• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.215-218
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• 2009

In this paper, Dual-band bandpass filter studied design using Parallel Coupled SIR(Stepped Impedance Resonator). This Dual-band bandpass filter design SIR of half-wavelength by Parallel-coupled type that is available to RFID system and Changed structure in Meander form by size reduce. Because seen Dual-band bandpass filter is designed so that is applicable for frequency 433MHz and 2.45GHz of RFID system is very wide distance between two pass-band, establish 433MHz by fundamental frequency and controlled 2.45GHz by 2st spurious resonance frequency bandstop filter of 1st spurious resonance frequency and Parallel coupled SIR Combine to remove 1st spurious resonance frequency.

• Journal of Ship and Ocean Technology
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• v.4 no.1
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• pp.28-36
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• 2000

Numerical simulation based on the superposition of ring waves generated by the linear periodic source distributions for the plunger type wave maker was accomplished. The characteristics of directional spreading function were investigated. Mirror images are also introduced to consider reflections of side-wall together with the reflection coefficient to account for the imperfect reflection from the real side wall in the long experimental towing tank. Unexpected spurious waves, resulting from the combined effect of finite breadth of segmented wave maker, wavelength and main wave maker, wavelength and main wave propagating direction, were observed in the line source method and also in the analysis of the directivity. The influence of spurious waves to the directional spreading function was also investigated.

• Journal of the Optical Society of Korea
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• v.18 no.4
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• pp.330-334
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• 2014

In this paper, we present an incoherent dual-parallel modulation linearized optical link employing two different optical wavelengths. Comparing with previous dual-parallel modulation, this linearization method prevents the recreation of distortion products and can be readily implemented. Furthermore, a dual-wavelength dual-parallel modulation linearized optical link constructed with the commercially available devices is experimentally demonstrated with a spurious-free dynamic range of $122.5dB.Hz^{4/5}$. More than 25 dB suppression of the intermodulation distortion, 15.6 dB improvement of spurious-free dynamic range and 1.5 dB improvement of compression dynamic range are achieved after linearization.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.4
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• pp.83-85
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• 2008

Redundant spurious loops and overlapping segments in stability lobe diagrams cannot be removed easily by regular methods. A programmatic approach is presented to detect multiple spurious loops occurring within the lobes. They are identified by reorganizing the numerical lobe data into speed-depth corners for subsequent removal. The same principle is then extended to remove overlapping segments of adjacent lobes to obtain a final continuous stability map. Unlike existing methods, the proposed methodology requires no interface with additional editing software, and can also yield stability lobe diagrams more quickly. The methodology is presented with lobe diagrams constructed using milling and turning models.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.7-11
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• 2002

A novel microstrip type law-pass filter using thin or thick film resistors is proposed to efficiently eliminate harmonic spurious response in stop-band. The proposed low-pass filter shows the spurious suppression enhancement of 20 dB over a conventional one. The designed low-pass filter could be used as a harmonic rejection filter of a local oscillator for Ku-band satellite payload system.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.486-490
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• 2008

본 논문에서는 Spurious NAK Suppression알고리즘을 통하여 RLP의 성능향상에 대한 기법을 제안한다. 일반적으로, Hybrid ARQ기법에서는 MAC과 Physical Layer에서의 Retransmission 및 Error Correction으로 무선환경에서의 Error를 줄이고 latency를 보장하고 있다. 그러나 Hybrid ARQ에서의 Multiple SAW나 Selective-ARQ에 의해서 인접한 Packet들 간의 out-of-sequence문제가 발생할 수 밖에 없으며, upper layer인 RLP(혹은 RLC)에서는 이를 re-sequencing하여야 하는 부담감이 생기게 된다. 본 논문에서는 RLP receiver에서의 re-sequencing방법에 있어서, 효율적으로 RLP-NAK의 전송시점을 결정하는 NAK suppression 방법을 제안하고 있으며, 실험을 통하여 높은 성능향상을 보임을 확인할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.1003-1006
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• 2008

인터넷상에서 TCP 프로토콜은 사실상 표준으로써 널리 이용되고 있다. 그러나 네트워크 환경이 발전해 감에 따라서 무선 네트워크, CDMA, 3G 네크워크등 다양한 환경이 공존하게 되었고, 이러한 환경에서 TCP의 성능저하가 이슈가 되어 많은 연구가 진행되었으며, 많은 알고리즘들이 발표되었다. 본 논문에서는 무선환경에서 다양한 TCP 성능저하 원인 중에서 spurious RTO에 관한 문제를 해결하고자 한다. 이 전의 연구인 E-RTO는 delay spike문제를 효과적으로 다루고 있다 하지만 delay spike이후 혼잡 윈도우를 회복하는 과정을 효과적으로 다루고 있지 못하다. 우리는 BCR를 제안하여 이러한 문제를 해결하고자 한다. BCR의 성능평가는 NS2를 이용하여 이루어 졌으며 throughput, goodput에서 좋은 성능을 보여주고 있다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.7
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• pp.661-668
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• 2004

A novel method to reject the spurious signals which are occurred at Weaver-type low-IF transmitter was proposed in this paper. The spurious signals are generated by the gain and phase imbalances of I/Q channel or imperfect characteristics of 90$^{\circ}$ phase shifter in local oscillator for I/Q channel source. By deriving the gain and phase-based functions from RF spurious signal with the channel imbalance information, the lie channel imbalances were deduced as functions with magnitude and sign dependent on I/Q channel imbalance degree. The proposed method compensates the estimated I/Q channel imbalances by correlation values between the down-converted signal obtained by squaring the output signal itself using a simple mixer and the modified baseband signal. By comparing two signals after A/D conversion, the magnitude and sign of each type of imbalances can be determined separately and simultaneously. Based on the I/Q channel imbalance compensation, the spurious signals can be reduced by adjusting the gain and phase values of I or Q channel signal. The way to estimate the channel imbalances of the up-conversion mixer was presented and verified by using theoretical derivations and computer simulations.

• Journal of Institute of Control, Robotics and Systems
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• v.1 no.1
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• pp.33-37
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• 1995

순환 신경회로망의 응용에서 종종 대두되는 국지극소점을 확인하고 제거하는 효과적인 방법을 제안한다. 신경망의 학습과정에서 밝혀지는 국지극소점에 대하여 부상관성을 부과하여 에너지표면을 재조정함으로서 원하는 상태에서 회로망이 안정에 도달하게 한다. 이때 의사상태(spurious states)는 안정조건을 적용함으로서 확인되는데 이과정은 특별히 설계된 병렬회로에 의하여 효율적으로 처리된다. 이와같은 부학습(unlearning)의 결과로서 순환신경망의 저장용량과 수렴성능의 개선을 이룰수 있다.

• Proceedings of the IEEK Conference
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• 2002.06d
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• pp.65-68
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• 2002

In an automatic fingerprint recognition system, a thinning process after binarization is commonly used. However it gives rise to spurs and holes often causing many spurious minutiae. Thus, more elaborate postprocessing is urgently needed to remove such spurious minutiae. To overcome this problem, we present a method of extracting minutiae based on horizontal and vertical run-length encoding from a binary fingerprint image without thinning process. Experimental results show that the proposed method for extracting minutiae is fairly reliable and fast, when il is compared to other method adopting a thinning process.