• 한국음향학회지
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• 제24권1호
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• pp.38-42
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• 2005

기존의 음성신호와 다른 주파수 대역을 사용하여 데이터 통신이 가능한 ADSL 모뎀 송수신단의 CMOS 아날로그 저역 능동필터를 각각 설계하여 제안하였다. 설계된 필터는 2.5V의 저전압 동작이 가능하며, 각각의 설계사양에 따라 송신단에서는 138kHz의 차단주파수값을 갖는 저역통과 능동필터가 수신단에서는 1,100kHz의 차단주파수 특성을 갖는 저역통과능동필터가 설계 되었다. 이득과 단위이득주파수 특성 면에서 개선된 high-swing cascode방식의 저전압 능동소자가 필터를 설계하기 위한 기본 블록으로 이용되었다. 제안된 소자와 설계 제안된 필터는 $0.251{\mu}m\;CMOS\;n-well$ 공정 파라미터를 이용하여 그 특성이 검증되었다.

• 융합신호처리학회논문지
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• 제10권1호
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• pp.66-71
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• 2009

3GPP에서는 넓은 서비스 영역과 높은 이동성의 장점을 가지는 3G 이동통신과 높은 데이터 전송률의 장점을 가지는 WLAN간 인터워킹 시스템에 대한 표준화 및 기술 개발이 진행되고 있다. 3GPP와 WLAN 이종망간의 서비스 연속성을 지원하기 위해서는 seamless handover를 지원해야하며 이를 위해서는 핸드오버시 발생하는 지연을 최소화해야 한다. 본 논문에서는 행드오버 과정에서 발생하는 지연 시간의 많은 부분을 차지하는 인증 메커니즘을 실제 USIM 기반의 인증 테스트베드에 구현하여 분석하였다. EAP-AKA 완전 인증 방법과 빠른 재인증 방법에 대해 단말과 AAA 서버에서 발생하는 지연 시간을 구체적으로 분석하였고, 실험 결과 빠른 재인증 방법이 인증에 소요되는 시간을 48.6% 단축시킬 수 있는 것으로 측정되었다.

• Rapid Communication in Photoscience
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• 제4권1호
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• pp.1-8
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• 2015

For understanding molecular mechanisms of photochemical reactions, in particular reactions of proteins with biological functions, it is important to elucidate both the initial reactions from the photoexcited states and the series of subsequent chemical reactions, e.g., conformation, intermolecular interactions (hydrogen bonding, hydrophobic interactions), and inter-protein interactions (oligomer formation, dissociation reactions). Although time-resolved detection of such dynamics is essential, these dynamics have been very difficult to track by traditional spectroscopic techniques. Here, relatively new approaches for probing the dynamics of protein photochemical reactions using time-resolved transient grating (TG) are reviewed. By using this method, a variety of spectrally silent dynamics can be detected and such data provide a valuable description about the reaction scheme. Herein, a blue light sensor protein TePixD is the exemplar. The initial photochemistry for TePixD occurs around the chromophore and is detected readily by light absorption, but subsequent reactions are spectrally silent. The TG experiments revealed conformational changes and changes in inter-protein interactions, which are essential for TePixD function. The TG experiments also showed the importance of fluctuations of the intermediates as the driving force of the reaction. This technique is complementary to optical absorption detection methods. The TG signal contains a variety of unique information, which is difficult to obtain by other methods. The advantages and methods for signal analyses are described in detail in this review.

• 생명과학회지
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• 제19권3호
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• pp.305-310
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• 2009

플라스미드 pGKV21에는 229-nt single-strand DNA initiation (ssi) signal이 존재한다. Asymmetric PCR 기법으로 합성된 229-nt ssDNA 단편을 이용하여 실제로 RNA polymerase에 의한 priming ability와 protein interaction을 확인하였다. in vitro primer RNA 합성 실험 결과, 229-nt ssDNA 단편은 filamentous M13 phage의 주형 DNA에서와 비슷한 효율로 시발체 RNA를 합성하였으며, 이 반응은 strand-specific하게 이루어졌다. DNase I footprinting과 gel retardation 실험 결과, RNA polymerase와 SSB 단백질은 229-nt ssDNA 단편에 stable interaction을 하며, 시발체 RNA를 합성하였다. 또한, in vivo 조건 하에서 RNA polymerase의 저해제인 rifampicin을 처리하여 세포내에 ssDNA 중간체가 집적되는 정도를 비교하여 본 결과, 플라스미드 pGKV21은 rifampicin-sensitive RNA polymerase가 상보가닥 합성에 관여 함을 보여 주었다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2010년도 추계학술대회
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• pp.211-213
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• 2010

본 논문에서는 직교 주파수 다중화 (OFDM) 신호의 새로운 peak to average power ratio (PAPR) 감쇄 기법을 제안한다. 제안 기법은 시간영역에서 OFDM 심볼의 동상 (in-phase) 성분 및 직교 (quadrature) 성분을 회전시키고 재조합한다. 제안 기법은 기존의 partial transmit sequence (PTS) 기법과 비교하여 계산량을 현저히 줄일 수 있는 장점이 있었음에도 모의 실험을 통해 얻어진 PAPR의 complementary cumulative distribution function (CCDF)는 PTS와 비교할 때 거의 같은 성능을 보였다. 더욱이 제안된 기법은 additive white Gaussian (AWGN) 채널 및 다중 경로 페이딩 채널 (multi-path fading channel)에서 일반적인 OFDM 신호를 전송할 때와 거의 같은 BER (bit error rate) 성능을 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.491-493
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• 2004

In this paper, a direct controller for nonlinear plants using a neural network is presented. The controller is composed of an approximate controller and a neural network auxiliary controller. The approximate controller gives the rough control and the neural network controller gives the complementary signal to further reduce the output tracking error. This method does not put too much restriction on the type of nonlinear plant to be controlled. In this method, a RBF neural network is trained and the system has a stable performance for the inputs it has been trained for. Simulation results show that it is very effective and can realize a satisfactory control of the nonlinear system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 D
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• pp.1949-1950
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• 2006

In this paper, a direct controller for nonlinear plants using a neural network is presented. The controller is composed of an approximate controller and a neural network auxiliary controller. The approximate controller gives the rough control and the neural network controller gives the complementary signal to further reduce the output tracking error. This method does not put too much restriction on the type of nonlinear plant to be controlled. In this method, a RBF neural network is trained and the system has a stable performance for the inputs it has been trained for. Simulation results show that it is very effective and can realize a satisfactory control of the nonlinear system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.2827-2829
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• 2005

In this paper, a direct controller for nonlinear plants using a neural network is presented. The controller is composed of an approximate controller and a neural network auxiliary controller. The approximate controller gives the rough control and the neural network controller gives the complementary signal to further reduce the output tracking error. This method does not put too much restriction on the type of nonlinear plant to be controlled. In this method, a RBF neural network is trained and the system has a stable performance for the inputs it has been trained for. Simulation results show that it is very effective and can realize a satisfactory control of the nonlinear system.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.39-42
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• 2006

The paper reports on the first experimental evidence for space-observed manifestation of the open ocean tsunami in the microwave radar backscatter (in C- and Ku-bands). Significant variations of the radar cross section synchronous with the sea level anomaly were found in the geophysical data record of the altimetry satellite Jason-1 for the track which crossed the head wave of the catastrophic tsunami of 26 December 2004. The simultaneous analysis of the available complementary data provided by the satellite three-channel radiometer enabled us to exclude meteorological factors as possible causes of the observed signal modulation. A possible physical mechanism of modulation of short wind waves due to transformation of the thin boundary layer in the air by a tsunami wave is discussed. The results open new possibilities of monitoring tsunamis from space..

• Journal of information and communication convergence engineering
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• 제13권3호
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• pp.189-196
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• 2015

In this paper, we present a rotating auto-zeroing offset cancellation technique, which can improve the performance of touch screen sensing circuits. Our target touch screen detection method employs multiple continuous sine waves to achieve a high speed for large touch screens. While conventional auto-zeroing schemes cannot handle such continuous signals properly, the proposed scheme does not suffer from switching noise and provides effective offset cancellation for continuous signals. Experimental results show that the proposed technique improves the signal-to-noise ratio by 14 dB compared to a conventional offset cancellation scheme. For the realistic simulation results, we used Cadence SPECTRE with an accurate TSP model and noise source. We also applied an asymmetric device size (10% MOS size mismatch) to the OP Amp design in order to measure the effectiveness of offset cancellation. We implemented the proposed circuit as part of a touch screen controller system-on-chip by using a Magnachip/SK Hynix 0.18-µm complementary metal-oxide semiconductor (CMOS) process.