439 research outputs found

    Processing and Transmission of Information

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    Contains reports on three research projects.National Aeronautics and Space Administration (Grant NGL-22-009-013)Joint Services Electronics Programs (U.S. Army, U.S. Navy, and U.S. Air Force) under Contract DA 28-043-AMC-02536(E

    The Community Reinvestment Act: Its Impact on Lending in Low-Income Communities in the United States

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    This paper reviews data and research studies that demonstrate that CRA has helped to increase lending to low-income borrowers and in low-income neighborhoods, and that expanded CRA lending has been accomplished while maintaining sound lending practices and bank profitability. The paper also discusses literature that draws alternative conclusions, as well as studies that find, despite increases in lending and banking services to low- and moderate-income areas and to minority borrowers, that disparities still exist between the services afforded to these communities and those offered to the market as a whole

    Criteria for Continuous-Variable Quantum Teleportation

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    We derive an experimentally testable criterion for the teleportation of quantum states of continuous variables. This criterion is especially relevant to the recent experiment of Furusawa et al. [Science 282, 706-709 (1998)] where an input-output fidelity of 0.58±0.020.58 \pm 0.02 was achieved for optical coherent states. Our derivation demonstrates that fidelities greater than 1/2 could not have been achieved through the use of a classical channel alone; quantum entanglement was a crucial ingredient in the experiment.Comment: 12 pages, to appear in Journal of Modern Optic

    Optically preamplified receiver with low quantum limit

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    Hologram selection in realistic indoor optical wireless systems with angle diversity receivers

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    In this paper, we introduce a new adaptive optical wireless system that employs a finite vocabulary of stored holograms. We propose a fast delay, angle, and power adaptive holograms (FDAPA-Holograms) approach based on a divide and conquer (DandC) methodology and evaluate it with angle diversity receivers in a mobile optical wireless system. The ultimate goal is to increase the signal-to-noise ratio (SNR), reduce the effect of intersymbol interference, and eliminate the need to calculate the hologram at each transmitter and receiver location. A significant improvement is achieved in the presence of demanding background illumination noise, receiver noise, multipath propagation, mobility, and shadowing typical in a realistic indoor environment. The combination of beam delay, angle, and power adaptation offers additional degrees of freedom in the link design, resulting in a system that is able to achieve higher data rates (5 Gb/s). At a higher data rate of 5 Gb/s and under eye safety regulations, the proposed FDAPA-Holograms system offers around 13 dB SNR with full mobility in a realistic environment where shadowing exists. The fast search algorithm introduced that is based on a D&C algorithm reduces the computation time required to identify the optimum hologram. Simulation results show that the proposed system, FDAPA-Holograms, can reduce the time required to identify the optimum hologram position from 64 ms taken by a classic adaptive hologram to about 14 ms

    Synthesis and Isolation of {110}-Faceted Gold Bipyramids and Rhombic Dodecahedra

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    Two {110}-faceted gold nanostructures—rhombic dodecahedra and obtuse triangular bipyramids—have been synthesized via a Ag-assisted, seed-mediated growth method. The combination of a Cl−-containing surfactant with a low concentration of Ag+ plays a role in the stabilization of the {110} facets. To the best of our knowledge, this is the first reported synthesis of a {110}-faceted bipyramid structure

    Synthesis and Isolation of {110}-Faceted Gold Bipyramids and Rhombic Dodecahedra

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    Two {110}-faceted gold nanostructures—rhombic dodecahedra and obtuse triangular bipyramids—have been synthesized via a Ag-assisted, seed-mediated growth method. The combination of a Cl−-containing surfactant with a low concentration of Ag+ plays a role in the stabilization of the {110} facets. To the best of our knowledge, this is the first reported synthesis of a {110}-faceted bipyramid structure

    Unrepeatered DPSK transmission over 360 km SMF-28 fibre using URFL based amplification

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    Unrepeatered 42.7 Gb/s per channel RZ-DPSK transmission over standard SMF-28 fibre with novel URFL based amplification using fibre Bragg gratings is investigated. OSNR and gain performance are studied experimentally and through simulations. Error free transmission for 16 channels across the full C-band with direct detection was experimentally demonstrated for 280 km span length, as well as 6-channel transmission at 340 km and single-channel transmission up to 360 km (75 dB) without employing ROPA or specialty fibres

    10  Gbps Mobile Visible Light Communication System Employing Angle Diversity, Imaging Receivers, and Relay Nodes

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    Over the last decade, visible light communication (VLC) systems have typically operated between 50 Mbps and 3.4 Gbps. In this paper, we propose and evaluate mobile VLC systems that operate at 10 Gbps. The enhancements in channel bandwidth and data rate are achieved by the introduction of laser diodes (LDs), angle diversity receivers (ADR), imaging receivers, relay nodes and delay adaptation techniques. We propose three mobile VLC systems; an ADR relay assisted LD-VLC (ADRR-LD), an imaging relay assisted LD-VLC (IMGR-LD) and select-the-best imaging relay assisted LD-VLC (SBIMGR-LD). The ADR and imaging receiver are proposed for the VLC system to mitigate the intersymbol interference (ISI), maximise the signal to noise ratio (SNR) and reduce the impact of multipath dispersion due to mobility. The combination of IMGR-LD with a delay adaptation technique adds a degree of freedom to the link design, which results in a VLC system that has the ability to provide high data rates under mobility. The proposed IMGR-LD system achieves significant improvements in the SNR over other systems in the worst case scenario in the considered real indoor environment

    A Directional Entropic Force Approach to Assemble Anisotropic Nanoparticles into Superlattices

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102143/1/14230_ftp.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/102143/2/ange_201306009_sm_miscellaneous_information.pd
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