203,779 research outputs found

    Conceptual structures for modeling in CIM

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    The International Standards Organization (ISO) will release in 1993 the first version of the STEP standard, which is dedicated to the exchange of product model data, and is seen as the basis of the next generation of enterprise information modeling tools. Almost in the same time frame ANSI will release the Information Resource Dictionary System(IRDS) Conceptual Schema standard, which recommends the conceptual graphs (CGs) or other representation languages based on logic to be used for enterprise information modeling and integration. In this paper we develop the foundations for the utilization of conceptual structures (CS) in combination with EXPRESS and STEP Application Protocols in the field of Computer Integrated Manufacturing (CIM). The most important result described here is a mapping of EXPRESS into CGs. Around it we develop the architecture of a system able to analyze and translate some of the semantics of information models. Our overall strategy consists of representing the semantics of the language, including the informal meanings represented in the EXPRESS manual in plain English, in a systematic way in CS, and then use this block of knowledge, that can be processed by a machine, for the increasingly automatic analysis, translation and integration of enterprise information models. The work here described is one of the components of a prototype of a model management system under development at IBM, Kingston NY, coordinated by the CIM Architecture group

    Investigating the effectiveness of a professional development program for secondary physics teachers

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    National studies have exposed a shortage of highly-qualified high school physics teachers, with over 25% of physics teaching vacancies in Iowa being very difficult to fill or unable to be filled. In an effort to improve the nation’s education system, there have been broad changes in the framework of what constitutes high-quality teaching which supports a trend away from traditional, lecture-based teaching methods and towards interactive, student-centered methods. This study analyzed the impact of a professional development program that aimed to prepare more high-quality high school physics teachers by building physics content knowledge through the use of reformed teaching techniques that could then be applied in their classrooms. The Iowa Physics Teacher Instruction and Resources (IPTIR) program was a three-year professional development program with a total of 35 high school science teacher participants. Program staff administered conceptual and pedagogical evaluation to teachers, and collected conceptual assessment data from their students. Analysis of this data provided insight into the program’s effectiveness as well as implications for future professional development programs. The IPTIR program enabled 20 out-of-field high school physics teachers to obtain a State of Iowa physics teaching endorsement, and improved the content knowledge of the teachers and their students through the use of interactive engagement techniques such as PRISMS PLUS learning cycles and Modeling Instruction. The results of this study reveal the effectiveness of programs such as IPTIR, and emphasize a need for further similar programs to produce more quality high school physics teachers

    Continued Use Of Intra-Organizational Blogs: Impacts Of Habits, Network Externalities, And Ranking

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    Enterprise 2.0 applications, such as blogging systems, are increasingly prevailing in corporate contexts. As intra-organizational blogs are expected to provide a new approaching to building a flexible intra-organizational networking platform which could effectively facilitate knowledge sharing, it is worthwhile to address why and how the employees may accept a blogging system and keep blogging continually. Drawing upon the existing literature, this paper proposes a conceptual model which suggests that the continued use of internal blogging among employees is jointly driven by the forces of habituation and network externalities, while these forces can be shaped by managerial incentives such as a ranking mechanism. To empirically test the proposed model, actual usage data are collected from the internal blogging platform of a large Chinese company, so as to measure all the related constructs. Statistical results from a structural equation modeling (SEM) analysis illustrate that the model effectively explains the continued use of corporate internal blogging systems. By using the actual record data obtained from an in-practice system, our study manages to avoid the self-report bias which inevitably perplexes conventional survey-based research. We believe that the findings of this paper would contribute to the literature of Enterprise 2.0 user behavior on both theoretical and methodological perspectives, while providing helpful practical insights for better promoting the use of blogging systems in corporate contexts

    Modelling approaches for relating effects of change in river flow to populations of Atlantic salmon and brown trout

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    Modelling approaches for relating discharge to the biology of Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., growing in rivers are reviewed. Process-based and empirical models are set within a common framework of input of water flow and output of characteristics of fish, such as growth and survival, which relate directly to population dynamics. A continuum is envisaged incorporating various contributions of process and empirical structure as practical and appropriate to specific goals. This framework is compared with, and shown to differ from, approaches whose output is in the form of quantity and form of habitat (or usable area) based on its frequency of use by fish, which then is assumed to have some relationship with fish performance. A simple conceptual modeling approach is also developed to relate water flow to fish population characteristics to assess the likelihood of simple relationships between flow and usable area thresholds. Basic predictions of the model are tested against empirical data from a long-term individual-based study of juvenile S. salar and resident brook trout, Salvelinus fontinalis (Mitchell), in West Brook, Massachusetts. For this system, growth rates of both species increased linearly with flow during spring, summer and autumn months and bore no relation to Q95 or wetted-width discontinuities. Winter is identified as a season during which water might be abstracted most safely, but cautiously given sparse knowledge of wild salmonid fish at this time of year. These results, together with the fundamental conceptual problems inherent in usable area-based approaches, suggest that models that relate directly to fish performance outcomes may be more robust as a basis for flow prescriptions. However, this utility will depend strongly on our ability to generalize from a limited set of empirical studies and to use the results of these studies of management actions to inform and improve future models

    Towards Agent-Based Model Specification of Smart Grid: A Cognitive Agent-Based Computing Approach

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    A smart grid can be considered as a complex network where each node represents a generation unit or a consumer, whereas links can be used to represent transmission lines. One way to study complex systems is by using the agent-based modeling paradigm. The agent-based modeling is a way of representing a complex system of autonomous agents interacting with each other. Previously, a number of studies have been presented in the smart grid domain making use of the agent-based modeling paradigm. However, to the best of our knowledge, none of these studies have focused on the specification aspect of the model. The model specification is important not only for understanding but also for replication of the model. To fill this gap, this study focuses on specification methods for smart grid modeling. We adopt two specification methods named as Overview, design concept, and details and Descriptive agent-based modeling. By using specification methods, we provide tutorials and guidelines for model developing of smart grid starting from conceptual modeling to validated agent-based model through simulation. The specification study is exemplified through a case study from the smart grid domain. In the case study, we consider a large set of network, in which different consumers and power generation units are connected with each other through different configuration. In such a network, communication takes place between consumers and generating units for energy transmission and data routing. We demonstrate how to effectively model a complex system such as a smart grid using specification methods. We analyze these two specification approaches qualitatively as well as quantitatively. Extensive experiments demonstrate that Descriptive agent-based modeling is a more useful approach as compared with Overview, design concept, and details method for modeling as well as for replication of models for the smart grid

    Ontology-driven conceptual modeling: A'systematic literature mapping and review

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    All rights reserved. Ontology-driven conceptual modeling (ODCM) is still a relatively new research domain in the field of information systems and there is still much discussion on how the research in ODCM should be performed and what the focus of this research should be. Therefore, this article aims to critically survey the existing literature in order to assess the kind of research that has been performed over the years, analyze the nature of the research contributions and establish its current state of the art by positioning, evaluating and interpreting relevant research to date that is related to ODCM. To understand and identify any gaps and research opportunities, our literature study is composed of both a systematic mapping study and a systematic review study. The mapping study aims at structuring and classifying the area that is being investigated in order to give a general overview of the research that has been performed in the field. A review study on the other hand is a more thorough and rigorous inquiry and provides recommendations based on the strength of the found evidence. Our results indicate that there are several research gaps that should be addressed and we further composed several research opportunities that are possible areas for future research

    Enterprise model verification and validation : an approach

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    This article presents a verification and validation approach which is used here in order to complete the classical tool box the industrial user may utilize in enterprise modeling and integration domain. This approach, which has been defined independently from any application domain is based on several formal concepts and tools presented in this paper. These concepts are property concepts, property reference matrix, properties graphs, enterprise modeling domain ontology, conceptual graphs and formal reasoning mechanisms
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