A Theory of Pyramidal Ownership and Family Business Groups

We provide a rationale for pyramidal ownership (the control of a firm through a chain of ownership relations) that departs from the traditional argument that pyramids arise to separate cash flow from voting rights. With a pyramidal structure, a family uses a firm it already controls to set up a new firm. This structure allows the family to 1) access the entire stock of retained earnings of the original firm, and 2) to share the new firm's non-diverted payoff with minority shareholders of the original firm. Thus, pyramids are attractive if external funds are costlier than internal funds, and if the family is expected to divert a large fraction of the new firm's payoff; conditions that hold in an environment with poor investor protection. The model can differentiate between pyramids and dual-class shares even in situations in which the same deviation from one share-one vote can be achieved with either method. Unlike the traditional argument, our model is consistent with recent empirical evidence that some pyramidal firms are associated with small deviations between ownership and control. We also analyze the creation of business groups (a collection of multiple firms under the control of a single family) and find that, when they arise, they are likely to adopt a pyramidal ownership structure. Other predictions of the model are consistent with systematic and anecdotal evidence on pyramidal business groups.

Public space regeneration strategies: the case of Salou

Salou, which is one of the many highly specialized tourist resorts located on the Spanish Mediterranean coast, is a hundred kilometres south of Barcelona. Within its narrow boundaries of 1.481 ha, Salou hosts 7.4 million overnight stays per year and is home to 52 hotels. A ratio which ranks Salou amongst the tenth most visited municipalities in Spain. Distance from Salou’s historical town centre, the area of Carles Buigas Avenue (CB) emerges as being the heart of the municipality’s tourism and leisure industry. Salou developed, as did so many other Spanish coastal touristic locations, during the sixties and seventies as a consequence of the increasing demand for sun and beach destinations amongst the European and Spanish middle classes. Unfortunately, the “ageing” of this built up area clamours for close attention today. The visible physi-cal degradation of the property is becoming a cause for concern and preoccupation amongst the main property owners and investors: public administration, hotel managers, shopkeepers and neighbours. Hotels emerge as the key problem within the set physical boundaries of this study. They occupy approximately 50% of the total land surface, 28 out of a total of 52 hotels within the town being con-centrated in that area. This accumulation of hotels also breaks the particularity of the predominance of second residences which is so customary along the Spanish Coast. This paper delves into the data and proposals obtained from analysing the public space of the CB area. Similarly, as a consequence of the previous analysis, a set of proposals for intervention are also presented. The proposals are conceived to be developed within different time scales, in response to political and social willingness and economic capacity. The objective of the work is to induce an urban and tourism paradigm shift in the area, thus facilitating the emergence of a new tourism model. Solu-tions are urgently needed to provide specific answers to a particular scenario, which has similitudes to those of other Mediterranean Coastal Developments specialized in tourism activities, which too, after being operative for more than forty years, are suffering from deterioration or abandonment. Despite it still being an open process, the study understands that due to the complexity of the com-mitted task and the scale of the area, the goal will require the active commitment and collaboration of the property owners (administration, hotel managers, investors and neighbours).Postprint (published version

Wavelets Applied to the Detection of Point Sources of UHECRs

In this work we analyze the effect of smoothing maps containing arrival directions of cosmic rays with a gaussian kernel and kernels of the mexican hat wavelets of orders 1, 2 and 3. The analysis is performed by calculating the amplification of the signal-to-noise ratio for several anisotropy patterns (noise) and different number of events coming from a simulated source (signal) for an ideal detector capable of observing the full sky with equal probability. We extend this analysis for a virtual detector located within the array of detectors of the Pierre Auger Observatory, considering an acceptance law.Comment: 9 pages, 8 figures. Proceedings of the Young Researchers Meeting, 2010. Available in: http://www.ifi.unicamp.br/physicae/ojs-2.1.1/index.php/physicae/article/view/191; Physicae, Proceedings of the Young Researchers Meeting, Vol 1, 201

Implementing and Tuning an Autonomous Racing Car Testbed

Achieving safe autonomous driving is far from a vision at present days, with many examples like Uber, Google and the most famous of all Tesla, as they successfully deployed self driving cars around the world. Researchers and engineers have been putting tremendous efforts and will continue to do so in the following years into developing safe and precise control algorithms and technologies that will be included in future self driving cars. Besides these well known autonomous car deployments, some focus has also been put into autonomous racing competitions, for example the Roborace. The fact is that although significant progress that has been made, testing on real size cars in real environments requires immense financial support, making it impossible for many research groups to enter the game. Consequently, interesting alternatives appeared, such as the F1 Tenth, which challenges students, researchers and engineers to embrace in a low cost autonomous racing competition while developing control algorithms, that rely on sensors and strategies used in real life applications. This thesis focus on the comparison of different control algorithms and their effectiveness, that are present in a racing aspect of the F1 Tenth competition. In this thesis, efforts were put into developing a robotic autonomous car, relying on Robot Operative System, ROS, that not only meet the specifications from the F1 Tenth rules, but also allowed to establish a testbed for different future autonomous driving research.Obter uma condução autónoma segura está longe de uma visão dos dias de hoje, com exemplos como a Uber, Google e o mais famoso deles todos, a Tesla, que já foram globalmente introduzidos com sucesso. Investigadores e engenheiros têm colocado um empenho tremendo e vão continuar a fazê-lo nos próximos anos, a desenvolver algoritmos de controlo precisos e seguros, bem como tecnologias que serão colocados nos carros autónomos do futuro. Para além destes casos de sucesso bem conhecidos, algum foco tem sido colocado em competições de corridas de carros autónomos, como por exemplo o Roborace. O facto ´e que apesar do progresso significante que tem sido feito, fazer testes em carros reais em cenários verdadeiros, requer grande investimento financeiro, tornando impossível para muitos grupos de investigação investir na área. Consequentemente, apareceram alternativas relevantes, tal como o F1 Tenth, que desafia estudantes, investigadores e engenheiros a aderir a uma competição de baixos custos de corridas autónomas, enquanto desenvolvem algoritmos de controlo, que dependem de sensores e estratégias usadas em aplicações reais. Esta tese foca-se na comparação de diferentes algoritmos de controlo e na eficácia dos mesmos, que estão presentes num cenário de corrida da competição do F1 Tenth. Nesta tese, foram colocados muitos esforços para o desenvolvimento de um carro autónomo robótico, baseado em Robot Operative System, ROS, que não só vai de encontro `as especificações do F1 Tenth, mas que também permita estabelecer uma plataforma para futuras investigações de condução autónoma

Verified Correctness and Security of mbedTLS HMAC-DRBG

We have formalized the functional specification of HMAC-DRBG (NIST 800-90A), and we have proved its cryptographic security--that its output is pseudorandom--using a hybrid game-based proof. We have also proved that the mbedTLS implementation (C program) correctly implements this functional specification. That proof composes with an existing C compiler correctness proof to guarantee, end-to-end, that the machine language program gives strong pseudorandomness. All proofs (hybrid games, C program verification, compiler, and their composition) are machine-checked in the Coq proof assistant. Our proofs are modular: the hybrid game proof holds on any implementation of HMAC-DRBG that satisfies our functional specification. Therefore, our functional specification can serve as a high-assurance reference.Comment: Appearing in CCS '1

Should Business Groups be Dismantled?The Equilibrium Costs of Efficient Internal Capital Markets

We analyze the relationship between conglomerates’ internal capital markets and the efficiency of economy-wide capital allocation, and identify a novel cost of conglomeration that arises from an equilibrium framework. Because of financial market imperfections engendered by imperfect investor protection, conglomerates that engage in “winner-picking” (Stein, 1997) find it optimal to allocate scarce capital internally to mediocre projects, even when other firms in the economy have higher productivity projects that are in need of additional capital. This bias for internal capital allocation can decrease allocative efficiency even when conglomerates have efficient internal capital markets, because a substantial presence of conglomerates might make it harder for other firms in the economy to raise capital. We also argue that the negative externality associated with conglomeration is particularly costly for countries that are at intermediary levels of financial development. In such countries, a high degree of conglomeration, generated for example by the control of the corporate sector by family business groups, may decrease the efficiency of the capital market. Our theory generates novel empirical predictions that cannot be derived in models that ignore the equilibrium effects of conglomerates. These predictions are consistent with anecdotal evidence that the presence of business groups in developing countries inhibits the growth of new independent firms due to lack of finance

Micro Frontends para Aplicações Web

Over the course of the last ten years, web applications have stood out as the go to when it comes to software development, replacing the traditional desktop apps. As a result of this, customer demand has been on the rise, leaving companies with their hands full as they try to meet expectations. In the year 2011, the world was introduced to the concept of Microservices, which came to revolutionize the software development industry by splitting typical backend monolithic codebases into smaller, more manageable chunks that were able to be developed, deployed and tested independently. This in turn facilitated customer deliveries as it opened the door to iterative and incremental developments, preventing customers from having to wait months, or even sometimes years, to receive a fully functional product since they could now be handed constant updates in time periods as short as 15 days. However, even though this expedited today’s backend developments, a web application is not only composed by a server-side layer, but also a client-side one. Today’s application frontends still rely on the traditional monolithic architecture which presents the same issues that backend developments once did and, due to the ever-increasing popularity of the online world, these types of solutions have been growing massively and escalating those problems. By having these architectural discrepancies between frontend and backend codebases, iterative and incremental software developed can never be fully realized as all microservices still depend on the same monolithic frontend. This is where Micro Frontends come in. The concept behind this model is to take the teachings microservices provided and expand them to the client-side. By organizing applications into several components, each with its respective business sub-domain, vertical teams can then be assembled and take full ownership of said sub-domain, ultimately implementing the component from end-to-end. Since a Micro Frontend based architecture is still a somewhat recent concept, information is lacking and makes the assessment of its viability hard to reach. As such, this dissertation aims to study its feasibility by studying and comparing possible alternatives, ultimately describing its advantages and disadvantages, and finally presenting a proof-of-concept application.Ao longo dos últimos dez anos, as aplicações web têm-se destacado no que diz respeito ao desenvolvimento de software, substituindo as aplicações desktop tradicionais. Consequentemente, a quantidade de clientes neste mercado tem vindo a aumentar, deixando as empresas com dificuldades ao tentar atender às expectativas. Em 2011, o mundo tecnológico foi apresentado ao conceito de Microsserviços, o qual veio revolucionar a indústria de desenvolvimento de software ao dividir soluções monolíticas em peças de menor dimensão e mais facilmente geridas que possibilitaram os processos de desenvolvimento, implantação e teste de forma independente. Deste modo os microserviços permitiram a adoção de desenvolvimentos iterativos e incrementais, que por sua vez vieram evitar morosas esperas por parte dos clientes para receber o seu produto desejado em troca de entregas de, por exemplo, 15 em 15 dias (a duração por defeito de um sprint na maioria das metodologias de desenvolvimento de software ágeis). No entanto, embora isso tenha acelerado o desenvolvimento de código relativo ao backend, uma aplicação web não é composta apenas por uma camada do lado do servidor, mas também do lado do cliente. Atualmente, o desenvolvimento de aplicações de frontend tende a utilizar uma arquitetura monolítica tradicional, a qual apresenta os mesmos problemas que os desenvolvimentos de backend anteriormente apresentavam. Devido ao aumento de popularidade das aplicações web, essas mesmas soluções monolíticas têm crescido exponencialmente, agravando os problemas. Com as discrepâncias arquiteturais entre projetos de frontend e backend, o conceito de desenvolvimento de software iterativo e incremental nunca pode ser cumprido na totalidade, pois todos os microsserviços implementados dependem do mesmo frontend monolítico. Para solucionar os problemas supramencionados, surgiu o conceito de Micro Frontends. O principal propósito da arquitetura de Micro Frontends é aplicar os conceitos providenciados pelos microsserviços e expandi-los para o lado do cliente. Ao organizar as soluções em vários componentes, cada um com seu respectivo subdomínio do negócio da aplicação, torna-se possível a criação de equipas verticais, as quais assumem controlo total do referido subdomínio, implementando o componente de ponta a ponta. Visto que uma arquitetura de Micro Frontends ainda é um conceito relativamente recente, avaliar a sua fiabilidade torna-se uma tarefa difícil. Deste modo, esta dissertação procura estudar este modelo e comparar as diferentes alternativas de implementação, descrevendo as suas vantagens e desvantagens e, por fim, apresentando uma prova de conceito