The implementation of information strategies to support sustainable procurement

In our research context, sustainable procurement can be seen as a process to reduce damage to the environment by integrating certain aspects into making procurement decisions, such as value for money throughout the whole life cycle and being of benefit to society and the economy. This research has found more than one way of interpreting the ‘sustainable system’, for example, ‘green-friendly’ versus remaining effective in the long term. Sustainable procurement requires specific information to support the procurement process. The study reported in this thesis aimed to investigate the type of information needed in order for organisations to make correct sustainable procurement decisions. From these findings, information architecture for sustainable procurement in UK universities has been derived. While the initial focus has been on the information needed to make informed decisions in purchasing sustainable information technology (IT) equipment, it is believed that the framework would also be more widely applicable to other types of purchases. To ensure that these findings would support the university aspiration in terms of sustainability practices, a goal-context modelling technique called VMOST/B-SCP was chosen to analyse the sustainable procurement strategy in order to evaluate the alignment of IT strategy and its business strategy. A goal-context model using VMOST/B-SCP was produced to evaluate the procurement strategy, with this validated by procurement staff. This research helps to improve the way that goals and context are identified by integrating another technique, namely, social network analysis (SNA) to produce actor network diagrams. The VMOST/B-SCP technique is transferrable to the mapping of action strategies. The findings from goal-context modelling show that a goal-context model is not static: it changes as external circumstances and organisational priorities change. Most changes to the strategy occurred where external entities on which the change programme depended did not act as planned. The actor networks produced in our version of VMOST/B-SCP can be used to identify such risks. This research was pioneering in its use of VMOST/B-SCP in examining a business change while it was actually taking place rather than after it had been completed (and thus needed to accommodate changes in objectives and strategies). In addition, the research analysed a system with some IT support but where human-operated procedures predominated. The original B-SCP framework used Jackson’s problem frames which focus on possible software components: in our scenario, SNA-inspired actor diagrams were found to be more appropriate

Comunicações sem fios confiáveis para aplicações veiculares

Doutoramento em Engenharia ElectrotécnicaIn the last decades the number of vehicles travelling in European road has raised significantly. Unfortunately, this brought a very high number of road accidents and consequently various injuries and fatalities. Even after the introduction of passive safety systems, such as seat belts, airbags, and some active safety systems, such as electronic brake system (ABS) and electronic stabilization (ESP), the number of accidents is still too high. Approximately eight per cent of the fatal accidents occur in motorways, in the Portuguese case, the number of fatalities has remained constant in the first decade of the 21st century. The evolution of wireless communications, along with the north-American and European policies that reserve spectrum near the 5,9GHz band for safety applications in the vehicular environment, has lead to the development of several standards. Many of these applications are based on the possibility of using a wireless communication system to warn drivers and passengers of events occurring on the road that can put at risk their own safety. Some examples of safety applications are the hard-brake warning, the wrong-way warning and the accident warning. This work aims to contribute in defining a communication protocol that guarantees the timely dissemination of safety critical events, occurring in scenarios with a high number of vehicles or in the neighbourhood of so called motorway “blackspots”, to all vehicles in the zone of interest. To ensure information integrity and user trust, the proposed system is based on the motorway infrastructure, which will validate all events reported by the vehicles with the usage of several means, such as video surveillance or other sensors. The usage of motorway infrastructure that has full motorway coverage using fixed stations also known as road side units, allows to have a global vision of the interest zone, avoiding the problems associated to networks that depend solely on vehicle to vehicle communication, generally total ad-hoc networks. By using the infrastructure, it is possible to control medium access, avoiding possible badly intended intrusions and also avoiding the phenomenon known as alarm showers or broadcast storm that occur when all vehicles want to simultaneously access the medium to warn others of a safety event. The thesis presented in this document is that it is possible to guarantee in time information about safety events, using an architecture where the road side units are coordinated among themselves, and communicate with on board units (in vehicles) that dynamically register and deregister from the system. An exhaustive and systematic state of the art of safety applications and related research projects is done, followed by a study on the available wireless communications standards that are able to support them. The set of standards IEEE802.11p and ETSI-G5 was created for this purpose and is found to be the more adequate, but care is taken to define a scenario where WAVE enabled and non-enabled vehicles can coexist. The WAVE medium access control protocol suffers from collision problems that do not guarantee a bounded delay, therefore a new protocol (V-FTT) is proposed, based on the adaptation of the Flexible Time Triggered protocol to the vehicular field. A theoretical analysis of the V-FTT applied to WAVE and ETSI-G5 is done, including quantifying a real scenario based on the A5 motorway from Lisbon to Cascais, one of the busiest Portuguese motorways. We conclude the V-FTT protocol is feasible and guarantees a bounded delay.Nas últimas décadas tem-se assistido a um aumento do número de veículos a circular nas vias rodoviárias europeias, trazendo consigo um elevado número de acidentes e como consequência muitos feridos e vítimas mortais. Apesar da introdução de sistemas de segurança passivos, tais como cintos de segurança, airbags e de alguns sistemas de segurança activos, tais como o sistema electrónico de travagem (ABS) e o sistema electrónico de estabilidade (ESP), o número de acidentes continua a ser demasiado elevado. Aproximadamente oito por cento dos acidentes fatais na Europa ocorrem em auto-estradas, no caso Português, o número de vítimas mortais tem-se mantido constante ao longo da primeira década do século XXI. A evolução das comunicações sem fios, acompanhada de políticas europeias e norte-americanas no sentido de reservar frequências próximas dos 5,9GHz para aplicações de segurança no ambiente veicular, levou à especificação de várias normas. A maior parte destas aplicações baseiam-se na possibilidade de usar um sistema confiável de comunicação sem fios para alertar os condutores e passageiros de veículos para eventos ocorridos nas estradas que possam colocar em risco a sua segurança. Exemplos de aplicações de segurança crítica são o aviso de travagem brusca, o aviso de veículo em contra mão e o aviso de acidente na estrada. Este trabalho contribui para a definição de protocolos de comunicação capazes de garantir que a informação sobre eventos relacionados com situações de segurança crítica, que ocorram em cenários com um elevado número de veículos em zonas urbanas ou na vizinhança dos chamados “pontos negros” das auto-estradas, é disseminada com pontualidade por todos os veículos localizados na zona de interesse Por uma questão da integridade das comunicações e confiança dos condutores, o sistema proposto baseia-se na infra-estrutura do concessionário da auto-estrada, que validará os eventos reportados pelos veículos usando vários meios à sua disposição, como por exemplo sistemas de videovigilância e outros sensores. O uso de uma infra-estrutura de comunicações, que dispõe de cobertura integral a partir de estações fixas, permite uma visão global da zona coberta, evitando os problemas associados a redes baseadas apenas na comunicação entre veículos, que são em geral totalmente ad-hoc. O uso da infra-estrutura permite, entre outras vantagens, controlar o acesso ao meio, evitando simultaneamente intrusões de estranhos ao sistema e o fenómeno conhecido como “chuva de alarmes” desencadeado quando todos os veículos querem aceder simultaneamente ao meio para avisar os restantes da existência dum evento de segurança crítica. A tese apresentada neste documento defende que é possível garantir informação atempada sobre eventos que põem em risco a segurança dos veículos a partir de uma arquitectura de interligação entre as estações de comunicações fixas, coordenadas entre si, e unidades móveis (veículos) que se registam e se desligam dinamicamente do sistema. Nesta tese faz-se um levantamento exaustivo e sistemático das aplicações de segurança abordando projectos de investigação relacionados, estudam-se as tecnologias de comunicação sem fios disponíveis e a sua possibilidade de suportar aplicações de segurança rodoviária. Desta análise, conclui-se que a norma norte americana WAVE/IEEE802.11p e a europeia ETSI-G5, criadas especificamente para o efeito são as que mais se adequam à finalidade desejada. Considera-se que o cenário de utilização é evolutivo, podendo coexistirem veículos que não dispõem de sistemas de comunicação com outros que suportam a norma WAVE. Dado que o protocolo de acesso ao meio proposto pela norma WAVE não garante um acesso determinístico ao meio partilhado, propõe-se um novo protocolo, o Vehicular Flexible Time-Triggered protocol (VFTT). Faz-se a análise teórica da viabilidade do protocolo proposto para a norma WAVE e respectiva norma europeia (ETSI-G5). Quantifica-se o protocolo VFTT para um cenário real: a auto-estrada A5 Lisboa-Cascais, uma das autoestradas portuguesas mais movimentadas. Conclui-se que o protocolo é viável e garante um atraso restringido temporalmente

Air Traffic Management Abbreviation Compendium

As in all fields of work, an unmanageable number of abbreviations are used today in aviation for terms, definitions, commands, standards and technical descriptions. This applies in general to the areas of aeronautical communication, navigation and surveillance, cockpit and air traffic control working positions, passenger and cargo transport, and all other areas of flight planning, organization and guidance. In addition, many abbreviations are used more than once or have different meanings in different languages. In order to obtain an overview of the most common abbreviations used in air traffic management, organizations like EUROCONTROL, FAA, DWD and DLR have published lists of abbreviations in the past, which have also been enclosed in this document. In addition, abbreviations from some larger international projects related to aviation have been included to provide users with a directory as complete as possible. This means that the second edition of the Air Traffic Management Abbreviation Compendium includes now around 16,500 abbreviations and acronyms from the field of aviation

Intramembrane proteolysis of ephrin-B2 by γ-secretase regulates podosome dynamics and migration of microglia

The Eph-ephrin system plays pivotal roles during development and adulthood in cell-cell interaction, cell adhesion and migration. It has previously been shown that ephrin-B1 and 2 can be cleaved intramembranously by the γ-secretase. γ-Secretase mediated processing of ephrin-B has furthermore been linked to activation of Src, a kinase crucial for focal adhesion and podosome phosphorylation. Due to the finding that many familial Alzheimer’s disease (FAD) mutations are located in the catalytic subunit of the γ-secretase, i.e. presenilin, the γ-secretase has in the past decades mainly been subject of investigation in early Alzheimer’s disease (EOAD) studies. Additionally, the positive correlation between occurrence of late onset Alzheimer’s disease (LOAD) and mutations in genes mainly expressed by microglia has drawn attention to these cells. In this study, the role of γ-secretase and ephrin signaling on downstream effectors, podosomal turnover and the migration of embryonic stem cell derived microglia (ESdM) was tested. We demonstrate extracellular shedding and subsequent intramembranous ephin-B2 cleavage by the γ-secretase upon EphB1 receptor binding in a microglial cell model. It was furthermore found that proteolytic release of the ephrin-B2 intracellular domain (ICD) stimulates Src and FAK activity. ESdM from presenilin double knock out (PSdKO) and wild type (WT) mice were transduced with either WT presenilin 1 (PS1 WT) or with non-functional presenilin containing an inactivating mutation (PS1 DN). A rescue cell type of the PSdKO PS1 DN cells was generated, which additionally expressed the ephrin-B2 ICD. Expression of non-functional presenilin 1 could not rescue phosphorylation of Src and FAK. Cell motility and podosomal morphology were also changed in these cells. More specifically, this genotype was associated with decreased motility and an enlargement of podosomal surface. Also, the present results indicate impaired cleavage of podosomal proteins like FAK, talin and vinculin in cells with inactive γ-secretase. Interestingly, ephrin-B2 ICD expression could fully rescue this phenotype, indicating that ephrin-B2 ICD mediated activation of Src and FAK modulates podosomal dynamics in microglial cells. Together, these results identify γ-secretase as well as ephrin-B2 as important regulators of microglial migration

Rhodes University Research Report 2006

[From Preface] Rhodes University defines as one of its three core activities the production of knowledge through stimulating imaginative and rigorous research of all kinds (fundamental, applied, policy-oriented, etc.), and in all disciplines and fields. Though a small university with less than 6 000 students, the student profile and research output (publications, Master’s and Doctoral graduates) of Rhodes ensures that it occupies a distinctive place in the overall South African higher education landscape. For one, almost 25% of Rhodes’ students are postgraduates. Coming from a diversity of countries, these postgraduates ensure that Rhodes is a cosmopolitan and fertile environment of thinking and ideas. For another, Rhodes has the best research output of all South African universities, a testimony to the dedication and passion of its academics for research and the commitment of the University to nurture and cultivate knowledge production of all kinds. During 2006, Rhodes academics published 113 books and book chapters, 312 articles, and contributed 636 papers to conferences. One hundred and seventy students graduated with Master’s degrees and 47 with Doctorates. In a number of areas Rhodes’ academics are at the cutting-edge of research, pushing the frontiers knowledge production. The award of a Department of Science and Technology sponsored Research Chair in Chemistry to Professor Nyokong is one indicator of national recognition of this reality. Rhodes researchers are at the forefront of a number of national projects, and also continue to attract research funding from a variety of international and national research agencies and industry. Rhodes possesses an admirable research culture, and provides the intellectual space for the flourishing and debate of ideas, as evidenced by the number and diversity of seminars, public lectures, and the quality of local and international academics that visit Rhodes. A number of Rhodes academics also make important contributions to national public debate, enhancing the visibility of Rhodes in the intellectual life of South Africa. Rhodes University is committed to maintain and, in the years to come, to enhance its research output, to broaden its research base, to bring on steam new generations of researchers (who are also increasing women and black), and to continue being a distinctive South African university in the domain of knowledge production

Maritime transport properties and competition law issues: partial function cooperation agreements in liner and tramp shipping

PhDThe thesis deals with selected competition issues that occur within the dynamic and high-risk market of shipping, examining competition law issues in liner consortia and tramp pools through an EU Competition Law prism. These partial function joint ventures are the predominant form of alliances in the maritime sector. Liner trade is primarily organised in consortia, while pools are the most common form of tramp shipping alliance. The thesis' synthetic and analytic research incorporates the methodology and structure used in its competition law bibliography, while the legal analysis is informed with sources from microeconomics and maritime economics. The issues that are examined in relation to shipping include the four main areas of competition law: the relevant market, indicators of dominance, compliance of the alliance agreements with Article 101 TFEU and abusive conducts by dominant undertakings under Article 102 TFEU. The development of the above areas aims to demonstrate the interaction of sector particularities with competition law as a whole

Développement d'algorithmes parallèles pour la simulation d'écoulements de fluides dans les milieux poreux

Problématique de la mécanique des fluides numérique en milieu poreux -- Méthode de Boltzmann sur réseau -- Origines -- Principe de la méthode -- Implantation numérique de MBR-BGK -- Réduction de la mémoire utilisée par MBR-BGK -- Amélioration de la performance de calcul de MBR-BGK -- Méthodes de MBR-BGK adaptatives -- Aspects parallèles de la méthode de Boltzmann sur réseau -- Contenu parallèle -- Communications -- Équilibrage de tâches -- Résumé et objectifs spécifiques -- On improving the performance of large parallel Lattice Boltzmann flow simulations in heterogeneous porous media -- The Lattice Boltzmann method -- Data structure and memory usage optimization -- Parallel workload balance & communication strategies -- Numerical experiments -- Conclusions and perspectives -- Development of theoretical parallel performance models for heterogeneous porous media -- A parallel workload balanced and memory efficient Lattice-Boltzmann algorithm with single unit BGK relaxation time -- LBM implementation, data structure and memory requirements -- Parallel workload balance & communication strategies -- Results and discussions -- Concluding remarks -- Effect of particle size distribution and packing compression on fluid permeability as predicted by Lattice-Boltzmann simulations