• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.4
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• pp.226-233
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• 2003

Directional elements are fundamental to protection scheme security and selectivity, performing such critical tasks as supervising distance elements and controlling overcurrent elements. But, conventional operating principles for directional detection based on negative or zero sequence quantify do not satisfy the requirements for improved sensitivity and fast operation under any fault conditions. In this paper, new algorithm for directional elements is proposed. The proposed algorithm use the positive-sequence superimposed voltages and currents in order to be used in all fault conditions. Also, because this algorithm uses a voltage compensation method. it can be well operated under strong source conditions.

• Journal of KIISE:Software and Applications
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• v.33 no.12
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• pp.1008-1021
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• 2006

Product line engineering(PLE) is one of the recent and effective reuse approaches that enables developing a number of applications by instantiating a core asset. Elements of a core asset are product line architecture(PLA), component, and decision model. Among these elements, PLA is the key element since it defines the overall structure of the core asset. Although numerous PLE methodologies have been introduced, it is still unclear what should be the elements of a PLA and how to systematically instantiate it for specific applications. Formal specifications can play a key role in defining detailed and precise instantiation process. In this paper, we first present a meta model of PLA and show how to specify PLA in a formal language, Object-Z. Then, we propose instantiation rules using formal specification and those rules precisely define constraints for instantiating PLA. By applying the proposed formal specification, we believe PLA instantiation can be carried out precisely and correctly, yielding high quality software development.

• Journal of Korea Society of Digital Industry and Information Management
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• v.11 no.2
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• pp.153-166
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• 2015

This paper proposes a trans-media branding for the trans-media-based cultural content marketing strategy. Trans-media brand analytical framework is proposed with previous studies. And mobile messenger Character 'Line Friends' is analyzed for the text. Trans-media branding is accessible through a multi-platform in the technological environment. Consumer culture, as well as participate include business models to generate revenue also as brand equity. While the character elements that make up the story from the perspective of cultural content storytelling act as an independent cultural goods. Character is segmented elements. Therefore, trans- media branding of the characters are more meaningful. 'Line Friends' trans-media branding can be summarized as follows: First, it takes advantage of the characteristics of the existing Information-Technology-based mobile. Second, it puts consistently found the content of the attributes of Mobile Messenger 'communication' and 'friendship'. And third, while the content of each platform is constantly linked with other platforms, the brand is positioned inside the window effect.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.5
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• pp.1073-1077
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• 2011

The breaking capacity of circuit breakers could be no more increased in the electric power system. This is because the fault current increases due to continuous increases in electric power demand and facilities. To solve the problem, it is necessary to come up with an alternative. The superconducting fault current limiter (SFCL) has received an attention among various alternatives. The SFCL effectively reduce a fault current in cooperation with a power circuit breaker. A various types of the SFCL are suggested and a study on them have been progressed. As a result of it, the SFCL can be applyed to the electric power system in the near future. But, a study on recovery behaviors of the SFCL is not enough for applying to the electric power system. If the superconducting elements do not completely recover to the superconducting state after fault operation, it might be a breakdown of the superconducting elements due to heavy power burden and it gives an bad influence on the working of other electric devices. Additionally, the distribution power system has reclosing operation such as open-0.3sec-closed/open-3min-closed/open procedure. So we need to study more about improvement of the recovery behaviors of the SFCL. In this paper, we analyzed the recovery behaviors of a flux-coupling type SFCL according to reclosing operation when a single line-to-ground fault occurred and we compared recovery behaviors of the SFCL with and without a neutral line between secondary reactors and superconducting elements. Also, the flux-coupling type SFCL has advantageous for increases of capacity by controlling the variation in turn ratios between two reactors. Consequently, when the number of turns of the secondary reactors increased, the power burden of the superconducting elements was bigger due to the increase of impedances of the secondary reactors. To distribute the power burden, two superconducting elements connected in series and the balanced quenching of the superconducting elements was induced by connecting a neutral line.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.103-106
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• 2002

This paper has studied a remote AMR(Automatic Meter Reading) system using the power line and the telephone line as a communication media and the digital power meter. In the developed system, because we have used the power line and telephone, the facility is very easy and then its cost is not expensive. The system includes following elements: a digital power meter, an indoor communication system using a power line modem and a telephone line interface system for sending data to the utility company.

• Structural Engineering and Mechanics
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• v.42 no.3
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• pp.353-362
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• 2012

In this paper decay and mapped elastodynamic infinite elements, based on modified Bessel shape functions and appropriate for Soil-Structure Interaction problems are described and discussed. These elements can be treated as a new form of the recently proposed Elastodynamic Infinite Elements with United Shape Functions (EIEUSF) infinite elements. The formulation of 2D horizontal type infinite elements (HIE) is demonstrated, but by similar techniques 2D vertical (VIE) and 2D corner (CIE) infinite elements can also be formulated. It is demonstrated that the application of the elastodynamical infinite elements is the easier and appropriate way to achieve an adequate simulation including basic aspects of Soil-Structure Interaction. Continuity along the artificial boundary (the line between finite and infinite elements) is discussed as well and the application of the proposed elastodynamical infinite elements in the Finite Element Method is explained in brief. Finally, a numerical example shows the computational efficiency of the proposed infinite elements.

• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.538-547
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• 1986

The 8 rare earth elements were determined in the monazite concentrates by X-ray fluorescence spectrometry. The spectral line overlapping interferences from the other elements were investigated and the correction methods of interferences were studied using line overlap coefficients. The coefficients were calculated from the ratios of the intensities measured at the diffracted angle (2${\theta}$) of the analytical lines of other elements to the intensity of pure rare earth oxide. The coefficients were used to correct the line overlaps by a regression analysis. The linearities of calibration curves from the corrected intensities were remarkably improved, and their standard deviations were decreased. The analytical results agreed with that of the inductively coupled plasma(ICP) spectrometry within an allowable error range.

• Journal of Welding and Joining
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• v.33 no.3
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• pp.62-67
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• 2015

A very large shell-structure built in shipyards like ship hulls or offshore structures are joined by welding through full process. As the welding contains a high thermal cycle at a local area, the welded structures should be distorted unavoidably. Because a distorted ship block should be revised to the designed value before the next stage, the ability to predict and to control the weld distortion is an accuracy level of the yard itself. Despite the ship block size, several present thermal distortion methodologies can deal those sizes, but it is a different story to deal full ship size model. Even a fully constructed ship hull not remaining any welding can have an accuracy issue like outfitting installation problems. Any present thermal distortion methodology cannot accept this size for its recommended element size and the number. The ordinary welding breadth at erection stage is about 20~40 mm. It can hardly be a good choice to make finite element model of these sizes considering human effort and computational environment. The finite element model for structure analysis of a ship hull is prepared at front-end engineering design stage which is the first process of the project. The element size of the model is as fine as the longitudinal space, and it is not proper to obtain a weld distortion at the erection stage. In this study, a methodology is suggested that a weldment can be shrunk at original place instead of using structural finite element model. We cut the original shell elements at erection weld-line and put truss elements between the edges of cut elements for weld shrinkage. Additional truss elements are used to facsimile transverse weld shrinkage which cannot be from the weld-line truss element shrink. They attach to weld-line truss element like twigs from barks. The capacity of developed elements is verified through an accuracy check of erection process of a container vessel at the apt. hull. It can be a useful tool for verifying a centering accuracy after renew and for block-separating planning considering accuracy.

• Journal of the Korean Institute of Rural Architecture
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• v.2 no.3
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• pp.65-76
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• 2000

This study aims to clarify the characteristics of townhouse corresponding to the changing life style for the future, and suited to the small and medium urban areas of Korea(focused on Chongju area) from its traditionality and regionality's point of view. The results of this study are as follows; 1. The traditional design elements of Chongju area : 1) A court; a court of inner building - light, wind. 2) A balcony; intermediate space, cornice. 3) Eave line; a horizontal line for approach. 2. The regional design elements of Chongju area : 1) Maintenance of skyline which had the same building height as strip of road. 2) The formal spatial design elements to think about natural view. 3) Simple appearance and delicate detail.

• Structural Engineering and Mechanics
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• v.84 no.1
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• pp.129-141
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• 2022

It has previously been proposed that the yield-line method of analysis for reinforced concrete slabs could be automated via the use of rigid finite elements, assuming all deformations occur along element edges. However, the solutions obtained using this approach can be observed to be highly sensitive to mesh topology. To address this, a revised formulation that incorporates modified yield criteria to account for the presence of non-zero shear forces at interfaces between elements is proposed. The resulting formulation remains simple, with linear programming (LP) still used to obtain solutions for problems involving Johansen's square yield criteria. The results obtained are shown to agree well with literature solutions for various slab problems involving uniform loading and a range of geometries and boundary conditions.