2,288 research outputs found

    Three decades of strategic management research on M&As: Citations, co-citations, and topics

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    Merger and acquisitions (M&As) strategies have been growingly deployed by firms for their domestic and international expansion, to redefine their business scope or take advantage of emerging opportunities. In this paper we conduct a bibliometric study of the extant strategy research on M&As, assessed by the articles published in the main journal for strategic management studies over the period 1984-2010. Results reveal the highest impact works (articles and books), the intellectual ties among authors and theories that form five main clusters of research, and the topics delved into. Performance effects, M&As as diversification strategies and RBV and capabilities-based topics have dominated the extant research. The study contributes to the extant knowledge on M&As by taking stock of the accumulated knowledge and research direction, complementing other literature reviews with a strategic management specific perspective. Thus, we provide a rear view of the field which facilitates detecting untapped gaps that may be munificent avenues for future research.info:eu-repo/semantics/publishedVersio

    Orbit Representations from Linear mod 1 Transformations

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    We show that every point x0[0,1]x_0\in [0,1] carries a representation of a CC^*-algebra that encodes the orbit structure of the linear mod 1 interval map fβ,α(x)=βx+αf_{\beta,\alpha}(x)=\beta x +\alpha. Such CC^*-algebra is generated by partial isometries arising from the subintervals of monotonicity of the underlying map fβ,αf_{\beta,\alpha}. Then we prove that such representation is irreducible. Moreover two such of representations are unitarily equivalent if and only if the points belong to the same generalized orbit, for every α[0,1[\alpha\in [0,1[ and β1\beta\geq 1

    Schumpeter’s (1934) influence on entrepreneurship (and management) research

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    Entrepreneurship research has flourished since de 1980s, following the institutional development that created schools and courses, research centers and dedicated journals. This paper examines the impact of Joseph Schumpeter, one of the main “knowledge producers” whose concepts and ideas on the entrepreneur, entrepreneurship and innovation have shaped the discipline and much of the research on entrepreneurship, and has influenced the thought on other areas of management. Methodologically, we conducted a bibliometric study of the articles published in 16 high stature international journals, over a period of 30 years, between 1981 and 2010. On a sample of 412 articles citing Schumpeter, we analyzed and mapped citations, co-citations and research themes. We further establish distinctions between entrepreneurship and management research. This study presents a manner to examine the influence of a scholar, and a set of conceptualizations he has introduced, on a discipline. Schumpeter has had an imprint in the multidisciplinary and wealth of research themes that entrepreneurship scholars have delved upon but also in other management disciplines, where his perspectives on entrepreneurship, the entrepreneur and innovation have contributed to much of the research conducted to date. Although entrepreneurship has remained largely multidisciplinary and drawing from the main management theories there is a growing body of entrepreneurship-specific literature.info:eu-repo/semantics/publishedVersio

    Ilustração. Imagem da Modernidade em Portugal = Ilustración. Imagen de la modernidad en Portugal

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    [por] Este trabalho investiga a relação entre a imagem ilustrada e a experiência da modernidade. Nas margens da arte da gravura e de uma nova matriz industrial, a imagem ilustrada torna visível um espectro social abrangente e participa na formação de novos sujeitos da política e da esfera pública. É também uma forma atravessada por impulsos contraditórios — pelo humor e pelo pendor científico; pela visão atomizada e pela produção de séries que procuram recodificar a sociedade. A investigação de imagens recreativas e instrutivas, retratos fisiológicos e carica­turas, publicadas sobretudo na imprensa ilustrada do século XIX, internacional e portuguesa, permite entender melhor as representações políticas que emergem com a dissolução da ideia de soberania do Antigo Regime.[eng] This paper investigates the relationship between the illustrated image and the experience of mo­dernity. In the cross-line between an industrial matrix and the art of engraving, illustration gives visibility to a comprehensive social spectrum and participates in the formation of new subjects of politics and the public sphere. It is also a media touched by contradictory impulses — humor and scientific bias; atomized vision and production of series, aiming to recode society. The investigation of recreational and instructional images, physiological portraits and caricatures, published mainly in the illustrated press of the nineteenth century (in Portugal and abroad), will allow a better understanding of the political representations that emerge with the dissolution of the Ancient Regime’s idea of sovereignty .[spa] Este trabajo investiga la relación entre la imagen ilustrada y la experiencia de la modernidad. En los márgenes del arte del grabado y de una nueva matriz de producción industrial, la imagen ilustrada dota de visibilidad a un espectro social amplio y participa en la formación de nuevos sujetos de la política y de la esfera pública. Es también una forma atravesada por impulsos contradictorios: el humor y una cierta inclinación científica, una visión atomizada y la producción de series que buscan recodificar la sociedad. La investigación de imágenes recreativas e instructivas, retratos fisiológicos y caricaturas, publicadas sobre todo en la prensa ilustrada del siglo XIX, internacional y portuguesa, permite entender mejor las representaciones políticas que emergen con la disolución de la idea de soberanía del Antiguo Régimen

    Al-doped ZnO ceramic sputtering targets based on nanocrystalline powders produced by emulsion detonation synthesis – deposition and application as a transparent conductive oxide material

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    Transparent conducting oxides (TCOs) have been largely used in the optoelectronic industry due to their singular combination of low electrical resistivity and high optical transmittance. They are usually deposited by magnetron sputtering systems being applied in several devices, specifically thin film solar cells (TFSCs). Sputtering targets are crucial components of the sputtering process, with many of the sputtered films properties dependent on the targets characteristics. The present thesis focuses on the development of high quality conductive Al-doped ZnO (AZO) ceramic sputtering targets based on nanostructured powders produced by emulsion detonation synthesis method (EDSM), and their application as a TCO. In this sense, the influence of several processing parameters was investigated from the targets raw-materials synthesis to the application of sputtered films in optoelectronic devices. The optimized manufactured AZO targets present a final density above 99 % with controlled grain size, an homogeneous microstructure with a well dispersed ZnAl2O4 spinel phase, and electrical resistivities of ~4 × 10-4 Ωcm independently on the Al-doping level among 0.5 and 2.0 wt. % Al2O3. Sintering conditions proved to have a great influence on the properties of the targets and their performance as a sputtering target. It was demonstrated that both deposition process and final properties of the films are related with the targets characteristics, which in turn depends on the initial powder properties. In parallel, the influence of several deposition parameters in the film´s properties sputtered from these targets was investigated. The sputtered AZO TCOs showed electrical properties at room temperature that are superior to simple oxides and comparable to a reference TCO – indium tin oxide (ITO), namely low electrical resistivity of 5.45 × 10-4 Ωcm, high carrier mobility (29.4 cm2V-1s-1), and high charge carrier concentration (3.97 × 1020 cm-3), and also average transmittance in the visible region > 80 %. These superior properties allowed their successful application in different optoelectronic devices

    High performance data processing

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    Dissertação de mestrado em Informatics EngeneeringÀ medida que as aplicações atingem uma maior quantidade de utilizadores, precisam de processar uma crescente quantidade de pedidos. Para além disso, precisam de muitas vezes satisfazer pedidos de utilizadores de diferentes partes do globo, onde as latências de rede têm um impacto significativo no desempenho em instalações monolíticas. Portanto, distribuição é uma solução muito procurada para melhorar a performance das camadas aplicacional e de dados. Contudo, distribuir dados não é uma tarefa simples se pretendemos assegurar uma forte consistência. Isto leva a que muitos sistemas de base de dados dependam de protocolos de sincronização pesados, como two-phase commit, consenso distribuído, bloqueamento distribuído, entre outros, enquanto que outros sistemas dependem em consistência fraca, não viável para alguns casos de uso. Esta tese apresenta o design, implementação e avaliação de duas soluções que têm como objetivo reduzir o impacto de assegurar garantias de forte consistência em sistemas de base de dados, especialmente aqueles distribuídos pelo globo. A primeira é o Primary Semi-Primary, uma arquitetura de base de dados distribuída com total replicação que permite que as réplicas evoluam independentemente, para evitar que os clientes precisem de esperar que escritas precedentes que não geram conflitos sejam propagadas. Apesar das réplicas poderem processar tanto leituras como escritas, melhorando a escalabilidade, o sistema continua a oferecer garantias de consistência forte, através do envio da certificação de transações para um nó central. O seu design é independente de modelos de dados, mas a sua implementação pode tirar partido do controlo de concorrência nativo oferecido por algumas base de dados, como é mostrado na implementação usando PostgreSQL e o seu Snapshot Isolation. Os resultados apresentam várias vantagens tanto em ambientes locais como globais. A segunda solução são os Multi-Record Values, uma técnica que particiona dinâmicamente valores numéricos em múltiplos registros, permitindo que escritas concorrentes possam executar com uma baixa probabilidade de colisão, reduzindo a taxa de abortos e/ou contenção na adquirição de locks. Garantias de limites inferiores, exigido por objetos como saldos bancários ou inventários, são assegurados por esta estratégia, ao contrário de muitas outras alternativas. O seu design é também indiferente do modelo de dados, sendo que as suas vantagens podem ser encontradas em sistemas SQL e NoSQL, bem como distribuídos ou centralizados, tal como apresentado na secção de avaliação.As applications reach an wider audience that ever before, they must process larger and larger amounts of requests. In addition, they often must be able to serve users all over the globe, where network latencies have a significant negative impact on monolithic deployments. Therefore, distribution is a well sought-after solution to improve performance of both applicational and database layers. However, distributing data is not an easy task if we want to ensure strong consistency guarantees. This leads many databases systems to rely on expensive synchronization controls protocols such as two-phase commit, distributed consensus, distributed locking, among others, while other systems rely on weak consistency, unfeasible for some use cases. This thesis presents the design, implementation and evaluation of two solutions aimed at reducing the impact of ensuring strong consistency guarantees on database systems, especially geo-distributed ones. The first is the Primary Semi-Primary, a full replication distributed database architecture that allows different replicas to evolve independently, to avoid that clients wait for preceding non-conflicting updates. Al though replicas can process both reads and writes, improving scalability, the system still ensures strong consistency guarantees, by relaying transactions’ certifications to a central node. Its design is independent of the underlying data model, but its implementation can take advantage of the native concurrency control offered by some systems, as is exemplified by an implementation using PostgreSQL and its Snapshot Isolation. The results present several advantages in both throughput and response time, when comparing to other alternative architectures, in both local and geo-distributed environments. The second solution is the Multi-Record Values, a technique that dynami cally partitions numeric values into multiple records, allowing concurrent writes to execute with low conflict probability, reducing abort rate and/or locking contention. Lower limit guarantees, required by objects such as balances or stocks, are ensure by this strategy, unlike many other similar alternatives. Its design is also data model agnostic, given its advantages can be found in both SQL and NoSQL systems, as well as both centralized and distributed database, as presented in the evaluation section

    Legal Gender Recognition in Portugal: A Path to Self-Determination

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    This paper presents research on the enforcement and impact of the first legal gender recognition legislation in Portugal (Law no.7/2011). The study describes how the administrative process created by the law functioned during its initial 5-year period, and identifies challenges and processes of resistance to this legal innovation. Simultaneously, it seeks to assess the impact of the law on the social and psychological well-being of trans people, including in their access to vital spheres of social life such as education and employment. The research employs a mixed-methods approach and a multi-informant methodology: an online questionnaire was completed by 68 trans and non-binary people, and semi-structured in-depth interviews were carried out with various selected stakeholders: representatives of trans and LGBTIQ+ organisations (n=5), health professionals identified as experts in the topic and as gatekeepers in legal gender recognition processes (n=12), and trans people (n=6). Results show, on the one hand, the significant positive impact that legal gender recognition has on the psychological well-being and social welfare of the participants. On the other hand, results also show several challenges and forms of resistance to the implementation of the law, in particular those challenges resulting from the fact that legal gender recognition depended on a clinical diagnosis and the provision of a clinical report
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