• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.16-18
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• 2005

웹은 사용자가 원하는 정보를 쉽고 정확하게 검색할 수 있도록 웹 문서를 자료구조화하여 보다 신뢰성 있는 패턴을 추출하고 사용자의 특성과 행동 패턴을 적용하여 개인화 하여야한다. 본 논문에서는 개인화하기 위한 전처리 과정으로서 웹 문서를 구조화 하는 방법을 제안한다. 제안 방법은 기본적으로 웹 문서 태그의 하이퍼링크를 깊이 우선 탐색 알고리즘을 사용하여 방향그래프를 만드는 것이다. 이때 웹 문서 태그 탐색 시 플래시, 스크립트 등의 찾기 힘든 하이퍼링크를 찾는 문제와 '뒤로' 버튼 사용 시 웹 접근로그에 기록되지 않는 문제점을 보완한다. 이를 위해 클릭 스트림을 스택에 저장하여 이미 만들어진 방향그래프와 비교하여 새롭게 찾은 정점과 간선을 추가함으로써 보다 신뢰성높은 방향그래프를 만든다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.175-177
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• 2006

According to the recommendation of International Maritime Organization, the Ministry Of Maritime Affairs and Fisheries (MOMAF) of Korea provides the real time Differential Global Positioning System service using maritime radio beacon from 1999. Due to the benefit of DGPS service, the need of this system is increased from various user groups for acquiring the better accuracy and integrity. Therefore, MOMAF has extended their service to inland by installing the additional 6 DGPS stations. This nationwide DGPS service will be fully deployed at 2007. In addition to the extension of service area, MOMAF has a plan to upgrade their nationwide DGPS to High Accuracy Nationwide DGPS (HANDGPS). The planned HANDGPS service of Korea will be a kind of long range RTK or Wide Area RTK techniques to provide under 1m accuracy and start their service from 2009 using the various broadcasting and communication media like as radio beacon, Wibro, Digital Multimedia Broadcasting, High Speed Packet Data Access. The introduction of nationwide DGPS system of Korea and its evolution plan will be addressed in this paper. The research activities related with HANDGPS in Korea is also presented.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.1
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• pp.120-130
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• 2009

In recent years, many mobile wireless communication devices and applications have been deployed on the planet. The mobile multi-hop wireless network models appeared to provide means to access to networks where few infrastructure exists. However, the mobile multi-hop wireless networks have weaker points in attacks and intrusions than the wired and one-hop wireless networks. In this paper, the secure routing issues in most mobile multi-hop wireless network models are surveyed in depth. The state-of-the-art technologies and research activities are explained. Finally, the issues and technologies for the secure routing specific to a maritime network model are sufficiently discussed as conclusions.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1272-1273
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• 2008

PRAM(Phase change access memory) has desirable characteristics including high speed, low cost, low power, and simple process. PRAM is based on the reversible phase transition between resistive amorphous and conductive crystalline states of chalcogenide. However, PRAM needs high reset current for operation. PRAM have to reduce reset current for high density and competitiveness. Therefore, we have investigated the reset current of PRAM with top electrode contact hole size using 3-D finite element analysis tool in this paper.

• Journal of the Korean Institute of Navigation
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• v.22 no.4
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• pp.21-29
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• 1998

The marine self-organizing VHF data link is a digital radio link with self-organizing ability, which exploits the STDMA algorithm and operates in marine VHF channels. It can support the applications of surveillance, situation awareness and communication. It is the core technology of the Universal AIS which is considered as a future surveillance system at sea by the IMO. In this paper, the operational principle of the marine self-organizing VHF data link is introduced. Simultaneously, a new access protocol is proposed to enhance the marine self-organizing VHF data link so as to support point-to-point communication. The point-to-point communication is one of the most important bases to establish dynamic internetworks among computers on the bridges in the future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.388-389
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• 2011

Work at height by Rope access, including the marine plants are used in many industries, worldwide these workers are demanding IRATA certification due to danger of work. Also, the largest cause of death in National Industrial Accident is crash but nevertheless the training for worker at height is not carry out almost. In the here, introduce the kind of IRATA qualifications, training and membership, etc. and propose how could apply to korea it.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.218-219
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• 2008

In this paper, we have investigated the phase change memory device with cell structure using three-dimensional finite element analysis tool for reducing reset current. From the simulation, the reset current of PRAM with $SiO_2$ inserting layer is greatly reduced, compared with the conventional device.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.97-98
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• 2007

In this paper, we analyzed the reset current variation of PRAM device with top electrode using the 3-D finite element analysis tool. As thickness of phase change material thin film decreased, reset current caused by phase transition highly increased. Joule's heat which was generated at the contact surface of phase change material and bottom electrode of PRAM was given off through top electrode to which was transferred phase change material. As thermal conductivity of top electrode decreased, heating temperate was increased.

• Journal of Advanced Navigation Technology
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• v.21 no.3
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• pp.306-311
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• 2017

In the future ubiquitous network, information will collect data from various sensors in the field. Since the sensor nodes are equipped with small, often irreplaceable, batteries with limited power capacity, it is essential that the network be energy-efficient in order to maximize its lifetime. In this paper, we propose an effective network routing method that can operate with low power as well as the transmission of data and information obtained from sensor networks, and identified the number of sensors with the best connectivity to help with the proper placement of the sensor. These purposes of this research are the development of the sensor middle-ware to integrate the maritime information and the proposal of the routing algorithm for gathering the maritime information of various sensors. In addition, for more secure ship navigation, we proposed a method to construct a sensor network using various electronic equipments that are difficult to access in a ship, and then construct a communication system using NMEA(the national marine electronics association), a ship communication standard, in the future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.06a
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• pp.315-316
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• 2022

In order to reduce maritime accidents and promote maritime safety and the happiness of the sea people, the Ministry of Oceans and Fisheries has been providing Intelligent Maritime Traffic Information services to the public from the end of January 2021. Various information is generated and collected through this service, and research and development is underway to develop and verify a service algorithm by applying the collected information to data science to realize a safer and more efficient intelligent maritime traffic information service. In order to develop and implement this, a data pipeline system that connects the collected and stored data and can access, use, and store data from multiple systems smoothly is required. Therefore, in this study, a data pipeline that can be used in various systems such as a datascience based service algorithm development environment and an intelligent maritime transportation service test-bed was designed.