• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.5
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• pp.552-567
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• 2017

The floating crane vessel in waves gives rise to the motion of the lifted object which is connected to the hoisting wire. The dynamic tension induced by the lifted object also affects the motion responses of the floating crane vessel in return. In this study, coupled motion responses of a floating crane vessel and a lifted subsea manifold during deep-water installation operations were investigated by both experiments and numerical calculations. A series of model tests for the deep-water lifting operation were performed at Ocean Engineering Basin of KRISO. For the model test, the vessel with a crane control system and a typical subsea manifold were examined. To validate the experimental results, a frequency-domain motion analysis method is applied. The coupled motion equations of the crane vessel and the lifted object are solved in the frequency domain with an additional linear stiffness matrix due to the hoisting wire. The hydrodynamic coefficients of the lifted object, which is a significant factor to affect the coupled dynamics, are estimated based on the perforation value of the structure and the CFD results. The discussions were made on three main points. First, the motion characteristics of the lifted object as well as the crane vessel were studied by comparing the calculation results. Second, the dynamic tension of the hoisting wire were evaluated under the various wave conditions. Final discussion was made on the effect of passive heave compensator on the motion and tension responses.

• International Journal of Naval Architecture and Ocean Engineering
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• v.13 no.1
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• pp.208-222
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• 2021

Managing with the presence of sea ice is the primary challenge in the operation of floating platforms in the Arctic region. It is widely accepted that offshore structures operating in Arctic conditions need station-keeping methods as well as ice management by icebreakers. Dynamic Positioning (DP) is one of the station-keeping methods that can provide mobility and flexibility in marine operations. The presence of sea ice generates complex external forces and moments acting on the vessel, which need to be counteracted by the DP system. In this paper, an icevaning control algorithm is proposed that enables Arctic offshore vessels to perform DP operations. The proposed icevaning control enables each vessel to be oriented toward the direction of the mean environmental force induced by ice drifting so as to improve the operational safety and reduce the overall thruster power consumption by having minimum external disturbances naturally. A mathematical model of an Arctic offshore vessel is summarized for the development of the new icevaning control algorithm. To determine the icevaning action of the Arctic offshore vessel without any measurements and estimation of ice conditions including ice drift, task and null space are defined in the vessel model, and the control law is formulated in the task space. A backstepping technique is utilized to handle the nonlinearity of the Arctic offshore vessel's dynamic model, and the Lyapunov stability theory is applied to guarantee the stability of the proposed icevaning control algorithm. Experiments are conducted in the ice tank of the Korea Research Institute of Ships and Ocean Engineering to demonstrate the feasibility of the proposed approach.

• The Journal of Information Technology
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• v.8 no.1
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• pp.95-112
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• 2005

This paper will look into the Main Substance and Some Problems of 24 hours Advance Cargo Manifest Declaration Rule, focuses on the Policy implication of Korea's and counter measures of our parties concerned about 24-hour advance vessel manifest rule. The 24-hour rule requires cargo owners to submit cargo manifest information to U.S. Customs 24 hours before vessel sailing from the final foreign port to a U.S. port. Cargo manifest information must be complete, accurate, and timely. As of February 2, 2003 manifest information can be submitted by paper or electronically. Cargo descriptions must be at a level of detail consistent with Harmonized Tariff Schedule (HTS) codes used by U.S. Customs. HTS codes are 10 digits. Electronic submissions are made via the Automated Manifest System (AMS) run by U.S. Customs.

• Journal of the Korean Society of Marine Environment & Safety
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• v.4 no.2
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• pp.53-62
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• 1998

International Maritime Organizatin(IMO) has been chosen some of agreements for regulating the international stability criteria of fishing vessels and recommended that each goverment adopts theirs into the domestic law. As a result, 77/93 Fishing Safety Agreement was ratified. Among the above agreement, contents of stability was not only applied to domestic law, but also strenghten considerably compared with existing stability criteria. And even if the calculation guide of stability with recommendations was regualted, Analysis of stability on domestic fishing vessels never have been used according to such a caculation method. Moreover, the caculation of stability criteria caused by strong wind, rolling effect and deck inflow was not considered in the existing basic design program. Therefore, the development of stability criteria program available for such a caculation has been of vital impotance. This research has developed a stability criteria program under 77/93 Fishing Safety Agreement. Also through development of stability criteria program, the stability performance of fishing vessel with 69ton stow-nesting was evaluated.

• Journal of the Korean Society of Marine Environment & Safety
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• v.2 no.S1
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• pp.53-73
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• 1996

Almost of all the impediments to enchancing ship safety and preventing vessel-source marine pollution arise from the interaction between direct and indirect factors. The direct factors come from human errores and failure in complince with the international convention standards for the operation of vessels. The indirect factors derive from the will and attitudes of the countries taking little responsibilities with appropriate seriousness for policing their fleets. By focusing in these aspects, this paper intends to propose a new international regime to improve the implementation capability of national maritime administration of each member government of IMO(International Maritime Organization).

• Journal of Korean Port Research
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• v.11 no.1
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• pp.129-137
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• 1997

The traditional approaches to determine the flag of convenience and second register of flagging-out in Korea international ship register and investigater and weakness of those approaches are revealed. A realistic approach to determine the paper company of shipping and sub-standard vessel of shipbuilding is suggested by introducing register factors obtained from Norwegian and Denish international ship register experiment for the new register.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.482-487
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• 2017

It is necessary to respond to criminal cases on board of pelagic fishing boats in the international waters with domestic legal judgement and international legal judgement due to a natural limitation by geographical long distance while it is possible to deal with domestic criminal cases with prompt response by using air crafts or patrol vessels. In other words, according to the flag of the vessel, the legal status of the water where is the crime scene, the nationalities of the victim and the perpetrator, it is required to judge if Korea can exert their jurisdiction and there is an issue if Korea Coast Guard exert their law enforcement effectively with this natural problem. In this paper, I propose a systemic improvement for a swift investigation for henceforth similar case's occurrence by analyzing the jurisdiction, the suspect's handling, the basic cause of the murder on-board which are based on the case of the vessel No.803 Gwang-Hyeon which was happened recently.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.15 no.4
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• pp.268-276
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• 2015

A ship's sailing route or plan is determined by the master as the decision maker of the vessel, and depends on the characteristics of the navigational environment and the conditions of the ship. The trajectory, which appears as a result of the ship's navigation, is monitored and stored by a Vessel Traffic Service center, and is used for an analysis of the ship's navigational pattern and risk assessment within a particular area. However, such an analysis is performed in the same manner, despite the different navigational environments between coastal areas and the harbor limits. The navigational environment within the harbor limits changes rapidly owing to construction of the port facilities, dredging operations, and so on. In this study, a support vector machine was used for processing and modeling the trajectory data. A K-fold cross-validation and a grid search were used for selecting the optimal parameters. A complicated traffic route similar to the circumstances of the harbor limits was constructed for a validation of the model. A group of vessels was composed, each vessel of which was given various speed and course changes along a specified route. As a result of the machine learning, the optimal route and voyage data model were obtained. Finally, the model was presented to Vessel Traffic Service operators to detect any anomalous vessel behaviors. Using the proposed data modeling method, we intend to support the decision-making of Vessel Traffic Service operators in terms of navigational patterns and their characteristics.

• International Journal of Control, Automation, and Systems
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• v.5 no.4
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• pp.456-462
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• 2007

Tracking error performance is investigated for the typical maneuvering pattern of the anti-ship missile for tracking filters based on IMM filter in both clear and cluttered environments. Threatening targets to a navel vessel can be categorized into having three kinds of maneuvering patterns such as Waver, Pop-Up, and High-Diver maneuvers, which are classified according to launching platform or acceleration input to be applied. In this paper, the tracking errors for three kinds of maneuvering targets are represented and are investigated through simulation results. Studying estimation errors for each maneuvering target allows us to have insight into the most threatening maneuvering pattern and to construct the test maneuvering scenario for radar system validation.

• Journal of the Society of Naval Architects of Korea
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• v.49 no.4
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• pp.327-332
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• 2012

International Towing Tank Conference (ITTC) recommended verifying a ship's ability to move transversely at zero forward speed without altering heading by a crabbing test. In sea trial, all available propellers/rudders/thrusters should be used to find the maximum possible transverse speed. For estimating crabbing ability in the design stage, tests to estimate possible swaying force and yawing moment range using all available propellers/rudders/thrusters are conducted. By butterfly diagram, which compares possible swaying force and yawing moment range with external swaying force and yawing moment by wind, a ship's crabbing ability can be estimated. In this study, model tests of a cruise vessel equipped with bow thrusters and POD system were conducted to find out her crabbing ability in the design stage. To mimic quay condition, a model quay-wall was set in the towing tank.