• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.2
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• pp.447-454
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• 2011

Power-line interference(PLI) can distort certain regions in analysing the ECG signal. In particular, the regions such as P and R wave that are important element in diagnosing with arrhythmia is expressed as different type of noise according to the case whether power-line frequency is multiples of sampling frequency and or not. Noise characteristics is also divided into linearity and non-linearity. In this paper, adaptive subtraction method for removing variable PLI of ECG signal is proposed. We classify the multiple relationship between power line and sampling frequency as Multiple and Non-multiple. PLI of Linear segment is extracted through moving average filter, PLI of non-linear segment is extracted through the interference component that is extracted in the linear segment and stored in the temporary buffer. The performance of P wave and R wave detection is evaluated by using 119 data record of MIT-BIH arrhythmia database. The achieved scores indicate P wave detection rate of 97.91%, R wave detection rate of 96.66% and P wave detection rate of 99.01%, R wave detection rate of 97.93% accuracy respectively for Notch filter and proposed subtraction method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.559-562
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• 2017

In city, tracing of power transmission lines is difficult due to compound installation of overhead and underground lines, transposition, bad view caused by trees or big buildings. It is hard problem for electrical technician on site to trace power transformers or power lines to serve customers in 3 phase -4 wires power distribution systems. It is necessary that the correct and fast tracing method is required for load balancing among distribution lines. Old technology use to trace off-lines with high power impulse injection. Our proposed method use to trace live lines with very small power high frequency signal injection. Typical power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. Two end communication terminals are required to be synchronized between them for determination on electrically same phases. Challenging issue is to achieve synchronization without GPS providing synchronizing time. A novel power transformer and wire identification system is designed and implemented. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.3
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• pp.267-274
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• 2004

In this paper, a new on-line dead-time compensation method is proposed. The output voltage errors due to the dead-time effect is considered as disturbance voltages. The magnitude of the disturbance voltages is estimated using a time delay control technique and the disturbance voltages are calculated using the estimated values, measured currents, and position information. The calculated disturbance voltages are fed to voltage references in order to compensate the dead-time effect. The proposed method is applied to a PM synchronous motor drive system and implemented in a digital manner using a digital signal processor (DSP) TMS320C31. The experiments are carried out for this system to show the effectiveness of the proposed method and the results show the validity of the proposed method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.2
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• pp.234-241
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• 2000

During the EFT immunity test, the fast transient voltage is injected to the power or signal line. The radiated noise from these lines influences the near-by EUT, and consequently, the reliability of the test result can be jeopardized. The measured data of the field strength and wave shape of the noise were compared with the result of the mathematical analysis using transmission line model. When the tests were performed by the conditions the same as stated in IEC 61000-4-4, the results showed that the magnitude of the radiated electric field strength was about 2.4KV/m, and it can cause severe interference to the intended operation of EUT.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.3
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• pp.291-298
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• 2016

In this paper, we studied about the radiated emission of EFT(Electrical Fast Transient)/Burst signal, referenced IEC-61000-4-4 of the international EMC standard and its effect on EUT(Equipment Under the Test) when EFT/Burst signal (Conducted noise) induced on a power cable to EUT. Firstly, we set up test sample by the standard and +4 kV standard signal is induced by EFT/Burst signal generator with 1 m length power cable for 1 minute. Consequently, we found not only induced EFT/Burst signal along power line, but also directly radiated emission signal from EFT/Burst signal generator (Radiated emission noise of EFT/Burst). The radiated emission signal of EFT/Burst was 30 dB which is higher than limit of CISPR 22 which is international EMC standard. Moreover, we measured the electric field strength by changing distance from maximum radiated emission point to electric field strength tester. As a result, this electric field strength was 23 V/m which is higher than international EMC standard test level(CISPR 24). Therefore, it was confirmed that the probability of malfunction may be high when radiated emission of EFT/Burst noise exists near the EUT.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.362-364
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• 1998

The transmission of information by inductive loop is required for train-safety and fast running. FSK modulation has been used for transmission of information in fast running. Transmission channel between train and ground must be protected from interference of power line. To protect transmission data from noises, the analysis on the transmission line must be performed in advance. In this paper, transmission line is analyzed in view of reflection and time delay in both noise and signal.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.215-216
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• 2005

To decrease and remove of much noises that is detected in PD (partial discharge) measuring test. we forced on detection of those. We made W-LC filter for measuring PD. which adapted that to field test. We tested after design laboratory circumstances like field line. and then the phase change properties of detected signal in UHF sensor were measured by Lemke Probe and oscilloscope (TDS-3054. Tektronix). Eventually we checked decrement of noises from experimental result. Also from experimental result at the joint box of 22.9[kV] distribution line. we obtained reasonable data which enable noises to decrease. Hereafter those results will be adapted at ultra-high voltage for trouble prevention and on-line cable watch. diagnosis of those.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.11
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• pp.1184-1190
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• 2003

In this paper, we investigated the characteristics of compensation for distorted NRZ signal and RZ signal in 320 Gbps WDM system as a function of channel input power, fiber dispersion coefficient and transmission length, respectively. The considered WDM transmission system is based on mid-span spectral inversion(MSSI) compensation method having highly nonlinear dispersion shifted fiber(HNL-DSF) optical phase conjugator(OPC) in the mid-way of total transmission line. We confirmed that the signal input power range compensated by MSSI is broadened by using RZ as a signal format in WDM system with small fiber dispersion coefficient, The range of fiber dispersion coefficient compensating overall distorted WDM channels is limited, because degree of compensation for distorted channel with low conjugated-wave power becomes gradually degrade as fiber dispersion coefficient becomes gradually higher. It is showed that RZ format and NRZ format is suited for long-haul transmission in WDM system with small fiber dispersion coefficient and with large fiber dispersion coefficient, respectively.

• Journal of Electrical Engineering and Technology
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• v.1 no.3
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• pp.359-365
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• 2006

Since the start of the KSTAR (Korea Superconducting Tokamak Advanced Research) project, Instrumentation and Control (I&C) of the Neutral Beam Test Facility (NB-TF) has been striving to answer diverse requests arising from various facets during the project's development and construction phases. Hard-wired electrical circuits have been designed, tested, fabricated, and finally installed to the relevant parts of the system. In relation to the vacuum system I&C, controlling functions for the rotary pumps, a Roots pump, two turbomolecular pumps, and four cryosorption pumps have been constructed. I&C for the ion source operation are the temperature and flow rate signal monitoring, Langmuir probe signal measurements, gradient grid current measurements, and arc detector circuit. For the huge power system to be monitored or safely operated, many temperature measurement functions have also been implemented for the beam line components like the neutralizer, bending magnet, ion dump, and calorimeter. Nearly all of the control and probe signals between the NB test stand and the control room were made to be transmitted through the optical cables. Failures of coolant flow or beam line vacuum pressure were made to be safely blocked from influencing the system by an appropriate interlock circuit that will shut down the extraction voltage application to the system or prevent damages to the vacuum components. Preliminary estimation of the beam power through the calorimetric measurement shows that 87.9% of the total power of the 60kV/18A beam with 200 seconds duration is absorbed by the calorimeter surface. Most of these I&C results would be highly appropriate for the construction of the main NBI facility for the KSTAR national fusion research project.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.2
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• pp.27-33
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• 2022

The small infrared image homing sensor is the eye of a guided weapon that has an infrared image sensor that identifies a target on the ground through day and night infrared image processing and searches, detects, and tracks the target. Inside the guided weapon since the power supply and communication line are used together with various components, the part against electromagnetic wave interference is very important. In particular, the effect of CE (Conducted Emission) through the power and communication lines connected by cables is very important. Through this method, it is possible to directly affect other components of the guided weapon. In this paper, the EMI filter and cable design for avoiding electromagnetic interference to the power input through the cable and the communication line are described. Also, the designed EMI filter is manufactured After the CE102 test of MIL-STD-461G, design satisfaction will be explained.