• Korean Journal of Computational Design and Engineering
• /
• v.18 no.3
• /
• pp.211-223
• /
• 2013

Today's ever-increasingly competitive shipbuilding market makes it essential for a shipbuilding company to have more efficient production processes and higher productivity as well as better design ability to obtain its competitiveness. A well-established production execution schedule plays an indispensable role to achieve this goal. Most shipbuilding companies carry out an evaluation on their mid-term plan once it is established. However, no evaluation activity exists for a production execution schedule, because practically all the companies depend on the field workers for the production execution scheduling. In this study, a prototype of a ship production execution schedule evaluation system is developed based on the component based design (CBD) methodology. This system enables one to make a production execution schedule that reflects up-to-date shipyard situation and to validate whether the schedule is feasible or not by running a production simulation according to the schedule. Users can also make use of the system as a decision supporting tool that compares several different execution schedules and evaluates which one is the best execution schedule.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.05a
• /
• pp.364-366
• /
• 2017

Unlike general ships, offshore plants require high reliability due to their long operating time at fixed positions when they are operated. Sensor-based status information is required for user and maintenance worker to ensure safety. In this paper, we propose a monitoring system for safety diagnosis and inspection of cargo lift for offshore plant. It consists of a sensor unit mounted on the cargo Lift, an embedded system measurement unit, and a monitoring unit for real-time data verification. It is based on the ship standard network IEC 61162-450 for the exchange of operating information and sensor measurement information in accordance with the upgrading and integration of equipment in maritime.

• Proceedings of KOSOMES biannual meeting
• /
• 2007.05a
• /
• pp.109-113
• /
• 2007

Yacht have an high powered main engine relatively light hull, so the noise generated from the engine have a bad influence upon the crew and passenger. Recently, cruise yacht is made an attempt by domestic production skill, however the insulation skill of the noise made by the main engine is not satisfy the real purchasing power of the buyer. Like this, yacht cabin's noise level is becoming the barometer to decide the purchase. the method to insufficient. However, if we use the skill of the monitoring equipment and the genetic algorithm system, the circumference of the main engine can be enclosed by an high quality absorbtion wall and the noise levels of the cabins are improved. In this study, the sound absorbtion barrier is experimentally researched by change the volume and the length of the neck for the Helmholtz resonator as the resonator can absorb the noise effectively.

• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.4
• /
• pp.441-445
• /
• 2000

Considering international status of our country as world class ship builder and geographical characteristics encircled by sea in three facets, controlling of air pollutants emission from marine engines becomes more and more important issue in recent days. Implementation of immediate pollutants emission control regulation and standardization of test and certification procedure are required to reduce air pollution from marine engines. But cost increments due to additional equipment of emission control device and development and certification test expenses as well as depreciation of fuel economy should be considered. To satisfy those air pollution reduction and economic requirements, we should make our own interpretation of IMO standard and implementation schedule depending on our country's status. For this purpose we measured NOx emission from small and middle class marine engines to calculate emission factor and total pollutant emission in our country. With the comparison and analysis of other countries emission control regulation we proposed basic data of total emission from marine engine and future emission control standard in our country. According to our estimation, 62% of total NOx emission of marine engines comes from fishing boat and 38% from commercial vessels. The portion of NOx emission from marine engine is 18.6% of whole country NOx emission. Due to the voyage characteristics of middle and large vessel and necessity of international harmonization of marine engine pollutants emission control standard, it is inevitable to adopt IMO standard for middle and large marine engines. But considering technological and cost effect of fishing boat operating in near sea, it is resonable to set a standard within 80% of measured value at the moment and gradually implement the same IMO standard in near future.

• Journal of Advanced Marine Engineering and Technology
• /
• v.38 no.4
• /
• pp.456-462
• /
• 2014

In this paper, we develop a facility management system which provides fault effect and replacement alarm function of each component for supporting effective maintenance of facility. To do this, we use weighting method to each component, calculate importance of each component, and make them to hierarchy structure using bill of materials of facility. Also, we draw fault cause and fault effect of components based on failure modes effects and criticality analysis, and define criteria of severity, occurrence and detection to get risk priority number. To apply these concepts, we develop and test the facility management system to verify its practicality. In the future, we expect the developed system to apply many domains such as maintenance of ship and offshore plant.

• Journal of the Korea Society for Simulation
• /
• v.22 no.1
• /
• pp.31-40
• /
• 2013

Recent development in science and technology has modernized the weapon systems of ROKN (Republic Of Korea Navy). Although the cost of purchasing, operating, and maintaining the cutting-edge weapon systems has been increased significantly, the national defense expenditure is under a tight budget constraint. In order to maintain the availability of ships with low cost, we need an efficient and scientific method for managing repairable parts. In this study, we propose a simulation model that computes the availability of ship's repairable parts. Our model is based on the METRIC (Multi Echelon Technique Repairable Item Control) model and extends to five sub-models to reflect the realistic situations that arise in the navy, such as planned maintenance, condemnation, lateral transshipment, and cannibalization. We have performed simulations to compute the availability of repairable parts while setting the part-level consistent throughout the five models and carried out two sensitivity analyses. The simulation results show the differences in the part availability in different models. The experiments confirm our claim that ROKN needs an inventory management system that captures the operational characteristics of the navy.

• Bulletin of the Society of Naval Architects of Korea
• /
• v.2 no.1
• /
• pp.9-14
• /
• 1965

Ship designers make every efforts to get faster ships in accordance with the development of the Naval Architecture. But for the speed lying over factor length ratio 2.5-3.0, we could put a powerful engine into the conventional round bottom displacement type vessels, but it is very difficult in view point of economy, weight and volume. The principal cause of these speed obstacles is the wave making resistance and researchers are trying to decrease this resistance. One of the resolving ways, planing hulls were applied to small high boats. Planing hull's advantage is not restricted to speed, but the workmanship of the planing hull is easier than those of displacement type vessels of round bottom. Planing hull, therefore, are widely applicable to the intermediate speed boats, which don't have enough high speed to take planing advantage, as well as high speed boats. We will discuss related phenomena of the planing hull in details and this paper we particularly interested in the interjection point(speed length ratio 3.0-3.5 by Mr. D. De Groots) between semi-planing and full planing hulls on the resistance characteristic curve. The paper by Prof. Keuck Chun Kim, "Some Characteristics of Straight Framed V-bottom Hull Forms", Journal of the society of Naval Architects of Korea, Vol.1, No.1, Dec.5, 1964, is referred to the V-bottom hull forms belonging to low speed region and determines practical applicable limit of the speed length ratio combined with construction costs, under which are still used by large commercial vessels. This is the interesting contrast between his and authors. We will further discuss the speed length ratio which is considered as a beginning point to planing effect. For this analysis, we choose 3 model ships: Model (1) and (2) have the same principal dimensions, model 3 varied dimension. Model (1) is full-planing hull, (2) is semi-planing hull and (3) is complete planing hull. They are aimed to collect proper design data for purposed ships.

• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.4
• /
• pp.104-113
• /
• 1992

The hydrodynamic problem is treated here when a pressurized bag is submerged partially into water and the end points of it oscillate. SES(Surface Effect Ship)has a bag filled with pressurized air at the stern in order to prevent the air leakage, and the pitch motion of SES is largely affected by the hydrodynamic force of the bag. The shape of a bag can be determined with the pressure difference between inside and outside. Once the hydrodynamic pressure is given, the shape of a bag can be obtained, however in order to calculate the hydrodynamic pressure we should know the shape change of the bag, and vice versa. Therefore the type of boundary condition on the surface of a bag is a moving boundary like a free surface boundary. In this paper, the formulation of this problem was done and linearized. The calculation scheme for the radiation problem of an oscillating bag is shown in comparison with the case that the bag is treated as rigid body. The hydrodynamic forces are calculated for various values of the pressure inside the bag and the submerged depth.

• Journal of Korea Port Economic Association
• /
• v.26 no.2
• /
• pp.99-118
• /
• 2010

This objective of this study is to thoroughly analyze the policies of international organizations and major advanced countries relevant to the realization of Green port To construct Green ports, there first must be competition to build such ports in sustainable, fixed quantities. Second, there is a great need for cooperation and support networks made binding by mutual agreements on ship recycling. Third, there is a need for scientific research on responses to changes in environmental regulations and on environmental issues. Today, the majority of the world's ports use gasoline or electric energy, and improving capacities for self-sufficiency through development of new and renewable energy is judged to be a pressing task. The conditions for an eco-friendly port is that it must be an important center for economic and industrial activity, and valuable as a site where people live and work, with residences and work places existing in close proximity.

• Journal of Digital Contents Society
• /
• v.18 no.2
• /
• pp.393-401
• /
• 2017

As the importance of software in various industry areas has been increased, the number of accidents related to software safety are growing up. The key industries such as railroads, aviation and medicine, recommend IEC 61508 and international safety standards for their own to achieve functional safety and reduce the issues caused by that. For equipment of ship navigation, there are not any particular standards or guidance which Korean users can introduce as considering software functional safety. This article defines the procedure and outcomes of the risk analysis in order to secure software functional safety in marine navigational equipment and applies them to an echo sounder as a case study.