• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5A
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• pp.618-633
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• 2000

In this paper, a Gaussian interpolation filter and cubic interpolation filter are presented to do more accurate channel estimation compared to the conventional linear interpolation filter for COFDM systems. In addition to an interpolation filter, a low pass filter using FFT and IFFT is also presented to reduce the noisy components of a channel estimate obtained by an interpolation filter. Channel estimates after low-pass filtering combined with interpolation filters can lower the error floor compared to the use of only interpolation filters. Computer simulation demonstrates that the presented channel estimation methods exhibit an improved performance compared to the conventional linear interpolation filter for COFDM systems in time-varying multipath fading channel and0.1 ~ 0.2 dB of Eb/No difference at BER=10-4 when the perfect channel estimation is compared.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.17-31
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• 2003

This study is about throughput analysis of the shared right turn lane at signalized intersection with lane width change. It is expected that the increased width of the right turn shared lane causes to increase the volume of right turn on red(RTOR) In this study, the throughput computation is designed to take into account the lost time which is caused by the blocked right turn due to the stop of through traffic. The saturation flow rate of right turn using the rest of lane after through traffic stops is included as well. Results show that the different RTOR volume levels due to the various shared lane width leads to a difference in throughput. For the shared right turn lanes. throughput capacity for various lane widths is bigger than that of the KHCM as much as from 1.1 to 2.1 times.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10d
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• pp.571-575
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• 2006

통일에 대비한 남북한 인터넷 통합을 위한 준비작업으로서 통일 국가도메인 제정에 대한 논의가 계속되어 왔다. 분단상태의 남북한이 국가 도메인을 하나로 통합하여 공동으로 사용한다는 상징성이 크다는 점에서 남북한 모두가 동의할 수 있는 도메인을 제정하는 일은 중요하다. 통일 국가도메인에 대한 기존 제안들은 우리나라의 현 영문 국호인 'Korea'를 전제로 한 것들이었다. 논자는 일제 강점기 이전까지 우리 나라 영문 국호로 'Corea'가 사용되었다는 주장에 근거한 국호 영문표기 변경 논의가 남북 학술대회와 국회 결의안 등을 통해 공론화되어 많은 호응을 얻고 있음에 주목하였고, 남북한 국호의 영문표기 변경 논의와 연계하여 통일 국가도메인 제정을 추진하는 것이 시의적절하고 효율성도 높다고 판단하였다. 본 논문에서는 통일국가 도메인에 대한 기존 논의들을 검토하고 유사국가들의 국가도메인(ccTLD) 등록 사례를 통해 통일 국가도메인의 등록 가능성을 탐색한 후 통일 국가도메인명으로서 '.uc'(United Corea)를 최종 제안하였다.

• Korean Deer Journal
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• no.24
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• pp.4-11
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• 1995

꽃사슴에 있어서 계절간 소화율의 차이와 사료의 통과속도와의 관계를 암사슴 4두를 공시하여 겨울과 여름에 각각 실시하였다. 사료의 통과속도는 Cr염색법을 이용하였고, 또한 비중별(0.91, 1.20, 1.55, 2.10g/ml) 통과속도의 차이를 규명하기 위하여 plastic particle(PP)를 이용하여 조사하였다. 건물, 유기물, 조단백질 그리고 NDF의 소화율은 겨울철보다 여름철이 높은 경향이었으나 유의적인 차이는 없었다(P>0.05). 그리고 분중의 경시적인 Cr 회수율과 누적회수율에서 계절간에 차이가 나타나지 않았다. 비중별 회수율에 있어서도 계절간의 차이는 나타나지 않았으나, 비중간의 차이는 유의성 있는 차이(P<0.05)를 보였다. 비중 0.90에서는 모든 사슴이 $6\%$의 미만의 낮은 회수율을 보였으나 1.20이상부터 회수율은 높아졌고, 비중 2.10의 PP는 $75\%$ 이상이 회수되었다. 그리나 비중 1.20과 1.55의 PP는 개체간 변이가 심하게 나타나 최대 $95.1\%$에서 최저$1.3\%$의 범위를 보였다. 반추에 의한 이빨자국을 기초로 반추율을 조사한 결과, 비중 0.90의 PP는 약 $70\%$ 반추율을 보였으나 비중 2.10의 PP는 $5\%$미만의 반추율을 나타내어 비중이 높을수록 반추되지 않고 보다 빨리 2-3위구를 통과하기 때문에 통과속도가 빨랐던 것으로 나타났다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.2
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• pp.159-164
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• 2004

In this paper, we have proposed the folded feed structure for the spurious harmonic suppression and we have designed the SIR CPW bandpass filter using this feed structure. The characteristic of the proposed feed structure was similar to that of the lowpass filter has wide stopband region and this can be used usefully to the spurious harmonic suppression of the bandpass filter. From the simulation and the measurement result, SIR CPW bandpass filter with folded feed structure has good harmonic suppression characteristics up to 5.8 f$\sub$0/ with -20 dB suppression level.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.12
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• pp.1432-1437
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• 2010

This paper proposes a new design method of bandpass filter with single dual-mode resonator. In the proposed method, a coupling coefficient between two resonators was obtained by considering a dual-mode resonator as two single resonators. Based on the obtained coupling coefficient, two resonant frequencies of dual-mode resonator were calculated and then arranged according to a transmission zero's location of required filter. To verify the proposed theory, two WLAN bandpass filters which have a transmission zero to a lower and an upper stopband repectively were designed and implemented.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.12
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• pp.2458-2467
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• 1994

This paper proposes a new design method for obtaining the impulse responses which satisfy the prescribed conditions designing for maximally flat FIR lowpass filters and highpass filters. The bandpass filters and band-reject filters have been directly derived from the addition and subtraction of impulse responses of a lowpass filter and a highpass filter. The two-dimensional maximally flat FIR lowpass filter, highpass filters, bandpass filters and band-reject filters with zero-phase have been designed by transforming the impulses of the one-dimensional filters designed in this research, which do not destroy lines and edges at the image signal processing.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.9-12
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• 2010

This paper discusses experimental data for the assessment of flow discharging characteristics of double swirl coaxial injectors operating at fuel-rich conditions. Combustion tests employing liquid oxygen and kerosene (Jet A-1) were conducted and a discharge coefficient was utilized for defining flow characteristics. A mass flow rate, a pressure, and a temperature were measured to estimate discharge coefficients. Fuel injectors revealed a fixed value of a discharge coefficient regardless of matched LOx injector design, chamber pressure, and mixture ratio. However, oxidizer injectors showed varying discharging coefficients depending on chamber pressure and mixture ratio. Flame structure variations seem to affect flow discharging characteristics of the oxidizer side.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.12
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• pp.128-132
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• 2008

This paper presents a filter design technique with the embedded passive elements using the low temperature co-fired ceramic (LTCC) process. For the high performance and size reduction, the parasitic elements of the proposed multi-layer structure are positively considered by using the proposed circuit transformation procedures. As a result, the compact low ass filter (LPF) not only has at least 50% more compact thickness than other reported compact structures, but also provides ideal LPF response between 0.5GHz and 5GHz.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.108-114
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• 1998

This paper presents the design and fabrication of waveguide E-plane metal insert bandpass filter for milli-meter waves which is analyzed transmission characteristics by calculating the generalized scattering matrix using mode-matching method. The bandpass filter was fabricated to verify the proposed method by the WR-34 rectangular waveguide to operate in 30.085 ~ 30.885 GHz. The fabricated waveguide E-plane metal insert band- pass filter was established the fact that it is so adaptive for milli-meter waves due to the measured data closely consistent with the results of analysis using mode-matching method, that is, the maximum value of insertion loss is 0.8 dB and the return loss is below -15 dB.