• 한국해양환경ㆍ에너지학회지
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• 제5권3호
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• pp.28-34
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• 2002

최근에 음성인식 및 음성합성 기술의 발달로 음성을 이용한 정보안내시스템이 다양한 분야에서 개발되어 활용되고 있다. 선박에서도 선교업무의 피로도를 감소시키고, 비상상황시 효과적인 대처를 위해 항행정보안내시스템의 필요성이 커지고 있다. 그러나 음성을 이용한 선박의 정보안내시스템은 목표와는 달리 큰 호응을 얻지 못하고 있다. 주된 이유는 기능 및 인터페이스의 설계가 개발자 위주로 시작되었기 때문에, 사용과정이 복잡하여 실제 항해사가 사용하는데 망설인다는 점이다. 둘째로는 음성인식률이 사람에 따라, 혹은 환경에 따라 변하기 때문에, 시스템의 안정성이 떨어진다는 점이다. 이런 이유로 인해, 현재 IBS에서는 비상상황시 음성경보기능이 활용되고 있을 뿐이다 본 연구에서는 이러한 문제점을 개선하고, 음성기술을 안전운항에 적극적으로 활용하기 위하여, 사용자 중심의 시스템을 설계하였다. 우선, 실제 항해사와의 면담의 피드백과정을 통해 음성을 이용한 항행정보안내시스템의 요구기능을 결정하였다 그리고 음성인식이 사용자에 독립적이며, 안정적인 음성인식엔진을 적용하였다. 여기서, 음성지령과정을 단순화하기 위해 확인과정을 자동화하였고, 음성인식상의 오류는 자동수정기능으로 보완하였다. 본 논문에서 개발한 음성을 이용한 시뮬레이터 기반 항행정보안내시스템은 항해사의 실시간 선박 운항 시뮬레이션을 통해 운용성능을 시험하였다.

• 해양환경안전학회지
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• 제2권S1호
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• pp.63-73
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• 1996

The assesment of the safety of ship's transit in a curved narrow channl consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by shop's workload, and shiphandler's subjective evaluation. In this study to examine the correlation between shiphandler's subjectice evaluation and the maneuvering risk, the real-time and full-mission shiphandling simulator in the Korean Marine Training & Research Institutes(KMTRI) was utilized. In the conning bridge of the shiphandling simulator, 50 experienced masters conducted masters conducted the modeled vessel of 60,000 deadweight tonnage along the designed channel under 3 different envrinmental conditions. The findings were as follows: (1) The frequencies of stress levels, work difficulties, vessel controllability and overall workload of shiphandlers are similar irrespective of environmental conditions and they are able to be represented as shiphandler's subjective evaluation. (2) It is possible to assess and analyze theoretically the correlation between the shiphandler's subjective ecaluation and maneuvering risk each environmental cindition by quantifying the data obtioned from the tests. The results are as follows: ① As the degree of maneuvering risk increases, the shiphandler's subjective evaluation increases sharply near the curvature area of the desgined channel. ② In the area of the curvature of the designed channel, maneuvering risk increases sharply with the danger of running aground under the environmental condition of current and wind comung from the stem.

• 한국항해학회지
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• 제20권1호
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• pp.1-10
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• 1996

The assesment of the safety of ship's transit in a curved narrow channel consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload, and shiphandler's subjective evaluation. In this study, to examine the correlation between shiphandler's subjective evaluation and the maneuvering safety, the real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institute(KMTRI) was utilized. On the conning bridge of the shiphandling simulator, 50 experienced masters have conducted the modeled vessel of 60, 000 deadweight tonnage along the designed channel under 3 different environmental conditions. It was possible to assess and analyze theoretically the correlation between the shiphandler's subjective evaluation and maneuvering difficulty under each environmental condition by quantifying the data obtained from the tests. The results are as follows: $\circled1$ As the degree of maneuvering difficulty increases, the shiphandler's subjective evaluation increases in the designed channel under the designed environmental condition. $\circled2$ In the straight area, not the bend of the designed channel, maneuvering difficulty increases sharply under the environmental condition of current and wind coming from the stern.

• 해양환경안전학회지
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• 제2권1호
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• pp.35-45
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• 1996

The assesment of the safety of ship's transit in a curved narrow channel consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload, and shiphandler's subjective evaluation. In this study to examine the correlation between shiphandler's subjective evaluation and the maneuvering risk, the real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institutes(KMTRI) was utilized. On the conning bridge of the shiphandling simulator, 50 experienced masters conducted the modeled vessel of 60,000 deadweight tonnage along the designed channel under 3 different environmental conditions. The findings were as follows : (1) The frequencies of stress levels, work difficulties, vessel controllability and overall workload of shiphandlers are similar irrespective of environmental conditions and they are able to be represented as shiphandler's subjective evaluation. (2) It s possible to assess and analyze theoretically the correlation between the shiphandler's subjective evaluation and maneuvering risk under each environmental condition by quantifying the data obtained from the test. The results are as follows : ① As the degree of maneuvering risk increases, the shiphandler's subjective evaluation increases sharply near the curvature area of the designed channel. ② In the area of the curvature of the designed channel, maneuvering risk sincreases sharply with the danger of running aground under the environmental condition of current and wind coming from the stern.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2016년도 춘계학술대회
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• pp.199-201
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• 2016

항해장비의 성능이 고도화되고 있으나 해기사의 항해기기 운용능력, 즉 해양사고 저감을 위한 항해사의 위험 예견 능력과 회피의무의 중요성은 지속적으로 증대되고 있다. 이 능력과 의무는 항해사의 인지능력으로도 표현할 수 있다. 해기능력이 상이한 각 선교팀이 선박 조종시뮬레이터로 인명구조조선을 실시하여 나타난 선박의 항적을 기반으로 인지상황 발생 초기대응별 사례를 분석하고, 단계별 항적, ROT 값 등 분석 자료를 인지교육모델, 해기사의 상황인식평가 기초자료로 활용하고자 한다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2005년도 학술대회 논문집
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• pp.371-376
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• 2005

In this paper, a new a new full-bridge soft-switching phase shift PWM DC-DC Converter has been proposed, which is suitable for fuel cell based power generation system. The proposed converter has outstanding advantage over the conventional DC-DC converter with respect to high efficiency, high power density, and hish component utilization. In special. the proposed converter has predominant high boosting output voltage and high efficiency characteristics under the inherently severs low output voltage of the fuel cell through the overall load conditions. Moreover, the developed converter has been experimentally tested with the help of a fuel cell simulator, and can generate the V-I characteristics of proton exchange membrane(PEM) fuel cell, so that the performance of the proposed converter could be effectively examined and the validity of the converter could be verified.

• 전력전자학회논문지
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• 제26권2호
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• pp.150-157
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• 2021

Nowadays, a DC microgrid that can link various distributed power sources is gaining much attention. Accordingly, research on fault situations, such as line-to-line and line-to-ground faults of the DC microgrid, has been conducted to improve grid reliability. However, the blackout of an AC system and the oscillation of a DC bus voltage have not been reported or have not been sufficiently verified by previous research. In this study, a 20 kW DC microgrid testbed using a power HIL simulation technique is proposed. This testbed can simulate various fault conditions without any additional grid facilities and dangerous experiments. It includes the blackout of the DC microgrid caused by the AC utility grid's blackout, a drastic load increment, and the DC bus voltage oscillation caused by the LCL filter of the voltage source converter. The effectiveness of the proposed testbed is verified by using Opal-RT's OP5707 real-time simulator with a 3 kW prototype three-port dual-active-bridge converter.

• Structural Engineering and Mechanics
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• 제49권4호
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• pp.509-521
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• 2014

In this paper two protocols of Wireless Sensor Networks (WSN) are examined through both a simulation and a case study. The simulation was performed with the optimized network (OPNET) simulator while comparing the performance of the Ad-Hoc on demand Distance Vector (AODV) and the Dynamic Source Routing (DSR) protocols. This is compared and shown with real-world measurement of deflection from eight wireless sensor nodes. The wireless sensor response results were compared with accelerometer sensors for validation purposes. It was found that although the computer simulation suggests the AODV protocol is more accurate, in the case study no distinct difference was found. However, it was shown that AODV is still more beneficial in the field as it has a longer battery life enabling longer surveying times. This is a significant finding as a large factor in determining the use of wireless network sensors as a method of assessing structural response has been their short battery life. Thus if protocols which enhance battery life, such as the AODV protocol, are employed it may be possible in the future to couple wireless networks with solar power extending their monitoring periods.

• 한국항해항만학회지
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• 제27권6호
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• pp.611-618
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• 2003

It can be said that the relationship between the maneuvering ability of operators and the navigational environment affects the safe degree of navigation in the collision avoidance situation. In order to reduce the occurrence probability of accident and to maintain the safety, it is necessary to clarify the relationship between human behavior and navigational environment. In this study, therefore, we analyzed and discussed the relationship between the maneuvering characteristics and the safety focused on human behavior as a fundamental factor of marine accidents using ship handling simulator and questionnaire. As a result, we concluded that navigational environment changes variously and the maneuvering ability of operators also varies with the navigational environment, and the ship handling characteristics strongly affect the occurrence probability of accident.

• 한국항해학회지
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• 제25권4호
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• pp.443-453
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• 2001

선박조종시뮬레이터는 해기사의 교육 훈련, 항만 수로 설계 시 안전성 평가, 선박설계시 조종성능의 검토등으로 널리 활용되고 있다. 본 논문은 최근 한국해양대학교에서 개발한 선박조종시뮬레이터를 소개하고 개발 과정과 활용에 대하여 논의한다. 본 시뮬레이터는 Operation Panel, Instructor's Console, Ship Dynamics Calculation, 3D Bridge View, 2D Bird's Eye View 및 Navigational Indicators의 6구성요소로 이루어져 있으며, 이를 위해 8대의 퍼스널 컴퓨터가 배치되어 있다. 모든 구성요소들은 효율적인 정보 교환을 위하여 분산처리네트워크 방식으로 연결되어 있다. 또한, 본 논문은 항만내에서의 저속 시 조종운동 수학모델과 가상현실 모델링에 대해서도 논의한다. 마지막으로, 부산항에 대한 2축2타선박의 접안 조종 시뮬레이션 예를 보여주고 있다.