• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.26-28
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• 2016

선박 항해에 있어 GPS (global positioning system)는 선박의 3차원 위치를 추정하여 항로의 이탈이나, 항만 접안을 위하여 활용된다. 따라서 위성을 활용한 위치 정확도 향상을 위하여 본 논문에서는 GPS와 BeiDou의 결합 항법을 제안한다. GPS와 BeiDou 시스템을 결합하여 가시위성의 수를 증가시킬 수 있고, 이에 따라 정밀한 위치를 추정할 수 있다. 본 논문에서 제안한 GPS/BeiDou 결합 항법의 성능 평가를 위하여 실제 수신된 위성 데이터를 활용하였고, GPS 단독 측위와의 가시위성 개수 및 위치정확도를 비교, 분석 하였다.

• Journal of Navigation and Port Research
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• v.28 no.9
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• pp.775-781
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• 2004

This study aims at helping Chinese container liners keep constant competitiveness in the heated competition Analytic Hierarchy Process (AHP), a mathematics-based, multi-criteria decision analysis methodology is applied in the study to the performance evaluation on the three biggest Chinese container liners: COSCON, CSCL, and Sinolines. Through the final results of AHP model, we completely learn the current situation of Chinese liners, therefore they are able to enhance the competitive advantage from modifying operation strategy and competition strategy in accordance with the shipping market.

• Journal of Korean Port Research
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• v.11 no.1
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• pp.121-128
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• 1997

To analyze the ocean wave more efficiently, more fine grids are used with relatively less computer memory. Each element of free surface is discretized into more fine grids because the ocean waves are much influenced by the mesh used in the finite difference scheme. According to the flow analysis, remarkable improvements could be seen in the free surface generation. The multi grid is applied to confirm the validity of scheme. The Baldwin Lomax turbulence model is used for the analysis of S103 Inuid ship. Finally some discussion on experiments was made for the physical phenomena of the viscous

• Journal of ILASS-Korea
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• v.12 no.1
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• pp.45-57
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• 2007

This paper presents both experimental and numerical studies regarding nozzles used for the SI engine application, particularly for the intake-port fuel injection type. The atomization mechanism of the multi-hole plate nozzle was investigated experimentally. It was found that the nozzle design added turbulence into the liquid-film jet and the jet disintegrated rapidly. Based on the results, various plate types for the nozzle were developed and tested; six hole nozzle for liquid jet interaction, plate-type nozzle with flat duct channel, and the simpler structured nozzle. The spray characteristics of the prototype nozzles were examined experimentally while the internal flow of the nozzle was investigated computationally. It was shown that turbulent liquid-film was injected and atomization quality was improved by controlling the internal flow condition of the plate-type nozzle.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.135-140
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• 2004

In this paper, we study the posture control of an underwater vehicle with nonholonomic constraint. Generally, systems with nonholnomic constraints cannot be stabilized to an equilibrium points by smooth state feedback control. Therefore, we proposed a control strategy for posture control of the underwater vehicle using backstepping control. The proposed control scheme is applied to the posture control of an underwater vehicle and verified the effectiveness of control strategy by numerical simulation.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.13-15
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• 2011

전원 공급이 제한되거나 전원 공급이 불가능한 소형 요트, 작업선, 바지선 등에도 항해 안전을 위한 다양한 항법장치가 필요하고, 해양사고 발생 시 사고원인을 분석하기 위한 기능이 필요하다. 그러나 기존 상선 및 수상레저용 개별 항법 장치는 고가, 대용량 전원공급, 조작의 어려움, 넓은 설치 공간의 필요 등의 문제점이 있다. 본 연구에서는 3축 반도체 가속도 센서와 3축 반도체 경사 센서 및 다양한 기상 측정 센서와 CCD 카메라, 방수 캡슐에 내장된 메모리 등을 이용한 소형 스마트 항법 장치(Multi-Tasking Integrated Navigation System, MINS)를 설계하였다. 기존에 개발된 다양한 기술과 상용 센서 등을 이용하면 MINS 개발이 가능함을 알았고, 이러한 MINS 개발에 필요한 시스템을 제안하였다.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.209-213
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• 2002

MRA(Multi-resolution analysis) algorithm by Wavelet and morphology with $3{\times}3$ SQ(square) SE(structure element) is efficient to remove ship's radar clutter progressively and enhances detecting performance. Smoothing efficiency of RMM (Recursive mathematical Morphology) is better than that of Morphology. So, to get a better result than that of old algorithms, this paper proposes a new MRA algorithm which uses Wavelet and Recursive mathematical Morphology with $3{\times}3$ RHR(rhombus) SE. Simulation result of the proposed algorithm shows that PSNR is 0.65~1.50db better than that of old method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1993.10a
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• pp.25-32
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• 1993

The design theory of a generalized n-way power divider with arbitrary dividing rations for CATV and/or MATV systems which consists of ideal multi-winding transformers and resistors only was presented. Since the circuit elements have not frequency dependence the proposed power divider is to be of exetremely broad band-width. Furthermore as a result of computer simulation the frequency characteristics are very good in spite of errors of turn numbers and hence it was confirmed that the proposed design theory is valid.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.285-290
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• 2006

This paper presents an adaptive neural network based controller and its application to Dynamic Positioning (DP) control system of ship. The proposed neural network based controller is developed for station-keeping and low-speed maneuvering control of ship. At first, the DP system configuration is described. And then, to validate the proposed DP system, computer simulations of station-keeping and low-speed maneuvering performance of a multi-purpose supply ship are presented under the influence of measurement noise, external disturbances such as sea current, wave, and wind. The simulations have shown the feasibility of the DP system in various maneuvering situations.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.482-485
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• 2006

다채널 시각비교 수신기(R100-40T, Euro-80)를 이용한 GPS C/A 코드 시각비교 데이터와 Ashtech Z12T 수신기를 이용한 P3 코드 시각비교 데이터를 통합 모니터링함으로서, 간편하게 시각비교 결과를 확인 할 수 있게 GUI(Graphic User Interface) 환경으로 구현하였다. 수신기들은 현재 KRISS(Korea Research Institute of Standards and Science)에서 사용 중인 위성이용 시각비교 수신기들이다. 본 시각비교 통합 모니터링 프로세스를 통해서 GPS C/A code 시각비교 데이터와 P3 code 시각비교 데이터 각각을 비교 분석함으로써 시각비교 결과의 신뢰성을 검증하는데 사용한다.