• Journal of the Institute of Convergence Signal Processing
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• v.23 no.1
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• pp.28-36
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• 2022

Currently, the automation and intelligence of the shipbuilding industry have improved its work production capacity and cost competitiveness, but the reduction rate of safety accidents among industrial site workers is still low and the damage caused by safety accidents is very serious, so there is a need for improvement according to the workplace. This research aims to demonstrate the connectivity between smart safety helmets in the demonstration area to verify the effectiveness along with the development of smart helmets for worker protection and environmental safety in shipyards. For efficient communication between workers, impact noise of over 95dB was confirmed in the workplace, and noise reduction was required. To solve this problem, the filtering performance was compared and analyzed using the Butterworth, Chebyshev, and elliptic algorithms. The connectivity test and noise reduction method between smart helmets proposed in this study will increase the usability and safety of the field through the development of advanced smart helmets tailored to the shipbuilding workplace in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.3
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• pp.295-300
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• 2010

The international convention on standards of training, certification and watch-keeping for seafarers, 1978(1978 STCW convention) has been established as a minimum standard and competence of seafarers, and contributed to reduce marine accidents caused by human errors. The convention has been partly amended several times according to environmental change of ship's operation and there were comprehensive revisions in so called 1995 amended STCW convention. In these years, ships are in tendency of increasing size and speed, and also adopted high technologies. These kinds of changes brought STW sub-committee up for discussions to modify the convention to cope with new environments from the year of 2006. As the result, major amendaments to STCW convention have been adopted at a diplomatic conference in Manila, Philippine in June 2010, thereby new global standards will be in force to train and certify seafarers to operate technologically advanced ships before long. This paper is to introduce major amendaments such as ship's security, ECDIS and leadership etc. in this Manila amendments and to clarify some articles to be adopted in programs for education and training of seafarers in Korea.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.5
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• pp.85-97
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• 2009

Continuous increase of traffic demand has caused confirmed congestion, fuel consumption, emission, safety, etc. as serious social problems at the present time. The Smart Highway Project has been conducted by the supervision of Ministry of Land, Transport and Maritime Affaire to solve such problems since 2007. The Smart Highway Project includes LDWS (Lane Departure Warning System), a system to prevent broadside collisions and accidents, as a sub-technology of road-vehicle associating technologies. This system warns drivers when their vehicle deviates from the lane where they are traveling at high-speed on the highway. In this paper, the LDWS was evaluated using CBA to analyze the socio-economic consequences. Estimated benefits include reduction of accidents and convenience of drivers. In addition, the economics according to the distribution rate is various when it comes to Lane Departure Warning Technology, the economics of both cases - positive scenario and negative scenario, which was analyzed. As a result, the Benefit-Cost ratio(B/C) of negative scenario showed 0.97 in 2020 and 1.36 in 2030 while B/C ratio of the positive scenario showed 1.04 in 2020 and 1.59 in 2030, which indicated that the higher distribution rate is, the higher the economics generates. Therefore, it is judged that the introduction of Lane Departure Warning Technology will result in high economics.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.103-103
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• 2015

유류유출사고와 같이 하천 수표면의 흐름에 따라 이동 확산하는 부유성 오염물질의 혼합해석을 위해 많은 연구자들은 입자추적모형을 사용한 혼합모의를 수행해왔다. 입자추적모형에서 오염물질의 혼합은 평균 유속 분포에 의한 결정론적인 이동과 난류유동에 의한 무작위적인 혼합으로 나타내며, 난류혼합에 의한 수평확산은 난류확산계수로 조절한다. 따라서 표면흐름에 의한 난류확산계수의 산정을 위해 많은 연구자들은 부유성 입자를 이용한 실내실험을 수행하여 수평확산계수를 산정했고(Engelund, 1969; Cederwall, 1971), 최근에는 GPS의 발전으로 인해 해양영역에서 GPS를 장착한 표면부자를 활용한 확산실험을 통해 수평확산계수를 산정한 바 있다(Kjellson and $D{\ddot{o}}{\ddot{o}}s$, 2012; Alpers 등, 2013). 하천수질오염사고의 약 43.5%가 유류유출에 의한 것이며(환경부, 2013), 이에 따라 표면흐름에 의한 오염물질 혼합해석이 필요하나, 하천에서 수평확산계수 산정을 위한 현장실험연구는 부족한 상황이다. 따라서 본 연구에서는 낙동강 본류에서 GPS부자를 이용한 입자추적실험을 수행하여 표면흐름에 의한 확산계수를 산정했다. GPS부자를 이용한 입자추적실험은 낙동강의 강정고령보 하류와 구미보 하류의 각각 세 지점에서 수행되었다. GPS부자는 바람에 의한 교란을 최소화하기 위해 지름 10 cm의 구형으로 제작하였으며 시범테스트를 통해 입자의 주 궤적 변화가 크지 않은 지점에 GPS부자를 투입했다. GPS부자는 오염물질의 사고유출을 가정하여 한 지점에 투입했고 GPS부자 사이의 간섭을 최소화하기 위해 25 ~ 35개의 GPS부자를 이용했다. 표면흐름에 의해 이동하는 부자의 위치는 GPS에 시계열로 저장됐고 ADCP를 이용하여 실험당시의 수리량을 측정했다. 입자위치의 시계열자료로부터 GPS부자의 확산범위의 시간변화를 계산했고 단순 모멘트법을 이용하여 종, 횡 방향 확산계수를 계산했다. 그 결과, 종 방향 확산계수는 $0.003{\sim}0.041m^2/s$로 계산되었고 횡 방향 확산 계수는 $0.001{\sim}0.012m^2/s$로 계산되어, 흐름방향의 유속성분에 의한 확산이 지배적인 것으로 나타났다. 지류 합류부에서는 이송이 지배적인 혼합이 발생되었고(Pe>1) Pe의 증가에 따라 수평확산계수가 감소되었다. 25~35개 GPS부자 궤적의 앙상블 평균으로부터 계산한 Integral time scale은 모멘트법으로부터 계산한 종, 횡 방향 확산계수와 비례하는 것으로 나타나, Taylor(1921)의 이론과 일치했다. 또한 실험수로에서 수행된 기존연구결과와 비교한 결과, 하폭 대 수심비, 마찰항의 증가에 따라 수평확산계수가 증가하는 경향을 나타내었다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.403-408
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• 2015

A text-based communication system has been developed with a communication function on AIS and display and input function on ECDIS as a way to complement voice communication. It features no linguistic error and is not affected by VHF restrictions on use and noise. The text communication system is designed to use messages for clear intentions and further improves convenience of users by using various UI through software. It works without additional hardware installation and modification and can transmit a sentence by selecting only via Message Banner Interface without keyboard input and furthermore has a advantage to enhance processing speed through its own message coding and decoding. It is determined as the most useful alternative to reduce language limitations and recognition errors of the user and solve the problem of various voice communications on VHF. In addition, it will help to prevent collisions between ships with decrease in VHF use, accurate communication and request of cooperation based on text at heavy traffic areas.

• Spatial Information Research
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• v.22 no.5
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• pp.19-26
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• 2014

International attention on the Northern Sea Route has been increased as the decreased sea-ice extents in Northern Sea raise the possibility to develop new sea routes and natural resources. However, to protect ships' safety and pristine environments in polar waters, International Maritime Organization(IMO) has been developing the Polar Code to regulate polar shipping. The marine navigation supporting system is essential for ships traveling long distance in the Northern Sea as they are affected by ocean weather and sea-ice. Therefore, to cope with the IMO Polar Code, this research proposes the functional requirements to develop the marine navigation supporting system for the Northern Sea Route. The functional requirements derived from the IMO Polar code consist of arctic voyage risk map, arctic voyage planning and MSI(Marine Safety Information) methods, based on which the navigation supporting system is able to provide dynamic and safe-economical sea route service using the sea-ice observation and prediction technologies. Also, a requirement of the system application is derived to apply the marine navigation supporting system for authorizing ships operating in the Northern Sea. To reflect the proposed system in the Polar Code, continual international exchange and policy proposals are necessary along with the development of sea-ice observation and prediction technologies.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.184-192
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• 2022

Valve internal leakage is caused by damage to the internal parts of the valve, resulting in accidents and shutdowns of the piping system. This study investigated the possibility of a real-time leak detection method using the acoustic emission (AE) signal generated from the piping system during the internal leakage of a butterfly valve. Datasets of raw time-domain AE signals were collected and postprocessed for each operation mode of the valve in a systematic manner to develop a data-driven model for the detection and classification of internal leakage, by applying machine learning algorithms. The aim of this study was to determine whether it is possible to treat leak detection as a classification problem by applying two classification algorithms: support vector machine (SVM) and convolutional neural network (CNN). The results showed different performances for the algorithms and datasets used. The SVM-based binary classification models, based on feature extraction of data, achieved an overall accuracy of 83% to 90%, while in the case of a multiple classification model, the accuracy was reduced to 66%. By contrast, the CNN-based classification model achieved an accuracy of 99.85%, which is superior to those of any other models based on the SVM algorithm. The results revealed that the SVM classification model requires effective feature extraction of the AE signals to improve the accuracy of multi-class classification. Moreover, the CNN-based classification can be a promising approach to detect both leakage and valve opening as long as the performance of the processor does not degrade.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.812-817
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• 2011

Rolling stocks are often subjected to the effects of natural cross wind or train wind pressure due to the crossing train. These wind pressure cause the falling-off in running stability and turnover problem. It is sometimes reported that trains are blown over by a gust of wind in overseas. So, many countries enact regulations to secure the safety for wind speed. In this study, we analyzed the difference between the regulation for turnover safety of train which was enacted by Ministry of Land. Transport and Maritime Affairs and that based on the multi-body model. In case of multi-body model, it is assumed that the degrees of freedom for carbody and bogie are assigned an independent values respectively. The results show that the latter approach based on multi-body model can access the safety of turnover and replace the computational method which is accessing with lateral force, derailment coefficient and decrement of wheel load.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.588-590
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• 2022

Sharing both locations and positions of ships makes it possible to utilize critical item for their safe and efficient navigation in such diversifying meantime environments. AIS is the representative technology for the sharing solutions. The AIS is even used in airspace and ground stations, so that AIS could facilitate the ships' safety navigation and their prevention/rescue from endangers. Due to AIS's many advantages, IMO(International Maritime Organization) made adapting the AIS mandatory for international passenger ships and the ships that are over than 300 tons. AIS uses VHF band areas for transmitting information and the information can be propagated to several hundreds km in range. Due to the large range, AIS monitoring system can acquire huge number of ships, which makes system performance lower and busier. In this paper, we propose the strategy of AIS information extraction for efficient monitoring system. Thus, the monitoring system has higher processing performance and lower network usage. As well as, the proposal affects the monitoring system has more capacity to include other systems' targets, in result.

• 한국가스학회:학술대회논문집
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• 2007.04a
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• pp.195-200
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• 2007

본 연구는 도심지에 위치한 LPG 충전소를 연구범위로 하여 공간정보의 활용이 가장 많이 요구되는 안전관리 분야의 업무를 중심으로 공간정보를 효율적으로 구축 활용하기 위하여 데이터베이스를 중심으로 위험관리정보 시스템을 개발하였다. 이를 바탕으로 정량적 위험성 평가의 자동화를 통해 나타난 위험성을 실시간에 제어하기 위한 필요조건을 표준화하여 기초 정보자료로 구축, 이를 지리정보기능과 연동하여 LPG 충전소의 안전검사의 효율화, 사전 위험성 평가, 사고대응 판단의 효과적인 의사결정을 유도 할 수 있는 기반을 제공한다. 위험관리정보시스템(RMIS, Risk Management Information System) 개발절차는 다음과 같다 첫째, 도심지에 위치한 LPG 충전소 위험성 평가를 수행함에 있어서 기본적인 데이터인 부지내(On-site) 관련 자료와 부지 외(Off-site) 관련 자료를 관계형 데이터베이스(RDB, Relational Database)로 개발하였다. 둘째, Visual Basic을 이용하여 사용자가 효과적으로 위험을 관리 제어 할 수 있는 위험관리 통합 데이터베이스 시스템 개발하였다. 셋째, 위험관리 통합 데이터베이스 시스템과 지리정보시스템에 연동을 통한 의사결정 방안 제시하였다. 위험관리정보시스템(RMIS) 프로그램을 개발을 통하여 다음과 같은 결과를 도출하였다. 첫째, 위험관리 데이터 이용하여 사용자와 검사자가 효과적으로 위험을 사전관리 할 수 있는 공유정보를 구축하였다. 둘째, 위험 관리를 부지 내와 부지 외로 나누어 관리함으로서 시설 내부 뿐 만 아니라 시설외부에 미치는 영향을 모두 고려하여 구축하므로 서, 중대사고에 대응 할 수 있는 종합적인 안전관리 기반을 조성하였다. 셋째, 사용자 인터페이스를 바탕으로 비상사태 발생시에 신속하고 정확한 의사결정을 할 수 있는 기반을 조성하였다. 제공하여 응용GIS 구축의 생산성 및 품질 향상에 기여할 뿐만 아니라 우리의 최종목표인 GIS 소프트웨어 자동 생산에도 크게 기여할 것으로 사료된다. 등)을 교통망상에 표시할 수 있음으로서 의사결정에 보다 많은 도움을 줄 수 있을 것이다. 비트율의 증가와 화질 열화는 각각 최대 1.32%와 최대 0.11dB로 무시할 수 있을 정도로 작음을 확인 하였다.을 알 수 있었다. 현지관측에 비해 막대한 비용과 시간을 절약할 수 있는 위성영상해석방법을 이용한 방법은 해양수질파악이 가능할 것으로 판단되며, GIS를 이용하여 다양하고 복잡한 자료를 데이터베이스화함으로써 가시화하고, 이를 기초로 공간분석을 실시함으로써 환경요소별 공간분포에 대한 파악을 통해 수치모형실험을 이용한 각종 환경영향의 평가 및 예측을 위한 기초자료로 이용이 가능할 것으로 사료된다.염총량관리 기본계획 시 구축된 모형 매개변수를 바탕으로 분석을 수행하였다. 일차오차분석을 이용하여 수리매개변수와 수질매개변수의 수질항목별 상대적 기여도를 파악해 본 결과, 수리매개변수는 DO, BOD, 유기질소, 유기인 모든 항목에 일정 정도의 상대적 기여도를 가지고 있는 것을 알 수 있었다. 이로부터 수질 모형의 적용 시 수리 매개변수 또한 수질 매개변수의 추정 시와 같이 보다 세심한 주의를 기울여 추정할 필요가 있을 것으로 판단된다.변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전략은 존재하므로 이러한 전략을 개발 및 활용할 수 있으며, 특히, 한국주