Abstract The only observable outcome of the audit process is normally the issued audit report, which, at least in its standard form, does not contain much information about audit quality (Balsam et al. 2003). Auditor quality is multidimensional and inherently unobservable, and there is no single auditor characteristic that can be used as a proxy for it. In the absence of direct measures for quality, audit consumers must assess the quality by using quality surrogates, or the overall reputation of an auditor (e.g. Shapiro 1983, Riley 2001). The purpose of this dissertation is to enhance our understanding of the determinants and implications of quality-differentiated audits through four inter-related essays. The findings of the essays shed light on the various ways in which client firms strive to signal high audit and consequent earnings quality. From the supply-side perspective, the essays of this dissertation provide evidence how some (individual) auditors have been able to establish a reputation higher than the generic reputation. Importantly, this dissertation adds to the ongoing debate about the regulator changes and initiatives in the European Union and the U.S.A. requiring disclosure of engagement partner identity. The rationale behind such a requirement is that it could bring within investors’ reach greater transparency and accountability in the auditing process thereby helping to restore investor confidence in the capital markets. Consistent with this rationale, the results of this dissertation support the view that audit markets (and/or firm insiders) infer audit quality, at least to some extent, from the characteristics of the individual audit partner in charge.

Orientador: Christian Rodolfo Esteve Rothenberg / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-27T04:14:12Z (GMT). No. of bitstreams: 1 Fernandes_EderLeao_M.pdf: 1013570 bytes, checksum: 6c396641a9ce6faceedd380180040736 (MD5) Previous issue date: 2015 / Resumo: OpenFlow é a mais proeminente tecnologia para a implementação de Redes Definidas por Software (RDS). Projetada como uma interface de controle entre switches e controladores, o protocolo pode ser visto como um conjunto de instruções para programar a lógica de encaminhamento em comutadores da rede. A primeira versão do OpenFlow atraiu a atenção de pesquisadores da indústria e universidades interessados nos potenciais benefícios prometidos por RDS. Rápidamente surgiram ferramentas para experimentação em OpenFlow 1.0, incluindo comutadores, controladores e software para testes e emulação. Após o início da padronização do protocolo pela OpenNetworkFoundation, o protocolo OpenFlow evoluiu rapidamente dando origem à novas especificações. As novas funcionalidades aumentaram as possibilidades de experimentos, gerando entusiasmo. Porém, o desenvolvimento das ferramentas de experimen- tação não acompanharam o mesmo rítmo do protocolo. Para preencher essa lacuna, nosso projeto desenvolveu um comutador em software com suporte a OpenFlow 1.3. Guiado pelo objetivo de ser simples e básicos requisitos de desempenho, a proposta da ferramenta é ser uma opção, fácil e funcional para desenvolvedores de aplicações RDS buscando utilizar as novas funcionalidades do OpenFlow 1.3. Em suma, o software desenvolvido nesse projeto foi o primeiro comutador OpenFlow 1.3 do mundo. Lançado como projeto de código aberto, possibilitou a pesquisadores de todo o mundo a prototipagem e demonstração de soluções não possíveis anteriormente / Abstract: OpenFlow is the most prominent technology to enable Software Defined Networking (SDN). Designed as a control interface between switches and controllers, the protocol can be considered an instruction set to program the network forwarding logic. The first OpenFlow version attracted attention from both the industry and academy researchers interested in SDN promised benefits. Quickly, a toolset for OpenFlow 1.0 was available, which included switches, controllers, test and emulation software. When the protocol standardization process started by the Open Network Foundation, OpenFlow evolved fast and new specifications emerged in the last years. New features empowered the protocol and created enthusiasm; however projects of experimentation tools did not followed the OpenFlow fast pace. This work addresses one of these gaps, implementing an experimenter friendly OpenFlow 1.3 software switch. Driven by simplicity and basic performance requirements, the tool purpose is to be a functional and easy option for SDN developers that want to take advantage of the benefits brought by more recent OpenFlow versions. Overall, this project resulted in the open source release of the first OpenFlow 1.3 switch, allowing researchers from all around the globe to prototype and demonstrate solutions not possible until this work. Keywords: Computer Networks; Software Defined / Mestrado / Engenharia de Computação / Mestre em Engenharia Elétrica

La thèse intitulée "Conception, caractérisation et optimisation d’un transistor à effet de champ haute tension en Carbure de Silicium (SiC) et de leur diode associée", s’est déroulée au sein du laboratoire AMPERE sous la direction du Prof. D. PLANSON. Des premiers démonstrateurs de JFET ont été réalisés. Le blocage du JFET n'est pas efficace, ceci étant lié aux difficultés de réalisation technologique. Le premier travail a consisté en leur caractérisation précise puis en leur simulation, en tenant compte des erreurs de processus de fabrication. Ensuite, un nouveau masque a été dessiné en tenant en compte des problèmes technologiques identifiés. Les performances électriques de la nouvelle génération du composant ont ainsi démontré une amélioration importante au niveau de la tenue en tension. Dans le même temps, de nouveaux problèmes se sont révélés, qu’il sera nécessaire de résoudre dans le cadre de travaux futurs. Par ailleurs, les aspects de tenue en court-circuit des JFETs en SiC commercialement disponibles ont été étudiés finement. Les simulations électrothermiques par TCAD ont révélé les modes de défaillances. Ceci a permis d'établir finalement des modèles physiques valables pour les JFETs en SiC. / Silicon carbide (SiC) has higher critical electric field for breakdown and lower intrinsic carrier concentration than silicon, which are very attractive for high power and high temperature power electric applications. In this thesis, a new 3.3kV/20A SiC-4H JFET is designed and fabricated for motor drive (330kW). This breakdown voltage is beyond the state of art of the commercial unipolar SiC devices. The first characterization shows that the breakdown voltage is lower (2.5kV) than its theoretical value. Also the on-state resistance is more important than expected. By means of finite element simulation the origins of the failure are identified and then verified by optical analysis. Hence, a new layout is designed followed by a new generation of SiC-4H JFET is fabricated. Test results show the 3.3kV JFET is developed successfully. Meanwhile, the electro-thermal mechanism in the SiC JFETs under short circuit is studied by means of TCAD simulation. The commercial 1200V SIT (USCi) and LV-JFET (Infineon) are used as sample. A hotspot inside the structures is observed. And the impact the bulk thickness and the canal doping on the short circuit capability of the devices are shown. The physical models validated by this study will be used on our 3.3kV once it is packaged.

The goal of the diploma thesis is a design of the reconstruction of the Solnice railway station in aim to fulfil the requirements for the movement of persons with reduced mobility. It was necessary to design platforms with a height of the platform edge 550 mm above rail level in that context. Furthermore the increased length of tracks as well as a modification of the connection of sidings of Škoda company and of the timber plant was required. There was also included the design of reconstruction of drainage system of railway tracks.

The topic of this thesis is the study of reconstruction railway station Moravské Bránice and railway station Rakšice in order to insert new platforms, according to current legislation. In railway station Moravské Bránice it was necessary to design at least 3 platform edges, in railway station Rakšice it was necessary to design at least 2 platform edges.

The aim of the diploma thesis is the reconstruction of the railway station Krahulov in aim to fulfil the requirements for people with limited mobility. In connection with the change of the platform was resolved adjustment rails and drainage while maintaining a connection to an adjacent sidings.

The goal of the diploma thesis is a design of the reconstruction of the Polička railway station in aim to fulfil the requirements for the movement of people with reduced mobility. It was necessary to design platforms with a height of the platform edge 550 mm above rail level. It was also required to increase the design speed in main tracks as well as to reconstruct conections of sidings. There was also included the design of reconstruction of drainage system of railway tracks.

The diploma thesis deals with the reconstruction of the railway station Žďárec u Skutče. The station is situated on the track Havlíčkův Brod – Pardubice-Rosice nad Labem. The aim of the reconstruction is to design the platform so that it meets the requirements of mobility-impaired persons. The work deals with track layout adjustments, the reconstruction of both the subgrade and the permanent way and the design of drainage. Also a bill of quantities and costs estimates were reckones.

The aim of the diploma thesis is design of the Vsetín railway station reconstruction according to the current operation and the requirements for persons with reduced mobility. The two new double face island platforms with the height of 550 mm above the top of rail is designed. Further, the speed in passing running lines and also the curves in front of Polanka throat of the station is increased.

The aim of thesis is to design a reconstruction of railway station Studenec, so it would suit current and future traffic. The main purpose of reconstruction is increasing the line speed. The reconstruction reflects on requirements for persons with reduced mobility under applicable legislation.