• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.167-178
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• 2007

In general, it is known that the concrete ballast track is possible to reduce a cost of maintenance activities cause of maintenance free by restrictive maintenance in application of track ballast structures. However, if deteriorations and fracture mechanism of a material are considered, proper maintenance activities and repairing are continually required. For the problems, we evaluated an economical efficiency of the gravel ballast and the concrete ballast on a proper level of maintenance activities. As the method based on history path is difficult to obtain sufficient reliabilities cause of an absence of real data for maintenance activities, we chose the delphi survey method by professional group, and we obtained the appropriate index and profiles for maintenance activities. As a result, we founded that effects for cost reduction can be expected by preventive maintenance management, and we proposed economical restrictions and life cycle cost for track ballast structures in a life cycle.

• Proceedings of the KSRS Conference
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• v.1
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• pp.483-486
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• 2006

The study describes the monitoring of the Bay of Bengal as a ballast water exchangeable sea using MODIS/Aqua-derived diffuse attenuation coefficient (K(490)) synchronized with in situ ballast water sampling and analysis along the LNG carrier's route between Japan and Qatar from 2002 to 2005. Based on the relationship between K(490) and corresponding in situ plankton cell densities, the Bay of Bengal is recognized as a ballast water exchangeable sea to meet the regulation of ballast water performance standard of International Maritime Organization (IMO). Furthermore the Bay of Bengal with more than 200m depth and more than 200 nautical mile distance from shore is extracted based on the regulation of ballast water exchange area of IMO. However, an anomalously high K(490) area is found off the coast of Sri Lanka during the northeast monsoon in 2005, which corresponds higher cell densities than the criterion set by the regulation of IMO. The phenomenon of high cell density in the Bay of Bengal seems to be related with the phytoplankton bloom during the northeast monsoon. Seasonal and annual variability of phytoplankton bloom will be investigated to establish an early routing system for avoiding the high cell density area in advance.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.2
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• pp.163-170
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• 2017

The International Convention for the Control and Management of Ships' Ballast Water and Sediments (hereafter "BWM Convention") will be enforced beginning on September 8, 2017. Even though the STCW Convention (International Convention on Standards of Training, Certification and Watchkeeping for Seafarers) and other international instruments require all ship personnel be qualified under certain competencies and standards, the International Maritime Organization (hereafter "IMO") has no unified requirements for training ship personnel on ballast water management. When the BWM Convention enters into force, all officers and crew on board ships should be intimately familiar with the guidelines and procedures outlined by the BWM Convention, regarding, among other topics, proper record keeping techniques and measures, the layout of the ballast control system, methods of ballast water exchange, and inspections by the port state control. To ensure that officers and crew members are adequately familiar, this paper proposes new competency requirements for ballast water management training and education to be added to the STCW Code. To support the introduction of these new competency requirements, this paper explores the evolution of the BWM Convention and examines how international regulations will be used to implement it.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.149-150
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• 2006

Displayed result that handle particle contaminant and hydrospace organism included in number of ballast that is happened in ship using automatic back washing filter. Reason that remove first contaminant that is included in number of ballast is that heighten processing effect of after processing process. of the filter. Another advantage is to drop oft the solids with controlling revolution of drum screen in pretreatment filtration process. The fact that it is easy to attach and detach a several type of screen for getting the expected water quality is another advantage. Filter rotation speed at 1.0rpm is filter resistance 3.0bar and 3.0rpm is filter resistance 2.8bar. Filter out impurities from ballast water over 6.0rpm is filter resistance 2.6bar and 10rpm is filter resistance 2.5bar. Filtration system removal aquatic organism over $80{\mu}m$ in ballast water. This study shows that the filtration treatment system has a potential for the treatment of ballast water.

• Journal of the Korean Society for Railway
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• v.12 no.4
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• pp.481-487
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• 2009

On the paved track, the railway ballast is used as aggregate for the filling layer using the pre-packed concrete method. The condition of ballast as the paved track aggregate ensure that the compressive strength, particle distribution size for the pouring and surface clearance to increase the adhesive strength with mortar. It is profitable to recycle the existing railway ballast as a economical supply. In order to increase recycling characteristic, it is necessary to apply the similar criterion which does not exceed the conventional railway ballast criterion. Consequently, this paper was to investigate physical characteristics of existing ballast, particle size distribution, compressive and flexural strength, bearing capacity and filling capacity to prepare the aggregate's recycling. As a result, optimized aggregate criterion is suggested.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.6 s.144
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• pp.673-678
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• 2005

IMO adopted ' International Convention for The Control and Management of Ships' Ballast Water and Sediments ' on February 13th 2004. According to this convention, a ballast water treatment system should be installed in all ships obligatorily up to a standard date. When the system is installed, economic propriety should be considered. The economic propriety analysis examines the profit of a relevant project which can be presented by a equation, (Profit) = (income) - (expense) - (tax). However, the ballast water system is not for the profit during the life cycle but for the satisfaction of the regulation. Therefore, the expense should be minimum against the profit. This study presents the LCC(Life-Cycle Cost) analysis for economic evaluation of several ballast water system of foreign products.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.2
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• pp.121-128
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• 1998

A new magnetic ballast was designed and developed to get high luminous efficiency. The core material of new magnetic ballast was G-9 and its shape of core is modified. The diameter of the coil was upgraded to 0.5[mm], and a new power-saving circuit was designed for the semiconductor ignition starter. The experimental results of the ballast showed reduction of the electric loss in the magnetic ballast about 1.7Watt (0.5[%]). The luminous efficiency was increased by 6.2 lm/Watt (7.6[%]) and the ballast efficiency factor(BEF) of 1.09(7.6[%]). The prototype was tested through national standard testing procedure. A high efficient energy-using equipment (the second grade in the efficiency of energy consumption) was certified. The saving power of 1.7[W] was shown by lighting appratus for fluorescent lamps. The result will be used for the high efficient magnetic ballast technology.nology.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.435-439
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• 2002

This paper describes a design and fabrication of an electronic ballast for 70[W] ceramic discharge metal halide lamps. The proposed ballast is composed of a rectifier, an active power factor correction circuit (PFC), a half-bridge inverter, a LC resonant circuit and a microprocessor. The developed ballast also includes a specially designed time circuit which provides reignition of lamps. Running frequency of the ballast is set at 40[kHz] to avoid acoustic-resonance and flickering. From the experimental results, input power factor and efficiency of the ballast are estimated 99.8[%] and 93.1[%)] respectively.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.10
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• pp.1989-1994
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• 2009

This study purposes are improvement of system (lamp & ballast) efficacy with and optical characteristics through the developed ceramic arc tube. The designed electronic ballast is substituted for conventional magnetic ballast. These electric signal and optical, thermal characteristics through the improving efficacy of lighting system compared with conventional magnetic ballast. properties of lamp by driving method is researching in ballast. Particularly, electronic ballasts, which improved against weakness of Magnetic Ballast, are researching and applying to control of ceramic metal-halide lamp. but One major limitation is the acoustic resonance problem in CMH lamps at high-frequency operation. In order to avoid acoustic resonance, driving frequency decided 21[kHz]. Before discharge in this paper. The PSpice simulation result obtained sufficient voltage gain and the ignition voltage obtained over 3[kV] at 75[kHz]. After discharge, driving voltage obtained approximately 90[Vrms] at 21[kHz].

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.6
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• pp.9-17
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• 2006

In this paper, we analyzed and measured the characteristics of the ballasts for HID lamps according to the cable properties. The ignition voltage and the steady state voltage and current are depend on the feature and the length of the cables. So we measured characteristics at 25[m] and 100[m] distances used by a low frequency electronic ballast a high frequency electronic ballast and a magnetic ballast. By measured and analyzed result of characteristics for various kinds of ballast and cables, we concluded that the electronic ballast driving with the low frequency is better than my other ballasts, and that the capacitance between the cables is important.