O regime da arbitragem tributária

Mestrado em Fiscalidade

An analysis of the impact of bus contention on the WCET in multicores

The use of multicores is becoming widespread inthe field of embedded systems, many of which have real-time requirements. Hence, ensuring that real-time applications meet their timing constraints is a pre-requisite before deploying them on these systems. This necessitates the consideration of the impact of the contention due to shared lowlevel hardware resources like the front-side bus (FSB) on the Worst-CaseExecution Time (WCET) of the tasks. Towards this aim, this paper proposes a method to determine an upper bound on the number of bus requests that tasks executing on a core can generate in a given time interval. We show that our method yields tighter upper bounds in comparison with the state of-the-art. We then apply our method to compute the extra contention delay incurred by tasks, when they are co-scheduled on different cores and access the shared main memory, using a shared bus, access to which is granted using a round-robin arbitration (RR) protocol.

Response time analysis of COTS-Based multicores considering the contention on the shared memory bus

The current industry trend is towards using Commercially available Off-The-Shelf (COTS) based multicores for developing real time embedded systems, as opposed to the usage of custom-made hardware. In typical implementation of such COTS-based multicores, multiple cores access the main memory via a shared bus. This often leads to contention on this shared channel, which results in an increase of the response time of the tasks. Analyzing this increased response time, considering the contention on the shared bus, is challenging on COTS-based systems mainly because bus arbitration protocols are often undocumented and the exact instants at which the shared bus is accessed by tasks are not explicitly controlled by the operating system scheduler; they are instead a result of cache misses. This paper makes three contributions towards analyzing tasks scheduled on COTS-based multicores. Firstly, we describe a method to model the memory access patterns of a task. Secondly, we apply this model to analyze the worst case response time for a set of tasks. Although the required parameters to obtain the request profile can be obtained by static analysis, we provide an alternative method to experimentally obtain them by using performance monitoring counters (PMCs). We also compare our work against an existing approach and show that our approach outperforms it by providing tighter upper-bound on the number of bus requests generated by a task.

Finding an upper bound on the increase in execution time due to contention on the memory bus in COTS-based multicore systems

Contention on the memory bus in COTS based multicore systems is becoming a major determining factor of the execution time of a task. Analyzing this extra execution time is non-trivial because (i) bus arbitration protocols in such systems are often undocumented and (ii) the times when the memory bus is requested to be used are not explicitly controlled by the operating system scheduler; they are instead a result of cache misses. We present a method for finding an upper bound on the extra execution time of a task due to contention on the memory bus in COTS based multicore systems. This method makes no assumptions on the bus arbitration protocol (other than assuming that it is work-conserving).

Static-priority scheduling over wireless networks with multiple broadcast domains

We propose a wireless medium access control (MAC) protocol that provides static-priority scheduling of messages in a guaranteed collision-free manner. Our protocol supports multiple broadcast domains, resolves the wireless hidden terminal problem and allows for parallel transmissions across a mesh network. Arbitration of messages is achieved without the notion of a master coordinating node, global clock synchronization or out-of-band signaling. The protocol relies on bit-dominance similar to what is used in the CAN bus except that in order to operate on a wireless physical layer, nodes are not required to receive incoming bits while transmitting. The use of bit-dominance efficiently allows for a much larger number of priorities than would be possible using existing wireless solutions. A MAC protocol with these properties enables schedulability analysis of sporadic message streams in wireless multihop networks.

A framework for memory contention analysis in multi-core platforms

The last decade has witnessed a major shift towards the deployment of embedded applications on multi-core platforms. However, real-time applications have not been able to fully benefit from this transition, as the computational gains offered by multi-cores are often offset by performance degradation due to shared resources, such as main memory. To efficiently use multi-core platforms for real-time systems, it is hence essential to tightly bound the interference when accessing shared resources. Although there has been much recent work in this area, a remaining key problem is to address the diversity of memory arbiters in the analysis to make it applicable to a wide range of systems. This work handles diverse arbiters by proposing a general framework to compute the maximum interference caused by the shared memory bus and its impact on the execution time of the tasks running on the cores, considering different bus arbiters. Our novel approach clearly demarcates the arbiter-dependent and independent stages in the analysis of these upper bounds. The arbiter-dependent phase takes the arbiter and the task memory-traffic pattern as inputs and produces a model of the availability of the bus to a given task. Then, based on the availability of the bus, the arbiter-independent phase determines the worst-case request-release scenario that maximizes the interference experienced by the tasks due to the contention for the bus. We show that the framework addresses the diversity problem by applying it to a memory bus shared by a fixed-priority arbiter, a time-division multiplexing (TDM) arbiter, and an unspecified work-conserving arbiter using applications from the MediaBench test suite. We also experimentally evaluate the quality of the analysis by comparison with a state-of-the-art TDM analysis approach and consistently showing a considerable reduction in maximum interference.

A Generic and Compositional Framework for Multicore Response Time Analysis

23rd International Conference on Real-Time Networks and Systems (RTNS 2015). 4 to 6, Nov, 2015, Main Track. Lille, France. Best Paper Award Nominee

A lei aplicável ao processo de arbitragem internacional

This paper is the author’s Master’s Thesis. It aims to study the content of lexarbitri, i.e. the relevant law regarding international arbitration. Under both Portuguese law and UNCITRAL model law, the seat’s legal provisions shall be applied at all times. Contrarily, French and Swiss legislations allow parties and arbitrators to apply any arbitration law to international arbitration, whether the seat law or a foreign arbitration law. There is not a sole understanding towards the criteria to determine the legal provisions that shall govern international arbitration. Traditionally, the lexarbitri would correspond to the arbitration law of the seat of the arbitration. The territorialist criteria remains in force under the majority of arbitration laws that the author has consulted. However, it has been criticized by several authorities in international arbitration, who suggest that the arbitration shall be governed by the law of the seat or of the place in which the award is to be enforcement, whichever better grants its enforcement – the cumulative doctrine; or the arbitration shall be governed by a set of provisions that make up the autonomous transnational legal, regardless of the legal provisions of the law of the seat – the transnational doctrine. The author intends to debate the three mentioned understandings regarding the lexarbitriand further explains why the territorialist criteria is the most adequate to the characteristics and demands of international arbitration, to the governing instruments in force and to the need for a useful award.

A arbitragem como alternativa para diminuir a morosidade do sistema judiciário brasileiro

This thesis is about arbitration, a form of alternative dispute resolution, as a solution for the slowness of the Brazilian Judiciary. The paper starts with an approach of the fundamental rights, highlighting their positivation, important to distinguish them from human rights, the four dimensions of the fundamental rights and, lastly, the analysis of their features, emphasizing their characters of complementarity and universality. After, it starts to discourse about the “access to Justice”, an important fundamental right, and, to delimitate the role of the Judiciary and the problems related to solve cases in a reasonable amount of time. Next, it exposes other alternative forms of dispute resolutions that, like the arbitration, can help to the concretization of a faster and more effective Justice. Then, it discusses the historical evolution of the arbitration in Brazil, highlighting the contemporary features of the institute, which were more visible with the ratification of the New York Convention and the promulgation of Law nº 9.307/1996. In addition, it analyses the possible changes that will come with the New Brazilian Procedure Law Code and the PL 7.108/2014, intended to change the current Arbitration Law. It also explains the main arbitration attributes, describing the peculiarities of the arbitral convention, the arbitrator role, and the arbitral award aspects. At least, it lists the main reasons someone should choose arbitration instead the Judiciary, considering the Brazilian Courts reality.

Relatório de estágio no Centro de Arbitragem Comercial da Câmara de Comércio e Indústria Portuguesa

This report is the outcome of an internship that took place in Centro de Arbitragem Comercial da Câmara de Comércio e Indústria Portuguesa and its completion is an essential part of the path towards obtaining the Master’s Degree in Faculdade de Direito da Universidade Nova de Lisboa. This report has been structured in two stages – firstly, the presentation of the Centro de Arbitragem Comercial, focusing on its field of expertise, organic structure, principles and advantages. Then, the description of the activities developed within the Secretariat over the several stages of the arbitration procedure – since the reception of the arbitration requirement in institutional proceedings, terms of reference in ad hoc procedures, through the monitoring of the arbitral tribunal sessions (preliminary hearings, submission of evidence and final allegations) and the notification of the arbitration award. The second stage of this report is related to the description of the functions and powers of the President of Centro de Arbitragem Comercial. Firstly, it defines those powers by analyzing the statutes and rules of proceedings of the Centro de Arbitragem, drawing comparisons between the above mention and the rules of proceedings of others arbitral institutional centres, some of them are international references. The report assesses and describes the presidential powers, such as: configuration and composition of the arbitral tribunal (including arbitrator’s replacements, excuses and refusals); deadline extensions; determination of procedural rules and decision-making on any procedural incidents which arise before the constitution of the arbitral tribunal; definition of arbitration costs and fees; joinder of parties and consolidation of proceedings admission; and appointment of an emergency arbitrator. Lastly, this report analyzes some decisions delivered by the President in the respective institutional procedures which took place in the Centre.

Relatório de estágio curricular no Centro de Arbitragem Comercial da Câmara de Comércio e Indústria portuguesa

This report is the outcome of an internship that took place in Centro de Arbitragem Comercial da Câmara de Comércio e Indústria Portuguesa and its completion is an essential part of the path towards obtaining the Master’s Degree in Faculdade de Direito da Universidade Nova de Lisboa. This report has been structured in two stages – firstly, the presentation of the Centro de Arbitragem Comercial, focusing on its field of expertise, organic structure, principles and advantages. Then, the description of the activities developed within the Secretariat over the several stages of the arbitration procedure – since the reception of the arbitration requirement in institutional proceedings, terms of reference in ad hoc procedures, through the monitoring of the arbitral tribunal sessions (preliminary hearings, submission of evidence and final allegations) and the notification of the arbitration award. The second stage of this report is related to the description of the functions and powers of the President of Centro de Arbitragem Comercial. Firstly, it defines those powers by analyzing the statutes and rules of proceedings of the Centro de Arbitragem, drawing comparisons between the above mention and the rules of proceedings of others arbitral institutional centres, some of them are international references. The report assesses and describes the presidential powers, such as: configuration and composition of the arbitral tribunal (including arbitrator’s replacements, excuses and refusals); deadline extensions; determination of procedural rules and decision-making on any procedural incidents which arise before the constitution of the arbitral tribunal; definition of arbitration costs and fees; joinder of parties and consolidation of proceedings admission; and appointment of an emergency arbitrator. Lastly, this report analyzes some decisions delivered by the President in the respective institutional procedures which took place in the Centre.

Arbitragem de consumo no direito brasileiro

This dissertation analyzes how the current Constitution and the Brazilian law establish consumer protection, arbitration and access to justice. Following we try to demonstrate why arbitration is a method rarely used in the resolution of consumer disputes in Brazil. It also examines the doctrinal and jurisprudential aspects of the conflict between the Brazilian Arbitration Law (Law nº. 9.307/96), which allows the arbitration clause in contracts of adhesion, and the Consumer Protection Code (Law nº 8.078/90) that in article 51, VII, considers as abusive the arbitration clause. Furthermore, analyzes new proposed bills under scrutiny by the National Congress on the issue and identifies the causes, in the Brazilian legal system, hampering the use of arbitration in consumer relations. Concludes that there are no principle obstacles preventing consumer litigations to be settled by arbitration. High costs, mistrust, oppression, misinformation of consumers and non-participation of the State, being a totally private institute, are factors that generate distrust, suspicion, and have prevented the development of arbitration in consumer relations in Brazil.

A lei aplicável ao processo de arbitragem internacional

This paper is the author’s Master’s Thesis. It aims to study the content of lexarbitri, i.e. the relevant law regarding international arbitration. Under both Portuguese law and UNCITRAL model law, the seat’s legal provisions shall be applied at all times. Contrarily, French and Swiss legislations allow parties and arbitrators to apply any arbitration law to international arbitration, whether the seat law or a foreign arbitration law. There is not a sole understanding towards the criteria to determine the legal provisions that shall govern international arbitration. Traditionally, the lexarbitri would correspond to the arbitration law of the seat of the arbitration. The territorialistcriteria remains in force under the majority of arbitration laws that the author has consulted.However, it has been criticized by several authorities in international arbitration, who suggest that the arbitration shall be governed by the law of the seat or of the place in which the award is to be enforcement, whichever better grants its enforcement – the cumulative doctrine; or the arbitration shall be governed by a set of provisions that make up the autonomous transnational legal, regardless of the legal provisions of the law of the seat – the transnational doctrine. The author intends to debate the three mentioned understandings regarding the lexarbitriand further explains why the territorialist criteria is the most adequate to the characteristics and demands of international arbitration, to the governing instruments in force and to the need for a useful award.

Relatório de estágio curricular no Centro de Arbitragem Comercial

The main purpose of this report is to present the work developed during the curricular internship on the Commercial Arbitration Centre of the Portuguese Chamber of Commerce and Industry. It is structured in two parts. The first, in which i´ll present the CAC, its organic structure and its activities. In this part I will also show the work I´ve done during the internship, as well as i´m going to identified, and comment, the tasks performed. The second part presents a study on arbitration awards that aimed to determine the amount “split the baby awards”, that is to say those that condemn in (approximately) half of the request. In addition to these data, I collected from sentences other, such as the duration of the cases, the number of foreign persons in each process, the number of foreign arbitrators, the language of proceedings etc. What is expected with this paperwork is to be able to clarify, and make known, some aspects on Arbitration in Portugal, thus contributing to the strengthening of the role of the Arbitration and Arbitral Justice.

A escolha do direito aplicável ao mérito do litígio na arbitragem comercial internacional

Dissertação de mestrado em Direito dos Contratos e da Empresa