• Korean Journal of Remote Sensing
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• v.30 no.2
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• pp.173-183
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• 2014

Field survey research on damages caused by volcanic activities has plenty of difficulties due to human resources, safety and costs issues. Remote sensing application using satellite image is one of very useful tools to overcome those issues. In this study, we monitored the volcanic activities of Sinabung volcano in 2010, which is located in Sumatra island, Indonesia by using Landsat 7 ETM+ satellite images acquired on 17 April, 2009 and 30 July, 2012. We found that the area of pyroclastic flow inundation after 2010 has been tripled roughly, since extracting the pyroclastic flow inundation before and after 2010 eruption from classification. The result from modeling of pyroclastic flow inundation has been compared with the extracted pyroclastic flow inundation from Landsat 7 ETM+ images. As a result, we confirmed that the length of inundation area from the modeling was calculated to 92% accurate, but the width of inundation area was somewhat imprecisely estimated in the volcanic area having the sharp slope and only calculated to 17% accurate.

• Journal of Korea Multimedia Society
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• v.14 no.8
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• pp.1094-1107
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• 2011

We can use panorama systems or image based modeling systems when we want to make 3D space model and look around result. Panorama systems make 3D model to stitch images and map cylinder or cube. The structure of 3D model, made by panorama system, is not same as structure of a real room, so user can't infer a real structure. Typically, Image based modeling systems work on a desktop computer. That makes it difficult to reconstruct 3D model in real time and take long time for processing. In this paper, we propose a 3D panorama modeling system that uses images on a mobile device. This system reconstructs a 3D space model, similar with a real room in real time, from multiple images captured part of rooms. Using this system, user can reconstruct various shape of space and look around a 3D space model.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.582-585
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• 2016

This study intends to provide initial evacuation distances for the public in case of accidental releases of hydrogen fluoride (HF). HF is a very toxic chemical that is widely used in the chemical, electrical, and electronics industries. Consequence modeling programs, such as ALOHA and PHAST, were used to help formulate a contingency plan in case of an HF leak. For the purpose of this study, the release of entire quantity of HF in 10 min is defined as a worst-case scenario and the release from a partial line rupture is used as an alternative case scenario as National Institute of Chemical Safety (NICS) guidelines. Once the discharge rates were calculated based on the scenarios, the ERPG-2 endpoint distances have been obtained for representative daytime and nighttime weather conditions. This paper presents graphs that can be used to enact swift evacuation orders and emergency response plans in the case of accidental releases of HF.

• Geophysics and Geophysical Exploration
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• v.17 no.4
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• pp.209-215
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• 2014

In order to develop a new mineral exploration technique, a study was carried out about the potential mapping of Moisan area using SIP (Spectral Induced Polarization) data. The SIP inversion results were classified according to the geological regions, and the distribution characteristics of resistivity and phase values of SIP data were analyzed at the ore region. Based on the characteristics of SIP of ore bodies, we performed 3D potential mapping of Moisan area. The analyzed potential map was verified using that the locations and patterns of high potential regions of the results are well matched with those of the known ore bodies. If we get the higher spatial resolution SIP data, the potential mapping technique using SIP data can be effectively applied to the estimation of mining deposit.

• Journal of the Korea Institute of Building Construction
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• v.16 no.4
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• pp.341-348
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• 2016

The aim of this study is to suggest design requirements on the military barriers which are installed to reduce critical damage on protective facilities against sudden pin-point attacks caused by North Korean artilleries. For this purpose, site investigation and review of design drawings associated with barriers built in the contact areas are conducted. With identified data concerning barriers, the geometric modeling, which is used in the structural analysis, is performed. And then, the possible threat of North Korea is determined based on intelligence preparation of battlefields. Once the structural modeling and threat analysis are completed, structural damage on barriers and protective facilities are assessed in terms of impact, penetration, scabbing, and blast pressure effects. According to the analysis results, the thickness of barriers should be 450mm at least and current established barriers need to be structurally reinforced via sectional enlargement.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.153-161
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• 2004

The systematic material and labor management planning should be established on accomplished EVM data. The matrix method of integrated cost and schedule was used with common category concept according to the construction project control system. The construction project control system was suggested through analyzing process and data modeling based on integrated cost, schedule and material. Information of construction project can be developed the relationship between the field data and the integrated cost, schedule database. Process and data modelling is provide a standard data format which are related to the material, labor management based on integrated cost, schedule database.

• Economic and Environmental Geology
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• v.49 no.3
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• pp.225-242
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• 2016

Rock physics serves as a useful tool for seismic reservoir characterization and monitoring by providing quantitative relationships between rock properties and seismic data. Rock physics models can predict effective moduli for reservoirs with different mineral components and pore fluids from well-log data. The distribution of reservoirs and fluids for the entire seismic volume can also be estimated from rock physics models. The first part of this report discusses the Voigt, Reuss, and Hashin-Shtrikman bounds for effective elastic moduli and the Gassmann fluid substitution. The second part reviews various contact models for moderate- to high-porosity sands. In the third part, constant-cement model, known to work well for the sand that gradually loses porosity with deteriorating sorting, was applied to the well-log data from an oil field in the North Sea. Lastly, the rock physics template constructed from the constant-cement model and the results from the prestack inversion of 2D seismic data were combined to predict the lithology and fluid types for the sand reservoir of this oil field.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.380-384
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• 2016

홍수완화의 관점에서 강을 관리하기 위하여 수자원의 이용과 생태계보전, 하천흐름과 형태학적 변화들에 대하여 충분히 이해하고 합리적으로 설명하는 것이 필요하다. 최근에 수변지역에서 발달된 식생은 홍수시에 감속영역과 생물들의 피난처를 제공하는 것 이외에 횡단방향의 혼합작용을 활성화하여 유사와 식물의 씨앗 및 입자성 유기물(POM)을 포착하는 기능을 하고 특히 흐름과 유사이송 및 하도 지형변화에 큰 영향을 주기 때문에 중요하다. 입자성 유기물(POM)은 하천생태계를 지탱하는 에너지원으로서 다양한 형태로 존재하고 미생물의 분해를 받아 무기화된 식생의 번무와 물질순환의 시발점이 되기도 하지만 현재까지 식생영역 내에서 그 공급과정에 관련이 있는 운동기구에 관한 연구는 아직 부족한 실정이다. 따라서 본 연구는 식생영역의 유사퇴적 및 분급작용, 입자성 유기물의 포착을 일으키는 원인과 흐름의 특징 중 식생영역 내에서 흐름방향으로 감속에 주목하여 수리 모형실험을 실시하였고 수변식생에서 부유사와 POM의 퇴적과정에 대하여 검토 및 모델링을 실시하였다. 수리 모형실험 결과 CPOM과 FPOM 모두 유사의 퇴적없이 그 자체로는 퇴적이 되지 않았고 수변식생의 종방향 이송의 경우 식생에 의해 퇴적된 부유사가 사련 형태로 형성이 되어 CPOM이 사련의 배후에서 캡쳐 되었다. 또한 두가지 샘플 움직임의 상호작용은 사련의 파고와 파장의 전파속도를 감소시켰다. 식생지역에서 횡방향 분산의 경우에 대해서는 각각의 유사 크기에 대한 퇴적물의 능선은 식생의 경계를 따라 형성되었고 운동의 범위는 유사 퇴적의 능선에 의해 촉진되어 횡방향으로 확산하며 확장되었다. 이러한 결과를 바탕으로 제한된 경험적인 지식보다 오히려 실험을 통하여 식생을 동반하는 장소에서 유사와 POM의 거동특성 차이 및 간섭작용을 명확히 한 후 현장에서 관측된 현상과 비교 검증이 필요하다고 사료되며 추후에 운동기구를 모델링 및 업그레이드 해 나가는 것이 앞으로의 하천생태계 예측평가에 필요하다고 판단된다.

• Journal of the Korean Society for Library and Information Science
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• v.55 no.4
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• pp.267-291
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• 2021

Due to the global pandemic caused by COVID-19 in 2020, there have been major changes in the education sites. Universities have fully introduced remote learning, which was considered as an auxiliary education, and non-face-to-face classes have become commonplace, and professors and students are making great efforts to adapt to the new educational environment. In order to improve the quality of non-face-to-face lectures amid these changes, it is necessary to study the factors affecting lecture satisfaction. Therefore, This paper presents a new methodology using big data to identify the factors affecting university lecture satisfaction changed before and after COVID-19. We use Topic Modeling method to analyze lecture reviews before and after COVID-19, and identify factors affecting lecture satisfaction. Through this, we suggest the direction for university education to move forward. In addition, we can identify the factors of satisfaction and dissatisfaction of lectures from multiangle by establishing a topic classification model with an F1-score of 0.84 based on KoBERT, a deep learning language model, and further contribute to continuous qualitative improvement of lecture satisfaction.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.7
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• pp.764-770
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• 2019

In this research, text mining techniques were used to analyze the papers related to the "4th Industry". In order to analyze the papers, total of 685 papers were collected by searching with the keyword "4th industry" in Korea Journal Index(KCI) from 2016 to 2019. We used Python-based web scraping program to collect papers and use topic modeling techniques based on LDA algorithm implemented in R language for data analysis. As a result of perplexity analysis on the collected papers, nine topics were determined optimally and nine representative topics of the collected papers were extracted using the Gibbs sampling method. As a result, it was confirmed that artificial intelligence, big data, Internet of things(IoT), digital, network and so on have emerged as the major technologies, and it was confirmed that research has been conducted on the changes due to the major technologies in various fields related to the 4th industry such as industry, government, education field, and job.