952 research outputs found

    A model-based approach to language integration

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    The interactions of several languages within a soft- ware system pose a number of problems. There is several anecdotal and empirical evidence supporting such concerns. This paper presents a solution to achieve proper language integration in the context of language workbenches and with limited effort. A simple example is presented to show how cross- language constraints can be addressed and the quality of the support attainable, which covers error-checking and refactoring. A research agenda is then presented, to support future work in the area of language integration, taking advantage of modern language workbenches features

    Polycrystalline Superalloy Membranes Produced by Load-Free Coarsening of Incoherent Îł'-Precipitates: Microstructure Evolution and Mechanical Properties

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    Nanoporous superalloy membranes are a functional extension of the use of nickel-based alloys. The material, which is usually used for high-temperature applications, consists mainly of the two phases Îł and Îł'. Through coarsening of the precipitates and thus forming of a bicontinuous Îł/Îł' network, membranes can be produced by removing either of these phases. From the single-crystalline alloy CMSX-4, the bicontinuous network can be formed either thermo-mechanically by directional coarsening of coherent precipitates or by load-free coalescence of incoherent precipitates. Recent investigations have shown that membranes also can be produced from polycrystalline starting material in both ways. In this article, the process route for membranes by load-free coarsening of incoherent Îł' precipitates from a carbon-free version of the polycrystalline alloy Nimonic 115 is presented. This manufacturing method has the advantage of its simplicity and in comparison to single-crystalline membranes it can be realized in larger scales. We discuss the microstructure and show the mechanical properties by means of tensile tests. Despite the grain boundaries as a mechanical weak link, polycrystalline membranes show promising mechanical properties. Their strength even exceeds that of the single-crystalline membranes despite the significantly higher pore volume content

    Do capuchin monkeys (Sapajus apella) use exploration to form intuitions about physical properties?

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    We are grateful to the Royal Zoological Society of Scotland (RZSS) and the University of St Andrews for core financial support to the RZSS Edinburgh Zoo’s Living Links Research Facility where this project was carried out.Humans’ flexible innovation relies on our capacity to accurately predict objects’ behaviour. These predictions may originate from a “physics-engine” in the brain which simulates our environment. To explore the evolutionary origins of intuitive physics, we investigate whether capuchin monkeys’ object exploration supports learning. Two capuchin groups experienced exploration sessions involving multiple copies of two objects, one object was easily opened (functional), the other was not (non-functional). We used two within-subject conditions (enrichment-then-test, and test-only) with two object sets per group. Monkeys then underwent individual test sessions where the objects contained rewards, and they choose one to attempt to open. The monkeys spontaneously explored, performing actions which yielded functional information. At test, both groups chose functional objects above chance. While high performance of the test-only group precluded us from establishing learning during exploration, this study reveals the promise of harnessing primates’ natural exploratory tendencies to understand how they see the world.Publisher PDFPeer reviewe

    Implementing Feature Variability for Models and Code with Projectional Language Workbenches

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    Abstract Product line engineering deals with managing and implementing the variability among a set of related products. We distinguish between two kinds of variability: configuration and customization. Customization variability can be described using programming language code or creative construction DSLs, whereas configuration variability is described using configuration based approaches, such as feature models. Many product lines have both kinds of variability, and they need to be integrated efficiently. This paper describes an approach for product line engineering using projectional language workbenches. These represent code and models with the same fundamental technology, enabling the mixing of models and code. They make the tight integration between several domain-specific languages possible and simple. Since they can store arbitrary information in models, it is possible to overlay configuration variability over customization variability (i.e. apply feature model-based configuration to code and models). Because of the projectional approach to editing, programs can be shown with or without the dependencies on feature models, they can even be rendered (and edited) for a specific variant. This approach leads to highly integrated and productive tools for product line development. The paper explains the approach, outlines the implementation of a prototype tool based on Jetbrains MPS and illustrates the benefits using a small product line for embedded systems

    Incrementalizing Lattice-Based Program Analyses in Datalog

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    Program analyses detect errors in code, but when code changes frequently as in an IDE, repeated re-analysis from-scratch is unnecessary: It leads to poor performance unless we give up on precision and recall. Incremental program analysis promises to deliver fast feedback without giving up on precision or recall by deriving a new analysis result from the previous one. However, Datalog and other existing frameworks for incremental program analysis are limited in expressive power: They only support the powerset lattice as representation of analysis results, whereas many practically relevant analyses require custom lattices and aggregation over lattice values. To this end, we present a novel algorithm called DRedL that supports incremental maintenance of recursive lattice-value aggregation in Datalog. The key insight of DRedL is to dynamically recognize increasing replacements of old lattice values by new ones, which allows us to avoid the expensive deletion of the old value. We integrate DRedL into the analysis framework IncA and use IncA to realize incremental implementations of strong-update points-to analysis and string analysis for Java. As our performance evaluation demonstrates, both analyses react to code changes within milliseconds

    Information seeking about tool properties in great apes

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    M.B. was supported by a scholarship of the German National Academic Foundation. J.C. was supported by the “SOMICS” ERC Synergy grant (nr. 609819).Evidence suggests that great apes engage in metacognitive information seeking for food items. To support the claim that a domain-general cognitive process underlies ape metacognition one needs to show that selective information seeking extends to non-food items. In this study, chimpanzees (Pan troglodytes) and orangutans (Pongo abelii) either had to determine the location of a desired food item or a property of a non-food item (length of a tool). We manipulated whether subjects received prior information about the item’s location or property. During the test, subjects had the opportunity to seek the respective information. Results show that apes engaged in more information seeking when they had no prior knowledge. Importantly, this selective pattern of information seeking applied to food as well as to tools.Publisher PDFPeer reviewe

    How Are Techno-Stressors Associated with Mental Health and Work Outcomes? A Systematic Review of Occupational Exposure to Information and Communication Technologies within the Technostress Model

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    The technostress model has introduced different factors to consider when assessing how information and communication technologies impact individuals in different work settings. This systematic review gathers evidence regarding associations between occupational exposure to technostress and health or work outcomes. In addition, we highlight typical methodological constraints of the technostress model. We conducted electronic literature searches in June 2020 (PubMed, PubMed Central, Web of Science, Scopus, PsycInfo, PsycArticles) and independently screened 321 articles. We report on 21 articles meeting eligibility criteria (working population, technostress exposure, health or work outcome, quantitative design). The most frequently examined techno-stressors, i.e., factors of technostress, were techno-overload and techno-invasion. Techno-stressors were consistently associated with adverse health and work outcomes, apart from a positive impact on work engagement. However, studies may be subject to considerable conceptual overlap between exposure and outcome measures. Future technostress research would benefit from reducing heterogeneity in technostress measures, assessing their external validity and focussing on specific techno-stressors

    Cooperative problem solving in giant otters (Pteronura brasiliensis) and Asian small-clawed otters (Aonyx cinerea)

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    Open access funding provided by Max Planck Society.Cooperative problem solving has gained a lot of attention over the past two decades but the range of species studied is still small. This limits the possibility of understanding the evolution of the socio-cognitive underpinnings of cooperation. Lutrinae show significant variations in socio-ecology but their cognitive abilities are not well studied. In the first experimental study of otter social cognition, we presented two species - giant otters and Asian small-clawed otters - with a cooperative problem-solving task. The loose string task requires two individuals to simultaneously pull on either end of a rope in order to access food. This task has been used with a larger number of species (for the most part primates and birds) and thus allows for wider cross species comparison. We found no differences in performance between species. Both giant otters and Asian small-clawed otters were able to solve the task successfully when the coordination requirements were minimal. However, when the temporal coordination demands were increased, performance decreased either due to a lack of understanding of the role of a partner or due to difficulty inhibiting action. In conclusion, two species of otters show some ability to cooperate, quite similar to most other species presented with the same task. However, to draw further conclusions and more nuanced comparisons between the two otter species further studies with varied methodologies will be necessary.Publisher PDFPeer reviewe
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