112 research outputs found

    The impact of duality on managerial decisions and performance: Evidence from the mutual fund industry

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    We study the decisions and performance of managers who are also chair of the board (duality managers). We hypothesize that duality managers take more risky decisions and deliver worse performance than non-duality managers due to reduced level of control and replacement risk. Using the mutual fund industry as our laboratory we provide strong support for these hypotheses: Duality managers take risk that they could easily avoid, deviate from their benchmarks, make extreme decisions, and, consequently, deliver extreme performance outcomes. Furthermore, their average underperformance is 2.5 percent. All effects are the stronger, the more power the manager has in the board

    MICP-L: Mesh-based ICP for Robot Localization using Hardware-Accelerated Ray Casting

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    Triangle mesh maps have proven to be a versatile 3D environment representation for robots to navigate in challenging indoor and outdoor environments exhibiting tunnels, hills and varying slopes. To make use of these mesh maps, methods are needed that allow robots to accurately localize themselves to perform typical tasks like path planning and navigation. We present Mesh ICP Localization (MICP-L), a novel and computationally efficient method for registering one or more range sensors to a triangle mesh map to continuously localize a robot in 6D, even in GPS-denied environments. We accelerate the computation of ray casting correspondences (RCC) between range sensors and mesh maps by supporting different parallel computing devices like multicore CPUs, GPUs and the latest NVIDIA RTX hardware. By additionally transforming the covariance computation into a reduction operation, we can optimize the initial guessed poses in parallel on CPUs or GPUs, making our implementation applicable in real-time on a variety of target architectures. We demonstrate the robustness of our localization approach with datasets from agriculture, drones, and automotive domains

    Strategies for novel transparent conducting sol-gel oxide coatings

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    Transparent conducting coatings of doped SnO2 and Zn2SnO4 have been deposited by the sol—gel technique on borosilicate and alumosilicate glass substrates, respectively. As films of SnO2 : Sb (ATO) show some intrinsic drawbacks, which are discussed in this report, alternative dopants for SnO2 such as Ta, Nb and W, were examined concerning the electrical and optical properties of the deposited coatings. In this way, coatings with resistivities on the order of

    Editorial preface

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    Total scattering reveals the hidden stacking disorder in a 2D covalent organic framework

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    Interactions between extended π-systems are often invoked as the main driving force for stacking and crystallization of 2D organic polymers. In covalent organic frameworks (COFs), the stacking strongly influences properties such as the accessibility of functional sites, pore geometry, and surface states, but the exact nature of the interlayer interactions is mostly elusive. The stacking mode is often identified as eclipsed based on observed high symmetry diffraction patterns. However, as pointed out by various studies, the energetics of eclipsed stacking are not favorable and offset stacking is preferred. This work presents lower and higher apparent symmetry modifications of the imine-linked TTI-COF prepared through high- and low-temperature reactions. Through local structure investigation by pair distribution function analysis and simulations of stacking disorder, we observe random local layer offsets in the low temperature modification. We show that while stacking disorder can be easily overlooked due to the apparent crystallographic symmetry of these materials, total scattering methods can help clarify this information and suggest that defective local structures could be much more prevalent in COFs than previously thought. A detailed analysis of the local structure helps to improve the search for and design of highly porous tailor-made materials

    Editorial: Expanding knowledge geographies

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    In this editorial, we sketch out an agenda committed to exploring and fostering situated yet global perspectives on the manifold connections, disconnections, and differences within Europe, as well as between Europe and other parts of the world and discuss how we seek to advance this agenda and some of the continuing practical hurdles we face

    Broadband Purcell enhanced emission dynamics of quantum dots in linear photonic crystal waveguides

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    The authors investigate the spontaneous emission dynamics of self-assembled InGaAs quantum dots embedded in GaAs photonic crystal waveguides. For an ensemble of dots coupled to guided modes in the waveguide we report spatially, spectrally, and time-resolved photoluminescence measurements, detecting normal to the plane of the photonic crystal. For quantum dots emitting in resonance with the waveguide mode, a ~21x enhancement of photoluminescence intensity is observed as compared to dots in the unprocessed region of the wafer. This enhancement can be traced back to the Purcell enhanced emission of quantum dots into leaky and guided modes of the waveguide with moderate Purcell factors up to ~4x. Emission into guided modes is shown to be efficiently scattered out of the waveguide within a few microns, contributing to the out-of-plane emission and allowing the use of photonic crystal waveguides as broadband, efficiency-enhancing structures for surface-emitting diodes or single photon sources.Comment: 13 pages, 4 figure
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