• Economic and Environmental Geology
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• v.41 no.6
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• pp.747-761
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• 2008

In order to experiment the acoustic remote classification of seabed sediment, we achieved ground-truth data(i.e. video and grab samples, etc.) and developed post-processing for automatic classification procedure on the basis of 300 kHz MultiBeam Echo Sounder(MBES) backscattering data, which was acquired using KONGBERG Simrad EM3000 at Sock-Cho Port, East Sea of South Korea. Sonar signal and its classification performance were identified with geo-referenced video imagery with the aid of GIS (Geographic Information System). The depth range of research site was from 5 m to 22.7 m, and the backscattering amplitude showed from -36dB to -15dB. The mean grain sizes of sediment from equi-distanced sampling site(50 m interval) varied from 2.86$(\phi)$ to 0.88(\phi). To acquire the main feature for the seabed classification from backscattering amplitude of MBES, we evaluated the correlation factors between the backscattering amplitude and properties of sediment samples. The performance of seabed remote classification proposed was evaluated with comparing the correlation of human expert segmentation to automatic algorithm results. The cross-model perception error ratio on automatic classification algorithm shows 8.95% at rocky bottoms, and 2.06% at the area representing low mean grain size.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.314-314
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• 2022

기후변화로 인해 집중호우 등 설계강우량을 초과하는 강우가 빈번하게 발생하고 있으며, 이에 따라 농촌유역의 홍수 및 침수의 발생빈도 및 강도가 증가하고 있다. 국내 농업용 저수지 약 17,500여개 중 약 70%는 70년 이상 경과된 노후시설로 분류되고 있으며, 특히 농어촌공사에서 관리하는 3,411개의 저수지를 제외한 시군관리 저수지는 체계적인 유지보수가 이루어지지 않고 있다. 이로 인해 홍수기 농업용 저수지의 월류 및 붕괴에 따른 하류지역 침수 피해가 빈번하게 일어나고 있다. 농촌유역 침수 피해 저감을 위한 대책을 수립하기 위해서는 먼저 정확한 침수 피해 평가가 수행되어야 하지만, 우리나라에는 현재 농촌유역에 특화된 침수 피해 평가 체계가 부족한 실정이다. 본 연구에서는 농촌유역의 맞춤형 침수 피해 평가 체계를 개발하고자 한다. 농촌유역의 농업용 저수지를 포함한 농업수리구조물의 붕괴 등에 따른 하류 침수 모의 기법을 개발하고, 농작물의 종류를 고려한 침수심 및 침수시간에 따른 침수피해 모의 체계를 개발하고자 한다. 본 연구에서 개발한 농촌유역 맞춤형 침수 피해 평가 체계는 향후 농촌유역의 체계적인 재난관리를 위한 정책 수립에 활용될 수 있을 것으로 기대된다.

• The KIPS Transactions:PartA
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• v.17A no.1
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• pp.45-52
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• 2010

The National Assessment of Educational Achievement has been conducted in the form of sampling assessment until 2007, but it was converted into sampling assessment one hundred percent working with relevant whole students in 2008. Therefore, the necessity of new study on the national assessment system of educational achievement was on the rise. The National Assessment System of Educational Achievement, which was implemented in this thesis was designed to analyze educational achievement status all over the province, total score and score frequency distribution per subject, item difficulty and item discrimination, degree of attraction of wrong answers, educational achievement per subject, gender, region, office of education, school, individual and status of students with high educational achievement.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.29-34
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• 2007

본 논문은 다양한 시스템이 존재하는 컴퓨터 네트워크 상의 위험을 분석 평가하기 위한 방법을 소개한다. 실시간으로 위험을 구성하는 요소들의 상태가 변화하는 상황에서 자산의 강도 평가, 위협 가능성 분석, 취약성에 대한 기존 통제 분석이 필요하다. 기존 통제 구성은 네트워크 토폴로지를 이용한 네트워크 베이스, 응용 어플리케이션에 기반한 호스트 베이스 통제가 있으며, 이들은 컴퓨터 네트워크상의 실질적인 취약성을 효과적으로 식별하는데 도움을 준다. 또한 가능성 분석은 위험평가 과정에서 불필요한 위협 정보를 효과적으로 제거하여 줄 수 있을 것이다.

• Journal of Korea Water Resources Association
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• v.52 no.3
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• pp.195-206
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• 2019

In this study, the vulnerable period assessment method for weekly groundwater resources management was developed considering correlation between data of groundwater level, river level, precipitation applying critical infiltration concept. The vulnerable periods of 3 case study were assessed using data of groundwater, precipitation, river level, and results were compared. The weights for between observation stations were calculated using correlation of groundwater, precipitation, river level data, and weights that could be considered recently trend of data for each observation station. The vulnerable period was assessed using final calculated weights and multi criteria decision method, compared result for each case study. The developed method can be a quantitative basis for the establishment of efficient groundwater resources management and the decision of specific countermeasure applyment.

• Journal of the Korea Society of Computer and Information
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• v.26 no.2
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• pp.229-235
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• 2021

Blockchain, recognized as one of the core technologies of the 4th industrial revolution, is an Internet-based distributed data management system which does not require centralized control. Blockchain is characterized by the integrity and reliability of information, and blockchains can be used where such characteristics are required. Typical applications of blockchain include finance, transaction, and evaluation management. In this paper, we designed a blockchain-based evaluation management system that allows users to freely create and manage evaluation instances. Evaluation managers can create an evaluation instance according to their purpose and allocate evaluation items and evaluators. When the evaluators finish evaluating the evaluation items, the evaluation manager can aggregate the evaluation results for the instance. Someone, who want to perform evaluation for various purposes but do not have an evaluation system, can implement the evaluation system relatively simply by using this system. In addition, due to the characteristic of the blockchain, evaluators cannot modify the evaluation scores they have already recorded, and neither the system administrator nor the evaluation administrator can modify the evaluation scores. For this reason, the reliability of the evaluation increases.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.3
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• pp.21-28
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• 2008

To evaluate the seismic performance of multi-degree of freedom(MDF) systems, repeated nonlinear response history analyses are often conducted, which require extensive computational efforts. To reduce the amount of computation required, equivalent single degree of freedom(SDF) systems representing complex multi-degree of freedom(MDF) systems have been developed. For the equivalent SDF systems, bilinear models and trilinear models have been most commonly used. In these models, the P-$\Delta$ effect due to gravity loads during earthquakes can be accounted for by assigning negative stiffness after elastic range. This study evaluates the adequacy of equivalent SDF systems having these hysteretic models to predict the actual response of steel moment resisting frames(SMRF). For this purpose, this study conducts cyclic pushover analysis, nonlinear time history analysis and incremental dynamic analysis(IDA) for SAC-Los Angeles 9-story buildings using nonlinear MDF models(exact) and equivalent SDF models(approximate). In addition, this study considers the strength limited model.

• Review of KIISC
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• v.5 no.1
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• pp.73-84
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• 1995

본 논문에서는 국내 정보보호 체계를 수립하기 위하여 외국에서의 정보보호 체계분석의 일환으로 영국의 정보보호 시스템 평사승인 체계에 대하여 분석하였다. 먼저 영국에서의 정보기관 구조를 소개하고, 정보보호 체계와 관련한 조직의 구성 및 임무에 대하여 기술하였다. 또한 영국의 정보보호 시스템 평가승인 절차를 분석하였으며 영국의 암호 알고리즘과 평가 기준서인ITSEC에 대해 분석하였다.

• Water for future
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• v.45 no.8
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• pp.106-111
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• 2012

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.75-80
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• 2004