• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.595-602
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• 2021

Marine accidents are mostly caused by medium and small ships, and are continuously increasing. In this paper, we propose an architecture of the speech synthesis based automatic safety navigation support service providing system for small ships that equiped onboard systems compared with vessels. The main purpose of the system is to prevent marine accidents by providing synthesized voice safety messages to nearby ships. The safety navigation support service is operated by connecting GPS and AIS to synthesize voice safety messages, automatically broadcast through VHF. Therefore, we developed a data processing module, a staged risk analysis module, a voice synthesis safety message generation module, and a VHF broadcasting equipment control module, which are components of the system. In addition, we conducted laboratory-level and sea-trial demonstration tests using the developed the system, which verified usefulness of the proposed service.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.8
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• pp.1205-1212
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• 2022

Cyber threat targeting ICS (Industrial Control System) has indicated drastic increases over the past decade and Cyber Incident in Critical Infrastructure such as Energy, Gas Terminal and Petrochemical industries can lead to disaster-level accidents including casualties and large-scale fires. In order to effectively respond to cyber attacks targeting ICS, a multi-layered defense-in-depth strategy considering Control System Architecture is necessary. In particular, the centralized security log system integrating OT (Operational Technology) and IT (Information Technology) plays an important role in the ICS incident response plan. The paper suggests the way of implementing centralized security log system that collects security events and logs using OPC Protocol from Level 0 to Level 5 based on IEC62443 Purdue Model to integrate ICS security logs with SIEM (Security Information Event Management) operated in IT environment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.281-293
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• 2023

Industrial control systems (ICS) are increasingly targeted by security incidents as attackers' knowledge of ICS characteristics grows and their connectivity to information technology expands. Vulnerabilities related to ICS are growing rapidly, but patching all vulnerabilities in a timely manner is challenging. The common vulnerability assessment system used to patch vulnerabilities has limitations as it does not consider weaponization after discovery. To address this, this study defines criteria for classifying attacker skill levels based on open information including operating technology and vulnerability information in ICS. The study also proposes a method to evaluate vulnerability severity that reflects actual risk and urgency by incorporating the corresponding attribute in the existing severity score calculation. Case studies based on actual accidents involving vulnerabilities were conducted to confirm the effectiveness of the evaluation method in the ICS environment.

• Review of KIISC
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• v.33 no.6
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• pp.5-14
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• 2023

최근 산업제어시스템을 대상으로 하는 보안 사고가 지속적으로 증가함에 따라서 이상탐지 시스템에 대한 다양한 연구가 진행되고 있다. 특히 AI 기술의 급속한 발달과 함께 수준 높은 AI기반 이상탐지시스템이 연구되고 있다. 이러한 AI 모델은 산업제어시스템 환경에서 적용할 수 있도록 실시간의 처리가 필요하며, 데이터 세트의 학습에는 산업제어시스템 특성을 고려하는 것이 요구된다. 따라서, 데이터 세트가 산업제어시스템에서 적합하게 활용될 수 있는지 판별할 수 있는 세부 기준을 마련하게 된다면, 우수한 데이터 세트의 활용을 통해 산업제어시스템을 위한 AI 모델의 성능이 향상될 것으로 보인다. 본 논문에서는 산업제어시스템의 AI 침입 탐지시스템의 성능 향상을 위한 데이터 품질 연구의 동향을 조사하고, 향후 발전을 위한 방향성을 구체적인 평가항목을 통해 제시하고자 한다.

• Journal of the Korean earth science society
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• v.39 no.1
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• pp.103-116
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• 2018

The purpose of this study was to explore $6^{th}$ graders learning progression for lunar phase change focusing astronomical systems thinking. By analyzing the results of previous studies, we developed the constructed-response items, set up the hypothetical learning progressions, and developed the item analysis framework based on the hypothetical learning progressions. Before and after the instruction on the lunar phase change, we collected test data using the constructed-response items. The results of the assessment were used to validate the hypothetical learning progression. Through this, we were able to explore the learning progression of the earth-moon system in a bottom-up. As a result of the study, elementary students seemed to have difficulty in the transformation between the earth-based perspective and the space-based perspective. In addition, based on the elementary school students' learning progression on lunar phase change, we concluded that the concept of the lunar phase change was a bit difficult for elementary students to learn in elementary science curriculum.

• Journal of the Korean Institute of Gas
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• v.14 no.4
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• pp.6-11
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• 2010

The continuous fatal accidents like explosion or fire cause huge losses of both life and property in laboratories even though safety management system has been built and periodical checkups and safety diagnosis have been implementing in universities and enterprise-affiliated research institutes since Act on the Establishment of Safe Laboratory Environment was enacted in 2005 to prevent accidents in research laboratories. Cause analysis and safety management measures to prevent recurrence of accidents are urgently needed because accidents in research laboratories occur repeatedly with similar contents. This study will show results of analysis on incidents and accidents occurred in laboratories in universities and enterprise-affiliated research institutes using Root Cause Analysis Method and propose classified map of cause investigation and improvements so as to improve safety management in research laboratories.

• Environmental and Resource Economics Review
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• v.26 no.2
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• pp.139-172
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• 2017

Nuclear safety measures such as safety technology, culture, and regulation affects nuclear performances. This paper analyzes the change of nuclear performance by considering nuclear safety measures. Nuclear performance and technical data ranging 1970 to 2015 are collected from the Power Reactor Information System (PRIS) of IAEA. The result of panel regression analysis shows that overall engineering level, maintenance engineering and productivity decrease the forced loss rate (FLR). FLR structurally increase after Chernobyl accident in 1986 whereas after TMI and Fukushima accidents FLR didn't show any significant changes. The structural increase of FLR after Chernobyl are likely to result from the efforts of international communities for nuclear safety culture which makes nuclear operating company pay more opportunity cost to achieve nuclear safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.105-111
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• 2018

This study aims to evaluate the safety for cable stayed bridge due to damages on the cable system. Many cable supported bridges, including cable stayed bridge and suspension bridge, have been built in the Korean peninsula. This requires efficient maintenance and management since this structure has complex structural components and system. This large structure also often faces risks either from manmade or natural phenomenon. In 2015 one cable-stayed bridge in South Korea had been struck by a bolt of lightning on the cables. This event had led to fire on cables. These cables had been damaged and putting the bridge at risk. This bridge was back in used after a few weeks of investigations and replacements of the cables. However, enormous social and economic expense were paid for recovery. After this event risk based management for infra structures is required by public demands. Therefore, this study was initiated and aimed to evaluate risks on the cable system due to potential damages. In this paper one cable-stayed bridge in South Korea was selected and investigated its safety based on the damage scenarios of cable system for efficient and prompt management, and for supporting decision making. FEM analysis was conducted to evaluate the safety of the bridges due to damages on the cable system.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.429-429
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• 2021

2019년 발생한 인천광역시 붉은 수돗물 사태로 급수구역에 포함된 26만 1천 세대, 63만 5천 명이 직·간접적인 피해를 입은 바 있다. 경제적 피해액으로 추정할 경우 최소 1,280억 원 이상으로 보고된 바 있으며, 이와 같은 상수관망의 수질사고 확산은 장기간 동안 시민의 건강과 생활환경 수준을 저하시킨다. 따라서 상수도시스템의 수질사고확산 모델링 및 방지기술을 통한 수질안전성의 재확인이 필요하며, 이것은 상수도시스템의 지속가능성을 높여 국민이 체감하는 물 환경 수준 제고에 기여가 가능하다. 관망 내 수질해석을 직접적으로 수행하는 모델은 국외적으로 다양하게 개발(PODDS, EPANET-MSX, EPANET2.2 등)된 바 있으나 검·보정을 위한 수질측정 자료 부족 등으로 적용이 제한적이라는 한계가 현재에도 존재한다. 이를 보완하기 위해 수질자료에 비해 그 양이 많고 획득방법이 상대적으로 수월한 수리학적 계측자료 및 해석결과를 활용한 관로 내 체류시간 등을 활용한 연구가 수행된 바 있다. 그러나 이와 같은 수리학적 해석 결과를 활용하는 경우에도 계측자료를 기반으로 한 수리학적 검·보정은 필수적이라 할 수 있다. 본 연구에서는 관로 내 체류시간에 직접적인 영향을 미치는 유량 및 유속자료를 중심으로 수리학적 관망해석의 결과를 최적 검·보정하는 방법론을 제안하였다. 기존 상수관망 수리해석의 검·보정은 일부 지점에서 수압을 측정하고, 수리해석 결과로 도출되는 해당 지점의 수압이 실측된 결과와 유사하도록 관로의 유속계수를 적절히 보정하는 형태로 진행되었다. 그러나 본 연구에서는 관로유량과 유속자료의 목적함수 내 가중치를 수압자료보다 크게 설정하여 체류시간 중심의 검·보정이 수행될 수 있도록 하였으며, 검·보정 대상인자 역시 대수용가의 수요량, 수요패턴, 그리고 관로유속계수로 확장된 모형을 구축하였다. 최적화 기법으로는 메타휴리스틱 기법중 하나인 화음탐색법을 활용하였다. EPANET 2.2 Toolkit과 Visual Basic .Net을 연계하여 프로그래밍하였으며, 개발된 모형을 실제 지방상수도 시스템에 적용하여 분석하였다.

• Journal of Internet Computing and Services
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• v.7 no.1
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• pp.31-38
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• 2006

The importance of the Security Risk Analysis has emerged as security breaches and information leaks has occurred in the companies and organization: threats toward information system and its vulnerabilities has grown up as the dependence on the information-communication systems goes higher as a result of technological advances in IT industry, A Risk Analysis Tool helps to mitigate overall risk of an organization by analysing and evaluating critical information systems and providing security measures against threats to systems and its vulnerabilities as a means to identify the inherent dangers and prevent security intrusion incident, This paper defines risk analysis process by introducing Common Criteria Scheme and suggest a risk analysis tool that can be easily implemented by an information security manager.