• Journal of Navigation and Port Research
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• v.28 no.6
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• pp.525-530
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• 2004

Due to the rapid growth of Chinese ports, currently, research for the improvement of competitiveness of Busan port have been intensively studied. These research have mostly evaluated or analyzed competitiveness of ports, and then, based on results of analysis, have suggested some strategies for enhancing competitiveness of Busan port. However. although implications of these previous studies are practically available to build policies for Busan port, basic studies such as identification of port competitiveness( or port selection) related factors for reasonable evaluation and analysis which have contributions in academic area have been very rare. The primary objective of this study is to investigate port selection criteria, based on empirical data Especially, in this study, we classify internal /external factors, and present importances of external factors that have yet to be empirically identified in previous studies.

• Journal of Navigation and Port Research
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• v.39 no.3
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• pp.157-163
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• 2015

Recently, there has been much interest in the e-Navigation that applies a variety of digital devices to shipboard thanks to the high interest to maritime safety and the rapid development of ICT technologies. The e-Navigation proposes a new ICT paradigm in maritime information service and maritime safety. This study proposes the shore-based maritime information service platform that enables the converged services of various kinds of maritime data and the standard ENC based on IHO S-100. The proposed maritime information service platform enables the harmonized integration, presentation and web services of ENC, sensed data such as AIS, ocean weather and currents, and geospatial data. Also, the platform enables the mobile maritime information service through WebApp or App software operating in mobile devices of smart phone or web pad. Finally, the proposed platform accommodates the standard ENC of the existing S-57 and the new S-101, and the standard web services of WMS and WMTS of ISO 19100 and OGC.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2007.12a
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• pp.198-199
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• 2007

Relation between SSTs(Sea Surface Temperatures) in the South Sea and intensity of typhoons which passed through the South Sea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 6 years(2000-2005) is higher 1.21$^{circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon am be seen by the central pressure. The minimum central pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum central pressure of the last 6 years(2000-2005) is lower 9hPa than t1m during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.671-674
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• 2007

In this paper, the EM wave absorber was designed and fabricated for ETC system, because ETC system has some problems including signal error and system-to-system interference. We fabricated some samples in different composition ratio of MnZn-ferrite, Carbon and CPE, confirmed that optimum composition ratio of Mn2n-ferrite, Carbon, CPE was 40 : 15 : 45 wt%. Complex relative permittivity and complex relative permeability was calculated by the measured data. And absorption abilities were simulated according to different thickness of the EM wave absorbers using complex relative permittivity and permeability. The EM wave absorber was fabricated based on simulated data Simulated and measured values agree well. As a result, the developed EM wave absorber has a thickness of 3.38 mm and absorption ability over 20 dB at 5.8 GHz.

• Journal of Navigation and Port Research
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• v.31 no.8
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• pp.683-687
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• 2007

Hydroelastic deformation of pontoon type floating structure in waves is critical in structural design. Therefore, it is necessary to develop additional technology that make to dissipate the wave energy as the submerged horizontal plate. In this study, we investigate the characteristics of hydrodynamic interaction effect by the submerged plate affecting to the radiation forces on a pontoon type floating structure using numerical analysis. We have developed the numerical method based on the composite grid system that consists of moving and fixed grid to compute the radiation forces due to the heaving motion of pontoon type floating structure and submerged plate. The numerical simulations based on the finite difference method are carried out to solve the fully nonlinear free surface involving the breaking waves and compared with the experimental data to confirm the reliability of the numerical method. Then, we discuss the interaction effects on the hydrodynamic forces that could influence on the hydroelastic response of floating structure.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.85-86
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• 2012

e-Navigation strategy IMO promotes is defined as it is necessary to network to provide various maritime safety information to in land and on board users, and it is expected to provide a large amount and diverse kinds of maritime spatial information services to them frequently. However, as there are some limits to transmit that by current mobile maritime communication technologies, it is required to simplify and optimize the information. In this study, tree node and convex hull method is applied to S-100 SD spatial information to generalize and we arranged the efficiency and effect of generalization by storing in XML form which can be used in general.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.507-509
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• 2012

IHO has established S-100 Standard profiled from ISO 19100 GIS standards for standardization and improvement of hydrographic data and are developing S-10X Standards. IMO is implementing the e-Navigation strategy for maritime safety and marine environment protection and has established the CMDS as information standard framework which will be developed from the S-100 standard. The development domain of e-Navigation can be divided into onboard, communication network, onshore and VTS is a core actor in onshore system. In this study, we analyzed the effects of S-100 standard development on VTS through e-Navigation strategy of IMO and suggested the cooperation between hydrographic fields and VTS fields under e-Navigation strategy.

• Journal of Navigation and Port Research
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• v.32 no.5
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• pp.403-407
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• 2008

Relations between variation of SSTs(sea surface temperatures) in the South Sea of Korea and intensity of typhoons which passed through the South Sea of Korea was analyzed for 36 years from 1970 to 2005. The SSTs in the South Sea show the rising trends continuously. The mean SST of the last 10 years(1996-2005) is higher $1.03^{\circ}C$ than the mean SST during 10 years(1970-1979). The rising trends are especially strong after 1994. The intensity of typhoon can be shown by the minimum sea level pressure. The minimum sea level pressures of typhoons which passed through the South Sea show the descending trends. The mean minimum sea level pressure of the last 10 years(1996-2005) is lower 10.1hPa than that during 10 years(1970-1979). The correlation analysis shows that the rising of SSTs in the South Sea has relations with the strengthening of intensity of typhoons.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.269-273
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• 2013

Underwater acoustic channels are generally recognized as one of the most difficult communication media because of the multipath propagation, dispersion, and so on. MIMO (Multiple-input multiple-output) techniques have been actively pursued in underwater acoustic communications recently to increase the data rate over the bandwidth-limited channels. The transmit diversity techniques can be applied in this case, and one of them is Alamouti's scheme. In this paper the performances of the transmit diversity technique are evaluated via experiment. Two transmitters and two receivers were used in experiment, and the experiment was performed in indoor water tank. The error rate 5~8% was confirmed in experimental results, and these are the improved values than the error rate 14.8% for SISO(Single-input single-output) channel under same data rate condition.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.191-193
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• 2016

인적오류 예방은 해양사고 예방에 가장 중요한 이슈로 현재 인식되고 있다. 현재 이러한 인적오류를 예방하기 위한 다양한 과학적인 기법들이 등장하고 있으나, 실제 인적오류를 예방할 수 있는 기법은 아직 개발되어 있지 못한 실정이다. 그 이유는 인적오류의 발생 원인과 특징이 사람을 대상으로 하기 때문에 실로 방대하고 원인식별이 어려우며, 원인과 결과 사이의 인과관계 구축에는 한계가 있기 때문이다. 기존 개발된 다양한 기법들은 이론적으로는 완벽할 수 있으나, 실제 방대한 원인과 결과 사이에 형성된 연계체인을 모두 흡수하기가 곤란하기 때문이다. 현재 IMO의 공식안전성평가(FSA) 기법이 해상분야에 널리 적용되고 있으나 구체적으로 어떠한 기법을 적용하여 인적오류를 적용할 수 있는지에 대해서는 아직도 애매모호한 실정이다. FTA, ETA, FEMA, SWIFT 등 다양한 분석기법의 등장과 AI, Fuzzy, MMC, Kalman 등 기초과학분야의 기본적인 이론과 기술을 적용할 수 있으나 인간의 인적오류 식별과 분석 및 평가와 예측에는 한계가 있는 것이 현재의 실정이다. 한편 최근에는 기존에 많은 문제점을 내포하고 있는 것으로 고려되었던 베이지안 네트워크(Bayesian Network, BN)가 다시 분석과 예측 분야에 등장하고 있는데, BN의 장점을 수용하고 단점을 해결할 수 있는 방법들이 연구되고 있기 때문이다. BN의 장점은 전방추론과 후방추론을 적용하여 사고의 원인과 결과를 분석한 후, 이에 대한 해결 방안을 식별할 수 있기 때문이다. BN의 단점은 이진(binary) 구조의 데이터만을 수용할 수 있기 때문에 상관 변수들이 방대한 경우 계산시간이 방대해지고 이를 모두 수용할 수 있는 방법이 없기 때문이다. 따라서 BN 구조를 어떻게 설계하는냐가 최근의 이수로 등장하고 있다. 본 연구에서는 이러한 제 문제점을 고찰하고 인적오류 모델 개발에 최적인 방법 또는 기술을 모색하는데 있다.