• The Journal of the Acoustical Society of Korea
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• v.32 no.6
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• pp.472-483
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• 2013

Actual maritime exercise for improving the capability of submarine sonar operator leads to a lot of cost and constraints. Sonar simulator maximizes the capability of sonar operator and training effect by solving these problems and simulating a realistic battlefield environment. In this study, a passive sonar simulator algorithm is suggested, where the simulator is divided into three modules: maneuvering module, noise source module, and sound propagation module. Maneuvering module is implemented in three-dimensional coordinate system and time interval is set as the rate of vessel changing course. Noise source module consists of target noise, ocean ambient noise, and self noise. Target noise is divided into modulated/unmodulated and narrowband/broadband signals as their frequency characteristics, and they are applied to ship radiated noise level depending on the vessel tonnage and velocity. Ocean ambient noise is simulated depending on the wind noise considering the waveguide effect and other ambient noise. Self noise is also simulated for flow noise and insertion loss of sonar-dome. The sound propagation module is based on ray propagation, where summation of amplitude, phase, and time delay for each eigen-ray is multiplied by target noise in the frequency domain. Finally, simulated results based on various scenarios are in good agreement with generated noise in the real ocean.

• 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.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2008.04a
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• pp.117-122
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• 2008

본 연구에서는 수소 경제의 핵심 인프라 시설인 수소 충전소의 조업자 안전 운전을 위한 교육 및 훈련 프로그램을 구축하였으며, 개발된 프로그램은 크게 수소안전교육 모듈, 수소 충전소 가상체험 모듈, 가상 사고 시나리오 모듈로 구성되어 있다. 수소안전교육 모듈에서는 수소 사고의 특징과 안전 물성 등의 자료를 수록함으로써 수소에 안전에 대한 이해를 돕도록 하였으며, 가상체험 모듈에서는 충전소의 구성과 용도를 3D Virtual Reality 기술을 도입해 간접 체험할 수 있도록 하였다. 또한 가상사고 모듈에서는 수소 충전소에서 일어날 수 있는 사고에 대한 동적 모사를 수행하여 사고의 전개 과정 및 결과를 체험해 볼 수 있도록 하였다. 이와 함께 사고가 일어났을 경우 신속하고 정확한 대응을 통해 피해를 최소화하기 위한 ERP(Emergency Response Plan)과 SOP(Standard Operating Procedure)를 개발하였다.

• Journal of the Korea Institute of Military Science and Technology
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• v.15 no.1
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• pp.36-45
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• 2012

In this thesis, we propose an integrated simulation method of virtual tank simulators and an entity-based constructive simulation model for small unit tactical training. To do this, we first identify requirements for virtual-constructive integrated simulation in a synthetic environment. We then propose a virtual and constructive interoperation method where individual combat entities of virtual-constructive models are interacting with each others. We develop a method of aggregating individual combat entities into a larger combat unit and disaggregating an unit into entities from time to time. We also present a way of sharing synthetic environment information between the models. Finally, we suggest that for more effective interoperability, virtual and constructive models should be developed by using common combat object models. The proposed interoperation method can be extended to further live-virtual-constructive models.

• Proceedings of the KIEE Conference
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• summer
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• pp.339-341
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• 2004

전력 계통은 거대한 네트워크화되고 있으며, 전력계통을 신뢰성 있게 운용하는 것이 어려워지고 있다. 이에 따라 전력계통에 대한 숙련된 운전기술이 필요하게 되고, 실제 전력계통 모의를 통한 미경험 고장의 처리기술을 습득해야할 필요성이 생기게 되었다. 그러한 취지에서 각종 유틸리티는 운용자 지원 소프트웨어나 고장의 발생과 복구를 훈련할 수 있는 시뮬레이터를 대부분 구비하고 있다. 이러한 프로그램의 핵심적인 기능은 고장의 시나리오를 실제 계통에서 발생할 수 있는 고장으로 상정하고, 전문가 그룹에 의해 도출된 복구절차에 의해 복구 과정을 훈련하는 것이다. 전력계통이 복잡화되고 거대화됨에 따라 복구절차 또한 복잡화되고 있으므로 기존의 Case-by-case에 의해 복구절차를 생성하는데는 한계가 있다. 그러므로 본 연구에서는 Lex라는 구문분석기와 Yacc라는 파서를 이용하여 복구절차 생성시 복구 절차를 적절한 그룹을 만들고, 과 그룹을 통해서 조합 가능한 모든 복구 조작 순서를 생성하기 위한 그룹핑 알고리즘을 구현하고자한다.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.32 no.2
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• pp.11-19
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• 2024

Flight simulators are crucial devices for aircraft piloting training and simulation, requiring regular inspections to maintain performance and operational quality. This study explores the development of an automated inspection system for flight simulators to automate quality inspections of control loading systems (CLS). While quality inspection of the control loading system (CLS) is essential for flight simulators, manual inspections are common practice. To address this, we developed an Auto Qualification Test Guide (Auto QTG) using artificial control logic and sensor data and applied it to the militarily simulator. Experimental results demonstrate that Auto QTG successfully automates quality inspections of CLS, enhancing accuracy and efficiency. This automated inspection system is expected to contribute to improving the operation and maintenance of flight simulators.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.160-166
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• 2021

In this study, we aim to develop a scenario for educational utilization of disaster response robots that can be used at fire sites and analyze the effectiveness of scenarios according to robot utilization education. Our scenarios were developed based on direction, reality, and rationality determined through the use of a questionnaire survey distributed to current firefighters. In addition, the educational utilization of disaster response robots and training effectiveness were analyzed through repetitive robot control training by a robot development team, current firefighters, and college students. Robot control was divided into direct control, monitor control, and simulation control, and tests were carried out five times. As a result of the analysis of the robot control test, the average time spent for each group was 28 seconds for college students, followed by development teams (30second) and incumbent firefighters (38second). According to the individual analysis results, firefighters (maximum 35second) in direct control, the development team (maximum 14second) in monitor control, and firefighters (maximum 22second) in simulation control showed the effect of shortening control time. These results show that robot control education and training is necessary for robots to be used more effectively at disaster sites.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.6
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• pp.275-284
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• 2023

Virtual reality simulations are used for education and training in various fields, and are especially widely used in the medical field recently. The education/training simulator consists of tactile/force feedback generation and image/sound output hardware that provides a sense similar to a doctor's treatment of a real patient using real surgical tools, and software that produces realistic images and tactile feedback. Existing simulators are complicated and expensive because they have to use various types of hardware to simulate various surgical instruments used during surgery. In this paper, we propose a dental surgical simulation system using a force feedback device and a morphable haptic controller. Haptic hardware determines whether the surgical tool collides with the surgical site and provides a sense of resistance and vibration. In particular, haptic controllers that can be deformed, such as length changes and bending, can express various senses felt depending on the shape of various surgical tools. When the user manipulates the haptic feedback device, events such as movement of the haptic feedback device or button clicks are delivered to the simulation system, resulting in interaction between dental surgical tools and oral internal models, and thus haptic feedback is delivered to the haptic feedback device. Using these basic techniques, we provide a realistic training experience of impacted wisdom tooth extraction surgery, a representative dental surgery technique, in a virtual environment represented by sophisticated three-dimensional models.

• Journal of Korean Ophthalmic Optics Society
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• v.9 no.1
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• pp.1-9
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• 2004

In this study, we presented a research about the development of the phoropter simulation program for education using the 3-D virtual reality in order to study the ophthalmic optics rather efficiently. Especially, by putting the facility such as the refractive error analysis of the eyeball in the cyber tutor inside, we have made the learner to learn and confirm the present situation of refractive correction through refractive power of principal meridians. By organizing the system which induces the active involvement of the learner and showing the result of the execution to the learner intuitively, the implementation of the more efficient education-environment can be possible. Consequently, it is expected that this program will be greatly helpful for the optician training as well as the ophthalmic optics education. As a next phase of study, we will develope the development technique of this simulator more and extend the cyber tutor contents more and make the web service version of this program to be provided through the internet network in order to inspire the learning desire of the learner more and more.

• Journal of Korea Multimedia Society
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• v.11 no.8
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• pp.1146-1159
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• 2008

This paper proposes a method for determining material property of a haptic model which represents the haptic behavior of a target object. This paper also presents a haptic rendering framework. We adapt elastography to obtain the physical property of a target object. One of the key differences between the proposed framework and a traditional method is that the physical property of the target object can be easily set into a haptic model. For evaluating the proposed method, we construct a real-time palpation prototype simulator. In our work, a human liver is selected as a target object and the liver is represented by Shape-retaining Chain Linked Model(S-chain model) for satisfying the real-time performance. We conduct experiments whether a user easily distinguishes abnormal portions from normal portions. From the experimental results, we evaluate that the proposed method provides the discriminable force to users in real-time.