• 한국항공운항학회지
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• 제10권1호
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• pp.35-44
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• 2002

Inertial Navigation System(INS) has been used in the field of air navigation for a long time but is not popular in general aviation due to high price. Recently low-price GPS is available but vulnerable to radio interference. As an alternative on these problems, GPS/INS integrated navigation system has been considered. GPS/INS is capable of implementing navigation with low-price inertial sensors but its accuracy is dependent upon how much drift of INS may be calibrated by using GPS. In order to apply GPS/INS to air navigation, it must be investigated how long drift of INS in case of no GPS aiding will be bounded within requirements for safe flight. From the above motivation, the flight test for GPS/INS navigation system was conducted in order to make sense its performance in air navigation and its result was shown.

• Journal of Positioning, Navigation, and Timing
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• 제12권3호
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• pp.289-294
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• 2023

As technologies such as cameras, Laser Imaging, Detection, and Ranging (LiDAR), and Global Navigation Satellite Systems (GNSS) become more sophisticated and common, their use in autonomous driving technologies is being explored in various fields. In the maritime area, technologies related to collision avoidance between ships are being developed to evaluate and avoid the risk of collision between ships by setting various scenarios. However, the position of each vessel used in the process of developing collision avoidance technology between vessels uses data obtained through GNSS, and may include a position error of 10 m or more depending on the situation. In this paper, a study on the dynamic safety navigation range including the positional inaccuracy of the ship is conducted. By combining the concept of the protection level obtained using GNSS raw data with a conventional safe navigation range, a safer navigation range can be calculated for dynamic navigation. The calculated range is verified using data obtained while sailing in an actual sea environment.

• 한국항해학회지
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• 제24권5호
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• pp.373-383
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• 2000

The ship’s safe mooring stability is a principles for the safe cargo handling works at the mooring berth. Today numerous standards, guidelines and recommendations concerning mooring practices, fittings and equipments exist throughout the worldwide maritime industries. In recently, the mooring facilities were constructed as dolphin types at the open sea area apart far from shoreside instead of enclosed coastline area in accordance with increasing ship’s size and for preventing environmental pollution. Therefore the exciting wave condition must be considered as a basic environmental criteria with the wind force and current force for all of the mooring ships at the sea berth facilities. In this study, this added wave force as one of the environmental external forces by using the theoretical formula was applied to the LNG ship in Pyeongtaeg harbor needed the special mooring stability of the sea berth. Through this research, it can be confirmed that wave force is the very important factor in the mooring force and the strength of wave force works much more in the full laden condition than in the lightship condition. And also the wave force changes to non-linear states according to the wave frequency and wave length. In addition, the maximum limit criteria of environmental force of prohibiting the entering ship on the berth and loading works controlled by the port authority concerned of Pyeongtaeg port fully satisfies the condition of the mooring limit force recommended by OCIMF that the safe permitted force of the mooring line have to be within 55 % of MBL.

• 로봇학회논문지
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• 제15권1호
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• pp.55-61
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• 2020

Getting on and off an elevator is one of the most important parts for multi-floor navigation of a mobile robot. In this study, we proposed the method for the pose recognition of elevator doors, safe path planning, and motion estimation of a robot using RGB-D sensors in order to safely get on and off the elevator. The accurate pose of the elevator doors is recognized using a particle filter algorithm. After the elevator door is open, the robot builds an occupancy grid map including the internal environments of the elevator to generate a safe path. The safe path prevents collision with obstacles in the elevator. While the robot gets on and off the elevator, the robot uses the optical flow algorithm of the floor image to detect the state that the robot cannot move due to an elevator door sill. The experimental results in various experiments show that the proposed method enables the robot to get on and off the elevator safely.

• 한국항해학회지
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• 제20권3호
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• pp.13-30
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• 1996

It is general that large ships entering or leaving a port located in the East coast of Korean peninsular are often exposed athwart to swell while maneuvering in the vicinity of breakwater at harbor enterance or to prevailing wind inside the port in winter. Particulary, Many VLCCs laden with ore coal are calling at Pohang Port, on account of which it is likely that one of those VLCCs block the port if they were to run aground in fairway due to adverse circumstance of swell, prevailing winds or improper shiphandling. This accident may result in delay of delivery of raw material for Pohang Steel Mill which will bring about shortcomings of steel products for nationwide relevant industries causing national economic shock. Therefore, This study basically aims at establishment of certain criteria for safe unberthing of VLCC in this port to prevent such unexpected disaster because any VLLC is highly affected by external forces when in ballast condition. Computer simulations are unavoidable to fulfull this study successfuly and many simulations have been carried out repeatedly to find a model of safe unberthing under various unfavourable wind conditions. The "PC-based ship maneuvering simulator for training purpose" was used to perform numerous simulations at the least economic burden and to verify its availability that it can be used not only for training but also some other purposes. purposes.

• 한국항해항만학회지
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• 제34권10호
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• pp.735-740
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• 2010

이 연구는 천수역에서 강한 바람과 조류하에 근접 항행중인 두 선박간의 상호유체력이 선박조종운동에 미치는 영향에 대해서 다룬다. 천수역에서 추월 및 피추월관계에 있는 대형선박의 조종운동은 바람, 조류 및 두 선박간의 상호유체력으로 인하여 상당히 복잡해진다. 이 연구의 목적은 안전항행을 위하여 천수역에서 강한 바람 및 조류하에 근접 항행중인 두 대형선박에게 요구되어지는 두 선박간의 속도에 따른 안전항과거리에 대해서 검토, 고찰하고자 한다.

• 한국항해학회지
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• 제20권2호
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• pp.15-32
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• 1996

The Internation Maritime Organization (IMO) has required that ships other than cellular-ships which carry cargo units and other entities should be provided with a cargo securing manual. A number of serious accidents has resulted from improper stowage and insufficient securing of heavy cargo. The cargo claims caused by the accidents stated above not only reduce the number of shippers but also reduce their benefits. The following four basic safe items should be considered carefully in the carriage by sea in case of two tiers loading of heavy cargoes packed with wooden case if it is a general cargo ship. a) Safe stowing place b) Safe lashing c) Protecting crushing goods d) Adequate dunnage. All operators of cargoes must be reminded that only the proper stowge and securing of heavy cargos can prevent from the occurrence of such accidents in the future. This paper intends to analyze the unigue damage mechanism for two tiers loading of heavy cargoes on the general cargo ships encountered in the rough sea, and suggest the countermeusere to prevent the identical accidents in the future.

• 한국항해항만학회지
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• 제37권1호
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• pp.55-61
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• 2013

In this paper, ship accidents are analyzed briefly and the main objective is to investigate a potential technological approach for risk assessment of vessel stability. Ship nonlinear motion equation and main parameters that induce ship capsizing in beam seas have analyzed, the survival probability of a ferry in random status have estimated and finally find out a risk assessment concept for ship's intact stability estimation by safe basin simulation method. Since a few main parameters are considered in the paper, it is expected to be more accurately for estimating ship survival probability when considering ship rolling initial condition and all other impact parameters in the future research.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제14권2호
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• pp.105-112
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• 2014

The International Maritime Organization has determined that more than 80% of maritime accidents are caused by human error. A variety of methods have been considered to reduce maritime accidents caused by such human error. Navigators operate by observing surrounding maritime situations and analyzing information using various navigational devices. This study proposes a system to ensure safe navigation by assisting navigators through the delivery of maritime safety information (MSI) between land and sea. In the future, supplementing the system through long-term on-the-ship tests is necessary by defining MSI in relation to maritime service portfolio regions.