• Molecules and Cells
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• 제37권9호
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• pp.656-663
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• 2014

Gintonin, a novel, ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand, elicits $[Ca^{2+}]_i$ transients in neuronal and non-neuronal cells via pertussis toxin-sensitive and pertussis toxin-insensitive G proteins. The slowly activating delayed rectifier $K^+$ ($I_{Ks}$) channel is a cardiac $K^+$ channel composed of KCNQ1 and KCNE1 subunits. The C terminus of the KCNQ1 channel protein has two calmodulin-binding sites that are involved in regulating $I_{Ks}$ channels. In this study, we investigated the molecular mechanisms of gintonin-mediated activation of human $I_{Ks}$ channel activity by expressing human $I_{Ks}$ channels in Xenopus oocytes. We found that gintonin enhances $I_{Ks}$ channel currents in concentration- and voltage-dependent manners. The $EC_{50}$ for the $I_{Ks}$ channel was $0.05{\pm}0.01{\mu}g/ml$. Gintonin-mediated activation 1 of the $I_{Ks}$ channels was blocked by an LPA1/3 receptor antagonist, an active phospholipase C inhibitor, an $IP_3$ receptor antagonist, and the calcium chelator BAPTA. Gintonin-mediated activation of both the $I_{Ks}$ channel was also blocked by the calmodulin (CaM) blocker calmidazolium. Mutations in the KCNQ1 $[Ca^{2+}]_i$/CaM-binding IQ motif sites (S373P, W392R, or R539W)blocked the action of gintonin on $I_{Ks}$ channel. However, gintonin had no effect on hERG $K^+$ channel activity. These results show that gintonin-mediated enhancement of $I_{Ks}$ channel currents is achieved through binding of the $[Ca^{2+}]_i$/CaM complex to the C terminus of KCNQ1 subunit.

• 한국통신학회논문지
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• 제33권11C호
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• pp.868-873
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• 2008

본 논문에서는 수직 자기기록 채널에서 연집에러에 따른 LDPC(low density parity check) 부호의 성능을 분석한다. 수직 자기기록 채널에서 연집에러가 발생하면 수신부에서는 채널상태정보(channel state information)를 통하여 연집에러 부분을 알아낸 후 채널검출기의 연판정(Log Likelihood Ratio) 값을 0으로 초기화하는 방법을 사용한다. 패리티 검사 행렬은 부호율이 0.94인 (4336,4096)와 (8672,8192)를 사용한다. 그리고 채널 검출기는 연산량이 적은 SOVA(soft output Viterbi algorithm)를 사용한다.

• 한국통신학회논문지
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• 제28권4C호
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• pp.384-391
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• 2003

Blind channel identification and equalization attempt to identify the communication channel and to remove the inter-symbol interference caused by a communication channel without using any known trainning sequences. In this paper, we propose a blind adaptive channel identification and equalization algorithm with phase offset compensation for single-input multiple-output (SIMO) channel. It is based on the one-step forward multichannel linear prediction error method and can be implemented by an RLS algorithm. Phase offset problem, we use a blind adaptive algorithm called the constant modulus derotator (CMD) algorithm based on condtant modulus algorithm (CMA). Moreover, unlike many known subspace (SS) methods or cross relation (CR) methods, our proposed algorithms do not require channel order estimation. Therefore, our algorithms are robust to channel order mismatch.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.119-122
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• 2006

In this study, bottom-up type powder processing and top-down type SPD (severe plastic deformation) approaches were combined in order to achieve full density of 1 vol.% carbon nanotube (CNT)-metal matrix composites with superior mechanical properties by improved particle bonding and least grain growth, which were considered as a bottle neck of the bottom-up method using the conventional powder metallurgy of compaction and sintering. ECAP (equal channel angular pressing), the most promising method in SPD, was used for the CNT-Cu powder consolidation. The powder ECAP processing with 1, 2, 4 and 8 route C passes was conducted at room temperature. It was found by mechanical testing of the consolidated 1 vol.% CNT-Cu that high mechanical strength could be achieved effectively as a result of the Cu matrix strengthening and improved particle bonding during ECAP. The ECAP processing of powders is a viable method to achieve fully density CNT-Cu nanocomposites.

• Clinical and Experimental Pediatrics
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• 제53권10호
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• pp.909-912
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• 2010

Familial hypokalemic periodic paralysis is an autosomal-dominant channelopathy characterized by episodic muscle weakness with hypokalemia. The respiratory and cardiac muscles typically remain unaffected, but we report an atypical case of a family with hypokalemic periodic paralysis in which the affected members presented with frequent respiratory insufficiency during severe attacks. Molecular analysis revealed a heterozygous c.664 C>T transition in the sodium channel gene $SCN4A$, leading to an Arg222Trp mutation in the channel protein. The patients described here presented unusual clinical characteristics that included a severe respiratory phenotype, an incomplete penetrance in female carriers, and a different response to medications.

• 한국통신학회논문지
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• 제36권3C호
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• pp.170-174
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• 2011

본 논문은 양방향 중계 채널(Two-Way Relay Channel) 에서 기존에 연구되었던 협력 통신(Cooperative Communication) 에서 네트워크 부호화(Network Coding)에 대해 간단히 소개한다. 협력 통신 시스템에서의 직교성을 이용한 새로운 네트워크 부호화 기법을 제안한다. 제안된 직교 사상 네트워크 부호화 기법은 기존에 널리 사용되고 있는 DF(Decode-and-Forward) 모듈러 합 기법의 전송률을 유지하면서 DF 기법의 단점인 오류 전파(Error Propagation) 현상을 제거하여 향상된 BER(Bit Error Rate) 성능을 보인다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권1호
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• pp.17-22
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• 2001

The floating-gate MOSFETs were fabricated by employing 1.5 m n-well CMOS process and their optical-electrical properties were characterized for the application to CMOS image sensor system. Based on the simulation of energy band diagram and operating mechanism of parasitic BJT were proposed as solutions for the increase of photo-current value. In order to realize them, MOSFETs having multi-gate and channel structures were fabricated and 60% increase in photo-current was achieved through enlargement of depletion layer and parallel connection of parasitic BJTs by channel division.

• 전자공학회논문지C
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• 제34C권2호
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• pp.19-28
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• 1997

This paper presents the design of an SSIC chip for synchronization between main and sub pictures in the multi channel TV system (MUCTS). This chip can resolve problems in MUCTS, such as passing through and vertical jolt phenomena. In addition, this chip rpvivides compatibility for normal/doulble scan, interlace/progressive and normal (4:3)/wide (16:9) systems and has high hjorizontal and vertical resolutions (340) dots and 150 lines). In each mode there are 1 channel, 3 channel, and 4 position display functions. This MUCTS chip including three A/D coverters, a D/A converter and seven line memories was fabricated with one chip by using the $0.8\mu\textrm{m}$ CMOS technology. The application areas of this MUCTS ASIC chip include the wide TV, projection TV and te next generation TV for the DBS (direct broadcast system).

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2001년도 추계종합학술대회
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• pp.749-752
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• 2001

본 논문에서는 AIS 용 채널 접속 알고리즘을 분석하고 이를 구현하기 위한 모듈화 된 함수로 설계한 결과를 제시하였다. 먼저 ITU-R M.1371에서 규정한 RATDMA, ITDMA, FATDMA 및 SOTDMA 알고리즘의 기능을 분석하였으며 각각의 알고리즘을 모듈화 된 함수로 설계하였다. 설계한 채널 접속 알고리즘의 기능을 검증하기 위해 PC 상에서 C 언어를 이용하여 구현하고 모의 실험을 수행하였다. 실험 결과 설계한 채널 접속 알고리즘이 슬롯 할당을 제대로 수행함을 확인하였으며 표준안에서 제시한 요구를 만족함을 확인하였다.

• ETRI Journal
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• 제43권2호
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• pp.344-356
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• 2021

CRAFT is a tweakable block cipher introduced in 2019 that aims to provide strong protection against differential fault analysis. In this paper, we show that CRAFT is vulnerable to side-channel cube attacks. We apply side-channel cube attacks to CRAFT with the Hamming weight leakage assumption. We found that the first half of the secret key can be recovered from the Hamming weight leakage after the first round. Next, using the recovered key bits, we continue our attack to recover the second half of the secret key. We show that the set of equations that are solvable varies depending on the value of the key bits. Our result shows that 99.90% of the key space can be fully recovered within a practical time.