• Korean Journal of Remote Sensing
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• v.34 no.5
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• pp.801-810
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• 2018

Ship monitoring using satellite synthetic aperture radar (SAR) images consists of ship detection, ship discrimination, and ship classification. A large number of methods have been proposed to improve the detection and discrimination capabilities, while only a few studies exist for ship classification. Thus, many studies for the ship classification are needed to construct ship monitoring system having high performance. Note that constructing database (DB), which contains both SAR images and labels of various ships, is important for research on the ship classification. In the airborne SAR classification, many methods have been developed using moving and stationary target acquisition and recognition (MSTAR) DB. However, there has been no publicly available DB for research on the ship classification using satellite SAR images. Recently, Shanghai Key Laboratory has constructed OpenSARShip DB using both SAR images of various ships generated from Sentinel-1 satellite of European Space Agency (ESA) and automatic identification system (AIS) information. Thus, the applicability of OpenSARShip DB for ship classification should be investigated by using the concepts of airborne SAR classification which have shown high performances. In this study, ship classification using satellite SAR images are conducted by applying the concepts of airborne SAR classification to OpenSARShip DB, and then the applicability of OpenSARShip DB is investigated by analyzing the classification performances.

• Journal of Mechanical Science and Technology
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• v.18 no.11
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• pp.1923-1931
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• 2004

Manufacturing of complex surface plates in stern and stem is a major factor in cost of a preliminary ship design by computing process. If these hull plate parts are effectively classified, it helps to compute the processing cost and find the way to cut-down the processing cost. This paper presents a new method to classify surface plates effectively in the preliminary ship design using neural network. A neural-network-based ship hull plate classification program was developed and tested for the automatic classification of ship design. The input variables are regarded as Gaussian curvature distributions on the plate. Various applicable rules of network topology are applied in the ship design. In automation of hull plate classification, two different numbers of input variables are used. By observing the results of the proposed method, the effectiveness of the proposed method is discussed. As a result, high prediction rate was achieved in the ship design. Accordingly, to the initial design stage, the ship hull plate classification program can be used to predict the ship production cost. And the proposed method will contribute to reduce the production cost of ship.

• Ocean Systems Engineering
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• v.4 no.1
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• pp.53-62
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• 2014

The detection of ship wakes image can demonstrate substantial information regarding on a ship, such as its tonnage, type, direction, and speed of movement. Consequently, the wake target recognition is a favorable way for ship identification. This paper proposes a Local Binary Pattern (LBP) approach to extract image features (wakes) for training an Improved Back Propagation Artificial Neural Network (IBPANN) to identify ship speed. This method is applied to sort and recognize the ship wakes of five different speeds images, the result shows that the detection accuracy is satisfied as expected, the average correctness rates of wakes target recognition at the five speeds may be achieved over 80%. Specifically, the lower ship's speed, the better accurate rate, sometimes it's accuracy could be close to 100%. In addition, one significant feature of this method is that it can receive a higher recognition rate than the nearest neighbor classification method.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.663-666
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• 2004

An analysis of the annual frequency of collapse(AF) is performed for each bridge pier exposed to ship collision. AF is computed for each bridge component and vessel classification. The summation of AFs computed over all of the vessel classification intervals for a specific component should equal the annual frequency of collapse of the component. The designer should use judgment in developing a distribution of the vessel frequency data based on discrete groupings or categories of vessel size by DWT. In the present study the effect of vessel classification on the annual frequency of collapse in the ship collision risk assessment is investigated by illustrative numerical examples based on the vessel frequency data of the domestic harbor. The DWT interval for larger vessels has more effect on the ship collision risk. Therefore the expert judgement in determining the larger DWT interval is required because the design impact lateral resistances of bridge components depend on the ship collision risk.

• Korean Journal of Remote Sensing
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• v.38 no.4
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• pp.435-446
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• 2022

Identifying ship types is an important process to prevent illegal activities on territorial waters and assess marine traffic of Vessel Traffic Services Officer (VTSO). However, the Terrestrial Automatic Identification System (T-AIS) collected at the ground station has over 50% of vessels that do not contain the ship type information. Therefore, this study proposes a method of identifying ship types through the Random Forest Classifier (RFC) from dynamic and static data of AIS and V-Pass for one year and the Ulsan waters. With the hypothesis that six features, the speed, course, length, breadth, time, and location, enable to estimate of the ship type, four classification models were generated depending on length or breadth information since 81.9% of ships fully contain the two information. The accuracy were average 96.4% and 77.4% in the presence and absence of size information. The result shows that the proposed method is adaptable to identifying ship types.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.4
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• pp.361-369
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• 2018

The ship surveyor makes a scheme of reasonable ship operation by examining whether the ship has been properly constructed in accordance with the rule of classification societies and international conventions or whether the facilities of the ship in operation meet the standard stipulated by law. Even though the ship surveyors of classification society generally consist of people who have the skill of design or operation of a ship, it takes a long time to train a surveyor to the maturity level. This paper describes the development of survey simulator based on virtual ship environment that enables the surveyor minimize trial and errors to survey the ships. By using VR(Virtual Reality) based survey simulator, surveyors possibly achieve improvement of competence in survey quality by means of safe and immersive training environment. In order to improve the usability and utility of the VR simulator, the ship 3D model has been generated using 3D CAD model for design and production in shipyard. Through this, we suggested the possibility of consistent use of 3D model as the digital twin of a ship.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.3
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• pp.777-784
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• 1994

A design expert system for the ship structural design is developed to support inexperienced designers. To establish the knowledge-base, an expert system development shell, Nexpert, is used. Knowledge is extracted from the rules of a classification society of ships, and also from an existing ship structural program that is being used by ship designers. This knowledge is systematized using the objectoriented concept. The design support system is constructed by adding additional functions which are required for the conventional engineering design work. Added functions are; calculation of longitudinal strength, database of existing ship designs, graphical user interface, and visualization of design results. It is observed that visualizing the relationships among the rules, which are activated to draw a certain design decision, is helpful. The system can easily be updated according to changes of the rule books of ship classification societies.

• Korean Journal of Computational Design and Engineering
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• v.8 no.2
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• pp.122-132
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• 2003

STEP AP218 has a standard schema to represent the structural model of a midship section. While it helps to exchange ship structural models among heterogeneous automation systems, most shipyards and classification societies still exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a QUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP2l8 model, we have developed a shape generation library, and generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.

• Journal of Ocean Engineering and Technology
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• v.14 no.3
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• pp.100-105
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• 2000

Port State Control (PSC) is the inspection of foreign ships in national ports for the purpose of verifying that the condition of the ships and its equipments comply with the requirement of international conventions and the ship is manned and operated in compliance with applicable international laws. On the other hand, check items in PSC are nearly similar to periodical survey of Classification Societies, because they have the same background regarding safety and maritime pollution prevention. The purpose of this study is to develope computer-aided information system for ship inspection item which is useful for effective implementation of Port State Control. For this work, the status of PSC is reviewed, and the related scheme of ship survey system in Classification Societies is investigated. On these bases, a computer software integrated database system and object-oriented technique is developed. The developed system is expected helpful to establish and maintain an effective system of Port State Control.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2000.10a
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• pp.165-170
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• 2000

Port State Control (PSC) is the inspection of foreign ships in national ports for the purpose of verifying th\ulcorner the condition of the ships and its equipments comply with the requirement of international conventions and the ship is manned and operated in compliance with applicable international laws. On the other hand, check items in PSC are nearly similar to periodical survey of Classification Societies, because they have the same background regarding safety and maritime pollution prevention. The purpose of this study is to develope computer-aided information systems for ship inspection item which is useful for effective implementation of Port State Control. For this work, the status of PSC is reviewed, and the related scheme of ship survey system in Classification Societies is investigated. On these bases, a computer software integrated database system and object-oriented technique is developed. The developed system is expected helpful to establish and maintain an effective system of Port State Control.