Mortgage securitization and its credit risk control

This dissertation concentrate on the mortgage securitization and its credit risk, which are criticized as the main causes of the financial crisis. From the point of the veiw of mortgage's evolution, the nature, structure and function of mortgage has been radically changed, yet the mortgage law did not give appropriate response to this market change. Meanwhile, the U.S legilslations facilitating the mortgage securitization also have rotten the legal foundations for mortgage market self-regulation and sustained development. In contrast, the EU covered bond system has kept financial stability for 200 years' time, and their statutory approach has been proved to be able to control the credit risk and incentive problems very well, in combination of market self-regulation and public regulation. So the future reform should be directed to strengthen the market's capacity of self-regulation and improve the public regulation. For the development of mortgage securitization in China, it is suggested to introduce the EU covered bond system for the reason of the equilibrium between funding efficiency and financial stability.

Measurement of the ZZ production cross section and limits on anomalous neutral triple gauge couplings with ATLAS

The main work of this thesis concerns the measurement of the production cross section using LHC 2011 data collected at a center-of-mass energy equal to 7 TeV by the ATLAS detector and resulting in a total integrated luminosity of 4.6 inverse fb. The ZZ total cross section is finally compared with the NLO prediction calculated with modern Monte Carlo generators. In addition, the three differential distributions (∆φ(l,l), ZpT and M4l) are shown unfolded back to the underlying distributions using a Bayesian iterative algorithm. Finally, the transverse momentum of the leading Z is used to provide limits on anoumalus triple gauge couplings forbidden in the Standard Model.

Use of shared memory in the context of embedded multi-core processors: exploration of the technology and its limits

Modern embedded systems embrace many-core shared-memory designs. Due to constrained power and area budgets, most of them feature software-managed scratchpad memories instead of data caches to increase the data locality. It is therefore programmers’ responsibility to explicitly manage the memory transfers, and this make programming these platform cumbersome. Moreover, complex modern applications must be adequately parallelized before they can the parallel potential of the platform into actual performance. To support this, programming languages were proposed, which work at a high level of abstraction, and rely on a runtime whose cost hinders performance, especially in embedded systems, where resources and power budget are constrained. This dissertation explores the applicability of the shared-memory paradigm on modern many-core systems, focusing on the ease-of-programming. It focuses on OpenMP, the de-facto standard for shared memory programming. In a first part, the cost of algorithms for synchronization and data partitioning are analyzed, and they are adapted to modern embedded many-cores. Then, the original design of an OpenMP runtime library is presented, which supports complex forms of parallelism such as multi-level and irregular parallelism. In the second part of the thesis, the focus is on heterogeneous systems, where hardware accelerators are coupled to (many-)cores to implement key functional kernels with orders-of-magnitude of speedup and energy efficiency compared to the “pure software” version. However, three main issues rise, namely i) platform design complexity, ii) architectural scalability and iii) programmability. To tackle them, a template for a generic hardware processing unit (HWPU) is proposed, which share the memory banks with cores, and the template for a scalable architecture is shown, which integrates them through the shared-memory system. Then, a full software stack and toolchain are developed to support platform design and to let programmers exploiting the accelerators of the platform. The OpenMP frontend is extended to interact with it.

Mitochondrial respiratory supercomplex association limits production of reactive oxygen species from Complex I

Evidence accumulated in the last ten years has demonstrated that a large proportion of the mitochondrial respiratory chain complexes in a variety of organisms is arranged in supramolecular assemblies called supercomplexes or respirasomes. Besides conferring a kinetic advantage (substrate channeling) and being required for the assembly and stability of Complex I, indirect considerations support the view that supercomplexes may also prevent excessive formation of reactive oxygen species (ROS) from the respiratory chain. Following this line of thought we have decided to directly investigate ROS production by Complex I under conditions in which the complex is arranged as a component of the supercomplex I1III2 or it is dissociated as an individual enzyme. The study has been addressed both in bovine heart mitochondrial membranes and in reconstituted proteoliposomes composed of complexes I and III in which the supramolecular organization of the respiratory assemblies is impaired by: (i) treatment either of bovine heart mitochondria or liposome-reconstituted supercomplex I-III with dodecyl maltoside; (ii) reconstitution of Complexes I and III at high phospholipids to protein ratio. The results of this investigation provide experimental evidence that the production of ROS is strongly increased in either model; supporting the view that disruption or prevention of the association between Complex I and Complex III by different means enhances the generation of superoxide from Complex I . This is the first demonstration that dissociation of the supercomplex I1III2 in the mitochondrial membrane is a cause of oxidative stress from Complex I. Previous work in our laboratory demonstrated that lipid peroxidation can dissociate the supramolecular assemblies; thus, here we confirm that preliminary conclusion that primary causes of oxidative stress may perpetuate reactive oxygen species (ROS) generation by a vicious circle involving supercomplex dissociation as a major determinant.

Credit-Default-Swaps and the 2008 Financial Crisis: An Inquiry into the Underlying Legal Origins and the European Union’s Regulatory Reforms

After the 2008 financial crisis, the financial innovation product Credit-Default-Swap (CDS) was widely blamed as the main cause of this crisis. CDS is one type of over-the-counter (OTC) traded derivatives. Before the crisis, the trading of CDS was very popular among the financial institutions. But meanwhile, excessive speculative CDSs transactions in a legal environment of scant regulation accumulated huge risks in the financial system. This dissertation is divided into three parts. In Part I, we discussed the primers of the CDSs and its market development, then we analyzed in detail the roles CDSs had played in this crisis based on economic studies. It is advanced that CDSs not just promoted the eruption of the crisis in 2007 but also exacerbated it in 2008. In part II, we asked ourselves what are the legal origins of this crisis in relation with CDSs, as we believe that financial instruments could only function, positive or negative, under certain legal institutional environment. After an in-depth inquiry, we observed that at least three traditional legal doctrines were eroded or circumvented by OTC derivatives. It is argued that the malfunction of these doctrines, on the one hand, facilitated the proliferation of speculative CDSs transactions; on the other hand, eroded the original risk-control legal mechanism. Therefore, the 2008 crisis could escalate rapidly into a global financial tsunami, which was out of control of the regulators. In Part III, we focused on the European Union’s regulatory reform towards the OTC derivatives market. In specific, EU introduced mandatory central counterparty clearing obligation for qualified OTC derivatives, and requires that all OTC derivatives shall be reported to a trade repository. It is observable that EU’s approach in re-regulating the derivatives market is different with the traditional administrative regulation, but aiming at constructing a new market infrastructure for OTC derivatives.