• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.11
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• pp.30-35
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• 2008

An analog type turbine control system in a nuclear power plant in Korea was replaced by a digital type control system successfully. The turbine simulator was used to verify and validate the perfection of newly developed digital control system prior to its actual installation. In this paper, the newly developed turbine speed control system, ie. governor will be introduced together with how to simulate entire control loop. After that, we will compare the comparison of simulation result in laboratory with pre startup simulation result. Eventually the performance of actual operation result was testified.

• Design & Manufacturing
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• v.17 no.3
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• pp.1-7
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• 2023

Blow molding is a manufacturing process in which thermoplastic preforms are preheated and then pneumatically expanded within a mold to produce hollow products of various shapes. The two-step process, a type of blow molding method, requires the output of multiple infrared lamps to be adjusted individually, so the process of finding initial conditions hinders productivity. In this study, digital twin technology was applied to solve this problem. A blow molding simulation technique was established and simulation-based metadata was generated. A response surface ROM (Reduced Order Model) was built using the generated metadata. Then, a dynamic ROM was constructed using the results of 3D heat transfer analysis. Through this, users can quickly check the product wall thickness uniformity according to changes in the control value of the heating lamp for products of various shapes, and at the same time, check the temperature distribution of the preform in real time.

• Nuclear Engineering and Technology
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• v.53 no.1
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• pp.131-141
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• 2021

Simulation is a widely used functional verification method for FBD programs of PLC-based digital I&C system in nuclear power plants. It is difficult, however, to estimate the thoroughness (i.e., effectiveness or quality) of a simulation in the absence of any clear measure for the estimation. This paper proposes two sets of structural coverage adequacy criteria for the FBD simulation, toggle coverage and modified condition/decision coverage, which can estimate the thoroughness of simulation scenarios for FBD programs, as recommended by international standards for functional safety. We developed two supporting tools to generate numerous simulation scenarios and to measure automatically the coverages of the scenarios. The results of our experiment on five FBD programs demonstrated that the measures and tools can help software engineers estimate the thoroughness and improve the simulation scenarios quantitatively.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.113-114
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• 2011

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.147.3-147
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• 2001

We have proposed a digital control method, where the controlled variable is a joint angular velocity, of space robot manipulators using the transpose of Generalized Jacobian Matrix. The explicit relationship between the control law and the sampling period, however, is unknown because the controller gains include the sampling period implicitly. This paper presents a novel digital control method which explicitly describes the relation between the sampling period and the controller gains. Computer simulation of a 3-DOF planar space robot manipulator is peformed. Simulation result demonstrates the effctiveness of the proposed method.

• The Pure and Applied Mathematics
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• v.22 no.3
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• pp.299-313
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• 2015

In this paper, we show the effectiveness of copulas by comparing the correlation of market data of year 2010 with those of years 2006-2009 and investigate copula functions as pricing methods of digital and rainbow options through real market data. We propose an accurate method of pricing rainbow options by using the correlation coefficients obtained from the copula functions depending on strike prices between assetes instead of simple traditional correlation coefficients.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.206-211
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• 1998

In audio techniques calculation of digital filters is accelerated considerably by use of wave variables instead of voltages and currents. The suitability of wave variables for digital simulation of power converters was investigated and the results are reported in this paper. The original method is described briefly, modelling of switches and diode rectifiers is presented, examples are given and the features of the method are discussed.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.2
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• pp.78-83
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• 2007

In this paper, the digital model of the micro-factory has been established, inspected and evaluated by progress of assembly, manipulation and examination. The new paradigm of the system analysis is realized by digital simulation of the factory. The digital manufacturing system of the micro-factory was simulated through UML(Unified Modeling Language) with the object-oriented logical model analysis method and then the micro lens module assembly system was simulated with MST(Micro System Technology) Application Module.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.7
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• pp.1439-1445
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• 2009

This paper introduces a simulation model regarding the process analysis of a digital doorlock mixed assembly process. The objective of the simulation model is to evaluate the performance of various design aspects of process alternatives. To develop the simulation model, a time study is performed for each process. Next, by using ARENA, a simulation model is conducted based on the process analysis and the line balancing methodology. We found out several problems for mixed assembly process, and then suggest several alternatives to improve the system.

• Korean Journal of Computational Design and Engineering
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• v.15 no.2
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• pp.94-105
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• 2010

Todays, there is fast transition about the new manufacturing IT methodologies from the conceptual phase into the practical application phase for the strengthening of enterprise competitiveness in manufacturing industry. One of those new methodologies is PLM (Product Life-cycle Management). PLM methodology consists of 3D CAD for the product design, PDM (Product Data Management) for the data management based on the collaboration platform and lastly DM (Digital Manufacturing). DM has evoluted from the stand-alone computer simulation of early 1980s, and now it covers the overall production development and production. Unfortunately, there exist serious critical problems about the actual application of DM for the real work. This is owing to the transition of the point of view from stand-alone type application (such as flow simulation or robot simulation) to that of business process about product development and production management. In this paper, we propose an application framework for the successful project with the digital manufacturing methodology with the concept of Information Strategy Planning, which enables the systematic diagnosis and the quantitative evaluation. Also, we introduce the actual practice of the proposing framework with the ISP project for 'Analysis & Simulation Technique of manufacturing process project' that is being conducted by Chungnam Techno Park.