• Korean Journal of Computational Design and Engineering
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• v.13 no.5
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• pp.342-351
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• 2008

ISO 10303-AP241 is an Application Protocol of ISO 10303, which specifies the representation of AEC facility's life cycle information. The Working Draft of AP241 was submitted to the TC184/SC4 of ISO in July, 2007 by Korean team of ISO TC184/SC4/WG3. This paper introduces the currently developed draft Ap241 core model, and describes the life cycle support modules which are required to represent the life cycle information of AEC facilities. The draft core model is developed as a generic data model which is useful as a basis for implementation in a data warehouse. This core model could be used in combination with reference data such as PLCS RDL, Gellish table and RDL of ISO 15926. These concepts already exists in ISO 10303-AP221, AP239 and ISO 15926. In order to support maintenance and feedback of operational information concerning the AEC facilities, the AP241 team re-used many modules from AP239, and developed various STEP Application Modules which are adapted from the ISO 15926.

• Journal of Korean Society on Water Environment
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• v.31 no.5
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• pp.491-506
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• 2015

Distributed models represent watersheds using a network of numerous, uniform calculation units to provide spatially detailed and consistent evaluations across the watershed. However, these models have a disadvantage in general requiring a high computing cost. Semi-distributed models, on the other hand, delineate watersheds using a simplified network of non-uniform calculation units requiring a much lower computing cost than distributed models. Employing a simplified network of non-uniform units, however, semi-distributed models cannot but have limitations in spatially-consistent simulations of hydrogeochemical processes and are often not favoured for such a task as identifying critical source areas within a watershed. Aiming to overcome these shortcomings of both groups of models, a hybrid watershed model STREAM (Spatio-Temporal River-basin Ecohydrology Analysis Model) was developed in this study. Like a distributed model, STREAM divides a watershed into square grid cells of a same size each of which may have a different set of hydrogeochemical parameters reflecting the spatial heterogeneity. Like many semi-distributed models, STREAM groups individual cells of similar hydrogeochemical properties into representative cells for which real computations of the model are carried out. With this hybrid structure, STREAM requires a relatively small computational cost although it still keeps the critical advantage of distributed models.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.11
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• pp.58-67
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• 2014

A grid-connected inverter used for renewable energy resources produces harmonic components in the switching frequency. To effectively reduce switching harmonic components, several types of filter are generally used in the output stage of the grid-connected inverter. Many research works on LCL filter design have been done to maintain the performance with low cost. However, it is not easy to make the filter design be economical and optimal due to the varying characteristic of magnetic core and redundancy design by experience. In this paper, a design method for a LCL filter is presented through the inductor optimization scheme in view of the size and cost when the inductor is manufactured using the magnetic core. The effectiveness is verified through tests using a 3kW grid-connected inverter by simulations and experiments.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.5
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• pp.56-63
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• 2007

This study used the nearest feature model to connect forest patches within the western Geum River Basin. Due to many different forest patch sizes, 3 alternative methods were tested to determine the best way to establish an ecological network with forest patches. Alternative 1 used all forest patches to determine whether patches were large enough. Alternative 2 used forest patches over 10 ha in size. Alternative 3 used natural conservation indices to select forest patches containing better qualities in the natural conservation level. As a result 635 out of 724 patches of over 10 ha were selected for comparison. Alternative 1 showed that forest patches of less than 10 ha were outliers interrupting the establishment of the ecological network. They generated an unnecessary ecological network to link core areas to comparison features. The ecological network was improved by using forest patches greater than 10 ha in size(Alternative 2). Each comparison feature was much more hierarchically connected to core areas in Alternative 2 than in Alternative 1. Forest patches filtered by natural conservation indices were useful for obtaining the best ecological network. Alternative 3 clearly showed the connections in the ecological network between core areas and forest.

• KIEAE Journal
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• v.10 no.5
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• pp.71-76
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• 2010

Recently, the construction and plan of super-tall building is attention link of new town development or urban core regeneration. Super-tall Buildings have many advantages and a lot of affects in urban contexts. Also, construction of super-tall building is will be able to social problem like urban core's decline, loss of openspace, incompatible urban scape, traffic congestion of urban core. But, compares to super-tall buildings affects in urban contexts, there was not extra ordinary study about super-tall building by the urban scale approaches. Therefore, need about study materplan planning of the site which is made to meet super-tall building and urban contexts. There are two main processes in this study. First, to analyze the factors affect to masterplan planning of the super-tall building's site. Through the analyzed factors, classify type of super-tall buildings and identify the type's state. Second, to classify and set the elements of masterplan planning factor in the site. Identify the masterplan planning factor's state by deployment materplan planning factor set the current applied to the constructed super-tall buildings. Through this process, identified the recent trend and providied the basic elements of materplan planning of super-tall building's site.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.69-72
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• 2004

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, we present measurement results of electrical characteristics of a ring-shaped electrodeless fluorescent lamp as a function of frequency and number of coil turns using a highly permeable Mn-Zn ferrite. It is found that the impedance are increased while the quality factor decreases as frequency increases.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1217-1233
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• 2018

Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2960-2973
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• 2022

Since Fukushima nuclear power plant (NPP) accident in 2011, the importance of research on various severe accident phenomena has been emphasized. Particularly, detailed analysis of combustion risk is necessary following the containment damage caused by combustion in the Fukushima accident. Many studies have been conducted to evaluate the risk of local hydrogen concentration increases and flame propagation using computational code. In particular, the potential for combustion by local hydrogen concentration in specific areas within the containment has been emphasized. In this study, the process of flame propagation generated inside a reactor core to containment during a loss of coolant accident (LOCA) was analyzed using MELCOR 2.1 code. Later in the LOCA scenario, it was expected that hydrogen combustion occurred inside the reactor core owing to oxygen inflow through the cold leg break area. The main driving force of the oxygen intrusion is the elevated containment pressure due to the molten corium-concrete interaction. The thermal and mechanical loads caused by the flame threaten the integrity of the containment. Additionally, the containment spray system effectiveness in this situation was evaluated because changes in pressure gradient and concentrations of flammable gases greatly affect the overall behavior of ignition and subsequent containment integrity.

• Journal of Platform Technology
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• v.10 no.2
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• pp.3-9
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• 2022

In this paper, to maximize the performance of the scatter communication in multi-core and many-core processors, a technique that considers the communication situation of the processing node is applied to a multi-core processor composed of 32 processing nodes. Since the existing scatter algorithm cannot recognize the communication conditions of the processing nodes, communication is generally performed according to an initially set transmission order. In this case, scatter communication starts only after the communication currently being performed by all processing nodes inside the processor is finished. The scatter communication performance was improved by this technique, and it was confirmed that there was a performance improvement of up to 78.93% compared to the existing algorithm through BFM simulation.

• Journal of the Korean Society of Systems Engineering
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• v.15 no.2
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• pp.98-107
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• 2019

The defense system development process is a process of developing various systems that perform functions in various functional areas such as battlefield awareness, command control, force application, and logistical support. In other words, the defense system development process is a process of developing many systems simultaneously in various functional areas. Various systems developed through this process should be interoperable so that they can be integrated and operated in a joint warfighting environment. To successfully implement this, the US Department of Defense uses the Joint Capability Integrated Development System(JCIDS) for the defense system development, and within this JCIDS processes the Capability Based Assessment(CBA) methodology as its core technology. This CBA methodology transforms the mission activity requirements to functional capability requirements logically and transforms the functional capability requirements to system requirements logically also. Smart City is a city that improves the convenience and quality of life of the citizen by integrates various systems that perform various functions of the city and smarties various functional systems with smart services by using IT technology. In other words, defense system development and smart city development have a common feature of the process of developing many systems simultaneously in various functional areas. In order to address the problem of having to develop many systems simultaneously in each functional area, it is important to logically transform the various mission scenarios into functions and logically transform the functions into systems. Therefore, a joint capability integrated development system and its core methodology, Capability Based Assessment(CBA), can be applied to smart city development. This paper proposes a method for performing a smart city concept design method using the capability based evaluation (CBA) method.