• Title/Summary/Keyword: Navigation environment condition

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The Northern Sea Route Transit Modeling of Icebreaking Cargo Vessels (쇄빙상선의 북극해 항로 항행 모델링)

  • Jeong, Seong-Yeob;Choi, Kyung-Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.3 s.153
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    • pp.340-347
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    • 2007
  • Main purpose of the study is to develop a transit model for icebreaking cargo vessels in the Northern Sea Route and to select optimum sea routes with the shortest navigation time and the lowest operation cost. This numerical model executed with basic information such as ship capabilities, transit directions and months of transit, can calculate total transit distance and elapsed time, mean speed, operation cost for each vessel. In the transit model. environment information such as the site-specific ice conditions, wave and wind states are utilized for four different months (April, June, August, and October) along the Northern Sea Route. The model also defines a necessary period of an icebreaker escort. Then the optimum sea routes are selected and visually displayed on the digital map using a commercial software ArcGIS. Usefulness of the selected sea routes is discussed.

MIMO-aided Efficient Communication Resource Scheduling Scheme in VDES

  • Sung, Juhyoung;Cho, Sungyoon;Jeon, Wongi;Park, Kyungwon;Ahn, Sang Jung;Kwon, Kiwon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.8
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    • pp.2736-2750
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    • 2022
  • As demands for the maritime communications increase, a variety of functions and information are required to exchange via elements of maritime systems, which leads communication traffic increases in maritime frequency bands, especially in VHF (Very High Frequency) band. Thus, effective resource management is crucial to the future maritime communication systems not only to the typical terrestrial communication systems. VHF data exchange system (VDES) enables to utilize more flexible configuration according to the communication condition. This paper focuses on the VDES communication system among VDES terminals such as shore stations, ship stations and aids to navigation (AtoN) to address efficient resource allocation. We propose a resource management method considering a MIMO (Multiple Input Multiple Output) technique in VDES, which has been widely used for modern terrestrial wireless networks but not for marine environments by scheduling the essential communication resources. We introduce the general channel model in marine environment and give two metrics, spectral and the energy efficiencies to examine our resource scheduling algorithm. Based on the simulation results and analysis, the proposed method provides a possibility to enhance spectral and energy efficiencies. Additionally, we present a trade-off relationship between spectral and energy efficiencies. Furthermore, we examine the resource efficiencies related to the imperfect channel estimation.

Development of a Real-time Ship Operational Efficiency Analysis Model (선박운항데이터 기반 실시간 선박운항효율 분석 모델 개발)

  • Taemin Hwang;Hyoseon Hwang;Ik-Hyun Youn
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.1
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    • pp.60-66
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    • 2023
  • Currently, the maritime industry is focusing on developing technologies that promote autonomy and intelligence, such as smart ships, autonomous ships, and eco-friendly technologies, to enhance ship operational efficiency. Many countries are conducting research on different methods to ensure ship safety while increasing operational efficiency. This study aims to develop a real-time ship operational efficiency analysis model using data analysis methods to address the current limitations of the present technologies in the real-time evaluation of operational efficiency. The model selected ship operational efficiency factors and ship operational condition factors to compare the operational efficiency of the ship with present and classified factors to determine whether the present ship operational efficiency is appropriate. The study involved selecting a target ship, collecting data, preprocessing data, and developing classification models. The results of the research were obtained by determining the improved ship operational efficiency based on the ship operational condition factors to support ship operators.

A Study on the Development of Designated Model of Places of Refuge location from IMO Recommendations (IMO 권고에 따른 선박 피난처 입지 지정 모델 개발에 관한 연구)

  • Lee, Chang-Hyun;Park, Seong-Hyun
    • Journal of Navigation and Port Research
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    • v.38 no.4
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    • pp.357-366
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    • 2014
  • On December of 2003, IMO's $23^{rd}$ Assembly discussed 'Guidelines on places of refuge for ships in need of assistance' At the discussion, Res. A.949(23) has been selected to appoint recommended place of refuge for countries signatory to the IMO Convention. IMO defines "Places of Refuge" as a places where a ship in need of assistance can take action to enable it to stabilize its condition and reduce the hazards to navigation, and to protect human life and the environment. Appointing and managing a Place of refuge can be a delicate problem because of its close connection to each country's coastal and environmental protection policies. However, in case of marine accident, the appointment or management of the place of refuge has a potential to avoid further damage and reduce to the minimum any environmental and estate losses. Currently a number of foreign countries, designated and operated a place of refuge. But, place of refuge selected method criteria were different by country and also does not have any standardized designating place of refuge model. Therefor, this study suggested the model of assigned places of refuge according to objective indication in order to assign reasonable and efficient places of refuge in domestic waters in the future by investigating and analyzing imported facts in considering the assignment of places of refuge in foreign countries and describing these imported data into quantitative value. In designating the model place of refuge, the final place of refuge location was presented by evaluating the probability of marine accidents, analyzing the location, and evaluating the supporting establishment.

Numerical Prediction of Ship Induced Wave and its Propagation Using Nonlinear Dispersive Wave Model (비선형분산파랑모형을 이용한 항주파의 발생과 전파에 관한 수치예측모형 개발)

  • Shin, Seung-Ho;Jeong, Dae-Deug
    • Journal of Navigation and Port Research
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    • v.27 no.5
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    • pp.527-537
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    • 2003
  • The characteristics of ship induced waves caused by navigation become widely different from both ship's speed and water depth condition. The ship induced waves specially generated in coastwise routes frequently give rise to call unforeseen danger for swimmers and small boats as well as shoreline erosion or sea wall destruction in coastal zones. The main concern of ship induced wave study until now is either how to reduce ship resistance or how to manoeuvre the ship safely under a constant water depth in the view point of shipbuilding engineers. Moreover, due to the trends for appearance of the high speed ships at the shallow coastal water, we are confronted with the danger of damages from those ship induced waves. Therefore, it is necessary to examine the development of ship induced waves and the influence of their deformation effects according to its propagation ray. In present study, in order to predict the development of the ship induced waves and their propagation under the conditions of complicate and variable shallow water depth with varying ship's speed, we constructed a computer model using Boussinesq equation with a fixed coordinate system and verified the model results by comparison with experimental results. Additionally, the model was applied under the variable water depth based on actual passage and we then confirmed the importance of the variable water depth consideration.

EcoBlog: 4d Spatial Framework for Ecological Virtual Community (EcoBlog: 생태학적 가상 커뮤니티 구현을 위한 4 차원 공간 프레임워크)

  • Lertlakkhanakul, Jumphon;Bae, Nu-Ri;Choi, Jin-Won;Chun, Chung-Yoon
    • 한국HCI학회:학술대회논문집
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    • 2006.02a
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    • pp.937-944
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    • 2006
  • Although people's anxiety about the environmental problem has been getting higher, they are not provided good quality of knowledge about the environment. Based on this situation, Ecoblog can be a new type of online community to educate the public in ecological knowledge. Especially, Ecoblog can be utilized as a method of "preventive education", and it will contribute to reduce great amounts of environmental budget to restore contaminated environment to previous condition. Ecoblog also utilizes the concept of blog which user can create and append their site with chosen themes. A weblog or a blog is a non-commercial webpage regularly updated through the use of a blogging software which allows the user to "publish" kinds of amalgamations of text and graphics to the page as posts. The technology offered in Ecoblog is utilizing the concept of 4D place and game metaphor in order to provide users the sense of participation, interaction and immersion among them and the growing community. Thus, it requires applying the CAAD technology by implementing semantically well-defined building data model as a core database to create a 4D virtual community. This research focuses on defining a 4d spatial framework suitable for developing an online ecological community. Through our study, the state-of-the-art of online community has been studied at the first step. Second, the scenario of using EcoBlog described with content, visualization and navigation are defined based on the critical features derived at the first step. Finally, a 4d spatial framework composed of semantic building data model, content and rule database is constructed to propose factors that are necessary to establish an ecological virtual community. In conclusion, our framework could enhance the comprehension and interaction between users and virtual buildings in the ecological community by integrating the concept of game design, 4D CAD and semantic data model. Such framework can be applied to any online community for an educational purpose.

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Alcohol Drinking Status of Officers on a Ship and Drunk-navigation Experiments Using Ship Handling Simulator

  • Yang Chan-Su;Yang Young-Hoon;Kim Hong-Tae
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.12 no.1 s.24
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    • pp.39-45
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    • 2006
  • Based on the previous studies on alcohol effects on human behaviour and performance in transportation system such as air-plane and car driving, the alcohol exposure before and on watch of a ship has a great influence on subsequent behaviour. In this paper, to examine the drinking status of officers on board multiple choice questionnaires are circularized under instruction and surveyed for 118 officers. According to the results of the questionnaire survey on alcohol dependency (Alcoholism) that was invented by WHO, over 27 % of those surveyed represented alcohol abuse symptoms. In addition to that, the existing state and awareness for on-board-drinking was summarized to make a scenario of drink-operation with a ship handling simulator to investigate the effect of alcohol (0.08 g% blood alcohol concentrations) on ship operational performance. A main effect for alcohol was found indicating that ship operational performance was comparatively impaired by this alcohol relative to performance in the non-alcohol condition The results of this research can be applied to minimize marine accidents as basic data.

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On the Countermeasure for Preventing the Accident of Cargo Handling in Port (항만하역관할의 원인분석 및 예방대책에 관하여)

  • 박용욱;이철영
    • Journal of the Korean Institute of Navigation
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    • v.17 no.3
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    • pp.57-68
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    • 1993
  • The economy of Korea has grown up significantly in its scale. It has, therefore, become imperative to develop countermeasures to prevent work related injuries and occupational illnesses resultining from haza-rdous working conditions and handling harmful substances. A lot of cargo handling accident in port have occurred due to the characteristics of poor working environment, diversity of working place and method, fluctuation of the amount of cargo and handling of heavy, long, harmful and dangerous cargo, etc. According to '91 industrial accident analysis carried out by the ministry of labour, the number of the stevedores injured by cargo handling accident in port were 1, 432 persons (the death accident : 22 per-sons), the amount of industrial accident compensation in port was 6.7 billion won (the amount of economic loss : 33.6 billion won), and the injury occurance rate of the stevedoring industry was higher than that of the whole industry. This paper, therefore, aims to the actual status of the stevedoring industry and to extract the main cau-ses of the accidents related to cargo handling in port through factor analysis using the data of the accide-nts in the whole habour from 1990 to 1992, and to suggest the countermeasures to prevent such accident. The main causes of the accident and countermeasures are found to be as follows through the factor analy-sis : Factor1, factor2, and factor3 related to a defect of human being and management, a defect of state and environment, and an insufficiency of education and law are extracted. The short-term countermeasures to prevent these accidents are 1) to consolidate the safety and health organization in the working spot, 2) to secure a safe condition in working spot before dock work, 3) to strengthen a dock worker's safety educa-tion. The long-term countermeasures are 1) to promote a decasualisation of dock workers, 2) to modernize the cargo working methods through constructing exclusive pier and introducing exclusive cargo handling equipment, 3) to establish a exclusive dock accident prevention organization and the dock workers law. Factor 4, factor5, factor6, and factor7 related to an unfitness, a deficiency of technical knowledge, a nonfu-lfilment of safety measures, and a bad arrangement are extracted. The countermeasures to prevent these accidents are 1) to perform a complete safety inspection of cargo handling equipments and tools and to carry out the dock work according to a working plan, 2) to publish and supply technical safety books, safety instruction book, safety check list, etc., 3) to strengthen the safety patrol at the working spot in habour and to activate a safety fund, 4) to maintain always a clean workshop with the safety consciousness in which the good arragement of the working spot is considered to be the beginning of safety.

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Collision Strength Assessment for Double Hull Type Product Carrier Using Finite Element Analysis (이중 선체 화학 운반선의 충돌 강도 평가)

  • Paik, Jeom-Kee;Lee, Jae-Myung;Lee, Kyung-Ern;Won, Suk-Hee;Kim, Chelo-Hong;Ko, Jae-Yong
    • Journal of Navigation and Port Research
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    • v.28 no.6
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    • pp.481-489
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    • 2004
  • Ship collisions and grounding continue to occur regardless of continuous efforts to prevent such accidents. With the increasing demand for safety at sea and for protection of the environment, it is of crucial importance to be able to reduce the probability of accidents, assess their consequences and ultimately minimize or prevent potential damages to the ships and the marine environment. Numerical simulations for actual collision problem are conducted with a special attention with respect to finite element size, fracture criteria and material properties, which require a careful consideration to improve the accuracy. A parametric analysis varying colliding speed, angle, design loading condition is conducted using nonlinear finite element analysis method for 46,00 dwt Product/chemical carrier. The relationship between the absorbed energy and indentation are derived quantitatively using the insights observed from this study, and a novel design concept for assessing the anti-collision performance are proposed.

Suppression of Coupled Pitch-Roll Motions using Quasi-Sliding Mode Control (준 슬라이딩 모드 제어를 이용한 선박의 종동요 및 횡동요 억제)

  • Lee, Sang-Do;Cuong, Truong Ngoc;Xu, Xiao;You, Sam-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.27 no.2
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    • pp.211-218
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    • 2021
  • This paper addressed the problems of controlling the coupled pitch-roll motions in a marine vessel exposed to the regular waves in the longitudinal and transversal directions. Stabilization of the pitch and roll motions can be regarded as the essential task to ensure the safety of a ship's navigation. One of the important features in the pitch-roll motions is the resonance phenomena, which result in unexpected large responses in terms of pitch and roll modes in some specific conditions. Besides, owing to its inherent characteristics of coupled combination and nonlinearity of restoring terms, the vessel shows various dynamical behaviors according to the system parameters, especially in the pitch responses. Above all, it can be seen that suppression of pitch rate remains the most significant challenge to overcome for ship maneuvering safety studies. To secure the stable upright condition, a quasi-sliding mode control scheme is employed to reduce the undesirable pitch and roll responses as well as chattering elimination. The Lyapunov theory is adopted to guarantee the closed stability of the pitch-roll system. Numerical simulations demonstrate the effectiveness of the control scheme. Finally, the control goals of state convergences and chattering reduction are effectively realized through the proposed control synthesis.