• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.52-54
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• 2018

울산신항 북방파제(제3공구)축조공사에서는 국내 최초로 선박제조용 F/D(Floating Dock)선을 적용하여 케이슨 제작 및 거치공사를 실시하였으며, 공장형 슬립폼 제작장(IP-CCV)를 적용한 경우 보다 공기단축 및 원가절감의 효과가 있었다. F/D선 공법 순서는 작업부두에 F/D선 접안, 케이슨 제작, F/D선 진수장 이동, F/D선 및 케이슨 진수, 케이슨 예인 및 거치의 순서로 시행되었으며, 현재 턴키공사의 설계특화 내용으로 활용되어 시공안정성 향상 및 공기, 공사비 절감 방안으로 적용되고 있다. 향후 남북관계가 원만히 해결되어 동해안 항만개발이 가속화되면 국외특허공법(IP-CCV)에 의존없이 경쟁력있는 공법이라 판단된다.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1275-1282
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• 2022

In this study, real-time character navigation using AR lens developed by Nreal is developed. Real-time character navigation is not possible with general marker-based AR because NPC characters must guide while moving in an unspecified space. To replace this, a markerless AR system was developed using Digital Twin technology. Existing markerless AR is operated based on hardware such as GPS, gyroscope, and magnetic sensor, so location accuracy is low and processing time in the system is long, resulting in low reliability in real-time AR environment. In order to solve this problem, using the SLAM technique to construct a space into a 3D object and to construct a markerless AR based on point location, AR can be implemented without any hardware intervention in a real-time AR environment. This real-time AR environment configuration made it possible to implement a navigation system using characters in tourist attractions such as Suncheon Bay Garden and Suncheon Drama Filming Site.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.245-246
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• 2017

본 연구에서는 선박 내 비상 상황을 대비한 가상훈련을 위한 선박 내 구조 구축 프레임워크를 개발하였다. 실제 환경과 가상 환경을 유사하게 제공함으로써 environment fidelity를 높이면 몰입감이 증대하여 가상훈련의 효과를 높일 수 있다. 이를 위해 스테레오 카메라 등을 이용한 raw한 스캔 데이터에 대해서 3가지 단계(Empyting, Smoothing, Refurnishing)를 통해 최종적으로 가상훈련에서 사용할 수 있는 형태의 가상환경을 얻을 수 있다. 본 프레임워크를 통해 가상 환경을 구축하고 구축된 가상 환경을 이용하여 실제 가상훈련을 수행하였다.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.251-256
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• 2013

This paper is mainly concerned with the ship-bank interaction by model test. The experiments for the characteristics of hydrodynamic interaction forces and moments between vessel and bank with a mound were carried out in the seakeeping and maneuvering basin. A series of tests were carried out with ship model in parallel course along a vertical sidewall with a mound with varying lateral spacing between model ship and sidewall, length of sidewall and water depth. From the experimental results, it indicated that the hydrodynamic interaction effects increase as length of sidewall with a mound increases. Furthermore, for lateral spacing less than about 0.2L between vessel and bank, it can be concluded that the bank effects increase largely as the lateral spacing between vessel and bank decreases. However, for spacing between vessel and bank more than about 0.3L, the interaction effects increase slowly as lateral spacing decreases. Also, for the water depth to draft ratio(h/d) less than about 1.5, the hydrodynamic interaction effects increase dramatically as h/d decreases.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.65-73
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• 2002

GPS in the United States and GLONASS of the old Soviet Union are used currently as satellite navigation systems. Plans are being made to use the Galileo satellite system in Europe, and these plans focus on a combined application of the satellite navigation systems. In this study, we examined the possibility of effective application of a combination of GPS/GLONASS in urban areas, where 3-dimensional positioning is impossible with GPS alone. We analyzed the 3-D coordinate deviation of a GLONASS satellite by integration interval and compared it with GLONASS satellite coordinates in precise ephmerides by transforming it into WGS84. We also programmed GPS/GLONASS, analyzed 3-D positioning accuracy by static surveying and kinematic surveying with Ashtech Z18 receivers and Legacy receivers, and then compared the results to those of GPS surveying. As a result, we are able to decide the integration interval for producing GLONASS satellite coordinates in navigation and geographical information and construct a GPS/GLONASS data processing system by developing a DGPS/DGLONASS positioning program. If more than four GLONASS satellites are observed, the accuracy of GPS/GLONASS is better than that of GPS positioning. As a result of kinematic surveying in a congested urban area with skyscrapers, we discovered that the GPS/LONASS combination is very effective.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.51-59
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• 2003

Marine Casualty Forecasting System (MCFS) is to broadcast the prediction number and risk level of marine casualties as like daily weather forecasting. The MCFS consists of marine casualty numerical D/B, prediction model and, three-dimensional statistics visualization system. The implementation procedure for the numerical D/B is described in the paper. The data relating to a total of 724 ship casualties in the west-southern sea area (latitude 33$^{\circ}$N∼35$^{\circ}$ and longitude 124$^{\circ}$E∼127$^{\circ}$E) of Korean peninsula for 11 years (1999∼2000) have been compiled. The analysis method of numerical D/B is proposed and discussed its usability.

• Journal of Positioning, Navigation, and Timing
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• v.1 no.1
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• pp.35-43
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• 2012

The UGV is one of the special field robot developed for mine detection, surveillance and transportation. To achieve successfully the missions of the UGV, the accurate and reliable navigation data should be provided. This paper presents design and implementation of multi-sensor-based open architecture integrated navigation for localization of UGV. The presented architecture hierarchically classifies the integrated system into four layers and data communications between layers are based on the distributed object oriented middleware. The navigation manager determines the navigation mode with the QoS information of each navigation sensor and the integrated filter performs the navigation mode-based data fusion in the filtering process. Also, all navigation variables including the filter parameters and QoS of navigation data can be modified in GUI and consequently, the user can operate the integrated navigation system more usefully. The conventional GPS/INS integrated system does not guarantee the long-term reliability of localization when GPS solution is not available by signal blockage and intentional jamming in outdoor environment. The presented integration algorithm, however, based on the adaptive federated filter structure with FDI algorithm can integrate effectively the output of multi-sensor such as 3D LADAR, vision, odometer, magnetic compass and zero velocity to enhance the accuracy of localization result in the case that GPS is unavailable. The field test was carried out with the UGV and the test results show that the presented integrated navigation system can provide more robust and accurate localization performance than the conventional GPS/INS integrated system in outdoor environments.

• 한국HCI학회:학술대회논문집
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• 2008.02a
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• pp.200-204
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• 2008

In this paper, to solve localization problem for out-door navigation of robotic vehicles, a particle filter based 3D object recognition framework that can estimate the pose of a building or its entrance is presented. A particle filter framework of multiple evidence fusion and model matching in a sequence of images is presented for robust recognition and pose estimation of 3D objects. The proposed approach features 1) the automatic selection and collection of an optimal set of evidences 2) the derivation of multiple interpretations, as particles representing possible object poses in 3D space, and the assignment of their probabilities based on matching the object model with evidences, and 3) the particle filtering of interpretations in time with the additional evidences obtained from a sequence of images. The proposed approach has been validated by the stereo-camera based experimentation of 3D object recognition and pose estimation, where a combination of photometric and geometric features are used for evidences.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.715-718
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• 2005

Mobile devices is getting to include more functions according to the demand of digital convergence. Applications based on 3D graphic calculation such as 3D games and navigation are one of the functions. 3D graphic calculation requires heavy calculation. Therefore, we need dedicated 3D graphic hardware unit with high performance. 3D graphic calculation needs a lot of complicated floating-point arithmetic operation. However, most of current mobile 3D graphics processors do not have efficient architecture for mobile devices because they are based on those for conventional computer systems. In this paper, we propose arithmetic units for special functions of lighting operation of 3D graphics. Transcendental arithmetic units are designed using approximation of logarithm function. Special function units for lighting operation such as reciprocal, square root, reciprocal of square root, and power can be obtained. The proposed arithmetic unit has lower error rate and smaller silicon area than conventional arithmetic architecture.

• Journal of Navigation and Port Research
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• v.44 no.2
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• pp.65-72
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• 2020

Mankind has been using ships for more than 5,000 years and has developed a range of related technologies. However, despite such a long history, compared to aircraft with a history of approximately one century, the pace of progress has been markedly slow. Even though technological progress of ships or the installation of various navigation equipment have been achieved, seaborne collisions have occurred quite frequently. This study analyzed the TCAS( Traffic Collision Avoidance System) that has contributed to the prevention of collisions with other transport methods including aircraft to suggest a collision avoidance system that can be deployed for ships. To apply the technologies applied to aircraft that move in 3D to ships that move in 2D, the difference in the operational environment between the two modes was analyzed to identify elements that need to be applied to ships. The suggested display of data on the collision prevention system is one that manipulates the augmented reality display device used in automobiles that over the past few years has undergone rapid development. Based on the presentation of technological elements that need to be considered when adopting the SCAS or the Seaborne Collision Avoidance System as suggested in this study, the authors hope to contribute to the prevention of collisions.