• Title/Summary/Keyword: MC

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A Study on MC DS-CDMA with Subcarrier-Spacing over Nakagami-m Fading Channel (나카가미-m 페이딩 채널에서 부반송파 간격에 따른 MC DS-CDMA 시스템에 관한 연구)

  • Kim Won-Sub;Park Jin-Soo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.12 s.91
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    • pp.1199-1206
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    • 2004
  • In this paper, we analyzed the orthogonal MC DS-CDMA system and no-overlapping MC DS-CDMA System, which were divided by the normalized spacing between adjacent subcarrier over Nakagami-m fading channels. In order to reduce the number of selective paths occurring in the MC system, the Hybrid SCMRC technique was applied, which was compared with the case when the MRC technique was used. As a result of simulations, it was found that the Hybrid SC/MRC method could be replaced by the MRC method and if the number of subcarriers was increased when the given bandwidth was fixed, the interval between subcarriers increased and bigger bandwidths were required. an, the number or subcarriers should be selected in consideration or given bandwidth.

An Improved Quine-McCluskey Algorithm for Circuit Minimization (회로 최소화를 위한 개선된 Quine-McCluskey 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.3
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    • pp.109-117
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    • 2014
  • This paper revises the Quine-McCluskey Algorithm to circuit minimization problems. Quine-McCluskey method repeatedly finds the prime implicant and employs additional procedures such as trial-and-error, branch-and-bound, and Petrick's method as a means of circuit minimization. The proposed algorithm, on the contrary, produces an implicant chart beforehand to simplify the search for the prime implicant. In addition, it determines a set cover to streamline the search for $1^{st}$ and $2^{nd}$ essential prime implicants. When applied to 3-variable and 4-variable experimental data, the proposed algorithm has indeed proved to obtain the optimal solutions much more simply and accurately than the Quine-McCluskey method.

Studies on the Compatability of the blend of PVA and Methyl cellulose (PVA/메틸셀루로스 블랜드의 상용성에 관한 연구)

  • Park, Jun-Seo;Park, Jang-Woo
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.5 no.2
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    • pp.1-8
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    • 1999
  • The state of compatability of poly(vinyl alcohol)(PVA) and methyl cellulose(MC), prepared by an aqueous solution casting, were investigated over the entire compositions by dynamical mechanical analyzer(DMA) and differential scanning calorimetry(DSC). The glass transition temperatures of the blends, estimated by DMA, indicate that the blends of PVA and MC showed a definite degree of partial miscibility by showing two glass transition temperatures below 80 wt % MC contents in the blends and one glass transition temperature above 80 wt % of MC contents. The DSC results show a depression of melting point and crystallization temperature of PVA in the blends containing more than 80 wt % MC. This indicates that a considerable compatibility in the blend above 80 wt % MC contents may be attribute to the presence of interaction of hydroxyl groups of component polymers through hydrogen bonding. The DMA study of the effect of plasticizer on the polymers showed that water was a good plasticizer for PVA and PEG400 for MC. The addition of water and PEG400 in the blends showed a synergic plasticizing effect on these blends, which resulted in the large extent of the improvement of the compatibility. The elongation of PVA, MC and blonds was found to increase with addition of PEG400 in the blends, but the tensile strength to decrease with addition of plasticizer.

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A Study of Alexander McQueen's Jacket (알렉산더 맥퀸(Alexander McQueen)의 재킷에 관한 연구)

  • Lee, Jeong-Eun;Do, Wol-Hee;Lee, Mi-Suk
    • Fashion & Textile Research Journal
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    • v.18 no.2
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    • pp.194-206
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    • 2016
  • This study analyzed jackets by Alexander McQueen that have always pleased customers with traditional tailoring via every season's collection. This study categorized and then analyzed jackets by components such as silhouette, jacket length, collar, lapel, sleeve, shoulder line, and closure methods. To achieve the research goal, the study referred to photographs of 501 jackets introduced in signature brand collections by Alexander McQueen between 1996 and 2010. The analysis results on McQueen's jackets with the general components of the clothes indicated that the frequency of traditional tailoring components (such as lapels, tight sleeves, natural shoulder lines, and a button closing method) was higher than the frequency of designs of dramatic, deconstructive patterns examined by previously-conducted research. This shows that Alexander McQueen was cognizant to the responsibilities as a tailor and the basics of tailoring when developing jacket designs. This study also confirmed how McQueen enjoyed adding exaggerated jacket design components by making various use of details that emphasize drastic shapes like the hourglass silhouette, wing collar (that covers the shoulders), peaked lapel collar, kimono sleeve, bell sleeve, crescent shoulder, and pagoda shoulder.

Antifungal Activity of Root Colonizing Pseudomonas fluorescens MC07 is Responsible for Its Disease Suppression Ability (근권 정창 세균 Pseudomonas fluorescens MC07의 항진균 활성과 병 억제 능력)

  • 김진우;박병근;황인규;박창석
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.606-611
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    • 1998
  • An antagonistic bacterium, Pseudomonas flurorescens MC07 inhibited the mycelial growth of Rhizoctonia solani, Pythium ultimum, Fusarium oxysporum, and Phytophthora capsici in on potato dextrose agan (PDA) and other media. The strain MC07 conlonizes various plant roots and possesses antifungal activity. To determine the role of antifungal activity of the bacterium in disease suppression, a mutant Okm3-4 which lost its activity was isolated after screening 2,500 colonies generated by Omegon-Km insertions. The mutant Okm3-4 showed diminished growth inhibition of R. solani, P. ultimum, F. oxysporum, and Ph. capsici in vitro and had reduced suppressive effects on sesame damping.-off compared to the parental strain. In soils, accumulation of the pathogens by continuous cropping, 90% of sesame plants were killed by natural infection of damping-off whereas, only 29% of plants grown from seeds treated with MC07 were killed. On the other hand, 85% of plants died when sesame seeds were treated with the Okm3-4 cells. This indicated that antifungal activity of MC07 in vitro is directly responsible for the suppression of damping-off disease. Emergence rates of sesame seeds in pots containing diseased soil were 33%. However, MC07 treatments on seeds significantly improved emergence rates, which has similar effects of Benomyl treatment. The mutant Okm3-4 exhibited 53% of emergence rate. This indicated that antifungal activity of MC07 also affects the emergence rate of sesame seeds.

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Studies on the viability and infectivity of Fasciola hepatica metacercariae (간질(Fasciola hepatica) 피낭유충의 생존성 및 감염성에 관한 연구)

  • Kim, Ji-ho;Kim, Jong-taek;Cho, Shin-hyeong;Lee, Chung-gil
    • Korean Journal of Veterinary Research
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    • v.38 no.1
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    • pp.161-166
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    • 1998
  • Fasciola hepatica eggs were obtained from the bile of infected cattle at a local abattoir. Metacercariae(MC) were produced using Lymnaea viridis, the intermediate host of the parasite. They were stored in distilled water at refrigerator($3{\sim}5^{\circ}C$) and at room temperature($22{\sim}27^{\circ}C$). The viability and infectivity of the MC were determined at monthly intervals for 12 months. The viability was determined by both microscope and excystation, and the infectivity by infecting mice. The MC stored at room temperature had a high viability up until 60 days, and thereafter the viability declined rapidly ; at day 120, only 2.5% of the MC were excysted. Most of the MC stored at refrigerator retained the viability up until 90 days, and thereafter the viability declined slowly ; about half of them were viable at day 210 and 5% of them retained the viability until day 270. The survival rates of the MC determined by microscope were always higher than those determined by excystation(p<0.05). The infectivity of the MC wisely followed the viability at the two different storage temperatures. Most of the mice infected orally with the MC died within 3-9 weeks of acute fasciolosis.

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Performance Evaluation of Uplink MC-DS-CDMA Transmission Systems (상향링크 MC-DS-CDMA 전송 시스템의 성능 분석)

  • Choi, Seung-Kuk
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.12
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    • pp.2649-2656
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    • 2010
  • MC-DS-CDMA is technique where a single data symbol is transmitted at multiple subcarriers which are orthogonal to each other. With this technique, frequency diversity can be achieved. The performance of uplink MC-DS-CDMA systems with the application of MRRC antenna diversity over time variant channels is analyzed. Time variant channels lead to interchannel interference which increases the bit error rate in the receiver. The BER performance of this system over multipath fading environment is evaluated, considering the channel estimation error, carrier frequency offset, and the nonlinear high power amplifier.

The influence of visual information on place of articulation in Korean speech perception: The McGurk effect in Korean subjects (한국어 말소리 지각에 미치는 조음에 관한 시각정보의 영향: 한국인의 McGurk 효과)

  • Choi Yang-Gyu;Nam Kichun
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.293-296
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    • 2002
  • 운동이론(motor theory)에 따르면 조음에 관한 정보는 말소리 지각에 중요한 역할을 한다고 한다. 조음에 관한 시각정보가 자음지각에 중요함을 시사하는 것이 바로 McGurk 효과이다. McGurk 효과는 말소리 지각에서 청각정보와 시각정보가 상충될 때 지각의 결과는 청각에 의한 조음정보와 시각에 의한 조음정보가 통합(integration)되어서 나타나는 것을 말한다. 예컨대, 시각적으로는 /ga/를 발음하는 모습을 보여주면서 동시에 청각적으로는 /ba/를 들려주면 그 결과로 /da/로 지각된다. 마찬가지로 시각적으로는 /ka/를, 청각적으로는 /ma/를 제시하면 /na/로 지각된다. 따라서 McGurk 효과는 시각적인 조음 정보가 자동적으로, 무의식적으로 말소리 지각과정에 통합됨은 보여준다. 한편 이러한 McGurk 효과는 문화마다 그 강도가 다르게 나타난다는 보고가 있다(Sekiyama, 1997). 예컨대, 일본가 중국 원어민의 경우 미국 원어민보다 McGurk 효과가 약하게 나타났다. 본 연구는 한국인에게는 McGurk 효과가 어떠한 양상으로 나타날지를 규명해 보고 아울러 기존의 미국, 일본 그리고 중국 원어민에 대한 연구결과와 비교 분석해 보았다.

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Performance analysis of multi-carrier CDMA system using an orthogonal pair of quadrature filter banks (직교 쌍 필터 뱅크 기반 다중 반송파 CDMA 시스템의 성능분석)

  • 이재철
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.25 no.9B
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    • pp.1570-1578
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    • 2000
  • A quadrature pair of filter banks that are composed of a pair of cosine and sine modulated filter banks is applied to MC-CDMA data transmultiplexing in the view point of mitigating inter-channel interferences. Exploiting superior capabilities of wavelet properties in composing the filter banks the proposed scheme is capable of compromising inter-channel interference problems better than the conventional DFT-based MC-CDMA due to superior subchannelization effects. To verify the behavior of our proposed MC-CDMA system based on the quadrature filter banks the reverse-link bit error rates with respect to signal-to-noise ratio under Rayleigth fading and additive white Gaussian noise channel environments are computed. The results show an improved system performance over the conventional MC-CDMA in the view point of minimizing interference effects.

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Performance analysis of a MC-CDMA cellular system with antenna arrays in a fading channel (페이딩 채널 환경에서 안테나 어래이를 갖는 MC-CDMA 셀룰라 시스템의 성능 분석)

  • 김찬규;조용수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.12
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    • pp.2686-2695
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    • 1997
  • The MC-CDMA(multi-carrier code division multiple access) technique is known to be appropriate for high data-rate wireless communications such as mobile multimedia communication due to its robustness to multipath fading and its capability of handing high data rates with a simple one-tap equalizer. In this paepr, the performance of a MC-CDMA cellular system employing antenna arrays at the based station in a fading channel is presented. It is whown that the interference from other users within the cell can be significantly reduced for both reverse link (mobile to base station) and forward link (base station to mobile) using a MC-CDMA with antenna arrays, thus incresig the system's user-capacity. Computer simulations that demonstrate user-capacity improvement of the proposed approach are discussed.

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