377 research outputs found

    Priority-enabled Scheduling for Resizable Parallel Applications

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    In this paper, we illustrate the impact of dynamic resizability on parallel scheduling. Our ReSHAPE framework includes an application scheduler that supports dynamic resizing of parallel applications. We propose and evaluate new scheduling policies made possible by our ReSHAPE framework. The framework also provides a platform to experiment with more interesting and sophisticated scheduling policies and scenarios for resizable parallel applications. The proposed policies support scheduling of parallel applications with and without user assigned priorities. Experimental results show that these scheduling policies significantly improve individual application turn around time as well as overall cluster utilization

    Erbium doped LaF3 nanoparticles incorporated in silicondioxide thin films for active integrated optical applications

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    We report on the low-cost processing of erbium doped lanthanum trifluoride (LaF3:Er) nanoparticles dispersed in silicondioxide (SiO2) films prepared through the sol-gel method. The influence of particle concentration and annealing temperature on the optical properties and its implications on scattering in the visible wavelength range will be discussed. Uniform, crackfree and low loss films have been obtained by spincoating multiple layers followed by several annealing steps. The lanthanum trifluoride host shields the erbium from the OH-groups present in the silicondioxide, resulting in a higher excited state lifetime of the erbium due to the reduced OH-quenching

    A QKD Protocol Extendable to Support Entanglement and Reduce Unauthorized Information Gain by Randomizing the Bases Lists with Key Values and Invalidate Explicit Privacy Amplification

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    This paper suggests an improvement to the BB84 scheme in Quantum key distribution. The original scheme has its weakness in letting quantifiably more information gain to an eavesdropper during public announcement of unencrypted bases lists. The security of the secret key comes at the expense of the final key length. We aim at exploiting the randomness of preparation (measurement) basis and the bit values encoded (observed), so as to randomize the bases lists before they are communicated over the public channel. A proof of security is given for our scheme and proven that our protocol results in lesser information gain by Eve in comparison with BB84 and its other extensions. Moreover, an analysis is made on the feasibility of our proposal as such and to support entanglement based QKD. The performance of our protocol is compared in terms of the upper and lower bounds on the tolerable bit error rate. We also quantify the information gain (by Eve) mathematically using the familiar approach of the concept of Shannon entropy. The paper models the attack by Eve in terms of interference in a multi-access quantum channel. Besides, this paper also hints at the invalidation of a separate privacy amplification step in the "prepare-and-measure" protocols in general.Comment: 13 pages, 1 figure, submitted for review to the USENIX 200

    Prediction of Shot Start Pressure for Rifled Gun System

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    Determination of short start pressure (SSP) for gun system has always been of paramount interest for gun designers. In this paper, a generalised model has been developed for theoretical prediction of SSP for rifled gun system using dimensional analysis approach. For this, parameters affecting the SSP of the gun like rifling dimensions, driving band dimensions, material properties of driving band, projectile mass and diameter are taken into consideration. For a particular case of large caliber rifled gun system, the model is established using linear relations among dimensionless groups of parameters. The model has been validated by data available from the open literature

    Thiamine Pyrophosphate Riboswitches Are Targets for the Antimicrobial Compound Pyrithiamine

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    SummaryThiamine metabolism genes are regulated in numerous bacteria by a riboswitch class that binds the coenzyme thiamine pyrophosphate (TPP). We demonstrate that the antimicrobial action of the thiamine analog pyrithiamine (PT) is mediated by interaction with TPP riboswitches in bacteria and fungi. For example, pyrithiamine pyrophosphate (PTPP) binds the TPP riboswitch controlling the tenA operon in Bacillus subtilis. Expression of a TPP riboswitch-regulated reporter gene is reduced in transgenic B. subtilis or Escherichia coli when grown in the presence of thiamine or PT, while mutant riboswitches in these organisms are unresponsive to these ligands. Bacteria selected for PT resistance bear specific mutations that disrupt ligand binding to TPP riboswitches and derepress certain TPP metabolic genes. Our findings demonstrate that riboswitches can serve as antimicrobial drug targets and expand our understanding of thiamine metabolism in bacteria

    Development of mixed anaerobic culture for degrading high concentrations of chlorophenols

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    This study details the development of mixed anaerobic culture capable of degrading high concentrations of chlorophenols; 4-chlorophenol (MCP), 2,4-dichlorophenol (DCP) and pentachlorophenol (PCP) were used for that purpose. The role of glucose concentration and the relative potential of mixed culture for acclimatization of different chlorophenols under anaerobic conditions were studied. Methane production, pH and their reduction in concentrations of glucose and chlorophenols were measured at regular intervals. It was observed that after 350 days of acclimatization, anaerobic cultures degraded up to 200 ppm MCP, 200 ppm DCP and 250 ppm PCP. It was also found that the biogenic substrate such as glucose increased the rate of chlorophenols acclimatization and degradation

    Operational framework based on modeling languages to support product repository implementation.

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    Part 3: Tools and MethodologiesInternational audienceEmbracing Product Lifecycle Management approach involves integrating a product repository in the company information system. From customer's needs to disposal stage, several product representations exist. The product repository purpose is to secure consistency of one product representation with the others. This paper presents an operational modeling framework that supports product repository implementation. In order to ensure consistency, this framework identifies correspondences between entities of languages (“trade” languages and standard languages). The presented concepts are illustrated with correspondences between language entities of product designed and productplanned to be built Bills of Materials

    The Open Assembly Model for the Exchange of Assembly and Tolerance Information: Overview and Example

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    In early design phases an effective information exchange among CAD (Computer Aided Design) tools depends on a standardized representation for the product data in all PLM (Product Lifecycle Management) tools. The NIST Core Product Model (CPM) and its extension are proposed to provide the required base-level product model that is open, non-proprietary, generic, extensible, independent of any one product development process and capable of capturing the full engineering context commonly shared in product development [1]. The Open Assembly Model (OAM) Model extends CPM to provide a standard representation and exchange protocol for assembly. The assembly information model emphasizes the nature and information requirements for part features and assembly relationships. The model includes both assembly as a concept and assembly as a data structure. For the latter it uses the model data structures of ISO 10303, informally known as the Standard for the Exchange of Product model data (STEP)[2]. The objective of the paper is to show how the OAM can be used to realize seamless integration of product information, with an emphasis on assembly, throughout all phases of a product design. A gearbox design example is used to illustrate the process

    The Open Assembly Model for the Exchange of Assembly and Tolerance Information: Overview and Example

    Get PDF
    In early design phases an effective information exchange among CAD (Computer Aided Design) tools depends on a standardized representation for the product data in all PLM (Product Lifecycle Management) tools. The NIST Core Product Model (CPM) and its extension are proposed to provide the required base-level product model that is open, non-proprietary, generic, extensible, independent of any one product development process and capable of capturing the full engineering context commonly shared in product development [1]. The Open Assembly Model (OAM) Model extends CPM to provide a standard representation and exchange protocol for assembly. The assembly information model emphasizes the nature and information requirements for part features and assembly relationships. The model includes both assembly as a concept and assembly as a data structure. For the latter it uses the model data structures of ISO 10303, informally known as the Standard for the Exchange of Product model data (STEP)[2]. The objective of the paper is to show how the OAM can be used to realize seamless integration of product information, with an emphasis on assembly, throughout all phases of a product design. A gearbox design example is used to illustrate the process
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