31 research outputs found

    Testing TIP Open Source Solutions in Deployed Optical Networks

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    Standardization in optical networking enables operators to benefit from using open source components. We investigate quality of transmission of open source hard- and software in the Deutsche Telekom RandD SASER network and optimize the working point

    Your Proof Fails? Testing Helps to Find the Reason

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    Applying deductive verification to formally prove that a program respects its formal specification is a very complex and time-consuming task due in particular to the lack of feedback in case of proof failures. Along with a non-compliance between the code and its specification (due to an error in at least one of them), possible reasons of a proof failure include a missing or too weak specification for a called function or a loop, and lack of time or simply incapacity of the prover to finish a particular proof. This work proposes a new methodology where test generation helps to identify the reason of a proof failure and to exhibit a counter-example clearly illustrating the issue. We describe how to transform an annotated C program into C code suitable for testing and illustrate the benefits of the method on comprehensive examples. The method has been implemented in STADY, a plugin of the software analysis platform FRAMA-C. Initial experiments show that detecting non-compliances and contract weaknesses allows to precisely diagnose most proof failures.Comment: 11 pages, 10 figure

    No association between islet cell antibodies and coxsackie B, mumps, rubella and cytomegalovirus antibodies in non-diabetic individuals aged 7–19 years

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    Viral antibodies were tested in a cohort of 44 isletcell antibody-positive individuals age 7–19 years, and 44 of their islet cell antibody-negative age and sex-matched classmates selected from a population study of 4208 pupils who had been screened for islet cell antibodies. Anti-coxsackie B1-5 IgM responses were detected in 14 of 44 (32%) of the islet cell antibody-positive subjects and in 7 of 44 (16%) control subjects. This difference did not reach the level of statistical significance. None of the islet cell antibody-positive subjects had specific IgM antibodies to mumps, rubella, or cytomegalovirus. There was also no increase in the prevalence or the mean titres of anti-mumps-IgG or IgA and anti-cytomegalovirus-IgG in islet cell antibody-positive subjects compared to control subjects. These results do not suggest any association between islet cell antibodies, and possibly insulitis, with recent mumps, rubella or cytomegalo virus infection. Further studies are required to clarify the relationship between islet cell antibodies and coxsackie B virus infections

    Software-Defined Networks for Future Networks and Services: Main Technical Challenges and Business Implications

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    In 2013, the IEEE Future Directions Committee (FDC) formed an SDN work group to explore the amount of interest in forming an IEEE Software-Defined Network (SDN) Community. To this end, a Workshop on "SDN for Future Networks and Services" (SDN4FNS'13) was organized in Trento, Italy (Nov. 11th-13th 2013). Following the results of the workshop, in this paper, we have further analyzed scenarios, prior-art, state of standardization, and further discussed the main technical challenges and socio-economic aspects of SDN and virtualization in future networks and services. A number of research and development directions have been identified in this white paper, along with a comprehensive analysis of the technical feasibility and business availability of those fundamental technologies. A radical industry transition towards the "economy of information through softwarization" is expected in the near future

    Determination of Gallbladder Stone Composition with Ultrasound — in Vivo and in Vitro Studies

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    Extension of all-optical network-transparent domains based on normalized transmission sections

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    This paper presents a technique that significantly simplifies the design and operation of transparent optical wavelength-division-multiplexing (WDM) networks. Since most of the signal degradations arise due to the interaction of linear and nonlinear physical effects along the fiber links, a link design concept based on erbium-doped fiber amplification is developed and optimized such that originally degrading effects mutually compensate each other, leading to approximately noise-limited transmission. In extensive numerical simulations as well as laboratory experiments, an optimized modular link design is identified. Regenerator-free transmission of a single-channel 10-Gb/s nonreturn-to-zero signal over 4000 km is achieved in a recirculating loop experiment with less than a 3-dB penalty. Reliable WDM transmission is demonstrated over 1600 km, showing the high robustness of this concept. Finally the link design concept is applied in a WDM field trial using deployed standard single-mode fibers (S-SMFs) of the optical network infrastructure of Deutsche Telekom. Between the German cities of Berlin and Darmstadt, 10-Gb/s synchronous digital hierarchy (SDH)-based data, 10-Gb/s duobinary-encoded data, and a native Gigabit Ethernet signal have been transmitted error-free over a maximum distance of 1720 km, thus demonstrating the feasibility of the design concept under realistic field conditions. The presented design approach substantially supports link setup and rerouting procedures by supplying simple rules to identify the maximum number of dispersion-compensated S-SMF amplified spans which can be cascaded for a given tolerable penalty

    Design and experiments of an Automatic Switched Optical Network (ASON)

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    The purpose of this paper is to describe the activities and the preliminary results of the ISTProject LION, whose main objective is to design and test a robust and managed transport network based on an ASON

    Side chain redistribution as a strategy to boost organic electrochemical transistor performance and stability

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    A series of glycolated polythiophenes for use in organic electrochemical transistors (OECTs) is designed and synthesized, differing in the distribution of their ethylene glycol chains that are tethered to the conjugated backbone. While side chain redistribution does not have a significant impact on the optoelectronic properties of the polymers, this molecular engineering strategy strongly impacts the water uptake achieved in the polymers. By careful optimization of the water uptake in the polymer films, OECTs with unprecedented steady-state performances in terms of [μC*] and current retentions up to 98% over 700 electrochemical switching cycles are developed
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