• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.4
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• pp.471-478
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• 2014

Navy forces of ROK asked for more than 90% operational availability in the requirement document of combat ship. This study proposes the evaluation methodology of operational availability with the evaluation process, calculation formula, analysis of operational test data. As the case study, the developed methodology is proved to apply for 00 batch-I naval ship using the data to be acquired during the operational test period. The operational availability by test data was 90.03%, and it was satisfied with objective value 90%. The paper will contribute not only to establish the evaluation methodology of operational availability for combat ship but also other general weapon system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.149-150
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• 2022

External forces acting on the mooring facilities include wave, wind, current, and ship's kinetic energy. In particular, the ship's kinetic energy is changing as the ship become larger, and larger carrying capacity. It was intended to analyze the berthing velocity measurement data at on tanker terminals equipped with a DAS (Docking Aid System) through statistical means and algorithms and use it as basic data for safer and more efficient pier design and pilotage.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.89-97
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• 2010

The ship-borne gravity data is essential to construct geoid in Korea surrounding ocean area. The altimeter data was used in previous study, however, the ship-borne gravity data could be used due to more ship-borne data was collected by improvement of instrument, positioning system. Therefore, the study on verification of precision of ship-borne gravity data and practical usage analysis is needed. In this study, free-air anomaly having 16.47mGal and 18.86mGal as mean and standard deviation was obtained after consistent processing such as Eotvos correction, Kalman Filter, Cross-over adjustment etc. The calculated free-air anomaly was compared to DNSC08 altimeter data and the difference was computed having -0.88mGal and 9.46mGal of mean and standard deviation. The reason causing those differences are owing to spatial limits of data acquisition and effects of ocean topography. To use ship-borne gravity data for precision geoid development, the efforts to overcome the limits of data collection and study for data combination should be proceeded.

• Korean Journal of Computational Design and Engineering
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• v.16 no.3
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• pp.227-235
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• 2011

Ship handling simulator should have capabilities of calculating ship motions (heave, pitch, and roll) at given sea state and displaying the calculated motions through a real-time 3D visualization system. Motion solver of a ship handling simulator generally calculates those motions in addition to position for an own ship, a main simulation target, but provides only position information for traffic ships. Therefore, it is required to simulate real-time traffic ship and buoy motions coupled with ocean waves in a ship handling simulator for the realistic visualization. In the paper, the authors propose a simple dynamics model by which ship and buoy motions are calculated with the input data of wave height and discuss a method for the implementation of a ship and buoy motions calculation module.

• Journal of Navigation and Port Research
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• v.34 no.2
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• pp.105-110
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• 2010

The studies on automatic ship collision avoidance system, which have been carried out in the last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation field 3-4 years ago because of the absence of any tool to give other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the automatic ship collision avoidance support system which considers ship's manoeuvrability into it's collision avoidance algorithm. One of the important part in ship collision avoidance system is collision decision module which can calculate collision risk with other ships and act properly to avoid the situation. Many of previous researches are using present ship's dynamic data such as present speed, position and course to calculate collision risk. However when a ship commences avoidance action, the real situation is quite different with one that has been estimated by the ship's initial data due to the ship's manoeuvring characteristic. Therefore it is better to take into account ship's manoeuvring characteristic from the stage of collision decision in ship collision avoidance system. In this study, these effects are included in the developed system. The proposed system are verified its usefulness in numerical simulation environments.

• Korean Journal of Computational Design and Engineering
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• v.16 no.3
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• pp.187-196
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• 2011

Generally, BOM (Bill of Material) means a part list which is needed to manufacture or assemble a product or part. During manufacturing processes, BOM is inevitably required for most of enterprise processes such as design, procurement, production planning/control, resource planning, and financial works. Every manufacturing industry uses many kinds of BOM's that are adjusted to the requirement of functions of their work division. Moreover, BOM evolves in different forms according to the product development phases such as conceptual design; function design, detail design, and production design because it is necessary to use different product structures to keep product data generated throughout the lifecycle of a product. This includes all data and information related to the all the product development phases. Shipbuilding works also are processed and controlled based on BOM. However, effective maintenance of ship outfitting BOM data is getting difficult as the amount and complexity of data have increased due to variety and long lifecycle of ship. For the effective management of outfitting BOM data, two aspects must be considered. One is how to classify numerous BOMs type and the others how to display BOMs. So this study suggests a method to classify BOM types and propose two categories - Structure BOM, Display BOM. Base on this result, we propose the integrated ship outfitting BOMs model and analysis outfitting BOMs.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.312-315
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• 2003

The paper presents a small. unmanned remote controlled probing ship that can reduce the cost for acquiring data of marine and coastal environments. The control system is composed of three microprocessors. one is for overall mission control. another for control of propulsion motors. and the other for sensor operation. For communication system, we adopt direct and indirect methods based on the wireless modem of commercial cellular telephone. The former is a direct communication between the modems of the ship and the server. and the latter is an indirect communication via internet between the ship and the server. The system is equipped with a digital compass and a GPS system for position estimation, and extended Kalman filter is used for the data association. The performance of the ship is demonstrated with the results produced by sets of experiments.

• Journal of Ocean Engineering and Technology
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• v.37 no.5
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• pp.198-204
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• 2023

In response to the complexity and time demands of conventional methods for estimating the hydrodynamic coefficients, this study aims to revolutionize ship maneuvering analysis by utilizing automatic identification system (AIS) data and the Support Vector Regression (SVR) algorithm. The AIS data were collected and processed to remove outliers and impute missing values. The rate of turn (ROT), speed over ground (SOG), course over ground (COG) and heading (HDG) in AIS data were used to calculate the rudder angle and ship velocity components, which were then used as training data for a regression model. The accuracy and efficiency of the algorithm were validated by comparing SVR-based estimated hydrodynamic coefficients and the original hydrodynamic coefficients of the Mariner class vessel. The validated SVR algorithm was then applied to estimate the hydrodynamic coefficients for real ships using AIS data. The turning circle test wassimulated from calculated hydrodynamic coefficients and compared with the AIS data. The research results demonstrate the effectiveness of the SVR model in accurately estimating the hydrodynamic coefficients from the AIS data. In conclusion, this study proposes the viability of employing SVR model and AIS data for accurately estimating the hydrodynamic coefficients. It offers a practical approach to ship maneuvering prediction and control in the maritime industry.

• Journal of the military operations research society of Korea
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• v.12 no.1
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• pp.78-86
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• 1986

This paper analyzes how a shipowner or charterer may determine the specification of optimal ship size for a given route with respect to certain market requirements. The theory of optimal ship size, a methodology for estimating scale economics, and the various factors affecting ship size are examined using a typical conventional cargo ship and bulk cargo carriers based on shipowners' cost data.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.5
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• pp.379-384
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• 2013

For effective ship management in VTS(Vessel Traffic Service), it needs to assess the external force acting on ship. Big data in maritime traffic can be roughly categorized into two groups. One is the traffic information including ship's particulars. The other is the external force information e.g., wind, sea wave, tidal current. This paper proposes the method to assess the external force acting on ship using big data in maritime traffic. To approach Big data in maritime traffic, we propose the Waterway External Force Code(WEF code) which consist of wind, wave, tidal and current information, Speed Over the Water(SOW) of each ship, weather information. As a results, the external force acting a navigating ship is estimated.