• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.97-100
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• 2007

This study deals with the sound insulation performance of the damping sheet, which is widely used in a train. The wall of train is assumed to be a plate made of steel and two damping sheets. In case of damping sheet only, the sound transmission loss follows the mass law. If a steel plate is attached to damping sheet, the transmission loss is found to be higher than single of only steel plate, as we can anticipated, about $3{\sim}5$ dB. This is very well known consequence that is because the density of area increases. However, the increase of the transmission loss is not higher than what we can expect by the mass law. That's because the steel is perfectly blocked from the transmission of the air ; There is no defect in that material.

• Journal of Welding and Joining
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• v.33 no.4
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• pp.57-62
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• 2015

Non-destructive techniques are used widely in the metal industry in order to control the quality of materials. Eddy current testing(ECT) is one of the most extensively used non-destructive techniques for inspecting electrically conductive materials at very high speeds that does not require any contact between the test piece and the sensor. The New ECT sensor which can detect inner defects was developed regardless the condition of surface. This sensor is verified to do experiment which measure the loss of induced electromotive force. The loss of induced electromotive force was measured in 5.4% and this low frequency ECT device can detect internal defects at depth 20 mm.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.230-234
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• 1995

The loss of offsite power test was successfully performed on YGN 4 to demonstrate that the reactor can be shutdown and the RCS can be maintained in a hot standby condition following a loss of all offsite Alternating Current (AC) power. Following the loss of main generator and all offsite AC power, the ensile emergency diesel generators were automatically started and the plant was stabilized via natural circulation. Plant conditions were maintained in hot standby for at least 30 minutes before offsite power was restored. Thus, the capability of equipment, controls and instrumentation necessary to remove decay heat from the core using only ensile emergency power was demonstrated, thereby satisfying all objectives and acceptance criteria of the test.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.1
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• pp.107-112
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• 2009

This study was conducted for verification and systematization of estimation method about the headloss using CFD(Computational Fluid Dynamics). Head loss which happens between the inlet and outlet of in-line mixer can be a major factor for the design and construction. Also, this Case studies about the sensitivity related to the velocity in the piping system. As result, program's default calculation function was used to get each side's total pressure and the differential of each total pressure could be defined as head loss from in-line mixer. In the case of adopting pipe surface friction factor and geometry loss, Calculation residual can be much more reduced. It was found that residual of value between CFD method and field test ranged about 3 through 18 precent.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.10
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• pp.678-689
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• 2004

The major concern of networked control system is network uncertainties such as time delay and data loss. Because these uncertainties may degrade the performance of networked control system and destabilize the entire system. Therefore, the performance and the stability variation of networked control system due to network uncertainties must be considered first in designing networked control system. In particular, the stability analysis of networked control system is most important issue since time delay and data loss can make the overall systems unstable. In this paper, we present a new stability analysis method of networked control system with time delay and data loss, which is impossible in previous works. The proposed method can determine maximum time delay and allowable transmission rate that preserve stability performance of networked control system. The results of the simulation validate effectiveness of our stability analysis method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.189-196
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• 2002

As the quantity of transported goods increases, there is a lot of mechanical trouble with loading facilities. So it tremendously produces not only economic loss but also time loss. To reduce the loss from the trouble of leading facilities, it is necessary to analyse the distribution of the problem's occurrence and use the analyzed data to minimize the outbreak of trouble. So the data can be usefully used when designing or manufacturing and it also can be utilized for proper maintenance of operating equipment, frequency of inspection and repair, know-how of checking on equipment and purchasing of spare parts. And it is possible to minimize the loss if the propel maintenance is adapted

• The Transactions of the Korean Institute of Power Electronics
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• v.6 no.5
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• pp.453-459
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• 2001

In this paper, the loss analyses of two soft switching techniques for two-transistor forward converter are performed. The sums of snubber conduction and capacitive turn-on losses for two transistors are calculated to compare the losses of the two techniques. While the conventional soft switching technique shows the loss difference between two transistors, the proposed soft switching technique shows equal as well as lower losses In two transistors. Thus, it can be said that even thermal distribution and higher reliability can be obtained by the proposed soft switching technique.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.4
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• pp.551-559
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• 2008

Increase in power consumption can cause a serious stability problem of an electric power system without construction of new power plants or transmission lines. Also, it can generate large power loss of the system. In costly and environmentally effective manner to avoid constructing the new infrastructures such as power plants and transmission lines, etc, the distributed generation(DG) has paid great attentions so far as a solution for the above problem. Selection of optimal location and size of the DG is the necessary process to maintain the stability and reliability of existing system effectively. However, the systematic and cardinal rule for this issue is still open question. In this paper, the method to determine optimal location of the DG is proposed by considering power loss when the DG is connected to an electric power grid. Also, optimal size of not only the corresponding single DG but also the multi-DGs is determined with the proposed systematic approach. The IEEE benchmark 30-bus test system is analyzed to evaluate the feasibility and effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.441-444
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• 2003

Network uncertainties such as data loss and time delay can vary the stability property of networked control system. Therefore, these uncertainties must be considered first in designing networked control system. In this paper, we present a new stability analysis method of networked control system with data loss and time delay. The proposed method can determine maximum allowable time delay and minimum allowable transmission rate that preserves stability performance of networked control system. The results of the simulation validate effectiveness of our stability analysis method.

• Journal of Veterinary Science
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• v.25 no.2
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• pp.26.1-26.6
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• 2024

Bone loss from the kerf of the sawblade may influence the final outcomes when employing three-dimensional-printed surgical guides. However, no studies have systematically addressed saw blade-induced bone loss. This study aims to quantify bone loss and propose a reduction guide to minimize the fracture gap. The postoperative gap tended to decrease as the amount of gap compensation increased. Osteotomy gaps can be attributed to the thickness of the saw blade, and the proposed methodology addresses this surgical error. Surgeons can proactively plan and design reduction guides with applied compensation using the method described in this study.