3,368 research outputs found

    A Comparison of State-Based Modelling Tools for Model Validation

    Get PDF
    In model-based testing, one of the biggest decisions taken before modelling is the modelling language and the model analysis tool to be used to model the system under investigation. UML, Alloy and Z are examples of popular state-based modelling languages. In the literature, there has been research about the similarities and the differences between modelling languages. However, we believe that, in addition to recognising the expressive power of modelling languages, it is crucial to detect the capabilities and the weaknesses of analysis tools that parse and analyse models written in these languages. In order to explore this area, we have chosen four model analysis tools: USE, Alloy Analyzer, ZLive and ProZ and observed how modelling and validation stages of MBT are handled by these tools for the same system. Through this experiment, we not only concretise the tasks that form the modelling and validation stages of MBT process, but also reveal how efficiently these tasks are carried out in different tools

    Production Chains in an Interregional Framework: Identification by Means of Average Propagation Lengths

    Get PDF
    When linkages between industries are studied from the perspective of production chains, sequencing is important. In this respect, both the strength of the linkages and the distance between industries are relevant. Distance is measured by the average propagation length, defined as the average number of steps it takes a stimulus in one industry to propagate and affect another industry. Using the 1985 intercountry input-output table for six European countries, we present three applications. These are, visualizing the production structure by graphing its production chains, analyzing intercountry linkages between industries, and determining the role that each country plays within the system

    Turing Impossibility Properties for Stack Machine Programming

    Full text link
    The strong, intermediate, and weak Turing impossibility properties are introduced. Some facts concerning Turing impossibility for stack machine programming are trivially adapted from previous work. Several intriguing questions are raised about the Turing impossibility properties concerning different method interfaces for stack machine programming.Comment: arXiv admin note: substantial text overlap with arXiv:0910.556

    Study of fault-tolerant software technology

    Get PDF
    Presented is an overview of the current state of the art of fault-tolerant software and an analysis of quantitative techniques and models developed to assess its impact. It examines research efforts as well as experience gained from commercial application of these techniques. The paper also addresses the computer architecture and design implications on hardware, operating systems and programming languages (including Ada) of using fault-tolerant software in real-time aerospace applications. It concludes that fault-tolerant software has progressed beyond the pure research state. The paper also finds that, although not perfectly matched, newer architectural and language capabilities provide many of the notations and functions needed to effectively and efficiently implement software fault-tolerance

    Assertion-based slicing and slice graphs

    Get PDF
    This paper revisits the idea of slicing programs based on their axiomatic semantics, rather than using criteria based on control/data dependencies. We show how the forward propagation of preconditions and the backward propagation of postconditions can be combined in a new slicing algorithm that is more precise than the existing specification-based algorithms. The algorithm is based on (i) a precise test for removable statements, and (ii) the construction of a \emph{slice graph}, a program control flow graph extended with semantic labels and additional edges that ``short-circuit'' removable commands. It improves on previous approaches in two aspects: it does not fail to identify removable commands; and it produces the smallest possible slice that can be obtained (in a sense that will be made precise). Iteration is handled through the use of loop invariants and variants to ensure termination. The paper also discusses in detail applications of these forms of slicing, including the elimination of (conditionally) unreachable and dead code, and compares them to other related notions.Fundação para a Ciência e a Tecnologia (FCT

    Foreign Direct Investment and Structural Reforms: Evidence from Eastern Europe and Latin America

    Full text link
    This paper investigates the role of structural reforms ñ privatization, financial reform and trade liberalizationñ as determinants of FDI inflows based on newly constructed dataset on structural reforms for 19 Latin American and 25 Eastern European countries between 1989 and 2004. Our main finding is a strong empirical relationship from reforms to FDI, in particular, from financial liberalization and privatization. These results are robust to different measures of reforms, split samples, and potential endogeneity and omitted variables biases.http://deepblue.lib.umich.edu/bitstream/2027.42/64417/1/wp906.pd
    corecore