• International Journal of Naval Architecture and Ocean Engineering
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• v.8 no.5
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• pp.423-433
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• 2016

In this paper, we consider the cybersecurity issue of ship information system (SIS) from a new perspective which is called opacity. For a SIS, its confidential information (named as "secret") may be leaked through the working behaviors of each Distributed Control Unit (DCU) from an outside observer called an "intruder" which is able to determine ship's mission state by detecting the source of each data flow from the corresponding DCUs in SIS. Therefore we proposed a dual layer mechanism to enforce opacity by activating non-essential DCU during secret mission. This mechanism is calculated by two types of insertion functions: Safety-assured insertion function ($f_{IS}$) and Admissibility-assured insertion function ($f_{IA}$). Due to different objectives, $f_{IS}$ is designed to confuse intruder by constructing a non-secret behaviors from a unsafe one, and the division of $f_{IA}$ is to polish the modified output behaviors back to normal. We define the property of "$I_2$-Enforceability" that dual layer insertion functions has the ability to enforce opacity. By a given mission map of SIS and the marked secret missions, we propose an algorithm to select $f_{IS}$ and compute its matchable $f_{IA}$ and then the DCUs which should be activated to release non-essential data flow in each step is calculable.

• Journal of the Society of Naval Architects of Korea
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• v.40 no.6
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• pp.58-68
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• 2003

Despite the availability of 3D CAD systems, the designers in shipyards still use 2D CAD systems because of the need to produce drawings rapidly and a shortage of labor. The design information of ship structure contained in 2D drawings is represented by symbols that are well known among designers in shipyard. The shapes of symbols are recognized by analysis of experienced and knowledgeable designers. We propose a method for automatic recognition of 2D symbols and extraction of design information from the midship drawings. The shape and rationale of 20 symbols used in ship design have been analyzed, and symbols have been classified according to the analysis. Based on the classified symbols, the developed system recognizes the symbols expressed in 2D drawings. The meaningless geometric shape is translated into the design information including designer's intents. The extracted design data can be applied to the downstream design process in shipyards, and the 3D ship model can be automatically created.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.6
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• pp.473-481
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• 2023

In this study, a simulation system was developed to verify autonomous navigation algorithm in complex maritime traffic areas. In particular, real-world maritime traffic scenario was applied by considering near real-time maritime traffic information provided by Korean e-Navigation service. For this, a navigation simulation system of Unmanned Surface Vehicle (USV) was integrated with an e-Navigation equipment, called Electronic Chart System (ECS). To verify autonomous navigation algorithm in the simulation system, initial conditions including initial position of an own ship and a set of paths for the ship to follow are assigned by an operator. Then, considering real-world maritime traffic information obtained from the service, the simulation is implemented in which the ship repeatedly travels by avoiding surrounding obstacles (e.g., approaching ships). In this paper, the developed simulation system and its application on verification of the autonomous navigation algorithm in complex maritime traffic areas are introduced.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.6
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• pp.745-751
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• 2013

In naval gun firing, firing accuracy comes from the combination of each component's accuracy in CFCS (Command and Fire Control System) like tracking sensors and gun. Generally, battery alignment is done to correct the error between gun and tracking sensor by using boresight telescope on harbor and sea. But normally, the battery alignment can compensate only the static alignment error and ignore dynamic alignment error which is caused by own ship movement. There was no research on this dynamic alignment error until now. We propose a new way to analyze dynamic arrangement error by using image of boresight telescope. In case of the dynamic alignment error was due to time delay of own ship attitude information, we propose the way to compensate it.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.62-65
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• 2022

NCS(Naval Combat System) is a system that maximizes the combat effectiveness for the naval ships by providing track detection, tracking, thereat analysis, engagement, hit assessment and many other capabilities using ship integrated heterogeneous sensor and weapon systems. In order to achieve the purpose of the NCS, every crew is require to be proficient in the operation of NCS. In accordance with the goal, NCS provides a onboard training function, and the crew conducts system operation proficiency and teamwork training on the ship. Training instructors for control training should have a high standard of training environment control and monitoring capabilities, which need to be studied. This paper studies a 3D display method for visualizing the training situation of training instructors.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.3
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• pp.130-140
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• 2024

In this paper, we present a method of applying the kalman filter to control and correct errors in camera sensor recognition depending on the sea state environment. First, the specifications of the ship were described and the degree of error due to rolling was measured. After presenting the distance from the surface of the water to the sidelight required for simulation through PKMR-211, the ship selected as the model, error correction was performed using the camera error value as a variable in the feedback control system. In the experiment, the degree of rolling of the ship was expressed as variables 𝛼 and 𝛽, expressed in angles, and the angle change according to distance was compared. When comparing the error before and after applying the kalman filter in sea state 4, it decreased from +1.5556° to -1.1544° in red light regardless of distance, and the same result was confirmed in green light. Through this, calculations were performed considering the movement of the ship according to the maritime environment, and the future maneuverability of the ship was presented after error correction.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.5
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• pp.388-395
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• 2014

This paper presents a method that generates alternatives of spatial arrangement for naval ships with limited information. To attain this end, GA (General Arrangement) methodology and GA reports of existing naval ships are analyzed. In order to improve the current naval ship spatial arrangement method that relies on the experience and know-hows of designers, we propose a systematic spatial arrangement process using SLP (Systematic Layout Planning), which determines relative positions of the components by analyzing relationships among them. The proposed method, along with the GA process, is applied to a virtual naval ship and layout alternatives are generated to verify usefulness of the method.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.10a
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• pp.272-276
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• 2003

In this paper, current application of VR in naval architecture and ocean eng. Design is surveyed and VR process is implemented in ship navigation system. So far, very sophisticated VR applications have announced but not published yet. The reason not published may be that the application is for the navy ship of which the information could not be opened to the public. Also there is another area implementing Simulation Based Design, i..e., visualization of the integration process from initial design to the manufacturing. Herein, the tendency of VR in this area is surveyed, so the international application of VR is introduced. Trough the analysis the most appropriate applicability of VR in this area can be distinguished. And to show the application, ship navigation VR is programmed using OpenGL graphics software.

• Journal of the Korea Society of Computer and Information
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• v.28 no.11
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• pp.125-134
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• 2023

In this paper, we propose an efficient surveillance RADAR(RAdio Detection And Ranging) interface control unit(ICU) design in the naval combat system. The proposed design applied a standardized architecture for modules that can be shared in ship combat system software. An error detection function for each link was implemented to increase the recognition speed of disconnection. Messages that used to be sent periodically for human-computer interaction(HCI) are now only transmitted when there is a change in the datagram. This can reduce the processing load of the console. The proposed design supplements the radar with the waterfall scope and time-limited splash recognition in relation to the hit check and zeroing of the shot when the radar processing ability is low due to the adoption of a low-cost commercial radar in the ship. Therefore, it is easy for the operator to determine whether the shot is hit or not, the probability of wrong recognition can be reduced, and the radar's resources can be obtained more effectively.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.8
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• pp.91-98
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• 2010

The Korean navy has been using the ICS(Integrated Communication System) to transfer a command, control and information on the naval ship. The major equipment for the ICS has been imported from abroad, so that there were some problems such as lack of logistics support, leaking military secrets. This paper describes considerations for the development and the key technology of the domestic ICS which is developed to solve the problems mentioned above and to integrate various future communication elements on the naval ship.