• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.10-17
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• 2018

To prepare the integrated safety management system 'e-navigation', research is being conducted on the route exchange for sharing intended routes between ship and ship, and between ship and land. But they don't have enough specific grounds for the effects of route exchange and the necessity of its introduction and focus on technical aspects like the implementation of route exchange. This study tried to quantitatively analyze the effects of route exchange on sailing safety with the use of ship handling simulation, integrate simulation performers' subjective evaluations, and investigate the effects of route exchange. The ship-to-ship route exchange resulted in the initial collision avoidance action time was 3.43 minutes faster, the collision avoidance direction change rate was 60 %, the proximity to target A was 31 %, and Mean Rudder Angle Index decreased by 57 %. In addition, 95 % of the survey respondents had an effect on the decision making of collision avoidance, 85 % had a positive impact on safety navigation, 90 % had an accident prevention effect, 70 % reduced the psychological burden of officers, and 70 % should be introduced in practice.

• ETRI Journal
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• v.14 no.4
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• pp.106-114
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• 1992

교환기는 통신시스팀의 꽃이라고 일컬어질 수 있을 만큼 중요한 역할을 담당하고 있으며 그 비중은 날이 갈수록 높아지고 있는 실정이다. 특히 교환국별 교환회선수의 결정은 통신시스팀의 기본구조, 나아가서는 고객의 만족도를 결정하는 가장 중요한 요인으로서 인식되고 있다. 본 연구에서는 그래프 이론의 최단경로 알고리듬을 이용하여 교환국별로 소요되는 적정 교환회선수를 결정하는 방법을 제시한다.

• Journal of Navigation and Port Research
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• v.38 no.3
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• pp.217-225
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• 2014

The system that covers gathering, integrating, exchanging, presenting and analyzing of information within ships and shores for the safety and security in Marine Environment is known as e-Navigation Policy. Northern Europe has been conducting research and development. It came up into a concept that deals with ship's route information between vessels as well as vessels to shores which is better known as route exchange system. The research showed substantial advantages on navigational safety by exchanging the route information between vessels in vicinity and vessels to shores. Therefore, upon the adaptation of route exchange System as a major function in integrated navigational system, the existing procedures in VTS could be changed for betterment. In this study, it was verified the effectiveness of route exchange system by the adaptation of a recent collision accident occurred in Korean coast and suggested that route exchange system which would be carried out by the discretion of VTS center in VTS area. Finally, it proposed the new functions for outstanding services and procedures of integrating traffic organization services on coastal VTS for an effective route exchange system in Korean coastal area.

• Journal of KIISE:Information Networking
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• v.28 no.1
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• pp.1-10
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• 2001

파장경로주가 통신망은 근원지에서 목적지까지 정보가 빛의 형태로 전달되는 전광 통신망이다. 정보는 빛의 길을 통해 전달되어 지는데 이는 광 채널들을 교환 연결방식을 이용하여 연결함으로써 만들어진다. 링크간의 연결이 복수개의 광섬유로 이루어진 파장 경로주기 통신망에서는 광섬유간의 교환능력을 통해 더욱 효율적으로 채널들을 이용할 수 있다. 이논문에서는 주어진 연결 요구들을 충족시키는 오프라인 채널 지정문제를 통하여 링이나 트리 구조를 갖는 통신망에서 광섬유간의 교환 능력이 미치는 영향을 조사해 보았다. 주어진 연결 요구들은 하나의 변수인 부하로 나타내 진다. 링의 형태를 갖는 통신망에서 부하를 교환기의 크기에 대한 함수로 나타냄으로써 교환기의 크기가 미치는 영향을 수량화했고 트리의 형태를 가는 통신망에서는 일반적으로 부하가 L일 때 하나의 링크에 L개의 채널을 사용하여 채널 지정을 얻기에는 광섬유간의 교환이 충분하지 않다는 반증을 보였다.

• Journal of KIISE:Information Networking
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• v.27 no.2
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• pp.187-196
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• 2000

Failures in ATM networks can occur at virtual path (VP) links, virtual path switches, and virtual channel (VC) switches. Restoration schemes have been proposed for VP link and VP switch failures, however, none for VC switch failures. In general, VC switches are used for edge nodes in protection domains. Since even only one VC switch failure can cause a critical problem, new restoration schemes for VC switch failures are highly required. Restoration schemes at the VP level proposed so far can be categorized into those using the flooding algorithm and those using the backup virtual path (BVP) concept. Even though the latter cannot handle unpredictable failures, it has some advantages such as fast restoration and low spare capacity requirement. In this paper, we propose new restoration schemes using a new type of BVPs to handle VC switch failures. The simulation results show that the proposed schemes can restore virtual connection failures due to VC switch failures without degrading restorability for VP failures.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.1
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• pp.66-74
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• 1994

Gradient projection (GP) technique is applied for solving the optical routing problem (ORP) in high speed packet switched networks. The ORP minimizing average network packet loss probability is non-convex due to packet losses at intermediate switching nodes and its routing solution cannot be directly sought by the GP algorithm. Thus the non-convex ORP is transformed into a convex problem called the reduced-ORP (R-ORP) for which the GP algorithm can be used to obtain a routing solution. Through simulations, the routing solution of the R-ORP is shown to be a good approximation to that of the original ORP. Theoretical upper bound of difference between two (ORP and R-ORP) routing solutions is also derived.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.07a
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• pp.267-271
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• 2003

IETF mobileip WG에서 MN(Mobile Node)의 위치를 나타내는‘바인딩정보’를 안전하게 CN(Correspond Node)에게 송신하여 최적경로를 설정하는 RR(Return Routability)프로토콜을 드래프트 문서로 제안하고 있다［1］. 하지만 이 프로토콜은 최적경로설정이 MN에 의해 시작됨에 따라 최적경로설정 지연에 따른 최적경로설정 확률의 저하와 불필요한 메시지 교환에 따른 통신부담을 문제점으로 지적할 수 있다. 본 논문에서는 상기와 같은 문제점 해결방안으로 HA(Home Agent)가 CN으로부터 첫번째 패킷을 수신했을 때 최적경로설정을 시작하도록 개선된 RR프로토콜을 제안하였다. 이를 통해서 최적경로 설정에 소용되는 시간을 단축하고 교환되는 메시지 수를 감소시켜 통신부담 경감효과를 얻을 수 있다. 이럼에도 불구하고 기존의 RR프로토콜과 동일한 보안수준을 제공한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.201-203
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• 2013

선박의 출항부터 입항까지 전 과정에서 선박 안전과 보안 및 해양환경 보호 증진을 목적으로 선박과 육상 관련 정보의 수집, 통합, 교환, 표현 및 분석을 수행하고자 하는 e-Navigation 정책 하에 북유럽에서는 선박들 간 및 선박 대 육상 간 Way Point로 구성된 선박의 Route 정보를 교환하여 항행정보로 사용하는 개념인 Route Exchange 방안을 연구 중으로 향후 e-Navigation 시스템에서는 선박통합항행시스템의 주요 기능으로써 구현 및 현 VTS 관제 방식에도 큰 변화를 가져올 것으로 예상된다. 이에 따라 이 연구는 북유럽에서 선행 연구 중인 Route Exchange 개념을 소개하고 실제 사고사례를 통해 Route Sharing의 필요성을 제기하며 항만과 연안 VTS 관제 해역 내 적용 시에 고려되어야 할 문제점 및 방향성 제시와 함께 시급히 개선되어져야 할 관제장비 기능에 대하여 소개함으로써 관제해역 내 적정 Route Exchange 도입방안을 모색한다.

• The KIPS Transactions:PartD
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• v.11D no.7 s.96
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• pp.1409-1416
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• 2004

Recently, due to the popularity and explosive growth of the Internet, information exchange is increasing dramatically over the Internet. Also the XML is becoming a standard as well as a major tool of data exchange on the Internet. so that in retrieving the XML document. the problem for speeding up evaluation of path-oriented queries is a main issue. In this paper, we propose a new indexing technique to advance the searching performance of path-oriented queries in document databases. In the new indexing technique, an abbreviation-path file to perform path-oriented queries efficiently is generated which is able to use its hash-code value to index keys. Also this technique can be further enhanced by combining the Extendible Hashing technique with the abbreviation path file to expedite a speed up evaluation of retrieval.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.2
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• pp.281-286
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• 2017

SNS is a platformwhere users build a social relationship and share opinions and informations. To do these, it supports a text, an image and a video data. As it is possible to exploit the location data of a smart device, SNS tries to use the location data. However,since SNS does not support the coordinate data, it provides the restricted function sharing the image map instead of the vector map. In this paper, we propose a chatting systemsharing pathsto support the coordinate data on a classical SNS. On the proposed system, it is possible for usersjoined in a roomto watch a vector map of same area and exchange texts. If a user builds a path on the map, the system propagates the coordinate data of the generated path and the other users joined in the room watch the path immediately. The implemented chatting systemhasthe benefit to share the information related a map between users using coordinate data.