• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.121-129
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• 2012

Any development plan of a Korean space-based navigational system has been neither designed nor introduced yet. However, the demand for the development of a domestic regional satellite navigation system can be originated from the outside of market. The growing dependency on satellite navigational systems in Korea eventually requires the retainment and the operation of a domestic navigational satellite system. There is not many choices on the orbit designs and the system design concepts of a regional augmented navigation satellite system or a regional navigation satellite system for the service on the vicinity of the Korean peninsular. Space situational awareness (SSA) has been a rising issue for both national security and more realistic space business in Korea. Also SSA related technologies in Korea is a newly inaugurated area and is necessary to generate a navigation messages and maintain a future Korean navigation satellite system. In this study, the availability of Japanese Quasi Zenith Satellite System (QZSS) expected to be deployed definitely sooner than Korean counter-part is analyzed. The availability of the similar configured system over Korea is investigated with assumed QZSS type orbit. Also, feasible configuration of orbits for domestic navigation satellite system is suggested. And the observability of a ground-based optical tracking system as a secondary tracking capability is analyzed.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.468-483
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• 2001

In order to enhance the performance, cursor stability, which is a variant of isolation lvel 2 in relational DBMSs, has been widely used in place of isolation level 3, which uses strict two phase locking. However, cursor stability is much less usable in object-relational DBMSs (ORDBMSs) because navigational applications in ORDBMSs can suffer from critical inconsistency problems such as dangling pointers, lost updates, and reading inconsistent complex objects. In this paper, we propose a new isolation level, navigation stability, that prevents the inconsistency problems of cursor stability for navigational applications, while avoiding significant degradation of the concurrency of level 3. First, we analyze the inconsistency problems of cursor stability for navigational applications. Second, we define navigation stability as an extension of cursor stability and show that it solves those inconsistency problems of cursor stability in ORDBMSs. For workloads consisting of transactions of long duration, compared with level 3, the throughput of navigation stability is enhanced by up to 200%; the average response time reduced by as much as 55%; and the abort ratio reduced by as much as 77%. From these results, we conclude that navigation stability is a useful isolation level in ORDBMSs that can be used in place of isolation level 3 to improve the performance and concurrency without significantly sacrificing consistency.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.103-109
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• 2005

At the adjacent sea area of Busan Central Wharf, a variety of vessels, such as middle-large passenger ships, small fast sailing ships, container ships, cargo ships and working ships as well as small miscellaneous vessels are freely sailing comparatively without special steering and sailing Rules and marine traffic control because exclusive wharfs in accord with their purpose and use have been arranged in each wharf. In this research, we analyzed traffic stream and navigational characteristics of main traffic route based on statistics and distribution of tracks by ship's type and tonnage of the passing vessels after conducting marine traffic survey twice using exclusive software by targeting the sea area during the period of time. We examined the traffic safety of the passing vessels by classifying the sea area by each function based on the analysis about this traffic situation, and analyzing the effect by designating 'Buknea passage'. We also studied the plan for the effective rearrangement of Central Wharf considering basically the traffic safety oif arrival and departure in a point if view of navigators.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.111-116
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• 2005

The approaching waters of Po-hang port will be increased the traffic volume and passage of larger vessel according to the opening of Young-il new port in 2006. But the adjacent area of Po-hang port still exist the danger elements of safe navigation, the disordered navigation and traffic congestion. Therefore the safety of traffic must be improved in Po-hang vicinity area. This paper describes the status of marine traffic flow and navigational characteristics based on the marine traffic survey using the exclusive software, and the results of marine traffic survey classify into the ship's types and tonnage and track history of passing ships through the statistical method. Finally the examinations of main traffic route, traffic flow and navigational characteristics are discussed, and these results can be utilized the best design of ship's routing at the Po-hang approaching water.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.63-70
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• 2006

Now AIS (Automatic Identification System) has been under full operation for ocean-going vessels, and it is expected not only to identify target ships but also to take collision avoidance using AIS information with Radar and ARFA information in restricted waters. AIS information is very useful not only for target identifications but also for taking collision avoidance, but OOW (Officer OF Watch-keeping) should take care of systematic observation of AIS because of miss-operation or malfunction of AIS. In this paper, we propose the application of Onboard Ship Handling Simulator with visual system displayed 3D scene added AIS performance such as blind areas of Island, microwave propagation, ok. and maneuvering simulation using TK models, applied real time AIS information and research the effectiveness of this system for ship handling in restricted waters, and discus the principal issues through the on board experiments. Conclusion will be expected that; 1) systematic observation of ASS information using visual scene simulator with AIS information will be effectively done, 2) observation compared with Radar and ARPA information will be also useful to make a systematic observation, 3) using the recording and replay function of simulation will be useful not only for systematic observation but also to measure and to encourage officers' skill.

• Journal of the Korea Society for Simulation
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• v.18 no.4
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• pp.9-20
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• 2009

Navigation system providing route-guidance and traffic information is one of the most widely used driver-support system these days. Most of the navigation system is based on the 2D map paradigm so the information is ed and encoded from the real world. As a result it imposes a cognitive burden to the driver to interpret and translate the ed information to real world information. As a new concept of navigation system, augmented-reality navigation system (AR navigation) is suggested recently. It provides navigational guidance by imposing graphical information on real image captured by camera mounted on a vehicle in real-time. The ultimate goal of navigation system is to assist the driving task with least driving workload whether it is based on the abstracted graphic paradigm or realistic image paradigm. In this paper, we describe the comparative studies on how map navigation and AR navigation affect for driving tasks by experimental research. From the result of this research we obtained a basic knowledge about the two paradigms of navigation systems. On the basis of this knowledge, we are going to find the optimal design of navigation system supporting driving task most effectively, by analyzing characteristics of driving tasks and navigational information from the human-vehicle interface point of view.

• Journal of the Korean Institute of Navigation
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• v.18 no.1
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• pp.1-21
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• 1994

The safety of the ship manoeuver is dependent not only on the inherent characteristics of the ship itself and environmental conditions, but also on the skill and experience of the ship operator. As the ship operator's judgement is related to his experience and skill, based on outside information, piloted controllability also depends upon the effectiveness, accuracy and reliability of various information which is obtainable from navigational equipments and aids to navigation that are available to the ship ope-rator. Although these factors, human factors and informational factors, have been pointed out as major factors which affect the controllability of a ship, there was no a comprehensive examination on the effect of these two factors. In this thesis, therefore, an attempt was made to examine whether or not there is clear indication that these two factors affect the controllability of a ship in reality. Experiments were conducted using the port design simulator of the Korea Maritime University.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.233-234
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• 2013

본 논문에서는 전자해도 응용 서비스를 위한 SENC 자료구조의 설계를 제안한다. SENC란 System Electonic Navigational Chart의 약어이며 전자해도 시스템이라고 부른다. 전자해도 시스템의 배포 형식은 전자해도 데이터를 전자해도 시스템으로 운용하는 시스템 환경에 맞게 재구성한 SENC 데이터로 저장, 관리한다. SENC를 구성하기 위해선 방대한 양의 전자해도 데이터가 필요하고 이 많은 데이터들을 저장, 관리, 검색할 수 있는 알고리즘이 필요하다. 전자해도 시스템을 효율적으로 관리하기 위한 알고리즘들을 설계하고 이 알고리즘을 이용한 간단한 구현화면을 제작하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.05a
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• pp.570-571
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• 2011

최근 선박 및 해상 물류 자동화는 물류증대와 복잡한 선박의 운용에 비하여 근무조건이 상대적으로 열악한 형편이다. 때문에 과도한 선원의 업무량으로 인하여 IMO(International Maritime Organization, 국제해사기구)에서는 선박이 운항함에 있어 해상에서 발생 할 수 있는 모든 사고(인명, 해상오염, 선박의 손실)를 미연에 예방할 수 있는 최소한의 장비로 선교항해 당지경보시스템 (BNWAS)을 모든 여객선과 국제항을 운항하는 150GT 이상의 모든 선박에 탑재하도록 하고 있다. 본 논문은 선교항해 당지경보시스템의 Alarm 상태를 원격에서 관리할 수 있는 서버 관리 프로그램을 개발하여 적절한 조치를 할 수 있는 지능형 선교항해 당지경보시스템을 제시하고자 한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.556-557
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• 2012

선박의 안전한 운전을 위하여 선박 내/외에 다양한 계측장비를 추가하여 선박의 안전한 운항을 돕고 있다. 이러한 계측장비들과의 통신은 일반적인 RS-422,485 통신을 기반으로 NMEA0183과 고속의 통신 속도를 지원하는 CAN 통신 기반의 NMEA2000 프로토콜을 표준으로 하고 있다. 본 논문에서는 NMEA0183 프로토콜을 지원하도록 하고 NMEA0183 프로토콜 기반의 특정 선박용 통신 데이터를 사용자가 선택적으로 모니터링하고 체크할 수 있는 지능형 단말기를 설계하였다. 이러한 간단한 펌웨어 기반의 다기능 인디케이트(indicator)는 선박 내에서 사용할 수 있는 간편한 이동용 통신 프로토콜 체크기와 다양한 데이터를 선택적으로 모니터링 할 수 있는 다기능 인디케이트를 개발하여 실용 가능성을 제시하고 한다.