538 research outputs found

    The Case for Mandatory Ownership Disclosure

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    The use of equity derivatives to conceal economic ownership of shares (“hidden ownership”) is increasingly drawing attention from the financial community, as is the exercise of voting power without corresponding economic interest (“empty voting”). Market participants and commentators have called for expansion of ownership disclosure rules, and policymakers on both sides of the Atlantic are now contemplating how to respond. Yet, in order to design appropriate responses it is key to understand why we have ownership disclosure rules in the first place. This understanding currently appears to be lacking, which may explain why we observe divergent approaches between countries. The case for mandatory ownership disclosure has also received remarkably little attention in the literature, which has focused almost exclusively on mandatory issuer disclosure. Perhaps this is because most people assume that ownership disclosure is a good thing. But why is such information important, and to whom? This paper aims to answer these fundamental questions, using the European disclosure regime as an example. First, the paper identifies two main objectives of ownership disclosure: improving market efficiency and corporate governance. Next, the paper explores the various mechanisms through which ownership disclosure performs these tasks. This sets the stage for an analysis of hidden ownership and empty voting that demonstrates why these phenomena are so problematic.ownership disclosure; market efficiency; corporate governance; monitoring; hidden ownership; empty voting; hedge fund activism

    Modelling dependencies in genetic-marker data and its application to haplotype analysis

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    The objective of this thesis is to develop new methods to reconstruct haplotypes from phaseunknown genotypes. The need for new methodologies is motivated by the increasing availÂŹ ability of high-resolution marker data for many species. Such markers typically exhibit correlations, a phenomenon known as Linkage Disequilibrium (LD). It is believed that reÂŹ constructed haplotypes for markers in high LD can be valuable for a variety of application areas in population genetics, including reconstructing population history and identifying genetic disease variantsTraditionally, haplotype reconstruction methods can be categorized according to whether they operate on a single pedigree or a collection of unrelated individuals. The thesis begins with a critical assessment of the limitations of existing methods, and then presents a uniÂŹ fied statistical framework that can accommodate pedigree data, unrelated individuals and tightly linked markers. The framework makes use of graphical models, where inference entails representing the relevant joint probability distribution as a graph and then using associated algorithms to facilitate computation. The graphical model formalism provides invaluable tools to facilitate model specification, visualization, and inference.Once the unified framework is developed, a broad range of simulation studies are conducted using previously published haplotype data. Important contributions include demonstrating the different ways in which the haplotype frequency distribution can impact the accuracy of both the phase assignments and haplotype frequency estimates; evaluating the effectiveness of using family data to improve accuracy for different frequency profiles; and, assessing the dangers of treating related individuals as unrelated in an association study

    Complete CFD analysis of a Velocity XL-5 RG with flight-test verification

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    The Texas A&M Flight Research Laboratory (FRL) recently received delivery of its newest aircraft, the Velocity XL-5 RG. The Velocity can fly faster than the other aircraft owned by the FRL and does not have a propeller in the front of the aircraft to disrupt the air flow. These are definite advantages that make the Velocity an attractive addition to the FRL inventory to be used in boundary-layer stability and transition control. Possible mounting locations built into the aircraft for future projects include hard points in the wings and roof of the fuselage. One of the drawbacks of the aircraft is that it has a canard ahead of the main wing that could disrupt the incoming flow for a wing glove or research requiring test pieces mounted to the hard point in the wing. Therefore, it is necessary to understand the influence the canard and the impact of its wake on the wing of the aircraft before any in-depth aerodynamic research could be completed on the aircraft. A combination of in-flight measurements of the canard wake and Computational Fluid Dynamics (CFD) were used to provide a clear picture of the flowfield around the aircraft. The first step of the project consisted of making a 3-D CAD model of the aircraft. This model was then used for the CFD simulations in Fluent. 2-D, 3-D, inviscid, and viscous simulations were preformed on the aircraft. A pressure rake was designed to house a 5-hole probe and 18 Pitot probes that extended forward of the main wing to measure the location and strength of the canard wake at various flight conditions. There were five primary test points that were recorded at multiple times over the course of three flights. Once all of the data were collected from the flights, the freestream conditions became the inputs into the final, 3-D CFD simulations on the aircraft. The good agreement between the CFD results and the in-flight measurements provided the necessary verification of the CFD model of the aircraft. These results can be used in the future planning and execution of experiments involving the Velocity XL-5 RG

    The Case for Mandatory Ownership Disclosure

    Get PDF
    The use of equity derivatives to conceal economic ownership of shares (“hidden ownership”) is increasingly drawing attention from the financial community, as is the exercise of voting power without corresponding economic interest (“empty voting”). Market participants and commentators have called for expansion of ownership disclosure rules, and policymakers on both sides of the Atlantic are now contemplating how to respond. Yet, in order to design appropriate responses it is key to understand why we have ownership disclosure rules in the first place. This understanding currently appears to be lacking, which may explain why we observe divergent approaches between countries. The case for mandatory ownership disclosure has also received remarkably little attention in the literature, which has focused almost exclusively on mandatory issuer disclosure. Perhaps this is because most people assume that ownership disclosure is a good thing. But why is such information important, and to whom? This paper aims to answer these fundamental questions, using the European disclosure regime as an example. First, the paper identifies two main objectives of ownership disclosure: improving market efficiency and corporate governance. Next, the paper explores the various mechanisms through which ownership disclosure performs these tasks. This sets the stage for an analysis of hidden ownership and empty voting that demonstrates why these phenomena are so problematic

    The Case for Mandatory Ownership Disclosure

    Get PDF
    The use of equity derivatives to conceal economic ownership of shares (“hidden ownership”) is increasingly drawing attention from the financial community, as is the exercise of voting power without corresponding economic interest (“empty voting”). Market participants and commentators have called for expansion of ownership disclosure rules, and policymakers on both sides of the Atlantic are now contemplating how to respond. Yet, in order to design appropriate responses it is key to understand why we have ownership disclosure rules in the first place. This understanding currently appears to be lacking, which may explain why we observe divergent approaches between countries. The case for mandatory ownership disclosure has also received remarkably little attention in the literature, which has focused almost exclusively on mandatory issuer disclosure. Perhaps this is because most people assume that ownership disclosure is a good thing. But why is such information important, and to whom? This paper aims to answer these fundamental questions, using the European disclosure regime as an example. First, the paper identifies two main objectives of ownership disclosure: improving market efficiency and corporate governance. Next, the paper explores the various mechanisms through which ownership disclosure performs these tasks. This sets the stage for an analysis of hidden ownership and empty voting that demonstrates why these phenomena are so problematic

    A capacitance spectroscopy-based platform for realizing gate-defined electronic lattices

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    Electrostatic confinement in semiconductors provides a flexible platform for the emulation of interacting electrons in a two-dimensional lattice, including in the presence of gauge fields. This combination offers the potential to realize a wide host of quantum phases. Here we present a measurement and fabrication scheme that builds on capacitance spectroscopy and allows for the independent control of density and periodic potential strength imposed on a two-dimensional electron gas. We characterize disorder levels and (in)homogeneity and develop and optimize different gating strategies at length scales where interactions are expected to be strong. A continuation of these ideas might see to fruition the emulation of interaction-driven Mott transitions or Hofstadter butterfly physics

    Rapid and robust association mapping of expression quantitative trait loci

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    We applied a simple and efficient two-step method to analyze a family-based association study of gene expression quantitative trait loci (eQTL) in a mixed model framework. This two-step method produces very similar results to the full mixed model method, with our method being significantly faster than the full model. Using the Genetic Analysis Workshop 15 (GAW15) Problem 1 data, we demonstrated the value of data filtering for reducing the number of tests and controlling the number of false positives. Specifically, we showed that removing non-expressed genes by filtering on expression variability effectively reduced the number of tests by nearly 50%. Furthermore, we demonstrated that filtering on genotype counts substantially reduced spurious detection. Finally, we restricted our analysis to the markers and transcripts that were closely located. We found five times more signals in close proximity (cis-) to transcripts than in our genome-wide analysis. Our results suggest that careful pre-filtering and partitioning of data are crucial for controlling false positives and allowing detection of genuine effects in genetic analysis of gene expression

    Numerical simulations with a first order BSSN formulation of Einstein's field equations

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    We present a new fully first order strongly hyperbolic representation of the BSSN formulation of Einstein's equations with optional constraint damping terms. We describe the characteristic fields of the system, discuss its hyperbolicity properties, and present two numerical implementations and simulations: one using finite differences, adaptive mesh refinement and in particular binary black holes, and another one using the discontinuous Galerkin method in spherical symmetry. The results of this paper constitute a first step in an effort to combine the robustness of BSSN evolutions with very high accuracy numerical techniques, such as spectral collocation multi-domain or discontinuous Galerkin methods.Comment: To appear in Physical Review
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