• Journal of Navigation and Port Research
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• v.33 no.10
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• pp.665-669
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• 2009

When maneuvering a ship in a narrow channel or under bridge, the ship operator may take actions of slowdown engine and altering course in order to avoid possible navigational dangers, which may reduce difficulties on navigation or collsion avoidance against other ship and/or bridge. In this paper, taking notice of the stress caused by these actions of slowdown engine and altering course, survey is carried out for whether it is possible to quantify the stress by time delay as an index. Based on the ship handling simulator experiment, it is verified that difficulty of navigation changes is highly correlated with the time delay, which result from compensation actions of slowdown engine and altering course.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.3B
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• pp.248-253
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• 2011

Collision avoidance algorithm of vessels have been studied to avoid collision and grounding of a vessel due to human error. In this paper, We propose a collision avoidance algorithm using bayesian estimation theory for safety sailing and reduced risk of collision accident. We calculate collision risk for efficient collision avoidance using bayesian algorithm and determined the safest and most effective collision risk is predicted by using re-planned with re-evaluated collision risk in the future(t=t'). Others ship position is assumed to be informed from AIS. Experimental results show that we estimate the safest and most effective collision risk.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.9 no.2
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• pp.91-99
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• 2001

오늘날 위성항법, 위성통신을 이용한 항공항법감시의 새로운 변화 가운데 국제민간항공기구(ICAO)에서 VDL(VHF Digital Link) Mode 4로 채택된 STDMA (Self-organized Time Division Multiple Access)에 관심이 증대되고 있다. 해양분야에서는 선박위치 자동인식시스템(AIS) 및 선박운행관리시스템(VTS)에서 2002년부터 적용될 예정이고, 항공분야에서는 향후 몇 년후에는 ADS-B, SMGCS에서 응용될 가능성이 높다. 본 연구에서는 STDMA를 이용한 SMGCS구현을 위한 기술개발로서 사전에 측지된 기준국으로부터 실시간으로 GPS 보정값을 생성, 전송하도록 하는 실시간 DGPS기술과 동기신호에 따라 시분할 다중접속을 구현한 소프트웨어 기반의 TDMA기술을 구현하였으며 이를 연구원내에서 차량이동 실험을 수행하여 다수의 이동국간에 측위값을 상호전송함으로써 각각의 위치를 실기간으로 파악할 수 있음을 보였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.753-756
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• 2001

Automatic Identification System(ALS) employed SOTDMA for the multiple access method. In SOTDMA systems, slot reuse may result in discrimination or garbling. Especially Gaussian Minimum Shift Keying(GMSK) Co-Channel Interference(CCI) resulted from the slot reuse in the Aloha zone degrades the system performance such as capacity In this paper we introduce some useful techniques to cancel the CCI and discuss the methodology which is applicable to AIS-SOTDMA

• Journal of the Society of Naval Architects of Korea
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• v.31 no.3
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• pp.112-118
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• 1994

In this paper, statistical approach to prediction of A-weighted noise level in ship cabins. based on multiple linear regression analysis, is conducted. The best regression formula is composed of seven parameters of the deadweight, the type of ship, the location of engines and cabins, the type of deckhouse and the propeller skew angle. Verification work was carried out with other 210 cabins' data in 6 ships. As a result, the formula ensures the accuracy of 3 dB(A) in 77 % of cases.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.36-37
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• 2022

선박의 안천한 항해를 돕기 위하여 해상에 항로표지를 설치하여 운영하고 있다. 해상 ICT(Information and Communications Technology)의 발달로 AtoN AIS(Automatic Identification System) 및 CDMA(Code Division Multiple Access), LTE(Long Term Evolution) 등 다중통신망을 이용하여 항로표지의 상태를 감시하고 제어가 가능해짐에 따라 해양수산부에서는 항로표지 관리운영시스템을 운영하고 있다. e-Navigation 및 자율운항선박 분야 등에 항로표지 스마트화를 위해 정확한 항로표지 정보가 요구된다. 본 논문에서는 정확한 항로표지 정보 제공을 위해 관리운영시스템 표준소프트웨어 문제점을 분석하고 개선방안에 대해서 소개한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.2
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• pp.138-144
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• 2013

Large and small marine accidents which are related to vessel's navigation are happening continuously and these maritime accidents have caused loss of lives and properties, and serious maritime environmental pollution damage. It is also true that maritime pollution damage is increasing due to these accidents, probability of growth of seaborne volume and complicated maritime traffic environment. Korea, recently, is developing an evaluation index which can assess sea risk through the evaluation of maritime traffic environment and provide danger and general information with relation to maritime traffic environment on target sea area to evaluate maritime traffic safety. In this paper, we intend to confirm the validity of maritime traffic safety on the basis of vessel navigator's risk consciousness and various sailing conditions by using the ship handling simulator. To confirm the validity of sailing vessel's maritime traffic safety, we use analysis of variance. By using analysis of variance, we analyze vessel navigator's characteristics, distance, speed and encounter type between vessels. Through multiple comparison of each factor's risk difference, we can confirm the change of numerical value of risk difference in statistical aspect.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.91-100
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• 2012

Although Korea's coastal areas increasingly experience marine accident due to frequent ship encounters, increased vessel traffic and large vessel, there is a no specific model to evaluate the navigating vessel's risk for the given situation. The maritime transport environmental assessment is necessary due to the amended marine traffic law. However, marine safety diagnosis is now evaluated by foreign models. In this paper, therefore, we suggest a domestic model catering to and reflecting the characteristics of Korea's costal areas as well as those of vessel navigator's risk. We can evaluate subjective risks using this model, and can establish the model output as maritime risk exposure assessment system. We have performed analyses of variance and multiple comparison to identify the factor affecting subjective risks. As a result, measurable subjective risks of maritime traffic accident based on our suggested model can be expressed using the maritime risk exposure assessment system with geographic information system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.4
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• pp.378-386
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• 2013

In this paper, we propose a multi-way relaying system, in which N communicating nodes interchange their information one another by the help of a multiple-antenna non-regenerative relay station (RS). While the conventional multi-way relaying requires 2N transmission phases to complete the data exchange, the proposed system completes the mission with N phases composed of one multiple access phase and N-1 broadcast phases. For effective broadcast transmission, the proposed system pairs users for signal transmission with a new RS beamforming matrix not to interfere with the nodes of different pairs and a self-interference canceler at each node. The performance evaluation in terms of the average sum rate shows that the proposed system outperforms the conventional one with more significant gain when the number of RS antennas is comparable to the number of communicating nodes. The proposed schemes can be applicable to marine communications where the ships need to share their information with extended coverage.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.204-205
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• 2017

항로표지는 선박의 안전과 운항능률의 증진에 필수적인 수단으로 해상교통에 필수적이다. 등명기는 육상 및 해상에서 광파표지로 다양하게 활용되고 있으며 최근들어 장수명 및 저전력 소비의 장점을 갖춘 LED 광원의 적용이 확산되고 있다. 본 연구는 다중 배광 및 픽셀라이팅 기술 구현을 통해 등부표의 회전 운동에도 수평빔 유지제어가 가능한 신형 LED 등명기를 개발하여 암전 영역 제거 및 등질 인지향상을 통해 해양 사고 방지 및 해양 안전 향상을 목표로 한다. 등부표용 신형 LED 등명기 개발을 위해 다중 렌즈 및 픽셀 라이팅과 같은 광원/광학 기술과 제어 구동 시스템 설계 기술의 적용하였다. 본 연구에서 개발한 신형 LED 등명기는 등부표에 최적화된 수평배광 유지가 가능한 세계 최초의 등명기 시스템으로 국제 표준 제안 등을 통해 향후 세계 시장 진출을 추진하고자 한다.