• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.06a
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• pp.141-146
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• 1999

An experimental investigation on the leakage characteristics of a labyrinth seal, high-low seal, is studied. Pressure distribution and leakage flow rate are measured along with the shaft speed and the pressure difference between the entrance and the exit. Pressure distribution vanes almost linearly along the seal and the leakage flow rate increases as the increase of the pressure difference. Furthermore, it is found that both the shaft speed and the shaft vibration have no influence on the leakage of the labyrinth seal.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.93-96
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• 2008

A transmitter (TX) leakage cancellation scheme using a Micro Controller Unit (MCU) is introduced. This paper highlights an adaptive anti-leakage signal generation via an MCU, which plays the key role in reducing the TX leakage signal level. High transmitter-to-receiver (TX-to-RX) isolation is verified with measurement results.

• Journal of Information Technology Services
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• v.19 no.4
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• pp.13-30
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• 2020

Not only does it cause damage to individuals and businesses due to the occurrence of large-scale personal information leakage accidents, but it also causes many problems socially. Companies are embodying efforts to deal with the threat of personal information leakage. However, it is difficult to obtain detailed information related to personal information leakage accidents, so there are limitations to research activities related to leakage accidents. This study collects information on personal information leakage incidents reported through the media for 15 years from 2005 to 2019, and analyzes how the personal information leakage incidents occurring to companies are related to the characteristics of the company. Through the research results, it is possible to grasp the general characteristics of personal information leakage accidents, and it may be helpful in decision making for prevention and response to personal information leakage accidents.

• Journal of Magnetics
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• v.21 no.3
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• pp.437-441
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• 2016

Dipole model based analytical expression is proposed to estimate the length and depth of the rectangular defect on ferromagnetic pipe. Among the three leakage profiles of Magnetic Flux Leakage (MFL), radial and axial leakage profiles are considered in this work. Permeability variation of the specimen is ignored by considering the flux density as close to saturation level of the inspected specimen. Comparing the profile of both the components, radial leakage profile furnishes the better estimation of defect parameter. This is evident from the results of error percentage of length and depth of the defect. Normalized pattern of the proposed analytical model radial leakage profile is good agreement with the experimentally obtained profile support the performance of proposed expression.

• Journal of Applied Reliability
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• v.14 no.4
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• pp.230-235
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• 2014

The failure modes of pneumatic directional control valves include leakage, wear of the spool seal, and sticking of the spool. Among them, the main failure mode of the valve is leakage. The leakage is caused by the wear of the spool seal. However, due to the characteristics of the seal material, the leakage rate is fluctuated a lot rather than constantly increased over time. If life analysis is performed using the first time data of leakage failure, predicted life cycles can be different from the real life cycles. This paper predicts life cycles of the pilot pneumatic directional control valve based on the three point moving average which considers the average of the fluctuating leakage rate.

• 유체기계공업학회:학술대회논문집
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• 2002.12a
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• pp.63-68
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• 2002

ADC(Automatic Discharge Connector) is commonly used for the easy maintenance of the submersible pumps. However, the small gap between the flange of the base plate and that of the pipe due to the head rise, the flow momentum change and the mis-installation makes leakage flow that may be a great loss to the pumping system. In this study, the performance degradation was predicted with the simple leakage flow model through the gap. The newly developed ADC was tested and the leakage performance was compared with the old one and also no-leakage piping system. The newly developed ADC reduced the leakage flow in a satisfactory way in comparison with the old model.

• Tribology and Lubricants
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• v.20 no.4
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• pp.183-189
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• 2004

The floating ring seal is used in an oxidizer and a fuel pump of the turbo pump unit in the liquid rocket engine to optimize a leakage without rubbing phenomenon. The damper floating ring seal, one of the floating ring seals, is with round hole pattern surfaces. It can reduce the leakage by increased friction factor that obtained from experimental data. In this paper, the leakage test about floating ring seal and damper floating ring seal was conducted. The test result showed the leakage performance of damper floating ring seal was better than the leakage performance of floating ring seal. With the leakage test the lock-up and rotation test about seal was conducted and that position is measured. The relatively large lock-up eccentric ratio was obtained from the test result of damping floating ring seal. The attitude angle of seal increases with increasing of shaft rotation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.6
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• pp.82-87
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• 2013

Electrical leakage happens when faults in electrical apparatus or power lines occur. It causes electrical fires and electric shocks. In order to reduce accidents caused by electrical leakage current, it is important to detect faults effectively and shut off the power. In this paper, firstly we analyzed statistics of electrical fires and electric shocks caused by electrical leakage current. Secondly, standards of allowable leakage current and body impedance models were analyzed. Lastly, effective application methods for breaking electrical leakage current were suggested. The results will provide useful preventive measures of electrical fires and electric shocks caused by electrical leakage.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.517-519
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• 2008

A new transformer winding method is proposed in this paper. Generally, PWM ZVS topologies use a leakage inductor to achieve ZVS operation. However, the leakage inductance of the transformer is not often enough to meet ZVS condition. Therefore, an additional leakage inductor is necessary, which causes large core loss because high input voltage is applied to the additional leakage inductor during a short commutation period. In this paper, a new separated leakage inductor winding (SLW) method is proposed. With the proposed winding method, a leakage inductor and a transformer can be combined in one ferrite core. Therefore, size and core loss of the additional leakage inductor can be reduced. Experimental results demonstrate that the proposed winding method can achieve a significant efficiency improvement in a 1210.8W (12V, 100.9A) prototype converter.

• The KSFM Journal of Fluid Machinery
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• v.6 no.2 s.19
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• pp.23-28
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• 2003

ADC (Automatic Discharge Connector) is commonly used for the easy maintenance of the submersible pumps. However, the small gap between the flange of the base plate and that of the pipe due to the head rise, the flow momentum change and the mis-installation make a leakage flow that may be a great loss to the pumping system. In this study, the performance degradation was predicted with the simple leakage flow model through the gap. The newly developed ADC was tested, and the leakage performance was compared with the old one and also no-leakage piping system. The newly developed ADC reduced the leakage flow in a satisfactory way in comparison with the old model.