12,386 research outputs found

    Deceit: A flexible distributed file system

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    Deceit, a distributed file system (DFS) being developed at Cornell, focuses on flexible file semantics in relation to efficiency, scalability, and reliability. Deceit servers are interchangeable and collectively provide the illusion of a single, large server machine to any clients of the Deceit service. Non-volatile replicas of each file are stored on a subset of the file servers. The user is able to set parameters on a file to achieve different levels of availability, performance, and one-copy serializability. Deceit also supports a file version control mechanism. In contrast with many recent DFS efforts, Deceit can behave like a plain Sun Network File System (NFS) server and can be used by any NFS client without modifying any client software. The current Deceit prototype uses the ISIS Distributed Programming Environment for all communication and process group management, an approach that reduces system complexity and increases system robustness

    Dual refractive index and viscosity sensing using polymeric nanofibers optical structures

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    Porous materials have demonstrated to be ideal candidates for the creation of optical sensors with very high sensitivities. This is due both to the possibility of infiltrating the target substances into them and to their notable surface-to-volume ratio that provides a larger biosensing area. Among porous structures, polymeric nanofibers (NFs) layers fabricated by electrospinning have emerged as a very promising alternative for the creation of low-cost and easy-to-produce high performance optical sensors, for example, based on Fabry-Perot (FP) interferometers. However, the sensing performance of these polymeric NFs sensors is limited by the low refractive index contrast between the NFs porous structure and the target medium when performing in-liquid sensing experiments, which determines a very low amplitude of the FP interference fringes appearing in the spectrum. This problem has been solved with the deposition of a thin metal layer (∼ 3 nm) over the NFs sensing layer. We have successfully used these metal-coated FP NFs sensors to perform several real-time and in-flow refractive index sensing experiments. From these sensing experiments, we have also determined that the sponge-like structure of the NFs layer suffers an expansion/compression process that is dependent of the viscosity of the analyzed sample, what thus gives the possibility to perform a simultaneous dual sensing of refractive index and viscosity of a fluid

    Roaming Edge vNFs using Glasgow Network Functions

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    While the network edge is becoming more important for the provision of customized services in next generation mobile networks, current NFV architectures are unsuitable to meet the increasing future demand. They rely on commodity servers with resource-hungry Virtual Machines that are unable to provide the high network function density and mobility requirements necessary for upcoming wide-area and 5G networks. In this demo, we showcase Glasgow Network Functions (GNF), a virtualization framework suitable for next generation mobile networks that exploits lightweight network functions (NFs) deployed at the edge and transparently following users' devices as they roam between cells
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