• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.799-806
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• 2018

In this paper, we analyzed the communication distances in the flat and spherical earth model using the main specifications of the wireless communication device under development to be installed in the unmanned surface vehicle(USV). We installed the wireless communication device on the test ship and the actual communication test was performed in the South Sea of Korea, it compared the experimental result with the simulated results. If the installation altitude of the transmitting and receiving antennas is low, there is not the big difference between the two models. However, when the altitude of one of the two antennas is high, the spherical earth model has similar results to the experimental data. As the altitude of the antenna installation increases, fading occurs in a certain section. We expect that this fading can be overcome through antenna technologies such as space diversity.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.5
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• pp.827-834
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• 2022

Recently, marine surveys using unmanned ships are attracting attention, and research on small unmanned ships using sails is on the rise. Sail drones can be used for marine surveys, monitoring, and pollution management. Therefore, in this study, using the method of estimating the ship speed for twin sail drones, the optimal conditions for sailing are checked, and the performance to be considered in the initial design stage, such as the motion performance and resistance of the sail drone. Consequently, the twin sail drone had a speed lower than 2.0 m/s, and the stability satisfied the rule by DNV. In addition, the maximum speed at an angle of attack of 20° at TWA 100° was 1.69 m/s and that at an angle of attack of 25° at TWA 100° was 1.74 m/s.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2020.11a
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• pp.163-164
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• 2020

Along with the increase in global volume of goods, logistics companies are trying to reduce costs by increasing the size of ships carrying cargo, increasing the efficiency of quantitative equipment at ports, and unmanned electric vehicles on land. Korean naval ports are also facing the same situation as the global trend. In the past, small and medium-sized ships such as FF, PCC, and beheaded eagles are being retired for their longevity, and their positions are being replaced by large ships such as KDX, FFG, and LST-II. In particular, large ships such as Dokdo and the next light aircraft carriers are also being prepared. Unlike general merchant ships, naval ships require periodic inspections and preventive maintenance, so repair piers such as maintenance depots are in operation. The naval maintenance depot mainly uses trailers, trucks, and truck-type cranes to carry out loading and unloading of heavy ships, and the application or development of automation and unmanned equipment performed by the private sector is inadequate, and self-improvement cases are also very weak. This study aims to improve the efficiency of the military logistics system through research on the logistics system such as transport, storage and unloading of heavy goods and maintenance products of naval ships.

• Journal of Navigation and Port Research
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• v.43 no.6
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• pp.377-383
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• 2019

Naval ships that are navigating always have the possibility of colliding, but there is no clear maneuvering procedure for collision avoidance, and there is a tendency to depend entirely on the intuitive judgment of the Officer Of Watch (OOW). In this study, we conducted a questionnaire survey when and how to avoid collision for the OOW in a Constant Bearing, Decreasing Range (CBDR) situation wherein the naval ships encountered obstacles. Using the results of the questionnaire survey, we analyzed the CBDR situation of encountering obstacles, and how to avoid collision in day/night. The most difficult to maneuver areas were Pyeongtaek, Mokpo, and occurred mainly in narrow channels. The frequency appeared on average about once every four hours, and there were more of a large number of ships encountering situations than the 1:1 situation. The method of check of collision course confirmation was more reliable with the eye confirmation results, and priority was given to distance at closest point of approach (DCPA) and time at closest point of approach (TCPA). There was not a difference in DCPA between the give-way ship and stand-on ship, but a difference between day and night. Also, most navigators prefer to use maneuvering & shifting when avoiding collisions, and steering is 10-15°, shifting ±5knots, and the drift course was direction added stern of the obstacles to the direction of it. These results will facilitate in providing officers with standards for collision avoidance, and also apply to the development of AI and big data based unmanned ship collision avoidance algorithms.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.256-265
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• 2021

Ground, sea and air mobility, such as vehicles, ships, and airplanes, are generally operated by people. Based on the innovative development of autonomous decision-making systems and artificial intelligence (AI) following the recent fourth industrial revolution, research and development on maritime autonomous surface ships (MASS) is been actively performed around the world. Before the realization of the commercialization of MASS in international maritime transport, it is urgent to clarify the characteristics of this ship and its international legal status. This paper aims to analyze the concern of whether a ship without crew members will eventually be operated as a fully unmanned ship or can be recognized as a ship under international law as the number of crew members is gradually reduced owing to the development stage of autonomous ships. Consequently, based on the United Nations Convention on the Law of the Sea (UNCLOS) and the regulations of the International Maritime Organization (IMO), it was found that MASS has the same international legal status as general ships. In addition this paper presents the working principles of enacting and revising the IMO Conventions and international legal measures necessary for the safe operation of MASS.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.5
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• pp.645-661
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• 2012

Recently, pirates are infesting on the sea and they have been hijacking the several vessels for example Samho Dream and Samho Jewelry of Korea. One of the items to reduce the risk is to adopt the invader detection system. If the pirates break in to the ship, the detection system can monitor the pirates and then call the security alarm. The crew can gain time to hide to the safe room and the report can be automatically sent to the control room to cope with the situation. For the invader detection, an unmanned observation system was proposed using the image detection algorithm that extracts the invader image from the recording image. To detect the motion area, the difference value was calculated between the current image and the prior image of the invader, and the 'AND' operator was used in calculated image and edge line. The image noise was reduced based on the morphology operation and then the image was transformed into morphological information. Finally, a neural network model was applied to recognize the invader. In the experimental results, it was confirmed that the proposed approach can improve the performance of the recognition in the invader monitoring system.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.11
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• pp.1085-1091
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• 2014

This paper presents the guidance and control design for automatic carrier landing of a UAV (Unmanned Aerial Vehicle). Differently from automatic landing on a runway on the ground, the motion of a carrier deck is not fixed and affected by external factors such as ship movement and sea state. For this reason, robust guidance/control law is required for safe shipboard landing by taking the relative geometry between the UAV and the carrier deck into account. In this work, linear quadratic optimal controller and longitudinal/lateral trajectory tracking guidance algorithm are developed based on a linear UAV model. The feasibility of the proposed control scheme and guidance law for the carrier landing are verified via numerical simulations using X-Plane and Matlab/simulink.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.104-106
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• 2015

최근 인간의 개입을 최소화하면서 임무를 수행할 수 있는 무인항공기에 대한 활용도가 높아지는 가운데 무인선(Uamanned Maritime Vessel) 운용에 대한 관심도 높아지고 있다. 국내에서 무인선(Uamanned Maritime Vessel) 관련 프로젝트는 오염 방제 지원, 불법조업 감시, 조난자 수색 구조 등의 감시 및 구난 방제 지원 임무와 수로조사, 해양 기상 모니터링, 적조 감시 등 해양 조사 등을 목적으로 무인선(Uamanned Maritime Vessel)을 개발하는 중이다. 무인선은 관제센터(Maritime Control Station) 또는 모선을 통하여 원격 통제로 임무를 수행하게 되며, 이를 위하여 다양한 정보가 무선통신을 통하여 유인선-무인선, 무인선-무인선, 무인선-관제센터 간에 실시간으로 제공될 것으로 예상되어진다. 본 연구에서는 ITU-R Study Group Woking Party 5B를 분석한 후, 국내 개발 예정인 무인선(Uamanned Maritime Vessel) 운용을 위하여 요구되는 통신 서비스를 구분하여 정의 및 분류하고, 이를 바탕으로 데이터 전송속도, 트래픽 이용시간, 교통량을 바탕으로 필요한 주파수 산정을 위한 기초자료를 제공하는데 목적이 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.254-255
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• 2016

The Human have sought convenience through advancing Science skill, The Generation that unman control all machine have came. the unman - vehicle have used and applied flight, ship, car, manufacturing all over the world. plus which, that is researching. but pros and cons of unman - vehicle is that unman control machine, It mean that unman - vehicle have high possibility which have collision with obstacle on driving. I will show you that this evading collision will be made from fuzzy control and video recognition and sensor recognition.I look for good effect for this system.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.4
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• pp.225-234
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• 2022

The flow field measurement above whole area of the flight deck on 'Landing Platform Helicopter (LPH)' was performed by using PIV system in wind tunnel. In various heading angle conditions (0deg, -30deg, -45deg, -60deg, -75deg and ±90deg), the velocity fields such as U velocity & V velocity were measured at three different height above flight deck. Due to the geometrical characteristics of several bodies like deck, crane and super-structure, various vortex were generated. When the heading angle is 0deg, the deck edge vortex by flight deck and massive separation by super-structure were clearly observed by visualization with smoke and PIV, respectively. In other heading angles, the acceleration of flow in space between crane and super-structure were detected. And area with flow separation by super-structure is directly related to the heading angle of vessel.