544 research outputs found

    Succinct Representations for Abstract Interpretation

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    Abstract interpretation techniques can be made more precise by distinguishing paths inside loops, at the expense of possibly exponential complexity. SMT-solving techniques and sparse representations of paths and sets of paths avoid this pitfall. We improve previously proposed techniques for guided static analysis and the generation of disjunctive invariants by combining them with techniques for succinct representations of paths and symbolic representations for transitions based on static single assignment. Because of the non-monotonicity of the results of abstract interpretation with widening operators, it is difficult to conclude that some abstraction is more precise than another based on theoretical local precision results. We thus conducted extensive comparisons between our new techniques and previous ones, on a variety of open-source packages.Comment: Static analysis symposium (SAS), Deauville : France (2012

    A simple abstraction of arrays and maps by program translation

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    We present an approach for the static analysis of programs handling arrays, with a Galois connection between the semantics of the array program and semantics of purely scalar operations. The simplest way to implement it is by automatic, syntactic transformation of the array program into a scalar program followed analysis of the scalar program with any static analysis technique (abstract interpretation, acceleration, predicate abstraction,.. .). The scalars invariants thus obtained are translated back onto the original program as universally quantified array invariants. We illustrate our approach on a variety of examples, leading to the " Dutch flag " algorithm

    Climate change affecting oil palm agronomy, and oil palm cultivation increasing climate change, require amelioration

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    Palm oil is used in various valued commodities and is a large global industry worth over US$ 50 billion annually. Oil palms (OP) are grown commercially in Indonesia and Malaysia and other countries within Latin America and Africa. The large-scale land-use change has high ecological, economic, and social impacts. Tropical countries in particular are affected negatively by climate change (CC) which also has a detrimental impact on OP agronomy, whereas the cultivation of OP increases CC. Amelioration of both is required. The reduced ability to grow OP will reduce CC, which may allow more cultivation tending to increase CC, in a decreasing cycle. OP could be increasingly grown in more suitable regions occurring under CC. Enhancing the soil fauna may compensate for the effect of CC on OP agriculture to some extent. The effect of OP cultivation on CC may be reduced by employing reduced emissions from deforestation and forest degradation plans, for example, by avoiding illegal fire land clearing. Other ameliorating methods are reported herein. More research is required involving good management practices that can offset the increases in CC by OP plantations. Overall, OP-growing countries should support the Paris convention on reducing CC as the most feasible scheme for reducing CC.Portuguese Foundation for Science and Technology (FCT), Grant/Award Number: UID/ BIO/04469/2013, COMPETE 2020 (POCI01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004); European Regional Development Fund through Norte2020—Programa Operacional Regional do Norteinfo:eu-repo/semantics/publishedVersio

    A formally verified compiler back-end

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    This article describes the development and formal verification (proof of semantic preservation) of a compiler back-end from Cminor (a simple imperative intermediate language) to PowerPC assembly code, using the Coq proof assistant both for programming the compiler and for proving its correctness. Such a verified compiler is useful in the context of formal methods applied to the certification of critical software: the verification of the compiler guarantees that the safety properties proved on the source code hold for the executable compiled code as well

    Vorticity Propagation for Spin-up and Spin-down in a Rotating Tank

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    PENGARUH SISTEM PENGENDALIAN INTERNAL, WHISTLEBLOWING SYSTEM DAN GOOD CORPORATE GOVERNANCE TERHADAP PENCEGAHAN FRAUD DENGAN MORALITAS INDIVIDU SEBAGAI VARIABEL MODERASI (STUDI EMPIRIS PADA BANK DI KOTA AMBON)

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    This research aims to empirically test the influence of the internal control system, Whistleblowing System and Good corporate governance on fraud prevention, as well as test whether individual morality is able to moderate the internal control system, Whistleblowing System and Good corporate governance on fraud prevention. The sample in this study was 37 bank employees at Bank BRI, BTN, Mandiri and BPD Maluku. The sampling technique uses Pruposive Sampling by determining samples based on certain criteria. Data analysis techniques use SPSS 23 software. The research results show that the internal control system, Whistleblowing System and Good corporate governance have no effect on fraud prevention. while individual morality is able to moderate the influence of the internal control system, Whistleblowing System and Good corporate governance on fraud prevention

    Performance of an endcap prototype of the ATLAS accordion electromagnetic calorimeter

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    The design and construction of a lead-liquid argon endcap calorimeter prototype using an accordion geometry and conceived as a sector of the inner wheel of the endcap calorimeter of the future ATLAS experiment at the LHC is described. The performance obtained using electron beam data is presented. The main results are an energy resolution with a sampling term below 11%/E(GeV)11\%/\sqrt{E(\rm GeV)} and a small local constant term, a good linearity of the response with the incident energy and a global constant term of 0.8\% over an extended area in the rapidity range of 2.2<η<2.92.2 < \eta <2.9. These properties make the design suitable for the ATLAS electromagnetic endcap calorimeter

    Performance of a large scale prototype of the ATLAS accordion electromagnetic calorimeter

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    A 2 m long prototype of a lead-liquid argon electromagnetic calorimeter with accordion-shaped electrodes, conceived as a sector of the barrel calorimeter of the future ATLAS experiment at the LHC, has been tested with electron and pion beams in the energy range 10 to 287 GeV. A sampling term of 10%/root E(GeV) was obtained for electrons in the rapidity range 0 < eta < 1, while the constant term measured over an area of about 1 m(2) is 0.69%. With a cell size of 2.7 cm the position resolution is. about 4 mm/root E(GeV)
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