• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.667-672
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• 2007

The source of wayside noise for the train are the aerodynamic noise, wheel/rail noise, and power unit noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The Structure borne noise is mainly a low frequency problem. The train noise and vibration nearby the elevated railway make one specific issue. In this paper, the train noise and structure borne noise by train are measured. From the results, we investigated the effect on the sound absorption tunnel for elevated railway.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.688-694
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• 2001

The 84m discharge line of moisture separator reheater(MSR) in Kori-2 had been suffered by excessive vibration from the beginning of power generation. In 1993, a complementary measure was taken to reduce the vibration level by adding several supports in the MSR pipeline. However, the piping vibration was beyond the allowable limit and an appropriate countermeasure was required to prevent the fatigue failure of the pipeline from the abnormal vibration. In this study, the vibrational characteristics of MSR pipeline and the countermeasure for abnormal vibration was investigated. Among the several vibration reduction methods, piping layout change by smoothing the pipeline was applied to the MSR pipeline in Kori-2. Applying the countermeasure, the vibration level was found to dramatically reduce from 17cm/sec to l.0cm/sec at the full-power operation condition.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.4
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• pp.467-473
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• 1999

We have realized the two kinds of power line communication systems by the FSK MODEM. The first approach is the DS-SS (Direct suquence-spread spectrum) technique using 8 bits pseudo noise, the other is Convolutional coding method by the new algorithm. Their characteristics are comparied with each other by experimenting their Bit Error Rates (BER) in high level of Noise. The results have showed that two systems are useful to the application of HA (Home Automation) systems.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2660-2662
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• 2003

In this paper, an appropriate modulation method was implemented as their results presented in details and verified by the simulations. The data compensation method at momentary high noise occurrence by using retransmission request techniques that uses error checking was discussed. Finally, application of other modulation method by detection of error rate per bit according to variation of channel error caused by electric equipment that is connected to power line was studied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.37-40
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• 2002

Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in cable TV.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.1
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• pp.99-106
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• 2003

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. The maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system. In order to realize these tasks autonomously, the there dimensional position of target object such as electric line and the stand of insulator must be recognized accurately and rapidly. The insertion task of an electric line into a sleeve is selected as the typical task of the maintenance of active electric power distribution lines in this paper. A modified hough transform is applied to the recognition of the center of electric line and optimal target position calculation method is newly derived in order to recognize the center 3 dimensional position of the electric line. By the proposed method, it is proved that the center position of the electric line can be recognized without respect to the noise of image and the shape of electric lines and the insertion task of an electric tine is realized.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.11a
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• pp.287-290
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• 2007

This study examines the characteristics of noise occerred at a hydroelectric power plant by using the on-line partial discharge measured by eletrical detecting method under the high voltage rotating machines. In addition, it analyzes the noise pattern into frequency and its scale component by using the FTT technique.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.74-77
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• 1993

Estimation and removal of power line interference in the electrocardiogram using adaptive noise cancelling techniques is presented. The system identification concepts are used to design the noise cancelling filter and the prediction error method is used to adjust filter coefficients. Computer simulation were performed to compare this method with the Lekov's method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.8
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• pp.645-650
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• 2010

The continuous increase demand for electric power leads to the additional construction of transmission facilities, but it is not easy to acquire right-of-way for transmission facilities. Therefor, there is a need for compact tower that can be built on a narrow right-of-way the compact tower with polymer insulation arm is a solution. It can be upgrading conventional 154 kV transmission line voltages to 345 kV levels. However transmission voltage is increasing, environment interference (corona noise, radio interference, etc.) will occur gradually. This environment interference is depending on the electrical clearances of tower and configuration of conductors. Therefore the analysis of the factors of environmental interference is necessary in order to upgrading transmission voltage. This paper presents the design factor of a compact tower to meet the environmental interference standard.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.245-249
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• 2006

Corona characteristics of conductors are dependent on the electric field conditions in the immediate vicinity of the conductors. In case of DC transmission line, particularly, the space charge plays an important role in the electric field distribution. Therefore, DC corona cage simulation is necessary for long-term test in the same conditions. This paper presents the results of designing and constructing hardwares such as DC power supply, measurement system and DAS to carry out the simulation. The corona cage longitudinally is divided into five equal length sections and three inner sections of those are isolated from the ground of outer cage. The measurement items are radio noise, corona current, television noise, audible noise and meteorological conditions. In the next step, various simulations about the type and configuration of two or three candidate conductors will be conducted. And then finally an environmentally-friendly conductor for HVDC overhead transmission line will be decided.