• 한국컴퓨터정보학회논문지
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• 제27권2호
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• pp.125-134
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• 2022

본 논문에서는 블록체인 응용 서비스의 견고성을 제고하기 위한 BR2K 기법의 확장 방법을 제안한다. BR2K(Blockchain application, Replication & Recovery technique using Kubernetes) 기법은 서비스 복제와 신속 재가동을 통해 블록체인 서비스의 견고성을 지원하기 위하여 최근에 개발된 기법이다. 제안하는 기법은 기존 BR2K 기법을 확장하여 서비스 상태에 대한 메타 정보인 상태 버전 및 이를 안전하게 관리하기 위한 방법을 제공하고, 이를 이용하여 서비스 상태 복구에 대한 시점을 결정한다. 또한 이 기법은 BR2K 기법에서 서비스 복구 센터 역할을 수행하는 서비스 레지스트리와 상태 버전 정보를 활용하여 서비스 복구와 새로운 서비스 노드의 합류를 위한 체계적인 서비스 상태 백업을 제공한다. 이를 바탕으로 새로운 서비스 노드가 일관성을 가지며 새로운 복제 서비스에 합류하도록 지원할 수 있으며, 그 결과 새로운 서비스 노드가 운영 중인 BR2K 서비스에 신속하게 추가될 수 있어 서비스의 견고성이 제고된다. 또한 시범적인 블록체인 응용 서비스에 확장된 기법을 적용하고 가상 머신으로 구성된 쿠버네티스 환경에서 이를 테스트하여, 장애 상황 속에서 서비스 복제의 일관성과 신속한 서비스 복구에 대한 유효성을 확인한다.

• ALGAE
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• 제34권2호
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• pp.141-151
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• 2019

The 1982-83, 1986-87, 1991-92, and 1997-98 El $Ni{\tilde{n}}o$-Southern Oscillations (ENSOs) were compared with regards to their strength and timing in the tropical Pacific Ocean, changes in ocean temperature and wave intensity, and their impacts to giant kelp populations in the Northeast Pacific. The Multivariate ENSO Index, oceanographic data, and kelp abundance data all show that the 1982-83 and 1997-98 ENSOs were stronger and resulted in greater losses of giant kelp than the 1986-87 and 1991-92 ENSOs, but that the 1982-83 and 1997-98 ENSOs differed with regard to the arrival of destructive waves relative to when the ocean waters warmed and cooled. The 1982-83 ENSO was more destructive to the giant kelp populations in central California, USA than the 1997-98 ENSO, but the 1997-98 ENSO was more destructive to the giant kelp in southern California. These events appeared similarly destructive to the populations in Baja California, Mexico. Recovery of the kelp populations also varied among the two strong ENSOs due to the ocean conditions following each ENSO. In southern and Baja California, recovery was slow following the 1982-83 ENSO, while recovery was more rapid following the 1997-98 ENSO. Unfortunately, the monitoring programs used to evaluate the kelp populations stopped shortly after the 1997-98 ENSO, resulting in a lack of data for comparisons with the more recent weak ENSOs that occurred between 2002 and 2010, or with the strong ENSO that occurred in 2014-2016. This supports the need for continued long-term monitoring programs to better understand how climate anomalies impact coastal ecosystems.

• Journal of Audiology & Otology
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• 제25권1호
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• pp.27-35
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• 2021

Background and Objectives: This study aimed to evaluate the clinical features and the clinical factors associated with prognosis of sudden sensorineural hearing loss (SSNHL) in diabetic patients. Subjects and Methods: Forty-nine diabetic with unilateral SSNHL were retrospectively included. All patients received systemic high dose steroid therapy within one month after onset and had more than one month of follow-up audiogram. The basic characteristics of the patients, initial and follow-up audiograms, laboratory data, and methods of steroid treatment were collected. Results: Compared to reference values in healthy subjects, 79%, 55%, and 45% of the patients had higher values of mean neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR), respectively. Older patients had significantly less degree of hearing loss, but they also had significantly worse hearing thresholds in the unaffected ear. After steroid treatment, less than half patients (47%) showed hearing recovery. Simultaneous intratympanic dexamethasone (ITD) injections with systemic steroid did not confer an additional hearing gain or an earlier recovery rate in diabetic patients with SSNHL. In the multivariate analysis, initial hearing thresholds of affected ear and timing of steroid treatment were significantly associated with hearing prognosis in diabetic patients with SSNHL. Conclusions: Diabetic patients with SSNHL tended to have increased NLR, LMR, and PLR, which are reported to be associated with microvascular angiopathy. Simultaneous ITD injections to improve hearing recovery in diabetic patients with SSNHL seems unnecessary.

• 대한청각학회지
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• 제25권1호
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• pp.27-35
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• 2021

Background and Objectives: This study aimed to evaluate the clinical features and the clinical factors associated with prognosis of sudden sensorineural hearing loss (SSNHL) in diabetic patients. Subjects and Methods: Forty-nine diabetic with unilateral SSNHL were retrospectively included. All patients received systemic high dose steroid therapy within one month after onset and had more than one month of follow-up audiogram. The basic characteristics of the patients, initial and follow-up audiograms, laboratory data, and methods of steroid treatment were collected. Results: Compared to reference values in healthy subjects, 79%, 55%, and 45% of the patients had higher values of mean neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), and lymphocyte-monocyte ratio (LMR), respectively. Older patients had significantly less degree of hearing loss, but they also had significantly worse hearing thresholds in the unaffected ear. After steroid treatment, less than half patients (47%) showed hearing recovery. Simultaneous intratympanic dexamethasone (ITD) injections with systemic steroid did not confer an additional hearing gain or an earlier recovery rate in diabetic patients with SSNHL. In the multivariate analysis, initial hearing thresholds of affected ear and timing of steroid treatment were significantly associated with hearing prognosis in diabetic patients with SSNHL. Conclusions: Diabetic patients with SSNHL tended to have increased NLR, LMR, and PLR, which are reported to be associated with microvascular angiopathy. Simultaneous ITD injections to improve hearing recovery in diabetic patients with SSNHL seems unnecessary.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1999년도 학술대회
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• pp.239-242
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• 1999

본 논문에서는 8VSB수신기가 다중경로신호에 따른 성능이 나쁜 것에 대한 원인 분석과 나아가 개선책을 제시하기 위해 다중경로 신호가 디지털 지상파 TV의 수신성능에 미치는 영향에 대해 수신단의 STR(Symbol Timing Recovery)과 등화기를 중심으로 분석한다. 첫째 등화기의 성능 분석을 위해 에코의지연시간이 7.5 $\mu$sec일 때 시불변 환경에서 전산 모의 실험을 하였다. 등화기 수렴후의 에로 레벨에 따른 TOV(Threshold of Visibility) S/N(Signal to Noise)를 구해보면 호주의 실험실 측정과는 달리 0dB에서도 S/N이 26dB 정도이면 등화기는 안정적으로 수렴한다. 둘째 세그먼트 동기 복원을 세그먼트 싱크 필터(Segment Sync:+1, +1. -1, -1)를 사용했을 때 짧은 시간 지연 에코와 긴 시간 지연 에코에 대해 S 커브를 보면 짧은 시간 지연에코에서는 심볼 타이밍이 어긋났으며 긴 시간 지연 에로에서는 문제가 없이 타이밍 동기가 된다. 셋째 짧은 시간 지연 에코신호가 있을 때 세그먼트 동기 복원과 등화기를 연동한 전산 모의 실험을 하여 에코의 영향을 분석하고 FSE(Fractionally Spaced Equalizer) 등화기 사용에 따른 장점을 분석한다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제21권1호
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• pp.12-19
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• 2018

Pediatric patients require specialized attention and have diverse demands for proper growth and development, and thus need a different approach and interest in nutritional assessment and supply. Enteral nutrition is the most basic and important method of nutritional intervention, and its indications should be identified. Also, the sites, modes, types, and timing of nutritional intervention according to the patient's condition should be determined. In addition, various complications associated with enteral nutrition supply should be identified, and prevention and treatment are required. This approach to enteral nutrition and proper administration can help in the proper growth and recovery of pediatric patients with nutritional imbalances or nutritional needs.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2010년도 하계학술대회
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• pp.185-187
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• 2010

최근 3D HDTV에 대한 연구가 활발히 이루어지고 있다. 우리나라에서도 3D HDTV 표준을 제정하기 위한 준비가 이루어지고 있으며, 이와 같은 흐름에 맞추어 기존의 ATSC 전송 방식을 확장한 전송 방식이 연구되고 있다. 확장된 ATSC 전송 방식은 지상파 3D HDTV 방송을 목표로 하고, 프레임 구조를 중국의 지상파 방송 표준인 DMB-T와 유사하게 PN 시퀀스와 데이터로 이루어진 방식으로 이용하고자 한다. 연구되고 있는 확장된 전송방식은 기존의 ATSC 시스템의 VSB 변조방식을 기반으로 한다. 프레임 구조는 PN 시퀀스와 데이터 심볼의 구조를 가지며 이 PN을 이용하여 심볼 타이밍 오차를 복구한다. PN을 이용하기 위해 수신 단에서는 가장먼저 프레임 동기를 이루어야 하므로, 본 논문에서는 확장된 ATSC 전송 시스템 방식에 적용 가능한 프레임 동기와 심볼 타이밍 복구에 관한 방식을 제안하였다.

• Journal of Information Display
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• 제10권1호
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• pp.37-44
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• 2009

AiPi technology incorporates an embedded clock and control scheme with a point-to-point bus topology, thereby having the smallest possible number of interface lines between a timing controller and column drivers. A point-to-point architecture boosts the data rate and reduces the number of interface lines, because impedance matching can be easily achieved. An embedded clock and control scheme is implemented by means of multi-level signalling, which results in a simple clock/data recovery circuitry. A 46" AiPi-based 10-bit FHD prototype requires only 20 interface lines, compared to 38 lines for mini-LVDS. The measured maximum data rate per data pair is more than 800 Mbps.

• 전자공학회논문지A
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• 제32A권1호
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• pp.1-13
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• 1995

In this paper, a specification for wireless LAN MODEM using direct sequence spread spectrum (DS/SS) technique is presented. Some algorithms and hardware architectures for an efficient implementation of the DS/SS MODEM are suggested. In the method, all baseband signal processing are done digitally for single chip implementation. Schemes of DQPSK baseband modulation/demodulation, despreading with digital matched filter, digital timing recovery, and efficient carrier sensing are among the discussed algorithms. We also performed various kinds of simulations to evaluate the system performance and to extract parameters for hardware implementation. In addition, the pictorial view of ASIC of the SS MODEM is also shown.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.775-779
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• 1999

This paper presents design of AGC(Automatic Gain Control) and DC offset remover suitable for cable modem which makes use of QAM(Quadrature Amplitude Modulation) scheme. Since QAM has multi-level signal characteristic, for high-order QAM, the constellation is dense and the distance of decision boundary between adjacent symbols is short. So AGC and DC offset remover must be designed optionally for preventing performance degradation. AGC is designed into feedback type and is related to the STR(Symbol Timing Recovery)and Paff interpolation algorithm. Whereas AGC need to perform average power detection during many symbols by comparison with the reference power, DC offset remover uses only the instant polarity decision such that simple implementation can be achieved with good performance. Though the AGC and DC offset remover are simulated here only for 256 QAM scheme for convenience'sake, it can be applied to other multi-level QAM or PSK modulation scheme.