181,566 research outputs found

    Conceptual modelling: framework, principles, and future research

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    The conceptual modelling task in a simulation project is very important and yet is still generally regarded as more of an art than a science. The meaning and nature of conceptual modelling are discussed and a framework set out. The overall aim should be to choose the best model for the project and conceptual modelling can be viewed as a difficult optimisation problem that can be tackled effectively using a creative search process that develops alternative models and predicts their performance throughout the project. An experiment relating model characteristics to some aspects of performance is described and this type of experiment may inform the process of predicting model performance. Based on advice from the literature and my own previous work on conceptual modelling 17 principles of conceptual modelling are suggested. Conceptual modelling research is still at an early stage and ideas for future research are proposed

    TumorML: Concept and requirements of an in silico cancer modelling markup language

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    This paper describes the initial groundwork carried out as part of the European Commission funded Transatlantic Tumor Model Repositories project, to develop a new markup language for computational cancer modelling, TumorML. In this paper we describe the motivations for such a language, arguing that current state-of-the-art biomodelling languages are not suited to the cancer modelling domain. We go on to describe the work that needs to be done to develop TumorML, the conceptual design, and a description of what existing markup languages will be used to compose the language specification

    Improving automation standards via semantic modelling: Application to ISA88

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    Standardization is essential for automation. Extensibility, scalability, and reusability are important features for automation software that rely in the efficient modelling of the addressed systems. The work presented here is from the ongoing development of a methodology for semi-automatic ontology construction methodology from technical documents. The main aim of this work is to systematically check the consistency of technical documents and support the improvement of technical document consistency. The formalization of conceptual models and the subsequent writing of technical standards are simultaneously analyzed, and guidelines proposed for application to future technical standards. Three paradigms are discussed for the development of domain ontologies from technical documents, starting from the current state of the art, continuing with the intermediate method presented and used in this paper, and ending with the suggested paradigm for the future. The ISA88 Standard is taken as a representative case study. Linguistic techniques from the semi-automatic ontology construction methodology is applied to the ISA88 Standard and different modelling and standardization aspects that are worth sharing with the automation community is addressed. This study discusses different paradigms for developing and sharing conceptual models for the subsequent development of automation software, along with presenting the systematic consistency checking methodPeer ReviewedPostprint (author's final draft

    VR-PMS: a new approach for performance measurement and management of industrial systems

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    A new performance measurement and management framework based on value and risk is proposed. The proposed framework is applied to the modelling and evaluation of the a priori performance evaluation of manufacturing processes and to deciding on their alternatives. For this reason, it consistently integrates concepts relevant to objectives, activity, and risk in a single framework comprising a conceptual value/risk model, and it conceptualises the idea of value- and risk based performance management in a process context. In addition, a methodological framework is developed to provide guidelines for the decision-makers or performance evaluators of the processes. To facilitate the performance measurement and management process, this latter framework is organized in four phases: context establishment, performance modelling, performance assessment, and decision-making. Each phase of the framework is then instrumented with state of-the-art quantitative analysis tools and methods. For process design and evaluation, the deliverable of the value- and risk-based performance measurement and management system (VR-PMS) is a set of ranked solutions (i.e. alternative business processes) evaluated against the developed value and risk indicators. The proposed VR-PMS is illustrated with a case study from discrete parts manufacturing but is indeed applicable to a wide range of processes or systems

    Vers une ontologie de domaine dédiée à la description des traces anthropiques dans l'art pariétal

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    International audienceThe Franco-Cantabrian region occupies an important place in the distribution of Palaeolithic cave art in Europe. Successive discoveries have indeed led to extensive studies of cave art, involving teams composed of experts from different professional fields. The collaboration of these multidisciplinary teams implies manipulation of heterogeneous data sets. The inherent question concerns the semantic articulation of the produced elements and moreover the structuration of heterogeneous data.How are the analytical elements produced by different experts semantically linked ? What are the terminology repositories and the controlled vocabularies of the domain ? How to structure and articulate this heterogeneous data in order to cross-reference it and thusly extract the potential knowledge encompassed ? Aiming towards a domain ontology, a knowledge conceptual model for the description of anthropogenic traces, this work states the adopted methodology.Archeological documentation and controlled vocabulary represent effectively a consequential source of domain terminology, participating in the conceptual modelling of 5 top-level classes. Representing human-made markings, anthropogenic traces are at the heart of the proposed ontology. Their support, theme, representation technique and finally the alteration acting on the support represent the following classes. These are considered to be necessary and sufficient for the anthropogenic traces description. Their sub-classes are thereafter developed and questionned. These classes and their properties are to be merged with the CIDOC Conceptual Reference Model and its extensions.The proposed ontology can serve as a basis for a possible information system and is a response to a need for semantic structuring of heterogeneous data. This articulation of the analytical elements produced within a domain is indeed interesting from the perspective of the extraction of new knowledge resulting from a crossing of information layers. This work is part of a larger project and is intended to be implemented within an information system. The conceptual modelling of the proposed classes remains nevertheless to be evaluated through experimentation by the experts in the field

    Biological processes modelling for MBR systems: A review of the state-of-the-art focusing on SMP and EPS

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    A mathematical correlation between biomass kinetic and membrane fouling can improve the understanding and spread of Membrane Bioreactor (MBR) technology, especially in solving the membrane fouling issues. On this behalf, this paper, produced by the International Water Association (IWA) Task Group on Membrane modelling and control, reviews the current state-of-the-art regarding the modelling of kinetic processes of biomass, focusing on modelling production and utilization of soluble microbial products (SMP) and extracellular polymeric substances (EPS). The key findings of this work show that the new conceptual approaches focus on the role of different bacterial groups in the formation and degradation of SMP/EPS. Even though several studies have been published regarding SMP modelling, there still needs to be more information due to the highly complicated SMP nature to facilitate the accurate modelling of membrane fouling. The EPS group has seldom been addressed in the literature, probably due to the knowledge deficiency concerning the triggers for production and degradation pathways in MBR systems, which require further efforts. Finally, the successful model applications showed that proper estimation of SMP and EPS by modelling approaches could optimise membrane fouling, which can influence the MBR energy consumption, operating costs, and greenhouse gas emissions

    Wind turbine wake models developed at the Technical University of Denmark: A review

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    AbstractWind turbine wakes are one of the most important aspects in wind power meteorology because they decrease the power production and increase the loading of downstream wind turbines. Therefore, there is a continuous need to find a ‘good’ wake model to properly plan wind power plant-level control strategies, predict the performance and understand the fatigue loads of turbines. In this paper, six widely used approaches of wake modelling (Jensen, Larsen, Dynamic Wake Meandering, Fuga and, Ellipsys3D LES and RANS together with their interpretations) that were developed at Technical University of Denmark, are described and the model subcomponents are analysed. The models are evaluated using data from the Sexbierum (onshore) and the Lillgrund (offshore) wind farms to understand how to best utilize them.The paper provides a comprehensive conceptual background to wake modelling combined with the overview of the state-of-the-art models including their implementations on operating wind farms

    A Conceptual Model for Scholarly Research Activity

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    This paper presents a conceptual model for scholarly research activity, developed as part of the conceptual modelling work within the ???Preparing DARIAH??? European e-Infrastructures project. It is inspired by cultural-historical activity theory, and is expressed in terms of the CIDOC Conceptual Reference Model, extending its notion of activity so as to also account, apart from historical practice, for scholarly research planning. It is intended as a framework for structuring and analyzing the results of empirical research on scholarly practice and information requirements, encompassing the full research lifecycle of information work and involving both primary evidence and scholarly objects; also, as a framework for producing clear and pertinent information requirements, and specifications of digital infrastructures, tools and services for scholarly research. We plan to use the model to tag interview transcripts from an empirical study on scholarly information work, and thus validate its soundness and fitness for purpose

    Parsimonious Catchment and River Flow Modelling

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    It is increasingly the case that models are being developed as “evolving” products rather than\ud one-off application tools, such that auditable modelling versus ad hoc treatment of models becomes a\ud pivotal issue. Auditable modelling is particularly vital to “parsimonious modelling” aimed at meeting\ud specific modelling requirements. This paper outlines various contributory factors and aims to seed\ud proactively a research topic by inextricably linking value/risk management to parsimonious modelling.\ud Value management in modelling may be implemented in terms of incorporating “enough detail” into a\ud model so that the synergy among the constituent units of the model captures that of the real system. It is a\ud problem of diminishing returns, since further reductions in the constituent units will create an\ud unacceptable difference between the model and the real system; conversely, any further detail will add to\ud the cost of modelling without returning any significant benefit. The paper also defines risk management\ud in relation to modelling. It presents a qualitative framework for value/risk management towards\ud parsimonious modelling by the categorisation of “modelling techniques” in terms of “control volume.
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