• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.1
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• pp.29-36
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• 2013

This paper deals with the analysis of the customer voltage characteristic in distribution system interconnected with large scale PV system. There would be many power quality issues which are caused by reverse power flow of PV system interconnected with distribution system. In order to analyze the effect of PV system on the customer voltage, detailed modeling method of distribution system and modified modelling method of PV system are proposed using PSCAD/EMTDC in this paper. So far, less than dozens KW of PV system can be simulated with the existing modelling method. Therefore, a new modeling method which can simulate the large scale PV system is proposed by considering the relationship equation on the phase and voltage in the current control algorithm. From the simulation result of proposed modelling method, it is confirmed that an optimal operation method in distribution system is suggested by analyzing the effect of PV system on customer voltage.

• Journal of Navigation and Port Research
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• v.32 no.3
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• pp.245-250
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• 2008

Recently the numerical prediction technique is applied to many fields, because numerical models are developed so much for last decades. The real-time ocean prediction system is one of them and is capable of providing the real-time marine information for users to promote the safety af maritime traffic and preservation of marine resources. The system is composed of observing system, data distribution system and modelling system. In this study authors develop the modelling system and show the results as preliminary study for establishing the real-time ocean prediction system in Busan port. The system test is performed only for M2 tidal modelling due to the lack qf observation data, thus a full-scale test is required in future if enough data are provided Also observing system and data distribution system will be constructed continuously in future, then service for real-time data for users will be initiated.

• Journal of Korean Institute of Industrial Engineers
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• v.12 no.1
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• pp.119-131
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• 1986

Described in this paper is a modelling methodology for mass production system simulation. The mass production system under consideration consists of various types of flow lines, special purpose production facilities, conveyor lines, palletized carts, and storage facilities. This type of production system is typical in home appliance industry, automobile industry, footwear industry, etc. where a variety of product mix are mass-produced. The modelling methodology is based on the "discrete-event formalism", and an "activity-oriented world view" is adopted to formalize the system description. A distinctive feature of the modelling methodology is that only the static structure (ie, system components) is included in the fixed model. The dynamic structure of the system is specified through a "data-driven" mechanism, which is an extension of the "experimental frame" concept. Each type of system components (ie, flow line, conveyors, carts, etc.) is formally modeled by using Activity Cycle Diagrams. The issue of "model structuring" is also addressed. The modeling methodology has been successfully applied in a real simulation study of a mass production system.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.3
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• pp.281-301
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• 2023

The shipboard combat system is a key system for naval combat that supports a command and control process cycle consisting of Detect - Control - Engage in real time to ensure ship viability and conduct combat missions. Modern combat systems were developed on the basis of Open Architecture(OA) to maximize acceptance of latest technology and interoperability between systems, and actively introduced the COTS(Commercial-of-the-shelf). However, as a result of that, vulnerabilities inherent in COTS SW and HW also occurred in the combat system. The importance of combat system cybersecurity is being emphasized but cybersecurity research reflecting the characteristics of the combat system is still lacking in Korea. Therefore, in this paper, we systematically identify combat system threats by applying Data Flow Diagram, Microsoft STRIDE threat modelling methodology. The threats were analyzed using the Attack Tree & Misuse case. Finally we derived the applicable security requirements which can be used at stages of planning and designing combat system and verified security requirements through NIST 800-53 security control items.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.5
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• pp.117-125
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• 2003

Since the recorded information used for operation of a catchment modelling system contain errors that influence the calibration of catchment modelling system control parameter values, the accurate estimation of these parameters is difficult. Despite these influences, existing traditional calibration approaches focus only on achieving the best "curve fitting" between simulated and recorded data, and not on generic evaluation of control parameter values. This paper introduces an Early Stopping Technique which is aimed at avoiding the procedure of curve-fitting through monitoring improvements in the objective function used for assessing the optimal parameter set. Application of this approach to the calibration of SWMM (Storm Water Management Model) on the Centennial Park catchment in Sydney, Australia is outlined. outlined.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.4
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• pp.414-427
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• 1990

This paper presents the development of the graphic simulator for an assembly workcell. The assembly workcell consists of two PUMA 560 manipulators, a conveyor belt system, a work table, and a vision sensor. In this study, the Petri Net theory is applied to model the assembly workcell and to construct the simulator. The event scheduling approach is used to simulate the cell. In order to show the graphic display of the simulation process, robot modelling, component modelling, and world modelling are included. The developed simulator is used to display the transition of the system state during the simulation. It is also used as a tool in selection the best resource states by studying the performance of the system as the resource states are changed.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.31-34
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• 2002

It studied modelling about employing analog PSS in domestic 500MW grade standard thermoelectric power plant in this paper. Modeling and parameters were verified by simulation of PSS response characteristics measured in AVR step examination and using power plant system model parameters decided by generator characteristics test. Through this PSS modelling research, contributed in domestic electrical power system small signal stability as that do modelling to be possible exact analysis of power system.

• Journal of Power Electronics
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• v.9 no.6
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• pp.854-865
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• 2009

Super-lift dc-dc converters are a series of advanced step-up dc-dc topologies that provide high voltage transfer gains by super-lift techniques. This paper presents a developed graphical modelling method for super-lift converters and gives a thorough analysis with a consideration of the effects caused by parasitic parameters and diodes' forward voltage drop. The general guidelines for constructing and deriving graphical models are provided for system analysis. By applying it to examples, the proposed method shows the advantages of high convenience and feasibility. Both the circuit simulation and experimental results are given to support the theoretical analysis.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10a
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• pp.562-566
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• 1988

The purpose of this study is to develop a personal computer aided 3-D geometric modeller. To perform this study, we set up a cube, a cylinder, and a prism as a primitive in the first segment of this study. By modelling the 3-D object through their transformation, addition, and subtraction, we proved the validity of the developed algorithm and its computer program. Some examples show the results of applying the program to modelling a few simple shape of the machine parts. These results met the first aim of this study.

• Proceedings of the Korea Society for Simulation Conference
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• 2001.10a
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• pp.205-208
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• 2001

A lumped electrical circuit is an approximate representation of the field within a curtain frequency range. The finite element modelling is a synonym of the equivalent circuit. The electric conduction field and electric potential wave field have been modelled by an admittance network and an LC low-pass filter network. Here in the present paper, the equivalent magnetic circuit representation is created for a magnetostatic field by the finite element modelling in two dimension.