• International Journal of Naval Architecture and Ocean Engineering
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• v.7 no.3
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• pp.640-653
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• 2015

In order to develop the challenging process of placing Aids to Navigation (AtoN), we propose performance measures which quantifies the effect of such placement. The best placement of AtoNs is that from which the navigator can best recognize the information provided by an AtoN. The visibility of AtoNs depends mostly on light sources, the weather condition and the position of the navigator. Visual recognition is enabled by achieving adequate contrast between the AtoN light source and background light. Therefore, the performance measures can be formulated through the amount of differences between these two lights. For simplification, this approach is based on the values of the human factor suggested by International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). Performance measures for AtoN placement can be evaluated through AtoN Simulator, which has been being developed by KIOST/KRISO in Korea and has been launched by Korea National Research Program. Simulations for evaluation are carried out at waterway in Busan port in Korea.

• The Journal of the Acoustical Society of Korea
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• v.38 no.1
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• pp.96-105
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• 2019

Ocean reverberation is the most limiting factor in designing realistic and real-time system for sonar simulator. The simulation for an ocean reverberation requires a lot of computational loads, so it is hard to embed program and generate real-time signal in the sonar simulator. In this study, we simulate a time-domain bottom reverberation signal based on Harrison's energy-flux bottom reverberation model by applying Doppler effects as ship maneuvering and autoregressive model. Finally, the bottom reverberation signal with realistic characteristics could be generated for the simulation of ONR reverberation modeling workshop-I problem XI and East Sea ocean environments.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.1
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• pp.22-30
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• 2021

The ship wake generated by rotation of the propeller yields changes of characteristics of sound wave such as attenuation and scattering. To develope a battle field environment simulator for military purposes, it is very important to understand acoustical properties of ship wake. Existing research results have limitations in direct application because they performed under simple conditions or model ships were applied. In this study, we developed a ship wake generation model based on the ship's geometric wake distribution theory. The model can provide spatial distribution and void fraction with various marine environments as well as ship size. Through the developed model, geometric distribution features of ship wake according to the ship's maneuvering conditions were successfully simulated. In addition, changes of the bubble void fraction with time at any location within the battle field environment were identified. Therefore, the developed model is expected to be used in the development of a simulator to measure the acoustic characteristics of the ship wake.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1103-1109
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• 2021

ECS is a control device so that the warship can perform the mission stably by controlling and monitoring the entire propulsion system. As the recent provisions of the warship, it's propelling system is complicated than past, as the demand performance and mission of the warships are diverse. In accordance with the complicated propulsion system configuration, the demand for automatic control function of the ECS is increasing for convenient and stable propulsion system control for convenient and stable. As a result, verification of ECS stability and reliability is required. In this paper, we develop an interlocking signal simulator for verifying ECS control logic and communication protocol for warship with CODLOG propulsion systems. The simulator developed was implemented to simulate a signal of gas turbine, propulsion motors, diesel generator and 11 kinds of auxiliary equipment. The reliability of ECS was verified through the ECS communication program and the I/O signal static test with the simulator.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.8
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• pp.1268-1274
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• 2009

Various evaluation systems using simulators have been adopted widely for the purpose of training and examination, including marine engineering education area. This paper suggests a PC based evaluation scoring system for simulators where the operation ability of machineries and background knowledges of trainees or examinees are able to be assessed relatively. The scores are based on the 100 point resulted from their responses for a given evaluation scenario under a PID tuning simulation. The mistakes they make during the operation time are integrated firstly to get error sum, and the error sum is transformed secondly to 100 point score according to a formula where the knowledge level of examinee's groups can be compensated and considered reasonably. The implementation result of evaluation system for the given control loop is described and analyzed to show the effectiveness of the suggested configuration as an evaluation tool.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.480-486
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• 2012

There has been an increasing interest in new industry and demand creations by the convergence and integration between IT and infrastructure and BT, NT, and CT and the convergence of IT and spread of cloud computing have changed the IT service environment. Even in the educational field, the convergence and integration of contents with various IT have rapidly emerged and learning equipments for the educational purpose have expanded to the mobile media platform from PCs so that learning without limitations to time, place and equipment has become possible. Contents necessary for the smart education are under way by research development utilizing cyber reality and simulation, and 3D technologies. The purpose of this study is to propose marine contents use and service plans for the educational purpose in order to produce various types of contents for the marine life and environment, to improve the school achievement by stimulating interest and to provide individually customized learning.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.45-51
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• 2003

The ship's signal sound dispersed by air, obstacles, and noises due to absorption, reflection, and disturbances, respectively. It is one of the factors of marine casualties by misjudgment if receiving direction The last target of this study is to prevent inherent marine casualty using the analysis-evaluation techniques if the interferences of ship's signal sound. In this work, three-dimensional sound field control model is proposed to simulate various sound transmitting characteristics according to sea environments at sea The efficiency test of the model was carried out using VR-based ship simulator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.12
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• pp.1314-1317
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• 2014

In this letter, we designed monopole microstrip antenna for WLAN / WiMAX system. The monopole antenna is designed by FR-4 substrate with size is $30mm{\times}40mm$. The proposed antenna is based on a planar monopole design which cover WLAN and WiMAX frequency bands. To obtainthe optimized parameters, we used the simulator, CST's Microwave Studio Program and found the parameters that greatly effect antenna characteristics. Using the obtained parameters, the antenna is designed. Thus the proposed antenna satisfied the -10 dB impedance bandwidth requirement while simultaneously covering the WLAN and WiMAX bands. And characteristics of gain and radiation patterns are obtained for WLAN/WiMAX frequency bands.

• Proceedings of KOSOMES biannual meeting
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• 2004.11a
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• pp.49-56
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• 2004

It has been estimated that up to $80\%$ of all marine accidents have human elements as a cause. t of these, human elements of crew fatigue is main causes of marine accident. Crew fatigue involves sleep, schedule. workload. off-time. alcohol health and stress. With a ship handling simulator, the effect of alcohol on ship operational performance is studied for each 0.05 and $0.08g\%$ blood alcohol concentrations. A main effect for alcohol was found indicating that ship operational performance was significantly impaired by this alcohol relative to performance in the non-alcohol condition. The results of this research can be applied to minimize marine accidents as basic data.

• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.407-414
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• 2010

The fairway within the area of Yul-do and Songdo located near the Myeongnyang-sudo approaches south of Mokpo harbor is well guided by traffic separation scheme and other navigational aids. However, that part of the waterways where Yul-do is located sits at the cross-roads of marine traffic and is subjected to some potential risks in the voyage navigation: the effect of climatic phenomenon, the disregard of most ships in using the western sector of the fairway creating a congestion in the eastern sector, and lastly, the disadvantageous erect of the location and height of Yul-do island that hinders good lookout. This study investigates the environmental conditions that prevailed in the area in the span of 5-year period and the marine traffic situation taken from the data within the 72-hour period The navigational hazards and marine casualties are also be presented. The results are analyzed and are made the basis of a proposal for an improved separation of traffic. Thereafter, an evaluation is carried out by using the components of marine traffic flow simulation and ES modeling index. It is evaluated through simulation by the use of full-mission ship handling simulator.