• Nuclear Engineering and Technology
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• v.41 no.5
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• pp.739-746
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• 2009

This paper introduces facility operation modeling and simulation based primarily on a discrete event system modeling scheme. Many modern industrial facilities are so complex that their operational status cannot be estimated by simple calculations. In general, a facility can consist of many processes and transfers of material between processes that may be modeled as a discrete event system. This paper introduces the current status of studies on operation modeling and simulation for typical nuclear facilities, along with some examples. In addition, this paper provides insights about how a discrete event system can be applied to a model for a nuclear facility. A headend facility is chosen for operation modeling and the simulation, and detailed procedure is thoroughly described from modeling to an analysis of discrete event results. These kinds of modeling and simulation are very important because they can contribute to facility design and operation in terms of prediction of system behavior, quantification of facility capacity, bottleneck identification and efficient operation scheduling.

• The Journal of Information Technology and Database
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• v.8 no.1
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• pp.41-65
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• 2001

This study proposes evaluation dimensions of object-oriented systems modelling tools and activities available in object-oriented systems development practices. The dimensions ale developed based on previous research in cognitive psychology, information systems modeling study, and object-oriented systems analysis arid design areas. The proposed dimension is composed of two dimensions. The one dimension includes abstraction levels of modelling and the other includes process and representation in modeling activities. Experts on object-oriented modeling were selected to evaluate the practical validity of the proposed dimensions and applications of major object-oriented modeling tools during systems development project. Most of the tools were observed to be used for representing objects rather than for modeling the process of related objects. The proposed modeling dimension will be evaluated for acquiring general validity in future empirical research.

• Journal of the Korea Society of Computer and Information
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• v.24 no.10
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• pp.11-23
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• 2019

This paper designs and proposes a file conversion process to IFC file, the international standard file format for BIM, in order to ensure mutual compatability and manageability among users of commercial BIM modeling and design softwares in the civil engineering area. The proposed process insert additional properties consisting of the properties of quantity calculation codes and properties of CBS/OBS/WBS standard classification scheme, to the three dimensional object shape information of the converted IFC files, using add-in converters for commercial BIM modeling softwares. In addition, a process of integrated use of IFC files for open web-based quantity, process(4D), and construction cost(5D) management is additionally designed and implemented. Based on these works, the ultimate goal of this study is to propose a novel process for integrated use of open web-based quantity, process(4D), and construction cost(5D), from the design stage of BIM modeling to the final construction stage in the civil engineering area.

• Korean Journal of Chemical Engineering
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• v.35 no.12
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• pp.2327-2335
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• 2018

Fluid catalytic cracking (FCC) is an important chemical process that is widely used to produce valuable petrochemical products by cracking heavier components. However, many difficulties exist in modeling the FCC process due to its complexity. In this study, a dynamic process model of a FCC process is suggested and its structural observability is analyzed. In the process modeling, yield function for the kinetic model of the riser reactor was applied to explain the product distribution. Hydrodynamics, mass balance and energy balance equations of the riser reactor and the regenerator were used to complete the modeling. The process model was tested in steady-state simulation and dynamic simulation, which gives dynamic responses to the change of process variables. The result was compared with the measured data from operating plaint. In the structural analysis, the system was analyzed using the process model and the process design to identify the structural observability of the system. The reactor and regenerator unit in the system were divided into six nodes based on their functions and modeling relationship equations were built based on nodes and edges of the directed graph of the system. Output-set assignment algorithm was demonstrated on the occurrence matrix to find observable nodes and variables. Optimal locations for minimal addition of measurements could be found by completing the whole output-set assignment algorithm of the system. The result of this study can help predict the state more accurately and improve observability of a complex chemical process with minimal cost.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.3
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• pp.74-84
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• 2015

The core activities of a bicycle manufacturer are design, engineering analysis, and manufacturing. Therefore, it is important to develop a configuration design system for bicycles in order to automate the design process and facilitate the use of design data in engineering analysis and manufacturing. In this paper, we present a method to develop a bicycle configuration design system based on the part-shape information model. The proposed method enables the construction of a CAD library using modeling functions with equations and parameters that are common to most 3D mechanical CAD systems. Furthermore, the part-shape information model ensures the independence between the configuration design system and the library, making it possible to extend the CAD library flexibly without changing the system architecture.

• Architectural research
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• v.16 no.3
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• pp.93-100
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• 2014

Existing BIM(Building Information Modeling) based energy evaluation tools cannot be utilized enough for the potential performance of BIM because most of them have not provided the integrated model for energy evaluation, assessment of the material, cost of the construction, and so on. This research aims to propose and develop a new application, EcoBIM, to support an integrated evaluation of the energy and cost efficiencies of the design alternatives within the design process. The proposed application functions as a BIM-based evaluation system that calculates energy-savings performance as well as the construction cost of the alternatives at the design stage. This study mainly focuses on the possibilities of developing the proposed technology. We also suggest an advanced design process using the proposed system, corresponding to changes of national regulations in Korea. This study deduce that EcoBIM can allow architects to make suitable decisions regarding energy- and cost-efficient designs. The proposed design process will allow architects not only to check the eco-friendly performance of design alternatives but also predict the operation cost in a certain period in the future. EcoBIM can prevent large-scale design changes required to obtain environmental certification and enable the owner to make an informed decision about the initial investment of construction according to the result of the analysis of the energy requirement at the design stage.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2011.09a
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• pp.23-33
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• 2011

The key features of an intelligent and dynamic design methodology for rock engineering projects has been introduced and summarized firstly, which include some new functions such as intelligent recognition of mechanical rockmass parameters, strategies to select modeling methods and codes, integrated feedback modeling and information, and technical auditing in rock engineering design process. Then typical examples of applications of the dynamic design methodology in some large slopes, underground powerhouses in China are summarized. The discussions are given for the future of the methodology.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.1
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• pp.14-19
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• 2002

This paper describes an automatic parts design system for gears, brake, and clutch. These parts are important components of the power transmission assembly. In conventional design process, the design of power transmission requires a number of recurrent calculations and drawings. In this paper, we propose a three-dimensional automatic design system that reduces the number of recurrent calculations and drawings. The system consists of three modules for designing gear, brake, and clutch. The proposed system has been applied to develop a transmission of forklift truck and shown to be a useful system.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.10a
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• pp.126-132
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• 2004

The database design for the management of bridge measurement information is presented in this paper. To express the associated data generated during the whole process of ambient measurement efficiently, requirements analysis for database construction is performed. And to define objects and organize schema conceptual and logical design are performed, which convert data model into logical schema. Finally, physical design is performed using DDL(data defined language). This database is based on the object-relational data modeling approach that has rich expressive power and good reusability in comparison with the traditional entity-relational modeling.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1449-1454
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• 2003

For many industrial processes there are good static models used for process design and steady state operation. By using system identification techniques, it is possible to obtain black-box models with reasonable complexity that describe the system well in specific operating conditions [1]. But black-box models using inductive modeling(IM) is not suitable for model based control because they are only valid for specific operating conditions. Thus we need to use deductive modeling(DM) for a wide operating range. Furthermore, deductive modeling is several merits: First, the model is possible to be modularized. Second, we can increase and decrease the model complexity. Finally, we are able to use model for plant design. Power plant must be able to operate well at dramatic load change and consider safety and efficiency. This paper proposes a simplified nonlinear model of an industrial boiler, one of component parts of a power plant, by DM method and applies optimal control to the model.