23 research outputs found

    Type-based allocation analysis for co-recursion in lazy functional languages

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    This paper presents a novel type-and-effect analysis for pre-dicting upper-bounds on memory allocation costs for co-recursive def-initions in a simple lazily-evaluated functional language. We show thesoundness of this system against an instrumented variant of Launch-bury’s semantics for lazy evaluation which serves as a formal cost model.Our soundness proof requires an intermediate semantics employing indi-rections. Our proof of correspondence between these semantics that weprovide is thus a crucial part of this work.The analysis has been implemented as an automatic inference system.We demonstrate its effectiveness using several example programs thatpreviously could not be automatically analysed.Postprin

    The problems of selecting problems

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    We face several teaching problems where a set of exercises has to be selected based on their capability to make students discover typical misconceptions or their capability to evaluate the knowledge of the students. We consider four different optimization problems, developed from two basic decision problems. The first two optimization problems consist in selecting a set of exercises reaching some required levels of coverage for each topic. In the first problem we minimize the total time required to present the selected exercises, whereas the surplus coverage of topics is maximized in the second problem. The other two optimization problems consist in composing an exam in such a way that each student misconception reduces the overall mark of the exam to some specific required extent. In particular, we consider the problem of minimizing the size of the exam fulfilling these mark reduction constraints, and the problem of minimizing the differences between the required marks losses due to each misconception and the actual ones in the composed exam. For each optimization problem, we formally identify its approximation hardness and we heuristically solve it by using a genetic algorithm. We report experimental results for a case study based on a set of real exercises of Discrete Mathematics, a Computer Science degree subject

    A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

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    Proving the Correctness of the STG Machine

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    Automatic Amortised Analysis of Dynamic Memory Allocation for Lazy Functional Programs

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    This paper describes the first successful attempt, of which we are aware, to define an automatic, type-based static analysis of resource bounds for lazy functional programs. Our analysis uses the automatic amortisation approach developed by Jost and Hofmann, which was previously restricted to eager evaluation. In this paper, we extend this work to a lazy setting by capturing the costs of unevaluated expressions in type annotations and by amortising the payment of these costs using a notion of lazy potential. We present our analysis as a proof system for predicting heap allocations of a minimal functional language (including higher-order functions and recursive data types) and define a formal cost model based on Launchbury's natural semantics for lazy evaluation. We prove the soundness of our analysis with respect to the cost model. Our approach is illustrated by a number of representative and non-trivial examples that have been analyed using a prototype implementation of our analysis.<br/

    Carnivore taphonomy in South America: a review of actualistic studies and their implications in the southern Neotropics

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    Actualistic studies on mammalian carnivore taphonomy in southern South America are reviewed here, including pumas, small cats, foxes, and other, smaller carnivores. Patterns for different carnivore taxa and their variation are elicited. Also temporal and spatial variability is analysed, and comparisons are made to other carnivores and regions. While generally these Neotropical carnivores produce low damage intensity, stronger modifications and their implications are described as well. These patterns and their variation are put in context by taking into account the particular physical and biotic conditions in the southern Neotropics.Fil: Mondini, Nora Mariana. Universidad Nacional de CĂłrdoba; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - CĂłrdoba. Instituto de AntropologĂ­a de CĂłrdoba. Universidad Nacional de CĂłrdoba. Facultad de FilosofĂ­a y Humanidades. Instituto de AntropologĂ­a de CĂłrdoba; Argentin
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