• Journal of Korea Water Resources Association
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• v.52 no.8
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• pp.515-529
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• 2019

Geospatial information for river network and watershed boundary have played a fundamental roles in terms of river management, planning and design, hydrological and hydraulic analysis. Irrespective of their importance, the lack of punctual update and improper maintenance in currently available river-related geospatial information systems has revealed inconsistency issues between individual systems and spatial inaccuracy with regard to reflecting dynamically transferring riverine geography. Given that digital elevation models (DEMs) of high spatial resolution enabling to reproduce precise river network are only available adjacent to national rivers, DEMs with poor spatial resolution lead to generate unreliable river network information and thereby reduce their extensible applicabilities. This study first of all evaluated published spatial information available in Korea with respect to their spatial accuracy and consistency, and also provides a methodology and tool to modify existing low resolution of DEMs by means of striation of conventional or digitized river network to replicate input river network in various degree of further delineation. The tool named FSND was designed to be operated in ArcGIS ModelBuilder which ensures to automatically simulate river network striation to DEMs and delineation with different flow accumulation threshold. The FNSD was successfully validated in Seom River basin to identify its replication of given river network manually digitized based on recent aerial photograph in conjunction with a DEM with 30 meter spatial resolution. With the derived accuracy of reproducibility, substantiation of a various order of river network and watershed boundary from the striated DEM posed tangible possibility for highly extending DEMs with low resolution to be capable of producing reliable riverine spatial information subsequently.

• Korean Journal of Heritage: History & Science
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• v.48 no.2
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• pp.48-63
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• 2015

This study began with the purpose of awakening an interest in Korean Nu-jung and seeking application plan based on Nu-jung of Aneuisamdong. Also it intends to suggest activation plan of Nu-jung while using the culture of taste for the arts and classical scholar of ancestors with the physical place named Nu-jung as the medium. As concrete ways to activate Nu-jung, we suggested plans which use the game of go(Baduk), main material of the culture of taste for the arts and classical scholar, and increase availability by planning a program adding picturesqueness of Nu-jung. By bringing the material named the game of go(Baduk) to the place named Nu-jung, we suggested the plan capable of experiencing the culture of taste for the arts and classical scholar and also expecting local promotion and economical effect. And the plan is to design and conduct night program, 1 night 2 days program, tailored program, and so on by combining the material of the culture of taste for the arts and classical scholar with the medium named 'Dal(the moon)' in the static place named Nu-jung. The plans above are applicable to most of Nu-jung scattered all over the country, which means that we have a lot of Nu-jung in Korea and, at the same time, we have abundant contents to be used as cultural properties. Now it's important how to develop and use these contents through the connection with various academic fields in terms of managing cultural properties. By understanding the value of the original form of culture while emerging from simply using cultural properties, we can use cultural properties in a higher level. For this, preserving cultural properties should be supported by continuous interdisciplinary study.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.9
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• pp.541-550
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• 2019

An emergency generator is key equipment for fire-fighting to supply power to fire-fighting facilities, which protect property and people in cases of fire accidents. A rated load test for emergency generators must be carried out by connecting an emergency load to the generator in accordance with related regulations. However, a no-load test has been performed for emergency generators in general since serious problems can occur when the main power is cut off, including the damage of customer devices and shut down of critical loads. Therefore, this paper proposes a load test method for an emergency generator using energy storage system (ESS) without the interruption of main power. The emergency power system was also modeled based on PSCAD/EMTDC software, and a 200-kW scale ESS load test device was implemented. The simulation and test results show that the load test method is useful and practical for an emergency power supply system.

• Environmental and Resource Economics Review
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• v.28 no.1
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• pp.121-145
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• 2019

This paper investigates the relationship between the oil price and the major petroleum products prices at the trading hubs such as Singapore, North West Europe and the US New York Harbor. We focus on the lead-lag relationship between the weekly petroleum prices from 2009 to 2016 based on the vector error correction model. We find that the oil price leads the prices of petroleum products in the long term, while there is bidirectional causality in the short term. On the other hand, prices of petroleum products in regions with high import dependency, such as Europe gas oil and jet fuel price, are exogenous in the long term. We also present evidence that prices of petroleum products in region with a large global-market share lead prices in other regions. However, if the region is in an over-production situation and low industry concentration, it may lose its price leadership due to intense competition. The result in this study can provide a useful information to petroleum refining companies in forecasting fluctuations of product price, and hence in planning their regional arbitrage trading activities.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.633-642
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• 2021

Growing demand for electricity, when combined with the need to limit carbon emissions, drives a huge increase in renewable energy industry. In the electric power system, electricity supply always needs to be balanced with electricity demand and network losses to maintain safe, dependable, and stable system operation. There are three broad challenges when it comes to a power system with a high penetration of renewable energy: transient stability, small signal stability, and frequency stability. Transient stability analyze the system response to disturbances such as the loss of generation, line-switching operations, faults, and sudden load changes in the first several seconds following the disturbance. Small signal stability refers to the system's ability to maintain synchronization between generators and steady voltages when it is subjected to small perturbations such as incremental changes in system load. Frequency stability refers to the ability of a power system to maintain steady frequency following a severe system upset resulting in significant imbalance between generation and load. In this paper, we discusses these stability using system simulation by renewable energy deployment plan, and also analyses the influence of the renewable energy sources to the grid stability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.667-675
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• 2021

The purpose of this study is as follows: First, to analyze the spatial structure of Jeju by analyzing the rate of parking demand and supply; Second, to determine the parking service imbalance between regions; and third, to elucidate the causes of this spatial structural parking service imbalance and provide effective measures. Due to the rapid population and tourism growth, Jeju is suffering from traffic congestion and serious parking problems. For this, the ways to efficiently utilize the existing parking spaces were identified through spatial structure analysis based on the parking demand and supply in the Jeju area. As short-term policy, the following changes were proposed: switching to small-scale eup or myeon blocks of parking space, use of shared parking system, and repairing side streets in residential areas. As mid-to-long-term policy, it is linked to other means of transportation as follows: parking demand management policy through modal share by reorganizing public transportation routes or expanding traffic facilities; securing park-and-ride lots; and different parking pricing for different time periods. To implement these policies, each area of the public sector, private sector, and private-public partnership should develop the bond of sympathy by areas and participants.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.4
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• pp.59-69
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• 2011

In this study I examined the status of the borrowed scenery of Soshaewon and analyzed the structure of Byeolseo Gardenusing "Soshaewon Sisun(瀟灑園詩選)", which consists of a collection of poems written by people who visited Soshaewon during Joseon Dynasty with bibliographical explanations and "the Thirty Poems of Soshaewon", written by Yang, Gyeong Ji who was the fifth generation from Yang, San Bo. This study expanded the concept of borrowed scenery to include visual, synaesthetic, temporary and ideal features based on the theory of borrowed scenery in "Won Ya(園冶)", which emphasized the time feature and change, and explained that a landscape garden could be perfected by the presence of borrowed scenery beyond the previous borrowed landscape which was recognized through visual value. It would be correct to understand that the visitors to Soshaewon accomplished imaginary scenery(意境) through recreating Soshaewon into a space that stimulated poetic sentiment and aesthetic sensitivity by creating four types of borrowed scenery of a landscape garden composed of both real and fictitious scenery. At present the scope of Soshaewon tends to be limited to its inner garden covering the stream garden. However, in this study I took a new approach in defining the scope of Soshaewon, providing three types of Byeolseo Garden area ; more specifically, the expanded scope of Soshaewon covers the outer garden that secured the outlook of visual, temporary and synaesthetic objects for borrowed scenery and the right to use by purchasing more area by the descendants and the ideological garden that was composed of the ideal borrowed scenery created by the Confucian friends and colleagues who praised the Jeungamcheon Stream area and various famous mountains longing for the immortal world.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.810-818
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• 2021

A leakage current of ESS is classified mainly by the occurrence from a PCS(Power Conditioning System) section and an unbalanced grid current. The reason for the leakage current from the PCS section is a voltage change by IGBT (Insulated Gate Bipolar Transistor) switching and stray capacitance between the IGBT and heatsink. The leakage current caused by the grid unbalanced current flows to the ESS through the neutral line of grid-connected transformer for the ESS with a three limb iron type of Yg-wire connection. This paper proposes a mechanism for the occurrence of leakage current caused by stray capacitance, which is calculated using the heatsink formula, from the aspect of the PCS section and grid unbalance current. Based on the proposed mechanisms, this study presents the modeling of the leakage current occurrence using PSCAD/EMTDC S/W and evaluates the characteristics of leakage currents from the PCS section and grid unbalanced current. From the simulation result, the leakage current has a large influence on the battery side by confirming that the leakage current from the PCS is increased from 7[mA] to 34[mA], and the leakage current from an unbalanced load to battery housing is increased from 3.96[mA] to 10.76[mA] according to the resistance of the housings and the magnitude of the ground resistance.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.201-212
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• 2021

Curriculum content interest has been studied in terms of teachers rather than students in ways that help revise curriculum and develop textbooks. In this study, 227 first-year high school students were interested in what they learned in middle school and what they learned in high school, focusing on meaningful assumptions and contents for middle school and high school students. We analyze this difference in interest by gender and achievement level. According to the research results, first-year high school students, who are in the middle and high school transition period, have relatively high interest in themselves, such as youth development, compared to family needs or interest in family life. There were no gender differences, but there were differences in content interest depending on the level of achievement. This means that the content interest should be interpreted by considering various variables such as the development of learners, the situation of learners in the school-level transition period, and the entrance examination of universities. The results of this study will provide implications for future curriculum revisions, textbook development, and curriculum considerations, and will need to be carefully analyzed and utilized based on a learner-centered perspective.

• The Journal of the Korea Contents Association
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• v.22 no.7
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• pp.486-497
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• 2022

The aim of this study was to subdivide and present the units and the standards of knowledge integration in creating the students' integrated knowledge from content knowledge in college writing classes. For these, it analyzed three typical writing textbooks being used in colleges and examined the ways of presentation on forming integrated knowledge by text qualitative analysis methods. The analysis procedure and the presentation followed Creswell's spiral analysis model It is a method model which repeats the procedure from material collection and analysis to presentation circularly. This examination illustrates three dimensions of the units in forming content knowledge. Also, it suggested those should be all treated for the more systematic education: the units of the whole text, the paragraphs, and the sentences. In the next chapter, the standards and contents of knowledge integration were suggested in each process. For the process of knowledge selection, the suitability and the contradictoriness between the text materials and author's thesis were proposed as the standards and contents. For the process of organization and integration, the corresponsive integration, contradictive integration, background integration, synthetic integration were suggested. Finally the procedure knowledge such as correct expression and spelling, source indication were shown for the process of expression and citation. Furthermore, it showed, in terms of expression, the process of paraphrasing frequently practiced in writing textbooks needs to be exercised in the three dimensions including summarization, connection, and interpretation(or transformation). This result, however, calls for the further study about the subdividing processes to enhance the adequateness to writing textbooks in the level of universities and for a more refined syllabus on the systematic knowledge integration. Accordingly, it suggested the tasks mentioned above for further study.