5 research outputs found

    Development of a Formal Verification Methodology for B Specifications using PERF formal toolkit. Application to safety requirements of railway systems.

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    The design of complex systems involves several design models supporting different analysis techniques for validation and verification purposes. These activities lead to the definition of heterogeneous modelling languages and analysis techniques. In this setting, meeting certification standards becomes a key issue in system engineering. Reducing heterogeneity due to the presence of different modelling languages can be addressed by providing an integrated framework in which involved modelling languages and techniques are formalised. In such a framework, checking global requirements fulfilment on heterogeneous models of a complex critical system becomes possible in many cases. The work presented in this thesis addresses the problem of integrated verification of system design models in the context of transportation systems, in particular railway systems. It has been achieved in context of the B-PERFect project of RATP (Parisian Public Transport Operator and Maintainer) aiming at applying formal verification using the PERF approach on the integrated safety-critical models of embedded software related to railway domain expressed in a single unifying modelling language: High Level Languge (HLL). We also discuss integrated verification at the system level. The proposed method for verification of safety-critical software is a bottom-up approach, starting from the source code to the high-level specification. This work addresses the particular case of the B method. It presents a certified translation of B formal models to HLL models. The proposed approach uses Isabelle/HOL as a unified logical framework to describe the formal semantics and to formalise the transformation relation between both modelling languages. The developed Isabelle/HOL models are proved in order to guarantee the correctness of our translation process. Moreover, we have also used weakbisimulation relation to check semantic preservation after transformations. In this thesis, we also present the implementation of the defined transformation syntactic rules as the B2HLL tool. Moreover, we show the model animation process we set up to validate the B2HLL translator tool with respect to the formalised transformation rules we defined in Isabelle/HOL. This approach helps us to validate definitions, lemmas and theorems of our formalised specifications. We have used the B2HLL tool to translate multiple B models, and we also show that when models are translated into this unified modelling language, HLL, it becomes possible to handle verification of properties expressed across different models

    The influence of the open-endedness of data on the data scientists’ work practice and occupational identity

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    Data scientists have emerged as the primary knowledge workers in the age of big data and AI. More research needs to focus on the actual work of data scientists in interacting with data. Data scientists are highly dependent on data, and data plays a significant role in shaping what data scientists do and who they are. The openness of data interpretation challenges data scientists to extract insights for their business clients. Therefore, this research focuses on studying the influence of the open-endedness of data on the data scientists’ work practices and occupational identity. This research aims to explain (1) how data scientists navigate the open-endedness of data to extract valuable insights and (2) how the open-endedness of data shapes their occupational identity. By conducting semi-structured interviews and participant observation, this research gains two key findings. First, data scientists navigate the openendedness of data by performing a validation process that consists of three phases: validating problems, validating data, and validating algorithms. In doing the validation, data scientists engage in the act of making judgements. Second, because of the need to constantly make judgements, there is a contradiction between the identity that data scientists enact and espouse. Data scientists espouse objectivity while enacting their subjective judgments. This research contributes to the literature about data scientists, particularly their work practice and occupational identity

    XX Workshop de Investigadores en Ciencias de la Computación - WICC 2018 : Libro de actas

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    Actas del XX Workshop de Investigadores en Ciencias de la Computación (WICC 2018), realizado en Facultad de Ciencias Exactas y Naturales y Agrimensura de la Universidad Nacional del Nordeste, los dìas 26 y 27 de abril de 2018.Red de Universidades con Carreras en Informática (RedUNCI

    XX Workshop de Investigadores en Ciencias de la Computación - WICC 2018 : Libro de actas

    Get PDF
    Actas del XX Workshop de Investigadores en Ciencias de la Computación (WICC 2018), realizado en Facultad de Ciencias Exactas y Naturales y Agrimensura de la Universidad Nacional del Nordeste, los dìas 26 y 27 de abril de 2018.Red de Universidades con Carreras en Informática (RedUNCI
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