• Journal of Ocean Engineering and Technology
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• v.35 no.1
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• pp.1-12
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• 2021

As increasing the international community's awareness of greenhouse gas reduction, the demand for eco-friendly ship fuel has accelerated recently. The fundamental aim of this study is to develop a new type of fully electrified ferry for passengers and cars considering Korean domestic coastal environmental conditions. Several technical difficulties are encountered in applying a fully electric propulsion system based on removable battery systems into a ship due to limitations imposed by the batteries' size and capacity. This paper reviews and analyzes marine environment regulations strengthened recently, technology trends related to fully electric propulsion vessels in each country, and Korean domestic coastal environments. We propose a new fully electrified car ferry design with a displacement of 400 t applied in Korea. It is powered by removable battery systems pre-charged in a safe inland charging station. The mobile battery system is developed to enable roll-on and roll-off using wheels. The characteristics of the ship motion are analyzed based on the weight and location of the battery systems. We expect our battery systems to be applicable to larger ships in the future.

• Journal of the Korean Institute of Navigation
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• v.16 no.2
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• pp.53-78
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• 1992

GMDSS-the Global Maritime Distress and Safety system which is utilizing the new technologies such as satellite communication system, DSC and NBCP-is effectuated not only by the amendment of SOLAS but also by the conference of RR and IMO's MSC, and will be the major factor of the variation of the demand and supply of Radio Operators. To cope with the GMDSS voluntarily, regulations relating to the radio installation, the posting of Radio Operators, the bounds of duty, etc. must be established and the demand and supply of Radio Operators which take charge of the system must be accomplished pertinently. In this study, the authors suggested some practical schemes to improve the effect of policy as follow. 1. The Ministry of Communication must supervise strictly the arrangement of Radio Operators, especially relating tot he legally qualified complement of Radio Station, and must review the official certification system to upgrade the quality of Radio Operators. 2. The Ministry of Communication must take overall charge of the qualitifications and technical standards of Radio Operators, the extent of their engagement, etc. which are provided by International Regulations. 3. Relating Administrations must cooperate with Shipping Companies in onboard-training to foster and ensure the manpower of Radio Operators. 4. Institutional devices to drive the resolute investment in education and training for mariners, especially for the ship's officers, must be prepared. 5. The Communication Administration and the Korea Maritime and Port Adminstration(KMPA) must cooperate mutually in the balance of the demand and supply of Radio Operators and use make their best to realize more harmonious policies on the demand and supply of manpower.

• Journal of Navigation and Port Research
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• v.33 no.8
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• pp.563-572
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• 2009

The steel industry, as the national representative strategic industry of our country, has played the motive power for the economic growth of Korea in 1970s as the positive support of the government and the management endeavor of the private were harmonized. However, in case of our country, we have mostly relied on import of the raw materials for the steel industry, and as the weight of the imported raw materials is heavy, the steel industry is the industry whose transport burden is big as it is called 'transport industry'. So, the transport rationalization will be the important task of the steel industry. This study has analyzed the economic efficiency per the transport route (container ship vs bulk ship) of the sea transport related to import/export of the steel scrap on the level acquiring the stable supply of the steel scrap. For this, this study firstly researched the status of domestic/foreign steel industry. And analyzed the world crude steel production volume, steel scrap consumption volume and world steel scrap trading structure. Also, in order to compare the transport logistics expenses between two transport devices, namely, container ship and bulk ship, this study calculated the logistics expenses per ton by using the traffic hours and traffic expenses items as the imported/exported scrap freights of 'D' company.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.5
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• pp.799-810
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• 2022

Welding work is a production work method widely used throughout the industry, and various types of welding technologies exist. In addition, many methods are being studied to automate these welding operations using robots, but in the ship manufacturing field, welding such as painting, cutting, and grinding is also the most common operation, but the manual operation ratio is higher than in other industries. Such a high manual labor ratio in the field of ship manufacturing not only causes quality problems and production delays according to the skill of workers, but also causes problems in the supply and demand of manpower. Therefore, this paper analyzed the reason why the automation rate is low in welding work at ship manufacturing sites compared to other industries, and analyzed the production process and field environment for small and medium-sized ship manufacturing companies that repeatedly manufactured with a small quantity production method. Based on the analysis results, it is intended to propose a robot system that can easily move between workplaces and secure uniform welding quality and productivity by collaborating simple welding tasks with humans. Finally, the simulation environment is constructed and analyzed to secure the suitability of robot system application to current production site environment, work process, and productivity, rather than to develop and apply the proposed robot system. Through such pre-simulation and robot system suitability analysis, it is expected to reduce trial and error that may occur in actual field installation and operation, and to improve the possibility of robot application and positive perception of robot system at ship manufacturing sites.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.1
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• pp.26-36
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• 2020

Thousands of pelagic and demersal fishes inhabit the waters around Korea and many of them are overexploited. One of the reasons is technological development, which increases the efficiency of the vessels continuously. The analysis was conducted to identify the change of fishing power index to develop the vessel and gear technology that may have improved the fishing efficiency of the otter trawl fishery from 1960s to 2010s. Gross tonnage was decreased stably, but horse power was increased annually. The perimeter of net mouth was somewhat longer, but little changed. Color fish finder was utilized from the mid-1960s. Hydraulic net drum were introduced in the early 1990s, and supply rate was gradually increased. Surveys on the supply and upgrading of fishing equipment utilized visiting research. Therefore, the relative fishing power index in the trawl fishery increased about two to three times in the 2010s compared to the 1980s. The results are expected to contribute to reasonable fisheries stock management.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.791-798
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• 2016

In this study, numerical simulations on the effects of bilge keel on roll motion were conducted. The numerical simulations were performed on a 110 m class PSV using the commercial viscous flow analysis software Star-CCM+. Before conducting the study on the 110 m class PSV, an additional simulation of DTMB 5512 was performed and compared with the experimental results to validate the feasibility of the numerical simulation. In the simulation on PSV, a nondimensional damping coefficient was calculated using a free roll decay simulation, and the response amplitude operator (RAO) for the roll motion was calculated with a nondimensional damping coefficient at two conditions (with/without bilge keel).

• Journal of Advanced Navigation Technology
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• v.17 no.6
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• pp.609-615
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• 2013

As with any ships, adequate power provision is crucial, especially on the ocean navigating ships far from the land. In order to resolve the effective and economic power supply system of any ship in operation, in this paper, we propose a power management system that intelligently controls the power supply in ships. Power management systems in this design consist of a power load detection system, a generator configuration system, and a power monitoring system respectively. The CT / PT sensor is used to measure amount of current and power in the power detection system, and according to the collected information from various sensor, the generator configuration system will switch on and off the main / sub generator effectively. Finally, the power monitoring system will display all status information of this power management system at a glance for users. This power management systems implemented in this paper is evaluated via real-time experiments, which works well as designed, and certified by KSCIEC61892-1:2012 and KSCIEC60950-1:2008.

• Korea Trade Review
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• v.47 no.5
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• pp.289-304
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• 2022

Korea's LNG and crude oil are the most important energy and export raw materials, but 100% import resources by overseas. However, tanker shipping companies, which play the most crucial role in energy cargo security, are very small in number and size, which can be a factor in the supply chain crisis. Therefore, this paper studied the policy of expanding tanker transportation necessary for the transport of crude oil and LNG in Korea. In the existing literature, there was no policy study necessary for tanker ships, but referring only to the importance of overseas energy development and transportation, so we tried to derive various demands necessary for expanding the tanker fleet through expert interviews and AHP which was conducted on 89 related energy institutions to derive policies and their priorities. The results of the study are as follows. As for the policy, the financial support policy was the highest priority, followed by the business and the mutual cooperation policy of related agencies. Tax support (22.6%) and ship financing (19.4%) were the highest priorities, followed by the Energy Intermediate Promotion Act (11.9%), Tanker Guarantee Insurance (10.6%), Energy Budget Independence (9.3%), and Korea Trader Development (8.2%). Energy governance (6.3%), information center establishment (6.2%), and energy procurement committee (5.5%) ranked seventh, eighth, and ninth. The research results show that it is necessary to supply sufficient ships to the market through the expansion of ship finance for tankers and to follow business support policies such as guarantee insurance. In addition, it was also possible to derive that the financial resources need to be determined by law and independent budgets for consistency and continuity.

• Journal of IKEEE
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• v.13 no.4
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• pp.9-14
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• 2009

This paper describes measurement of an on-ship power supply noise in mixed-signal integrated circuits. To measure the on-chip power supply noise, we can check the effects of analog circuits and compensate it. This circuit consists of two independent measurement channels, each consisting of a sample and hold circuit and a frequency to digital converter which has a buffer and voltage controlled oscillator(VCO). The time-based voltage information and frequency-based power spectrum density(PSD) can be achieved by a simple analog to digital conversion scheme. The buffer works like a unit-gain buffer with a wide bandwidth and VCO has a high gain to improve resolution. This circuit was fabricated in a 0.18um CMOS technology and has 2.06mV/count. The noise measurement circuit consumes 15mW and occupies $0.768mm^2$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.457-466
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• 2015

In this paper, the academic research on the value chain and the supply chain of offshore business are conducted for the investigation of the offshore business comprehensive configuration. Then, the assembly and ergonomic simulation was conducted for the purpose of advanced validation of offshore project.. With respect to the simulation analysis, the assembly simulation model(w.r.t. drill ship) and the ergonomic simulation model(w.r.t. FPSO) are constructed. Through the assembly simulation of drillship, the production processes could be validated in terms of availability. Also, the problem of topside design of FPSO was found by ergonomic simulation.