• Journal of information and communication convergence engineering
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• 제8권4호
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• pp.355-364
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• 2010

A session transfer method, referred to as a Recipient Serving-call session control function (S-CSCF) Assured (RSA), is proposed in order to support both session mobility and consistency in IP multimedia subsystem (IMS) based next generation network (NGN). RSA session transfer simplifies a basic session transfer operation specified in [1] by using the user agent client (UAC) like characteristics of an S-CSCF. To show its efficiency, the session transfer delay and the traffic cost of RSA session transfer are investigated and compared with those of existing session transfer applications, including Assured and Consultative session transfers, by practically considering multiple session transfer failures. It is shown that RSA session transfer can further improve user experience by reducing session transfer delay as well as traffic cost than Assured and Consultative session transfers.

• Journal of Advanced Marine Engineering and Technology
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• 제39권10호
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• pp.1049-1053
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• 2015

This paper proposes to include engine information in Maritime Service Portfolio (MSP) for effective implementation of e-Navigation. Even though engine information is one of most important element to e-Navigation, MSP consists of mainly about navigation and communication information not included engine information. Furthermore, in reality, engine information sent from ship side such as mainly noon report and Planned Maintenance System (PMS) is too limited to make e-Navigation possibly. Therefore, Remote diagnostic structure receiving and sending data of engine information must be included in MSP for implementation of e-Navigation. Also, it has to be designed, and developed by Software Quality Assurance (SQA).

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.165-169
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• 2007

Due to the complexity of underwater acoustic channel, signal estimation in underwater acoustic communication field is considerably affected from time-varying multipath fading channels. On this reason, the original signals should have many long training signals to estimate the channel and the purposed signals, and the bit rate of signals having information may have small rate. In order to avoid this loss of efficiency in underwater communication, this paper employed a blind channel identification method which don't use training signals. Simulations have predicted performance of the employed method in multipath environment and an aquatic plant experiment has verified the simulation results.

• 한국정보통신학회논문지
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• 제19권7호
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• pp.1525-1530
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• 2015

본 논문에서는 성능을 향상시키기 위해 터보부호화기를 이용한 터보등화기법의 성능을 수중 실험의 데이터를 이용하여 분석 하였다. 다중 경로전달로 인해 왜곡된 데이터를 보상하기 위해 LMS-DFE 등화기와 터보 채널 부호기를 연접하여 서로간의 반복적인 연산을 통하여 성능을 개선하는 반복 기반의 터보 등화기 구조를 적용하였다. 문경시 경천호에서의 실제 수중 실험을 통하여 터보부호 기반의 터보등화기의 오류확률이 93%를 나타내었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.89-90
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• 2008

We present an implementation and it's real-sea test of an underwater acoustic communication system, which allows the system to reduce complexity and increase robustness in time variant underwater environments. For easy adaptation to complicated and time-varying environments of the ocean, all-digital transmitter and receiver systems were implemented. For frame synchronization the CAZAC sequence was used, and QPSK modulation/demodulation method with carrier frequency of 25kHz and a bandwidth of 5kHz were applied to generate 10kbps transmission rate including overhead. To improve transmission quality, we used several techniques and algorithms such as adaptive beamforming, adaptive equalizer, and convolution coding/Viterbi decoding. For the verification of the system performance, measurement of BER has been done in a very shallow water with depth of 20m at JangMok, Geoje. During the experiment, image data were successfully transmitted up to about 9.6km.

• 한국인터넷방송통신학회논문지
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• 제18권6호
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• pp.11-19
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• 2018

최근 GIS(Geographic Information System)을 중심으로 다양한 정보를 지도위에 제공하고 있으며, 대표적으로 국외의 경우 구글맵, 오픈스트리트맵, 빙맵 등이 있고, 국내의 경우 네이버지도, 다음지도, 브이월드맵 등이 GIS 기술의 한 부분인 WMS(Web Map Service)를 이용하여 서비스를 제공하고 있다. 본 논문에서는 현재 서비스되고 있는 벡터장 데이터 정보를 이용하여, 조류의 흐름도 와 스트림라인의 표출 방안 알고리즘 연구 및 사용자 편의성을 고려한 해양예측모델 데이터의 가시화 방안에 대해 연구를 수행하였다. 기존의 조류 흐름도 표출 및 스트림라인 표출 알고리즘과 제안하는 방식의 성능을 비교를 하여, 기존의 기술 보다 2배 이상 빠른 표출이 되는 것을 확인하였다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.24-29
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• 2004

A small, highly-trained crew working on the ship's automation has contributed to the improvement of operation efficiency and the labor environment on board ship. However, at the same time, having a small crew adds more responsibility to the ship's officers to safely operate and manage the ship. Recently, development on the system to concentrate important information being scattered at the various pieces of navigational equipment has been actively studied, using information and computer technology. The purpose of this study is to set up and implement an integrated marine data networking and communication system on the training-research ship. Information relating to navigation, engine and office automation were investigated and analyzed, and implementation methods associated with navigation, engine and the management information system were designed and presented. In addition, the networking system and navigational signal interface unit for the integrated communication system, and the data communication method between the ship and land are also discussed.

• 한국해양공학회지
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• 제18권6호
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• pp.44-50
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• 2004

A small, highly-trained crew working on the ship's automation has contributed to the improvement of operations and the labor environment on board ship. However, at the same time, having a small crew adds more responsibility to the ship's officers to safely operate and manage the ship. With the use of information and computer technology, efforts are being made towards the development of a system that will concentrate important information from the various pieces of navigational equipment. The purpose of this study is to set up and implement an integrated marine data networking and communication system on the training-research ship. Information relating to navigation, engine and office automation are investigated and analyzed, and implementation methods associated with navigation, engine and management information system were designed and presented. In addition, the networking system of the navigational signal interface unit for the integrated communication system, and the data communication method between the ship and land are also discussed.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2239-2244
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• 2013

산업용 기기는 전력 공급용 전선으로 인해 이동성에 제약이 따른다. 최근 자유로운 이동성이 요구되는 산업용 기기의 무선 전력 공급에 관한 연구가 많은 주목을 받고 있다. 본 논문에서는 근거리에서 장비의 배터리에 무선으로 전력을 공급하는 자기 유도방식의 시스템을 제안한다. 제안하는 시스템은 13.56 MHz에서 동작하며, 송수신 전력 모듈간의 거리는 20~30 mm으로 설계하였다. 실험을 통해 제안하는 시스템으로 약 15 V 의 배터리를 충전하는데 135 분이 걸리는 것을 확인하였다.

• 한국항행학회논문지
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• 제20권3호
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• pp.182-189
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• 2016

본 논문에서는 해양관측을 위한 멀티 홉 릴레이 네트워크 기반의 부이 시스템을 제안한다. 제안된 시스템은 다양한 센서 모듈과 게이트웨이, 무선 통신부, 원격 모니터링부로 구성된다. 센서 모듈은 다양한 통신 인터페이스와 통합되고 CAN 버스 기반의 단일화된 프로토콜을 통하여 제안하는 부이 시스템의 게이트웨이와 연결된다. 제안한 시스템은 원격 모니터링 사이트와 무선으로 데이터를 주고 받으며 통신 커버리지를 더욱 확대하기 위하여 LTE 통신 및 XBee 메쉬 네트워크 모듈을 사용한다. 필드 테스트를 통하여 제안하는 다중 홉 릴레이 네트워크 기반의 부이 시스템이 다중 홉을 이용하여 부이의 통신 도달 거리를 더욱 확장할 수 있음을 확인할 수 있다.