• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2288-2296
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• 2015

This paper proposes a novel systematic modeling approach for an integrated single-stage power converter in order to predict its dynamic characteristics. The basic strategy of the proposed modeling is substituting the internal converters with an equivalent current source, and then deriving the dynamic equations under a standalone operation using the state-space averaging technique. The proposed approach provides an intuitive modeling solution and simplified mathematical process with accurate dynamic prediction. The simulation and experimental results by using an integrated boost-flyback converter prototype provide verification consistent with theoretical expectations.

• Journal of the Korean housing association
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• v.12 no.2
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• pp.97-107
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• 2001

The survey was conducted to analyze the consciousness of residents about the re-modeling living space. The results of this study are as following; 1) The most of respondents have answered very positively in the idea of re-modeling in the near future. Re-modeling will be done in the entire space of housing. 2) It is shown that the desire of re-modeling is various, for example, the higher desire of expansion is arisen by someone who has the smaller space. 3) There are some cases; such as the space of balcony is added to the living room to expand the space of living room or the space of balcony is added to the bed room to expand the space of bed room. In this cases there might be some needs in architect technique.

• Proceedings of the Korean System Dynamics Society
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• 2006.04a
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• pp.19-40
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• 2006

A system dynamics model is developed to investigate the applicability of the agent based modeling concept in the system dynamics model. The assumed problem is to forecast the size and structure of the organization with the developing market environment. The agent based modeling concept is applied to the organization part, and the other parts of the model such as market, facilities, etc. are developed with the traditional system dynamics technique. The simulation results show the agent based modeling part can be combined with the traditional system dynamics modeling with more precisions. However, the complexity increases and the simulation times are longer than those of the traditional method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.12
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• pp.2091-2097
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• 2007

This paper described the verification of modeling technique of underground distribution from comparison between field test and simulation. It needs more exact transient phenomenon analysis model to establish lightning protection of underground distribution line. Although, there were a lot of transient phenomenon researches, nobody could has verified the confidence of modeling from field tests in interior until now. So, simulation model verified field test is needed to analyse transient phenomenon of underground distribution system. The examination must be accomplished in many different condition before suggesting these verified analysis model. In this paper, the conditions were examined and the various data results on the different line composition was compared with the EMTP simulation, when the lightning impulse test was accomplished at underground distribution line. Also the value between field test and simulation was very closed and the method of modeling has demonstrated confidence, when the method is used to analyse domestic transient phenomenon of underground distribution.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.954-957
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• 2002

The objective of design process modeling is a systematic support of rapid redesign process fur a modified input data. The design process modeling is realized by storing key parameters or geometric entities used in the intermediate design steps and reusing them for change of the designed parts or assemblies according to the modified input. In this paper, we adopted and implemented the design process modeling approach to our injection mold design system developed based on the Unigraphics system. It was proved that the productivity of mold redesign process is raised highly by introducing the design process modeling technique mold design system.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.384-389
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• 2008

In this paper, we propose a UML modeling of ATO on-board software. An automatic train operation (ATO) system is a real-time control system, which operates a train without a manual operation by a driver. For the safe and comfortable service, real-time embedded software for ATO on-board equipment should have both of high performance and reliability. UML-based object-oriented modeling technique is introduced and used widely to design software that satisfies this requirement. We used Rhapsody, which is a modeling tool for real-time embedded software, to model the construction and the behavior of ATO on-board equipment. As a result, ATO on-board software which performs the profile calculation and the real-time speed control is designed and implemented. The brief modeling result including behavioral characteristics and the simulation results are presented.

• Korean Journal of Computational Design and Engineering
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• v.7 no.1
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• pp.1-8
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• 2002

A Hotchkiss spring has been widely utilized for commercial vehicle. Usually, the Hotchkiss spring has non-linear characteristics, i.e. it has a piecewise spring stiffness as well as hysterisis phenomenon. Therefore, the modeling of the Hotchkiss spring requires many considerations to fulfill satisfactory vehicle kinematic and dynamic relationships. Also, the spring has difficulties in modeling for presenting contact mechanism. In this paper, the modeling technique for the Hotchkiss spring has been descried. The modeling covers non-linear characteristics as well as contact problems for multi-body dynamic simulation. The force-displacement results are compared with experimental and FEM ones. Also, the comparison between three link type leaf spring model and proposed one has been considered in this paper.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.57 no.2
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• pp.96-101
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• 2008

The field of load modeling has attracted the attention since it plays an important role for improving the accuracy of stability analysis and power flow estimation. Also, load modeling is an essential factor in the simulation and evaluation of power system performance. However, conventional load modeling techniques have some limitations with respect to accuracy for nonlinear and composite loads. Thus, precision load modeling technique and reasonable application method is needed for more accurate power system analysis. In this paper, we develop an intelligent load modeling method based. on neural network and application techniques for power system. The proposed method makes it possible to effectively estimate the load model for nonlinear models as well as linear models. Reasonable application method is also proposed for stability analysis. To demonstrate the validity of the proposed method, various experiments are performed and their results are presented.

• Nuclear Engineering and Technology
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• v.50 no.5
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• pp.698-708
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• 2018

This article introduces a methodology of designing a wavelet operator suitable for multiscale modeling. The operator matrix transforms states of a multivariable system onto projection space. In addition, it imposes a specific structure on the system matrix in a multiscale environment. To be specific, the article deals with a diagonalizing transform that is useful for decoupled control of a system. It establishes that there exists a definite relationship between the model in the measurement space and that in the projection space. Methodology for deriving the multirate perfect reconstruction filter bank, associated with the wavelet operator, is presented. The efficacy of the proposed technique is demonstrated by modeling the point kinetics nuclear reactor. The outcome of the multiscale modeling approach is compared with that in the single-scale approach to bring out the advantage of the proposed method.

• International conference on construction engineering and project management
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• 2017.10a
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• pp.242-244
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• 2017

Excavation for construction is implemented in natural geographical terrain using a variety of construction equipment. Therefore, 3D excavation simulation requires integration of geographical and equipment modeling. This paper proposes a technique that integrates geographical and equipment modeling for 3D simulations of construction excavation. The geographical model uses a digital map to show ground surface changes during excavation and the equipment model shows equipment movement and placement. This combination produced a state of the art 3D simulation environment that can be used for machine guidance. An equipment operator can use the 3D excavation simulation to help construction equipment operators with decisions during excavation work and consequently improve productivity.