• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.5
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• pp.52-56
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• 1996

Fluorescent lamps are widely accepted to energy efficient commercial lighting applications. In designing a fluorescent lamp system, a ballast design heavily relies on the characteristic of a fluorescent lamp under consideration. Especially, at startup time, the transient characteristic of a fluorescent lamp puts much tighter specification of a design. In this paper, based on the transient characteristic at the startup time, a transient behavioral model of a fluorescent lamp is presented with an equivalent circuit. The model is applicable to the wide range of fluorescent lamps provided by different manufacturers. The experimental results are compared with the results provided by PSPICE simulation. The result shows the model is effective In practice. As a result, we could identify more accurate startup constraints to decide the design of either an electro mechanical or an electronic ballast.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1223-1228
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• 2007

Since KHSL 2nd phase was adapted as a main track design, the interests of concrete slab track system have been gradually increased in the division of rail track engineering and many engineering companies have been trying to adapt a concrete slab track system at this moment. Advantages of this system proved in advanced country, japan and Germany etc. are excellent maintenance, track stability and increasing of buckling resistance This developed turnout is same with the KHSR 1st phase's design and applications rules, components and signaling system since it observes KTX specification. Comparing it with the former turnout, High-elasticity pad, lubrication-free roller slide plate and Rheda2000 PC sleeper are only different. The purpose of this study is the development of high speed turnout on concrete slab track and its application on site. Now these studies are going to show the verification and confidence about the interface between ballast-track and concrete slab track by finding and solving the possible problems when it is installed on site and to make these turnouts applied perfectly and completely on concrete slab track. Its first trial construction in korea had been successfully completed at Sangju-station on July 20th ,2007 thanks to KORAIL and KR. Hereunder Sampyo E&C trys to introduce all of turnout technologies on concrete slab track system with Rheda 2000 sleeper

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_1
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• pp.907-915
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• 2020

Specification selection, Layout, specifications and combinations of Power Drives, and Ship motions were studied for FGPP(Floating Gas-fired Power Plants), which are still needed in areas such as the Caribbean, Latin America, and Southeast Asia where electricity is not sufficiently supplied. From this study, the optimal equipment layout in ships was derived. In addition, the difference between engine and turbine was verified through LCOE(Levelized Cost of Energy) comparison according to the type and combination of Power Drives. Analysis of Hs(Significant Height of wave) and Tp(spectrum Peak Period of wave) for places where this FGPP will be tested or applied enables design according to wave characteristics in Brazil and Indonesia. Normalized Sloshing Pressures of FGPP and LNG Carrier are verified using a sloshing analysis program, which is CFD(Computational Fluid Dynamics) software developed by ABS(American Bureau of Shipping). Power Transmission System is studied with Double bus with one Circuit Breaker Topology. A nd the CFD analysis allowed us to calculate linear roll damping coefficients for more accurate full load conditions and ballast conditions. Through RAO(Response Amplitude Operator) analysis, we secured data that could minimize the movement of ships according to the direction of waves and ship placement by identifying the characteristics of large movements in the beam sea conditions. The FGPP has been granted an AIP(Approval in Principle) from a classification society, the ABS.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.8
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• pp.551-557
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• 2022

LRU (Line Replacement Unit) modifications are often required for military aircraft due to aging. Recently, LRU modifications were proceeded for KA-O (Armed Airborne Controller) by replacing the ejection seat and adding avionic equipment, which made the aircraft's operational CG (Center of Gravity) on fuel consumption curve become out of the range of the specification requested. The off-ranged CG should be corrected by introducing an appropriate method. This study proposes a procedure for revising and verifying the empty weight CG altered due to LRU modification for small military aircraft (e.g., KA-O). In the proposed method, first, the change of empty weight CG of KA-O due to the LRU modifications is comprehensively examined. Then, several ballast masses are added to the engine mount strut to restore the empty weight CG on the fuel consumption curve to a safe operational range. The installations are verified via stress and fatigue analysis for various operating conditions. Considering that open information is not very available for the revision of empty weight CG, this study is valuable because it presents an established procedure for correcting and verifying empty weight CG during aircraft modification.