification besides adequate component sizing. The use of an LED as a sensor was investigated, in a short-range, low-data-rate perspective. Results show successful communication in an LED-to-LED configuration, with enhanced range when using LED strings as sensors. Besides, LEDs present spectral selective sensitivity, which makes them good contenders for a multi-colour LED-to-LED system, such as in the use of RGB displays and lamps. Ultimately, the present work shows evidence that LEDs can be used as a dual-purpose device, enabling not only illumination, but also bi-directional data communication.

Switching mode power amplifier for bluetooth applications

Modern fully integrated transceivers architectures, require circuits with low area, low cost, low power, and high efficiency. A key block in modern transceivers is the power amplifier, which is deeply studied in this thesis. First, we study the implementation of a classical Class-A amplifier, describing the basic operation of an RF power amplifier, and analysing the influence of the real models of the reactive components in its operation. Secondly, the Class-E amplifier is deeply studied. The different types of implementations are reviewed and theoretical equations are derived and compared with simulations. There were selected four modes of operation for the Class-E amplifier, in order to perform the implementation of the output stage, and the subsequent comparison of results. This led to the selection of the mode with the best trade-off between efficiency and harmonics distortion, lower power consumption and higher output power. The optimal choice was a parallel circuit containing an inductor with a finite value. To complete the implementation of the PA in switching mode, a driver was implemented. The final block (output stage together with the driver) got 20 % total efficiency (PAE) transmitting 8 dBm output power to a 50 W load with a total harmonic distortion (THD) of 3 % and a total consumption of 28 mW. All implementations are designed using standard 130 nm CMOS technology. The operating frequency is 2.4 GHz and it was considered an 1.2 V DC power supply. The proposed circuit is intended to be used in a Bluetooth transmitter, however, it has a wider range of applications.

Cultural journalism in a digital environment : new models, practices and possibilities

Both culture coverage and digital journalism are contemporary phenomena that have undergone several transformations within a short period of time. Whenever the media enters a period of uncertainty such as the present one, there is an attempt to innovate in order to seek sustainability, skip the crisis or find a new public. This indicates that there are new trends to be understood and explored, i.e., how are media innovating in a digital environment? Not only does the professional debate about the future of journalism justify the need to explore the issue, but so do the academic approaches to cultural journalism. However, none of the studies so far have considered innovation as a motto or driver and tried to explain how the media are covering culture, achieving sustainability and engaging with the readers in a digital environment. This research examines how European media which specialize in culture or have an important cultural section are innovating in a digital environment. Specifically, we see how these innovation strategies are being taken in relation to the approach to culture and dominant cultural areas, editorial models, the use of digital tools for telling stories, overall brand positioning and extensions, engagement with the public and business models. We conducted a mixed methods study combining case studies of four media projects, which integrates qualitative web features and content analysis, with quantitative web content analysis. Two major general-interest journalistic brands which started as physical newspapers – The Guardian (London, UK) and Público (Lisbon, Portugal) – a magazine specialized in international affairs, culture and design – Monocle (London, UK) – and a native digital media project that was launched by a cultural organization – Notodo, by La Fábrica – were the four case studies chosen. Findings suggest, on one hand, that we are witnessing a paradigm shift in culture coverage in a digital environment, challenging traditional boundaries related to cultural themes and scope, angles, genres, content format and delivery, engagement and business models. Innovation in the four case studies lies especially along the product dimensions (format and content), brand positioning and process (business model and ways to engage with users). On the other hand, there are still perennial values that are crucial to innovation and sustainability, such as commitment to journalism, consistency (to the reader, to brand extensions and to the advertiser), intelligent differentiation and the capability of knowing what innovation means and how it can be applied, since this thesis also confirms that one formula doesn´t suit all. Changing minds, exceeding cultural inertia and optimizing the memory of the websites, looking at them as living, organic bodies, which continuously interact with the readers in many different ways, and not as a closed collection of articles, are still the main challenges for some media.

Empowerment and intentions to resist future change: the moderating effect organization-based self-esteem

Nowadays, organizations face a constant need for adaptability, increasing the importance of change management. Our study focuses of how empowering leadership influences intentions to resist future changes, mediated by the effects of psychological and structural empowerment. From the responses of the two questionnaires (N1=230; Ntf=113), we found that empowering leadership fosters psychological and structural empowerment. Structural empowerment was the main driver in reducing intentions to resist future change when an employee has high organization-based self-esteem. Our findings add to the literature by examining how we can anticipate and manage change under an empowering context, building on social exchange and uncertainty reduction theories

The role of information systems in business process redesign : a case of Turkish electricity market

This study is specifically concerned with the effect of the Enterprise Resource Planning (ERP) on the Business Process Redesign (BPR). Researcher’s experience and the investigation on previous researches imply that BPR and ERP are deeply related to each other and a study to found the mentioned relation further is necessary. In order to elaborate the hypothesis, a case study, in particular Turkish electricity distribution market and the phase of privatization are investigated. Eight companies that have taken part in privatization process and executed BPR serve as cases in this study. During the research, the cases are evaluated through critical success factors on both BPR and ERP. It was seen that combining the ERP Solution features with business processes lead the companies to be successful in ERP and BPR implementation. When the companies’ success and efficiency were compared before and after the ERP implementation, a considerable change was observed in organizational structure. It was spotted that the team composition is important in the success of ERP projects. Additionally, when the ERP is in driver or enabler role, the companies can be considered successful. On the contrary, when the ERP has a neutral role of business processes, the project fails. In conclusion, it can be said that the companies, which have implemented the ERP successfully, have accomplished the goals of the BPR.

Operation modes of battery chargers for electric vehicles in the future smart grids

This paper presents an on-board bidirectional battery charger for Electric Vehicles (EVs), which operates in three different modes: Grid-to- Vehicle (G2V), Vehicle-to-Grid (V2G), and Vehicle-to-Home (V2H). Through these three operation modes, using bidirectional communications based on Information and Communication Technologies (ICT), it will be possible to exchange data between the EV driver and the future smart grids. This collaboration with the smart grids will strengthen the collective awareness systems, contributing to solve and organize issues related with energy resources and power grids. This paper presents the preliminary studies that results from a PhD work related with bidirectional battery chargers for EVs. Thus, in this paper is described the topology of the on-board bidirectional battery charger and the control algorithms for the three operation modes. To validate the topology it was developed a laboratory prototype, and were obtained experimental results for the three operation modes.

Dynamic range prediction for an electric vehicle

Electric Vehicles (EVs) have limited energy storage capacity and the maximum autonomy range is strongly dependent of the driver's behaviour. Due to the fact of that batteries cannot be recharged quickly during a journey, it is essential that a precise range prediction is available to the driver of the EV. With this information, it is possible to check if the desirable destination is achievable without a stop to charge the batteries, or even, if to reach the destination it is necessary to perform an optimized driving (e.g., cutting the air-conditioning, among others EV parameters). The outcome of this research work is the development of an Electric Vehicle Assistant (EVA). This is an application for mobile devices that will help users to take efficient decisions about route planning, charging management and energy efficiency. Therefore, it will contribute to foster EVs adoption as a new paradigm in the transportation sector.

Vehicle-to-anything application (v2anything app) for electric vehicles

This paper presents a mobile information system denominated as Vehicle-to-Anything Application (V2Anything App), and explains its conceptual aspects. This application is aimed at giving relevant information to Full Electric Vehicle (FEV) drivers, by supporting the integration of several sources of data in a mobile application, thus contributing to the deployment of the electric mobility process. The V2Anything App provides recommendations to the drivers about the FEV range autonomy, location of battery charging stations, information of the electricity market, and also a route planner taking into account public transportations and car or bike sharing systems. The main contributions of this application are related with the creation of an Information and Communication Technology (ICT) platform, recommender systems, data integration systems, driver profile, and personalized range prediction. Thus, it is possible to deliver relevant information to the FEV drivers related with the electric mobility process, electricity market, public transportation, and the FEV performance.

Spectrum-based energy leak localization

Dissertação de Mestrado em Engenharia Informática

Validador RCAAP: ferramenta para promover a interoperabilidade e a qualidade dos metadados

O Validador RCAAP é uma ferramenta desenvolvida no âmbito do projeto RCAAP – Repositório Científico de Acesso Aberto de Portugal com o objetivo de aferir o grau de conformidade de um repositório ou revista com as diretrizes definidas no campo de ação do projeto. Apesar da aplicação de normas padronizadas, como o Dublin Corei e o OAI-PMHii, as representações locais comprometem, muitas vezes, a qualidade dos metadados e a interoperabilidade técnica. No âmbito do projeto RCAAP utilizam-se as diretrizes DRIVER como o padrão de interoperabilidade dos repositórios portugueses. Para além de assegurarem a necessária uniformização entre os repositórios e revistas integrantes do RCAAP, garantem e facilitam a integração e a interoperabilidade. Esta apresentação pretende expor as características e objetivos do Validador RCAAP e destacar os desenvolvimentos da segunda versão desta ferramenta, que oferece aos gestores de repositórios e revistas um serviço capaz de promover a qualidade e harmonia dos metadados, permitindo a interoperabilidade à escala nacional ou internacional.

Contribuição para equipamento didático de máquina de medição por coordenadas

Dissertação de mestrado integrado em Engenharia Mecânica