109,991 research outputs found

    Mathematical Formula Recognition and Automatic Detection and Translation of Algorithmic Components into Stochastic Petri Nets in Scientific Documents

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    A great percentage of documents in scientific and engineering disciplines include mathematical formulas and/or algorithms. Exploring the mathematical formulas in the technical documents, we focused on the mathematical operations associations, their syntactical correctness, and the association of these components into attributed graphs and Stochastic Petri Nets (SPN). We also introduce a formal language to generate mathematical formulas and evaluate their syntactical correctness. The main contribution of this work focuses on the automatic segmentation of mathematical documents for the parsing and analysis of detected algorithmic components. To achieve this, we present a synergy of methods, such as string parsing according to mathematical rules, Formal Language Modeling, optical analysis of technical documents in forms of images, structural analysis of text in images, and graph and Stochastic Petri Net mapping. Finally, for the recognition of the algorithms, we enriched our rule based model with machine learning techniques to acquire better results

    The influence of problem features and individual differences on strategic performance in simple arithmetic

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    The present study examined the influence of features differing across problems (problem size and operation) and differing across individuals (daily arithmetic practice, the amount of calculator use, arithmetic skill, and gender) on simple-arithmetic performance. Regression analyses were used to investigate the role of these variables in both strategy selection and strategy efficiency. Results showed that more-skilled and highly practiced students used memory retrieval more often and executed their strategies more efficiently than less-skilled and less practiced students. Furthermore, calculator use was correlated with retrieval efficiency and procedural efficiency but not with strategy selection. Only very small associations with gender were observed, with boys retrieving slightly faster than girls. Implications of the present findings for views on models of mental arithmetic are discussed

    Engineering Object-Oriented Semantics Using Graph Transformations

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    In this paper we describe the application of the theory of graph transformations to the practise of language design. We have defined the semantics of a small but realistic object-oriented language (called TAAL) by mapping the language constructs to graphs and their operational semantics to graph transformation rules. In the process we establish a mapping between UML models and graphs. TAAL was developed for the purpose of this paper, as an extensive case study in engineering object-oriented language semantics using graph transformation. It incorporates the basic aspects of many commonly used object-oriented programming languages: apart from essential imperative programming constructs, it includes inheritance, object creation and method overriding. The language specification is based on a number of meta-models written in UML. Both the static and dynamic semantics are defined using graph rewriting rules. In the course of the case study, we have built an Eclipse plug-in that automatically transforms arbitrary TAAL programs into graphs, in a graph format readable by another tool. This second tool is called Groove, and it is able to execute graph transformations. By combining both tools we are able to visually simulate the execution of any TAAL program

    Category Theory and Model-Driven Engineering: From Formal Semantics to Design Patterns and Beyond

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    There is a hidden intrigue in the title. CT is one of the most abstract mathematical disciplines, sometimes nicknamed "abstract nonsense". MDE is a recent trend in software development, industrially supported by standards, tools, and the status of a new "silver bullet". Surprisingly, categorical patterns turn out to be directly applicable to mathematical modeling of structures appearing in everyday MDE practice. Model merging, transformation, synchronization, and other important model management scenarios can be seen as executions of categorical specifications. Moreover, the paper aims to elucidate a claim that relationships between CT and MDE are more complex and richer than is normally assumed for "applied mathematics". CT provides a toolbox of design patterns and structural principles of real practical value for MDE. We will present examples of how an elementary categorical arrangement of a model management scenario reveals deficiencies in the architecture of modern tools automating the scenario.Comment: In Proceedings ACCAT 2012, arXiv:1208.430

    Effects of problem size, operation, and working-memory span on simple-arithmetic strategies: differences between children and adults?

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    Adult’s simple-arithmetic strategy use depends on problem-related characteristics, such as problem size and operation, and on individual-difference variables, such as working-memory span. The current study investigates (a) whether the effects of problem size, operation, and working-memory span on children’s simple-arithmetic strategy use are equal to those observed in adults, and (b) how these effects emerge and change across age. To this end, simple-arithmetic performance measures and a working-memory span measure were obtained from 8-year-old, 10-year-old, and 12-year old children. Results showed that the problem-size effect in children results from the same strategic performance differences as in adults (i.e., size-related differences in strategy selection, retrieval efficiency, and procedural efficiency). Operation-related effects in children were equal to those observed in adults as well, with more frequent retrieval use on multiplication, more efficient strategy execution in addition, and more pro-nounced changes in multiplication. Finally, the advantage of having a large working-memory span was also present in children. The differences and similarities across children’s and adult’s strategic performance and the relevance of arithmetic models are discussed

    Capitalizing on Volunteers? Skills: Volunteering By Occupation in America

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    Examines how volunteers are using their professional and occupational skills during volunteer activities, based on data from the 2005, 2006, and 2007 Volunteer Supplements to the Current Population Survey
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