• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.66-68
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• 2015

최적항로 지원 시스템은 실해역 속도 성능 예측방법에서의 선택 근거확보와 정확도 평가를 위한 효과 검증이 반드시 필요하다. 하지만 이 같은 성능검증에 있어서 동일한 선박에 대한 다양한 대안 항로에서의 동시성능계측이 불가능하기 때문에 효과를 직접 비교하기는 상당히 어렵다. 따라서 본 논문에서는 최적항로 지원 시스템의 효과 검증을 위한 간접적인 절차를 제안하였고, 시스템의 내부 분석코드를 이용하여 효과를 비교 검증하였다. 그 절차는 1) 계산의 근거 인기상 정보의 정확성 검증, 2) 실제 항로에서의 성능예측계산의 신뢰성 확인, 3) 신뢰성이 확보된 계산방법을 이용한 최적항로선택, 4) 실제 항로와 최적항로의 연료 효율성 비교의 4단계로 이루어진다. 대상 선박은 폴라리스쉬핑의 솔라돌핀호(208k BC)이며 실선 운항 데이터는 최적항로 지원 시스템을 통하여 직접 계측하였다. 그 결과 호주-한국 항차에서 최적항로를 항해할 경우 약 6.0%의 연료 절감 효과를 기대할 수 있음을 확인하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.263-264
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• 2023

본 연구는 자율운항선박의 실제 해상에서의 성능 검증하기 위한 실험을 진행하였다. 먼저 SAS(Samsung Autonomous System)을 활용하여 시뮬레이션을 진행하였다. 시뮬레이션은 Imazu 조우 모델을 기반으로 실험을 진행하였다. 시뮬레이션에서 조우 선박은 2-4척으로 정면, 횡단, 추월 등이 뒤섞인 상황을 가정하였다. 결과 분석은 6가지 항목(속력, Heading, Rate of Turn, Collison Risk Index, DCPA, TCPA, Closest Distance, XTD(Cross-Track Distance))을 분석하였다. 2 차례의 실해역 실험을 진행하였다. 목포-제주도 구간에서 실해역 실험을 진행 후 목포-이어도-독도 항로에서 실해역 실험을 진행하였다. 실해역 실험 결과 Imazu 모델 기반 시뮬레이션과 비슷한 결과를 보였다.

• Journal of Navigation and Port Research
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• v.32 no.8
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• pp.583-588
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• 2008

The planing craft is designed specifically to achieve comparatively high speed on the surface of the water. In general, the stepped hull craft has effect improvement in speed and fuel-efficiency because of the reduction of total resistance by a small wetted surface area without corresponding stepped hull craft. In this paper, the high speed stepped hull crafts with respect to the number of bottom steps were performed to compare the effect of resistance performance using at-sea model-test method. In conclusion, the stepped hull craft with twin-step was proved to be effective to reduce the total resistance.

• Journal of Navigation and Port Research
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• v.36 no.3
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• pp.157-162
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• 2012

A planing craft is designed specifically to achieve comparatively high speed on the surface of the water. The frictional resistance of planing craft can be reduced further by injecting air to the craft's bottom. In this paper, the resistance characteristics of high speed planing crafts with & without air injection at the bottom were compared by sea model-test method. As a result, we conformed that planing craft with air injection has much greater the effect of resistance reduction.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.5
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• pp.252-261
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• 2022

The present study concerns assessing the operability of a surface combatant, based on the Percent-Time-Operable (PTO). For validation of the seakeeping analysis in the regular waves, the model test is first conducted in a towing tank. The seakeeping analysis results in the regular waves are expanded to the irregular waves, considering the wave spectra around the Korean peninsula and in North Pacific. The seakeeping criteria of the surface combatant in transit, combat, replenishment operation, and survival condition are defined by the literature review. An annual operation scenario of the surface combatant in two operation areas, i.e., advance speed and wave direction, are combined with the seakeeping analysis results to assess PTO. The main constraints of operability of the surface combatant are identified as the pitch angle and vertical velocity at the helicopter deck.

• The Journal of the Acoustical Society of Korea
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• v.30 no.1
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• pp.9-16
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• 2011

When a hydrofoil ship plies at high speed, there exist possibilities of collision with ocean mammals dwelling near the surface. An active sonar located within the immersed hydrofoil structure that provides the lift for the vessel, can be used for early warning of their presence. The proper functioning of the active sonar system depends on its ability to reject noise and pick up the target signal. In this article, we measured the noise on a hydrofoil of an operating ship with two flush-mounted hydrophones. The measurements were conducted for the purpose of (1) identifying the effect of operating state of machinery likes engine, cooler and generator (2) observing the change of noise depending on the measuring position (3) observing the change of noise with increasing ship speed. To verify our experiment, experiments were performed three times and the measured results are compared with other investigations and they show similarity to each other. The results are analyzed with frequency domain in order to apply to operating active sonar detecting system and focus on high frequency band within sonar's operating frequency region. Through these experiments and analysis, it is expected that we can identify the generated noise around hydrofoil where active sonar is installed and these results lead us to design active sonar that could distinguish target signal from noise more effectively.

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.7
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• pp.887-892
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• 2023

Vessel traffic service(VTS) centers are equipped with RADAR, AIS(Automatic Identification System), weather sensors, and VHF(Very High Frequency). VTS operators use this equipment to observe the movement of ships operating in the VTS area and provide information. The VTS data generated by these various devices is highly valuable for analyzing maritime traffic situation. However, owing to a lack of compatibility between system manufacturers or policy issues, they are often not systematically managed. Therefore, we developed the VTS Bigdata Platform that could efficiently collect, store, and manage control data collected by the VTS, and this paper describes its design and implementation. A microservice architecture was applied to secure operational stability that was one of the important issues in the development of the platform. In addition, the performance of the platform could be improved by dualizing the storage for real-time navigation information. The implemented system was tested using real maritime data to check its performance, identify additional improvements, and consider its feasibility in a real VTS environment.