• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.128-133
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• 2005

An iris-coupled partial H-plane filter as a new type of partial H-plane filter is proposed. The proposed filter can be compared with conventional H-plane filter and uses an iris-type evanescent waveguide as a coupling structure. Filter design technique based on numerical simulation is developed to design and compare the proposed filter and H-plane filter. Designed iris-coupled partial H-plane filter has the same frequency response as that of the conventional H-plane filter while its cross section is one quarter. A good agreement between measurements and theoretical prediction is achieved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.746-752
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• 2006

In this paper, a compact partial H-plane filter with periodic structure is proposed. Guided wavelength of periodic structure' is reduced by slow wave effect. Cross-section and length of partial H-plane filter with periodic structure are considerably reduced by 75% and 30%, respectively, as compared with conventional E-plane filter. In addition, spurious responses of the bandpass filter are improved. To design bandpass filter with periodic structure, we have analyzed a periodic structure of partial H-plane waveguide and derived equations of the periodic filter. Measured results are in good agreement with simulated results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2286-2292
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• 2011

In this paper we present the design of Low Noise Amplifier(LNA), mixer and filter for RF front-end part of partial discharge monitoring system. The monitoring system of partial discharge in high voltage power machinery is used to prevent many kinds of industrial accidents, and is usually composed of three parts - sensor, RF front-end and digital microcontroller unit. In our study, LNA, mixer and filter are key components of the RF front-end. The LNA consists of common gate and common source-cascaded structure and uses the resistive feedback for broad band matching. A coupled line structure is utilized to implement the filter, of which size is reduced by the meander structure. The mixer is designed using dual gate structure for high isolation between RF and local oscillator signal.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.4
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• pp.44-55
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• 1993

In this paper, we proposed a new optical method for the efficient recognition of Korean characters. There are six filters in the proposed method which employed the concepts of amplitude-modulated phase-only filter(AMPOF) and spatial frequency modulation(SFM). Here, amplitude modulation is used to achieve improved correlation discrimination and SFM is to reduce the number of filters. We also used a simplified synthetic discriminant function(SDF) for distortion invariance of input image. In order to recognize the partial rotation invariant Korean characters, the proposed distortion invariant minimum average correlation energy (MACE) filter is synthesized SFM, partial rotation invariant filter (PRIF), AMPOF and MACE for partial rotation invariance in the frequency domain. The advantage of the proposed filters is to supress the sidelobes of cross correlation peak away from the autocorrelation peak and to produce sharp correlation peaks. We performed simulation and optical experiment for some of Korea characters using the proposed method. The results show that the proposed method has more improved discriminant ability and reduced processing time than the conventional methods.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.107-113
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• 2008

This paper presents half wavelength partial H-plane filters with multiple attenuation poles using narrow H-plane slot of evanescent waveguide. The narrow H-plane slot operates as an admittance inverter o( the bandpass filter and, simultaneously, generates an attenuation pole at particular frequency. Therefore, proposed filters with attenuation poles are simply implemented without any additional coupling and extra modification of the structure. The number of attenuation poles of the filters equals to that of the H-plane slots. Moreover, proposed filters are compact waveguide filter since ones are embodied by partial H-plane waveguide which has 1/4 cross section of conventional waveguide. The third and fourth-order half wavelength filters having 4 and 5 attenuation poles, respectively, are designed in H-band and their frequency responses are confirmed by simulation and measurement.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.1
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• pp.24-34
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• 2009

DPF(Diesel Particulate Filter)s have been used to reduce the most of PM(particulate matters) from the exhaust emissions of diesel engine vehicles. Metal foam is one of promising materials for the DPFs due to its cost effectiveness, good thermal conductivity and high mechanical strength. It can be fabricated with various pore sizes and struct thickness and coated with catalytic wash-coats with low cost. In order to design metal foam filter and analyze the flow phenomena, pressure drop and filtration experiment are carried out. Partial DPF which has PM reduction efficiency of more than 50 % is designed in this paper. Also, CFD analysis are performed for different configurations of clean filters in terms of pressure drop, uniformity index, and velocity magnitude at face of filter. Filter thickness and the gap between front and rear filters are optimized and recommended for manufacturing purpose.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.4
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• pp.97-102
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• 2007

This paper presents our implemented, synthesized and tested on demand and partial reconfiguration approaches for FIR filters using Xilinx Virtex FPGAs. Our scope is implementation of a low-power, area-efficient autonomously reconfigurable digital signal processing architecture that is tailored for the realization of arbitrary response FIR filters on Xilinx Virtex4 FPGAs. The implementation of design addresses area efficiency and flexibility allowing dynamically inserting and/or removing the partial modules to implement the partial reconfigurable FIR filters with various taps. This partial reconfigurable FIR filter design shows the configuration time improvement, good area efficiency and flexibility by using the dynamic partial reconfiguration method.

• Proceedings of the KIEE Conference
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• 2008.09a
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• pp.218-221
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• 2008

Due to a variable noises in the field underground lines, clear technology of noises is very important in the diagnosis technology of partial discharge. Therefore we progressed filter test to improve the measuring test of partial discharge in a field. We applied to field test after making W-LC filter for partial discharge measurement, and then designed experimental environment such as under- ground distribution lines of field. Measuring sensor for test was UHF sensor. And we analysed those using the Lemke Probe and oscilloscope (TDS-3054, Tektro- nix). Finally, we obtained excellent data of noise decrement in the joint box of 22.9[kV] distribution lines from above experiment.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.72-74
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• 2007

Due to a variable noises in the field underground lines, clear technology of noises is very important in the diagnosis technology of partial discharge. Therefore we progressed filter test to improve the measuring test of partial discharge in a field. We applied to field test after making W-LC filter for partial discharge measurement, and then designed experimental environment such as underground distribution lines of field. Measuring sensor for test was UHF sensor. And we analysed those using the Lemke Probe and oscilloscope (TDS-3054, Tektronix). Finally, we obtained excellent data of noise decrement in the joint box of 22.9[kV] distribution lines from above experiment.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2277-2279
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• 2005

Due to a variable noises in the field underground lines, clear technology of noises is very important in the diagnosis technology of partial discharge. Therefore we progressed filter test to improve the measuring test of partial discharge in a field. We applied to field test after making W-LC filter for partial discharge measurement, and then designed experimental environment such as under-ground distribution lines of field. Measuring sensor for test was UHF sensor. And we analysed those using the Lemke Probe and oscilloscope (TDS-3054, Tektronix). Finally, we obtained excellent data of noise decrement in the joint box of 22.9[kV] distribution lines from above experiment.