• Journal of the Society of Naval Architects of Korea
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• v.45 no.3
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• pp.315-321
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• 2008

A large ship usually consists of 300 to 500 blocks, for which it is extremely difficult to monitor the whole manufacturing processes from assembly to erection. In an effort to unify all the data and procedures, shipbuilding companies are installing ERP systems, which have brought great improvement throughout the company as a whole. In some departments, however, the ERP systems are not being fully utilized. This paper analyzes and solves the problems revealed especially at the production departments after an ERP system is installed. In this research, firstly a TOC(Theory of Constraints) analysis is done to find out the best solution for those problems. Secondly, based on the solution found, a Monitoring System for hull construction processes is developed with an improved user interface. The visualization of data is designed to reflect the needs of the production departments. The new system supplements the ERP system in that it selectively utilizes the unified data base and is operated under ERP environment. The system is installed in the production departments and its usefulness is verified.

• Journal of the Society of Naval Architects of Korea
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• v.45 no.2
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• pp.144-150
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• 2008

Ships and offshore structures are exposed to wave and engine excitation loadings during navigation and cargo/ballasting operations. These excessive loads may cause damages to hull and may result loss of life the ship. Therefore, it is important to develop a system that allow accurate measurements of global hull loads. The objective of the study is developing a fiber optic monitoring system that is capable of monitoring, recording and warning of the vessel performance. A method for measurement of global loads on a vessel, using strain measurements from a network of fiber optic strain sensors and extensive finite-element analyses(FEA) with idealistic load cases, is presented. The method has been successfully validated on the idealized ship structure model with strain sensors.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.9-17
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• 2006

Performing inspections for Hull Condition Monitoring and Assessment as stipulated in IACS unified requirements and IMO's Condition Assessment Scheme (CAS) IMO Resolution MEPC.94(46), 2001, Condition Assessment Scheme, IMO Resolution MEPC.111(50), 2003, Amendments to regulation 13G, addition of new regulation 13H involves a huge amount of measurement data to be collected, processed, analysed and maintained. Information to be recorded consists of thickness measurements and visual assessment of coating and cracks. The amount of data and increasing requirements with respect to condition assessment demand efficient computer support. Currently, due to the lack of standardization for this kind of data, the thickness measurements are recorded manually on ship drawings or tables. In this form, handling of the measurements is tedious and error-prone and assessment is difficult. Data reporting and analysis takes a long time, leading to some repairs being performed only at the next docking of the ship or making an additional docking necessary. The recently started ED funded project CAS addresses this topic and develops-as a first step-a data model for Hull Condition Monitoring and Assessment (HCMA) based on XML-technology. The model includes simple geometry representation to facilitate a graphically supported data collection as well as an easy visualisation of the measurement results. In order to ensure compatibility with the current way of working, the content of the data model is strictly confined to the requirements of the measurement process. Appropriate data interfaces to classification software will enable rapid assessment by the classification societies, thus improving the process in terms of time and cost savings. In particular, decision-making can be done while the ship is still in the dock for maintenance.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.2
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• pp.155-161
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• 2009

Engine builders have separately developed and applied torsional, axial and structural vibration monitoring system on most marine engines. These systems displayed their results for engine or ship operation engineers and were not regularly stored at the hardware of computer. So, the history and trend of various engine and hull vibrations were not supported for preventive maintenance and to protect the failure of these activity or function. The integrated vibration or stress monitoring system(EVAMOS : engine vibration analysis and monitoring system) in marine diesel engine, its accessories and hull structure have been developed by the dynamics laboratory of Mokpo Maritime University during last 3 years. This paper introduces the design conception and ability of commercial software EVAMOS with field data on several actual tests.

• Bulletin of the Society of Naval Architects of Korea
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• v.24 no.2
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• pp.62-68
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• 1987

• Journal of Sensor Science and Technology
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• v.21 no.4
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• pp.276-282
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• 2012

Vessels receive stress during their navigations as well as during their cargo operations. This stress may cause damages to the hull and may result in accidents. So the hull stress monitoring system(HSMS) is recommended in order to prevent these accidents. In this paper, we manufactured fiber Bragg grating(FBG) sensor and the model ship for towing tank experiments. The strain characteristics of the model ship on the water wave were measured through the towing tank experiment. The FBG sensors and electric strain gauges were attached on the connection jig, and then the characteristics of the FBG sensor were compared with those of the electric strain gauge. The strain of model ship was increased according to the increment of the amplitude of water wave. In particular, the largest strain was measured in the center of the model ship. As the wave period increased, the strain of model ship was decreased.

• Journal of the Society of Naval Architects of Korea
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• v.36 no.4
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• pp.128-136
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• 1999

This paper suggests a new object-oriented methodology, ESBD(Evolutionary Simulation Based Design), for the development of an automated manufacturing system in shipbuilding. The target system, AHMS(Automated Hull-piece Manufacturing System), is a virtualized and distributed system controlling the manufacturing processes of storing, surface-pretreatment, cutting, 1st and 2nd curvature generation of material plates. The control and product-flow simulation is applied for the real-time product monitoring and product data management(PDM). The prototype system of AHMS also outlines the layout of the new automated factory.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.150-151
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• 2015

선박의 에너지효율을 정량화하는 것은 선박의 Performance를 분석함에 있어 매우 중요하다. 또한, 분석된 결과를 토대로 Performance를 개선할 수 있는 Factor를 찾아야 할 것이다. 이 연구에서는 선박의 선체저항을 어떻게 정량화하고 그 방법론을 연구하는 것에 목적이 있으며 실제 선박에 적용 가능한 것인지 실해역에서 운항중인 선박의 데이터를 이용하여 방법론을 검증하고자 하였다.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1111-1116
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• 2011

Power distribution systems onboard vessels are typically configured without any live line connected to hulls for earthing purpose, where the line to hull voltages are affected and deformed depending on the impedances consisting of insulation resistances and distributed capacitances between power lines and hull. An insulation fault at power lines causes the line to hull voltages to increase to a higher level which brings more possibilities to electric shock and deterioration of insulation material. This study focuses on how to configure a module which enables to continuously monitor the voltages between power line and hull based on the vector diagram by analyzing the neutral point of 3 phase voltages and the algorithm for plotting method on the PC monitors.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.6
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• pp.761-767
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• 2007

We have developed novel optical-fiber sensors based on strain-induced long-period fiber gratings for monitoring the deformation of a hull. They have no external pressure for sustaining the mechanical formed gratings. The pressure, which provides a force to form the periodic grating along the single mode fiber, was realized by the bonding strength of a photopolymer. To reduce the polarization dependency of the sensors caused by the asymmetry structure of gratings, a Faraday Rotator Mirror (FRM) was utilized in this experiment. We have realized the polarization-insensitive function of the proposed sensors. The change of an external strain are measured by an optical spectrum analyzer. When the external stain increases. the attenuation at the resonant wavelength decreases and the loss peak was slightly shifted to the shorter wavelength.