• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.233-246
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• 2022

The design and the construction were carried out by installing new caissons on the back or the front of existing caissons to increase the structural stability of caisson breakwaters. In this study, we used the ANSYS AQWA program to analyze the wave forces acting on individual caissons according to the effects of wave-structure interaction when new caissons were additionally installed on existing caisson breakwaters. The wave force characteristics acting on the individual caisson were analyzed according to the distance among caissons in frequency domain analysis. In addition, the dynamic wave force characteristics were closely examined on the basis of the frequency at which the unusual distribution of wave forces occurs in irregular wave conditions using time domain analysis.

• Journal of the Korean Geotechnical Society
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• v.24 no.9
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• pp.33-40
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• 2008

This paper describes the performance of ground improvement project using prefabricated vertical drains of condition, in which approximately 10m dredged fill overlies original soft foundation layer in the coastal area composed of soft marine clay with high water content and high compressibility. From field monitoring results, excessive ground settlement compared with predicted settlement in design stage developed during the following one year. In order to predict the final consolidation behavior, recalculation of consolidation settlements and back analysis using observed settlements were conducted. Field monitoring results of surface settlements were evaluated, and then corrected because large shear deformation occurred by construction events in the early stages of consolidation. To predict the consolidation behavior, material functions and in-situ conditions from laboratory consolidation test were re-analyzed. Using these results, height of additional embankment is estimated to satisfy residual settlement limit and maintain an adequate ground elevation. The recalculated time-settlement curve has been compared with field monitoring results after additional surcharge was applied. It might be used for verification of recalculated results.

• Journal of The Geomorphological Association of Korea
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• v.18 no.4
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• pp.79-96
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• 2011

Volcanic landforms are classified into the volcanic edifice produced through constructive processes of eruption and the crater generated by destructive processes of eruption. Both landforms are distributed around Korean Peninsula including attaching islands. However, only a few regions such as Mt. Baekdu, Jeju Island, Ulleung Island, and Chugaryeong, which are closely related with the volcanic eruption occurred during the Quaternary, could be considered as a volcanic landform. It results in categorizing the volcanic landform as an unusual topography in Korea. The study of Korean researchers on the volcanic landform were regularized in 1970s on Jeju Island, in 1980s on Ulleung Island, and in 1990s on Mt. Baekdu, respectively. Oreums and lava tubes in Jeju Island have been also examined since 1980s. Compared with other fields of geomorphology, researches as well as researchers on the volcanic landform are very few in Korea. Geomorphologists are expected to perform an active research in that the volcanic landform of Korea have diverse values.

• Journal of Intelligence and Information Systems
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• v.28 no.4
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• pp.251-273
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• 2022

Recently, research on applying text analysis to deep learning has steadily continued. In particular, researches have been actively conducted to understand the meaning of words and perform tasks such as summarization and sentiment classification through a pre-trained language model that learns large datasets. However, existing pre-trained language models show limitations in that they do not understand specific domains well. Therefore, in recent years, the flow of research has shifted toward creating a language model specialized for a particular domain. Domain-specific pre-trained language models allow the model to understand the knowledge of a particular domain better and reveal performance improvements on various tasks in the field. However, domain-specific further pre-training is expensive to acquire corpus data of the target domain. Furthermore, many cases have reported that performance improvement after further pre-training is insignificant in some domains. As such, it is difficult to decide to develop a domain-specific pre-trained language model, while it is not clear whether the performance will be improved dramatically. In this paper, we present a way to proactively check the expected performance improvement by further pre-training in a domain before actually performing further pre-training. Specifically, after selecting three domains, we measured the increase in classification accuracy through further pre-training in each domain. We also developed and presented new indicators to estimate the specificity of the domain based on the normalized frequency of the keywords used in each domain. Finally, we conducted classification using a pre-trained language model and a domain-specific pre-trained language model of three domains. As a result, we confirmed that the higher the domain specificity index, the higher the performance improvement through further pre-training.

• Journal of The Korean Association For Science Education
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• v.36 no.3
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• pp.435-443
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• 2016

The purpose of this study is to analyze the mismatch between instructional design and teaching practice of pre-service science teachers and to investigate the cause of these mismatches. Twenty pre-service science teachers took part in teaching practicum for four weeks from Apr. 2015 to May 2015 and we analyzed their lesson plans and videos of these lessons. After that, we interviewed the pre-service science teachers in order to know the cause of these mismatches and additional informations. The main findings are as follows. First, in the introductory stage, we found more mismatch in the "attention and motivation stimulation" area than any other area. Many pre-service science teachers corrected their 'motivation practice' in different forms. Second, we found out that the most mismatch occurred in the evolving stage. Many pre-service science teachers added learning contents in "learning content presentation" area. Third, in the closing stage, many pre-service science teachers omitted the "leaning content summary" area in the lack of time. Fourth, the number of mismatches by internal factors is similar of by external factors. The mismatches by external factors were mainly by feedback of guidance teacher and change by students' response. In addition, we discussed the implications related to reflective mentoring program, importance of guidance teacher, importance of time management etc.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.971-976
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• 2007

In the U.S., utility damages or utility delay caused by conflicts during the underground utility relocation is one of the weighty problem in the construction industry. Also, in domestic case, delay and additional cost caused by underground utility(i.e, electricity, communication, gas, water supply and sewerage) relocation has been happened so that there is an increase of claims for responsibility between owners and contractors. However, there is insufficient survey for the recent circumstance of additional cost for delay and design changes caused by utility relocation and shortage of enough research for solving and analyzing of causes and their ripple effect. This research presents a result of the study about the best practices of FHWA(Federal Highway Administration), SHAs(State Highway Agencies) and the utility companies managing utility relocation. Also, it presents the basic concept of SUE(Subsurface Utility Engineering), the most reliable tool of FHWA presented, and investigates the developing status about SUE in Korea. At the end of this paper, this research proposes a practical and more applicable study about the efficient utility relocation focusing on local industry.

• KDI Journal of Economic Policy
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• v.35 no.1
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• pp.1-32
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• 2013

Economic sanctions and inducements are types of 'policy instruments' based on 'economic tools' to influence other international actors. Ongoing debates on sanctions and inducements have exposed drawbacks for relying on individual case studies. There are some studies in the literature that attempt theoretical analysis of sanctions and inducements, but they are mostly based on rational choice theory. In reality, however, there exist so many cases that cannot be explained by rational choice theory. These are called anomalies or exceptions. The literature introduces specific variables to interpret these anomalies and thus sacrifice the universality of the theory. From this point of view, prospect theory would present an effective tool to analyze economic sanctions and inducements. It is a behavioral economic theory that tries to model a decisions making process in reality. The theory says that people make decisions based on subjective value of losses and gains from an individual reference point, and that people evaluate these losses and gains using heuristics. Thus prospect theory could offer a different frame which has greater explanatory range without adding new variables. As a result of this study, target's losses of 'back down' towards economic sanctions loom larger when the reference point level increases, therefore, the effectiveness of sanctions decreases. However, target's losses of 'stand firm' towards economic inducements loom larger under the same condition of reference point, therefore, the effectiveness of inducements increases. The findings of the paper suggest meaningful implications to the economic policy towards North Korea.

• The Korean Journal of Archival Studies
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• no.42
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• pp.287-326
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• 2014

Documenting environmental conflicts will be a priority target for documenting localities, because those conflicts are critical events that make intensive 'place experiences' of local residents. This study is to design a narrative structure for documenting conflicts in the process of Transmission Towers Construction in Miryang. This study begins with analysing the characteristics of environmental conflicts, and draws a conflicts documentation model including basic rules, narrative structure and development process. Basic rules are set up as mixed documentation of memory and evidence, application of 'frame', and dynamic description. Based on the rules, this study suggests a dynamic and open narrative framework adopting the metadata model of ISO 23081. This model is applied to documenting Transmission Towers Construction Conflicts in Mi-ryang. The full narrative and 'frame' of the conflicts are set after analysing development and issues of the conflicts, stakeholder, and properties of each conflict problem. Records descriptions are related to the context(each event occurred in the conflicting conditions, mandates, and stakeholder) descriptions to make multiple narratives in digital environments. Event description contains elements for articulating the 'frame' of each party of the conflict. The merits of this model are; i) to accumulate the adequate context information systematically by adopting dynamic narrative model, and ii) to acquire the new items and connect them to related items easily and consistently through multi-entity description. This documentation model of environmental conflicts may support to shape the collective memory of community, and to achieve good governance by managing conflicts in the process of locating non-preferred facilities with due regard to values and perceptions of residents and communities.

• Explosives and Blasting
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• v.30 no.2
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• pp.59-65
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• 2012

This study improved constructability and cost efficiency that are disadvantages of existing a mechanical excavation & similar blasting methods(plasma, gel, etc) and introduced cases of development and practical applications of Low vibration explosives(LoVEX) that minimizes blast vibration. The low vibration explosives(LoVEX) is suitable to Type-1 in standard blasting patterns of Ministry of Land, Transport and Maritime Affairs(MLTM) and delay blasting is possible. Moreover, the low vibration explosives improve construction and work efficiency while the level of vibration is reduced to about 60~70% of normal emulsion explosives. Additionally, this study suggested standard blasting patterns, the prediction equation of blasting vibration, and construction methods.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.207.1-207.1
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• 2015

차세대 디스플레이 소자로서 TAOS TFT (transparent amorphous oxide semiconductor Thin Film Transistor)가 주목 받고 있다. 또한, 최근에는 값 비싼 전자 제품을 저렴하고 간단히 처분 할 수 있는 시스템으로 대신 하는 연구가 진행되고 있다. 그중, cellulose-fiber에 전기적 시스템을 포함시키는 e-paper에 대한 관심이 활발하다. cellulose fiber는 가볍고 깨지지 않으며 휘는 성질을 가지고 있다. 가격도 저렴하고 가공이 용이하여 차세대 기판의 재료로서 주목받고 있다. 하지만, cellulose-fiber 위에는 고온의 열처리공정과 고품질 박막 성장이 어려워서 TFT 제작에 어려움을 겪고 있다. 이러한 문제를 해결하기 위해서 산화물 반도체를 이용하여 TFT를 제작한 사례가 보고되고 있다. 또한, 채널 물질 뿐만 아니라 cellulose fiber에도 다른 물질을 첨가하거나 증착하여 전기적 화학적 특성을 개선시킨 사례도 많이 보고되고 있다. 본 연구에서는 가장 저품질의 용지로 알려진 신문지와 A4용지를 gate dielectric을 이용하여서 a-IGZO TFT를 제작하였다. 하지만, cellulose fiber로 만들어진 TFT의 경우에는 고온의 열처리가 불가능 하다. 따라서 저온에서 높을 효율은 보이는 microwave energy를 이용하여 열처리를 진행하였다. 추가적으로 저품질의 종이의 특성을 개선시키기 위해서 high-k metal-oxide solution precursor를 첨가 하여 TFT의 특성을 개선시켰다. 결과적으로 cellulose fiber에 metal-oxide solution precursor을 첨가하는 공정과 micro wave를 조사하는 방법을 사용하여 100도 이하에서 cellulose fiber를 저렴하고 우수한 성능의 TFT를 제작에 성공하였다.