626 research outputs found

    Reliability improvement of electronic circuits based on physical failure mechanisms in components

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    Traditionally the position of reliability analysis in the design and production process of electronic circuits is a position of reliability verification. A completed design is checked on reliability aspects and either rejected or accepted for production. This paper describes a method to model physical failure mechanisms within components in such a way that they can be used for reliability optimization, not after, but during the early phase of the design process. Furthermore a prototype of a CAD software tool is described, which can highlight components likely to fail and automatically adjust circuit parameters to improve product reliability

    A high‐throughput Raman notch filter set

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    A chevron‐type Raman notch filter (RNF) set is described. lt combines a high signal throughput (up to 90% around 1600 cm−1 and ≳80% between and 700 and 2700 cm−1) with a laser line suppression of 108–109. The filter set can be used to replace the first two dispersion stages in triple‐stage Raman monochromators commonly employed in multichannel detection systems. This yields a gain in intensity of the detected Raman signal of a factor of 4. It is shown that in Raman spectrometers with a backscatter geometry, the filter set can also be used to optically couple the microscope and the spectrometer. This leads to a further increase in signal intensity of a factor of 3–4 as compared to the situation where a beam splitter is used. Additional advantages of the RNF set are the fact that signal throughput is almost polarization independent over a large spectral interval and that it offers the possibility to simultaneously record Stokes and anti‐Stokes spectra

    Completeness and complexity of reasoning about call-by-value in Hoare logic

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    We provide a sound and relatively complete Hoare logic for reasoning about partial correctness of recursive procedures in presence of local variables and the call-by-value parameter mechanism and in which the correctness proofs support contracts and are linear in the length of the program. We argue that in spite of the fact that Hoare logics for recursive procedures were intensively studied, no such logic has been proposed in the literature

    History-based specification and verification of Java collections in KeY (keynote)

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    Software libraries, such as the Java Collection Framework, are used by many applications: Thus their correctness is of utmost importance. The state-of-the-art KeY system can be used to formally reason about program correctness of Java programs. Recently, KeY has been used to show major flaws in the Java Collection Framework. However, some methods are challenging for verification, namely those involving parameters of interface type. This lecture discussed a new history-based specification method for reasoning about the correctness of clients and arbitrary implementations of interfaces, and the Collection interface in particular

    The mid-Cretaceous North Atlantic nutrient trap: Black shales and OAEs

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    Organic-rich sediments are the salient marine sedimentation product in the mid-Cretaceous of the ocean basins formed in the Mesozoic. Oceanic anoxic events (OAEs) are discrete and particularly organic-rich intervals within these mid-Cretaceous organic-rich sequences and are defined by pronounced carbon isotope excursions. Marine productivity during OAEs appears to have been enhanced by the increased availability of biolimiting nutrients in seawater due to hydrothermal alteration of submarine basalts in the Pacific and proto-Indian oceans. The exact mechanisms behind the deposition of organic-rich sediments in the mid-Cretaceous are still a matter of discussion, but a hypothesis which is often put forward is that their deposition was a consequence of the coupling of a particular paleogeography with changes in ocean circulation and nutrient supply. In this study, we used a global coupled climate model to investigate oceanic processes that affect the interbasinal exchange of nutrients as well as their spatial distribution and bioavailability. We conclude that the mid-Cretaceous North Atlantic was a nutrient trap as a consequence of an estuarine circulation with respect to the Pacific. Organic-rich sediments in the North Atlantic were deposited below regions of intense upwelling. We suggest that enhanced productivity during OAEs was a consequence of upwelling of Pacific-derived nutrient-rich seawater associated with submarine igneous events

    The logic of separation logic: Models and proofs

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    The standard semantics of separation logic is restricted to finite heaps. This restriction already gives rise to a logic which does not satisfy compactness, hence it does not allow for an effective, sound and complete axiomatization. In this paper we therefore study both the general model theory and proof theory of the separation logic of finite and infinite heaps over arbitrary (first-order) models. We show that we can express in the resulting logic finiteness of the models and the existence of both countably infinite and uncountable models. We further show that a sound and complete sequent calculus still can be obtained by restricting the second-order quantification over heaps to first-order definable heaps

    Verifying OpenJDK's LinkedList using KeY

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    As a particular case study of the formal verification of state-of-the-art, real software, we discuss the specification and verification of a corrected version of the implementation of a linked list as provided by the Java Collection framework

    Economie van mais in bedrijfsverband

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    In dit rapport staan de financiële gevolgen van managementmaatregelen op het gebied van snijmaos. Belangrijke aandachtspunten zijn bemesting, onkruidbestrijding, opbrengst en kwaliteit, mechanisatie en voeding
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