• Journal of the Society of Naval Architects of Korea
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• v.46 no.5
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• pp.488-497
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• 2009

The freak wave, also known as New-Year-Wave in the north Atlantic, is relatively large and spontaneous ocean surface wave that can sink even large ships and destroy maritime structures. To understand oceanic conditions that develop freak waves, we simulated and generated two versions of scale-downed waves (1:64 and 1:42) in a numerical wave tank and compared the results with the experiment in wave flume. Both of the breaking and non-breaking waves were generated in the simulation. The numerical simulation was implemented based on the finite volume method and a genetic optimization algorithm. Random values were assigned as the initial values for the parameter in the control function, which produced signals representing the motion of wave-maker. The same signal obtained from the optimization process was used for both of the simulation and the experiment. By varying the object function and restrictions of the simulation, a best profile of design wave was selected based on the characteristics, height and period of simulated waves. Results showed that the simulation and experiment with the scale of 1:42 agreed better with freak waves in the natural condition. The presented simulation method will contribute to saving the time and cost for conducting subsequent response analyses of motion under freak waves in the course of the model test for ship and maritime structure.

• Journal of Ocean Engineering and Technology
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• v.15 no.3
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• pp.120-127
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• 2001

The potential pollution problems resulting from tanker collision necessitate the requirement for an effective structural design and the development of relevant safety regulations. During a few decades, the great effort has been made by the international Maritime Organization and the Administration, etc, to reduce oil spillage from collision accidents. However there is still a need for investigation in the light of structural evaluation method for the experiments and rational analysis, and design development for an operational purpose of ships. This study aims for investigating a complicated structural response of bow structures of simplified models and oil carriers for assessing the energy dissipation and crushing mechanics of the striking vessels through a methodology of the numerical analysis for the various models and its design changes. Through these study an optimal bow construction absorbing great portion of kinetic energy at the least penetration depth prior to reach to the cargo area and an effective location of collision bulkhead are investigated. In order to obtain a rational results in this study, three stages of collision simulation procedures have been performed step by step as follows; 1) 16 simplified ship models are used to investigate the structural response against bow collision with variation of primary and secondary members. Mass and speed are also varied in four conditions. 2) 21 models consisted of 5 sizes of the full scaled oil carriers are used to perform the collision simulation with the various sizes and deadweight delivered in a recent which are complied with SOLAS and MARPOL. 3) 36 models of 100l oil carrier are used to investigate the structural response and its influence to the collision bulkhead against bow collision in variation with location of collision bulkhead, primary members, framing system and colliding conditions, etc. By the first study using simplified models the response of the bow collision is synthetically evaluated for the parameters influencing to the absorbed energy, penetration depth and impact force, etc.

• Journal of Korean Society of Disaster and Security
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• v.9 no.1
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• pp.39-45
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• 2016

The disasters in Korea, such as the Sewol Ferry Ship sinking disaster has had problems related to the medical response system, with the problems of emergency medical support team in the site, the cooperation between medical staff and fire department officer at disaster site, field medical support and hospital acceptance of the wounded in trouble, the lack of specific systematic medical response manual. Therefore, from May 2014, when the disaster emergency information center in Central Emergency Medical Center starts, collection, modification and education of scattered preexisting disaster emergency medical manual had appeared as important issues. So, it was necessary to develop the early medical response system to disaster. The correction planning of disaster emergency medical response system by Central Emergency Medical Center included quick response system with the fast medical team operation, but the practical application was not enough. So the researcher and his team developed the first Korean disaster emergency medical response manual and the process of development was documented and arranged with the application by education and training.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.37-44
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• 2020

The change of fishing power index was analyzed to identify the development of the vessel and gear technology that may improve the fishing efficiency of the offshore conger eel pot fishery from 1980s to 2015. Gross tonnage per fishing vessel was rapidly increased annually. The standard of pot was maintained, but the number of pot used rapidly increased by using conger eel pot hauling devices, carrying and loading devices, main line hauler, casting devices and slide type pot. Fish finder system to identify fishing ground information and the conger eel pot hauling devices were modernized, and supply rate was also increased. Therefore, the relative fishing power index in the offshore conger eel pot fishery increased from 1.0 in 1980 to 1.3 in 1990, to 1.8 in 2000 and to 2.0 in 2015. The results are expected to contribute to reasonable fisheries stock management of the offshore conger eel pot fishery.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.1
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• pp.40-47
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• 2011

Mobile harbor which is a novel concept of ocean transportation to bring the containers from the cargo ship waiting on the ocean away is being focused now. To provide the mobile harbor with the stable loading/unloading condition, it is necessary to develop the oscillation mitigation technologies such as anti-rolling system. Anti-rolling system using AMD(Active Mass Driving) has merits that it can handle the disturbances more actively and mitigate the rolling oscillation faster than other type anti-rolling system. However, rack-and-pinion type AMD has problems such as big friction noise from gears and motor, wear and tear, and continuous maintenance. In this paper, novel anti-rolling system using Maglev type AMD for mobile harbor is suggested in order to resolve the problems caused by the friction. This novel anti-rolling system doesn't make any friction because it supports the moving mass by using magnetic levitation force and moves it by using propulsion force from the linear motor. The demo system of the novel anti-rolling system using maglev type AMD has been developed in order to investigate its feasibility. This paper presents the procedures and results of development of this demo system.

• Korean Journal of Remote Sensing
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• v.27 no.6
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• pp.677-692
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• 2011

Suspended sediment is an important oceanic variable for monitoring changes in coastal environment related to physical and biogeochemical processes. In order to estimate suspended sediment concentration (SSC) from satellite data, we derived SSC coefficients by fitting satellite remote sensing reflectances to in-situ suspended sediment measurements. To collect in-situ suspended sediment, we conducted ship cruises at 16 different locations three times for the periods of Sep.-November 2009 and Jul. 2010 at the passing time of Landsat $ETM_+$. Satellite data and in-situ data measured by spectroradiometers were converted to remote sensing reflectances ($R_{rs}$). Statistical approaches proved that the exponential formula using a single band of $R_{rs}$(565) was the most appropriate equation for the estimation of SSC in this study. Satellite suspended sediment using the newly-derived coefficients showed a good agreement with insitu suspended sediment with an Root Mean Square (RMS) error of 1-3 g/$m^3$. Satellite-observed SSCs tended to be overestimated at shallow depths due to bottom reflection presumably. This implies that the satellite-based SSCs should be carefully understood at the shallow coastal regions. Nevertheless, the satellite-derived SSCs based on the derived SSC coefficients, for the most cases, reasonably coincided with the pattern of in-situ suspended sediment measurements in the study region.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.8 no.4
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• pp.121-138
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• 1983

This study beings with investigations of the purpose and background of the International Convention on Standards of Training, Certification and Watchkeeping for Seafarers of 1978 stipulated in London(STCW Convention) which will be put into effect internationally on and after the 28th April, 1984. I tried to confirm those common points on requirements of the qualification between the radio officer regulated in the STCW Convention and the radiocommunication operator's general cergifications administration is taken as a model for the comparative analysis, as Korea and Japan have meny similar aspects, especially legal and social aspects. Therefore, as one of urgent tasks of Korean Telecommunications Administraion preparing for the STCW Convention, I stressed on the partial amendment of the Radio Law. The gist of major amendment proposed is as follows : (1) to introduce a new system on the radio operator for ship stations. (2) to adapt the general cergificate of radiocommunication operator. This year, 1983, was proclaimed World Communications Year (WCY'83) by the U.N to provide the opportunity for all countries to undertake an in-depth review and analysis of their policies on communications development. In this regards, there must be a stimulation for the accelerated development of Communications Infrastructures in Korea.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.05a
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• pp.210-214
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• 2006

Along with the development of industrious society, the shape of city and the way of life have changed in accordance. The development of the city deepened gravitation of the city population, leading to the lack of housing and land, and apartment complexes became an alternative way of securing a number of families into a small space of land. Apartment can have a lot of families reside In a small space of land, and it can also be satisfactory to individual's privacy and anti-crime measures. On the other hand, there are negative problems with it. Among them, contacts with neighboring people showed that they only greeted each other when they met in the walkway. As shown in this, one of the reasons that there is a lack of friend ship activities is because there is short of space for common use. And in comparison to those of stairway walkway, apartments with one-passage walk way showed a higher level of contacts with neighbors. It is assumed that apartments with one-passage walk way have more chances to meet neighbors than do those of stairway walkway. This study analyzed the phases appearing in neighbor relations through investigation of the literature, and presented a coping measure. One solution is to prepare flower beds from the outside of walkway by enlarging the width of the walkway in apartments with one-passage walk way, and providing benches in front of flower beds so that residents can take a rest there. The more often residential people take a rest there, the more frequently they can meet each other. Accordingly this can solve problems of contacts with neighbors and the dreary scene of walkway can become a wider view in a nature friendly environment, bringing them to an active acquaintance activities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.164-170
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• 2015

This study proposes the improvement of maritime traffic management for domestic ships and fishing vessels by introducing the e-navigation environment. This study discusses the development of present Vessel Traffic service (VTS) in a systematic aspect and a fuctional aspect. The concept and architecture of e-navigation operation system based on the General Information Center on Maritime Safety and Security (GICOMS) are proposed as a solution for the improvement of maritime traffic management in Korean coastal waters. Especially, means of data exchange between ships and ship-shore based on the Maritime Cloud and regional e-Data Center are discussed. This study will help to the implementation of the Korean e-navigation project which focuses on the safety of small ships and fishing vessels. In the future, it is needed to study for the development and operation of accident prevention system under the e-navigation environment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.2
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• pp.207-214
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• 2015

In this paper the independence axiom, one of two principal axioms of axiomatic design theory, is applied to the leveling system development as an design criteria. After functional requirements and corresponding design parameters constitute an initial design matrix for the leveling system, sequence, which is compatible with the independence axiom, of the design parameters of the design matrix is determined and independent components of block leveling system are revealed. As a result of axiomatic design, system configuration related to the design sequence is developed. In order to verify and validate the developed block leveling system, test with real hull block leveling work in site by using total station which is used to acquire three dimensional coordinate of target point is performed. Comparison with measured data and output data from the block leveling system shows the system accuracy is under 1 mm so that the developed system is verified and validated to be used in site.