• 제목/요약/키워드: ASR

검색결과 408건 처리시간 0.026초

크기가 제한된 제어기를 갖는 비정합 불확실성의 가변구조 시스템을 위한 점근 안정 영역 추정 (Estimation of the Asymptotic Stability Region for a Mismatched Uncertain Variable Structure System with a Bounded Controller)

  • 최한호
    • 전기학회논문지
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    • 제56권3호
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    • pp.600-603
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    • 2007
  • We propose a method to estimate the asymptotic stability region(ASR) of a mismatched uncertain variable structure system with a bounded controller. The uncertain system under consideration may have mismatched parameter uncertainties in the state matrix. Using linear matrix inequalities(LMIs) we estimate the ASR and we show the quadratic stability of the closed-loop control system in the estimated ASR. We also give a simple LMI-based algorithm for estimating the ASR. Finally, we give a numerical example in order to show the effectiveness of our method.

쇄석 골재의 알칼리-실리카 반응에 관한 실험적 연구( 제 2보 : 첨가알칼리량 및 종류가 알칼리-실리카 반응에 미치는 영향) (A Experimental Study on the Alkali-Silica Reaction of Crushed Stones (Part 2 : The Influence of the Alkali Content and the Kind of Added Alkali to the Alkali-Silica Reaction))

  • 이영수;윤재환;정재동;노재호;이양수;조일호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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    • pp.108-112
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    • 1993
  • The term Alkali-Silica Reaction (ASR) is used to describe a reaction between certain siliceous aggregates and hydroxyl ions present in the pore fluid of a concrete. The ASR is affected by the content of alkali, the particle size and the content of reactive aggregate, water-cement ratio, humidity, temperature and so on. In this paper, the fluence of alkali content and kind of added alkali to the ASR was studied. As a result, the more the content of alkali was increased, the more the mortar-bar was expand and the expansion of mortar-bar was showed differently with the added alkali kinds, The reaction products by ASR were observed by SEM(Scanning Electron Microscope) and analyzed by EDXA(Energy Dispersive X-ray Analysis) also and showed a gel composed of alkali(Na+, K+), silica and calcium.

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Average Rate Performance of Two-Way Amplify-and-Forward Relaying in Asymmetric Fading Channels

  • Park, Jae-Cheol;Song, Iick-Ho;Lee, Sung-Ro;Kim, Yun-Hee
    • Journal of Communications and Networks
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    • 제13권3호
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    • pp.250-256
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    • 2011
  • A two-way relaying (TWR) system is analyzed, where two source terminals with unequal numbers of antennas exchange data via an amplify-and-forward relay terminal with a single antenna. In the system considered herein, the link quality between the sources and relay can generally be asymmetric due to the nonidentical antenna configuration, power allocation, and relay location. In such a general setup, accurate bounds on the average sum rate (ASR) are derived when beamforming or orthogonal space time block coding is employed at the sources. We show that the proposed bounds are almost indistinguishable from the exact ASR under various system configurations. It is also observed that the ASR performance of the TWR system with unequal numbers of source antennas is more sensitive to the relay location than to the power allocation.

ASR 시스템에 대한 오디오 적대적 공격 연구 동향 분석 (A Survey on Adversarial Attacks Against ASR Systems)

  • 김나현;이연준
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2023년도 춘계학술발표대회
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    • pp.215-216
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    • 2023
  • 오디오 적대적 공격 연구는 최근 몇 년 동안 빠르게 발전해 왔다. 이전에는 음성 신호를 직접 수정하거나 추가하여 공격을 수행하는 방법이 일반적이었지만 최근에는 딥러닝 모델을 이용한 적대적 공격 기술이 주목을 받고 있다. 이러한 적대적 공격은 현재 다양한 분야에 널리 쓰이는 ASR 시스템에 심각한 보안 위협이 될 수 있다. 이에 본 논문에서는 현재까지의 음성신호 적대적 공격 기술과 방어기술의 연구 흐름을 분석하여 더욱 강건한 ASR 시스템을 구축하는 데 기여하고자 한다.

공항 airside용 제설제의 기본물질에 대한 포장 영향성 평가 연구 (Pavement Impact Evaluation of Basic Materials of Airport Airside Deicers)

  • 김영웅;유광호;조창렬;조남현
    • 한국도로학회논문집
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    • 제18권6호
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    • pp.25-34
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    • 2016
  • OBJECTIVES : This is a basic research for the domestic production of airport-airside deicers. This research selected basic materials for deicers appropriate for the pavement of domestic airports by evaluating the deicing performances of basic materials used in international-standard airport deicers and their impacts on pavements. METHODS : Laboratory investigation was conducted to evaluate the asphalt surface tensile strength, concrete scaling impact, ASR impact, and deicing performances of sodium formate (NaFm), potassium formate (KFm), sodium acetate (NaAc), and potassium acetate (KAc), which are the basic de-icing materials commonly used at international airports, approved by the FAA. In addition, the analyses were also performed on the airside deicer urea, which is currently used in domestic airports. RESULTS : Laboratory investigation confirmed that sodium formate, potassium formate, sodium acetate, and potassium acetate had superior surface tensile strength, concrete scaling impact, and deicing performance compared to airside urea, but they also had greater impacts on concrete ASR. Among these materials, sodium formate had the best asphalt surface tensile strength, concrete scaling impact, and deicing performance, while also having the greatest impact on ASR; hence, mitigation plans for ASR were needed, if it were to be used as airport-airside deicer. CONCLUSIONS : It is necessary to consider additional additives to prevent ASR of concrete pavements when developing airport-airside deicers using sodium formate, potassium formate, sodium acetate, and potassium acetate.

자동음성인식 기술을 이용한 모바일 기반 발음 교수법과 영어 학습자의 발음 향상에 관한 연구 (The Study on Automatic Speech Recognizer Utilizing Mobile Platform on Korean EFL Learners' Pronunciation Development)

  • 박아영
    • 디지털콘텐츠학회 논문지
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    • 제18권6호
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    • pp.1101-1107
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    • 2017
  • 본 논문은 스마트폰의 플랫폼에 내장되어 있는 자동음성인식 기술을 활용하여 영어 학습자의 발음에 대한 즉각적인 문자 피드백을 제공하는 모바일 기반 발음 교수법이 영어 학습자의 자음 발음 (V-B, R-L, G-Z) 인식과 출력에 미치는 영향에 대해 연구했다. 특히, 자동음성인식 기술을 이용한 모바일 기반 발음 교수법을 사용한 그룹, 전통적인 교사 중심의 발음 교수법 그룹, 그리고 이 둘을 합친 하이브리드 교수법 그룹으로 나누어 영어 학습자의 발음 평가 결과를 (인지, 출력) 비교, 분석했다. ANCOVA를 이용한 분석 결과, 영어 학습자의 발음 출력에 있어 하이브리드 교수법 그룹이 (M=82.71, SD =3.3) 전통적인 교수법 그룹 (M=62.6, SD=4.05) 보다 유의미하게 높은 결과를 나타냈다 (p<.05).

Measuring Socioeconomic Disparities in Cancer Incidence in Tehran, 2008

  • Rohani-Rasaf, Marzieh;Moradi-Lakeh, Maziar;Ramezani, Rashid;Asadi-Lari, Mohsen
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권6호
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    • pp.2955-2960
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    • 2012
  • Background: Health disparities exist among and within countries, while developing and low income countries suffer more. The aim of this study was to quantify cancer disparities with regard to socioeconomic position (SEP) in 22 districts of Tehran, Iran. Method: According to the national cancer registry, 7599 new cancer cases were recorded within 22 districts of Tehran in 2008. Based on combined data from census and a population-based health equity study (Urban HEART), socioeconomic position (SEP) was calculated for each district. Index of disparity, absolute and relative concentration indices (ACI & RCI) were used for measuring disparities in cancer incidence. Results: The overall cancer age standardised rate (ASR) was 117.2 per 100,000 individuals (120.4 for men and 113.5 for women). Maximum ASR in both genders was seen in districts 6, 3, 1 and 2. Breast, colorectal, stomach, skin and prostate were the most common cancers. Districts with higher SEP had higher ASR (r=0.9, p<0.001). Positive ACI and RCI indicated that cancer cases accumulated in districts with high SEP. Female disparity was greater than for men in all measures. Breast, colorectal, prostate and bladder ASR ascended across SEP groups. Negative ACI and RCI in cervical and skin cancers in women indicate their aggregation in lower SEP groups. Breast cancer had the highest absolute disparities measure. Conclusion: This report provides an appropriate guide and new evidence on disparities across geographical, demographic and particular SEP groups. Higher ASR in specific districts warrants further research to investigate the background predisposing factors.

무선 ATM에서의 트래픽 형태 및 채널 오율에 기반한 적응 오류 제어 (Adaptive Error Control Based on Traffic Type and Channel Error Rate in Wireless ATM)

  • 김영웅;조동호
    • 한국통신학회논문지
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    • 제24권10A호
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    • pp.1532-1538
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    • 1999
  • 일반적으로 무선 환경은 유선환경에 비하여 높은 오뉼을 가지기 때문에, 낮은 오율을 가지는 유선망의 DLC(Data Link Control)계층 프로토콜을 무선망에 그대로 적용하는 것은 적합하지 않다. 또한 기존의 무선망을 위한 DLC계층 프로토콜 역시 저속의 데이터 서비스에 최적화되어 있으므로, 고속화 및 멀티미디어화 되고 있는 현재의 무선 환경에는 적합하지 않다. 따라서, 오늘날의 이동통신 환경에 부합되는 새로운 DLC계층 프로토콜이 요구된다. 본 논문에서는 다양한 트래픽 속성을 지원하고, 고속 및 멀티미디어 데이터 서비스에 적합한 WATM (Wireless Asynchronous Transfer Mode)에서의 오류 제어 방안을 제시한다. 본 논문에서 제시하는 오류 제어 방안은 실시간 트래픽에 대해서 ASR ARQ(Adaptive Selective Repeat Automatic Repeat Request) 프로토콜의 ACK(acknowledgement)를 삭제하여 성능을 개선하고 오율이 클 때 FEC를 사용하여 손실율을 줄였다. 비실시간 트래픽에 대해서는 ACK를 삭제한 ASR ARQ를 사용하여 성능을 개선하고 오율이 클 때 FEC를 적용하여 지연시간을 줄였다. 시뮬레이션에 의한 성능 분석 결과, 본 논문에서 제안한 방안은 기\ulcorner의 ASR ARQ 프로토콜에 비하여 지연과 처리율 측면에서 개선된 성능을 나타내었다.

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Differential Symbiotic Response of Phage-typed Strains of Bradyrhizobium japonicum with Soybean Cultivars

  • Appunu Chinnaswamy;Dhar Banshi
    • Journal of Microbiology
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    • 제44권3호
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    • pp.363-368
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    • 2006
  • In this study, native Byadyrhizobium strains were isolated from the host plant, Glycine max, harvested from fields in Madhya Pradesh, India, and were typed by Iytic rhizobiophages. Eight indigenous (Soy2, ASR011, ASR031, ASR032, MSR091, ISR050, ISR076 and ISR078) and two exotic strains (USDA123 and CB1809), all of which evidenced a distinct reaction with six phages, were employed in this study. The symbiotic interaction of these strains was studied initially using soybean cultivar JS335 in a sand culture in a controlled environment, and the efficiency was assessed based on the nodule number, nodule dry weight, plant dry weight, nitrogenase activity, and total accumulation of N per plant. Symbiotic effectiveness was found to be highest with the native phage-sensitive isolate ASR011, whereas it was at a minimum with the phage-resistant isolates, ISR050 and ISR078. Additionally, the effectiveness of these strains was evaluated using six soybean cultivars belonging to different maturity groups; namely, Brags, Lee, Pusa20, PK416, JS33S and NRC37. Analysis of variance data evidenced significant differences due to both symbionts, for the majority of the tested parameters. The CB1809, USDA123, and ASR011 strains evidenced relatively superior symbiotic effectiveness with soybean cultivars Brags, Lee and JS335. Strain ISR078 evidenced no significant responses with any of the cultivars. The ASR031 strain performed moderately well with all tested cultivars. The symbiotic response of all the strains was quite poor with cultivar PK416. Our studies showed that a significant relationship existed between the phage sensitivity and symbiotic efficiency of the bacterial strains with the host-cultivars.

Response of Saccharomyces cerevisiae to Ethanol Stress Involves Actions of Protein Asr1p

  • Ding, Junmei;Huang, Xiaowei;Zhao, Na;Gao, Feng;Lu, Qian;Zhang, Ke-Qin
    • Journal of Microbiology and Biotechnology
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    • 제20권12호
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    • pp.1630-1636
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    • 2010
  • During the fermentation process of Saccharomyces cerevisiae, yeast cells must rapidly respond to a wide variety of external stresses in order to survive the constantly changing environment, including ethanol stress. The accumulation of ethanol can severely inhibit cell growth activity and productivity. Thus, the response to changing ethanol concentrations is one of the most important stress reactions in S. cerevisiae and worthy of thorough investigation. Therefore, this study examined the relationship between ethanol tolerance in S. cerevisiae and a unique protein called alcohol sensitive RING/PHD finger 1 protein (Asr1p). A real-time PCR showed that upon exposure to 8% ethanol, the expression of Asr1 was continuously enhanced, reaching a peak 2 h after stimulation. This result was confirmed by monitoring the fluorescence levels using a strain with a green fluorescent protein tagged to the C-terminal of Asr1p. The fluorescent microscopy also revealed a change in the subcellular localization before and after stimulation. Furthermore, the disruption of the Asr1 gene resulted in hypersensitivity on the medium containing ethanol, when compared with the wild-type strain. Thus, when taken together, the present results suggest that Asr1 is involved in the response to ethanol stress in the yeast S. cerevisiae.