The Experts below are selected from a list of 202347 Experts worldwide ranked by ideXlab platform
Bernhard Thalheim - One of the best experts on this subject based on the ideXlab platform.
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NLDB - Syntax, semantics and pragmatics of Conceptual Modelling
Natural Language Processing and Information Systems, 2012Co-Authors: Bernhard ThalheimAbstract:Models, Modelling languages, Modelling frameworks and their background have dominated Conceptual Modelling research and information systems engineering for last four decades. Conceptual models are mediators between the application world and the implementation or system world. Currently Conceptual Modelling is rather a craft and at the best an art. We target on a science and culture of Conceptual Modelling. Models are governed by their purpose. They are used by a community of practice and have a function within application cases. Language-based models use a language as a carrier. Therefore, semiotics of models must be systematically developed. This paper thus concentrates on the linguistic foundation of Conceptual Modelling.
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The science and art of Conceptual Modelling
Transactions on Large-Scale Data- and Knowledge-Centered Systems VI, 2012Co-Authors: Bernhard ThalheimAbstract:Conceptual Modelling is one of the central activities in Computer Science. Conceptual models are mainly used as intermediate artifact for system construction. They are schematic descriptions of a system, a theory, or a phenomenon of an origin thus forming a model. A Conceptual model is a model enhanced by concepts. The process of Conceptual Modelling is ruled by the purpose of Modelling and the models. It is based on a number of Modelling acts, on a number of correctness conditions, on Modelling principles and postulates, and on paradigms of the background or substance theories. Purposes determine the (surplus) value of a model. Conceptual Modelling is performed by a modeller that directs the process based on his/her experience, education, understanding, intention and attitude. Conceptual models are products that are used by other stakeholders such as programmers, learners, business users, and evaluators. Conceptual models use a language as a carrier for the Modelling artifact and are restricted by the expressiveness of this carrier. This paper aims at a discussion of a general theory of Modelling as a culture and an art. A general theory of Modelling also considers Modelling as an apprenticeship and as a technology. It is thus an art. Modelling is on of the main elements of Computer Science culture that consists of commonly accepted behaviour patterns, arts, consensus, institutions, and all other supporting means and thoughts.
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Handbook of Conceptual Modeling - The Theory of Conceptual Models, the Theory of Conceptual Modelling and Foundations of Conceptual Modelling
Handbook of Conceptual Modeling, 2011Co-Authors: Bernhard ThalheimAbstract:Conceptual Modelling is a widely applied practice and has led to a large body of knowledge on constructs that might be used for Modelling and on methods that might be useful for Modelling. It is commonly accepted that database application development is based on Conceptual Modelling. It is, however, surprising that only very few publications have been published on a theory of Conceptual Modelling. Modelling is typically supported by languages that are well-founded and easy to apply for the description of the application domain, the requirements and the system solution. It is thus based on a theory of Modelling constructs. Modelling is ruled by its purpose, e.g., construction of a system, simulation of real-world situations, theory construction, explanation of phenomena, or documentation of an existing system. Modelling is also an engineering activity with engineering steps and engineering results. It is thus engineering.
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the theory of Conceptual models the theory of Conceptual Modelling and foundations of Conceptual Modelling
Handbook of Conceptual Modeling, 2011Co-Authors: Bernhard ThalheimAbstract:Conceptual Modelling is a widely applied practice and has led to a large body of knowledge on constructs that might be used for Modelling and on methods that might be useful for Modelling. It is commonly accepted that database application development is based on Conceptual Modelling. It is, however, surprising that only very few publications have been published on a theory of Conceptual Modelling. Modelling is typically supported by languages that are well-founded and easy to apply for the description of the application domain, the requirements and the system solution. It is thus based on a theory of Modelling constructs. Modelling is ruled by its purpose, e.g., construction of a system, simulation of real-world situations, theory construction, explanation of phenomena, or documentation of an existing system. Modelling is also an engineering activity with engineering steps and engineering results. It is thus engineering.
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DEXA (1) - The science of Conceptual Modelling
Lecture Notes in Computer Science, 2011Co-Authors: Bernhard ThalheimAbstract:Conceptual Modelling is one of the central activities in Computer Science. Conceptual models are mainly used as intermediate artifact for system construction. They are schematic descriptions of a system, a theory, or a phenomenon of an origin thus forming a model. A Conceptual model is a model enhanced by concepts. The process of Conceptual Modelling is ruled by the purpose of Modelling and the models. It is based on a number of Modelling acts, on a number of correctness conditions, on Modelling principles and postulates, and on paradigms of the background or substance theories. Purposes determine the (surplus) value of a model. Conceptual Modelling is performed by a modeller that directs the process based on his/her experience, education, understanding, intention and attitude. Conceptual models are products that are used by other stakeholders such as programmers, learners, business users, and evaluators. Conceptual models use a language as a carrier for the Modelling artifact and are restricted by the expressiveness of this carrier. This paper aims at a discussion of a general theory of Modelling as a culture and an art. A general theory of Modelling also considers Modelling as an apprenticeship and as a technology. It is thus an art. Modelling is on of the main elements of Computer Science culture that consists of commonly accepted behaviour patterns, arts, consensus, institutions, and all other supporting means and thoughts.
Ron Weber - One of the best experts on this subject based on the ideXlab platform.
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Conceptual Modelling and ontology: Possibilities and pitfalls
Journal of Database Management, 2003Co-Authors: Ron WeberAbstract:Conceptual Modelling is an activity undertaken during information systems development work to build a representation of selected semantics about some real-world domain. Ontological theories have been developed to account for the structure and behavior of the real world in general. In this paper, I discuss why ontological theories can be used to inform Conceptual Modelling research, practice, and pedagogy. I provide examples from my research to illustrate how a particular ontological theory has enabled me to improve my understanding of certain Conceptual Modelling practices and grammars. I describe, also, how some colleagues and I have used this theory to generate several counter-intuitive, sometimes surprising predictions about widely advocated Conceptual Modelling practices — predictions that subsequently were supported in empirical research we undertook. Finally, I discuss several possibilities and pitfalls I perceive to be associated with our using ontological theories to underpin research on Conceptual Modelling.
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Conceptual Modelling and ontology possibilities and pitfalls
International Conference on Conceptual Modeling, 2002Co-Authors: Ron WeberAbstract:The task of Conceptual Modelling is to build a high-quality representation of selected phenomena in some domain. The Conceptual models that result facilitate the design,implementation, operation, and maintenance of information systems. Because Conceptual Modelling activities usually occur during the initial stages of the systems development process, Modelling errors and omissions that are not detected early often have costly repercussions. Thus, research that seeks to improve Conceptual-Modelling practice is important.
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should optional properties be used in Conceptual Modelling a theory and three empirical tests
Information Systems Research, 2001Co-Authors: Francois Bodart, Arvind Patel, Marc Sim, Ron WeberAbstract:An important feature of some Conceptual Modelling grammars is the features they provide to allow database designers to show real-world thingsmay ormay not possess a particular attribute or relationship. In the entity-relationship model, for example, the fact that a thing may not possess an attribute can be represented by using a special symbol to indicate that the attribute is optional. Similarly, the fact that a thing may or may not be involved in a relationship can be represented by showing the minimum cardinality of the relationship as zero. Whether these practices should be followed, however, is a contentious issue. An alternative approach is to eliminate optional attributes and relationships from Conceptual schema diagrams by using subtypes that have only mandatory attributes and relationships.In this paper, we first present a theory that led us to predict that optional attributes and relationships should be used in Conceptual schema diagrams only when users of the diagrams require a surface-level understanding of the domain being represented by the diagrams. When users require a deep-level understanding, however, optional attributes and relationships should not be used because they undermine users' abilities to grasp important domain semantics. We describe three experiments which we then undertook to test our predictions. The results of the experiments support our predictions.
Patrick Willems - One of the best experts on this subject based on the ideXlab platform.
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modular Conceptual Modelling approach and software for sewer hydraulic computations
Water Resources Management, 2017Co-Authors: Vincent Wolfs, Patrick WillemsAbstract:A major challenge in urban water management is the identification of cost-effective and future-proof strategies that can cope with the rapid urbanization and changing environmental conditions. Water quantity Modelling forms a key-element in the development of such strategies. Conventional detailed hydrodynamic models are not well suited for use in decision support systems due to several important drawbacks. Therefore, this paper presents a novel and computationally efficient Conceptual Modelling approach for sewer water quantity simulations. A modular framework is considered that combines well-established model structures with machine learning techniques. This flexible framework ensures that even complex flow dynamics can be emulated accurately. An accompanying software tool was developed to facilitate model configuration. As an example, a full hydrodynamic sewer model of a city in Belgium was transformed into a Conceptual model. This model delivered precise results, while the calculation time was 106 times shorter than the detailed model.
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development of a semi automated model identification and calibration tool for Conceptual Modelling of sewer systems
Water Science and Technology, 2013Co-Authors: Vincent Wolfs, Mauricio Villazon, Patrick WillemsAbstract:Applications such as real-time control, uncertainty analysis and optimization require an extensive number of model iterations. Full hydrodynamic sewer models are not sufficient for these applications due to the excessive computation time. Simplifications are consequently required. A lumped Conceptual Modelling approach results in a much faster calculation. The process of identifying and calibrating the Conceptual model structure could, however, be time-consuming. Moreover, many Conceptual models lack accuracy, or do not account for backwater effects. To overcome these problems, a Modelling methodology was developed which is suited for semi-automatic calibration. The methodology is tested for the sewer system of the city of Geel in the Grote Nete river basin in Belgium, using both synthetic design storm events and long time series of rainfall input. A MATLAB/Simulink ® tool was developed to guide the modeller through the step-wise model construction, reducing significantly the time required for the Conceptual Modelling process.
Kathy Kotiadis - One of the best experts on this subject based on the ideXlab platform.
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a participative and facilitative Conceptual Modelling framework for discrete event simulation studies in healthcare
Journal of the Operational Research Society, 2014Co-Authors: Kathy Kotiadis, Antuela A Tako, Christos VasilakisAbstract:Existing approaches to Conceptual Modelling (CM) in discrete-event simulation do not formally support the participation of a group of stakeholders. Simulation in healthcare can benefit from stakeholder participation as it makes possible to share multiple views and tacit knowledge from different parts of the system. We put forward a framework tailored to healthcare that supports the interaction of simulation modellers with a group of stakeholders to arrive at a common Conceptual model. The framework incorporates two facilitated workshops. It consists of a package including: three key stages and sub-stages; activities and guidance; tools and prescribed outputs. The CM framework is tested in a real case study of an obesity system. The benefits of using this framework in healthcare studies and more widely in simulation are discussed. The paper also considers how the framework meets the CM requirements.
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A participative Modelling framework for developing Conceptual models in healthcare simulation studies
Proceedings of the 2010 Winter Simulation Conference, 2010Co-Authors: Antuela A Tako, Christos Vasilakis, Kathy KotiadisAbstract:Conceptual Modelling, one of the first stages in a simulation study, is about understanding the situation under study and deciding what and how to model. We argue that stakeholder involvement as part of Conceptual Modelling could lead to a more successful simulation study with better prospects for implementation. Our work is mainly applied in health care studies, which are characterized by many stakeholders with multiple views and objectives and often a politically charged environment. We develop a participative Conceptual Modelling framework, which uses tools from soft systems methodology, a problem structuring approach. The benefit of this approach lies in that it supports the Conceptual Modelling process by engaging stakeholders in a structured and participative way. It involves facilitated workshops, using a set of tools developed. A case study of the Conceptual Modelling process undertaken for an obesity system is provided to illustrate the proposed framework and tools.
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Conceptual Modelling knowledge acquisition and model abstraction
Winter Simulation Conference, 2008Co-Authors: Kathy Kotiadis, Stewart RobinsonAbstract:Conceptual Modelling has gained a lot of interest in recent years and simulation modellers are particularly interested in understanding the processes involved in arriving at a Conceptual model. This paper contributes to this understanding by discussing the artifacts of Conceptual Modelling and two specific Conceptual Modelling processes: knowledge acquisition and model abstraction. Knowledge acquisition is the process of finding out about the problem situation and arriving at a system description. Model abstraction refers to the simplifications made in moving from a system description to a Conceptual model. Soft Systems Methodology has tools that can help a modeller with knowledge acquisition and model abstraction. These tools are drawing rich pictures, undertaking analyses `one?, `two?, `three?, and constructing a root definition and the corresponding purposeful activity model. The use of these tools is discussed with respect to a case study in health care.
Carson Woo - One of the best experts on this subject based on the ideXlab platform.
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Using Conceptual Models to Theorize about the Relationship Between Records and Risk in the Global Financial Crisis
Financial Analysis and Risk Management, 2013Co-Authors: Kafui Monu, Lior Limonad, Victoria Lemieux, Carson WooAbstract:Financial records can be used to help identify operational and systemic risks associated with financial transactions since they provide evidence of how a transaction may occur. They are necessary for regulation of the financial system and in order to assert legal and financial claims. In some cases financial institutions do not adequately record information, which can lead to many problems, as was the case during and in the aftermath of the financial crisis of 2007–2009. In these cases it would be useful to understand exactly how missing or incomplete records affected the situation, why they were missing or incomplete, in what ways this situation may have contributed to risk buildup in the financial system, and how the situation could be rectified or even prevented. In this study we suggest using Conceptual Modelling, a technique more often used for systems development, to gain an understanding of financial records creation, transmission, and management in the processes along the private label residential mortgage-backed securities originate to distribute supply chain. Conceptual Modelling is the act of representing the physical and social domain using specific abstractions of it. The study discusses how three different Conceptual Modelling techniques were used to explore the relationship between records and risk in the context of the financial crisis. From experiences with using these different Conceptual Modelling approaches, we conclude that Conceptual Modelling is valuable as a tool to help understand and model relationships and dynamics in financial risk management and as a tool to generate new insights that would otherwise have been more difficult to see.
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theoretical foundations for Conceptual Modelling in information systems development
Decision Support Systems, 1995Co-Authors: Yair Wand, David E Monarchi, Jeffrey Parsons, Carson WooAbstract:Conceptual Modelling in information systems development is the creation of an enterprise model for the purpose of designing the information system. It is an important aspect of systems analysis. The value of a Conceptual Modelling language (CML) lies in its ability to capture the relevant knowledge about a domain. To determine which constructs should be included in a CML it would be beneficial to use some theoretical guidelines. However, this is usually not done. The purpose of this paper is to promote the idea that theories related to human knowledge can be used as foundations for Conceptual Modelling in systems development. We suggest the use of ontology, concept theory, and speech act theory. These approaches were chosen because: (1) they deal with important and different aspects relevant to Conceptual Modelling and (2) they have already been used in the context of systems analysis. For each approach we discuss: the rationale for its use, its principles, its application to Conceptual Modelling, and its limitations. We also demonstrate the concepts of the three approaches by analysing an example. The analysis also serves to show how each approach deals with different aspects of Modelling.