• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.971-980
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• 2010

In this paper, we present a navigation control algorithm for mobile robots that move in environments having static and moving obstacles. The algorithm includes a global and a local path-planning algorithm that uses $D^*$ search algorithm, a fuzzy logic for determining the immediate level of danger due to collision, and a fuzzy logic for evaluating the required wheel velocities of the mobile robot. To apply the $D^*$ search algorithm, the two-dimensional space that the robot moves in is decomposed into small rectangular cells. The algorithm is verified by performing simulations using the Python programming language as well as by using the dynamic equations for a two-wheeled mobile robot. The simulation results show that the algorithm can be used to move the robot successfully to reach the goal position, while avoiding moving and unknown static obstacles.

• Information Systems Review
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• v.11 no.2
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• pp.209-231
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• 2009

In recent, a general trend is observed towards more customized products and shorter product life cycles in manufacturing enterprises. In these enterprises, customers often wish to influence the product they order and to get a variant of product that meets their requirements. This is called as customer-oriented make-to-order manufacturing environment. This paper establishes a methodology of implementing information system for developing product data integration system (PDIS) which is suitable for customer-oriented make-to-order manufacturing enterprise, and also presents the case of implementing PDIS for a ship engine product in 'H' heavy industry using the established methodology. At present, the implemented PDIS is successfully operating. As a result, PDIS reduces delivery time and improves customer relationships. Moreover, the case shows that PDIS can be used as a tool for improving inter-department coordination within a company during product life cycle.

• Journal of Advanced Marine Engineering and Technology
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• v.40 no.5
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• pp.418-428
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• 2016

In this study, a Vessel Shore Report Management System (VSRMS) is developed for the International Maritime Organization (IMO), Maritime Service Portfolio (MSP) Number 8, which comprises vessel shore reporting. Several documents have to be completed before the arrival/departure of a vessel at a port, as each national port has its own reporting format and data. The present vessel reporting system is inefficient, time-consuming, and involves excessive paperwork, which results in duplications and errors. To solve this problem, in this study, the vessel reporting formats and data contents of various national ports are investigated, as at present, the reporting documents required by the current IMO standard includes insufficient information which is requested by national ports. Initially, the vessel reporting information of various national ports are collected and analyzed. Subsequently, a database structure for managing vessel reporting data for ports worldwide is devised. To make the transfer of data and the exchange of information of vessel reports much more reliable, efficient, and paper-free, VSRMS, which is a software application for the simplification and facilitation of vessel report formalities, is developed. This application is developed using the latest Microsoft C#.Net Programming Language in the Microsoft Visual Studio framework 4.5. It provides a user interface and a backend MySQL server used for database management. SAP Crystal Reports 2013 is used for designing and generating vessel reports in the original report formats. The VSRMS can facilitate vessel reporting and improve data accuracy through the reduction of input data, efficient data exchange, and reduction of the cost of communication. Adoption of the VSRMS will allow the vessel shore reporting system to be automated, resulting in enhanced work efficiency for shipping companies. Based on this information system and architecture, the consensus of various international organizations, such as the IMO, the International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA), the Federation of National Associations of Ship Brokers and Agents (FONASBA), and the Baltic and International Maritime Council (BIMCO), is required so that vessel reporting is standardized internationally.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.39-43
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• 2008

It is generally recognized that monitering of bio-molecules, which are related to the ocean environment, becomes more important. So far, for the detection of the bio-molecules, ocean samples were brought to laboratory to be analyzed using a complicate and expensive measuring system The "ship and dip" method takes a relatively long time to complete a analysis cycle and causes significant errors due to the time difference between the analysis processes. In order to overcome the drawbacks, developments of sensors for the detection of bio-molecules were suggested using nano-technology, such as nano-spintronic device, carbon nano tube device, and nano-semiconductors. The pros and cons of the technology were examined and reinvestigated to overcome the technical problems in the application to real sensors.

• Journal of the Korean Society of Marine Environment & Safety
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• v.14 no.1
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• pp.15-20
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• 2008

Contaminated sediments are the actual cause for deterioration of coastal-ecosystem. So the developed countries have been in the process of making an effort to develop new techniques for monitoring and solving this problem since 1960. In this research, suction type pump dredging system of pilot size for collecting the filth from the seabed has been designed and manufactured that can prevent or minimize the secondary pollution by filth diffusion. For the practical use, the application possibility of the developed system has been checked through a system performance test. And, the evaluation of system performance according to the underwater body type has been carried out for system optimization by using CFD. The performance tests for checking the efficiency of sediment collecting system are done under two conditions i.e. when the system is non-operational and when the system is self-propelled. The results of this research showed the possibility of the development of dredging system to remove just the upper parts of filth from seabed.

• Proceedings of KOSOMES biannual meeting
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• 2007.11a
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• pp.145-148
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• 2007

In this paper a development if data acquisition system for machinery monitoring and its condition analysis is discussed A suitable data acquisition system should be adopted to get desirable monitoring results for ship's machinery. 1he compactness and moderate cost are also considered to compose the data acquisition system 1he basic components if data acquisition system for monitoring are introduced and automatic data saving function with variable time interval and remote monitoring system are also proposed An experiment to get vibration data for rotating machinery is executed to verify the effectiveness if the data acquisition system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.33 no.1
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• pp.17-23
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• 2020

In this study, the behaviors of a vessel and the ground during the vessel impacting an underwater slope that is part of an artificial protective island are analyzed using the coupled Eulerian-Lagrangian scheme. To consider the large deformation including the shear failure of soil, the Eulerian domain is used to model the ground and water, while the impacting objects are modeled as the Lagrangian domain. For efficiency, the mass scaling scheme is applied to the modeling of the impacting objects, and the ground is modeled by setting the Eulerian volume fraction values. To verify the applicability of the constructed model, a dynamic penetration anchor problem is analyzed. The impacting vessel is modeled using solid elements following the external shape of a container ship, and an analysis of a collision on the slope is performed. As a result, collision behaviors such as displacement, velocity, and dissipation energy are estimated, and the necessity of a parametric study as further research is established.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.46-52
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• 2006

For ships, heat resistant coating is applied on the aluminized steel pipe systems dealing with high temperature steam over $200^{\circ}C$. The coatings on these steam pipes should retain both heat resistance and anti-corrosion properties to provide long-term resistance against coating defects (rust, delamination and crack) under the harsh outdoor environment including repeated seawater wetting and condensation. Thus, it is important to improve the coating qualities and to reduce maintenance works for these steam pipe systems. In this study, five different commercial heat resistant coatings (A, B, C, D, E) were selected for evaluation. Various physical properties of these coatings were evaluated on the coatings applied on the aluminized steam pipes. FT-IR analysis was also employed to identify the factors contributing the degree of heat resistance and durability of each coating material. The results indicated that the heat resistance capacity of coatings increased with the increase of silicon content as well as the decrease of substituent content. Both products C and D showed the best coating qualifies, which can be standard coating systems for future steam pipe areas.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.1
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• pp.72-85
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• 2001

A study for the structural strength evaluation on the doubler plate subjected to the biaxial in-plane compression has been performed through the systematic evaluation process. In order to estimate the proper static strength of doubler plate, elasto-plastic large deflection analysis is introduced including the contact effect between main plate and doubler. The characteristics of stiffness and strength variation are discussed based on their results. A1so, in order to compare the doubler structure with the original strength of main plate without doubler, a simple formula for the evaluation of the equivalent flat plate thickness is derived based on the additional series analysis of flat plate structure. Using this derived equation, the thickness change of a equivalent flat plate is analyzed according to the variation of various design parameters of doubler plate and some design guides are suggested in order to maintain the original strength of main plate without doubler reinforcement. Finally, correlation between derived equivalent flat plate formula and the developed buckling strength formulas by author et a1. is discovered and these relations are formulated for the future development of simple strength evaluation formula of doubler plate structure.

• Journal of the Society of Naval Architects of Korea
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• v.38 no.1
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• pp.9-26
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• 2001

In this paper. the development of a pusher-barge hull form which enables the continuous transportation along the coast and canal is performed. For the design stage of the hull forms. these are developed for Kyungin canal which is will be drawn up as the next contribution project of the Korean government are adopted. The model tests for the designed ship are carried out in the Inha University Towing Tank and the numerical simulations are done with a finite difference method based on MAC scheme. At first, the experiments are performed with designed model ships from low speed to high speed including service speed(6knots) among the corresponding designed speed. Resistance characteristics of designed ships are compared with experimental results of other several pusher-barge hull shapes. Next, the numerical simulations are performed for three cases, that is pusher only, barge only and pusher-barge condition in the designed speed. Each calculations are carried out in deep and restricted water condition. The flow characteristics around hulls in the latter condition are compared with those in the former condition.